General discussion of feasibility study

International Nuclear Information System (INIS)

Calori, F.

1976-01-01

Fundamentals, objectives and parameters of feasibility studies in the field of nuclear power project planning are discussed in a general way. Technical and economic problems to be considered are pointed out. In special cases, IAEA offers its aid and support. (UA) [de

Observational constraints on Hubble parameter in viscous generalized Chaplygin gas

Science.gov (United States)

Thakur, P.

2018-04-01

Cosmological model with viscous generalized Chaplygin gas (in short, VGCG) is considered here to determine observational constraints on its equation of state parameters (in short, EoS) from background data. These data consists of H(z)-z (OHD) data, Baryonic Acoustic Oscillations peak parameter, CMB shift parameter and SN Ia data (Union 2.1). Best-fit values of the EoS parameters including present Hubble parameter (H0) and their acceptable range at different confidence limits are determined. In this model the permitted range for the present Hubble parameter and the transition redshift (zt) at 1σ confidence limits are H0= 70.24^{+0.34}_{-0.36} and zt=0.76^{+0.07}_{-0.07} respectively. These EoS parameters are then compared with those of other models. Present age of the Universe (t0) have also been determined here. Akaike information criterion and Bayesian information criterion for the model selection have been adopted for comparison with other models. It is noted that VGCG model satisfactorily accommodates the present accelerating phase of the Universe.

Nash equilibria in quantum games with generalized two-parameter strategies

International Nuclear Information System (INIS)

Flitney, Adrian P.; Hollenberg, Lloyd C.L.

2007-01-01

In the Eisert protocol for 2x2 quantum games [J. Eisert, et al., Phys. Rev. Lett. 83 (1999) 3077], a number of authors have investigated the features arising from making the strategic space a two-parameter subset of single qubit unitary operators. We argue that the new Nash equilibria and the classical-quantum transitions that occur are simply an artifact of the particular strategy space chosen. By choosing a different, but equally plausible, two-parameter strategic space we show that different Nash equilibria with different classical-quantum transitions can arise. We generalize the two-parameter strategies and also consider these strategies in a multiplayer setting

Generalization of binary tensor product schemes depends upon four parameters

International Nuclear Information System (INIS)

Bashir, R.; Bari, M.; Mustafa, G.

2018-01-01

This article deals with general formulae of parametric and non parametric bivariate subdivision scheme with four parameters. By assigning specific values to those parameters we get some special cases of existing tensor product schemes as well as a new proposed scheme. The behavior of schemes produced by the general formulae is interpolating, approximating and relaxed. Approximating bivariate subdivision schemes produce some other surfaces as compared to interpolating bivariate subdivision schemes. Polynomial reproduction and polynomial generation are desirable properties of subdivision schemes. Capability of polynomial reproduction and polynomial generation is strongly connected with smoothness, sum rules, convergence and approximation order. We also calculate the polynomial generation and polynomial reproduction of 9-point bivariate approximating subdivision scheme. Comparison of polynomial reproduction, polynomial generation and continuity of existing and proposed schemes has also been established. Some numerical examples are also presented to show the behavior of bivariate schemes. (author)

General methods for modified projective synchronization of hyperchaotic systems with known or unknown parameters

Science.gov (United States)

Tang, Yang; Fang, Jian-an

2008-03-01

This work is concerned with the general methods for modified projective synchronization of hyperchaotic systems. A systematic method of active control is developed to synchronize two hyperchaotic systems with known parameters. Moreover, by combining the adaptive control and linear feedback methods, general sufficient conditions for the modified projective synchronization of identical or different chaotic systems with fully unknown or partially unknown parameters are presented. Meanwhile, the speed of parameters identification can be regulated by adjusting adaptive gain matrix. Numerical simulations verify the effectiveness of the proposed methods.

Diabatic models with transferrable parameters for generalized chemical reactions

International Nuclear Information System (INIS)

Reimers, Jeffrey R; McKemmish, Laura K; McKenzie, Ross H; Hush, Noel S

2017-01-01

Diabatic models applied to adiabatic electron-transfer theory yield many equations involving just a few parameters that connect ground-state geometries and vibration frequencies to excited-state transition energies and vibration frequencies to the rate constants for electron-transfer reactions, utilizing properties of the conical-intersection seam linking the ground and excited states through the Pseudo Jahn-Teller effect. We review how such simplicity in basic understanding can also be obtained for general chemical reactions. The key feature that must be recognized is that electron-transfer (or hole transfer) processes typically involve one electron (hole) moving between two orbitals, whereas general reactions typically involve two electrons or even four electrons for processes in aromatic molecules. Each additional moving electron leads to new high-energy but interrelated conical-intersection seams that distort the shape of the critical lowest-energy seam. Recognizing this feature shows how conical-intersection descriptors can be transferred between systems, and how general chemical reactions can be compared using the same set of simple parameters. Mathematical relationships are presented depicting how different conical-intersection seams relate to each other, showing that complex problems can be reduced into an effective interaction between the ground-state and a critical excited state to provide the first semi-quantitative implementation of Shaik’s “twin state” concept. Applications are made (i) demonstrating why the chemistry of the first-row elements is qualitatively so different to that of the second and later rows, (ii) deducing the bond-length alternation in hypothetical cyclohexatriene from the observed UV spectroscopy of benzene, (iii) demonstrating that commonly used procedures for modelling surface hopping based on inclusion of only the first-derivative correction to the Born-Oppenheimer approximation are valid in no region of the chemical

Computer-assisted semen analysis parameters as predictors for fertility of men from the general population

DEFF Research Database (Denmark)

Larsen, L; Scheike, Thomas Harder; Jensen, Tina Kold

2000-01-01

The predictive value of sperm motility parameters obtained by computer-assisted semen analysis (CASA) was evaluated for the fertility of men from general population. In a prospective study with couples stopping use of contraception in order to try to conceive, CASA was performed on semen samples...

Definition of a matrix of the generalized parameters asymmetrical multiphase transmission lines

Directory of Open Access Journals (Sweden)

Suslov V.M.

2005-12-01

Full Text Available Idle time, without introduction of wave characteristics, algorithm of definition of a matrix of the generalized parameters asymmetrical multiphase transmission lines is offered. Definition of a matrix of parameters is based on a matrix primary specific of parameters of line and simple iterative procedure. The amount of iterations of iterative procedure is determined by a set error of performance of the resulted matrix ratio between separate blocks of a determined matrix. The given error is connected by close image of with a margin error determined matrix.

Phthalate exposure and reproductive parameters in young men from the general Swedish population.

Science.gov (United States)

Axelsson, Jonatan; Rylander, Lars; Rignell-Hydbom, Anna; Jönsson, Bo A G; Lindh, Christian H; Giwercman, Aleksander

2015-12-01

In animals, exposure to certain phthalates negatively affects the male reproductive function. Human results are conflicting and mostly based on subfertile males, in whom the association between exposure and reproductive function may differ from the general population. To study if levels of phthalate metabolites were associated with semen quality and reproductive hormones in general Swedish men. We recruited 314 young men delivering semen, urine and blood samples at the same visit. We analyzed reproductive hormones and several semen parameters including progressive motility and high DNA stainability (HDS)-a marker for sperm immaturity. In urine, we analyzed metabolites of phthalates, including diethylhexyl phthalate (DEHP). We studied associations between urinary levels of the metabolites and seminal as well as serum reproductive parameters, accounting for potential confounders. DEHP metabolite levels, particularly urinary mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), were negatively associated with progressive sperm motility, which was 11 (95% CI: 5.0-17) percentage points lower in the highest quartile of MECPP than in the lowest. Further, men in the highest quartile of the DEHP metabolite monoethylhexyl phthalate had 27% (95% CI: 5.5%-53%) higher HDS than men in the lowest quartile. DEHP metabolite levels seemed negatively associated with sperm motility and maturation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Relaxation of structural parameters and potential coefficients of nonrigid molecules. General symmetry properties and application to ab initio study of 1,2-difluoroethane

Science.gov (United States)

Ha, T.-K.; Günthard, H. H.

1989-07-01

Structural parameters like bond length, bond angles, etc. and harmonic and anharmonic potential coefficients of molecules with internal rotation, inversion or puckering modes are generally assumed to vary with the large amplitude internal coordinates in a concerted manner (relaxation). Taking the coordinate vectors of the nuclear configuration of semirigid molecules with relaxation (SRMRs) as functions of relaxing structural parameters and finite amplitude internal coordinate, the isometric group of SRMRs is discussed and the irreducible representations of the latter are shown to classify into engendered and nonengendered ones. On this basis a concept of equivalent sets of nuclei SRMRs is introduced and an analytical expression is derived which defines the most general functional form of relaxation increments of all common types of structural parameters compatible with isometric symmetry. This formula is shown to be a close analog of an analytical expression defining the transformations induced by the isometric group of infinitesimal internal coordinates associated with typical structural parameters. Furthermore analogous formulae are given for the most general form of the relaxation of harmonic potential coefficients as a function of finite internal coordinates. The general relations are illustrated by ab initio calculations for 1,2-difluoroethane at the MP4/DZP//HF/4-31G* level for twelve values of the dihedral angle including complete structure optimization. The potential to internal rotation is found to be in essential agreement with experimentally derived data. For a complete set of ab initio structural parameters the associated relaxation increments are represented as Fourier series, which are shown to confirm the form predicted by the general formula and the isometric group of 1,2-difluoroethane. Depending on type of the structural parameters (bond length, bond angles, etc.), the associated relaxation increments appear to follow some simple rules. Similarly

Study of pipe-whip parameters in pipelines

International Nuclear Information System (INIS)

Guerreiro, J.N.C.; Loula, A.F.D.; Galeao, A.C.N.R.

1980-01-01

The problem of the high energy pipe-whip, assuming an elastic-plastic behavior for the tube material and taking in account the internal pressure, is studied. The constraints are simulated as bilinear springs and viscous dampers. A general research, based on the finite element method was developed to analyse the phenomenon. The influence of the following parameters: gap, damping coefficient, stiffness, constraints positioning and internal pressure of the tube is studied. (Author) [pt

Beyond bixels: Generalizing the optimization parameters for intensity modulated radiation therapy

International Nuclear Information System (INIS)

Markman, Jerry; Low, Daniel A.; Beavis, Andrew W.; Deasy, Joseph O.

2002-01-01

Intensity modulated radiation therapy (IMRT) treatment planning systems optimize fluence distributions by subdividing the fluence distribution into rectangular bixels. The algorithms typically optimize the fluence intensity directly, often leading to fluence distributions with sharp discontinuities. These discontinuities may yield difficulties in delivery of the fluence distribution, leading to inaccurate dose delivery. We have developed a method for decoupling the bixel intensities from the optimization parameters; either by introducing optimization control points from which the bixel intensities are interpolated or by parametrizing the fluence distribution using basis functions. In either case, the number of optimization search parameters is reduced from the direct bixel optimization method. To illustrate the concept, the technique is applied to two-dimensional idealized head and neck treatment plans. The interpolation algorithms investigated were nearest-neighbor, linear and cubic spline, and radial basis functions serve as the basis function test. The interpolation and basis function optimization techniques were compared against the direct bixel calculation. The number of optimization parameters were significantly reduced relative to the bixel optimization, and this was evident in the reduction of computation time of as much as 58% from the full bixel optimization. The dose distributions obtained using the reduced optimization parameter sets were very similar to the full bixel optimization when examined by dose distributions, statistics, and dose-volume histograms. To evaluate the sensitivity of the fluence calculations to spatial misalignment caused either by delivery errors or patient motion, the doses were recomputed with a 1 mm shift in each beam and compared to the unshifted distributions. Except for the nearest-neighbor algorithm, the reduced optimization parameter dose distributions were generally less sensitive to spatial shifts than the bixel

On the analysis of glow curves with the general order kinetics: Reliability of the computed trap parameters

Energy Technology Data Exchange (ETDEWEB)

Ortega, F. [Facultad de Ingeniería (UNCPBA) and CIFICEN (UNCPBA – CICPBA – CONICET), Av. del Valle 5737, 7400 Olavarría (Argentina); Santiago, M.; Martinez, N.; Marcazzó, J.; Molina, P.; Caselli, E. [Instituto de Física Arroyo Seco (UNCPBA) and CIFICEN (UNCPBA – CICPBA – CONICET), Pinto 399, 7000 Tandil (Argentina)

2017-04-15

Nowadays the most employed kinetics for analyzing glow curves is the general order kinetics (GO) proposed by C. E. May and J. A. Partridge. As shown in many articles this kinetics might yield wrong parameters characterizing trap and recombination centers. In this article this kinetics is compared with the modified general order kinetics put forward by M. S. Rasheedy by analyzing synthetic glow curves. The results show that the modified kinetics gives parameters, which are more accurate than that yield by the original general order kinetics. A criterion is reported to evaluate the accuracy of the trap parameters found by deconvolving glow curves. This criterion was employed to assess the reliability of the trap parameters of the YVO{sub 4}: Eu{sup 3+} compounds.

Analysis of Loss of Control Parameters for Aircraft Maneuvering in General Aviation

Directory of Open Access Journals (Sweden)

Sameer Ud-Din

2018-01-01

Full Text Available A rapid increase in the occurrence of loss of control in general aviation has raised concern in recent years. Loss of control (LOC pertains to unique characteristics in which external and internal events act in conjunction. The Federal Aviation Administration (FAA has approved an Integrated Safety Assessment Model (ISAM for evaluating safety in the National Airspace System (NAS. ISAM consists of an event sequence diagram (ESD with fault trees containing numerous parameters, which is recognized as casual risk model. In this paper, we outline an integrated risk assessment framework to model maneuvering through cross-examining external and internal events. The maneuvering is in the critical flight phase with a high number of LOC occurrences in general aviation, where highly trained and qualified pilots failed to maintain aircraft control irrespective of the preventive nature of the events. Various metrics have been presented for evaluating the significance of these parameters to identify the most important ones. The proposed sensitivity analysis considers the accident, fatality, and risk reduction frequencies that assist in the decision-making process and foresees future risks from a general aviation perspective.

Associations between urinary phthalate concentrations and semen quality parameters in a general population

Science.gov (United States)

Bloom, M.S.; Whitcomb, B.W.; Chen, Z.; Ye, A.; Kannan, K.; Buck Louis, G.M.

2015-01-01

STUDY QUESTION Are urinary phthalate concentrations associated with altered semen quality parameters among males recruited from the general population? SUMMARY ANSWER Urinary levels of metabolites of phthalate diesters are associated with lower total sperm counts, larger sperm head sizes, and higher percentages of morphologically abnormal sperm. WHAT IS KNOWN ALREADY High dose experiments in rats implicate phthalates as anti-androgens. Studies involving infertile men seeking care suggest that phthalates influence measures of semen quality raising concern about the implications for men in the general population. STUDY DESIGN, SIZE, DURATION This prospective cohort study comprised 501 male partners in couples discontinuing contraception to become pregnant, who were recruited from 16 US counties using population-based sampling frameworks from 2005 to 2009. PARTICIPANTS/MATERIALS, SETTING, METHODS Urine and semen samples were obtained at baseline from 473 (94%) men, of whom 378 (80%) men provided a second sample the following month. Urine was analyzed for 14 monoester metabolites of phthalate diesters by high-performance liquid chromatography coupled to tandem mass spectrometry. Semen samples were analyzed for 34 quality parameters categorized as general, motility, morphology, sperm head and sperm chromatin structure. MAIN RESULTS AND THE ROLE OF CHANCE Urinary mono-[2-(carboxymethyl) hexyl] phthalate (MCMHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-benzyl phthalate (MBzP), and mono-isononyl phthalate (MNP) were significantly associated with lower total sperm counts and concentrations, larger sperm head sizes, higher proportions of megalo head sperm morphology, and/or other morphological changes. Urinary mono-methyl phthalate (MMP) and mono-cyclohexyl phthalate (MCPP) were significantly associated with lower sperm motility, and urine mono-2-ethylhexyl phthalate (MEHP) was significantly associated with higher sperm motility. LIMITATIONS, REASONS FOR

Generalized dislocated lag function projective synchronization of fractional order chaotic systems with fully uncertain parameters

International Nuclear Information System (INIS)

Wang, Cong; Zhang, Hong-li; Fan, Wen-hui

2017-01-01

In this paper, we propose a new method to improve the safety of secure communication. This method uses the generalized dislocated lag projective synchronization and function projective synchronization to form a new generalized dislocated lag function projective synchronization. Moreover, this paper takes the examples of fractional order Chen system and Lü system with uncertain parameters as illustration. As the parameters of the two systems are uncertain, the nonlinear controller and parameter update algorithms are designed based on the fractional stability theory and adaptive control method. Moreover, this synchronization form and method of control are applied to secure communication via chaotic masking modulation. Many information signals can be recovered and validated. Finally, simulations are used to show the validity and feasibility of the proposed scheme.

Adaptive generalized function projective lag synchronization of different chaotic systems with fully uncertain parameters

International Nuclear Information System (INIS)

Wu Xiangjun; Lu Hongtao

2011-01-01

Highlights: → Adaptive generalized function projective lag synchronization (AGFPLS) is proposed. → Two uncertain chaos systems are lag synchronized up to a scaling function matrix. → The synchronization speed is sensitively influenced by the control gains. → The AGFPLS scheme is robust against noise perturbation. - Abstract: In this paper, a novel projective synchronization scheme called adaptive generalized function projective lag synchronization (AGFPLS) is proposed. In the AGFPLS method, the states of two different chaotic systems with fully uncertain parameters are asymptotically lag synchronized up to a desired scaling function matrix. By means of the Lyapunov stability theory, an adaptive controller with corresponding parameter update rule is designed for achieving AGFPLS between two diverse chaotic systems and estimating the unknown parameters. This technique is employed to realize AGFPLS between uncertain Lue chaotic system and uncertain Liu chaotic system, and between Chen hyperchaotic system and Lorenz hyperchaotic system with fully uncertain parameters, respectively. Furthermore, AGFPLS between two different uncertain chaotic systems can still be achieved effectively with the existence of noise perturbation. The corresponding numerical simulations are performed to demonstrate the validity and robustness of the presented synchronization method.

Modal Parameter Identification from Responses of General Unknown Random Inputs

DEFF Research Database (Denmark)

Ibrahim, S. R.; Asmussen, J. C.; Brincker, Rune

1996-01-01

Modal parameter identification from ambient responses due to a general unknown random inputs is investigated. Existing identification techniques which are based on assumptions of white noise and or stationary random inputs are utilized even though the inputs conditions are not satisfied....... This is accomplished via adding. In cascade. A force cascade conversion to the structures system under consideration. The input to the force conversion system is white noise and the output of which is the actual force(s) applied to the structure. The white noise input(s) and the structures responses are then used...

Estimating the parameters of a generalized lambda distribution

International Nuclear Information System (INIS)

Fournier, B.; Rupin, N.; Najjar, D.; Iost, A.; Rupin, N.; Bigerelle, M.; Wilcox, R.; Fournier, B.

2007-01-01

The method of moments is a popular technique for estimating the parameters of a generalized lambda distribution (GLD), but published results suggest that the percentile method gives superior results. However, the percentile method cannot be implemented in an automatic fashion, and automatic methods, like the starship method, can lead to prohibitive execution time with large sample sizes. A new estimation method is proposed that is automatic (it does not require the use of special tables or graphs), and it reduces the computational time. Based partly on the usual percentile method, this new method also requires choosing which quantile u to use when fitting a GLD to data. The choice for u is studied and it is found that the best choice depends on the final goal of the modeling process. The sampling distribution of the new estimator is studied and compared to the sampling distribution of estimators that have been proposed. Naturally, all estimators are biased and here it is found that the bias becomes negligible with sample sizes n ≥ 2 * 10(3). The.025 and.975 quantiles of the sampling distribution are investigated, and the difference between these quantiles is found to decrease proportionally to 1/root n.. The same results hold for the moment and percentile estimates. Finally, the influence of the sample size is studied when a normal distribution is modeled by a GLD. Both bounded and unbounded GLDs are used and the bounded GLD turns out to be the most accurate. Indeed it is shown that, up to n = 10(6), bounded GLD modeling cannot be rejected by usual goodness-of-fit tests. (authors)

Impact of seasonal variation, age and smoking status on human semen parameters: The Massachusetts General Hospital experience

Science.gov (United States)

Chen, Zuying; Godfrey-Bailey, Linda; Schiff, Isaac; Hauser, Russ

2004-01-01

Background To investigate the relationship of human semen parameters with season, age and smoking status. Methods The present study used data from subjects recruited into an ongoing cross-sectional study on the relationship between environmental agents and semen characteristics. Our population consisted of 306 patients who presented to the Vincent Memorial Andrology Laboratory of Massachusetts General Hospital for semen evaluation. Sperm concentration and motility were measured with computer aided sperm analysis (CASA). Sperm morphology was scored using Tygerberg Kruger strict criteria. Regression analyses were used to investigate the relationships between semen parameters and season, age and smoking status, adjusting for abstinence interval. Results Sperm concentration in the spring was significantly higher than in winter, fall and summer (p seasons. There were no statistically significant relationships between semen parameters and smoking status, though current smokers tended to have lower sperm concentration. We also did not find a statistically significant relationship between age and semen parameters. Conclusions We found seasonal variations in sperm concentration and suggestive evidence of seasonal variation in sperm motility and percent sperm with normal morphology. Although smoking status was not a significant predictor of semen parameters, this may have been due to the small number of current smokers in the study. PMID:15507127

Admissible Estimators in the General Multivariate Linear Model with Respect to Inequality Restricted Parameter Set

Directory of Open Access Journals (Sweden)

Shangli Zhang

2009-01-01

Full Text Available By using the methods of linear algebra and matrix inequality theory, we obtain the characterization of admissible estimators in the general multivariate linear model with respect to inequality restricted parameter set. In the classes of homogeneous and general linear estimators, the necessary and suffcient conditions that the estimators of regression coeffcient function are admissible are established.

Estimation of the shape parameter of a generalized Pareto distribution based on a transformation to Pareto distributed variables

OpenAIRE

van Zyl, J. Martin

2012-01-01

Random variables of the generalized Pareto distribution, can be transformed to that of the Pareto distribution. Explicit expressions exist for the maximum likelihood estimators of the parameters of the Pareto distribution. The performance of the estimation of the shape parameter of generalized Pareto distributed using transformed observations, based on the probability weighted method is tested. It was found to improve the performance of the probability weighted estimator and performs good wit...

Generalized intermediate long-wave hierarchy in zero-curvature representation with noncommutative spectral parameter

Science.gov (United States)

Degasperis, A.; Lebedev, D.; Olshanetsky, M.; Pakuliak, S.; Perelomov, A.; Santini, P. M.

1992-11-01

The simplest generalization of the intermediate long-wave hierarchy (ILW) is considered to show how to extend the Zakharov-Shabat dressing method to nonlocal, i.e., integro-partial differential, equations. The purpose is to give a procedure of constructing the zero-curvature representation of this class of equations. This result obtains by combining the Drinfeld-Sokolov formalism together with the introduction of an operator-valued spectral parameter, namely, a spectral parameter that does not commute with the space variable x. This extension provides a connection between the ILWk hierarchy and the Saveliev-Vershik continuum graded Lie algebras. In the case of ILW2 the Fairlie-Zachos sinh-algebra was found.

[Drug advertising to the general public: conceptual parameters of a risk producer practice].

Science.gov (United States)

Nascimento, Alvaro César

2010-11-01

This article analyzes some concepts relating to marketing, advertising, medications, regulation and manipulation. It discusses ethical and health surveillance parameters of drugs advertising for the general public. The focus of this work is the analysis of contradictions from a conceptual point of view between the practice of pharmaceutical advertising as a tool for the increase of sales and the conquest of markets versus the policy of rational use of medicines. Academic studies and monitoring of drugs advertising conducted by the National Health Surveillance Agency show that the contents of the advertising pieces oriented towards the general public overestimate the - sometimes dubious - qualities of their medication, focusing almost exclusively on the benefits and put them in a central position in the therapeutic process. They also fail to mention the risks inherent in their use. Rather than focusing on regulatory proposals aimed at creating constraints to this practice, this article discusses the impossibility, considering the interests of public health, of the coexistence of marketing with the policies for the correct, rational and safe use of drugs.

Benefit of general anesthesia monitored by bispectral index compared with monitoring guided only by clinical parameters. Systematic review and meta-analysis

Directory of Open Access Journals (Sweden)

Carlos Rogério Degrandi Oliveira

Full Text Available Abstract Background: The bispectral index parameter is used to guide the titration of general anesthesia; however, many studies have shown conflicting results regarding the benefits of bispectral index monitoring. The objective of this systematic review with meta-analysis is to evaluate the clinical impact of monitoring with the bispectral index parameter. Methods: The search for evidence in scientific information sources was conducted during December 2013 to January 2015, the following primary databases: Medline/PubMed, LILACS, Cochrane, CINAHL, Ovid, SCOPUS and TESES. The criteria for inclusion in the study were randomized controlled trials, comparing general anesthesia monitored, with bispectral index parameter with anesthesia guided solely by clinical parameters, and patients aged over 18 years. The criteria for exclusion were studies involving anesthesia or sedation for diagnostic procedures, and intraoperative wake-up test for surgery of the spine. Results: The use of monitoring with the bispectral index has shown benefits reducing time to extubation, orientation in time and place, and discharge from both the operating room and post anesthetic care unit. The risk of nausea and vomiting after surgery was reduced by 12% in patients monitored with bispectral index. Occurred a reduction of 3% in the risk of cognitive impairment postoperatively at 3 months postoperatively and 6% reduction in the risk of postoperative delirium in patients monitored with bispectral index. Furthermore, the risk of intraoperative memory has been reduced by 1%. Conclusion: Clinically, anesthesia monitoring with the BIS can be justified because it allows advantages from reducing the recovery time after waking, mainly by reducing the administration of general anesthetics as well as the risk of adverse events.

Spillover effects in epidemiology: parameters, study designs and methodological considerations

Science.gov (United States)

Benjamin-Chung, Jade; Arnold, Benjamin F; Berger, David; Luby, Stephen P; Miguel, Edward; Colford Jr, John M; Hubbard, Alan E

2018-01-01

Abstract Many public health interventions provide benefits that extend beyond their direct recipients and impact people in close physical or social proximity who did not directly receive the intervention themselves. A classic example of this phenomenon is the herd protection provided by many vaccines. If these ‘spillover effects’ (i.e. ‘herd effects’) are present in the same direction as the effects on the intended recipients, studies that only estimate direct effects on recipients will likely underestimate the full public health benefits of the intervention. Causal inference assumptions for spillover parameters have been articulated in the vaccine literature, but many studies measuring spillovers of other types of public health interventions have not drawn upon that literature. In conjunction with a systematic review we conducted of spillovers of public health interventions delivered in low- and middle-income countries, we classified the most widely used spillover parameters reported in the empirical literature into a standard notation. General classes of spillover parameters include: cluster-level spillovers; spillovers conditional on treatment or outcome density, distance or the number of treated social network links; and vaccine efficacy parameters related to spillovers. We draw on high quality empirical examples to illustrate each of these parameters. We describe study designs to estimate spillovers and assumptions required to make causal inferences about spillovers. We aim to advance and encourage methods for spillover estimation and reporting by standardizing spillover parameter nomenclature and articulating the causal inference assumptions required to estimate spillovers. PMID:29106568

Role of perisynaptic parameters in neurotransmitter homeostasis - computational study of a general synapse

Science.gov (United States)

Pendyam, Sandeep; Mohan, Ashwin; Kalivas, Peter W.; Nair, Satish S.

2015-01-01

Extracellular neurotransmitter concentrations vary over a wide range depending on the type of neurotransmitter and location in the brain. Neurotransmitter homeostasis near a synapse is achieved by a balance of several mechanisms including vesicular release from the presynapse, diffusion, uptake by transporters, non-synaptic production, and regulation of release by autoreceptors. These mechanisms are also affected by the glia surrounding the synapse. However, the role of these mechanisms in achieving neurotransmitter homeostasis is not well understood. A biophysical modeling framework was proposed to reverse engineer glial configurations and parameters related to homeostasis for synapses that support a range of neurotransmitter gradients. Model experiments reveal that synapses with extracellular neurotransmitter concentrations in the micromolar range require non-synaptic neurotransmitter sources and tight synaptic isolation by extracellular glial formations. The model was used to identify the role of perisynaptic parameters on neurotransmitter homeostasis, and to propose glial configurations that could support different levels of extracellular neurotransmitter concentrations. Ranking the parameters based on their effect on neurotransmitter homeostasis, non-synaptic sources were found to be the most important followed by transporter concentration and diffusion coefficient. PMID:22460547

Quantum correction and ordering parameter for systems connected by a general point canonical transformation

International Nuclear Information System (INIS)

Yeon, Kyu Hwang; Hong, Suc Kyoung; Um, Chung In; George, Thomas F.

2006-01-01

With quantum operators corresponding to functions of the canonical variables, Schroedinger equations are constructed for systems corresponding to classical systems connected by a general point canonical transformation. Using the operator connecting quantum states between systems before and after the transformation, the quantum correction term and ordering parameter are obtained

Oyster Creek cycle 10 nodal model parameter optimization study using PSMS

International Nuclear Information System (INIS)

Dougher, J.D.

1987-01-01

The power shape monitoring system (PSMS) is an on-line core monitoring system that uses a three-dimensional nodal code (NODE-B) to perform nodal power calculations and compute thermal margins. The PSMS contains a parameter optimization function that improves the ability of NODE-B to accurately monitor core power distributions. This functions iterates on the model normalization parameters (albedos and mixing factors) to obtain the best agreement between predicted and measured traversing in-core probe (TIP) reading on a statepoint-by-statepoint basis. Following several statepoint optimization runs, an average set of optimized normalization parameters can be determined and can be implemented into the current or subsequent cycle core model for on-line core monitoring. A statistical analysis of 19 high-power steady-state state-points throughout Oyster Creek cycle 10 operation has shown a consistently poor virgin model performance. The normalization parameters used in the cycle 10 NODE-B model were based on a cycle 8 study, which evaluated only Exxon fuel types. The introduction of General Electric (GE) fuel into cycle 10 (172 assemblies) was a significant fuel/core design change that could have altered the optimum set of normalization parameters. Based on the need to evaluate a potential change in the model normalization parameters for cycle 11 and in an attempt to account for the poor cycle 10 model performance, a parameter optimization study was performed

Sex hormones and quantitative ultrasound parameters at the heel in men and women from the general population.

Science.gov (United States)

Pätzug, Konrad; Friedrich, Nele; Kische, Hanna; Hannemann, Anke; Völzke, Henry; Nauck, Matthias; Keevil, Brian G; Haring, Robin

2017-12-01

The present study investigates potential associations between liquid chromatography-mass spectrometry (LC-MS) measured sex hormones, dehydroepiandrosterone sulphate, sex hormone-binding globulin (SHBG) and bone ultrasound parameters at the heel in men and women from the general population. Data from 502 women and 425 men from the population-based Study of Health in Pomerania (SHIP-TREND) were used. Cross-sectional associations of sex hormones including testosterone (TT), calculated free testosterone (FT), dehydroepiandrosterone sulphate (DHEAS), androstenedione (ASD), estrone (E1) and SHBG with quantitative ultrasound (QUS) parameters at the heel, including broadband ultrasound attenuation (BUA), speed of sound (SOS) and stiffness index (SI) were examined by analysis of variance (ANOVA) and multivariable quantile regression models. Multivariable regression analysis showed a sex-specific inverse association of DHEAS with SI in men (Beta per SI unit = - 3.08, standard error (SE) = 0.88), but not in women (Beta = - 0.01, SE = 2.09). Furthermore, FT was positively associated with BUA in men (Beta per BUA unit = 29.0, SE = 10.1). None of the other sex hormones (ASD, E1) or SHBG was associated with QUS parameters after multivariable adjustment. This cross-sectional population-based study revealed independent associations of DHEAS and FT with QUS parameters in men, suggesting a potential influence on male bone metabolism. The predictive role of DHEAS and FT as a marker for osteoporosis in men warrants further investigation in clinical trials and large-scale observational studies.

Determination of a PWR key neutron parameters uncertainties and conformity studies applications

International Nuclear Information System (INIS)

Bernard, D.

2002-01-01

The aim of this thesis was to evaluate uncertainties of key neutron parameters of slab reactors. Uncertainties sources have many origins, technologic origin for parameters of fabrication and physical origin for nuclear data. First, each contribution of uncertainties is calculated and finally, a factor of uncertainties is associated to key slab parameter like reactivity, isotherm reactivity coefficient, control rod efficiency, power form factor before irradiation and lifetime. This factors of uncertainties were computed by Generalized Perturbations Theory in case of step 0 and by directs calculations in case of irradiation problems. One of neutronic conformity applications was about fabrication and nuclear data targets precision adjustments. Statistic (uncertainties) and deterministic (deviations) approaches were studied. Then neutronics key slab parameters uncertainties were reduced and so nuclear performances were optimised. (author)

A generalized Zakharov-Shabat equation with finite-band solutions and a soliton-equation hierarchy with an arbitrary parameter

International Nuclear Information System (INIS)

Zhang Yufeng; Tam, Honwah; Feng Binlu

2011-01-01

Highlights: → A generalized Zakharov-Shabat equation is obtained. → The generalized AKNS vector fields are established. → The finite-band solution of the g-ZS equation is obtained. → By using a Lie algebra presented in the paper, a new soliton hierarchy with an arbitrary parameter is worked out. - Abstract: In this paper, a generalized Zakharov-Shabat equation (g-ZS equation), which is an isospectral problem, is introduced by using a loop algebra G ∼ . From the stationary zero curvature equation we define the Lenard gradients {g j } and the corresponding generalized AKNS (g-AKNS) vector fields {X j } and X k flows. Employing the nonlinearization method, we obtain the generalized Zhakharov-Shabat Bargmann (g-ZS-B) system and prove that it is Liouville integrable by introducing elliptic coordinates and evolution equations. The explicit relations of the X k flows and the polynomial integrals {H k } are established. Finally, we obtain the finite-band solutions of the g-ZS equation via the Abel-Jacobian coordinates. In addition, a soliton hierarchy and its Hamiltonian structure with an arbitrary parameter k are derived.

Exploring Alternative Characteristic Curve Approaches to Linking Parameter Estimates from the Generalized Partial Credit Model.

Science.gov (United States)

Roberts, James S.; Bao, Han; Huang, Chun-Wei; Gagne, Phill

Characteristic curve approaches for linking parameters from the generalized partial credit model were examined for cases in which common (anchor) items are calibrated separately in two groups. Three of these approaches are simple extensions of the test characteristic curve (TCC), item characteristic curve (ICC), and operating characteristic curve…

Parameter Optimization for Feature and Hit Generation in a General Unknown Screening Method-Proof of Concept Study Using a Design of Experiment Approach for a High Resolution Mass Spectrometry Procedure after Data Independent Acquisition.

Science.gov (United States)

Elmiger, Marco P; Poetzsch, Michael; Steuer, Andrea E; Kraemer, Thomas

2018-03-06

High resolution mass spectrometry and modern data independent acquisition (DIA) methods enable the creation of general unknown screening (GUS) procedures. However, even when DIA is used, its potential is far from being exploited, because often, the untargeted acquisition is followed by a targeted search. Applying an actual GUS (including untargeted screening) produces an immense amount of data that must be dealt with. An optimization of the parameters regulating the feature detection and hit generation algorithms of the data processing software could significantly reduce the amount of unnecessary data and thereby the workload. Design of experiment (DoE) approaches allow a simultaneous optimization of multiple parameters. In a first step, parameters are evaluated (crucial or noncrucial). Second, crucial parameters are optimized. The aim in this study was to reduce the number of hits, without missing analytes. The obtained parameter settings from the optimization were compared to the standard settings by analyzing a test set of blood samples spiked with 22 relevant analytes as well as 62 authentic forensic cases. The optimization lead to a marked reduction of workload (12.3 to 1.1% and 3.8 to 1.1% hits for the test set and the authentic cases, respectively) while simultaneously increasing the identification rate (68.2 to 86.4% and 68.8 to 88.1%, respectively). This proof of concept study emphasizes the great potential of DoE approaches to master the data overload resulting from modern data independent acquisition methods used for general unknown screening procedures by optimizing software parameters.

Numerical simulations of generalized Langevin equations with deeply asymptotic parameters

International Nuclear Information System (INIS)

Bao Jingdong; Li Rongwu; Wu Wei

2004-01-01

A unified algorithm for solving Langevin equations with deeply asymptotic parameters is proposed and tested. The method consists of identifying solvable linear friction and implementing the force evaluations by use of the Runge-Kutta method. We apply the present scheme to the periodic motion of an overdamped particle subjected to a multiplicative white noise. The accurate calculations for the temporal velocity of the particle and its correlation function can be realized by introducing an inertial term. It is shown that the fluctuation around the steady quantity increases with decreasing time step in the overdamped white-noise algorithm, however, a massive white-noise technique greatly reduces this spurious drift, and the result can converge to the correct value if the added inertia approaches zero. The other application is the simulation of generalized Langevin equation with an exponential memory friction, this allows us to treat a weak non-Markovian process

Normal Values for Heart Electrophysiology Parameters of Healthy Swine Determined on Electrophysiology Study.

Science.gov (United States)

Noszczyk-Nowak, Agnieszka; Cepiel, Alicja; Janiszewski, Adrian; Pasławski, Robert; Gajek, Jacek; Pasławska, Urszula; Nicpoń, Józef

2016-01-01

Swine are a well-recognized animal model for human cardiovascular diseases. Despite the widespread use of porcine model in experimental electrophysiology, still no reference values for intracardiac electrical activity and conduction parameters determined during an invasive electrophysiology study (EPS) have been developed in this species thus far. The aim of the study was to develop a set of normal values for intracardiac electrical activity and conduction parameters determined during an invasive EPS of swine. The study included 36 healthy domestic swine (24-40 kg body weight). EPS was performed under a general anesthesia with midazolam, propofol and isoflurane. The reference values for intracardiac electrical activity and conduction parameters were calculated as arithmetic means ± 2 standard deviations. The reference values were determined for AH, HV and PA intervals, interatrial conduction time at its own and imposed rhythm, sinus node recovery time (SNRT), corrected sinus node recovery time (CSNRT), anterograde and retrograde Wenckebach points, atrial, atrioventricular node and ventricular refractory periods. No significant correlations were found between body weight and heart rate of the examined pigs and their electrophysiological parameters. The hereby presented reference values can be helpful in comparing the results of various studies, as well as in more accurately estimating the values of electrophysiological parameters that can be expected in a given experiment.

Generalized Dependence of Semi-Microscopic Folding-Model Parameters for Alpha-Particles in the Field of Low and Medium Energy

CERN Document Server

Kuterbekov, K A; Penionzhkevich, Yu E; Zholdybaev, T K

2003-01-01

Energy and mass dependences of the semi-microscopic alpha-particle potential parameters have been investigated for the first time. In general, a good description of elastic and inelastic differential and total reaction cross sections for different nuclei using the revealed global parameters has been obtained within the framework of semi-microscopic approaches.

A general CPL-AdS methodology for fixing dynamic parameters in dual environments.

Science.gov (United States)

Huang, De-Shuang; Jiang, Wen

2012-10-01

The algorithm of Continuous Point Location with Adaptive d-ary Search (CPL-AdS) strategy exhibits its efficiency in solving stochastic point location (SPL) problems. However, there is one bottleneck for this CPL-AdS strategy which is that, when the dimension of the feature, or the number of divided subintervals for each iteration, d is large, the decision table for elimination process is almost unavailable. On the other hand, the larger dimension of the features d can generally make this CPL-AdS strategy avoid oscillation and converge faster. This paper presents a generalized universal decision formula to solve this bottleneck problem. As a matter of fact, this decision formula has a wider usage beyond handling out this SPL problems, such as dealing with deterministic point location problems and searching data in Single Instruction Stream-Multiple Data Stream based on Concurrent Read and Exclusive Write parallel computer model. Meanwhile, we generalized the CPL-AdS strategy with an extending formula, which is capable of tracking an unknown dynamic parameter λ in both informative and deceptive environments. Furthermore, we employed different learning automata in the generalized CPL-AdS method to find out if faster learning algorithm will lead to better realization of the generalized CPL-AdS method. All of these aforementioned contributions are vitally important whether in theory or in practical applications. Finally, extensive experiments show that our proposed approaches are efficient and feasible.

Deriving amplification factors from simple site parameters using generalized regression neural networks: implications for relevant site proxies

Science.gov (United States)

Boudghene Stambouli, Ahmed; Zendagui, Djawad; Bard, Pierre-Yves; Derras, Boumédiène

2017-07-01

Most modern seismic codes account for site effects using an amplification factor (AF) that modifies the rock acceleration response spectra in relation to a "site condition proxy," i.e., a parameter related to the velocity profile at the site under consideration. Therefore, for practical purposes, it is interesting to identify the site parameters that best control the frequency-dependent shape of the AF. The goal of the present study is to provide a quantitative assessment of the performance of various site condition proxies to predict the main AF features, including the often used short- and mid-period amplification factors, Fa and Fv, proposed by Borcherdt (in Earthq Spectra 10:617-653, 1994). In this context, the linear, viscoelastic responses of a set of 858 actual soil columns from Japan, the USA, and Europe are computed for a set of 14 real accelerograms with varying frequency contents. The correlation between the corresponding site-specific average amplification factors and several site proxies (considered alone or as multiple combinations) is analyzed using the generalized regression neural network (GRNN). The performance of each site proxy combination is assessed through the variance reduction with respect to the initial amplification factor variability of the 858 profiles. Both the whole period range and specific short- and mid-period ranges associated with the Borcherdt factors Fa and Fv are considered. The actual amplification factor of an arbitrary soil profile is found to be satisfactorily approximated with a limited number of site proxies (4-6). As the usual code practice implies a lower number of site proxies (generally one, sometimes two), a sensitivity analysis is conducted to identify the "best performing" site parameters. The best one is the overall velocity contrast between underlying bedrock and minimum velocity in the soil column. Because these are the most difficult and expensive parameters to measure, especially for thick deposits, other

Detecting generalized synchronization of chaotic dynamical systems. A kernel-based method and choice of its parameter

International Nuclear Information System (INIS)

Suetani, Hiromichi; Iba, Yukito; Aihara, Kazuyuki

2006-01-01

An approach based on the kernel methods for capturing the nonlinear interdependence between two signals is introduced. It is demonstrated that the proposed approach is useful for characterizing generalized synchronization with a successful simple example. An attempt to choose an optimal kernel parameter based on cross validation is also discussed. (author)

How good is controlled attenuation parameter and fatty liver index for assessing liver steatosis in general population: correlation with ultrasound.

Science.gov (United States)

Carvalhana, Sofia; Leitão, Jorge; Alves, Ana C; Bourbon, Mafalda; Cortez-Pinto, Helena

2014-07-01

Liver steatosis measurement by controlled attenuation parameter (CAP) is a non-invasive method for diagnosing steatosis, based on transient elastography. Its usefulness as screening procedure for hepatic steatosis in general population has not been previously evaluated. The aim of this study was to evaluate the diagnostic accuracy of CAP and fatty liver index (FLI) for detection and quantification of steatosis in general population. Recruitment was done from a prospective epidemiological study of the general adult population. Steatosis was evaluated using CAP, FLI and ultrasound (US). Steatosis scored according to Hamaguchi's US scoring, from 0 (S0) to 6 (S6) points. Hepatic steatosis defined by score ≥2 (S≥2) and moderate/severe steatosis by score ≥4 (S≥4). Performance of CAP and FLI for diagnosing steatosis compared with US was assessed using areas under receiver operating characteristic curves (AUROC). From 219 consecutive individuals studied, 13 (5.9%) excluded because of failure/unreliable liver stiffness measurements. Steatosis prevalence: S≥2 38.4% and S≥4 12.1%. CAP significantly correlated with steatosis (ρ = 0.73, P steatosis score (ρ = 0.76; P steatosis quantification in the general population. Larger studies are needed for validation. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The generalized Q-S synchronization between the generalized Lorenz canonical form and the Roessler system

International Nuclear Information System (INIS)

Yang Yunqing; Chen Yong

2009-01-01

In this paper, we investigate the generalized Q-S synchronization between the generalized Lorenz canonical form and the Roessler system. Firstly, we transform an arbitrary generalized Lorenz system to the generalized Lorenz canonical form, and the relation between the parameter of the generalized Lorenz system and the parameter of the generalized Lorenz canonical form are shown. Secondly, we extend the scheme present by [Yan ZY. Chaos 2005;15:023902] to study the generalized Q-S synchronization between the generalized Lorenz canonical form and the Roessler system, the more general controller is obtained. By choosing different parameter in the generalized controller obtained here, without much extra effort, we can get the controller of synchronization between the Chen system and the Roessler system, the Lue system and the Roessler system, the classic Lorenz system and the Roessler system, the Hyperbolic Lorenz system and the Roessler system, respectively. Finally, numerical simulations are used to perform such synchronization and verify the effectiveness of the controller.

A generalized Fellner-Schall method for smoothing parameter optimization with application to Tweedie location, scale and shape models.

Science.gov (United States)

Wood, Simon N; Fasiolo, Matteo

2017-12-01

We consider the optimization of smoothing parameters and variance components in models with a regular log likelihood subject to quadratic penalization of the model coefficients, via a generalization of the method of Fellner (1986) and Schall (1991). In particular: (i) we generalize the original method to the case of penalties that are linear in several smoothing parameters, thereby covering the important cases of tensor product and adaptive smoothers; (ii) we show why the method's steps increase the restricted marginal likelihood of the model, that it tends to converge faster than the EM algorithm, or obvious accelerations of this, and investigate its relation to Newton optimization; (iii) we generalize the method to any Fisher regular likelihood. The method represents a considerable simplification over existing methods of estimating smoothing parameters in the context of regular likelihoods, without sacrificing generality: for example, it is only necessary to compute with the same first and second derivatives of the log-likelihood required for coefficient estimation, and not with the third or fourth order derivatives required by alternative approaches. Examples are provided which would have been impossible or impractical with pre-existing Fellner-Schall methods, along with an example of a Tweedie location, scale and shape model which would be a challenge for alternative methods, and a sparse additive modeling example where the method facilitates computational efficiency gains of several orders of magnitude. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2017, The Authors Biometrics published by Wiley Periodicals, Inc. on behalf of International Biometric Society.

A general method of estimating stellar astrophysical parameters from photometry

NARCIS (Netherlands)

Belikov, A. N.; Roeser, S.

2008-01-01

Context. Applying photometric catalogs to the study of the population of the Galaxy is obscured by the impossibility to map directly photometric colors into astrophysical parameters. Most of all-sky catalogs like ASCC or 2MASS are based upon broad-band photometric systems, and the use of broad

DETERMINATION ALGORITHM OF OPTIMAL GEOMETRICAL PARAMETERS FOR COMPONENTS OF FREIGHT CARS ON THE BASIS OF GENERALIZED MATHEMATICAL MODELS

Directory of Open Access Journals (Sweden)

O. V. Fomin

2013-10-01

Full Text Available Purpose. Presentation of features and example of the use of the offered determination algorithm of optimum geometrical parameters for the components of freight cars on the basis of the generalized mathematical models, which is realized using computer. Methodology. The developed approach to search for optimal geometrical parameters can be described as the determination of optimal decision of the selected set of possible variants. Findings. The presented application example of the offered algorithm proved its operation capacity and efficiency of use. Originality. The determination procedure of optimal geometrical parameters for freight car components on the basis of the generalized mathematical models was formalized in the paper. Practical value. Practical introduction of the research results for universal open cars allows one to reduce container of their design and accordingly to increase the carrying capacity almost by100 kg with the improvement of strength characteristics. Taking into account the mass of their park this will provide a considerable economic effect when producing and operating. The offered approach is oriented to the distribution of the software packages (for example Microsoft Excel, which are used by technical services of the most enterprises, and does not require additional capital investments (acquisitions of the specialized programs and proper technical staff training. This proves the correctness of the research direction. The offered algorithm can be used for the solution of other optimization tasks on the basis of the generalized mathematical models.

On parameter estimation in deformable models

DEFF Research Database (Denmark)

Fisker, Rune; Carstensen, Jens Michael

1998-01-01

Deformable templates have been intensively studied in image analysis through the last decade, but despite its significance the estimation of model parameters has received little attention. We present a method for supervised and unsupervised model parameter estimation using a general Bayesian form...

Generalized Extreme Value's shape parameter and its nature for extreme precipitation using long time series and Bayesian approach

Science.gov (United States)

Ragulina, Galina; Reitan, Trond

2016-04-01

Assessing the probability of extreme precipitation events is of great importance in civil planning. This requires understanding of how return values change with different return periods, which is essentially described by the Generalized Extreme Value distribution's shape parameter. Some works in the field have suggested a constant shape parameter, while our analysis indicates a non-universal value. We first re-analyse an older precipitation dataset (169 stations) extended by Norwegian data (71 stations). We show that while each set seems to have a constant shape parameter, it differs between the two datasets, indicating regional differences. For a more comprehensive analysis of spatial effects, we examine a global dataset (1495 stations). We provide shape parameter maps for two models. We find clear evidence for the shape parameter being dependent on elevation while the effect of latitude remains uncertain. Our results confirm an explanation in terms of dominating precipitation systems based on a proxy derived from the Köppen-Geiger climate classification.

Comment on 'Immirzi parameter in quantum general relativity'

International Nuclear Information System (INIS)

Samuel, Joseph

2001-01-01

The Immirzi parameter is a free parameter which appears in the physical predictions of loop quantum gravity and is sometimes viewed as a quantization ambiguity. Interpretations have been offered for the Immirzi ambiguity, but there does not appear to be a clear understanding or even a consensus about its origin and significance. We show that a previously discussed example containing a 'finite dimensional analogue' of the Immirzi ambiguity is fallacious, in the sense that the ambiguity in this example is not intrinsic to the system, but introduced artificially by compactifying the configuration space

Modeling phase equilibria of alkanols with the simplified PC-SAFT equation of state and generalized pure compound parameters

DEFF Research Database (Denmark)

Grenner, Andreas; Kontogeorgis, Georgios; von Solms, Nicolas

2007-01-01

The simplified PC-SAFT equation of state has been applied to liquid-liquid, vapor-liquid and solid-liquid equilibria for mixtures containing 1-or 2-alkanols with alkanes, aromatic hydrocarbons, CO2 and water. For the alkanols we use generalized pure compound parameters. This means that two...... of the physical pure compound parameters, in (segment number) and or (segment diameter), are obtained from linear extrapolations, since m and m sigma(3), increase linearly with respect to the molar mass, and moreover, the two association parameters (association energy and association volume) were assumed...... to be constant for all alkanols. Only the dispersion energy is fitted to experimental data. Thus it is possible to estimate parameters for several 1-and 2-alkanols. The final aim is to develop a group contribution approach for PC-SAFT which is suitable for complex compounds, considering that the motivation...

Multi-parameter vital sign database to assist in alarm optimization for general care units.

Science.gov (United States)

Welch, James; Kanter, Benjamin; Skora, Brooke; McCombie, Scott; Henry, Isaac; McCombie, Devin; Kennedy, Rosemary; Soller, Babs

2016-12-01

Continual vital sign assessment on the general care, medical-surgical floor is expected to provide early indication of patient deterioration and increase the effectiveness of rapid response teams. However, there is concern that continual, multi-parameter vital sign monitoring will produce alarm fatigue. The objective of this study was the development of a methodology to help care teams optimize alarm settings. An on-body wireless monitoring system was used to continually assess heart rate, respiratory rate, SpO 2 and noninvasive blood pressure in the general ward of ten hospitals between April 1, 2014 and January 19, 2015. These data, 94,575 h for 3430 patients are contained in a large database, accessible with cloud computing tools. Simulation scenarios assessed the total alarm rate as a function of threshold and annunciation delay (s). The total alarm rate of ten alarms/patient/day predicted from the cloud-hosted database was the same as the total alarm rate for a 10 day evaluation (1550 h for 36 patients) in an independent hospital. Plots of vital sign distributions in the cloud-hosted database were similar to other large databases published by different authors. The cloud-hosted database can be used to run simulations for various alarm thresholds and annunciation delays to predict the total alarm burden experienced by nursing staff. This methodology might, in the future, be used to help reduce alarm fatigue without sacrificing the ability to continually monitor all vital signs.

Optimization of GATE and PHITS Monte Carlo code parameters for uniform scanning proton beam based on simulation with FLUKA general-purpose code

Energy Technology Data Exchange (ETDEWEB)

Kurosu, Keita [Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); Takashina, Masaaki; Koizumi, Masahiko [Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); Das, Indra J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Moskvin, Vadim P., E-mail: vadim.p.moskvin@gmail.com [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States)

2014-10-01

Although three general-purpose Monte Carlo (MC) simulation tools: Geant4, FLUKA and PHITS have been used extensively, differences in calculation results have been reported. The major causes are the implementation of the physical model, preset value of the ionization potential or definition of the maximum step size. In order to achieve artifact free MC simulation, an optimized parameters list for each simulation system is required. Several authors have already proposed the optimized lists, but those studies were performed with a simple system such as only a water phantom. Since particle beams have a transport, interaction and electromagnetic processes during beam delivery, establishment of an optimized parameters-list for whole beam delivery system is therefore of major importance. The purpose of this study was to determine the optimized parameters list for GATE and PHITS using proton treatment nozzle computational model. The simulation was performed with the broad scanning proton beam. The influences of the customizing parameters on the percentage depth dose (PDD) profile and the proton range were investigated by comparison with the result of FLUKA, and then the optimal parameters were determined. The PDD profile and the proton range obtained from our optimized parameters list showed different characteristics from the results obtained with simple system. This led to the conclusion that the physical model, particle transport mechanics and different geometry-based descriptions need accurate customization in planning computational experiments for artifact-free MC simulation.

Optimization of GATE and PHITS Monte Carlo code parameters for uniform scanning proton beam based on simulation with FLUKA general-purpose code

International Nuclear Information System (INIS)

Kurosu, Keita; Takashina, Masaaki; Koizumi, Masahiko; Das, Indra J.; Moskvin, Vadim P.

2014-01-01

Although three general-purpose Monte Carlo (MC) simulation tools: Geant4, FLUKA and PHITS have been used extensively, differences in calculation results have been reported. The major causes are the implementation of the physical model, preset value of the ionization potential or definition of the maximum step size. In order to achieve artifact free MC simulation, an optimized parameters list for each simulation system is required. Several authors have already proposed the optimized lists, but those studies were performed with a simple system such as only a water phantom. Since particle beams have a transport, interaction and electromagnetic processes during beam delivery, establishment of an optimized parameters-list for whole beam delivery system is therefore of major importance. The purpose of this study was to determine the optimized parameters list for GATE and PHITS using proton treatment nozzle computational model. The simulation was performed with the broad scanning proton beam. The influences of the customizing parameters on the percentage depth dose (PDD) profile and the proton range were investigated by comparison with the result of FLUKA, and then the optimal parameters were determined. The PDD profile and the proton range obtained from our optimized parameters list showed different characteristics from the results obtained with simple system. This led to the conclusion that the physical model, particle transport mechanics and different geometry-based descriptions need accurate customization in planning computational experiments for artifact-free MC simulation

The Source and Impact of Specific Parameters that Enhance Well-Being in Daily Life.

Science.gov (United States)

Stewart, William C; Reynolds, Kelly E; Jones, Lydia J; Stewart, Jeanette A; Nelson, Lindsay A

2016-08-01

The purpose of this study was to review four parameters (forgiveness, gratitude, hope and empathy) frequently noted when evaluating well-being. We reviewed clinical studies from 1966 to present. We included 63 articles. All four of the parameters were shown to generally improve an individual's well-being. These parameters demonstrated a positive influence within more specific societal issues including improvement in social relationships, delinquent behavior and physical health. These parameters were generally derived from training and religion. This study suggests that these parameters may improve either one of general well-being, pro-social and positive relational behavior and demonstrate positive health effects.

A generalized TRL algorithm for s-parameter de-embedding

International Nuclear Information System (INIS)

Colestock, P.; Foley, M.

1993-04-01

At FNAL bench measurements of the longitudinal impedance of various beamline components have been performed using stretched wire methods. The basic approach is to use a network analyzer (NWA) to measure the transmission and reflection characteristics (s-parameters) of the beam line component. It is then possible to recover the effective longitudinal impedance from the s-parameters. Several NWA calibration procedures have been implemented in an effort to improve the accuracy of these measurements. These procedures are mathematical techniques for extracting the s-parameters of a test device from external NWA measurements which include the effect of measurement fixtures. The TRL algorithm has proven to be the most effective of these techniques. This method has the advantage of properly accounting for the nonideal calibration standards used in the NWA measurements

ESTIMATION OF PARAMETERS AND RELIABILITY FUNCTION OF EXPONENTIATED EXPONENTIAL DISTRIBUTION: BAYESIAN APPROACH UNDER GENERAL ENTROPY LOSS FUNCTION

Directory of Open Access Journals (Sweden)

Sanjay Kumar Singh

2011-06-01

Full Text Available In this Paper we propose Bayes estimators of the parameters of Exponentiated Exponential distribution and Reliability functions under General Entropy loss function for Type II censored sample. The proposed estimators have been compared with the corresponding Bayes estimators obtained under Squared Error loss function and maximum likelihood estimators for their simulated risks (average loss over sample space.

A study of school adjustment, self-concept, self-esteem, general wellbeing and parent child relationship in Juvenile Idiopathic Arthritis.

Science.gov (United States)

Yadav, Anita; Yadav, T P

2013-03-01

To assess school adjustment, self-concept, self-esteem, general wellbeing and parent-child relationship in children with Juvenile Idiopathic Arthritis (JIA)and to study the correlation of these parameters with chronicity of disease, number of active joints, laboratory parameters of disease activity and JIA subtypes. A total of 64 children (32 cases and 32 controls) were recruited for analysis. Self report questionnaires which included PGI General Wellbeing Measure, Adjustment Inventory for School Students, Parent Child Relationship Scale, Self Esteem Inventory and Self Concept Questionnaires were used to assess all the enrolled subjects. Cases had significantly lower general physical well being (p self-esteem, self-concept, adjustment in school, general wellbeing and evokes disturbed parent-child relationship.

Virtual walks in spin space: A study in a family of two-parameter models

Science.gov (United States)

Mullick, Pratik; Sen, Parongama

2018-05-01

We investigate the dynamics of classical spins mapped as walkers in a virtual "spin" space using a generalized two-parameter family of spin models characterized by parameters y and z [de Oliveira et al., J. Phys. A 26, 2317 (1993), 10.1088/0305-4470/26/10/006]. The behavior of S (x ,t ) , the probability that the walker is at position x at time t , is studied in detail. In general S (x ,t ) ˜t-αf (x /tα) with α ≃1 or 0.5 at large times depending on the parameters. In particular, S (x ,t ) for the point y =1 ,z =0.5 corresponding to the Voter model shows a crossover in time; associated with this crossover, two timescales can be defined which vary with the system size L as L2logL . We also show that as the Voter model point is approached from the disordered regions along different directions, the width of the Gaussian distribution S (x ,t ) diverges in a power law manner with different exponents. For the majority Voter case, the results indicate that the the virtual walk can detect the phase transition perhaps more efficiently compared to other nonequilibrium methods.

Impact of Material and Architecture Model Parameters on the Failure of Woven Ceramic Matrix Composites (CMCs) via the Multiscale Generalized Method of Cells

Science.gov (United States)

Liu, Kuang C.; Arnold, Steven M.

2011-01-01

It is well known that failure of a material is a locally driven event. In the case of ceramic matrix composites (CMCs), significant variations in the microstructure of the composite exist and their significance on both deformation and life response need to be assessed. Examples of these variations include changes in the fiber tow shape, tow shifting/nesting and voids within and between tows. In the present work, the effects of many of these architectural parameters and material scatter of woven ceramic composite properties at the macroscale (woven RUC) will be studied to assess their sensitivity. The recently developed Multiscale Generalized Method of Cells methodology is used to determine the overall deformation response, proportional elastic limit (first matrix cracking), and failure under tensile loading conditions. The macroscale responses investigated illustrate the effect of architectural and material parameters on a single RUC representing a five harness satin weave fabric. Results shows that the most critical architectural parameter is weave void shape and content with other parameters being less in severity. Variation of the matrix material properties was also studied to illustrate the influence of the material variability on the overall features of the composite stress-strain response.

Reference tissue modeling with parameter coupling: application to a study of SERT binding in HIV

Energy Technology Data Exchange (ETDEWEB)

Endres, Christopher J; Pomper, Martin G [Russell H Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States); Hammoud, Dima A, E-mail: endres@jhmi.edu [Radiology and Imaging Sciences, National Institutes of Health/Clinical Center, Bethesda, MD (United States)

2011-04-21

When applicable, it is generally preferred to evaluate positron emission tomography (PET) studies using a reference tissue-based approach as that avoids the need for invasive arterial blood sampling. However, most reference tissue methods have been shown to have a bias that is dependent on the level of tracer binding, and the variability of parameter estimates may be substantially affected by noise level. In a study of serotonin transporter (SERT) binding in HIV dementia, it was determined that applying parameter coupling to the simplified reference tissue model (SRTM) reduced the variability of parameter estimates and yielded the strongest between-group significant differences in SERT binding. The use of parameter coupling makes the application of SRTM more consistent with conventional blood input models and reduces the total number of fitted parameters, thus should yield more robust parameter estimates. Here, we provide a detailed evaluation of the application of parameter constraint and parameter coupling to [{sup 11}C]DASB PET studies. Five quantitative methods, including three methods that constrain the reference tissue clearance (k{sup r}{sub 2}) to a common value across regions were applied to the clinical and simulated data to compare measurement of the tracer binding potential (BP{sub ND}). Compared with standard SRTM, either coupling of k{sup r}{sub 2} across regions or constraining k{sup r}{sub 2} to a first-pass estimate improved the sensitivity of SRTM to measuring a significant difference in BP{sub ND} between patients and controls. Parameter coupling was particularly effective in reducing the variance of parameter estimates, which was less than 50% of the variance obtained with standard SRTM. A linear approach was also improved when constraining k{sup r}{sub 2} to a first-pass estimate, although the SRTM-based methods yielded stronger significant differences when applied to the clinical study. This work shows that parameter coupling reduces the

Studies on water quality parameters due to operation of PHWR at KAPS

International Nuclear Information System (INIS)

Jha, Mukesh; John, Jaison T.; Joshi, C.P.; Vyas, P.V.; Hegde, A.G.

2005-01-01

The paper elucidates the effect of water quality due to operation of Pressurised Heavy Water Reactor located at Kakrapar as water is the essential commodity for all living beings. It is the main concern in recent times for environmental protection, there is a pressure on all type of industries including nuclear power stations to discharge various types of effluents in such a manner that pollution in surrounding environment is kept to the minimum. Owing the wastewater discharge modes of Kakrapar atomic power station behavior of effluents resulting impact on environment and general public will be guided by the water quality of the aquatic system. To ensure the quality of water, the study of water quality parameters are taken up and the investigated parameters showed no degradation in ecosystem due to the operation of PHWR at KAPS. (author)

Transmuted Generalized Inverse Weibull Distribution

OpenAIRE

Merovci, Faton; Elbatal, Ibrahim; Ahmed, Alaa

2013-01-01

A generalization of the generalized inverse Weibull distribution so-called transmuted generalized inverse Weibull dis- tribution is proposed and studied. We will use the quadratic rank transmutation map (QRTM) in order to generate a flexible family of probability distributions taking generalized inverse Weibull distribution as the base value distribution by introducing a new parameter that would offer more distributional flexibility. Various structural properties including explicit expression...

McDonald Generalized Linear Failure Rate Distribution

Directory of Open Access Journals (Sweden)

Ibrahim Elbatal

2014-10-01

Full Text Available We introduce in this paper a new six-parameters generalized version of the generalized linear failure rate (GLFR distribution which is called McDonald Generalized Linear failure rate (McGLFR distribution. The new distribution is quite flexible and can be used effectively in modeling survival data and reliability problems. It can have a constant, decreasing, increasing, and upside down bathtub-and bathtub shaped failure rate function depending on its parameters. It includes some well-known lifetime distributions as special sub-models. Some structural properties of the new distribution are studied. Moreover we discuss maximum likelihood estimation of the unknown parameters of the new model.

Bayesian conjugate analysis using a generalized inverted Wishart distribution accounts for differential uncertainty among the genetic parameters--an application to the maternal animal model.

Science.gov (United States)

Munilla, S; Cantet, R J C

2012-06-01

Consider the estimation of genetic (co)variance components from a maternal animal model (MAM) using a conjugated Bayesian approach. Usually, more uncertainty is expected a priori on the value of the maternal additive variance than on the value of the direct additive variance. However, it is not possible to model such differential uncertainty when assuming an inverted Wishart (IW) distribution for the genetic covariance matrix. Instead, consider the use of a generalized inverted Wishart (GIW) distribution. The GIW is essentially an extension of the IW distribution with a larger set of distinct parameters. In this study, the GIW distribution in its full generality is introduced and theoretical results regarding its use as the prior distribution for the genetic covariance matrix of the MAM are derived. In particular, we prove that the conditional conjugacy property holds so that parameter estimation can be accomplished via the Gibbs sampler. A sampling algorithm is also sketched. Furthermore, we describe how to specify the hyperparameters to account for differential prior opinion on the (co)variance components. A recursive strategy to elicit these parameters is then presented and tested using field records and simulated data. The procedure returned accurate estimates and reduced standard errors when compared with non-informative prior settings while improving the convergence rates. In general, faster convergence was always observed when a stronger weight was placed on the prior distributions. However, analyses based on the IW distribution have also produced biased estimates when the prior means were set to over-dispersed values. © 2011 Blackwell Verlag GmbH.

Qualitative Parameters of Practice during University Studies

Science.gov (United States)

Stasiunaitiene, Egle; Norkute, Odeta

2011-01-01

In this article, relevance of practice during university studies is highlighted, as well as the main stages of its organisation, qualitative parameters, as well as criteria and indicators that validate them are defined. Discussion on the idea that taking into consideration qualitative parameters of organising practice as a component of studies…

A Generalized Estimating Equations Approach to Model Heterogeneity and Time Dependence in Capture-Recapture Studies

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Akanda Md. Abdus Salam

2017-03-01

Full Text Available Individual heterogeneity in capture probabilities and time dependence are fundamentally important for estimating the closed animal population parameters in capture-recapture studies. A generalized estimating equations (GEE approach accounts for linear correlation among capture-recapture occasions, and individual heterogeneity in capture probabilities in a closed population capture-recapture individual heterogeneity and time variation model. The estimated capture probabilities are used to estimate animal population parameters. Two real data sets are used for illustrative purposes. A simulation study is carried out to assess the performance of the GEE estimator. A Quasi-Likelihood Information Criterion (QIC is applied for the selection of the best fitting model. This approach performs well when the estimated population parameters depend on the individual heterogeneity and the nature of linear correlation among capture-recapture occasions.

Study of the size effect by accurately determining the crystal parameters

International Nuclear Information System (INIS)

Seguin, Remy

1973-01-01

The size factor η = da/adC was measured by comparing the variations in the crystal parameter as a function of the concentration, samples of Al of various degrees of purity and Al - V and Al - Cu alloys with concentrations of less than 1 000 ppm being used. The results confirm the experimental results obtained with alloys supersaturated by ultra-rapid tempering but are not consistent with theoretical values, which appear to be too large for the case of transition elements in solution in Al. The parameter was determined from Kossel diagrams obtained using an electron probe microanalyzer. The measurement methods were developed and generalized by plotting curves representing the variation of the parameter as a function of temperature between 20 and 60 deg. C. Values were obtained for the parameter at given temperatures (± 0.1 deg. C) with an accuracy of Δa/a ≅ 8.10 -6 . (author) [fr

The Transmuted Generalized Inverse Weibull Distribution

Directory of Open Access Journals (Sweden)

Faton Merovci

2014-05-01

Full Text Available A generalization of the generalized inverse Weibull distribution the so-called transmuted generalized inverse Weibull distribution is proposed and studied. We will use the quadratic rank transmutation map (QRTM in order to generate a flexible family of probability distributions taking the generalized inverseWeibull distribution as the base value distribution by introducing a new parameter that would offer more distributional flexibility. Various structural properties including explicit expressions for the moments, quantiles, and moment generating function of the new distribution are derived. We propose the method of maximum likelihood for estimating the model parameters and obtain the observed information matrix. A real data set are used to compare the flexibility of the transmuted version versus the generalized inverse Weibull distribution.

A new general method for simultaneous fitting of temperature and concentration dependence of reaction rates yields kinetic and thermodynamic parameters for HIV reverse transcriptase specificity.

Science.gov (United States)

Li, An; Ziehr, Jessica L; Johnson, Kenneth A

2017-04-21

Recent studies have demonstrated the dominant role of induced fit in enzyme specificity of HIV reverse transcriptase and many other enzymes. However, relevant thermodynamic parameters are lacking, and equilibrium thermodynamic methods are of no avail because the key parameters can only be determined by kinetic measurement. By modifying KinTek Explorer software, we present a new general method for globally fitting data collected over a range of substrate concentrations and temperatures and apply it to HIV reverse transcriptase. Fluorescence stopped-flow methods were used to record the kinetics of enzyme conformational changes that monitor nucleotide binding and incorporation. The nucleotide concentration dependence was measured at temperatures ranging from 5 to 37 °C, and the raw data were fit globally to derive a single set of rate constants at 37 °C and a set of activation enthalpy terms to account for the kinetics at all other temperatures. This comprehensive analysis afforded thermodynamic parameters for nucleotide binding ( K d , Δ G , Δ H , and Δ S at 37 °C) and kinetic parameters for enzyme conformational changes and chemistry (rate constants and activation enthalpy). Comparisons between wild-type enzyme and a mutant resistant to nucleoside analogs used to treat HIV infections reveal that the ground state binding is weaker and the activation enthalpy for the conformational change step is significantly larger for the mutant. Further studies to explore the structural underpinnings of the observed thermodynamics and kinetics of the conformational change step may help to design better analogs to treat HIV infections and other diseases. Our new method is generally applicable to enzyme and chemical kinetics. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Male reproductive system parameters in a two-generation reproduction study of ammonium perfluorooctanoate in rats and human relevance.

Science.gov (United States)

York, Raymond G; Kennedy, Gerald L; Olsen, Geary W; Butenhoff, John L

2010-04-30

Ammonium perfluorooctanoate (ammonium PFOA) is an industrial surfactant that has been used primarily as a processing aid in the manufacture of fluoropolymers. The environmental and metabolic stability of PFOA together with its presence in human blood and long elimination half-life have led to extensive toxicological studies in laboratory animals. Two recent publications based on observations from the Danish general population have reported: (1) a negative association between serum concentrations of PFOA in young adult males and their sperm counts and (2) a positive association among women with time to pregnancy. A two-generation reproduction study in rats was previously published (2004) in which no effects on functional reproduction were observed at doses up to 30mg ammonium PFOA/kg body weight. The article contained the simple statement: "In males, fertility was normal as were all sperm parameters". In order to place the recent human epidemiological data in perspective, herein we provide the detailed male reproductive parameters from that study, including sperm quality and testicular histopathology. Sperm parameters in rats from the two-generation study in all ammonium PFOA treatment groups were unaffected by treatment with ammonium PFOA. These observations reflected the normal fertility observations in these males. No evidence of altered testicular and sperm structure and function was observed in ammonium PFOA-treated rats whose mean group serum PFOA concentrations ranged up to approximately 50,000ng/mL. Given that median serum PFOA in the Danish cohorts was approximately 5ng/mL, it seems unlikely that concentrations observed in the general population, including those recently reported in Danish general population, could be associated causally with a real decrement in sperm number and quality.

General hybrid projective complete dislocated synchronization with non-derivative and derivative coupling based on parameter identification in several chaotic and hyperchaotic systems

International Nuclear Information System (INIS)

Sun Jun-Wei; Shen Yi; Zhang Guo-Dong; Wang Yan-Feng; Cui Guang-Zhao

2013-01-01

According to the Lyapunov stability theorem, a new general hybrid projective complete dislocated synchronization scheme with non-derivative and derivative coupling based on parameter identification is proposed under the framework of drive-response systems. Every state variable of the response system equals the summation of the hybrid drive systems in the previous hybrid synchronization. However, every state variable of the drive system equals the summation of the hybrid response systems while evolving with time in our method. Complete synchronization, hybrid dislocated synchronization, projective synchronization, non-derivative and derivative coupling, and parameter identification are included as its special item. The Lorenz chaotic system, Rössler chaotic system, memristor chaotic oscillator system, and hyperchaotic Lü system are discussed to show the effectiveness of the proposed methods. (general)

Chemically induced transition phenomena in polyurethanes as seen from generalized mode Grueneisen parameters

Energy Technology Data Exchange (ETDEWEB)

Mueller, U; Philipp, M; Bactavatchalou, R; Sanctuary, R; Baller, J; Zielinski, B; Krueger, J K [Laboratoire de Physique des Materiaux, Universite du Luxembourg, 162A, Avenue de la Faiencerie, L-1115 (Luxembourg); Possart, W; Alnot, P [Laboratoire Europeen de Recherche, Universitaire Saarland-Lorraine (Luxembourg)], E-mail: ulrich.mueller@uni.lu

2008-05-21

Many phenomenological properties of reactive polymers like polyurethanes increase or decrease continuously in the course of the curing process before saturating at the end of the chemical reaction. This holds true for instance for the mass density, the refractive index, the chemical turnover and the hypersonic properties. The reason for this monotone behaviour is that the chemical reaction behaves like a continuous succession of irreversible phase transitions. These transitions are superposed by the sol-gel transition and possibly by the chemically induced glass transition, with the drawback that the latter two highlighted transitions are often hidden by the underlying curing process. In this work we propose generalized mode Grueneisen parameters as an alternative probe for elucidating the polymerization process itself and the closely related transition phenomena. As a model system we use polyurethane composed of a diisocyanate and varying ratios of difunctional and trifunctional alcohols.

Genetic parameters for racing records in trotters using linear and generalized linear models.

Science.gov (United States)

Suontama, M; van der Werf, J H J; Juga, J; Ojala, M

2012-09-01

Heritability and repeatability and genetic and phenotypic correlations were estimated for trotting race records with linear and generalized linear models using 510,519 records on 17,792 Finnhorses and 513,161 records on 25,536 Standardbred trotters. Heritability and repeatability were estimated for single racing time and earnings traits with linear models, and logarithmic scale was used for racing time and fourth-root scale for earnings to correct for nonnormality. Generalized linear models with a gamma distribution were applied for single racing time and with a multinomial distribution for single earnings traits. In addition, genetic parameters for annual earnings were estimated with linear models on the observed and fourth-root scales. Racing success traits of single placings, winnings, breaking stride, and disqualifications were analyzed using generalized linear models with a binomial distribution. Estimates of heritability were greatest for racing time, which ranged from 0.32 to 0.34. Estimates of heritability were low for single earnings with all distributions, ranging from 0.01 to 0.09. Annual earnings were closer to normal distribution than single earnings. Heritability estimates were moderate for annual earnings on the fourth-root scale, 0.19 for Finnhorses and 0.27 for Standardbred trotters. Heritability estimates for binomial racing success variables ranged from 0.04 to 0.12, being greatest for winnings and least for breaking stride. Genetic correlations among racing traits were high, whereas phenotypic correlations were mainly low to moderate, except correlations between racing time and earnings were high. On the basis of a moderate heritability and moderate to high repeatability for racing time and annual earnings, selection of horses for these traits is effective when based on a few repeated records. Because of high genetic correlations, direct selection for racing time and annual earnings would also result in good genetic response in racing success.

PRELIMINARY STUDY OF HEMATOLOGICAL PARAMETERS IN HERZEGOVINIAN DONKEY

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Dunja Rukavina

2016-02-01

Full Text Available Herzegovinian donkey is a very important animal resource of Bosnia and Herzegovina. There have been no works attempted at determining the normal values of hematological parameters of Herzegovinian donkey. For this reason, the objective of the present study was to investigate some hematological parameters in Herzegovinian donkey. The research was performed on 30 apparently healthy donkeys (18 female and 12 male of ages from 1 to 20 years. Blood samples (3 ml were obtained by jugular vein puncture (vena jugularis externa in vacuum tubes with EDTA. The mean value of hematocrit was 29.19 %, hemoglobin concentration 10.6 g/dl, mean corpuscular hemoglobin concentration 36.33 g/dl, white blood cells 9.33 x109/L, granulocytes (109/L 5.45 x109/L, granulocytes (% 59.47%, lymphocyte/monocyte (109/L 3.89 x109/L, lymphocyte/monocyte (% 40.53% and platelet cells 148.97 x109/L. Parameters were determined using an automated analyzer IDEXX QBC VET AutoRead. Data were analyzed by SPSS V 15. All hematological parameters (except platelet cells were consistent with the recommended reference ranges for donkeys, and the values found in literature so far. Platelet cells values were much lower than in the literature for the other donkey breeds and the recommended reference ranges for donkeys. The slight differences found between our results and those reported in the previous works confirm the need for further studies to investigate the reference values of hematological parameters of Herzegovinian donkey. This work is a contribution to the study of hematological parameters of Herzegovinian donkey, and we expect these data to be applied to the further studies.

Correlations between skin hydration parameters and corneocyte-derived parameters to characterize skin conditions.

Science.gov (United States)

Masaki, Hitoshi; Yamashita, Yuki; Kyotani, Daiki; Honda, Tatsuya; Takano, Kenichi; Tamura, Toshiyasu; Mizutani, Taeko; Okano, Yuri

2018-03-30

Skin hydration is generally assessed using the parameters of skin surface water content (SWC) and trans-epidermal water loss (TEWL). To date, few studies have characterized skin conditions using correlations between skin hydration parameters and corneocyte parameters. The parameters SWC and TEWL allow the classification of skin conditions into four distinct Groups. The purpose of this study was to assess the characteristics of skin conditions classified by SWC and TEWL for correlations with parameters from corneocytes. A human volunteer test was conducted that measured SWC and TEWL. As corneocyte-derived parameters, the size and thick abrasion ratios, the ratio of sulfhydryl groups and disulfide bonds (SH/SS) and CP levels were analyzed. Volunteers were classified by their median SWC and TEWL values into 4 Groups: Group I (high SWC/low TEWL), Group II (high SWC/high TEWL), Group III (low SWC/low TEWL), and Group IV (low SWC/high TEWL). Group IV showed a significantly smaller size of corneocytes. Groups III and IV had significantly higher thick abrasion ratios and CP levels. Group I had a significantly lower SH/SS value. The SWC/TEWL value showed a decline in order from Group I to Group IV. Groups classified by their SWC and TEWL values showed characteristic skin conditions. We propose that the SWC and TEWL ratio is a comprehensive parameter to assess skin conditions. © 2018 Wiley Periodicals, Inc.

Bootstrap consistency for general semiparametric M-estimation

KAUST Repository

Cheng, Guang

2010-10-01

Consider M-estimation in a semiparametric model that is characterized by a Euclidean parameter of interest and an infinite-dimensional nuisance parameter. As a general purpose approach to statistical inferences, the bootstrap has found wide applications in semiparametric M-estimation and, because of its simplicity, provides an attractive alternative to the inference approach based on the asymptotic distribution theory. The purpose of this paper is to provide theoretical justifications for the use of bootstrap as a semiparametric inferential tool. We show that, under general conditions, the bootstrap is asymptotically consistent in estimating the distribution of the M-estimate of Euclidean parameter; that is, the bootstrap distribution asymptotically imitates the distribution of the M-estimate. We also show that the bootstrap confidence set has the asymptotically correct coverage probability. These general onclusions hold, in particular, when the nuisance parameter is not estimable at root-n rate, and apply to a broad class of bootstrap methods with exchangeable ootstrap weights. This paper provides a first general theoretical study of the bootstrap in semiparametric models. © Institute of Mathematical Statistics, 2010.

Diagnostics and tolerance optimization of nuclear facilities parameters

International Nuclear Information System (INIS)

Novak, M.; Otcenasek, P.

1988-01-01

The possibilities are discussed of applying the theory of tolerances for assessing the service life of systems in nuclear power. The approach proceeds from the postulate that the nuclear power plant is on the one hand an extremely sophisticated technical system and on the other a system with well defined demands on the state and properties of components and of the whole system, with rationally defined limits, conditions of permissible states and limit values. It is stated that the basic ideas of the theory of the hot channel may be extended and generalized. The theory was initially limited to the study of relations between deviations in nucleaer and non-nuclear parameters in the fuel assembly, and the temperature field; it can be generalized to the analysis of permissible parameter tolerances of the whole system. The foundations are outlined of the theory of tolerances of general technical system parameters. Brief attention is also paid to the general possibilities of the use of life curves for designing the system such as would extend its service life. (Z.M.). 10 figs., 5 refs

Symmetries and conservation laws for generalized Hamiltonian systems

International Nuclear Information System (INIS)

Cantrijn, F.; Sarlet, W.

1981-01-01

A class of dynamical systems which locally correspond to a general first-order system of Euler-Lagrange equations is studied on a contact manifold. These systems, called self-adjoint, can be regarded as generalizations of (time-dependent) Hamiltonian systems. It is shown that each one-parameter family of symmetries of the underlying contact form defines a parameter-dependent constant of the motion and vice versa. Next, an extension of the classical concept of canonical transformations is introduced. One-parameter families of canonical transformations are studied and shown to be generated as solutions of a self-adjoint system. Some of the results are illustrated on the Emden equation. (author)

Image Denoising via Bayesian Estimation of Statistical Parameter Using Generalized Gamma Density Prior in Gaussian Noise Model

Science.gov (United States)

Kittisuwan, Pichid

2015-03-01

The application of image processing in industry has shown remarkable success over the last decade, for example, in security and telecommunication systems. The denoising of natural image corrupted by Gaussian noise is a classical problem in image processing. So, image denoising is an indispensable step during image processing. This paper is concerned with dual-tree complex wavelet-based image denoising using Bayesian techniques. One of the cruxes of the Bayesian image denoising algorithms is to estimate the statistical parameter of the image. Here, we employ maximum a posteriori (MAP) estimation to calculate local observed variance with generalized Gamma density prior for local observed variance and Laplacian or Gaussian distribution for noisy wavelet coefficients. Evidently, our selection of prior distribution is motivated by efficient and flexible properties of generalized Gamma density. The experimental results show that the proposed method yields good denoising results.

Study of Parameters that Determine Railway Line Capacity

Directory of Open Access Journals (Sweden)

Josip Kukec

2005-07-01

Full Text Available In this work the study focuses on:- determining the elements required to determine the locationfor the installation of the main signals,- calculated block lengths, and- calculations of optimal head ways, that have not been studiedin detail although they deserve special attention due totheir impact.Generally speaking, the signals are installed in compliancewith the local circumstances, i. e. according to the technicaland technological characteristics and conditions determinedby the traffic places of work they protect.The distribution and length of the blocks depend on: therailway line and its exploitation characteristics, structure andtype of trains that run on the railway line, traffic organisationand signalisation system, as well as technical and exploitationcharacte1istics of the traction vehicles and the rolling stock.What has to be considered is that the minimum section lengthcannot be shorter than the length of the braking distance, i. e.the length of the longest train which runs on the respective railwayline.The study of these parameters is supplemented by the calculationof the reduction in throughput capacity depending on thelack of uniformity in the operation of trains, which, in order tomaintain the design quality of the transportation se1vice, and inthe activities of establishing and implementing the business policyshouldn't be left out nor bypassed.

Parameter study of a screw-pinch reactor with circular cross-section

International Nuclear Information System (INIS)

Bustraan, M.; Franken, W.M.P.; Klippel, H.Th.; Muysken, M.; Verschuur, K.A.

1977-04-01

In the framework of system studies on pulsed high-β fusion reactors, a parameter study of a reactor based on a screw pinch with a circular cross-section has been performed. The plasma is heated to ignition in two stages. First, the cold plasma is heated by fast implosion in order to guarantee pitch conservation of the inward moving magnetic field lines. The relevant implosion theory has been generalized to a β<1 plasma. In the second stage, an adiabatic compression heats the plasma to the ignition temperature at which point α-particle heating takes over. For stability reasons, β is kept below 0.25. The choice of a particular set of basic parameter values is justified by global design considerations of the reactor. These considerations, e.g. on blanket design and electrotechnical requirements, are presented in some detail. A computer program searches for optimal reactors, i.e. for which at a given thermal output the net efficiency is a maximum. The parameters of a Reference Screw-Pinch Reactor and some other numerical examples are given. The main conclusions are: the net efficiency, although increasing with output energy, is low because of ohmic losses in the compression coil system; the application of sustained fields generated by superconducting coils to reduce these ohmic losses is problematical; a belt-shaped screw pinch in which higher values of β may be reached, improves the net efficiency and alleviates the technical requirements; heating by implosion and adiabatic compression of a plasma with values of β as low as considered here, is inefficient. Therefore, other means of heating the plasma to ignition may be attractive

Anxiolytic and antidepressive effects of magnesium in rats and their effect on general behavioural parameters

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Samardžić Janko

2011-01-01

Full Text Available Magnesium (Mg is an essential element that catalyses more than 300 enzyme systems. Its effects on the central nervous system are exhibited through the blocking of activity of N-methyl D-aspartat (NMDA receptors and potentiating of GABA-ergic neurotransmission. Due to the vast importance of these two neurotransmission systems in the fine regulation of the central integrative function activity, the aim of this research was to test the anxiolytic and antidepressive effects of magnesium, after acute and repeated application, and its influence on general behavioural parameters. In this research Wistar albino rats were treated with increasing doses of Mg chloride 6-hydrate (MgCl 10, 20, 30 mg/kg. In order to determine anxiolytic and antidepressive properties of magnesium two models were used: elevated plus maze (EPM and forced swim test (FST. Behavioural parameters (stillness and mobility were recorded during acute and repeated administration of the active substance. Results of EPM testing showed no significant difference between groups, p>0.05. After acute application of increasing doses of magnesium chloride hydrate in FST, we showed the statistically significant difference in immobility time between the group of animals treated with Mg and the control group treated with the solvent, p<0.01. The statistically significant difference between groups treated with the lowest and the middle dose of magnesium and the controls was observed already on the first day of examining behavioural parameters (p=0.020, p=0.010. Our research has showed that magnesium, following acute administration, increases locomotor activity, and has an antidepressive but not an anxiolytic effect.

Importance theory for lumped-parameter systems

International Nuclear Information System (INIS)

Cady, K.B.; Kenton, M.A.; Ward, J.C.; Piepho, M.G.

1981-01-01

A general sensitivity theory has been developed for nonlinear lumped parameter system simulations. The point of departure is general perturbation theory for nonlinear systems. Importance theory as developed here allows the calculation of the sensitivity of a response function to any physical or design parameter; importance of any equation or term or physical effect in the system model on the response function; variance of the response function caused by the variances and covariances of all physical parameters; and approximate effect on the response function of missing physical phenomena or incorrect parameters

Study of Operating Parameters for Accelerated Anode Degradation in SOFCs

DEFF Research Database (Denmark)

Ploner, Alexandra; Hagen, Anke; Hauch, Anne

2017-01-01

Solid oxide fuel cell (SOFC) applications require lifetimes of several years on the system level. A big challenge is to demonstrate such exceptionally long lifetimes in ongoing R&D projects. Accelerated or compressed testing are alternative methods to obtain this. Activities in this area have been...... carried out without arriving at a generally accepted methodology. This is mainly due to the complexity of degradation mechanisms on the single SOFC components as function of operating parameters. In this study, we present a detailed analysis of approx. 180 durability tests regarding degradation of single...... SOFC components as function of operating conditions. Electrochemical impedance data were collected on the fresh and long-term tested SOFCs and used to de-convolute the individual losses of single SOFC cell components – electrolyte, cathode and anode. The main findings include a time-dependent effect...

Aromatherapy for reducing colonoscopy related procedural anxiety and physiological parameters: a randomized controlled study.

Science.gov (United States)

Hu, Pei-Hsin; Peng, Yen-Chun; Lin, Yu-Ting; Chang, Chi-Sen; Ou, Ming-Chiu

2010-01-01

Colonoscopy is generally tolerated, some patients regarding the procedure as unpleasant and painful and generally performed with the patient sedated and receiving analgesics. The effect of sedation and analgesia for colonoscopy is limited. Aromatherapy is also applied to gastrointestinal endoscopy to reduce procedural anxiety. There is lack of information about aromatherapy specific for colonoscopy. In this study, we aimed to performed a randomized controlled study to investigate the effect of aromatherapy on relieve anxiety, stress and physiological parameters of colonoscopy. A randomized controlled trail was carried out and collected in 2009 and 2010. The participants were randomized in two groups. Aromatherapy was then carried out by inhalation of Sunflower oil (control group) and Neroli oil (Experimental group). The anxiety index was evaluated by State Trait Anxiety Inventory-state (STAI-S) score before aromatherapy and after colonoscopy as well as the pain index for post-procedural by visual analogue scale (VAS). Physiological indicators, such as blood pressure (systolic and diastolic blood pressure), heart rate and respiratory rate were evaluated before and after aromatherapy. Participates in this study were 27 subjects, 13 in control group and 14 in Neroli group with average age 52.26 +/- 17.79 years. There was no significance of procedural anxiety by STAI-S score and procedural pain by VAS. The physiological parameters showed a significant lower pre- and post-procedural systolic blood pressure in Neroli group than control group. Aromatic care for colonoscopy, although with no significant effect on procedural anxiety, is an inexpensive, effective and safe pre-procedural technique that could decrease systolic blood pressure.

Ergodicity of the generalized lemon billiards

Energy Technology Data Exchange (ETDEWEB)

Chen, Jingyu [Department of Computer Science, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801-2302 (United States); Mohr, Luke; Zhang, Hong-Kun, E-mail: hongkun@math.umass.edu; Zhang, Pengfei [Department of Mathematics and Statistics, UMass Amherst, Amherst, Massachusetts 01003 (United States)

2013-12-15

In this paper, we study a two-parameter family of convex billiard tables, by taking the intersection of two round disks (with different radii) in the plane. These tables give a generalization of the one-parameter family of lemon-shaped billiards. Initially, there is only one ergodic table among all lemon tables. In our generalized family, we observe numerically the prevalence of ergodicity among the some perturbations of that table. Moreover, numerical estimates of the mixing rate of the billiard dynamics on some ergodic tables are also provided.

Correction: General optimization procedure towards the design of a new family of minimal parameter spin-component-scaled double-hybrid density functional theory.

Science.gov (United States)

Roch, Loïc M; Baldridge, Kim K

2018-02-07

Correction for 'General optimization procedure towards the design of a new family of minimal parameter spin-component-scaled double-hybrid density functional theory' by Loïc M. Roch and Kim K. Baldridge, Phys. Chem. Chem. Phys., 2017, 19, 26191-26200.

Clinical TVA-based studies: a general review

Directory of Open Access Journals (Sweden)

Thomas eHabekost

2015-03-01

Full Text Available In combination with whole report and partial report tasks, the Theory of Visual Attention (TVA can be used to estimate individual differences in five basic attentional parameters: The visual processing speed, the storage capacity of visual short-term memory, the perceptual threshold, the efficiency of top-down selectivity, and the spatial bias of attentional weighting. TVA-based assessment has been used in about 30 studies to investigate attentional deficits in a range of neurological and psychiatric conditions: (a neglect and simultanagnosia, (b reading disturbances, (c aging and neurodegenerative diseases, and most recently (d neurodevelopmental disorders. The article introduces TVA based assessment, discusses its methodology and psychometric properties, and reviews the progress made in each of the four research fields. The empirical results demonstrate the general usefulness of TVA-based assessment for many types of clinical neuropsychological research. The method’s most important qualities are cognitive specificity and theoretical grounding, but it is also characterized by good reliability and sensitivity to minor deficits. The review concludes by pointing to promising new areas for clinical TVA-based research.

Can establishment success be determined through demographic parameters? A case study on five introduced bird species.

Directory of Open Access Journals (Sweden)

Ana Sanz-Aguilar

Full Text Available The dominant criterion to determine when an introduced species is established relies on the maintenance of a self-sustaining population in the area of introduction, i.e. on the viability of the population from a demographic perspective. There is however a paucity of demographic studies on introduced species, and establishment success is thus generally determined by expert opinion without undertaking population viability analyses (PVAs. By means of an intensive five year capture-recapture monitoring program (involving >12,000 marked individuals we studied the demography of five introduced passerine bird species in southern Spain which are established and have undergone a fast expansion over the last decades. We obtained useful estimates of demographic parameters (survival and reproduction for one colonial species (Ploceus melanocephalus, confirming the long-term viability of its local population through PVAs. However, extremely low recapture rates prevented the estimation of survival parameters and population growth rates for widely distributed species with low local densities (Estrilda troglodytes and Amandava amandava but also for highly abundant yet non-colonial species (Estrilda astrild and Euplectes afer. Therefore, determining the establishment success of introduced passerine species by demographic criteria alone may often be troublesome even when devoting much effort to field-work. Alternative quantitative methodologies such as the analysis of spatio-temporal species distributions complemented with expert opinion deserve thus their role in the assessment of establishment success of introduced species when estimates of demographic parameters are difficult to obtain, as is generally the case for non-colonial, highly mobile passerines.

General epidemiological parameters of viral hepatitis A, B, C, and E in six regions of China: a cross-sectional study in 2007.

Science.gov (United States)

Lu, Jian; Zhou, Yongdong; Lin, Xiaojing; Jiang, Yongzhen; Tian, Ruiguang; Zhang, Yonghui; Wu, Jia; Zhang, Fengwei; Zhang, Yong; Wang, Yue; Bi, Shengli

2009-12-24

Viral hepatitis is a serious health burden worldwide. To date, few reports have addressed the prevalence of hepatitis A, B, C, and E in China. Therefore, the general epidemiological parameters of viral hepatitis remain unknown. In this cross-sectional study, we performed a serological prevalence analysis of viral hepatitis A, B, C, and E in 8,762 randomly selected Chinese subjects, which represented six areas of China. The overall prevalence of anti-Hepatitis C virus antibody (anti-HCV) was 0.58%, which was much lower than was estimated by WHO. The prevalences of Hepatitis B virus surface antigen (HBsAg), anti-Hepatitis B virus surface protein antibody (HBsAb), and anti-Hepatitis B virus core protein antibody (HBcAb) were 5.84%, 41.31%, and 35.92%, respectively, whereas in the group of subjects less than 5 years old, these prevalences were 1.16%, 46.77%, and 8.69% respectively, which suggests that the Hepatitis B virus (HBV)-carrier population is decreasing, and the nationwide HBV vaccine program has contributed to the lowered HBV prevalence in the younger generation in China. Meanwhile, a large deficit remains in coverage provided by the national HBV immune program. In addition, our data suggested the possibility that HBsAb may not last long enough to protect people from HBV infection throughout life. The overall prevalence of anti-Hepatitis A virus antibody (anti-HAV) and anti-Hepatitis E virus antibody (anti-HEV) were as high as 72.87% and 17.66%, respectively. The indices increased with age, which suggests that a large proportion of Chinese adults are protected by latent infection. Furthermore, the pattern of HEV infection was significantly different among ethnic groups in China. Our study provided much important information concerning hepatitis A, B, C, and E prevalence in China and will contribute to worldwide oversight of viral hepatitis.

Generating three-parameter sensor

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Filinyuk M. A.

2014-08-01

Full Text Available Generating sensors provide the possibility of getting remote information and its easy conversion into digital form. Typically, these are one-parameter sensors formed by combination of a primary transmitter (PT and a sine wave generator. Two-parameter sensors are not widely used as their implementation causes a problem with ambiguity output when measuring the PT. Nevertheless, the problem of creating miniature, thrifty multi-parameter RF sensors for different branches of science and industry remains relevant. Considering ways of designing RF sensors, we study the possibility of constructing a three-parameter microwave radio frequency range sensor, which is based on a two-stage three-parameter generalized immitance convertor (GIC. Resistive, inductive and capacitive PT are used as sensing elements. A mathematical model of the sensor, which describes the relation of the sensor parameters to the parameters of GIC and PT was developed. The basic parameters of the sensor, its transfer function and sensitivity were studied. It is shown that the maximum value of the power generated signal will be observed at a frequency of 175 MHz, and the frequency ranges depending on the parameters of the PT will be different. Research results and adequacy of the mathematical model were verified by the experiment. Error of the calculated dependences of the lasing frequency on PT parameters change, compared with the experimental data does not exceed 2 %. The relative sensitivity of the sensor based on two-stage GIC showed that for the resistive channel it is about 1.88, for the capacitive channel –1,54 and for the inductive channel –11,5. Thus, it becomes possible to increase the sensor sensitivity compared with the sensitivity of the PT almost 1,2—2 times, and by using the two stage GIC a multifunctional sensor is provided.

Switched generalized function projective synchronization of two identical/different hyperchaotic systems with uncertain parameters

International Nuclear Information System (INIS)

Li Hongmin; Li Chunlai

2012-01-01

In this paper, we investigate two switched synchronization schemes, namely partial and complete switched generalized function projective synchronization, by using the adaptive control method. Partial switched synchronization of chaotic systems means that the state variables of the drive system synchronize with partial different state variables of the response system, whereas complete switched synchronization of chaotic systems means that all the state variables of the drive system synchronize with complete different state variables of the response system. Because the switched synchronization scheme exists in many combinations, it is a promising type of synchronization as it provides greater security in secure communications. Based on the Lyapunov stability theory, the adaptive control laws and the parameter update laws are derived to make the states of two identical/different hyperchaotic systems asymptotically synchronized up to a desired scaling function. Finally, numerical simulations are performed to verify and illustrate the analytical results.

Reduction of coupling parameters and duality

International Nuclear Information System (INIS)

Oehme, R.; Max-Planck-Institut fuer Physik, Muenchen

2000-01-01

The general method of the reduction in the number of coupling parameters is discussed. Using renormalization group invariance, theories with several independent couplings are related to a set of theories with a single coupling parameter. The reduced theories may have particular symmetries, or they may not be related to any known symmetry. The method is more general than the imposition of invariance properties. Usually, there are only a few reduced theories with an asymptotic power series expansion corresponding to a renormalizable Lagrangian. There also exist 'general' solutions containing non-integer powers and sometimes logarithmic factors. As an example for the use of the reduction method, the dual magnetic theories associated with certain supersymmetric gauge theories are discussed. They have a superpotential with a Yukawa coupling parameter. This parameter is expressed as a function of the gauge coupling. Given some standard conditions, a unique, isolated power series solution of the reduction equations is obtained. After reparameterization, the Yukawa coupling is proportional to the square of the gauge coupling parameter. The coefficient is given explicitly in terms of the numbers of colors and flavors. 'General' solutions with non-integer powers are also discussed. A brief list is given of other applications of the reduction method. (orig.)

On the Use of Generalized Volume Scattering Models for the Improvement of General Polarimetric Model-Based Decomposition

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Qinghua Xie

2017-01-01

Full Text Available Recently, a general polarimetric model-based decomposition framework was proposed by Chen et al., which addresses several well-known limitations in previous decomposition methods and implements a simultaneous full-parameter inversion by using complete polarimetric information. However, it only employs four typical models to characterize the volume scattering component, which limits the parameter inversion performance. To overcome this issue, this paper presents two general polarimetric model-based decomposition methods by incorporating the generalized volume scattering model (GVSM or simplified adaptive volume scattering model, (SAVSM proposed by Antropov et al. and Huang et al., respectively, into the general decomposition framework proposed by Chen et al. By doing so, the final volume coherency matrix structure is selected from a wide range of volume scattering models within a continuous interval according to the data itself without adding unknowns. Moreover, the new approaches rely on one nonlinear optimization stage instead of four as in the previous method proposed by Chen et al. In addition, the parameter inversion procedure adopts the modified algorithm proposed by Xie et al. which leads to higher accuracy and more physically reliable output parameters. A number of Monte Carlo simulations of polarimetric synthetic aperture radar (PolSAR data are carried out and show that the proposed method with GVSM yields an overall improvement in the final accuracy of estimated parameters and outperforms both the version using SAVSM and the original approach. In addition, C-band Radarsat-2 and L-band AIRSAR fully polarimetric images over the San Francisco region are also used for testing purposes. A detailed comparison and analysis of decomposition results over different land-cover types are conducted. According to this study, the use of general decomposition models leads to a more accurate quantitative retrieval of target parameters. However, there

A Comparative Study of Distribution System Parameter Estimation Methods

Energy Technology Data Exchange (ETDEWEB)

Sun, Yannan; Williams, Tess L.; Gourisetti, Sri Nikhil Gup

2016-07-17

In this paper, we compare two parameter estimation methods for distribution systems: residual sensitivity analysis and state-vector augmentation with a Kalman filter. These two methods were originally proposed for transmission systems, and are still the most commonly used methods for parameter estimation. Distribution systems have much lower measurement redundancy than transmission systems. Therefore, estimating parameters is much more difficult. To increase the robustness of parameter estimation, the two methods are applied with combined measurement snapshots (measurement sets taken at different points in time), so that the redundancy for computing the parameter values is increased. The advantages and disadvantages of both methods are discussed. The results of this paper show that state-vector augmentation is a better approach for parameter estimation in distribution systems. Simulation studies are done on a modified version of IEEE 13-Node Test Feeder with varying levels of measurement noise and non-zero error in the other system model parameters.

Robust Adaptive Sliding Mode Control for Generalized Function Projective Synchronization of Different Chaotic Systems with Unknown Parameters

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Xiuchun Li

2013-01-01

Full Text Available When the parameters of both drive and response systems are all unknown, an adaptive sliding mode controller, strongly robust to exotic perturbations, is designed for realizing generalized function projective synchronization. Sliding mode surface is given and the controlled system is asymptotically stable on this surface with the passage of time. Based on the adaptation laws and Lyapunov stability theory, an adaptive sliding controller is designed to ensure the occurrence of the sliding motion. Finally, numerical simulations are presented to verify the effectiveness and robustness of the proposed method even when both drive and response systems are perturbed with external disturbances.

Generalizing the order and the parameters of macro-operators by explanation-based learning - Extension of Explanation-Based Learning on Partial Order

International Nuclear Information System (INIS)

Li, Huihua

1992-01-01

The traditional generalization methods such as FIKE's macro-operator learning and Explanation-Based Learning (EBL) deal with totally ordered plans. They generalize only the plan operators and the conditions under which the generalized plan can be applied in its initial total order, but not the partial order among operators in which the generalized plan can be successfully executed. In this paper, we extend the notion of the EBL on the partial order of plans. A new method is presented for learning, from a totally or partially ordered plan, partially ordered macro-operators (generalized plans) each of which requires a set of the weakest conditions for its reuse. It is also valuable for generalizing partially ordered plans. The operators are generalized in the FIKE's triangle table. We introduce the domain axioms to generate the constraints for the consistency of generalized states. After completing the triangle table with the information concerning the operator destructions (interactions), we obtain the global explanation of the partial order on the operators. Then, we represent all the necessary ordering relations by a directed graph. The exploitation of this graph permits to explicate the dependence between the partial orders and the constraints among the parameters of generalized operators, and allows all the solutions to be obtained. (author) [fr

Systematic parameter study of dynamo bifurcations in geodynamo simulations

Science.gov (United States)

Petitdemange, Ludovic

2018-04-01

We investigate the nature of the dynamo bifurcation in a configuration applicable to the Earth's liquid outer core, i.e. in a rotating spherical shell with thermally driven motions with no-slip boundaries. Unlike in previous studies on dynamo bifurcations, the control parameters have been varied significantly in order to deduce general tendencies. Numerical studies on the stability domain of dipolar magnetic fields found a dichotomy between non-reversing dipole-dominated dynamos and the reversing non-dipole-dominated multipolar solutions. We show that, by considering weak initial fields, the above transition disappears and is replaced by a region of bistability for which dipolar and multipolar dynamos coexist. Such a result was also observed in models with free-slip boundaries in which the geostrophic zonal flow can develop and participate to the dynamo mechanism for non-dipolar fields. We show that a similar process develops in no-slip models when viscous effects are reduced sufficiently. The following three regimes are distinguished: (i) Close to the onset of convection (Rac) with only the most critical convective mode (wave number) being present, dynamos set in supercritically in the Ekman number regime explored here and are dipole-dominated. Larger critical magnetic Reynolds numbers indicate that they are particularly inefficient. (ii) in the range 3 10) , the relative importance of zonal flows increases with Ra in non-magnetic models. The field topology depends on the magnitude of the initial magnetic field. The dipolar branch has a subcritical behavior whereas the multipolar branch has a supercritical behavior. By approaching more realistic parameters, the extension of this bistable regime increases. A hysteretic behavior questions the common interpretation for geomagnetic reversals. Far above the dynamo threshold (by increasing the magnetic Prandtl number), Lorentz forces contribute to the first order force balance, as predicted for planetary dynamos. When

Mixed integer evolution strategies for parameter optimization.

Science.gov (United States)

Li, Rui; Emmerich, Michael T M; Eggermont, Jeroen; Bäck, Thomas; Schütz, M; Dijkstra, J; Reiber, J H C

2013-01-01

Evolution strategies (ESs) are powerful probabilistic search and optimization algorithms gleaned from biological evolution theory. They have been successfully applied to a wide range of real world applications. The modern ESs are mainly designed for solving continuous parameter optimization problems. Their ability to adapt the parameters of the multivariate normal distribution used for mutation during the optimization run makes them well suited for this domain. In this article we describe and study mixed integer evolution strategies (MIES), which are natural extensions of ES for mixed integer optimization problems. MIES can deal with parameter vectors consisting not only of continuous variables but also with nominal discrete and integer variables. Following the design principles of the canonical evolution strategies, they use specialized mutation operators tailored for the aforementioned mixed parameter classes. For each type of variable, the choice of mutation operators is governed by a natural metric for this variable type, maximal entropy, and symmetry considerations. All distributions used for mutation can be controlled in their shape by means of scaling parameters, allowing self-adaptation to be implemented. After introducing and motivating the conceptual design of the MIES, we study the optimality of the self-adaptation of step sizes and mutation rates on a generalized (weighted) sphere model. Moreover, we prove global convergence of the MIES on a very general class of problems. The remainder of the article is devoted to performance studies on artificial landscapes (barrier functions and mixed integer NK landscapes), and a case study in the optimization of medical image analysis systems. In addition, we show that with proper constraint handling techniques, MIES can also be applied to classical mixed integer nonlinear programming problems.

Effects of cell phone use on semen parameters: Results from the MARHCS cohort study in Chongqing, China.

Science.gov (United States)

Zhang, Guowei; Yan, Huan; Chen, Qing; Liu, Kaijun; Ling, Xi; Sun, Lei; Zhou, Niya; Wang, Zhi; Zou, Peng; Wang, Xiaogang; Tan, Lu; Cui, Zhihong; Zhou, Ziyuan; Liu, Jinyi; Ao, Lin; Cao, Jia

2016-05-01

Epidemiological and experimental evidence for detrimental effects of cell phone use on semen quality is still equivocal. And that recruiting participants from infertility clinic not from general population may raise the possibility of a selection bias. To investigate effects of cell phone use on semen parameters in a general population,We screened and documented the cell phone use information of 794 young men from the Male Reproductive Health in Chongqing College students (MARHCS) cohort study in 2013, followed by 666 and 568 in 2014 and 2015, respectively. In the univariate regression analyses, we found that the daily duration of talking on the cell phone was significantly associated with decreased semen parameters, including sperm concentration [β coefficient=-6.32% per unit daily duration of talking on the cell phone (h); 95% confidence interval (CI), -11.94, -0.34] and total sperm count (-8.23; 95% CI, -14.38, -1.63) in 2013; semen volume (-8.37; 95% CI, -15.93, -0.13) and total sperm count (-16.59; 95% CI, -29.91, -0.73) in 2015]. Internet use via cellular networks was also associated with decreased sperm concentration and total sperm counts in 2013 and decreased semen volume in 2015. Multivariate analyses were used to adjust for the effects of potential confounders, and significant negative associations between internet use and semen parameters remained. Consistent but nonsignificant negative associations between talking on the cell phone and semen parameters persisted throughout the three study years, and the negative association was statistically significant in a mixed model that considered all three years of data on talking on the cell phone and semen quality. Our results showed that certain aspects of cell phone use may negatively affect sperm quality in men by decreasing the semen volume, sperm concentration, or sperm count, thus impairing male fertility. Copyright © 2016 Elsevier Ltd. All rights reserved.

A generalized nonlinear tempeature response function for some growth and developmental parameters in kiwifruit (Actinidia deliciosa (A. Chev. C. F. Liang & A. R. Ferguson

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Streck Nereu Augusto

2003-01-01

Full Text Available Temperature is a major factor that affects metabolic processes in living organisms. Thermal time has been widely used to account for the effects of temperature on crop growth and development. However, the thermal time approach has been criticized because it assumes a linear relationship between the rate of crop growth or development and temperature. The response of the rate of crop growth and development to temperature is nonlinear. The objective of this study was to develop a generalized nonlinear temperature response function for some growth and developmental parameters in kiwifruit (Actinidia deliciosa (A. Chev. C. F. Liang & A. R. Ferguson. The nonlinear function has three coefficients (the cardinal temperatures, which were 0ºC, 25ºC, and 40ºC. Data of temperature response of relative growth rate, relative leaf area growth, net photosynthesis rate, and leaf appearance rate in kiwifruit (female cv. Hayward at two light levels, which are from published research, were used as independent data for evaluating the performance of the nonlinear and the thermal time functions. The results showed that the generalized nonlinear response function is better than the thermal time approach, and the temperature response of several growth and developmental parameters in kiwifruit can be described with the same response function.

Robust Parameter Coordination for Multidisciplinary Design

Institute of Scientific and Technical Information of China (English)

无

2006-01-01

This paper introduced a robust parameter coordination method to analyze parameter uncertainties so as to predict conflicts and coordinate parameters in multidisciplinary design. The proposed method is based on constraints network, which gives a formulated model to analyze the coupling effects between design variables and product specifications. In this model, interval boxes are adopted to describe the uncertainty of design parameters quantitatively to enhance the design robustness. To solve this constraint network model, a general consistent algorithm framework is designed and implemented with interval arithmetic and the genetic algorithm, which can deal with both algebraic and ordinary differential equations. With the help of this method, designers could infer the consistent solution space from the given specifications. A case study involving the design of a bogie dumping system demonstrates the usefulness of this approach.

SU-E-T-254: Optimization of GATE and PHITS Monte Carlo Code Parameters for Uniform Scanning Proton Beam Based On Simulation with FLUKA General-Purpose Code

Energy Technology Data Exchange (ETDEWEB)

Kurosu, K [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Department of Medical Physics ' Engineering, Osaka University Graduate School of Medicine, Osaka (Japan); Takashina, M; Koizumi, M [Department of Medical Physics ' Engineering, Osaka University Graduate School of Medicine, Osaka (Japan); Das, I; Moskvin, V [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN (United States)

2014-06-01

Purpose: Monte Carlo codes are becoming important tools for proton beam dosimetry. However, the relationships between the customizing parameters and percentage depth dose (PDD) of GATE and PHITS codes have not been reported which are studied for PDD and proton range compared to the FLUKA code and the experimental data. Methods: The beam delivery system of the Indiana University Health Proton Therapy Center was modeled for the uniform scanning beam in FLUKA and transferred identically into GATE and PHITS. This computational model was built from the blue print and validated with the commissioning data. Three parameters evaluated are the maximum step size, cut off energy and physical and transport model. The dependence of the PDDs on the customizing parameters was compared with the published results of previous studies. Results: The optimal parameters for the simulation of the whole beam delivery system were defined by referring to the calculation results obtained with each parameter. Although the PDDs from FLUKA and the experimental data show a good agreement, those of GATE and PHITS obtained with our optimal parameters show a minor discrepancy. The measured proton range R90 was 269.37 mm, compared to the calculated range of 269.63 mm, 268.96 mm, and 270.85 mm with FLUKA, GATE and PHITS, respectively. Conclusion: We evaluated the dependence of the results for PDDs obtained with GATE and PHITS Monte Carlo generalpurpose codes on the customizing parameters by using the whole computational model of the treatment nozzle. The optimal parameters for the simulation were then defined by referring to the calculation results. The physical model, particle transport mechanics and the different geometrybased descriptions need accurate customization in three simulation codes to agree with experimental data for artifact-free Monte Carlo simulation. This study was supported by Grants-in Aid for Cancer Research (H22-3rd Term Cancer Control-General-043) from the Ministry of Health

Sleep respiratory parameters in children with idiopathic epilepsy: A cross-sectional study.

Science.gov (United States)

Gogou, Maria; Haidopoulou, Katerina; Eboriadou, Maria; Pavlidou, Efterpi; Hatzistylianou, Maria; Pavlou, Evaggelos

2016-10-01

The aim of this study is to explore and compare through polysomnography respiratory sleep parameters between children with idiopathic epilepsy and healthy children. Our cross-sectional study included 40 children with idiopathic epilepsy and 27 healthy children, who underwent overnight polysomnography. Data about sleep respiratory parameters were obtained and statistically analyzed. The level of statistical significance was set at 0.05. The prevalence of Obstructive Sleep Apnea Syndrome was significantly higher in the epilepsy group (35% vs 7.4%, pepilepsy group was 10.6 (95% Confidence Intervals: 3.08-37.08) in comparison to the control group. The mean value of the obstructive apnea-hypopnea index was significantly higher in children with epilepsy compared to healthy children (2.46±1.22 vs 1.21±0.83, p=0.027). The mean values of central apnea index and desaturation index were comparable between these two groups. Longest apnea duration was significantly higher in the group of poor seizure control. All other sleep respiratory variables did not differ significantly between children with poor and good seizure control and between children with generalized and focal epilepsy. Children with epilepsy seem to present more prominent sleep breathing instability in comparison to healthy children, which mainly includes a predisposition to obstructive respiratory events. More studies are needed to investigate the relationship between sleep apneas and seizure control. Copyright © 2016 Elsevier B.V. All rights reserved.

Approaches to automatic parameter fitting in a microscopy image segmentation pipeline: An exploratory parameter space analysis.

Science.gov (United States)

Held, Christian; Nattkemper, Tim; Palmisano, Ralf; Wittenberg, Thomas

2013-01-01

Research and diagnosis in medicine and biology often require the assessment of a large amount of microscopy image data. Although on the one hand, digital pathology and new bioimaging technologies find their way into clinical practice and pharmaceutical research, some general methodological issues in automated image analysis are still open. In this study, we address the problem of fitting the parameters in a microscopy image segmentation pipeline. We propose to fit the parameters of the pipeline's modules with optimization algorithms, such as, genetic algorithms or coordinate descents, and show how visual exploration of the parameter space can help to identify sub-optimal parameter settings that need to be avoided. This is of significant help in the design of our automatic parameter fitting framework, which enables us to tune the pipeline for large sets of micrographs. The underlying parameter spaces pose a challenge for manual as well as automated parameter optimization, as the parameter spaces can show several local performance maxima. Hence, optimization strategies that are not able to jump out of local performance maxima, like the hill climbing algorithm, often result in a local maximum.

Approaches to automatic parameter fitting in a microscopy image segmentation pipeline: An exploratory parameter space analysis

Directory of Open Access Journals (Sweden)

Christian Held

2013-01-01

Full Text Available Introduction: Research and diagnosis in medicine and biology often require the assessment of a large amount of microscopy image data. Although on the one hand, digital pathology and new bioimaging technologies find their way into clinical practice and pharmaceutical research, some general methodological issues in automated image analysis are still open. Methods: In this study, we address the problem of fitting the parameters in a microscopy image segmentation pipeline. We propose to fit the parameters of the pipeline′s modules with optimization algorithms, such as, genetic algorithms or coordinate descents, and show how visual exploration of the parameter space can help to identify sub-optimal parameter settings that need to be avoided. Results: This is of significant help in the design of our automatic parameter fitting framework, which enables us to tune the pipeline for large sets of micrographs. Conclusion: The underlying parameter spaces pose a challenge for manual as well as automated parameter optimization, as the parameter spaces can show several local performance maxima. Hence, optimization strategies that are not able to jump out of local performance maxima, like the hill climbing algorithm, often result in a local maximum.

Generalized Multiparameters Fractional Variational Calculus

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Om Prakash Agrawal

2012-01-01

Full Text Available This paper builds upon our recent paper on generalized fractional variational calculus (FVC. Here, we briefly review some of the fractional derivatives (FDs that we considered in the past to develop FVC. We first introduce new one parameter generalized fractional derivatives (GFDs which depend on two functions, and show that many of the one-parameter FDs considered in the past are special cases of the proposed GFDs. We develop several parts of FVC in terms of one parameter GFDs. We point out how many other parts could be developed using the properties of the one-parameter GFDs. Subsequently, we introduce two new two- and three-parameter GFDs. We introduce some of their properties, and discuss how they can be used to develop FVC. In addition, we indicate how these formulations could be used in various fields, and how the generalizations presented here can be further extended.

Energy transfer by magnetopause reconnection and the substorm parameter epsilon

International Nuclear Information System (INIS)

Gonzalez-Alarcon, W.D.; Gonzalez, A.L.C. de.

1983-01-01

An expression for the magnetopause reconnection power based on the dawn-dusk component of the reconnection electric field, that reduces to the substorm parameter epsilon for the limit that involves equal geomagnetic (B sub(G)) and magnetosheath (B sub(M)) magnetic field amplitudes at the magnetopause, is contrasted with the expression based on the whole reconnection electric field vector obtained by Gonzalez. The correlation examples of this report show that this (more general) expression for the reconnection power seems to correlate with the empirical dissipation parameter U sub(T) from Akasofu, with slightly better correlation coefficients than those obtained from similar correlations between the parameter epsilon and U sub(T). Thus, these (better) correlations show up for the more familiar values of the ratio B sub(G) / B sub(M) > 1. Nevertheless, the (expected) relatively small difference that seems to exist between these correlation coefficients suggests that, for practical purposes, the parameter epsilon could be used as well (instead of the more general expression) in similar correlation studies due to its impler format. On the other hand, studies that refer mainly to the difference in the magnitudes of epsilon and of the more general expression are expected to give results with less negligible differences. (Author) [pt

Regionalization of SWAT Model Parameters for Use in Ungauged Watersheds

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Indrajeet Chaubey

2010-11-01

Full Text Available There has been a steady shift towards modeling and model-based approaches as primary methods of assessing watershed response to hydrologic inputs and land management, and of quantifying watershed-wide best management practice (BMP effectiveness. Watershed models often require some degree of calibration and validation to achieve adequate watershed and therefore BMP representation. This is, however, only possible for gauged watersheds. There are many watersheds for which there are very little or no monitoring data available, thus the question as to whether it would be possible to extend and/or generalize model parameters obtained through calibration of gauged watersheds to ungauged watersheds within the same region. This study explored the possibility of developing regionalized model parameter sets for use in ungauged watersheds. The study evaluated two regionalization methods: global averaging, and regression-based parameters, on the SWAT model using data from priority watersheds in Arkansas. Resulting parameters were tested and model performance determined on three gauged watersheds. Nash-Sutcliffe efficiencies (NS for stream flow obtained using regression-based parameters (0.53–0.83 compared well with corresponding values obtained through model calibration (0.45–0.90. Model performance obtained using global averaged parameter values was also generally acceptable (0.4 ≤ NS ≤ 0.75. Results from this study indicate that regionalized parameter sets for the SWAT model can be obtained and used for making satisfactory hydrologic response predictions in ungauged watersheds.

Constitutive Equation with Varying Parameters for Superplastic Flow Behavior

Science.gov (United States)

Guan, Zhiping; Ren, Mingwen; Jia, Hongjie; Zhao, Po; Ma, Pinkui

2014-03-01

In this study, constitutive equations for superplastic materials with an extra large elongation were investigated through mechanical analysis. From the view of phenomenology, firstly, some traditional empirical constitutive relations were standardized by restricting some strain paths and parameter conditions, and the coefficients in these relations were strictly given new mechanical definitions. Subsequently, a new, general constitutive equation with varying parameters was theoretically deduced based on the general mechanical equation of state. The superplastic tension test data of Zn-5%Al alloy at 340 °C under strain rates, velocities, and loads were employed for building a new constitutive equation and examining its validity. Analysis results indicated that the constitutive equation with varying parameters could characterize superplastic flow behavior in practical superplastic forming with high prediction accuracy and without any restriction of strain path or deformation condition, showing good industrial or scientific interest. On the contrary, those empirical equations have low prediction capabilities due to constant parameters and poor applicability because of the limit of special strain path or parameter conditions based on strict phenomenology.

Micro Loudspeaker Behaviour versus 6½" Driver, Micro Loudspeaker Parameter Drift

DEFF Research Database (Denmark)

Pedersen, Bo Rohde

2010-01-01

This study tested micro loudspeaker behavior from the perspective of loudspeaker parameter drift. The main difference between traditional transducers and micro loudspeakers, apart from their size, is their suspension construction. The suspension generally is a loudspeaker's most unstable parameter......, and the study investigated temperature drift and signal dependency. There is investigated three different micro loudspeakers and compared their behavior to that of a typical bass mid-range loudspeaker unit. There is measured all linear loudspeaker parameters at different temperatures....

Integral Parameters of the Thermal Neutron Scattering Law

International Nuclear Information System (INIS)

Purohit, S.N.

1964-09-01

Integral parameters of the thermal neutron scattering law - the thermalization binding parameter (M 2 ), the Placzek's moments of the generalized frequency spectrum of dynamical modes and the energy transfer moments of the scattering law - are theoretically discussed. A detailed study of the variation of M 2 , the thermalization time constant and the effective temperature of the vibrating atoms, with the relative weight between intra-molecular vibrations and hindered rotations for H 2 O, is presented. Theoretical results for different scattering models of H 2 O are compared with the measurements of integral experiments. A set of integral parameters for D 2 O, using Butler's model, have been obtained. Importance of the structure of hindered rotations of H 2 O and D 2 O in the study of integral parameters has also been discussed

Study of excitation energy dependence of nuclear level density parameter

International Nuclear Information System (INIS)

Mohanto, G.; Nayak, B.K.; Saxena, A.

2016-01-01

In the present study, we have populated CN by fusion reaction and excitation energy of the intermediate nuclei is determined after first chance α-emission to investigate excitation energy dependence of the NLD parameter. Evaporated neutron spectra were measured following alpha evaporation for obtaining NLD parameter for the reaction 11 B + 197 Au, populating CN 208 Po. This CN after evaporating an α-particle populates intermediate nucleus 204 Pb. The 204 Pb has magic number of Z=82. Our aim is to study the excitation energy dependence of NLD parameter for closed shell nuclei

Sparsity regularization for parameter identification problems

International Nuclear Information System (INIS)

Jin, Bangti; Maass, Peter

2012-01-01

The investigation of regularization schemes with sparsity promoting penalty terms has been one of the dominant topics in the field of inverse problems over the last years, and Tikhonov functionals with ℓ p -penalty terms for 1 ⩽ p ⩽ 2 have been studied extensively. The first investigations focused on regularization properties of the minimizers of such functionals with linear operators and on iteration schemes for approximating the minimizers. These results were quickly transferred to nonlinear operator equations, including nonsmooth operators and more general function space settings. The latest results on regularization properties additionally assume a sparse representation of the true solution as well as generalized source conditions, which yield some surprising and optimal convergence rates. The regularization theory with ℓ p sparsity constraints is relatively complete in this setting; see the first part of this review. In contrast, the development of efficient numerical schemes for approximating minimizers of Tikhonov functionals with sparsity constraints for nonlinear operators is still ongoing. The basic iterated soft shrinkage approach has been extended in several directions and semi-smooth Newton methods are becoming applicable in this field. In particular, the extension to more general non-convex, non-differentiable functionals by variational principles leads to a variety of generalized iteration schemes. We focus on such iteration schemes in the second part of this review. A major part of this survey is devoted to applying sparsity constrained regularization techniques to parameter identification problems for partial differential equations, which we regard as the prototypical setting for nonlinear inverse problems. Parameter identification problems exhibit different levels of complexity and we aim at characterizing a hierarchy of such problems. The operator defining these inverse problems is the parameter-to-state mapping. We first summarize some

A General 2D Meshless Interpolating Boundary Node Method Based on the Parameter Space

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Hongyin Yang

2017-01-01

Full Text Available The presented study proposed an improved interpolating boundary node method (IIBNM for 2D potential problems. The improved interpolating moving least-square (IIMLS method was applied to construct the shape functions, of which the delta function properties and boundary conditions were directly implemented. In addition, any weight function used in the moving least-square (MLS method was also applicable in the IIMLS method. Boundary cells were required in the computation of the boundary integrals, and additional discretization error was not avoided if traditional cells were used to approximate the geometry. The present study applied the parametric cells created in the parameter space to preserve the exact geometry, and the geometry was maintained due to the number of cells. Only the number of nodes on the boundary was required as additional information for boundary node construction. Most importantly, the IIMLS method can be applied in the parameter space to construct shape functions without the requirement of additional computations for the curve length.

Statistical Inference for Data Adaptive Target Parameters.

Science.gov (United States)

Hubbard, Alan E; Kherad-Pajouh, Sara; van der Laan, Mark J

2016-05-01

Consider one observes n i.i.d. copies of a random variable with a probability distribution that is known to be an element of a particular statistical model. In order to define our statistical target we partition the sample in V equal size sub-samples, and use this partitioning to define V splits in an estimation sample (one of the V subsamples) and corresponding complementary parameter-generating sample. For each of the V parameter-generating samples, we apply an algorithm that maps the sample to a statistical target parameter. We define our sample-split data adaptive statistical target parameter as the average of these V-sample specific target parameters. We present an estimator (and corresponding central limit theorem) of this type of data adaptive target parameter. This general methodology for generating data adaptive target parameters is demonstrated with a number of practical examples that highlight new opportunities for statistical learning from data. This new framework provides a rigorous statistical methodology for both exploratory and confirmatory analysis within the same data. Given that more research is becoming "data-driven", the theory developed within this paper provides a new impetus for a greater involvement of statistical inference into problems that are being increasingly addressed by clever, yet ad hoc pattern finding methods. To suggest such potential, and to verify the predictions of the theory, extensive simulation studies, along with a data analysis based on adaptively determined intervention rules are shown and give insight into how to structure such an approach. The results show that the data adaptive target parameter approach provides a general framework and resulting methodology for data-driven science.

Statistical study of waves distribution in the inner magnetosphere using geomagnetic indices and solar wind parameters

Science.gov (United States)

Aryan, H.; Yearby, K.; Balikhin, M. A.; Krasnoselskikh, V.; Agapitov, O. V.

2013-12-01

The interaction of gyroresonant wave particles with chorus waves largely determine the dynamics of the Earth's radiation belts that effects the acceleration and loss of radiation belt electrons. The common approach is to present model waves distribution in the inner magnetosphere under different values of geomagnetic activity as expressed by the geomagnetic indices. However it is known that solar wind parameters such as bulk velocity (V) and density (n) are more effective in the control of high energy fluxes at the geostationary orbit. Therefore in the present study the set of parameters of the wave distribution is expanded to include the solar wind parameters in addition to the geomagnetic indices. The present study examines almost four years (01, January, 2004 to 29, September, 2007) of Cluster STAFF-SA, Double Star TC1 and OMNI data in order to present a combined model of wave magnetic field intensities for the chorus waves as a function of magnetic local time (MLT), L-shell (L*), geomagnetic activity, and solar wind velocity and density. Generally, the largest wave intensities are observed during average solar wind velocities (3006cm-3. On the other hand the wave intensity is lower and limited between 06:00 to 18:00 MLT for V700kms-1.

Study of electroweak parameters at LEP

International Nuclear Information System (INIS)

Blum, W.

1991-10-01

The measurement of the line shape and asymmetry parameters of the Z 0 in its leptonic and hadronic decays are reviewed. Progress is reported about a considerable increase in measurement accuracy. Several tests of the Standard Model confirm it to better than one per cent. New values for the effective mixing parameter are derived from the line shape parameters averaged over the four LEP experiments. The corresponding limits on the top mass are presented. (orig.)

Competitive Modes for the Detection of Chaotic Parameter Regimes in the General Chaotic Bilinear System of Lorenz Type

Science.gov (United States)

Mallory, Kristina; van Gorder, Robert A.

We study chaotic behavior of solutions to the bilinear system of Lorenz type developed by Celikovsky and Vanecek [1994] through an application of competitive modes. This bilinear system of Lorenz type is one possible canonical form holding the Lorenz equation as a special case. Using a competitive modes analysis, which is a completely analytical method allowing one to identify parameter regimes for which chaos may occur, we are able to demonstrate a number of parameter regimes which admit a variety of distinct chaotic behaviors. Indeed, we are able to draw some interesting conclusions which relate the behavior of the mode frequencies arising from writing the state variables for the Celikovsky-Vanecek model as coupled oscillators, and the types of emergent chaotic behaviors observed. The competitive modes analysis is particularly useful if all but one of the model parameters are fixed, and the remaining free parameter is used to modify the chaos observed, in a manner analogous to a bifurcation parameter. Through a thorough application of the method, we are able to identify several parameter regimes which give new dynamics (such as specific forms of chaos) which were not observed or studied previously in the Celikovsky-Vanecek model. Therefore, the results demonstrate the advantage of the competitive modes approach for detecting new parameter regimes leading to chaos in third-order dynamical systems.

Astrophysical parameters of ten poorly studied open star clusters

International Nuclear Information System (INIS)

Tadross, Ashraf Latif; El-Bendary, Reda; Osman, Anas; Ismail, Nader; Bakry, Abdel Aziz

2012-01-01

We present the fundamental parameters of ten open star clusters, nominated from Kronberger et al. who presented some newly discovered stellar groups on the basis of the Two Micron All Sky Survey photometry and Digitized Sky Survey visual images. Star counts and photometric parameters (radius, membership, distance, color excess, age, luminosity function, mass function, total mass, and dynamical relaxation time) have been determined for these ten clusters for the first time. In order to calibrate our procedures, the main parameters (distance, age, and color excess) have been re-estimated for another five clusters, which are also studied by Kronberger et al. (research papers)

Integral Parameters of the Thermal Neutron Scattering Law

Energy Technology Data Exchange (ETDEWEB)

Purohit, S N

1964-09-15

Integral parameters of the thermal neutron scattering law - the thermalization binding parameter (M{sub 2}), the Placzek's moments of the generalized frequency spectrum of dynamical modes and the energy transfer moments of the scattering law - are theoretically discussed. A detailed study of the variation of M{sub 2}, the thermalization time constant and the effective temperature of the vibrating atoms, with the relative weight between intra-molecular vibrations and hindered rotations for H{sub 2}O, is presented. Theoretical results for different scattering models of H{sub 2}O are compared with the measurements of integral experiments. A set of integral parameters for D{sub 2}O, using Butler's model, have been obtained. Importance of the structure of hindered rotations of H{sub 2}O and D{sub 2}O in the study of integral parameters has also been discussed.

Application of generalized estimating equations to a study in vitro of radiation sensitivity

International Nuclear Information System (INIS)

Cologne, J.B.; Carter, R.L.; Fujita, Shoichiro; Ban, Sadayuki.

1993-08-01

We describes an application of the generalized estimating equation (GEE) method (Liang K-Y, Zeger SL: Longitudinal data analysis using generalized linear models. Biometrika 73:13-22, 1986) for regression analyses of correlated Poisson data. As an alternative to the use of an arbitrarily chosen working correlation matrix, we demonstrate the use of GEE with a reasonable model for the true covariance structure among repeated observations within individuals. We show that, under such a split-plot design with large clusters, the asymptotic relative efficiency of GEE with simple (independence or exchangeable) working correlation matrices is rather low. We also illustrate the use of GEE with an empirically estimated model for overdispersion in a large study of radiation sensitivity where cluster size is small and a simple working correlation structure is sufficient. We conclude by summarizing issues and needs for further work concerning efficiency of the GEE parameter estimates in practice. (author)

Seasonal and spatial variation in broadleaf forest model parameters

Science.gov (United States)

Groenendijk, M.; van der Molen, M. K.; Dolman, A. J.

2009-04-01

Process based, coupled ecosystem carbon, energy and water cycle models are used with the ultimate goal to project the effect of future climate change on the terrestrial carbon cycle. A typical dilemma in such exercises is how much detail the model must be given to describe the observations reasonably realistic while also be general. We use a simple vegetation model (5PM) with five model parameters to study the variability of the parameters. These parameters are derived from the observed carbon and water fluxes from the FLUXNET database. For 15 broadleaf forests the model parameters were derived for different time resolutions. It appears that in general for all forests, the correlation coefficient between observed and simulated carbon and water fluxes improves with a higher parameter time resolution. The quality of the simulations is thus always better when a higher time resolution is used. These results show that annual parameters are not capable of properly describing weather effects on ecosystem fluxes, and that two day time resolution yields the best results. A first indication of the climate constraints can be found by the seasonal variation of the covariance between Jm, which describes the maximum electron transport for photosynthesis, and climate variables. A general seasonality we found is that during winter the covariance with all climate variables is zero. Jm increases rapidly after initial spring warming, resulting in a large covariance with air temperature and global radiation. During summer Jm is less variable, but co-varies negatively with air temperature and vapour pressure deficit and positively with soil water content. A temperature response appears during spring and autumn for broadleaf forests. This shows that an annual model parameter cannot be representative for the entire year. And relations with mean annual temperature are not possible. During summer the photosynthesis parameters are constrained by water availability, soil water content and

Generalized double-humped logistic map-based medical image encryption

Directory of Open Access Journals (Sweden)

Samar M. Ismail

2018-03-01

Full Text Available This paper presents the design of the generalized Double Humped (DH logistic map, used for pseudo-random number key generation (PRNG. The generalized parameter added to the map provides more control on the map chaotic range. A new special map with a zooming effect of the bifurcation diagram is obtained by manipulating the generalization parameter value. The dynamic behavior of the generalized map is analyzed, including the study of the fixed points and stability ranges, Lyapunov exponent, and the complete bifurcation diagram. The option of designing any specific map is made possible through changing the general parameter increasing the randomness and controllability of the map. An image encryption algorithm is introduced based on pseudo-random sequence generation using the proposed generalized DH map offering secure communication transfer of medical MRI and X-ray images. Security analyses are carried out to consolidate system efficiency including: key sensitivity and key-space analyses, histogram analysis, correlation coefficients, MAE, NPCR and UACI calculations. System robustness against noise attacks has been proved along with the NIST test ensuring the system efficiency. A comparison between the proposed system with respect to previous works is presented.

Geotechnical parameters for three deep ocean study areas

International Nuclear Information System (INIS)

Nicholson, D.P.

1989-01-01

This chapter summarizes the results of geotechnical measurements made on cores taken at the three deep ocean sites that have been studied in detail as part of the international programme assessing the feasibility of deep ocean disposal of heat-generating radioactive waste. The capabilities of existing sampling methods and the adequacy of the available data for providing the geotechnical parameters needed to evaluate the technical feasibility of deep ocean disposal are discussed. It is concluded that, while it has not been possible to obtain core samples of sufficient quality and depth to provide all the parameters needed for the assessment, no fundamental differences between the sediments at the study areas and those found on land or in shallow water have been identified. (author)

Reactor parameters for European economic, safety and environmental studies

International Nuclear Information System (INIS)

Hancox, R.; Cooke, P.I.H.; Spears, W.R.

1990-01-01

Parameter sets for five 1200 MW e tokamak reactors were developed for the European Study Group on the Environmental, Safety-related and Economic Potential of Fusion Power, showing today's perception of the range of reactors likely to be available as a result of the Commission's fusion programme. On the basis of the cost of generating electricity, relative to a fission reactor, a reference set was chosen and endorsed by the Group for further studies including that on the environmental impact of fusion power. Key physics and technology parameters for the reference reactor are compared with values used in the ITER design, and with those from American studies. (author)

Direct and inverse problems for the generalized relativistic Toda lattice and the connection with general orthogonal polynomials

International Nuclear Information System (INIS)

Gago-Alonso, A; Santiago-Moreno, L; Piñeiro-Díaz, L R

2008-01-01

We study finite nonlinear dynamical systems that are somehow more general and complex than the relativistic Toda lattice. Our dynamical systems have a matrix representation very similar to the ones that were previously studied. It is defined in terms of a one-parameter family (D(x), M(x)) of matrices, where D(x) is a Hessenberg matrix and M(x) is a lower triangular matrix. The Jordan matrix associated with M −1 (x)D(x) is a constant of motion and the auxiliary spectral data have explicit time evolution. Using the connection between Hessenberg matrices and general orthogonal polynomials we associated to our system a one-parameter family of scalar products that we use to prove the integrability of the system. In particular the inverse transform is given by an orthogonalization process on a given scalar product

Study of pressure-volume relationships and higher derivatives of bulk modulus based on generalized equations of state

International Nuclear Information System (INIS)

Kushwah, S.S.; Shrivastava, H.C.; Singh, K.S.

2007-01-01

We have generalized the pressure-volume (P-V) relationships using simple polynomial and logarithmic expansions so as to make them consistent with the infinite pressure extrapolation according to the model of Stacey. The formulations are used to evaluate P-V relationships and pressure derivatives of bulk modulus upto third order (K', K'' and K''') for the earth core material taking input parameters based on the seismological data. The results based on the equations of state (EOS) generalized in the present study are found to yield good agreement with the Stacey EOS. The generalized logarithmic EOS due to Poirier and Tarantola deviates substantially from the seismic values for P, K and K'. The generalized Rydberg EOS gives almost identical results with the Birch-Murnaghan third-order EOS. Both of them yield deviations from the seismic data, which are in opposite direction as compared to those found from the generalized Poirier-Tarantola logarithmic EOS

A software for parameter estimation in dynamic models

Directory of Open Access Journals (Sweden)

M. Yuceer

2008-12-01

Full Text Available A common problem in dynamic systems is to determine parameters in an equation used to represent experimental data. The goal is to determine the values of model parameters that provide the best fit to measured data, generally based on some type of least squares or maximum likelihood criterion. In the most general case, this requires the solution of a nonlinear and frequently non-convex optimization problem. Some of the available software lack in generality, while others do not provide ease of use. A user-interactive parameter estimation software was needed for identifying kinetic parameters. In this work we developed an integration based optimization approach to provide a solution to such problems. For easy implementation of the technique, a parameter estimation software (PARES has been developed in MATLAB environment. When tested with extensive example problems from literature, the suggested approach is proven to provide good agreement between predicted and observed data within relatively less computing time and iterations.

Statistical study of chorus wave distributions in the inner magnetosphere using Ae and solar wind parameters

Science.gov (United States)

Aryan, Homayon; Yearby, Keith; Balikhin, Michael; Agapitov, Oleksiy; Krasnoselskikh, Vladimir; Boynton, Richard

2014-08-01

Energetic electrons within the Earth's radiation belts represent a serious hazard to geostationary satellites. The interactions of electrons with chorus waves play an important role in both the acceleration and loss of radiation belt electrons. The common approach is to present model wave distributions in the inner magnetosphere under different values of geomagnetic activity as expressed by the geomagnetic indices. However, it has been shown that only around 50% of geomagnetic storms increase flux of relativistic electrons at geostationary orbit while 20% causes a decrease and the remaining 30% has relatively no effect. This emphasizes the importance of including solar wind parameters such as bulk velocity (V), density (n), flow pressure (P), and the vertical interplanetary magnetic field component (Bz) that are known to be predominately effective in the control of high energy fluxes at the geostationary orbit. Therefore, in the present study the set of parameters of the wave distributions is expanded to include the solar wind parameters in addition to the geomagnetic activity. The present study examines almost 4 years (1 January 2004 to 29 September 2007) of Spatio-Temporal Analysis of Field Fluctuation data from Double Star TC1 combined with geomagnetic indices and solar wind parameters from OMNI database in order to present a comprehensive model of wave magnetic field intensities for the chorus waves as a function of magnetic local time, L shell (L), magnetic latitude (λm), geomagnetic activity, and solar wind parameters. Generally, the results indicate that the intensity of chorus emission is not only dependent upon geomagnetic activity but also dependent on solar wind parameters with velocity and southward interplanetary magnetic field Bs (Bz < 0), evidently the most influential solar wind parameters. The largest peak chorus intensities in the order of 50 pT are observed during active conditions, high solar wind velocities, low solar wind densities, high

Estimating Convection Parameters in the GFDL CM2.1 Model Using Ensemble Data Assimilation

Science.gov (United States)

Li, Shan; Zhang, Shaoqing; Liu, Zhengyu; Lu, Lv; Zhu, Jiang; Zhang, Xuefeng; Wu, Xinrong; Zhao, Ming; Vecchi, Gabriel A.; Zhang, Rong-Hua; Lin, Xiaopei

2018-04-01

Parametric uncertainty in convection parameterization is one major source of model errors that cause model climate drift. Convection parameter tuning has been widely studied in atmospheric models to help mitigate the problem. However, in a fully coupled general circulation model (CGCM), convection parameters which impact the ocean as well as the climate simulation may have different optimal values. This study explores the possibility of estimating convection parameters with an ensemble coupled data assimilation method in a CGCM. Impacts of the convection parameter estimation on climate analysis and forecast are analyzed. In a twin experiment framework, five convection parameters in the GFDL coupled model CM2.1 are estimated individually and simultaneously under both perfect and imperfect model regimes. Results show that the ensemble data assimilation method can help reduce the bias in convection parameters. With estimated convection parameters, the analyses and forecasts for both the atmosphere and the ocean are generally improved. It is also found that information in low latitudes is relatively more important for estimating convection parameters. This study further suggests that when important parameters in appropriate physical parameterizations are identified, incorporating their estimation into traditional ensemble data assimilation procedure could improve the final analysis and climate prediction.

Program for parameter studies of steam generators

International Nuclear Information System (INIS)

Mathisen, R.P.

1982-11-01

R2-GEN is a computer code for stationary thermal parameter studies of steam generators. The geometry and data are valid for Ringhals-2 generators. Subroutines and relevant calculations are included. The program is based on a heterogeneous flow model and some applications on tubes with varying contamination are presented. (G.B.)

A numerical study of non-linear crack tip parameters

Directory of Open Access Journals (Sweden)

F.V. Antunes

2015-07-01

Full Text Available Crack closure concept has been widely used to explain different issues of fatigue crack propagation. However, different authors have questioned the relevance of crack closure and have proposed alternative concepts. The main objective here is to check the effectiveness of crack closure concept by linking the contact of crack flanks with non-linear crack tip parameters. Accordingly, 3D-FE numerical models with and without contact were developed for a wide range of loading scenarios and the crack tip parameters usually linked to fatigue crack growth, namely range of cyclic plastic strain, crack tip opening displacement, size of reversed plastic zone and total plastic dissipation per cycle, were investigated. It was demonstrated that: i LEFM concepts are applicable to the problem under study; ii the crack closure phenomenon has a great influence on crack tip parameters decreasing their values; iii the Keff concept is able to explain the variations of crack tip parameters produced by the contact of crack flanks; iv the analysis of remote compliance is the best numerical parameter to quantify the crack opening level; v without contact there is no effect of stress ratio on crack tip parameters. Therefore it is proved that the crack closure concept is valid.

Optimisation of parameters for co-precipitation of uranium and plutonium - results of simulation studies

International Nuclear Information System (INIS)

Pandey, N.K.; Velvandan, P.V.; Murugesan, S.; Ahmed, M.K.; Koganti, S.B.

1999-01-01

Preparation of plutonium oxide from plutonium nitrate solution generally proceeds via oxalate precipitation route. In a nuclear fuel reprocessing scheme this step succeeds the partitioning step (separation of uranium and plutonium). Results of present studies confirm that it is possible to avoid partitioning step and recover plutonium and uranium as co-precipitated product. This also helps in minimising the risk of proliferation of fissile material. In this procedure, the solubility of uranium oxalate in nitric acid is effectively used. Co-precipitation parameters are optimised with simulated solutions of uranium nitrate and thorium nitrate (in place of plutonium). On the basis of obtained results a reconversion flow-sheet is designed and reported here. (author)

Study on orthorhombic parameters for 3D elastic full waveform inversion

KAUST Repository

Oh, Juwon

2015-08-21

For a better understanding of the influence of the parameterizations on the multi-parameter full waveform inversion (FWI) for 3D elastic orthorhombic media, we analyze the virtual sources for each cij parameter. Because the virtual sources for cij parameters can be regarded as bases of the virtual sources for other parameterizations, the insights developed here explains many of the scattering phenomena of the different parameters. The resulting radiation patterns provide insights on which parameter set is the best in the multi-parameter FWI for 3D elastic orthorhombic media. In this study, we analyze the virtual source for each cij parameter as a linear combination of several moment tensors. After that, we analyze the strain fields deformed by incident waves as momenta of the virtual source and their influences on sensitivity kernels of each cij parameter.

Study on orthorhombic parameters for 3D elastic full waveform inversion

KAUST Repository

Oh, Juwon; Alkhalifah, Tariq Ali

2015-01-01

For a better understanding of the influence of the parameterizations on the multi-parameter full waveform inversion (FWI) for 3D elastic orthorhombic media, we analyze the virtual sources for each cij parameter. Because the virtual sources for cij parameters can be regarded as bases of the virtual sources for other parameterizations, the insights developed here explains many of the scattering phenomena of the different parameters. The resulting radiation patterns provide insights on which parameter set is the best in the multi-parameter FWI for 3D elastic orthorhombic media. In this study, we analyze the virtual source for each cij parameter as a linear combination of several moment tensors. After that, we analyze the strain fields deformed by incident waves as momenta of the virtual source and their influences on sensitivity kernels of each cij parameter.

Generalized Probability Functions

Directory of Open Access Journals (Sweden)

Alexandre Souto Martinez

2009-01-01

Full Text Available From the integration of nonsymmetrical hyperboles, a one-parameter generalization of the logarithmic function is obtained. Inverting this function, one obtains the generalized exponential function. Motivated by the mathematical curiosity, we show that these generalized functions are suitable to generalize some probability density functions (pdfs. A very reliable rank distribution can be conveniently described by the generalized exponential function. Finally, we turn the attention to the generalization of one- and two-tail stretched exponential functions. We obtain, as particular cases, the generalized error function, the Zipf-Mandelbrot pdf, the generalized Gaussian and Laplace pdf. Their cumulative functions and moments were also obtained analytically.

Delivery parameters, neonatal parameters and incidence of urinary incontinence six months postpartum: a cohort study.

Science.gov (United States)

Wesnes, Stian Langeland; Hannestad, Yngvild; Rortveit, Guri

2017-10-01

Contradictory results have been reported regarding most delivery parameters as risk factors for urinary incontinence. We investigated the association between the incidence of urinary incontinence six months postpartum and single obstetric risk factors as well as combinations of risk factors. This study was based on the Norwegian Mother and Child Cohort Study, conducted by the Norwegian Institute of Public Health during 1998-2008. This substudy was based on 7561 primiparous women who were continent before and during pregnancy. Data were obtained from questionnaires answered at weeks 15 and 30 of pregnancy and six months postpartum. Data were linked to the Medical Birth Registry of Norway. Single and combined delivery- and neonatal parameters were analyzed by logistic regression analyses. Birthweight was associated with significantly higher risk of urinary incontinence six months postpartum [3541-4180 g: odds ratio (OR) 1.4, 95% confidence interval (CI) 1.2-1.6; >4180 g: OR 1.6, 95% CI 1.2-2.0]. Fetal presentation, obstetric anal sphincter injuries, episiotomy and epidural analgesia were not significantly associated with increased risk of urinary incontinence. The following combinations of risk factors among women delivering by spontaneous vaginal delivery increased the risk of urinary incontinence six months postpartum; birthweight ≥3540 g and ≥36 cm head circumference; birthweight ≥3540 g and forceps, birthweight ≥3540 g and episiotomy; and ≥36 cm head circumference and episiotomy. Some combinations of delivery parameters and neonatal parameters seem to act together and may increase the risk of incidence of urinary incontinence six months postpartum in a synergetic way. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

Study of Hematological Parameters in Children Suffering from Iron Deficiency Anaemia in Chattagram Maa-o-Shishu General Hospital, Chittagong, Bangladesh

Science.gov (United States)

Mohammed Mujib, Abu Syed; Halder, Milton; Monirul Hasan, Chowdhury Mohammad

2014-01-01

A total of 150 (30.61%) anemic patients out of 490 patients diagnosed to have iron deficiency anemia (IDA) have been selected for the first time in Bangladesh. For detailed study, blood samples from 150 anemic patients along with 25 controls were analyzed. Analysis of variance showed significant P value between mean platelet volume (MPV) in females (8.08 μm3) and males (7.59 μm3) (P iron deficiency anemia patients. Besides, the value of white blood cells (WBC) in males (10946.08/cmm) was significantly higher than in females (9470.833/cmm) (P anemias with only one of three biochemical parameters decreased and control showed that this group does not have iron deficiency. PMID:25400943

Estimating resist parameters in optical lithography using the extended Nijboer-Zernike theory

NARCIS (Netherlands)

Dirksen, P.; Braat, J.J.M.; Janssen, A.J.E.M.

2006-01-01

This study presents an experimental method to determine the resist parameters at the origin of a general blurring of a projected aerial image. The resist model includes the effects of diffusion in the horizontal plane and image blur that originates from a stochastic variation of the focus parameter.

Generalized massive optimal data compression

Science.gov (United States)

Alsing, Justin; Wandelt, Benjamin

2018-05-01

In this paper, we provide a general procedure for optimally compressing N data down to n summary statistics, where n is equal to the number of parameters of interest. We show that compression to the score function - the gradient of the log-likelihood with respect to the parameters - yields n compressed statistics that are optimal in the sense that they preserve the Fisher information content of the data. Our method generalizes earlier work on linear Karhunen-Loéve compression for Gaussian data whilst recovering both lossless linear compression and quadratic estimation as special cases when they are optimal. We give a unified treatment that also includes the general non-Gaussian case as long as mild regularity conditions are satisfied, producing optimal non-linear summary statistics when appropriate. As a worked example, we derive explicitly the n optimal compressed statistics for Gaussian data in the general case where both the mean and covariance depend on the parameters.

An experimental study on effect of process parameters in deep ...

African Journals Online (AJOL)

The effects of various deep drawing process parameters were determined by experimental study with the use of Taguchi fractional factorial design and analysis of variance for AA6111 Aluminum alloy. The optimum process parameters were determined based on their influence on the thickness variation at different regions ...

Hecke algebras with unequal parameters

CERN Document Server

Lusztig, G

2003-01-01

Hecke algebras arise in representation theory as endomorphism algebras of induced representations. One of the most important classes of Hecke algebras is related to representations of reductive algebraic groups over p-adic or finite fields. In 1979, in the simplest (equal parameter) case of such Hecke algebras, Kazhdan and Lusztig discovered a particular basis (the KL-basis) in a Hecke algebra, which is very important in studying relations between representation theory and geometry of the corresponding flag varieties. It turned out that the elements of the KL-basis also possess very interesting combinatorial properties. In the present book, the author extends the theory of the KL-basis to a more general class of Hecke algebras, the so-called algebras with unequal parameters. In particular, he formulates conjectures describing the properties of Hecke algebras with unequal parameters and presents examples verifying these conjectures in particular cases. Written in the author's precise style, the book gives rese...

Generalized synchronization-based multiparameter estimation in modulated time-delayed systems

Science.gov (United States)

Ghosh, Dibakar; Bhattacharyya, Bidyut K.

2011-09-01

We propose a nonlinear active observer based generalized synchronization scheme for multiparameter estimation in time-delayed systems with periodic time delay. A sufficient condition for parameter estimation is derived using Krasovskii-Lyapunov theory. The suggested tool proves to be globally and asymptotically stable by means of Krasovskii-Lyapunov method. With this effective method, parameter identification and generalized synchronization of modulated time-delayed systems with all the system parameters unknown, can be achieved simultaneously. We restrict our study for multiple parameter estimation in modulated time-delayed systems with single state variable only. Theoretical proof and numerical simulation demonstrate the effectiveness and feasibility of the proposed technique. The block diagram of electronic circuit for multiple time delay system shows that the method is easily applicable in practical communication problems.

Variational estimation of process parameters in a simplified atmospheric general circulation model

Science.gov (United States)

Lv, Guokun; Koehl, Armin; Stammer, Detlef

2016-04-01

Parameterizations are used to simulate effects of unresolved sub-grid-scale processes in current state-of-the-art climate model. The values of the process parameters, which determine the model's climatology, are usually manually adjusted to reduce the difference of model mean state to the observed climatology. This process requires detailed knowledge of the model and its parameterizations. In this work, a variational method was used to estimate process parameters in the Planet Simulator (PlaSim). The adjoint code was generated using automatic differentiation of the source code. Some hydrological processes were switched off to remove the influence of zero-order discontinuities. In addition, the nonlinearity of the model limits the feasible assimilation window to about 1day, which is too short to tune the model's climatology. To extend the feasible assimilation window, nudging terms for all state variables were added to the model's equations, which essentially suppress all unstable directions. In identical twin experiments, we found that the feasible assimilation window could be extended to over 1-year and accurate parameters could be retrieved. Although the nudging terms transform to a damping of the adjoint variables and therefore tend to erases the information of the data over time, assimilating climatological information is shown to provide sufficient information on the parameters. Moreover, the mechanism of this regularization is discussed.

Order parameter free enhanced sampling of the vapor-liquid transition using the generalized replica exchange method.

Science.gov (United States)

Lu, Qing; Kim, Jaegil; Straub, John E

2013-03-14

The generalized Replica Exchange Method (gREM) is extended into the isobaric-isothermal ensemble, and applied to simulate a vapor-liquid phase transition in Lennard-Jones fluids. Merging an optimally designed generalized ensemble sampling with replica exchange, gREM is particularly well suited for the effective simulation of first-order phase transitions characterized by "backbending" in the statistical temperature. While the metastable and unstable states in the vicinity of the first-order phase transition are masked by the enthalpy gap in temperature replica exchange method simulations, they are transformed into stable states through the parameterized effective sampling weights in gREM simulations, and join vapor and liquid phases with a succession of unimodal enthalpy distributions. The enhanced sampling across metastable and unstable states is achieved without the need to identify a "good" order parameter for biased sampling. We performed gREM simulations at various pressures below and near the critical pressure to examine the change in behavior of the vapor-liquid phase transition at different pressures. We observed a crossover from the first-order phase transition at low pressure, characterized by the backbending in the statistical temperature and the "kink" in the Gibbs free energy, to a continuous second-order phase transition near the critical pressure. The controlling mechanisms of nucleation and continuous phase transition are evident and the coexistence properties and phase diagram are found in agreement with literature results.

Effects of two-temperature parameter and thermal nonlocal parameter on transient responses of a half-space subjected to ramp-type heating

Science.gov (United States)

Xue, Zhang-Na; Yu, Ya-Jun; Tian, Xiao-Geng

2017-07-01

Based upon the coupled thermoelasticity and Green and Lindsay theory, the new governing equations of two-temperature thermoelastic theory with thermal nonlocal parameter is formulated. To more realistically model thermal loading of a half-space surface, a linear temperature ramping function is adopted. Laplace transform techniques are used to get the general analytical solutions in Laplace domain, and the inverse Laplace transforms based on Fourier expansion techniques are numerically implemented to obtain the numerical solutions in time domain. Specific attention is paid to study the effect of thermal nonlocal parameter, ramping time, and two-temperature parameter on the distributions of temperature, displacement and stress distribution.

On a generalized Dirac oscillator interaction for the nonrelativistic limit 3 D generalized SUSY model oscillator Hamiltonian of Celka and Hussin

International Nuclear Information System (INIS)

Jayaraman, Jambunatha; Lima Rodrigues, R. de

1994-01-01

In the context of the 3 D generalized SUSY model oscillator Hamiltonian of Celka and Hussin (CH), a generalized Dirac oscillator interaction is studied, that leads, in the non-relativistic limit considered for both signs of energy, to the CH's generalized 3 D SUSY oscillator. The relevance of this interaction to the CH's SUSY model and the SUSY breaking dependent on the Wigner parameter is brought out. (author). 6 refs

Experimental design for estimating parameters of rate-limited mass transfer: Analysis of stream tracer studies

Science.gov (United States)

Wagner, Brian J.; Harvey, Judson W.

1997-01-01

Tracer experiments are valuable tools for analyzing the transport characteristics of streams and their interactions with shallow groundwater. The focus of this work is the design of tracer studies in high-gradient stream systems subject to advection, dispersion, groundwater inflow, and exchange between the active channel and zones in surface or subsurface water where flow is stagnant or slow moving. We present a methodology for (1) evaluating and comparing alternative stream tracer experiment designs and (2) identifying those combinations of stream transport properties that pose limitations to parameter estimation and therefore a challenge to tracer test design. The methodology uses the concept of global parameter uncertainty analysis, which couples solute transport simulation with parameter uncertainty analysis in a Monte Carlo framework. Two general conclusions resulted from this work. First, the solute injection and sampling strategy has an important effect on the reliability of transport parameter estimates. We found that constant injection with sampling through concentration rise, plateau, and fall provided considerably more reliable parameter estimates than a pulse injection across the spectrum of transport scenarios likely encountered in high-gradient streams. Second, for a given tracer test design, the uncertainties in mass transfer and storage-zone parameter estimates are strongly dependent on the experimental Damkohler number, DaI, which is a dimensionless combination of the rates of exchange between the stream and storage zones, the stream-water velocity, and the stream reach length of the experiment. Parameter uncertainties are lowest at DaI values on the order of 1.0. When DaI values are much less than 1.0 (owing to high velocity, long exchange timescale, and/or short reach length), parameter uncertainties are high because only a small amount of tracer interacts with storage zones in the reach. For the opposite conditions (DaI ≫ 1.0), solute

Parameter studies for a two-component fusion experiment

International Nuclear Information System (INIS)

Towner, H.H.

1975-01-01

The sensitivity of the energy multiplication of a two-component fusion experiment is examined relative to the following parameters: energy confinement time (tau/sub E/), particle confinement time (tau/sub p/), effective Z of the plasma (Z/sub eff/), injection rate (j/sub I/) and injection energy (E/sub I/). The Energy Research and Development Administration recently approved funding for such a fusion device (the Toroidal Fusion Test Reactor or TFTR) which will be built at the Princeton Plasma Physics Laboratory. Hence, such a parameter study seems both timely and necessary. This work also serves as an independent check on the design values proposed for the TFTR to enable it to achieve energy breakeven (F = 1). Using the nominal TFTR design parameters and a self-consistent ion-electron power balance, the maximum F-value is found to be approximately 1.2 which occurs at an injection energy of approximately 210 KeV. The injector operation, i.e. its current and energy capability are shown to be a very critical factor in the TFTR performance. However, if the injectors meet the design objectives, there appears to be sufficient latitude in the other parameters to offer reasonable assurance that energy breakeven can be achieved. (U.S.)

Parameter study on infilled steel frames with discretely connected precast concrete panels

NARCIS (Netherlands)

Teeuwen, P.A.; Kleinman, C.S.; Snijder, H.H.; Hofmeyer, H.; Chan, S.L.

2009-01-01

This paper presents a parameter study on infilled steel frames with discretely connected precast concrete infill panels having window openings. In this study, finite element simulations were carried out to study the infilled frame performance by varying several parameters. A recently developed

Exploratory Study for Continuous-time Parameter Estimation of Ankle Dynamics

Science.gov (United States)

Kukreja, Sunil L.; Boyle, Richard D.

2014-01-01

Recently, a parallel pathway model to describe ankle dynamics was proposed. This model provides a relationship between ankle angle and net ankle torque as the sum of a linear and nonlinear contribution. A technique to identify parameters of this model in discrete-time has been developed. However, these parameters are a nonlinear combination of the continuous-time physiology, making insight into the underlying physiology impossible. The stable and accurate estimation of continuous-time parameters is critical for accurate disease modeling, clinical diagnosis, robotic control strategies, development of optimal exercise protocols for longterm space exploration, sports medicine, etc. This paper explores the development of a system identification technique to estimate the continuous-time parameters of ankle dynamics. The effectiveness of this approach is assessed via simulation of a continuous-time model of ankle dynamics with typical parameters found in clinical studies. The results show that although this technique improves estimates, it does not provide robust estimates of continuous-time parameters of ankle dynamics. Due to this we conclude that alternative modeling strategies and more advanced estimation techniques be considered for future work.

Dynamic Parameter Identification of Subject-Specific Body Segment Parameters Using Robotics Formalism: Case Study Head Complex.

Science.gov (United States)

Díaz-Rodríguez, Miguel; Valera, Angel; Page, Alvaro; Besa, Antonio; Mata, Vicente

2016-05-01

Accurate knowledge of body segment inertia parameters (BSIP) improves the assessment of dynamic analysis based on biomechanical models, which is of paramount importance in fields such as sport activities or impact crash test. Early approaches for BSIP identification rely on the experiments conducted on cadavers or through imaging techniques conducted on living subjects. Recent approaches for BSIP identification rely on inverse dynamic modeling. However, most of the approaches are focused on the entire body, and verification of BSIP for dynamic analysis for distal segment or chain of segments, which has proven to be of significant importance in impact test studies, is rarely established. Previous studies have suggested that BSIP should be obtained by using subject-specific identification techniques. To this end, our paper develops a novel approach for estimating subject-specific BSIP based on static and dynamics identification models (SIM, DIM). We test the validity of SIM and DIM by comparing the results using parameters obtained from a regression model proposed by De Leva (1996, "Adjustments to Zatsiorsky-Seluyanov's Segment Inertia Parameters," J. Biomech., 29(9), pp. 1223-1230). Both SIM and DIM are developed considering robotics formalism. First, the static model allows the mass and center of gravity (COG) to be estimated. Second, the results from the static model are included in the dynamics equation allowing us to estimate the moment of inertia (MOI). As a case study, we applied the approach to evaluate the dynamics modeling of the head complex. Findings provide some insight into the validity not only of the proposed method but also of the application proposed by De Leva (1996, "Adjustments to Zatsiorsky-Seluyanov's Segment Inertia Parameters," J. Biomech., 29(9), pp. 1223-1230) for dynamic modeling of body segments.

On the Interplay between Order Parameter Dynamics and System Parameter Dynamics in Human Perceptual-Cognitive-Behavioral Systems.

Science.gov (United States)

Frank, T D

2015-04-01

Previous research has demonstrated that perceiving, thinking, and acting are human activities that correspond to self-organized patterns. The emergence of such patterns can be completely described in terms of the dynamics of the pattern amplitudes, which are referred to as order parameters. The patterns emerge at bifurcations points when certain system parameters internal and external to a human agent exceed critical values. At issue is how one might study the order parameter dynamics for sequences of consecutive, emergent perceptual, cognitive, or behavioral activities. In particular, these activities may in turn impact the system parameters that have led to the emergence of the activities in the first place. This interplay between order parameter dynamics and system parameter dynamics is discussed in general and formulated in mathematical terms. Previous work that has made use of this two-tiered framework of order parameter and system parameter dynamics are briefly addressed. As an application, a model for perception under functional fixedness is presented. Finally, it is argued that the phenomena that emerge in this framework and can be observed when human agents perceive, think, and act are just as likely to occur in pattern formation systems of the inanimate world. Consequently, these phenomena do not necessarily have a neurophysiological basis but should instead be understood from the perspective of the theory of self-organization.

Band parameters of phosphorene

DEFF Research Database (Denmark)

Lew Yan Voon, L. C.; Wang, J.; Zhang, Y.

2015-01-01

Phosphorene is a two-dimensional nanomaterial with a direct band-gap at the Brillouin zone center. In this paper, we present a recently derived effective-mass theory of the band structure in the presence of strain and electric field, based upon group theory. Band parameters for this theory...... are computed using a first-principles theory based upon the generalized-gradient approximation to the density-functional theory. These parameters and Hamiltonian will be useful for modeling physical properties of phosphorene....

A null-parameter formula for storage-evapotranspiration relationship based on generalized proportionality hypothesis and its applications

Science.gov (United States)

Han, P. F.; Wang, X. S.; Istanbulluoglu, E.

2017-12-01

Different formulas have been developed to estimate the mean annual evapotranspiration ratio (E/P) at catchment scale from the mean annual aridity index (Ep/P) based on the Budyko framework. A major challenge in using the Budyko framework for the inter-annual behaviors of a catchment is the missed storage in these formulas. Efforts have been contributed to modify the formulas for estimating the annual E/P from both of the annual Ep/P and the change in storage, leading to a significant increase in the number of empirical parameters. In this paper we develop a null-parameter formula of the storage-evapotranspiration relationship based on a new interpretation of the proportionality hypothesis, which takes the storage in the soil-plant-atmosphere continuum (SPAC) as the accessible water for the evapotranspiration processes. According to the formula, the annual E/P depends on the annual Ep/P and S/P values where S is the initial SPAC storage in a year. The difference between the S values of two years represents the inter-annual change in storage in the SPAC system. An annual water balance model including groundwater storage for a basin is required to estimate the annual runoff and S/P from year to year. We develop a tri-parameters model using this null-parameter formula to minimize the number of parameters and successfully applied to investigate the NLRB basin in Nebraska, USA. For mean annual water balance, the tri-parameters model results in one-parameter formulas to estimate both of the mean annual E/P and S/P so that the status of storage can be included in the Budyko framework. The tri-parameters model is further extended to a twin-zones model for the effect of irrigation in croplands and applied to reconstruct the hydrological behaviors in the natural state for 12 catchments in Illinois, USA, with different cropland areas. It is found in the Illinois examples (where Ep/P is less than 2) that the annual E/P increases with the increasing Ep/P almost in a linear

SYVAC3 parameter distribution package

Energy Technology Data Exchange (ETDEWEB)

Andres, T; Skeet, A

1995-01-01

SYVAC3 (Systems Variability Analysis Code, generation 3) is a computer program that implements a method called systems variability analysis to analyze the behaviour of a system in the presence of uncertainty. This method is based on simulating the system many times to determine the variation in behaviour it can exhibit. SYVAC3 specializes in systems representing the transport of contaminants, and has several features to simplify the modelling of such systems. It provides a general tool for estimating environmental impacts from the dispersal of contaminants. This report describes a software object type (a generalization of a data type) called Parameter Distribution. This object type is used in SYVAC3, and can also be used independently. Parameter Distribution has the following subtypes: beta distribution; binomial distribution; constant distribution; lognormal distribution; loguniform distribution; normal distribution; piecewise uniform distribution; Triangular distribution; and uniform distribution. Some of these distributions can be altered by correlating two parameter distribution objects. This report provides complete specifications for parameter distributions, and also explains how to use them. It should meet the needs of casual users, reviewers, and programmers who wish to add their own subtypes. (author). 30 refs., 75 tabs., 56 figs.

Study of a generalized birks formula for the scintillation response of a CaMoO4 crystal

Science.gov (United States)

Lee, J. Y.; Kim, H. J.; Kang, Sang Jun; Lee, M. H.

2017-12-01

We have investigated the scintillation characteristics of CaMoO4 (CMO) crystals by using a gamma source and various internal alpha sources. A 137Cs source with 662-keV gamma-rays was used for the gamma-quanta light yield calibration. Internal radioactive contaminations provided alpha particles with different energies from 5.41 to 7.88 MeV. We developed a C++ program based on the ROOT package for the fitting of parameters in a generalized Birks semi-empirical formula by combining the experimental and the simulation data. Results for the fitted Birks parameters are k b1 = 3.3 × 10 -3 (g/MeVcm2) for the 1st parameter and k b2 = 7.9 × 10 -5 (g/MeVcm2)2 for the 2nd parameter. The χ2/n.d.f. (Number of Degree of Freedom) is calculated as 0.1/4. We were able to estimate the 238U and 234U contaminations in a CMO crystal by using the generalized Birks semi-empirical formula.

Parameter uncertainty in CGE Modeling of the environmental impacts of economic policies

International Nuclear Information System (INIS)

Abler, D.G.; Shortle, J.S.; Rodriguez, A.G.

1999-01-01

This study explores the role of parameter uncertainty in Computable General Equilibrium (CGE) modeling of the environmental impacts of macroeconomic and sectoral policies, using Costa Rica as a case for study. A CGE model is constructed which includes eight environmental indicators covering deforestation, pesticides, overfishing, hazardous wastes, inorganic wastes, organic wastes, greenhouse gases, and air pollution. The parameters are treated as random variables drawn from prespecified distributions. Evaluation of each policy option consists of a Monte Carlo experiment. The impacts of the policy options on the environmental indicators are relatively robust to different parameter values, in spite of the wide range of parameter values employed. 33 refs

Parameter uncertainty in CGE Modeling of the environmental impacts of economic policies

Energy Technology Data Exchange (ETDEWEB)

Abler, D.G.; Shortle, J.S. [Agricultural Economics, Pennsylvania State University, University Park, PA (United States); Rodriguez, A.G. [University of Costa Rica, San Jose (Costa Rica)

1999-07-01

This study explores the role of parameter uncertainty in Computable General Equilibrium (CGE) modeling of the environmental impacts of macroeconomic and sectoral policies, using Costa Rica as a case for study. A CGE model is constructed which includes eight environmental indicators covering deforestation, pesticides, overfishing, hazardous wastes, inorganic wastes, organic wastes, greenhouse gases, and air pollution. The parameters are treated as random variables drawn from prespecified distributions. Evaluation of each policy option consists of a Monte Carlo experiment. The impacts of the policy options on the environmental indicators are relatively robust to different parameter values, in spite of the wide range of parameter values employed. 33 refs.

POPULATION SYNTHESIS OF HOT SUBDWARFS: A PARAMETER STUDY

International Nuclear Information System (INIS)

Clausen, Drew; Wade, Richard A.; Kopparapu, Ravi Kumar; O'Shaughnessy, Richard

2012-01-01

Binaries that contain a hot subdwarf (sdB) star and a main-sequence companion may have interacted in the past. This binary population has historically helped determine our understanding of binary stellar evolution. We have computed a grid of binary population synthesis models using different assumptions about the minimum core mass for helium ignition, the envelope binding energy, the common-envelope ejection efficiency, the amount of mass and angular momentum lost during stable mass transfer, and the criteria for stable mass transfer on the red giant branch and in the Hertzsprung gap. These parameters separately and together can significantly change the entire predicted population of sdBs. Nonetheless, several different parameter sets can reproduce the observed subpopulation of sdB + white dwarf and sdB + M dwarf binaries, which has been used to constrain these parameters in previous studies. The period distribution of sdB + early F dwarf binaries offers a better test of different mass transfer scenarios for stars that fill their Roche lobes on the red giant branch.

Modalities of Generalization Through Single Case Studies.

Science.gov (United States)

Zittoun, Tania

2017-06-01

The value of case studies for theory building is still doubted in psychology. The paper argues for the importance of case studies and the possibility of generalizing from these for a specific sociocultural understanding of human development. The paper first clarifies the notion of abduction within case studies, drawing on pragmatists James and Peirce and expanding it with the work of Lewin, and argues that it is the core mechanism that allows generalization from case studies. The second section presents the possibility of generalizing from individual single case studies, for which not only the subjective perspective, but also the dynamics by which the social and cultural environment guide and enable the person's development, have to be accounted for. The third section elaborates the question of institutional case studies, where the challenge is to account both for institutional dynamics, and for persons' trajectories within; this is exemplified with an ongoing study on the process of obtaining citizenship in Switzerland. The paper briefly concludes by highlighting two possible implications of the paper, one concerning the process of theoretical reasoning, the other, the fact that sociocultural psychology could itself be seen as an institution in-the-making.

Broken-pair, generalized seniority and interacting boson approximations in a spectroscopic study of Sn nuclei

International Nuclear Information System (INIS)

Bonsignori, K.; Allaart, K.; Egmond, A. van

1983-01-01

A broken-pair study of Sn nuclei is reported in which the model space includes two broken pair states. It is shown that for even Sn nuclei, with a rather simple Gaussian interaction and with single-particle-energies derived from data on odd nuclei, the main features of the excitation spectra up to about 3.5 MeV may be reproduced in this way. The idea of the generalized seniority scheme, that the composition of S-pair operator and that of the D-pair operator may be independent of the total number of pairs, is confirmed by the pair structures which result from energy minimization and diagonalization for each number of pairs separately. A general procedure is described to derive IBA parameters when the valence orbits are nondegenerate. Numerical results for Sn nuclei are given. (U.K.)

Band parameters of phosphorene

International Nuclear Information System (INIS)

Lew Yan Voon, L C; Wang, J; Zhang, Y; Willatzen, M

2015-01-01

Phosphorene is a two-dimensional nanomaterial with a direct band-gap at the Brillouin zone center. In this paper, we present a recently derived effective-mass theory of the band structure in the presence of strain and electric field, based upon group theory. Band parameters for this theory are computed using a first-principles theory based upon the generalized-gradient approximation to the density-functional theory. These parameters and Hamiltonian will be useful for modeling physical properties of phosphorene. (paper)

A Generalized QMRA Beta-Poisson Dose-Response Model.

Science.gov (United States)

Xie, Gang; Roiko, Anne; Stratton, Helen; Lemckert, Charles; Dunn, Peter K; Mengersen, Kerrie

2016-10-01

Quantitative microbial risk assessment (QMRA) is widely accepted for characterizing the microbial risks associated with food, water, and wastewater. Single-hit dose-response models are the most commonly used dose-response models in QMRA. Denoting PI(d) as the probability of infection at a given mean dose d, a three-parameter generalized QMRA beta-Poisson dose-response model, PI(d|α,β,r*), is proposed in which the minimum number of organisms required for causing infection, K min , is not fixed, but a random variable following a geometric distribution with parameter 0Poisson model, PI(d|α,β), is a special case of the generalized model with K min = 1 (which implies r*=1). The generalized beta-Poisson model is based on a conceptual model with greater detail in the dose-response mechanism. Since a maximum likelihood solution is not easily available, a likelihood-free approximate Bayesian computation (ABC) algorithm is employed for parameter estimation. By fitting the generalized model to four experimental data sets from the literature, this study reveals that the posterior median r* estimates produced fall short of meeting the required condition of r* = 1 for single-hit assumption. However, three out of four data sets fitted by the generalized models could not achieve an improvement in goodness of fit. These combined results imply that, at least in some cases, a single-hit assumption for characterizing the dose-response process may not be appropriate, but that the more complex models may be difficult to support especially if the sample size is small. The three-parameter generalized model provides a possibility to investigate the mechanism of a dose-response process in greater detail than is possible under a single-hit model. © 2016 Society for Risk Analysis.

Statistical parameter characteristics of gas-phase fluctuations for gas-liquid intermittent flow

Energy Technology Data Exchange (ETDEWEB)

Matsui, G.; Monji, H.; Takaguchi, M. [Univ. of Tsukuba (Japan)

1995-09-01

This study deals with theoretical analysis on the general behaviour of statistical parameters of gas-phase fluctuations and comparison of statistical parameter characteristics for the real void fraction fluctuations measured with those for the wave form modified the real fluctuations. In order to investigate the details of the relation between the behavior of the statistical parameters in real intermittent flow and analytical results obtained from information on the real flow, the distributions of statistical parameters for general fundamental wave form of gas-phase fluctuations are discussed in detail. By modifying the real gas-phase fluctuations to a trapezoidaly wave, the experimental results can be directly compared with the analytical results. The analytical results for intermittent flow show that the wave form parameter, and the total amplitude of void fraction fluctuations, affects strongly on the statistical parameter characteristics. The comparison with experiment using nitrogen gas-water intermittent flow suggests that the parameters of skewness and excess may be better as indicators of flow pattern. That is, the macroscopic nature of intermittent flow can be grasped by the skewness and the excess, and the detailed flow structure may be described by the mean and the standard deviation.

Statistical parameter characteristics of gas-phase fluctuations for gas-liquid intermittent flow

International Nuclear Information System (INIS)

Matsui, G.; Monji, H.; Takaguchi, M.

1995-01-01

This study deals with theoretical analysis on the general behaviour of statistical parameters of gas-phase fluctuations and comparison of statistical parameter characteristics for the real void fraction fluctuations measured with those for the wave form modified the real fluctuations. In order to investigate the details of the relation between the behavior of the statistical parameters in real intermittent flow and analytical results obtained from information on the real flow, the distributions of statistical parameters for general fundamental wave form of gas-phase fluctuations are discussed in detail. By modifying the real gas-phase fluctuations to a trapezoidaly wave, the experimental results can be directly compared with the analytical results. The analytical results for intermittent flow show that the wave form parameter, and the total amplitude of void fraction fluctuations, affects strongly on the statistical parameter characteristics. The comparison with experiment using nitrogen gas-water intermittent flow suggests that the parameters of skewness and excess may be better as indicators of flow pattern. That is, the macroscopic nature of intermittent flow can be grasped by the skewness and the excess, and the detailed flow structure may be described by the mean and the standard deviation

Parameter identifiability and redundancy: theoretical considerations.

Directory of Open Access Journals (Sweden)

Mark P Little

Full Text Available BACKGROUND: Models for complex biological systems may involve a large number of parameters. It may well be that some of these parameters cannot be derived from observed data via regression techniques. Such parameters are said to be unidentifiable, the remaining parameters being identifiable. Closely related to this idea is that of redundancy, that a set of parameters can be expressed in terms of some smaller set. Before data is analysed it is critical to determine which model parameters are identifiable or redundant to avoid ill-defined and poorly convergent regression. METHODOLOGY/PRINCIPAL FINDINGS: In this paper we outline general considerations on parameter identifiability, and introduce the notion of weak local identifiability and gradient weak local identifiability. These are based on local properties of the likelihood, in particular the rank of the Hessian matrix. We relate these to the notions of parameter identifiability and redundancy previously introduced by Rothenberg (Econometrica 39 (1971 577-591 and Catchpole and Morgan (Biometrika 84 (1997 187-196. Within the widely used exponential family, parameter irredundancy, local identifiability, gradient weak local identifiability and weak local identifiability are shown to be largely equivalent. We consider applications to a recently developed class of cancer models of Little and Wright (Math Biosciences 183 (2003 111-134 and Little et al. (J Theoret Biol 254 (2008 229-238 that generalize a large number of other recently used quasi-biological cancer models. CONCLUSIONS/SIGNIFICANCE: We have shown that the previously developed concepts of parameter local identifiability and redundancy are closely related to the apparently weaker properties of weak local identifiability and gradient weak local identifiability--within the widely used exponential family these concepts largely coincide.

Desert plains classification based on Geomorphometrical parameters (Case study: Aghda, Yazd)

Science.gov (United States)

Tazeh, mahdi; Kalantari, Saeideh

2013-04-01

This research focuses on plains. There are several tremendous methods and classification which presented for plain classification. One of The natural resource based classification which is mostly using in Iran, classified plains into three types, Erosional Pediment, Denudation Pediment Aggradational Piedmont. The qualitative and quantitative factors to differentiate them from each other are also used appropriately. In this study effective Geomorphometrical parameters in differentiate landforms were applied for plain. Geomorphometrical parameters are calculable and can be extracted using mathematical equations and the corresponding relations on digital elevation model. Geomorphometrical parameters used in this study included Percent of Slope, Plan Curvature, Profile Curvature, Minimum Curvature, the Maximum Curvature, Cross sectional Curvature, Longitudinal Curvature and Gaussian Curvature. The results indicated that the most important affecting Geomorphometrical parameters for plain and desert classifications includes: Percent of Slope, Minimum Curvature, Profile Curvature, and Longitudinal Curvature. Key Words: Plain, Geomorphometry, Classification, Biophysical, Yazd Khezarabad.

Study of inflationary generalized cosmic Chaplygin gas for standard and tachyon scalar fields

Energy Technology Data Exchange (ETDEWEB)

Sharif, M.; Saleem, Rabia [University of the Punjab, Department of Mathematics, Lahore (Pakistan)

2014-07-15

We consider an inflationary universe model in the context of the generalized cosmic Chaplygin gas by taking the matter field as standard and tachyon scalar fields. We evaluate the corresponding scalar fields and scalar potentials during the intermediate and logamediate inflationary regimes by modifying the first Friedmann equation. In each case, we evaluate the number of e-folds, scalar as well as tensor power spectra, scalar spectral index, and the important observational parameter, the tensor-scalar ratio in terms of inflation. The graphical behavior of this parameter shows that the model remains incompatible with WMAP7 and Planck observational data in each case. (orig.)

Study of inflationary generalized cosmic Chaplygin gas for standard and tachyon scalar fields

International Nuclear Information System (INIS)

Sharif, M.; Saleem, Rabia

2014-01-01

We consider an inflationary universe model in the context of the generalized cosmic Chaplygin gas by taking the matter field as standard and tachyon scalar fields. We evaluate the corresponding scalar fields and scalar potentials during the intermediate and logamediate inflationary regimes by modifying the first Friedmann equation. In each case, we evaluate the number of e-folds, scalar as well as tensor power spectra, scalar spectral index, and the important observational parameter, the tensor-scalar ratio in terms of inflation. The graphical behavior of this parameter shows that the model remains incompatible with WMAP7 and Planck observational data in each case. (orig.)

Incorporating Nuisance Parameters in Likelihoods for Multisource Spectra

CERN Document Server

Conway, J.S.

2011-01-01

We describe here the general mathematical approach to constructing likelihoods for fitting observed spectra in one or more dimensions with multiple sources, including the effects of systematic uncertainties represented as nuisance parameters, when the likelihood is to be maximized with respect to these parameters. We consider three types of nuisance parameters: simple multiplicative factors, source spectra "morphing" parameters, and parameters representing statistical uncertainties in the predicted source spectra.

Generalized Smooth Transition Map Between Tent and Logistic Maps

Science.gov (United States)

Sayed, Wafaa S.; Fahmy, Hossam A. H.; Rezk, Ahmed A.; Radwan, Ahmed G.

There is a continuous demand on novel chaotic generators to be employed in various modeling and pseudo-random number generation applications. This paper proposes a new chaotic map which is a general form for one-dimensional discrete-time maps employing the power function with the tent and logistic maps as special cases. The proposed map uses extra parameters to provide responses that fit multiple applications for which conventional maps were not enough. The proposed generalization covers also maps whose iterative relations are not based on polynomials, i.e. with fractional powers. We introduce a framework for analyzing the proposed map mathematically and predicting its behavior for various combinations of its parameters. In addition, we present and explain the transition map which results in intermediate responses as the parameters vary from their values corresponding to tent map to those corresponding to logistic map case. We study the properties of the proposed map including graph of the map equation, general bifurcation diagram and its key-points, output sequences, and maximum Lyapunov exponent. We present further explorations such as effects of scaling, system response with respect to the new parameters, and operating ranges other than transition region. Finally, a stream cipher system based on the generalized transition map validates its utility for image encryption applications. The system allows the construction of more efficient encryption keys which enhances its sensitivity and other cryptographic properties.

Nuclear Criticality Technology and Safety Project parameter study database

International Nuclear Information System (INIS)

Toffer, H.; Erickson, D.G.; Samuel, T.J.; Pearson, J.S.

1993-03-01

A computerized, knowledge-screened, comprehensive database of the nuclear criticality safety documentation has been assembled as part of the Nuclear Criticality Technology and Safety (NCTS) Project. The database is focused on nuclear criticality parameter studies. The database has been computerized using dBASE III Plus and can be used on a personal computer or a workstation. More than 1300 documents have been reviewed by nuclear criticality specialists over the last 5 years to produce over 800 database entries. Nuclear criticality specialists will be able to access the database and retrieve information about topical parameter studies, authors, and chronology. The database places the accumulated knowledge in the nuclear criticality area over the last 50 years at the fingertips of a criticality analyst

Assessment of input function distortions on kinetic model parameters in simulated dynamic 82Rb PET perfusion studies

International Nuclear Information System (INIS)

Meyer, Carsten; Peligrad, Dragos-Nicolae; Weibrecht, Martin

2007-01-01

Cardiac 82 rubidium dynamic PET studies allow quantifying absolute myocardial perfusion by using tracer kinetic modeling. Here, the accurate measurement of the input function, i.e. the tracer concentration in blood plasma, is a major challenge. This measurement is deteriorated by inappropriate temporal sampling, spillover, etc. Such effects may influence the measured input peak value and the measured blood pool clearance. The aim of our study is to evaluate the effect of input function distortions on the myocardial perfusion as estimated by the model. To this end, we simulate noise-free myocardium time activity curves (TACs) with a two-compartment kinetic model. The input function to the model is a generic analytical function. Distortions of this function have been introduced by varying its parameters. Using the distorted input function, the compartment model has been fitted to the simulated myocardium TAC. This analysis has been performed for various sets of model parameters covering a physiologically relevant range. The evaluation shows that ±10% error in the input peak value can easily lead to ±10-25% error in the model parameter K 1 , which relates to myocardial perfusion. Variations in the input function tail are generally less relevant. We conclude that an accurate estimation especially of the plasma input peak is crucial for a reliable kinetic analysis and blood flow estimation

STUDIES OF CHANGES OF SOME BLOOD PARAMETERS AMONG WORKERS OF CEMENT OF EL MA EL ABIOD TEBESSA ALGERIA

Directory of Open Access Journals (Sweden)

M. Aouimeur

2015-08-01

Full Text Available In Algeria, the industrial development engenders the appearance of the sanitary and environmental problems resulting from the pollution due to these certain industries such as the industry cimentière. With the aim of estimating the sanitary state of the workers of the cement works; a study was made for 30 workers of the cement works. This study is based on the determination of the values of 07 parameters hématologiques (red blood cells, haemoglobin, hématocrite, average spherical volume, The corpuscular concentration averages in haemoglobin, The corpuscular content averages in haemoglobin and the number of white blood cells and two parameters considered as markers premature of the inflammation (sedimentation speed and protein-C-reactive. These results are compared with two other populations, one of the inhabitants of the region and other one of the inhabitants far from the cement works avec 60 km. The statistical analyses are based on the comparison of the variances and the analysis in main constituent (ACP. The comparison of the variance of the various variable of the individuals show a resemblance between the workers and the inhabitants close to the cement works but significant differences appeared between both populations and those of the cement works for some parameters. The global analysis of these results with the ACP showed a general coherence. The observation of the groups allowed removing some peculiarities.This distribution shows the relation between the functional state and the variation of the parameters.

Effectiveness of random search in SVM hyper-parameter tuning

NARCIS (Netherlands)

Gomes Mantovani, R.; Rossi, A.L.D.; Vanschoren, J.; Bischl, B.; de Carvalho, A.C.P.L.F.

2015-01-01

Classification is one of the most common machine learning tasks. SVMs have been frequently applied to this task. In general, the values chosen for the hyper-parameters of SVMs affect the performance of their induced predictive models. Several studies use optimization techniques to find a set of

A population-based study of the associations of stroke occurrence with weather parameters in Siberia, Russia (1982-92).

Science.gov (United States)

Feigin, V L; Nikitin, Y P; Bots, M L; Vinogradova, T E; Grobbee, D E

2000-03-01

Previous studies have established a seasonal variation in stroke occurrence, but none have assessed the influence of inclement weather conditions on stroke incidence in a general population of Russia. We performed a stroke population-based study in the Oktiabrsky District of Novosibirsk, Siberia, Russia. Included in the analysis were 1929 patients with their first occurrence of ischemic stroke (IS), 215 patients with their first occurrence of intracerebral hemorrhage (ICH) and 64 patients with their first occurrence of subarachnoid hemorrhage (SAH): all patients were aged between 25 and 74 years. The cumulative daily occurrence of total strokes and stroke subtypes was evaluated in relation to aggregated daily mean values of ambient temperature, relative humidity and air pressure by means of Poisson regression analysis to estimate the rate ratio (RR) with corresponding confidence interval (CI) and to identify the weather parameters of most importance. In a multivariate analysis, with adjustment for the effects of season, solar and geomagnetic activity, and age of the patients, low ambient temperature (RR 1.32; 95% CI 1.05-1.66) and mean value of air pressure (RR 0.986; 95% CI 0.972-0.999) were important predictors of IS occurrence, while mild ambient temperature (RR 1.52; 95% CI 1. 04-2.22) was an important predictor of ICH occurrence. No relationship between SAH occurrence and any one of the weather parameters studied was revealed. There was no interaction between any meteorological variables that was statistically significant. Inclement weather conditions are associated with the occurrence of IS and ICH in Siberia, Russia. Among the meteorological parameters studied, low ambient temperature and mean air pressure are the most important predictors of IS occurrence, whereas the occurrence of ICH is associated with mild ambient temperature. There is no association between any one of the weather parameters studied and the occurrence of SAH.

The Study of Deposition Parameters, Properties for PVD TixN and CrxN Coatings Using a Closed Field Unbalanced Magnetron Sputter Ion Plating System

Institute of Scientific and Technical Information of China (English)

Hailin Sun; Susan Field; Jian Chen; Dennis. G. Teer

2004-01-01

Closed Field Unbalanced Magnetron Sputter Ion Plating (CFUBMSIP) systems have been used increasingly for PVD coating in recent years. TiN and CrN coatings, commonly used as the basic coating for a number of different hard coatings, have been chosen to study the coating process parameters for the CFUBMSIP system. In this paper, the process parameters, such as substrate temperature, substrate bias and OEM control, have been carefully examined to achieve hard and wear-resistance coatings with good adhesion. The coating structure and orientation were found to change according to the coating parameters. The Rockwell test and Scratch test were carried out to examine the coating adhesion; pin-on-disc testing was used to estimate the wear-resistant; micro-hardness was also used to determine coating hardness. HSS drill testing has been carried out to study the general properties of the coating for cutting tool application. A combination of process parameters can be selected to achieve good performance for the TiN and CrN coatings.

GUP parameter from quantum corrections to the Newtonian potential

Energy Technology Data Exchange (ETDEWEB)

Scardigli, Fabio, E-mail: fabio@phys.ntu.edu.tw [Dipartimento di Matematica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano (Italy); Department of Applied Mathematics, University of Waterloo, Ontario N2L 3G1 (Canada); Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Lambiase, Gaetano, E-mail: lambiase@sa.infn.it [Dipartimento di Fisica “E.R. Caianiello”, Universita' di Salerno, I-84084 Fisciano (Italy); INFN – Gruppo Collegato di Salerno (Italy); Vagenas, Elias C., E-mail: elias.vagenas@ku.edu.kw [Theoretical Physics Group, Department of Physics, Kuwait University, P.O. Box 5969, Safat 13060 (Kuwait)

2017-04-10

We propose a technique to compute the deformation parameter of the generalized uncertainty principle by using the leading quantum corrections to the Newtonian potential. We just assume General Relativity as theory of Gravitation, and the thermal nature of the GUP corrections to the Hawking spectrum. With these minimal assumptions our calculation gives, to first order, a specific numerical result. The physical meaning of this value is discussed, and compared with the previously obtained bounds on the generalized uncertainty principle deformation parameter.

Revisiting Boltzmann learning: parameter estimation in Markov random fields

DEFF Research Database (Denmark)

Hansen, Lars Kai; Andersen, Lars Nonboe; Kjems, Ulrik

1996-01-01

This article presents a generalization of the Boltzmann machine that allows us to use the learning rule for a much wider class of maximum likelihood and maximum a posteriori problems, including both supervised and unsupervised learning. Furthermore, the approach allows us to discuss regularization...... and generalization in the context of Boltzmann machines. We provide an illustrative example concerning parameter estimation in an inhomogeneous Markov field. The regularized adaptation produces a parameter set that closely resembles the “teacher” parameters, hence, will produce segmentations that closely reproduce...

The Power of Heterogeneity: Parameter Relationships from Distributions

Science.gov (United States)

Röding, Magnus; Bradley, Siobhan J.; Williamson, Nathan H.; Dewi, Melissa R.; Nann, Thomas; Nydén, Magnus

2016-01-01

Complex scientific data is becoming the norm, many disciplines are growing immensely data-rich, and higher-dimensional measurements are performed to resolve complex relationships between parameters. Inherently multi-dimensional measurements can directly provide information on both the distributions of individual parameters and the relationships between them, such as in nuclear magnetic resonance and optical spectroscopy. However, when data originates from different measurements and comes in different forms, resolving parameter relationships is a matter of data analysis rather than experiment. We present a method for resolving relationships between parameters that are distributed individually and also correlated. In two case studies, we model the relationships between diameter and luminescence properties of quantum dots and the relationship between molecular weight and diffusion coefficient for polymers. Although it is expected that resolving complicated correlated relationships require inherently multi-dimensional measurements, our method constitutes a useful contribution to the modelling of quantitative relationships between correlated parameters and measurements. We emphasise the general applicability of the method in fields where heterogeneity and complex distributions of parameters are obstacles to scientific insight. PMID:27182701

Uncertainties of the 50-year wind from short time series using generalized extreme value distribution and generalized Pareto distribution

DEFF Research Database (Denmark)

Larsén, Xiaoli Guo; Mann, Jakob; Rathmann, Ole

2015-01-01

This study examines the various sources to the uncertainties in the application of two widely used extreme value distribution functions, the generalized extreme value distribution (GEVD) and the generalized Pareto distribution (GPD). The study is done through the analysis of measurements from...... as a guideline for applying GEVD and GPD to wind time series of limited length. The data analysis shows that, with reasonable choice of relevant parameters, GEVD and GPD give consistent estimates of the return winds. For GEVD, the base period should be chosen in accordance with the occurrence of the extreme wind...

Modifying factors for metabolic parameters

International Nuclear Information System (INIS)

Inaba, Jiro

1990-01-01

Studies on factors which influence the metabolic parameter for calculation of radiation doses from intakes of radionuclides are very important for estimation of the doses for the general public, because the present procedures recommended by the International Commission on Radiological Protection is for occupationally exposed workers and the underlying metabolic and dosimetric models have been developed from studies on adult man and experiments on adult animals and from observations on radionuclides in physico-chemically simple form. Many factors have been reported to influence the metabolic parameters. Among them, the food-chain involvement of radionuclides and the age-dependence in humans and animals are most significant as environmental and physiological factor, respectively. In connection with the age-dependence of dose calculation, the ICRP started a new programme. They organized a Task Group on Age-Dependent Dose-Factors where relevant information on metabolic and biokinetic parameters are presently being reviewed for development of a set of dose factors for the following age-groups: infant, 1-year-old, 5-year-old, 10-year-old, 15-year-old, and ICRP Reference Man. The first stage of the work is for age-dependent integrated organ and effective dose factors for radioisotopes of the following elements: hydrogen, carbon, iodine, cesium, strontium, plutonium and americium. (author)

A System for Extracting Study Design Parameters from Nutritional Genomics Abstracts

Directory of Open Access Journals (Sweden)

Kelly Cassidy

2013-06-01

Full Text Available The extraction of study design parameters from biomedical journal articles is an important problem in natural language processing (NLP. Such parameters define the characteristics of a study, such as the duration, the number of subjects, and their profile. Here we present a system for extracting study design parameters from sentences in article abstracts. This system will be used as a component of a larger system for creating nutrigenomics networks from articles in the nutritional genomics domain. The algorithms presented consist of manually designed rules expressed either as regular expressions or in terms of sentence parse structure. A number of filters and NLP tools are also utilized within a pipelined algorithmic framework. Using this novel approach, our system performs extraction at a finer level of granularity than comparable systems, while generating results that surpass the current state of the art.

Multi-Objective Parameter Selection for Classifers

Directory of Open Access Journals (Sweden)

Christoph Mussel

2012-01-01

Full Text Available Setting the free parameters of classifiers to different values can have a profound impact on their performance. For some methods, specialized tuning algorithms have been developed. These approaches mostly tune parameters according to a single criterion, such as the cross-validation error. However, it is sometimes desirable to obtain parameter values that optimize several concurrent - often conflicting - criteria. The TunePareto package provides a general and highly customizable framework to select optimal parameters for classifiers according to multiple objectives. Several strategies for sampling andoptimizing parameters are supplied. The algorithm determines a set of Pareto-optimal parameter configuration and leaves the ultimate decision on the weighting of objectives to the researcher. Decision support is provided by novel visualization techniques.

Statistical distributions applications and parameter estimates

CERN Document Server

Thomopoulos, Nick T

2017-01-01

This book gives a description of the group of statistical distributions that have ample application to studies in statistics and probability.  Understanding statistical distributions is fundamental for researchers in almost all disciplines.  The informed researcher will select the statistical distribution that best fits the data in the study at hand.  Some of the distributions are well known to the general researcher and are in use in a wide variety of ways.  Other useful distributions are less understood and are not in common use.  The book describes when and how to apply each of the distributions in research studies, with a goal to identify the distribution that best applies to the study.  The distributions are for continuous, discrete, and bivariate random variables.  In most studies, the parameter values are not known a priori, and sample data is needed to estimate parameter values.  In other scenarios, no sample data is available, and the researcher seeks some insight that allows the estimate of ...

Correlated ab initio calculations of spectroscopic parameters of SnO within the framework of the higher-order generalized Douglas-Kroll transformation.

Science.gov (United States)

Wolf, Alexander; Reiher, Markus; Hess, Bernd Artur

2004-05-08

The first molecular calculations with the generalized Douglas-Kroll method up to fifth order in the external potential (DKH5) are presented. We study the spectroscopic parameters and electron affinity of the tin oxide molecule SnO and its anion SnO(-) applying nonrelativistic as well as relativistic calculations with higher orders of the DK approximation. In order to guarantee highly accurate results close to the basis set limit, an all-electron basis for Sn of at least quintuple-zeta quality has been constructed and optimized. All-electron CCSD(T) calculations of the potential energy curves of both SnO and SnO(-) reproduce the experimental values very well. Relative energies and valence properties are already well described with the established standard second-order approximation DKH2 and the higher-order corrections DKH3-DKH5 hardly affect these quantities. However, an accurate description of total energies and inner-shell properties requires superior relativistic schemes up to DKH5. (c) 2004 American Institute of Physics.

General optimization procedure towards the design of a new family of minimal parameter spin-component-scaled double-hybrid density functional theory.

Science.gov (United States)

Roch, Loïc M; Baldridge, Kim K

2017-10-04

A general optimization procedure towards the development and implementation of a new family of minimal parameter spin-component-scaled double-hybrid (mSD) density functional theory (DFT) is presented. The nature of the proposed exchange-correlation functional establishes a methodology with minimal empiricism. This new family of double-hybrid (DH) density functionals is demonstrated using the PBEPBE functional, illustrating the optimization procedure to the mSD-PBEPBE method, and the performance characteristics shown for a set of non-covalent complexes covering a broad regime of weak interactions. With only two parameters, mSD-PBEPBE and its cost-effective counterpart, RI-mSD-PBEPBE, show a mean absolute error of ca. 0.4 kcal mol -1 averaged over 66 weak interacting systems. Following a successive 2D-grid refinement for a CBS extrapolation of the coefficients, the optimization procedure can be recommended for the design and implementation of a variety of additional DH methods using any of the plethora of currently available functionals.

Parameter uncertainty and model predictions: a review of Monte Carlo results

International Nuclear Information System (INIS)

Gardner, R.H.; O'Neill, R.V.

1979-01-01

Studies of parameter variability by Monte Carlo analysis are reviewed using repeated simulations of the model with randomly selected parameter values. At the beginning of each simulation, parameter values are chosen from specific frequency distributions. This process is continued for a number of iterations sufficient to converge on an estimate of the frequency distribution of the output variables. The purpose was to explore the general properties of error propagaton in models. Testing the implicit assumptions of analytical methods and pointing out counter-intuitive results produced by the Monte Carlo approach are additional points covered

On the soft supersymmetry-breaking parameters in gauge-mediated models

International Nuclear Information System (INIS)

Wagner, C.E.M.

1998-01-01

Gauge mediation of supersymmetry breaking in the observable sector is an attractive idea, which naturally alleviates the flavor changing neutral current problem of supersymmetric theories. Quite generally, however, the number and quantum number of the messengers are not known; nor is their characteristic mass scale determined by the theory. Using the recently proposed method to extract supersymmetry-breaking parameters from wave-function renormalization, we derived general formulae for the soft supersymmetry-breaking parameters in the observable sector, valid in the small and moderate tan β regimes, for the case of split messengers. The full leading-order effects of top Yukawa and gauge couplings on the soft supersymmetry-breaking parameters are included. We give a simple interpretation of the general formulae in terms of the renormalization group evolution of the soft supersymmetry-breaking parameters. As a by-product of this analysis, the one-loop renormalization group evolution of the soft supersymmetry-breaking parameters is obtained for arbitrary boundary conditions of the scalar and gaugino mass parameters at high energies. (orig.)

GUP parameter from quantum corrections to the Newtonian potential

Directory of Open Access Journals (Sweden)

Fabio Scardigli

2017-04-01

Full Text Available We propose a technique to compute the deformation parameter of the generalized uncertainty principle by using the leading quantum corrections to the Newtonian potential. We just assume General Relativity as theory of Gravitation, and the thermal nature of the GUP corrections to the Hawking spectrum. With these minimal assumptions our calculation gives, to first order, a specific numerical result. The physical meaning of this value is discussed, and compared with the previously obtained bounds on the generalized uncertainty principle deformation parameter.

Maximum Likelihood Estimates of Parameters in Various Types of Distribution Fitted to Important Data Cases.

OpenAIRE

HIROSE,Hideo

1998-01-01

TYPES OF THE DISTRIBUTION:13;Normal distribution (2-parameter)13;Uniform distribution (2-parameter)13;Exponential distribution ( 2-parameter)13;Weibull distribution (2-parameter)13;Gumbel Distribution (2-parameter)13;Weibull/Frechet Distribution (3-parameter)13;Generalized extreme-value distribution (3-parameter)13;Gamma distribution (3-parameter)13;Extended Gamma distribution (3-parameter)13;Log-normal distribution (3-parameter)13;Extended Log-normal distribution (3-parameter)13;Generalized ...

Parameter identification of chaos system based on unknown parameter observer

International Nuclear Information System (INIS)

Wang Shaoming; Luo Haigeng; Yue Chaoyuan; Liao Xiaoxin

2008-01-01

Parameter identification of chaos system based on unknown parameter observer is discussed generally. Based on the work of Guan et al. [X.P. Guan, H.P. Peng, L.X. Li, et al., Acta Phys. Sinica 50 (2001) 26], the design of unknown parameter observer is improved. The application of the improved approach is extended greatly. The works in some literatures [X.P. Guan, H.P. Peng, L.X. Li, et al., Acta Phys. Sinica 50 (2001) 26; J.H. Lue, S.C. Zhang, Phys. Lett. A 286 (2001) 148; X.Q. Wu, J.A. Lu, Chaos Solitons Fractals 18 (2003) 721; J. Liu, S.H. Chen, J. Xie, Chaos Solitons Fractals 19 (2004) 533] are only the special cases of our Corollaries 1 and 2. Some observers for Lue system and a new chaos system are designed to test our improved method, and simulations results demonstrate the effectiveness and feasibility of the improved approach

Study of an advanced General Aviation Turbine Engine (GATE)

Science.gov (United States)

Gill, J. C.; Short, F. R.; Staton, D. V.; Zolezzi, B. A.; Curry, C. E.; Orelup, M. J.; Vaught, J. M.; Humphrey, J. M.

1979-01-01

The best technology program for a small, economically viable gas turbine engine applicable to the general aviation helicopter and aircraft market for 1985-1990 was studied. Turboshaft and turboprop engines in the 112 to 746 kW (150 to 1000 hp) range and turbofan engines up to 6672 N (1500 lbf) thrust were considered. A good market for new turbine engines was predicted for 1988 providing aircraft are designed to capitalize on the advantages of the turbine engine. Parametric engine families were defined in terms of design and off-design performance, mass, and cost. These were evaluated in aircraft design missions selected to represent important market segments for fixed and rotary-wing applications. Payoff parameters influenced by engine cycle and configuration changes were aircraft gross mass, acquisition cost, total cost of ownership, and cash flow. Significant advantage over a current technology, small gas turbine engines was found especially in cost of ownership and fuel economy for airframes incorporating an air-cooled high-pressure ratio engine. A power class of 373 kW (500 hp) was recommended as the next frontier for technology advance where large improvements in fuel economy and engine mass appear possible through component research and development.

Student performance of the general physical examination in internal medicine: an observational study

Science.gov (United States)

2014-01-01

Background Many practicing physicians lack skills in physical examination. It is not known whether physical examination skills already show deficiencies after an early phase of clinical training. At the end of the internal medicine clerkship students are expected to be able to perform a general physical examination in every new patient encounter. In a previous study, the basic physical examination items that should standardly be performed were set by consensus. The aim of the current observational study was to assess whether medical students were able to correctly perform a general physical examination regarding completeness as well as technique at the end of the clerkship internal medicine. Methods One hundred students who had just finished their clerkship internal medicine were asked to perform a general physical examination on a standardized patient as they had learned during the clerkship. They were recorded on camera. Frequency of performance of each component of the physical examination was counted. Adequacy of performance was determined as either correct or incorrect or not assessable using a checklist of short descriptions of each physical examination component. A reliability analysis was performed by calculation of the intra class correlation coefficient for total scores of five physical examinations rated by three trained physicians and for their agreement on performance of all items. Results Approximately 40% of the agreed standard physical examination items were not performed by the students. Students put the most emphasis on examination of general parameters, heart, lungs and abdomen. Many components of the physical examination were not performed as was taught during precourses. Intra-class correlation was high for total scores of the physical examinations 0.91 (p internal medicine clerkship. Possible causes and suggestions for improvement are discussed. PMID:24712683

Salivary caries parameters: Comparative study among Yemeni khat chewers and nonchewers

OpenAIRE

Khaled Rashad Al-Alimi; Abdul Aziz Abdul Razak; Roslan Saub

2014-01-01

Background/purpose: Millions of people in Yemen and East African countries chew khat for more than 5 hours daily for its amphetamine-like effects. Previous studies have associated khat chewing with salivary glands enlargement, inflammation, and xerostomia. However, no information is available on the possible effects of this habit on salivary parameters. This comparative study aims to evaluate salivary parameters, such as salivary flow rate, pH, and viscosity among Yemeni khat chewers and nonc...

Gauge-fixing parameter dependence of two-point gauge-variant correlation functions

International Nuclear Information System (INIS)

Zhai, C.

1996-01-01

The gauge-fixing parameter ξ dependence of two-point gauge-variant correlation functions is studied for QED and QCD. We show that, in three Euclidean dimensions, or for four-dimensional thermal gauge theories, the usual procedure of getting a general covariant gauge-fixing term by averaging over a class of covariant gauge-fixing conditions leads to a nontrivial gauge-fixing parameter dependence in gauge-variant two-point correlation functions (e.g., fermion propagators). This nontrivial gauge-fixing parameter dependence modifies the large-distance behavior of the two-point correlation functions by introducing additional exponentially decaying factors. These factors are the origin of the gauge dependence encountered in some perturbative evaluations of the damping rates and the static chromoelectric screening length in a general covariant gauge. To avoid this modification of the long-distance behavior introduced by performing the average over a class of covariant gauge-fixing conditions, one can either choose a vanishing gauge-fixing parameter or apply an unphysical infrared cutoff. copyright 1996 The American Physical Society

Higher education and general studies in Nigeria: A philosophical ...

African Journals Online (AJOL)

Higher education and general studies in Nigeria: A philosophical investigation. ... Mgbakoigba: Journal of African Studies ... national policy on education on tertiary or higher education reveals a startling chasm of gap between the goals of the policy through General Studies Programme and their expected actualizations.

[Study of the plantar arch: correlations between podometrical and radiological parameters. results of a prospective study of 79 cases].

Science.gov (United States)

Maes, R; Dojcinovic, S; Andrianne, Y; Burny, F

2006-01-01

The authors present a prospective study on the potential correlations between eight footprint parameters and three radiological parameters in the study of the plantar arch. Seventy nine patients were evaluated in 2001. The eight footprint parameters were as fellows : the arch angle, the Chippaux-Smirak's index, the Quamra's contact index 2,3 and 4, the Schwartz's footprint angle, the Staheli's arch index and the arch length index. The three radiological parameters were as fellows : the Djian-Annonier's angle, the Méary's angle and the calcaneal inclination. This prospective study confirms the best correlation, found in others studies, obtained between the Djian-Annonier's angle and the Chippaux-Smirak. The use of the Méary's angle and the calcaneal inclination is not justified because they have bad correlations with footprint parameters.

Random walks on generalized Koch networks

International Nuclear Information System (INIS)

Sun, Weigang

2013-01-01

For deterministically growing networks, it is a theoretical challenge to determine the topological properties and dynamical processes. In this paper, we study random walks on generalized Koch networks with features that include an initial state that is a globally connected network to r nodes. In each step, every existing node produces m complete graphs. We then obtain the analytical expressions for first passage time (FPT), average return time (ART), i.e. the average of FPTs for random walks from node i to return to the starting point i for the first time, and average sending time (AST), defined as the average of FPTs from a hub node to all other nodes, excluding the hub itself with regard to network parameters m and r. For this family of Koch networks, the ART of the new emerging nodes is identical and increases with the parameters m or r. In addition, the AST of our networks grows with network size N as N ln N and also increases with parameter m. The results obtained in this paper are the generalizations of random walks for the original Koch network. (paper)

Review of 241 Pu resonance parameters

International Nuclear Information System (INIS)

Derrien, H.

1981-10-01

The status of 241 Pu resonance parameters is reviewed. The most important recent results are compared in some energy ranges, both from single level and multilevel point of view. It appears that an accurate set of resonance parameters is not still obtained for a general description of the cross-sections in the resonance region. Some recommendations are given for further experiments or evaluations

Sex hormones and quantitative ultrasound parameters at the heel in men and women from the general population

Directory of Open Access Journals (Sweden)

Konrad Pätzug

2017-12-01

Conclusions: This cross-sectional population-based study revealed independent associations of DHEAS and FT with QUS parameters in men, suggesting a potential influence on male bone metabolism. The predictive role of DHEAS and FT as a marker for osteoporosis in men warrants further investigation in clinical trials and large-scale observational studies.

Sleep Parameters in Short Daily versus Conventional Dialysis: An Actigraphic Study

Directory of Open Access Journals (Sweden)

Ludimila D’Avila e Silva Allemand

2017-01-01

Full Text Available Previous studies have observed worse sleep quality in patients undergoing conventional dialysis as compared to daily dialysis. Our aim was to compare the sleep parameters of patients undergoing daily or conventional dialysis using an objective measure (actigraphy. This cross-sectional study was performed in three dialysis centers, including a convenience sample (nonprobability sampling of 73 patients (36 patients on daily hemodialysis and 37 patients on conventional hemodialysis. The following parameters were evaluated: nocturnal total sleep time (NTST, expressed in minutes; wake time after sleep onset (WASO, expressed in minutes; number of nighttime awakenings; daytime total sleep time (DTST, expressed in minutes; number of daytime naps; and nighttime percentage of sleep (% sleep. The Mini-Mental State Examination and the Beck Depression Inventory were also administered. The mean age was 53.4  ±  17.0 years. After adjustment of confounding factors using multiple linear regression analysis, no difference in actigraphy parameters was detected between the groups: NTST (p=0.468, WASO (p=0.88, % sleep (p=0.754, awakenings (p=0.648, naps (p=0.414, and DTST (p=0.805. Different from previous studies employing qualitative analysis, the present assessment did not observe an influence of hemodialysis modality on objective sleep parameters in chronic renal patients.

Parameters of importance to determine in geoscientific site studies

International Nuclear Information System (INIS)

Andersson, Johan; Almen, K.E.; Ericsson, L.O.; Karlsson, Fred; Stroem, A.; Fredriksson, Anders; Stanfors, R.

1996-12-01

This report identifies and describes parameters, that may be determined in a site characterization study, for performing functional and safety analyses of a deep rock repository for radioactive wastes. The report discusses data needs for rock engineering and for description of other environmental aspects. It is intended that the report be used as a basis for formulating the criteria of acceptance in evaluating a candidate site. The report describes how different parameters influence the safety function, and how they are evaluated in practice. The logical order of performing measurements, due to the need of in-data and influence on other measurements is also discussed. 65 refs

Simulation Study on the Controllable Dielectrophoresis Parameters of Graphene

Science.gov (United States)

Ji, Jian-Long; Liu, Ya-Li; Ge, Yang; Xie, Sheng-Dong; Zhang, Xi; Sang, Sheng-Bo; Jian, Ao-Qun; Duan, Qian-Qian; Zhang, Qiang; Zhang, Wen-Dong

2017-03-01

The method of using dielectrophoresis (DEP) to assemble graphene between micro-electrodes has been proven to be simple and efficient. We present an optimization method for the kinetic formula of graphene DEP, and discuss the simulation of the graphene assembly process based on the finite element method. The simulated results illustrate that the accelerated motion of graphene is in agreement with the distribution of the electric field squared gradient. We also conduct research on the controllable parameters of the DEP assembly such as the alternating current (AC) frequency, the shape of micro-electrodes, and the ratio of the gap between electrodes to the characteristic/geometric length of graphene (λ). The simulations based on the Clausius-Mossotti factor reveal that both graphene velocity and direction are influenced by the AC frequency. When graphene is close to the electrodes, the shape of micro-electrodes will exert great influence on the velocity of graphene. Also, λ has a great influence on the velocity of graphene. Generally, the velocity of graphene would be greater when λ is in the range of 0.4-0.6. The study is of a theoretical guiding significance in improving the precision and efficiency of the graphene DEP assembly. Supported by the Basic Research Project of Shanxi Province under Grant No 2015021092, the National Natural Science Foundation of China under Grant Nos 61471255, 61474079, 61501316, 51505324 and 51622507, and the National High-Technology Research and Development Program of China under Grant No 2015AA042601.

Experimental Study of Generalized Subspace Filters for the Cocktail Party Situation

DEFF Research Database (Denmark)

Christensen, Knud Bank; Christensen, Mads Græsbøll; Boldt, Jesper B.

2016-01-01

This paper investigates the potential performance of generalized subspace filters for speech enhancement in cocktail party situations with very poor signal/noise ratio, e.g. down to -15 dB. Performance metrics output signal/noise ratio, signal/ distortion ratio, speech quality rating and speech...... intelligibility rating are mapped as functions of two algorithm parameters, revealing clear trade-off options between noise, distortion and subjective performances and a recommended choice of trade-off. Given sufficiently good noise statistics, SNR improvements around 20 dB as well as PESQ quality and STOI...

General quantum variational calculus

Directory of Open Access Journals (Sweden)

Artur M. C. Brito da Cruz

2018-02-01

Full Text Available We develop a new variational calculus based in the general quantum difference operator recently introduced by Hamza et al. In particular, we obtain optimality conditions for generalized variational problems where the Lagrangian may depend on the endpoints conditions and a real parameter, for the basic and isoperimetric problems, with and without fixed boundary conditions. Our results provide a generalization to previous results obtained for the $q$- and Hahn-calculus.

Thermal Hydraulic design parameters study for severe accidents using neural networks

Energy Technology Data Exchange (ETDEWEB)

Roh, Chang Hyun; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Chang, Keun Sun [Sunmoon University, Asan (Korea, Republic of)

1998-12-31

To provide the information on severe accident progression is very important for advanced or new type of nuclear power plant (NPP) design. A parametric study, therefore, was performed to investigate the effect of thermal hydraulic design parameters on severe accident progression of pressurized water reactors (PWRs). Nine parameters, which are considered important in NPP design or severe accident progression, were selected among the various thermal hydraulic design parameters. The backpropagation neural network (BPN) was used to determine parameters, which might more strongly affect the severe accident progression, among nine parameters. For training, different input patterns were generated by the latin hypercube sampling (LHS) technique and then different target patterns that contain core uncovery time and vessel failure time were obtained for Young Gwang Nuclear (YGN) Units 3 and 4 using modular accident analysis program (MAAP) 3.0B code. Three different severe accident scenarios, such as two loss of coolant accidents (LOCAs) and station blackout (SBO), were considered in this analysis. Results indicated that design parameters related to refueling water storage tank (RWST), accumulator and steam generator (S/G) have more dominant effects on the progression of severe accidents investigated, compared to the other six parameters. 9 refs., 5 tabs. (Author)

Thermal Hydraulic design parameters study for severe accidents using neural networks

Energy Technology Data Exchange (ETDEWEB)

Roh, Chang Hyun; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Chang, Keun Sun [Sunmoon University, Asan (Korea, Republic of)

1997-12-31

To provide the information on severe accident progression is very important for advanced or new type of nuclear power plant (NPP) design. A parametric study, therefore, was performed to investigate the effect of thermal hydraulic design parameters on severe accident progression of pressurized water reactors (PWRs). Nine parameters, which are considered important in NPP design or severe accident progression, were selected among the various thermal hydraulic design parameters. The backpropagation neural network (BPN) was used to determine parameters, which might more strongly affect the severe accident progression, among nine parameters. For training, different input patterns were generated by the latin hypercube sampling (LHS) technique and then different target patterns that contain core uncovery time and vessel failure time were obtained for Young Gwang Nuclear (YGN) Units 3 and 4 using modular accident analysis program (MAAP) 3.0B code. Three different severe accident scenarios, such as two loss of coolant accidents (LOCAs) and station blackout (SBO), were considered in this analysis. Results indicated that design parameters related to refueling water storage tank (RWST), accumulator and steam generator (S/G) have more dominant effects on the progression of severe accidents investigated, compared to the other six parameters. 9 refs., 5 tabs. (Author)

Accelerated Brain DCE-MRI Using Iterative Reconstruction With Total Generalized Variation Penalty for Quantitative Pharmacokinetic Analysis: A Feasibility Study.

Science.gov (United States)

Wang, Chunhao; Yin, Fang-Fang; Kirkpatrick, John P; Chang, Zheng

2017-08-01

To investigate the feasibility of using undersampled k-space data and an iterative image reconstruction method with total generalized variation penalty in the quantitative pharmacokinetic analysis for clinical brain dynamic contrast-enhanced magnetic resonance imaging. Eight brain dynamic contrast-enhanced magnetic resonance imaging scans were retrospectively studied. Two k-space sparse sampling strategies were designed to achieve a simulated image acquisition acceleration factor of 4. They are (1) a golden ratio-optimized 32-ray radial sampling profile and (2) a Cartesian-based random sampling profile with spatiotemporal-regularized sampling density constraints. The undersampled data were reconstructed to yield images using the investigated reconstruction technique. In quantitative pharmacokinetic analysis on a voxel-by-voxel basis, the rate constant K trans in the extended Tofts model and blood flow F B and blood volume V B from the 2-compartment exchange model were analyzed. Finally, the quantitative pharmacokinetic parameters calculated from the undersampled data were compared with the corresponding calculated values from the fully sampled data. To quantify each parameter's accuracy calculated using the undersampled data, error in volume mean, total relative error, and cross-correlation were calculated. The pharmacokinetic parameter maps generated from the undersampled data appeared comparable to the ones generated from the original full sampling data. Within the region of interest, most derived error in volume mean values in the region of interest was about 5% or lower, and the average error in volume mean of all parameter maps generated through either sampling strategy was about 3.54%. The average total relative error value of all parameter maps in region of interest was about 0.115, and the average cross-correlation of all parameter maps in region of interest was about 0.962. All investigated pharmacokinetic parameters had no significant differences between

Stability margin of linear systems with parameters described by fuzzy numbers.

Science.gov (United States)

Husek, Petr

2011-10-01

This paper deals with the linear systems with uncertain parameters described by fuzzy numbers. The problem of determining the stability margin of those systems with linear affine dependence of the coefficients of a characteristic polynomial on system parameters is studied. Fuzzy numbers describing the system parameters are allowed to be characterized by arbitrary nonsymmetric membership functions. An elegant solution, graphical in nature, based on generalization of the Tsypkin-Polyak plot is presented. The advantage of the presented approach over the classical robust concept is demonstrated on a control of the Fiat Dedra engine model and a control of the quarter car suspension model.

On the Soft Supersymmetry Breaking Parameters in Gauge-Mediated Models

CERN Document Server

Wagner, C E M

1998-01-01

Gauge mediation of supersymmetry breaking in the observable sector is an attractive idea, which naturally alleviates the flavour changing neutral current problem of supersymmetric theories. Quite generally, however, the number and quantum number of the messengers are not known; nor is their characteristic mass scale determined by the theory. Using the recently proposed method to extract supersymmetry-breaking parameters from wave-function renormalization, we derived general formulae for the soft supersymmetry-breaking parameters in the observable sector, valid in the small and moderate $\\tan\\beta$ regimes, for the case of split messengers. The full leading-order effects of top Yukawa and gauge couplings on the soft supersymmetry-breaking parameters are included. We give a simple interpretation of the general formulae in terms of the renormalization group evolution of the soft supersymmetry-breaking parameters. As a by-product of this analysis, the one-loop renormalization group evolution of the soft supersymm...

Generalized Bekenstein-Hawking system: logarithmic correction

International Nuclear Information System (INIS)

Chakraborty, Subenoy

2014-01-01

The present work is a generalization of the recent work [arXiv.1206.1420] on the modified Hawking temperature on the event horizon. Here the Hawking temperature is generalized by multiplying the modified Hawking temperature by a variable parameter α representing the ratio of the growth rate of the apparent horizon to that of event horizon. It is found that both the first and the generalized second law of thermodynamics are valid on the event horizon for any fluid distribution. Subsequently, the Bekenstein entropy is modified on the event horizon and the thermodynamical laws are examined. Finally, an interpretation of the parameters involved is presented. (orig.)

Study of photodissociation parameters of carboxyhemoglobin

International Nuclear Information System (INIS)

Kuz'min, V V; Salmin, V V; Provorov, A S; Salmina, A B

2008-01-01

The general properties of photodissociation of carboxyhemoglobin (HbCO) in buffer solutions of whole human blood are studied by the flash photolysis method on a setup with intersecting beams. It is shown that the efficiency of photoinduced dissociation of the HbCO complex virtually linearly depends on the photolytic irradiation intensity for the average power density not exceeding 45 mW cm -2 . The general dissociation of the HbCO complex in native conditions occurs in a narrower range of values of the saturation degree than in model experiments with the hemoglobin solution. The dependence of the pulse photolysis efficiency of HbCO on the photolytic radiation wavelength in the range from 550 to 585 nm has a broad bell shape. The efficiency maximum corresponds to the electronic Q transition (porphyrin π-π* absorption) in HbCO at a wavelength of 570 nm. No dissociation of the complex was observed under given experimental conditions upon irradiation of solutions by photolytic radiation at wavelengths above 585 nm. (laser applications and other topics in quantum electronics)

Impact of relativistic effects on cosmological parameter estimation

Science.gov (United States)

Lorenz, Christiane S.; Alonso, David; Ferreira, Pedro G.

2018-01-01

Future surveys will access large volumes of space and hence very long wavelength fluctuations of the matter density and gravitational field. It has been argued that the set of secondary effects that affect the galaxy distribution, relativistic in nature, will bring new, complementary cosmological constraints. We study this claim in detail by focusing on a subset of wide-area future surveys: Stage-4 cosmic microwave background experiments and photometric redshift surveys. In particular, we look at the magnification lensing contribution to galaxy clustering and general-relativistic corrections to all observables. We quantify the amount of information encoded in these effects in terms of the tightening of the final cosmological constraints as well as the potential bias in inferred parameters associated with neglecting them. We do so for a wide range of cosmological parameters, covering neutrino masses, standard dark-energy parametrizations and scalar-tensor gravity theories. Our results show that, while the effect of lensing magnification to number counts does not contain a significant amount of information when galaxy clustering is combined with cosmic shear measurements, this contribution does play a significant role in biasing estimates on a host of parameter families if unaccounted for. Since the amplitude of the magnification term is controlled by the slope of the source number counts with apparent magnitude, s (z ), we also estimate the accuracy to which this quantity must be known to avoid systematic parameter biases, finding that future surveys will need to determine s (z ) to the ˜5 %- 10 % level. On the contrary, large-scale general-relativistic corrections are irrelevant both in terms of information content and parameter bias for most cosmological parameters but significant for the level of primordial non-Gaussianity.

Indecomposability parameters in chiral logarithmic conformal field theory

International Nuclear Information System (INIS)

Vasseur, Romain; Jacobsen, Jesper Lykke; Saleur, Hubert

2011-01-01

Work of the last few years has shown that the key algebraic features of Logarithmic Conformal Field Theories (LCFTs) are already present in some finite lattice systems (such as the XXZ spin-1/2 chain) before the continuum limit is taken. This has provided a very convenient way to analyze the structure of indecomposable Virasoro modules and to obtain fusion rules for a variety of models such as (boundary) percolation etc. LCFTs allow for additional quantum numbers describing the fine structure of the indecomposable modules, and generalizing the 'b-number' introduced initially by Gurarie for the c=0 case. The determination of these indecomposability parameters (or logarithmic couplings) has given rise to a lot of algebraic work, but their physical meaning has remained somewhat elusive. In a recent paper, a way to measure b for boundary percolation and polymers was proposed. We generalize this work here by devising a general strategy to compute matrix elements of Virasoro generators from the numerical analysis of lattice models and their continuum limit. The method is applied to XXZ spin-1/2 and spin-1 chains with open (free) boundary conditions. They are related to gl(n+m|m) and osp(n+2m|2m)-invariant superspin chains and to non-linear sigma models with supercoset target spaces. These models can also be formulated in terms of dense and dilute loop gas. We check the method in many cases where the results were already known analytically. Furthermore, we also confront our findings with a construction generalizing Gurarie's, where logarithms emerge naturally in operator product expansions to compensate for apparently divergent terms. This argument actually allows us to compute indecomposability parameters in any logarithmic theory. A central result of our study is the construction of a Kac table for the indecomposability parameters of the logarithmic minimal models LM(1,p) and LM(p,p+1).

The Generalized Higher Criticism for Testing SNP-Set Effects in Genetic Association Studies

Science.gov (United States)

Barnett, Ian; Mukherjee, Rajarshi; Lin, Xihong

2017-01-01

It is of substantial interest to study the effects of genes, genetic pathways, and networks on the risk of complex diseases. These genetic constructs each contain multiple SNPs, which are often correlated and function jointly, and might be large in number. However, only a sparse subset of SNPs in a genetic construct is generally associated with the disease of interest. In this article, we propose the generalized higher criticism (GHC) to test for the association between an SNP set and a disease outcome. The higher criticism is a test traditionally used in high-dimensional signal detection settings when marginal test statistics are independent and the number of parameters is very large. However, these assumptions do not always hold in genetic association studies, due to linkage disequilibrium among SNPs and the finite number of SNPs in an SNP set in each genetic construct. The proposed GHC overcomes the limitations of the higher criticism by allowing for arbitrary correlation structures among the SNPs in an SNP-set, while performing accurate analytic p-value calculations for any finite number of SNPs in the SNP-set. We obtain the detection boundary of the GHC test. We compared empirically using simulations the power of the GHC method with existing SNP-set tests over a range of genetic regions with varied correlation structures and signal sparsity. We apply the proposed methods to analyze the CGEM breast cancer genome-wide association study. Supplementary materials for this article are available online. PMID:28736464

Determination of resist parameters using the extended Nijboer-Zernike theory

NARCIS (Netherlands)

Dirksen, P.; Braat, J.; Janssen, A.J.E.M.; Leeuwestein, A.; Kwinten, H.; Van Steenwinckel, D.

2004-01-01

This study presents an experimental method to determine the resist parameters that are at the origin of a general blurring of the projected aerial image. The resist model includes the effects of diffusion in the horizontal plane and a second cause for image blur that originates from a stochastic

The reliable solution and computation time of variable parameters Logistic model

OpenAIRE

Pengfei, Wang; Xinnong, Pan

2016-01-01

The reliable computation time (RCT, marked as Tc) when applying a double precision computation of a variable parameters logistic map (VPLM) is studied. First, using the method proposed, the reliable solutions for the logistic map are obtained. Second, for a time-dependent non-stationary parameters VPLM, 10000 samples of reliable experiments are constructed, and the mean Tc is then computed. The results indicate that for each different initial value, the Tcs of the VPLM are generally different...

Bayesian `hyper-parameters' approach to joint estimation: the Hubble constant from CMB measurements

Science.gov (United States)

Lahav, O.; Bridle, S. L.; Hobson, M. P.; Lasenby, A. N.; Sodré, L.

2000-07-01

Recently several studies have jointly analysed data from different cosmological probes with the motivation of estimating cosmological parameters. Here we generalize this procedure to allow freedom in the relative weights of various probes. This is done by including in the joint χ2 function a set of `hyper-parameters', which are dealt with using Bayesian considerations. The resulting algorithm, which assumes uniform priors on the log of the hyper-parameters, is very simple: instead of minimizing \\sum \\chi_j2 (where \\chi_j2 is per data set j) we propose to minimize \\sum Nj (\\chi_j2) (where Nj is the number of data points per data set j). We illustrate the method by estimating the Hubble constant H0 from different sets of recent cosmic microwave background (CMB) experiments (including Saskatoon, Python V, MSAM1, TOCO and Boomerang). The approach can be generalized for combinations of cosmic probes, and for other priors on the hyper-parameters.

Study on the Energetic Parameters in a Photothermic Sensor with ...

African Journals Online (AJOL)

Study on the Energetic Parameters in a Photothermic Sensor with Black Polymeric Film. ... The evolution of incidental solar illumination on the horizontal plan of sensor and the temperature distribution are studied. Results showed that the ... Keywords: film, solar energy, greenhouse effect, design, radiation, illumination.

The normative study of acoustic parameters in normal Egyptian ...

African Journals Online (AJOL)

Yehia A. Abo-Ras

2013-03-21

Mar 21, 2013 ... all children were subjected to computerized acoustic analysis using Multidimensional voice program ... cal quality is important for social relations to happen effectively. ... lish comparative parameters with the normal values of the acoustic ... from lower age ranges in the normative studies since the child's.

Psychoacoustic parameters and its measuring system; Onshitsu hyoka wo hyokasuru tame no parameter to keisoku system

Energy Technology Data Exchange (ETDEWEB)

Ohashi, M.; Imaizumi, H.; Ono, T. [Ono Sokki Co. Ltd., Tokyo (Japan)

1998-05-01

Human auditory sensation has both extremely excellent performance and general versatility as sound analyzer. At present, it is impossible to make equipment with the same functions as human being, and describe an auditory sensation function as acoustic sensor even by any physical analysis techniques. However, extraction of auditory sensation parameters is becoming possible by using psychoacoustics and binaural signal processing. This paper mainly explains the calculation method of sound quality evaluation parameters derived from psychoacoustic results based on a sound quality evaluation system under development by the authors. This system is based on binaural measurement by dummy head, and calculates psychoacoustic parameters such as loudness, sharpness, roughness, fluctuation strength and tonality through frequency analysis of the measured stereo signals. The system also calculates 2-D parameters such as sensory pleasantness and unbiased annoyance based on the above parameters. 12 refs., 4 figs.

A prospective randomized study comparing percutaneous nephrolithotomy under combined spinal-epidural anesthesia with percutaneous nephrolithotomy under general anesthesia.

Science.gov (United States)

Singh, Vishwajeet; Sinha, Rahul Janak; Sankhwar, S N; Malik, Anita

2011-01-01

A prospective randomized study was executed to compare the surgical parameters and stone clearance in patients who underwent percutaneous nephrolithotomy (PNL) under combined spinal-epidural anesthesia (CSEA) versus those who underwent PNL under general anesthesia (GA). Between January 2008 to December 2009, 64 patients with renal calculi were randomized into 2 groups and evaluated for the purpose of this study. Group 1 consisted of patients who underwent PNL under CSEA and Group 2 consisted of patients who underwent PNL under GA. The operative time, stone clearance rate, visual pain analog score, mean analgesic dose and mean hospital stay were compared amongst other parameters. The difference between visual pain analog score after the operation and the dose of analgesic requirement was significant on statistical analysis between both groups. PNL under CSEA is as effective and safe as PNL under GA. Patients who undergo PNL under CESA require lesser analgesic dose and have a shorter hospital stay. Copyright © 2011 S. Karger AG, Basel.

Gravitational wave tests of general relativity with the parameterized post-Einsteinian framework

International Nuclear Information System (INIS)

Cornish, Neil; Sampson, Laura; Yunes, Nicolas; Pretorius, Frans

2011-01-01

Gravitational wave astronomy has tremendous potential for studying extreme astrophysical phenomena and exploring fundamental physics. The waves produced by binary black hole mergers will provide a pristine environment in which to study strong-field dynamical gravity. Extracting detailed information about these systems requires accurate theoretical models of the gravitational wave signals. If gravity is not described by general relativity, analyses that are based on waveforms derived from Einstein's field equations could result in parameter biases and a loss of detection efficiency. A new class of ''parameterized post-Einsteinian'' waveforms has been proposed to cover this eventuality. Here, we apply the parameterized post-Einsteinian approach to simulated data from a network of advanced ground-based interferometers and from a future space-based interferometer. Bayesian inference and model selection are used to investigate parameter biases, and to determine the level at which departures from general relativity can be detected. We find that in some cases the parameter biases from assuming the wrong theory can be severe. We also find that gravitational wave observations will beat the existing bounds on deviations from general relativity derived from the orbital decay of binary pulsars by a large margin across a wide swath of parameter space.

Second harmonic generation in generalized Thue-Morse ferroelectric superlattices

International Nuclear Information System (INIS)

Wang Longxiang; Yang Xiangbo; Chen Tongsheng

2009-01-01

In this paper the second harmonic generation (SHG) in generalized Thue-Morse (GTM(m, n)) ferroelectric superlattices is studied. Under the small-signal approximation, the SHG spectra in both real and reciprocal spaces are investigated. It is found that: (1) only when the structure parameters l, l A , and l B are all chosen to be proper, can SHG in GTM(m, n) ferroelectric superlattices be generated; (2) for Family A of generalized Thue-Morse, GTM(m, 1) ferroelectric systems, with the increase of parameter m, the intense peaks of SHG concentrate on the long wavelength 1.4-1.5μm (the fundamental beam (FB) wavelength is within 0.8-1.5μm), but for Family B of generalized Thue-Morse, GTM(1, n) ferroelectric superlattices, with the increase of parameter n, the intense peaks of SHG concentrate on the middle wavelength 1.1-1.2μm; and (3) for GTM(m, 1) ferroelectric superlattices, the bigger the m, the stronger the relative integral intensity (RII) of SHG would be, but for GTM(1, n) ferroelectric systems, the bigger the n, the weaker the RII of SHG would be.

Effect of Epidural Block under General Anesthesia on Pulse Transit Time

International Nuclear Information System (INIS)

Choi, Byeong Cheol; Kim, Seong Min; Jung, Dong Keun; Kim, Gi Ryon; Lee, He Jeong; Jeon, Gye Rock

2005-01-01

Epidural block under general anesthesia has been widely used to control postoperative pain. In this anesthetic state many hemodynamic parameters are changed. Moreover pulse transit time is influenced by this memodynamic change. PPT change in the finger and the toe due to relaxation of arterial wall muscle after general anesthesia and epidural block under general anesthesia. This study, in the both general anesthesia and epidural block under general anesthesia, ΔPTT of the toe and of the finger are measured. In addition, ΔPTT(toe-finger) of the epidural block under general anesthesia and of the general anesthesia were compared

Developing the Parameters of Scholarship in Postgraduate Coursework Studies

Science.gov (United States)

McLay, Allan F.

2013-01-01

Scholarship parameters, in relation to postgraduate coursework studies, are developed against the expectations of the Boyer classifications of scholarship (Boyer, 1990) with particular emphasis on the role of minor thesis development. An example is presented in which postgraduate coursework students are required to undertake a three semester minor…

Peristaltic propulsion of generalized Burgers' fluids through a non-uniform porous medium: a study of chyme dynamics through the diseased intestine.

Science.gov (United States)

Tripathi, D; Anwar Bég, O

2014-02-01

A mathematical study of the peristaltic flow of complex rheological viscoelastic fluids using the generalized fractional Burgers' model through a non-uniform channel is presented. This model is designed to study the movement of chyme and undigested chyme (biophysical waste materials) through the small intestine to the large intestine. To simulate blockages and impedance of debris generated by cell shedding, infections, adhesions on the wall and undigested material, a drag force porous media model is utilized. This effectively mimicks resistance to chyme percolation generated by solid matrix particles in the regime. The conduit geometry is mathematically simulated as a sinusoidal propagation with linear increment in shape of the bolus along the length of channel. A modified Darcy-Brinkman model is employed to simulate the generalized flows through isotropic, homogenous porous media, a simplified but physically robust approximation to actual clinical situations. To model the rheological properties of chyme, a viscoelastic Burgers' fluid formulation is adopted. The governing equations are simplified by assuming long wavelength and low Reynolds number approximations. Numerical and approximate analytical solutions are obtained with two semi-numerical techniques, namely the homotopy perturbation method and the variational iteration method. Visualization of the results is achieved with Mathematica software. The influence of the dominant hydromechanical and geometric parameters such as fractional viscoelastic parameters, wave number, non-uniformity constant, permeability parameter, and material constants on the peristaltic flow characteristics are depicted graphically. Copyright © 2013 Elsevier Inc. All rights reserved.

Modeling the X-ray Process, and X-ray Flaw Size Parameter for POD Studies

Science.gov (United States)

Koshti, Ajay M.

2014-01-01

Nondestructive evaluation (NDE) method reliability can be determined by a statistical flaw detection study called probability of detection (POD) study. In many instances, the NDE flaw detectability is given as a flaw size such as crack length. The flaw is either a crack or behaving like a crack in terms of affecting the structural integrity of the material. An alternate approach is to use a more complex flaw size parameter. The X-ray flaw size parameter, given here, takes into account many setup and geometric factors. The flaw size parameter relates to X-ray image contrast and is intended to have a monotonic correlation with the POD. Some factors such as set-up parameters, including X-ray energy, exposure, detector sensitivity, and material type that are not accounted for in the flaw size parameter may be accounted for in the technique calibration and controlled to meet certain quality requirements. The proposed flaw size parameter and the computer application described here give an alternate approach to conduct the POD studies. Results of the POD study can be applied to reliably detect small flaws through better assessment of effect of interaction between various geometric parameters on the flaw detectability. Moreover, a contrast simulation algorithm for a simple part-source-detector geometry using calibration data is also provided for the POD estimation.

Micro Data and General Equilibrium Models

DEFF Research Database (Denmark)

Browning, Martin; Hansen, Lars Peter; Heckman, James J.

1999-01-01

Dynamic general equilibrium models are required to evaluate policies applied at the national level. To use these models to make quantitative forecasts requires knowledge of an extensive array of parameter values for the economy at large. This essay describes the parameters required for different...... economic models, assesses the discordance between the macromodels used in policy evaluation and the microeconomic models used to generate the empirical evidence. For concreteness, we focus on two general equilibrium models: the stochastic growth model extended to include some forms of heterogeneity...

Evidence for a General ADHD Factor from a Longitudinal General School Population Study

Science.gov (United States)

Normand, Sebastien; Flora, David B.; Toplak, Maggie E.; Tannock, Rosemary

2012-01-01

Recent factor analytic studies in Attention-Deficit/Hyperactivity Disorder (ADHD) have shown that hierarchical models provide a better fit of ADHD symptoms than correlated models. A hierarchical model includes a general ADHD factor and specific factors for inattention, and hyperactivity/impulsivity. The aim of this 12-month longitudinal study was…

Current definition and a generalized federbush model

International Nuclear Information System (INIS)

Singh, L.P.S.; Hagen, C.R.

1978-01-01

The Federbush model is studied, with particular attention being given to the definition of currents. Inasmuch as there is no a priori restriction of local gauge invariance, the currents in the interacting case can be defined more generally than in Q.E.D. It is found that two arbitrary parameters are thereby introduced into the theory. Lowest order perturbation calculations for the current correlation functions and the Fermion propagators indicate that the theory admits a whole class of solutions dependent upon these parameters with the closed solution of Federbush emerging as a special case. The theory is shown to be locally covariant, and a conserved energy--momentum tensor is displayed. One finds in addition that the generators of gauge transformations for the fields are conserved. Finally it is shown that the general theory yields the Federbush solution if suitable Thirring model type counterterms are added

General analytical procedure for determination of acidity parameters of weak acids and bases.

Science.gov (United States)

Pilarski, Bogusław; Kaliszan, Roman; Wyrzykowski, Dariusz; Młodzianowski, Janusz; Balińska, Agata

2015-01-01

The paper presents a new convenient, inexpensive, and reagent-saving general methodology for the determination of pK a values for components of the mixture of diverse chemical classes weak organic acids and bases in water solution, without the need to separate individual analytes. The data obtained from simple pH-metric microtitrations are numerically processed into reliable pK a values for each component of the mixture. Excellent agreement has been obtained between the determined pK a values and the reference literature data for compounds studied.

General Methods for Evolutionary Quantitative Genetic Inference from Generalized Mixed Models.

Science.gov (United States)

de Villemereuil, Pierre; Schielzeth, Holger; Nakagawa, Shinichi; Morrissey, Michael

2016-11-01

Methods for inference and interpretation of evolutionary quantitative genetic parameters, and for prediction of the response to selection, are best developed for traits with normal distributions. Many traits of evolutionary interest, including many life history and behavioral traits, have inherently nonnormal distributions. The generalized linear mixed model (GLMM) framework has become a widely used tool for estimating quantitative genetic parameters for nonnormal traits. However, whereas GLMMs provide inference on a statistically convenient latent scale, it is often desirable to express quantitative genetic parameters on the scale upon which traits are measured. The parameters of fitted GLMMs, despite being on a latent scale, fully determine all quantities of potential interest on the scale on which traits are expressed. We provide expressions for deriving each of such quantities, including population means, phenotypic (co)variances, variance components including additive genetic (co)variances, and parameters such as heritability. We demonstrate that fixed effects have a strong impact on those parameters and show how to deal with this by averaging or integrating over fixed effects. The expressions require integration of quantities determined by the link function, over distributions of latent values. In general cases, the required integrals must be solved numerically, but efficient methods are available and we provide an implementation in an R package, QGglmm. We show that known formulas for quantities such as heritability of traits with binomial and Poisson distributions are special cases of our expressions. Additionally, we show how fitted GLMM can be incorporated into existing methods for predicting evolutionary trajectories. We demonstrate the accuracy of the resulting method for evolutionary prediction by simulation and apply our approach to data from a wild pedigreed vertebrate population. Copyright © 2016 de Villemereuil et al.

Adaptive Parameter Estimation of Person Recognition Model in a Stochastic Human Tracking Process

Science.gov (United States)

Nakanishi, W.; Fuse, T.; Ishikawa, T.

2015-05-01

This paper aims at an estimation of parameters of person recognition models using a sequential Bayesian filtering method. In many human tracking method, any parameters of models used for recognize the same person in successive frames are usually set in advance of human tracking process. In real situation these parameters may change according to situation of observation and difficulty level of human position prediction. Thus in this paper we formulate an adaptive parameter estimation using general state space model. Firstly we explain the way to formulate human tracking in general state space model with their components. Then referring to previous researches, we use Bhattacharyya coefficient to formulate observation model of general state space model, which is corresponding to person recognition model. The observation model in this paper is a function of Bhattacharyya coefficient with one unknown parameter. At last we sequentially estimate this parameter in real dataset with some settings. Results showed that sequential parameter estimation was succeeded and were consistent with observation situations such as occlusions.

[Dementia friendly care services in general hospitals : Representative results of the general hospital study (GHoSt)].

Science.gov (United States)

Hendlmeier, Ingrid; Bickel, Horst; Hessler, Johannes Baltasar; Weber, Joshua; Junge, Magdalena Nora; Leonhardt, Sarah; Schäufele, Martina

2017-11-06

Mostly model projects report on special care services and procedures for general hospital patients with cognitive impairment. The objective of this study was to determine the frequency of special care services and procedures in general hospitals on the basis of a representative cross-sectional study. From a list of all general hospitals in southern Germany we randomly selected a specified number of hospitals und somatic wards. The hospitals were visited and all older patients on the selected wards on that day were included in the study. Information about care services and their utilization was collected with standardized instruments. A total of 33 general hospitals and 172 wards participated in the study. The patient sample included 1469 persons over 65 (mean age 78.6 years) and 40% of the patients showed cognitive impairments. The staff reported that the most frequent measures for patients with cognitive impairments concerned patients with wandering behavior (63.1%), efforts to involve the patients' relatives to help with their daily care (60.1%), conducting nonintrusive interviews to identify cognitive impairments (59.9%), allocation to other rooms (58%) and visual aids for place orientation of patients (50.6%). In accordance with earlier studies our results show that other dementia friendly services implemented in pilot projects were rare. The existing special services for patients with cognitive impairment were rarely used by the patients or their relatives. The results demonstrate the urgent need to improve special care services and routines for identification of elderly patients with cognitive impairment and risk of delirium in general hospitals.

The exponentiated generalized Pareto distribution | Adeyemi | Ife ...

African Journals Online (AJOL)

Recently Gupta et al. (1998) introduced the exponentiated exponential distribution as a generalization of the standard exponential distribution. In this paper, we introduce a three-parameter generalized Pareto distribution, the exponentiated generalized Pareto distribution (EGP). We present a comprehensive treatment of the ...

Experimental studies of generalized parton distributions

International Nuclear Information System (INIS)

Kabuss, E.M.

2014-01-01

Generalized parton distributions (GPD) provide a new way to study the nucleon structure. Experimentally they can be accessed using hard exclusive processes such as deeply virtual Compton scattering and meson production. First insights to GPDs were already obtained from measurements at DESY, JLAB and CERN, while new ambitious studies are planned at the upgraded JLAB at 12 GeV and at CERN. Here, some emphasis will be put onto the planned COMPASS II programme. (author)

Role of the parameters involved in the plan optimization based on the generalized equivalent uniform dose and radiobiological implications

International Nuclear Information System (INIS)

Widesott, L; Strigari, L; Pressello, M C; Landoni, V; Benassi, M

2008-01-01

We investigated the role and the weight of the parameters involved in the intensity modulated radiation therapy (IMRT) optimization based on the generalized equivalent uniform dose (gEUD) method, for prostate and head-and-neck plans. We systematically varied the parameters (gEUD max and weight) involved in the gEUD-based optimization of rectal wall and parotid glands. We found that the proper value of weight factor, still guaranteeing planning treatment volumes coverage, produced similar organs at risks dose-volume (DV) histograms for different gEUD max with fixed a = 1. Most of all, we formulated a simple relation that links the reference gEUD max and the associated weight factor. As secondary objective, we evaluated plans obtained with the gEUD-based optimization and ones based on DV criteria, using the normal tissue complication probability (NTCP) models. gEUD criteria seemed to improve sparing of rectum and parotid glands with respect to DV-based optimization: the mean dose, the V 40 and V 50 values to the rectal wall were decreased of about 10%, the mean dose to parotids decreased of about 20-30%. But more than the OARs sparing, we underlined the halving of the OARs optimization time with the implementation of the gEUD-based cost function. Using NTCP models we enhanced differences between the two optimization criteria for parotid glands, but no for rectum wall

RATIONAL APPROXIMATIONS TO GENERALIZED HYPERGEOMETRIC FUNCTIONS.

Science.gov (United States)

Under weak restrictions on the various free parameters, general theorems for rational representations of the generalized hypergeometric functions...and certain Meijer G-functions are developed. Upon specialization, these theorems yield a sequency of rational approximations which converge to the

A general form of the cross energy parameter of equations of state

DEFF Research Database (Denmark)

Coutinho, Joao A. P.; Panayiotis, Vlamos; Kontogeorgis, Georgios

2000-01-01

. The proposed rule is derived from molecular considerations, namely, the London−Mie theory. The typically used geometric mean (GM) and other combining rules can be deducted from this expression from different values of the parameter n, which is the attractive tail of the Mie potential. We show that using this n...

Sebaran Generalized Extreme Value (GEV dan Generalized Pareto (GP untuk Pendugaan Curah Hujan Ekstrim di Wilayah DKI Jakarta

Directory of Open Access Journals (Sweden)

Achi Rinaldi

2016-06-01

Full Text Available Extreme event such as extreme rainfall have been analyzed and most concern for the country all around the world. There are two common distribution for extreme value which are Generalized Extreme Value distribution and Generalized Pareto distribution. These two distribution have shown good performace to estimate the parameter of  extreme value. This research was aim to estimate parameter of extreme value using GEV distribution and GP distribution, and also to characterized effect of extreme event such as flood. The rainfall data was taken from BMKG for 5 location in DKI Jakarta. Both of distribution shown a good perfromance. The resut showed that Tanjung Priok station has biggest location parameter for GEV and also the biggest scale parameter for GP, that mean the biggest probability to take flood effect of the extreme rainfall.

Study of some physiological parameters among mobile phone users

International Nuclear Information System (INIS)

Anwar, S.M.; Gabr, S.A.

2002-01-01

Forty male mobile users in additional to twenty males as control group similar in age and socio economically matched were chosen for this study. Blood pressure, complete blood picture, five parameters of semen quality and four sex hormones (LH, FSH, prolactin and testosterone)were measured. Elevated significant differences for blood pressure (P<0.01) for the exposed group and some changes in mean values of haematologic parameters, although all values were within the normal range. Minor semen quality and hormonal levels changes between the two groups, including a higher mean follicle-stimulating hormone level; for mobile users (8.10 vs 6.00 mIU/mL), and a slightly higher mean luteinizing hormone level (11.73 vs 10.16 mLU/mL) were noted in the user group

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

Science.gov (United States)

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

2014-01-01

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

Generalized L1 penalized matrix factorization

DEFF Research Database (Denmark)

Rasmussen, Morten Arendt

2017-01-01

Traditionally, chemometric models consists of parameters found by solving a least squares criterion. However, these models can suffer from overfitting, as well as being hard to interpret because of the large number of active parameters. This work proposes the use of a generalized L1 norm penalty ...

Thyroid status and mortality in nonagenarians from long-lived families and the general population

DEFF Research Database (Denmark)

van Vliet, Nicolien A.; van der Spoel, Evie; Beekman, Marian

2017-01-01

(TSH), free thyroxine (fT4) and free triiodothyronine (fT3) were measured. In nonagenarians from long-lived families and from the general population, associations between thyroid parameters and mortality were similar. We found no interaction between study population and parameters of thyroid status...

Unstable Modes and Order Parameters of Bistable Signaling Pathways at Saddle-Node Bifurcations: A Theoretical Study Based on Synergetics

Directory of Open Access Journals (Sweden)

Till D. Frank

2016-01-01

Full Text Available Mathematical modeling has become an indispensable part of systems biology which is a discipline that has become increasingly popular in recent years. In this context, our understanding of bistable signaling pathways in terms of mathematical modeling is of particular importance because such bistable components perform crucial functions in living cells. Bistable signaling pathways can act as switches or memory functions and can determine cell fate. In the present study, properties of mathematical models of bistable signaling pathways are examined from the perspective of synergetics, a theory of self-organization and pattern formation founded by Hermann Haken. At the heart of synergetics is the concept of so-called unstable modes or order parameters that determine the behavior of systems as a whole close to bifurcation points. How to determine these order parameters for bistable signaling pathways at saddle-node bifurcation points is shown. The procedure is outlined in general and an explicit example is worked out in detail.

A general first-order global sensitivity analysis method

International Nuclear Information System (INIS)

Xu Chonggang; Gertner, George Zdzislaw

2008-01-01

Fourier amplitude sensitivity test (FAST) is one of the most popular global sensitivity analysis techniques. The main mechanism of FAST is to assign each parameter with a characteristic frequency through a search function. Then, for a specific parameter, the variance contribution can be singled out of the model output by the characteristic frequency. Although FAST has been widely applied, there are two limitations: (1) the aliasing effect among parameters by using integer characteristic frequencies and (2) the suitability for only models with independent parameters. In this paper, we synthesize the improvement to overcome the aliasing effect limitation [Tarantola S, Gatelli D, Mara TA. Random balance designs for the estimation of first order global sensitivity indices. Reliab Eng Syst Safety 2006; 91(6):717-27] and the improvement to overcome the independence limitation [Xu C, Gertner G. Extending a global sensitivity analysis technique to models with correlated parameters. Comput Stat Data Anal 2007, accepted for publication]. In this way, FAST can be a general first-order global sensitivity analysis method for linear/nonlinear models with as many correlated/uncorrelated parameters as the user specifies. We apply the general FAST to four test cases with correlated parameters. The results show that the sensitivity indices derived by the general FAST are in good agreement with the sensitivity indices derived by the correlation ratio method, which is a non-parametric method for models with correlated parameters

Inflation and cosmological parameter estimation

Energy Technology Data Exchange (ETDEWEB)

Hamann, J.

2007-05-15

In this work, we focus on two aspects of cosmological data analysis: inference of parameter values and the search for new effects in the inflationary sector. Constraints on cosmological parameters are commonly derived under the assumption of a minimal model. We point out that this procedure systematically underestimates errors and possibly biases estimates, due to overly restrictive assumptions. In a more conservative approach, we analyse cosmological data using a more general eleven-parameter model. We find that regions of the parameter space that were previously thought ruled out are still compatible with the data; the bounds on individual parameters are relaxed by up to a factor of two, compared to the results for the minimal six-parameter model. Moreover, we analyse a class of inflation models, in which the slow roll conditions are briefly violated, due to a step in the potential. We show that the presence of a step generically leads to an oscillating spectrum and perform a fit to CMB and galaxy clustering data. We do not find conclusive evidence for a step in the potential and derive strong bounds on quantities that parameterise the step. (orig.)

Markov chain beam randomization: a study of the impact of PLANCK beam measurement errors on cosmological parameter estimation

Science.gov (United States)

Rocha, G.; Pagano, L.; Górski, K. M.; Huffenberger, K. M.; Lawrence, C. R.; Lange, A. E.

2010-04-01

We introduce a new method to propagate uncertainties in the beam shapes used to measure the cosmic microwave background to cosmological parameters determined from those measurements. The method, called markov chain beam randomization (MCBR), randomly samples from a set of templates or functions that describe the beam uncertainties. The method is much faster than direct numerical integration over systematic “nuisance” parameters, and is not restricted to simple, idealized cases as is analytic marginalization. It does not assume the data are normally distributed, and does not require Gaussian priors on the specific systematic uncertainties. We show that MCBR properly accounts for and provides the marginalized errors of the parameters. The method can be generalized and used to propagate any systematic uncertainties for which a set of templates is available. We apply the method to the Planck satellite, and consider future experiments. Beam measurement errors should have a small effect on cosmological parameters as long as the beam fitting is performed after removal of 1/f noise.

One-parameter Darboux transformations in thermodynamics

International Nuclear Information System (INIS)

Rosu, Haret C.

2002-01-01

The quantum oscillator thermodynamic actions are the conjugate intensive parameters for the frequency in any frequency changing process. These oscillator actions fulfill simple Riccati equations. Interesting Darboux transformations of the fundamental Planck and pure vacuum actions are discussed here in some detail. It is shown that the one-parameter 'Darboux-Transformed-Thermodynamics' refers to superpositions of boson and fermion excitations of positive and negative absolute temperature, respectively. A Darboux generalization of the fluctuation-dissipation theorem is also briefly sketched

Noise disturbance in open-plan study environments: a field study on noise sources, student tasks and room acoustic parameters.

Science.gov (United States)

Braat-Eggen, P Ella; van Heijst, Anne; Hornikx, Maarten; Kohlrausch, Armin

2017-09-01

The aim of this study is to gain more insight in the assessment of noise in open-plan study environments and to reveal correlations between noise disturbance experienced by students and the noise sources they perceive, the tasks they perform and the acoustic parameters of the open-plan study environment they work in. Data were collected in five open-plan study environments at universities in the Netherlands. A questionnaire was used to investigate student tasks, perceived sound sources and their perceived disturbance, and sound measurements were performed to determine the room acoustic parameters. This study shows that 38% of the surveyed students are disturbed by background noise in an open-plan study environment. Students are mostly disturbed by speech when performing complex cognitive tasks like studying for an exam, reading and writing. Significant but weak correlations were found between the room acoustic parameters and noise disturbance of students. Practitioner Summary: A field study was conducted to gain more insight in the assessment of noise in open-plan study environments at universities in the Netherlands. More than one third of the students was disturbed by noise. An interaction effect was found for task type, source type and room acoustic parameters.

Thermal-Hydraulic Sensitivity Study of Intermediate Loop Parameters for Nuclear Hydrogen Production System

Energy Technology Data Exchange (ETDEWEB)

Jeong, Jong Hwa; Lee, Heung Nae; Park, Jea Ho [KONES Corp., Seoul (Korea, Republic of); Lee, Won Jae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Sang Il; Yoo, Yeon Jae [Hyundai Engineering Co., Seoul (Korea, Republic of)

2016-10-15

The heat generated from the VHTR is transferred to the intermediate loop through Intermediate Heat Exchanger (IHX). It is further passed on to the Sulfur-Iodine (SI) hydrogen production system (HPS) through Process Heat Exchanger (PHX). The IL provides the safety distance between the VHTR and HPS. Since the IL performance affects the overall nuclear HPS efficiency, it is required to optimize its design and operation parameters. In this study, the thermal-hydraulic sensitivity of IL parameters with various coolant options has been examined by using MARS-GCR code, which was already applied for the case of steam generator. Sensitivity study of the IL and PHX parameters has been carried out based on their thermal-hydraulic performance. Several parameters for design and operation, such as the pipe diameter, safety distance and surface area, are considered for different coolant options, He, CO{sub 2} and He-CO{sub 2} (2:8). It was found that the circulator work is the major factor affecting on the overall nuclear hydrogen production system efficiency. Circulator work increases with the safety distance, and decreases with the operation pressure and loop pipe diameter. Sensitivity results obtained from this study will contribute to the optimization of the IL design and operation parameters and the optimal coolant selection.

Non-Douglas-Kazakov phase transition of two-dimensional generalized Yang-Mills theories

International Nuclear Information System (INIS)

Khorrami, M.; Alimohammadi, M.

2007-01-01

In two-dimensional Yang-Mills and generalized Yang-Mills theories for large gauge groups, there is a dominant representation determining the thermodynamic limit of the system. This representation is characterized by a density, the value of which should everywhere be between zero and one. This density itself is determined by means of a saddle-point analysis. For some values of the parameter space, this density exceeds one in some places. So one should modify it to obtain an acceptable density. This leads to the well-known Douglas-Kazakov phase transition. In generalized Yang-Mills theories, there are also regions in the parameter space where somewhere this density becomes negative. Here too, one should modify the density so that it remains nonnegative. This leads to another phase transition, different from the Douglas-Kazakov one. Here the general structure of this phase transition is studied, and it is shown that the order of this transition is typically three. Using carefully-chosen parameters, however, it is possible to construct models with the order of the phase transition not equal to three. A class of these non-typical models is also studied. (orig.)

Studies on Pidotimod Enantiomers With Chiralpak-IA: Crystal Structure, Thermodynamic Parameters and Molecular Docking.

Science.gov (United States)

Dou, Xiaorui; Su, Xin; Wang, Yue; Chen, Yadong; Shen, Weiyang

2015-11-01

Pidotimod, a synthetic dipeptide, has two chiral centers with biological and immunological activity. Its enantiomers were characterized by x-ray crystallographic analysis. A chiral stationary phase (CSP) Chiralpak-IA based on amylose derivatized with tris-(3, 5-dimethylphenyl carbamate) was used to separate pidotimod enantiomers. The mobile phase was prepared in a ratio of 35:65:0.2 of methyl-tert-butyl-ether and acetonitrile trifluoroaceticacid. In addition, thermodynamics and molecular docking methods were used to explain the enantioseparation mechanism by Chiralpak-IA. Thermodynamic studies were carried out from 10 to 45 °C. In general, both retention and enantioselectivity decreased as the temperature increased. Thermodynamic parameters indicate that the interaction force between the pidotimod enantiomer (4S, 2'R) and IA CSP is stronger and their complex model is more stable. According to GOLD molecular docking simulation, Van der Waals force is the leading cause of pidotimod enantiomers separation by IA CSP. © 2015 Wiley Periodicals, Inc.

Generalized linear differential equations in a Banach space : continuous dependence on a parameter

Czech Academy of Sciences Publication Activity Database

Monteiro, G.A.; Tvrdý, Milan

2013-01-01

Roč. 33, č. 1 (2013), s. 283-303 ISSN 1078-0947 Institutional research plan: CEZ:AV0Z10190503 Keywords : generalized differential equations * continuous dependence * Kurzweil-Stieltjes integral Subject RIV: BA - General Mathematics Impact factor: 0.923, year: 2013 http://aimsciences.org/journals/displayArticlesnew.jsp?paperID=7615

Oncoplastic round block technique has comparable operative parameters as standard wide local excision: a matched case-control study.

Science.gov (United States)

Lim, Geok-Hoon; Allen, John Carson; Ng, Ruey Pyng

2017-08-01

Although oncoplastic breast surgery is used to resect larger tumors with lower re-excision rates compared to standard wide local excision (sWLE), criticisms of oncoplastic surgery include a longer-albeit, well concealed-scar, longer operating time and hospital stay, and increased risk of complications. Round block technique has been reported to be very suitable for patients with relatively smaller breasts and minimal ptosis. We aim to determine if round block technique will result in operative parameters comparable with sWLE. Breast cancer patients who underwent a round block procedure from 1st May 2014 to 31st January 2016 were included in the study. These patients were then matched for the type of axillary procedure, on a one to one basis, with breast cancer patients who had undergone sWLE from 1st August 2011 to 31st January 2016. The operative parameters between the 2 groups were compared. 22 patients were included in the study. Patient demographics and histologic parameters were similar in the 2 groups. No complications were reported in either group. The mean operating time was 122 and 114 minutes in the round block and sWLE groups, respectively (P=0.64). Length of stay was similar in the 2 groups (P=0.11). Round block patients had better cosmesis and lower re-excision rates. A higher rate of recurrence was observed in the sWLE group. The round block technique has comparable operative parameters to sWLE with no evidence of increased complications. Lower re-excision rate and better cosmesis were observed in the round block patients suggesting that the round block technique is not only comparable in general, but may have advantages to sWLE in selected cases.

A qualitative study of collaboration in general practice: understanding the general practice nurse's role.

Science.gov (United States)

McInnes, Susan; Peters, Kath; Bonney, Andrew; Halcomb, Elizabeth

2017-07-01

To explore the nature of collaboration between registered nurses and general practitioners in Australian general practice. There is international recognition that collaboration between health professionals can improve care coordination, enhance health outcomes, optimise the work environment and reduce healthcare costs. However, effective collaboration requires a clear understanding of each team member's role. A qualitative approach guided by Naturalistic Inquiry was used to elicit and interpret participant narratives. Eight general practitioners and fourteen registered nurses working in general practice were purposefully recruited. Data were collected via individual, semi-structured face-to-face interviews during February to May 2015. Interviews were audio recorded and transcribed verbatim. Data were analysed using thematic analysis. Data revealed three overarching themes. This study presents the data for the overarching theme 'Understanding the general practice registered nurse's role'. Many general practitioner participants lacked clarity around the role and scope of practice of the registered nurse. At the same time, nursing participants often articulated their role as an assistant rather than as an independent health professional. This limited collaboration and the nurses' role within the team. Collaboration was enhanced when general practitioners actively sought an understanding of the registered nurses scope of practice. Clarifying the nurses' role promotes collaboration and supports nurses to work to the full extent of their practice. This is important in terms of optimising the nurses' role within the team and reinforcing their professional identity. Identification of key issues around understanding the nurses' role may help inform strategies that improve collaboration and workplace relations. © 2016 John Wiley & Sons Ltd.

Study on Parameters Modeling of Wind Turbines Using SCADA Data

Directory of Open Access Journals (Sweden)

Yonglong YAN

2014-08-01

Full Text Available Taking the advantage of the current massive monitoring data from Supervisory Control and Data Acquisition (SCADA system of wind farm, it is of important significance for anomaly detection, early warning and fault diagnosis to build the data model of state parameters of wind turbines (WTs. The operational conditions and the relationships between the state parameters of wind turbines are complex. It is difficult to establish the model of state parameter accurately, and the modeling method of state parameters of wind turbines considering parameter selection is proposed. Firstly, by analyzing the characteristic of SCADA data, a reasonable range of data and monitoring parameters are chosen. Secondly, neural network algorithm is adapted, and the selection method of input parameters in the model is presented. Generator bearing temperature and cooling air temperature are regarded as target parameters, and the two models are built and input parameters of the models are selected, respectively. Finally, the parameter selection method in this paper and the method using genetic algorithm-partial least square (GA-PLS are analyzed comparatively, and the results show that the proposed methods are correct and effective. Furthermore, the modeling of two parameters illustrate that the method in this paper can applied to other state parameters of wind turbines.

Scanning anisotropy parameters in complex media

KAUST Repository

Alkhalifah, Tariq Ali

2011-01-01

Parameter estimation in an inhomogeneous anisotropic medium offers many challenges; chief among them is the trade-off between inhomogeneity and anisotropy. It is especially hard to estimate the anisotropy anellipticity parameter η in complex media. Using perturbation theory and Taylor’s series, I have expanded the solutions of the anisotropic eikonal equation for transversely isotropic (TI) media with a vertical symmetry axis (VTI) in terms of the independent parameter η from a generally inhomogeneous elliptically anisotropic medium background. This new VTI traveltime solution is based on a set of precomputed perturbations extracted from solving linear partial differential equations. The traveltimes obtained from these equations serve as the coefficients of a Taylor-type expansion of the total traveltime in terms of η. Shanks transform is used to predict the transient behavior of the expansion and improve its accuracy using fewer terms. A homogeneous medium simplification of the expansion provides classical nonhyperbolic moveout descriptions of the traveltime that are more accurate than other recently derived approximations. In addition, this formulation provides a tool to scan for anisotropic parameters in a generally inhomogeneous medium background. A Marmousi test demonstrates the accuracy of this approximation. For a tilted axis of symmetry, the equations are still applicable with a slightly more complicated framework because the vertical velocity and δ are not readily available from the data.

Scanning anisotropy parameters in complex media

KAUST Repository

Alkhalifah, Tariq Ali

2011-03-21

Parameter estimation in an inhomogeneous anisotropic medium offers many challenges; chief among them is the trade-off between inhomogeneity and anisotropy. It is especially hard to estimate the anisotropy anellipticity parameter η in complex media. Using perturbation theory and Taylor’s series, I have expanded the solutions of the anisotropic eikonal equation for transversely isotropic (TI) media with a vertical symmetry axis (VTI) in terms of the independent parameter η from a generally inhomogeneous elliptically anisotropic medium background. This new VTI traveltime solution is based on a set of precomputed perturbations extracted from solving linear partial differential equations. The traveltimes obtained from these equations serve as the coefficients of a Taylor-type expansion of the total traveltime in terms of η. Shanks transform is used to predict the transient behavior of the expansion and improve its accuracy using fewer terms. A homogeneous medium simplification of the expansion provides classical nonhyperbolic moveout descriptions of the traveltime that are more accurate than other recently derived approximations. In addition, this formulation provides a tool to scan for anisotropic parameters in a generally inhomogeneous medium background. A Marmousi test demonstrates the accuracy of this approximation. For a tilted axis of symmetry, the equations are still applicable with a slightly more complicated framework because the vertical velocity and δ are not readily available from the data.

Parameter motivated mutual correlation analysis: Application to the study of currency exchange rates based on intermittency parameter and Hurst exponent

Science.gov (United States)

Cristescu, Constantin P.; Stan, Cristina; Scarlat, Eugen I.; Minea, Teofil; Cristescu, Cristina M.

2012-04-01

We present a novel method for the parameter oriented analysis of mutual correlation between independent time series or between equivalent structures such as ordered data sets. The proposed method is based on the sliding window technique, defines a new type of correlation measure and can be applied to time series from all domains of science and technology, experimental or simulated. A specific parameter that can characterize the time series is computed for each window and a cross correlation analysis is carried out on the set of values obtained for the time series under investigation. We apply this method to the study of some currency daily exchange rates from the point of view of the Hurst exponent and the intermittency parameter. Interesting correlation relationships are revealed and a tentative crisis prediction is presented.

A covariance correction that accounts for correlation estimation to improve finite-sample inference with generalized estimating equations: A study on its applicability with structured correlation matrices.

Science.gov (United States)

Westgate, Philip M

2016-01-01

When generalized estimating equations (GEE) incorporate an unstructured working correlation matrix, the variances of regression parameter estimates can inflate due to the estimation of the correlation parameters. In previous work, an approximation for this inflation that results in a corrected version of the sandwich formula for the covariance matrix of regression parameter estimates was derived. Use of this correction for correlation structure selection also reduces the over-selection of the unstructured working correlation matrix. In this manuscript, we conduct a simulation study to demonstrate that an increase in variances of regression parameter estimates can occur when GEE incorporates structured working correlation matrices as well. Correspondingly, we show the ability of the corrected version of the sandwich formula to improve the validity of inference and correlation structure selection. We also study the relative influences of two popular corrections to a different source of bias in the empirical sandwich covariance estimator.

Effect of anapanasati meditation technique through electrophotonic imaging parameters: A pilot study.

Science.gov (United States)

Deo, Guru; Itagi R, Kumar; Thaiyar M, Srinivasan; Kuldeep, Kushwah K

2015-01-01

Mindfulness along with breathing is a well-established meditation technique. Breathing is an exquisite tool for exploring subtle awareness of mind and life itself. This study aimed at measuring changes in the different parameters of electrophotonic imaging (EPI) in anapanasati meditators. To carry out this study, 51 subjects comprising 32 males and 19 females of age 18 years and above (mean age 45.64 ± 14.43) were recruited voluntarily with informed consent attending Karnataka Dhyana Mahachakra-1 at Pyramid Valley International, Bengaluru, India. The design was a single group pre- post and data collected by EPI device before and after 5 days of intensive meditation. Results show significant changes in EPI parameter integral area with filter (physiological) in both right and left side, which reflects the availability of high functional energy reserve in meditators. The researchers observed similar trends without filter (psycho-physiological) indicating high reserves of energy at psycho-physiological level also. Activation coefficient, another parameter of EPI, reduced showing more relaxed state than earlier, possibly due to parasympathetic dominance. Integral entropy decreased in the case of psycho-physiological parameters left-side without filter, which indicates less disorder after meditation, but these changes were not significant. The study showed a reversed change in integral entropy in the right side without filter; however, the values on both sides with filter increased, which indicates disorder. The study suggests that EPI can be used in the recording functional physiological and psychophysiological status of meditators at a subtle level.

EX VIVO STUDY OF QUANTITATIVE ULTRASOUND PARAMETERS IN FATTY RABBIT LIVERS

Science.gov (United States)

Ghoshal, Goutam; Lavarello, Roberto J.; Kemmerer, Jeremy P.; Miller, Rita J.; Oelze, Michael L.

2012-01-01

Nonalcoholic fatty liver disease (NAFLD) affects more than 30% of Americans, and with increasing problems of obesity in the United States, NAFLD is poised to become an even more serious medical concern. At present, accurate classification of steatosis (fatty liver) represents a significant challenge. In this study, the use of high-frequency (8 to 25 MHz) quantitative ultrasound (QUS) imaging to quantify fatty liver was explored. QUS is an imaging technique that can be used to quantify properties of tissue giving rise to scattered ultrasound. The changes in the ultrasound properties of livers in rabbits undergoing atherogenic diets of varying durations were investigated using QUS. Rabbits were placed on a special fatty diet for 0, 3, or 6 weeks. The fattiness of the livers was quantified by estimating the total lipid content of the livers. Ultrasonic properties, such as speed of sound, attenuation, and backscatter coefficients, were estimated in ex vivo rabbit liver samples from animals that had been on the diet for varying periods. Two QUS parameters were estimated based on the backscatter coefficient: effective scatterer diameter (ESD) and effective acoustic concentration (EAC), using a spherical Gaussian scattering model. Two parameters were estimated based on the backscattered envelope statistics (the k parameter and the μ parameter) according to the homodyned K distribution. The speed of sound decreased from 1574 to 1565 m/s and the attenuation coefficient increased from 0.71 to 1.27 dB/cm/MHz, respectively, with increasing fat content in the liver. The ESD decreased from 31 to 17 μm and the EAC increased from 38 to 63 dB/cm3 with increasing fat content in the liver. A significant increase in the μ parameter from 0.18 to 0.93 scatterers/mm3 was observed with increasing fat content in the liver samples. The results of this study indicate that QUS parameters are sensitive to fat content in the liver. PMID:23062376

Reproductive factors and serum uric acid levels in females from the general population: the KORA F4 study.

Directory of Open Access Journals (Sweden)

Doris Stöckl

Full Text Available OBJECTIVE: Hyperuricemia is associated with an increased risk of metabolic and cardiovascular diseases. There are pronounced sex differences in the levels of uric acid. It is largely unknown whether or not reproductive parameters which induce hormonal changes are responsible for this. We examined if there are associations between reproductive parameters and uric acid levels in a female population-based sample. METHODS: In this cross-sectional analysis, data of 1530 women aged 32 to 81 years participating in the KORA F4 study, conducted between 2006 and 2008 in Southern Germany were used. Reproductive parameters were obtained by standardized interviews. Uric acid levels were tested by the uricase method. The whole study sample and stratified in pre- and postmenopausal women was analyzed. RESULTS: Menopausal status and earlier age at menarche were associated with higher serum uric acid levels (age-adjusted: p-values 0.003, <0.001 respectively; after multivariable adjustment, including BMI: p-values 0.002, 0.036. A history of oral contraceptive use showed an association with uric acid levels only after multivariable adjustment (p-value 0.009. Hot flushes showed an association with uric acid levels only after age-adjustment (p-value 0.038, but lost significance after adding other confounders. Other reproductive factors, including parity, current or ever use of hormone replacement therapy, current use of oral contraceptives, hysterectomy, bilateral oophorectomy, or depressive mood related to menopausal transition were not associated with uric acid levels. CONCLUSIONS: Postmenopausal status, earlier age at menarche and a history of oral contraceptive use were independently associated with higher serum uric acid concentrations in women from the general population. Further studies, especially longitudinal population-based studies investigating the relationship of female reproductive parameters with uric acid levels are necessary to confirm our findings.

Self-Intersection Local Times of Generalized Mixed Fractional Brownian Motion as White Noise Distributions

International Nuclear Information System (INIS)

Suryawan, Herry P.; Gunarso, Boby

2017-01-01

The generalized mixed fractional Brownian motion is defined by taking linear combinations of a finite number of independent fractional Brownian motions with different Hurst parameters. It is a Gaussian process with stationary increments, posseses self-similarity property, and, in general, is neither a Markov process nor a martingale. In this paper we study the generalized mixed fractional Brownian motion within white noise analysis framework. As a main result, we prove that for any spatial dimension and for arbitrary Hurst parameter the self-intersection local times of the generalized mixed fractional Brownian motions, after a suitable renormalization, are well-defined as Hida white noise distributions. The chaos expansions of the self-intersection local times in the terms of Wick powers of white noises are also presented. (paper)

Shifted one-parameter supersymmetric family of quartic asymmetric double-well potentials

International Nuclear Information System (INIS)

Rosu, Haret C.; Mancas, Stefan C.; Chen, Pisin

2014-01-01

Extending our previous work (Rosu, 2014), we define supersymmetric partner potentials through a particular Riccati solution of the form F(x)=(x−c) 2 −1, where c is a real shift parameter, and work out the quartic double-well family of one-parameter isospectral potentials obtained by using the corresponding general Riccati solution. For these parametric double well potentials, we study how the localization properties of the two wells depend on the parameter of the potentials for various values of the shifting parameter. We also consider the supersymmetric parametric family of the first double-well potential in the Razavy chain of double well potentials corresponding to F(x)=1/2 sinh2x−2((1+√(2))sinh2x)/((1+√(2))cosh2x+1) , both unshifted and shifted, to test and compare the localization properties. - Highlights: • Quartic one-parameter DWs with an additional shift parameter are introduced. • Anomalous localization feature of their zero modes is confirmed at different shifts. • Razavy one-parameter DWs are also introduced and shown not to have this feature

Shifted one-parameter supersymmetric family of quartic asymmetric double-well potentials

Energy Technology Data Exchange (ETDEWEB)

Rosu, Haret C., E-mail: hcr@ipicyt.edu.mx [IPICYT, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San José 2055, Col. Lomas 4a Sección, 78216 San Luis Potosí, S.L.P. (Mexico); Mancas, Stefan C., E-mail: mancass@erau.edu [Department of Mathematics, Embry-Riddle Aeronautical University, Daytona Beach, FL 32114-3900 (United States); Chen, Pisin, E-mail: pisinchen@phys.ntu.edu.tw [Leung Center for Cosmology and Particle Astrophysics (LeCosPA) and Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China)

2014-10-15

Extending our previous work (Rosu, 2014), we define supersymmetric partner potentials through a particular Riccati solution of the form F(x)=(x−c){sup 2}−1, where c is a real shift parameter, and work out the quartic double-well family of one-parameter isospectral potentials obtained by using the corresponding general Riccati solution. For these parametric double well potentials, we study how the localization properties of the two wells depend on the parameter of the potentials for various values of the shifting parameter. We also consider the supersymmetric parametric family of the first double-well potential in the Razavy chain of double well potentials corresponding to F(x)=1/2 sinh2x−2((1+√(2))sinh2x)/((1+√(2))cosh2x+1) , both unshifted and shifted, to test and compare the localization properties. - Highlights: • Quartic one-parameter DWs with an additional shift parameter are introduced. • Anomalous localization feature of their zero modes is confirmed at different shifts. • Razavy one-parameter DWs are also introduced and shown not to have this feature.

Generalized Empirical Likelihood-Based Focused Information Criterion and Model Averaging

Directory of Open Access Journals (Sweden)

Naoya Sueishi

2013-07-01

Full Text Available This paper develops model selection and averaging methods for moment restriction models. We first propose a focused information criterion based on the generalized empirical likelihood estimator. We address the issue of selecting an optimal model, rather than a correct model, for estimating a specific parameter of interest. Then, this study investigates a generalized empirical likelihood-based model averaging estimator that minimizes the asymptotic mean squared error. A simulation study suggests that our averaging estimator can be a useful alternative to existing post-selection estimators.

Cosmological parameter estimation using Particle Swarm Optimization

Science.gov (United States)

Prasad, J.; Souradeep, T.

2014-03-01

Constraining parameters of a theoretical model from observational data is an important exercise in cosmology. There are many theoretically motivated models, which demand greater number of cosmological parameters than the standard model of cosmology uses, and make the problem of parameter estimation challenging. It is a common practice to employ Bayesian formalism for parameter estimation for which, in general, likelihood surface is probed. For the standard cosmological model with six parameters, likelihood surface is quite smooth and does not have local maxima, and sampling based methods like Markov Chain Monte Carlo (MCMC) method are quite successful. However, when there are a large number of parameters or the likelihood surface is not smooth, other methods may be more effective. In this paper, we have demonstrated application of another method inspired from artificial intelligence, called Particle Swarm Optimization (PSO) for estimating cosmological parameters from Cosmic Microwave Background (CMB) data taken from the WMAP satellite.

Cosmological parameter estimation using Particle Swarm Optimization

International Nuclear Information System (INIS)

Prasad, J; Souradeep, T

2014-01-01

Constraining parameters of a theoretical model from observational data is an important exercise in cosmology. There are many theoretically motivated models, which demand greater number of cosmological parameters than the standard model of cosmology uses, and make the problem of parameter estimation challenging. It is a common practice to employ Bayesian formalism for parameter estimation for which, in general, likelihood surface is probed. For the standard cosmological model with six parameters, likelihood surface is quite smooth and does not have local maxima, and sampling based methods like Markov Chain Monte Carlo (MCMC) method are quite successful. However, when there are a large number of parameters or the likelihood surface is not smooth, other methods may be more effective. In this paper, we have demonstrated application of another method inspired from artificial intelligence, called Particle Swarm Optimization (PSO) for estimating cosmological parameters from Cosmic Microwave Background (CMB) data taken from the WMAP satellite

Subset selection from generalized logistic populations

NARCIS (Netherlands)

Laan, van der M.J.; Laan, van der P.

1997-01-01

We give an introduction to the logistic and generalized logistic distributions. These generalized logistic distributions Type-I, Type-II and Type-III are indexed by a real valued parameter. They have been derived as mixtures with the standard logistic distribution and for discrete values of the

General B factory design considerations

International Nuclear Information System (INIS)

Zisman, M.S.

1992-12-01

We describe the general considerations that go into the design of an asymmetric B factory collider. Justification is given for the typical parameters of such a facility, and the physics and technology challenges that arise from these parameter choices are discussed. Cost and schedule issues for a B factory are discussed briefly. A summary of existing proposals is presented, noting their similarities and differences

A study of the infrared spectrum of psi Persei .1. A parameter study of the disc model

NARCIS (Netherlands)

Marlborough, JM; Waters, LBFM

We report a parameter study of emission lines arising from a disc surrounding a Be star, using parameters appropriate to the Be star psi Per. We concentrate on the Hn line and on some IR recombination lines (Br alpha, Br gamma, Pf gamma, and HI 17-6). The model we use is a simple cone-like disc

Posture with elevated and extended thorax. The influence of the position on some haemodynamic and ventilatory parameters under general anaesthesia.

Science.gov (United States)

Videbaek, F

1980-12-01

The effects of a change in posture from flat supine to supine with elevated and extended thorax have been investigated in 12 healthy patients under general anaesthesia prior to elective surgery on the stomach. The following parameters were measured: pulse rate, mean arterial blood pressure (MABP), central venous pressure (CVP), ventilation pressure, oesophageal pressure, and arterial oxygen and carbon dioxide tensions. Changes were measured as deviations from initial values before the change of position at 4 and 15 min after the change. One patient (8%) had a 31% fall in MABP and a 87% fall in CVP, requiring treatment outside the standard procedure, but acceptable values were obtained by simple means. Eleven patients showed only minor changes: a mean initial rise in pulse rate of 10% and a fall in CVP of 25%, after which the pulse rate returned to the initial level and the CVP remained stable. MABP was unchanged, as were ventilation pressure, oesophageal pressure and gas tensions. On the basis of reports in the literature and findings in this study, it is concluded that otherwise healthy patients tolerate the posture well, the slight risk of haemodynamic complications being outweighed by the surgical advantages. This posture should be used with caution in patients who may be haemodynamically unable to compensate.

Postural Sway Parameters and Gait Symmetry in Preschool Children: Cross-sectional study

Directory of Open Access Journals (Sweden)

Fabiane E de Sá

Full Text Available Abstract The most important function of posture is to ensure the maintenance of control during the start and the continuation of human movement, moreover, posture serves as a reference for the production of precise movements. The aim of this study was to relate the postural sway parameters and gait symmetry in preschool children.This study is a cross-sectional study, conducted in 49 children with a mean age of 4.65 ± 0.44 years. Initially, height and body mass of children were measured using anthropometric scales. Next, an electronic baropodometer was used to evaluate the distribution of dynamic plantar pressure (gait and stabilometry (balance.A Student t test or Mann-Whitney test for comparing two groups was used. To correlate variables, a Pearson's correlation or Spearman's correlation coefficient was used. The stabilometric parameters showed no significant difference between an eyes open test and eyes closed test in preschool child. We found a moderate relationship between axis inclination and cadence symmetry (R=0.40;p=0.007. Postural sway parameters have relationship cadence symmetry of the gait in preschool children.

Calibration and validation of a general infiltration model

Science.gov (United States)

Mishra, Surendra Kumar; Ranjan Kumar, Shashi; Singh, Vijay P.

1999-08-01

A general infiltration model proposed by Singh and Yu (1990) was calibrated and validated using a split sampling approach for 191 sets of infiltration data observed in the states of Minnesota and Georgia in the USA. Of the five model parameters, fc (the final infiltration rate), So (the available storage space) and exponent n were found to be more predictable than the other two parameters: m (exponent) and a (proportionality factor). A critical examination of the general model revealed that it is related to the Soil Conservation Service (1956) curve number (SCS-CN) method and its parameter So is equivalent to the potential maximum retention of the SCS-CN method and is, in turn, found to be a function of soil sorptivity and hydraulic conductivity. The general model was found to describe infiltration rate with time varying curve number.

On Drift Parameter Estimation in Models with Fractional Brownian Motion by Discrete Observations

Directory of Open Access Journals (Sweden)

Yuliya Mishura

2014-06-01

Full Text Available We study a problem of an unknown drift parameter estimation in a stochastic differen- tial equation driven by fractional Brownian motion. We represent the likelihood ratio as a function of the observable process. The form of this representation is in general rather complicated. However, in the simplest case it can be simplified and we can discretize it to establish the a. s. convergence of the discretized version of maximum likelihood estimator to the true value of parameter. We also investigate a non-standard estimator of the drift parameter showing further its strong consistency. 

Modeling annual extreme temperature using generalized extreme value distribution: A case study in Malaysia

Science.gov (United States)

Hasan, Husna; Salam, Norfatin; Kassim, Suraiya

2013-04-01

Extreme temperature of several stations in Malaysia is modeled by fitting the annual maximum to the Generalized Extreme Value (GEV) distribution. The Augmented Dickey Fuller (ADF) and Phillips Perron (PP) tests are used to detect stochastic trends among the stations. The Mann-Kendall (MK) test suggests a non-stationary model. Three models are considered for stations with trend and the Likelihood Ratio test is used to determine the best-fitting model. The results show that Subang and Bayan Lepas stations favour a model which is linear for the location parameters while Kota Kinabalu and Sibu stations are suitable with a model in the logarithm of the scale parameters. The return level is the level of events (maximum temperature) which is expected to be exceeded once, on average, in a given number of years, is obtained.

Kazhdan-Lusztig cells with unequal parameters

CERN Document Server

Bonnafé, Cédric

2017-01-01

This monograph provides a comprehensive introduction to the Kazhdan-Lusztig theory of cells in the broader context of the unequal parameter case. Serving as a useful reference, the present volume offers a synthesis of significant advances made since Lusztig’s seminal work on the subject was published in 2002. The focus lies on the combinatorics of the partition into cells for general Coxeter groups, with special attention given to induction methods, cellular maps and the role of Lusztig's conjectures. Using only algebraic and combinatorial methods, the author carefully develops proofs, discusses open conjectures, and presents recent research, including a chapter on the action of the cactus group. Kazhdan-Lusztig Cells with Unequal Parameters will appeal to graduate students and researchers interested in related subject areas, such as Lie theory, representation theory, and combinatorics of Coxeter groups. Useful examples and various exercises make this book suitable for self-study and use alongside lecture c...

Performance evaluation of generalized M-modeled atmospheric optical communications links

DEFF Research Database (Denmark)

Lopez-Gonzalez, Francisco J.; Garrido-Balsellss, José María; Jurado-Navas, Antonio

2016-01-01

, the behavior of the atmospheric optical channel is treated as a superposition of a finite number of Generalized-K distributed sub-channels, controlled by a discrete Negative-Binomial distribution dependent on the turbulence parameters. Unlike other studies, here, the closed-form mathematical expressions...

Study on Nonlinear Vibration Analysis of Gear System with Random Parameters

Science.gov (United States)

Tong, Cao; Liu, Xiaoyuan; Fan, Li

2018-03-01

In order to study the dynamic characteristics of gear nonlinear vibration system and the influence of random parameters, firstly, a nonlinear stochastic vibration analysis model of gear 3-DOF is established based on Newton’s Law. And the random response of gear vibration is simulated by stepwise integration method. Secondly, the influence of stochastic parameters such as meshing damping, tooth side gap and excitation frequency on the dynamic response of gear nonlinear system is analyzed by using the stability analysis method such as bifurcation diagram and Lyapunov exponent method. The analysis shows that the stochastic process can not be neglected, which can cause the random bifurcation and chaos of the system response. This study will provide important reference value for vibration engineering designers.

The Influence Study of Ultrasonic honing parameters to workpiece surface temperature

Directory of Open Access Journals (Sweden)

Zhang Xiaoqiang

2016-01-01

Full Text Available Ultrasonic vibration honing(UVH, a machine technology, has a lot of advantages. Lower grinding temperature is a significant character and is beneficial for both processing and workpiece surface. But the high temperature caused by big honing pressure becomes the main factor to produce workpiece heat damage in grinding zone. In various honing parameter combinations, the showing effect is different. Based on the thermodynamics classical theory, established the heat transfer equation for grinding zone, simplified the model and obtained the two-dimenssion temperature field expression for workpiece, then simulated the temperature changing trend in a variety of conditions. It is shown that themain temp is in a range of 700K to 1200K. In addition, the variation is huge for every parameter. The study provides a theoretical basis for deeply seeking reasonable machining parameter and obtaining better workpiece quality.

The performance of a prototype device designed to evaluate general quality parameters of X-ray equipment

Science.gov (United States)

Murata, C. H.; Fernandes, D. C.; Lavínia, N. C.; Caldas, L. V. E.; Pires, S. R.; Medeiros, R. B.

2014-02-01

The performance of radiological equipment can be assessed using non-invasive methods and portable instruments that can analyze an X-ray beam with just one exposure. These instruments use either an ionization chamber or a state solid detector (SSD) to evaluate X-ray beam parameters. In Brazil, no such instruments are currently being manufactured; consequently, these instruments come at a higher cost to users due to importation taxes. Additionally, quality control tests are time consuming and impose a high workload on the X-ray tubes when evaluating their performance parameters. The assessment of some parameters, such as the half-value layer (HVL), requires several exposures; however, this can be reduced by using a SSD that requires only a single exposure. One such SSD uses photodiodes designed for high X-ray sensitivity without the use of scintillation crystals. This sensitivity allows one electron-hole pair to be created per 3.63 eV of incident energy, resulting in extremely high and stable quantum efficiencies. These silicon photodiodes operate by absorbing photons and generating a flow of current that is proportional to the incident power. The aim of this study was to show the response of the solid sensor PIN RD100A detector in a multifunctional X-ray analysis system that is designed to evaluate the average peak voltage (kVp), exposure time, and HVL of radiological equipment. For this purpose, a prototype board that uses four SSDs was developed to measure kVp, exposure time, and HVL using a single exposure. The reproducibility and accuracy of the results were compared to that of different X-ray beam analysis instruments. The kVp reproducibility and accuracy results were 2% and 3%, respectively; the exposure time reproducibility and accuracy results were 2% and 1%, respectively; and the HVL accuracy was ±2%. The prototype's methodology was able to calculate these parameters with appropriate reproducibility and accuracy. Therefore, the prototype can be considered

Studies of a general flat space/boson star transition model in a box through a language similar to holographic superconductors

Science.gov (United States)

Peng, Yan

2017-07-01

We study a general flat space/boson star transition model in quasi-local ensemble through approaches familiar from holographic superconductor theories. We manage to find a parameter ψ 2, which is proved to be useful in disclosing properties of phase transitions. In this work, we explore effects of the scalar mass, scalar charge and Stückelberg mechanism on the critical phase transition points and the order of transitions mainly from behaviors of the parameter ψ 2. We mention that properties of transitions in quasi-local gravity are strikingly similar to those in holographic superconductor models. We also obtain an analytical relation ψ 2 ∝ ( μ - μ c )1/2, which also holds for the condensed scalar operator in the holographic insulator/superconductor system in accordance with mean field theories.

Stakeholder experiences with general practice pharmacist services: a qualitative study.

Science.gov (United States)

Tan, Edwin C K; Stewart, Kay; Elliott, Rohan A; George, Johnson

2013-09-11

To explore general practice staff, pharmacist and patient experiences with pharmacist services in Australian general practice clinics within the Pharmacists in Practice Study. Qualitative study. Two general practice clinics in Melbourne, Australia, in which pharmacists provided medication reviews, patient and staff education, medicines information and quality assurance services over a 6-month period. Patients, practice staff and pharmacists. Semi-structured telephone interviews with patients, focus groups with practice staff and semi-structured interviews and periodic narrative reports with practice pharmacists. Data were analysed thematically and theoretical frameworks used to explain the findings. 34 participants were recruited: 18 patients, 14 practice staff (9 general practitioners, 4 practice nurses, 1 practice manager) and 2 practice pharmacists. Five main themes emerged: environment; professional relationships and integration; pharmacist attributes; staff and patient benefits and logistical challenges. Participants reported that colocation and the interdisciplinary environment of general practice enabled better communication and collaboration compared to traditional community and consultant pharmacy services. Participants felt that pharmacists needed to possess certain attributes to ensure successful integration, including being personable and proactive. Attitudinal, professional and logistical barriers were identified but were able to be overcome. The findings were explained using D'Amour's structuration model of collaboration and Roger's diffusion of innovation theory. This is the first qualitative study to explore the experiences of general practice staff, pharmacists and patients on their interactions within the Australian general practice environment. Participants were receptive of colocated pharmacist services, and various barriers and facilitators to integration were identified. Future research should investigate the feasibility and sustainability of

Characterizing parameters of Jatropha curcas cell cultures for microgravity studies

Science.gov (United States)

Vendrame, Wagner A.; Pinares, Ania

2013-06-01

Jatropha (Jatropha curcas) is a tropical perennial species identified as a potential biofuel crop. The oil is of excellent quality and it has been successfully tested as biodiesel and in jet fuel mixes. However, studies on breeding and genetic improvement of jatropha are limited. Space offers a unique environment for experiments aiming at the assessment of mutations and differential gene expression of crops and in vitro cultures of plants are convenient for studies of genetic variation as affected by microgravity. However, before microgravity studies can be successfully performed, pre-flight experiments are necessary to characterize plant material and validate flight hardware environmental conditions. Such preliminary studies set the ground for subsequent spaceflight experiments. The objectives of this study were to compare the in vitro growth of cultures from three explant sources (cotyledon, leaf, and stem sections) of three jatropha accessions (Brazil, India, and Tanzania) outside and inside the petriGAP, a modified group activation pack (GAP) flight hardware to fit petri dishes. In vitro jatropha cell cultures were established in petri dishes containing a modified MS medium and maintained in a plant growth chamber at 25 ± 2 °C in the dark. Parameters evaluated were surface area of the explant tissue (A), fresh weight (FW), and dry weight (DW) for a period of 12 weeks. Growth was observed for cultures from all accessions at week 12, including subsequent plantlet regeneration. For all accessions differences in A, FW and DW were observed for inside vs. outside the PetriGAPs. Growth parameters were affected by accession (genotype), explant type, and environment. The type of explant influenced the type of cell growth and subsequent plantlet regeneration capacity. However, overall cell growth showed no abnormalities. The present study demonstrated that jatropha in vitro cell cultures are suitable for growth inside PetriGAPs for a period of 12 weeks. The parameters

Calculation of generalized secant integral using binomial coefficients

International Nuclear Information System (INIS)

Guseinov, I.I.; Mamedov, B.A.

2004-01-01

A single series expansion relation is derived for the generalized secant (GS) integral in terms of binomial coefficients, exponential integrals and incomplete gamma functions. The convergence of the series is tested by the concrete cases of parameters. The formulas given in this study for the evaluation of GS integral show good rate of convergence and numerical stability

Probabilistic analysis of glass elements with three-parameter Weibull distribution

International Nuclear Information System (INIS)

Ramos, A.; Muniz-Calvente, M.; Fernandez, P.; Fernandez Cantel, A.; Lamela, M. J.

2015-01-01

Glass and ceramics present a brittle behaviour so a large scatter in the test results is obtained. This dispersion is mainly due to the inevitable presence of micro-cracks on its surface, edge defects or internal defects, which must be taken into account using an appropriate failure criteria non-deterministic but probabilistic. Among the existing probability distributions, the two or three parameter Weibull distribution is generally used in adjusting material resistance results, although the method of use thereof is not always correct. Firstly, in this work, the results of a large experimental programme using annealed glass specimens of different dimensions based on four-point bending and coaxial double ring tests was performed. Then, the finite element models made for each type of test, the adjustment of the parameters of the three-parameter Weibull distribution function (cdf) (λ: location, β: shape, d: scale) for a certain failure criterion and the calculation of the effective areas from the cumulative distribution function are presented. Summarizing, this work aims to generalize the use of the three-parameter Weibull function in structural glass elements with stress distributions not analytically described, allowing to apply the probabilistic model proposed in general loading distributions. (Author)

Pre-segmented 2-Step IMRT with subsequent direct machine parameter optimisation – a planning study

International Nuclear Information System (INIS)

Bratengeier, Klaus; Meyer, Jürgen; Flentje, Michael

2008-01-01

Modern intensity modulated radiotherapy (IMRT) mostly uses iterative optimisation methods. The integration of machine parameters into the optimisation process of step and shoot leaf positions has been shown to be successful. For IMRT segmentation algorithms based on the analysis of the geometrical structure of the planning target volumes (PTV) and the organs at risk (OAR), the potential of such procedures has not yet been fully explored. In this work, 2-Step IMRT was combined with subsequent direct machine parameter optimisation (DMPO-Raysearch Laboratories, Sweden) to investigate this potential. In a planning study DMPO on a commercial planning system was compared with manual primary 2-Step IMRT segment generation followed by DMPO optimisation. 15 clinical cases and the ESTRO Quasimodo phantom were employed. Both the same number of optimisation steps and the same set of objective values were used. The plans were compared with a clinical DMPO reference plan and a traditional IMRT plan based on fluence optimisation and consequent segmentation. The composite objective value (the weighted sum of quadratic deviations of the objective values and the related points in the dose volume histogram) was used as a measure for the plan quality. Additionally, a more extended set of parameters was used for the breast cases to compare the plans. The plans with segments pre-defined with 2-Step IMRT were slightly superior to DMPO alone in the majority of cases. The composite objective value tended to be even lower for a smaller number of segments. The total number of monitor units was slightly higher than for the DMPO-plans. Traditional IMRT fluence optimisation with subsequent segmentation could not compete. 2-Step IMRT segmentation is suitable as starting point for further DMPO optimisation and, in general, results in less complex plans which are equal or superior to plans generated by DMPO alone

Generalized Cherednik-Macdonald identities

NARCIS (Netherlands)

Stokman, J.V.

2008-01-01

We derive generalizations of the Cherednik-Macdonald constant term identities associated to root systems which depend, besides on the usual Multiplicity function, symmetrically on two additional parameters omega +/-. They are natural analogues of the Cherednik-Macdonald constant term q-identities in

Testing the generalized partial credit model

OpenAIRE

Glas, Cornelis A.W.

1996-01-01

The partial credit model (PCM) (G.N. Masters, 1982) can be viewed as a generalization of the Rasch model for dichotomous items to the case of polytomous items. In many cases, the PCM is too restrictive to fit the data. Several generalizations of the PCM have been proposed. In this paper, a generalization of the PCM (GPCM), a further generalization of the one-parameter logistic model, is discussed. The model is defined and the conditional maximum likelihood procedure for the method is describe...

Main hematological parameters of sturgeon species (Acipenseridae (review

Directory of Open Access Journals (Sweden)

M. Simon

2017-03-01

Full Text Available Purpose. To analyze scientific sources on the physiological, biochemical, ecological and genetic features of the main hematological paremeters and patterns of their variability in sturgeon species (Acipenseridae. To examine the fundamental aspects of lipid and protein metabolism in blood serum and the effect of biotic and abiotic factors on them. To highlight the common features of serum enzymes. Findings. A review of scientific papers revealed that although hematological parameters of sturgeons are generally similar to those of teleosts and mammals, there are a number of significant differences. In addition, many hematological parameters are characterized by species specificity, even within a family. Special attention is given to the variability of hematological parameters under the effect of factors of both internal and external environment. The paper describes the effects of sex and age, as well as the seasons of the year on the compositio of sturgeon blood. The fundamentals of the use of serum proteins in genetic and population studies are outlined. The features of the functioning of hemoglobin in sturgeon’s red blood cells are examined. The main hematological parameters involved in the formation and maturation of sexual products, and their effect on fertility are reviewed. For example, the spawners, which hadn’t put reproductive product, are characterized by a low rate of hemoglobin, increase in erythrocyte sedimentation speed and also a rise of the level of crude protein in blood and β-lipoproteid serum.The biochemical parameters (total protein and fractions, glucose, creatinine, cholesterol, the activity of some enzymes (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, creatine kinase in serum are examined. Practical value. The systematized data on the main hematological parameters and patterns of their variability in sturgeon species will be useful for both scientits and fish farmers. This is due to the

Genetic algorithm parameters tuning for resource-constrained project scheduling problem

Science.gov (United States)

Tian, Xingke; Yuan, Shengrui

2018-04-01

Project Scheduling Problem (RCPSP) is a kind of important scheduling problem. To achieve a certain optimal goal such as the shortest duration, the smallest cost, the resource balance and so on, it is required to arrange the start and finish of all tasks under the condition of satisfying project timing constraints and resource constraints. In theory, the problem belongs to the NP-hard problem, and the model is abundant. Many combinatorial optimization problems are special cases of RCPSP, such as job shop scheduling, flow shop scheduling and so on. At present, the genetic algorithm (GA) has been used to deal with the classical RCPSP problem and achieved remarkable results. Vast scholars have also studied the improved genetic algorithm for the RCPSP problem, which makes it to solve the RCPSP problem more efficiently and accurately. However, for the selection of the main parameters of the genetic algorithm, there is no parameter optimization in these studies. Generally, we used the empirical method, but it cannot ensure to meet the optimal parameters. In this paper, the problem was carried out, which is the blind selection of parameters in the process of solving the RCPSP problem. We made sampling analysis, the establishment of proxy model and ultimately solved the optimal parameters.

Cosmological perturbations in a family of deformations of general relativity

International Nuclear Information System (INIS)

Krasnov, Kirill; Shtanov, Yuri

2010-01-01

We study linear cosmological perturbations in a previously introduced family of deformations of general relativity characterized by the absence of new degrees of freedom. The homogeneous and isotropic background in this class of theories is unmodified and is described by the usual Friedmann equations. The theory of cosmological perturbations is modified and the relevant deformation parameter has the dimension of length. Gravitational perturbations of the scalar type can be described by a certain relativistic potential related to the matter perturbations just as in general relativity. A system of differential equations describing the evolution of this potential and of the stress-energy density perturbations is obtained. We find that the evolution of scalar perturbations proceeds with a modified effective time-dependent speed of sound, which, contrary to the case of general relativity, does not vanish even at the matter-dominated stage. In a broad range of values of the length parameter controlling the deformation, a specific transition from the regime of modified gravity to the regime of general relativity in the evolution of scalar perturbations takes place during the radiation domination. In this case, the resulting power spectrum of perturbations in radiation and dark matter is suppressed on the comoving spatial scales that enter the Hubble radius before this transition. We estimate the bounds on the deformation parameter for which this suppression does not lead to observable consequences. Evolution of scalar perturbations at the inflationary stage is modified but very slightly and the primordial spectrum generated during inflation is not noticeably different from the one obtained in general relativity

General principles of control method of passenger car bodies bending vibration parameters

Science.gov (United States)

Skachkov, A. N.; Samoshkin, S. L.; Korshunov, S. D.; Kobishchanov, V. V.; Antipin, D. Ya

2018-03-01

Weight reduction of passenger cars is a promising direction of reducing the cost of their production and increasing transportation profitability. One way to reduce the weight of passenger cars is the lightweight metal body design by means of using of high-strength aluminum alloys, low-alloy and stainless steels. However, it has been found that the limit of the lightweight metal body design is not determined by the total mode of deformation, but its flexural rigidity, as the latter influences natural frequencies of body bending vibrations. With the introduction of mandatory certification for compliance with the Customs Union technical regulations, the following index was confirmed: “first natural frequency of body bending vibrations in the vertical plane”. This is due to the fact that vibration, noise and car motion depend on this index. To define the required indexes, the principles of the control method of bending vibration parameters of passenger car bodies are proposed in this paper. This method covers all stages of car design – development of design documentation, manufacturing and testing experimental and pilot models, launching the production. The authors also developed evaluation criteria and the procedure of using the results for introduction of control method of bending vibration parameters of passenger car bodies.

Inhomogeneous Quantum Invariance Group of Multi-Dimensional Multi-parameter Deformed Boson Algebra

International Nuclear Information System (INIS)

Altintas Azmi Ali; Arik Metin; Arikan Ali Serdar; Dil Emre

2012-01-01

We investigate the inhomogeneous invariance quantum group of the d-dimensional d-parameter deformed boson algebra. It is found that the homogeneous part of this quantum group is given by the d-parameter deformed general linear group. We construct the R-matrix which collects all information about the non-commuting structure of the quantum group for the two-dimensional case. (general)

Accounting for parameter uncertainty in the definition of parametric distributions used to describe individual patient variation in health economic models

OpenAIRE

Degeling, Koen; IJzerman, Maarten J.; Koopman, Miriam; Koffijberg, Hendrik

2017-01-01

Background Parametric distributions based on individual patient data can be used to represent both stochastic and parameter uncertainty. Although general guidance is available on how parameter uncertainty should be accounted for in probabilistic sensitivity analysis, there is no comprehensive guidance on reflecting parameter uncertainty in the (correlated) parameters of distributions used to represent stochastic uncertainty in patient-level models. This study aims to provide this guidance by ...

Monte Carlo parameter studies and uncertainty analyses with MCNP5

International Nuclear Information System (INIS)

Brown, F. B.; Sweezy, J. E.; Hayes, R.

2004-01-01

A software tool called mcnp p study has been developed to automate the setup, execution, and collection of results from a series of MCNP5 Monte Carlo calculations. This tool provides a convenient means of performing parameter studies, total uncertainty analyses, parallel job execution on clusters, stochastic geometry modeling, and other types of calculations where a series of MCNP5 jobs must be performed with varying problem input specifications. (authors)

Generalized Chaplygin gas and cosmic microwave background radiation constraints

International Nuclear Information System (INIS)

Bento, M.C.; Bertolami, O.; Sen, A.A.

2003-01-01

We study the dependence of the location of the cosmic microwave background radiation peaks on the parameters of the generalized Chaplygin gas model, whose equation of state is given by p=-A/ρ α , where A is a positive constant and 0<α≤1. We find, in particular, that observational data arising from Archeops, BOOMERANG, supernova and high-redshift observations allow constraining significantly the parameter space of the model. Our analysis indicates that the emerging model is clearly distinguishable from the α=1 Chaplygin case and the ΛCDM model

Seismic analysis of steam generator and parameter sensitivity studies

International Nuclear Information System (INIS)

Qian Hao; Xu Dinggen; Yang Ren'an; Liang Xingyun

2013-01-01

Background: The steam generator (SG) serves as the primary means for removing the heat generated within the reactor core and is part of the reactor coolant system (RCS) pressure boundary. Purpose: Seismic analysis in required for SG, whose seismic category is Cat. I. Methods: The analysis model of SG is created with moisture separator assembly and tube bundle assembly herein. The seismic analysis is performed with RCS pipe and Reactor Pressure Vessel (RPV). Results: The seismic stress results of SG are obtained. In addition, parameter sensitivities of seismic analysis results are studied, such as the effect of another SG, support, anti-vibration bars (AVBs), and so on. Our results show that seismic results are sensitive to support and AVBs setting. Conclusions: The guidance and comments on these parameters are summarized for equipment design and analysis, which should be focused on in future new type NPP SG's research and design. (authors)

An MCMC Study of General Squark Flavour Mixing in the MSSM

Energy Technology Data Exchange (ETDEWEB)

Herrmann, Björn [Annecy, LAPTH; De Causmaecker, Karen [Intl. Solvay Inst., Brussels; Fuks, Benjamin [UPMC, Paris (main); Mahmoudi, Farvah [Lyon, Ecole Normale Superieure; O' Leary, Ben [Wurzburg U.; Porod, Werner [Wurzburg U.; Sekmen, Sezen [Kyungpook Natl. U.; Strobbe, Nadja [Fermilab

2015-10-05

We present an extensive study of non-minimally flavour violating (NMFV) terms in the Lagrangian of the Minimal Supersymmetric Standard Model (MSSM). We impose a variety of theoretical and experimental constraints and perform a detailed scan of the parameter space by means of a Markov Chain Monte-Carlo (MCMC) setup. This represents the first study of several non-zero flavour-violating elements within the MSSM. We present the results of the MCMC scan with a special focus on the flavour-violating parameters. Based on these results, we define benchmark scenarios for future studies of NMFV effects at the LHC.

Study on Material Parameters Identification of Brain Tissue Considering Uncertainty of Friction Coefficient

Science.gov (United States)

Guan, Fengjiao; Zhang, Guanjun; Liu, Jie; Wang, Shujing; Luo, Xu; Zhu, Feng

2017-10-01

Accurate material parameters are critical to construct the high biofidelity finite element (FE) models. However, it is hard to obtain the brain tissue parameters accurately because of the effects of irregular geometry and uncertain boundary conditions. Considering the complexity of material test and the uncertainty of friction coefficient, a computational inverse method for viscoelastic material parameters identification of brain tissue is presented based on the interval analysis method. Firstly, the intervals are used to quantify the friction coefficient in the boundary condition. And then the inverse problem of material parameters identification under uncertain friction coefficient is transformed into two types of deterministic inverse problem. Finally the intelligent optimization algorithm is used to solve the two types of deterministic inverse problems quickly and accurately, and the range of material parameters can be easily acquired with no need of a variety of samples. The efficiency and convergence of this method are demonstrated by the material parameters identification of thalamus. The proposed method provides a potential effective tool for building high biofidelity human finite element model in the study of traffic accident injury.

SIMULATION AND PREDICTION OF THE PROCESS BASED ON THE GENERAL LOGISTIC MAPPING

Directory of Open Access Journals (Sweden)

V. V. Skalozub

2013-11-01

Full Text Available Purpose. The aim of the research is to build a model of the generalzed logistic mapping and assessment of the possibilities of its use for the formation of the mathematical description, as well as operational forecasts of parameters of complex dynamic processes described by the time series. Methodology. The research results are obtained on the basis of mathematical modeling and simulation of nonlinear systems using the tools of chaotic dynamics. Findings. A model of the generalized logistic mapping, which is used to interpret the characteristics of dynamic processes was proposed. We consider some examples of representations of processes based on enhanced logistic mapping varying the values of model parameters. The procedures of modeling and interpretation of the data on the investigated processes, represented by the time series, as well as the operational forecasting of parameters using the generalized model of logistic mapping were proposed. Originality. The paper proposes an improved mathematical model, generalized logistic mapping, designed for the study of nonlinear discrete dynamic processes. Practical value. The carried out research using the generalized logistic mapping of railway transport processes, in particular, according to assessment of the parameters of traffic volumes, indicate the great potential of its application in practice for solving problems of analysis, modeling and forecasting complex nonlinear discrete dynamical processes. The proposed model can be used, taking into account the conditions of uncertainty, irregularity, the manifestations of the chaotic nature of the technical, economic and other processes, including the railway ones.

[Generalization of the Lotka-Volterra equation].

Science.gov (United States)

Nazarenko, V G

1976-01-01

A complete qualitative study of Lotka--Volterra model with cooperative interactions in the system predator-prey is carried out. The model is as follows: (see abstract). The character of all possible stationary states is investigated in the first quadrant of the phase plane of the model variables depending on the system parameters. It is shown that for the generalized model considered unstable and stable limit cycles only of the infinite amplitude are possible in the first quadrant.

The Legion Support for Advanced Parameter-Space Studies on a Grid

National Research Council Canada - National Science Library

Natrajan, Anand; Humphrey, Marty A; Grimshaw, Andrew S

2006-01-01

.... Legion provides tools and services that support advanced parameter-space studies, i.e., studies that make complex demands such as transparent access to distributed files, fault-tolerance and security. We demonstrate these benefits with a protein-folding experiment in which a molecular simulation package was run over a grid managed by Legion.

Physiological health parameters among college students to promote chronic disease prevention and health promotion

Directory of Open Access Journals (Sweden)

David R. Black

2017-09-01

Full Text Available This study aimed to provide physiologic health risk parameters by gender and age among college students enrolled in a U.S. Midwestern University to promote chronic disease prevention and ameliorate health. A total of 2615 college students between 18 and 25 years old were recruited annually using a series of cross-sectional designs during the spring semester over an 8-year period. Physiologic parameters measured included body mass index (BMI, percentage body fat (%BF, blood serum cholesterol (BSC, and systolic (SBP and diastolic (DBP blood pressure. These measures were compared to data from NHANES to identify differences in physiologic parameters among 18–25 year olds in the general versus college-enrolled population. A quantitative instrument assessed health behaviors related to physical activity, diet, and licit drug use. Results suggest that average physiologic parameters from 18 to 25 year olds enrolled in college were significantly different from parameters of 18–25 year olds in the general population. Generally, men reported higher percentiles for BMI, SBP, and DBP than women, but lower %BF and BSC percentiles than women at each age. SBP and DBP significantly increased with age and alcohol use. Students in the lowest (5th and highest percentiles (95th and 75th, for most age groups, demonstrated DBP, BMI, and %BF levels potentially problematic for health and future development of chronic disease based on percentiles generated for their peer group. Newly identified physiologic parameters may be useful to practitioners serving college students 18–25 years old from similar institutions in determining whether behavior change or treatment interventions are appropriate.

Quantum Walks on the Line with Phase Parameters

Science.gov (United States)

Villagra, Marcos; Nakanishi, Masaki; Yamashita, Shigeru; Nakashima, Yasuhiko

In this paper, a study on discrete-time coined quantum walks on the line is presented. Clear mathematical foundations are still lacking for this quantum walk model. As a step toward this objective, the following question is being addressed: Given a graph, what is the probability that a quantum walk arrives at a given vertex after some number of steps? This is a very natural question, and for random walks it can be answered by several different combinatorial arguments. For quantum walks this is a highly non-trivial task. Furthermore, this was only achieved before for one specific coin operator (Hadamard operator) for walks on the line. Even considering only walks on lines, generalizing these computations to a general SU(2) coin operator is a complex task. The main contribution is a closed-form formula for the amplitudes of the state of the walk (which includes the question above) for a general symmetric SU(2) operator for walks on the line. To this end, a coin operator with parameters that alters the phase of the state of the walk is defined. Then, closed-form solutions are computed by means of Fourier analysis and asymptotic approximation methods. We also present some basic properties of the walk which can be deducted using weak convergence theorems for quantum walks. In particular, the support of the induced probability distribution of the walk is calculated. Then, it is shown how changing the parameters in the coin operator affects the resulting probability distribution.

Optimal Designs for the Generalized Partial Credit Model

OpenAIRE

Bürkner, Paul-Christian; Schwabe, Rainer; Holling, Heinz

2018-01-01

Analyzing ordinal data becomes increasingly important in psychology, especially in the context of item response theory. The generalized partial credit model (GPCM) is probably the most widely used ordinal model and finds application in many large scale educational assessment studies such as PISA. In the present paper, optimal test designs are investigated for estimating persons' abilities with the GPCM for calibrated tests when item parameters are known from previous studies. We will derive t...

Generalized synchronization and coherent structures in spatially extended systems

International Nuclear Information System (INIS)

Basnarkov, Lasko; Duane, Gregory S.; Kocarev, Ljupco

2014-01-01

We study the synchronization of a coupled pair of one-dimensional Kuramoto–Sivashinsky systems, with equations augmented by a third-space-derivative term. With two different values of a system parameter, the two systems synchronize in the generalized sense. The phenomenon persists even in the extreme case when one of the equations is missing the extra term. Master–slave synchronization error is small, so the generalized synchronization relationship is useful for predicting the state of the master from that of the slave, or conversely, for controlling the slave. The spatial density of coupling points required to bring about generalized synchronization appears to be related to the wavelength of traveling wave solutions, and more generally to the width of coherent structures in the separate systems

Determining frequentist confidence limits using a directed parameter space search

International Nuclear Information System (INIS)

Daniel, Scott F.; Connolly, Andrew J.; Schneider, Jeff

2014-01-01

We consider the problem of inferring constraints on a high-dimensional parameter space with a computationally expensive likelihood function. We propose a machine learning algorithm that maps out the Frequentist confidence limit on parameter space by intelligently targeting likelihood evaluations so as to quickly and accurately characterize the likelihood surface in both low- and high-likelihood regions. We compare our algorithm to Bayesian credible limits derived by the well-tested Markov Chain Monte Carlo (MCMC) algorithm using both multi-modal toy likelihood functions and the seven yr Wilkinson Microwave Anisotropy Probe cosmic microwave background likelihood function. We find that our algorithm correctly identifies the location, general size, and general shape of high-likelihood regions in parameter space while being more robust against multi-modality than MCMC.

Study of Temperature Coefficients for Parameters of Photovoltaic Cells

Directory of Open Access Journals (Sweden)

Daniel Tudor Cotfas

2018-01-01

Full Text Available The temperature is one of the most important factors which affect the performance of the photovoltaic cells and panels along with the irradiance. The current voltage characteristics, I-V, are measured at different temperatures from 25°C to 87°C and at different illumination levels from 400 to 1000 W/m2, because there are locations where the upper limit of the photovoltaic cells working temperature exceeds 80°C. This study reports the influence of the temperature and the irradiance on the important parameters of four commercial photovoltaic cell types: monocrystalline silicon—mSi, polycrystalline silicon—pSi, amorphous silicon—aSi, and multijunction InGaP/InGaAs/Ge (Emcore. The absolute and normalized temperature coefficients are determined and compared with their values from the related literature. The variation of the absolute temperature coefficient function of the irradiance and its significance to accurately determine the important parameters of the photovoltaic cells are also presented. The analysis is made on different types of photovoltaics cells in order to understand the effects of technology on temperature coefficients. The comparison between the open-circuit voltage and short-circuit current was also performed, calculated using the temperature coefficients, determined, and measured, in various conditions. The measurements are realized using the SolarLab system, and the photovoltaic cell parameters are determined and compared using the LabVIEW software created for SolarLab system.

Preoperative nutrition status and postoperative outcome in elderly general surgery patients: a systematic review.

Science.gov (United States)

van Stijn, Mireille F M; Korkic-Halilovic, Ines; Bakker, Marjan S M; van der Ploeg, Tjeerd; van Leeuwen, Paul A M; Houdijk, Alexander P J

2013-01-01

Poor nutrition status is considered a risk factor for postoperative complications in the adult population. In elderly patients, who often have a poor nutrition status, this relationship has not been substantiated. Thus, the aim of this systematic review was to assess the merit of preoperative nutrition parameters used to predict postoperative outcome in elderly patients undergoing general surgery. A systematic literature search of 10 consecutive years, 1998-2008, in PubMed, EMBASE, and Cochrane databases was performed. Search terms used were nutrition status, preoperative assessment, postoperative outcome, and surgery (hip or general), including their synonyms and MeSH terms. Limits used in the search were human studies, published in English, and age (65 years or older). Articles were screened using inclusion and exclusion criteria. All selected articles were checked on methodology and graded. Of 463 articles found, 15 were included. They showed profound heterogeneity in the parameters used for preoperative nutrition status and postoperative outcome. The only significant preoperative predictors of postoperative outcome in elderly general surgery patients were serum albumin and ≥ 10% weight loss in the previous 6 months. This systematic review revealed only 2 preoperative parameters to predict postoperative outcome in elderly general surgery patients: weight loss and serum albumin. Both are open to discussion in their use as a preoperative nutrition parameter. Nonetheless, serum albumin seems a reliable preoperative parameter to identify a patient at risk for nutrition deterioration and related complicated postoperative course.

Study of Material Densification of In718 in the Higher Throughput Parameter Regime

Science.gov (United States)

Cordner, Samuel

2016-01-01

Selective Laser Melting (SLM) is a powder bed fusion additive manufacturing process used increasingly in the aerospace industry to reduce the cost, weight, and fabrication time for complex propulsion components. Previous optimization studies for SLM using the Concept Laser M1 and M2 machines at NASA Marshall Space Flight Center have centered on machine default parameters. The objective of this project is to characterize how heat treatment affects density and porosity from a microscopic point of view. This is performs using higher throughput parameters (a previously unexplored region of the manufacturing operating envelope for this application) on material consolidation. Density blocks were analyzed to explore the relationship between build parameters (laser power, scan speed, and hatch spacing) and material consolidation (assessed in terms of density and porosity). The study also considers the impact of post-processing, specifically hot isostatic pressing and heat treatment, as well as deposition pattern on material consolidation in the higher energy parameter regime. Metallurgical evaluation of specimens will also be presented. This work will contribute to creating a knowledge base (understanding material behavior in all ranges of the AM equipment operating envelope) that is critical to transitioning AM from the custom low rate production sphere it currently occupies to the world of mass high rate production, where parts are fabricated at a rapid rate with confidence that they will meet or exceed all stringent functional requirements for spaceflight hardware. These studies will also provide important data on the sensitivity of material consolidation to process parameters that will inform the design and development of future flight articles using SLM.

Generalized Ordinary Differential Equation Models.

Science.gov (United States)

Miao, Hongyu; Wu, Hulin; Xue, Hongqi

2014-10-01

Existing estimation methods for ordinary differential equation (ODE) models are not applicable to discrete data. The generalized ODE (GODE) model is therefore proposed and investigated for the first time. We develop the likelihood-based parameter estimation and inference methods for GODE models. We propose robust computing algorithms and rigorously investigate the asymptotic properties of the proposed estimator by considering both measurement errors and numerical errors in solving ODEs. The simulation study and application of our methods to an influenza viral dynamics study suggest that the proposed methods have a superior performance in terms of accuracy over the existing ODE model estimation approach and the extended smoothing-based (ESB) method.

An Evaluation of the Instruction of Generalization in Elementary School Social Studies Program

Directory of Open Access Journals (Sweden)

Mükerrem AKBULUT TAŞ

2011-11-01

Full Text Available Generalizations are important content materials that should be instructed in the Social Studies program. The instruction of generalizations and the causal relationships emphasized in generalizations are important for students to have meaningful learning experiences and to gain causal reasoning and critical thinking skills. Social Studies program emphasizes the acquisition of creating scientific generalization skill as a fundamental skill to be instructed directly, and the importance of generalization instruction is highlighted. Therefore, this study is important in that it draws attention to the importance of teaching generalization and creates basis for the future research in the field. In this regard, it aims at evaluating the instruction of the generalizations in the “Our Country and the World” unit in Social Studies program for 6th grades in Primary School. In line with this general purpose, the instruction of the generalizations in the unit was analyzed qualitatively. The study was conducted with three social studies teachers working in three different schools located in Seyhan, Adana. The data were collected through the observation technique with a view to obtaining in depth data about the instruction of generalization in social studies lesson. Semi-structured observation form, prepared in the light of the generalization content elements, was used as the data collection tool. These content elements consisted of four aspects: generalization statement, concepts related to generalization, cause-effect relationships between concepts, and facts about generalization. In addition to observation, document analysis was conducted with a view to supporting results and strengthening the implications. The documentary analysis was performed based on the generalizations and previously identified elements about the generalizations in the scope of the six topics in the “Our Country and the World” unit. The data collected from the observations were

Determination of complex microcalorimeter parameters with impedance measurements

International Nuclear Information System (INIS)

Saab, T.; Bandler, S.R.; Chervenak, J.; Figueroa-Feliciano, E.; Finkbeiner, F.; Iyomoto, N.; Kelley, R.L.; Kilbourne, C.A.; Lindeman, M.A.; Porter, F.S.; Sadleir, J.

2006-01-01

The proper understanding and modeling of a microcalorimeter's response requires accurate knowledge of a handful of parameters, such as C, G, α. While a few of these parameters are directly determined from the IV characteristics, some others, notoriously the heat capacity (C) and α, appear in degenerate combinations in most measurable quantities. The consideration of a complex microcalorimeter leads to an added ambiguity in the determination of the parameters. In general, the dependence of the microcalorimeter's complex impedance on these various parameters varies with frequency. This dependence allows us to determine individual parameters by fitting the prediction of the microcalorimeter model to impedance data. In this paper we describe efforts at characterizing the Goddard X-ray microcalorimeters. With the parameters determined by this method, we compare the pulse shape and noise spectra predictions to data taken with the same devices

On the study of level density parameters for some deformed light nuclei

International Nuclear Information System (INIS)

Sonmezoglu, S.

2005-01-01

The nuclear level density, which is the number of energy levels/MeV at an excitation energy Ex , is a characteristic property of every nucleus. Total level densities are among the key quantities in statistical calculations in many fields, such as nuclear physics, astrophysics, spallation s neutrons measurements, and studies of intermediate-energy heavy-ion collisions. The nuclear level density is an important physical quantity both from the fundamental point of view as well as in understanding the particle and gamma ray emission in various reactions. In light and heavy deformed nucleus, the gamma-ray energies drop with decreasing spin in a very regular fashion. The nuclear level density parameters have been usually used in investigation of the nuclear level density. This parameter itself changes with excitation energy depending on both shell effect in the single particle model and different excitation modes in the collective models. In this study, the energy level density parameters of some deformed light nucleus (40 C a, 47 T i, 59 N i, 79 S e, 80 B r) are determined by using energy spectrum of the interest nucleus for different band. In calculation of energy-level density parameters dependent upon excitation energy of nuclei studied, a model was considered which relies on the fact that energy levels of deformed light nuclei, just like those of deformed heavy nuclei, are equidistant and which relies on collective motions of their nucleons. The present calculation results have been compared with the corresponding experimental and theoretical results. The obtained results are in good agreement with the experimental results

Study of some parameters of the fibrinogen - fibrin transformation reaction

International Nuclear Information System (INIS)

Hollard, D.; Suscillon, M.; Marcille, G.; Rambaud, F.; Baloyan, M.

1966-01-01

The authors studied the action of some parameters on the reaction of transformation fibrinogen-fibrin. The five parameters studied are: the concentration of substratum: a certain quantity of enzyme determines an optimum quantity of fibrinogen; the concentration of enzyme: a certain quantity of substratum defines an optimum quantity of enzyme, beyond which the excess of enzyme is unable to act, the substratum being saturated by the enzyme; the concentration of Ca ions: between 0,07 and 0,10 mg of Ca by mg of fibrinogen, the reaction appears with a great speed. Between 0,02 and 0,40 mg of Ca by mg of fibrinogen the fibrin stabilisation is possible, the FSF can act only inside the definite bounds; the ph of the solution: the reaction of the transformation appears with its maximum intensity on physiological ph, the polymerisation is not possible on acid ph; the temperature has an effect which could not really be verified owing to the fact that the technical realisation is difficult. (author) [fr

Kerr-Taub-NUT General Frame, Energy, and Momentum in Teleparallel Equivalent of General Relativity

Directory of Open Access Journals (Sweden)

Gamal G. L. Nashed

2012-01-01

Full Text Available A new exact solution describing a general stationary and axisymmetric object of the gravitational field in the framework of teleparallel equivalent of general relativity (TEGR is derived. The solution is characterized by three parameters “the gravitational mass M, the rotation a, and the NUT L.” The vierbein field is axially symmetric, and the associated metric gives the Kerr-Taub-NUT spacetime. Calculation of the total energy using two different methods, the gravitational energy momentum and the Riemannian connection 1-form Γα̃β, is carried out. It is shown that the two methods give the same results of energy and momentum. The value of energy is shown to depend on the mass M and the NUT parameter L. If L is vanishing, then the total energy reduced to the energy of Kerr black hole.

Nodes in an alternatively defined order parameter in HTSC

Science.gov (United States)

Nettel, Stephen

2008-10-01

In a previous study the BCS wave function was generalized to include the motion of the center-of-mass of Cooper pairs. It was found that the Ginsburg-Landau order parameter could be identified with a wave function describing this motion. Here attention is focussed on the effects of replacing free electron orbitals by Bloch waves. In the copper oxides, where the Fermi surface lies contiguous to the Brillouin zone boundary, and with pairs coupled by soft phonon modes, limitations on the wave vectors associated with the center-of-mass coordinates are found. These limitations lead to nodes in the Fourier transform of the Ginsburg-Landau order parameter. Possible relevance of the nodes to the more recently discovered properties of high TC superconductors is discussed.

Nodes in an alternatively defined order parameter in HTSC

International Nuclear Information System (INIS)

Nettel, Stephen

2008-01-01

In a previous study the BCS wave function was generalized to include the motion of the center-of-mass of Cooper pairs. It was found that the Ginsburg-Landau order parameter could be identified with a wave function describing this motion. Here attention is focussed on the effects of replacing free electron orbitals by Bloch waves. In the copper oxides, where the Fermi surface lies contiguous to the Brillouin zone boundary, and with pairs coupled by soft phonon modes, limitations on the wave vectors associated with the center-of-mass coordinates are found. These limitations lead to nodes in the Fourier transform of the Ginsburg-Landau order parameter. Possible relevance of the nodes to the more recently discovered properties of high T C superconductors is discussed

Casimir pistons with general boundary conditions

Directory of Open Access Journals (Sweden)

Guglielmo Fucci

2015-02-01

Full Text Available In this work we analyze the Casimir energy and force for a scalar field endowed with general self-adjoint boundary conditions propagating in a higher dimensional piston configuration. The piston is constructed as a direct product I×N, with I=[0,L]⊂R and N a smooth, compact Riemannian manifold with or without boundary. The study of the Casimir energy and force for this configuration is performed by employing the spectral zeta function regularization technique. The obtained analytic results depend explicitly on the spectral zeta function associated with the manifold N and the parameters describing the general boundary conditions imposed. These results are then specialized to the case in which the manifold N is a d-dimensional sphere.

Parameter uncertainty in simulations of extreme precipitation and attribution studies.

Science.gov (United States)

Timmermans, B.; Collins, W. D.; O'Brien, T. A.; Risser, M. D.

2017-12-01

The attribution of extreme weather events, such as heavy rainfall, to anthropogenic influence involves the analysis of their probability in simulations of climate. The climate models used however, such as the Community Atmosphere Model (CAM), employ approximate physics that gives rise to "parameter uncertainty"—uncertainty about the most accurate or optimal values of numerical parameters within the model. In particular, approximate parameterisations for convective processes are well known to be influential in the simulation of precipitation extremes. Towards examining the impact of this source of uncertainty on attribution studies, we investigate the importance of components—through their associated tuning parameters—of parameterisations relating to deep and shallow convection, and cloud and aerosol microphysics in CAM. We hypothesise that as numerical resolution is increased the change in proportion of variance induced by perturbed parameters associated with the respective components is consistent with the decreasing applicability of the underlying hydrostatic assumptions. For example, that the relative influence of deep convection should diminish as resolution approaches that where convection can be resolved numerically ( 10 km). We quantify the relationship between the relative proportion of variance induced and numerical resolution by conducting computer experiments that examine precipitation extremes over the contiguous U.S. In order to mitigate the enormous computational burden of running ensembles of long climate simulations, we use variable-resolution CAM and employ both extreme value theory and surrogate modelling techniques ("emulators"). We discuss the implications of the relationship between parameterised convective processes and resolution both in the context of attribution studies and progression towards models that fully resolve convection.

New general relativity

International Nuclear Information System (INIS)

Hayashi, K.; Shirafuji, T.

1979-01-01

A gravitational theory is formulated on the Weitzenboeck space-time, characterized by the vanishing curvature tensor (absolute parallelism) and by the torsion tensor formed of four parallel vector fields. This theory is called new general relativity, since Einstein in 1928 first gave its original form. New general relativity has three parameters c 1 , c 2 , and lambda, besides the Einstein constant kappa. In this paper we choose c 1 = 0 = c 2 , leaving open lambda. We prove, among other things, that (i) a static, spherically symmetric gravitational field is given by the Schwarzschild metric, that (ii) in the weak-field approximation an antisymmetric field of zero mass and zero spin exists, besides gravitons, and that (iii) new general relativity agrees with all the experiments so far carried out

Hypergeometric Functions with Integral Parameter Differences

DEFF Research Database (Denmark)

Karlsson, Per W.

1971-01-01

For a generalized hypergeometric function pFq(z) with positive integral differences between certain numerator and denominator parameters, a formula expressing the pFq(z) as a finite sum of lower-order functions is proved. From this formula, Minton's two summation theorems for p = q + 1, z = 1...

Parameter Optimisation for the Behaviour of Elastic Models over Time

DEFF Research Database (Denmark)

Mosegaard, Jesper

2004-01-01

Optimisation of parameters for elastic models is essential for comparison or finding equivalent behaviour of elastic models when parameters cannot simply be transferred or converted. This is the case with a large range of commonly used elastic models. In this paper we present a general method tha...

Thermal neutron diffusion parameters in homogeneous mixtures

Energy Technology Data Exchange (ETDEWEB)

Drozdowicz, K.; Krynicka, E. [Institute of Nuclear Physics, Cracow (Poland)

1995-12-31

A physical background is presented for a computer program which calculates the thermal neutron diffusion parameters for homogeneous mixtures of any compounds. The macroscopic absorption, scattering and transport cross section of the mixture are defined which are generally function of the incident neutron energy. The energy-averaged neutron parameters are available when these energy dependences and the thermal neutron energy distribution are assumed. Then the averaged diffusion coefficient and the pulsed thermal neutron parameters (the absorption rare and the diffusion constant) are also defined. The absorption cross section is described by the 1/v law and deviations from this behaviour are considered. The scattering cross section can be assumed as being almost constant in the thermal neutron region (which results from the free gas model). Serious deviations are observed for hydrogen atoms bound in molecules and a special study in the paper is devoted to this problem. A certain effective scattering cross section is found in this case on a base of individual exact data for a few hydrogenous media. Approximations assumed for the average cosine of the scattering angle are also discussed. The macroscopic parameters calculated are averaged over the Maxwellian energy distribution for the thermal neutron flux. An information on the input data for the computer program is included. (author). 10 refs, 4 figs, 5 tabs.

Thermal neutron diffusion parameters in homogeneous mixtures

International Nuclear Information System (INIS)

Drozdowicz, K.; Krynicka, E.

1995-01-01

A physical background is presented for a computer program which calculates the thermal neutron diffusion parameters for homogeneous mixtures of any compounds. The macroscopic absorption, scattering and transport cross section of the mixture are defined which are generally function of the incident neutron energy. The energy-averaged neutron parameters are available when these energy dependences and the thermal neutron energy distribution are assumed. Then the averaged diffusion coefficient and the pulsed thermal neutron parameters (the absorption rare and the diffusion constant) are also defined. The absorption cross section is described by the 1/v law and deviations from this behaviour are considered. The scattering cross section can be assumed as being almost constant in the thermal neutron region (which results from the free gas model). Serious deviations are observed for hydrogen atoms bound in molecules and a special study in the paper is devoted to this problem. A certain effective scattering cross section is found in this case on a base of individual exact data for a few hydrogenous media. Approximations assumed for the average cosine of the scattering angle are also discussed. The macroscopic parameters calculated are averaged over the Maxwellian energy distribution for the thermal neutron flux. An information on the input data for the computer program is included. (author). 10 refs, 4 figs, 5 tabs

Engineering parameters for expansion of MPT berths, Goa

Digital Repository Service at National Institute of Oceanography (India)

Jayakumar, S.; Chandramohan, P.; Jena, B.K.; Pednekar, P.S.

Comprehensive program for a harbour development and management requires general and detailed information on the coastal environment including engineering characteristics in addition to physical, chemical and biological parameters. Mormugao Port...

Testing a generalized cubic Galileon gravity model with the Coma Cluster

Energy Technology Data Exchange (ETDEWEB)

Terukina, Ayumu; Yamamoto, Kazuhiro; Okabe, Nobuhiro [Department of Physical Sciences, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Matsushita, Kyoko; Sasaki, Toru, E-mail: telkina@theo.phys.sci.hiroshima-u.ac.jp, E-mail: kazuhiro@hiroshima-u.ac.jp, E-mail: okabe@hiroshima-u.ac.jp, E-mail: matusita@rs.kagu.tus.ac.jp, E-mail: j1213703@ed.tus.ac.jp [Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan)

2015-10-01

We obtain a constraint on the parameters of a generalized cubic Galileon gravity model exhibiting the Vainshtein mechanism by using multi-wavelength observations of the Coma Cluster. The generalized cubic Galileon model is characterized by three parameters of the turning scale associated with the Vainshtein mechanism, and the amplitude of modifying a gravitational potential and a lensing potential. X-ray and Sunyaev-Zel'dovich (SZ) observations of the intra-cluster medium are sensitive to the gravitational potential, while the weak-lensing (WL) measurement is specified by the lensing potential. A joint fit of a complementary multi-wavelength dataset of X-ray, SZ and WL measurements enables us to simultaneously constrain these three parameters of the generalized cubic Galileon model for the first time. We also find a degeneracy between the cluster mass parameters and the gravitational modification parameters, which is influential in the limit of the weak screening of the fifth force.

Hematological parameters in children with Down syndrome

Directory of Open Access Journals (Sweden)

Renato Nisihara

2015-04-01

Full Text Available Introduction: There are few studies that investigated whether Down syndrome (DS interferes with references values for complete blood counts (CBC test in children with the syndrome. Objective: This study aimed to analyze the results of CBC performed in children with DS. Patients and methods: Data from CBC of DS children were included; at the time of examination they were aged between 2 and 10 years and had no clinical signs and/or symptoms of infectious disease. The hematological parameters analyzed were: total number of erythrocytes (RBC, hemoglobin (Hb concentration, hematological indices, platelet count, and total number of leucocytes. Additionally, we compared the collected parameters according to gender and age of the children studied. Results: A total of 203 CBC (100 girls and 103 boys were evaluated. In general, no significant differences were observed in studied parameters between the values found in samples of DS children and the values described in the literature as a reference for children in this age group. No difference in the prevalence of anemia was observed in relation to gender (p = 0.33, 14/103 (13.6% boys, and 11/100 (11% girls had anemia. However, the Hb and hematological indices values found in boys was significantly lower than in girls (p < 0.001. Conclusion: This investigation is the first one in Brazil to present and analyze the CBC results of DS children, reporting that their hematological indices are within the expected range for children without DS. Additionally, it was found that 12.3% of them had anemia.

A new concept of safety parameter display system

International Nuclear Information System (INIS)

Martinez, A.S.; Oliveira, L.F.S. de; Schirru, R.; Thome Filho, Z.D.; Silva, R.A. da.

1986-07-01

A general description of Angra-1 Parameter Display System (SSPA), a real time and on-line computerized monitoring system for the parameters related to the power plant safety is presented. This system has the main purpose of diminish the load on the Angra-1 power plant operators at an emergency event by supplying them with the additional tools serving as the basis for a prompt identification of the accident. The SSPA is a kind of safety parameter display system whose concept was introduced after Three Mile Island accident in USA. The SSPA comprises two nuclear applications independently considered. They are included into the Parameters Monitoring Integrated System (SIMP) and the safety critical function system (SFCS). (Author) [pt

Parameter studies of sediments in the Storegga Slide region

Science.gov (United States)

Yang, S. L.; Kvalstad, T.; Solheim, A.; Forsberg, C. F.

2006-09-01

Based on classification tests, oedometer tests, fall-cone tests and triaxial tests, physical and mechanical properties of sediments in the Storegga Slide region were analysed to assess parameter interrelationships. The data show good relationships between a number of physical and mechanical parameters. Goodness of fit between compression index and various physical parameters can be improved by multiple regression analysis. The interclay void ratio and liquidity index correlate well with the undrained shear strength of clay. Sediments with higher water content, liquid limit, activity, interclay void ratio, plasticity index and liquidity index showed higher compression index and/or lower undrained shear strength. Some relationships between parameters were tested by using data from two other sites south of the Storegga Slide. A better understanding of properties of sediments in regions such as that of the Storegga Slide can be obtained through this approach.

S-parameter at Non-Zero Temperature and Chemical Potential

DEFF Research Database (Denmark)

Søndergaard, Ulrik Ishøj; Sannino, Francesco; Pica, Claudio

2011-01-01

We compute the finite-temperature and matter density corrections to the S-parameter at the one loop level. At non-zero temperature T and matter density Lorentz symmetry breaks and therefore we suggest a suitable generalization of the S-parameter. By computing the plasma correction, we discover...... a reduction of the S-parameter in the physically relevant region of small external momenta for any non-zero chemical potential and T. In particular, the S-parameter vanishes at small m/T, where m is the mass of the fermions, due to the finite extent of the temporal direction. Our results are directly...

MALIGNANT OBSTRUCTIVE JAUNDICE: A STUDY OF INVESTIGATIVE PARAMETERS AND ITS OUTCOME

Directory of Open Access Journals (Sweden)

Tilakdas S. Shetty

2016-08-01

Full Text Available BACKGROUND Obstructive jaundice is a surgical condition that occurs when there is an obstruction to the passage of conjugated bilirubin from the liver cells to the intestine. This study has studied five clinical and nine laboratory parameters in patients presenting with malignant obstructive jaundice along with their radiological findings. By studying these parameters, the prognosis of patients with malignant obstructive jaundice and the best possible intervention could be predicted. AIM To study the various aetiopathological aspects associated with obstructive jaundice and investigative parameters of these patients thereby evaluating the prognosis. MATERIALS AND METHODS This observational study has been conducted in a tertiary institute by collecting data of 50 cases of malignant obstructive jaundice admitted to the surgical wards of BYL Nair Hospital from August 2011 to August 2014 with followup of 3 months to obtain mortality data. Male and female patients above 18 years and below 80 years of age with histologically proven malignant obstructive jaundice were included as part of this study. Data of retrospective cases were obtained from Medical Record section without disclosing the address or identification of the patient. RESULTS In this study, a total of 50 cases of histologically proven malignant obstructive jaundice were evaluated. 50 patients were studied out of which 33 were male and 17 were female. Majority of the patients were in the age group of 61-70 years i.e. 21 of them. 11 patients were between 41-50 years of age, 10 were less than 40 years of age and 8 were between 51-60 years. The most common presentation of the patients was with yellowish discolouration of sclera and urine (YDS/YDU seen in 44 patients followed by pruritus seen in 38 patients. Dilated Common Bile Duct with/without pancreatic duct dilatation was the most common finding on sonography followed by a mass seen in the head of the pancreas. Moderately differentiated

SITE-94. Chemical and physical transport parameters for SITE-94

Energy Technology Data Exchange (ETDEWEB)

Andersson, Karin [Chalmers Univ. of Technology, Goeteborg (Sweden). Technical Environmental Planning

1996-02-01

Important parameters are the interactions of radionuclides with solid surfaces, parameters describing the geometrical conditions like porosity, data on water composition (ionic strength, pH, redox conditions, complex formers etc) and data on the solids that may be of importance to the water and radionuclide chemistry. In this report some of these data of relevance for the Aespoe site are discussed. Based on a literature survey, sorption data as well as values for some other parameters have been selected for rock, fracture fillings and bentonite relevant to the chemical conditions in and around a repository at Aespoe. A comparison to data used for earlier, site-specific as well as general, safety assessments of underground repositories has been performed. The data are recommendations for modelling of radionuclide release from a hypothetical high level waste repository at Aespoe. Since the data to a large extent are not based on experimental measurements, more accurate predictions may be expected if more experimental data are available. Before such studies are performed for a specific site, a variational analysis in order to evaluate the importance of the single parameters is recommended. After such a study, the key parameters may be investigated in detail and the modelling can be expected to be more accurate what concerns influence of single parameters. However, the uncertainty in conceptual areas like how to model accurately the long term hydrology of the site etc still remains. 32 refs.

Renewal processes based on generalized Mittag-Leffler waiting times

Science.gov (United States)

Cahoy, Dexter O.; Polito, Federico

2013-03-01

The fractional Poisson process has recently attracted experts from several fields of study. Its natural generalization of the ordinary Poisson process made the model more appealing for real-world applications. In this paper, we generalized the standard and fractional Poisson processes through the waiting time distribution, and showed their relations to an integral operator with a generalized Mittag-Leffler function in the kernel. The waiting times of the proposed renewal processes have the generalized Mittag-Leffler and stretched-squashed Mittag-Leffler distributions. Note that the generalizations naturally provide greater flexibility in modeling real-life renewal processes. Algorithms to simulate sample paths and to estimate the model parameters are derived. Note also that these procedures are necessary to make these models more usable in practice. State probabilities and other qualitative or quantitative features of the models are also discussed.

Study of the characteristic parameters of the normal voices of Argentinian speakers

Directory of Open Access Journals (Sweden)

Edgardo Bonzi

2014-02-01

Full Text Available The voice laboratory permits to study the human voices using a method that is objective and noninvasive. In this work, we have studied the parameters of the human voice such as pitch, formant, jitter, shimmer and harmonic-noise ratio of a group of young people. This statistical information of parameters is obtained from Argentinian speakers. Received: 29 December 2013, Accepted: 27 May 2014; Reviewed by: J. Brum, Instituto de Física, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Edited by: E. Mizraji; DOI: http://dx.doi.org/10.4279/PIP.060002 Cite as: E V Bonzi, G B Grad, A M Maggi, M R Muñoz, Papers in Physics 6, 060002 (2014

Relative sensitivity of developmental and immune parameters in juvenile versus adult male rats after exposure to di(2-ethylhexyl) phthalate

International Nuclear Information System (INIS)

Tonk, Elisa C.M.; Verhoef, Aart; Gremmer, Eric R.; Loveren, Henk van; Piersma, Aldert H.

2012-01-01

The developing immune system displays a relatively high sensitivity as compared to both general toxicity parameters and to the adult immune system. In this study we have performed such comparisons using di(2-ethylhexyl) phthalate (DEHP) as a model compound. DEHP is the most abundant phthalate in the environment and perinatal exposure to DEHP has been shown to disrupt male sexual differentiation. In addition, phthalate exposure has been associated with immune dysfunction as evidenced by effects on the expression of allergy. Male wistar rats were dosed with corn oil or DEHP by gavage from postnatal day (PND) 10–50 or PND 50–90 at doses between 1 and 1000 mg/kg/day. Androgen-dependent organ weights showed effects at lower dose levels in juvenile versus adult animals. Immune parameters affected included TDAR parameters in both age groups, NK activity in juvenile animals and TNF-α production by adherent splenocytes in adult animals. Immune parameters were affected at lower dose levels compared to developmental parameters. Overall, more immune parameters were affected in juvenile animals compared to adult animals and effects were observed at lower dose levels. The results of this study show a relatively higher sensitivity of juvenile versus adult rats. Furthermore, they illustrate the relative sensitivity of the developing immune system in juvenile animals as compared to general toxicity and developmental parameters. This study therefore provides further argumentation for performing dedicated developmental immune toxicity testing as a default in regulatory toxicology. -- Highlights: ► In this study we evaluate the relative sensitivities for DEHP induced effects. ► Results of this study demonstrate the age-dependency of DEHP toxicity. ► Functional immune parameters were more sensitive than structural immune parameters. ► Immune parameters were affected at lower dose levels than developmental parameters. ► Findings demonstrate the susceptibility of the

Relative sensitivity of developmental and immune parameters in juvenile versus adult male rats after exposure to di(2-ethylhexyl) phthalate

Energy Technology Data Exchange (ETDEWEB)

Tonk, Elisa C.M., E-mail: ilse.tonk@rivm.nl [Department of Toxicogenomics, Maastricht University, Maastricht (Netherlands); Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Verhoef, Aart; Gremmer, Eric R. [Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Loveren, Henk van [Department of Toxicogenomics, Maastricht University, Maastricht (Netherlands); Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Piersma, Aldert H. [Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Institute for Risk Assessment Sciences, Veterinary Faculty, Utrecht University, Utrecht (Netherlands)

2012-04-01

The developing immune system displays a relatively high sensitivity as compared to both general toxicity parameters and to the adult immune system. In this study we have performed such comparisons using di(2-ethylhexyl) phthalate (DEHP) as a model compound. DEHP is the most abundant phthalate in the environment and perinatal exposure to DEHP has been shown to disrupt male sexual differentiation. In addition, phthalate exposure has been associated with immune dysfunction as evidenced by effects on the expression of allergy. Male wistar rats were dosed with corn oil or DEHP by gavage from postnatal day (PND) 10–50 or PND 50–90 at doses between 1 and 1000 mg/kg/day. Androgen-dependent organ weights showed effects at lower dose levels in juvenile versus adult animals. Immune parameters affected included TDAR parameters in both age groups, NK activity in juvenile animals and TNF-α production by adherent splenocytes in adult animals. Immune parameters were affected at lower dose levels compared to developmental parameters. Overall, more immune parameters were affected in juvenile animals compared to adult animals and effects were observed at lower dose levels. The results of this study show a relatively higher sensitivity of juvenile versus adult rats. Furthermore, they illustrate the relative sensitivity of the developing immune system in juvenile animals as compared to general toxicity and developmental parameters. This study therefore provides further argumentation for performing dedicated developmental immune toxicity testing as a default in regulatory toxicology. -- Highlights: ► In this study we evaluate the relative sensitivities for DEHP induced effects. ► Results of this study demonstrate the age-dependency of DEHP toxicity. ► Functional immune parameters were more sensitive than structural immune parameters. ► Immune parameters were affected at lower dose levels than developmental parameters. ► Findings demonstrate the susceptibility of the

Parameter Uncertainty on AGCM-simulated Tropical Cyclones

Science.gov (United States)

He, F.

2015-12-01

This work studies the parameter uncertainty on tropical cyclone (TC) simulations in Atmospheric General Circulation Models (AGCMs) using the Reed-Jablonowski TC test case, which is illustrated in Community Atmosphere Model (CAM). It examines the impact from 24 parameters across the physical parameterization schemes that represent the convection, turbulence, precipitation and cloud processes in AGCMs. The one-at-a-time (OAT) sensitivity analysis method first quantifies their relative importance on TC simulations and identifies the key parameters to the six different TC characteristics: intensity, precipitation, longwave cloud radiative forcing (LWCF), shortwave cloud radiative forcing (SWCF), cloud liquid water path (LWP) and ice water path (IWP). Then, 8 physical parameters are chosen and perturbed using the Latin-Hypercube Sampling (LHS) method. The comparison between OAT ensemble run and LHS ensemble run shows that the simulated TC intensity is mainly affected by the parcel fractional mass entrainment rate in Zhang-McFarlane (ZM) deep convection scheme. The nonlinear interactive effect among different physical parameters is negligible on simulated TC intensity. In contrast, this nonlinear interactive effect plays a significant role in other simulated tropical cyclone characteristics (precipitation, LWCF, SWCF, LWP and IWP) and greatly enlarge their simulated uncertainties. The statistical emulator Extended Multivariate Adaptive Regression Splines (EMARS) is applied to characterize the response functions for nonlinear effect. Last, we find that the intensity uncertainty caused by physical parameters is in a degree comparable to uncertainty caused by model structure (e.g. grid) and initial conditions (e.g. sea surface temperature, atmospheric moisture). These findings suggest the importance of using the perturbed physics ensemble (PPE) method to revisit tropical cyclone prediction under climate change scenario.

Further results on a family of generalized radiation integrals

International Nuclear Information System (INIS)

Galue, Leda; Kiryakova, Virginia

1994-01-01

In this paper we continue an investigation of a family of generalized radiation integrals. Several recurrence relations are presented. By differentiation of these integrals with respect to the parameters λ and μ we obtain also various integrals that include the logarithmic function in the integrand. Finally, we propose an algorithm for numerical evaluation of the generalized radiation integrals and illustrate it by tables of their values computed for selected values of the parameters. (author)

One-parameter families of supersymmetric isospectral potentials from Riccati solutions in function composition form

Energy Technology Data Exchange (ETDEWEB)

Rosu, Haret C., E-mail: hcr@ipicyt.edu.mx [IPICYT, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San José 2055, Col. Lomas 4a Sección, 78216 San Luis Potosí, S.L.P. (Mexico); Mancas, Stefan C., E-mail: mancass@erau.edu [Department of Mathematics, Embry–Riddle Aeronautical University, Daytona Beach, FL 32114-3900 (United States); Chen, Pisin, E-mail: pisinchen@phys.ntu.edu.tw [Leung Center for Cosmology and Particle Astrophysics (LeCosPA) and Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China)

2014-04-15

In the context of supersymmetric quantum mechanics, we define a potential through a particular Riccati solution of the composition form (F∘f)(x)=F(f(x)) and obtain a generalized Mielnik construction of one-parameter isospectral potentials when we use the general Riccati solution. Some examples for special cases of F and f are given to illustrate the method. An interesting result is obtained in the case of a parametric double well potential generated by this method, for which it is shown that the parameter of the potential controls the heights of the localization probability in the two wells, and for certain values of the parameter the height of the localization probability can be higher in the smaller well. -- Highlights: •Function-composition generalization of parametric isospectral potentials is presented. •Mielnik one-parameter family of harmonic potentials is obtained as a particular case. •Graphical discussion of regular and singular regions in the parameter space is given.

Thermodynamic study of fluid in terms of equation of state containing physical parameters

International Nuclear Information System (INIS)

Khasare, S. B.

2015-01-01

We introduce a simple condition for one mole fluid by considering the thermodynamics of molecules pointing towards the effective potential for the cluster. Efforts are made to estimate new physical parameter f in liquid state using the equation of state containing only two physical parameters such as the hard sphere diameter and binding energy. The temperature dependence of the structural properties and the thermodynamic behavior of the clusters are studied. Computations based on f predict the variation of numbers of particles at the contact point of the molecular cavity (radial distribution function). From the thermodynamic profile of the fluid, the model results are discussed in terms of the cavity due to the closed surface along with suitable energy. The present calculation is based upon the sample thermodynamic data for n-hexanol, such as the ultrasonic wave, density, volume expansion coefficient, and ratio of specific heat in the liquid state, and it is consistent with the thermodynamic relations containing physical parameters such as size and energy. Since the data is restricted to n-hexanol, we avoid giving the physical meaning of f, which is the key parameter studied in the present work. (paper)

The effect of uphill and downhill walking on gait parameters: A self-paced treadmill study.

Science.gov (United States)

Kimel-Naor, Shani; Gottlieb, Amihai; Plotnik, Meir

2017-07-26

It has been shown that gait parameters vary systematically with the slope of the surface when walking uphill (UH) or downhill (DH) (Andriacchi et al., 1977; Crowe et al., 1996; Kawamura et al., 1991; Kirtley et al., 1985; McIntosh et al., 2006; Sun et al., 1996). However, gait trials performed on inclined surfaces have been subject to certain technical limitations including using fixed speed treadmills (TMs) or, alternatively, sampling only a few gait cycles on inclined ramps. Further, prior work has not analyzed upper body kinematics. This study aims to investigate effects of slope on gait parameters using a self-paced TM (SPTM) which facilitates more natural walking, including measuring upper body kinematics and gait coordination parameters. Gait of 11 young healthy participants was sampled during walking in steady state speed. Measurements were made at slopes of +10°, 0° and -10°. Force plates and a motion capture system were used to reconstruct twenty spatiotemporal gait parameters. For validation, previously described parameters were compared with the literature, and novel parameters measuring upper body kinematics and bilateral gait coordination were also analyzed. Results showed that most lower and upper body gait parameters were affected by walking slope angle. Specifically, UH walking had a higher impact on gait kinematics than DH walking. However, gait coordination parameters were not affected by walking slope, suggesting that gait asymmetry, left-right coordination and gait variability are robust characteristics of walking. The findings of the study are discussed in reference to a potential combined effect of slope and gait speed. Follow-up studies are needed to explore the relative effects of each of these factors. Copyright © 2017. Published by Elsevier Ltd.

''Sheiva'' : a general purpose multi-parameter data acquisition and processing system at VECC

International Nuclear Information System (INIS)

Viyogi, Y.P.; Ganguly, N.K.

1982-01-01

A general purpose interactive software to be used with the PDP-15/76 on-line computer at VEC Centre for the acquisition and processing of data in nuclear physics experiments is described. The program can accommodate a maximum of thirty two inputs although the present hardware limits the number of inputs to eight. Particular emphasis is given to the problems of flexibility and ease of operation, memory optimisation and techniques dealing with experimenter-computer interaction. Various graphical methods for one- and two-dimensional data presentation are discussed. Specific problems of particle identification using detector telescopes have been dealt with carefully to handle experiments using several detector telescopes and those involving light particle-heavy particle coincidence studies. Steps needed to tailor this program towards utilisation for special experiments are also described. (author)

Two-parameter nonlinear spacetime perturbations: gauge transformations and gauge invariance

International Nuclear Information System (INIS)

Bruni, Marco; Gualtieri, Leonardo; Sopuerta, Carlos F

2003-01-01

An implicit fundamental assumption in relativistic perturbation theory is that there exists a parametric family of spacetimes that can be Taylor expanded around a background. The choice of the latter is crucial to obtain a manageable theory, so that it is sometime convenient to construct a perturbative formalism based on two (or more) parameters. The study of perturbations of rotating stars is a good example: in this case one can treat the stationary axisymmetric star using a slow rotation approximation (expansion in the angular velocity Ω), so that the background is spherical. Generic perturbations of the rotating star (say parametrized by λ) are then built on top of the axisymmetric perturbations in Ω. Clearly, any interesting physics requires nonlinear perturbations, as at least terms λΩ need to be considered. In this paper, we analyse the gauge dependence of nonlinear perturbations depending on two parameters, derive explicit higher-order gauge transformation rules and define gauge invariance. The formalism is completely general and can be used in different applications of general relativity or any other spacetime theory

Exploring cosmic origins with CORE: Cosmological parameters

Science.gov (United States)

Di Valentino, E.; Brinckmann, T.; Gerbino, M.; Poulin, V.; Bouchet, F. R.; Lesgourgues, J.; Melchiorri, A.; Chluba, J.; Clesse, S.; Delabrouille, J.; Dvorkin, C.; Forastieri, F.; Galli, S.; Hooper, D. C.; Lattanzi, M.; Martins, C. J. A. P.; Salvati, L.; Cabass, G.; Caputo, A.; Giusarma, E.; Hivon, E.; Natoli, P.; Pagano, L.; Paradiso, S.; Rubiño-Martin, J. A.; Achúcarro, A.; Ade, P.; Allison, R.; Arroja, F.; Ashdown, M.; Ballardini, M.; Banday, A. J.; Banerji, R.; Bartolo, N.; Bartlett, J. G.; Basak, S.; Baumann, D.; de Bernardis, P.; Bersanelli, M.; Bonaldi, A.; Bonato, M.; Borrill, J.; Boulanger, F.; Bucher, M.; Burigana, C.; Buzzelli, A.; Cai, Z.-Y.; Calvo, M.; Carvalho, C. S.; Castellano, G.; Challinor, A.; Charles, I.; Colantoni, I.; Coppolecchia, A.; Crook, M.; D'Alessandro, G.; De Petris, M.; De Zotti, G.; Diego, J. M.; Errard, J.; Feeney, S.; Fernandez-Cobos, R.; Ferraro, S.; Finelli, F.; de Gasperis, G.; Génova-Santos, R. T.; González-Nuevo, J.; Grandis, S.; Greenslade, J.; Hagstotz, S.; Hanany, S.; Handley, W.; Hazra, D. K.; Hernández-Monteagudo, C.; Hervias-Caimapo, C.; Hills, M.; Kiiveri, K.; Kisner, T.; Kitching, T.; Kunz, M.; Kurki-Suonio, H.; Lamagna, L.; Lasenby, A.; Lewis, A.; Liguori, M.; Lindholm, V.; Lopez-Caniego, M.; Luzzi, G.; Maffei, B.; Martin, S.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; McCarthy, D.; Melin, J.-B.; Mohr, J. J.; Molinari, D.; Monfardini, A.; Negrello, M.; Notari, A.; Paiella, A.; Paoletti, D.; Patanchon, G.; Piacentini, F.; Piat, M.; Pisano, G.; Polastri, L.; Polenta, G.; Pollo, A.; Quartin, M.; Remazeilles, M.; Roman, M.; Ringeval, C.; Tartari, A.; Tomasi, M.; Tramonte, D.; Trappe, N.; Trombetti, T.; Tucker, C.; Väliviita, J.; van de Weygaert, R.; Van Tent, B.; Vennin, V.; Vermeulen, G.; Vielva, P.; Vittorio, N.; Young, K.; Zannoni, M.

2018-04-01

We forecast the main cosmological parameter constraints achievable with the CORE space mission which is dedicated to mapping the polarisation of the Cosmic Microwave Background (CMB). CORE was recently submitted in response to ESA's fifth call for medium-sized mission proposals (M5). Here we report the results from our pre-submission study of the impact of various instrumental options, in particular the telescope size and sensitivity level, and review the great, transformative potential of the mission as proposed. Specifically, we assess the impact on a broad range of fundamental parameters of our Universe as a function of the expected CMB characteristics, with other papers in the series focusing on controlling astrophysical and instrumental residual systematics. In this paper, we assume that only a few central CORE frequency channels are usable for our purpose, all others being devoted to the cleaning of astrophysical contaminants. On the theoretical side, we assume ΛCDM as our general framework and quantify the improvement provided by CORE over the current constraints from the Planck 2015 release. We also study the joint sensitivity of CORE and of future Baryon Acoustic Oscillation and Large Scale Structure experiments like DESI and Euclid. Specific constraints on the physics of inflation are presented in another paper of the series. In addition to the six parameters of the base ΛCDM, which describe the matter content of a spatially flat universe with adiabatic and scalar primordial fluctuations from inflation, we derive the precision achievable on parameters like those describing curvature, neutrino physics, extra light relics, primordial helium abundance, dark matter annihilation, recombination physics, variation of fundamental constants, dark energy, modified gravity, reionization and cosmic birefringence. In addition to assessing the improvement on the precision of individual parameters, we also forecast the post-CORE overall reduction of the allowed

ESR study of advanced materials with new parameters frequency and pressure

CERN Document Server

Mizoguchi, K

2000-01-01

It is well known that electron spin resonance (ESR) is a useful technique to investigate the magnetic properties of electrons in condensed matter. The frequency, as an additional parameter to the temperature, gives us the possibility to study the anisotropic dynamics of charge carriers with spin, even in polycrystalline materials. Furthermore, the pressure provides us a way to discuss how interactions between the electrons and their environments are responsible for the novel physical properties in these advanced materials, such as ferromagnetisms, charge-density waves, superconductivity, and so on. Results obtained by using ESR with these parameters are overviewed. Studies as a function of the frequency are demonstrated, especially for the conductive polymers, polyacetylene, polyaniline, and polypyrrole with various dopants for which single crystals are not available yet. Alkali-electro-sodalite (AES), a kind of zeolite with a regular electron lattice known as an s-electron Mott insulator, and fullerene compo...

Exact solution for the generalized Telegraph Fisher's equation

International Nuclear Information System (INIS)

Abdusalam, H.A.; Fahmy, E.S.

2009-01-01

In this paper, we applied the factorization scheme for the generalized Telegraph Fisher's equation and an exact particular solution has been found. The exact particular solution for the generalized Fisher's equation was obtained as a particular case of the generalized Telegraph Fisher's equation and the two-parameter solution can be obtained when n=2.

Parameter estimation and inverse problems

CERN Document Server

Aster, Richard C; Thurber, Clifford H

2005-01-01

Parameter Estimation and Inverse Problems primarily serves as a textbook for advanced undergraduate and introductory graduate courses. Class notes have been developed and reside on the World Wide Web for faciliting use and feedback by teaching colleagues. The authors'' treatment promotes an understanding of fundamental and practical issus associated with parameter fitting and inverse problems including basic theory of inverse problems, statistical issues, computational issues, and an understanding of how to analyze the success and limitations of solutions to these probles. The text is also a practical resource for general students and professional researchers, where techniques and concepts can be readily picked up on a chapter-by-chapter basis.Parameter Estimation and Inverse Problems is structured around a course at New Mexico Tech and is designed to be accessible to typical graduate students in the physical sciences who may not have an extensive mathematical background. It is accompanied by a Web site that...

Centrifuge modeling of one-step outflow tests for unsaturated parameter estimations

Directory of Open Access Journals (Sweden)

H. Nakajima

2006-01-01

Full Text Available Centrifuge modeling of one-step outflow tests were carried out using a 2-m radius geotechnical centrifuge, and the cumulative outflow and transient pore water pressure were measured during the tests at multiple gravity levels. Based on the scaling laws of centrifuge modeling, the measurements generally showed reasonable agreement with prototype data calculated from forward simulations with input parameters determined from standard laboratory tests. The parameter optimizations were examined for three different combinations of input data sets using the test measurements. Within the gravity level examined in this study up to 40g, the optimized unsaturated parameters compared well when accurate pore water pressure measurements were included along with cumulative outflow as input data. With its capability to implement variety of instrumentations under well controlled initial and boundary conditions and to shorten testing time, the centrifuge modeling technique is attractive as an alternative experimental method that provides more freedom to set inverse problem conditions for the parameter estimation.

Centrifuge modeling of one-step outflow tests for unsaturated parameter estimations

Science.gov (United States)

Nakajima, H.; Stadler, A. T.

2006-10-01

Centrifuge modeling of one-step outflow tests were carried out using a 2-m radius geotechnical centrifuge, and the cumulative outflow and transient pore water pressure were measured during the tests at multiple gravity levels. Based on the scaling laws of centrifuge modeling, the measurements generally showed reasonable agreement with prototype data calculated from forward simulations with input parameters determined from standard laboratory tests. The parameter optimizations were examined for three different combinations of input data sets using the test measurements. Within the gravity level examined in this study up to 40g, the optimized unsaturated parameters compared well when accurate pore water pressure measurements were included along with cumulative outflow as input data. With its capability to implement variety of instrumentations under well controlled initial and boundary conditions and to shorten testing time, the centrifuge modeling technique is attractive as an alternative experimental method that provides more freedom to set inverse problem conditions for the parameter estimation.

Identification of strategy parameters for particle swarm optimizer through Taguchi method

Institute of Scientific and Technical Information of China (English)

KHOSLA Arun; KUMAR Shakti; AGGARWAL K.K.

2006-01-01

Particle swarm optimization (PSO), like other evolutionary algorithms is a population-based stochastic algorithm inspired from the metaphor of social interaction in birds, insects, wasps, etc. It has been used for finding promising solutions in complex search space through the interaction of particles in a swarm. It is a well recognized fact that the performance of evolutionary algorithms to a great extent depends on the choice of appropriate strategy/operating parameters like population size,crossover rate, mutation rate, crossover operator, etc. Generally, these parameters are selected through hit and trial process, which is very unsystematic and requires rigorous experimentation. This paper proposes a systematic based on Taguchi method reasoning scheme for rapidly identifying the strategy parameters for the PSO algorithm. The Taguchi method is a robust design approach using fractional factorial design to study a large number of parameters with small number of experiments. Computer simulations have been performed on two benchmark functions-Rosenbrock function and Griewank function-to validate the approach.

Do Class III patients have a different growth spurt than the general population?

Science.gov (United States)

Lee, Yun-Sik; Lee, Shin-Jae; An, Hongseok; Donatelli, Richard E; Kim, Soo-Hwan

2012-11-01

Understanding the timing and length of the growth spurt of Class III prognathic patients is fundamental to the strategy of interceptive orthopedic orthodontics as well as to the timing of orthognathic surgery. Consequently, this study was undertaken to determine whether there are any significant differences in the stature growth pattern of Class III subjects compared with non-Class III subjects and the general population. Twelve-year longitudinal stature growth data were collected for 402 randomly selected adolescents in the general population, 55 Class III mandibular prognathic patients, and 37 non-Class III patients. The growth data were analyzed by using the traditional linear interpolation method and nonlinear growth functions. The 6 stature growth parameters were measured: age at takeoff, stature at takeoff, velocity at takeoff, age at peak height velocity, stature at peak height velocity, and velocity at peak height velocity. Comparisons in the stature growth parameters and 15 cephalometric variables among the general population, Class III subjects, and non-Class III subjects were made with multivariate analysis. Patients with Class III prognathism did not have different growth parameters compared with Class II subjects or the general population. This study does not allow meaningful conclusions with regard to the relationship of mandibular size and stature growth pattern. The application of nonlinear growth curves vs the traditional linear interpolation method was also discussed. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Exact solution of an electroosmotic flow for generalized Burgers fluid in cylindrical domain

Directory of Open Access Journals (Sweden)

Masood Khan

Full Text Available The present paper reports a theoretical study of the dynamics of an electroosmotic flow (EOF in cylindrical domain. The Cauchy momentum equation is first simplified by incorporating the electrostatic body force in the electric double layer and the generalized Burgers fluid constitutive model. The electric potential distribution is given by the linearized Poisson–Boltzmann equation. After solving the linearized Poisson–Boltzmann equation, the Cauchy momentum equation with electrostatic body force is solved analytically by using the temporal Fourier and finite Hankel transforms. The effects of important involved parameters are examined and presented graphically. The results obtained reveal that the magnitude of velocity increases with increase of the Debye–Huckel and electrokinetic parameters. Further, it is shown that the results presented for generalized Burgers fluid are quite general so that results for the Burgers, Oldroyd-B, Maxwell and Newtonian fluids can be obtained as limiting cases. Keywords: Generalized Burgers fluid, Electroosmotic flow, Fourier and Hankel transform

A generalization of Baker's quadratic formulae for hyperelliptic p-functions

International Nuclear Information System (INIS)

Athorne, Chris

2011-01-01

We present a generalization of a compact form, due to Baker, for quadratic identities satisfied by the three-index p-functions on curves of genus g=2, and a further generalization of a new result in genus g=3. The compact forms involve a bordered determinant containing 2(g-1)(g+1) free parameters. -- Highlights: → Properties of Weierstrass P-functions for hyperelliptic curves. → Generalization of result of H.F. Baker for genus two case. → Compact formulae with maximal number of parameters in genus two and three cases.

Cosmological tests of general relativity

International Nuclear Information System (INIS)

Hut, P.

1977-01-01

It is stated that the general relativity theory could be tested on a cosmological scale by measuring the Hubble constant and the deceleration parameter, if, in addition, everything could be known about the matter filling the universe. If, on the other hand, nothing could be presupposed about the matter content of the universe general relativity could not be tested by measuring any number of time derivatives of the scale factor. But upon making the assumption of a universe filled with non-interacting mixture of non-relativistic matter and radiation general relativity can in principle be tested by measuring the first five derivatives of the scale factor. Some general relations are here presented using this assumption. (author)

Investigation of two and three parameter equations of state for cryogenic fluids

International Nuclear Information System (INIS)

Jenkins, S.L.; Majumdar, A.K.; Hendricks, R.C.

1990-01-01

Two-phase flows are a common occurrence in cryogenic engines and an accurate evaluation of the heat-transfer coefficient in two-phase flow is of significant importance in their analysis and design. The thermodynamic equation of state plays a key role in calculating the heat transfer coefficient which is a function of thermodynamic and thermophysical properties. An investigation has been performed to study the performance of two- and three-parameter equations of state to calculate the compressibility factor of cryogenic fluids along the saturation loci. The two-parameter equations considered here are van der Waals and Redlich-Kwong equations of state. The three-parameter equation represented here is the generalized Benedict-Webb-Rubin (BWR) equation of Lee and Kesler. Results have been compared with the modified BWR equation of Bender and the extended BWR equations of Stewart. Seven cryogenic fluids have been tested; oxygen, hydrogen, helium, nitrogen, argon, neon, and air. The performance of the generalized BWR equation is poor for hydrogen and helium. The van der Waals equation is found to be inaccurate for air near the critical point. For helium, all three equations of state become inaccurate near the critical point. 13 refs

Evaluation of design parameters in soil-structure systems through artificial intelligence

International Nuclear Information System (INIS)

Cremonini, M.G.; Vardanega, C.; Parvis, E.

1989-01-01

This study refers to development of an artificial intelligence tool to evaluate design parameters for a soil-structure system as the foundations of Class 1 buildings of a nuclear power plant (NPP). This is based on an expert analysis of a large amount of information, collected during a comprehensive program of site investigations and laboratory tests and stored on a computer data-bank. The methodology comprises the following steps: organization of the available information on the site characteristics in a data-base; implementation and extensive use of a specific knowledge based expert system (KBES) devoted to both the analysis, interpretation and check of the information in the data-base, and to the evaluation of the design parameters; determination of effective access criteria to the data-base, for purposes of reordering the information and extracting design properties from a large number of experimental data; development of design profiles for both index properties and strength/strain parameters; and final evaluation of the design parameters. Results are obtained in the form of: local and general site stratigraphy; summarized soil index properties, detailing the site setting; static and dynamic stress-strain parameters, G/G max behavior and damping factors; condolidation parameters and OCR ratio; spatial distribution of parameters on site area; identification of specific local conditions; and cross correlation of parameters, thus covering the whole range of design parameters for NPP soil-structure systems

Implementing general gauge mediation

International Nuclear Information System (INIS)

Carpenter, Linda M.; Dine, Michael; Festuccia, Guido; Mason, John D.

2009-01-01

Recently there has been much progress in building models of gauge mediation, often with predictions different than those of minimal gauge mediation. Meade, Seiberg, and Shih have characterized the most general spectrum which can arise in gauge-mediated models. We discuss some of the challenges of building models of general gauge mediation, especially the problem of messenger parity and issues connected with R symmetry breaking and CP violation. We build a variety of viable, weakly coupled models which exhibit some or all of the possible low energy parameters.

Validation of the Framingham general cardiovascular risk score in a multiethnic Asian population: a retrospective cohort study.

Science.gov (United States)

Chia, Yook Chin; Gray, Sarah Yu Weng; Ching, Siew Mooi; Lim, Hooi Min; Chinna, Karuthan

2015-05-19

This study aims to examine the validity of the Framingham general cardiovascular disease (CVD) risk chart in a primary care setting. This is a 10-year retrospective cohort study. A primary care clinic in a teaching hospital in Malaysia. 967 patients' records were randomly selected from patients who were attending follow-up in the clinic. Baseline demographic data, history of diabetes and smoking, blood pressure (BP), and serum lipids were captured from patient records in 1998. Each patient's Framingham CVD score was computed from these parameters. All atherosclerotic CVD events occurring between 1998 and 2007 were counted. In 1998, mean age was 57 years with 33.8% men, 6.1% smokers, 43.3% diabetics and 59.7% hypertensive. Median BP was 140/80 mm Hg and total cholesterol 6.0 mmol/L (1.3). The predicted median Framingham general CVD risk score for the study population was 21.5% (IQR 1.2-30.0) while the actual CVD events that occurred in the 10 years was 13.1% (127/967). The median CVD points for men was 30.0, giving them a CVD risk of more than 30%; for women it is 18.5, a CVD risk of 21.5%. Our study found that the Framingham general CVD risk score to have moderate discrimination with an area under the receiver operating characteristic curve (AUC) of 0.63. It also discriminates well for Malay (AUC 0.65, p=0.01), Chinese (AUC 0.60, p=0.03), and Indians (AUC 0.65, p=0.001). There was good calibration with Hosmer-Lemeshow test χ(2)=3.25, p=0.78. Taking into account that this cohort of patients were already on treatment, the Framingham General CVD Risk Prediction Score predicts fairly accurately for men and overestimates somewhat for women. In the absence of local risk prediction charts, the Framingham general CVD risk prediction chart is a reasonable alternative for use in a multiethnic group in a primary care setting. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Fuel cycle parameters for strategy studies

International Nuclear Information System (INIS)

Archinoff, G.H.

1979-05-01

This report summarizes seven fuel cycle parameters (efficiency, specific power, burnup, equilibrium net fissile feed, equilibrium net fissile surplus, first charge fissile content, and whether or not fuel reprocessing is required) to be used in long-term strategy analyses of fuel cycles based on natural UO 2 , low enriched uranium, mixed oxides, plutonium topped thorium, uranium topped thorium, and the fast breeder oxide cycle. (LL)

Estimating negative binomial parameters from occurrence data with detection times.

Science.gov (United States)

Hwang, Wen-Han; Huggins, Richard; Stoklosa, Jakub

2016-11-01

The negative binomial distribution is a common model for the analysis of count data in biology and ecology. In many applications, we may not observe the complete frequency count in a quadrat but only that a species occurred in the quadrat. If only occurrence data are available then the two parameters of the negative binomial distribution, the aggregation index and the mean, are not identifiable. This can be overcome by data augmentation or through modeling the dependence between quadrat occupancies. Here, we propose to record the (first) detection time while collecting occurrence data in a quadrat. We show that under what we call proportionate sampling, where the time to survey a region is proportional to the area of the region, that both negative binomial parameters are estimable. When the mean parameter is larger than two, our proposed approach is more efficient than the data augmentation method developed by Solow and Smith (, Am. Nat. 176, 96-98), and in general is cheaper to conduct. We also investigate the effect of misidentification when collecting negative binomially distributed data, and conclude that, in general, the effect can be simply adjusted for provided that the mean and variance of misidentification probabilities are known. The results are demonstrated in a simulation study and illustrated in several real examples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Generalized Phase Contrast

CERN Document Server

Glückstad, Jesper

2009-01-01

Generalized Phase Contrast elevates the phase contrast technique not only to improve phase imaging but also to cross over and interface with diverse and seemingly disparate fields of contemporary optics and photonics. This book presents a comprehensive introduction to the Generalized Phase Contrast (GPC) method including an overview of the range of current and potential applications of GPC in wavefront sensing and phase imaging, structured laser illumination and image projection, optical trapping and manipulation, and optical encryption and decryption. The GPC method goes further than the restrictive assumptions of conventional Zernike phase contrast analysis and achieves an expanded range of validity beyond weak phase perturbations. The generalized analysis yields design criteria for tuning experimental parameters to achieve optimal performance in terms of accuracy, fidelity and light efficiency. Optimization can address practical issues, such as finding an optimal spatial filter for the chosen application, ...

Long-term clinical parameters after switching to nocturnal haemodialysis : a Dutch propensity-score-matched cohort study comparing patients on nocturnal haemodialysis with patients on three-times-a-week haemodialysis/haemodiafiltration

NARCIS (Netherlands)

Jansz, Thijs Thomas; Özyilmaz, Akin; Grooteman, Muriel P C; Hoekstra, Tiny; Romijn, Marieke; Blankestijn, Peter J; Bots, Michael L; van Jaarsveld, Brigit C

2018-01-01

OBJECTIVES: Nocturnal haemodialysis (NHD), characterised by 8-hour sessions ≥3 times a week, is known to improve clinical parameters in the short term compared with conventional-schedule haemodialysis (HD), generally 3×3.5-4 hours a week. We studied long-term effects of NHD and used patients on

Bayesian inference in an item response theory model with a generalized student t link function

Science.gov (United States)

Azevedo, Caio L. N.; Migon, Helio S.

2012-10-01

In this paper we introduce a new item response theory (IRT) model with a generalized Student t-link function with unknown degrees of freedom (df), named generalized t-link (GtL) IRT model. In this model we consider only the difficulty parameter in the item response function. GtL is an alternative to the two parameter logit and probit models, since the degrees of freedom (df) play a similar role to the discrimination parameter. However, the behavior of the curves of the GtL is different from those of the two parameter models and the usual Student t link, since in GtL the curve obtained from different df's can cross the probit curves in more than one latent trait level. The GtL model has similar proprieties to the generalized linear mixed models, such as the existence of sufficient statistics and easy parameter interpretation. Also, many techniques of parameter estimation, model fit assessment and residual analysis developed for that models can be used for the GtL model. We develop fully Bayesian estimation and model fit assessment tools through a Metropolis-Hastings step within Gibbs sampling algorithm. We consider a prior sensitivity choice concerning the degrees of freedom. The simulation study indicates that the algorithm recovers all parameters properly. In addition, some Bayesian model fit assessment tools are considered. Finally, a real data set is analyzed using our approach and other usual models. The results indicate that our model fits the data better than the two parameter models.

Sensitivity of risk parameters to human errors for a PWR

International Nuclear Information System (INIS)

Samanta, P.; Hall, R.E.; Kerr, W.

1980-01-01

Sensitivities of the risk parameters, emergency safety system unavailabilities, accident sequence probabilities, release category probabilities and core melt probability were investigated for changes in the human error rates within the general methodological framework of the Reactor Safety Study for a Pressurized Water Reactor (PWR). Impact of individual human errors were assessed both in terms of their structural importance to core melt and reliability importance on core melt probability. The Human Error Sensitivity Assessment of a PWR (HESAP) computer code was written for the purpose of this study

A Longitudinal Study of Peripubertal Serum Organochlorine Concentrations and Semen Parameters in Young Men: The Russian Children’s Study

Science.gov (United States)

Mínguez-Alarcón, Lidia; Sergeyev, Oleg; Burns, Jane S.; Williams, Paige L.; Lee, Mary M.; Korrick, Susan A.; Smigulina, Luidmila; Revich, Boris; Hauser, Russ

2016-01-01

Background: Exposures to endocrine-disrupting chemicals during critical phases of testicular development may be related to poorer semen parameters. However, few studies have assessed the association between childhood organochlorine (OC) exposure and adult semen parameters. Objective: We examined whether peripubertal serum OC concentrations are associated with semen parameters among young Russian men. Methods: From 2003 through 2005, 516 boys were enrolled at age 8–9 years and followed for up to 10 years. Serum OCs were measured in the enrollment samples using high-resolution mass spectrometry. At 18–19 years, 133 young men provided 1 or 2 semen samples (256 samples) collected approximately 1 week apart, which were analyzed for volume, sperm concentration, and motility. Unadjusted and adjusted linear mixed models were used to examine the associations of quartiles of lipid-standardized concentrations of dioxins [2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), polychlorinated dibenzo-p-dioxins (PCDDs)], furans, polychlorinated biphenyls (PCBs), and corresponding toxic equivalents (TEQs) with semen parameters. Results: The median (range) for TCDD was 2.9 (0.4–12.1) pg/g lipid and PCDD TEQ was 8.7 (1.0–36.0) pg TEQ/g lipid. Higher quartiles of TCDD and PCDD TEQs were associated with lower sperm concentration, total sperm count, and total motile sperm count (p-trends ≤ 0.05). The highest quartile of peripubertal serum TCDD concentrations was associated with a decrease (95% CI) of 40% (18, 66%), 29% (3, 64%), and 30% (2, 70%) in sperm concentration, total sperm count, and total motile sperm count, respectively, compared with the lowest quartile. Similar associations were observed for serum PCDD TEQs with semen parameters. Serum PCBs, furans, and total TEQs were not associated with semen parameters. Conclusion: Higher peripubertal serum TCDD concentrations and PCDD TEQs were associated with poorer semen parameters. Citation: Mínguez-Alarcón L, Sergeyev O, Burns JS

Generalized qubits of the vibrational motion of a trapped ion

International Nuclear Information System (INIS)

Arevalo Aguilar, L.M.; Moya-Cessa, H.

2002-01-01

We present a method to generate qubits of the vibrational motion of an ion. The method is developed in the non-rotating-wave-approximation regime, therefore we consider regimes where the dynamics has not been studied. Because the solutions are valid for a more extended range of parameters we call them generalized qubits

Comparison of nonstationary generalized logistic models based on Monte Carlo simulation

Directory of Open Access Journals (Sweden)

S. Kim

2015-06-01

Full Text Available Recently, the evidences of climate change have been observed in hydrologic data such as rainfall and flow data. The time-dependent characteristics of statistics in hydrologic data are widely defined as nonstationarity. Therefore, various nonstationary GEV and generalized Pareto models have been suggested for frequency analysis of nonstationary annual maximum and POT (peak-over-threshold data, respectively. However, the alternative models are required for nonstatinoary frequency analysis because of analyzing the complex characteristics of nonstationary data based on climate change. This study proposed the nonstationary generalized logistic model including time-dependent parameters. The parameters of proposed model are estimated using the method of maximum likelihood based on the Newton-Raphson method. In addition, the proposed model is compared by Monte Carlo simulation to investigate the characteristics of models and applicability.

Parameter Estimation of Spacecraft Fuel Slosh Model

Science.gov (United States)

Gangadharan, Sathya; Sudermann, James; Marlowe, Andrea; Njengam Charles

2004-01-01

Fuel slosh in the upper stages of a spinning spacecraft during launch has been a long standing concern for the success of a space mission. Energy loss through the movement of the liquid fuel in the fuel tank affects the gyroscopic stability of the spacecraft and leads to nutation (wobble) which can cause devastating control issues. The rate at which nutation develops (defined by Nutation Time Constant (NTC can be tedious to calculate and largely inaccurate if done during the early stages of spacecraft design. Pure analytical means of predicting the influence of onboard liquids have generally failed. A strong need exists to identify and model the conditions of resonance between nutation motion and liquid modes and to understand the general characteristics of the liquid motion that causes the problem in spinning spacecraft. A 3-D computerized model of the fuel slosh that accounts for any resonant modes found in the experimental testing will allow for increased accuracy in the overall modeling process. Development of a more accurate model of the fuel slosh currently lies in a more generalized 3-D computerized model incorporating masses, springs and dampers. Parameters describing the model include the inertia tensor of the fuel, spring constants, and damper coefficients. Refinement and understanding the effects of these parameters allow for a more accurate simulation of fuel slosh. The current research will focus on developing models of different complexity and estimating the model parameters that will ultimately provide a more realistic prediction of Nutation Time Constant obtained through simulation.

The performance of a prototype device designed to evaluate general quality parameters of X-ray equipment

International Nuclear Information System (INIS)

Murata, C.H.; Fernandes, D.C.; Lavínia, N.C.; Caldas, L.V.E; Pires, S.R; Medeiros, R.B.

2014-01-01

The performance of radiological equipment can be assessed using non-invasive methods and portable instruments that can analyze an X-ray beam with just one exposure. These instruments use either an ionization chamber or a state solid detector (SSD) to evaluate X-ray beam parameters. In Brazil, no such instruments are currently being manufactured; consequently, these instruments come at a higher cost to users due to importation taxes. Additionally, quality control tests are time consuming and impose a high workload on the X-ray tubes when evaluating their performance parameters. The assessment of some parameters, such as the half-value layer (HVL), requires several exposures; however, this can be reduced by using a SSD that requires only a single exposure. One such SSD uses photodiodes designed for high X-ray sensitivity without the use of scintillation crystals. This sensitivity allows one electron-hole pair to be created per 3.63 eV of incident energy, resulting in extremely high and stable quantum efficiencies. These silicon photodiodes operate by absorbing photons and generating a flow of current that is proportional to the incident power. The aim of this study was to show the response of the solid sensor PIN RD100A detector in a multifunctional X-ray analysis system that is designed to evaluate the average peak voltage (kVp), exposure time, and HVL of radiological equipment. For this purpose, a prototype board that uses four SSDs was developed to measure kVp, exposure time, and HVL using a single exposure. The reproducibility and accuracy of the results were compared to that of different X-ray beam analysis instruments. The kVp reproducibility and accuracy results were 2% and 3%, respectively; the exposure time reproducibility and accuracy results were 2% and 1%, respectively; and the HVL accuracy was ±2%. The prototype's methodology was able to calculate these parameters with appropriate reproducibility and accuracy. Therefore, the prototype can be considered

A study of operating parameters on the linear spark ignition engine

International Nuclear Information System (INIS)

Lim, Ocktaeck; Hung, Nguyen Ba; Oh, Seokyoung; Kim, Gangchul; Song, Hanho; Iida, Norimasa

2015-01-01

Highlights: • An experimental and simulation study of a linear engine is conducted. • The effects of operating parameters on the generating power are investigated. • The air gap length has a significant influence on the generating power. • The generating power of the linear engine is optimized with the value of 111.3 W. • There are no problems for the linear engine after 100 h of durable test. - Abstract: In this paper, we present our experiment and simulation study of a free piston linear engine based on operating conditions and structure of the linear engine for generating electric power. The free piston linear engine includes a two-stroke free piston engine, linear generators, and compressors. In the experimental study, the effects of key parameters such as input caloric value, equivalence ratio, spark timing delay, electrical resistance, and air gap length on the piston dynamics and electric power output are investigated. Propane is used as a fuel in the free piston linear engine, and it is premixed with the air to make a homogeneous charge before go into the cylinder. The air and fuel mass flow rate are varied by a mass flow controller. The experimental results show that the maximum generating power is found with the value of 111 W at the input caloric value of 5.88 kJ/s, spark timing delay of 1.5 ms, equivalence ratio of 1.0, electric resistance of 30 Ω, and air gap length of 1.0 mm. In order to check the durability of the linear engine, a durable test is conducted during 100 h. The experimental results show that there are no problems for the linear engine after about one hundred hours of the durable test. Beside experimental study, a simulation study is conducted to predict operating behavior of the linear engine. In the simulation study, the two-stroke free piston linear engine is modeled and simulated through a combination of three mathematical models including a dynamic model, a linear alternator model and a thermodynamic model. These

Ergodicity and Parameter Estimates for Infinite-Dimensional Fractional Ornstein-Uhlenbeck Process

International Nuclear Information System (INIS)

Maslowski, Bohdan; Pospisil, Jan

2008-01-01

Existence and ergodicity of a strictly stationary solution for linear stochastic evolution equations driven by cylindrical fractional Brownian motion are proved. Ergodic behavior of non-stationary infinite-dimensional fractional Ornstein-Uhlenbeck processes is also studied. Based on these results, strong consistency of suitably defined families of parameter estimators is shown. The general results are applied to linear parabolic and hyperbolic equations perturbed by a fractional noise

The Onsager reciprocity relation and generalized efficiency of a thermal Brownian motor

International Nuclear Information System (INIS)

Tian-Fu, Gao; Jin-Can, Chen; Yue, Zhang

2009-01-01

Based on a general model of Brownian motors, the Onsager coefficients and generalized efficiency of a thermal Brownian motor are calculated analytically. It is found that the Onsager reciprocity relation holds and the Onsager coefficients are not affected by the kinetic energy change due to the particle's motion. Only when the heat leak in the system is negligible can the determinant of the Onsager matrix vanish. Moreover, the influence of the main parameters characterizing the model on the generalized efficiency of the Brownian motor is discussed in detail. The characteristic curves of the generalized efficiency varying with these parameters are presented, and the maximum generalized efficiency and the corresponding optimum parameters are determined. The results obtained here are of general significance. They are used to analyze the performance characteristics of the Brownian motors operating in the three interesting cases with zero heat leak, zero average drift velocity or a linear response relation, so that some important conclusions in current references are directly included in some limit cases of the present paper. (general)

A New 4D Hyperchaotic System and Its Generalized Function Projective Synchronization

Directory of Open Access Journals (Sweden)

Yuan Gao

2013-01-01

Full Text Available A new four-dimensional hyperchaotic system is investigated. Numerical and analytical studies are carried out on its basic dynamical properties, such as equilibrium point, Lyapunov exponents, Poincaré maps, and chaotic dynamical behaviors. We verify the realizability of the new system via an electronic circuit by using Multisim software. Furthermore, a generalized function projective synchronization scheme of two different hyperchaotic systems with uncertain parameters is proposed, which includes some existing projective synchronization schemes, such as generalized projection synchronization and function projective synchronization. Based on the Lyapunov stability theory, a controller with parameters update laws is designed to realize synchronization. Using this controller, we realize the synchronization between Chen hyperchaotic system and the new system to verify the validity and feasibility of our method.

Design method of general-purpose driving circuit for CCD based on CPLD

International Nuclear Information System (INIS)

Zhang Yong; Tang Benqi; Xiao Zhigang; Wang Zujun; Huang Shaoyan

2005-01-01

It is very important for studying the radiation damage effects and mechanism systematically about CCD to develop a general-purpose test platform. The paper discusses the design method of general-purpose driving circuit for CCD based on CPLD and the realization approach. A main controller has being designed to read the data file from the outer memory, setup the correlative parameter registers and produce the driving pulses according with parameter request strictly, which is based on MAX7000S by using MAX-PLUS II software. The basic driving circuit module has being finished based on this method. The output waveform of the module is the same figure as the simulation waveform. The result indicates that the design method is feasible. (authors)

Complexity, parameter sensitivity and parameter transferability in the modelling of floodplain inundation

Science.gov (United States)

Bates, P. D.; Neal, J. C.; Fewtrell, T. J.

2012-12-01

In this we paper we consider two related questions. First, we address the issue of how much physical complexity is necessary in a model in order to simulate floodplain inundation to within validation data error. This is achieved through development of a single code/multiple physics hydraulic model (LISFLOOD-FP) where different degrees of complexity can be switched on or off. Different configurations of this code are applied to four benchmark test cases, and compared to the results of a number of industry standard models. Second we address the issue of how parameter sensitivity and transferability change with increasing complexity using numerical experiments with models of different physical and geometric intricacy. Hydraulic models are a good example system with which to address such generic modelling questions as: (1) they have a strong physical basis; (2) there is only one set of equations to solve; (3) they require only topography and boundary conditions as input data; and (4) they typically require only a single free parameter, namely boundary friction. In terms of complexity required we show that for the problem of sub-critical floodplain inundation a number of codes of different dimensionality and resolution can be found to fit uncertain model validation data equally well, and that in this situation Occam's razor emerges as a useful logic to guide model selection. We find also find that model skill usually improves more rapidly with increases in model spatial resolution than increases in physical complexity, and that standard approaches to testing hydraulic models against laboratory data or analytical solutions may fail to identify this important fact. Lastly, we find that in benchmark testing studies significant differences can exist between codes with identical numerical solution techniques as a result of auxiliary choices regarding the specifics of model implementation that are frequently unreported by code developers. As a consequence, making sound

Estimating 3D Object Parameters from 2D Grey-Level Images

NARCIS (Netherlands)

Houkes, Z.

2000-01-01

This thesis describes a general framework for parameter estimation, which is suitable for computer vision applications. The approach described combines 3D modelling, animation and estimation tools to determine parameters of objects in a scene from 2D grey-level images. The animation tool predicts

Generalized image contrast enhancement technique based on Heinemann contrast discrimination model

Science.gov (United States)

Liu, Hong; Nodine, Calvin F.

1994-03-01

This paper presents a generalized image contrast enhancement technique which equalizes perceived brightness based on the Heinemann contrast discrimination model. This is a modified algorithm which presents an improvement over the previous study by Mokrane in its mathematically proven existence of a unique solution and in its easily tunable parameterization. The model uses a log-log representation of contrast luminosity between targets and the surround in a fixed luminosity background setting. The algorithm consists of two nonlinear gray-scale mapping functions which have seven parameters, two of which are adjustable Heinemann constants. Another parameter is the background gray level. The remaining four parameters are nonlinear functions of gray scale distribution of the image, and can be uniquely determined once the previous three are given. Tests have been carried out to examine the effectiveness of the algorithm for increasing the overall contrast of images. It can be demonstrated that the generalized algorithm provides better contrast enhancement than histogram equalization. In fact, the histogram equalization technique is a special case of the proposed mapping.

Bifurcation and Stability Analysis of the Equilibrium States in Thermodynamic Systems in a Small Vicinity of the Equilibrium Values of Parameters

Science.gov (United States)

Barsuk, Alexandr A.; Paladi, Florentin

2018-04-01

The dynamic behavior of thermodynamic system, described by one order parameter and one control parameter, in a small neighborhood of ordinary and bifurcation equilibrium values of the system parameters is studied. Using the general methods of investigating the branching (bifurcations) of solutions for nonlinear equations, we performed an exhaustive analysis of the order parameter dependences on the control parameter in a small vicinity of the equilibrium values of parameters, including the stability analysis of the equilibrium states, and the asymptotic behavior of the order parameter dependences on the control parameter (bifurcation diagrams). The peculiarities of the transition to an unstable state of the system are discussed, and the estimates of the transition time to the unstable state in the neighborhood of ordinary and bifurcation equilibrium values of parameters are given. The influence of an external field on the dynamic behavior of thermodynamic system is analyzed, and the peculiarities of the system dynamic behavior are discussed near the ordinary and bifurcation equilibrium values of parameters in the presence of external field. The dynamic process of magnetization of a ferromagnet is discussed by using the general methods of bifurcation and stability analysis presented in the paper.

Signal detection theory and vestibular perception: III. Estimating unbiased fit parameters for psychometric functions.

Science.gov (United States)

Chaudhuri, Shomesh E; Merfeld, Daniel M

2013-03-01

Psychophysics generally relies on estimating a subject's ability to perform a specific task as a function of an observed stimulus. For threshold studies, the fitted functions are called psychometric functions. While fitting psychometric functions to data acquired using adaptive sampling procedures (e.g., "staircase" procedures), investigators have encountered a bias in the spread ("slope" or "threshold") parameter that has been attributed to the serial dependency of the adaptive data. Using simulations, we confirm this bias for cumulative Gaussian parametric maximum likelihood fits on data collected via adaptive sampling procedures, and then present a bias-reduced maximum likelihood fit that substantially reduces the bias without reducing the precision of the spread parameter estimate and without reducing the accuracy or precision of the other fit parameters. As a separate topic, we explain how to implement this bias reduction technique using generalized linear model fits as well as other numeric maximum likelihood techniques such as the Nelder-Mead simplex. We then provide a comparison of the iterative bootstrap and observed information matrix techniques for estimating parameter fit variance from adaptive sampling procedure data sets. The iterative bootstrap technique is shown to be slightly more accurate; however, the observed information technique executes in a small fraction (0.005 %) of the time required by the iterative bootstrap technique, which is an advantage when a real-time estimate of parameter fit variance is required.

Comparative study for different statistical models to optimize cutting parameters of CNC end milling machines

International Nuclear Information System (INIS)

El-Berry, A.; El-Berry, A.; Al-Bossly, A.

2010-01-01

In machining operation, the quality of surface finish is an important requirement for many work pieces. Thus, that is very important to optimize cutting parameters for controlling the required manufacturing quality. Surface roughness parameter (Ra) in mechanical parts depends on turning parameters during the turning process. In the development of predictive models, cutting parameters of feed, cutting speed, depth of cut, are considered as model variables. For this purpose, this study focuses on comparing various machining experiments which using CNC vertical machining center, work pieces was aluminum 6061. Multiple regression models are used to predict the surface roughness at different experiments.

Trainability of hemodynamic parameters: A near-infrared spectroscopy based neurofeedback study.

Science.gov (United States)

Kober, Silvia Erika; Hinterleitner, Vanessa; Bauernfeind, Günther; Neuper, Christa; Wood, Guilherme

2018-05-18

We investigated the trainability of the hemodynamic response as assessed with near-infrared spectroscopy (NIRS) during one neurofeedback (NF) session. Forty-eight participants were randomly assigned to four different groups that tried to either increase or decrease oxygenated (oxy-Hb) or deoxygenated hemoglobin (deoxy-Hb) over the inferior frontal gyrus during imagery of swallowing movements. Deoxy-Hb could be successfully up-regulated while oxy-Hb could be successfully down-regulated during NF. Participants were not able to down-regulate deoxy-Hb or to up-regulate oxy-Hb. These results show that the natural course of oxy- and deoxy-Hb during movement imagery can be reinforced by providing real-time feedback of the corresponding NIRS parameter since deoxy-Hb generally increases and oxy-Hb decreases during imagery of swallowing. Furthermore, signal-to-noise ratio of deoxy-Hb but not of oxy-Hb improved during training. Our results provide new insights into the trainability of the hemodynamic response as assessed with NIRS and have an impact on the application of NIRS-based real-time feedback. Copyright © 2018 Elsevier B.V. All rights reserved.

The rho-parameter in supersymmetric models

International Nuclear Information System (INIS)

Lim, C.S.; Inami, T.; Sakai, N.

1983-10-01

The electroweak rho-parameter is examined in a general class of supersymmetric models. Formulae are given for one-loop contributions to Δrho from scalar quarks and leptons, gauge-Higgs fermions and an extra doublet of Higgs scalars. Mass differences between members of isodoublet scalar quarks and leptons are constrained to be less than about 200 GeV. (author)

A systematic study of distribution characters of infiltration parameters in an experimental basin by nuclear methods

International Nuclear Information System (INIS)

Gu Weizu; Lu Jieju; Lu Mingjiang; Chen Tingyang

1988-01-01

A case study of spatial variability of Philip's infiltration parameters was carried out in a small experimental catchment with an area of 0.8 ha by nuclear monitoring methods. Relationships between sorptivity S, parameter A and the average initial soil water content within 0.5 m depth of soil profiles over the catchment have been plotted. A watershed infiltration parameter distribution curve is set up and fitted approximately by f/F=1-(1-S/S M ) n . The parameters of composite infiltration response related to whole catchment are suggested. The author has studied it on an experimental basin by combined method of nuclear technology and micro-geomorphic analysis. The results are satisfactory. (author). 6 refs, 11 figs, 2 tabs

From conservation laws to port-Hamiltonian representations of distributed-parameter systems

NARCIS (Netherlands)

Maschke, B.M.; van der Schaft, Arjan; Piztek, P.

Abstract: In this paper it is shown how the port-Hamiltonian formulation of distributed-parameter systems is closely related to the general thermodynamic framework of systems of conservation laws and closure equations. The situation turns out to be similar to the lumped-parameter case where the

On Approaches to Analyze the Sensitivity of Simulated Hydrologic Fluxes to Model Parameters in the Community Land Model

Directory of Open Access Journals (Sweden)

Jie Bao

2015-12-01

Full Text Available Effective sensitivity analysis approaches are needed to identify important parameters or factors and their uncertainties in complex Earth system models composed of multi-phase multi-component phenomena and multiple biogeophysical-biogeochemical processes. In this study, the impacts of 10 hydrologic parameters in the Community Land Model on simulations of runoff and latent heat flux are evaluated using data from a watershed. Different metrics, including residual statistics, the Nash–Sutcliffe coefficient, and log mean square error, are used as alternative measures of the deviations between the simulated and field observed values. Four sensitivity analysis (SA approaches, including analysis of variance based on the generalized linear model, generalized cross validation based on the multivariate adaptive regression splines model, standardized regression coefficients based on a linear regression model, and analysis of variance based on support vector machine, are investigated. Results suggest that these approaches show consistent measurement of the impacts of major hydrologic parameters on response variables, but with differences in the relative contributions, particularly for the secondary parameters. The convergence behaviors of the SA with respect to the number of sampling points are also examined with different combinations of input parameter sets and output response variables and their alternative metrics. This study helps identify the optimal SA approach, provides guidance for the calibration of the Community Land Model parameters to improve the model simulations of land surface fluxes, and approximates the magnitudes to be adjusted in the parameter values during parametric model optimization.

A specialized ODE integrator for the efficient computation of parameter sensitivities

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Gonnet Pedro

2012-05-01

Full Text Available Abstract Background Dynamic mathematical models in the form of systems of ordinary differential equations (ODEs play an important role in systems biology. For any sufficiently complex model, the speed and accuracy of solving the ODEs by numerical integration is critical. This applies especially to systems identification problems where the parameter sensitivities must be integrated alongside the system variables. Although several very good general purpose ODE solvers exist, few of them compute the parameter sensitivities automatically. Results We present a novel integration algorithm that is based on second derivatives and contains other unique features such as improved error estimates. These features allow the integrator to take larger time steps than other methods. In practical applications, i.e. systems biology models of different sizes and behaviors, the method competes well with established integrators in solving the system equations, and it outperforms them significantly when local parameter sensitivities are evaluated. For ease-of-use, the solver is embedded in a framework that automatically generates the integrator input from an SBML description of the system of interest. Conclusions For future applications, comparatively ‘cheap’ parameter sensitivities will enable advances in solving large, otherwise computationally expensive parameter estimation and optimization problems. More generally, we argue that substantially better computational performance can be achieved by exploiting characteristics specific to the problem domain; elements of our methods such as the error estimation could find broader use in other, more general numerical algorithms.

Transmuted New Generalized Inverse Weibull Distribution

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Muhammad Shuaib Khan

2017-06-01

Full Text Available This paper introduces the transmuted new generalized inverse Weibull distribution by using the quadratic rank transmutation map (QRTM scheme studied by Shaw et al. (2007. The proposed model contains the twenty three lifetime distributions as special sub-models. Some mathematical properties of the new distribution are formulated, such as quantile function, Rényi entropy, mean deviations, moments, moment generating function and order statistics. The method of maximum likelihood is used for estimating the model parameters. We illustrate the flexibility and potential usefulness of the new distribution by using reliability data.

Long-time integrator for the study on plasma parameter fluctuations

International Nuclear Information System (INIS)

Zalkind, V.M.; Tarasenko, V.P.

1975-01-01

A device measuring the absolute value (x) of a fluctuating quantity x(t) averaged over a large number of realizations is described. The specific features of the device are the use of the time selector (Δ t = 50 μs - 1 ms) and the large time integration constant (tau = 30 hrs). The device is meant for studying fluctuations of parameters of a pulse plasma with a small repetition frequency

Unifying parameter estimation and the Deutsch-Jozsa algorithm for continuous variables

International Nuclear Information System (INIS)

Zwierz, Marcin; Perez-Delgado, Carlos A.; Kok, Pieter

2010-01-01

We reveal a close relationship between quantum metrology and the Deutsch-Jozsa algorithm on continuous-variable quantum systems. We develop a general procedure, characterized by two parameters, that unifies parameter estimation and the Deutsch-Jozsa algorithm. Depending on which parameter we keep constant, the procedure implements either the parameter-estimation protocol or the Deutsch-Jozsa algorithm. The parameter-estimation part of the procedure attains the Heisenberg limit and is therefore optimal. Due to the use of approximate normalizable continuous-variable eigenstates, the Deutsch-Jozsa algorithm is probabilistic. The procedure estimates a value of an unknown parameter and solves the Deutsch-Jozsa problem without the use of any entanglement.

Opium and heroin alter biochemical parameters of human's serum.

Science.gov (United States)

Kouros, Divsalar; Tahereh, Haghpanah; Mohammadreza, Afarinesh; Minoo, Mahmoudi Zarandi

2010-05-01

Iran is a significant consumer of opium, and, generally, of opioids, in the world. Addiction is one of the important issues of the 21st century and is an imperative issue in Iran. Long-term consumption of opioids affects homeostasis. To determine the effects of opium and heroin consumption on serum biochemical parameters. In a cross-sectional study, subjects who had consumed heroin (n = 35) or opium (n = 42) for more than two years and 35 nonaddict volunteers as the control group were compared in regard to various biochemical parameters such as fasting blood sugar (FBS), Na(+), K(+), Ca(2+), blood urea nitrogen (BUN), uric acid (UA), triglyceride (TG), cholesterol, creatinine, and total protein. Chromatography was used to confirm opioid consumption, and the concentration of biochemical parameters was determined by laboratory diagnostic tests on serum. No significant differences were found in Na(+), Ca(2+), BUN, UA, TG, creatinine, and total protein concentrations among the three groups. FBS, K(+), and UA levels were significantly lower in opium addicts compared to the control group. Serum Ca(2+) concentration of heroin addicts showed a significant decrease compared to that of the control group. Both addict groups showed a significant decrease in serum cholesterol levels. Chronic use of opium and heroin can change serum FBS, K(+), Ca(2+), UA, and cholesterol. This study, one of few on the effects of opium on serum biochemical parameters in human subjects, has the potential to contribute to the investigation of new approaches for further basic studies.

Robust Parameter and Signal Estimation in Induction Motors

DEFF Research Database (Denmark)

Børsting, H.

This thesis deals with theories and methods for robust parameter and signal estimation in induction motors. The project originates in industrial interests concerning sensor-less control of electrical drives. During the work, some general problems concerning estimation of signals and parameters...... in nonlinear systems, have been exposed. The main objectives of this project are: - analysis and application of theories and methods for robust estimation of parameters in a model structure, obtained from knowledge of the physics of the induction motor. - analysis and application of theories and methods...... for robust estimation of the rotor speed and driving torque of the induction motor based only on measurements of stator voltages and currents. Only contimuous-time models have been used, which means that physical related signals and parameters are estimated directly and not indirectly by some discrete...

Removing an intersubject variance component in a general linear model improves multiway factoring of event-related spectral perturbations in group EEG studies.

Science.gov (United States)

Spence, Jeffrey S; Brier, Matthew R; Hart, John; Ferree, Thomas C

2013-03-01

Linear statistical models are used very effectively to assess task-related differences in EEG power spectral analyses. Mixed models, in particular, accommodate more than one variance component in a multisubject study, where many trials of each condition of interest are measured on each subject. Generally, intra- and intersubject variances are both important to determine correct standard errors for inference on functions of model parameters, but it is often assumed that intersubject variance is the most important consideration in a group study. In this article, we show that, under common assumptions, estimates of some functions of model parameters, including estimates of task-related differences, are properly tested relative to the intrasubject variance component only. A substantial gain in statistical power can arise from the proper separation of variance components when there is more than one source of variability. We first develop this result analytically, then show how it benefits a multiway factoring of spectral, spatial, and temporal components from EEG data acquired in a group of healthy subjects performing a well-studied response inhibition task. Copyright © 2011 Wiley Periodicals, Inc.

Application of generalized perturbation theory to flux disadvantage factor calculations

International Nuclear Information System (INIS)

Sallam, O.H.; Akimov, I.S.; Naguib, K.; Hamouda, I.

1979-01-01

The possibility of using the generalized perturbation theory to calculate the perturbation of the flux disadvantage factors of reactor cell, resulting from the variation of the cell parameters, is studied. For simplicity the one-group diffusion approximation is considered. All necessary equations are derived for variations both of the cell dimensions. Numerical results are presented in the paper

Generalized stress field in granular soils heap with Rayleigh–Ritz method

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Gang Bi

2017-02-01

Full Text Available The stress field in granular soils heap (including piled coal will have a non-negligible impact on the settlement of the underlying soils. It is usually obtained by measurements and numerical simulations. Because the former method is not reliable as pressure cells instrumented on the interface between piled coal and the underlying soft soil do not work well, results from numerical methods alone are necessary to be doubly checked with one more method before they are extended to more complex cases. The generalized stress field in granular soils heap is analyzed with Rayleigh–Ritz method. The problem is divided into two cases: case A without horizontal constraint on the base and case B with horizontal constraint on the base. In both cases, the displacement functions u(x, y and v(x, y are assumed to be cubic polynomials with 12 undetermined parameters, which will satisfy the Cauchy's partial differential equations, generalized Hooke's law and boundary equations. A function is built with the Rayleigh–Ritz method according to the principle of minimum potential energy, and the problem is converted into solving two undetermined parameters through the variation of the function, while the other parameters are expressed in terms of these two parameters. By comparison of results from the Rayleigh–Ritz method and numerical simulations, it is demonstrated that the Rayleigh–Ritz method is feasible to study the generalized stress field in granular soils heap. Solutions from numerical methods are verified before being extended to more complicated cases.

A geometric parameter study of piezoelectric coverage on a rectangular cantilever energy harvester

International Nuclear Information System (INIS)

Patel, R; McWilliam, S; Popov, A A

2011-01-01

This paper proposes a versatile model for optimizing the performance of a rectangular cantilever beam piezoelectric energy harvester used to convert ambient vibrations into electrical energy. The developed model accounts for geometric changes to the natural frequencies, mode shapes and damping in the structure. This is achieved through the combination of finite element modelling and a distributed parameter electromechanical model, including load resistor and charging capacitor models. The model has the potential for use in investigating the influence of numerous geometric changes on harvester performance, and incorporates a model for accounting for changes in damping as the geometry changes. The model is used to investigate the effects of substrate and piezoelectric layer length, and piezoelectric layer thickness on the performance of a microscale device. Findings from a parameter study indicate the existence of an optimum sample length due to increased mechanical damping for longer beams and improved power output using thicker piezoelectric layers. In practice, harvester design is normally based around a fixed operating frequency for a particular application, and improved performance is often achieved by operating at or near resonance. To achieve unbiased comparisons between different harvester designs, parameter studies are performed by changing multiple parameters simultaneously with the natural frequency held fixed. Performance enhancements were observed using shorter piezoelectric layers as compared to the conventional design, in which the piezoelectric layer and substrate are of equal length

Universality for the parameter-mismatching effect on weak synchronization in coupled chaotic systems

International Nuclear Information System (INIS)

Lim, Woochang; Kim, Sang-Yoon

2004-01-01

To examine the universality for the parameter-mismatching effect on weak chaotic synchronization, we study coupled multidimensional invertible systems such as the coupled Henon maps and coupled pendula. By generalizing the method proposed in coupled one-dimensional (1D) noninvertible maps, we introduce the parameter sensitivity exponent δ to measure the degree of the parameter sensitivity of a weakly stable synchronous chaotic attractor. In terms of the parameter sensitivity exponents, we characterize the effect of the parameter mismatch on the intermittent bursting and the basin riddling occurring in the regime of weak synchronization. It is thus found that the scaling exponent μ for the average characteristic time (i.e., the average interburst time and the average chaotic transient lifetime) for both the bubbling and riddling cases is given by the reciprocal of the parameter sensitivity exponent, as in the simple system of coupled 1D maps. Hence, the reciprocal relation (i.e., μ = 1/δ) seems to be 'universal', in the sense that it holds in typical coupled chaotic systems of different nature

On a p-adic Cubic Generalized Logistic Dynamical System

International Nuclear Information System (INIS)

Mukhamedov, Farrukh; Rozali, Wan Nur Fairuz Alwani Wan

2013-01-01

Applications of p-adic numbers mathematical physics, quantum mechanics stimulated increasing interest in the study of p-adic dynamical system. One of the interesting investigations is p-adic logistics map. In this paper, we consider a new generalization, namely we study a dynamical system of the form f a (x) = ax(1−x 2 ). The paper is devoted to the investigation of a trajectory of the given system. We investigate the generalized logistic dynamical system with respect to parameter a and we restrict ourselves for the investigation of the case |a| p < 1. We study the existence of the fixed points and their behavior. Moreover, we describe their size of attractors and Siegel discs since the structure of the orbits of the system is related to the geometry of the p-adic Siegel discs.

Covariant second-order perturbations in generalized two-field inflation

International Nuclear Information System (INIS)

Tzavara, Eleftheria; Tent, Bartjan van; Mizuno, Shuntaro

2014-01-01

We examine the covariant properties of generalized models of two-field inflation, with non-canonical kinetic terms and a possibly non-trivial field metric. We demonstrate that kinetic-term derivatives and covariant field derivatives do commute in a proper covariant framework, which was not realized before in the literature. We also define a set of generalized slow-roll parameters, using a unified notation. Within this framework, we study the most general class of models that allows for well-defined adiabatic and entropic sound speeds, which we identify as the models with parallel momentum and field velocity vectors. For these models we write the exact cubic action in terms of the adiabatic and isocurvature perturbations. We thus provide the tool to calculate the exact non-Gaussianity beyond slow-roll and at any scale for these generalized models. We illustrate our general results by considering their long-wavelength limit, as well as with the example of two-field DBI inflation

General least-squares fitting procedures to minimize the volume of a hyperellipsoid

International Nuclear Information System (INIS)

Wadlinger, E.A.

1979-01-01

Several methods for determining the shape parameters, which in two dimensions are the Courant-Snyder parameters, and the volume of an ellipse or hyperellipse that represent a set of phase-space points in a two or more dimensional hyperspace are presented. The ellipse parameters are useful for matching a beam to an accelerating or transport system and in studies of emittance growth. The fitting procedure minimizes the total volume of a hyperellipse by adjusting the ellipse shape parameters. The total volume is the sum of the individual particle volumes defined by the hyperellipse that passes through the phase-space point of a particle. A two-dimensional space is considered first; the results are then generalized to higher dimensions. Computer programs using these techniques were written. 1 figure

Q-boson interferometry and generalized Wigner function

International Nuclear Information System (INIS)

Zhang, Q.H.; Padula, Sandra S.

2004-01-01

Bose-Einstein correlations of two identically charged Q bosons are derived considering these particles to be confined in finite volumes. Boundary effects on single Q-boson spectrum are also studied. We illustrate the effects on the spectrum and on the two-Q-boson correlation function by means of two toy models. We also derive a generalized expression for the Wigner function depending on the deformation parameter Q, which is reduced to its original functional form in the limit of Q→1

Synchronization and parameter identification of one class of realistic chaotic circuit

International Nuclear Information System (INIS)

Chun-Ni, Wang; Jun, Ma; Run-Tong, Chu; Shi-Rong, Li

2009-01-01

In this paper, the synchronization and the parameter identification of the chaotic Pikovsky–Rabinovich (PR) circuits are investigated. The linear error of the second corresponding variables is used to change the driven chaotic PR circuit, and the complete synchronization of the two identical chaotic PR circuits is realized with feedback intensity k increasing to a certain threshold. The Lyapunov exponents of the chaotic PR circuits are calculated by using different feedback intensities and our results are confirmed. The case where the two chaotic PR circuits are not identical is also investigated. A general positive Lyapunov function V, which consists of all the errors of the corresponding variables and parameters and changeable gain coefficient, is constructed by using the Lyapunov stability theory to study the parameter identification and complete synchronization of two non-identical chaotic circuits. The controllers and the parameter observers could be obtained analytically only by simplifying the criterion dV/dt < 0 (differential coefficient of Lyapunov function V with respect to time is negative). It is confirmed that the two non-identical chaotic PR circuits could still reach complete synchronization and all the unknown parameters in the drive system are estimated exactly within a short transient period

Agreement in cardiovascular risk rating based on anthropometric parameters

International Nuclear Information System (INIS)