Pasari, S.; Kundu, D.; Dikshit, O.
2012-12-01
Earthquake recurrence interval is one of the important ingredients towards probabilistic seismic hazard assessment (PSHA) for any location. Exponential, gamma, Weibull and lognormal distributions are quite established probability models in this recurrence interval estimation. However, they have certain shortcomings too. Thus, it is imperative to search for some alternative sophisticated distributions. In this paper, we introduce a three-parameter (location, scale and shape) exponentiated exponential distribution and investigate the scope of this distribution as an alternative of the afore-mentioned distributions in earthquake recurrence studies. This distribution is a particular member of the exponentiated Weibull distribution. Despite of its complicated form, it is widely accepted in medical and biological applications. Furthermore, it shares many physical properties with gamma and Weibull family. Unlike gamma distribution, the hazard function of generalized exponential distribution can be easily computed even if the shape parameter is not an integer. To contemplate the plausibility of this model, a complete and homogeneous earthquake catalogue of 20 events (M ≥ 7.0) spanning for the period 1846 to 1995 from North-East Himalayan region (20-32 deg N and 87-100 deg E) has been used. The model parameters are estimated using maximum likelihood estimator (MLE) and method of moment estimator (MOME). No geological or geophysical evidences have been considered in this calculation. The estimated conditional probability reaches quite high after about a decade for an elapsed time of 17 years (i.e. 2012). Moreover, this study shows that the generalized exponential distribution fits the above data events more closely compared to the conventional models and hence it is tentatively concluded that generalized exponential distribution can be effectively considered in earthquake recurrence studies.
Butters, M; Straub, M; Kraft, K; Bittner, R
1996-06-01
We assessed the nutritional status of general surgery patients with and without cancer from a western European population in this prospective study. Anamnestic (weight development, abdominal complaints) and anthropometric (fat tissue measurements) data were collected on six groups of patients: cancer of the stomach (n = 13), pancreas (n = 13), colorectal (n = 23), breast (n = 12), and two control groups with benign diseases, ages 20-45 and 50-75 y. From these data, body mass index and ideal body weight were calculated. Concentrations of albumin, transferrin, retinol-binding protein, prealbumin, and creatinine height index were determined by biochemical tests. A weight loss of more than 10% was found in only 31% of gastric and 61% of pancreatic cancer patients. Significant values from anthropometric data were also found only in these groups. In biochemical tests, only the creatinine height index was reduced in all patients with pancreatic cancer. The remaining laboratory changes were so unspecific in all other parameters that no conclusions could be drawn as to the status of the patient's nutritional condition. For the evaluation of nutritional status, only relatively simple and inexpensive anamnestic and anthropometric measurements are necessary.
Parameter space of general gauge mediation
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Rajaraman, Arvind [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)], E-mail: arajaram@uci.edu; Shirman, Yuri [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)], E-mail: yshirman@uci.edu; Smidt, Joseph [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)], E-mail: jsmidt@uci.edu; Yu, Felix [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)], E-mail: felixy@uci.edu
2009-07-27
We study a subspace of General Gauge Mediation (GGM) models which generalize models of gauge mediation. We find superpartner spectra that are markedly different from those of typical gauge and gaugino mediation scenarios. While typical gauge mediation predictions of either a neutralino or stau next-to-lightest supersymmetric particle (NLSP) are easily reproducible with the GGM parameters, chargino and sneutrino NLSPs are generic for many reasonable choices of GGM parameters.
Zhang, Haitao; Xu, Liang; Chen, Changxi; Jonas, Jost B
2008-04-01
To evaluate the distribution of central corneal thickness and its associations in the adult Chinese population. The Beijing Eye Study 2006 is a population-based study including 3,251 (73.3%) subjects (aged 45+ years) out of 4,439 subjects who participated in the survey in 2001 and who returned for re-examination. Central corneal thickness (CCT) measurements were performed by slit lamp-based optical coherence tomography. Central corneal thickness measurement data were available for 3,100 (95.4%) subjects. Mean CCT was 556.2+/-33.1 microm (median: 553 microm; range: 429-688 microm). In multiple regression analysis, CCT was significantly associated with optic disc area (P = 0.043), urban region (P measurements (P measured by pneumotonometry) increased for each microm central corneal thickness increase by 0.03 mmHg. In the adult Chinese population, CCT was significantly associated optic disc area, urban region, and male gender. Intraocular pneumotonometric pressure measurements increased for each microm increase in central corneal thickness by 0.03 mmHg. CCT was not associated with age and refractive error.
Generalized Schur functions and augmented Schur parameters
Dijksma, Aad; Wanjala, Gerald; Forster, KH; Jonas, P; Langer, H
2006-01-01
Every Schur function s(z) is the uniform limit of a sequence of finite Blaschke products on compact subsets of the open unit disk. The Blaschke products in the sequence are defined inductively via the Schur parameters of s(z). In this note we prove a similar result for generalized Schur functions.
Jonas, Jost B; Nangia, Vinay; Sinha, Ajit; Gupta, Rajesh
2011-09-01
To investigate the normal distribution of corneal refractive power (CRP) and its associations with other ocular and systemic parameters in the Central Indian population. Population-based study. The Central India Eye and Medical Study is a population-based study performed in a rural region of Central India. The study comprised 4711 subjects aged 30+ years. A detailed ophthalmic and medical examination was performed. Horizontal and vertical CRP were measured using a non-automatic keratometer. Corneal refractive power. After excluding pseudophakic or aphakic eyes, keratometric measurements were available on 9024 eyes of 4617 study participants (98.0%) with a mean age of 49.1±13.2 years (range, 30-100 years) and a mean refractive error of -0.20±1.52 diopters (D). Mean horizontal CRP was 44.60±1.68 D (mean ± standard deviation; range, 36.5-52.0 D), and vertical CRP was 44.62±1.74 D (range, 37.75-52.0 D) with no significant difference between both parameters (P=0.27). In multivariate analysis, CRP was significantly (P eyes with CRP ≥48 D were excluded. Horizontal CRP increased with higher age, lower level of education, lower body height, thinner central cornea, deeper anterior chamber, shorter axial length, and myopic refractive error. The association with age may be of importance for refractive surgery. The association of a steeper cornea with a shorter body stature and a shorter axial length parallels an association between shorter body length and shorter axial length without association with refractive error. The association among steeper cornea, shorter body length, and lower educational level complements the association between shorter body length and lower educational level. The correlation between steeper cornea and deeper anterior chamber may be explained geometrically. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.
General collision branching processes with two parameters
Institute of Scientific and Technical Information of China (English)
CHEN AnYue; LI JunPing
2009-01-01
A new class of branching models, the general collision branching processes with two parameters, is considered in this paper. For such models, it is necessary to evaluate the absorbing probabilities and mean extinction times for both absorbing states. Regularity and uniqueness criteria are firstly established. Explicit expressions are then obtained for the extinction probability vector, the mean extinction times and the conditional mean extinction times. The explosion behavior of these models is investigated and an explicit expression for mean explosion time is established. The mean global holding time is also obtained. It is revealed that these properties are substantially different between the super-explosive and sub-explosive cases.
Regularization Parameter Selections via Generalized Information Criterion.
Zhang, Yiyun; Li, Runze; Tsai, Chih-Ling
2010-03-01
We apply the nonconcave penalized likelihood approach to obtain variable selections as well as shrinkage estimators. This approach relies heavily on the choice of regularization parameter, which controls the model complexity. In this paper, we propose employing the generalized information criterion (GIC), encompassing the commonly used Akaike information criterion (AIC) and Bayesian information criterion (BIC), for selecting the regularization parameter. Our proposal makes a connection between the classical variable selection criteria and the regularization parameter selections for the nonconcave penalized likelihood approaches. We show that the BIC-type selector enables identification of the true model consistently, and the resulting estimator possesses the oracle property in the terminology of Fan and Li (2001). In contrast, however, the AIC-type selector tends to overfit with positive probability. We further show that the AIC-type selector is asymptotically loss efficient, while the BIC-type selector is not. Our simulation results confirm these theoretical findings, and an empirical example is presented. Some technical proofs are given in the online supplementary material.
General collision branching processes with two parameters
Institute of Scientific and Technical Information of China (English)
2009-01-01
A new class of branching models,the general collision branching processes with two parameters,is considered in this paper.For such models,it is necessary to evaluate the absorbing probabilities and mean extinction times for both absorbing states.Regularity and uniqueness criteria are firstly established.Explicit expressions are then obtained for the extinction probability vector,the mean extinction times and the conditional mean extinction times.The explosion behavior of these models is investigated and an explicit expression for mean explosion time is established.The mean global holding time is also obtained.It is revealed that these properties are substantially different between the super-explosive and sub-explosive cases.
Galesloot, Tessel E; Geurts-Moespot, Anneke J; den Heijer, Martin; Sweep, Fred C G J; Fleming, Robert E; Kiemeney, Lambertus A L M; Vermeulen, Sita H; Swinkels, Dorine W
2013-09-01
Genome-wide association studies have convincingly shown that single nucleotide polymorphisms (SNPs) in HFE and TMPRSS6 are associated with iron parameters. It was commonly thought that these associations could be explained by the intermediate effect on hepcidin concentration. A recent study in an isolated Italian population, however, concluded that these associations were not exclusively dependent on hepcidin values. We report here the second study to investigate the role of hepcidin in the associations between common variants in HFE and TMPRSS6 with iron parameters. We extracted 101 SNPs in HFE and TMPRSS6 from genome-wide imputed SNP data of 1832 individuals from the general population (Nijmegen Biomedical Study). Single locus and haplotype associations with serum iron parameters and hepcidin were studied using linear regression analyses. We found that HFE rs1800562 and TMPRSS6 rs855791 are the main determinants of HFE and TMPRSS6 related variation in serum iron, ferritin, transferrin saturation, and total iron binding capacity. These SNPs are associated with the ratios hepcidin/ferritin (pserum hepcidin (p>0.2). Adjustment for hepcidin or the ratio hepcidin/ferritin did not decrease the strength of the SNP-iron parameter associations. Our results do not support an intermediate role for hepcidin in the SNP-iron parameter associations, which confirms previous findings, and indicate a pleiotropic SNP effect on the hepcidin ratios and the iron parameters. Taken together, this suggests that there might be other, yet unknown, serum hepcidin independent mechanisms which play a role in the association of HFE and TMPRSS6 variants with serum iron parameters.
Sieve likelihood ratio inference on general parameter space
Institute of Scientific and Technical Information of China (English)
SHEN Xiaotong; SHI Jian
2005-01-01
In this paper,a theory on sieve likelihood ratio inference on general parameter spaces(including infinite dimensional) is studied.Under fairly general regularity conditions,the sieve log-likelihood ratio statistic is proved to be asymptotically x2 distributed,which can be viewed as a generalization of the well-known Wilks' theorem.As an example,a emiparametric partial linear model is investigated.
Nangia, Vinay; Jonas, Jost B; Sinha, Ajit; Matin, Arshia; Kulkarni, Maithili
2010-04-01
To evaluate the distribution of central corneal thickness (CCT) and its associations in an adult Indian population. Population-based study. The Central India Eye and Medical Study is a population-based study performed in a rural region close to Nagpur in Central India; it included 4711 subjects (ages 30+ years) of 5885 eligible subjects (response rate, 80.1%). The participants underwent a detailed ophthalmic and medical examination, including 200 standardized questions on socioeconomic background, lifestyle, social relations, and psychiatric depression. This study was focused on CCT as measured by sonography and its associations. Intraocular pressure was measured by applanation tonometry. Central corneal thickness and intraocular pressure. Central corneal thickness measurement data were available on 9370 (99.4%) eyes. Mean CCT was 514+/-33 microm (median, 517 microm; range, 290-696 microm). By multiple regression analysis, CCT was associated significantly with younger age (Peyes with a corneal refractive power of 45 or more diopters were excluded, the relationship between CCT and axial length was no longer statistically significant (P>0.05), whereas all other relationships remained significant. Intraocular pressure readings increased significantly (Peyes that had thick corneas or steep corneas. Central corneal thickness and steepness of the anterior corneal surface may thus both have to be taken into account when applanation tonometry is performed. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.
On generalized trigonometric functions with two parameters
Bhayo, Barkat Ali; Vuorinen, Matti
2011-01-01
The generalized $p$-trigonometric and ($p,q$)-trigonometric functions were introduced by P. Lindqvist and S. Takeuchi, respectively. We prove some inequalities and present a few conjectures for the ($p,q$)-functions.
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Muluken Birhanu
2017-01-01
Full Text Available Hematological parameter changes are the most common complications in malaria. We aimed to determine the hematological parameters and hemozoin-containing leukocytes and their association with disease severity in malaria infected children aged between 1 and 15 years. A facility-based cross-sectional study was conducted at Pawe General Hospital from July 31 to December 30, 2014. Demographic and clinical data were collected using structured questionnaire. Blood specimen was collected from each study participant for hematological investigations. Data were analyzed using SPSS version 20. The overall prevalence of anemia was 40.3%, most of which were mildly anemic. Leukocytosis was found in 15.4% of study participants. More than a fourth (27% of the children had severe malaria. Hemozoin-containing monocytes and neutrophils were found in 80.1% and 58.9% of the study participants, respectively. Under-five years of age (AOR = 3.01, 95% CI: 1.83–7.39, P5% (AOR = 6.26, 95% CI: 2.14–14.29, P5% (AOR = 7.93, 95% CI: 3.09–16.86, P<0.001, and high density parasitemia (AOR = 1.90, 95% CI: 1.13–3.18, P=0.015 were associated with severe malaria. Hemozoin-containing leukocytes, leukocytosis, and other identified associated factors should be considered for proper management of children with severe malaria.
Estimating parameters for generalized mass action models with connectivity information
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Voit Eberhard O
2009-05-01
Full Text Available Abstract Background Determining the parameters of a mathematical model from quantitative measurements is the main bottleneck of modelling biological systems. Parameter values can be estimated from steady-state data or from dynamic data. The nature of suitable data for these two types of estimation is rather different. For instance, estimations of parameter values in pathway models, such as kinetic orders, rate constants, flux control coefficients or elasticities, from steady-state data are generally based on experiments that measure how a biochemical system responds to small perturbations around the steady state. In contrast, parameter estimation from dynamic data requires time series measurements for all dependent variables. Almost no literature has so far discussed the combined use of both steady-state and transient data for estimating parameter values of biochemical systems. Results In this study we introduce a constrained optimization method for estimating parameter values of biochemical pathway models using steady-state information and transient measurements. The constraints are derived from the flux connectivity relationships of the system at the steady state. Two case studies demonstrate the estimation results with and without flux connectivity constraints. The unconstrained optimal estimates from dynamic data may fit the experiments well, but they do not necessarily maintain the connectivity relationships. As a consequence, individual fluxes may be misrepresented, which may cause problems in later extrapolations. By contrast, the constrained estimation accounting for flux connectivity information reduces this misrepresentation and thereby yields improved model parameters. Conclusion The method combines transient metabolic profiles and steady-state information and leads to the formulation of an inverse parameter estimation task as a constrained optimization problem. Parameter estimation and model selection are simultaneously carried out
Adaptive generalized functional synchronization of Chaotic systems with unknown parameters
Institute of Scientific and Technical Information of China (English)
Wang Dong-Feng; Han Pu
2008-01-01
A universal adaptive generalized functional synchronization approach to any two different or identical chaotic systems with unknown parameters is proposed,based on a unified mathematical expression of a large class of chaotic system.Self-adaptive parameter law and control law are given in the form of a theorem.The synchronization between the three-dimensional R(o)ssler chaotic system and the four-dimensional Chen's hyper-chaotic system is studied as an example for illustration.The computer simulation results demonstrate the feasibility of the method proposed.
Generalized M-Fluctuation Tests for Parameter Instability
Zeileis, Achim; Hornik, Kurt
2003-01-01
A general class of fluctuation tests for parameter instability in an M-estimation framework is suggested. The tests are based on partial sum processes of M-estimation scores for which functional central limit theorems are derived under the null hypothesis of parameter stability and local alternatives. Special emphasis is given to parameter instability in (generalized) linear regression models and it is shown that the introduced M-fluctuation tests contain a large number of parameter instabili...
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.
Dathe, Margitta; Meyer, Jana; Beyermann, Michael; Maul, Björn; Hoischen, Christian; Bienert, Michael
2002-02-01
Model compounds of modified hydrophobicity (Eta), hydrophobic moment (mu) and angle subtended by charged residues (Phi) were synthesized to define the general roles of structural motifs of cationic helical peptides for membrane activity and selectivity. The peptide sets were based on a highly hydrophobic, non-selective KLA model peptide with high antimicrobial and hemolytic activity. Variation of the investigated parameters was found to be a suitable method for modifying peptide selectivity towards either neutral or highly negatively charged lipid bilayers. Eta and mu influenced selectivity preferentially via modification of activity on 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) bilayers, while the size of the polar/hydrophobic angle affected the activity against 1-palmitoyl-2-oleoylphosphatidyl-DL-glycerol (POPG). The influence of the parameters on the activity determining step was modest in both lipid systems and the activity profiles were the result of the parameters' influence on the second less pronounced permeabilization step. Thus, the activity towards POPC vesicles was determined by the high permeabilizing efficiency, however, changes in the structural parameters preferentially influenced the relatively moderate affinity. In contrast, intensive peptide accumulation via electrostatic interactions was sufficient for the destabilization of highly negatively charged POPG lipid membranes, but changes in the activity profile, as revealed by the modification of Phi, seem to be preferentially caused by variation of the low permeabilizing efficiency. The parameters proved very effective also in modifying antimicrobial and hemolytic activity. However, their influence on cell selectivity was limited. A threshold value of hydrophobicity seems to exist which restricted the activity modifying potential of mu and Phi on both lipid bilayers and cell membranes.
Parameter Estimation for a Computable General Equilibrium Model
DEFF Research Database (Denmark)
Arndt, Channing; Robinson, Sherman; Tarp, Finn
2002-01-01
We introduce a maximum entropy approach to parameter estimation for computable general equilibrium (CGE) models. The approach applies information theory to estimating a system of non-linear simultaneous equations. It has a number of advantages. First, it imposes all general equilibrium constraints...
Parameter Estimation for a Computable General Equilibrium Model
DEFF Research Database (Denmark)
Arndt, Channing; Robinson, Sherman; Tarp, Finn
We introduce a maximum entropy approach to parameter estimation for computable general equilibrium (CGE) models. The approach applies information theory to estimating a system of nonlinear simultaneous equations. It has a number of advantages. First, it imposes all general equilibrium constraints...
Galesloot, T.E.; Geurts-Moespot, A.; Heijer, M. den; Sweep, F.C.; Fleming, R.E.; Kiemeney, L.A.L.M.; Vermeulen, S.; Swinkels, D.W.
2013-01-01
BACKGROUND: Genome-wide association studies have convincingly shown that single nucleotide polymorphisms (SNPs) in HFE and TMPRSS6 are associated with iron parameters. It was commonly thought that these associations could be explained by the intermediate effect on hepcidin concentration. A recent
Learning regularization parameters for general-form Tikhonov
Chung, Julianne; Español, Malena I.
2017-07-01
Computing regularization parameters for general-form Tikhonov regularization can be an expensive and difficult task, especially if multiple parameters or many solutions need to be computed in real time. In this work, we assume training data is available and describe an efficient learning approach for computing regularization parameters that can be used for a large set of problems. We consider an empirical Bayes risk minimization framework for finding regularization parameters that minimize average errors for the training data. We first extend methods from Chung et al (2011 SIAM J. Sci. Comput. 33 3132-52) to the general-form Tikhonov problem. Then we develop a learning approach for multi-parameter Tikhonov problems, for the case where all involved matrices are simultaneously diagonalizable. For problems where this is not the case, we describe an approach to compute near-optimal regularization parameters by using operator approximations for the original problem. Finally, we propose a new class of regularizing filters, where solutions correspond to multi-parameter Tikhonov solutions, that requires less data than previously proposed optimal error filters, avoids the generalized SVD, and allows flexibility and novelty in the choice of regularization matrices. Numerical results for 1D and 2D examples using different norms on the errors show the effectiveness of our methods.
Linear generalized synchronization of chaotic systems with uncertain parameters
Institute of Scientific and Technical Information of China (English)
Jia Zhen
2008-01-01
A more general form of projective synchronization,so called linear generalized synchronization(LGS)is proposed,which includes the generalized projective synchronization(GPS)and the hybrid projective synchronization(HPS)as its special cases.Based on the adaptive technique and Lyapunov stability theory,a general method for achieving the LGS between two chaotic or hyperchaotic systems with uncertain parameters in any scaling matrix is presented.Some numerical simulations are provided to show the effectiveness and feasibility of the proposed synchronization method.
Parameter Estimation for Generalized Brownian Motion with Autoregressive Increments
Fendick, Kerry
2011-01-01
This paper develops methods for estimating parameters for a generalization of Brownian motion with autoregressive increments called a Brownian ray with drift. We show that a superposition of Brownian rays with drift depends on three types of parameters - a drift coefficient, autoregressive coefficients, and volatility matrix elements, and we introduce methods for estimating each of these types of parameters using multidimensional times series data. We also cover parameter estimation in the contexts of two applications of Brownian rays in the financial sphere: queuing analysis and option valuation. For queuing analysis, we show how samples of queue lengths can be used to estimate the conditional expectation functions for the length of the queue and for increments in its net input and lost potential output. For option valuation, we show how the Black-Scholes-Merton formula depends on the price of the security on which the option is written through estimates not only of its volatility, but also of a coefficient ...
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Abu Syed Mohammed Mujib
2014-01-01
Full Text Available 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<0.05 in 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<0.05. The significant correlation was observed among hemoglobin levels with hematocrits, hemoglobin with RBC, RBC with hematocrits, and MCV with MCH as well as MCH with MCHC. However, the negative correlation was observed between the hematological variables neutrophils and lymphocytes (r=-0.989. The common complaints we have found in the survey were weight loss 73.33%, attention problem 68%, dyspepsia 65%, decrease of appetite 72%, weakness 68%, diarrhea 65%, and headache 55% among IDA patients. ANOVA showed significant statistical difference in all the hematological and biochemical parameters. Analysis of variance test between anemias with only one of three biochemical parameters decreased and control showed that this group does not have iron deficiency.
A general method of estimating stellar astrophysical parameters from photometry
Belikov, A N
2008-01-01
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 photometric bands complicates the determination of the astrophysical parameters for individual stars. This paper presents an algorithm for determining stellar astrophysical parameters (effective temperature, gravity and metallicity) from broad-band photometry even in the presence of interstellar reddening. This method suits the combination of narrow bands as well. We applied the method of interval-cluster analysis to finding stellar astrophysical parameters based on the newest Kurucz models calibrated with the use of a compiled catalog of stellar parameters. Our new method of determining astrophysical parameters allows all possible solutions to be located in the effective temperature-gravity-metallicity space for the star and se...
Testing for one Generalized Linear Single Order Parameter
DEFF Research Database (Denmark)
Ellegaard, Niels Langager; Christensen, Tage Emil; Dyre, Jeppe
work the order parameter may be chosen to have a non-exponential relaxation. The model predictions contradict the general consensus of the properties of viscous liquids in two ways: (i) The model predicts that following a linear isobaric temperature step, the normalized volume and entalpy relaxation...... functions are identical. This assumption conflicts with some (but not all) reports, utilizing the Tool-Narayanaswamy formalism to extrapolate from non-linear measurements to the linear regime. (ii) The model predicts that the theoretical "linear Prigogine-Defay" ratio is one. This ratio has never been...... responses or extrapolate from measurements of a glassy state away from equilibrium. Starting from a master equation description of inherent dynamics, we calculate the complex thermodynamic response functions. We device a way of testing for the generalized single order parameter model by measuring 3 complex...
Yang, Cheng-Hsiung; Wu, Cheng-Lin
2014-01-01
An adaptive control scheme is developed to study the generalized adaptive chaos synchronization with uncertain chaotic parameters behavior between two identical chaotic dynamic systems. This generalized adaptive chaos synchronization controller is designed based on Lyapunov stability theory and an analytic expression of the adaptive controller with its update laws of uncertain chaotic parameters is shown. The generalized adaptive synchronization with uncertain parameters between two identical new Lorenz-Stenflo systems is taken as three examples to show the effectiveness of the proposed method. The numerical simulations are shown to verify the results.
Inversion of generalized relaxation time distributions with optimized damping parameter
Florsch, Nicolas; Revil, André; Camerlynck, Christian
2014-10-01
Retrieving the Relaxation Time Distribution (RDT), the Grains Size Distribution (GSD) or the Pore Size Distribution (PSD) from low-frequency impedance spectra is a major goal in geophysics. The “Generalized RTD” generalizes parametric models like Cole-Cole and many others, but remains tricky to invert since this inverse problem is ill-posed. We propose to use generalized relaxation basis function (for instance by decomposing the spectra on basis of generalized Cole-Cole relaxation elements instead of the classical Debye basis) and to use the L-curve approach to optimize the damping parameter required to get smooth and realistic inverse solutions. We apply our algorithm to three examples, one synthetic and two real data sets, and the program includes the possibility of converting the RTD into GSD or PSD by choosing the value of the constant connecting the relaxation time to the characteristic polarization size of interest. A high frequencies (typically above 1 kHz), a dielectric term in taken into account in the model. The code is provided as an open Matlab source as a supplementary file associated with this paper.
A study of parameter identification
Herget, C. J.; Patterson, R. E., III
1978-01-01
A set of definitions for deterministic parameter identification ability were proposed. Deterministic parameter identificability properties are presented based on four system characteristics: direct parameter recoverability, properties of the system transfer function, properties of output distinguishability, and uniqueness properties of a quadratic cost functional. Stochastic parameter identifiability was defined in terms of the existence of an estimation sequence for the unknown parameters which is consistent in probability. Stochastic parameter identifiability properties are presented based on the following characteristics: convergence properties of the maximum likelihood estimate, properties of the joint probability density functions of the observations, and properties of the information matrix.
Institute of Scientific and Technical Information of China (English)
TAO Hua-xue; GUO Jin-yun
2005-01-01
The unknown parameter's variance-covariance propagation and calculation in the generalized nonlinear least squares remain to be studied now,which didn't appear in the internal and external referencing documents. The unknown parameter's variance-covariance propagation formula, considering the two-power terms, was concluded used to evaluate the accuracy of unknown parameter estimators in the generalized nonlinear least squares problem. It is a new variance-covariance formula and opens up a new way to evaluate the accuracy when processing data which have the multi-source,multi-dimensional, multi-type, multi-time-state, different accuracy and nonlinearity.
On Parameters Estimation of Lomax Distribution under General Progressive Censoring
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Bander Al-Zahrani
2013-01-01
Full Text Available We consider the estimation problem of the probability S=P(Y
Evaluation of oxidative and antioxidative parameters in generalized anxiety disorder.
Emhan, Ali; Selek, Salih; Bayazıt, Hüseyin; Fatih Karababa, İbrahim; Katı, Mahmut; Aksoy, Nurten
2015-12-30
Generalized anxiety disorder (GAD) is a prevalent psychiatric disorder. The exact causes of GAD still unknown, in addition to neurochemical and neuroanatomic disorders, genetic and environmental factors are discussed in etiology. In our study we aimed to evaluate the oxidative metabolism's status and investigate the role of oxidative metabolites in GAD. Blood samples were taken from enrolled subjects in appropriate way and total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were studied in Harran University Biochemistry Labs. Results were compared between groups. The patients' TOS and OSI levels were significantly higher than control group. The patients' TAS levels were significantly lower than controls'. According to our findings, oxidative stress mechanism might have a role in GAD pathophysiology. In the future, total antioxidants may be used as a biologic marker in GAD etiology but more research is needed.
Parameter Estimation for a Computable General Equilibrium Model
DEFF Research Database (Denmark)
Arndt, Channing; Robinson, Sherman; Tarp, Finn
. Second, it permits incorporation of prior information on parameter values. Third, it can be applied in the absence of copious data. Finally, it supplies measures of the capacity of the model to reproduce the historical record and the statistical significance of parameter estimates. The method is applied...
Markov Chain Monte Carlo Estimation of Item Parameters for the Generalized Graded Unfolding Model
de la Torre, Jimmy; Stark, Stephen; Chernyshenko, Oleksandr S.
2006-01-01
The authors present a Markov Chain Monte Carlo (MCMC) parameter estimation procedure for the generalized graded unfolding model (GGUM) and compare it to the marginal maximum likelihood (MML) approach implemented in the GGUM2000 computer program, using simulated and real personality data. In the simulation study, test length, number of response…
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...
On a six-parameter generalized Burr XII distribution
A. K. Olapade
2008-01-01
In this paper, we derive a probability density function that generalizes the Burr XII distribution. The cumulative distribution function and the $n^{th}$ moment of the generalized distribution are obtained while the distribution of some order statistics of the distribution are established. A theorem that relate the new distribution to another statistical distribution is established.
Institute of Scientific and Technical Information of China (English)
Zhang Ruo-Xun; Yang Shi-Ping
2008-01-01
This paper presents a general method of the generalized projective synchronization and the parameter identification between two different chaotic systems with unknown parameters.This approach is based on Lyapunov stability theory,and employs a combination of feedback control and adaptive control.With this method one can achieve the generalized projective synchronization and realize the parameter identifications between almost all chaotic (hyperchaotic) systems with unknown parameters.Numerical simulations results are presented to demonstrate the effectiveness of the method.
Elongational Viscosity Rheological Parameter Study
1982-06-01
can prepare a simple table of collapse ratios as a function of prts.-orc ±t,.s. ii Table. Collapse Ratios as a Function of Pressure Ratios (i = 1.4...that were used in this study were all water soluble polyrner systems. The two polymers used were carboxymethylcellulose (CMC) 40U t
Aleksandrova, Irina
2016-01-01
The existing studies, concerning the dressing process, focus on the major influence of the dressing conditions on the grinding response variables. However, the choice of the dressing conditions is often made, based on the experience of the qualified staff or using data from reference books. The optimal dressing parameters, which are only valid for the particular methods and dressing and grinding conditions, are also used. The paper presents a methodology for optimization of the dressing parameters in cylindrical grinding. The generalized utility function has been chosen as an optimization parameter. It is a complex indicator determining the economic, dynamic and manufacturing characteristics of the grinding process. The developed methodology is implemented for the dressing of aluminium oxide grinding wheels by using experimental diamond roller dressers with different grit sizes made of medium- and high-strength synthetic diamonds type ??32 and ??80. To solve the optimization problem, a model of the generalized utility function is created which reflects the complex impact of dressing parameters. The model is built based on the results from the conducted complex study and modeling of the grinding wheel lifetime, cutting ability, production rate and cutting forces during grinding. They are closely related to the dressing conditions (dressing speed ratio, radial in-feed of the diamond roller dresser and dress-out time), the diamond roller dresser grit size/grinding wheel grit size ratio, the type of synthetic diamonds and the direction of dressing. Some dressing parameters are determined for which the generalized utility function has a maximum and which guarantee an optimum combination of the following: the lifetime and cutting ability of the abrasive wheels, the tangential cutting force magnitude and the production rate of the grinding process. The results obtained prove the possibility of control and optimization of grinding by selecting particular dressing
Evolution of the Brans-Dicke Parameter in Generalized Chameleon Cosmology
Institute of Scientific and Technical Information of China (English)
Mubasher Jami; D.Momeni
2011-01-01
@@ Motivated by an earlier study of Sahoo and Singh[Mod.Phys.Lett.A 17(2002)2409],we investigate the time dependence of the Brans-Dicke parameter ω(t)for an expanding Universe in the generalized Brans-Dicke Chameleon cosmology,and obtain an explicit dependence of ω(t)in different expansion phases of the Universe.Also,we discuss how the observed accelerated expansion of the observable Universe can be accommodated in the present formalism.%Motivated by an earlier study of Sahoo and Singh [Mod. Phys. Lett. A 17(2002)2409], we investigate the time dependence of the Brans-Dicke parameter ui(t) for an expanding Universe in the generalized Brans-Dicke Chameleon cosmology, and obtain an explicit dependence of uj(t) in different expansion phases of the Universe. Also, we discuss how the observed accelerated expansion of the observable Universe can be accommodated in the present formalism.
Energy Technology Data Exchange (ETDEWEB)
Maynard, K.; Royer, J.F. [Meteo-France CNRM, 42 Avenue G. Coriolis, 31057, Toulouse Cedex 1 (France)
2004-06-01
During the last two decades, several land surface schemes for use in climate, regional and/or mesoscale, hydrological and ecological models have been designed. Incorrect parametrization of land-surface processes and prescription of the surface parameters in atmospheric modeling, can result in artificial changes of the horizontal gradient of the sensible heat flux. Thus, an error in horizontal temperature gradient within the lower atmosphere may be introduced. The reliability of the model depends on the quality of boundary layer scheme implemented and its sensitivity to the bare soil and vegetation parameters. In this study, a series of sensitivity experiments has been conducted over broad time scales, using a version of the ARPEGE Climate Model coupled to the ISBA land surface scheme in order to investigate model sensitivity to separate changes in land surface parameters over Africa. Effects of perturbing vegetation cover, distribution of soil depth, albedo of vegetation, roughness length, leaf area index and minimum stomatal resistance were explored by using a simple statistical analysis. Identifying which parameters are important in controlling turbulent energy fluxes, temperature and soil moisture is dependent on which variables are used to determine sensibility, which type of vegetation and climate regime is being simulated and the magnitude and sign of the parameter change. This study does not argue that a particular parameter is important in ISBA, rather it shows that no general ranking of parameters is possible. So, it is essential to specify all land surface parameters with greater precision when attempting to determine the climate response to modification of the land surface. The implication of ISBA being sensitive to parameters that cannot be validated suggests that there will always be considerable doubt over the predictive quality of land-surface schemes. (orig.)
Integral Parameters of the Generalized Frequency Spectra of Moderators
Energy Technology Data Exchange (ETDEWEB)
Purohit, S.N.
1966-06-15
A study of the integral quantities - M{sub 2} (the second energy transfer moment of the scattering kernel weighted by the Maxwellian distribution), (v{sigma}{sub s}){sub min} (the minimum value of the scattering cross section times velocity) and the moments of frequency spectrum including the effective temperature and Debye-Waller integrals - in terms of the frequency spectrum of the dynamical modes is presented. Numerical results for H{sub 2}O, D{sub 2}O, Be, BeO and C using the available frequency spectra have been obtained. In the estimation of M{sub 2} and (v{sigma}{sub s}){sub min} the first term of the Placzek mass expansion is obtained exactly and the correction by the Doppler approximation method. In addition, the exact results for the Doppler approximation and the gas model have also been given.
Determining Rheological Parameters of Generalized Yield-Power-Law Fluid Model
Directory of Open Access Journals (Sweden)
Stryczek Stanislaw
2004-09-01
Full Text Available The principles of determining rheological parameters of drilling muds described by a generalized yield-power-law are presented in the paper. Functions between tangent stresses and shear rate are given. The conditions of laboratory measurements of rheological parameters of generalized yield-power-law fluids are described and necessary mathematical relations for rheological model parameters given. With the block diagrams, the methodics of numerical solution of these relations has been presented. Rheological parameters of an exemplary drilling mud have been calculated with the use of this numerical program.
General RG Equations for Physical Neutrino Parameters and their Phenomenological Implications
Casas, J A; Ibarra, Alejandro; Navarro, I
2000-01-01
The neutral leptonic sector of the Standard Model presumably consists of three neutrinos with non-zero Majorana masses with properties further determined by three mixing angles and three CP-violating phases. We derive the general renormalization group equations for these physical parameters and apply them to study the impact of radiative effects on neutrino physics. In particular, we examine the existing solutions to the solar and atmospheric neutrino problems, derive conclusions on their theoretical naturalness, and show how some of the measured neutrino parameters could be determined by purely radiative effects. For example, the mass splitting and mixing angle suggested by solar neutrino data could be entirely explained as a radiative effect if the small angle MSW solution is realized. On the other hand, the mass splitting required by atmospheric neutrino data is probably determined by unknown physics at a high energy scale. We also discuss the effect of non-zero CP-violating phases on radiative corrections...
Brembs, Björn; Hempel de Ibarra, Natalie
2006-01-01
We have used a genetically tractable model system, the fruit fly Drosophila melanogaster to study the interdependence between sensory processing and associative processing on learning performance. We investigated the influence of variations in the physical and predictive properties of color stimuli in several different operant-conditioning procedures on the subsequent learning performance. These procedures included context and stimulus generalization as well as color, compound, and conditional discrimination (colors and patterns). A surprisingly complex dependence of the learning performance on the colors' physical and predictive properties emerged, which was clarified by taking into account the fly-subjective perception of the color stimuli. Based on estimates of the stimuli's color and brightness values, we propose that the different tasks are supported by different parameters of the color stimuli; generalization occurs only if the chromaticity is sufficiently similar, whereas discrimination learning relies on brightness differences.
PARAMETER REGION FOR EXISTENCE OF SOLITONS IN GENERALIZED KdV EQUATION
Institute of Scientific and Technical Information of China (English)
ShengPingxing
2003-01-01
This paper considers the generalized KdV equation with or without natural boundary conditions and provides a parameter region for solitons and solitary waves,and also modifies a result of Zabusky's.The solitary bifurcation has been discussed.
Directory of Open Access Journals (Sweden)
Liu Gang
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.
A General Approach for Synchronization of Chaotic Systems with Parameters Perturbation
Institute of Scientific and Technical Information of China (English)
LONG Min; QIU Shui-Sheng; PENG Fei
2005-01-01
By making use of the theory of stability for dynamical systems, a general approach for synchronization of chaotic systems with parameters perturbation is presented, and a general method for determining control function is introduced. The Rossler system is employed to verify the effectiveness of the method, and the theoretical results are confirmed by simulations.
Institute of Scientific and Technical Information of China (English)
Jia Zhen; Lu Jun-An; Deng Guang-Ming; Zhang Qun-Jiao
2007-01-01
In this paper is investigated the generalized projective synchronization of a class of chaotic (or hyperchaotic) systems, in which certain parameters can be separated from uncertain parameters. Based on the adaptive technique, the globally generalized projective synchronization of two identical chaotic (hyperchaotic) systems is achieved by designing a novel nonlinear controller. Furthermore, the parameter identification is realized simultaneously. A sufficient condition for the globally projective synchronization is obtained. Finally, by taking the hyperchaotic Lü system as example, some numerical simulations are provided to demonstrate the effectiveness and feasibility of the proposed technique.
Kamiński, Marcin; Ossowski, Rafał Leszek
2014-01-01
The paper presents the results concerning a new problem of homogenization of the fluids filled with a random volume fraction of nanoparticles. We use a variety of probabilistic and statistical methods applied for numerical determination of the effective physical properties of different fluids filled with nanoparticles. The new probabilistic approach in the form of a higher order stochastic perturbation method is employed here, which is based on a higher order Taylor expansion of input random quantities and the resulting homogenized parameters using a general order series with random coefficients; it is contrasted with the Monte Carlo simulation and analytical symbolic integration. All computer methods are used to determine up to the fourth probabilistic moments and coefficients for effective specific heat, viscosity, heat conductivity and mass density for some nanofluids of modern technological importance. The volume fraction of the nanoparticles is treated in this study as the input Gaussian parameter truncated to the positive values and uniquely defined by the expectation, where its coefficient of variation is an additional parameter in our analysis. Computational experiments are performed here using computer algebra system MAPLE and they demonstrate a very good agreement of the probabilistic characteristics computed using analytical, perturbation and simulation methods.
First-order method of zoom lens design by means of generalized parameters.
Khorokhorov, Alexei M; Piskunov, Dmitry E; Shirankov, Alexander F
2016-08-01
A method of paraxial zoom lens design is proposed that makes it possible to determine the optical powers and component movements of a zoom lens with the required zoom ratio. The method is based on the theory of generalized parameters, which can be used to analyze a zoom system by varying only one parameter. All possible zoom lenses with two movable components are considered for an object at infinity.
Directory of Open Access Journals (Sweden)
Ece Ayli
2016-01-01
Full Text Available The runner design is the most challenging part of the turbine design process. Several parameters determine the performance and cavitation characteristics of the runner: the metal angle (flow beta angle, the alpha angle, the blade beta angle, the runner inlet and outlet diameters, and the blade height. All of these geometrical parameters need to be optimized to ensure that the head, flow rate and power requirements of the system are met. A hydraulic designer has to allocate time to optimize these parameters and should be experienced in carrying out the iterative design process. In this article, the turbine runner parameters that affect the performance and cavitation characteristics of designed turbines are examined in detail. Furthermore, turbines are custom designed according to the properties of hydroelectric power plants; this makes the design process even more challenging, as the rotational speed, runner geometry, system head and flow rate vary for each turbine. The effects of the design parameters are examined for four different turbine runners specifically designed and used in actual power plants in order to obtain general results and generalizations applicable to turbine design aided by computational fluid dynamics (CFD. The flow behavior, flow angles, head losses, pressure distribution, and cavitation characteristics are computed, analyzed, and compared. To assist hydraulic designers, the general influences of these parameters on the performance of turbines are summarized and empirical formulations are derived for runner performance characterization.
Vanommeslaeghe, K.; Raman, E. Prabhu; MacKerell, A. D.
2012-01-01
Molecular mechanics force fields are widely used in computer-aided drug design for the study of drug candidates interacting with biological systems. In these simulations, the biological part is typically represented by a specialized biomolecular force field, while the drug is represented by a matching general (organic) force field. In order to apply these general force fields to an arbitrary drug-like molecule, functionality for assignment of atom types, parameters and partial atomic charges is required. In the present article, algorithms for the assignment of parameters and charges for the CHARMM General Force Field (CGenFF) are presented. These algorithms rely on the existing parameters and charges that were determined as part of the parametrization of the force field. Bonded parameters are assigned based on the similarity between the atom types that define said parameters, while charges are determined using an extended bond-charge increment scheme. Charge increments were optimized to reproduce the charges on model compounds that were part of the parametrization of the force field. A “penalty score” is returned for every bonded parameter and charge, allowing the user to quickly and conveniently assess the quality of the force field representation of different parts of the compound of interest. Case studies are presented to clarify the functioning of the algorithms and the significance of their output data. PMID:23145473
A statistical study of the interdependence of solar wind parameters
Institute of Scientific and Technical Information of China (English)
Shollykutty John; P. J. Kurian
2009-01-01
Correlation analysis of solar wind parameters, namely solar wind velocity, pro- ton density, proton temperature and mean interplanetary magnetic field (IMF) from the ACE spacecraft data near Earth, was done. To our best knowledge, this study is a novel one since we consider here only the parameters inside the solar wind, including the mean IMF and, hence, the solar wind is a self consistent system. We have proposed a Multiple Linear Regression (MLR) model for the prediction of the response variable (solar wind velocity) using the parameters proton density, proton temperature and mean IMF mea- sured as dally averages. About 60% of the observed value can be predicted using this model. It is shown that, in general, the correlation between solar wind parameters is sig- nificant. A deviation from the prediction at the solar maximum is interpreted. These results are verified by a graphical method.
Study on Solitary Waves of a General Boussinesq Model
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
In this paper, we employ the bifurcation method of dynamical systems to study the solitary waves and periodic waves of a generalized Boussinesq equations. All possible phase portraits in the parameter plane for the travelling wave systems are obtained. The possible solitary wave solutions, periodic wave solutions and cusp waves for the general Boussinesq type fluid model are also investigated.
Colistete, R C; Goncalves, S V B
2004-01-01
The type Ia supernovae (SNe Ia) observational data are used to estimate the parameters of a cosmological model with cold dark matter and the generalized Chaplygin gas model (GCGM). The GCGM depends essentially on five parameters: the Hubble constant, the parameter $\\bar{A}$ related to the velocity of the sound, the equation of state parameter $\\alpha$, the curvature of the Universe and the fraction density of the generalized Chaplygin gas (or the cold dark matter). The parameter $\\alpha$ is allowed to take negative values and to be greater than 1. The Bayesian parameter estimation yields $\\alpha = - 0.86^{+6.01}_{-0.15}$, $H_0 = 62.0^{+1.32}_{-1.42} km/Mpc.s$, $\\Omega _{k0}=-1.26_{-1.42}^{+1.32}$, $\\Omega_{m0} = 0.00^{+0.86}_{-0.00}$, $\\Omega_{c0} = 1.39^{+1.21}_{-1.25}$, $\\bar A =1.00^{+0.00}_{-0.39}$, $t_0 = 15.3^{+4.2}_{-3.2}$ and $q_0 = -0.80^{+0.86}_{-0.62}$, where $t_0$ is the age of the Universe and $q_0$ is the value of the deceleration parameter today. Our results indicate that a Universe completely ...
A parameter identifiability study of two chalk tracer tests
Directory of Open Access Journals (Sweden)
S. A. Mathias
2006-08-01
Full Text Available As with most fractured rock formations, Chalk is highly heterogeneous. Therefore, meaningful estimates of model parameters must be obtained at a scale comparable with the process of concern. These are frequently obtained by calibrating an appropriate model to observed concentration-time data from radially convergent tracer tests (RCTT. Arguably, an appropriate model should consider radially convergent dispersion (RCD and Fickian matrix diffusion. Such a model requires the estimation of at least four parameters. A question arises as to whether or not this level of model complexity is supported by the information contained within the calibration data. Generally modellers have not answered this question due to the calibration techniques employed. A dual-porosity model with RCD was calibrated to two tracer test datasets from different UK Chalk aquifers. A multivariate sensitivity analysis, which assumed only a priori upper and lower bounds for each model parameter, was undertaken. Rather than looking at measures of uncertainty, the shape of the multivariate objective function surface was used to determine whether a parameter was identifiable. Non-identifiable parameters were then removed and the procedure was repeated until all remaining parameters were identifiable.
It was found that the single fracture model (SFM (which ignores mechanical dispersion obtained the best mass recovery, excellent model performance and best parameter identifiability in both the tests studied. However, there was no objective evidence suggesting that mechanical dispersion was negligible. Moreover, the SFM (with just two parameters was found to be good at approximating the Single Fracture Dispersion Model SFDM (with three parameters when different, and potentially erroneous parameters, were used. Overall, this study emphasises the importance of adequate temporal sampling of breakthrough curve data prior to peak concentrations, to ensure adequate characterisation of
Multi-parameter vital sign database to assist in alarm optimization for general care units.
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, SpO2 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.
[Drug advertising to the general public: conceptual parameters of a risk producer practice].
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.
Marginal Maximum A Posteriori Item Parameter Estimation for the Generalized Graded Unfolding Model
Roberts, James S.; Thompson, Vanessa M.
2011-01-01
A marginal maximum a posteriori (MMAP) procedure was implemented to estimate item parameters in the generalized graded unfolding model (GGUM). Estimates from the MMAP method were compared with those derived from marginal maximum likelihood (MML) and Markov chain Monte Carlo (MCMC) procedures in a recovery simulation that varied sample size,…
Constraining Parameters of Generalized Cosmic Chaplygin Gas in Loop Quantum Cosmology
Ranjit, Chayan
2014-01-01
We have assumed the FRW universe in loop quantum cosmology (LQC) model filled with the dark matter and the Generalized Cosmic Chaplygin gas (GCCG) type dark energy where dark matter follows the linear equation of state. We present the Hubble parameter in terms of the observable parameters $\\Omega_{m0}$ and $H_{0}$ with the redshift $z$ and the other parameters like $A$, $B$, $w_{m}$, $ \\omega$ and $\\alpha$ which coming from our model. From Stern data set (12 points)\\& SNe Type Ia 292 data (from \\cite{Riess1,Riess2,Astier}) we have obtained the bounds of the arbitrary parameters by minimizing the $\\chi^{2}$ test. The best-fit values of the parameters are obtained by 66\\%, 90\\% and 99\\% confidence levels. Next due to joint analysis with Stern+BAO and Stern+BAO+CMB observations, we have also obtained the bounds of the parameters ($A,B$) by fixing some other parameters $\\alpha$, $w_{m}$ and $\\omega$. From the best fit values of the parameters, we have obtained the distance modulus $\\mu(z)$ for our theoretical...
Parameter Studies for the VISTA Spacecraft Concept
Energy Technology Data Exchange (ETDEWEB)
Orth, C D
2000-11-21
The baseline design for the VISTA spacecraft concept employs a diode-pumped solid-state laser (DPSSL) driver. This type of driver is now under development at LLNL and elsewhere as an extension of the mature solid-state (glass) laser technology developed for terrestrial applications of inertial confinement fusion (ICF). A DPSSL is repratable up to at least 30 Hz, and has an efficiency soon to be experimentally verified of at least 10%. By using a detailed systems code including the essential physics of a DPSSL, we have run parameter studies for the baseline roundtrip (RT) to Mars with a 100-ton payload. We describe the results of these studies as a function of the optimized (minimum) RT flight duration. We also demonstrate why DT fuel gives the best performance, although DD, D3He, or even antimatter can be used, and why DT-ignited DD is probably the fuel most preferred. We also describe the overall power flow, showing where the fusion energy is ultimately utilized, and estimate the variation in performance to the planets dictated by variations in target gain and other parameters.
Post-Newtonian parameter γ in generalized non-local gravity
Zhang, Xue; Wu, YaBo; Yang, WeiQiang; Zhang, ChengYuan; Chen, BoHai; Zhang, Nan
2017-10-01
We investigate the post-Newtonian parameter γ and derive its formalism in generalized non-local (GNL) gravity, which is the modified theory of general relativity (GR) obtained by adding a term m 2 n-2 R☐-n R to the Einstein-Hilbert action. Concretely, based on parametrizing the generalized non-local action in which gravity is described by a series of dynamical scalar fields ϕ i in addition to the metric tensor g μν, the post-Newtonian limit is computed, and the effective gravitational constant as well as the post-Newtonian parameters are directly obtained from the generalized non-local gravity. Moreover, by discussing the values of the parametrized post-Newtonian parameters γ, we can compare our expressions and results with those in Hohmann and Järv et al. (2016), as well as current observational constraints on the values of γ in Will (2006). Hence, we draw restrictions on the nonminimal coupling terms F̅ around their background values.
Post-Newtonian parameter $\\gamma$ for multiscalar-tensor gravity with a general potential
Hohmann, Manuel; Kuusk, Piret; Randla, Erik; Vilson, Ott
2016-01-01
We compute the parametrized post-Newtonian parameter $\\gamma$ in the case of a static point source for multiscalar-tensor gravity with completely general nonderivative couplings and potential in the Jordan frame. Similarly to the single massive field case $\\gamma$ depends exponentially on the distance from the source and is determined by the length of a vector of non-minimal coupling in the space of scalar fields and its orientation relative to the mass eigenvectors. Using data from the Cassini tracking experiment, we estimate bounds on a general theory with two scalar fields. Our formalism can be utilized for a wide range of models, which we illustrate by applying it to nonminimally coupled Higgs SU(2) doublet, general hybrid metric-Palatini gravity, linear ($\\Box^{-1}$) and quadratic ($\\Box^{-2}$) nonlocal gravity.
Generalized function of the parameters in the storage-discharge relation for low flows
Fujimura, Kazumasa; Iseri, Yoshihiko; Kanae, Shinjiro; Murakami, Masahiro
2015-04-01
The accurate estimation of low flows can contribute to better water resource management and more reliable evaluation of the impact of climate change on water resources. For the case of low flows, the nonlinearity of the discharge Q associated with the storage S was originally proposed by Horton (1936) as the power function Q=KSN, where K is a constant and N is the exponent. Although the Q(S) relations for groundwater runoff from unconfined aquifers have been treated as second-order polynomial functions on the basis of the hydraulic investigation by Ding (1966), the general power function Q = KNSN was introduced into the unit hydrograph model for overland flow and the parameters K and N were calibrated by Ding (2011). According to recent studies, the value of the exponent N is varied between 1 and 3 or higher by calibration (e.g., Wittenberg, 1994 and Ding, 2011); however, it is currently unclear whether the optimum value of N has the rule. Fujimura et al. (2014) applied the general power function Q = KNSN for low flows in mountainous basins over a period spanning more than 10 years using hourly data, and carried out sensitivity analysis using a hydrological model for 19 900 sets of the two parameters K and N, in which the exponent N was varied between 1 and 100 in steps of 0.5. The results showed that the optimum relation between N and K could be characterized by the exponential function K=1/(α Nβ), where α and β are constants. Moreover, the lowest error in the sensitivity analysis was obtained by using an exponent N of 100. The aim of this study is to extend the previous study of Fujimura et al. to clarify the properties of the K(N) relations. A sensitivity analysis is performed efficiently using a hydrological model, in which the exponent N is varied between 1 and 100 000 along the neighborhood of the exponential function K=1/(α Nβ). The hourly hydrological model used in this study comprises the Diskin-Nazimov infiltration model, groundwater recharge and
Synthetic Weyl points in generalized parameter space and their topological properties
Wang, Qiang; Liu, Hui; Wan, Xiangang; Zhu, Shining; Chan, C T
2016-01-01
Weyl fermions1 do not appear in nature as elementary particles, but they are now found to exist as nodal points in the band structure of electronic and classical wave crystals. Novel phenomena such as Fermi arcs and chiral anomaly have fueled the interest of these topological points which are frequently perceived as monopoles in momentum space. Here, we demonstrate that generalized Weyl points can exist in a parameter space and we report the first observation of such nodal points in one-dimensional photonic crystals in the optical range. The reflection phase inside the band gap of a truncated photonic crystal exhibits vortexes in the parameter space where the Weyl points are defined and they share the same topological charges as the Weyl points. These vortexes guarantee the existence of interface states, the trajectory of which can be understood as "Fermi arcs" emerging from the Weyl nodes.
Lai, Zhi-Hui; Leng, Yong-Gang
2015-01-01
A two-dimensional Duffing oscillator which can produce stochastic resonance (SR) is studied in this paper. We introduce its SR mechanism and present a generalized parameter-adjusted SR (GPASR) model of this oscillator for the necessity of parameter adjustments. The Kramers rate is chosen as the theoretical basis to establish a judgmental function for judging the occurrence of SR in this model; and to analyze and summarize the parameter-adjusted rules under unmatched signal amplitude, frequency, and/or noise-intensity. Furthermore, we propose the weak-signal detection approach based on this GPASR model. Finally, we employ two practical examples to demonstrate the feasibility of the proposed approach in practical engineering application. PMID:26343671
Lai, Zhi-Hui; Leng, Yong-Gang
2015-08-28
A two-dimensional Duffing oscillator which can produce stochastic resonance (SR) is studied in this paper. We introduce its SR mechanism and present a generalized parameter-adjusted SR (GPASR) model of this oscillator for the necessity of parameter adjustments. The Kramers rate is chosen as the theoretical basis to establish a judgmental function for judging the occurrence of SR in this model; and to analyze and summarize the parameter-adjusted rules under unmatched signal amplitude, frequency, and/or noise-intensity. Furthermore, we propose the weak-signal detection approach based on this GPASR model. Finally, we employ two practical examples to demonstrate the feasibility of the proposed approach in practical engineering application.
Directory of Open Access Journals (Sweden)
Zhi-Hui Lai
2015-08-01
Full Text Available A two-dimensional Duffing oscillator which can produce stochastic resonance (SR is studied in this paper. We introduce its SR mechanism and present a generalized parameter-adjusted SR (GPASR model of this oscillator for the necessity of parameter adjustments. The Kramers rate is chosen as the theoretical basis to establish a judgmental function for judging the occurrence of SR in this model; and to analyze and summarize the parameter-adjusted rules under unmatched signal amplitude, frequency, and/or noise-intensity. Furthermore, we propose the weak-signal detection approach based on this GPASR model. Finally, we employ two practical examples to demonstrate the feasibility of the proposed approach in practical engineering application.
Generalized two-mode coherent-entangled state with real parameters
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
The coherent-entangled state |α, x; λ> with real parameters λ is proposed in the two-mode Fock space, which exhibits the properties of both the coherent and entangled states. The completeness relation of |α, x; λ> is proved by virtue of the technique of integral within an ordered product of operators. The corresponding squeezing operator is derived, with its own squeezing properties. Furthermore, generalized P-representation in the coherent-entangled state is constructed. Finally, it is revealed that superposition of the coherent-entangled states may produce the EPR entangled state.
Bianchi Type-II inﬂationary models with constant deceleration parameter in general relativity
Indian Academy of Sciences (India)
C P Singh; S Kumar
2007-05-01
Einstein's ﬁeld equations are considered for a locally rotationally symmetric Bianchi Type-II space–time in the presence of a massless scalar ﬁeld with a scalar potential. Exact solutions of scale factors and other physical parameters are obtained by using a special law of variation for Hubble's parameter that yields a constant value of deceleration parameter. To get inﬂationary solutions, a ﬂat region is considered in which the scalar potential is constant. Power-law and exponential cases are studied and in both solutions there is an anisotropic expansion of the cosmic ﬂuid, but the ﬂuid has vanishing vorticity. A detailed study of geometrical and kinematical properties of solutions has been carried out.
A general method for parameter estimation in light-response models.
Chen, Lei; Li, Zhong-Bin; Hui, Cang; Cheng, Xiaofei; Li, Bai-Lian; Shi, Pei-Jian
2016-06-13
Selecting appropriate initial values is critical for parameter estimation in nonlinear photosynthetic light response models. Failed convergence often occurs due to wrongly selected initial values when using currently available methods, especially the kind of local optimization. There are no reliable methods that can resolve the conundrum of selecting appropriate initial values. After comparing the performance of the Levenberg-Marquardt algorithm and other three algorithms for global optimization, we develop a general method for parameter estimation in four photosynthetic light response models, based on the use of Differential Evolution (DE). The new method was shown to successfully provide good fits (R(2) > 0.98) and robust parameter estimates for 42 datasets collected for 21 plant species under the same initial values. It suggests that the DE algorithm can efficiently resolve the issue of hyper initial-value sensitivity when using local optimization methods. Therefore, the DE method can be applied to fit the light-response curves of various species without considering the initial values.
A general method for parameter estimation in light-response models
Chen, Lei; Li, Zhong-Bin; Hui, Cang; Cheng, Xiaofei; Li, Bai-Lian; Shi, Pei-Jian
2016-06-01
Selecting appropriate initial values is critical for parameter estimation in nonlinear photosynthetic light response models. Failed convergence often occurs due to wrongly selected initial values when using currently available methods, especially the kind of local optimization. There are no reliable methods that can resolve the conundrum of selecting appropriate initial values. After comparing the performance of the Levenberg–Marquardt algorithm and other three algorithms for global optimization, we develop a general method for parameter estimation in four photosynthetic light response models, based on the use of Differential Evolution (DE). The new method was shown to successfully provide good fits (R2 > 0.98) and robust parameter estimates for 42 datasets collected for 21 plant species under the same initial values. It suggests that the DE algorithm can efficiently resolve the issue of hyper initial-value sensitivity when using local optimization methods. Therefore, the DE method can be applied to fit the light-response curves of various species without considering the initial values.
An alternative order-parameter for non-equilibrium generalized spin models on honeycomb lattices
Sastre, Francisco; Henkel, Malte
2016-04-01
An alternative definition for the order-parameter is proposed, for a family of non-equilibrium spin models with up-down symmetry on honeycomb lattices, and which depends on two parameters. In contrast to the usual definition, our proposal takes into account that each site of the lattice can be associated with a local temperature which depends on the local environment of each site. Using the generalised voter motel as a test case, we analyse the phase diagram and the critical exponents in the stationary state and compare the results of the standard order-parameter with the ones following from our new proposal, on the honeycomb lattice. The stationary phase transition is in the Ising universality class. Finite-size corrections are also studied and the Wegner exponent is estimated as ω =1.06(9).
On the Generalization Capabilities of the Ten-Parameter Jiles-Atherton Model
Directory of Open Access Journals (Sweden)
Gabriele Maria Lozito
2015-01-01
Full Text Available This work proposes an analysis on the generalization capabilities for the modified version of the classic Jiles-Atherton model for magnetic hysteresis. The modified model takes into account the use of dynamic parameterization, as opposed to the classic model where the parameters are constant. Two different dynamic parameterizations are taken into account: a dependence on the excitation and a dependence on the response. The identification process is performed by using a novel nonlinear optimization technique called Continuous Flock-of-Starling Optimization Cube (CFSO3, an algorithm belonging to the class of swarm intelligence. The algorithm exploits parallel architecture and uses a supervised strategy to alternate between exploration and exploitation capabilities. Comparisons between the obtained results are presented at the end of the paper.
Parameter estimation in the presence of the most general Gaussian dissipative reservoir
Jarzyna, Marcin; Zwierz, Marcin
2017-01-01
We analyze the performance of quantum parameter estimation in the presence of the most general Gaussian dissipative reservoir. We derive lower bounds on the precision of phase estimation and a closely related problem of frequency estimation. For both problems we show that it is impossible to achieve the Heisenberg limit asymptotically in the presence of such a reservoir. However, we also find that for any fixed number of probes used in the setup there exists a Gaussian dissipative reservoir, which, in principle, allows for the Heisenberg-limited performance for that number of probes. We discuss a realistic implementation of a frequency estimation scheme in the presence of a Gaussian dissipative reservoir in a cavity system.
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.
Mullah, Muhammad Abu Shadeque; Benedetti, Andrea
2016-11-01
Besides being mainly used for analyzing clustered or longitudinal data, generalized linear mixed models can also be used for smoothing via restricting changes in the fit at the knots in regression splines. The resulting models are usually called semiparametric mixed models (SPMMs). We investigate the effect of smoothing using SPMMs on the correlation and variance parameter estimates for serially correlated longitudinal normal, Poisson and binary data. Through simulations, we compare the performance of SPMMs to other simpler methods for estimating the nonlinear association such as fractional polynomials, and using a parametric nonlinear function. Simulation results suggest that, in general, the SPMMs recover the true curves very well and yield reasonable estimates of the correlation and variance parameters. However, for binary outcomes, SPMMs produce biased estimates of the variance parameters for high serially correlated data. We apply these methods to a dataset investigating the association between CD4 cell count and time since seroconversion for HIV infected men enrolled in the Multicenter AIDS Cohort Study.
Directory of Open Access Journals (Sweden)
Samardžić Janko
2013-01-01
Full Text Available Background/Aim. Zinc is an essential element which has considerable interaction with gamma-aminobutyric acid A type receptors (GABAA and glutamate receptors in the central nervous system (CNS. It is believed that zinc acts as a potent inhibitor of glutamate N-methyl-D-aspartate (NMDA receptors, and binding to structurally specific site on the GABAA receptor leads to inhibition of GABA dependent Cl-pass. The aim of our research was to test the anxiolytic and antidepressant effects of zinc after single application and its influence on general behavioural parameters after repeated administration. Methods. Male Wistar rats were treated with increasing doses of zinc histidine dehydrate (10, 20, 30 mg/kg, i.p.. To determine anxiolytic and antidepressant properties of zinc two models were used: elevated plus maze (EPM and forced swim test (FST. Behavioural parameters (stillness and mobility were, also, recorded after single and repeated administration of active substance. Results. Testing animals in the EPM showed a statistically significant difference as follows: dose of 20 mg/kg significantly increased the time animals spent in open arms, indicating an acute anxiolytic effect, while doses of 30 mg/kg significantly reduced the time in the open arms, indicating a potentially anxiogenic effect. Testing the animals by FST showed a statistically significant difference in immobility time of animals treated with the lowest applied (10 mg/kg and highest applied (30 mg/kg doses of zinc, compared to the control group. The first day of testing behavioral parameters showed the tendency to increase locomotor activity of the animals with the lowest dose of zinc (10 mg/kg, while the following day revealed a reduced activity with the highest dose applied (30 mg/kg. Conclusion. Zinc has important effects on the CNS: After single application, in all doses zinc showed antidepressant effects. The effects of zinc on anxiety and locomotor activity showed dose
Directory of Open Access Journals (Sweden)
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.
A Generalized Information Criterion for Parameters under an Umbrella Order Restriction
Institute of Scientific and Technical Information of China (English)
宋海燕; 陶剑; 史宁中
2005-01-01
The detection of the configuration of parameters is one of the most important problems im statistical studies. It is well known that the Akaike's information criterion (AIC) is a key tool for this problem (see [1]). Usually, the AIC is defined as: AIC(μ) := l(μ) -p, where l(μ) is the log-likelihood with the maximum likelihood estimator (MLE) μ for μ,
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...
Holographic study on the jet quenching parameter in anisotropic systems
Wang, Luying
2016-01-01
We first calculate the jet quenching parameter of an anisotropic plasma with a U(1) chemical potential via the AdS/CFT duality. The effects of charge, anisotropy parameter and quark motion direction on the jet quenching parameter are investigated. We then discuss the situation of anisotropic black brane in the IR region. We study both the jet quenching parameters along the longitudinal direction and transverse plane.
Holographic study of the jet quenching parameter in anisotropic systems
Energy Technology Data Exchange (ETDEWEB)
Wang, Luying [Shanghai University, Department of Physics, Shanghai (China); Wu, Shang-Yu [National Chiao Tung University, Department of Electrophysics, Hsinchu (China)
2016-11-15
We first calculate the jet quenching parameter of an anisotropic plasma with a U(1) chemical potential via AdS/CFT duality. The effects of charge, anisotropy parameter, and quark motion direction on the jet quenching parameter are investigated. We then discuss the situation of an anisotropic black brane in the IR region. We study both the jet quenching parameters along the longitudinal direction and the transverse plane. (orig.)
Computer technology forecast study for general aviation
Seacord, C. L.; Vaughn, D.
1976-01-01
A multi-year, multi-faceted program is underway to investigate and develop potential improvements in airframes, engines, and avionics for general aviation aircraft. The objective of this study was to assemble information that will allow the government to assess the trends in computer and computer/operator interface technology that may have application to general aviation in the 1980's and beyond. The current state of the art of computer hardware is assessed, technical developments in computer hardware are predicted, and nonaviation large volume users of computer hardware are identified.
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
Fragoso, Wallace; Allegrini, Franco; Olivieri, Alejandro C
2016-08-24
Generalized analytical sensitivity (γ) is proposed as a new figure of merit, which can be estimated from a multivariate calibration data set. It can be confidently applied to compare different calibration methodologies, and helps to solve literature inconsistencies on the relationship between classical sensitivity and prediction error. In contrast to the classical plain sensitivity, γ incorporates the noise properties in its definition, and its inverse is well correlated with root mean square errors of prediction in the presence of general noise structures. The proposal is supported by studying simulated and experimental first-order multivariate calibration systems with various models, namely multiple linear regression, principal component regression (PCR) and maximum likelihood PCR (MLPCR). The simulations included instrumental noise of different types: independently and identically distributed (iid), correlated (pink) and proportional noise, while the experimental data carried noise which is clearly non-iid.
Griffith, Roger L; Newman, Jeffrey A; Moustakas, Leonidas A; Stern, Daniel; Comerford, Julia M; Davis, Marc; Lotz, Jennifer M; Barden, Marco; Conselice, Christopher J; Capak, Peter L; Faber, S M; Kirkpatrick, J Davy; Koekemoer, Anton M; Koo, David C; Noeske, Kai G; Scoville, Nick; Sheth, Kartik; Shopbell, Patrick; Willmer, Christopher N A; Weiner, Benjamin
2012-01-01
We present the Advanced Camera for Surveys General Catalog (ACS-GC), a photometric and morphological database using publicly available data obtained with the Advanced Camera for Surveys (ACS) instrument on the Hubble Space Telescope. The goal of the ACS-GC database is to provide a large statistical sample of galaxies with reliable structural and distance measurements to probe the evolution of galaxies over a wide range of look-back times. The ACS-GC includes over 490,000 astronomical sources (stars + galaxies) derived from the AEGIS, COSMOS, GEMS, and GOODS surveys. Galapagos was used to construct photometric (SExtractor) and morphological (Galfit) catalogs. The analysis assumes a single S\\'ersic model for each object to derive quantitative structural parameters. We include publicly available redshifts from the DEEP2, COMBO-17, TKRS, PEARS, ACES, CFHTLS,and zCOSMOS surveys to supply redshifts (spectroscopic and photometric) for a considerable fraction (~71%) of the imaging sample. The ACS-GC includes color po...
Dong, Yi; Mihalas, Stefan; Russell, Alexander; Etienne-Cummings, Ralph; Niebur, Ernst
2011-11-01
When a neuronal spike train is observed, what can we deduce from it about the properties of the neuron that generated it? A natural way to answer this question is to make an assumption about the type of neuron, select an appropriate model for this type, and then choose the model parameters as those that are most likely to generate the observed spike train. This is the maximum likelihood method. If the neuron obeys simple integrate-and-fire dynamics, Paninski, Pillow, and Simoncelli (2004) showed that its negative log-likelihood function is convex and that, at least in principle, its unique global minimum can thus be found by gradient descent techniques. Many biological neurons are, however, known to generate a richer repertoire of spiking behaviors than can be explained in a simple integrate-and-fire model. For instance, such a model retains only an implicit (through spike-induced currents), not an explicit, memory of its input; an example of a physiological situation that cannot be explained is the absence of firing if the input current is increased very slowly. Therefore, we use an expanded model (Mihalas & Niebur, 2009 ), which is capable of generating a large number of complex firing patterns while still being linear. Linearity is important because it maintains the distribution of the random variables and still allows maximum likelihood methods to be used. In this study, we show that although convexity of the negative log-likelihood function is not guaranteed for this model, the minimum of this function yields a good estimate for the model parameters, in particular if the noise level is treated as a free parameter. Furthermore, we show that a nonlinear function minimization method (r-algorithm with space dilation) usually reaches the global minimum.
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.
General analytical procedure for determination of acidity parameters of weak acids and bases.
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 Practitioner Antimicrobial Stewardship Programme Study (GAPS)
DEFF Research Database (Denmark)
Avent, Minyon L; Hansen, Malene Plejdrup; Gilks, Charles;
2016-01-01
BACKGROUND: There is a strong link between antibiotic consumption and the rate of antibiotic resistance. In Australia, the vast majority of antibiotics are prescribed by general practitioners, and the most common indication is for acute respiratory infections. The aim of this study is to assess...... have previously been demonstrated to be effective at reducing antibiotic prescribing for acute respiratory infections, are: delayed prescribing; patient decision aids; communication training; commitment to a practice prescribing policy for antibiotics; patient information leaflet; and near patient...... testing with C-reactive protein. In addition, two sub-studies are nested in the main study: (1) point prevalence estimation carriage of bacterial upper respiratory pathogens in practice staff and asymptomatic patients; (2) feasibility of direct measures of antibiotic resistance by nose/throat swabbing...
Directory of Open Access Journals (Sweden)
Magda Dettlaff
2016-01-01
Full Text Available Given a graph \\(G=(V,E\\, the subdivision of an edge \\(e=uv\\in E(G\\ means the substitution of the edge \\(e\\ by a vertex \\(x\\ and the new edges \\(ux\\ and \\(xv\\. The domination subdivision number of a graph \\(G\\ is the minimum number of edges of \\(G\\ which must be subdivided (where each edge can be subdivided at most once in order to increase the domination number. Also, the domination multisubdivision number of \\(G\\ is the minimum number of subdivisions which must be done in one edge such that the domination number increases. Moreover, the concepts of paired domination and independent domination subdivision (respectively multisubdivision numbers are defined similarly. In this paper we study the domination, paired domination and independent domination (subdivision and multisubdivision numbers of the generalized corona graphs.
Energy Technology Data Exchange (ETDEWEB)
Kalmykov, M.Yu.; Kniehl, B.A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik
2008-07-15
We prove the following theorems: 1) The Laurent expansions in {epsilon} of the Gauss hypergeometric functions {sub 2}F{sub 1}(I{sub 1}+a{epsilon},I{sub 2}+b{epsilon};I{sub 3}+(p)/(q)+c{epsilon};z), {sub 2}F{sub 1}(I{sub 1}+(p)/(q)+a{epsilon},I{sub 2}+(p/q)+b{epsilon};I{sub 3}+(p)/(q)+c{epsilon};z) and {sub 2}F{sub 1}(I{sub 1}+(p)/(q)+ a{epsilon},I{sub 2}+b{epsilon};I{sub 3}+(p)/(q)+c{epsilon};z), where I{sub 1},I{sub 2},I{sub 3},p,q are arbitrary integers, a,b,c are arbitrary numbers and {epsilon} is an infinitesimal parameter, are expressible in terms of multiple polylogarithms of q-roots of unity with coefficients that are ratios of polynomials; 2) The Laurent expansion of the Gauss hypergeometric function {sub 2}F{sub 1}(I{sub 1}+(p)/(q)+a{epsilon},I{sub 2}+b{epsilon};I{sub 3}+c{epsilon};z) is expressible in terms of multiple polylogarithms of q-roots of unity times powers of logarithm with coefficients that are ratios of polynomials; 3) The multiple inverse rational sums {sigma}{sup {infinity}}{sub j=1}({gamma}(j))/({gamma}(1+j-(p)/(q))) (z{sup j})/(j{sup c}) S{sub a{sub 1}}(j-1).. S{sub a{sub p}}(j-1) and the multiple rational sums {sigma}{sup {infinity}}{sub j=1} ({gamma}(j+(p)/(q)))/({gamma}(1+j)) (z{sup j})/(j{sup c}) S{sub a{sub 1}}(j-1).. S{sub a{sub p}}(j-1), where S{sub a}(j)={sigma}{sup j}{sub k=1}(1)/(k{sup a}) is a harmonic series and c is an arbitrary integer, are expressible in terms of multiple polylogarithms; 4) The generalized hypergeometric functions {sub p}F{sub p.1}((vector)A+(vector)a{epsilon};(vector)B+(vector)b{epsilon},(p)/(q)+B{sub p-1};z) and {sub p}F{sub p-1}((vector)A+(vector)a{epsilon},(p)/(q)+A{sub p};(vector)B+(vector)b{epsilon};z) are expressible in terms of multiple polylogarithms with coefficients that are ratios of polynomials. (orig.)
A Study of Surrogate Parameters of Birth Weight
Directory of Open Access Journals (Sweden)
Kadam Y
2005-01-01
Full Text Available Research question : Which anthropometric parameter is correlating highly with birth weight? Can we use this parameter as a screening test for predicting birth weight? What is their cut-off value? Hypothesis: Various anthropometric parameters of newborn correlate each other positively. Objective : To find out the most effective anthropometric parameter in the newborn to assess birth weight so that newborn with LBW can be identified.. Study design: Hospital based cross-sectional study. Participants : Newborn babies born in KIMS, Karad. Results : Relatively highest correlation was observed between birth weight & thigh circumfirence (T.C. (r = 0.8637 & next with chest circumfirence (C.C.. (r = 0.8247 Cut-off values of T.C. & C.C. had better sensitivity, specificity & predictive value for identifying LBW babies. Conclusion : T.C. is the best effective parameter to predict birth weight. Next to it is C.C.
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.
General solar energy information user study
Energy Technology Data Exchange (ETDEWEB)
Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.
1981-03-01
This report describes the results of a series of telephone interviews with groups of users of information on general solar energy. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The report is 1 of 10 discussing study results. The overall study provides baseline data about information needs in the solar community. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from 13 groups of respondents are analyzed in this report: Loan Officers, Real Estate Appraisers, Tax Assessors, Insurers, Lawyers, Utility Representatives, Public Interest Group Representatives, Information and Agricultural Representatives, Public Interest Group Representatives, Information and Agricultural Specialists at State Cooperative Extension Service Offices, and State Energy Office Representatives. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.
Studies on the correlation of some aggregate parameters in the ...
African Journals Online (AJOL)
Global Journal of Pure and Applied Sciences ... Studies on the correlation of some aggregate parameters in the drains of a service facility ... coefficient of determination, R2, shows that each regression model is adequate for future prediction of
The study of functional parameter of the electric coal brushes
Directory of Open Access Journals (Sweden)
Claudia Staşac
2008-05-01
Full Text Available These paper present a study about the analyzeof the functional parameters of the electrical coal brush.The analyze was made with an experimental device, andthe results was prelucrate in MathCAD software.
Directory of Open Access Journals (Sweden)
T. M. Volosovets
2015-04-01
Full Text Available Introduction. The nature of local pathogenetic mechanisms of periodontal tissue lesions is the result of the interaction of various etiopathogenetical determinants. The researchers almost do not consider influence of persistent herpes virus infection on the state of immunobiological organism resistance and deterioration of the overall prognosis of dental disease. Aim. To identify the features of laboratory parameters in 45 patients with periodontal pathology associated with herpes virus infection. Material and methods. Laboratory study of 45 people with periodontal pathology associated with herpes virus infection (group I, 20 individuals with periodontal pathology without concomitant herpes infection (group II and 10 individuals without periodontal pathology and without concomitant herpes viral infections (control group, namely: determining the amount of gingival fluid according to M. Barer et al. and determining therein the content of inflammatory mediators – histamine and serotonin according to B. Mykhailychenko, adsorption reaction of microorganisms was studied according to M. Danilevsky and T. Bilenchuk. Results. Amount of gingival fluid in persons of I and II groups had significant difference (p<0,05 between both among them and in comparison with the control group. The content of histamine and serotonin in the gingival fluid of individuals of I and II groups had significant difference (p<0,05 between them, it was also significantly (p<0,01 higher than the corresponding figures for patients of the control group. Indices of RAM-positive cells in patients of groups I and II were significantly lower (p<0,05 than in the control group. In addition, indices of group I were significantly lower (p <0,05 than in group II. Conclusions. Persistent herpes infection significantly affects the state of immunobiological organism resistance and worsens the overall prognosis of periodontal tissue pathology.
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...
General review of flashing jet studies.
Polanco, Geanette; Holdø, Arne Erik; Munday, George
2010-01-15
The major concern on the management of superheated liquids, in industrial environments, is the large potential hazards involved in cases of any accidental release. There is a possibility that a violent phase change could take place inside the fluid released generating a flashing jet. This violent phase change might produce catastrophic consequences, such as explosions, fires or toxic exposure, in the installations and in the surroundings. The knowledge and understanding of the mechanisms involved in those releases become an important issue in the prevention of these consequences and the minimization of their impact. This work presents a comprehensive review of information about flashing processes. The review begins with a description of the single phase jet followed by a description of the two-phase flashing jet. The concepts and implications of the thermodynamic and mechanical effects on the behaviour of the jets are considered at the beginning of the review. Following the review is devoted to the classification of the different study approaches used to understand flashing processes in the past, highlighting various critical parameters on the behaviour and the hazard consequences of flashing jets. The review also contains an extensive compilation of experimental, theoretical and numerical data relating to these phenomena, which includes information on the distinct characteristics of the jet, since type of jet, velocity distribution, expansion angle and mass phase change all require individual estimation.
General review of flashing jet studies
Energy Technology Data Exchange (ETDEWEB)
Polanco, Geanette, E-mail: gpolanco@usb.ve [Simon Bolivar University, Caracas (Venezuela, Bolivarian Republic of); Holdo, Arne Erik, E-mail: Erik.Holdo@coventry.ac.uk [Narvik University College, Narvik (Norway); Munday, George, E-mail: G.Munday@isaaconsult.co.uk [Coventry University, Coventry (United Kingdom)
2010-01-15
The major concern on the management of superheated liquids, in industrial environments, is the large potential hazards involved in cases of any accidental release. There is a possibility that a violent phase change could take place inside the fluid released generating a flashing jet. This violent phase change might produce catastrophic consequences, such as explosions, fires or toxic exposure, in the installations and in the surroundings. The knowledge and understanding of the mechanisms involved in those releases become an important issue in the prevention of these consequences and the minimization of their impact. This work presents a comprehensive review of information about flashing processes. The review begins with a description of the single phase jet followed by a description of the two-phase flashing jet. The concepts and implications of the thermodynamic and mechanical effects on the behaviour of the jets are considered at the beginning of the review. Following the review is devoted to the classification of the different study approaches used to understand flashing processes in the past, highlighting various critical parameters on the behaviour and the hazard consequences of flashing jets. The review also contains an extensive compilation of experimental, theoretical and numerical data relating to these phenomena, which includes information on the distinct characteristics of the jet, since type of jet, velocity distribution, expansion angle and mass phase change all require individual estimation.
Institute of Scientific and Technical Information of China (English)
赵旭; 薛留根; 李婧兰; 程维虎
2012-01-01
The generalized Pareto distribution（GPD） is one of the most important distribution in statistics analysis.This paper is based on sample quantiles of the GPD.First,the shape parameter estimator that has high estimated precision is solved,then the approximated generalized least squares estimation expressions of the location and scale parameters are obtained for the GPD.The proposed method is easy and has no limitation for the shape parameter.In addition,it has high estimation accuracy under Monte-Carlo simulation tests.%广义Pareto分布（generalized Pareto distribution,GPD）是统计分析中的一个极为重要的分布.对基于广义Pareto分布的若干个样本分位数进行了研究.首先,求解具有较高精度的形状参数的参数估计;其次,得出广义Pareto分布位置参数及尺度参数的近似广义最小二乘估计.本方法简单易行,对形状参数的存在条件没有限制,通过Monte Carlo模拟验证了该方法具有较高的精度.
QUALITY CONTROL PARAMETERS OF BRIHAT DASHAMULA TAILA: A PRELIMINARY STUDY
Directory of Open Access Journals (Sweden)
Sharma Vinay
2011-05-01
Full Text Available Standard analytical parameters of a number of Ayurvedic oils have been described in API. Brihat Dashamula Taila is one of the most commonly used oil by Ayurvedic Physicians. But there no standard analytical parameters are available in any authentic texts. Therefore this study aimed to set the quality control parameters with SOP of Brihat Dashamula Taila and found values like Refractive index (1.47 at 400C, specific gravity (0.923 at 250C Acid value (1.2, Iodine value (92.6 and Saponification value (86.34 may be considered as standard.
Astrophysical parameters of ten poorly studied open star clusters
Institute of Scientific and Technical Information of China (English)
Ashraf Latif Tadross; Reda El-Bendary; Anas Osman; Nader Ismail; Abdel Aziz Bakry
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 reestimated for another five clusters,which are also studied by Kronberger et al.
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...
Chen, Yuh-Ing; Huang, Chi-Shen
2014-02-28
In the pharmacokinetic (PK) study under a 2x2 crossover design that involves both the test and reference drugs, we propose a mixed-effects model for the drug concentration-time profiles obtained from subjects who receive different drugs at different periods. In the proposed model, the drug concentrations repeatedly measured from the same subject at different time points are distributed according to a multivariate generalized gamma distribution, and the drug concentration-time profiles are described by a compartmental PK model with between-subject and within-subject variations. We then suggest a bioequivalence test based on the estimated bioavailability parameters in the proposed mixed-effects model. The results of a Monte Carlo study further show that the proposed model-based bioequivalence test is not only better on maintaining its level but also more powerful for detecting the bioequivalence of the two drugs than the conventional bioequivalence test based on a non-compartmental analysis or the one based on a mixed-effects model with a normal error variable. The application of the proposed model and test is finally illustrated by using data sets in two PK studies.
Denoising Algorithm Based on Generalized Fractional Integral Operator with Two Parameters
Directory of Open Access Journals (Sweden)
Hamid A. Jalab
2012-01-01
Full Text Available In this paper, a novel digital image denoising algorithm called generalized fractional integral filter is introduced based on the generalized Srivastava-Owa fractional integral operator. The structures of n×n fractional masks of this algorithm are constructed. The denoising performance is measured by employing experiments according to visual perception and PSNR values. The results demonstrate that apart from enhancing the quality of filtered image, the proposed algorithm also reserves the textures and edges present in the image. Experiments also prove that the improvements achieved are competent with the Gaussian smoothing filter.
Review Study on Runway Capacity Parameters and Improvement
Safrilah; Putra, J. C. P.
2017-06-01
The demand of air travel continues to increase over time, due to its short travel time, reliability and safety. Problems then arise when airport capacity, especially airside (mainly runway) capacity cannot cope with the demand. Some airports build the expensive additional infrastructure, while some others believe that manage on system is more efficient and effective. The study gathering information from various source about parameters related to runway capacity so that the improvement made in the future will solve right on target. To accommodate wide number of factors, the study classify the parameters into five categories in which operation/procedure related parameters play an important role (52%). To facilitate future research on runway capacity, the study also tabulates methods used by various scholars to improve runway capacity
Weber, Ulrike; Base, Eva; Ristl, Robin; Mora, Bruno
2015-08-01
Frequently used parameters for evaluation of left ventricular systolic function are load-sensitive. However, the impact of preload alterations on speckle-tracking echocardiographic parameters during anesthesia has not been validated. Therefore, two-dimensional (2D) speckle-tracking echocardiography radial strain (RS) was assessed during general anesthesia, simulating 3 different preload conditions. Single-center prospective observational study. University hospital. Thirty-three patients with normal left ventricular systolic function undergoing major surgery. Transgastric views of the midpapillary level of the left ventricle were acquired at 3 different positions. Fractional shortening (FS), fractional area change (FAC), and 2D speckle-tracking echocardiography RS were analyzed in the transgastric midpapillary view. Considerable correlation above 0.5 was found for FAC and FS in the zero and Trendelenburg positions (r = 0.629, r = 0.587), and for RS and FAC in the anti-Trendelenburg position (r = 0.518). In the repeated-measures analysis, significant differences among the values measured at the 3 positions were found for FAC and FS. For FAC, there were differences up to 2.8 percentage points between the anti-Trendelenburg position and the other 2 positions. For FS, only the difference between position zero and anti-Trendelenburg was significant, with an observed change of 1.66. Two-dimensional RS was not significantly different at all positions, with observed changes below 1 percentage point. Alterations in preload did not result in clinically relevant changes of RS, FS, or FAC. Observed changes for RS were smallest; however, the variation of RS was larger than that of FS or FAC. Copyright © 2015 Elsevier Inc. All rights reserved.
Directory of Open Access Journals (Sweden)
Makram KRIT
2016-01-01
Full Text Available This paper presents several iterative methods based on Stochastic Expectation-Maximization (EM methodology in order to estimate parametric reliability models for randomly lifetime data. The methodology is related to Maximum Likelihood Estimates (MLE in the case of missing data. A bathtub form of failure intensity formulation of a repairable system reliability is presented where the estimation of its parameters is considered through EM algorithm . Field of failures data from industrial site are used to fit the model. Finally, the interval estimation basing on large-sample in literature is discussed and the examination of the actual coverage probabilities of these confidence intervals is presented using Monte Carlo simulation method.
Institute of Scientific and Technical Information of China (English)
Zheng-yan Lin; Yu-ze Yuan
2012-01-01
Semiparametric models with diverging number of predictors arise in many contemporary scientific areas. Variable selection for these models consists of two components: model selection for non-parametric components and selection of significant variables for the parametric portion.In this paper,we consider a variable selection procedure by combining basis function approximation with SCAD penalty.The proposed procedure simultaneously selects significant variables in the parametric components and the nonparametric components.With appropriate selection of tuning parameters,we establish the consistency and sparseness of this procedure.
A generalized ARFIMA process with Markov-switching fractional differencing parameter
Tsay, Wen-Jen; Härdle, Wolfgang Karl
2007-01-01
We propose a general class of Markov-switching-ARFIMA processes in order to combine strands of long memory and Markov-switching literature. Although the coverage of this class of models is broad, we show that these models can be easily estimated with the DLV algorithm proposed. This algorithm combines the Durbin-Levinson and Viterbi procedures. A Monte Carlo experiment reveals that the finite sample performance of the proposed algorithm for a simple mixture model of Markov-switching mean and ...
Reference tissue modeling with parameter coupling: application to a study of SERT binding in HIV
Endres, Christopher J.; Hammoud, Dima A.; Pomper, Martin G.
2011-04-01
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 [11C]DASB PET studies. Five quantitative methods, including three methods that constrain the reference tissue clearance (kr2) to a common value across regions were applied to the clinical and simulated data to compare measurement of the tracer binding potential (BPND). Compared with standard SRTM, either coupling of kr2 across regions or constraining kr2 to a first-pass estimate improved the sensitivity of SRTM to measuring a significant difference in BPND 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 kr2 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 variance of parameter estimates and may better discriminate between
Indian Academy of Sciences (India)
Shishir B Sahay; T Meghasyam; Rahul K Roy; Gaurav Pooniwala; Sasank Chilamkurthy; Vikram Gadre
2015-06-01
This paper is targeted towards a general readership in signal processing. It intends to provide a brief tutorial exposure to the Fractional Fourier Transform, followed by a report on experiments performed by the authors on a Generalized Time Frequency Transform (GTFT) proposed by them in an earlier paper. The paper also discusses the extension of the uncertainty principle to the GTFT. This paper discusses some analytical results of the GTFT. We identify the eigenfunctions and eigenvalues of the GTFT. The time shift property of the GTFT is discussed. The paper describes methods for estimation of parameters of individual chirp signals on receipt of a noisy mixture of chirps. A priori knowledge of the nature of chirp signals in the mixture – linear or quadratic is required, as the two proposed methods fall in the category of model-dependent methods for chirp parameter estimation.
Comparative visualization for parameter studies of dataset series.
Malik, Muhammad Muddassir; Heinzl, Christoph; Eduard Gröller, M
2010-01-01
This paper proposes comparison and visualization techniques to carry out parameter studies for the special application area of dimensional measurement using 3D X-ray computed tomography (3DCT). A dataset series is generated by scanning a specimen multiple times by varying parameters of an industrial 3DCT device. A high-resolution series is explored using our planar-reformatting-based visualization system. We present a novel multi-image view and an edge explorer for comparing and visualizing gray values and edges of several datasets simultaneously. Visualization results and quantitative data are displayed side by side. Our technique is scalable and generic. It can be effective in various application areas like parameter studies of imaging modalities and dataset artifact detection. For fast data retrieval and convenient usability, we use bricking of the datasets and efficient data structures. We evaluate the applicability of the proposed techniques in collaboration with our company partners.
Indian Academy of Sciences (India)
S Sindhu; C S Menon
2006-09-01
The generalized Grüneisen parameters ($_{j}^{'}$) and ($_{j}^{''}$) for cadmium and zirconium were calculated from the second- and third-order elastic constants to determine the low temperature limit of the volume thermal expansion of these metals of hexagonal symmetry. The low temperature limit of cadmium and zirconium was calculated to be positive values indicating a positive volume expansion down to 0 K even though many Grüneisen gammas were found to be negative.
Yedavalli, R. K.
1992-01-01
The problem of analyzing and designing controllers for linear systems subject to real parameter uncertainty is considered. An elegant, unified theory for robust eigenvalue placement is presented for a class of D-regions defined by algebraic inequalities by extending the nominal matrix root clustering theory of Gutman and Jury (1981) to linear uncertain time systems. The author presents explicit conditions for matrix root clustering for different D-regions and establishes the relationship between the eigenvalue migration range and the parameter range. The bounds are all obtained by one-shot computation in the matrix domain and do not need any frequency sweeping or parameter gridding. The method uses the generalized Lyapunov theory for getting the bounds.
Yedavalli, R. K.
1992-01-01
The problem of analyzing and designing controllers for linear systems subject to real parameter uncertainty is considered. An elegant, unified theory for robust eigenvalue placement is presented for a class of D-regions defined by algebraic inequalities by extending the nominal matrix root clustering theory of Gutman and Jury (1981) to linear uncertain time systems. The author presents explicit conditions for matrix root clustering for different D-regions and establishes the relationship between the eigenvalue migration range and the parameter range. The bounds are all obtained by one-shot computation in the matrix domain and do not need any frequency sweeping or parameter gridding. The method uses the generalized Lyapunov theory for getting the bounds.
Hammerle, Albin; Wohlfahrt, Georg; Schoups, Gerrit
2014-05-01
Advances in automated data collection systems enabled ecologists to collect enormous amounts of varied data. Data assimilation (or data model synthesis) is one way to make sense of this mass of data. Given a process model designed to learn about ecological processes these data can be integrated within a statistical framework for data interpretation and extrapolation. Results of such a data assimilation framework clearly depend on the information content of the observed data, on the associated uncertainties (data uncertainties, model structural uncertainties and parameter uncertainties) and underlying assumptions. Parameter estimation is usually done by minimizing a simple least squares objective function with respect to the model parameters - presuming Gaussian, independent and homoscedastic errors (formal approach). Recent contributions to the (ecological) literature, however, have questioned the validity of this approach when confronted with significant errors and uncertainty in the model forcing (inputs) and model structure. Very often residual errors are non-Gaussian, correlated and heteroscedastic. Thus these error sources have to be considered and residual-errors have to be described in a statistically correct fashion order to draw statistically sound conclusions about parameter- and model predictive-uncertainties. We examined the effects of a generalized likelihood (GL) function on the parameter estimation of a carbon balance model. Compared with the formal approach, the GL function allows for correlation, non-stationarity and non-normality of model residuals. Carbon model parameters have been constrained using three different datasets, each of them modelled by its own GL function. As shown in literature the use of different datasets for parameter estimation reduces the uncertainty in model parameters and model predictions and does allow for a better quantification and for more insights into model processes.
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.
Li, Mao-Fen; Fan, Li; Liu, Hong-Bin; Guo, Peng-Tao; Wu, Wei
2013-01-01
Estimation of daily global solar radiation (Rs) from routinely measured temperature data has been widely developed and used in many different areas of the world. However, many of them are site specific. It is assumed that a general model for estimating daily Rs using temperature variables and geographical parameters could be achieved within a climatic region. This paper made an attempt to develop a general model to estimate daily Rs using routinely measured temperature data (maximum (Tmax, °C) and minimum (Tmin, °C) temperatures) and site geographical parameters (latitude (La, °N), longitude (Ld, °E) and altitude (Alt, m)) for Guizhou and Sichuan basin of southwest China, which was classified into the hot summer and cold winter climate zone. Comparison analysis was carried out through statistics indicators such as root mean squared error of percentage (RMSE%), modeling efficiency (ME), coefficient of residual mass (CRM) and mean bias error (MBE). Site-dependent daily Rs estimating models were calibrated and validated using long-term observed weather data. A general formula was then obtained from site geographical parameters and the better fit site-dependent models with mean RMSE% of 38.68%, mean MBE of 0.381 MJ m-2 d-1, mean CRM of 0.04 and mean ME value of 0.713.
Study on a General Hopf Hierarchy
Cui, Min-Jie; Lou, Sen-Yue
2016-04-01
By using a general symmetry theory related to invariant functions, strong symmetry operators and hereditary operators, we find a general integrable hopf heirarchy with infinitely many general symmetries and Lax pairs. For the first order Hopf equation, there exist infinitely many symmetries which can be expressed by means of an arbitrary function in arbitrary dimensions. The general solution of the first order Hopf equation is obtained via hodograph transformation. For the second order Hopf equation, the Hopf-diffusion equation, there are five sets of infinitely many symmetries. Especially, there exist a set of primary branch symmetry with which contains an arbitrary solution of the usual linear diffusion equation. Some special implicit exact group invariant solutions of the Hopf-diffusion equation are also given. Supported by the National Natural Science Foundation of China Grant under Nos. 11435005, 11175092, and 11205092, Shanghai Knowledge Service Platform for Trustworthy Internet of Things under Grant No. ZF1213 and K.C. Wong Magna Fund in Ningbo University
A STUDY OF SEASONAL PHYSICOCHEMICAL PARAMETERS IN RIVER USMA
Directory of Open Access Journals (Sweden)
A. I. Ugwu
2012-01-01
Full Text Available Growing populations may put stresses on natural waters by impairing both the quality of the water and the hydrological budget. Abuja, being relatively a new city and the new Federal Capital Territory of Nigeria, has scarce physicochemical data on its water resources that could assist in making robust decision in mitigating the impact of human societies on natural waters; which may not only preserve natural areas, but improve the quality of life of her growing population. A Study of Seasonal Physicochemical Parameters in River Usuma, Abuja Nigeria was carried out between 2011 and 2012. The water quality was studied at seven sites at upstream and downstream among the towns traversed by the River. Physicochemical parameters of the samples were measured; moreover, possible sources of contamination were analyzed. The parameters measured include; sodium (Na, potassium (K, Biochemical Oxygen Demand (BOD; Dissolve Oxygen (DO, pH, temperature, Electrical Conductivity (EC, Total Dissolved Solids (TDS, Total Suspended Solids (TSS, total alkalinity, Total Phosphate (TP, Total Nitrate (TN, Total Sulphate (TS and Total Chloride (TC. The mean values of the measured parameters were compared with National Standard for Drinking Water Quality (NSDWQ and U.S. Environmental Protection Agency (USEPA standards. The findings show that all the physicochemical parameters measured were within the tolerable values except TSS that exceeded with the mean values of 6.8, 4.9 and 8.4 mg L-1 respectively for all the seasons. The values of EC and TDS posed a caution that anthropogenic activities are on the daily increase within the study area. The water resources data base which could have validated the observed values is scarce. Therefore, frequent monitoring of physicochemical parameters of Abuja water resources is imperative.
Developing the Parameters of Scholarship in Postgraduate Coursework Studies
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…
Energy Technology Data Exchange (ETDEWEB)
Liu, Qing; Shi, Chaowei [Hefei National Laboratory for Physical Sciences at The Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026 (China); Yu, Lu [Hefei National Laboratory for Physical Sciences at The Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026 (China); High Magnetic Field Laboratory, Chinese Academy of Science, Hefei, Anhui, 230031 (China); Zhang, Longhua [Hefei National Laboratory for Physical Sciences at The Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026 (China); Xiong, Ying, E-mail: yxiong73@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at The Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026 (China); Tian, Changlin, E-mail: cltian@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at The Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026 (China); High Magnetic Field Laboratory, Chinese Academy of Science, Hefei, Anhui, 230031 (China)
2015-02-13
Internal backbone dynamic motions are essential for different protein functions and occur on a wide range of time scales, from femtoseconds to seconds. Molecular dynamic (MD) simulations and nuclear magnetic resonance (NMR) spin relaxation measurements are valuable tools to gain access to fast (nanosecond) internal motions. However, there exist few reports on correlation analysis between MD and NMR relaxation data. Here, backbone relaxation measurements of {sup 15}N-labeled SH3 (Src homology 3) domain proteins in aqueous buffer were used to generate general order parameters (S{sup 2}) using a model-free approach. Simultaneously, 80 ns MD simulations of SH3 domain proteins in a defined hydrated box at neutral pH were conducted and the general order parameters (S{sup 2}) were derived from the MD trajectory. Correlation analysis using the Gromos force field indicated that S{sup 2} values from NMR relaxation measurements and MD simulations were significantly different. MD simulations were performed on models with different charge states for three histidine residues, and with different water models, which were SPC (simple point charge) water model and SPC/E (extended simple point charge) water model. S{sup 2} parameters from MD simulations with charges for all three histidines and with the SPC/E water model correlated well with S{sup 2} calculated from the experimental NMR relaxation measurements, in a site-specific manner. - Highlights: • Correlation analysis between NMR relaxation measurements and MD simulations. • General order parameter (S{sup 2}) as common reference between the two methods. • Different protein dynamics with different Histidine charge states in neutral pH. • Different protein dynamics with different water models.
Correlation of Clinicohaematological Parameters in Paediatric Dengue: A Retrospective Study
Directory of Open Access Journals (Sweden)
Ramakrishna Pai Jakribettu
2015-01-01
Full Text Available Dengue is one of the arthropod-borne (arbo viral diseases transmitted by female mosquito Aedes aegypti. Dengue fever has a wide spectrum of clinical presentation ranging from flu-like illness to severe complicated stage of dengue hemorrhagic fever leading to mortality. This was a retrospective study conducted in a tertiary care hospital in Coastal Karnataka, South India, to know the correlation between the clinical presentation and haematological parameters in the paediatric cases presented with dengue symptoms. A total of 163 paediatric cases who presented fever and dengue-like illness were included in the study. Of which, 69 were confirmed dengue patients. Critical analysis showed that there was a significant difference in the haematological parameters like total leucocyte count, percent differential leucocyte count, and platelets count, in the erythrocyte sedimentation rate (P<0.05 to 0.0001. Additionally, when compared to nondengue patients, even the liver function and renal function parameters were significantly deranged (P<0.05 to 0.0001. Stratification based on NS1, IgG, and IgM showed significant alterations in the haematological, hepatic, and renal parameters. With respect to the treatment a small percentage of patients, that is, 8% (4 patients, required platelet transfusion as their counts went below 20,000/μL. Two patients succumbed to their illness while three required ICU stay.
Study of General Incomplete Star Interconnection Networks
Institute of Scientific and Technical Information of China (English)
史云涛; 侯紫峰; 宋建平
2002-01-01
The star networks, which were originally proposed by Akers and Harel, have suffered from a rigorous restriction on the number of nodes. The general incomplete star networks (GISN) are proposed in this paper to relieve this restriction. An efficient labeling scheme for GISN is given, and routing and broadcasting algorithms are also presented for GISN. The communication diameter of GISN is shown to be bounded by 4n - 7. The proposed single node broadcasting algorithm is optimal with respect to time complexity O(n log2 n).
Advanced General Aviation Turbine Engine (GATE) study
Smith, R.; Benstein, E. H.
1979-01-01
The small engine technology requirements suitable for general aviation service in the 1987 to 1988 time frame were defined. The market analysis showed potential United States engines sales of 31,500 per year providing that the turbine engine sales price approaches current reciprocating engine prices. An optimum engine design was prepared for four categories of fixed wing aircraft and for rotary wing applications. A common core approach was derived from the optimum engines that maximizes engine commonality over the power spectrum with a projected price competitive with reciprocating piston engines. The advanced technology features reduced engine cost, approximately 50 percent compared with current technology.
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.
Dahms, Rainer N
2015-05-01
The fidelity of Gradient Theory simulations depends on the accuracy of saturation properties and influence parameters, and require equations of state (EoS) which exhibit a fundamentally consistent behavior in the two-phase regime. Widely applied multi-parameter EoS, however, are generally invalid inside this region. Hence, they may not be fully suitable for application in concert with Gradient Theory despite their ability to accurately predict saturation properties. The commonly assumed temperature-dependence of pure component influence parameters usually restricts their validity to subcritical temperature regimes. This may distort predictions for general multi-component interfaces where temperatures often exceed the critical temperature of vapor phase components. Then, the calculation of influence parameters is not well defined. In this paper, one of the first studies is presented in which Gradient Theory is combined with a next-generation Helmholtz energy EoS which facilitates fundamentally consistent calculations over the entire two-phase regime. Illustrated on pentafluoroethane as an example, reference simulations using this method are performed. They demonstrate the significance of such high-accuracy and fundamentally consistent calculations for the computation of interfacial properties. These reference simulations are compared to corresponding results from cubic PR EoS, widely-applied in combination with Gradient Theory, and mBWR EoS. The analysis reveals that neither of those two methods succeeds to consistently capture the qualitative distribution of obtained key thermodynamic properties in Gradient Theory. Furthermore, a generalized expression of the pure component influence parameter is presented. This development is informed by its fundamental definition based on the direct correlation function of the homogeneous fluid and by presented high-fidelity simulations of interfacial density profiles. The new model preserves the accuracy of previous temperature
Numerical studies of identification in nonlinear distributed parameter systems
Banks, H. T.; Lo, C. K.; Reich, Simeon; Rosen, I. G.
1989-01-01
An abstract approximation framework and convergence theory for the identification of first and second order nonlinear distributed parameter systems developed previously by the authors and reported on in detail elsewhere are summarized and discussed. The theory is based upon results for systems whose dynamics can be described by monotone operators in Hilbert space and an abstract approximation theorem for the resulting nonlinear evolution system. The application of the theory together with numerical evidence demonstrating the feasibility of the general approach are discussed in the context of the identification of a first order quasi-linear parabolic model for one dimensional heat conduction/mass transport and the identification of a nonlinear dissipation mechanism (i.e., damping) in a second order one dimensional wave equation. Computational and implementational considerations, in particular, with regard to supercomputing, are addressed.
A study of the safety of tenoxicam in general practice.
Caughey, D; Waterworth, R F
1989-11-08
An open, noncomparative study was undertaken to examine the safety of tenoxicam, a new nonsteroidal antiinflammatory drug (NSAID) in general practice. One thousand two hundred and sixty-seven patients with rheumatic conditions were recruited by 392 general practitioners throughout New Zealand. Forty-three point six percent of patients recruited were over 65 years of age, 62.5% had some form of concomitant disease and 76.3% of patients were already receiving NSAIDs. Three hundred and four (23.9%) patients experienced adverse drug reactions, the commonest being gastrointestinal (11.4%), central and peripheral nervous system disorders (2.8%) and skin reactions (2.5%). The profile of adverse drug reactions in those more than 65 was similar to those in patients under 65 years. Of the reactions reported, 14.7% were considered severe. Three peptic ulcers were reported. There were no unexpected adverse drug reactions. Eight hundred and forty-nine patients completed 6 months treatment. Subjective assessments of overall efficacy, pain at night, pain on movement and stiffness made before treatment and at 1, 3 and 6 months posttreatment showed that tenoxicam significantly improved all parameters. The clinical response was maintained throughout the 6 month study period and was not different in patients less than or greater than 65 years.
Radiation Hydrodynamic Parameter Study of Inertial Fusion Energy Reactor Chambers
Sacks, Ryan; Moses, Gregory
2014-10-01
Inertial fusion energy reactors present great promise for the future as they are capable of providing baseline power with no carbon footprint. Simulation work regarding the chamber response and first wall insult is performed with the 1-D radiation hydrodynamics code BUCKY. Simulation with differing chamber parameters are implemented to study the effect of gas fill, gas mixtures and chamber radii. Xenon and argon gases are of particular interest as shielding for the first wall due to their high opacity values and ready availability. Mixing of the two gases is an attempt to engineer a gas cocktail to provide the maximum amount of shielding with the least amount of cost. A parameter study of different chamber radii shows a consistent relationship with that of first wall temperature (~1/r2) and overpressure (~1/r3). This work is performed under collaboration with Lawrence Livermore National Laboratory.
Studying the $\\rho$ resonance parameters with staggered fermions
Fu, Ziwen
2016-01-01
We deliver a lattice study of $\\rho$ resonance parameters with p-wave $\\pi\\pi$ scattering phases, which are extracted by finite-size methods at one center-of-mass frame and four moving frames for six MILC lattice ensembles with pion masses ranging from $346$ to $ 176$ MeV. The effective range formula is applied to describe the scattering phases as a function of the energy covering the resonance region, this allows us to extract $\\rho$ resonance parameters and to investigate the quark-mass dependence. Lattice studies with three flavors of the Asqtad-improved staggered fermions enable us to use the moving-wall source technique on large lattice spatial dimensions ($L=64$) and small light $u/d$ quarks. Numerical computations are carried out at two lattice spacings, $a \\approx 0.12$ and $0.09$ fm.
Studying the ρ resonance parameters with staggered fermions
Fu, Ziwen; Wang, Lingyun
2016-08-01
We deliver a lattice study of ρ resonance parameters with p -wave π π scattering phases, which are extracted by finite-size methods at one center-of-mass frame and four moving frames for six lattice ensembles from the MILC Collaboration with pion masses ranging from 346 to 176 MeV. The effective range formula is applied to describe the scattering phases as a function of the energy covering the resonance region; this allows us to extract ρ resonance parameters and to investigate the quark-mass dependence. Lattice studies with three flavors of Asqtad-improved staggered fermions enable us to use the moving-wall source technique on large lattice spatial dimensions (L =64 ) and small light u /d quarks. Numerical computations are carried out at two lattice spacings, a ≈0.12 and 0.09 fm.
Brembs, Bjorn; de Ibarra, Natalie Hempel
2006-01-01
We have used a genetically tractable model system, the fruit fly "Drosophila melanogaster" to study the interdependence between sensory processing and associative processing on learning performance. We investigated the influence of variations in the physical and predictive properties of color stimuli in several different operant-conditioning…
New Predictive Hematologic Parameters in Chronic Rhinosinusitis: A Multicenter Study
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Beyhan Yilmaz
2016-12-01
Full Text Available INTRODUCTION: Our aim was to investigate whether Neutrophil-Lymphocyte Ratio (NLR, Platelet-Lymphocyte Ratio (PLR and Mean Platelet Volume parameters (MPV may be utilized as inflammatory markers of chronic rhinosinusitis with nasal polyps (CRSwNP and without nasal polyps (CRSsNP. METHODS: This retrospective multicenter study was performed on 647 patients who were underwent endoscopic sinus surgery. Clinical and preoperative laboratory data of patients were screened retrospectively. The study and control groups were compared for the parameters NLR, PLR, MPV, neutrophils, lymphocytes, and platelets. RESULTS: Of the 647 patients, 313 were in the CRSwNP group, 334 were in the CRSsNP group. There were 93 individuals in the control group. NLR and PLR levels were significantly higher in study groups compared to control group (p < 0.001. But no statistically significant differences were identified between CRSwNP group and CRSsNP group in terms of NLR, PLR, MPV levels. DISCUSSION AND CONCLUSION: We speculate that high NLR and PLR values may be useful inflammatory indicator for CRSwNP and CRSsNP groups. We believe these parameters will have increasing clinical use in the future on treatment options and prognosis.
Study on mechanical parameters of fractured rock masses
Institute of Scientific and Technical Information of China (English)
无
2011-01-01
The equivalent strength parameters of fractured rock masses are prerequisite for stability analysis of geotechnical engineering projects constructed in fractured rock masses which are encountered frequently in western china.Based on generated mesh of fractured rock masses,combined with statistic damage constitutive model of intact rock and damage model of structural plane,progressive failure of fractured rock masses is studied using finite element method(FEM) .Furthermore,Scale effect and anisotropy of compressive strength of fractured rock masses are studied.Study results show that the strength decreases and tend towards stability rapidly from intact rock to fractured rock masses,and the anisotropy of strength of fractured rock masses is not significant.At last,based on numerical simulation conducted on 10 m scale rock masses under different confining pressures,the equivalent strength parameters of fractured rock masses are gained and the results are compared with Hoek-Brown criteria.The method developed is helpful for determination of strength parameters of fractured rock masses.
Directory of Open Access Journals (Sweden)
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.
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.
STUDI PARAMETER OSEANOGRAFI DI PERAIRAN SELAT MADURA KABUPATEN BANGKALAN
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Aries Dwi Siswanto
2014-04-01
Full Text Available Fenomena dan dinamika di perairan laut menjadi salah satu hal penting yang harus dipertimbangkan dalam berbagai aktifitas yang dilakukan dilingkungan perairan laut. Pergerakan massa air laut dinamis sepanjang waktu memberikan pengaruh terhadap dinamika perairan. Angin menjadi salah satu parameter penting yang berpengaruh terhadap fenomena dan dinamika perairan laut. Beberapa parameter oseanografi yang dipengaruhi oleh angin adalah arus dan gelombang. Parameter lainnya yaitu pasang surut, yang dipengaruhi oleh letak bulan dan matahari menjadikan dinamika lautan semakin kompleks. Arus, gelombang, dan pasang surut diduga berpangaruh signifikan terhadap kompleksitas di lautan. Tujuan dari penelitian ini adalah untuk mengkaji karakteristik parameter oseanografi di perairan Selat Madura, Kabupaten Bangkalan. Data utama penelitian berupa data arus, pasang surut, dan gelombang. Data pasang surut diperoleh dari BMKG Perak, Surabaya. Data yang digunakan adalah data bulan September 2012. Data arus dan gelombang diolah secara deskriptif untuk mengetahui dominasi arah dan kecepatan, sedangkan data pasut diolah menggunakan metode Admiralty untuk mengetahui tipe pasang surut perairan. Hasil analisa menunjukkan kisaran arus relatif kecil (0,28-3.54 cm/detik dengan arah Timur laut, Timur dan Tenggara. Karakteristik gelombang menunjukkan kecenderungan semakin besar pada setiap minggunya dengan pola harian cenderung stabil sepanjang hari. Tipe pasang surut campuran condong ke harian ganda.Kata Kunci: hidrooseanografi, total suspended solid (TSS STUDY OF OCEANOGRAPHYC PARAMETERS IN THE MADURA STRAIT WATERS OF BANGKALAN DISTRICTABSTRACTPhenomenon and the dynamics in marine waters become important to be considered in some activities. The movement of sea water mass is dynamic along the time which gives influence toward waters dynamics. Wind become one of the important parameters influenced the phenomenon and sea waters dynamics. Some oceanography parameters were
Cosmic ray driven dynamo in galactic disks. A parameter study
MichaÅHanasz,; Kowal, Grzegorz; Lesch, Harald
2008-01-01
We present a parameter study of the magnetohydrodynamical dynamo driven by cosmic rays in the interstellar medium (ISM) focusing on the efficiency of magnetic field amplification and the issue of energy equipartition between magnetic, kinetic and cosmic ray (CR) energies. We perform numerical CR-MHD simulations of the ISM using the extended version of ZEUS-3D code in the shearing box approximation and taking into account the presence of Ohmic resistivity, tidal forces and vertical disk gravity. CRs are supplied in randomly distributed supernova (SN) remnants and are described by the diffusion-advection equation, which incorporates an anisotropic diffusion tensor. The azimuthal magnetic flux and total magnetic energy are amplified depending on a particular choice of model parameters. We find that the most favorable conditions for magnetic field amplification correspond to magnetic diffusivity of the order of $3\\times 10^{25} \\cm^2\\s^{-1}$, SN rates close to those observed in the Milky Way, periodic SN activity...
Study of some parameters interstellar transport using of magnetic umbrella
Čermák, Martin
2013-01-01
Interstellar transport is an object of interest in many sci-fi stories. In history a lot of sci-fi predictions have turned into reality, such as communications satellites, deep-sea submarines and journies to the moon. In this work we study some physical parameters of a space ship which uses a magnetic umbrella. Our spaceship generates a magnetic field in its neighborhood and captures charged protons into a magnetic trap. These particles are taken into a fusion reactor. The obtained energy and waste in form of helium are used as a fuel in an ion engine. With the help of elementary physics we can work out the basic physical parameters of the ship, e.g. maximal velocity, acceleration of the ship or acceleration time period.
Key Parameter Study of 65Mn Steel in Warm Rolling
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Zhi-Jie Li
2013-02-01
Full Text Available For study warm rolling process, warm compression experiment of ferrite combined with pearlite colony was conducted using the Gleeble-3500 thermal/mechanical simulator system. The warm deformation was carried out at temperature (500~700°C and the strain rate (0.001~10/sec. Based on the flow stress data, the key parameter was calculated. The results show that the warm-working process of carbon steel conforms to hyperbolic sine equation. The relationship of and T could be described by parameter Z (temperature compensation of strain rate factor. The value of apparent n (stress index and Q (deformation activation energy was calculated, the draught pressure calculated was 1.87×104 t during warm rolling process at 600°C.
GEANT4 for breast dosimetry: parameters optimization study.
Fedon, C; Longo, F; Mettivier, G; Longo, R
2015-08-21
Mean glandular dose (MGD) is the main dosimetric quantity in mammography. MGD evaluation is obtained by multiplying the entrance skin air kerma (ESAK) by normalized glandular dose (DgN) coefficients. While ESAK is an empirical quantity, DgN coefficients can only be estimated with Monte Carlo (MC) methods. Thus, a MC parameters benchmark is needed for effectively evaluating DgN coefficients. GEANT4 is a MC toolkit suitable for medical purposes that offers to the users several computational choices. In this work we investigate the GEANT4 performances testing the main PhysicsLists for medical applications. Four electromagnetic PhysicsLists were implemented: the linear attenuation coefficients were calculated for breast glandularity 0%, 50%, 100% in the energetic range 8-50 keV and DgN coefficients were evaluated. The results were compared with published data. Fit equations for the estimation of the G-factor parameter, introduced by the literature for converting the dose delivered in the heterogeneous medium to that in the glandular tissue, are proposed and the application of this parameter interaction-by-interaction or retrospectively is discussed. G4EmLivermorePhysicsList shows the best agreement for the linear attenuation coefficients both with theoretical values and published data. Moreover, excellent correlation factor (r2>0.99) is found for the DgN coefficients with the literature. The final goal of this study is to identify, for the first time, a benchmark of parameters that could be useful for future breast dosimetry studies with GEANT4.
Oliveira, Carlos Rogério Degrandi; Bernardo, Wanderley Marques; Nunes, Victor Moisés
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. 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. 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%. 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. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.
Oliveira, Carlos Rogério Degrandi; Bernardo, Wanderley Marques; Nunes, Victor Moisés
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. 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. 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%. 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. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.
A Student Guide to Studying General Chemistry.
Schlenker, Richard M.
This is a guide for introductory college chemistry students who are new to the subject of chemistry and who have been exposed to linear and second-order algebra equations and the concept of slope. The guide presents directions on the following topics: (1) How to prepare for lectures and take notes; (2) How to study chemistry outside of class using…
Studies on the key parameters in segmental lining design
Institute of Scientific and Technical Information of China (English)
Zhenchang Guan; Tao Deng; Gang Wang; Yujing Jiang
2015-01-01
The uniform ring model and the shell-spring model for segmental lining design are reviewed in this article. The former is the most promising means to reflect the real behavior of segmental lining, while the latter is the most popular means in practice due to its simplicity. To understand the relationship and the difference between these two models, both of them are applied to the engineering practice of Fuzhou Metro Line I, where the key parameters used in both models are described and compared. The effective ratio of bending rigidity h reflecting the relative stiffness between segmental lining and surrounding ground and the transfer ratio of bending moment x reflecting the relative stiffness between segment and joint, which are two key parameters used in the uniform ring model, are especially emphasized. The reasonable values for these two key parameters are calibrated by comparing the bending moments calculated from both two models. Through case studies, it is concluded that the effective ratio of bending rigidity h increases significantly with good soil properties, increases slightly with increasing overburden, and decreases slightly with increasing water head. Meanwhile, the transfer ratio of bending moment x seems to only relate to the properties of segmental lining itself and has a minor relation with the ground conditions. These results could facilitate the design practice for Fuzhou Metro Line I, and could also provide some references to other projects with respect to similar scenarios.
Picozzi, Matteo; Oth, Adrien; Parolai, Stefano; Bindi, Dino; De Landro, Grazia; Amoroso, Ortensia
2017-04-01
The accurate determination of stress drop, seismic efficiency and how source parameters scale with earthquake size is an important for seismic hazard assessment of induced seismicity. We propose an improved non-parametric, data-driven strategy suitable for monitoring induced seismicity, which combines the generalized inversion technique together with genetic algorithms. In the first step of the analysis the generalized inversion technique allows for an effective correction of waveforms for the attenuation and site contributions. Then, the retrieved source spectra are inverted by a non-linear sensitivity-driven inversion scheme that allows accurate estimation of source parameters. We therefore investigate the earthquake source characteristics of 633 induced earthquakes (ML 2-4.5) recorded at The Geysers geothermal field (California) by a dense seismic network (i.e., 32 stations of the Lawrence Berkeley National Laboratory Geysers/Calpine surface seismic network, more than 17.000 velocity records). We find for most of the events a non-selfsimilar behavior, empirical source spectra that requires ωγ source model with γ > 2 to be well fitted and small radiation efficiency ηSW. All these findings suggest different dynamic rupture processes for smaller and larger earthquakes, and that the proportion of high frequency energy radiation and the amount of energy required to overcome the friction or for the creation of new fractures surface changes with the earthquake size. Furthermore, we observe also two distinct families of events with peculiar source parameters that, in one case suggests the reactivation of deep structures linked to the regional tectonics, while in the other supports the idea of an important role of steeply dipping fault in the fluid pressure diffusion.
Collisionless expansion of pulsed radio frequency plasmas. II. Parameter study
Schröder, T.; Grulke, O.; Klinger, T.; Boswell, R. W.; Charles, C.
2016-01-01
The plasma parameter dependencies of the dynamics during the expansion of plasma are studied with the use of a versatile particle-in-cell simulation tailored to a plasma expansion experiment [Schröder et al., J. Phys. D: Appl. Phys. 47, 055207 (2014); Schröder et al., Phys. Plasmas 23, 013511 (2016)]. The plasma expansion into a low-density ambient plasma features a propagating ion front that is preceding a density plateau. It has been shown that the front formation is entangled with a wave-breaking mechanism, i.e., an ion collapse [Sack and Schamel, Plasma Phys. Controlled Fusion 27, 717 (1985); Sack and Schamel, Phys. Lett. A 110, 206 (1985)], and the launch of an ion burst [Schröder et al., Phys. Plasmas 23, 013511 (2016)]. The systematic parameter study presented in this paper focuses on the influence on this mechanism its effect on the maximum velocity of the ion front and burst. It is shown that, apart from the well known dependency of the front propagation on the ion sound velocity, it also depends sensitively on the density ratio between main and ambient plasma density. The maximum ion velocity depends further on the initial potential gradient, being mostly influenced by the plasma density ratio in the source and expansion regions. The results of the study are compared with independent numerical studies.
Characterizing parameters of Jatropha curcas cell cultures for microgravity studies
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
Study of semen parameters in male partners among infertile couples
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Sheela N. Kulkarni
2015-08-01
Full Text Available Background: The Semen analysis provides valuable information about the etiology and fertility potential of an infertile male. The study was conducted to determine the abnormalities in semen parameters of male partners of infertile couples and to find out contribution of male factors. Methods: The descriptive study with cross sectional design was conducted in the department of Pathology at MIMSR medical college, Latur, Maharashtra, India, between January 2013 to December 2014. A total of 220 cases were analyzed during this period. Semen analysis was performed according to the methods and the standards defined by World Health Organisation (WHO 5th edition 2010. Results: Out of 220 male partners of infertile couples 96 (43.6% men had abnormal semen parameters. The male factor was responsible in 43.6% of cases. Asthenozoospermia constitutes maximum of 19.9%, followed by Oligozoospermia in 18.6%, Azoospermia in 10.9%, Oligoasthenoteratozoospermia in 7.3% and Oligoasthenozoospermia in 6.8% cases. Leucocytospermia was detected in 15.5% cases. Conclusions: Abnormal semen quality remains a significant contribution to overall infertility. Asthenozoospermia is the most common semen abnormality seen. [Int J Reprod Contracept Obstet Gynecol 2015; 4(4.000: 1016-1019
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
Parameter studies on flat copper and aluminum bridgefoils
Energy Technology Data Exchange (ETDEWEB)
Demana, T.E.; Lee, R.E.; Lee, R.S.; Von Holle, W.
1986-10-10
Developing models for the electrical behavior of exploding bridgewire circuits requires high-quality data of a type not usually generated in routine tests of detonator hardware. To obtain a precise measurement of the time of bridgewire burst relative to current start, one must simultaneously record the current, i, and either di/dt or the voltage across the bridgewire. To fully develop and test a model it is also necessary to vary the bridgewire cross sections and geometry, firing circuit characteristics and charging voltage for the firing circuits over as wide a range as possible. As a part of developing an electrical model for aluminum and copper bridgewires, we have conducted parameter studies on some flat copper and aluminum bridgewires. Most of the work was done on aluminum bridgewires, with a few experiments on copper. We will report the experimental results from these studies and compare them with model predictions.
Abbruzzese, G.; Campopiano, A.
1994-05-01
The secondary recrystallization (SR) process and the related effects on the magnetic properties of silicon-iron are discussed in the framework of the general statistical theory of grain growth including texture and Zener drag influence. It has been shown that SR in silicon-iron is related to a selective growth process experienced by Goss grains due to specific grain boundary conditions generated by the surrounding grains (texture). In this paper some examples showing the specific role of various microstructural parameters influencing the selectivity of SR (such as Zener drag intensity and its drop rate, initial grain size, etc.), are discussed and related to the magnetic properties, which are mainly controlled by the final average grain size and orientation.
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.
Widesott, L.; Strigari, L.; Pressello, M. C.; Benassi, M.; Landoni, V.
2008-03-01
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 (gEUDmax 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 gEUDmax with fixed a = 1. Most of all, we formulated a simple relation that links the reference gEUDmax 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 V40 and V50 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.
Vitale, Salvatore
2016-07-01
With the discovery of the binary-black-hole (BBH) coalescence GW150914 the era of gravitational-wave (GW) astronomy has started. It has recently been shown that BBH with masses comparable to or higher than GW150914 would be visible in the Evolved Laser Interferometer Space Antenna (eLISA) band a few years before they finally merge in the band of ground-based detectors. This would allow for premerger electromagnetic alerts, dramatically increasing the chances of a joint detection, if BBHs are indeed luminous in the electromagnetic band. In this Letter we explore a quite different aspect of multiband GW astronomy, and verify if, and to what extent, measurement of masses and sky position with eLISA could improve parameter estimation and tests of general relativity with ground-based detectors. We generate a catalog of 200 BBHs and find that having prior information from eLISA can reduce the uncertainty in the measurement of source distance and primary black hole spin by up to factor of 2 in ground-based GW detectors. The component masses estimate from eLISA will not be refined by the ground based detectors, whereas joint analysis will yield precise characterization of the newly formed black hole and improve consistency tests of general relativity.
Vitale, Salvatore
2016-07-29
With the discovery of the binary-black-hole (BBH) coalescence GW150914 the era of gravitational-wave (GW) astronomy has started. It has recently been shown that BBH with masses comparable to or higher than GW150914 would be visible in the Evolved Laser Interferometer Space Antenna (eLISA) band a few years before they finally merge in the band of ground-based detectors. This would allow for premerger electromagnetic alerts, dramatically increasing the chances of a joint detection, if BBHs are indeed luminous in the electromagnetic band. In this Letter we explore a quite different aspect of multiband GW astronomy, and verify if, and to what extent, measurement of masses and sky position with eLISA could improve parameter estimation and tests of general relativity with ground-based detectors. We generate a catalog of 200 BBHs and find that having prior information from eLISA can reduce the uncertainty in the measurement of source distance and primary black hole spin by up to factor of 2 in ground-based GW detectors. The component masses estimate from eLISA will not be refined by the ground based detectors, whereas joint analysis will yield precise characterization of the newly formed black hole and improve consistency tests of general relativity.
Study Of Performance Parameters Effects On OFDM Systems
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M.A. Mohamed
2012-05-01
Full Text Available The actual and next communication schemes tend to use OFDM systems in order to provide high baud rates, less intercarrier interference, and less intersymbol interference. OFDM has become the core of most 4G communication systems as fixed Wi-Fi system (IEEE802.11a standard, mobile Wi-Fi system (IEEE802.11b standard, fixed WiMAX system (IEEE802.16a standard, mobile WiMAX system (IEEE802.16e standard, and Long Term Evolution (LTE system. In this paper the detailed simulation of different OFDM systems with different constellation mapping schemes will be obtained using MATLAB-2011 program to study the effect of various design parameters on the system performance.
Studying the effects of dynamical parameters on reactor core temperature
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R Khodabakhsh
2015-01-01
Full Text Available In order to increase productivity, reduce depreciation, and avoid possible accidents in a system such as fuel rods' melting and overpressure, control of temperature changes in the reactor core is an important factor. There are several methods for solving and analysing the stability of point kinetics equations. In most previous analyses, the effects of various factors on the temperature of the reactor core have been ignored. In this work, the effects of various dynamical parameters on the temperature of the reactor core and stability of the system in the presence of temperature feedback reactivity with external reactivity step, ramp and sinusoidal for six groups of delayed neutrons were studied using the method of Lyapunov exponent. The results proved to be in good agreement with other works
Wen, Xiao-Yong; Yan, Zhenya
2015-12-01
We study higher-order rogue wave (RW) solutions of the coupled integrable dispersive AB system (also called Pedlosky system), which describes the evolution of wave-packets in a marginally stable or unstable baroclinic shear flow in geophysical fluids. We propose its continuous-wave (CW) solutions and existent conditions for their modulation instability to form the rogue waves. A new generalized N-fold Darboux transformation (DT) is proposed in terms of the Taylor series expansion for the spectral parameter in the Darboux matrix and its limit procedure and applied to the CW solutions to generate multi-rogue wave solutions of the coupled AB system, which satisfy the general compatibility condition. The dynamical behaviors of these higher-order rogue wave solutions demonstrate both strong and weak interactions by modulating parameters, in which some weak interactions can generate the abundant triangle, pentagon structures, etc. Particularly, the trajectories of motion of peaks and depressions of profiles of the first-order RWs are explicitly analyzed. The generalized DT method used in this paper can be extended to other nonlinear integrable systems. These results may be useful for understanding the corresponding rogue-wave phenomena in fluid mechanics and related fields.
Wen, Xiao-Yong; Yan, Zhenya
2015-12-01
We study higher-order rogue wave (RW) solutions of the coupled integrable dispersive AB system (also called Pedlosky system), which describes the evolution of wave-packets in a marginally stable or unstable baroclinic shear flow in geophysical fluids. We propose its continuous-wave (CW) solutions and existent conditions for their modulation instability to form the rogue waves. A new generalized N-fold Darboux transformation (DT) is proposed in terms of the Taylor series expansion for the spectral parameter in the Darboux matrix and its limit procedure and applied to the CW solutions to generate multi-rogue wave solutions of the coupled AB system, which satisfy the general compatibility condition. The dynamical behaviors of these higher-order rogue wave solutions demonstrate both strong and weak interactions by modulating parameters, in which some weak interactions can generate the abundant triangle, pentagon structures, etc. Particularly, the trajectories of motion of peaks and depressions of profiles of the first-order RWs are explicitly analyzed. The generalized DT method used in this paper can be extended to other nonlinear integrable systems. These results may be useful for understanding the corresponding rogue-wave phenomena in fluid mechanics and related fields.
Does Cigarette Smoking Affect Seminal Fluid Parameters? A Comparative Study
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Zakarya Bani Meri
2013-01-01
Full Text Available Objective: To study the effect of cigarette smoking on seminal fluid parameters, namely; volume, sperm concentration, and motility, as well as morphology, leukocyte infiltration, among males complaining of infertility.Methods: Between August 2010 and July 2011, seminal fluid analysis was done for 1438 males who are partners of couples who visited the infertility clinic at Prince Rashid Ben Al Hassan Hospital (PRH for infertility. The men who fit the inclusion criteria (n=960 were classified into two groups: group a (non-smokers; n=564 and group B (smokers; n=396, which represents 41.25% of the study group. Seminal fluid was collected using masturbation after 3-5 days of abstinence then analyzed for volume, sperm count, sperm concentration, motility and morphology. In order to analyze whether the number of cigarettes smoked per day has an effect on the spermatogram; the smoking men were divided into two subgroups: the heavy smokers (n=266 and non-heavy smokers (n=130.Results: A total of 960 adult males were enrolled. Their age ranged between 21 and 76 years, 564 were non-smokers with mean age of 36. 45±6.27 (Mean±SD. Three-hundred-and-ninety-six were smokers with a mean age of 34.35±4.25 (Mean±SD. There was a significant effect of smoking on the motility of sperms and the ratios of abnormality (p<0.005. Concentration appeared not to be affected by smoking. Furthermore, the group of heavy smokers were found to have lower sperm concentrations and a higher percentage of abnormal sperms compared to the non-heavy smokers.Conclusion: Cigarette smoking has a deleterious effect on some of the seminal fluid parameters (motility, morphology and leukocyte count which in turn may result in male subfertility.
Clinical TVA-based studies: a general review
Habekost, Thomas
2015-01-01
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. PMID:25852607
Study of an advanced General Aviation Turbine Engine (GATE)
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.
Clinical TVA-based studies: a general review.
Habekost, Thomas
2015-01-01
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.
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.
Li, An; Ziehr, Jessica L; Johnson, Kenneth A
2017-03-02
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 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 37C and the raw data were fit globally to derive a single set of rate constants at 37C 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 (Kd, ΔG, ΔH, ΔS at 37C), 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.
Cross, J. L.; Stevens, D. D.
1976-01-01
A computerized study of operational parameters affecting helicopter fuel consumption was conducted as an integral part of the NASA Civil Helicopter Technology Program. The study utilized the Helicopter Sizing and Performance Computer Program (HESCOMP) developed by the Boeing-Vertol Company and NASA Ames Research Center. An introduction to HESCOMP is incorporated in this report. The results presented were calculated using the NASA CH-53 civil helicopter research aircraft specifications. Plots from which optimum flight conditions for minimum fuel use that can be obtained are presented for this aircraft. The results of the study are considered to be generally indicative of trends for all helicopters.
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
Prognostic parameters and spinal metastases: a research study.
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Jefferson W Daniel
Full Text Available OBJECT: To identify pre-operative prognostic parameters for survival in patients with spinal epidural neoplastic metastasis when the primary tumour is unknown. METHODS: This study was a retrospective chart review of patients who underwent surgery for spinal epidural neoplastic metastases between February 1997 and January 2011. The inclusion criteria were as follows: known post-operative survival period, a Karnofsky Performance Score equal to or greater than 30 points and a post-operative neoplastic metastasis histological type. The Kaplan-Meier method was used to estimate post-operative survival, and the Log-Rank test was used for statistical inference. RESULTS: A total of 52 patients who underwent 52 surgical procedures were identified. The mean age at the time of spinal surgery was 53.92 years (std. deviation, 19.09. The median survival after surgery was 70 days (95% CI 49.97-90.02, and post-operative mortality occurred within 6 months in 38 (73.07% patients. Lung cancer, prostate cancer, myeloma and lymphoma, the 4 most common primary tumour types, affected 32 (61.53% patients. The three identified prognostic parameters were the following: pre-operative walking incapacity (American Spinal Injury Association, A and B, present in 86.53% of the patients (p-value = 0.107; special care dependency (Karnofsky Performance Score, 10-40 points, present in 90.38% of the patients (p-value = 0.322; and vertebral epidural neoplastic metastases that were in contact with the thecal sac (Weinstein-Boriani-Biagini, sector D, present in 94.23% of the patients (p-value = 0.643. When the three secondary prognostic parameters were combined, the mean post-operative survival was 45 days; when at least one was present, the survival was 82 days (p-value = 0.175. CONCLUSIONS: Walking incapacity, special care dependency and contact between the neoplastic metastases and the thecal sac can help determine the ultimate survival of this patient population and
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Sacramento Corral-Rivas
2014-02-01
Full Text Available Background We used mixed models with random components to develop height-diameter (h-d functions for mixed, uneven-aged stands in northwestern Durango (Mexico, considering the breast height diameter (d and stand variables as predictors. Methods The data were obtained from 44 permanent plots used to monitor stand growth under forest management in the study area. Results The generalized Bertalanffy-Richards model performed better than the other generalized models in predicting the total height of the species under study. For the genera Pinus and Quercus, the models were successfully calibrated by measuring the height of a subsample of three randomly selected trees close to the mean d, whereas for species of the genera Cupressus, Arbutus and Alnus, three trees were also selected, but they are specifically the maximum, minimum and mean d trees. Conclusions The presented equations represent a new tool for the evaluation and management of natural forest in the region.
A systematic study of finite BRST-BFV transformations in generalized Hamiltonian formalism
Batalin, Igor A.; Lavrov, Peter M.; Tyutin, Igor V.
2014-09-01
We study systematically finite BRST-BFV transformations in the generalized Hamiltonian formalism. We present explicitly their Jacobians and the form of a solution to the compensation equation determining the functional field dependence of finite Fermionic parameters, necessary to generate an arbitrary finite change of gauge-fixing functions in the path integral.
A systematic study of finite BRST-BFV transformations in generalized Hamiltonian formalism
Batalin, Igor A; Tyutin, Igor V
2014-01-01
We study systematically finite BRST-BFV transformations in the generalized Hamiltonian formalism. We present explicitly their Jacobians and the form of a solution to the compensation equation determining the functional field dependence of finite Fermionic parameters, necessary to generate arbitrary finite change of gauge-fixing functions in the path integral.
Batalin, Igor A; Tyutin, Igor V
2014-01-01
We study systematically finite BRST-BFV transformations in $Sp(2)$-extended generalized Hamiltonian formalism. We present explicitly their Jacobians and the form of a solution to the compensation equation determining the functional field dependence of finite Fermionic parameters, necessary to generate arbitrary finite change of gauge-fixing functions in the path integral.
Batalin, Igor A.; Lavrov, Peter M.; Tyutin, Igor V.
2014-09-01
We study systematically finite BRST-BFV transformations in Sp(2)-extended generalized Hamiltonian formalism. We present explicitly their Jacobians and the form of a solution to the compensation equation determining the functional field dependence of finite Fermionic parameters, necessary to generate arbitrary finite change of gauge-fixing functions in the path integral.
Helical CT study of cerebral perfusion and related hemodynamic parameters
Cenic, Aleksa; Lee, Ting-Yim; Craen, Rosemary A.; Gelb, Adrian W.
1997-05-01
A convenient method for assessing cerebral perfusion and related functional parameters has been developed using a third generation slip-ring CT scanner. Dynamic contrast- enhanced scanning at the same level was employed to image the cerebral circulation at the rate of 1 image per second. Using data acquired with this non-helical mode of scanning, we have developed a method for the simultaneous in-vivo determination of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT). These measurements are given in the same physiological units as positron emission tomography. In order to obtain accurate measurements of these parameters, methods were also developed to correct for recirculation and partial volume averaging in imaging small blood vessels. We have used 6 New Zealand white rabbits in our studies. For each rabbit, up to 3 CT measurements of CBF, CBV, and MTT were made at normocapnia under isoflurane anesthesia. Coronal sections through the brain were imaged while simultaneously imaging either a brain artery or the ear artery. Images were acquired for 1 minute as Isovue 300 was injected intravenously. In the acquired CT images, regions of interest in brain parenchyma and an artery were drawn. For each region of interest, the mean CT number in pre-contrast images was subtracted from the mean in post-contrast images to calculate the contrast concentration curves for the brain regions Q(t) and the arterial region Ca(t). Using a robust deconvolution method, the MTT was determined. CBV was then determined from the ratio of the areas of Q(t) and Ca(t). Finally, CBF was calculated from the Central Volume Principle. The mean regional CBF, CBV and MTT values were 73.3 +/- 5.1 ml/min/100g, 1.93 +/- 0.12 ml/100g and 1.80 +/- 0.18 s respectively. IN order to validate our CT CBF measurements, we also measured CBF using the well- established technique of microspheres with each CT study. The feasibility of our CT method to measure CBF accurately was
Some numerical studies of the evolution of generalized parton distributions
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Diehl, M.; Kugler, W.
2007-11-15
We study the evolution behavior of generalized parton distributions at small longitudinal momentum fraction. Particular attention is paid to the ratio of a generalized parton distribution and its forward limit, to the mixing between quarks and gluons, and to the dependence on the squared momentum transfer t. (orig.)
Yu, Xiaolin; Zhang, Shaoqing; Lin, Xiaopei; Li, Mingkui
2017-03-01
The uncertainties in values of coupled model parameters are an important source of model bias that causes model climate drift. The values can be calibrated by a parameter estimation procedure that projects observational information onto model parameters. The signal-to-noise ratio of error covariance between the model state and the parameter being estimated directly determines whether the parameter estimation succeeds or not. With a conceptual climate model that couples the stochastic atmosphere and slow-varying ocean, this study examines the sensitivity of state-parameter covariance on the accuracy of estimated model states in different model components of a coupled system. Due to the interaction of multiple timescales, the fast-varying atmosphere with a chaotic nature is the major source of the inaccuracy of estimated state-parameter covariance. Thus, enhancing the estimation accuracy of atmospheric states is very important for the success of coupled model parameter estimation, especially for the parameters in the air-sea interaction processes. The impact of chaotic-to-periodic ratio in state variability on parameter estimation is also discussed. This simple model study provides a guideline when real observations are used to optimize model parameters in a coupled general circulation model for improving climate analysis and predictions.
The little-studied cluster Berkeley 90. III. Cluster parameters
Marco, Amparo
2016-01-01
The open cluster Berkeley 90 is the home to one of the most massive binary systems in the Galaxy, LS III +46$^{\\circ}$11, formed by two identical, very massive stars (O3.5 If* + O3.5 If*), and a second early-O system (LS III +46$^{\\circ}$12 with an O4.5 IV((f)) component at least). Stars with spectral types earlier than O4 are very scarce in the Milky Way, with no more than 20 examples. The formation of such massive stars is still an open question today, and thus the study of the environments where the most massive stars are found can shed some light on this topic. To this aim, we determine the properties and characterize the population of Berkeley 90 using optical, near-infrared and WISE photometry and optical spectroscopy. This is the first determination of these parameters with accuracy. We find a distance of $3.5^{+0.5}_{-0.5}$ kpc and a maximum age of 3 Ma. The cluster mass is around $1000$ $M_{\\odot}$ (perhaps reaching $1500$ $M_{\\odot}$ if the surrounding population is added), and we do not detect cand...
The little-studied cluster Berkeley 90 - III. Cluster parameters
Marco, Amparo; Negueruela, Ignacio
2017-02-01
The open cluster Berkeley 90 is the home to one of the most massive binary systems in the Galaxy, LS III +46°11, formed by two identical, very massive stars (O3.5 If* + O3.5 If*), and a second early-O system (LS III +46°12 with an O4.5 IV((f)) component at least). Stars with spectral types earlier than O4 are very scarce in the Milky Way, with no more than 20 examples. The formation of such massive stars is still an open question today, and thus the study of the environments where the most massive stars are found can shed some light on this topic. To this aim, we determine the properties and characterize the population of Berkeley 90 using optical, near-infrared and WISE photometry and optical spectroscopy. This is the first determination of these parameters with accuracy. We find a distance of 3.5^{+0.5}_{-0.5} kpc and a maximum age of 3 Ma. The cluster mass is around 1000 M⊙ (perhaps reaching 1500 M⊙ if the surrounding population is added), and we do not detect candidate runaway stars in the area. There is a second population of young stars to the southeast of the cluster that may have formed at the same time or slightly later, with some evidence for low-activity ongoing star formation.
Prevalence of anal symptoms in general practice: a prospective study.
Tournu, Géraldine; Abramowitz, Laurent; Couffignal, Camille; Juguet, Frédéric; Sénéjoux, Agnès; Berger, Stéphane; Wiart, Anne-Laure; Bernard, Marc; Provost, Françoise; Pillant-Le Moult, Hélène; Bouchard, Dominique; Aubert, Jean-Pierre
2017-08-03
Anal disorders are largely underestimated in general practice. Studies have shown patients conceal anal symptoms leading to late diagnosis and treatment. Management by general practitioners is poorly described. The aim of this study is to assess the prevalence of anal symptoms and their management in general practice. In this prospective, observational, national study set in France, all adult patients consulting their general practitioner during 2 days of consultation were included. Anal symptoms, whether spontaneously revealed or not, were systematically collected and assessed. For symptomatic patients, the obstacles to anal examination were evaluated. The general practitioner's diagnosis was collected and a proctologist visit was systematically proposed in case of anal symptoms. If the proctologist was consulted, his or her diagnosis was collected. From October 2014 to April 2015, 1061 patients were included by 57 general practitioners. The prevalence of anal symptoms was 15.6% (95% CI: 14-18). However, 85% of these patients did not spontaneously share their symptoms with their doctors, despite a discomfort rating of 3 out of 10 (range 1-5). Although 65% of patients agreed to an anal examination, it was not proposed in 45% of cases with anal symptoms. Performing the examination was associated with a significantly higher diagnosis rate of 76% versus 20% (p anal symptoms are significant in general practice despite the impact on quality of life. Anal examination is seldom done. Improved training of general practitioners is required to break the taboo.
An experimental study on effect of process parameters in deep ...
African Journals Online (AJOL)
DR OKE
Literature review reveals that the research on various aspects of modeling, simulation and process optimization of deep .... methodology is valuable only when the design parameters are qualitative and discrete. .... Work hardening exponent.
Study of parameters of a facility generating compressive plasma flows
Leyvi, A. Ya
2017-05-01
The prosperity of plasma technologies stimulates making of a facility generating compressive plasma flows at the South Ural State University. The facility is a compact-geometry magnetoplasma compressor with the following parameters: stored energy up to 15 kJ, voltage of a bank from 3 to 5 kV; nitrogen, air, and other gases can serve as its operating gas. The investigation of parameters of the facility showed the following parameters of compressive plasma flows: impulse duration of up to 120 μs, discharge current of 50-120 kA, speed of plasma flow of 15-30 km/s. By contrast to the available facilities, the parameters of the developed facility can be adjusted in a wide range of voltage from 2 kV to 10 kV, its design permits generating CPF in horizontal and vertical positions.
Comparative Study of Algorithms for Automated Generalization of Linear Objects
Azimjon, S.; Gupta, P. K.; Sukhmani, R. S. G. S.
2014-11-01
Automated generalization, rooted from conventional cartography, has become an increasing concern in both geographic information system (GIS) and mapping fields. All geographic phenomenon and the processes are bound to the scale, as it is impossible for human being to observe the Earth and the processes in it without decreasing its scale. To get optimal results, cartographers and map-making agencies develop set of rules and constraints, however these rules are under consideration and topic for many researches up until recent days. Reducing map generating time and giving objectivity is possible by developing automated map generalization algorithms (McMaster and Shea, 1988). Modification of the scale traditionally is a manual process, which requires knowledge of the expert cartographer, and it depends on the experience of the user, which makes the process very subjective as every user may generate different map with same requirements. However, automating generalization based on the cartographic rules and constrains can give consistent result. Also, developing automated system for map generation is the demand of this rapid changing world. The research that we have conveyed considers only generalization of the roads, as it is one of the indispensable parts of a map. Dehradun city, Uttarakhand state of India was selected as a study area. The study carried out comparative study of the generalization software sets, operations and algorithms available currently, also considers advantages and drawbacks of the existing software used worldwide. Research concludes with the development of road network generalization tool and with the final generalized road map of the study area, which explores the use of open source python programming language and attempts to compare different road network generalization algorithms. Thus, the paper discusses the alternative solutions for automated generalization of linear objects using GIS-technologies. Research made on automated of road network
Directory of Open Access Journals (Sweden)
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.
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.
A genome-wide association study of optic disc parameters.
Directory of Open Access Journals (Sweden)
Wishal D Ramdas
2010-06-01
Full Text Available The optic nerve head is involved in many ophthalmic disorders, including common diseases such as myopia and open-angle glaucoma. Two of the most important parameters are the size of the optic disc area and the vertical cup-disc ratio (VCDR. Both are highly heritable but genetically largely undetermined. We performed a meta-analysis of genome-wide association (GWA data to identify genetic variants associated with optic disc area and VCDR. The gene discovery included 7,360 unrelated individuals from the population-based Rotterdam Study I and Rotterdam Study II cohorts. These cohorts revealed two genome-wide significant loci for optic disc area, rs1192415 on chromosome 1p22 (p = 6.72x10(-19 within 117 kb of the CDC7 gene and rs1900004 on chromosome 10q21.3-q22.1 (p = 2.67x10(-33 within 10 kb of the ATOH7 gene. They revealed two genome-wide significant loci for VCDR, rs1063192 on chromosome 9p21 (p = 6.15x10(-11 in the CDKN2B gene and rs10483727 on chromosome 14q22.3-q23 (p = 2.93x10(-10 within 40 kbp of the SIX1 gene. Findings were replicated in two independent Dutch cohorts (Rotterdam Study III and Erasmus Rucphen Family study; N = 3,612, and the TwinsUK cohort (N = 843. Meta-analysis with the replication cohorts confirmed the four loci and revealed a third locus at 16q12.1 associated with optic disc area, and four other loci at 11q13, 13q13, 17q23 (borderline significant, and 22q12.1 for VCDR. ATOH7 was also associated with VCDR independent of optic disc area. Three of the loci were marginally associated with open-angle glaucoma. The protein pathways in which the loci of optic disc area are involved overlap with those identified for VCDR, suggesting a common genetic origin.
Study of automatic designing of line heating technique parameters
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Based on experimental data of line heating, the methods of vector mapping, plane projection, and coordinate converting are presented to establish the spectra for line heating distortion discipline which shows the relationship between process parameters and distortion parameters of line heating. Back-propagation network (BP-net) is used to modify the spectra.Mathematical models for optimizing line heating techniques parameters, which include two-objective functions,are constructed. To convert the multi-objective optimization into a single-objective one, the method of changing weight coefficient is used, and then the individual fitness function is built up. Taking the number of heating lines, distance between the heating lines' border (line space), and shrink quantity of lines as three restrictive conditions,a hierarchy genetic algorithm (HGA) code is established by making use of information provided by the spectra, in which inner coding and outer coding adopt different heredity arithmetic operators in inherent operating. The numerical example shows that the spectra for line heating distortion discipline presented here can provide accurate information required by techniques parameter prediction of line heating process and the technique parameter optimization method based on HGA provided here can obtain good results for hull plate.
Study of parameters affecting enhanced coal bed methane
Energy Technology Data Exchange (ETDEWEB)
Katyal, S.; Valix, M.; Thambimuthu, K. [University of Sydney, Sydney, NSW (Australia). Dept. of Chemical Engineering
2007-02-15
Laboratory and field scale trials conducted so far indicate that injection of CO{sub 2} and N{sub 2} into deep coalbeds has the potential to enhance coalbed methane (ECBM) recovery while simultaneously sequestering CO{sub 2}. The work has identified that the fundamental processes involved in CO{sub 2} sequestration/CBM recovery in deep coalbeds are not fully understood and further research is needed to advance this technology. ECBM is affected by several parameters; prominent among them are coal characteristics, in-situ conditions prevailing in deep coalbeds, and changes arising from the interaction of coal with various fluids. These parameters do not act independently, thereby making it difficult to isolate their impacts separately. An attempt has been made in this article to classify these parameters and understand their role in ECBM. Past work in this area is reviewed and the future work that is critical for an improved understanding of ECBM recovery is discussed.
Investigating uncertainty in BPR formula parameters: a case study
DEFF Research Database (Denmark)
Manzo, Stefano; Nielsen, Otto Anker; Prato, Carlo Giacomo
uncertainty within the model. The research described in this paper investigated uncertainty in the BPR formula parameters. Within traffic assignment models, the relationship between travel time and traffic flows is commonly described by the BPR formula. The BPR formula works as a link performance function......; given free flow travel time, observed flow and link capacity, it uses parameters to fit the equation to various types of roadways and circumstances. Usually, the values for the parameters are pre-defined, based on assumptions and practice. The present paper describes a work implemented to define the BPR...... on their output highly unreliable. The main consequence of this inherent uncertainty is that modelled traffic flows cannot be expressed as a point estimate, because this would only represent one of the possible outputs generated by the model. Instead, modelled traffic flows are better expressed as a central...
Study on the optimum parameters for laser-solid interaction
Institute of Scientific and Technical Information of China (English)
Liyun Lin(林丽云); Shengbo Wang(王声波); Dahao Guo(郭大浩); Hongxing Wu(吴鸿兴); Xiaoping Xia(夏小平); Yusheng Dai(戴宇生)
2003-01-01
The optimum parameters for laser propulsion are discussed, such as laser induced pressure on targets,interaction parameters (Cm, Isp) and optimum laser intensity Is, etc. It is verified that the larger laserpower density will induce higher thrusting force. It is also found that, to drive a 1.010-kg target duringconfined laser ablation in vacuum and a 17.45-g one during direct laser ablation in air at the standardpressure, the needed minimum power intensities are on the same order of magnitude.
Study On Extrusion Technological Parameters Of Brown Rice
Institute of Scientific and Technical Information of China (English)
Zhu Yongyi; Zhou Xianqing; Ling Lizhong
2001-01-01
Extrusion is an efficient measure to improve the texture and physic-s of brown rice. The polynomial degree two model of extrusion parameters and gelatinized degree, water absorption index, water soluble index and moisture content of extruded matter was obtained by methods of single factor and response surface methodology, R2=0.9649, 0.8745, 0.9079, 0.8677. The optimal parameters of brown rice extrusion were figured out as follows:moisture nrice, 11.42%, speed of screw, 30rpm, feeding speed, and 20rpm.
A Reliability Generalization Study of the Geriatric Depression Scale.
Kieffer, Kevin M.; Reese, Robert J.
2002-01-01
Conducted a reliability generalization study of the Geriatric Depression Scale (T. Brink and others, 1982). Results from this investigation of 338 studies shows that the average score reliability across studies was 0.8482 and identifies the most important predictors of score reliability. (SLD)
Study made to establish parameters and limitations of explosive welding
Polhemus, F. C.
1967-01-01
It is theorized that metal jetting must be present for welding to occur, therefore an explosive weld interface may indicate the relation between the metal jet velocity and shock wave velocity in welding. Parameters for effecting explosive welding in patches of 3 or 4 inches in diameter were established, and found applicable to explosive welding of patches of various sizes.
SUSY Studies with Snowmass Point 5 mSUGRA Parameters
Borjanovic, I; Popovic, D; Physics at LHC, Vienna, 13-17 July 2004
2004-01-01
Achievable precision of SUSY masses and kinematic endpoints measurements at ATLAS detector was estimated for mSUGRA Snowmass Point 5 parameters which give stop quark lighter than for any other mSUGRA point. Characterisitic decays of left squark and gluino were analyzed.
Theoretical study of some electrical parameters of graphene
Das, D. K.; Roy, S.; Sahoo, S.
2016-10-01
Graphene, due to its numerous unique properties, is addressed as miraculous material by Novoselov et al. [Nature 490 (2012) 192]. It has ultrahigh heat and thermal conductivity. Several researchers over the globe are working on electrical properties of graphene like electrical resistance, electrical conductivity etc. In this paper, we estimate electrical resistivity, electrical conductivity and Lorenz number for graphene within the temperature range from 300 K to 500 K. Variation of these parameters with respect to temperature and sample size is also reported.
Shimizu, N.; Aihara, H.; Epifanov, D.
2016-07-01
Michel parameters are kinematic values defined as bilinear combinations of the coupling terms in the general matrix element of the Fermi interaction where all possible Lorentz-invariant scalar, vector and tensor terms are included. The leptonic τ decays provide an excellent laboratory in which to measure the Michel parameters. Any deviation of these parameters from the Standard Model expectation would indicate New Physics. Two Michel parameters, η bar and ξκ, can only be measured in the radiative leptonic decay. These parameters have previously been measured in the radiative decay of the muon but as yet have not been measured in τ decays. We report the results of a feasibility study of the measurement of η bar and ξκ in radiative leptonic τ decays at Belle and Belle II.
PARAMETER SETS FOR 10 TEV AND 100 TEV MUON COLLIDERS, AND THEIR STUDY AT THE HEMC 99 WORKSHOP
Energy Technology Data Exchange (ETDEWEB)
KING,B.J.
2000-05-05
A focal point for the HEMC'99 workshop was the evaluation of straw-man parameter sets for the acceleration and collider rings of muon colliders at center of mass energies of 10 TeV and 100 TeV. These self-consistent parameter sets are presented and discussed. The methods and assumptions used in their generation are described and motivations are given for the specific choices of parameter values. The assessment of the parameter sets during the workshop is then reviewed and the implications for the feasibility of many-TeV muon colliders are evaluated. Finally, a preview is given of plans for iterating on the parameter sets and, more generally, for future feasibility studies on many-TeV muon colliders.
Comparative study of radiation shielding parameters for bismuth borate glasses
Energy Technology Data Exchange (ETDEWEB)
Kaundal, Rajinder Singh, E-mail: rajinder_apd@yahoo.com [Department of Physics, School of Physical Sciences, Lovely Professional University, Phagwara, Punjab (India)
2016-07-15
Melt and quench technique was used for the preparation of glassy samples of the composition x Bi{sub 2}O{sub 3-}(1-x) B{sub 2}O{sub 3} where x= .05 to .040. XCOM computer program is used for the evaluation of gamma-ray shielding parameters of the prepared glass samples. Further the values of mass attenuation coefficients, effective atomic number and half value layer for the glassy samples have been calculated in the energy range from 1KeV to 100GeV. Rigidity of the glass samples have been analyzed by molar volume of the prepared glass samples. (author)
Parameter Impact on Sharing Studies Between UAS CNPC Satellite Transmitters and Terrestrial Systems
Kerczewski, Robert J.; Wilson, Jeffrey D.; Bishop, William D.
2015-01-01
In order to provide a control and non-payload communication (CNPC) link for civil-use unmanned aircraft systems (UAS) when operating in beyond-line-of-sight (BLOS) conditions, satellite communication links are generally required. The International Civil Aviation Organization (ICAO) has determined that the CNPC link must operate over protected aviation safety spectrum allocations. Although a suitable allocation exists in the 5030-5091 MHz band, no satellites provide operations in this band and none are currently planned. In order to avoid a very lengthy delay in the deployment of UAS in BLOS conditions, it has been proposed to use existing satellites operating in the Fixed Satellite Service (FSS), of which many operate in several spectrum bands. Regulatory actions by the International Telecommunications Union (ITU) are needed to enable such a use on an international basis, and indeed Agenda Item (AI) 1.5 for the 2015 World Radiocommunication Conference (WRC) was established to decide on the enactment of possible regulatory provisions. As part of the preparation for AI 1.5, studies on the sharing FSS bands between existing services and CNPC for UAS are being contributed by NASA and others. These studies evaluate the potential impact of satellite CNPC transmitters operating from UAS on other in-band services, and on the potential impact of other in-band services on satellite CNPC receivers operating on UAS platforms. Such studies are made more complex by the inclusion of what are essentially moving FSS earth stations, compared to typical sharing studies between fixed elements. Hence, the process of determining the appropriate technical parameters for the studies meets with difficulty. In order to enable a sharing study to be completed in a less-than-infinite amount of time, the number of parameters exercised must be greatly limited. Therefore, understanding the impact of various parameter choices is accomplished through selectivity analyses. In the case of sharing
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.
Sanz-Aguilar, Ana; Anadón, José D; Edelaar, Pim; Carrete, Martina; Tella, José Luis
2014-01-01
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.
"Two Cultures" Topics for General Studies Science Courses.
Larson, James H.
1982-01-01
Theses proposed in C. P. Snow's book "The Two Cultures," including uncommunicative scientific and literary groups, gap between rich and poor, overpopulation, and nuclear war remain viable topics. Discusses the scientific and literary cultural gap and what can be done in general studies science courses to ameliorate the condition. (Author/JN)
"Two Cultures" Topics for General Studies Science Courses.
Larson, James H.
1982-01-01
Theses proposed in C. P. Snow's book "The Two Cultures," including uncommunicative scientific and literary groups, gap between rich and poor, overpopulation, and nuclear war remain viable topics. Discusses the scientific and literary cultural gap and what can be done in general studies science courses to ameliorate the condition.…
"Two Cultures" Topics for General Studies Science Courses.
Larson, James H.
1982-01-01
Theses proposed in C. P. Snow's book "The Two Cultures," including uncommunicative scientific and literary groups, gap between rich and poor, overpopulation, and nuclear war remain viable topics. Discusses the scientific and literary cultural gap and what can be done in general studies science courses to ameliorate the condition.…
Computational Study on Effect of Synthetic Jet Design Parameters
Directory of Open Access Journals (Sweden)
Koichi Okada
2010-01-01
Full Text Available Effects of amplitude and frequency of synthetic jet on the characteristics of induced jet are investigated. To estimate effects of the parameters, flow inside the synthetic jet cavity and orifice and the outer flow is simultaneously simulated using large-eddy simulation (LES. Comparison of the present LES result with the experimental data shows that three-dimensional LES of the flow inside the cavity is essential for accurate estimation of the velocity and velocity fluctuation of the synthetic jet. Comparison of the present results under various flow conditions shows that amplitude and frequency can control profiles of time-averaged vertical velocity and fluctuation of the vertical velocity as well as damping rate of the induced velocity and fluctuation.
Performance Studies of Bulk Micromegas of Different Design Parameters
Bhattacharya, Purba; Majumdar, Nayana; Mukhopadhyay, Supratik; Sarkar, Sandip; Colas, Paul; Attie, David
2016-01-01
The present work involves the comparison of various bulk Micromegas detectors having different design parameters. Six detectors with amplification gaps of $64,~128,~192,~220 ~\\mu\\mathrm{m}$ and mesh hole pitch of $63,~78 ~\\mu\\mathrm{m}$ were tested at room temperature and normal gas pressure. Two setups were built to evaluate the effect of the variation of the amplification gap and mesh hole pitch on different detector characteristics. The gain, energy resolution and electron transmission of these Micromegas detectors were measured in Argon-Isobutane (90:10) gas mixture while the measurements of the ion backflow were carried out in P10 gas. These measured characteristics have been compared in detail to the numerical simulations using the Garfield framework that combines packages such as neBEM, Magboltz and Heed.
Study of Aerodynamic Parameters on Different Underling Surfaces
Institute of Scientific and Technical Information of China (English)
MAO Yuhao; LIU Shuhua; ZHANG Chenyi; LIU Lichao; LI Jing
2007-01-01
Aerodynamic parameters including the zero-plane displacement (d), roughness length (z0), and friction velocity (u*) on the different underlying surfaces of heavy-grazing site, medium-grazing site, light-grazing site, no-grazing site, dune, inter-dune, grassland, rice paddy site, wheat site, soybean site, and maize site have been computed based on the Monin-Obukhov similarity theory by utilizing the micrometeorologically observed data of dune and vegetation in the semi-arid area at Naiman, Inner Mongolia of China, conducted jointly by the Institute of Desert Research, Chinese Academy of Sciences and the National Institute of AgroEnvironmental Sciences of Japan in 1990-1994. And their relationships between wind speed and Richardson number are analyzed. The aerodynamic characteristics of different man-made disturbed grassland ecosystems are also compared. Result shows that the vegetation coverage and the above-ground biomass decrease with the increase in man-made stress of the grassland. The roughness length for different underlying surfaces is closely related to vegetation height, above-ground biomass, and ground surface undulation, and Richardson number Ri is also its influencing factor. The friction velocity varies largely on different underlying surfaces,and it is positively proportional to wind speed and roughness length. The aerodynamic parameters of various times on the same underlying surface are different, too. Above results indicate that grassland and vegetation are of significance in preventing desertification, especially in the arid and semi-arid land ecosystems. And the results of this paper are also important for constructing the land surface physical process as well as regional climate model.
Learning and generalization under ambiguity: an fMRI study.
Directory of Open Access Journals (Sweden)
J R Chumbley
2012-01-01
Full Text Available Adaptive behavior often exploits generalizations from past experience by applying them judiciously in new situations. This requires a means of quantifying the relative importance of prior experience and current information, so they can be balanced optimally. In this study, we ask whether the brain generalizes in an optimal way. Specifically, we used Bayesian learning theory and fMRI to test whether neuronal responses reflect context-sensitive changes in ambiguity or uncertainty about experience-dependent beliefs. We found that the hippocampus expresses clear ambiguity-dependent responses that are associated with an augmented rate of learning. These findings suggest candidate neuronal systems that may be involved in aberrations of generalization, such as over-confidence.
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.
Generalization of Rare Variant Association Tests for Longitudinal Family Studies.
Chien, Li-Chu; Hsu, Fang-Chi; Bowden, Donald W; Chiu, Yen-Feng
2016-02-01
Given the functional relevance of many rare variants, their identification is frequently critical for dissecting disease etiology. Functional variants are likely to be aggregated in family studies enriched with affected members, and this aggregation increases the statistical power to detect rare variants associated with a trait of interest. Longitudinal family studies provide additional information for identifying genetic and environmental factors associated with disease over time. However, methods to analyze rare variants in longitudinal family data remain fairly limited. These methods should be capable of accounting for different sources of correlations and handling large amounts of sequencing data efficiently. To identify rare variants associated with a phenotype in longitudinal family studies, we extended pedigree-based burden (BT) and kernel (KS) association tests to genetic longitudinal studies. Generalized estimating equation (GEE) approaches were used to generalize the pedigree-based BT and KS to multiple correlated phenotypes under the generalized linear model framework, adjusting for fixed effects of confounding factors. These tests accounted for complex correlations between repeated measures of the same phenotype (serial correlations) and between individuals in the same family (familial correlations). We conducted comprehensive simulation studies to compare the proposed tests with mixed-effects models and marginal models, using GEEs under various configurations. When the proposed tests were applied to data from the Diabetes Heart Study, we found exome variants of POMGNT1 and JAK1 genes were associated with type 2 diabetes.
FEM numerical model study of electrosurgical dispersive electrode design parameters.
Pearce, John A
2015-01-01
Electrosurgical dispersive electrodes must safely carry the surgical current in monopolar procedures, such as those used in cutting, coagulation and radio frequency ablation (RFA). Of these, RFA represents the most stringent design constraint since ablation currents are often more than 1 to 2 Arms (continuous) for several minutes depending on the size of the lesion desired and local heat transfer conditions at the applicator electrode. This stands in contrast to standard surgical activations, which are intermittent, and usually less than 1 Arms, but for several seconds at a time. Dispersive electrode temperature rise is also critically determined by the sub-surface skin anatomy, thicknesses of the subcutaneous and supra-muscular fat, etc. Currently, we lack fundamental engineering design criteria that provide an estimating framework for preliminary designs of these electrodes. The lack of a fundamental design framework means that a large number of experiments must be conducted in order to establish a reasonable design. Previously, an attempt to correlate maximum temperatures in experimental work with the average current density-time product failed to yield a good match. This paper develops and applies a new measure of an electrode stress parameter that correlates well with both the previous experimental data and with numerical models of other electrode shapes. The finite element method (FEM) model work was calibrated against experimental RF lesions in porcine skin to establish the fundamental principle underlying dispersive electrode performance. The results can be used in preliminary electrode design calculations, experiment series design and performance evaluation.
Optimisation study of a vehicle bumper subsystem with fuzzy parameters
Farkas, L.; Moens, D.; Donders, S.; Vandepitte, D.
2012-10-01
This paper deals with the design and optimisation for crashworthiness of a vehicle bumper subsystem, which is a key scenario for vehicle component design. The automotive manufacturers and suppliers have to find optimal design solutions for such subsystems that comply with the conflicting requirements of the regulatory bodies regarding functional performance (safety and repairability) and regarding the environmental impact (mass). For the bumper design challenge, an integrated methodology for multi-attribute design engineering of mechanical structures is set up. The integrated process captures the various tasks that are usually performed manually, this way facilitating the automated design iterations for optimisation. Subsequently, an optimisation process is applied that takes the effect of parametric uncertainties into account, such that the system level of failure possibility is acceptable. This optimisation process is referred to as possibility-based design optimisation and integrates the fuzzy FE analysis applied for the uncertainty treatment in crash simulations. This process is the counterpart of the reliability-based design optimisation used in a probabilistic context with statistically defined parameters (variabilities).
Comparative study on parameter estimation methods for attenuation relationships
Sedaghati, Farhad; Pezeshk, Shahram
2016-12-01
In this paper, the performance and advantages and disadvantages of various regression methods to derive coefficients of an attenuation relationship have been investigated. A database containing 350 records out of 85 earthquakes with moment magnitudes of 5-7.6 and Joyner-Boore distances up to 100 km in Europe and the Middle East has been considered. The functional form proposed by Ambraseys et al (2005 Bull. Earthq. Eng. 3 1-53) is selected to compare chosen regression methods. Statistical tests reveal that although the estimated parameters are different for each method, the overall results are very similar. In essence, the weighted least squares method and one-stage maximum likelihood perform better than the other considered regression methods. Moreover, using a blind weighting matrix or a weighting matrix related to the number of records would not yield in improving the performance of the results. Further, to obtain the true standard deviation, the pure error analysis is necessary. Assuming that the correlation between different records of a specific earthquake exists, the one-stage maximum likelihood considering the true variance acquired by the pure error analysis is the most preferred method to compute the coefficients of a ground motion predication equation.
Design Parameter Studies of Emission-Based Iron Opacity Measurements
Martin, Madison E.; London, Richard A.; Goluoglu, Sedat; Whitley, Heather D.
2016-10-01
Opacity is a critical parameter in the transport of radiation in systems such as inertial confinement fusion capsules and stars. The resolution of current disagreements between solar models and helioseismological observations would benefit from experimental validation of theoretical opacity models. Short pulse lasers can be used to heat targets to higher temperatures and densities than long pulse lasers and pulsed power machines, thus potentially enabling access to x-ray emission spectra at conditions relevant to solar models. The radiation-hydrodynamic code HYDRA is used to investigate the effects of modifying laser energy, laser pulse length, and target dimensions on the plasma conditions, x-ray emission, and inferred opacity of a buried layer iron target. The accuracy of the opacity inference is sensitive to tamper emission and optical depth effects. An example design that reaches temperatures and densities relevant to the radiative zone of the sun while reducing optical depth and tamper emission effects will be discussed. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC.
Hadron tomography studies by generalized parton distributions and distribution amplitudes
Kumano, S
2016-01-01
We discuss hadron-tomography studies for the nucleon and exotic hadrons by high-energy hadron reactions. First, the constituent-counting rule is explained for determining internal quark configurations of exotic-hadron candidates by scaling properties of high-energy exclusive cross sections. Next, possibilities are discussed for investigating the generalized parton distributions (GPDs) of the nucleon and exotic hadrons at J-PARC. In particular, we study hadronic $2 \\to 3$ process $p+p \\to N+\\pi+B$, exclusive Drell-Yan process, and exotic-hadron GPDs. For determining three-dimensional structure of unstable exotic hadrons, we consider $s$-$t$ crossed quantities of the GPDs called generalized distribution amplitudes (GDAs), which can be investigated at KEKB. We explain possible studies of the GDAs by two-photon processes.
Cardiovascular morbidity in COPD: A study of the general population
DEFF Research Database (Denmark)
Lange, Peter; Møgelvang, Rasmus; Marott, Jacob Louis
2010-01-01
Although there are a number of studies on the coexistence of heart disease and COPD among patients acutely admitted to hospital, this relationship has not been accurately described in the general population. Especially data on the prevalence of both reduced lung function and impaired left...... ventricular ejection fraction (LVEF) are sparse. We used data from the 4th examination of The Copenhagen City Heart Study, which comprises 5,890 individuals with data on pulmonary and cardiac symptoms, risk factors for cardiovascular diseases, pulmonary function tests, ECG and relevant medical history. Among...... ventricular hyperthrophy was significantly more frequent among individuals with COPD (17.7%) than among participants without COPD (12.1%.), yet this relationship was no longer significant after statistical adjustment for age and gender. In the general population, subjects with COPD have a higher prevalence...
Ramanayake, R P J C; De Silva, A H W; Perera, D P; Sumanasekera, R D N; Athukorala, L A C L; Fernando, K A T
2015-01-01
Worldwide Family Medicine has gained an important place in the undergraduate medical curriculum over the last few decades and general practices have become training centers for students. Exposure to patients early in the disease process, out patient management of common problems, follow up of chronic diseases and psychosocial aspects of health and disease are educational advantages of community based training but such training could have varying impact on patients, students and trainers. This study explored the views of General Practitioner (GP) trainers on their experience in training students. This qualitative study was conducted among GP trainers of the faculty of medicine, University of Kelaniya, Sri Lanka, to explore their experience on wide range of issues related to their role as GP trainers. The interviews were recorded and transcribed verbatim. Themes expressed were identified. Altruistic reasons, self-satisfaction, self-esteem and opportunity to improve their knowledge were the motivations for their involvement in teaching. Teachers were confident of their clinical and teaching skills. They perceived that patients were willing participants of the process and benefited from it. There was a positive impact on consultation dynamics. Time pressure was the major problem and ideal number of trainees per session was two. They were willing to attend teacher training workshops to update their knowledge. GP trainers driven by altruistic reasons were willing participants of student training process. The perceived advantages of involvement of teaching for trainers and patients were an encouragement for potential trainers. University should organize training sessions for trainers which will boost their knowledge, confidence and teaching skills which will eventually benefit students.
Study with lormetazepam as a hypnotic in general practice.
Pöldinger, W; Sastre-y-Hernández, M; Fichte, K
1983-01-01
Due to the increasing pressure to investigate new drugs under conditions met with in practice, Lormetazepam (0.5 mg) was investigated in nine general practices under the direction and collaboration of a psychiatrist used to investigations with psychopharmaceuticals. The results of a double-blind study, carried out in comparison to triazolam (0.5 mg), in a total of 94 ambulatory patients are presented.
Parameter ranking of stock market dynamics: a comparative study of ...
African Journals Online (AJOL)
... a comparative study of the mathematical models of competition and mutualistic interactions. ... Open Access DOWNLOAD FULL TEXT ... Our approach also permits us to gain some useful insights into the ability of the model to reflect what is ...
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.
Study on the oscillatory behaviour of the lattice parameter in ternary iron-nitrogen compounds
Energy Technology Data Exchange (ETDEWEB)
Gil Rebaza, A.V.; Desimoni, J. [Departamento de Fisica, Facultad de Ciencias Exactas, UNLP, CC No 67, 1900 La Plata (Argentina); Peltzer y Blanca, E.L., E-mail: eitelpyb@ing.unlp.edu.ar [Grupo de Estudio de Materiales y Dispositivos Electronicos (GEMyDE), Facultad de Ingenieria, UNLP, IFLYSIB-CONICET, CC No. 565, 1900 La Plata (Argentina)
2012-08-15
The structural properties of the XFe{sub 3}N (X=Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn) cubic ternary iron based nitrides as well as the preferential occupation site of X in the structure were studied using Full Potential Linearized Augmented Plane Wave method, within the Density Functional Theory formalism, Wien2k code, the exchange-correlation potential described with the Perdew-Burke-Ernzerhof expression, based in the Local Spin Density Approximation and Generalized Gradient Approximation. According the calculations, the Sc, Co, Ni, Cu and Zn, atoms preferred the corner sites of the cubes, while Ti, V, Cr and Mn occupy the centre of the faces of the equilibrium structures. The equilibrium structure lattice parameters have an oscillatory behaviour with the atomic number of X, with decreasing amplitude as the atomic number of X increases. This trend do not correlated with the atomic radii of X.
Study on the general model of hydrological frequency analysis
Institute of Scientific and Technical Information of China (English)
王浩; 秦大庸; 孙济良; 王建华
2001-01-01
On the basis of exponential Gamma distribution, this paper presents a model consisting of 11 kinds of distribution curves for the first time. The model contains several frequency curves used commonly in China and other countries, for example, Pearson type-3 distribution, Kritsky and Menkel (USSR) distribution, Logarithmic normal distribution, and so on. Through dealing with parameters, the model may be applicable to the hydrological extreme values of different climate regions, and has very strong flexibility. In this paper, a real case study using flood datum of 240 different hydrological stations in China is submitted and the calculating results are satisfactory.
Shogbon, Christopher; Brousseau, Jean-Luc; Zhang, Haifeng
2005-03-01
Static light scattering using a seven angle BI-MwA instrument has been used for the first time to obtain the molecular parameters as well as study the aggregation behavior of previously synthesized m-PBI samples in DMAc/LiCl solvent mixtures. Depolarization ratios for the samples were obtained using a BI-200SM goniometer system. Molecular parameters obtained were m-PBI(118) Mw: 179,300 g/mol; Rg: 36.4 nm; A2: 0.0016 cm^3mol/g^2 and m-PBI(159) Mw: 206,500 g/mol; Rg: 46.6 nm; A2: 0.0020 cm^3mol/g^2. The aggregation behavior of m-PBI(159) was studied as a function of salt concentration (0 to 7 %) at a fixed polymer concentration of 0.3 mg/mL. With increasing salt concentration, Rg decreases initially and goes through three maxima with a minimum Rg of 31.0 nm at 4 % LiCl. This result parallels the previously observed aggregation behavior of corn amylase in DMAc/LiCl. Thus our results suggest a general mechanism for the aggregation of semiflexible polymers which can be controlled by varying polymer or salt concentration.
Soil water balance scenario studies using predicted soil hydraulic parameters
Nemes, A.; Wösten, J.H.M.; Bouma, J.; Várallyay, G.
2006-01-01
Pedotransfer functions (PTFs) have become a topic drawing increasing interest within the field of soil and environmental research because they can provide important soil physical data at relatively low cost. Few studies, however, explore which contributions PTFs can make to land-use planning, in ter
Comparison study of selected geophysical and geotechnical parameters
DEFF Research Database (Denmark)
Nissen, Randi Warncke; Poulsen, Søren Erbs
2015-01-01
Successful foundation of constructions relies on accurate characterization of the geotechnical properties of the subsurface. By implementing data from geophysical surveys, the placement of geotechnical drillings can be significantly improved, potentially reducing the number of required drillings....... This case study is mainly to compare geophysical investigations (MEP/IP) with existing PACES data and information from geotechnical drillings....
Nakamura, Takashi
2012-01-01
In the present paper, we prove that self-approximation of $\\log \\zeta (s)$ with $d=0$ is equivalent to the Riemann Hypothesis. Next, we show self-approximation of $\\log \\zeta (s)$ with respect to all nonzero real numbers $d$. Moreover, we partially filled a gap existing in "The strong recurrence for non-zero rational parameters" and prove self-approximation of $\\zeta(s)$ for $0 \
Screening and cleaning of pulp—a study to the parameters affecting separation
Jokinen, H. (Hanna)
2007-01-01
Abstract The objective of this thesis was to determine the effects of design, operational and furnish quality parameters on pressure screen and hydrocyclone performance. The general contradictory interrelationships between capacity and selectivity in pressure screening and cleaning are commonly recognized, but deep understanding of the effects of design, operational and furnish quality parameters on the state of operation is missing. As separation selectivity is closely dependent ...
Hua, Yongzhao; Dong, Xiwang; Li, Qingdong; Ren, Zhang
2017-05-18
This paper investigates the time-varying formation robust tracking problems for high-order linear multiagent systems with a leader of unknown control input in the presence of heterogeneous parameter uncertainties and external disturbances. The followers need to accomplish an expected time-varying formation in the state space and track the state trajectory produced by the leader simultaneously. First, a time-varying formation robust tracking protocol with a totally distributed form is proposed utilizing the neighborhood state information. With the adaptive updating mechanism, neither any global knowledge about the communication topology nor the upper bounds of the parameter uncertainties, external disturbances and leader's unknown input are required in the proposed protocol. Then, in order to determine the control parameters, an algorithm with four steps is presented, where feasible conditions for the followers to accomplish the expected time-varying formation tracking are provided. Furthermore, based on the Lyapunov-like analysis theory, it is proved that the formation tracking error can converge to zero asymptotically. Finally, the effectiveness of the theoretical results is verified by simulation examples.
Numerical Study of Urban Canyon Microclimate Related to Geometrical Parameters
Directory of Open Access Journals (Sweden)
Andrea de Lieto Vollaro
2014-11-01
Full Text Available In this study a microclimate analysis on a particular urban configuration: the—street canyon—has been carried out. The analysis, conducted by performing numerical simulations using the finite volumes commercial code ANSYS-Fluent, shows the flow field in an urban environment, taking into account three different aspect ratios (H/W. This analysis can be helpful in the study on urban microclimate and on the heat exchanges with the buildings. Fluid-dynamic fields on vertical planes within the canyon, have been evaluated. The results show the importance of the geometrical configuration, in relation to the ratio between the height (H of the buildings and the width (W of the road. This is a very important subject from the point of view of “Smart Cities”, considering the urban canyon as a subsystem of a larger one (the city, which is affected by climate changes.
Microcirculation and atherothrombotic parameters in prolactinoma patients: a pilot study.
Reuwer, Anne Q; Sondermeijer, Brigitte M; Battjes, Suzanne; van Zijderveld, Rogier; Stuijver, Danka J F; Bisschop, Peter H; Twickler, Marcel Th B; Meijers, Joost C M; Schlingemann, Reinier O; Stroes, Erik S
2012-12-01
Atherothrombosis is a multifactorial process, governed by an interaction between the vessel wall, hemodynamic factors and systemic atherothrombotic risk factors. Recent in vitro, human ex vivo and animal studies have implicated the hormone prolactin as an atherothrombotic mediator. To address this issue, we evaluated the anatomy and function of various microvascular beds as well as plasma atherothrombosis markers in patients with elevated prolactin levels. In this pilot study, involving 10 prolactinoma patients and 10 control subjects, sidestream dark field (SDF) imaging revealed a marked perturbation of the sublingual microcirculation in prolactinoma patients compared to control subjects, as attested to by significant changes in microvascular flow index (2.74 ± 0.12 vs. 2.91 ± 0.05, respectively; P = 0.0006), in heterogeneity index (0.28 [IQR 0.18-0.31] vs. 0.09 [IQR 0.08-0.17], respectively; P = 0.002) and lower proportion of perfused vessels (90 ± 4.0% vs. 95 ± 3.0%, respectively; P = 0.016). In the retina, fluorescein angiography (FAG) confirmed these data, since prolactinoma patients more often have dilatated perifoveal capillaries. In plasma, prolactinoma patients displayed several pro-atherogenic disturbances, including a higher endogenous thrombin potential and prothrombin levels as well as decreased HDL-cholesterol levels. Prolactinoma patients are characterized by microvascular dysfunction as well as plasma markers indicating a pro-atherothrombotic state. Further studies are required to assess if prolactin is causally involved in atherothrombotic disease.
Generalizing a study of a rotating rod carrying a collar
Energy Technology Data Exchange (ETDEWEB)
Campos, I [Departamento de Fisica, Facultad de Ciencias, universidad Nacional Autonoma de Mexico, Apartado Postal 21-939, Mexico 04000 D.F. (Mexico); Del Valle, G; Hernandez, M G [Area de Fisica, Division de Ciencias Basicas e IngenierIa, Universidad Autonoma Metropolitana-Azcapotzalco, Apartado Postal 21-939, Mexico 04000 D.F. (Mexico); Jimenez, J L, E-mail: jlj@xanum.uam.m [Departamento de Fisica, Division de Ciencias Basicas e IngenierIa, Universidad Autonoma Metropolitana-Iztapalapa, Apartado Postal 21-939, Mexico 04000 D.F. (Mexico)
2010-11-15
The present work is a generalization of the work of Ribberfors and Reitz (2000 Eur. J. Phys. 21 151-7). These authors study a system consisting of a collar that is restricted to move in a path defined by a rod of some prescribed form which passes through the collar. We generalize the analysis of this system by means of canonical treatment. We show in this way that this excellent example can also be used in advanced courses on mechanics to show the power of the methods of analytical mechanics. We have that the present treatment of this example will be useful for advanced undergraduate and graduate students as well as for the teachers of these courses on classical mechanics. (letters and comments)
Comparative Study of Various SDLC Models on Different Parameters
Directory of Open Access Journals (Sweden)
Prateek Sharma
2015-04-01
Full Text Available The success of a software development project greatly depends upon which process model is used. This paper emphasizes on the need of using appropriate model as per the application to be developed. In this paper we have done the comparative study of the following software models namely Waterfall, Prototype, RAD (Rapid Application Development Incremental, Spiral, Build and Fix and V-shaped. Our aim is to create reliable and cost effective software and these models provide us a way to develop them. The main objective of this research is to represent different models of software development and make a comparison between them to show the features of each model.
Orientational order parameter studies in two symmetric dimeric liquid crystals - an optical study
Pardhasaradhi, P.; Datta Prasad, P. V.; Madhavi Latha, D.; Pisipati, V. G. K. M.; Padmaja Rani, G.
2012-12-01
The optical technique developed by [W. Kuczynski, B. Zywucki, and J. Malecki, Determination of orientational order parameter in various liquid-crystalline phases, Mol. Cryst. Liq. Cryst. 381 (2002), pp. 1-19; B.J. Zywucki and W. Kuczynski, IEEE transactions on optical phenomena - The orientational order in nematic liquid crystals from birefringence measurements, Dielectr. Electr. Insul. 8 (2001), pp. 512-515] is fabricated and used to determine the orientational order parameter in two dimeric liquid crystalline compounds nematic and SmA phases of α,ω-bis(4-alkylanilinebenzylidene-4‧-oxy)alkane (m.OnO.m) homologous series. The compounds studied are 5.O8O.5 and 5.O10O.5 which exhibit nematic and SmA, and nematic phases, respectively. The orientational order parameter in both the phases of nematic and SmA phases of the compound one and the nematic phase of the compound two are obtained using the principle of Newton's rings which gives directly the birefringence, δn of the liquid crystal dimer. The merits of the technique used are presented over the conventional techniques for the determination of orientational order parameter. The results for the two compounds are compared with those values estimated from n e, n o and density using the two internal field models due to Vuks and Neugebauer applicable to nematic phase.
Experimental Studies of the Transport Parameters of Warm Dense Matter
Energy Technology Data Exchange (ETDEWEB)
Chouffani, Khalid [Idaho State Univ., Pocatello, ID (United States)
2014-12-01
There is a need to establish fundamental properties of matter and energy under extreme physical conditions. Although high energy density physics (HEDP) research spans a wide range of plasma conditions, there is one unifying regime that is of particular importance and complexity: that of warm dense matter, the transitional state between solid state condensed matter and energetic plasmas. Most laboratory experimental conditions, including inertial confinement implosion, fall into this regime. Because all aspects of laboratory-created high-energy-density plasmas transition through the warm dense matter regime, understanding the fundamental properties to determine how matter and energy interact in this regime is an important aspect of major research efforts in HEDP. Improved understanding of warm dense matter would have significant and wide-ranging impact on HEDP science, from helping to explain wire initiation studies on the Sandia Z machine to increasing the predictive power of inertial confinement fusion modeling. The central goal or objective of our proposed research is to experimentally determine the electrical resistivity, temperature, density, and average ionization state of a variety of materials in the warm dense matter regime, without the use of theoretical calculations. Since the lack of an accurate energy of state (EOS) model is primarily due to the lack of experimental data, we propose an experimental study of the transport coefficients of warm dense matter.
Study on orthorhombic parameters for 3D elastic full waveform inversion
Oh, Ju-Won
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.
Torres-Pomales, Wilfredo
2015-01-01
This report documents a case study on the application of Reliability Engineering techniques to achieve an optimal balance between performance and robustness by tuning the functional parameters of a complex non-linear control system. For complex systems with intricate and non-linear patterns of interaction between system components, analytical derivation of a mathematical model of system performance and robustness in terms of functional parameters may not be feasible or cost-effective. The demonstrated approach is simple, structured, effective, repeatable, and cost and time efficient. This general approach is suitable for a wide range of systems.
Experimental study of effect of stenosis geometry on flow parameters
Directory of Open Access Journals (Sweden)
Veselý Ondřej
2015-01-01
Full Text Available A stenosis is a narrowing in a tubular organ or structure. In medicine, vessel stenosis poses health risks for people. In this work, experimental investigations of pressure loss coefficient for varying stenosis eccentricity and shape were performed. Five models of different geometry were studied; all models were stenosis of 75 % area reduction. The flow conditions approximate physiological flow. The measuring range of Reynolds number was from 130 to 2730, measured values of pressure loss coefficient were from 12 to 20. The steady experimental results indicated that static pressure loss coefficient is affected by the shape of stenosis, but it was affected more significantly by the eccentricity. Visualization experiments have been performed in Polycarbonate models.
Numerical study of three-parameter matrix eigenvalue problem by Rayleigh quotient method
Bora, Niranjan; Baruah, Arun Kumar
2016-06-01
In this paper, an attempt is done to find approximate eigenvalues and the corresponding eigenvectors of three-parameter matrix eigenvalue problem by extending Rayleigh Quotient Iteration Method (RQIM), which is generally used to solve generalized eigenvalue problems of the form Ax = λBx. Convergence criteria of RQIM will be derived in terms of matrix 2-norm. We will test the computational efficiency of the Method analytically with the help of numerical examples. All calculations are done in MATLAB software.
Gonzalo, Julio A
2013-01-01
In a historical perspective, compact solutions of Einstein's equations, including the cosmological constant and the curvature terms, are obtained, starting from two recent observational estimates of the Hubble's parameter (H0) and the "age" of the universe (t0). Cosmological implications for {\\Lambda}CDM ({\\Lambda} Cold Dark Matter), KOFL (k Open Friedman-Lemaitre), plus two mixed solutions are investigated, under the constraints imposed by the relatively narrow current uncertainties. Quantitative results obtained for the KOFL case seem to be compatible with matter density and the highest observed red-shifts from distant galaxies, while those obtained for the {\\Lambda}CDM may be more difficult to reconcile.
Ambient pressure sensitivity of microbubbles investigated through a parameter study
DEFF Research Database (Denmark)
Andersen, Klaus Scheldrup; Jensen, Jørgen Arendt
2009-01-01
Measurements on microbubbles clearly indicate a relation between the ambient pressure and the acoustic behavior of the bubble. The purpose of this study was to optimize the sensitivity of ambient pressure measurements, using the subharmonic component, through microbubble response simulations...... cycles driving pulse, a reduction of 4.6 dB is observed when changing pov from 0 to 25 kPa. Increasing the pulse duration makes the reduction even more clear. For a pulse with 64 cycles, the reduction is 9.9 dB. This simulation is in good correspondence with measurement results presented by Shi et al....... 1999, who found a linear reduction of 9.6 dB. Further simulations of Levovist show that also the shape and the acoustic pressure of the driving pulse are very important factors. The best pressure sensitivity of Levovist was found to be 0.88 dB/kPa. For Sonazoid, a sensitivity of 1.14 dB/kPa has been...
Study of Molecular Line Parameters down to Very Low Temperature
Mondelain, D.; Camy-Peyret, C.; Deng, W.; Payan, S.; Mantz, A. W.
2008-01-01
The impact of precise spectroscopic measurements on the P(9) multiplet in the v3 band of 12CH4, obtained using a newly developed cold Herriott cell coupled with a tunable diode laser spectrometer, is examined in the context of remote sensing of methane in the atmosphere. More specifically, the influence of the air-broadening temperature dependence, of line narrowing and of line-mixing effects is assessed when fitting high resolution atmospheric spectra recorded from a balloon in the solar occultation mode. This is achieved by considering residuals and retrieved methane volume mixing ratio profiles. By combining data from previous studies together with new measurements, the expression for the temperature dependence of the broadening coefficient has been revisited. It is shown that a correcting factor applied to the usual law gives better results, when considering all the available measurements from room temperature down to about 10-20 K, as compared to the usual expression of the width versus temperature. These results clearly demonstrate that collision broadening is more sensitive to long-range attractive forces when the temperature is decreased.
A general method to derive tissue parameters for Monte Carlo dose calculation with multi-energy CT
Lalonde, Arthur; Bouchard, Hugo
2016-11-01
To develop a general method for human tissue characterization with dual- and multi-energy CT and evaluate its performance in determining elemental compositions and quantities relevant to radiotherapy Monte Carlo dose calculation. Ideal materials to describe human tissue are obtained applying principal component analysis on elemental weight and density data available in literature. The theory is adapted to elemental composition for solving tissue information from CT data. A novel stoichiometric calibration method is integrated to the technique to make it suitable for a clinical environment. The performance of the method is compared with two techniques known in literature using theoretical CT data. In determining elemental weights with dual-energy CT, the method is shown to be systematically superior to the water-lipid-protein material decomposition and comparable to the parameterization technique. In determining proton stopping powers and energy absorption coefficients with dual-energy CT, the method generally shows better accuracy and unbiased results. The generality of the method is demonstrated simulating multi-energy CT data to show the potential to extract more information with multiple energies. The method proposed in this paper shows good performance to determine elemental compositions from dual-energy CT data and physical quantities relevant to radiotherapy dose calculation. The method is particularly suitable for Monte Carlo calculations and shows promise in using more than two energies to characterize human tissue with CT.
A general method to derive tissue parameters for Monte Carlo dose calculation with multi-energy CT.
Lalonde, Arthur; Bouchard, Hugo
2016-11-21
To develop a general method for human tissue characterization with dual- and multi-energy CT and evaluate its performance in determining elemental compositions and quantities relevant to radiotherapy Monte Carlo dose calculation. Ideal materials to describe human tissue are obtained applying principal component analysis on elemental weight and density data available in literature. The theory is adapted to elemental composition for solving tissue information from CT data. A novel stoichiometric calibration method is integrated to the technique to make it suitable for a clinical environment. The performance of the method is compared with two techniques known in literature using theoretical CT data. In determining elemental weights with dual-energy CT, the method is shown to be systematically superior to the water-lipid-protein material decomposition and comparable to the parameterization technique. In determining proton stopping powers and energy absorption coefficients with dual-energy CT, the method generally shows better accuracy and unbiased results. The generality of the method is demonstrated simulating multi-energy CT data to show the potential to extract more information with multiple energies. The method proposed in this paper shows good performance to determine elemental compositions from dual-energy CT data and physical quantities relevant to radiotherapy dose calculation. The method is particularly suitable for Monte Carlo calculations and shows promise in using more than two energies to characterize human tissue with CT.
Active Remote Sensing of Ocean Parameters, AN Engineering Study.
Byrne, James Dennis
A study is made of a proposed method to measure the sound velocity, turbidity, and calculate the temperature as a function of depth in the ocean. A laser is used to generate a beam of light which is scattered by the sea. Brillouin scattering causes shifts of the wavelength of the incident laser light by an amount proportional to the sound velocity in the sea. Several instrumental designs for measuring this shift are considered. Fabry-Perot interferometers were chosen for use in prototype instruments. Initial laboratory experiments are described. A field experiment with a single Fabry-Perot used photographically and photoelectrically is described. This field experiment achieved what we believe to be the first measurement of the Brillouin effect in seawater under field conditions. A new double Fabry-Perot instrument was designed which could be adapted to a lidar system. If a value for the salinity is assumed, the instrument can be used to determine temperature. The performance of this system as a temperature transducer was tested in the laboratory. Using ten second observations temperature was measured with an rms estimate of error of 0.4(DEGREES)C in fresh water. Sound velocity measurement accuracy is estimated at better than 0.1% m/sec over the range of temperatures which were measured. Using modern interferometers and a more powerful laser this result could be greatly improved. Recommendations and cost estimates for a future instrument are included. Auxiliary methods which could allow the unambiguous computation of temperature and salinity from sound velocity data are discussed in Appendix one.
Pre-segmented 2-Step IMRT with subsequent direct machine parameter optimisation – a planning study
Directory of Open Access Journals (Sweden)
Flentje Michael
2008-11-01
Full Text Available Abstract Background 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. Methods 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. Results 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. Conclusion 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.
Institute of Scientific and Technical Information of China (English)
赵旭; 程维虎; 李婧兰
2012-01-01
The generalized Pareto distribution (GPD) is one of the most important distribution in statistics analysis that has been widely used in finance, insurance, hydrology and meteorology applications and so on. While traditional estimation methods, such as maximum likelihood (ML), methods of moments (MOM) and probability weighted moments (PWM) methods have been extensively applied, the use of these methods are often restricted. Alternative approaches (e.g., generalized probability weighted moments, L-moments and LH-moments) exist but they use complete or non-censored samples. However, censored samples are often encountered in hydrology and meteorology fields. In this article, we propose a computationally easy method from censored data for fitting the GPD, which is resistant against extremely small or large outliers, I.e., they will be robust with the lower and upper breakdown points. This method is based on probability weighted moments. Firstly, we solve shape parameter estimator which has high estimated precision, then the location and scale parameters are given for the GPD. Simulation studies show that the proposed method performs well compared to traditional techniques.%广义Pareto分布(GPD)是统计分析中一个极为重要的分布,被广泛应用于金融、保险、水文及气象等领域.传统的参数估计方法如极大似然估计、矩估计及概率加权矩估计方法等已被广泛应用,但使用中存在一定的局限性.虽然提出很多改进方法如广义概率加权矩估计、L矩和LH矩法等,但都是研究完全样本的估计问题,而在水文及气象等应用领域常出现截尾样本.本文基于概率加权矩理论,利用截尾样本对三参数GPD提出一种应用范围广且简单易行的参数估计方法,可有效减弱异常值的影响.首先求解出具有较高精度的形状参数的参数估计,其次得出位置参数及尺度参数的参数估计.通过Monte Carlo模拟说明该方法估计精度较高.
Verma, Ashok K.; Margot, Jean-Luc; Greenberg, Adam H.
2017-08-01
We evaluated the prospects of quantifying the parameterized post-Newtonian parameter β and solar quadrupole moment {J}2⊙ with observations of near-Earth asteroids with large orbital precession rates (9 to 27 arcsec century-1). We considered existing optical and radar astrometry, as well as radar astrometry that can realistically be obtained with the Arecibo planetary radar in the next five years. Our sensitivity calculations relied on a traditional covariance analysis and Monte Carlo simulations. We found that independent estimates of β and {J}2⊙ can be obtained with precisions of 6 × 10-4 and 3 × 10-8, respectively. Because we assumed rather conservative observational uncertainties, as is the usual practice when reporting radar astrometry, it is likely that the actual precision will be closer to 2 × 10-4 and 10-8, respectively. A purely dynamical determination of solar oblateness with asteroid radar astronomy may therefore rival the helioseismology determination.
Study design, participation and characteristics of The Danish General Suburban Population Study
DEFF Research Database (Denmark)
Bergholdt, Helle Kirstine Mørup; Bathum, Lise; Kvetny, Jan
2013-01-01
The aim of this article was to describe the study design, participants and baseline characteristics of The Danish General Suburban Population Study (GESUS) and to compare suburban participants with age- and gender-matched urban participants from the Copenhagen General Population Study (CGPS)....
Study design, participation and characteristics of The Danish General Suburban Population Study
DEFF Research Database (Denmark)
Bergholdt, Helle Kirstine Mørup; Bathum, Lise; Kvetny, Jan;
2013-01-01
The aim of this article was to describe the study design, participants and baseline characteristics of The Danish General Suburban Population Study (GESUS) and to compare suburban participants with age- and gender-matched urban participants from the Copenhagen General Population Study (CGPS)....
Study design, participation and characteristics of the Danish General Suburban Population Study
DEFF Research Database (Denmark)
Bergholdt, Helle Kirstine Mørup; Kvetny, Jan; Rasmussen, Dorthe;
2013-01-01
The aim of this article was to describe the study design, participants and baseline characteristics of The Danish General Suburban Population Study (GESUS) and to compare suburban participants with age- and gender-matched urban participants from the Copenhagen General Population Study (CGPS)....
Directory of Open Access Journals (Sweden)
Solomon Olakunle Bilewu
2015-09-01
Full Text Available Hydrological models are very useful for predictions in many ungauged basins across the world. There are many hydrological models available for discharge data generation with different complexities and varied input parameter requirements. Studies have shown that models with many input parameters do not necessarily perform better than those with few input parameters. Basin morphometric parameters play significant roles in the conversion of rainfall to runoff and obtaining good estimates of these parameters for use in runoff models is sometime challenging as Inaccurate input into models can propagate errors and make the models to perform poorly. This study employs the method of principal component analysis to reduce the number of morphometric parameters required to run a runoff model without losing any major information. Parameters for five selected study basins in central Nigeria were measured and analysed. The result shows that three morphometric parameters (Fitness Ratio, Ruggedness Number and Watershed Eccentricity can adequately represent other parameters as an input into a runoff model for the basins. This reduces significantly the time and effort needed to compute all the parameters which in actual fact may not improve the quality or efficiency of the runoff model.
Energy Technology Data Exchange (ETDEWEB)
Wurster, R. [L-B-Systemtechnik GmbH (Germany)
2003-07-01
L-B Systemtechnik GmbH carried out this study on behalf of General Motors and in co-operation with BP, Exxon, Shell and Total. The study is available on the web as http://www.lbst.de/gm-wtw for downloading. This contribution presents current results, which are compared with other recent findings (e.g. the MIT study by Weiss et al. and the publication of Bossel/Elliasson). The marketing potentials of motor fuels from renewable energy sources (natural gas, Fischer-Tropsch diesel fuel, ethanol, methanol, RME, pressurised and liquid hydrogen) is compared. The contribution also presents fuel cost (Euro/a and Euro/km)for these fuels and drives. The data are derived from the LBST E2 database. [German] Die L-B-Systemtechnik GmbH (LBST) hat in 2001/2002 im Auftrag von General Motors und in Kooperation mit BP, Exxon, Shell und Total eine umfangreiche Well-to-Whell Studie fuer den technologischen Stand von 2010 durchgefuehrt. Die gesamte LBST/GM-Studie ist unter http://www.lbst.de/gm-wtw im Internet als PDF-Dokumente zum Herunterladen verfuegbar. Auf Basis dieser Untersuchung und im Vergleich zu anderen in Diskussion befindlichen neueren Arbeiten (z.B. MIT-Studie von Weiss et al., Bossel/Elliasson Papier) werden aktuelle Ergebnisse praesentiert und ableitbare Folgen fuer die Einfuehrung von Wasserstoff als Kraftstoff fuer Strassenfahrzeuge praesentiert und diskutiert. Es sollen auch die prinzipiell realisierbaren Marktpotentiale der verschiedenen verglichenenen Fahrzeugkraftstoffe (Erdgas, Fischer-Tropsch-Diesel, Ethanol, Methanol, RME, Druck- und Fluessigwasserstoff) auf Basis erneuerbarer Energiepotenziale in Europa vergleichend dargestellt werden. Nicht in der Studie untersuchte Kraftstoffkosten (Euro/MJ und Euro/km) fuer die praesentierten Kraftstoffpfade und Fahrzeugantriebe auf der Basis der LBST E2 database werden ebenfalls praesentiert. (orig.)
Institute of Scientific and Technical Information of China (English)
冷永刚; 赖志慧
2014-01-01
The stochastic resonance (SR) of two-dimensional Duffing oscillator is studied in this paper. We propose the generalized parameter-adjustment SR of Duffing oscillator. On the basis of Kramers rate, we build a discrimination function of the SR of Duffing oscillator, and we expound the generalized parameter-adjustment SR laws of Duffing oscil-lator under different noise intensity and signal frequency conditions. The general method of generating the generalized parameter-adjustment SR of Duffing oscillator is also given in this paper.%以二维Duffing振子的随机共振为研究对象，提出Duffing振子的广义调参随机共振。以Kramers逃逸速率为基础，建立了Duffing振子随机共振的判别函数，阐述了Duffing振子在不同噪声强度及信号频率输入条件下的广义调参随机共振规律，并给出了Duffing振子广义调参随机共振的一般方法。
Comparative study of the growth parameters of legumes grown in fipronil-stressed soils
Directory of Open Access Journals (Sweden)
Munees Ahemad
2011-06-01
Full Text Available In modern agronomy, insecticides of the diverse chemical families are repeatedly used to control various plant growth limiting insect pests and to improve plant productivity. However, the intensive application of these plant protecting agrochemicals results in their accumulation in soils in substantial concentration and deteriorates the soil fertility. Previous studies concerning the effect of insecticides are commonly confined to a specific legume and reports about the concurrent impact of any specific insecticide on more than one legume in parallel are rare. The present study was therefore, designed to assess the effect of insecticide fipronil simultaneously on common food legumes (chickpea, pea, lentil and green gram. In this study, fipronil displayed a varying degree of toxicity to the tested legumes. The highest toxicity of fipronil was observed in the shoot dry biomass, leghaemoglobin and chlorophyll content, and the seed protein in chickpea, nodule numbers and nodule biomass in pea, root dry biomass and shoot N in green gram, and nodule biomass, root N, root P, shoot P, and seed yield in lentil. Generally, the most toxic effect of fipronil was observed on the growth parameters of lentil plants.
Cardiovascular morbidity in COPD: A study of the general population
DEFF Research Database (Denmark)
Lange, Peter; Møgelvang, Rasmus; Marott, Jacob Louis
2010-01-01
ventricular ejection fraction (LVEF) are sparse. We used data from the 4th examination of The Copenhagen City Heart Study, which comprises 5,890 individuals with data on pulmonary and cardiac symptoms, risk factors for cardiovascular diseases, pulmonary function tests, ECG and relevant medical history. Among.......4% for moderate COPD (GOLD stage 2) and 2.5% for severe and very severe COPD (GOLD stages 3+4). Individuals with COPD were older and had a higher prevalence of cardiovascular risk factors and a higher prevalence of cardiovascular diseases. Among the echocardiographical findings, only the presence of left...... ventricular hyperthrophy was significantly more frequent among individuals with COPD (17.7%) than among participants without COPD (12.1%.), yet this relationship was no longer significant after statistical adjustment for age and gender. In the general population, subjects with COPD have a higher prevalence...
Studies of insulin resistance in congenital generalized lipodystrophy
DEFF Research Database (Denmark)
Søvik, O; Vestergaard, H; Trygstad, O
1996-01-01
suppressed lipid oxidation in the controls. It is concluded that patients with congenital generalized lipodystrophy may present severe insulin resistance with regard to hepatic glucose production as well as muscle glycogen synthesis and lipid oxidation. The results suggest a postreceptor defect in the action......, immunoreactive protein and mRNA levels. The patients had fasting hyperinsulinaemia, and the rate of total glucose disposal was severely impaired, primarily due to a decreased non-oxidative glucose metabolism. In the patient studied with muscle biopsy, the expected activation of glycogen synthase by insulin did...... not occur. In both patients there was severely increased hepatic glucose output in the basal state, suggesting a failure of insulin to suppress hepatic gluconeogenesis. During insulin infusion a substantially elevated rate of lipid oxidation remained in the patients, in contrast to the almost completely...
General Study of Perturbations in Bouncing and Cyclic Models
Mayes, Riley; Biswas, Tirthabir; Lattyak, Colleen
2015-04-01
Perturbations are important in both understanding and evaluating the importance of bounces and turnarounds in models that predict a cyclic evolution of our Universe. Moreover, tracking these perturbations through the entirety of the cycle is important as it provides an outlet for a qualitative comparison with Cosmic Microwave Background (CMB) observations. However, tracking these perturbations through each cycle proves difficult as the physics to describe bounces and turnarounds is not well established. Therefore, we first studied general anaytical and numerical techniques in order to understand the evolution of fluctuations in simple cosmological models where physics is better understood. In our research, we first developed analytical techniques from background solutions to establish a solid foundation for describing super-Hubble fluctuations in our early Universe. These analytical solutions were developed for both bounces and turnarounds allowing us to numerically verify and then further investigate the consequences of these solutions in models such as bounce inflation and cyclic inflation.
Institute of Scientific and Technical Information of China (English)
GUO Huiping; LIU Xueguan; YIN Hongcheng; CHAO Zengming; HUANG Peikang
2005-01-01
The study of constraints on the constitutive relationships of electromagnetic media is of great importance in the aspects of the medium characteristics analysis, the new article material synthesis and the medium parameters reconstruction, etc. According to the fact that the constitutive relationships should not conflict with the general physical laws, the constraints that the constitutive relationships of electromagnetic medium must satisfy have been summarized in this paper. These constraints include determinacy principle, objectivity principle, causality principle and permission principle. And the parameter constraints of the arbitrary linear homogenous time-invariant medium are obtained following the minimum energy consumption principle. This work provides a new way of ascertaining the constitutive relationships of the electromagnetic medium.
Bureau of Employment Security (DOL), Washington, DC.
THE POSSIBILITY OF PREDICTIVE ERROR WHEN APPLYING U.S. MAINLAND NORMS FOR THE GENERAL APTITUDE TEST BATTERY TO THE EMPLOYMENT COUNSELING AND SELECTION PROCESS IN PUERTO RICO, PROMPTED A STUDY TO ESTABLISH LOCAL NORMS FOR THE SPANISH LANGUAGE VERSION, BATERIA GENERAL DE PRUEBAS DE APTITUD. A STRATIFIED QUOTA SAMPLE OF 1,500 PERSONS WAS SELECTED…
Parameter estimation in chemical engineering ; a case study for resin production
Stortelder, W.J.H.
1996-01-01
In this report we present a study on parameter estimation in the field of resin production. The mathematical model of the chemical process contains a set of 12 differential algebraic equations (DAEs) and 16 unknown parameters; 8 series of measurements are available, performed under different initial
Study on plasma parameters and dust charging in an electrostatically plugged multicusp plasma device
Kakati, B.; Kausik, S. S.; Saikia, B. K.; Bandyopadhyay, M.
2011-06-01
The effect of the electrostatic confinement potential on the charging of dust grains and its relationship with the plasma parameters has been studied in an electrostatically plugged multicusp dusty plasma device. Electrostatic plugging is implemented by biasing the electrically isolated magnetic multicusp channel walls. The experimental results show that voltage applied to the channel walls can be a controlling parameter for dust charging.
Chakraborty, Debananda
2011-01-01
We consider the Klein-Gordon and sine-Gordon type equations with a point-like potential, which describes the wave phenomenon in disordered media with a defect. The singular potential term yields a critical phenomenon--that is, the solution behavior around the critical parameter value bifurcates into two extreme cases. Pinpointing the critical value with arbitrary accuracy is even more challenging. In this work, we adopt the generalized polynomial chaos (gPC) method to determine the critical values and the mean solutions around such values. First, we consider the critical value associated with the strength of the singular potential for the Klein-Gordon equation. We expand the solution in the random variable associated with the parameter. The obtained partial differential equations are solved using the Chebyshev collocation method. Due to the existence of the singularity, the Gibbs phenomenon appears in the solution, yielding a slow convergence of the numerically computed critical value. To deal with the singul...
Tanito, Masaki; Nitta, Koji; Katai, Maki; Kitaoka, Yasushi; Yokoyama, Yu; Omodaka, Kazuko; Nakazawa, Toru
2017-01-01
The Glaucoma Stereo Analysis Study (GSAS) is a multicenter collaborative study of the characteristics of glaucomatous optic disc morphology using a stereo fundus camera. Using GSAS dataset, the formulas for predicting different glaucomatous optic disc appearances were established. The GSAS dataset containing three-dimensionally-analyzed optic disc topographic parameters from 187 eyes with primary open-angle glaucoma was assessed with discrimination analyses to obtain formulas predictive of glaucomatous optic disc appearances: focal ischemic (FI); generalized enlargement (GE), myopic glaucomatous (MY), and senile sclerotic (SS). Using 38 optic disc parameters-substituted discrimination analyses with a stepwise forward-selection method, six parameters (temporal and nasal rim-disc ratios, mean cup depth, height variation contour, disc tilt angle, and rim decentering absolute) were selected into the formulas. The area under the receiver operating characteristic curves for predicting the four disc types with established formulas were 0.88, 0.91, 0.93, and 0.86 for FI, MY, SS, and GE, respectively. Age, visual acuity, refractive error, glaucoma (normal or high-tension glaucoma), and baseline intraocular pressure differed significantly among the four optic disc types, suggesting the appearances represent different clinical glaucoma phenotypes. Using six optic disc topographic parameters obtained by stereo fundus camera, the GSAS classification formulas predicted and quantified each component of different optic disc appearances in each eye and provided a novel parameter to describe glaucomatous optic disc characteristics. PMID:28178303
Study of polytropes with Generalized polytropic Equation of State
Azam, M; Noreen, I; Rehman, M A
2016-01-01
The aim of this paper is to discuss the theory of Newtonian and relativistic polytropes with generalized polytropic equation of state. For this purpose, we formulated the general framework to discuss the physical properties of polytrops with anisotropic inner fluid distribution under conformally flat condition in the presence of charge. We investigate the stability of these polytrops in the vicinity of generalized polytropic equation through Tolman-mass. It is concluded that one of the derived models is physically acceptable.
Study of polytropes with generalized polytropic equation of state
Azam, M.; Mardan, S. A.; Noureen, I.; Rehman, M. A.
2016-06-01
The aim of this paper is to discuss the theory of Newtonian and relativistic polytropes with a generalized polytropic equation of state. For this purpose, we formulated the general framework to discuss the physical properties of polytropes with an anisotropic inner fluid distribution under conformally flat condition in the presence of charge. We investigate the stability of these polytropes in the vicinity of a generalized polytropic equation through the Tolman mass. It is concluded that one of the derived models is physically acceptable.
Shigehara, T; Mishima, T; Cheon, T; Cheon, Taksu
1999-01-01
We propose a new method to construct a four parameter family of quantum-mechanical point interactions in one dimension, which is known as all possible self-adjoint extensions of the symmetric operator $T=-\\Delta \\lceil C^{\\infty}_{0}({\\bf R} \\backslash\\{0\\})$. It is achieved in the small distance limit of equally spaced three neighboring Dirac's $\\delta$ potentials. The strength for each $\\delta$ is appropriately renormalized according to the distance and it diverges, in general, in the small distance limit. The validity of our method is ensured by numerical calculations. In general cases except for usual $\\delta$, the wave function discontinuity appears around the interaction and one can observe such a tendency even at a finite distance level.
[Deafness in adults. Study of practices in general medicine].
Leveque, P; Kossowski, M; Pons, Y
2012-01-01
Deafness is a sensory disability responsible for communication disorder, sometimes impairing social life. In children, the hearing is an important concern for all stakeholders in early childhood (systematic neonatal screening, etc.). On the other hand, in the adult, it is rarely tested, and patients do consult when their audiometric status is already badly impaired. But their care is all the better if the deafness diagnosis is made early, as for the audio-prosthetic rehabilitation for example. Today, the general practitioner is the first link of the diagnostic and therapeutic management chain. The objective of this study was to evaluate the diagnostic practices of practitioners in front of deafness in adults. This prospective study included 74 practitioners based in "Ile de France" interviewed using a multiple choice questionnaire (MCQ) on otoscopic and audiometric diagnostics and a Script Concordance test (SC) on clinical adult deafness situations validated by a 5 experts panel. The obtained average score was 66.35% of correct answers to the MCQ and 47.76% to the SC. In our study, the surveyed practitioners showed a good level of otoscopic and audiometric diagnosis in the MCQ. However, their answers were not concordant with those of the expert panel in the SC. They have been particularly poorly performing on issues related to functional signs and their use in a given clinical situation, often driving to establish an otoscopic misdiagnosis while their diagnostic recognition of a pathological eardrum in the MCQ was rather good. These results reflect a lack of confidence in their otoscopic diagnosis related to the lack of knowledge of the causes of deafness in adults and their symptoms.
Sharma, Surendra P.; Huo, Winifred M.; Park, Chul
1988-01-01
A theoretical study of vibrational excitations and dissociations of nitrogen undergoing a nonequilibrium relaxation process upon heating and cooling is reported. The rate coefficients for collisional induced vibrational transitions and transitions from a bound vibrational state into a dissociative state have been calculated using an extension of the theory originally proposed by Schwarz (SSH) et al. (1952). High-lying vibrational states and dissociative states were explicitly included but rotational energy transfer was neglected. The transition probabilities calculated from the SSH theory were fed into the master equation, which was integrated numerically to determine the population distribution of the vibrational states as well as bulk thermodynamic properties. The results show that: (1) the transition rates have a minimum near the middle of the bound vibrational levels, causing a bottleneck in the vibrational relaxation and dissociation rates; (2) high vibrational states are always in equilibrium with the dissociative state; (3) for the heating case, only the low vibrational states relax according to the Landau-Teller theory; (4) for the cooling case, vibrational relaxation cannot be described by a rate equation; (5) Park's (1985, 1988) two-temperature model is approximately valid; and (6) the average vibrational energy removed in dissociation is about 30 percent of the dissociation energy.
Zang, Xizhe; Liu, Xinyu; Zhu, Yanhe; Zhao, Jie
2016-04-29
The study of human walking patterns mainly focuses on how control affects walking because control schemes are considered to be dominant in human walking. This study proposes that not only fine control schemes but also optimized body segment parameters are responsible for humans' low-energy walking. A passive dynamic walker provides the possibility of analyzing the effect of parameters on walking efficiency because of its ability to walk without any control. Thus, a passive dynamic walking model with a relatively human-like structure was built, and a parameter optimization process based on the gait sensitivity norm was implemented to determine the optimal mechanical parameters by numerical simulation. The results were close to human body parameters, thus indicating that humans can walk under a passive pattern based on their body segment parameters. A quasi-passive walking prototype was built on the basis of the optimization results. Experiments showed that a passive robot with optimized parameters could walk on level ground with only a simple hip actuation. This result implies that humans can walk under a passive pattern based on their body segment parameters with only simple control strategy implying that humans can opt to walk instinctively under a passive pattern.
Li, Taoran; Wu, Qiuwen; Zhang, You; Vergalasova, Irina; Lee, W Robert; Yin, Fang-Fang; Wu, Q Jackie
2013-11-01
Adaptive radiation therapy for prostate cancer using online reoptimization provides an improved control of interfractional anatomy variations. However, the clinical implementation of online reoptimization is currently limited by the low efficiency of current strategies and the difficulties associated with integration into the current treatment planning system. This study investigates the strategies for performing fast (~2 min) automatic online reoptimization with a clinical fluence-map-based treatment planning system; and explores the performance with different input parameters settings: dose-volume histogram (DVH) objective settings, starting stage, and iteration number (in the context of real time planning). Simulated treatments of 10 patients were reoptimized daily for the first week of treatment (5 fractions) using 12 different combinations of optimization strategies. Options for objective settings included guideline-based RTOG objectives, patient-specific objectives based on anatomy on the planning CT, and daily-CBCT anatomy-based objectives adapted from planning CT objectives. Options for starting stages involved starting reoptimization with and without the original plan's fluence map. Options for iteration numbers were 50 and 100. The adapted plans were then analyzed by statistical modeling, and compared both in terms of dosimetry and delivery efficiency. All online reoptimized plans were finished within ~2 min with excellent coverage and conformity to the daily target. The three input parameters, i.e., DVH objectives, starting stage, and iteration number, contributed to the outcome of optimization nearly independently. Patient-specific objectives generally provided better OAR sparing compared to guideline-based objectives. The benefit in high-dose sparing from incorporating daily anatomy into objective settings was positively correlated with the relative change in OAR volumes from planning CT to daily CBCT. The use of the original plan fluence map as the
Energy Technology Data Exchange (ETDEWEB)
Li, Taoran; Wu, Qiuwen; Zhang, You; Vergalasova, Irina; Lee, W. Robert; Yin, Fang-Fang; Wu, Q. Jackie [Duke Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)
2013-11-15
Purpose: Adaptive radiation therapy for prostate cancer using online reoptimization provides an improved control of interfractional anatomy variations. However, the clinical implementation of online reoptimization is currently limited by the low efficiency of current strategies and the difficulties associated with integration into the current treatment planning system. This study investigates the strategies for performing fast (∼2 min) automatic online reoptimization with a clinical fluence-map-based treatment planning system; and explores the performance with different input parameters settings: dose-volume histogram (DVH) objective settings, starting stage, and iteration number (in the context of real time planning).Methods: Simulated treatments of 10 patients were reoptimized daily for the first week of treatment (5 fractions) using 12 different combinations of optimization strategies. Options for objective settings included guideline-based RTOG objectives, patient-specific objectives based on anatomy on the planning CT, and daily-CBCT anatomy-based objectives adapted from planning CT objectives. Options for starting stages involved starting reoptimization with and without the original plan's fluence map. Options for iteration numbers were 50 and 100. The adapted plans were then analyzed by statistical modeling, and compared both in terms of dosimetry and delivery efficiency.Results: All online reoptimized plans were finished within ∼2 min with excellent coverage and conformity to the daily target. The three input parameters, i.e., DVH objectives, starting stage, and iteration number, contributed to the outcome of optimization nearly independently. Patient-specific objectives generally provided better OAR sparing compared to guideline-based objectives. The benefit in high-dose sparing from incorporating daily anatomy into objective settings was positively correlated with the relative change in OAR volumes from planning CT to daily CBCT. The use of the
Institute of Scientific and Technical Information of China (English)
LI Jun-Ling; GU Jun; QIU Guang-Min
2006-01-01
Quantum chemical parameters of 10 amino acids with D- and L-configurations were firstly calculated with semi-empirical AM1 method. Furthermore, the relationship between mole- cular structures of D-, L-amino acids and their sweetness were observed. The results show that upon different configurations of amino acids, the sweetness is relative with their formation heat, dipole moment, energy gap of frontier orbital and other parameters. The formation heats of the same amino acids possessing D- and L-configurations are different except glycine. The algebraic value of D- amino acid is generally larger than that of corresponding L-configuration with only one except of tyrosine. The dipole moment of D-amino acid is generally larger than that of corresponding L-amino acid except tyrosine and lysine. The lowest unoccupied orbital energy (ELUMO) of D-amino acid is higher than that of corresponding L-configuration except phenylalanine. △E of D-amino acid is larger than that of L-amino acid except histidine, phenylalanine and lysine. The larger gap will have advantage for its matching with frontier orbital energy of human protein acceptor, which strengthens the interaction between D-amino acid and sweet taste acceptor. Besides, the changing rules of these parameters are generally identical.
A General Approach to Study the Reliability of Complex Systems
Directory of Open Access Journals (Sweden)
G. M. Repici
2003-01-01
Full Text Available In recent years new complex systems have been developed in the automotive field to increase safety and comfort. These systems integrate hardware and software to guarantee the best results in vehicle handling and make products competitive on the market.However, the increase in technical details and the utilization and integration of these complicated systems require a high level of dynamic control system reliability. In order to improve this fundamental characteristic methods can be extracted from methods used in the aeronautical field to deal with reliability and these can be integrated into one simplified method for application in the automotive field.Firstly, as a case study, we decided to analyse VDC (the Vehicle Dynamics Control system by defining a possible approach to reliability techniques. A VDC Fault Tree Analysis represents the first step in this activity: FTA enables us to recognize the critical components in all possible working conditions of a car, including cranking, during 'key-on'-'key-off ' phases, which is particularly critical for the electrical on-board system (because of voltage reduction.By associating FA (Functional Analysis and FTA results with a good FFA (Functional Failure Analysis, it is possible to define the best architecture for the general system to achieve the aim of a high reliability structure.The paper will show some preliminary results from the application of this methodology, taken from various typical handling conditions from well established test procedures for vehicles.
A diachronic study of valency-changing categories. Guidelines and typological parameters
Kulikov, L.I.
2004-01-01
The paper opens with a general discussion of the regrettable of the synchronic and diachronic typological studies, due, in particular, to the lesser typological variety of data available for a historical linguistic research. As a general approach for a study of a given linguistic category (or
Energy Technology Data Exchange (ETDEWEB)
Papanicolaou, Fanos; Antoniou, Stella [Chemistry Department, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus); Pashalidis, Ioannis [Chemistry Department, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus)], E-mail: pspasch@ucy.ac.cy
2009-10-15
Phosphogypsum is a waste by-product of the phosphate fertilizer industry, which is usually disposed in the environment because of its restricted use in industrial applications. Physico-chemical conditions existing in stack fluids and leachates are of major importance and determine solubility and redox stability of phosphogypsum, as well as radionuclide release from stacks to terrestrial environments. The aim of this study is to assess the effect of key parameters (e.g. ionic strength, temperature, pH) on the solubility of phosphogypsum. Phosphogypsum sampling and in-situ measurements were carried out at a coastal stack in Cyprus, solubility experiments were performed in simulated laboratory systems and thermodynamic calculations by means of MINTEQA2, an equilibrium speciation model. Generally, increasing ionic strength and temperature leads to increased phosphogypsum solubility, with the former being much more effective. The increased solubility of phosphogypsum in saline solutions is attributed solely to ionic strength effects on the activity of ionic species in solution and no solid phase transformations could be observed. The effect of pH on phosphogypsum solubility seems to be insignificant at least in a pH range between 4 and 8. Regarding uranium levels, there is a strong correlation between salinity and uranium concentration and linear correlation between phosphogypsum solubility and uranium levels in stack solutions, indicating the incorporation of uranium into the gypsum lattice and the formation of a solid solution.
Papanicolaou, Fanos; Antoniou, Stella; Pashalidis, Ioannis
2009-10-01
Phosphogypsum is a waste by-product of the phosphate fertilizer industry, which is usually disposed in the environment because of its restricted use in industrial applications. Physico-chemical conditions existing in stack fluids and leachates are of major importance and determine solubility and redox stability of phosphogypsum, as well as radionuclide release from stacks to terrestrial environments. The aim of this study is to assess the effect of key parameters (e.g. ionic strength, temperature, pH) on the solubility of phosphogypsum. Phosphogypsum sampling and in-situ measurements were carried out at a coastal stack in Cyprus, solubility experiments were performed in simulated laboratory systems and thermodynamic calculations by means of MINTEQA2, an equilibrium speciation model. Generally, increasing ionic strength and temperature leads to increased phosphogypsum solubility, with the former being much more effective. The increased solubility of phosphogypsum in saline solutions is attributed solely to ionic strength effects on the activity of ionic species in solution and no solid phase transformations could be observed. The effect of pH on phosphogypsum solubility seems to be insignificant at least in a pH range between 4 and 8. Regarding uranium levels, there is a strong correlation between salinity and uranium concentration and linear correlation between phosphogypsum solubility and uranium levels in stack solutions, indicating the incorporation of uranium into the gypsum lattice and the formation of a solid solution.
Directory of Open Access Journals (Sweden)
Elaine Ferreira Lasaponari
2013-09-01
Full Text Available OBJECTIVE: to assess the efficiency of the Calatonia technique about clinical parameters and pain in the immediate post-surgical phase. METHOD: a randomised study was carried out with 116 patients subjected to a cholecystectomy, by laparoscopy, divided into an experimental group (58 patients and a placebo group (58 patients. The experimental group received the Calatonia technique, while the placebo was only subjected to non-intentional touches. RESULTS: The placebo group and the experimental group were considered homogeneous in terms of the variables: sex, age, physical status classification, duration of surgical procedures and also the time spent recovering in the Post-Anaesthetic Recovery Room. The only variable to show a statistically significant difference was the axillary temperature of the body. In relation to pain, the experimental group showed significant results, and hence it is possible to deduce that the relaxation caused by the Calatonia technique brought some relief of the general situation of pain. CONCLUSION: The application of Calatonia can take up the function of a resource complementary to assistance in the period immediately after surgery. Brazilian Register of Clinical Trials, UTN U1111-1129-9629.
Study of polytropes with generalized polytropic equation of state
Energy Technology Data Exchange (ETDEWEB)
Azam, M. [University of Education, Division of Science and Technology, Lahore (Pakistan); Mardan, S.A.; Noureen, I.; Rehman, M.A. [University of the Management and Technology, Department of Mathematics, Lahore (Pakistan)
2016-06-15
The aim of this paper is to discuss the theory of Newtonian and relativistic polytropes with a generalized polytropic equation of state. For this purpose, we formulated the general framework to discuss the physical properties of polytropes with an anisotropic inner fluid distribution under conformally flat condition in the presence of charge. We investigate the stability of these polytropes in the vicinity of a generalized polytropic equation through the Tolman mass. It is concluded that one of the derived models is physically acceptable. (orig.)
Directory of Open Access Journals (Sweden)
Prasad
2014-02-01
Full Text Available INTRODUCTION: Combining minimal invasive surgical and lesser invasive anesthesia technique reduces morbidity and mortality. The aim of the study is to compare spinal anesthesia with the gold standard general anesthesia for elective laparoscopic cholecystectomy. MATERIALS & METHODS: 60 healthy patients were randomized under spinal anesthesia (n=30 & General Anesthesia (n=30 . Hyperbaric 3ml bupivacaine plus 25mcg fenta nyl was administered for spinal group and conventional general anesthesia for GA group. Intraoperative parameters and post - operative pain and recovery were noted. Under spinal group any intraoperative discomfort were taken care by reassurance , drugs or con verted to GA. Questionnaire forms were provided for patients and surgeons to comment about the operation. RESULTS: None of the patients had significant hemodynamic and respiratory disturbance except for transient hypotension and bradycardia. Operative time was comparable. 6patients under spinal anesthesia had right shoulder pain , 2 patients were converted to GA and 4 patients were managed by injection midazolam and infiltration of lignocaine over the diaphragm. There was significant post - operative pain reli ef in spinal group. All the patients were comfortable and surgeons satisfied. CONCLUSION: Spinal anesthesia is adequate and safe for laparoscopic cholecystectomy in otherwise healthy patients and offers better postoperative pain control than general anesth esia without limiting recovery , but require cooperative patient , skilled surgeon , a gentle surgical technique and an enthusiastic anesthesiologist
Cui, Yunfeng; Bai, Jing
2005-01-01
Liver kinetic study of [18F]2-fluoro-2-deoxy-D-glucose (FDG) metabolism in human body is an important tool for functional modeling and glucose metabolic rate estimation. In general, the arterial blood time-activity curve (TAC) and the tissue TAC are required as the input and output functions for the kinetic model. For liver study, however, the arterial-input may be not consistent with the actual model input because the liver has a dual blood supply from the hepatic artery (HA) and the portal vein (PV) to the liver. In this study, the result of model parameter estimation using dual-input function is compared with that using arterial-input function. First, a dynamic positron emission tomography (PET) experiment is performed after injection of FDG into the human body. The TACs of aortic blood, PV blood, and five regions of interest (ROIs) in liver are obtained from the PET image. Then, the dual-input curve is generated by calculating weighted sum of both the arterial and PV input curves. Finally, the five liver ROIs' kinetic parameters are estimated with arterial-input and dual-input functions respectively. The results indicate that the two methods provide different parameter estimations and the dual-input function may lead to more accurate parameter estimation.
The Study of the Optimal Parameter Settings in a Hospital Supply Chain System in Taiwan
Directory of Open Access Journals (Sweden)
Hung-Chang Liao
2014-01-01
Full Text Available This study proposed the optimal parameter settings for the hospital supply chain system (HSCS when either the total system cost (TSC or patient safety level (PSL (or both simultaneously was considered as the measure of the HSCS’s performance. Four parameters were considered in the HSCS: safety stock, maximum inventory level, transportation capacity, and the reliability of the HSCS. A full-factor experimental design was used to simulate an HSCS for the purpose of collecting data. The response surface method (RSM was used to construct the regression model, and a genetic algorithm (GA was applied to obtain the optimal parameter settings for the HSCS. The results show that the best method of obtaining the optimal parameter settings for the HSCS is the simultaneous consideration of both the TSC and the PSL to measure performance. Also, the results of sensitivity analysis based on the optimal parameter settings were used to derive adjustable strategies for the decision-makers.
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Kurosu, Keita [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); Department of Radiology, Osaka University Hospital, 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. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Department of Radiation Oncology, St. Jude Children’s Research Hospital, Memphis, TN 38105 (United States)
2016-01-15
Spot scanning, owing to its superior dose-shaping capability, provides unsurpassed dose conformity, in particular for complex targets. However, the robustness of the delivered dose distribution and prescription has to be verified. Monte Carlo (MC) simulation has the potential to generate significant advantages for high-precise particle therapy, especially for medium containing inhomogeneities. However, the inherent choice of computational parameters in MC simulation codes of GATE, PHITS and FLUKA that is observed for uniform scanning proton beam needs to be evaluated. This means that the relationship between the effect of input parameters and the calculation results should be carefully scrutinized. The objective of this study was, therefore, to determine the optimal parameters for the spot scanning proton beam for both GATE and PHITS codes by using data from FLUKA simulation as a reference. The proton beam scanning system of the Indiana University Health Proton Therapy Center was modeled in FLUKA, and the geometry was subsequently and identically transferred to GATE and PHITS. Although the beam transport is managed by spot scanning system, the spot location is always set at the center of a water phantom of 600 × 600 × 300 mm{sup 3}, which is placed after the treatment nozzle. The percentage depth dose (PDD) is computed along the central axis using 0.5 × 0.5 × 0.5 mm{sup 3} voxels in the water phantom. The PDDs and the proton ranges obtained with several computational parameters are then compared to those of FLUKA, and optimal parameters are determined from the accuracy of the proton range, suppressed dose deviation, and computational time minimization. Our results indicate that the optimized parameters are different from those for uniform scanning, suggesting that the gold standard for setting computational parameters for any proton therapy application cannot be determined consistently since the impact of setting parameters depends on the proton irradiation
Picozzi, M.; Oth, A.; Parolai, S.; Bindi, D.; De Landro, G.; Amoroso, O.
2017-05-01
The accurate determination of stress drop, seismic efficiency, and how source parameters scale with earthquake size is an important issue for seismic hazard assessment of induced seismicity. We propose an improved nonparametric, data-driven strategy suitable for monitoring induced seismicity, which combines the generalized inversion technique together with genetic algorithms. In the first step of the analysis the generalized inversion technique allows for an effective correction of waveforms for attenuation and site contributions. Then, the retrieved source spectra are inverted by a nonlinear sensitivity-driven inversion scheme that allows accurate estimation of source parameters. We therefore investigate the earthquake source characteristics of 633 induced earthquakes (Mw 2-3.8) recorded at The Geysers geothermal field (California) by a dense seismic network (i.e., 32 stations, more than 17.000 velocity records). We find a nonself-similar behavior, empirical source spectra that require an ωγ source model with γ > 2 to be well fit and small radiation efficiency ηSW. All these findings suggest different dynamic rupture processes for smaller and larger earthquakes and that the proportion of high-frequency energy radiation and the amount of energy required to overcome the friction or for the creation of new fractures surface changes with earthquake size. Furthermore, we observe also two distinct families of events with peculiar source parameters that in one case suggests the reactivation of deep structures linked to the regional tectonics, while in the other supports the idea of an important role of steeply dipping faults in the fluid pressure diffusion.
Study on virtual redundancy among process parameters for accident management applications
Energy Technology Data Exchange (ETDEWEB)
Ahmed, Rizwan; Pak, Sukyoung; Heo, Gyunyoung [Kyung Hee Univ., Yongin (Korea, Republic of); Kim, Jungtaek; Park, Soo Yong; Ahn, Kwangil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2013-05-15
The research at this point can be divided into three streams, focused on the development of self powered sensors and instrumentation, developing intelligent systems that can diagnose and accident type and developing indirect ways that is, methods to assess the safety critical parameters from other statistically related parameters. This first approach is quite expensive, second approach suffers from the limitation that infinite number of accident scenarios cannot be simulated. However, the only way to access the parameters during severe accidents is through simulation codes. Even-though, the process parameters data contain uncertainty, this is the only thing to start with severe accident management. International Nuclear Energy Research Initiative (Inert) project has started research to address various aspects of safety management during severe accidents. As a part of Inert team, we are investigating correlations among process parameters in such a way that safety critical information could be secured by means of other non-safety or virtual parameters during a severe accident. This is known as virtual redundancy of information. This will improve the availability of information in case one channel for information is lost. In this paper, we will discuss methodology, preliminary results and directions for further study. We found that several process parameters exhibit distinct variation pattern for a particular accident and several other parameters can also have the similar trends which strengthens the possibility of having virtual redundancy of information.
Dobruch-Sobczak, Katarzyna; Zalewska, Elwira Bakuła; Gumińska, Anna; Słapa, Rafał Zenon; Mlosek, Krzysztof; Wareluk, Paweł; Jakubowski, Wiesław; Dedecjus, Marek
2016-12-01
The aims of our study were to determine whether shear wave elastography (SWE) can improve the conventional B-mode differentiation of thyroid lesions, determine the most accurate SWE parameter for differentiation and assess the influence of microcalcifications and chronic autoimmune thyroiditis on SWE values. We examined 119 patients with 169 thyroid nodules who prospectively underwent B-mode ultrasound and SWE using the same ultrasound machine. The parameters assessed using SWE were: mean elasticity within the entire lesion (SWE-whole) and mean (SWE-mean) and maximum (SWE-max) elasticity for a 2-mm-diameter region of interest in the stiffest portion of the lesion, excluding microcalcifications. The discriminant powers of a generalized estimating equation model including B-mode parameters only and a generalized estimation equation model including both B-mode and SWE parameters were assessed and compared using the area under the receiver operating characteristic curve, in association with pathologic verification. In total, 50 and 119 malignant and benign lesions were detected. In generalized estimated equation regression, the B-mode parameters associated with higher odds ratios (ORs) for malignant lesions were microcalcifications (OR = 4.3), hypo-echogenicity (OR = 3.13) and irregular margins (OR = 10.82). SWE-max was the only SWE independent parameter in differentiating between malignant and benign tumors (OR = 2.95). The area under the curve for the B-mode model was 0.85, whereas that for the model combining B-mode and SWE parameters was 0.87. There was no significant difference in mean SWE values between patients with and without chronic autoimmune thyroiditis. The results of the present study suggest that SWE is a valuable tool for the characterization of thyroid nodules, with SWE-max being a significant parameter in differentiating benign and malignant lesions, independent of conventional B-mode parameters. The combination of SWE parameters and
Talianu, Camelia; Andrei, Simona; Toanca, Florica; Stefan, Sabina
2016-04-01
Among the severe weather phenomena, whose frequency has increased during the past two decades, hail represents a major threat not only for agriculture but also for other economical fields. Generally, hail are produced in deep convective clouds, developed in an unstable environment. Recent studies have emphasized that besides the state of the atmosphere, the atmospheric composition is also very important. The presence of fine aerosols in atmosphere could have a high impact on nucleation processes, initiating the occurrence of cloud droplets, ice crystals and possibly the occurrence of graupel and/or hail. The presence of aerosols in the atmosphere, correlated with specific atmospheric conditions, could be predictors of the occurrence of hail events. The atmospheric investigation using multiwavelength Lidar systems can offer relevant information regarding the presence of aerosols, identified using their optical properties, and can distinguish between spherical and non-spherical shape, and liquid and solid phase of these aerosols. The aim of this study is to analyse the correlations between the presence and the properties of aerosols in atmosphere, and the production of hail events in a convective environment, using extensive and intensive optical parameters computed from lidar and ceilometer aerosols measurements. From these correlations, we try to evaluate if these aerosols can be taken into consideration as predictors for hail formation. The study has been carried out in Magurele - Romania (44.35N, 26.03E, 93m ASL) using two collocated remote sensing systems: a Raman Lidar (RALI) placed at the Romanian Atmospheric 3D Observatory and a ceilometer CL31 placed at the nearby Faculty of Physics, University of Bucharest. To evaluate the atmospheric conditions, radio sounding and satellite images were used. The period analysed was May 1st - July 15th, 2015, as the May - July period is climatologically favorable for deep convection events. Two hail events have been
Correct manipulation method of MBR operating parameters in membrane fouling studies.
Kayaalp, N; Kinaci, C
2013-01-01
In this study, various parameter manipulation methods, variable sludge retention time (SRT)-variable mixed liquor suspended solids (MLSS) concentration, constant SRT-variable MLSS concentration and variable SRT-constant MLSS concentration, were compared based on the interrelationships among the following membrane bioreactor operating parameters: SRT, food to microorganisms (biomass) (F/M) ratio, MLSS concentration, volumetric organic loading rate (OLR) and membrane flux. Although it is the most applied method, concurrent change of SRT (or F/M ratio) and MLSS concentration is not a good parameter manipulation method because it causes unnecessary changes in many other parameters such as viscosity, oxygen transfer efficiency and oxygen utilization rate. The method of constant SRT-variable MLSS concentration has similar disadvantages to the method of variable SRT-variable MLSS concentration. The best alternative parameter manipulation method to study membrane fouling is the method of variable SRT-constant MLSS concentration because this method eliminates unnecessary changes in other parameters. In addition, while changing OLR or hydraulic retention time (HRT), contrary to the common application, membrane flux should be kept constant because any change in flux overrides changes in other parameters. Accordingly, required changes in OLR or HRT should be made by adjusting membrane area rather than membrane flux.
Energy Technology Data Exchange (ETDEWEB)
Tobe, Kazuhiro [Department of Physics, Nagoya University,Nagoya, 464-8602 (Japan); Kobayashi-Maskawa Institute for the Origin of Particles and the Universe,Nagoya University, Nagoya, 464-8602 (Japan)
2016-10-21
In a general two Higgs doublet model (2HDM), the anomaly of muon anomalous magnetic moment (muon g-2) can be explained by μ−τ flavor violating Yukawa couplings, motivated by the recent CMS excess in Higgs boson decay h→μτ. We study Michel parameters for τ decays τ→lνν̄ (l=e, μ) in the 2HDM with the lepton flavor violation, and show that they can be sensitive to the flavor structure as well as the Lorentz and chiral structures of the model. We find that the correction to the Michel parameter ξ{sub μ} in τ→μνν̄ is correlated to the contribution to the muon g-2, and it can be as large as 10{sup −4}−10{sup −2} in the parameter region where the μ−τ flavor violating Yukawa couplings explain the muon g-2 anomaly. Therefore the precision measurement of the Michel parameter at the level of 10{sup −4}−10{sup −2} would significantly probe the interesting parameter space for the solution to the muon g-2 anomaly.
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.
Institute of Scientific and Technical Information of China (English)
何勇; 鲍一丹
2001-01-01
A Model S195 (8.8 kW) single cylinder was used in this study to determine the effect of four operational parameters, i.e. intake valve close angle, exhaust valve open angle, fuel delivery angle and fuel injection pressure on noise. Single factor and multi-factor quadratic regressive orthogonal methods were adopted in the experiments to find the relationship between the four parameters and noise. By means of optimization technique, the optimum operational parameters for two working conditions of the engine were selected and the test results showed that optimum adjustment could reduce noise by 2-4 dB.
A comprehensive parameter study of an active magnetic regenerator using a 2D numerical model
DEFF Research Database (Denmark)
Nielsen, Kaspar Kirstein; Bahl, Christian Robert Haffenden; Smith, Anders
2010-01-01
A two-dimensional numerical heat transfer model is used to investigate an active magnetic regenerator (AMR) based on parallel plates of magnetocaloric material. A large range of parameter variations are performed to study the optimal AMR. The parameters varied are the plate and channel thicknesses......, cycle frequency and fluid movement. These are cast into the non-dimensional units utilization, porosity and number of transfer units (NTU). The cooling capacity vs. temperature span is mapped as a function of these parameters and each configuration is evaluated through the maximum temperature span...
A study on the effect of CT imaging acquisition parameters on lung nodule image interpretation
Yu, Shirley J.; Wantroba, Joseph S.; Raicu, Daniela S.; Furst, Jacob D.; Channin, David S.; Armato, Samuel G., III
2009-02-01
Most Computer-Aided Diagnosis (CAD) research studies are performed using a single type of Computer Tomography (CT) scanner and therefore, do not take into account the effect of differences in the imaging acquisition scanner parameters. In this paper, we present a study on the effect of the CT parameters on the low-level image features automatically extracted from CT images for lung nodule interpretation. The study is an extension of our previous study where we showed that image features can be used to predict semantic characteristics of lung nodules such as margin, lobulation, spiculation, and texture. Using the Lung Image Data Consortium (LIDC) dataset, we propose to integrate the imaging acquisition parameters with the low-level image features to generate classification models for the nodules' semantic characteristics. Our preliminary results identify seven CT parameters (convolution kernel, reconstruction diameter, exposure, nodule location along the z-axis, distance source to patient, slice thickness, and kVp) as influential in producing classification rules for the LIDC semantic characteristics. Further post-processing analysis, which included running box plots and binning of values, identified four CT parameters: distance source to patient, kVp, nodule location, and rescale intercept. The identification of these parameters will create the premises to normalize the image features across different scanners and, in the long run, generate automatic rules for lung nodules interpretation independently of the CT scanner types.
Zhou, Liming; Yang, Yuxing; Yuan, Shiying
2006-02-01
A new algorithm, the coordinates transform iterative optimizing method based on the least square curve fitting model, is presented. This arithmetic is used for extracting the bio-impedance model parameters. It is superior to other methods, for example, its speed of the convergence is quicker, and its calculating precision is higher. The objective to extract the model parameters, such as Ri, Re, Cm and alpha, has been realized rapidly and accurately. With the aim at lowering the power consumption, decreasing the price and improving the price-to-performance ratio, a practical bio-impedance measure system with double CPUs has been built. It can be drawn from the preliminary results that the intracellular resistance Ri increased largely with an increase in working load during sitting, which reflects the ischemic change of lower limbs.
Energy Technology Data Exchange (ETDEWEB)
Link, J.M.; Yager, P.M.; /UC, Davis; Anjos, J.C.; Bediaga, I.; Castromonte, C.; Machado, A.A.; Magnin, J.; Massafferri, A.; de Miranda, J.M.; Pepe, I.M.; Polycarpo, E.; dos Reis, A.C.; /Rio de Janeiro, CBPF; Carrillo, S.; Casimiro, E.; Cuautle, E.; Sanchez-Hernandez, A.; Uribe, C.; Vazquez, F.; /CINVESTAV, IPN; Agostino, L.; Cinquini, L.; Cumalat,; /Colorado U. /Fermilab /Frascati /Guanajuato U. /Illinois U., Urbana /Indiana U. /Korea U. /Kyungpook Natl. U. /INFN, Milan /Milan U. /North Carolina U. /Pavia U. /INFN,
2005-09-01
Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement of the weak decay-asymmetry parameter a{sub {Lambda}{sub c}} in {Lambda}{sub c}{sup +} {yields} {Lambda}{pi}{sup +} decay. Comparing particle with antiparticle decays, we obtain the first measurement of the CP violation parameter {Alpha} {triple_bond} a{sub {Lambda}{sub c}} + a{sub {ovr {Lambda}{sub c}}}/a{sub {Lambda}{sub c}} - a{sub {ovr {Lambda}{sub c}}}. We obtain a{sub {Lambda}{sub c}} = -0.78 {+-} 0.16 {+-} 0.13 and {Alpha} = -0.07 {+-} 0.19 {+-} 0.12 where errors are statistical and systematic.
Dr. Suneeta Devi*, Asstt Prof MGKM Shahi
2016-01-01
Objectives of the study was to find the relationship between selected physiological parameters and motor fitness preditors of handball performance. For that a sample of 20 students of handball was selected from Ludhania district of punjab. Philips JCR- For motor fitness, Vital capacity Blood Pressure, Pulse Rate and Cornish Handball Test: (skill test) were the criterian of measures. Results shows direct relationship between physiological parameters with handball performance whereas moderate r...
Correlation study among water quality parameters an approach to water quality management.
Sinha, D K; Rastogi, G K; Kumar, R; Kumar, N
2009-04-01
To find out an approach to water quality management through correlation studies between various water quality parameters, the statistical regression analysis for six data points of underground drinking water of different hand pumps at J. P. Nagar was carried out. The comparison of estimated values with W.H.O drinking water standards revealed that water of the study area is polluted with reference to a number of physico-chemical parameters studied. Regression analysis suggests that conductivity of underground water is found to be significantly correlated with eight out of twelve water quality parameters studied. It may be suggested that the underground drinking water quality at J. P. Nagar can be checked very effectively by controlling the conductivity of water. The present study may be treated one step forward towards the water quality management.
Child dental fear and general emotional problems: a pilot study
Krikken, J.B.; ten Cate, J.M.; Veerkamp, J.S.J.
2010-01-01
AIM: This was to investigate the relation between general emotional and behavioural problems of the child and dental anxiety and dental behavioural management problems. BACKGROUND: Dental treatment involves many potentially unpleasant stimuli, which all may lead to the development of dental anxiety
Respiratory Diseases in Children: studies in general practice
J.H.J.M. Uijen (Hans)
2011-01-01
textabstractThe work presented in this thesis covers various aspects of the epidemiology, diagnosis and management of various respiratory symptoms and diseases in children frequently encountered in general practice. These respiratory tract symptoms and diseases can be categorized into symptoms and d
Child dental fear and general emotional problems: a pilot study
J.B. Krikken; J.M. ten Cate; J.S.J. Veerkamp
2010-01-01
AIM: This was to investigate the relation between general emotional and behavioural problems of the child and dental anxiety and dental behavioural management problems. BACKGROUND: Dental treatment involves many potentially unpleasant stimuli, which all may lead to the development of dental anxiety
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)
National study of parental confidence in general practitioners.
Freed, Gary L; Spike, Neil; O'Hara, Jonathan; Hiscock, Harriet; Rhodes, Anthea L
2017-09-03
To assess a national sample of Australian parental confidence in general practitioner (GP) care for illness and injury for their children. Cross-sectional, internet-based survey of a national, representative sample of parents of children birth - 17 years in Australia was used. Purposeful recruitment was used to achieve a national, representative sample of 2100 Australian parents, reflective of demographic and geographic distribution based on census data. Parents were asked to indicate their degree of confidence in a GP to handle medical problems as well as their preference for, and use of, paediatric speciality care for their children. Fewer than half of parents (44%) reported that they were completely confident in a GP to provide general care as defined as 'can handle almost all general health issues for my child'. A slightly greater proportion of parents (56%) were completely confident in a GP to provide care for minor injuries, defined as injuries not requiring an X-ray. Greater confidence in general care was seen among parents >40 years of age and those whose GP is always bulk billed. Parental confidence in GPs is an important issue. Our findings that fewer than half of parents are completely confident in their GP to provide general care to their child may be an influencing factor on current health-care utilisation trends. The potential implications of low parental confidence in GPs are greater numbers of emergency department presentations for children with lower urgency conditions and increased referrals of children for specialty care. © 2017 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).
The effect of uphill and downhill walking on gait parameters: A self-paced treadmill study.
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.
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.
Energy Technology Data Exchange (ETDEWEB)
Funke, F.; Greger, G.U.; Bleier, A.; Hellmann, S.; Morell, W. [Siemens AG, Power Generation Group, Erlangen (Germany)
1996-12-01
An extensive experimental parameter study was performed on the kinetics in the reaction system I{sub 2}/Ag and I{sup -}/Ag in a laboratory-scale apparatus.Starting with I{sub 2} or I{sup -} solutions and silver powder suspensions, the decrease of soluted I{sub 2} or I{sup -}, respectively, due to fixation on the silver particles, was monitored as function of time using the radioactive tracer I-131. The measured data were analyzed using a model of first order kinetics with respect to the iodine concentration. However, the analysis using first order kinetics had to be performed separately in an early, fast reaction phase and in a late, slow reaction phase. The reason for this unexpected behaviour was not identified. Thus, rate constant, two for each test, were deduced from 14 I{sub 2}/Ag main tests and from 36 I{sup -}/Ag tests. No dependencies of the rate constants were found on the parameters temperature, initial iodine concentration, presence of boric acid, type of silver educt, and pretreatment of the silver educt prior to the tests. However, the stirring of the reaction solution generally enhanced the kinetics highlighting the importance of mass transfer. The I{sup -}/Ag reaction proceeded only if there was no inertization of the reaction solution by sparging with nitrogen. The temperature-independent rate constant for the early, fast I{sub 2}/Ag reaction phase is 2E-5 m/s. However, a smaller rate constant of 6E-6 m/s is recommended for use in source term calculations with IMPAIR, which already contains a first order model. Analogously, the temperature-independent I{sup -}/Ag reaction rate constant is 8E-6 m/s in an early, fast reaction phase. For use in source term calculations, a smaller rate constant of 2E-6 m/s is recommended. The lower bound of the I{sup -}/Ag rate constant was 3E-8 m/s which could be used in very conservative source term calculations. (author) 20 figs., 6 tabs., 15 refs.
A Finite Element Study of the Bending Behavior of Beams Resting on Two-Parameter Elastic Foundation
Directory of Open Access Journals (Sweden)
Iancu-Bogdan Teodoru
2006-01-01
Full Text Available Although the Winkler’s model is a poor representation of the many practical subgrade or subbase materials, it is widely used in soil-structure problems for almost one and a half century. The foundations represented by Winkler model can not sustain shear stresses, and hence discontinuity of adjacent spring displacements can occur. This is the prime shortcoming of this foundation model which in practical applications may result in significant inaccuracies in the evaluated structural response. In order to overcome these problem many researchers have been proposed various mechanical foundation models considering interaction with the surroundings. Among them we shall mention the class of two-parameter foundations -- named like this because they have the second parameter which introduces interactions between adjacent springs, in addition to the first parameter from the ordinary Winkler’s model. This class of models includes Filonenko-Borodich, Pasternak, generalized, and Vlasov foundations. Mathematically, the equations to describe the reaction of the two-parameter foundations arc equilibrium ones, and the only difference is the definition of the parameters. For the convenience of discussion, the Pasternak foundation is adopted in present paper. In order to analyse the bending behavior of a Euler-Bernoulli beam resting on two-parameter elastic foundation a (displacement Finite Element (FE formulation, based on the cubic displacement function of the governing differential equation, is introduced. The resulting effects of shear stiffness of the Pasternak model on the mechanical quantities are discussed in comparison with those of the Winkler’s model. Some numerical case studies illustrate the accuracy of the formulation and the importance of the soil shearing effect in the vertical direction, associated with continuous elastic foundation.
Studies of the factors and the superhyperfine parameters for Ni3+ in the fluoroperovskites
Indian Academy of Sciences (India)
Y X Hu; S Y Wu; X F Wang; L L Li
2009-06-01
The factors and the ligand superhyperfine parameters ′ and ′ for Ni3+ in KMgF3, CsCaF3 and RbCaF3 are theoretically studied from the formulas of these parameters for a 3d7 ion under octahedral environments in the weak field scheme. The unpaired spin densities for the fluorine 2s, 2p and 2p orbitals are quantitatively determined from the molecular orbital and configuration interaction coefficients based on the cluster approach. The calculated results show good agreement with the experimental data, based on only one adjustable parameter (i.e., the proportionality factor related to the ligand s- and p-orbitals). The superhyperfine parameters for the axial and planar ligands in RbCaF3:Ni3+ are satisfactorily interpreted from the different impurity–ligand distances due to the elongation of the ligand octahedron during cubic-to-tetragonal phase transition.
Directory of Open Access Journals (Sweden)
R. T. Vashi
2015-09-01
Full Text Available Groundwater samples were collected from five talukas of Valsad district for one year (from August 2008 to July 2009 and were analyzed for their physicochemical characteristics. The present investigation is focused on determination of parameters like pH, Colour, Electrical Conductivity (EC, Total Hardness (TH, Calcium (Ca, Magnesium (Mg, Total Alkalinity (TA, Total Dissolved Solids (TDS, Silica, Chloride, Sulphate, Fluoride, Sodium, Chemical Oxygen Demand (COD and metals like Copper (Cu and Manganese (Mn. Correlation coefficients were determined to identify the highly correlated parameters and interrelated water quality parameters. Correlation matrix of Valsad district suggests that EC of groundwater is found to be significantly correlated with eight out of seventeen water quality parameters studied. It may be suggested that the quality of Valsad district can be checked very effectively by controlling EC of water.
Study Pulse Parameters versus Cavity Length for Both Dispersion Regimes in FM Mode Locked
Directory of Open Access Journals (Sweden)
Bushra Razooky Mhdi
2015-03-01
Full Text Available To demonstrate the effect of changing cavity length for FM mode locked on pulse parameters and make comparison for both dispersion regime , a plot for each pulse parameter as Lr function are presented for normal and anomalous dispersion regimes. The analysis is based on the theoretical study and the results of numerical simulation using MATLAB. The effect of both normal and anomalous dispersion regimes on output pulses is investigate Fiber length effects on pulse parameters are investigated by driving the modulator into different values. A numerical solution for model equations using fourth-fifth order, Runge-Kutta method is performed through MATLAB 7.0 program. Fiber length effect on pulse parameters is investigated by driving the modulator into different values of lengths. Result shows that, the output pulse width from the FM mode locked equals to τ= 501ns anomalous regime and τ=518ns in normal regime.
DEFF Research Database (Denmark)
Tutum, Cem Celal; Hattel, Jesper Henri
2010-01-01
The present paper considers the optimisation of process parameters in friction stir welding (FSW). More specifically, the choices of rotational speed and traverse welding speed have been investigated using genetic algorithms. The welding process is simulated in a transient, two-dimensional sequen......The present paper considers the optimisation of process parameters in friction stir welding (FSW). More specifically, the choices of rotational speed and traverse welding speed have been investigated using genetic algorithms. The welding process is simulated in a transient, two......, and this is presented as a Pareto optimal front. Moreover, a higher welding speed for a fixed rotational speed results, in general, in slightly higher stress levels in the tension zone, whereas a higher rotational speed for a fixed welding speed yields somewhat lower peak residual stress, however, a wider tension zone...
A study on regularization parameter choice in near-field acoustical holography
DEFF Research Database (Denmark)
Gomes, Jesper; Hansen, Per Christian
2008-01-01
Cumulative Periodogram (NCP). The latter method is new within NAH and it is based on the Fourier transform of the residual vector. The methods are used in connection with three NAH methods: Statistically Optimized Near-field Acoustical Holography (SONAH), the Inverse Boundary Element Method (IBEM......Regularization plays an important role in Near-field Acoustical Holography (NAH), and choosing the right amount of regularization is crucial in order to get a meaningful solution. An automated method such as the L-curve or Generalized Cross-Validation (GCV) is often used in NAH to choose...... a regularization parameter. These parameter choice methods (PCMs) are attractive, since they require no a priori knowledge about the noise. However, there seems to be no clear understanding of when one PCM is better than the other. This paper presents comparisons of three PCMs: GCV, L-curve and Normalized...
Theory and interpretation in qualitative studies from general practice
DEFF Research Database (Denmark)
Malterud, Kirsti
2016-01-01
Objective: In this article, I want to promote theoretical awareness and commitment among qualitative researchers in general practice and suggest adequate and feasible theoretical approaches. Approach: I discuss different theoretical aspects of qualitative research and present the basic foundations...... theory is a consistent and soundly based set of assumptions about a specific aspect of the world, predicting or explaining a phenomenon. Qualitative research is situated in an interpretative paradigm where notions about particular human experiences in context are recognized from different subject...... in qualitative analysis are presented, emphasizing substantive theories to sharpen the interpretative focus. Such approaches are clearly within reach for a general practice researcher contributing to clinical practice by doing more than summarizing what the participants talked about, without trying to become...
SIMULATION STUDY OF GENERALIZED PREDICTIVE CONTROL FOR TURBINE POWER
Institute of Scientific and Technical Information of China (English)
Shi Xiaoping; Li Dongmei
2004-01-01
A GPC (generalized predictive control) law is developed to control the power of a turbine, after transforming the nonlinear mathematical model of the power regulation system into a CARIMA(controlled auto-regressive integrated moving average) form. The effect of the new control law is compared with a traditional PID (proportional, integral and differential) control law by numerical simulation. The simulation results verify the effectiveness, the correctness and the advantage of the new control scheme.
Choice of Study Resources in General Chemistry by Students Who Have Little Time to Study
Bunce, Diane M.; Komperda, Regis; Dillner, Debra K.; Lin, Shirley; Schroeder, Maria J.; Hartman, JudithAnn R.
2017-01-01
Students with an insufficient amount of time to study are becoming more prevalent in the general college population as many who enroll in college have competing responsibilities (full-time jobs, childcare, etc.). Such students are likely to choose study resources that they consider to be both effective and efficient. Students at the U.S. Naval…
Virtual reality study of paranoid thinking in the general population.
Freeman, Daniel; Pugh, Katherine; Antley, Angus; Slater, Mel; Bebbington, Paul; Gittins, Matthew; Dunn, Graham; Kuipers, Elizabeth; Fowler, David; Garety, Philippa
2008-04-01
Judging whether we can trust other people is central to social interaction, despite being error-prone. A fear of others can be instilled by the contemporary political and social climate. Unfounded mistrust is called paranoia, and in severe forms is a central symptom of schizophrenia. To demonstrate that individuals without severe mental illness in the general population experience unfounded paranoid thoughts, and to determine factors predictive of paranoia using the first laboratory method of capturing the experience. Two hundred members of the general public were comprehensively assessed, and then entered a virtual reality train ride populated by neutral characters. Ordinal logistic regressions (controlling for age, gender, ethnicity, education, intellectual functioning, socio-economic status, train use, playing of computer games) were used to determine predictors of paranoia. The majority agreed that the characters were neutral, or even thought they were friendly. However, a substantial minority reported paranoid concerns. Paranoia was strongly predicted by anxiety, worry, perceptual anomalies and cognitive inflexibility. This is the most unambiguous demonstration of paranoid ideation in the general public so far. Paranoia can be understood in terms of cognitive factors. The use of virtual reality should lead to rapid advances in the understanding of paranoia.
Design of the image detection system for general parts geometric parameters%通用零件几何参数图像检测系统设计
Institute of Scientific and Technical Information of China (English)
张建; 温坚; 林菁
2009-01-01
Gave image detection system for general parts geometric parameters,the optical lens,industrial digital camera and micro-computer constitute the basic detection system;designed to test preparation,test system to adjust,image acquisition,etreatment,boundary identification,and system parameters to strike a job detect calibration process;described the detection aspect of the role and application of the key questions;designed detect application software;established a detection system,comparison test for typical parts.Gave the detection system is the best and practical.%为实现通用零件几何参数图像检测,采用光学镜头、工业数字摄像机和微型计算机构成基本检测系统,包括测试准备、测试系统调整、图像获取、预处理、边界确定、参数求取和系统标定等检测工作环节.阐述各检测环节的作用和应用中的关键问题、检测应用软件设计.通过所构建的检测系统,对典型零件进行对比测试表明,给出的通用零件几何参数图像检测系统是实用的.
Energy Technology Data Exchange (ETDEWEB)
Bakkegaard, Mads, E-mail: mbakkegaard@hotmail.com [Department of Rheumatology, Holbæk Hospital, Smedelundsgade 60, 4300 Holbæk (Denmark); Johannsen, Finn E., E-mail: f.e.johannsen@dadlnet.dk [Private Department of Rheumatology, Furesø-reumatologerne, Farum and ISMC, Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Bispebjerg Bakke 23, 2. Tværvej, Indgang 8, 1. sal, 2400 København NV (Denmark); Højgaard, Betina, E-mail: beho@kora.dk [Danish Institute for Local and Regional Government Research, Købmagergade 22, 1150 København K (Denmark); Langberg, Henning, E-mail: henninglangberg@gmail.com [Institute of Social Medicine, Department of Public Health and Centre for Healthy Ageing, Faculty of Heath Sciences, University of Copenhagen, Øster Farimagsgade 5, bygn. 24, postboks 2099, 1014 København (Denmark)
2015-03-15
Objectives: To study prospectively whether structural changes determined by ultrasound scanning (US) can be used as prognostic markers for outcome in patients with symptomatic Achilles tendinopathy (AT) and to investigate whether there exists an association between US findings and pain measured by visual analog scale (VAS) and a general assessment score (GA). Methods: 92 consecutive patients with AT symptoms were recruited from two outpatient clinics in rheumatology. The patients underwent a conservative treatment protocol consisting of reduced activities, controlled rehabilitation including eccentric exercises of the calf muscles and if needed supplemented with corticosteroid injections. The patients were examined clinically and by US (tendon thickness, hyper- and hypoechogenicity, calcification, bursitis, calcaneusspure, tenosynovitis, gray scale and color Doppler focusing on increased flow intra- or peritendinous). The clinical and US examination were performed at entry, 1, 2, 3 and at 6 month. Results: 42 women and 50 men were included (mean age of 47 years). They had symptoms for more than 13 months and a symptomatic Achilles tendon mean thickness of 7.4 ± 2.3 mm. Heterogeneity at the initial examination was found to be a prognostic marker for the clinical outcome. Tendon thickness, hypoechogenicity and increased flow at any time point were significantly correlated to pain at function, palpatory pain and morning pain at the same time points. A reduction in tendon thickness was statistically associated with a decrease in palpatory pain. Conclusion: Heterogeneity is a prognostic marker in AT. Tendon thickness, hypoechogenicity and increased Doppler activity can be used as objective outcome parameters for the treatment effect of AT.
DEFF Research Database (Denmark)
Kiil, Søren
2011-01-01
A mathematical model, describing the curing behaviour of a two-component, solvent-based, thermoset coating, is used to conduct a parameter study. The model includes curing reactions, solvent intra-film diffusion and evaporation, film gelation, vitrification, and crosslinking. A case study with a ...
Study on DC welding parameters of Al-alloy shaping based on arc-welding robot
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
The Al-alloy arc-welding shaping system based on arc-welding robot is established, and the Al-alloy shaping manufacture is realized with the DC (direct current) gas metal arc welding (GMAW). The research indicates that the metal transfer type of DC GMAW, heat input and the initial temperature of the workpiece greatly affect the Al-alloy shaping based on arc welding robot. On the penetration, the weld width and the reinforcement, the influence of welding parameters is analyzed by generalized regression neural network (GRNN) fitting.
Uncertainties of optical-model parameters for the study of the threshold anomaly
Abriola, Daniel; Testoni, J; Gollan, F; Martí, G V
2015-01-01
In the analysis of elastic-scattering experimental data, optical-model parameters (usually, depths of real and imaginary potentials) are fitted and conclusions are drawn analyzing their variations at bombardment energies close to the Coulomb barrier (threshold anomaly). The judgement about the shape of this variation (related to the physical processes producing this anomaly) depends on these fitted values but the robustness of the conclusions strongly depends on the uncertainties with which these parameters are derived. We will show that previous published studies have not used a common criterium for the evaluation of the parameter uncertainties. In this work, a study of these uncertainties is presented, using conventional statistic tools as well as bootstrapping techniques. As case studies, these procedures are applied to re-analyze detailed elastic-scattering data for the $^{12}$C + $^{208}$Pb and the $^6$Li + $^{80}$Se systems.
Institute of Scientific and Technical Information of China (English)
刘婉贞
2013-01-01
The paper aims to study the Bayes estimation of the parameter of the generalized Parato distribu-tion, basing on the parameter prior which is inverse Gamma prior distribution. Bayes estimators are obtained by us-ing the squared error loss function. The author also compares the MLE estimator with the Bayes estimator through Monte Carlo simulation.%本文在参数的先验分布为逆伽玛先验分布条件下研究广义Pareto分布参数的Bayes估计问题，并在平方误差损失函数下，导出了参数的Bayes估计。文末通过Monte Carlo数值模拟试验对极大似然估计和Bayes估计进行了比较。
混合双参数广义Pareto分布的参数估计%Estimation of Parameters of Mixed Generalized Pareto Distribution
Institute of Scientific and Technical Information of China (English)
刘媚; 汤银才
2009-01-01
Pareto分布族因其厚尾特点,在金融分析、寿命分析中都是非常重要的统汁模型,但是对于混合双参广义Pareto分布,在模型参数估计时,传统的矩法估计和极大似然估计在理论上可以实现,实践时比较困难,本文应用EM算法之ECM算法,研究了混合广义Pareto分布在完全数据场合下的参数估计问题,并模拟说明EM算法来估计混合广义Pareto分布是一种容易实现又非常有效的方法.%Generalized Pareto distribution plays an important role in financial and life time data analysis for its fat-tailed. However we may encounter enormous difficulties when we try to estimate the model by traditional methods such as maximize likelihood (ML) estimation and moment estimation, though they make sense theoretically. In this paper, we employ ECM algorithm of an extension EM algorithm to obtain the parameter estimation for the mixed Generalized Pareto model with complete sample. Simulations are also made to demonstrate the efficiency of this estimation.
Moynihan, Glenn; Teobaldi, Gilberto; O'Regan, David D.
2016-12-01
In approximate density-functional theory (DFT), the self-interaction error is an electron delocalization anomaly associated with underestimated insulating gaps. It exhibits a predominantly quadratic energy-density curve that is amenable to correction using efficient, constraint-resembling methods such as DFT + Hubbard U (DFT+U ). Constrained DFT (cDFT) enforces conditions on DFT exactly, by means of self-consistently optimized Lagrange multipliers, and while its use to automate error corrections is a compelling possibility, we show that it is limited by a fundamental incompatibility with constraints beyond linear order. We circumvent this problem by utilizing separate linear and quadratic correction terms, which may be interpreted either as distinct constraints, each with its own Hubbard U type Lagrange multiplier, or as the components of a generalized DFT+U functional. The latter approach prevails in our tests on a model one-electron system, H2+ , in that it readily recovers the exact total energy while symmetry-preserving pure constraints fail to do so. The generalized DFT+U functional moreover enables the simultaneous correction of the total energy and ionization potential, or the correction of either together with the enforcement of Koopmans' condition. For the latter case, we outline a practical, approximate scheme by which the required pair of Hubbard parameters, denoted as U1 and U2, may be calculated from first principles.
The Generalized Higher Criticism for Testing SNP-Set Effects in Genetic Association Studies.
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.
Exploratory Study for Continuous-time Parameter Estimation of Ankle Dynamics
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.
Periodontal parameters of osseointegrated dental implants. A 4-year controlled follow-up study.
Nishimura, K; Itoh, T; Takaki, K; Hosokawa, R; Naito, T; Yokota, M
1997-08-01
The aim of this study was to evaluate the periodontal parameters of osseointegrated dental implants. The condition of the peri-implant mucosa was assessed using periodontal parameters, i.e., of plaque index, bleeding on probing, probing pocket depth, probing attachment level and Periotest scores as well as a radiographic parameter, over a 4-year follow-up period. 32 non-submerged ITI dental implants, all placed in the mandible, were studied in 12 patients who had good oral hygiene. All patients were regularly recalled at 6-month intervals. The overall implant success rate was 100%. None of the implants showed any signs of inflammation, radiographic bone loss or any detectable mobility during the follow-up period. Methods similar to those used to evaluate the natural dentition were effectively employed to assess the clinical status of the dental implants. The diagnostic value of these parameters could not, however, be determined from this study due to the absence of any peri-implant tissue complications. The results indicated that some periodontal parameters of healthy peri-implant mucosa might be slightly different from healthy periodontal tissue.
Directory of Open Access Journals (Sweden)
Rajeev
2013-12-01
Full Text Available Organophosphorus compound is used for committing suicidal are on upswing in developing countries A grading system of severity of OP poisoning suggests that most cases can be managed in the ICU which cannot be applied to developing countries, where facilities for ICU management are rather limited. Hence, the pr esent study is undertaken to identify the factors both clinical and biochemical, which help in predicting the need for ventilator support and thus helping to reduce the mortality by timely institution of ventilator support. AIMS OF THE STUDY: To study the clinical and biochemical parameters in organophosphate poisoning, which help to predict the need for ventilator support. MATERIAL AND METHODS: This is a Descriptive Study done at Kempegowda Institute of Medical Sciences, Bangalore, with a sample size of 50 cases. Patients who fulfilled the inclusion criteria are assessed as per proforma specifically designed for the study. RESULTS: In this study population, 12 patients who reached the hospital for treatment > 4 hour of consumption, 11(91.7% required ventil ator support . In this study, out of patients with pinpoint pupils at admission required ventilator support. In this study, all patients ( required ventilator support with a fasciculation score of more than as compared to none with a bsent fasciculation. In this study, lower the Glasgow coma scale at admission, more vulnerable are the patients for ventilator support . In This study, patients with reduced levels of Pseudo cholinesterase i.e. out of patients ( required ventilato r support. CONCLUSION: Clinical and biochemical parameters such as Greater the time lag from consumption of OP poison till getting specific treatment, Lower GCS scoring, Generalized Fasiculations, Low Pseudo cholinesterase levels, Larger initial dose of At ropine required for Atropinization were strong predictors for the need for Assisted Ventilation in OP poisoning. Grading of the degree of the poisoning taking
A STUDY ON EFFECTIVENESS OF TREADMILL EXERCISE TRAINING IN GAIT PARAMETERS OF CHRONIC STROKE CASES
Directory of Open Access Journals (Sweden)
Abbas Divan Mohaideen
2014-04-01
Full Text Available Introduction: Stroke is the leading cause of death and the most common cause of disability. This study determined the effects of Treadmill Aerobic Exercise on spatial and temporal gait parameters among stroke patients. Materials & Methods: In this study, Thirty -nine subjects with hemiparetic stroke underwent Treadmill Aerobic Exercise four times weekly for six months from December 2006 to June 2007. This study has taken place in Department of Physical therapy and Rehabilitation, GSN multi Specialty hospital and research Centre, Hyderabad, India. We measured the spatial and temporal gait parameters of the subjects before and after Treadmill Aerobic Exercise training by the means of 30-foot timed walks, 6 minute distance walks with usual assistive devices and 8metre instrumented walkway without assistive devices. Pre and post training results were compared and contrast. Results: This study results that the Treadmill Aerobic Exercise improved 30-foot walks by 17% and 6 minute walk by 23%. Unassisted walking velocity increased 22%, stride length increased 13% and cadence increased 7%. Paretic and non-paretic step lengths increased significantly, and respective step times increased significantly. Discussion: Large study should be done with treadmill exercise training along with other skills for the better results to improve the gait parameters in chronic stroke cases. Conclusion: This study shows the evidence for positive changes in spatial and temporal gait parameters of subjects with stroke after Treadmill Aerobic Exercise.
Etiological study of generalized lymphadenopathy in a tertiary care hospital
Directory of Open Access Journals (Sweden)
Subrata Halder
2016-08-01
Results: Among 116 patients of generalized lymphadenopathy 59.5% were non-malignant causes where 40.5% diagnosed as malignant causes. Among them tuberculosis consist of 39 (33.6%, NHL 18 (15.5%, reactive lymphadenopathy 16 (13.8%, CLL and HD 8 (6.9% each, ALL 7 (6%, SLE 5(4.3%, Kikuchi's disease 4 (3.4%, AML and RA 3 (2.6% each and castleman's disease, phenytoin lymphadenopathy, metastatic lung and breast carcinoma 1 (0.9% each. Cervical groups of lymph nodes were most commonly involved 86 patients (74.1% followed by axillary groups 73 patients (62.9%. Lymph nodes size 1.5cm were due to malignant and non-malignant granulomatous cases. FNAC give definite diagnosis 80.9% malignant cases where 76.8% in non-malignant cases. HPE shown definite diagnosis in 100% cases both malignant and non-malignant diseases. Conclusions: Tuberculosis is most common cause of generalized lymphadenopathy followed by lymphoma. And reactive lymphadenitis is also an important consideration. [Int J Res Med Sci 2016; 4(8.000: 3542-3548
Directory of Open Access Journals (Sweden)
Truin Gert-Jan
2011-10-01
Full Text Available Abstract Background Considering the changes in dental healthcare, such as the increasing assertiveness of patients, the introduction of new dental professionals, and regulated competition, it becomes more important that general dental practitioners (GDPs take patients' views into account. The aim of the study was to compare patients' views on organizational aspects of general dental practices with those of GDPs and with GDPs' estimation of patients' views. Methods In a survey study, patients and GDPs provided their views on organizational aspects of a general dental practice. In a second, separate survey, GDPs were invited to estimate patients' views on 22 organizational aspects of a general dental practice. Results For 4 of the 22 aspects, patients and GDPs had the same views, and GDPs estimated patients' views reasonably well: 'Dutch-speaking GDP', 'guarantee on treatment', 'treatment by the same GDP', and 'reminder of routine oral examination'. For 2 aspects ('quality assessment' and 'accessibility for disabled patients' patients and GDPs had the same standards, although the GDPs underestimated the patients' standards. Patients had higher standards than GDPs for 7 aspects and lower standards than GDPs for 8 aspects. Conclusion On most aspects GDPs and patient have different views, except for social desirable aspects. Given the increasing assertiveness of patients, it is startling the GDP's estimated only half of the patients' views correctly. The findings of the study can assist GDPs in adapting their organizational services to better meet the preferences of their patients and to improve the communication towards patients.
Study of Some Power Influencing Parameters of a Solar Low Temperature Stirling Engine
Directory of Open Access Journals (Sweden)
Hind El Hassani
2014-06-01
Full Text Available The aim of this paper is to study experimentally and theoretically the effect of some geometrical parameters on low temperature differential Stirling engines (LT-SE performance. The studied parameters are: the phase angle, the compression ratio and the dead volume. Results show that for optimizing the performance of these engines, dead volume should be minimized, the compression ratio should be maximized and the optimal phase angle for the gamma type is 90°. For the adopted theoretical model, based on Schmidt theory, even if theoretical numerical results are different from those found experimentally, but it still remains a valid model for finding out some parameters effect on the LT-SE performance, and for calculating approximately the engine work and power. Key words: Stirling engine, low temperature, Solar, Phase angle, compression ratio, dead volume.
Field, James; German, Matthew; Waterhouse, Paula
2013-11-01
Most in vitro studies investigate the erosive process using relatively simple roughness parameters such as roughness average (Ra). In isolation, Ra may misrepresent the surface features. Further, few studies report baseline surface characteristics after sample preparation. This study aimed to test the hypothesis that measuring the bearing area parameters in addition to Ra may be useful when qualifying the surface of enamel at baseline and after an erosive challenge. The null hypothesis for this study was that the bearing area parameters provide no more useful information than Ra alone, when qualifying the surface of enamel at baseline and after an erosive challenge. Enamel slabs (n=20) were prepared from human (n=2) and bovine (n=4) incisor teeth and polished with 0.05μm paste. Roughness average (Ra) and bearing parameters (MR1, MR2, Rpk, Rk, Rvk) were used to record baseline characteristics. Specimens were subjected to erosion with 1% citric acid solution for 1min. Profilometric characteristics were recorded post-erosion, along with the maximum height changes within the profile. T-tests were carried out in order to compare baseline surface characteristics between tissue types. Post-erosion, analysis of variance (ANOVA) was used to test the effects of tissue type (bovine or human). There was no significant difference in Ra between human and bovine incisor enamel at baseline (human 0.11μm, bovine 0.12μm P>0.05), and no significant difference was observed post-erosion (human 0.23μm, bovine 0.20μm P>0.05). There were significant differences in bearing parameters at baseline and post-erosion that were not identified by the Ra measurement alone. The results suggest that if Ra alone is measured, important differences in surface characteristics may be missed. The null hypothesis is rejected, and the recommendation is made that bearing parameters are included within profile measurements in order to further triangulate the results of surface analysis studies. In
Huang, Ziqiang; Zhou, Yonggang; Chai, Wei; Ji, Weiping; Cui, Guopeng; Ma, Miaoqun; Zhu, Yin
2016-07-01
[Purpose] To study preoperative and postoperative hip circumference data of various types of congenital dysplasia of the hip treated with total hip replacement, including the femoral offset, femoral neck length, height, and hip abductor arm parameters. [Subjects and Methods] This study included seventy-eight cases of congenital dysplasia of the hip (I-III type). Furthermore, four parameters were measured, including the preoperative and postoperative femoral offset. Statistical data analysis was performed using the SPSS 13.0 software. [Results] The femoral offset was 33.3 ± 8.4 mm (preoperative) and 39.1 ± 7.1 mm (postoperative). The femoral head height was 59.5 ± 8.7 mm (preoperative) and 68.8 ± 11.0 mm (postoperative). The femoral neck length was 50.8 ± 10.8 mm (preoperative) and 61.5 ± 10.4 mm (postoperative). The hip abductor arm was 54.3 ± 9.6 mm (preoperative) 64.7 ± 10.1 mm (postoperative). The preoperative and postoperative parameters showed statistical differences. Furthermore, no significant differences were evidenced when comparing the postoperative hip parameters with the normal data parameters. [Conclusion] Total hip replacement on congenital dysplasia of the hip could lead to the rebuilt of an almost normal physiological anatomy for each hip case (type I-III).
A study of generalized second law of thermodynamics in modified f(R) Horava-Lifshitz gravity
Chattopadhyay, Surajit
2012-01-01
This work investigates the validity of the generalized second law of thermodynamics in modi?ed f(R) Horava-Lifshitz gravity proposed by Chaichian et al (2010) [Class. Quantum Grav. 27 (2010) 185021], which is invariant under foliation-preserving di?eomorphisms. It has been observed that the equation of state parameter behaves like quintessence (w > -1). We study the thermodynamics of the apparent, event and particle horizons in this modified gravity. We observe that under this gravity, the time derivative of total entropy stays at positive level and hence the generalized second law is validated.
Holland-Letz, Tim
2017-03-01
Dose-response modeling in areas such as toxicology is often conducted using a parametric approach. While estimation of parameters is usually one of the goals, often the main aim of the study is the estimation of quantities derived from the parameters, such as the ED50 dose. From the view of statistical optimal design theory such an objective corresponds to a c-optimal design criterion. Unfortunately, c-optimal designs often create practical problems, and furthermore commonly do not allow actual estimation of the parameters. It is therefore useful to consider alternative designs which show good c-performance, while still being applicable in practice and allowing reasonably good general parameter estimation. In effect, using optimal design terminology this means that a reasonable performance regarding the D-criterion is expected as well. In this article, we propose several approaches to the task of combining c- and D-efficient designs, such as using mixed information functions or setting minimum requirements regarding either c- or D-efficiency, and show how to algorithmically determine optimal designs in each case. We apply all approaches to a standard situation from toxicology, and obtain a much better balance between c- and D-performance. Next, we investigate how to adapt the designs to different parameter values. Finally, we show that the methodology used here is not just limited to the combination of c- and D-designs, but can also be used to handle more general constraint situations such as limits on the cost of an experiment.
Jensen, Benjamin D; Bandyopadhyay, Ananyo; Wise, Kristopher E; Odegard, Gregory M
2012-09-11
The development of innovative carbon-based materials can be greatly facilitated by molecular modeling techniques. Although the Reax Force Field (ReaxFF) can be used to simulate the chemical behavior of carbon-based systems, the simulation settings required for accurate predictions have not been fully explored. Using the ReaxFF, molecular dynamics (MD) simulations are used to simulate the chemical behavior of pure carbon and hydrocarbon reactive gases that are involved in the formation of carbon structures such as graphite, buckyballs, amorphous carbon, and carbon nanotubes. It is determined that the maximum simulation time step that can be used in MD simulations with the ReaxFF is dependent on the simulated temperature and selected parameter set, as are the predicted reaction rates. It is also determined that different carbon-based reactive gases react at different rates, and that the predicted equilibrium structures are generally the same for the different ReaxFF parameter sets, except in the case of the predicted formation of large graphitic structures with the Chenoweth parameter set under specific conditions.
21CMMC: An MCMC analysis tool enabling astrophysical parameter studies of the cosmic 21cm signal
Greig, Bradley
2015-01-01
We introduce 21CMMC: a parallelized, Monte Carlo Markov Chain analysis tool, incorporating the epoch of reionization (EoR) semi-numerical simulation 21CMFAST. 21CMMC estimates astrophysical parameter constraints from 21cm EoR experiments, accommodating a variety of EoR models, as well as priors on model parameters and the reionization history. To illustrate its utility, we consider two different EoR scenarios, one with a single population of galaxies (with a mass-independent ionizing efficiency) and a second, more general model with two different, feedback-regulated populations (each with mass-dependent ionizing efficiencies). As an example, combining three observations (z=8, 9 and 10) of the 21cm power spectrum with a conservative noise estimate and uniform model priors, we find that LOFAR/HERA/SKA can constrain common reionization parameters: the ionizing efficiency (or similarly the escape fraction), the mean free path of ionizing photons, and the log of the minimum virial temperature of star-forming halos...
Broer, H.W.; Lunter, G.A.; Vegter, G.
1998-01-01
We consider Hamiltonian systems near equilibrium that can be (formally) reduced to one degree of freedom. Spatiotemporal symmetries play a key role. The planar reduction is studied by equivariant singularity theory with distinguished parameters. The method is illustrated on the conservative spring-p
Software and Parameters for Detailed TPC Studies in the CLIC CDR
Killenberg, M.
2011-01-01
For the TPC occupancy and time stamping studies in the CLIC CDR the MarlinTPC software package has been used in combination with Mokka for the full detector simulation. This document describes the working principle of the Marlin processors used for digitisation and reconstruction, and lists the parameters for reference.
Model Study of Wave Overtopping of Marine Structure for a Wide Range of Geometric Parameters
DEFF Research Database (Denmark)
Kofoed, Jens Peter
2000-01-01
The objective of the study described in this paper is to enable estimation of wave overtopping rates for slopes/ramps given by a wide range of geometric parameters when subjected to varying wave conditions. To achieve this a great number of model tests are carried out in a wave tank using irregular...
Gavilán, Rosario G
2005-11-01
In this study, over 100 phytoclimatic indices and other climatic parameters were calculated using the climatic data from 260 meteorological stations in a Mediterranean territory located in the centre of the Iberian Peninsula. The nature of these indices was very different; some of them expressed general climatic features (e.g. continentality), while others were formulated for different Mediterranean territories and included particular limits of those indices that expressed differences in vegetation distribution. We wanted to know whether all of these indices were able to explain changes in vegetation on a spatial scale, and whether their boundaries worked similarly to the original territory. As they were so numerous, we investigated whether any of them were redundant. To relate vegetation to climate parameters we preferred to use its hierarchical nature, in discrete units (characterized by one or more dominant or co-dominant species), although it is known to vary continuously. These units give clearer results in this kind of phytoclimatic study. We have therefore used the main communities that represent natural potential vegetation. Multivariate and estimative analyses were used as statistical methods. The classification showed different levels of correlation among climatic parameters, but all of them were over 0.5. One hundred and eleven parameters were grouped into five larger groups: temperature (T), annual pluviothermic indices (PTY), summer pluviothermic indices (SPT), winter potential evapotranspiration (WPET) and thermal continentality indices (K). The remaining parameters showed low correlations with these five groups; some of them revealed obvious spatial changes in vegetation, such as summer hydric parameters that were zero in most vegetation types but not in high mountain vegetation. Others showed no clear results. For example, the Kerner index, an index of thermal continentality, showed lower values than expected for certain particular types of
Studies on the physico-chemical parameters in water of Keibul Lamjao National Park, Manipur, India.
Sharma, Aribam Satish Chandra; Gupta, Susmita; Singh, N Rajmuhon
2013-11-01
A study on the physico- chemical parameters of Keibul Lamjao National Park (KLNP) on seasonal basis was carried out for parameters like temperature, pH, transparency, turbidity, dissolved oxygen, chloride, hardness, calcium and magnesium at six selected Stations. The temperature ranged from 10.4 to 28 degrees C showing subtropical nature. pH was consistent both spatially and temporally except at one Station where it was alkaline having value ranging from 6.9 to 7.26. There was a trend in dissolved oxygen to be more during cold season. Electrical conductivity ranged between 105.56 to 201 microS cm(-1). It was high during the dry season and low during rainy season. Transparency and turbidity values indicated that in most Stations water was clear and the two parameters were found to be negatively correlated (r = -0.381). Based on the hardness (41 to 78 mg l(-1)), water was soft. Significant negative correlation (r = -0.532) was found between rainfall and hardness. Calcium and magnesium ions were found to be below the prescribed value of WHO. These two parameters were found to be positively correlated with hardness. ANOVA showed a significant variation in the parameters recorded during winter and monsoon season.
Zourmand, Alireza; Mirhassani, Seyed Mostafa; Ting, Hua-Nong; Bux, Shaik Ismail; Ng, Kwan Hoong; Bilgen, Mehmet; Jalaludin, Mohd Amin
2014-07-25
The phonetic properties of six Malay vowels are investigated using magnetic resonance imaging (MRI) to visualize the vocal tract in order to obtain dynamic articulatory parameters during speech production. To resolve image blurring due to the tongue movement during the scanning process, a method based on active contour extraction is used to track tongue contours. The proposed method efficiently tracks tongue contours despite the partial blurring of MRI images. Consequently, the articulatory parameters that are effectively measured as tongue movement is observed, and the specific shape of the tongue and its position for all six uttered Malay vowels are determined.Speech rehabilitation procedure demands some kind of visual perceivable prototype of speech articulation. To investigate the validity of the measured articulatory parameters based on acoustic theory of speech production, an acoustic analysis based on the uttered vowels by subjects has been performed. As the acoustic speech and articulatory parameters of uttered speech were examined, a correlation between formant frequencies and articulatory parameters was observed. The experiments reported a positive correlation between the constriction location of the tongue body and the first formant frequency, as well as a negative correlation between the constriction location of the tongue tip and the second formant frequency. The results demonstrate that the proposed method is an effective tool for the dynamic study of speech production.
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.
Jet pumps for thermoacoustic applications: design guidelines based on a numerical parameter study
Oosterhuis, Joris P; Wilcox, Douglas; van der Meer, Theo H
2015-01-01
The oscillatory flow through tapered cylindrical tube sections (jet pumps) is characterized by a numerical parameter study. The shape of a jet pump results in asymmetric hydrodynamic end effects which cause a time-averaged pressure drop to occur under oscillatory flow conditions. Hence, jet pumps are used as streaming suppressors in closed-loop thermoacoustic devices. A two-dimensional axisymmetric computational fluid dynamics model is used to calculate the performance of a large number of conical jet pump geometries in terms of time-averaged pressure drop and acoustic power dissipation. The investigated geometrical parameters include the jet pump length, taper angle, waist diameter and waist curvature. In correspondence with previous work, four flow regimes are observed which characterize the jet pump performance and dimensionless parameters are introduced to scale the performance of the various jet pump geometries. The simulation results are compared to an existing quasi-steady theory and it is shown that t...
Rassu, Giovanna; Gavini, Elisabetta; Spada, Gianpiera; Giunchedi, Paolo; Marceddu, Salvatore
2008-11-01
The preparation of ketoprofen spray-dried microspheres can be affected by the long drug recrystallization time. Polymer type and drug-polymer ratio as well as manufacturing parameters affect the preparation. The purpose of this work was to evaluate the possibility to obtain ketoprofen spray-dried microspheres using the Eudragit RS and RL; the influence of the spray-drying parameters on morphology, dimension, and physical stability of microspheres was studied. Ketoprofen microspheres based on Eudragit blend can be prepared by spray-drying and the nebulization parameters do not influence significantly particle properties; nevertheless, they can be affected by drying and storage methods. No effect of the container material is found.
Study of junction and bias parameters in readout of phase qubits
Energy Technology Data Exchange (ETDEWEB)
Zandi, Hesam, E-mail: zandi@ee.sharif.edu [School of Electrical Engineering, Sharif University of Technology, P.O. Box 11365-9363, Tehran (Iran, Islamic Republic of); Safaei, Shabnam [Department of Physics, Faculty of Sciences, Bilkent University, 08600 Ankara (Turkey); Khorasani, Sina; Fardmanesh, Mehdi [School of Electrical Engineering, Sharif University of Technology, P.O. Box 11365-9363, Tehran (Iran, Islamic Republic of)
2012-05-15
The exact numerical solution of the nonlinear Ginzburg-Landau equation for Josephson junctions is obtained, from which the precise nontrivial current density and effective potential of the Josephson junctions are found. Based on the resulting potential well, the tunneling probabilities of the associated bound states are computed which are in complete agreement with the reported experimental data. The effects of junction and bias parameters such as thickness of the insulating barrier, cross sectional area, bias current, and magnetic field are fully investigated using a successive perturbation approach. We define and compute figures of merit for achieving optimal operation of phase qubits and measurements of the corresponding states. Particularly, it is found that Josephson junctions with thicker barriers yield better performance in measurements of phase qubits. The variations of characteristic parameters such as life time of the states due to the above considered parameters are also studied and discussed to obtain the appropriate configuration setup.
EX VIVO STUDY OF QUANTITATIVE ULTRASOUND PARAMETERS IN FATTY RABBIT LIVERS
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
Tiberi, Lara; Costa, Giovanni
2017-04-01
The possibility to directly associate the damages to the ground motion parameters is always a great challenge, in particular for civil protections. Indeed a ground motion parameter, estimated in near real time that can express the damages occurred after an earthquake, is fundamental to arrange the first assistance after an event. The aim of this work is to contribute to the estimation of the ground motion parameter that better describes the observed intensity, immediately after an event. This can be done calculating for each ground motion parameter estimated in a near real time mode a regression law which correlates the above-mentioned parameter to the observed macro-seismic intensity. This estimation is done collecting high quality accelerometric data in near field, filtering them at different frequency steps. The regression laws are calculated using two different techniques: the non linear least-squares (NLLS) Marquardt-Levenberg algorithm and the orthogonal distance methodology (ODR). The limits of the first methodology are the needed of initial values for the parameters a and b (set 1.0 in this study), and the constraint that the independent variable must be known with greater accuracy than the dependent variable. While the second algorithm is based on the estimation of the errors perpendicular to the line, rather than just vertically. The vertical errors are just the errors in the 'y' direction, so only for the dependent variable whereas the perpendicular errors take into account errors for both the variables, the dependent and the independent. This makes possible also to directly invert the relation, so the a and b values can be used also to express the gmps as function of I. For each law the standard deviation and R2 value are estimated in order to test the quality and the reliability of the found relation. The Amatrice earthquake of 24th August of 2016 is used as case of study to test the goodness of the calculated regression laws.
A parameter study of self-consistent disk models around Herbig AeBe stars
Meijer, J; De Koter, A; Dullemond, C P; Van Boekel, R; Waters, L B F M
2008-01-01
We present a parameter study of self-consistent models of protoplanetary disks around Herbig AeBe stars. We use the code developed by Dullemond and Dominik, which solves the 2D radiative transfer problem including an iteration for the vertical hydrostatic structure of the disk. This grid of models will be used for several studies on disk emission and mineralogy in followup papers. In this paper we take a first look on the new models, compare them with previous modeling attempts and focus on the effects of various parameters on the overall structure of the SED that leads to the classification of Herbig AeBe stars into two groups, with a flaring (group I) or self-shadowed (group II) SED. We find that the parameter of overriding importance to the SED is the total mass in grains smaller than 25um, confirming the earlier results by Dullemond and Dominik. All other parameters studied have only minor influences, and will alter the SED type only in borderline cases. We find that there is no natural dichotomy between ...
Rahim-Taleghani, Sima; Fatemi, Alireza; Alavi Moghaddam, Mostafa; Shojaee, Majid; Abushouk, Abdelrahman Ibrahim; Forouzanfar, Mohammad Mehdi; Baratloo, Alireza
2017-03-01
This study was conducted to assess the correlation between central venous pressure (CVP) and venous blood gas (VBG) analysis parameters, to facilitate management of severe sepsis and septic shock in emergency department. This diagnostic study was conducted from January 2014 until June 2015 in three major educational medical centers, Tehran, Iran. For patients selected with diagnosis of septic shock, peripheral blood sample was taken for testing the VBG parameters and the anion gap (AG) was calculated. All the mentioned parameters were measured again after infusion of 500 cc of normal saline 0.9% in about 1 h. Totally, 93 patients with septic shock were enrolled, 63 male and 30 female. The mean age was 72.53 ± 13.03 and the mean Shock Index (SI) before fluid therapy was 0.79 ± 0.30. AG and pH showed significant negative correlations with CVP, While HCO3 showed a significant positive correlation with CVP. These relations can be affected by the treatment modalities used in shock management such as fluid therapy, mechanical ventilation and vasopressor treatment. It is likely that there is a significant statistical correlation between VBG parameters and AG with CVP, but further research is needed before implementation of the results of this study.
29 CFR 1607.5 - General standards for validity studies.
2010-07-01
..., such as those described in the Standards for Educational and Psychological Tests prepared by a joint... studies. A. Acceptable types of validity studies. For the purposes of satisfying these guidelines, users... they become accepted by the psychological profession. B. Criterion-related, content, and construct...
General Analysis on the Significance of Stylistic and Rhetoric Studies
Institute of Scientific and Technical Information of China (English)
于珊珊
2010-01-01
Stylistics is a scientific study of style. It’s a mode of encoding and decoding language and can be associated with various fields. In this paper,we talk about the great significances of stylistic and rhetoric studies. It refers to great help in expressing and understanding languages; in combining the linguistics and literary criticism and in foreign language teaching.
Study on Collision Between Two Ships Using Selected Parameters in Collision Simulation
Institute of Scientific and Technical Information of China (English)
Dong-Myung Bae; Aditya Rio Prabowo; Bo Cao; Ahmad Fauzan Zakki; Gunawan Dwi Haryadi
2016-01-01
In the present analysis, several parameters used in a numerical simulation are investigated in an integrated study to obtain their influence on the process and results of this simulation. The parameters studied are element formulation, friction coefficient, and material model. Numerical simulations using the non-linear finite element method are conducted to produce virtual experimental data for several collision scenarios. Pattern and size damages caused by collision in a real accident case are assumed as real experimental data, and these are used to validate the method. The element model study performed indicates that the Belytschko-Tsay element formulation should be recommended for use in virtual experiments. It is recommended that the real value of the friction coefficient for materials involved is applied in simulations. For the study of the material model, the application of materials with high yield strength is recommended for use in the side hull structure.
Directory of Open Access Journals (Sweden)
Mostafa Haghi
2016-10-01
Full Text Available Network-on-Chip (NoC paradigm has been proposed as an alternative bus-based schemes to achieve high performance and scalability in System-on-Chip (SoC design. Performance analysis and evaluation of on-chip interconnect architectures are widely considered. Time latency and throughput are two very critical parameters which play vital role to improve the system performance. In this work, these two elements are evaluated in both wire and wireless approaches under different conditions for networks contain 64,512 and 1024 number of cores. There are number of parameters those have direct and indirect effects on the delay and throughput, among all, these four are chosen: routing algorithm, buffer size, virtual channel and subnet. Thus this work is clustered into two general parts, in the first section the effect of algorithms and buffer size are calculated and then later on in second part when switching from wire approach to wireless, it’s shown that, virtual channel and subnet are able to influence the performance of a network on chip positively under some circumstances. We don't concentrate on approach and techniques here. Our target in this paper is to determine the critical points, trade-off and study the effect of mentioned parameters on entire system. Evaluation is done by means of Booksim and Noxim simulators which are based on system C.
EXPERIMENTAL STUDY ON INCIPIENT MOTION OF SEDIMENT PARTICLES ON GENERALIZED SLOPING FLUVIAL BEDS
Institute of Scientific and Technical Information of China (English)
Subhasish DEY
2001-01-01
This paper presents an experimental investigation on incipient motion of non-cohesive uniform sediment under a steady-uniform stream flow on generalized sloping fluvial beds (combined lateral and stream-wise slope). The characteristic parameters affecting the incipient motion of sediment particles, identified based on the physical reasoning and dimensional analysis, are the threshold shear stress ratio (ratio of threshold shear stress for sloping bed to that for horizontal bed), lateral slope,stream-wise slope and angle of repose of sediment particles. Experiments were carried out in two ducts (closed-conduit flow) having section of semicircular invert with three types of sediments. In an open channel flow (laboratory flume study), the uniform flow is a difficult, if not impossible,proposition for a steeply sloping channel and is impossible to obtain in an adversely sloping channel.To avoid this problem, the tests were conducted with a closed-conduit flow. Equation of critical bed shear stress for the initial movement of sediment particles on generalized sloping beds was obtained using the experimental data.
A general method to study equilibrium partitioning of macromolecules
DEFF Research Database (Denmark)
The distribution of macromolecules between a confined microscopic solution and a macroscopic bulk solution plays an important role in understanding separation processes such as Size Exclusion Chromatography (SEC). In this study, we have developed an efficient computational algorithm for obtaining...
plato and the teaching of entrepreneurship studies as general ...
African Journals Online (AJOL)
JONATHAN
2016-08-22
Aug 22, 2016 ... Mgbakoigba, Journal of African Studies. Vol.6 No.1. July 2016. 1 ... The second worry is the growing global melt down and the increasing rate of ..... Entrepreneurship and management in Nigeria: The concept, philosophy and ...
Cepeda-Cuervo, Edilberto; Núñez-Antón, Vicente
2013-01-01
In this article, a proposed Bayesian extension of the generalized beta spatial regression models is applied to the analysis of the quality of education in Colombia. We briefly revise the beta distribution and describe the joint modeling approach for the mean and dispersion parameters in the spatial regression models' setting. Finally, we motivate…
Cepeda-Cuervo, Edilberto; Núñez-Antón, Vicente
2013-01-01
In this article, a proposed Bayesian extension of the generalized beta spatial regression models is applied to the analysis of the quality of education in Colombia. We briefly revise the beta distribution and describe the joint modeling approach for the mean and dispersion parameters in the spatial regression models' setting. Finally, we…
Vitale, Salvatore
2016-01-01
With the discovery of the black hole binary (BBH) coalescence GW150914 the era of gravitational-wave (GW) astronomy has started. It has recently been shown that BBH with masses comparable to or higher than GW150914 would be visible in the eLISA band a few years before they finally merge in the band of ground-based detectors. This would allow for pre-merger electromagnetic alerts, dramatically increasing the chances of a joint detection, if BBH are indeed luminous in the electromagnetic band. In this paper we explore a quite different aspect of multi-band GW astronomy, and verify if, and to what extent, measurement of masses and sky position with eLISA could improve parameter estimation and tests of general relativity with ground-based detectors. We generate a catalog of 200 BBH and find that having prior information from eLISA can reduce the uncertainty in the measurement of source distance and primary black hole spin by up to factor of 2 in ground-based GW detectors. The component masses estimate from eLISA ...
Schneider, J F; Rempel, L A; Rohrer, G A
2012-10-01
The primary objective of this study was to determine genetic and genomic parameters among swine (Sus scrofa) farrowing traits. Genetic parameters were obtained using MTDFREML. Genomic parameters were obtained using GENSEL. Genetic and residual variances obtained from MTDFREML were used as priors for the Bayes C analysis of GENSEL. Farrowing traits included total number born (TNB), number born alive (NBA), number born dead (NBD), number stillborn (NSB), number of mummies (MUM), litter birth weight (LBW), and average piglet birth weight (ABW). Statistically significant heritabilities included TNB (0.09, P = 0.048), NBA (0.09, P = 0.041), LBW (0.20, P = 0.002), and ABW (0.26, P ABW (0.63, P ABW (0.31). Limited information is available in the literature about genomic parameters. Only the GP estimate for NSB is significantly lower than what has been published. The GP estimate for ABW is greater than the estimate for heritability found in this study. Other traits with significant heritability had GP estimates half the value of heritability. This research indicates that significant genetic markers will be found for TNB, NBA, LBW, and ABW that will have either immediate use in industry or provide a roadmap to further research with fine mapping or sequencing of areas of significance. Furthermore, these results indicate that genomic selection implemented at an early age would have similar annual progress as traditional selection, and could be incorporated along with traditional selection procedures to improve genetic progress of litter traits.
Directory of Open Access Journals (Sweden)
Vipa Thanachartwet
Full Text Available Few previous studies have monitored hemodynamic parameters to determine the physiological process of dengue or examined inferior vena cava (IVC parameters to assess cardiac preload during the clinical phase of dengue. From January 2013 to July 2015, we prospectively studied 162 hospitalized adults with confirmed dengue viral infection using non-invasive cardiac output monitoring and bedside ultrasonography to determine changes in hemodynamic and IVC parameters and identify the types of circulatory shock that occur in patients with dengue. Of 162 patients with dengue, 17 (10.5% experienced dengue shock and 145 (89.5% did not. In patients with shock, the mean arterial pressure was significantly lower on day 6 after fever onset (P = 0.045 and the pulse pressure was significantly lower between days 4 and 7 (P50% between days 4 and 5 (P<0.05. Hypovolemic shock was observed in 9 (52.9% patients and cardiogenic shock in 8 (47.1%, with a median (interquartile range time to shock onset of 6.0 (5.0-6.5 days after fever onset, which was the median day of defervescence. Intravascular hypovolemia occurred before defervescence, whereas myocardial dysfunction occurred on the day of defervescence until 2 weeks after fever onset. Hypovolemic shock and cardiogenic shock each occurred in approximately half of the patients with dengue shock. Therefore, dynamic measures to estimate changes in hemodynamic parameters and preload should be monitored to ensure adequate fluid therapy among patients with dengue, particularly patients with dengue shock.
Directory of Open Access Journals (Sweden)
Raju Bangalore Singe Gowda
2014-01-01
Full Text Available Rapid prototyping (RP has evolved as frontier technology in the recent times, which allows direct transformation of CAD files into functional prototypes where it tremendously reduces the lead time to produce physical prototypes necessary for design verification, fit, and functional analysis by generating the prototypes directly from the CAD data. Part quality in the rapid prototyping process is a function of build parameters such as hatch cure depth, layer thickness, orientation, and hatch spacing. Thus an attempt was made to identify, study, and optimize the process parameters governing the system which are related to part characteristics using Taguchi experimental design techniques quality. The part characteristics can be divided into physical part and mechanical part characteristics. The physical characteristics are surface finish, dimensional accuracy, distortion, layer thickness, hatch cure, and hatch file, whereas mechanical characteristics are flexural strength, ultimate tensile strength, and impact strength. Thus, this paper proposes to characterize the influence of the physical build parameters over the part quality. An L9 orthogonal array was designed with the minimum number of experimental runs with desired parameter settings and also by analysis tools such as ANOVA (analysis of variance. Establishment of experimentally verified correlations between the physical part characteristics and mechanical part characteristics to obtain an optimal process parameter level for betterment of part quality is obtained. The process model obtained by the empirical relation can be used to determine the strength of the prototype for the given set of parameters that shows the dependency of strength, which are essential for designers and RP machine users.
Directory of Open Access Journals (Sweden)
Z. Y. Shen
2012-01-01
Full Text Available The calibration of hydrologic models is a worldwide challenge due to the uncertainty involved in the large number of parameters. The difficulty even increases in a region with high seasonal variation of precipitation, where the results exhibit high heteroscedasticity and autocorrelation. In this study, the Generalized Likelihood Uncertainty Estimation (GLUE method was combined with the Soil and Water Assessment Tool (SWAT to quantify the parameter uncertainty of the stream flow and sediment simulation in the Daning River Watershed of the Three Gorges Reservoir Region (TGRA, China. Based on this study, only a few parameters affected the final simulation output significantly. The results showed that sediment simulation presented greater uncertainty than stream flow, and uncertainty was even greater in high precipitation conditions (from May to September than during the dry season. The main uncertainty sources of stream flow came from the catchment process while a channel process impacts the sediment simulation greatly. It should be noted that identifiable parameters such as CANMX, ALPHA_BNK, SOL_K could be obtained with an optimal parameter range using calibration method. However, equifinality was also observed in hydrologic modeling in TGRA. This study demonstrated that care must be taken when calibrating the SWAT model with non-identifiable parameters because these may lead to equifinality of the parameter values. It was anticipated this study would provide useful information for hydrology modeling related to policy development in the Three Gorges Reservoir Region (TGRA and other similar areas.
A general method to study equilibrium partitioning of macromolecules
DEFF Research Database (Denmark)
The distribution of macromolecules between a confined microscopic solution and a macroscopic bulk solution plays an important role in understanding separation processes such as Size Exclusion Chromatography (SEC). In this study, we have developed an efficient computational algorithm for obtaining...... the equilibrium partition coefficient (pore-to-bulk concentration ratio) and the concentration profile inside the confining geometry. The algorithm involves two steps. First, certain characteristic structure properties of the studied macromolecule are obtained by sampling its configuration space, and second those...... data are used for the computation of partition coefficient and concentration profile for any confinement size. Our algorithm is versatile to the model and type of the macromolecule studied, and is capable of handling three types of confining geometries (slit, rectangular channel and rectangular box...
Study of Material Densification of In718 in the Higher Throughput Parameter Regime
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.
Energy Technology Data Exchange (ETDEWEB)
Hellmann, S.; Funke, F.; Greger, G.U.; Bleier, A.; Morell, W. [Siemens AG, Power Generation Group, Erlangen (Germany)
1996-12-01
An extensive experimental parameter study was performed on the deposition and on the resuspension kinetics in the reaction system iodine/organically coated surfaces. Both reactions in the gas phase and in the liquid phase were investigated and kinetic rate constants suitable for modelling were derived. Previous experimental studies on the reaction of iodine with organic coated surfaces were mostly limited to temperatures below 100{sup o}C. Thus, this parameter study aims at filling a gap and providing kinetic data on heterogeneous reactions with organic surfaces in the accident-relevant temperature range of 100-160{sup o}C. Two types of laboratory experiments carried out at Siemens/KWU using coatings representative for German power plants (epoxy-tape paint), namely gas phase tests and liquid phase tests. (author) 6 figs., 6 tabs., 5 refs.
Roller, Justin M.; Maric, Radenka
2015-12-01
Catalytic materials are complex systems in which achieving the desired properties (i.e., activity, selectivity and stability) depends on exploiting the many degrees of freedom in surface and bulk composition, geometry, and defects. Flame aerosol synthesis is a process for producing nanoparticles with ample processing parameter space to tune the desired properties. Flame dynamics inside the reactor are determined by the input process variables such as solubility of precursor in the fuel; solvent boiling point; reactant flow rate and concentration; flow rates of air, fuel and the carrier gas; and the burner geometry. In this study, the processing parameters for reactive spray deposition technology, a flame-based synthesis method, are systematically evaluated to understand the residence times, reactant mixing, and temperature profiles of flames used in the synthesis of Pt nanoparticles. This provides a framework for further study and modeling. The flame temperature and length are also studied as a function of O2 and fuel flow rates.
HIGHER EDUCATION AND GENERAL STUDIES IN NIGERIA: A ...
African Journals Online (AJOL)
JONATHAN
is a life-lasting practice that has interpretation in purpose, type and level. ... Education is the sum total of the culture which a society deliberately gives its younger ... there were few theoretical abstractions, the major aim was to instill a sense of social ..... Making use of case studies from within Nigeria, Africa and other parts of.
Improving patient safety culture in general practice: An interview study
N.J. Verbakel (Natasha J.); A.A. de Bont (Antoinette); T.J. Verheij; C. Wagner (Cordula); D.L.M. Zwart (Dorien Lyd Marieke)
2015-01-01
textabstractBackground When improving patient safety a positive safety culture is key. As little is known about improving patient safety culture in primary care, this study examined whether administering a culture questionnaire with or without a complementary workshop could be used as an interventio
Large General Purpose Frame for Studying Force Vectors
Heid, Christy; Rampolla, Donald
2011-01-01
Many illustrations and problems on the vector nature of forces have weights and forces in a vertical plane. One of the common devices for studying the vector nature of forces is a horizontal "force table," in which forces are produced by weights hanging vertically and transmitted to cords in a horizontal plane. Because some students have…
Trajectories of picky eating during childhood : A general population study
Cano, Sebastian Cardona; Tiemeier, Henning; Van Hoeken, Daphne; Tharner, Anne; Jaddoe, Vincent W. V.; Hofman, Albert; Verhulst, Frank C.; Hoek, Hans W.
2015-01-01
ObjectiveThis cohort study describes the prevalence of picky eating and examines prognostic factors for picky eating trajectories during childhood. Methods4,018 participants of a population-based cohort with measurements from pregnancy onwards were included. Picky eating was assessed by maternal rep
Energy Technology Data Exchange (ETDEWEB)
Stojanovic, Ksenija [IChTM, Chemistry Centre, Njegoseva 12, 11001 Belgrade (Czechoslovakia); Faculty of Medicine, University of Belgrade, Visegradska 26, 11000 Belgrade (Czechoslovakia); Jovancicevic, Branimir; Vitorovic, Dragomir [IChTM, Chemistry Centre, Njegoseva 12, 11001 Belgrade (Czechoslovakia); Faculty of Chemistry,University of Belgrade, Studentski trg 12-16, 11001 Belgrade (Czechoslovakia); Golovko, Julia; Pevneva, Galina; Golovko, Anatoly [Institute of Petroleum Chemistry, 3, Academichesky Ave., 634055, Tomsk (Russian Federation)
2007-02-15
Hierarchy of triterpane, sterane, naphthalene and phenanthrene maturation parameters in oil-source rock correlations (Drmno depression, southeastern part of the Pannonian Basin, Serbia and Montenegro) was evaluated. Different triterpane and sterane parameters were found to be very similar in all investigated samples. Phenanthrene and naphthalene maturation parameters demonstrated much less uniformity, and thus higher applicability. In order to establish a detailed hierarchy of these maturation parameters, the factor analysis was used. Parameters based on isomerization reactions ({alpha} {yields} {beta}) of methylnaphthalenes and methylphenanthrenes, having high loadings, defined the statistically most significant factor 1. Parameters based on dealkylation processes of dimethyl- and trimethylphenanthrenes into methylphenanthrenes, having extremely high loadings values, determined factor 2. In the last significant, factor 3, high loadings were observed with triterpane and sterane parameters. The factor analysis involving just the phenanthrene and naphthalene isomerization parameters, classified methylphenanthrene isomerization parameters into factor 1. Among the naphthalene isomerization maturation parameters a certain hierarchy was also observed, which depended on whether the parameters represented isomer ratios which differed on the position of one or two alkyl groups. General conclusion based on factor analysis is in agreement with theoretical presumptions concerning the transformations of phenanthrene and naphthalene isomers. (author)
AMESCO General Study Environmental Impacts CO2-storage. Public summary
Energy Technology Data Exchange (ETDEWEB)
NONE
2007-07-15
The AMESCO study aims to supply environmental background information on CO2-storage in the Netherlands for the broad group of initiators and other stakeholders. By bringing together the information from the scientific world, companies and authorities and by analysing relevant policies it is intended to eludicate: which are the possible environmental effects of CO2-injection and storage; which are the possibilities for risk reduction or mitigation; which existing legislation is of relevance for CO2-storage in the deep surface; where are the gaps in knowledge and legislation with regard to CO2-storage. The report produced during the AMESCO study should be seen as a broad answer to the four questions mentioned above. In specific projects the report can be used as a background document during permitting procedures. This background information has to be supplemented with location specific information. The report can also be used as input for an environmental impact assessment (EIA). For practical reasons the AMESCO study was performed with the following scope limitations: (1) Focus on potential impacts and risks resulting from the storage of CO2; (2) Only consider CO2-storage in gas reservoirs; (3) Only consider onshore projects; (4) Only consider permanent storage; (5) Consider alternative options for CO2-storage in gas reservoirs; but not other forms of CO2-emission reduction. The scope is limited to depleted gas fields, from which the economically recoverable resources have already been taken.
Hertwig, Eileen; Fraedrich, Klaus
2016-01-01
A set of idealized experiments are performed to analyze the competing effects of declining atmospheric CO2 concentrations, the opening of an ocean gateway, and varying orbital parameters. These forcing mechanisms, which influence the global mean climate state, may have played a role for triggering climate transitions of the past (for example during the Eocene-Oligocene climate transition and the build-up of the Antarctic Ice Sheet). Sensitivity simulations with a coupled atmosphere-ocean general circulation model are conducted to test these three forcings and their roles for the global climate. The simulations are carried out under idealized conditions to focus on the essentials. The combination of all three forcings triggers a climate transition which resembles the onset of the Antarctic glaciation. In particular, the temperatures in the southern high latitudes decrease and snow accumulates constantly. Moreover, the relative importance of each possible forcing is explored. All three of the mechanisms (atmosp...
Study of the impact of environmental parameters on the operation of CMS RPCs
Assran, Yasser
2011-01-01
CMS (Compact Muon Solenoid) is a general purpose detector designed to run at the highest luminosity at Large Hadron Collider (LHC), CERN, Geneva, Switzerland. The muon system of the CMS experiment relies on Drift Tubes (DT), Cathode Strip Chambers (CSC) and Resistive Plate Chambers (RPC). RPCs are dedicated for the first level muon trigger and they are characterized by bakelite electrodes delimited in a specialized gas volume filled with operational gas mixture. This analysis has been done for the RPC chambers installed in CMS experiment at CERN. The Currents of CMS RPCs chambers are analyzed as a function of environmental parameters such as Temperature, Humidity and pressure, which are important for the operation of the muon detector system. A novel Neural Network approach has been used to analyze the data and to build a model using experimental measurements and combining the results of the simulations. Data from RPC Chambers in CMS experiment are taken and compared to the results from neural Network.
A Study of effect of Process Parameters of Abrasive jet machining
Directory of Open Access Journals (Sweden)
Jagtar Singh
2011-01-01
Full Text Available As Abrasive jet machining (AJM is similar to sand blasting and effectively removes hard and brittle materials. AJM has been applied to rough working such as deburring and rough finishing. With the increase of needs for machining of ceramics, semiconductors, electronic devices and L.C.D., AJM has become a useful technique for micromachining. This paper deals with various experiments which were conducted to assess the influence of abrasive jet machining (AJM process parameters on material removal rate and diameter of holes of glass plates using aluminum oxide type of abrasive particles. The experimental results of the present work are used to discuss thevalidity of proposed model as well as the other models. With the increase in nozzle tip distance (NTD, the top surface diameter and bottom surface diameter of hole increases as it is in general observation of abrasive jet machining process. As the pressure increases, the material removal rate (MRR is also increased.
Directory of Open Access Journals (Sweden)
Alexandra-Cristina Paunescu
2013-06-01
Full Text Available Background. The traditional diet of Inuit people comprises large amounts of fish and marine mammals that are rich in omega-3 polyunsaturated fatty acids (PUFAs. Results from in vitro studies, laboratory animal experiments and population studies suggest that omega-3 PUFA intake and a high omega-3/omega-6 ratio exert a positive effect on bone health. Objective. This longitudinal study was conducted to examine the relationship between omega-3 and omega-6 PUFA status and quantitative ultrasound (QUS parameters in Greenlandic Inuit women. Methods. The study included 118 Inuit women from Nuuk (Greenland, aged 49–64 years, whose QUS parameters measured at baseline (year 2000, along with PUFA status and covariates, and follow-up QUS measurements 2 years later (year 2002. QUS parameters [speed of sound (SOS; broadband ultrasound attenuation (BUA] were measured at the right calcaneus with a water-bath Lunar Achilles instrument. Omega-3 and omega-6 PUFA contents of erythrocyte membrane phospholipids were measured after transmethylation by gas chromatography coupled with a flame ionization detector. Relationships between QUS parameters and different PUFAs were studied in multiple linear regression models. Results. Increasing values of EPA, DHA and the omega-3/omega-6 PUFA ratio were associated with increased BUA values measured at follow-up (year 2002. These associations were still present in models adjusted for several confounders and covariates. We found little evidence of associations between PUFAs and SOS values. Conclusion. The omega-3 PUFA intake from marine food consumption seems to have a positive effect on bone intrinsic quality and strength, as revealed by higher BUA values in this group of Greenlandic Inuit women.
Mayotte, Jean-Marc; Grabs, Thomas; Sutliff-Johansson, Stacy; Bishop, Kevin
2017-06-01
This study examined how the inactivation of bacteriophage MS2 in water was affected by ionic strength (IS) and dissolved organic carbon (DOC) using static batch inactivation experiments at 4 °C conducted over a period of 2 months. Experimental conditions were characteristic of an operational managed aquifer recharge (MAR) scheme in Uppsala, Sweden. Experimental data were fit with constant and time-dependent inactivation models using two methods: (1) traditional linear and nonlinear least-squares techniques; and (2) a Monte-Carlo based parameter estimation technique called generalized likelihood uncertainty estimation (GLUE). The least-squares and GLUE methodologies gave very similar estimates of the model parameters and their uncertainty. This demonstrates that GLUE can be used as a viable alternative to traditional least-squares parameter estimation techniques for fitting of virus inactivation models. Results showed a slight increase in constant inactivation rates following an increase in the DOC concentrations, suggesting that the presence of organic carbon enhanced the inactivation of MS2. The experiment with a high IS and a low DOC was the only experiment which showed that MS2 inactivation may have been time-dependent. However, results from the GLUE methodology indicated that models of constant inactivation were able to describe all of the experiments. This suggested that inactivation time-series longer than 2 months were needed in order to provide concrete conclusions regarding the time-dependency of MS2 inactivation at 4 °C under these experimental conditions.
Process Parameter Study on Microwave-assisted Foam-mat Drying Properties of Corn Soaking Water
Institute of Scientific and Technical Information of China (English)
Zheng Xian-zhe
2016-01-01
In order to study the microwave-assisted foam-mat drying properties of corn soaking water and optimize process parameters, a quadratic regression orthogonal rotary method was used to analyze the influence of microwave power, material weight, material thickness and drying time on moisture content (dry basis), color value and protein content. Results showed that the primary and secondary sequence of parameters with regard to moisture content (d. b.) was drying time, microwave power, material weight and material thickness; the primary and secondary sequence of parameters with regard to color value was material weight, drying time, microwave power and material thickness; the primary and secondary sequence of parameters with regard to protein content was drying time, material weight, microwave power and material thickness. Optimum conditions were obtained as microwave power of 560 W, material weight of 46.88 g, material thickness of 6.20 mm and drying time of 8.01 min. The results might provide the theoretical basis and technical support for the microwave-assisted foam-mat drying of corn soaking water to produce yeast protein power.
[Microscopic innervation and vascularization of the tongue. General study].
Fuentes, A; Sanchiz, O
1992-01-01
Our study deals with 23 prenatal human tongues, and a comparative study was carried out on one neonatal tongue and a few human and animal postnatal tongues. Sagittal and coronal sections were stained with various techniques. After the 7th week, the development of the nerves and their relationships with the neighboring structures can be observed. There are very few capillaries making up the superficial vascular network under the epithelium. The vessels whose walls are beginning to develop include the future red blood cells with their basophilic nuclei. During the whole process of evolution, there is a tight correlation between the collagen fibers and the neighboring structures. The innervation and vascularization--the latter with changes in the vascular walls--progressively increase. A short time before birth, the nerve fibers include their characteristic components, except for the Schmidt-Lantermann fissures. A considerable innervation advances towards the papillae, and anterior and posterior nerve networks enter the papillae, whose connective tissue includes groups of corpuscles on serial sections.
Directory of Open Access Journals (Sweden)
Z. Y. Shen
2011-08-01
Full Text Available The calibration of hydrologic models is a worldwide difficulty due to the uncertainty involved in the large number of parameters. The difficulty even increases in the region with high seasonal variation of precipitation, where the results exhibit high heteroscedasticity and autocorrelation. In this study, the Generalized Likelihood Uncertainty Estimation (GLUE method was combined with Soil and Water Assessment Tool (SWAT to quantify the parameter uncertainty of the stream flow and sediment simulation in the Daning River Watershed of the Three Gorges Reservoir Region (TGRA, China. Based on this study, only a few parameters affected the final simulation output significantly. The results showed that sediment simulation presented greater uncertainty than stream flow, and uncertainty even increased in high precipitation condition than dry season. The main uncertainty sources of stream flow mainly came from the catchment process while channel process impacts the sediment simulation greatly. It should be noted that identifiable parameters such as CANMX, ALPHA_BNK, SOL_K could be obtained optimal parameter range using calibration method. However, equifinality was also observed in hydrologic modeling in TGRA. This paper demonstrated that care must be taken when calibrating the SWAT with non-identifiable parameters as these may lead to equifinality of the parameter values. It is anticipated this study would provide useful information for hydrology modeling related to policy development in the Three Gorges Reservoir Region (TGRA and other similar areas.
Directory of Open Access Journals (Sweden)
Sung Jun Ahn
Full Text Available OBJECTIVES: Glucose metabolism, perfusion, and water diffusion may have a relationship or affect each other in the same tumor. The understanding of their relationship could expand the knowledge of tumor characteristics and contribute to the field of oncologic imaging. The purpose of this study was to evaluate the relationships between metabolism, vasculature and cellularity of advanced hepatocellular carcinoma (HCC, using multimodality imaging such as ¹⁸F-FDG positron emission tomography (PET, dynamic contrast enhanced (DCE-MRI, and diffusion weighted imaging(DWI. MATERIALS AND METHODS: Twenty-one patients with advanced HCC underwent ¹⁸F-FDG PET, DCE-MRI, and DWI before treatment. Maximum standard uptake values (SUV(max from ¹⁸F-FDG-PET, variables of the volume transfer constant (K(trans from DCE-MRI and apparent diffusion coefficient (ADC from DWI were obtained for the tumor and their relationships were examined by Spearman's correlation analysis. The influence of portal vein thrombosis on SUV(max and variables of K(trans and ADC was evaluated by Mann-Whitney test. RESULTS: SUV(max showed significant negative correlation with K(trans(max (ρ = -0.622, p = 0.002. However, variables of ADC showed no relationship with variables of K(trans or SUV(max (p>0.05. Whether portal vein thrombosis was present or not did not influence the SUV max and variables of ADC and K(trans (p>0.05. CONCLUSION: In this study, SUV was shown to be correlated with K(trans in advanced HCCs; the higher the glucose metabolism a tumor had, the lower the perfusion it had, which might help in guiding target therapy.
Mathematical modelling of a self-polishing antifouling paint exposed to seawater: A parameter study
DEFF Research Database (Denmark)
Kiil, Søren; Weinell, Claus Erik; Pedersen, M. S.;
2002-01-01
A Fundamental mathematical model for a self-polishing antifouling paint was used to conduct a parameter study. The aims were to show how a mathematical model can reduce the amount of experimental work needed to estimate the behaviour of self-polishing antifouling paints at different conditions......, and to suggest ways of controlling biocide release rates. A case study with an antifouling paint based on the well-known tributyltin self-polishing copolymer system showed that the rate of paint polishing was influenced, to various degrees, by the following parameters: seawater pH and concentration of Na......Cl, pigment particle size. pigment volume concentration of the paint, the rate of pigment dissolution, and the pore size distribution of the leached layer. The modelling approach can be applied to any type of self-polishing antifouling paint provided that kinetic, solubility and diffusivity data are available...
ESR study of advanced materials with new parameters frequency and pressure
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...
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
Perturbative study on the analytic continuation for generalized gravitational entropy
Prudenziati, Andrea
2015-05-01
We study the analytic continuation used by Lewkowycz and Maldacena to prove the Ryu-Takayanagi formula for entanglement entropy, which is the holographic dual of the trace of the β -power of the Euclidean time evolution operator when β ∈R . This will be done perturbatively using a weakly time dependent Hamiltonian, corresponding to a small shift of the dual static background. The perturbation will be set to either satisfy the Lewkowycz-Maldacena proposal or a different analytic continuation, depending on its periodicity conditions. The two choices will be tested by computing the associated entropies and compared to the Ryu-Takayanagi formula. To our surprise we discover that, at first order, they both correctly reproduce the associated entanglement entropy. Furthermore in both cases we find unexpected divergent contributions that we have to discard in order to fit the minimal area computation, and an additional requirement on the β dependence on the metric.
Study on effective parameter of the triple-pressure reheat combined cycle performance
Ibrahim Thamir K.; Rahman M.M.
2013-01-01
The thermodynamic analyses of the triple-pressure reheat combined cycle gas turbines with duct burner are presented and discussed in this paper. The overall performance of a combined cycle gas turbine power plant is influenced by the ambient temperature, compression ratio and turbine inlet temperature. These parameters affect the overall thermal efficiency, power output and the heat-rate. In this study a thermodynamic model was development on an existing actual combined cycle gas turbin...
Parameter Extraction and Characteristics Study for Manganese-Type Lithium-Ion Battery
Somakettarin, Natthawuth; Funaki, Tsuyoshi
2016-01-01
In this paper, we propose the battery transient response model and parameter extraction method for studying the dynamic behaviors of Manganese-type Lithium-Ion battery. The background knowledge of the battery structure and its operating principle are also concluded. Several aspects of operating conditions, such as charging and discharging operations, environments of terminal currents and temperatures, are considered through the experiments for understanding the battery behaviors. The charact...
Le, V. N. P.; Thi, T. H. Hoang; Robins, E.; Flament, M. P.
2012-01-01
Interactions between particles are dependent on the physicochemical characteristics of the interacting particles but it is also important to consider the manufacturing process. Blending active pharmaceutical ingredient (API) with carrier is a critical stage that determines the blend homogeneity and is the first step towards obtaining the final quality of the powder blend. The aim of this work was to study parameters that influence the interactions between API and carrier in adhesive mixtures ...
Marze, Sébastien
2015-01-01
Despite the considerable number of in vivo and in vitro studies on the digestive fate of lipophilic nutrients, micronutrients, and bioactives, the effects of the structure and composition of foods on the physicochemical mechanisms of luminal digestion are still poorly understood. Studying them is indeed complex because the number of parameters is high and many of them are interdependent. To solve this problem, an in silico simulation based on a multi-agent system was recently proposed to study the intestinal bioaccessibility of lipophilic nutrients and micronutrients from a single oil droplet. The roles of lipolysis and solubilization in bile salt were included. The effects of several food and digestion parameters were in line with those reported in the experimental literature. The goal of the research reported in this new article was to include more digestion parameters in the simulation in order to make it more realistic against complex cases. This was done in one specific digestion condition reflecting in vitro experiments, using droplets of tricaprylin or triolein containing vitamin A. The structure and principles of the original model were kept, with independent local modifications in order to study each factor separately. First, a gastric step was added where lipolysis took place, and only a marginal effect on the following intestinal step was found. Then, the chemical form of vitamin A, either non-hydrolyzed retinyl ester or retinyl ester instantly hydrolyzed into retinol, was investigated by considering different localizations in the droplet, resulting in a higher bioaccessibility for the retinol. The case of a mixture of tricaprylin and triolein indicated an influence of the oil phase viscosity. The consideration of mixed micelles compared to simple bile salt micelles was also investigated, and resulted in a higher vitamin A bioaccessibility, especially with triolein. Finally, a full model including the most influential parameters was tested to simulate
STUDY OF THE PARAMETERS OF EFFICIENCY IN CENTRES FOR REPAIR OF AGRICULTURAL MACHINERY
2015-01-01
The paper makes a thorough study of the parameters of efficiency in the centers for the repair of agricultural machinery, considering production and technological structure, the basic principles for design of the process of service, the quantitative indicators for servicing. It presents a theoretical model for the management of services in the service business, taking into account the basic system requirements for maintenance of agricultural machinery, the main elements of the standards of cu...
Astafurov, Sergey; Shilko, Evgeny; Kolubaev, Evgeny; Psakhie, Sergey
2015-10-01
Computer simulation by the movable cellular automaton method was performed to study the dynamics of friction stir welding of duralumin plates. It was shown that the ratio of the rotation rate to the translational velocity of the rotating tool has a great influence on the quality of the welded joint. A suitably chosen ratio of these parameters combined with an additional ultrasonic impact reduces considerably the porosity and the amount of microcracks in the weld.
Shriver, Robert K; Cutler, Kerry; Doak, Daniel F
2012-09-01
Lichens are major components in many terrestrial ecosystems, yet their population ecology is at best only poorly understood. Few studies have fully quantified the life history or demographic patterns of any lichen, with particularly little attention to epiphytic species. We conducted a 6-year demographic study of Vulpicida pinastri, an epiphytic foliose lichen, in south-central Alaska. After testing multiple size-structured functions to describe patterns in each V. pinastri demographic rate, we used the resulting estimates to construct a stochastic demographic model for the species. This model development led us to propose solutions to two general problems in construction of demographic models for many taxa: how to simply but accurately characterize highly skewed growth rates, and how to estimate recruitment rates that are exceptionally difficult to directly observe. Our results show that V. pinastri has rapid and variable growth and, for small individuals, low and variable survival, but that these traits are coupled with considerable longevity (e.g., >50 years mean future life span for a 4-cm(2) thallus) and little deviation of the stochastic population growth rate from the deterministic expectation. Comparisons of the demographic patterns we found with those of other lichen studies suggest that their relatively simple architecture may allow clearer generalities about growth patterns for lichens than for other taxa, and that the expected pattern of faster growth rates for epiphytic species is substantiated.
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.
Jones, Willis A.
2010-01-01
The majority of research on general education assessment in recent years has focused primarily on predominately white institutions. Very little is known about general education assessment at historically black colleges and universities (HBCUS). Using descriptive analysis, this exploratory study examines the state of general education assessment at…
Directory of Open Access Journals (Sweden)
Bruno S. Moreira
2015-02-01
Full Text Available BACKGROUND: Falling is a common but devastating and costly problem of aging. There is no consensus in the literature on whether the spatial and temporal gait parameters could identify elderly people at risk of recurrent falls. OBJECTIVE: To determine whether spatiotemporal gait parameters could predict recurrent falls in elderly women. METHOD: One hundred and forty-eight elderly women (65-85 years participated in this study. Seven spatiotemporal gait parameters were collected with the GAITRite(r system. Falls were recorded prospectively during 12 months through biweekly phone contacts. Elderly women who reported two or more falls throughout the follow-up period were considered as recurrent fallers. Principal component analysis (PCA and discriminant analysis followed by biplot graph interpretation were applied to the gait parameters. RESULTS: After 12 months, 23 elderly women fell twice or more and comprised the recurrent fallers group and 110 with one or no falls comprised the non-recurrent fallers group. PCA resulted in three components that explained 88.3% of data variance. Discriminant analysis showed that none of the components could significantly discriminate the groups. However, visual inspection of the biplot showed a trend towards group separation in relation to gait velocity and stance time. PC1 represented gait rhythm and showed that recurrent fallers tend to walk with lower velocity and cadence and increased stance time in relation to non-recurrent fallers. CONCLUSIONS: The analyzed spatiotemporal gait parameters failed to predict recurrent falls in this sample. The PCA-biplot technique highlighted important trends or red flags that should be considered when evaluating recurrent falls in elderly females.
Ma, Jing; Larsen, Raino Mikael
2013-02-01
Dispersion and interfacial strain transfer of single walled carbon nanotubes (SWNTs) are two major challenges for the utilization of SWNTs as reinforcements in polymer composites. Surface modifications could help change the dispersion and interfacial properties. In this study, nanocomposites were fabricated by solution blending 1 wt % SWNTs with various modification (nonmodified, nitric acid functionalized, and amine functionalized SWNTs) and three kinds of polymeric materials (polycarbonate, polyvinylidene fluoride, and epoxy). Chemical compatibilities between SWNTs and solvents or polymers are calculated by the Hansen solubility parameters (HSP) method. The dispersion of the SWNTs in solvents is evaluated by dynamic light scattering. The dispersion of SWNTs in polymers evaluated by a light optical microscope (LOM) generally agrees with the HSP prediction. The strain transfer from the matrix to SWNTs is mainly related to the dispersion, the bundle size, the residual thermal stresses on the sample, and, to lesser degree, the HSP.
DEFF Research Database (Denmark)
Ma, Jing; Larsen, Mikael
2013-01-01
Dispersion and interfacial strain transfer of single walled carbon nanotubes (SWNTs) are two major challenges for the utilization of SWNTs as reinforcements in polymer composites. Surface modifications could help change the dispersion and interfacial properties. In this study, nanocomposites were...... fabricated by solution blending 1 wt % SWNTs with various modification (nonmodified, nitric acid functionalized, and amine functionalized SWNTs) and three kinds of polymeric materials (polycarbonate, polyvinylidene fluoride, and epoxy). Chemical compatibilities between SWNTs and solvents or polymers...... are calculated by the Hansen solubility parameters (HSP) method. The dispersion of the SWNTs in solvents is evaluated by dynamic light scattering. The dispersion of SWNTs in polymers evaluated by a light optical microscope (LOM) generally agrees with the HSP prediction. The strain transfer from the matrix...
Wang, Wenyu; Xiong, Zhao-Hua; Zhao, Xin-Yan
2016-09-01
In models with vector-like quark doublets, the mass matrices of up and down type quarks are related. Precise diagonalization of the mass matrices has become an obstacle in numerical studies. In this work we first propose a diagonalization method. As its application, in the Standard Model with one vector-like quark doublet we present the quark mass spectrum and Feynman rules for the calculation of B → Xsγ. We find that i) under the constraints of the CKM matrix measurements, the mass parameters in the bilinear term are constrained to a small value by the small deviation from unitarity; ii) compared with the fourth generation extension of the Standard Model, there is an enhancement to the B → Xsγ process in the contribution of vector-like quarks, resulting in a non-decoupling effect in such models. Supported by Natural Science Foundation of China (11375001) and Talents Foundation of Education Department of Beijing
Wang, Wenyu; Zhao, Xin-Yan
2016-01-01
In the models with vector like quark doublets, the mass matrices of up and down type quarks are related. Precise diagonalization for the mass matrices became an obstacle in the numerical studies. In this work we propose a diagonalization method at first. As its application, in the standard model with one vector like quark doublet we present quark mass spectrum, Feynman rules for the calculation of $B\\to X_s\\gamma$. We find that i) under the constraints of the CKM matrix measurements, the mass parameters in the bilinear term are constrained to a small value by the small deviation from unitarity; ii) compared with the fourth generation extension of the standard model, there is an enhancement to $B\\to X_s\\gamma$ process in the contribution of vector like quark, resulting a non-decoupling effect in such models.
Roe, Byron
2013-01-01
The effect of correlations between model parameters and nuisance parameters is discussed, in the context of fitting model parameters to data. Modifications to the usual $\\chi^2$ method are required. Fake data studies, as used at present, will not be optimum. Problems will occur for applications of the Maltoni-Schwetz \\cite{ms} theorem. Neutrino oscillations are used as examples, but the problems discussed here are general ones, which are often not addressed.
Role of Platelet Parameters on Sudden Sensorineural Hearing Loss: A Case-Control Study in Iran
2016-01-01
Sudden sensorineural hearing loss (SSNHL) is a common otological disorder characterized by a hearing loss greater than 30 dB over three consecutive frequencies, in less than 72 hours. It has been established that platelet parameters, such as mean platelet volume, are associated with ischemic heart events, whose clinical manifestations are similar to those of SSNHL. Hence, we aimed to determine if the platelet count, mean platelet volume and platelet distribution width are related to the occurrence and severity of sudden sensorineural hearing loss. A case-control prospective study was conducted in a teaching hospital in Iran. One hundred-eight patients with SSNHL and an equal number of healthy, age- and sex-matched controls were enrolled in the study. Peripheral venous blood samples were collected from the subjects, and the platelet count, mean platelet volume and platelet distribution width were measured with an automated blood cell counter. Analysis of the audiometry and hematological test results using SPSS22 software showed no statistical correlation between the platelet parameters and the occurrence of SSNHL, but correlation coefficients showed a significant correlation between PDW and hearing loss severity in patients group. However, further investigation is required to unequivocally establish the absence of correlation between the platelet parameters and occurrence of SSNHL. PMID:26829393
Fatolazadeh, Farzam; Naeeni, Mehdi Raoofian; Voosoghi, Behzad; Rahimi, Armin
2017-07-01
In this study, an inversion method is used to constrain the fault parameters of the 2010 Chile Earthquake using gravimetric observations. The formulation consists of using monthly Geopotential coefficients of GRACE observations in a conjunction with the analytical model of Okubo 1992 which accounts for the gravity changes resulting from Earthquake. At first, it is necessary to eliminate the hydrological and oceanic effects from GRACE monthly coefficients and then a spatio-spectral localization analysis, based on wavelet local analysis, should be used to filter the GRACE observations and to better refine the tectonic signal. Finally, the corrected GRACE observations are compared with the analytical model using a nonlinear inversion algorithm. Our results show discernible differences between the computed average slip using gravity observations and those predicted from other co-seismic models. In this study, fault parameters such as length, width, depth, dip, strike and slip are computed using the changes in gravity and gravity gradient components. By using the variations of gravity gradient components the above mentioned parameters are determined as 428 ± 6 Km, 203 ± 5 Km, 5 Km, 10°, 13° and 8 ± 1.2 m respectively. Moreover, the values of the seismic moment and moment magnitude are 2. 09 × 1022 N m and 8.88 Mw respectively which show the small differences with the values reported from USGS (1. 8 × 1022N m and 8.83 Mw).
A field study of effects of road traffic and railway noise on polysomnographic sleep parameters.
Aasvang, Gunn Marit; Øverland, Britt; Ursin, Reidun; Moum, Torbjørn
2011-06-01
The aim of this study was to explore and compare the effect of noise from railway and road traffic on sleep in subjects habitually exposed to nocturnal noise. Forty young and middle aged healthy subjects were studied with polysomnography (PSG) during two consecutive nights in their own bedroom. Noise measurements and recordings were conducted concurrently outside of the bedroom façade as well as inside the bedroom of each participant. Different noise exposure parameters were calculated (L(p,A,eq,night), L(p,A,Fmax,night), and L(AF5,night)) and analyzed in relation to whole-night sleep parameters. The group exposed to railway noise had significantly less Rapid eye movement, (REM) sleep than the group exposed to road traffic noise. A significant association was found between the maximum level (L(p,A,Fmax,night)) of railway noise and time spent in REM sleep. REM sleep was significantly shorter in the group exposed to at least a single railway noise event above 50 dB inside the bedroom. These results, obtained in an ecological valid setting, support previous laboratory findings that railway noise has a stronger impact than road traffic noise on physiological parameters during sleep, and that the maximum noise level is an important predictor of noise effects on sleep assessed by PSG, at least for railway noise. © 2011 Acoustical Society of America
Role of Platelet Parameters on Sudden Sensorineural Hearing Loss: A Case-Control Study in Iran.
Mirvakili, Abbas; Dadgarnia, Mohammad Hossein; Baradaranfar, Mohammad Hossein; Atighechi, Saeid; Zand, Vahid; Ansari, Abdollah
2016-01-01
Sudden sensorineural hearing loss (SSNHL) is a common otological disorder characterized by a hearing loss greater than 30 dB over three consecutive frequencies, in less than 72 hours. It has been established that platelet parameters, such as mean platelet volume, are associated with ischemic heart events, whose clinical manifestations are similar to those of SSNHL. Hence, we aimed to determine if the platelet count, mean platelet volume and platelet distribution width are related to the occurrence and severity of sudden sensorineural hearing loss. A case-control prospective study was conducted in a teaching hospital in Iran. One hundred-eight patients with SSNHL and an equal number of healthy, age- and sex-matched controls were enrolled in the study. Peripheral venous blood samples were collected from the subjects, and the platelet count, mean platelet volume and platelet distribution width were measured with an automated blood cell counter. Analysis of the audiometry and hematological test results using SPSS22 software showed no statistical correlation between the platelet parameters and the occurrence of SSNHL, but correlation coefficients showed a significant correlation between PDW and hearing loss severity in patients group. However, further investigation is required to unequivocally establish the absence of correlation between the platelet parameters and occurrence of SSNHL.
Role of Platelet Parameters on Sudden Sensorineural Hearing Loss: A Case-Control Study in Iran.
Directory of Open Access Journals (Sweden)
Abbas Mirvakili
Full Text Available Sudden sensorineural hearing loss (SSNHL is a common otological disorder characterized by a hearing loss greater than 30 dB over three consecutive frequencies, in less than 72 hours. It has been established that platelet parameters, such as mean platelet volume, are associated with ischemic heart events, whose clinical manifestations are similar to those of SSNHL. Hence, we aimed to determine if the platelet count, mean platelet volume and platelet distribution width are related to the occurrence and severity of sudden sensorineural hearing loss. A case-control prospective study was conducted in a teaching hospital in Iran. One hundred-eight patients with SSNHL and an equal number of healthy, age- and sex-matched controls were enrolled in the study. Peripheral venous blood samples were collected from the subjects, and the platelet count, mean platelet volume and platelet distribution width were measured with an automated blood cell counter. Analysis of the audiometry and hematological test results using SPSS22 software showed no statistical correlation between the platelet parameters and the occurrence of SSNHL, but correlation coefficients showed a significant correlation between PDW and hearing loss severity in patients group. However, further investigation is required to unequivocally establish the absence of correlation between the platelet parameters and occurrence of SSNHL.
Budzyński, Jacek; Anaszewicz, Marzena
2017-01-01
Atrial fibrillation (AF) and nutrition status abnormalities are two of the most significant epidemics in current health care. The aim of this study was to determine the relationship between the prevalence and outcome of AF, and the parameters of nutritional status among consecutive, real-life patients hospitalised in a university hospital. Analysis of the medical documentation of 4930 consecutive patients aged ≥ 18 years hospitalised for more than one day with diagnoses of cardiovascular disorders. Patients admitted with a diagnosis of AF (n = 512) compared to their counterparts without AF less frequently had an NRS-2002 score ≥ 3, normal range of body mass index (BMI), higher blood haemoglobin, and lower low density lipoprotein cholesterol (LDL-C) concentration. In logistic regression analysis, the risk of a hospitalisation due to AF was negatively related to BMI, NRS-2002 score, and the value of the difference between ideal and actual body mass. Urgent admission and having an NRS-2002 score ≥ 3 remained the only significant variables determining the risk of in-hospital death. Blood concentration of LDL-C and urgent admission were the only significant variables determining risk of 30-day rehospitalisation in the studied population. Inpatients with AF had a lower prevalence of normal body mass. Patients with an AF diagnosis had different risk factors for in-hospital death and 30-day rehospitalisation than their counterparts with diagnosis of cardiovascular diseases but without AF; however, the parameters of nutritional status played an important role in both patient groups. The obesity and cholesterol paradoxes were also observed.
MCNP5 study on kinetics parameters of coupled fast-thermal system HERBE
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Pešić Milan P.
2011-01-01
Full Text Available New validation of the well-known Monte Carlo code MCNP5 against measured criticality and kinetics data for the coupled fast-thermal HERBE System at the Reactor B critical assembly is shown in this paper. Results of earlier calculations of these criticality and kinetics parameters, done by combination of transport and diffusion codes using two-dimension geometry model are compared to results of new calculations carried out by the MCNP5 code in three-dimension geometry. Satisfactory agreements in comparison of new results with experimental data, in spite complex heterogeneous composition of the HERBE core, are achieved confirming that MCNP5 code could apply successfully to study on HERBE kinetics parameters after uncertainties in impurities in material compositions and positions of fuel elements in fast zone were removed.
A STUDY ON THE RELATIONS BETWEEN DIETARY PARAMETERS AND BLOOD PRESSURE IN 8 CHINESE COMMUNITIES
Institute of Scientific and Technical Information of China (English)
赵光胜; 袁晓源; 龚邦强; 黄友文; 董寿祺; 汪师贞; 张美祥; 张鸿修; 朱存
1992-01-01
Relations between 67 dietary parameters and blood pressure in 8 Chinese communities （745 men aged 40～59 years） were studied. Results showed. UNa, Na/K, Ca, Ca/Mg, parameters reflecting the protein-intake, serum levels of Sr, valine, cysteine,threonine, Vit A, Vit E, cholesterol, C16:0, C18:0, （saturated fatty acid）/（polyunsaturated fatty acid）,（C20:5+C22:6 （ω3））/（C18:2+C20:3+C20:4 （ω6））, γ-glutamyl transferase （an index of alcohol consumption） and plasma glucose correlated positively with BP, while serum levels of K, Mg, glycine, phenylalanine, leucine, VitC, C18:2, Ni, V, Co, Cr and Cd, inversely. And also, a metabolic imbalance among BP, blood glucose and lipids was exhibited.
Institute of Scientific and Technical Information of China (English)
Wang Yarong; Zhang Zhongdian; Li Dongqing
2006-01-01
Experimental investigations on the DC spot welding of Mg alloy AZ31B are presented. Experiments are carried out to study the influence of spot welding parameters (electrode force, welding heat input and welding time) on the tensile shear load and the diameter of nugget, based on an orthogonal test and analysis method. The optimum parameters are as follows:electrode force is 2 000 N, welding heat input is 80% and welding time is 6 cycles. The microstructure of spot weld is single fine equiaxed crystals in the nugget, of which the structure is β-Mg17Al12 precipitated on α-Mg boundaries induced by nonequilibrium freezing. And the surface condition of the workpiece has great influence on the joint quality.
Study of Microstructural Parameters of Screen Printed In2O3 Thick Film Sensors
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Sushma KULKARNI
2011-08-01
Full Text Available Indium Oxide (In2O3 thick films were prepared on alumina substrate by using standard screen printing technique. These films were dried and fired at temperatures between 650 0C to 950 0C for two hours in air atmosphere. The material characterization was done using X-ray energy dispersive analysis (EDAX, X-ray diffraction (XRD and a scanning electron microscope (SEM. The deposited films were polycrystalline in nature with a preferred orientation along the (222 plane. Structural parameters such as the crystallite size, texture coefficient, RMS microstrain, dislocation density and stacking fault probability have been studied. The results indicate that reported parameters changes with firing temperature. The crystallite size changes from 26.8 nm to 31 nm with respect to the firing temperature.
Experimental study on visco-elastic constitutive relationship and its parameters for geogrids
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
Geogrids are used as reinforcement materials widely in geotechnical and civil engineering fields. In this paper, a series of comparative tests on creep behavior of specific geo0grids are conducted in the laboratory under different combinations of loading levels and environmental temperature. Based on the test results, comparative analyses are made to study long-term behaviors of isochronous load-strain curves, creep curves and relaxation curves for the specified geogrids. Furthermore, a constitutive model based on theory of visco-elasticity and tests results is proposed for geogrids and a rational procedure is presented in detail for determining the relevant parameters of the proposed model. Finally, the effect of tests temperature on model parameter values is investigated.
DEFF Research Database (Denmark)
Seoane, Jose Miguel; Sin, Gürkan; Lardon, Laurent
2010-01-01
Start-Lip phenomena in microbial biokinetic assays are not captured by the most commonly used growth-related equations. In this Study we propose a new respirometric experimental design to estimate intrinsic growth parameters that allow us to avoid these limitations without data omission, separate...... mathematical treatment, or wake-up pulses prior to the analysis.. Identifiability and sensitivity analysis were performed to confirm the robustness of the new approach for obtaining unique and accurate estimates of growth kinetic parameters. The new experimental design was applied to establish the. metabolic...... burden caused by the carriage of a pWW0 TOL plasmid in the model organism Pseudomonas putida KT2440; The metabolic,burden associated was manifested as a reduction in the yield and the specific growth rate of the host, with both plasmid maintenance and the over-expression of recombinant proteins from...
Determination of Critical Parameters of Drug Substance Influencing Dissolution: A Case Study
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Erika Bojnanska
2014-01-01
Full Text Available The purpose of this study was to specify critical parameters (physicochemical characteristics of drug substance that can affect dissolution profile/dissolution rate of the final drug product manufactured by validated procedure from various batches of the same drug substance received from different suppliers. The target was to design a sufficiently robust drug substance specification allowing to obtain a satisfactory drug product. For this reason, five batches of the drug substance and five samples of the final peroral drug products were analysed with the use of solid state analysis methods on the bulk level. Besides polymorphism, particle size distribution, surface area, zeta potential, and water content were identified as important parameters, and the zeta potential and the particle size distribution of the drug substance seem to be critical quality attributes affecting the dissolution rate of the drug substance released from the final peroral drug formulation.
Study on the Stability of Supply Chain System Under Perturbations of Dynamic Parameters
Institute of Scientific and Technical Information of China (English)
YingjinLu; XiaowoTang; ZongfangZhou
2004-01-01
The stability of supply chain system is key to implement efficiently inventory policies and improve quality of service in the supply chain. If the supply chain system were unstable, the lead-time would be uncertain. As a result, directly affects the process of manufacture, and the service level. In this paper, we analyze the stability of the supply chain system under perturbations of dynamic parameters based on the Cobb-Douglas production function and study influences on supply chain performance. We prove that the supply chain system, with the increases of the re-production input funding, becomes unstable. Further, when the optimal combination of input parameter elements, the supply chain system becomes unstable.
Parameter study of RF excited diffusively cooled all-metal slab waveguide CO2 laser
Institute of Scientific and Technical Information of China (English)
Ning Su; Shuna Yao; Yanhong Zhong; Jianguo Xin
2005-01-01
@@ In this paper, we have investigated some parameters of a radio frequency (RF) excited diffusively cooled all-metal slab waveguide CO2 laser based on the modified Rigrod theory by introducing a waveguide coupling efficiency which designates the coupling between the waveguide and the resonator mirrors. The parameters of the laser small signal gain go, saturation intensity Is, and waveguide coupling efficiency η are studied theoretically and experimentally. In the experiments, three sets of output coupling flat mirrors with the different transitivities were used, and a maximum laser power output of 150 W was obtained from a gas discharge region of 2-mm height, 20-mm width, and 386-mm length coupled with a CASE-I optical waveguide resonator.
Generalized derivations and general relativity
Heller, M; Pysiak, L; Sasin, W
2013-01-01
We construct differential geometry (connection, curvature, etc.) based on generalized derivations of an algebra A. Such a derivation, introduced by Bresar in 1991, is given by a linear mapping u: A -> A such that there exists a usual derivation d of A satisfying the generalized Leibniz rule u(a b) = u(a) b + a d(b) for all a,b in A. The generalized geometry "is tested" in the case of the algebra of smooth functions on a manifold. We then apply this machinery to study the generalized general relativity. We define the Einstein-Hilbert action and deduce from it Einstein's field equations. We show that for a special class of metrics containing, besides the usual metric components, only one non-zero term, the action reduces to O'Hanlon action that is a Brans-Dicke action with potential and with the parameter \\omega equal to zero. We also show that the generalized Einstein equations (with zero energy-stress tensor) are equivalent to those of the Kaluza-Klein theory satisfying a "modified cylinder condition" and hav...
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
Sharif, M
2014-01-01
We consider an inflationary universe model in the context of generalized cosmic Chaplygin gas by taking matter field as standard and tachyon scalar fields. We evaluate the corresponding scalar fields and scalar potentials during 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 important observational parameter, i.e., tensor-scalar ratio in terms of inflatons. The graphical behavior of this parameter shows that the model remains incompatible with WMAP7 and Planck observational data in each case.
A STUDY OF INCID ENCE OF AWARENESS IN GENERAL AN ESTHESIA WITH INHALATIONAL AGENT (HALOTHANE
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Sreeraghu
2014-01-01
Full Text Available BACKGROUND AND OBJECTIVES : A wareness during general anesthesia is a frightening experience , which may result in serious emotional injury and post - traumatic disorders. Awareness have been reported with many anesthetic techniques , particularly surgical patient populations such as thos e requiring anesthesia for Obstetrics , Major trauma , and cardiac surgery are known to experience a high incidence ( 7 - 43% of awareness. In our study we have made an attempt to evaluate the incidence of awareness in surgical patients under general anesthesi a using inhalational agent ( Halothane with Nitrous oxide . In this study we have evaluated the incidence of awareness by using Blood Pressure , Heart Rate , Sweating , Tears score intraoperatively and interviewing patients post - operatively by standard questio nnaire . MATERIALS AND METHODS : Hundred patients undergoing surgical procedures under general Anesthesia were randomly selected for the study . They were posted to undergo surgery from November 2011 to July 2013 . Parameters observed : Intra - operatively Blood Pressure , Heart Rate , Sweating , Tears scoring was done at 0 minutes in the operation theatre before induction and 10 minutes after intubation and monitored every 10 minutes till the end of surgery. All the patients were interviewed in the post - operative pe riod soon after complete recovery and 24 hours later again with a set of 10 questions ( Questionnaire method . RESULTS : In our study we have a standard interview questionnaire in the post operative period to study the incidence of awareness. We found that n one of the patients had conscious recall of the events during surgery. In our study of 100 patients none of the patients had awareness. Injection atropine 20 mcg/kg body weight and injection pethidine 1mg/kg body weight were given as premedication. Inducti on agent used was injection thiopental sodium 5mg/kg body weight and maintained with Nitrous oxide , Halothane as
Basavaraj, C. K.; Vishwas, M.
2016-09-01
This paper discusses the process parameters for fused deposition modelling (FDM). Layer thickness, Orientation angle and shell thickness are the process variables considered for studies. Ultimate tensile strength, dimensional accuracy and manufacturing time are the response parameters. For number of experimental runs the taguchi's L9 orthogonal array is used. Taguchis S/N ratio was used to identify a set of process parameters which give good results for respective response characteristics. Effectiveness of each parameter is investigated by using analysis of variance. The material used for the studies of process parameter is Nylon.
PARAMETER ESTIMATION OF EXPONENTIAL DISTRIBUTION
Institute of Scientific and Technical Information of China (English)
XU Haiyan; FEI Heliang
2005-01-01
Because of the importance of grouped data, many scholars have been devoted to the study of this kind of data. But, few documents have been concerned with the threshold parameter. In this paper, we assume that the threshold parameter is smaller than the first observing point. Then, on the basis of the two-parameter exponential distribution, the maximum likelihood estimations of both parameters are given, the sufficient and necessary conditions for their existence and uniqueness are argued, and the asymptotic properties of the estimations are also presented, according to which approximate confidence intervals of the parameters are derived. At the same time, the estimation of the parameters is generalized, and some methods are introduced to get explicit expressions of these generalized estimations. Also, a special case where the first failure time of the units is observed is considered.
A Study on Physico-Chemical Parameters of Koilsagar Project, Mahabubnagar District, Telangana.
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S. Suresh
2015-03-01
Full Text Available A physiological background makes it quite evident that water is an important ecological factor in the life of organisms. In the present study water samples were collected from Koilsagar project, Mahabubnagar district in every month during June, 2013 to May, 2014. The Physico-Chemical parameters were studied included Temperature, pH, Total Dissolved Solids (TDS, Turbidity, Hardness, Alkalinity, Phosphate, Chloride, Nitrate, Calcium and Magnesium. The results indicate that the Koilsagar project water is nonpolluted and it can be used for Domestic, irrigation and pisciculture.
Ye, Li; Oueini, Razanne; Dickerson, Austin P.; Lewis, Scott E.
2015-01-01
This study used a series of text message inquiries sent to General Chemistry students asking: "Have you studied for General Chemistry I in the past 48 hours? If so, how did you study?" This method for collecting data is novel to chemistry education research so the first research goals were to investigate the feasibility of the technique…
Ye, Li; Oueini, Razanne; Dickerson, Austin P.; Lewis, Scott E.
2015-01-01
This study used a series of text message inquiries sent to General Chemistry students asking: "Have you studied for General Chemistry I in the past 48 hours? If so, how did you study?" This method for collecting data is novel to chemistry education research so the first research goals were to investigate the feasibility of the technique…
Donmez, Turgut; Erdem, Vuslat Muslu; Uzman, Sinan; Yildirim, Dogan; Avaroglu, Huseyin; Ferahman, Sina; Sunamak, Oguzhan
2017-03-01
Laparoscopic cholecystectomy (LC) is usually performed under the general anesthesia (GA). Aim of the study is to investigate the availability, safety and side effects of combined spinal/epidural anesthesia (CSEA) and comparison it with GA for LC. Forty-nine patients who have a LC plan were included into the study. The patients were randomly divided into GA (n = 25) and CSEA (n = 24) groups. Intraoperative and postoperative adverse events, postoperative pain levels were compared between groups. Anesthesia procedures and surgeries for all patients were successfully completed. After the organization of pneumoperitoneum in CSEA group, 3 patients suffered from shoulder pain (12.5%) and 4 patients suffered from abdominal discomfort (16.6%). All these complaints were recovered with IV fentanyl administration. Only 1 patient developed hypotension which is recovered with fluid replacement and no need to use vasopressor treatment. Postoperative shoulder pain was significantly less observed in CSEA group (25% vs. 60%). Incidence of postoperative nausea and vomiting (PONV) was less observed in CSEA group but not statistically significant (4.2% vs. 20%). In the group of CSEA, 3 patients suffered from urinary retention (12.5%) and 2 patients suffered from spinal headache (8.3%). All postoperative pain parameters except 6th hour, were less observed in CSEA group, less VAS scores and less need to analgesic treatment in CSEA group comparing with GA group. CSEA can be used safely for laparoscopic cholecystectomies. Less postoperative surgical field pain, shoulder pain and PONV are the advantages of CSEA compared to GA.
History of water quality parameters – a study on the Sinos River/Brazil
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GB Konzen
Full Text Available Water is increasingly becoming a valuable resource, constituting one of the central themes of environmental, economic and social discussions. The Sinos River, located in southern Brazil, is the main river from the Sinos River Basin, representing a source of drinking water supply for a highly populated region. Considering its size and importance, it becomes necessary to conduct a study to follow up the water quality of this river, which is considered by some experts as one of the most polluted rivers in Brazil. As for this study, its great importance lies in the historical analysis of indicators. In this sense, we sought to develop aspects related to the management of water resources by performing a historical analysis of the Water Quality Index (WQI of the Sinos River, using statistical methods. With regard to the methodological procedures, it should be pointed out that this study performs a time analysis of monitoring data on parameters related to a punctual measurement that is variable in time, using statistical tools. The data used refer to analyses of the water quality of the Sinos River (WQI from the State Environmental Protection Agency Henrique Luiz Roessler (Fundação Estadual de Proteção Ambiental Henrique Luiz Roessler, FEPAM covering the period between 2000 and 2008, as well as to a theoretical analysis focusing on the management of water resources. The study of WQI and its parameters by statistical analysis has shown to be effective, ensuring its effectiveness as a tool for the management of water resources. The descriptive analysis of the WQI and its parameters showed that the water quality of the Sinos River is concerning low, which reaffirms that it is one of the most polluted rivers in Brazil. It should be highlighted that there was an overall difficulty in obtaining data with the appropriate periodicity, as well as a long complete series, which limited the conduction of statistical studies such as the present one.
History of water quality parameters - a study on the Sinos River/Brazil.
Konzen, G B; Figueiredo, J A S; Quevedo, D M
2015-05-01
Water is increasingly becoming a valuable resource, constituting one of the central themes of environmental, economic and social discussions. The Sinos River, located in southern Brazil, is the main river from the Sinos River Basin, representing a source of drinking water supply for a highly populated region. Considering its size and importance, it becomes necessary to conduct a study to follow up the water quality of this river, which is considered by some experts as one of the most polluted rivers in Brazil. As for this study, its great importance lies in the historical analysis of indicators. In this sense, we sought to develop aspects related to the management of water resources by performing a historical analysis of the Water Quality Index (WQI) of the Sinos River, using statistical methods. With regard to the methodological procedures, it should be pointed out that this study performs a time analysis of monitoring data on parameters related to a punctual measurement that is variable in time, using statistical tools. The data used refer to analyses of the water quality of the Sinos River (WQI) from the State Environmental Protection Agency Henrique Luiz Roessler (Fundação Estadual de Proteção Ambiental Henrique Luiz Roessler, FEPAM) covering the period between 2000 and 2008, as well as to a theoretical analysis focusing on the management of water resources. The study of WQI and its parameters by statistical analysis has shown to be effective, ensuring its effectiveness as a tool for the management of water resources. The descriptive analysis of the WQI and its parameters showed that the water quality of the Sinos River is concerning low, which reaffirms that it is one of the most polluted rivers in Brazil. It should be highlighted that there was an overall difficulty in obtaining data with the appropriate periodicity, as well as a long complete series, which limited the conduction of statistical studies such as the present one.
Bouaziz, Laurène; de Boer-Euser, Tanja; Brauer, Claudia; Drogue, Gilles; Fenicia, Fabrizio; Grelier, Benjamin; de Niel, Jan; Nossent, Jiri; Pereira, Fernando; Savenije, Hubert; Thirel, Guillaume; Willems, Patrick
2016-04-01
International collaboration between institutes and universities is a promising way to reach consensus on hydrological model development. Education, experience and expert knowledge of the hydrological community have resulted in the development of a great variety of model concepts, calibration methods and analysis techniques. Although comparison studies are very valuable for international cooperation, they do often not lead to very clear new insights regarding the relevance of the modelled processes. We hypothesise that this is partly caused by model complexity and the used comparison methods, which focus on a good overall performance instead of focusing on specific events. We propose an approach that focuses on the evaluation of specific events. Eight international research groups calibrated their model for the Ourthe catchment in Belgium (1607 km2) and carried out a validation in time for the Ourthe (i.e. on two different periods, one of them on a blind mode for the modellers) and a validation in space for nested and neighbouring catchments of the Meuse in a completely blind mode. For each model, the same protocol was followed and an ensemble of best performing parameter sets was selected. Signatures were first used to assess model performances in the different catchments during validation. Comparison of the models was then followed by evaluation of selected events, which include: low flows, high flows and the transition from low to high flows. While the models show rather similar performances based on general metrics (i.e. Nash-Sutcliffe Efficiency), clear differences can be observed for specific events. While most models are able to simulate high flows well, large differences are observed during low flows and in the ability to capture the first peaks after drier months. The transferability of model parameters to neighbouring and nested catchments is assessed as an additional measure in the model evaluation. This suggested approach helps to select, among competing
Serra, Catarina; Simões, Nuno; Tadeu, António
2015-05-01
This paper compares experimental and heat transfer modeling results for thermography applications in building elements. Over the years most building envelope inspections using infrared thermography (IRT) have been focused on qualitative analysis using mostly passive thermography techniques. However, increased need for the monitorization and assessment of the energy performance and thermal behavior of buildings, along with ongoing structural safety concerns, has raised interest in quantitative studies and active IRT applications in buildings. Numerous other fields have benefited from developments in defect detection studies and from countless non-destructive testing applications. Pulse phase thermography, in which phase images are studied (instead of temperature images) using a long heating pulse have been proposed to be the most effective for Civil Engineering applications. However, the particular characteristics of building elements and materials, along with the complex nature of heat transfer phenomena, demand specific experimental procedures and processing techniques. In this paper, analytical solutions to simulate heat transfer in the frequency domain in multi-layered media are used to compute thermal wave phase results. These are compared to experimental IRT phase analysis results of experiments performed on test specimens simulating building elements with embedded defects. Crucial test parameters such as test duration and defect characteristics are changed and their influence is studied. In this way, this paper contributes to the understanding of building envelope thermal patterns using active IRT in defect detection studies and to the definition of test parameters.
Richardson, D.E.
1993-01-01
This dissertation presents a model for spatial and thematic digital generalization. To do so, the development of digital generalization over the last thirty years is first reviewedThe approach to generalization taken in this research differs from other existing works as it tackles the task from a da
Directory of Open Access Journals (Sweden)
Somesekhar
2016-04-01
Full Text Available BACKGROUND The metabolic syndrome is currently a major worldwide epidemic. It strongly associates with obesity, insulin resistance, type 2 diabetes, and cardiovascular diseases, which are major pathologies contributing to mortality and morbidity worldwide. The effect of PPAR-y on metabolic syndrome is significant it is critical regulator of adipogenesis the gain in PPAR-y is resulted in obesity but loss of PPAR–y by mutation is associated with loss of weight and insulin resistance. Telmisartan is an orally active, long-acting, non-peptide angiotensin type 1 (ATI receptor blocker. In addition to this, it has been identified as partial agonist/selective modulator of the nuclear hormone receptor PPAR-y. MATERIAL AND METHOD This is a prospective, randomised and open labelled 16 weeks study conducted in the Dept. of General Medicine, Konaseema Institute of Medical Science, Amalapuram. Present study is designed to study the effect of telmisartan on various metabolic parameters in hypertensive patients who fulfilled the criteria of metabolic syndrome. RESULT There was statistically significant change in all parameters most important was lipid profile; LDL concentration was decreased from 139.2 mg/dL to 120.2 mg/dL. Baseline triglyceride concentration was 161.0 mg/dL which was changed 152.8 mg/dL Total cholesterol was decreased from 203.2 to 193.8 mg/dL. CONCLUSION In our study, we have also found that use of telmisartan is associated with decrease in lipid concentration in addition to its effect on blood pressure regulation. But a long term study with high dose required of this drug is required because safety profile of this drug is better than thiazolidinedione. Financial part of this study is our limitation.
National Research Council Canada - National Science Library
Davidson, Anew J; Morton, Neil S; Arnup, Sarah J; de Graaff, Jurgen C; Disma, Nicola; Withington, Davinia E; Frawley, Geoff; Hunt, Rodney W; Hardy, Pollyanna; Khotcholava, Magda; von Ungern Sternberg, Britta S; Wilton, Niall; Tuo, Pietro; Salvo, Ida; Ormond, Gillian; Stargatt, Robyn; Locatelli, Bruno Guido; McCann, Mary Ellen; Absalom, Anthony
2015-01-01
...) may reduce the risk; however, the evidence is weak. The General Anesthesia compared to Spinal anesthesia study is a randomized, controlled trial designed to assess the influence of general anesthesia (GA...
Numerical modeling of ozone production in a pulsed homogeneous discharge: A parameter study
Energy Technology Data Exchange (ETDEWEB)
Nilsson, J.O.; Eninger, J.E. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Industrial Electrotechnology
1997-02-01
The pulsed volume discharge is an alternative for the efficient generation of ozone in compact systems. This paper presents a parameter study of the reactions in this kind of homogeneous discharge by using a numerical model which solves plasma chemical kinetic rate and energy equations. Results are presented of ozone generation efficiency versus ozone concentration for different parameter combinations. Two parameter regimes are identified and analyzed. In the plasma phase ozone formation regime, where significant amounts of ozone are produced during the discharge pulse, it is found that higher ozone concentrations can be obtained than in the neutral phase ozone formation regime, where most of the ozone is formed after the discharge pulse. In the two-step ozone formation process, the rate of conversion of atomic oxygen plays a key role. In both regimes the ozone generation efficiency increases as n is increased or T{sub 0} decreased. The maximum concentration is 3% at 10 amagat and 100 K. The results on ozone accumulation in multiple pulse discharges are presented. In contrast to the single pulse case, higher efficiency is achieved at lower gas density. This scaling can be explained by losses due to ion currents. A tradeoff can be made between ozone generation efficiency and the number of pulses required to reach a certain concentration.
Study of process parameter on mist lubrication of Titanium (Grade 5) alloy
Maity, Kalipada; Pradhan, Swastik
2017-02-01
This paper deals with the machinability of Ti-6Al-4V alloy with mist cooling lubrication using carbide inserts. The influence of process parameter on the cutting forces, evolution of tool wear, surface finish of the workpiece, material removal rate and chip reduction coefficient have been investigated. Weighted principal component analysis coupled with grey relational analysis optimization is applied to identify the optimum setting of the process parameter. Optimal condition of the process parameter was cutting speed at 160 m/min, feed at 0.16 mm/rev and depth of cut at 1.6 mm. Effects of cutting speed and depth of cut on the type of chips formation were observed. Most of the chips forms were long tubular and long helical type. Image analyses of the segmented chip were examined to study the shape and size of the saw tooth profile of serrated chips. It was found that by increasing cutting speed from 95 m/min to 160 m/min, the free surface lamella of the chips increased and the visibility of the saw tooth segment became clearer.
Structural parameters and X-ray Debye temperature determination study on copper-ferrite-aluminates
Lakhani, V. K.; Pathak, T. K.; Vasoya, N. H.; Modi, K. B.
2011-03-01
The compositional dependence of structural parameters and X-ray Debye temperature for CuAl xFe 2- xO 4 ( x = 0.0, 0.2, 0.4 and 0.6) spinel ferrite system has been studied by means of X-ray powder diffraction (XRD) patterns analysis at 300 K. The XRD data have been used to determine the lattice constant, X-ray density, distribution of cations among the tetrahedral and octahedral sites of spinel lattice, oxygen positional parameter, site radii, bond angle, bond length and interionic distances. The X-ray Debye temperatures have been determined from integrated intensities of selected Bragg reflections. It is found that Al 3+-substitution has marked influence on various parameters. A deficit of Cu 2+-cations at the octahedral sites of the spinel lattice leads to the absence of co-operative active Jahn-Teller distortion and the crystal structure retains into cubic. The increasing disagreement between observed and calculated intensities and reduction in intensity of diffracted beam with increasing Al-concentration have been explained based on preferred orientation and extinction effects. The effect of oxygen deficiency on intensity ratios of planes has been discussed in brief.
Pandya, Ankur; Jha, Prafulla K.
2017-04-01
Electron transport parameters such as electron effective mass, Fermi velocity of an electron and electron mobility are calculated for transition metal [manganese (Mn), cobalt (Co)]-doped armchair graphene nanoribbon (aGNR) via polar acoustical phonon [piezoelectric (PZ)] scattering and acoustical deformation potential (ADP) scattering under a high electric field and different doping concentrations. Moreover, the effect of dopant site on these electron transport parameters is also investigated. It is observed that the electron effective mass is reduced significantly in doped aGNR in comparison to pure GNR. It is observed that the net electron mobility contributed by both ADP and PZ mechanisms for Mn-doped aGNR as well as Co-doped aGNR varies in similar fashion as semiconductors wherein the net electron mobility (ADP + PZ) for Mn-doped aGNR is greater than that for the Co-doped graphene nanoribbon. Moreover, it is found that there is no impact of variation in dopant site on the electron transport parameters considered in this study.
Study of linear optical parameters of sodium sulphide nano-particles added ADP crystals
Kochuparampil, A. P.; Joshi, J. H.; Dixit, K. P.; Jethva, H. O.; Joshi, M. J.
2017-05-01
Ammonium Dihydrogen Phosphate (ADP) is one of the nonlinear optical crystals. It is having various applications like optical mixing, electro-optical modulator, harmonic generators, etc. Chalcogenide compounds are poorly soluble in water and difficult to add in the water soluble ADP crystals. The solubility of Chalcogenide compounds can be increased by synthesizing the nano-structured samples with suitable capping agent. In the present study sodium sulphide was added in to ADP to modify its linear optical parameters. Sodium sulphide nano particles were synthesized by co-precipitation technique using Ethylene diamine as capping agent followed by microwave irradiation. The powder XRD confirmed the nano-structured nature of sodium sulphide nano particles. The solubility of nanoparticles of sodium sulphide increased significantly in water compared to the bulk. Pure and Na2S added ADP crystals were grown by slow solvent evaporation method at room temperature. The presence of sodium in ADP was confirmed by AAS. The UV-Vis spectra were recorded for all crystals. Various optical parameters like, transmittance, energy band gap, extinction coefficient, refractive index, optical conductivity, etc. were evaluated. The electronic polarizibility of pure and doped crystals calculated from energy band gap. The effect of doping concentration was found on various parameters.
Ríos, Francisco; Fernández-Arteaga, Alejandro; Lechuga, Manuela; Jurado, Encarnación; Fernández-Serrano, Mercedes
2016-05-01
This paper reports a study of the anaerobic biodegradation of non-ionic surfactants alkyl polyglucosides applying the method by measurement of the biogas production in digested sludge. Three alkyl polyglucosides with different length alkyl chain and degree of polymerization of the glucose units were tested. The influence of their structural parameters was evaluated, and the characteristics parameters of the anaerobic biodegradation were determined. Results show that alkyl polyglucosides, at the standard initial concentration of 100 mgC L(-1), are not completely biodegradable in anaerobic conditions because they inhibit the biogas production. The alkyl polyglucoside having the shortest alkyl chain showed the fastest biodegradability and reached the higher percentage of final mineralization. The anaerobic process was well adjusted to a pseudo first-order equation using the carbon produced as gas during the test; also, kinetics parameters and a global rate constant for all the involved metabolic process were determined. This modeling is helpful to evaluate the biodegradation or the persistence of alkyl polyglucosides under anaerobic conditions in the environment and in the wastewater treatment.
Effective parameter study for the facile and controlled growth of silver molybdate nano/micro rods
Montenegro, Javier Esteban Enríquez; Singh, Dinesh Pratap
2016-11-01
Controlled growth of nano/micro structures by controlling the effective parameters is the basic requirement for the application point of view in various areas. Here we report the facile growth of silver molybdate nano/micro rods by mixing the solution of silver nitrate and ammonium molybdate at ambient condition followed by hydrothermal treatment at various temperatures for 12 h. To achieve the goal for the synthesis of long, high yield and homogeneous nanorods various effective parameters have been studied to set the most effective conditions for the growth. Among possible effective parameters first the temperature of the furnace was set by warring the temperature and then at the set temperature the concentration of reactants (NH4)6Mo7O24 and silver nitrate are varied respect to each other. The pH and temperature values were monitored during the mixing of the reactants. Structural/microstructural characterization revealed the optimum condition of 150°C of the furnace and the concentration of (NH4)6Mo7O24 and silver nitrate as described in various tables.
Before–After Field Study of Effects of Wind Turbine Noise on Polysomnographic Sleep Parameters
Jalali, Leila; Bigelow, Philip; Nezhad-Ahmadi, Mohammad-Reza; Gohari, Mahmood; Williams, Diane; McColl, Steve
2016-01-01
Wind is considered one of the most advantageous alternatives to fossil energy because of its low operating cost and extensive availability. However, alleged health-related effects of exposure to wind turbine (WT) noise have attracted much public attention and various symptoms, such as sleep disturbance, have been reported by residents living close to wind developments. Prospective cohort study with synchronous measurement of noise and sleep physiologic signals was conducted to explore the possibility of sleep disturbance in people hosting new industrial WTs in Ontario, Canada, using a pre and post-exposure design. Objective and subjective sleep data were collected through polysomnography (PSG), the gold standard diagnostic test, and sleep diary. Sixteen participants were studied before and after WT installation during two consecutive nights in their own bedrooms. Both audible and infrasound noises were also concurrently measured inside the bedroom of each participant. Different noise exposure parameters were calculated (LAeq, LZeq) and analyzed in relation to whole-night sleep parameters. Results obtained from PSG show that sleep parameters were not significantly changed after exposure. However, reported sleep qualities were significantly (P=0.008) worsened after exposure. Average noise levels during the exposure period were low to moderate and the mean of inside noise levels did not significantly change after exposure. The result of this study based on advanced sleep recording methodology together with extensive noise measurements in an ecologically valid setting cautiously suggests that there are no major changes in the sleep of participants who host new industrial WTs in their community. Further studies with a larger sample size and including comprehensive single-event analyses are warranted. PMID:27569407
Before–after field study of effects of wind turbine noise on polysomnographic sleep parameters
Directory of Open Access Journals (Sweden)
Leila Jalali
2016-01-01
Full Text Available Wind is considered one of the most advantageous alternatives to fossil energy because of its low operating cost and extensive availability. However, alleged health-related effects of exposure to wind turbine (WT noise have attracted much public attention and various symptoms, such as sleep disturbance, have been reported by residents living close to wind developments. Prospective cohort study with synchronous measurement of noise and sleep physiologic signals was conducted to explore the possibility of sleep disturbance in people hosting new industrial WTs in Ontario, Canada, using a pre and post-exposure design. Objective and subjective sleep data were collected through polysomnography (PSG, the gold standard diagnostic test, and sleep diary. Sixteen participants were studied before and after WT installation during two consecutive nights in their own bedrooms. Both audible and infrasound noises were also concurrently measured inside the bedroom of each participant. Different noise exposure parameters were calculated (LAeq, LZeq and analyzed in relation to whole-night sleep parameters. Results obtained from PSG show that sleep parameters were not significantly changed after exposure. However, reported sleep qualities were significantly (P = 0.008 worsened after exposure. Average noise levels during the exposure period were low to moderate and the mean of inside noise levels did not significantly change after exposure. The result of this study based on advanced sleep recording methodology together with extensive noise measurements in an ecologically valid setting cautiously suggests that there are no major changes in the sleep of participants who host new industrial WTs in their community. Further studies with a larger sample size and including comprehensive single-event analyses are warranted.
Before-after field study of effects of wind turbine noise on polysomnographic sleep parameters.
Jalali, Leila; Bigelow, Philip; Nezhad-Ahmadi, Mohammad-Reza; Gohari, Mahmood; Williams, Diane; McColl, Steve
2016-01-01
Wind is considered one of the most advantageous alternatives to fossil energy because of its low operating cost and extensive availability. However, alleged health-related effects of exposure to wind turbine (WT) noise have attracted much public attention and various symptoms, such as sleep disturbance, have been reported by residents living close to wind developments. Prospective cohort study with synchronous measurement of noise and sleep physiologic signals was conducted to explore the possibility of sleep disturbance in people hosting new industrial WTs in Ontario, Canada, using a pre and post-exposure design. Objective and subjective sleep data were collected through polysomnography (PSG), the gold standard diagnostic test, and sleep diary. Sixteen participants were studied before and after WT installation during two consecutive nights in their own bedrooms. Both audible and infrasound noises were also concurrently measured inside the bedroom of each participant. Different noise exposure parameters were calculated (LAeq, LZeq) and analyzed in relation to whole-night sleep parameters. Results obtained from PSG show that sleep parameters were not significantly changed after exposure. However, reported sleep qualities were significantly (P = 0.008) worsened after exposure. Average noise levels during the exposure period were low to moderate and the mean of inside noise levels did not significantly change after exposure. The result of this study based on advanced sleep recording methodology together with extensive noise measurements in an ecologically valid setting cautiously suggests that there are no major changes in the sleep of participants who host new industrial WTs in their community. Further studies with a larger sample size and including comprehensive single-event analyses are warranted.
STUDY ON ADAPTIVE PARAMETER DETERMINATION OF CLUSTER ANALYSIS IN URBAN MANAGEMENT CASES
Directory of Open Access Journals (Sweden)
J. Y. Fu
2017-09-01
Full Text Available The fine management for cities is the important way to realize the smart city. The data mining which uses spatial clustering analysis for urban management cases can be used in the evaluation of urban public facilities deployment, and support the policy decisions, and also provides technical support for the fine management of the city. Aiming at the problem that DBSCAN algorithm which is based on the density-clustering can not realize parameter adaptive determination, this paper proposed the optimizing method of parameter adaptive determination based on the spatial analysis. Firstly, making analysis of the function Ripley's K for the data set to realize adaptive determination of global parameter MinPts, which means setting the maximum aggregation scale as the range of data clustering. Calculating every point object’s highest frequency K value in the range of Eps which uses K-D tree and setting it as the value of clustering density to realize the adaptive determination of global parameter MinPts. Then, the R language was used to optimize the above process to accomplish the precise clustering of typical urban management cases. The experimental results based on the typical case of urban management in XiCheng district of Beijing shows that: The new DBSCAN clustering algorithm this paper presents takes full account of the data’s spatial and statistical characteristic which has obvious clustering feature, and has a better applicability and high quality. The results of the study are not only helpful for the formulation of urban management policies and the allocation of urban management supervisors in XiCheng District of Beijing, but also to other cities and related fields.
Study on Adaptive Parameter Determination of Cluster Analysis in Urban Management Cases
Fu, J. Y.; Jing, C. F.; Du, M. Y.; Fu, Y. L.; Dai, P. P.
2017-09-01
The fine management for cities is the important way to realize the smart city. The data mining which uses spatial clustering analysis for urban management cases can be used in the evaluation of urban public facilities deployment, and support the policy decisions, and also provides technical support for the fine management of the city. Aiming at the problem that DBSCAN algorithm which is based on the density-clustering can not realize parameter adaptive determination, this paper proposed the optimizing method of parameter adaptive determination based on the spatial analysis. Firstly, making analysis of the function Ripley's K for the data set to realize adaptive determination of global parameter MinPts, which means setting the maximum aggregation scale as the range of data clustering. Calculating every point object's highest frequency K value in the range of Eps which uses K-D tree and setting it as the value of clustering density to realize the adaptive determination of global parameter MinPts. Then, the R language was used to optimize the above process to accomplish the precise clustering of typical urban management cases. The experimental results based on the typical case of urban management in XiCheng district of Beijing shows that: The new DBSCAN clustering algorithm this paper presents takes full account of the data's spatial and statistical characteristic which has obvious clustering feature, and has a better applicability and high quality. The results of the study are not only helpful for the formulation of urban management policies and the allocation of urban management supervisors in XiCheng District of Beijing, but also to other cities and related fields.
Parameter sensitivity study of the biogeochemical model in the China coastal seas
Institute of Scientific and Technical Information of China (English)
JI Xuanliang; LIU Guimei; GAO Shan; WANG Hui
2015-01-01
In order to develop a coupled basin scale model of ocean circulation and biogeochemical cycling, we present a biogeochemical model including 12 components to study the ecosystem in the China coastal seas (CCS). The formulation of phytoplankton mortality and zooplankton growth are modified according to biological characteristics of CCS.The four sensitivity biological parameters, zooplankton assimilation efficiency rate (ZooAE_N), zooplankton basal metabolism rate (ZooBM), maximum specific growth rate of zooplankton (μ20) and maximum chlorophyll to carbon ratio (Chl2C_m) are obtained in sensitivity experiments for the phytoplankton, and experiments about the parameterμ20, half-saturation for phytoplankton NO3 uptake ( KNO3 ) and remineralization rate of small detritusN (SDeRRN) are conducted. The results demonstrate that the biogeochemical model is quite sensitive to the zooplankton grazing parameter when it ranges from 0.1 to 1.2 d–1. The KNO3 and SDeRRN also play an important role in determining the nitrogen cycle within certain ranges.The sensitive interval of KNO3 is from 0.1 to 1.5 (mmol/m3)–1, and interval of SEdRRN is from 0.01 and 0.1 d–1. The observational data from September 1998 to July 2000 obtained at SEATS station are used to validate the performance of biological model after parameters optimization. The results show that the modified model has a good capacity to reveal the biological process features, and the sensitivity analysis can save computational resources greatly during the model simulation.
The FERMI @ Elettra Technical Optimization Study: PreliminaryParameter Set and Initial Studies
Energy Technology Data Exchange (ETDEWEB)
Byrd, John; Corlett, John; Doolittle, Larry; Fawley, William; Lidia, Steven; Penn, Gregory; Ratti, Alex; Staples, John; Wilcox,Russell; Wurtele, Jonathan; Zholents, Alexander
2005-08-01
The goal of the FERMI {at} Elettra Technical Optimization Study is to produce a machine design and layout consistent with user needs for radiation in the approximate ranges 100 nm to 40 nm, and 40 nm to 10 nm, using seeded FEL's. The Study will involve collaboration between Italian and US physicists and engineers, and will form the basis for the engineering design and the cost estimation.
İpekdal, İlker H; Karadaş, Ömer; Ulaş, Ümit H; Vural, Okay
2013-01-01
This study aimed to compare the cortical excitability of patients with generalized tonic-clonic seizures (GTCSs) and that of patients with psychogenic non-epileptic seizures (PNESs). Patients were classified into groups according to their electroencephalogram (EEG) findings and seizure types: group 1 = GTCS with an abnormal EEG, group 2 = GTCS with a normal EEG and group 3 = PNES with a normal EEG. The control group included healthy volunteers with normal EEGs. Cortical silent period (CSP) and motor threshold (MT) were measured for all groups and the results were compared. CSPs were significantly prolonged in groups 1 and 2 when compared with group 3 and the control group. No differences were found between the MT measurements of all groups. The prolongation of CSP may demonstrate the differences between the pathophysiological mechanisms of GTCS and those of PNES. Copyright © 2012 S. Karger AG, Basel.
A study of relative permeability parameters on rock cores using a two-phase flow test
Directory of Open Access Journals (Sweden)
Chung-Hui Chiao
2017-01-01
Full Text Available To ensure sequestration safety, confirming the injectivity of the reservoir rock formation is of critical importance, requiring studies of the rock permeability to uncover the fluid migration scenarios within the porous reservoir rock. Two-phase (super-critical CO2-brine flow behavior following the post CO2 injection is believed to be a dominating factor; its flooding behavior within the porous rock media needs to be further clarified prior to confirming the feasibility of domestic CO2 geo-sequestration. This study aims to determine the relative permeability of rock cores obtained from field outcropping. A test facility was established to determine the relative permeability during drainage and imbibition processes using a core-flooding test characterized by displacement method. The test facility was assembled locally and is regarded as a pioneering attempt. By relevant data interpretation, the parameters of relative permeability for predicting the movement of super-critical CO2 after injection can be modeled. More reliable parameters can be obtained using history matching processes wherein time-elapsed data calibration is used in conjunction with a computer code, TOUGH2. The test results were iteratively calibrated using numerical simulation by conducting a history matching process. The K-S curves derived from best-fit parameters are believed to be the most relevant relative permeability for the reservoir rock. Through this preliminary study, a better understanding of some of the problems and limitations associated with the determination of the rock relative permeability using two-phase flow test is achieved, but more advanced research is required.
An X-ray diffraction study of defect parameters in a Ti-base alloy
Indian Academy of Sciences (India)
G Karmaker; P Mukherjee; A K Meikap; S K Chattopadhyay; S K Chatterjee
2001-12-01
Detailed studies based on the well established method of Fourier line shape analysis have been made on the X-ray diffraction profile of hexagonal titanium alloy of nominal composition Ti–6.58% Al–3.16% Mo–1.81% Zr–0.08% Fe–0.012% N–0.0078% C. While deformation fault probability, , has been found to be quite high compared to that of pure titanium, the deformation growth fault parameter, , shows a negative value ruling out the presence of growth fault in this alloy in the deformed state.
Energy Technology Data Exchange (ETDEWEB)
Kim, Yong Il; Choi, Chan Kyu; Yoo, Hong Hee [Hanyang University, Seoul (Korea, Republic of)
2012-01-15
For the design of a MEMS accelerometer, proper performance indices should be defined and employed. Performance indices are obtained using either an experimental method or a numerical method. In the present study, a vibration analysis model of a MEMS accelerometer is introduced to calculate three performance indices: sensitivity, measurable acceleration range, and measurable frequency range. The accuracy of the vibration analysis model is first validated by comparing its modal and transient results with those of a commercial finite element code. Measurable acceleration and frequency ranges versus allowable errors for electrical and mechanical sensitivities are obtained and the effects of system parameter variations on the three performance indices are investigated.
Directory of Open Access Journals (Sweden)
Mebrouk Djedid
2015-06-01
Full Text Available Most of the synthesized compounds which have liquid crystalline character in their composition comprise aromatic molecules. Furthermore there are few jobs that replace this type of molecules by inhomogeneous molecules that have LC character. We will replace the aromatic rings by units of 1,3,4-oxadiazole and study the effects of these new components of the transition temperatures and the Thermodynamic characteristics of n- alkanes in these two LC's phases. have been investigated by inverse gas chromatography. The transition temperatures obtained by GC are in good agreement with those found by DSC. The results are interpreted in terms of parameters “b” and related thermodynamic quantities
STUDY OF THE PARAMETERS OF EFFICIENCY IN CENTRES FOR REPAIR OF AGRICULTURAL MACHINERY
Directory of Open Access Journals (Sweden)
Natalia Stoyanova
2015-06-01
Full Text Available The paper makes a thorough study of the parameters of efficiency in the centers for the repair of agricultural machinery, considering production and technological structure, the basic principles for design of the process of service, the quantitative indicators for servicing. It presents a theoretical model for the management of services in the service business, taking into account the basic system requirements for maintenance of agricultural machinery, the main elements of the standards of customer service, choice of forms for maintenance of agricultural machinery. Opportunities are proposed for the optimization of repair activities in the centers for repair of agricultural machinery.
2013-11-14
... National Park Service Draft General Management Plan/Wilderness Study/Environmental Impact Statement... availability of a Draft General Management Plan (GMP)/Wilderness Study/Environmental Impact Statement (EIS) for... action alternative) reflects current management direction and serves as a baseline for comparison with...
Educational needs of general practitioners in palliative care : Outcome of a focus group study
Meijler, WJ; Van Heest, F; Otter, R; Sleijfer, DT
2005-01-01
Background. The objective of this study was to identify the general practitioner's perception of educational needs in palliative care. Method. A qualitative study with focus groups was performed. Results. General practitioners estimate palliative care as an important and valuable part of primary car
REMOVAL OF BORON USING CLAY-EFFECT OF PROCESS PARAMETERS,KINETIC AND ISOTHERM STUDIES
Directory of Open Access Journals (Sweden)
N. RAJAMOHAN
2016-03-01
Full Text Available In this study, a low-cost eco-friendly adsorbent was prepared from naturally available sarooj clay and is proposed for the removal of boron from aqueous phase. The effect of process parameters, namely initial pH, sorbent quantity, initial boron concentration, shaking speed and temperature were studied on the metal uptake under batch conditions. The process efficiency was observed to be strongly parameter dependent and the optimal pH was found to be 10.0.The uptake capacity decreased with increase in sorbent dose and increased with boron concentration. Temperature was found to have a positive influence confirming the endothermic nature of the process. Equilibrium sorption data were analysed using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm and represented well by Freundlich isotherm. The Freundlich constant was evaluated as 14.791 L g-1 at 35 °C.The mechanism of sorption was investigated using kinetic models, namely, pseudo-second order and intraparticle diffusion models .The batch experimental fitted well to pseudo-second order model and the rate constant was found to be 0.0017 g mg-1min-1 with an initial boron concentration of 100 mg L-1. The sorbent characteristics were studied using X-ray diffraction, scanning electron microscope with energy dispersive X-ray detector and X-ray fluorescence methods.
A study on parameter variation effects on battery packs for electric vehicles
Zhou, Long; Zheng, Yuejiu; Ouyang, Minggao; Lu, Languang
2017-10-01
As one single cell cannot meet power and driving range requirement in an electric vehicle, the battery packs with hundreds of single cells connected in parallel and series should be constructed. The most significant difference between a single cell and a battery pack is cell variation. Not only does cell variation affect pack energy density and power density, but also it causes early degradation of battery and potential safety issues. The cell variation effects on battery packs are studied, which are of great significant to battery pack screening and management scheme. In this study, the description for the consistency characteristics of battery packs was first proposed and a pack model with 96 cells connected in series was established. A set of parameters are introduced to study the cell variation and their impacts on battery packs are analyzed through the battery pack capacity loss simulation and experiments. Meanwhile, the capacity loss composition of the battery pack is obtained and verified by the temperature variation experiment. The results from this research can demonstrate that the temperature, self-discharge rate and coulombic efficiency are the major affecting parameters of cell variation and indicate the dissipative cell equalization is sufficient for the battery pack.
Van Der Kloet, Dalena; Giesbrecht, Timo; Franck, Erik; Van Gastel, Ann; De Volder, Ilse; Van Den Eede, Filip; Verschuere, Bruno; Merckelbach, Harald
2013-08-01
Dissociative disorders encompass a range of symptoms varying from severe absent-mindedness and memory problems to confusion about one's own identity. Recent studies suggest that these symptoms may be the by-products of a labile sleep-wake cycle. In the current study, we explored this issue in patients suffering from insomnia (N=46). We investigated whether these patients have raised levels of dissociative symptoms and whether these are related to objective sleep parameters. Patients stayed for at least one night in a specialized sleep clinic, while sleep EEG data were obtained. In addition, they completed self-report measures on dissociative symptoms, psychological problems, and sleep characteristics. Dissociative symptom levels were elevated in patients suffering from insomnia, and were correlated with unusual sleep experiences and poor sleep quality. Longer REM sleep periods and less time spent awake during the night were predictive of dissociation. This is the first study to show that insomnia patients have raised dissociative symptom levels and that their dissociative symptoms are related to objective EEG parameters. These findings are important because they may inspire sleep-related treatment methods for dissociative disorders. Copyright © 2013 Elsevier Inc. All rights reserved.
Toghi Eshghi, Amin; Lee, Soobum; Lee, Hanmin; Kim, Young-Cheol
2016-04-01
In this paper, we perform design parameter study and design optimization for a piezoelectric energy harvester considering vehicle speed variation. Initially, a FEM model using ANSYS is developed to appraise the performance of a piezoelectric harvester in a rotating tire. The energy harvester proposed here uses the vertical deformation at contact patch area from the car weight and centrifugal acceleration. This harvester is composed of a beam which is clamped at both ends and a piezoelectric material is attached on the top of that. The piezoelectric material possesses the 31 mode of transduction in which the direction of applied field is perpendicular to that of the electric field. To optimize the harvester performance, we would change the geometrical parameters of the harvester to obtain the maximum power. One of the main challenges in the design process is obtaining the required power while considering the constraints for harvester weight and volume. These two concerns are addressed in this paper. Since the final goal of this study is the development of an energy harvester with a wireless sensor system installed in a real car, the real time data for varied velocity of a vehicle are taken into account for power measurements. This study concludes that the proposed design is applicable to wireless tire sensor systems.
Study and optimization of thermo-physical parameters for a solar-still performance
Energy Technology Data Exchange (ETDEWEB)
Kaabi, A.; Zaidi, H. [Constantine Univ., Constantine (Algeria)
2006-07-01
The thermo-physical parameters of a static solar still with a greenhouse effect were studied. The simulation was conducted for each component of the still at the same initial temperature and time step. Analyzed parameters included the solar collector; brine; absorber; and insulator. The thermophysical changes of different still components were analyzed as well as their impacts on the solar still's output. The aim of the study was to enhance distilled water production. A Gauss-Seidel iterative method was used to solve thermophysical equations. Results of the study showed that maximum hourly production of distilled water was reached at 13:00 PM, when temperatures differences between the brine and the inner side of the still had a significant impact on system productivity. Three types of material were tested: copper, aluminum, and steel. Copper gave improved production, higher thermal conductivity; higher heat, and an improved coefficient of absorption. Production of distilled water increased when a black layer of nickel was added to the still. It was concluded that solar still efficiency increased when the absorber had a high thermal conductivity and a high specific heat. 14 refs., 6 figs.
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
Noreikaitė, Aurelija; Saint-Marcoux, Franck; Marquet, Pierre; Kaduševičius, Edmundas; Stankevičius, Edgaras
2017-03-01
The objective of the present study was to assess the effect of cyclosporine (CsA) on the pharmacokinetic parameters of mycophenolic acid (MPA), an active mycophenolate mofetil (MMF) metabolite, and to compare with the effect of everolimus (EVR).Anonymized medical records of 404 kidney recipients were reviewed. The main MPA pharmacokinetic parameters (AUC(0-12) and Cmax) were evaluated.The patients treated with a higher mean dose of CsA displayed higher MPA AUC(0-12) exposure in the low-dose MMF group (1000 mg/day) (40.50 ± 10.97 vs 28.08 ± 11.03 h mg/L; rs = 0.497, P MMF group (2000 mg/day) (43.00 ± 6.27 vs 28.85 ± 11.08 h mg/L; rs = 0.437, P MMF group (3000 mg/day) (56.75 ± 16.78 vs 36.20 ± 3.70 h mg/L; rs = 0.608, P MMF group (Cmax 22.83 ± 10.82 vs 12.08 ± 5.59 mg/L; rs = 0.507, P MMF group (22.77 ± 8.86 vs 13.00 ± 6.82 mg/L; rs = 0.414, P MMF + CsA and MMF + EVR) showed that MPA AUC(0-12) exposure was by 43% higher in the patients treated with a medium dose of MMF and EVR than in the patients treated with a medium dose of MMF and CsA.The data of the present study suggest a possible CsA versus EVR influence on MMF pharmacokinetics. Study results show that CsA has an impact on the main MPA pharmacokinetic parameters (AUC(0-12) and Cmax) in a CsA dose-related manner, while EVR mildly influence or does not affect MPA pharmacokinetic parameters. Low-dose CsA (lower than 180 mg/day) reduces MPA AUC(0-12) exposure under the therapeutic window and may lead to ineffective therapy, while a high-dose CsA (>240 mg/day) is related to greater than 10 mg/L MPA Cmax and increases the likelihood of adverse events.
A study on plasma parameters in Ar/SF6 inductively coupled plasma
Oh, Seung-Ju; Lee, Hyo-Chang; Chung, Chin-Wook
2017-01-01
Sulfur hexafluoride (SF6) gas or Ar/SF6 mixing gas is widely used in plasma processes. However, there are a little experimental studies with various external parameters such as gas pressure and mixing ratio. In this work, a study of the plasma parameters by changing the gas mixing ratio was done in an Ar/SF6 inductively coupled plasma from the measurement of the electron energy distribution function. At a low gas pressure, as the mixing ratio of SF6 gas increased at a fixed inductively coupled plasma (ICP) power, the electron density decreased and the electron temperature increased, while they were not changed drastically. At a high gas pressure, a remarkable increase in the electron temperature was observed with the decrease in the electron density. These variations are due to the electron loss reactions such as the electron attachment. It was also found that at a fixed ICP power, the negative ion creation with the diluted SF6 gas can change the discharge mode transition from an inductive mode to a capacitive mode at the high gas pressure. The electron attachment reactions remove the low energy electrons and change the mean electron energy towards higher energies with diluting SF6 gas at high pressure. The measured results were compared with the simplified global model, and the global model is in relatively good agreement with the measured plasma parameters except for the result in the case of the large portion of SF6 gas at the high pressure and the capacitive mode, which causes strong negative ion formation by the electron attachment reactions.
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K. Schneider-Zapp
2009-12-01
Full Text Available Evaporation is an important process in soil-atmosphere interaction. The determination of hydraulic properties is one of the crucial parts in the simulation of water transport in porous media. Schneider et al. (2006 developed a new evaporation method to improve the estimation of hydraulic properties in the dry range. In this study we used numerical simulations of the experiment to study the physical dynamics in more detail, to optimise the boundary conditions and to choose the optimal combination of measurements. The physical analysis exposed, in accordance to experimental findings in the literature, two different evaporation regimes, a soil-atmosphere boundary layer dominated regime (regime I in the saturated region and a hydraulically dominated regime (regime II. During this second regime a drying front forms which penetrates deeper into the soil as time passes. The sensitivity analysis showed that the result is especially sensitive at the transition between the two regimes. By using boundary condition changes it is possible to force the system to switch between the two regimes, e.g. from II back to I. Based on this findings a multistep experiment was developed. The response surfaces for all parameter combinations are flat and have a unique, localised minimum. Best parameter estimates are obtained if the evaporation flux and a potential measurement in 2 cm depth are used as target variables. Parameter estimation from simulated experiments with realistic measurement errors with a two-stage Monte-Carlo Levenberg-Marquardt procedure and manual rejection of obvious misfits lead to acceptable results for three different soil textures.
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K. Schneider-Zapp
2010-05-01
Full Text Available Evaporation is an important process in soil-atmosphere interaction. The determination of hydraulic properties is one of the crucial parts in the simulation of water transport in porous media. Schneider et al. (2006 developed a new evaporation method to improve the estimation of hydraulic properties in the dry range. In this study we used numerical simulations of the experiment to study the physical dynamics in more detail, to optimise the boundary conditions and to choose the optimal combination of measurements. The physical analysis exposed, in accordance to experimental findings in the literature, two different evaporation regimes: (i a soil-atmosphere boundary layer dominated regime (regime I close to saturation and (ii a hydraulically dominated regime (regime II. During this second regime a drying front (interface between unsaturated and dry zone with very steep gradients forms which penetrates deeper into the soil as time passes. The sensitivity analysis showed that the result is especially sensitive at the transition between the two regimes. By changing the boundary conditions it is possible to force the system to switch between the two regimes, e.g. from II back to I. Based on this findings a multistep experiment was developed. The response surfaces for all parameter combinations are flat and have a unique, localised minimum. Best parameter estimates are obtained if the evaporation flux and a potential measurement in 2 cm depth are used as target variables. Parameter estimation from simulated experiments with realistic measurement errors with a two-stage Monte-Carlo Levenberg-Marquardt procedure and manual rejection of obvious misfits lead to acceptable results for three different soil textures.
Zúñiga-Benítez, Henry; Peñuela, Gustavo A
2017-03-01
Methylparaben (MePB) is an organic compound employed mainly in the manufacture of different personal care products. However, it has been recently listed as a potential endocrine disrupter chemical. Therefore, the main objective of this work was to evaluate the degradation of MePB in aqueous solutions using heterogeneous photocatalysis with TiO2 and hydrogen peroxide. In this way, effects of pH and the initial concentrations of catalyst, H2O2, and pollutant on treatment were analyzed. A face centered, central composite design was used for determination of the influence of each parameter in the process and the conditions under which the pollutant suffers the highest rates of degradation were selected. In general, results indicate that combination TiO2/H2O2/light irradiation leads to ∼90 % of substrate removal after 30 min of reaction and that hydroxyl free radicals are the main specie responsible for organic matter elimination. Finally, in terms of mineralization and biodegradability, experimental results indicated that part of the organic matter was transformed into CO2 and water and the photo-treatment promoted an increase in samples biodegradability.
Neurotoxic effect of maneb in rats as studied by neurochemical and immunohistochemical parameters
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Nielsen, Brian Svend; Larsen, Erik Huusfeldt; Ladefoged, Ole;
2006-01-01
Epidemiological investigations document that workers in agriculture, horticulture and people living near areas with frequent use of pesticides have increased risk of developing symptoms of Parkinson's disease. This study investigated the neurotoxic effect of the fungicide maneb by morphological, ......-synuclein and synaptophysin in corpus striatum and the rest of the brain were not changed. No histological parameter was affected when studied in corpus striatum, and substantia nigra.......Epidemiological investigations document that workers in agriculture, horticulture and people living near areas with frequent use of pesticides have increased risk of developing symptoms of Parkinson's disease. This study investigated the neurotoxic effect of the fungicide maneb by morphological......) increased in a dose-related manner, as did the 5-HT concentrations in the rest of the brain indicating early sign of neurotoxicity. Striatal acetylcholinesterase activity was not affected. The concentrations of noradrenaline, dopamine, neurotransmitter amino acids and the levels of the proteins alpha...
PARAMETERS STUDIED FOR DEVELOPMENT OF GYMNEMA SYLVESTRE LEAF EXTRACTS: AS INJECTABLE ANTI-DIABETIC
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Killedar Suresh Ganpati
2012-04-01
Full Text Available In the present study a novel attempt has been made to consider the various parameters for development of Gymnema leaf extracts for injectable dosage form. Ethanolic and Water extracts of leaves were obtained by decoction and filtered through whatman paper no-1. Extracts were dried in vacuum dryer and stability and solubility was studied. Phytochemical screening and TLC study was carried out. Injections of different strength of dried extracts were made using normal saline and sterilized by autoclaving. The samples were then evaluated for quality control tests and content variation test by TLC and scanning densitometer. Dried extracts were found stable up to 390C and 65% relative humidity. Liquid extracts showed presence of triterpenoids, sugars and proteins. By TLC it was confirmed that Gymnemic acid-I found to be major active constituent.
Membrane reactor for water detritiation: a parametric study on operating parameters
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Mascarade, J.; Liger, K.; Troulay, M.; Perrais, C. [CEA, DEN, DTN/STPA/LIPC, Centre de Cadarache, Saint-Paul-lez-Durance (France); Joulia, X.; Meyer, X.M. [Universite de Toulouse, INPT, UPS, Laboratoire de Genie Chimique, Toulouse (France); CNRS, Laboratoire de Genie Chimique, Toulouse (France)
2015-03-15
This paper presents the results of a parametric study done on a single stage finger-type packed-bed membrane reactor (PBMR) used for heavy water vapor de-deuteration. Parametric studies have been done on 3 operating parameters which are: the membrane temperature, the total feed flow rate and the feed composition through D{sub 2}O content variations. Thanks to mass spectrometer analysis of streams leaving the PBMR, speciation of deuterated species was achieved. Measurement of the amounts of each molecular component allowed the calculation of reaction quotient at the packed-bed outlet. While temperature variation mainly influences permeation efficiency, feed flow rate perturbation reveals dependence of conversion and permeation properties to contact time between catalyst and reacting mixture. The study shows that isotopic exchange reactions occurring on the catalyst particles surface are not thermodynamically balanced. Moreover, the variation of the heavy water content in the feed exhibits competition between permeation and conversion kinetics.
Influence of occlusal loading on peri-implant clinical parameters. A pilot study.
Pellicer-Chover, Hilario; Viña-Almunia, José; Romero-Millán, Javier; Peñarrocha-Oltra, David; García-Mira, Berta; Peñarrocha-Diago, María
2014-05-01
To investigate the relation between occlusal loading and peri-implant clinical parameters (probing depth, bleeding on probing, gingival retraction, width of keratinized mucosa, and crevicular fluid volume) in patients with implant-supported complete fixed prostheses in both arches. This clinical study took place at the University of Valencia (Spain) dental clinic. It included patients attending the clinic for regular check-ups during at least 12 months after rehabilitation of both arches with implant-supported complete fixed ceramo-metallic prostheses. One study implant and one control implant were established for each patient using the T-Scan®III computerized system (Tesco, South Boston, USA). The maxillary implant closest to the point of maximum occlusal loading was taken as the study implant and the farthest (with least loading) as the control. Occlusal forces were registered with the T-Scan® III and then occlusal adjustment was performed to distribute occlusal forces correctly. Peri-implant clinical parameters were analyzed in both implants before and two and twelve months after occlusal adjustment. Before occlusal adjustment, study group implants presented a higher mean volume of crevicular fluid (51.3 ± 7.4 UP) than the control group (25.8 ± 5.5 UP), with statistically significant difference. Two months after occlusal adjustment, there were no significant differences between groups (24.6 ± 3.8 UP and 26 ± 4.5 UP respectively) (p=0.977). After twelve months, no significant differences were found between groups (24.4 ± 11.1 UP and 22.5 ± 8.9 UP respectively) (p=0.323). For the other clinical parameters, no significant differences were identified between study and control implants at any of the study times (p>0.05). Study group implants receiving higher occlusal loading presented significantly higher volumes of crevicular fluid than control implants. Crevicular fluid volumes were similar in both groups two and twelve months after occlusal adjustment.
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Amit K. Sharma
2011-02-01
Full Text Available The design of photoreactor and its modeling parameters for removal of environmental pollutants in water are described. The work will provide the instructions to design of photoreactor with modeling parameters, and to allow these parameters to communicate degradation efficiency of the analyte in water samples. The modeling parameters are outlined by which the photoreactor can use UV source to degrade the composition of pollutant. The operation of degradation through photoreactor is applied to the study of degradation rate of pollutant i.e. malathion and the produced informative data at various time intervals also correlated with UV-vis spectrophotometry for the validation of results. The purpose of designed photoreactor is to know the best percentage degradability of pollutants at micro to nano gram levels using nanosemiconductor sensitizer like TiO2. Such designs promises the high impact at very low levels, less time consuming process, low consumable solvents and suit for field application purposes which focuses the merits of the designed photoreactor.
[Study on molecular chain morphology and chain parameters of konjac glucomannan].
Li, Bin; Xie, Bi-jun
2003-11-01
To study the molecular chain morphology and chain parameters of konjac glucomannan (KGM). Solution behavior was studied by using light scattering(LS), gel permeation chromatograph (GPC) and method of viscosity. The molecular morphology was observed directly by atom force microscope (AFM) and transmission electron microscope (TEM). The average molecular weight (Mw), root-mean-square ratio of gyration(1/2), second Viral coefficients (A2) and multi-disperse coefficients (Mw/Mn) are 1.04 x 10(6), 105.0 +/- 0.9 nm, (-1.59 +/- 0.28) x 10(-3) mol.mL.g-2 and (1.020 +/- 0.003) respectively; Mark-Houwink equation was established as [eta] = 5.96 x 10(-2) Mw0.73, the molecular chain parameters were as follows: ML = 982.82 nm-1, q = 27.93 nm, d = 0.74 nm, h = 0.26 nm, L = 1,054.11 nm. Both the result showed by direct observation and the deduction drawn by solution behavior confirmed that the KGM molecular is stentering semi-flexible linear chain without branch.
Zhang, Anying; Pang, Xiaofeng; Yuan, Ping
2007-02-01
With the development of economy and coming of information era, the chance of exposure to electromagnetic fields with various frequencies has been increased for every human. The effects of electromagnetic radiattion on human being's health are versatile. To study the effects of bioelctronic parameters of rats in the electromagnetic radiations of HV transmission line, EEG, ECG and CMAP were measured in rats exposed to simulating high-voltage transmission line electromagnetic radiation for over one year. Brain tissues were studied by Fourier transform infrared spectroscopy. The results showed that no significant difference between exposed group and control group in EEG; however the FT-infrared spectra of brain tissues were different; the ECG of the exposed animals was considerably altered. Significant slowing of heart rate was observed in those rates exposed to EMFs; the latent period of CMAP in exposed group were not different compared with those of control group however there was a significant difference in wave amplitude of CMAP between the exposed group and control group. All results indicated that there must be some effects on bioelectric parameters of rats exposed to electromagnetic radiation of high-voltage transmission line for a long time.
Taş, Nilay; Korkmaz, Hakan; Yağan, Özgür; Korkmaz, Mukadder
2015-01-01
Backround Sugammadex is a reversal agent with well known advantages but it’s effects on haemostasis and bleeding have been a topic of interest. Septoplasty is a common surgical procedure with postoperative respiratory complications and bleeding. The aim of this study is to investigate the effects of sugammadex on postoperative coagulation parameters and bleeding after septoplasty procedure. Material/Methods In this randomized controlled study, fifty patients were grouped into two groups; neostigmine (Group N) vs. sugammadex (Group S). For the evaluation of PT, aPTT and INR, blood samples were taken for at the postoperative 120th minutes and alteration of these values with respect to preoperative values were documented. Postoperative bleeding was measured by evaluating the amount of blood absorbed on the nasal tip dressing during 3 hours postoperatively. Results Postoperative bleeding amount was significantly higher in the Group S compared to Group N (p=0.013). No significant difference was observed between two groups according to coagulation parameters (PT; p=0.953, aPTT; p=0.734, INR; p=0.612). Conclusions Sugammadex was associated with higher amount of postoperative bleeding than neostigmine in septoplasty patients. In surgical procedures having high risk of bleeding the safety of sugammadex need to be verified. PMID:26271275
Bickel, David R
2011-01-01
By leveraging recent advances in J. Rissanen's information-theoretic approach to model selection that has historical roots in the minimum description length (MDL) of a message, the Bayes-compatibility criterion of A. W. F. Edwards is recast in terms of predictive distributions to make the measure of support robust not only in the presence of nuisance parameters but also in the presence of multiple studies and multiple comparisons within each study. To qualify as a measure of support, a statistic must asymptotically approach the difference between the posterior and prior log-odds, where the parameter distributions considered are physical in the empirical Bayes or random effects sense that they correspond to real frequencies or proportions, e.g., of hypotheses, whether or not the distributions can be estimated and even whether or not data pertaining to the hypotheses are available. Because that Bayes-compatibility condition is weak, an optimality criterion is needed to uniquely specify a measure of support. Two...
Kang, Danbee; Kim, Im-Ryung; Im, Young Hyuck; Park, Yeon Hee; Ahn, Jin Seok; Lee, Jeong Eon; Nam, Seok Jin; Park, Hyeokgon; Kim, Eunjoo; Lee, Hae Kwang; Lee, Dong-Youn; Cho, Juhee
2015-08-01
The objective of this study is to evaluate objective changes in water content, sebum content, transepidermal water loss (TEWL), and melanin due to breast cancer chemotherapy, and their association with subjective symptoms. Prospective cohort study of 61 patients 18 years of age or older with a postoperative diagnosis of stage I-III breast cancer, who received adjuvant chemotherapy between February and September 2012 at an outpatient breast cancer clinic in Korea. Objective skin parameters, measured using a noninvasive bioengineering device, and patient-reported dryness and dullness were assessed before chemotherapy, after two cycles of chemotherapy, and 1, 3, and 6 months after completion of chemotherapy. Water content (-6.5 %), sebum (-75.5 %), and TEWL (-22.4 %) significantly decreased during chemotherapy compared to pre-chemotherapy levels (all p values skin changes were similar in patients with or without hormone therapy. Most of patients reported dryness (57.9 %) and dullness (49.1 %) after chemotherapy, and patient-reported dryness was significantly associated with decreased sebum content. Chemotherapy-induced substantial changes in objective skin composition parameters. These changes persisted after 6 months from completion of chemotherapy and were associated with patient-reported symptoms. Additional research is needed to translate these findings into interventions for improving the dermatologic quality of life of breast cancer patients undergoing chemotherapy.
In-vitro study of methylglyoxal and aspirin effects on fibrinolysis parameters.
Pouya, Fahima D; Zavar-Reza, Javad; Jalali, Beman A
2013-10-01
Methylglyoxal is a reactive α, β dicarbonyl aldehyde compound that originates from various biochemical pathways. Some studies suggest that increased methylglyoxal in blood leads to changes in fibrinolysis; however, the precise mechanism is not clear. The aim of this study was to compare different concentrations of methylglyoxal and aspirin on fibrinolysis in the plasma of healthy individuals in vitro. Different concentrations of methylglyoxal (5, 50, 100, and 500 μmol/l) and aspirin (1, 10, and 100 mg/l) were added to the plasma citrate. They were incubated at 37°C for 24 h. Then, fibrinolysis parameters were analyzed by the turbidimetric procedure at 405 nm. The Independent Samples t-test was utilized to compare them (P methylglyoxal at 500 μmol/l with aspirin 100 mg/l had significant changes in the maximum lysis velocity (0.163 ± 0.003), half-time lysis (240 ± 10.00), the total lysis time (485 ± 5.00), lag time in lysis (126 ± 5.77), compared with methylglyoxal at 500 μmol/l (0.104 ± 0.005), (276 ± 5.77), (570 ± 10.00), and (186 ± 5.77), respectively (P Methylglyoxal at 500 μmol/l with aspirin 1 mg/l did not significantly change in either parameter (P > 0.05). Methylglyoxal at 100 μmol/l with aspirin 1 mg/l did not significantly change in either fibrinolysis parameter (P > 0.05), compared with methylglyoxal at 100 μmol/l. Methylglyoxal at 5 μmol/l with aspirin (1, 10, 100 mg/l) changed in all fibrinolysis parameters (P methylglyoxal at 5 μmol/l. The other concentrations were compared in the same way. Aspirin (more than 1 mg/l) had more effect on higher concentrations of methylglyoxal. It increased the velocity of lysis of the clot and shortened clot lysis.
Baker, M. B.; Blyth, A. M.; Christian, H. J.; Latham, J.; Miller, K. L.; Gadian, A. M.
The lightning frequency model developed by Baker et al. [Baker, M.B., Christian, H.J., Latham, J., 1995. A computational study of the relationships linking lightning frequency and other thundercloud parameters, Q. J. R. Meteorol. Soc., 121, 1525-1548] has been refined and extended, in an effort to provide a more realistic framework from which to examine computationally the relationships that might exist between lightning frequency f (which is now being routinely measured from a satellite, using the NASA/MSFC Optical Transient Detector (OTD)) and a variety of cloud physical parameters. Specifically, superior or more comprehensive representations were utilised of: (1) glaciation via the Hallett-Mossop (H-M) process; (2) the updraught structure of the model cloud; (3) the liquid-water-content structure of the model cloud; (4) the role of the reversal temperature Trev in influencing lightning characteristics; (5) the critical breakdown field for lightning initiation; and (6) the electrical characteristics of the ice crystal anvil of the model cloud. Although our extended studies yielded some new insights into the problem, the basic pattern of relationships between f and the other parameters was very close to that reported by Baker et al. (1995). The more elaborate treatment of Trev restricted somewhat the range of conditions under which reverse-polarity lightning could be produced if the cloud glaciated via H-M, but confirmed the earlier conclusion that such lightning would not occur if the glaciation was of the Fletcher type. The computations yielded preliminary support for the hypothesis that satellite measurements of f might be used to determine values of the ice-content of cumulonimbus anvils: a parameter of climatological importance. The successful launch and continuing satisfactory functioning of the OTD [Christian, H.J., Goodman, S., 1992. Global observations of lightning from space, Proc. 9th Int. Conf. on Atmospheric Electricity, St. Petersburg, pp. 316
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Kushwah, S.S. [Department of Physics, Rishi Galav College, Morena, 476001 MP (India); Shrivastava, H.C. [Department of Physics, S.M.S. Government Model Science P.G. College, Gwalior, 474001 MP (India)]. E-mail: hcs2050@yahoo.com; Singh, K.S. [Department of Physics, R.B.S. College, Agra, UP (India)
2007-01-15
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.
de Boer-Euser, Tanja; Bouaziz, Laurène; De Niel, Jan; Brauer, Claudia; Dewals, Benjamin; Drogue, Gilles; Fenicia, Fabrizio; Grelier, Benjamin; Nossent, Jiri; Pereira, Fernando; Savenije, Hubert; Thirel, Guillaume; Willems, Patrick
2017-01-01
International collaboration between research institutes and universities is a promising way to reach consensus on hydrological model development. Although model comparison studies are very valuable for international cooperation, they do often not lead to very clear new insights regarding the relevance of the modelled processes. We hypothesise that this is partly caused by model complexity and the comparison methods used, which focus too much on a good overall performance instead of focusing on a variety of specific events. In this study, we use an approach that focuses on the evaluation of specific events and characteristics. Eight international research groups calibrated their hourly model on the Ourthe catchment in Belgium and carried out a validation in time for the Ourthe catchment and a validation in space for nested and neighbouring catchments. The same protocol was followed for each model and an ensemble of best-performing parameter sets was selected. Although the models showed similar performances based on general metrics (i.e. the Nash-Sutcliffe efficiency), clear differences could be observed for specific events. We analysed the hydrographs of these specific events and conducted three types of statistical analyses on the entire time series: cumulative discharges, empirical extreme value distribution of the peak flows and flow duration curves for low flows. The results illustrate the relevance of including a very quick flow reservoir preceding the root zone storage to model peaks during low flows and including a slow reservoir in parallel with the fast reservoir to model the recession for the studied catchments. This intercomparison enhanced the understanding of the hydrological functioning of the catchment, in particular for low flows, and enabled to identify present knowledge gaps for other parts of the hydrograph. Above all, it helped to evaluate each model against a set of alternative models.
Economic system as the basic object of study in the general educational institutions
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Михаил Бурла
2017-09-01
Full Text Available This article analyzes the prevailing practice of studying the economies at different levels in schools of Moldova, Russia and Ukraine. The main attention is paid to the development of methods of studying modern conceptual device that describes the nature, composition, structure and parameters of economic systems in educational institutions. In modern textbooks that are currently used in general education institutions there are some basic concepts and indicators, which allow to fully understand the world economy, economy of states and regions. There are such categories as “economic system”, “model of the economy”, “structure of the economy”, “the branch of the economy”, “sphere of economy”, “sector of economy”. The analysis of school textbooks on geography and other subjects indicates the need for detailed assimilation of information concerning systems, their types, composition, structure and functions. The study of economic and social geography should be paid main attention to the economic system. This article presents the author’s version of the “economic system” concept’s interpretation with all its constituent elements, reveals the functions of economic systems, the types of economic products and services produced by them, examines the levels from global to local ones with specific examples. Various types of economic structures are shown: 1 sectoral, reflecting the relationship between industries; 2 interbranch, reflecting the relationship between interindustry complexes; 3 territorial, reflecting the share of individual regions in national indicators or the share of countries in global indicators, as well as the spatial location of production and non-production facilities; 4 tiered, reflecting the relationship between the primary, secondary and tertiary sectors of the economy; 5 two-sphere, reflecting the relationship between the production and non-production spheres; 6 organizational and legal, reflecting the
The effect of posture and repetition on urodynamic parameters: A prospective randomized study
Jeon, Ho Joon; Choo, Min Soo
2017-01-01
Purpose To evaluate the effect of posture and repetition of filling cystometry on urodynamic parameters. Materials and Methods Seventy-one men with benign prostatic hyperplasia participated in a urodynamic study between September 2015 and August 2016 and were randomly assigned to a supine to supine (group SS, n=16), erect to erect (group EE, n=16), supine to erect (group SE, n=19) or erect to supine (group ES, n=20) group. The patients underwent filling cystometry twice. We evaluated the effect of posture and the effect of repetition on filling cystometric parameters. We also evaluated the correlation between overactive bladder (OAB) and detrusor overactivity (DO) and between maximum voided volume (MVV) and maximum cystometric capacity (MCC) for each posture and filling cystometry time. Results There was a decrease in bladder sensation and occurrence of DO, and an increase in bladder compliance and MCC in the supine posture group compared to that in the erect posture group. A more significant decrease in bladder sensation and occurrence of DO as well as an increase in MCC was seen during the second filling cystometry than the first one. The supine posture during first filling cystometry showed a better correlation between OAB and DO and between MVV and MCC than erect posture. Conclusions There were clear effects of posture and filling cystometry repetition on urodynamic parameters. The supine posture and repeated filling cystometry caused the bladder to be less sensitive and less overactive. The supine posture showed a better correlation to OAB symptoms than erect posture during first filling cystometry. PMID:28097266
Pedinotti, V.; Boone, A.; Ricci, S.; Biancamaria, S.; Mognard, N.
2014-11-01
During the last few decades, satellite measurements have been widely used to study the continental water cycle, especially in regions where in situ measurements are not readily available. The future Surface Water and Ocean Topography (SWOT) satellite mission will deliver maps of water surface elevation (WSE) with an unprecedented resolution and provide observation of rivers wider than 100 m and water surface areas greater than approximately 250 x 250 m over continental surfaces between 78° S and 78° N. This study aims to investigate the potential of SWOT data for parameter optimization for large-scale river routing models. The method consists in applying a data assimilation approach, the extended Kalman filter (EKF) algorithm, to correct the Manning roughness coefficients of the ISBA (Interactions between Soil, Biosphere, and Atmosphere)-TRIP (Total Runoff Integrating Pathways) continental hydrologic system. Parameters such as the Manning coefficient, used within such models to describe water basin characteristics, are generally derived from geomorphological relationships, which leads to significant errors at reach and large scales. The current study focuses on the Niger Basin, a transboundary river. Since the SWOT observations are not available yet and also to assess the proposed assimilation method, the study is carried out under the framework of an observing system simulation experiment (OSSE). It is assumed that modeling errors are only due to uncertainties in the Manning coefficient. The true Manning coefficients are then supposed to be known and are used to generate synthetic SWOT observations over the period 2002-2003. The impact of the assimilation system on the Niger Basin hydrological cycle is then quantified. The optimization of the Manning coefficient using the EKF (extended Kalman filter) algorithm over an 18-month period led to a significant improvement of the river water levels. The relative bias of the water level is globally improved (a 30
Directory of Open Access Journals (Sweden)
Rashmi Sharma, S Mukherjee
2011-01-01
Full Text Available It was a population based cross sectional study done with the objective of comparing some parameters (attitude & practice of gender discrimination (GD in rural and urban areas of Ahmedabad district. A population of 963 (446 urban & 517 rural showed alarmingly adverse sex ratio (SR as low as 562 among urban preschoolers. GD was prevalent in both study areas but manifested differently. Preference of male child by both partners an indicator of gender discrimination was seen in both areas, It correlated with female literacy, their low mean age at marriage and first conception. While urban areas showed more adverse sex ratio coupled with awareness and use of Ultrasonography (USG for sex determination and poor employment status, rural areas exhibited (along with adverse sex ratio poor literacy and employment status of females and poor contraceptive use
Effect of cadmium on physiological parameters of cereal and millet plants-A comparative study.
Asopa, Prem Prakash; Bhatt, Ritika; Sihag, Santosh; Kothari, S L; Kachhwaha, Sumita
2017-03-04
Metal load is an abiotic stress that becomes stronger by continual industrial production, wastage, and long-range transport of contaminants. It deteriorates the conditions of agricultural soil that leads to lower growth of cereals as well as decreasing nutritional value of harvested grains. Cadmium (Cd) entry by food chain also affects the health of population. The present study is focused on finding out the superior cereal variety under increasing Cd regime. The plants were grown in increasing Cd levels (0-1000 µM) in the medium and were investigated on 15th day of the exposure. Various parameters like antioxidative enzymes and osmoprotectant levels were studied in both roots and shoots. Cd accumulation in plant organs was determined by atomic absorption spectrophotometry (AAS). Analysis of stress tolerance mechanisms through reactive oxygen species (ROS) scavenging and better partitioning of Cd in roots indicated kodo millet to be more stress tolerant than wheat.
DEFF Research Database (Denmark)
Jensen, Bo Boye Busk
2007-01-01
The prediction of cleaning in pipe-lines is important for equipment manufacturers, who wish to optimize designs with respect to hygienic performance. Degree of cleaning correlates with the level of fluctuations in the signal recorded in discrete points during wall shear stress measurements using...... an electrochemical method. For optimization of process equipment with respect to cleaning, the levels of local fluctuations across entire surfaces are needed. Trends of fluctuations in the geometries used can be predicted using computational fluid dynamics (CFD). Two sensitivity studies were carried out...... of interest (shortened geometry). Both studies having a fully developed turbulent velocity inlet profile with changing turbulence parameters: turbulence intensity 0.01-30 per cent and turbulence length scale 7.5-30 per cent of inlet pipe diameter. For the full geometry no sensitivity in the fluctuation...
A study on biological media of ultrasonic nonlinear parameter B/A
Energy Technology Data Exchange (ETDEWEB)
Kim, Jeong Koo; Jung, Hong Ryang; Lim, Cheong Hwan [Hanseo Univ, Seosan (Korea, Republic of)
2001-06-01
This study deals with the relationship between the magnitude of ultrasonic nonlinear parameter B/A, and sound speed of amount of fat present in biological media to measure B/A system using a wide band ultrasonic transducer. To represent this case, mixtures of egg whites and egg yolk were studied. Even though the differences in density and sound speed of the two egg components were in the range of 1%, B/A increase parabolically as a function of the fat density, which is not in agreement with the Yoshizumi et al.'s suggestion. In skim, milk that dose not contain fat, both the B/A and the sound speed increase with the solubility. It is considered that protein could affect these values.
Study of gain variation as a function of physical parameters of GEM foil
Energy Technology Data Exchange (ETDEWEB)
Das, Supriya, E-mail: Supriya.Das@cern.ch
2016-07-11
The ALICE experiment at LHC has planned to upgrade the TPC by replacing the MWPC with GEM based detecting elements to restrict the IBF to a tolerable value. However the variation of the gain as a function of physical parameters of industrially produced large size GEM foils is needed to be studied as a part of the QA procedure for the detector. The size of the electron avalanche and consequently the gain for GEM based detectors depend on the electric field distribution inside the holes. Geometry of a hole plays an important role in defining the electric field inside it. In this work we have studied the variation of the gain as a function of the hole diameters using Garfield++ simulation package.
Provision of medical student teaching in UK general practices: a cross-sectional questionnaire study
Harding, Alex; Rosenthal, Joe; Al-Seaidy, Marwa; Gray, Denis Pereira; McKinley, Robert K
2015-01-01
Background Health care is increasingly provided in general practice. To meet this demand, the English Department of Health recommends that 50% of all medical students should train for general practice after qualification. Currently 19% of medical students express general practice as their first career choice. Undergraduate exposure to general practice positively influences future career choice. Appropriate undergraduate exposure to general practice is therefore highly relevant to workforce planning Aim This study seeks to quantify current exposure of medical students to general practice and compare it with past provision and also with postgraduate provision. Design and setting A cross-sectional questionnaire in the UK. Method A questionnaire regarding provision of undergraduate teaching was sent to the general practice teaching leads in all UK medical schools. Information was gathered on the amount of undergraduate teaching, how this was supported financially, and whether there was an integrated department of general practice. The data were then compared with results from previous studies of teaching provision. The provision of postgraduate teaching in general practice was also examined. Results General practice teaching for medical students increased from teaching in 1968 to 13.0% by 2008; since then, the percentage has plateaued. The total amount of general practice teaching per student has fallen by 2 weeks since 2002. Medical schools providing financial data delivered 14.6% of the clinical curriculum and received 7.1% of clinical teaching funding. The number of departments of general practice has halved since 2002. Provision of postgraduate teaching has tripled since 2000. Conclusion Current levels of undergraduate teaching in general practice are too low to fulfil future workforce requirements and may be falling. Financial support for current teaching is disproportionately low and the mechanism counterproductive. Central intervention may be required to solve
Meta-Learning Approach for Automatic Parameter Tuning: A Case Study with Educational Datasets
Molina, M. M.; Luna, J. M.; Romero, C.; Ventura, S.
2012-01-01
This paper proposes to the use of a meta-learning approach for automatic parameter tuning of a well-known decision tree algorithm by using past information about algorithm executions. Fourteen educational datasets were analysed using various combinations of parameter values to examine the effects of the parameter values on accuracy classification.…
Moolenaar, H.E.; Selten, F.M.
2004-01-01
Climate models contain numerous parameters for which the numeric values are uncertain. In the context of climate simulation and prediction, a relevant question is what range of climate outcomes is possible given the range of parameter uncertainties. Which parameter perturbation changes the climate i