Linearization effect in multifractal analysis: Insights from the Random Energy Model

Science.gov (United States)

Angeletti, Florian; Mézard, Marc; Bertin, Eric; Abry, Patrice

2011-08-01

The analysis of the linearization effect in multifractal analysis, and hence of the estimation of moments for multifractal processes, is revisited borrowing concepts from the statistical physics of disordered systems, notably from the analysis of the so-called Random Energy Model. Considering a standard multifractal process (compound Poisson motion), chosen as a simple representative example, we show the following: (i) the existence of a critical order q∗ beyond which moments, though finite, cannot be estimated through empirical averages, irrespective of the sample size of the observation; (ii) multifractal exponents necessarily behave linearly in q, for q>q∗. Tailoring the analysis conducted for the Random Energy Model to that of Compound Poisson motion, we provide explicative and quantitative predictions for the values of q∗ and for the slope controlling the linear behavior of the multifractal exponents. These quantities are shown to be related only to the definition of the multifractal process and not to depend on the sample size of the observation. Monte Carlo simulations, conducted over a large number of large sample size realizations of compound Poisson motion, comfort and extend these analyses.

Random linear network coding for streams with unequally sized packets

DEFF Research Database (Denmark)

Taghouti, Maroua; Roetter, Daniel Enrique Lucani; Pedersen, Morten Videbæk

2016-01-01

State of the art Random Linear Network Coding (RLNC) schemes assume that data streams generate packets with equal sizes. This is an assumption that results in the highest efficiency gains for RLNC. A typical solution for managing unequal packet sizes is to zero-pad the smallest packets. However, ...

On spectral properties of linear combinations of idempotents

Czech Academy of Sciences Publication Activity Database

Du, H.-K.; Deng, Ch-Y.; Mbekhta, M.; Müller, Vladimír

2007-01-01

Roč. 180, č. 3 (2007), s. 211-217 ISSN 0039-3223 R&D Projects: GA ČR(CZ) GA201/06/0128 Institutional research plan: CEZ:AV0Z10190503 Keywords : linear combinations of idempotents * closed range * complemented subspaces Subject RIV: BA - General Mathematics Impact factor: 0.568, year: 2007

Linear minimax estimation for random vectors with parametric uncertainty

KAUST Repository

Bitar, E

2010-06-01

In this paper, we take a minimax approach to the problem of computing a worst-case linear mean squared error (MSE) estimate of X given Y , where X and Y are jointly distributed random vectors with parametric uncertainty in their distribution. We consider two uncertainty models, PA and PB. Model PA represents X and Y as jointly Gaussian whose covariance matrix Λ belongs to the convex hull of a set of m known covariance matrices. Model PB characterizes X and Y as jointly distributed according to a Gaussian mixture model with m known zero-mean components, but unknown component weights. We show: (a) the linear minimax estimator computed under model PA is identical to that computed under model PB when the vertices of the uncertain covariance set in PA are the same as the component covariances in model PB, and (b) the problem of computing the linear minimax estimator under either model reduces to a semidefinite program (SDP). We also consider the dynamic situation where x(t) and y(t) evolve according to a discrete-time LTI state space model driven by white noise, the statistics of which is modeled by PA and PB as before. We derive a recursive linear minimax filter for x(t) given y(t).

Diffusion in the kicked quantum rotator by random corrections to a linear and sine field

International Nuclear Information System (INIS)

Hilke, M.; Flores, J.C.

1992-01-01

We discuss the diffusion in momentum space, of the kicked quantum rotator, by introducing random corrections to a linear and sine external field. For the linear field we obtain a linear diffusion behavior identical to the case with zero average in the external field. But for the sine field, accelerator modes with quadratic diffusion are found for particular values of the kicking period. (orig.)

A simulation-based goodness-of-fit test for random effects in generalized linear mixed models

DEFF Research Database (Denmark)

Waagepetersen, Rasmus

2006-01-01

The goodness-of-fit of the distribution of random effects in a generalized linear mixed model is assessed using a conditional simulation of the random effects conditional on the observations. Provided that the specified joint model for random effects and observations is correct, the marginal...... distribution of the simulated random effects coincides with the assumed random effects distribution. In practice, the specified model depends on some unknown parameter which is replaced by an estimate. We obtain a correction for this by deriving the asymptotic distribution of the empirical distribution...

A simulation-based goodness-of-fit test for random effects in generalized linear mixed models

DEFF Research Database (Denmark)

Waagepetersen, Rasmus Plenge

The goodness-of-fit of the distribution of random effects in a generalized linear mixed model is assessed using a conditional simulation of the random effects conditional on the observations. Provided that the specified joint model for random effects and observations is correct, the marginal...... distribution of the simulated random effects coincides with the assumed random effects distribution. In practice the specified model depends on some unknown parameter which is replaced by an estimate. We obtain a correction for this by deriving the asymptotic distribution of the empirical distribution function...

Throughput vs. Delay in Lossy Wireless Mesh Networks with Random Linear Network Coding

OpenAIRE

Hundebøll, Martin; Pahlevani, Peyman; Roetter, Daniel Enrique Lucani; Fitzek, Frank

2014-01-01

This work proposes a new protocol applying on–the–fly random linear network coding in wireless mesh net-works. The protocol provides increased reliability, low delay,and high throughput to the upper layers, while being obliviousto their specific requirements. This seemingly conflicting goalsare achieved by design, using an on–the–fly network codingstrategy. Our protocol also exploits relay nodes to increasethe overall performance of individual links. Since our protocolnaturally masks random p...

Systematic review and meta-analysis of published randomized controlled trials comparing purse-string vs conventional linear closure of the wound following ileostomy (stoma) closure.

Science.gov (United States)

Sajid, Muhammad Shafique; Bhatti, Muhammad I; Miles, William Fa

2015-05-01

The objective of this article is to systematically analyse the randomized, controlled trials comparing the effectiveness of purse-string closure (PSC) of an ileostomy wound with conventional linear closure (CLC). Randomized, controlled trials comparing the effectiveness of purse-string closure vs conventional linear closure (CLC) of ileostomy wound in patients undergoing ileostomy closure were analysed using RevMan®, and the combined outcomes were expressed as risk ratio (RR) and standardized mean difference (SMD). Three randomized, controlled trials, recruiting 206 patients, were retrieved from medical electronic databases. There were 105 patients in the PSC group and 101 patients in the CLC group. There was no heterogeneity among included trials. Duration of operation (SMD: -0.18; 95% CI: -0.45, 0.09; z = 1.28; P SMD: 0.01; 95% CI: -0.26, 0.28; z = 0.07; P infection (OR, 0.10; 95% CI: 0.03, 0.33; z = 3.78; P infection apparently without influencing the duration of operation and length of hospital stay. © The Author(s) 2014. Published by Oxford University Press and the Digestive Science Publishing Co. Limited.

Comparison of the Predictive Performance and Interpretability of Random Forest and Linear Models on Benchmark Data Sets.

Science.gov (United States)

Marchese Robinson, Richard L; Palczewska, Anna; Palczewski, Jan; Kidley, Nathan

2017-08-28

The ability to interpret the predictions made by quantitative structure-activity relationships (QSARs) offers a number of advantages. While QSARs built using nonlinear modeling approaches, such as the popular Random Forest algorithm, might sometimes be more predictive than those built using linear modeling approaches, their predictions have been perceived as difficult to interpret. However, a growing number of approaches have been proposed for interpreting nonlinear QSAR models in general and Random Forest in particular. In the current work, we compare the performance of Random Forest to those of two widely used linear modeling approaches: linear Support Vector Machines (SVMs) (or Support Vector Regression (SVR)) and partial least-squares (PLS). We compare their performance in terms of their predictivity as well as the chemical interpretability of the predictions using novel scoring schemes for assessing heat map images of substructural contributions. We critically assess different approaches for interpreting Random Forest models as well as for obtaining predictions from the forest. We assess the models on a large number of widely employed public-domain benchmark data sets corresponding to regression and binary classification problems of relevance to hit identification and toxicology. We conclude that Random Forest typically yields comparable or possibly better predictive performance than the linear modeling approaches and that its predictions may also be interpreted in a chemically and biologically meaningful way. In contrast to earlier work looking at interpretation of nonlinear QSAR models, we directly compare two methodologically distinct approaches for interpreting Random Forest models. The approaches for interpreting Random Forest assessed in our article were implemented using open-source programs that we have made available to the community. These programs are the rfFC package ( https://r-forge.r-project.org/R/?group_id=1725 ) for the R statistical

The separation-combination method of linear structures in remote sensing image interpretation and its application

International Nuclear Information System (INIS)

Liu Linqin

1991-01-01

The separation-combination method a new kind of analysis method of linear structures in remote sensing image interpretation is introduced taking northwestern Fujian as the example, its practical application is examined. The practice shows that application results not only reflect intensities of linear structures in overall directions at different locations, but also contribute to the zonation of linear structures and display their space distribution laws. Based on analyses of linear structures, it can provide more information concerning remote sensing on studies of regional mineralization laws and the guide to ore-finding combining with mineralization

Reliability of Broadcast Communications Under Sparse Random Linear Network Coding

OpenAIRE

Brown, Suzie; Johnson, Oliver; Tassi, Andrea

2018-01-01

Ultra-reliable Point-to-Multipoint (PtM) communications are expected to become pivotal in networks offering future dependable services for smart cities. In this regard, sparse Random Linear Network Coding (RLNC) techniques have been widely employed to provide an efficient way to improve the reliability of broadcast and multicast data streams. This paper addresses the pressing concern of providing a tight approximation to the probability of a user recovering a data stream protected by this kin...

Chaos from linear systems: implications for communicating with chaos, and the nature of determinism and randomness

International Nuclear Information System (INIS)

Hayes, Scott T

2005-01-01

A method is developed for producing deterministic chaotic motion from the linear superposition of a bi-infinite sequence of randomly polarized basis functions. The resultant waveform is also formally a random process in the usual sense. In the example given, a threedimensional embedding produces an idealized version of Lorenz motion. The one-dimensional approximate return map is piecewise linear; a tent or shift, depending on the Poincare section. The results are presented in an informal style so that they are accessible to a wide audience interested in both theory and applications of symbolic dynamics communication

A new neural network model for solving random interval linear programming problems.

Science.gov (United States)

Arjmandzadeh, Ziba; Safi, Mohammadreza; Nazemi, Alireza

2017-05-01

This paper presents a neural network model for solving random interval linear programming problems. The original problem involving random interval variable coefficients is first transformed into an equivalent convex second order cone programming problem. A neural network model is then constructed for solving the obtained convex second order cone problem. Employing Lyapunov function approach, it is also shown that the proposed neural network model is stable in the sense of Lyapunov and it is globally convergent to an exact satisfactory solution of the original problem. Several illustrative examples are solved in support of this technique. Copyright © 2017 Elsevier Ltd. All rights reserved.

MINIMUM ENTROPY DECONVOLUTION OF ONE-AND MULTI-DIMENSIONAL NON-GAUSSIAN LINEAR RANDOM PROCESSES

Institute of Scientific and Technical Information of China (English)

程乾生

1990-01-01

The minimum entropy deconvolution is considered as one of the methods for decomposing non-Gaussian linear processes. The concept of peakedness of a system response sequence is presented and its properties are studied. With the aid of the peakedness, the convergence theory of the minimum entropy deconvolution is established. The problem of the minimum entropy deconvolution of multi-dimensional non-Gaussian linear random processes is first investigated and the corresponding theory is given. In addition, the relation between the minimum entropy deconvolution and parameter method is discussed.

Throughput vs. Delay in Lossy Wireless Mesh Networks with Random Linear Network Coding

DEFF Research Database (Denmark)

Hundebøll, Martin; Pahlevani, Peyman; Roetter, Daniel Enrique Lucani

2014-01-01

This work proposes a new protocol applying on– the–fly random linear network coding in wireless mesh net- works. The protocol provides increased reliability, low delay, and high throughput to the upper layers, while being oblivious to their specific requirements. This seemingly conflicting goals ...

Robust linear registration of CT images using random regression forests

Science.gov (United States)

Konukoglu, Ender; Criminisi, Antonio; Pathak, Sayan; Robertson, Duncan; White, Steve; Haynor, David; Siddiqui, Khan

2011-03-01

Global linear registration is a necessary first step for many different tasks in medical image analysis. Comparing longitudinal studies1, cross-modality fusion2, and many other applications depend heavily on the success of the automatic registration. The robustness and efficiency of this step is crucial as it affects all subsequent operations. Most common techniques cast the linear registration problem as the minimization of a global energy function based on the image intensities. Although these algorithms have proved useful, their robustness in fully automated scenarios is still an open question. In fact, the optimization step often gets caught in local minima yielding unsatisfactory results. Recent algorithms constrain the space of registration parameters by exploiting implicit or explicit organ segmentations, thus increasing robustness4,5. In this work we propose a novel robust algorithm for automatic global linear image registration. Our method uses random regression forests to estimate posterior probability distributions for the locations of anatomical structures - represented as axis aligned bounding boxes6. These posterior distributions are later integrated in a global linear registration algorithm. The biggest advantage of our algorithm is that it does not require pre-defined segmentations or regions. Yet it yields robust registration results. We compare the robustness of our algorithm with that of the state of the art Elastix toolbox7. Validation is performed via 1464 pair-wise registrations in a database of very diverse 3D CT images. We show that our method decreases the "failure" rate of the global linear registration from 12.5% (Elastix) to only 1.9%.

Combined genetic algorithm and multiple linear regression (GA-MLR) optimizer: Application to multi-exponential fluorescence decay surface.

Science.gov (United States)

Fisz, Jacek J

2006-12-07

The optimization approach based on the genetic algorithm (GA) combined with multiple linear regression (MLR) method, is discussed. The GA-MLR optimizer is designed for the nonlinear least-squares problems in which the model functions are linear combinations of nonlinear functions. GA optimizes the nonlinear parameters, and the linear parameters are calculated from MLR. GA-MLR is an intuitive optimization approach and it exploits all advantages of the genetic algorithm technique. This optimization method results from an appropriate combination of two well-known optimization methods. The MLR method is embedded in the GA optimizer and linear and nonlinear model parameters are optimized in parallel. The MLR method is the only one strictly mathematical "tool" involved in GA-MLR. The GA-MLR approach simplifies and accelerates considerably the optimization process because the linear parameters are not the fitted ones. Its properties are exemplified by the analysis of the kinetic biexponential fluorescence decay surface corresponding to a two-excited-state interconversion process. A short discussion of the variable projection (VP) algorithm, designed for the same class of the optimization problems, is presented. VP is a very advanced mathematical formalism that involves the methods of nonlinear functionals, algebra of linear projectors, and the formalism of Fréchet derivatives and pseudo-inverses. Additional explanatory comments are added on the application of recently introduced the GA-NR optimizer to simultaneous recovery of linear and weakly nonlinear parameters occurring in the same optimization problem together with nonlinear parameters. The GA-NR optimizer combines the GA method with the NR method, in which the minimum-value condition for the quadratic approximation to chi(2), obtained from the Taylor series expansion of chi(2), is recovered by means of the Newton-Raphson algorithm. The application of the GA-NR optimizer to model functions which are multi-linear

On Linear Combinations of Two Orthogonal Polynomial Sequences on the Unit Circle

Directory of Open Access Journals (Sweden)

Suárez C

2010-01-01

Full Text Available Let be a monic orthogonal polynomial sequence on the unit circle. We define recursively a new sequence of polynomials by the following linear combination: , , . In this paper, we give necessary and sufficient conditions in order to make be an orthogonal polynomial sequence too. Moreover, we obtain an explicit representation for the Verblunsky coefficients and in terms of and . Finally, we show the relation between their corresponding Carathéodory functions and their associated linear functionals.

Improving biomedical information retrieval by linear combinations of different query expansion techniques.

Science.gov (United States)

Abdulla, Ahmed AbdoAziz Ahmed; Lin, Hongfei; Xu, Bo; Banbhrani, Santosh Kumar

2016-07-25

Biomedical literature retrieval is becoming increasingly complex, and there is a fundamental need for advanced information retrieval systems. Information Retrieval (IR) programs scour unstructured materials such as text documents in large reserves of data that are usually stored on computers. IR is related to the representation, storage, and organization of information items, as well as to access. In IR one of the main problems is to determine which documents are relevant and which are not to the user's needs. Under the current regime, users cannot precisely construct queries in an accurate way to retrieve particular pieces of data from large reserves of data. Basic information retrieval systems are producing low-quality search results. In our proposed system for this paper we present a new technique to refine Information Retrieval searches to better represent the user's information need in order to enhance the performance of information retrieval by using different query expansion techniques and apply a linear combinations between them, where the combinations was linearly between two expansion results at one time. Query expansions expand the search query, for example, by finding synonyms and reweighting original terms. They provide significantly more focused, particularized search results than do basic search queries. The retrieval performance is measured by some variants of MAP (Mean Average Precision) and according to our experimental results, the combination of best results of query expansion is enhanced the retrieved documents and outperforms our baseline by 21.06 %, even it outperforms a previous study by 7.12 %. We propose several query expansion techniques and their combinations (linearly) to make user queries more cognizable to search engines and to produce higher-quality search results.

Imipramine and Pregabalin Combination for Painful Polyneuropathy. A Randomized Controlled Trial

DEFF Research Database (Denmark)

Holbech, Jakob V; Bach, Flemming W; Finnerup, Nanna B

2015-01-01

Monotherapy with first-line drugs for neuropathic pain often fails to provide sufficient pain relief or has unacceptable side effects because of the need for high doses. The aim of this trial was to test whether the combination of imipramine and pregabalin in moderate doses would relieve pain more...... effectively than monotherapy with either of the drugs. This was a randomized, double-blind, placebo-controlled, crossover, multicenter trial consisting of four 5-week treatment periods in patients with painful polyneuropathy. Treatment arms were imipramine 75 mg/d vs pregabalin 300 mg/d vs combination therapy...... randomized, and 69 patients were included in the data analysis. The effect on average pain in comparison with placebo was: combination (-1.67 NRS points, P pregabalin (-0.48 NRS points, P = 0.03). The combination therapy had significantly lower pain...

Thin Cloud Detection Method by Linear Combination Model of Cloud Image

Science.gov (United States)

Liu, L.; Li, J.; Wang, Y.; Xiao, Y.; Zhang, W.; Zhang, S.

2018-04-01

The existing cloud detection methods in photogrammetry often extract the image features from remote sensing images directly, and then use them to classify images into cloud or other things. But when the cloud is thin and small, these methods will be inaccurate. In this paper, a linear combination model of cloud images is proposed, by using this model, the underlying surface information of remote sensing images can be removed. So the cloud detection result can become more accurate. Firstly, the automatic cloud detection program in this paper uses the linear combination model to split the cloud information and surface information in the transparent cloud images, then uses different image features to recognize the cloud parts. In consideration of the computational efficiency, AdaBoost Classifier was introduced to combine the different features to establish a cloud classifier. AdaBoost Classifier can select the most effective features from many normal features, so the calculation time is largely reduced. Finally, we selected a cloud detection method based on tree structure and a multiple feature detection method using SVM classifier to compare with the proposed method, the experimental data shows that the proposed cloud detection program in this paper has high accuracy and fast calculation speed.

On-chip power-combining techniques for watt-level linear power amplifiers in 0.18 μm CMOS

International Nuclear Information System (INIS)

Ren Zhixiong; Zhang Kefeng; Liu Lanqi; Li Cong; Chen Xiaofei; Liu Dongsheng; Liu Zhenglin; Zou Xuecheng

2015-01-01

Three linear CMOS power amplifiers (PAs) with high output power (more than watt-level output power) for high data-rate mobile applications are introduced. To realize watt-level output power, there are two 2.4 GHz PAs using an on-chip parallel combining transformer (PCT) and one 1.95 GHz PA using an on-chip series combining transformer (SCT) to combine output signals of multiple power stages. Furthermore, some linearization techniques including adaptive bias, diode linearizer, multi-gated transistors (MGTR) and the second harmonic control are applied in these PAs. Using the proposed power combiner, these three PAs are designed and fabricated in TSMC 0.18 μm RFCMOS process. According to the measurement results, the proposed two linear 2.4 GHz PAs achieve a gain of 33.2 dB and 34.3 dB, a maximum output power of 30.7 dBm and 29.4 dBm, with 29% and 31.3% of peak PAE, respectively. According to the simulation results, the presented linear 1.95 GHz PA achieves a gain of 37.5 dB, a maximum output power of 34.3 dBm with 36.3% of peak PAE. (paper)

Inhomogeneous Linear Random Differential Equations with Mutual Correlations between Multiplicative, Additive and Initial-Value Terms

NARCIS (Netherlands)

Roerdink, J.B.T.M.

1981-01-01

The cumulant expansion for linear stochastic differential equations is extended to the general case in which the coefficient matrix, the inhomogeneous part and the initial condition are all random and, moreover, statistically interdependent. The expansion now involves not only the autocorrelation

Linear-scaling implementation of the direct random-phase approximation

International Nuclear Information System (INIS)

Kállay, Mihály

2015-01-01

We report the linear-scaling implementation of the direct random-phase approximation (dRPA) for closed-shell molecular systems. As a bonus, linear-scaling algorithms are also presented for the second-order screened exchange extension of dRPA as well as for the second-order Møller–Plesset (MP2) method and its spin-scaled variants. Our approach is based on an incremental scheme which is an extension of our previous local correlation method [Rolik et al., J. Chem. Phys. 139, 094105 (2013)]. The approach extensively uses local natural orbitals to reduce the size of the molecular orbital basis of local correlation domains. In addition, we also demonstrate that using natural auxiliary functions [M. Kállay, J. Chem. Phys. 141, 244113 (2014)], the size of the auxiliary basis of the domains and thus that of the three-center Coulomb integral lists can be reduced by an order of magnitude, which results in significant savings in computation time. The new approach is validated by extensive test calculations for energies and energy differences. Our benchmark calculations also demonstrate that the new method enables dRPA calculations for molecules with more than 1000 atoms and 10 000 basis functions on a single processor

Expected number of real roots for random linear combinations of orthogonal polynomials associated with radial weights

OpenAIRE

Bayraktar, Turgay

2017-01-01

In this note, we obtain asymptotic expected number of real zeros for random polynomials of the form $$f_n(z)=\\sum_{j=0}^na^n_jc^n_jz^j$$ where $a^n_j$ are independent and identically distributed real random variables with bounded $(2+\\delta)$th absolute moment and the deterministic numbers $c^n_j$ are normalizing constants for the monomials $z^j$ within a weighted $L^2$-space induced by a radial weight function satisfying suitable smoothness and growth conditions.

The assessment of changes in brain volume using combined linear measurements

International Nuclear Information System (INIS)

Gomori, J.M.; Steiner, I.; Melamed, E.; Cooper, G.

1984-01-01

All linear measurements employed for evaluation of brain atrophy, were performed on 148 computed tomograms of patients aged 28 to 84 without evidence of any nervous system disorder. These included size of lateral, third and fourth ventricles, width of the Sylvian and frontal interhemispheric fissures and cortical sulci and size of the pre-pontine cistern. Various parameters indicated decrease in brain mass with age. Since the atrophic process is a diffuse phenomenon, integration of several measurements evaluating separate brain regions was made. The bicaudate ratio and the Sylvian fissure ratio (representing both central and cortical atrophy) were combined arithmetically, resulting in a correlation of 0.6390 with age (p<0.0005). With a computed canonical correlation analysis: a formula was obtained which combined measurements of the lateral and third ventricles, the Sylvian fissure and the pre-pontine cistern. This formula yealded a correlation of 0.67795 (p<0.0005). These linear measurements will enable simple and reliable assessment of reduction in brain volume during the normal aging process and in disorders accompanied by brain atrophy. (orig.)

Stability and complexity of small random linear systems

Science.gov (United States)

Hastings, Harold

2010-03-01

We explore the stability of the small random linear systems, typically involving 10-20 variables, motivated by dynamics of the world trade network and the US and Canadian power grid. This report was prepared as an account of work sponsored by an agency of the US Government. Neither the US Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the US Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the US Government or any agency thereof.

The invariant measure of random walks in the quarter-plane: respresentation in geometric terms

NARCIS (Netherlands)

Chen, Y.; Boucherie, Richardus J.; Goseling, Jasper

We consider the invariant measure of homogeneous random walks in the quarter-plane. In particular, we consider measures that can be expressed as a finite linear combination of geometric terms and present conditions on the structure of these linear combinations such that the resulting measure may

Advances in high power linearly polarized fiber laser and its application

Science.gov (United States)

Zhou, Pu; Huang, Long; Ma, Pengfei; Xu, Jiangming; Su, Rongtao; Wang, Xiaolin

2017-10-01

Fiber lasers are now attracting more and more research interest due to their advantages in efficiency, beam quality and flexible operation. Up to now, most of the high power fiber lasers have random distributed polarization state. Linearlypolarized (LP) fiber lasers, which could find wide application potential in coherent detection, coherent/spectral beam combining, nonlinear frequency conversion, have been a research focus in recent years. In this paper, we will present a general review on the achievements of various kinds of high power linear-polarized fiber laser and its application. The recent progress in our group, including power scaling by using power amplifier with different mechanism, high power linearly polarized fiber laser with diversified properties, and various applications of high power linear-polarized fiber laser, are summarized. We have achieved 100 Watt level random distributed feedback fiber laser, kilowatt level continuous-wave (CW) all-fiber polarization-maintained fiber amplifier, 600 watt level average power picosecond polarization-maintained fiber amplifier and 300 watt level average power femtosecond polarization-maintained fiber amplifier. In addition, high power linearly polarized fiber lasers have been successfully applied in 5 kilowatt level coherent beam combining, structured light field and ultrasonic generation.

Systematic errors due to linear congruential random-number generators with the Swendsen-Wang algorithm: a warning.

Science.gov (United States)

Ossola, Giovanni; Sokal, Alan D

2004-08-01

We show that linear congruential pseudo-random-number generators can cause systematic errors in Monte Carlo simulations using the Swendsen-Wang algorithm, if the lattice size is a multiple of a very large power of 2 and one random number is used per bond. These systematic errors arise from correlations within a single bond-update half-sweep. The errors can be eliminated (or at least radically reduced) by updating the bonds in a random order or in an aperiodic manner. It also helps to use a generator of large modulus (e.g., 60 or more bits).

Optimal Preventive Bank Supervision: Combining Random Audits and Continuous Intervention

OpenAIRE

Mohamed Belhaj; Nataliya Klimenko

2012-01-01

Early regulator interventions into problem banks are one of the key suggestions of Basel II. However, no guidance is given on their design. To fill this gap, we outline an incentive-based preventive supervision strategy that eliminates bad asset management in banks. Two supervision techniques are combined: continuous regulator intervention and random audits. Random audit technologies differ as to quality and cost. Our design ensures good management without excessive supervision costs, through...

Studies in astronomical time series analysis. IV - Modeling chaotic and random processes with linear filters

Science.gov (United States)

Scargle, Jeffrey D.

1990-01-01

While chaos arises only in nonlinear systems, standard linear time series models are nevertheless useful for analyzing data from chaotic processes. This paper introduces such a model, the chaotic moving average. This time-domain model is based on the theorem that any chaotic process can be represented as the convolution of a linear filter with an uncorrelated process called the chaotic innovation. A technique, minimum phase-volume deconvolution, is introduced to estimate the filter and innovation. The algorithm measures the quality of a model using the volume covered by the phase-portrait of the innovation process. Experiments on synthetic data demonstrate that the algorithm accurately recovers the parameters of simple chaotic processes. Though tailored for chaos, the algorithm can detect both chaos and randomness, distinguish them from each other, and separate them if both are present. It can also recover nonminimum-delay pulse shapes in non-Gaussian processes, both random and chaotic.

Typed Linear Chain Conditional Random Fields and Their Application to Intrusion Detection

Science.gov (United States)

Elfers, Carsten; Horstmann, Mirko; Sohr, Karsten; Herzog, Otthein

Intrusion detection in computer networks faces the problem of a large number of both false alarms and unrecognized attacks. To improve the precision of detection, various machine learning techniques have been proposed. However, one critical issue is that the amount of reference data that contains serious intrusions is very sparse. In this paper we present an inference process with linear chain conditional random fields that aims to solve this problem by using domain knowledge about the alerts of different intrusion sensors represented in an ontology.

Mean anisotropy of homogeneous Gaussian random fields and anisotropic norms of linear translation-invariant operators on multidimensional integer lattices

Directory of Open Access Journals (Sweden)

Phil Diamond

2003-01-01

Full Text Available Sensitivity of output of a linear operator to its input can be quantified in various ways. In Control Theory, the input is usually interpreted as disturbance and the output is to be minimized in some sense. In stochastic worst-case design settings, the disturbance is considered random with imprecisely known probability distribution. The prior set of probability measures can be chosen so as to quantify how far the disturbance deviates from the white-noise hypothesis of Linear Quadratic Gaussian control. Such deviation can be measured by the minimal Kullback-Leibler informational divergence from the Gaussian distributions with zero mean and scalar covariance matrices. The resulting anisotropy functional is defined for finite power random vectors. Originally, anisotropy was introduced for directionally generic random vectors as the relative entropy of the normalized vector with respect to the uniform distribution on the unit sphere. The associated a-anisotropic norm of a matrix is then its maximum root mean square or average energy gain with respect to finite power or directionally generic inputs whose anisotropy is bounded above by a≥0. We give a systematic comparison of the anisotropy functionals and the associated norms. These are considered for unboundedly growing fragments of homogeneous Gaussian random fields on multidimensional integer lattice to yield mean anisotropy. Correspondingly, the anisotropic norms of finite matrices are extended to bounded linear translation invariant operators over such fields.

Dynamics of random Boolean networks under fully asynchronous stochastic update based on linear representation.

Directory of Open Access Journals (Sweden)

Chao Luo

Full Text Available A novel algebraic approach is proposed to study dynamics of asynchronous random Boolean networks where a random number of nodes can be updated at each time step (ARBNs. In this article, the logical equations of ARBNs are converted into the discrete-time linear representation and dynamical behaviors of systems are investigated. We provide a general formula of network transition matrices of ARBNs as well as a necessary and sufficient algebraic criterion to determine whether a group of given states compose an attractor of length[Formula: see text] in ARBNs. Consequently, algorithms are achieved to find all of the attractors and basins in ARBNs. Examples are showed to demonstrate the feasibility of the proposed scheme.

Possibility/Necessity-Based Probabilistic Expectation Models for Linear Programming Problems with Discrete Fuzzy Random Variables

Directory of Open Access Journals (Sweden)

Hideki Katagiri

2017-10-01

Full Text Available This paper considers linear programming problems (LPPs where the objective functions involve discrete fuzzy random variables (fuzzy set-valued discrete random variables. New decision making models, which are useful in fuzzy stochastic environments, are proposed based on both possibility theory and probability theory. In multi-objective cases, Pareto optimal solutions of the proposed models are newly defined. Computational algorithms for obtaining the Pareto optimal solutions of the proposed models are provided. It is shown that problems involving discrete fuzzy random variables can be transformed into deterministic nonlinear mathematical programming problems which can be solved through a conventional mathematical programming solver under practically reasonable assumptions. A numerical example of agriculture production problems is given to demonstrate the applicability of the proposed models to real-world problems in fuzzy stochastic environments.

Predictive inference for best linear combination of biomarkers subject to limits of detection.

Science.gov (United States)

Coolen-Maturi, Tahani

2017-08-15

Measuring the accuracy of diagnostic tests is crucial in many application areas including medicine, machine learning and credit scoring. The receiver operating characteristic (ROC) curve is a useful tool to assess the ability of a diagnostic test to discriminate between two classes or groups. In practice, multiple diagnostic tests or biomarkers are combined to improve diagnostic accuracy. Often, biomarker measurements are undetectable either below or above the so-called limits of detection (LoD). In this paper, nonparametric predictive inference (NPI) for best linear combination of two or more biomarkers subject to limits of detection is presented. NPI is a frequentist statistical method that is explicitly aimed at using few modelling assumptions, enabled through the use of lower and upper probabilities to quantify uncertainty. The NPI lower and upper bounds for the ROC curve subject to limits of detection are derived, where the objective function to maximize is the area under the ROC curve. In addition, the paper discusses the effect of restriction on the linear combination's coefficients on the analysis. Examples are provided to illustrate the proposed method. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Orthogonality, Lommel integrals and cross product zeros of linear combinations of Bessel functions.

Science.gov (United States)

Ziener, Christian H; Kurz, Felix T; Buschle, Lukas R; Kampf, Thomas

2015-01-01

The cylindrical Bessel differential equation and the spherical Bessel differential equation in the interval [Formula: see text] with Neumann boundary conditions are considered. The eigenfunctions are linear combinations of the Bessel function [Formula: see text] or linear combinations of the spherical Bessel functions [Formula: see text]. The orthogonality relations with analytical expressions for the normalization constant are given. Explicit expressions for the Lommel integrals in terms of Lommel functions are derived. The cross product zeros [Formula: see text] and [Formula: see text] are considered in the complex plane for real as well as complex values of the index [Formula: see text] and approximations for the exceptional zero [Formula: see text] are obtained. A numerical scheme based on the discretization of the two-dimensional and three-dimensional Laplace operator with Neumann boundary conditions is presented. Explicit representations of the radial part of the Laplace operator in form of a tridiagonal matrix allow the simple computation of the cross product zeros.

The simultaneous use of several pseudo-random binary sequences in the identification of linear multivariable dynamic systems

International Nuclear Information System (INIS)

Cummins, J.D.

1965-02-01

With several white noise sources the various transmission paths of a linear multivariable system may be determined simultaneously. This memorandum considers the restrictions on pseudo-random two state sequences to effect simultaneous identification of several transmission paths and the consequential rejection of cross-coupled signals in linear multivariable systems. The conditions for simultaneous identification are established by an example, which shows that the integration time required is large i.e. tends to infinity, as it does when white noise sources are used. (author)

Linearization Method and Linear Complexity

Science.gov (United States)

Tanaka, Hidema

We focus on the relationship between the linearization method and linear complexity and show that the linearization method is another effective technique for calculating linear complexity. We analyze its effectiveness by comparing with the logic circuit method. We compare the relevant conditions and necessary computational cost with those of the Berlekamp-Massey algorithm and the Games-Chan algorithm. The significant property of a linearization method is that it needs no output sequence from a pseudo-random number generator (PRNG) because it calculates linear complexity using the algebraic expression of its algorithm. When a PRNG has n [bit] stages (registers or internal states), the necessary computational cost is smaller than O(2n). On the other hand, the Berlekamp-Massey algorithm needs O(N2) where N(≅2n) denotes period. Since existing methods calculate using the output sequence, an initial value of PRNG influences a resultant value of linear complexity. Therefore, a linear complexity is generally given as an estimate value. On the other hand, a linearization method calculates from an algorithm of PRNG, it can determine the lower bound of linear complexity.

Random Linear Network Coding for 5G Mobile Video Delivery

Directory of Open Access Journals (Sweden)

Dejan Vukobratovic

2018-03-01

Full Text Available An exponential increase in mobile video delivery will continue with the demand for higher resolution, multi-view and large-scale multicast video services. Novel fifth generation (5G 3GPP New Radio (NR standard will bring a number of new opportunities for optimizing video delivery across both 5G core and radio access networks. One of the promising approaches for video quality adaptation, throughput enhancement and erasure protection is the use of packet-level random linear network coding (RLNC. In this review paper, we discuss the integration of RLNC into the 5G NR standard, building upon the ideas and opportunities identified in 4G LTE. We explicitly identify and discuss in detail novel 5G NR features that provide support for RLNC-based video delivery in 5G, thus pointing out to the promising avenues for future research.

Time-Frequency Analysis of Non-Stationary Biological Signals with Sparse Linear Regression Based Fourier Linear Combiner

Directory of Open Access Journals (Sweden)

Yubo Wang

2017-06-01

Full Text Available It is often difficult to analyze biological signals because of their nonlinear and non-stationary characteristics. This necessitates the usage of time-frequency decomposition methods for analyzing the subtle changes in these signals that are often connected to an underlying phenomena. This paper presents a new approach to analyze the time-varying characteristics of such signals by employing a simple truncated Fourier series model, namely the band-limited multiple Fourier linear combiner (BMFLC. In contrast to the earlier designs, we first identified the sparsity imposed on the signal model in order to reformulate the model to a sparse linear regression model. The coefficients of the proposed model are then estimated by a convex optimization algorithm. The performance of the proposed method was analyzed with benchmark test signals. An energy ratio metric is employed to quantify the spectral performance and results show that the proposed method Sparse-BMFLC has high mean energy (0.9976 ratio and outperforms existing methods such as short-time Fourier transfrom (STFT, continuous Wavelet transform (CWT and BMFLC Kalman Smoother. Furthermore, the proposed method provides an overall 6.22% in reconstruction error.

Time-Frequency Analysis of Non-Stationary Biological Signals with Sparse Linear Regression Based Fourier Linear Combiner.

Science.gov (United States)

Wang, Yubo; Veluvolu, Kalyana C

2017-06-14

It is often difficult to analyze biological signals because of their nonlinear and non-stationary characteristics. This necessitates the usage of time-frequency decomposition methods for analyzing the subtle changes in these signals that are often connected to an underlying phenomena. This paper presents a new approach to analyze the time-varying characteristics of such signals by employing a simple truncated Fourier series model, namely the band-limited multiple Fourier linear combiner (BMFLC). In contrast to the earlier designs, we first identified the sparsity imposed on the signal model in order to reformulate the model to a sparse linear regression model. The coefficients of the proposed model are then estimated by a convex optimization algorithm. The performance of the proposed method was analyzed with benchmark test signals. An energy ratio metric is employed to quantify the spectral performance and results show that the proposed method Sparse-BMFLC has high mean energy (0.9976) ratio and outperforms existing methods such as short-time Fourier transfrom (STFT), continuous Wavelet transform (CWT) and BMFLC Kalman Smoother. Furthermore, the proposed method provides an overall 6.22% in reconstruction error.

Simple, efficient estimators of treatment effects in randomized trials using generalized linear models to leverage baseline variables.

Science.gov (United States)

Rosenblum, Michael; van der Laan, Mark J

2010-04-01

Models, such as logistic regression and Poisson regression models, are often used to estimate treatment effects in randomized trials. These models leverage information in variables collected before randomization, in order to obtain more precise estimates of treatment effects. However, there is the danger that model misspecification will lead to bias. We show that certain easy to compute, model-based estimators are asymptotically unbiased even when the working model used is arbitrarily misspecified. Furthermore, these estimators are locally efficient. As a special case of our main result, we consider a simple Poisson working model containing only main terms; in this case, we prove the maximum likelihood estimate of the coefficient corresponding to the treatment variable is an asymptotically unbiased estimator of the marginal log rate ratio, even when the working model is arbitrarily misspecified. This is the log-linear analog of ANCOVA for linear models. Our results demonstrate one application of targeted maximum likelihood estimation.

Simple, Efficient Estimators of Treatment Effects in Randomized Trials Using Generalized Linear Models to Leverage Baseline Variables

Science.gov (United States)

Rosenblum, Michael; van der Laan, Mark J.

2010-01-01

Models, such as logistic regression and Poisson regression models, are often used to estimate treatment effects in randomized trials. These models leverage information in variables collected before randomization, in order to obtain more precise estimates of treatment effects. However, there is the danger that model misspecification will lead to bias. We show that certain easy to compute, model-based estimators are asymptotically unbiased even when the working model used is arbitrarily misspecified. Furthermore, these estimators are locally efficient. As a special case of our main result, we consider a simple Poisson working model containing only main terms; in this case, we prove the maximum likelihood estimate of the coefficient corresponding to the treatment variable is an asymptotically unbiased estimator of the marginal log rate ratio, even when the working model is arbitrarily misspecified. This is the log-linear analog of ANCOVA for linear models. Our results demonstrate one application of targeted maximum likelihood estimation. PMID:20628636

Combining Step Gradients and Linear Gradients in Density.

Science.gov (United States)

Kumar, Ashok A; Walz, Jenna A; Gonidec, Mathieu; Mace, Charles R; Whitesides, George M

2015-06-16

Combining aqueous multiphase systems (AMPS) and magnetic levitation (MagLev) provides a method to produce hybrid gradients in apparent density. AMPS—solutions of different polymers, salts, or surfactants that spontaneously separate into immiscible but predominantly aqueous phases—offer thermodynamically stable steps in density that can be tuned by the concentration of solutes. MagLev—the levitation of diamagnetic objects in a paramagnetic fluid within a magnetic field gradient—can be arranged to provide a near-linear gradient in effective density where the height of a levitating object above the surface of the magnet corresponds to its density; the strength of the gradient in effective density can be tuned by the choice of paramagnetic salt and its concentrations and by the strength and gradient in the magnetic field. Including paramagnetic salts (e.g., MnSO4 or MnCl2) in AMPS, and placing them in a magnetic field gradient, enables their use as media for MagLev. The potential to create large steps in density with AMPS allows separations of objects across a range of densities. The gradients produced by MagLev provide resolution over a continuous range of densities. By combining these approaches, mixtures of objects with large differences in density can be separated and analyzed simultaneously. Using MagLev to add an effective gradient in density also enables tuning the range of densities captured at an interface of an AMPS by simply changing the position of the container in the magnetic field. Further, by creating AMPS in which phases have different concentrations of paramagnetic ions, the phases can provide different resolutions in density. These results suggest that combining steps in density with gradients in density can enable new classes of separations based on density.

Dynamic Average Consensus and Consensusability of General Linear Multiagent Systems with Random Packet Dropout

Directory of Open Access Journals (Sweden)

Wen-Min Zhou

2013-01-01

Full Text Available This paper is concerned with the consensus problem of general linear discrete-time multiagent systems (MASs with random packet dropout that happens during information exchange between agents. The packet dropout phenomenon is characterized as being a Bernoulli random process. A distributed consensus protocol with weighted graph is proposed to address the packet dropout phenomenon. Through introducing a new disagreement vector, a new framework is established to solve the consensus problem. Based on the control theory, the perturbation argument, and the matrix theory, the necessary and sufficient condition for MASs to reach mean-square consensus is derived in terms of stability of an array of low-dimensional matrices. Moreover, mean-square consensusable conditions with regard to network topology and agent dynamic structure are also provided. Finally, the effectiveness of the theoretical results is demonstrated through an illustrative example.

Effects of high-intensity pulse irradiation with linear polarized near-infrared rays and stretching on muscle tone in patients with cerebrovascular disease: a randomized controlled trial.

Science.gov (United States)

Takeuchi, Nobuyuki; Takezako, Nobuhiro; Shimonishi, Yuko; Usuda, Shigeru

2017-08-01

[Purpose] The purpose of this study was to clarify the influence of high-intensity pulse irradiation with linear polarized near-infrared rays (HI-LPNR) and stretching on hypertonia in cerebrovascular disease patients. [Subjects and Methods] The subjects were 40 cerebrovascular disease patients with hypertonia of the ankle joint plantar flexor muscle. The subjects were randomly allocated to groups undergoing treatment with HI-LPNR irradiation (HI-LPNR group), stretching (stretching group), HI-LPNR irradiation followed by stretching (combination group), and control group (10 subjects each). In all groups, the passive range of motion of ankle dorsiflexion and passive resistive joint torque of ankle dorsiflexion were measured before and after the specified intervention. [Results] The changes in passive range of motion, significant increase in the stretching and combination groups compared with that in the control group. The changes in passive resistive joint torque, significant decrease in HI-LPNR, stretching, and combination groups compared with that in the control group. [Conclusion] HI-LPNR irradiation and stretching has effect of decrease muscle tone. However, combination of HI-LPNR irradiation and stretching has no multiplier effect.

Phylogenetic mixtures and linear invariants for equal input models.

Science.gov (United States)

Casanellas, Marta; Steel, Mike

2017-04-01

The reconstruction of phylogenetic trees from molecular sequence data relies on modelling site substitutions by a Markov process, or a mixture of such processes. In general, allowing mixed processes can result in different tree topologies becoming indistinguishable from the data, even for infinitely long sequences. However, when the underlying Markov process supports linear phylogenetic invariants, then provided these are sufficiently informative, the identifiability of the tree topology can be restored. In this paper, we investigate a class of processes that support linear invariants once the stationary distribution is fixed, the 'equal input model'. This model generalizes the 'Felsenstein 1981' model (and thereby the Jukes-Cantor model) from four states to an arbitrary number of states (finite or infinite), and it can also be described by a 'random cluster' process. We describe the structure and dimension of the vector spaces of phylogenetic mixtures and of linear invariants for any fixed phylogenetic tree (and for all trees-the so called 'model invariants'), on any number n of leaves. We also provide a precise description of the space of mixtures and linear invariants for the special case of [Formula: see text] leaves. By combining techniques from discrete random processes and (multi-) linear algebra, our results build on a classic result that was first established by James Lake (Mol Biol Evol 4:167-191, 1987).

Adaptive rival penalized competitive learning and combined linear predictor model for financial forecast and investment.

Science.gov (United States)

Cheung, Y M; Leung, W M; Xu, L

1997-01-01

We propose a prediction model called Rival Penalized Competitive Learning (RPCL) and Combined Linear Predictor method (CLP), which involves a set of local linear predictors such that a prediction is made by the combination of some activated predictors through a gating network (Xu et al., 1994). Furthermore, we present its improved variant named Adaptive RPCL-CLP that includes an adaptive learning mechanism as well as a data pre-and-post processing scheme. We compare them with some existing models by demonstrating their performance on two real-world financial time series--a China stock price and an exchange-rate series of US Dollar (USD) versus Deutschmark (DEM). Experiments have shown that Adaptive RPCL-CLP not only outperforms the other approaches with the smallest prediction error and training costs, but also brings in considerable high profits in the trading simulation of foreign exchange market.

Combined impact of negative lifestyle factors on cardiovascular risk in children: a randomized prospective study

OpenAIRE

Meyer, Ursina; Schindler, Christian; Bloesch, Tamara; Schmocker, Eliane; Zahner, Lukas; Puder, Jardena J; Kriemler, Susi

2014-01-01

PURPOSE: Negative lifestyle factors are known to be associated with increased cardiovascular risk (CVR) in children, but research on their combined impact on a general population of children is sparse. Therefore, we aimed to quantify the combined impact of easily assessable negative lifestyle factors on the CVR scores of randomly selected children after 4 years. METHODS: Of the 540 randomly selected 6- to 13-year-old children, 502 children participated in a baseline health assessment, and ...

Feasibility of combining linear theory and impact theory methods for the analysis and design of high speed configurations

Science.gov (United States)

Brooke, D.; Vondrasek, D. V.

1978-01-01

The aerodynamic influence coefficients calculated using an existing linear theory program were used to modify the pressures calculated using impact theory. Application of the combined approach to several wing-alone configurations shows that the combined approach gives improved predictions of the local pressure and loadings over either linear theory alone or impact theory alone. The approach not only removes most of the short-comings of the individual methods, as applied in the Mach 4 to 8 range, but also provides the basis for an inverse design procedure applicable to high speed configurations.

Robust Management of Combined Heat and Power Systems via Linear Decision Rules

DEFF Research Database (Denmark)

Zugno, Marco; Morales González, Juan Miguel; Madsen, Henrik

2014-01-01

The heat and power outputs of Combined Heat and Power (CHP) units are jointly constrained. Hence, the optimal management of systems including CHP units is a multicommodity optimization problem. Problems of this type are stochastic, owing to the uncertainty inherent both in the demand for heat and...... linear decision rules to guarantee both tractability and a correct representation of the dynamic aspects of the problem. Numerical results from an illustrative example confirm the value of the proposed approach....

Testing the dual-route model of perceived gaze direction: Linear combination of eye and head cues.

Science.gov (United States)

Otsuka, Yumiko; Mareschal, Isabelle; Clifford, Colin W G

2016-06-01

We have recently proposed a dual-route model of the effect of head orientation on perceived gaze direction (Otsuka, Mareschal, Calder, & Clifford, 2014; Otsuka, Mareschal, & Clifford, 2015), which computes perceived gaze direction as a linear combination of eye orientation and head orientation. By parametrically manipulating eye orientation and head orientation, we tested the adequacy of a linear model to account for the effect of horizontal head orientation on perceived direction of gaze. Here, participants adjusted an on-screen pointer toward the perceived gaze direction in two image conditions: Normal condition and Wollaston condition. Images in the Normal condition included a change in the visible part of the eye along with the change in head orientation, while images in the Wollaston condition were manipulated to have identical eye regions across head orientations. Multiple regression analysis with explanatory variables of eye orientation and head orientation revealed that linear models account for most of the variance both in the Normal condition and in the Wollaston condition. Further, we found no evidence that the model with a nonlinear term explains significantly more variance. Thus, the current study supports the dual-route model that computes the perceived gaze direction as a linear combination of eye orientation and head orientation.

Linear magnetic spring and spring/motor combination

Science.gov (United States)

Patt, Paul J. (Inventor); Stolfi, Fred R. (Inventor)

1991-01-01

A magnetic spring, or a spring and motor combination, providing a linear spring force characteristic in each direction from a neutral position, in which the spring action may occur for any desired coordinate of a typical orthogonal coordinate system. A set of magnets are disposed, preferably symmetrically about a coordinate axis, poled orthogonally to the desired force direction. A second set of magnets, respectively poled opposite the first set, are arranged on the sprung article. The magnets of one of the sets are spaced a greater distance apart than those of the other, such that an end magnet from each set forms a pair having preferably planar faces parallel to the direction of spring force, the faces being offset so that in a neutral position the outer edge of the closer spaced magnet set is aligned with the inner edge of the greater spaced magnet set. For use as a motor, a coil can be arranged with conductors orthogonal to both the magnet pole directions and the direction of desired spring force, located across from the magnets of one set and fixed with respect to the magnets of the other set. In a cylindrical coordinate system having axial spring force, the magnets are radially poled and motor coils are concentric with the cylinder axis.

Arrhythmia recognition and classification using combined linear and nonlinear features of ECG signals.

Science.gov (United States)

Elhaj, Fatin A; Salim, Naomie; Harris, Arief R; Swee, Tan Tian; Ahmed, Taqwa

2016-04-01

Arrhythmia is a cardiac condition caused by abnormal electrical activity of the heart, and an electrocardiogram (ECG) is the non-invasive method used to detect arrhythmias or heart abnormalities. Due to the presence of noise, the non-stationary nature of the ECG signal (i.e. the changing morphology of the ECG signal with respect to time) and the irregularity of the heartbeat, physicians face difficulties in the diagnosis of arrhythmias. The computer-aided analysis of ECG results assists physicians to detect cardiovascular diseases. The development of many existing arrhythmia systems has depended on the findings from linear experiments on ECG data which achieve high performance on noise-free data. However, nonlinear experiments characterize the ECG signal more effectively sense, extract hidden information in the ECG signal, and achieve good performance under noisy conditions. This paper investigates the representation ability of linear and nonlinear features and proposes a combination of such features in order to improve the classification of ECG data. In this study, five types of beat classes of arrhythmia as recommended by the Association for Advancement of Medical Instrumentation are analyzed: non-ectopic beats (N), supra-ventricular ectopic beats (S), ventricular ectopic beats (V), fusion beats (F) and unclassifiable and paced beats (U). The characterization ability of nonlinear features such as high order statistics and cumulants and nonlinear feature reduction methods such as independent component analysis are combined with linear features, namely, the principal component analysis of discrete wavelet transform coefficients. The features are tested for their ability to differentiate different classes of data using different classifiers, namely, the support vector machine and neural network methods with tenfold cross-validation. Our proposed method is able to classify the N, S, V, F and U arrhythmia classes with high accuracy (98.91%) using a combined support

A speed estimation unit for induction motors based on adaptive linear combiner

International Nuclear Information System (INIS)

Marei, Mostafa I.; Shaaban, Mostafa F.; El-Sattar, Ahmed A.

2009-01-01

This paper presents a new induction motor speed estimation technique, which can estimate the rotor resistance as well, from the measured voltage and current signals. Moreover, the paper utilizes a novel adaptive linear combiner (ADALINE) structure for speed and rotor resistance estimations. This structure can deal with the multi-output systems and it is called MO-ADALINE. The model of the induction motor is arranged in a linear form, in the stationary reference frame, to cope with the proposed speed estimator. There are many advantages of the proposed unit such as wide speed range capability, immunity against harmonics of measured waveforms, and precise estimation of the speed and the rotor resistance at different dynamic changes. Different types of induction motor drive systems are used to evaluate the dynamic performance and to examine the accuracy of the proposed unit for speed and rotor resistance estimation.

Approximate Forward Difference Equations for the Lower Order Non-Stationary Statistics of Geometrically Non-Linear Systems subject to Random Excitation

DEFF Research Database (Denmark)

Köylüoglu, H. U.; Nielsen, Søren R. K.; Cakmak, A. S.

Geometrically non-linear multi-degree-of-freedom (MDOF) systems subject to random excitation are considered. New semi-analytical approximate forward difference equations for the lower order non-stationary statistical moments of the response are derived from the stochastic differential equations...... of motion, and, the accuracy of these equations is numerically investigated. For stationary excitations, the proposed method computes the stationary statistical moments of the response from the solution of non-linear algebraic equations....

A penalized linear and nonlinear combined conjugate gradient method for the reconstruction of fluorescence molecular tomography.

Science.gov (United States)

Shang, Shang; Bai, Jing; Song, Xiaolei; Wang, Hongkai; Lau, Jaclyn

2007-01-01

Conjugate gradient method is verified to be efficient for nonlinear optimization problems of large-dimension data. In this paper, a penalized linear and nonlinear combined conjugate gradient method for the reconstruction of fluorescence molecular tomography (FMT) is presented. The algorithm combines the linear conjugate gradient method and the nonlinear conjugate gradient method together based on a restart strategy, in order to take advantage of the two kinds of conjugate gradient methods and compensate for the disadvantages. A quadratic penalty method is adopted to gain a nonnegative constraint and reduce the illposedness of the problem. Simulation studies show that the presented algorithm is accurate, stable, and fast. It has a better performance than the conventional conjugate gradient-based reconstruction algorithms. It offers an effective approach to reconstruct fluorochrome information for FMT.

Modeling the Non-Linear Response of Fiber-Reinforced Laminates Using a Combined Damage/Plasticity Model

Science.gov (United States)

Schuecker, Clara; Davila, Carlos G.; Pettermann, Heinz E.

2008-01-01

The present work is concerned with modeling the non-linear response of fiber reinforced polymer laminates. Recent experimental data suggests that the non-linearity is not only caused by matrix cracking but also by matrix plasticity due to shear stresses. To capture the effects of those two mechanisms, a model combining a plasticity formulation with continuum damage has been developed to simulate the non-linear response of laminates under plane stress states. The model is used to compare the predicted behavior of various laminate lay-ups to experimental data from the literature by looking at the degradation of axial modulus and Poisson s ratio of the laminates. The influence of residual curing stresses and in-situ effect on the predicted response is also investigated. It is shown that predictions of the combined damage/plasticity model, in general, correlate well with the experimental data. The test data shows that there are two different mechanisms that can have opposite effects on the degradation of the laminate Poisson s ratio which is captured correctly by the damage/plasticity model. Residual curing stresses are found to have a minor influence on the predicted response for the cases considered here. Some open questions remain regarding the prediction of damage onset.

Tamsulosin, Solifenacin, and Their Combination for the Treatment of Stent-Related Symptoms: A Randomized Controlled Study.

Science.gov (United States)

Dellis, Athanasios E; Papatsoris, Athanasios G; Keeley, Francis X; Bamias, Aristotelis; Deliveliotis, Charalambos; Skolarikos, Andreas A

2017-01-01

To properly use the Ureteric Symptom Score Questionnaire (USSQ) to evaluate, in a randomized control study, the effect of tamsulosin, solifenacin, and their combination in improving symptoms and quality of life in patients with indwelling ureteral stents. After institutional review board approval, 260 patients with a ureteral stent were randomly assigned to receive tamsulosin 0.4 mg, solifenacin 5 mg, or placebo and further randomized to receive their combination. The validated USSQ was completed 1 and 4 weeks after stent insertion and 4 weeks after stent removal. Kruskal-Wallis test, chi-squared test (or Fisher's exact test), one-way analysis of variance, and T-test (or Wilcoxon rank-sum test if not normal data) were used for statistical analysis. The results were considered significant at p tamsulosin or solifenacin expressed significantly lower urinary (p tamsulosin and solifenacin alone or in combination, improves stent-related symptoms and has a positive impact on quality of life.

Combination Analgesia for Neonatal Circumcision: A Randomized Controlled Trial.

Science.gov (United States)

Sharara-Chami, Rana; Lakissian, Zavi; Charafeddine, Lama; Milad, Nadine; El-Hout, Yaser

2017-12-01

There is no consensus on the most effective pain management for neonatal circumcision. We sought to compare different modalities. This is a double-blinded randomized controlled trial comparing 3 combination analgesics used during circumcision (EMLA + sucrose; EMLA + sucrose + dorsal penile nerve block [DPNB]; EMLA + sucrose + ring block [RB]) with the traditional topical analgesic cream EMLA alone. The trial was set in the normal nursery of a teaching hospital. The sample included 70 healthy male newborns, randomly assigned to intervention and control groups at a 2:1 ratio. Infants were videotaped (face and torso) during the procedure for assessment of pain by 2 blinded, independent reviewers. The primary outcome measure is the Neonatal Infant Pain Scale score. Secondary outcomes include heart rate, oxygen saturation, and crying time. Neonatal Infant Pain Scale scores were significantly lower in the intervention groups (EMLA + sucrose, mean [SD]: 3.1 [1.33]; EMLA + sucrose + DPNB: 3 [1.33]; EMLA + sucrose + RB: 2.45 [1.27]) compared with the control (5.5 [0.53]). Between-group analyses showed RB + EMLA + sucrose to be significantly more effective than EMLA + sucrose; EMLA + sucrose + DPNB ( P = .009 and P = .002, respectively). Interrater reliability was κ = 0.843. Significant increase in heart rate (139.27 [9.63] to 163 [13.23] beats per minute) and crying time (5.78 [6.4] to 45.37 [12.39] seconds) were noted in the EMLA group. During neonatal circumcision in boys, the most effective analgesia is RB combined with oral sucrose and EMLA cream. Copyright © 2017 by the American Academy of Pediatrics.

Multivariate generalized linear mixed models using R

CERN Document Server

Berridge, Damon Mark

2011-01-01

Multivariate Generalized Linear Mixed Models Using R presents robust and methodologically sound models for analyzing large and complex data sets, enabling readers to answer increasingly complex research questions. The book applies the principles of modeling to longitudinal data from panel and related studies via the Sabre software package in R. A Unified Framework for a Broad Class of Models The authors first discuss members of the family of generalized linear models, gradually adding complexity to the modeling framework by incorporating random effects. After reviewing the generalized linear model notation, they illustrate a range of random effects models, including three-level, multivariate, endpoint, event history, and state dependence models. They estimate the multivariate generalized linear mixed models (MGLMMs) using either standard or adaptive Gaussian quadrature. The authors also compare two-level fixed and random effects linear models. The appendices contain additional information on quadrature, model...

Randomized combined modality trial in small cell carcinoma of the lung

International Nuclear Information System (INIS)

Maurer, L.H.; Tulloh, M.; Weiss, R.B.; Blom, J.; Leone, L.; Glidewell, O.; Pajak, T.F.

1980-01-01

A randomized trial of combined modality therapy employing combination chemotherapy (cyclophosphamide (CTX) and methotrexate (MTX), CTX, MTX and Vincristine (VCR) and CTX, VCR, and high-dose MTX with citrovorum rescue), and radiation therapy was compared to cyclophosphamide and radiation therapy in 258 patients with pulmonary small cell carcinoma. Patients were also randomized: (1) to determine the effects of prophylactic whole brain irradiation; (2) to establish the effects of maintenance chemotherapy. Survival, frequency of response, and site of relapse were different in patients with limited disease (LD) (disease confined to lung, mediastinum, and supraclavicular lymph nodes) when compared with disease spread beyond these sites (extensive disease) (ED). No survival advantage was seen in LD when combination chemotherapy was employed, although the frequency of complete remission was greater with three drugs than with one or two drugs (48% vs 32%). In ED frequency of response was greater for three drugs than for one and two drugs (60% vs 40%), but there was no survival advantage. The median survival time for complete responders was similar for limited or extensive disease (12.1 months), but 23.8% were alive at 24 months with LD compared to none with ED. Maintenance chemotherapy significantly prolonged survival by 16.8 months with 33% alive at 24 months compared to 9% who were unmaintained. Prophylactic whole brain irradiation prevented brain metastases with only 4% developing this complication as compared to 18% of control subjects, but did not influence survival

The linear programming bound for binary linear codes

NARCIS (Netherlands)

Brouwer, A.E.

1993-01-01

Combining Delsarte's (1973) linear programming bound with the information that certain weights cannot occur, new upper bounds for dmin (n,k), the maximum possible minimum distance of a binary linear code with given word length n and dimension k, are derived.

Selecting Optimal Parameters of Random Linear Network Coding for Wireless Sensor Networks

DEFF Research Database (Denmark)

Heide, J; Zhang, Qi; Fitzek, F H P

2013-01-01

This work studies how to select optimal code parameters of Random Linear Network Coding (RLNC) in Wireless Sensor Networks (WSNs). With Rateless Deluge [1] the authors proposed to apply Network Coding (NC) for Over-the-Air Programming (OAP) in WSNs, and demonstrated that with NC a significant...... reduction in the number of transmitted packets can be achieved. However, NC introduces additional computations and potentially a non-negligible transmission overhead, both of which depend on the chosen coding parameters. Therefore it is necessary to consider the trade-off that these coding parameters...... present in order to obtain the lowest energy consumption per transmitted bit. This problem is analyzed and suitable coding parameters are determined for the popular Tmote Sky platform. Compared to the use of traditional RLNC, these parameters enable a reduction in the energy spent per bit which grows...

Effects of combined linear and nonlinear periodic training on physical fitness and competition times in finswimmers.

Science.gov (United States)

Yu, Kyung-Hun; Suk, Min-Hwa; Kang, Shin-Woo; Shin, Yun-A

2014-10-01

The purpose of this study was to investigate the effect of combined linear and nonlinear periodic training on physical fitness and competition times in finswimmers. The linear resistance training model (6 days/week) and nonlinear underwater training (4 days/week) were applied to 12 finswimmers (age, 16.08± 1.44 yr; career, 3.78± 1.90 yr) for 12 weeks. Body composition measures included weight, body mass index (BMI), percent fat, and fat-free mass. Physical fitness measures included trunk flexion forward, trunk extension backward, sargent jump, 1-repetition-maximum (1 RM) squat, 1 RM dead lift, knee extension, knee flexion, trunk extension, trunk flexion, and competition times. Body composition and physical fitness were improved after the 12-week periodic training program. Weight, BMI, and percent fat were significantly decreased, and trunk flexion forward, trunk extension backward, sargent jump, 1 RM squat, 1 RM dead lift, and knee extension (right) were significantly increased. The 50- and 100-m times significantly decreased in all 12 athletes. After 12 weeks of training, all finswimmers who participated in this study improved their times in a public competition. These data indicate that combined linear and nonlinear periodic training enhanced the physical fitness and competition times in finswimmers.

New Trends in Pseudo-Random Number Generation

Science.gov (United States)

Gutbrod, F.

Properties of pseudo-random number generators are reviewed. The emphasis is on correlations between successive random numbers and their suppression by improvement steps. The generators under discussion are the linear congruential generators, lagged Fibonacci generators with various operations, and the improvement techniques combination, shuffling and decimation. The properties of the RANSHI generator are reviewed somewhat more extensively. The transition to 64-bit technology is discussed in several cases. The generators are subject to several tests, which look both for short range and for long range correlations. Some performance figures are given for a Pentium Pro PC. Recommendations are presented in the final chapter.

ComboCoding: Combined intra-/inter-flow network coding for TCP over disruptive MANETs

Directory of Open Access Journals (Sweden)

Chien-Chia Chen

2011-07-01

Full Text Available TCP over wireless networks is challenging due to random losses and ACK interference. Although network coding schemes have been proposed to improve TCP robustness against extreme random losses, a critical problem still remains of DATA–ACK interference. To address this issue, we use inter-flow coding between DATA and ACK to reduce the number of transmissions among nodes. In addition, we also utilize a “pipeline” random linear coding scheme with adaptive redundancy to overcome high packet loss over unreliable links. The resulting coding scheme, ComboCoding, combines intra-flow and inter-flow coding to provide robust TCP transmission in disruptive wireless networks. The main contributions of our scheme are twofold; the efficient combination of random linear coding and XOR coding on bi-directional streams (DATA and ACK, and the novel redundancy control scheme that adapts to time-varying and space-varying link loss. The adaptive ComboCoding was tested on a variable hop string topology with unstable links and on a multipath MANET with dynamic topology. Simulation results show that TCP with ComboCoding delivers higher throughput than with other coding options in high loss and mobile scenarios, while introducing minimal overhead in normal operation.

Non-linear operation of nanomechnical systems combining photothermal excitation and magneto-motive detection

International Nuclear Information System (INIS)

Koenig, Daniel R; Metzger, Constanze; Camerer, Stephan; Kotthaus, Joerg P

2006-01-01

We present a non-linear operation of a nanomechanical beam resonator by photothermal excitation at 4 K. The resonators dimensions are 10 μm in length, 200 nm in width, and 200 nm in height. The actuation mechanism is based on a pulsed diode laser focused onto the centre of the beam resonator. Thermally induced stress caused by the different thermal expansion coefficients of the bi-layer system periodically deflects the resonator. Magnetomotively detected amplitudes up to 150 nm are reached at the fundamental resonance mode at a frequency of 8.9 MHz. Furthermore, the third eigenmode of the resonator at a frequency 36 MHz is also excited. We conclude that the photothermal excitation at 4 K should be applicable up to the GHz regime, the operation in the non-linear regime can be used for performance enhancement of nanomechanical systems, and the combination of photothermal excitation and magneto-motive detection avoids undesired cross talk

On Complex Random Variables

Directory of Open Access Journals (Sweden)

Anwer Khurshid

2012-07-01

Full Text Available Normal 0 false false false EN-US X-NONE X-NONE In this paper, it is shown that a complex multivariate random variable  is a complex multivariate normal random variable of dimensionality if and only if all nondegenerate complex linear combinations of  have a complex univariate normal distribution. The characteristic function of  has been derived, and simpler forms of some theorems have been given using this characterization theorem without assuming that the variance-covariance matrix of the vector  is Hermitian positive definite. Marginal distributions of  have been given. In addition, a complex multivariate t-distribution has been defined and the density derived. A characterization of the complex multivariate t-distribution is given. A few possible uses of this distribution have been suggested.

Analysis and Optimization of Sparse Random Linear Network Coding for Reliable Multicast Services

DEFF Research Database (Denmark)

Tassi, Andrea; Chatzigeorgiou, Ioannis; Roetter, Daniel Enrique Lucani

2016-01-01

Point-to-multipoint communications are expected to play a pivotal role in next-generation networks. This paper refers to a cellular system transmitting layered multicast services to a multicast group of users. Reliability of communications is ensured via different random linear network coding (RLNC......) techniques. We deal with a fundamental problem: the computational complexity of the RLNC decoder. The higher the number of decoding operations is, the more the user's computational overhead grows and, consequently, the faster the battery of mobile devices drains. By referring to several sparse RLNC...... techniques, and without any assumption on the implementation of the RLNC decoder in use, we provide an efficient way to characterize the performance of users targeted by ultra-reliable layered multicast services. The proposed modeling allows to efficiently derive the average number of coded packet...

Integral linear momentum balance in combining flows for calculating the pressure drop coefficients

International Nuclear Information System (INIS)

Bollmann, A.

1983-01-01

Equations for calculating the loss coefficient in combining flows in tee functions are obtained by an integral linear momentum balance. It is a practice, when solving this type of problem, to neglect the pressure difference in the upstream location as well as the wall-fluid interaction in the lateral branch of the junction. In this work it is demonstrated the influence of the above parameters on the loss coefficient based on experimental values and by apropriate algebraic manipulation of the loss coefficient values published by previous investigators. (Author) [pt

Boosted regression trees, multivariate adaptive regression splines and their two-step combinations with multiple linear regression or partial least squares to predict blood-brain barrier passage: a case study.

Science.gov (United States)

Deconinck, E; Zhang, M H; Petitet, F; Dubus, E; Ijjaali, I; Coomans, D; Vander Heyden, Y

2008-02-18

The use of some unconventional non-linear modeling techniques, i.e. classification and regression trees and multivariate adaptive regression splines-based methods, was explored to model the blood-brain barrier (BBB) passage of drugs and drug-like molecules. The data set contains BBB passage values for 299 structural and pharmacological diverse drugs, originating from a structured knowledge-based database. Models were built using boosted regression trees (BRT) and multivariate adaptive regression splines (MARS), as well as their respective combinations with stepwise multiple linear regression (MLR) and partial least squares (PLS) regression in two-step approaches. The best models were obtained using combinations of MARS with either stepwise MLR or PLS. It could be concluded that the use of combinations of a linear with a non-linear modeling technique results in some improved properties compared to the individual linear and non-linear models and that, when the use of such a combination is appropriate, combinations using MARS as non-linear technique should be preferred over those with BRT, due to some serious drawbacks of the BRT approaches.

A random number generator for continuous random variables

Science.gov (United States)

Guerra, V. M.; Tapia, R. A.; Thompson, J. R.

1972-01-01

A FORTRAN 4 routine is given which may be used to generate random observations of a continuous real valued random variable. Normal distribution of F(x), X, E(akimas), and E(linear) is presented in tabular form.

Probabilistic Signal Recovery and Random Matrices

Science.gov (United States)

2016-12-08

that classical methods for linear regression (such as Lasso) are applicable for non- linear data. This surprising finding has already found several...we studied the complexity of convex sets. In numerical linear algebra , we analyzed the fastest known randomized approximation algorithm for...and perfect matchings In numerical linear algebra , we studied the fastest known randomized approximation algorithm for computing the permanents of

Short communication: Alteration of priors for random effects in Gaussian linear mixed model

DEFF Research Database (Denmark)

Vandenplas, Jérémie; Christensen, Ole Fredslund; Gengler, Nicholas

2014-01-01

such alterations. Therefore, the aim of this study was to propose a method to alter both the mean and (co)variance of the prior multivariate normal distributions of random effects of linear mixed models while using currently available software packages. The proposed method was tested on simulated examples with 3......, multiple-trait predictions of lactation yields, and Bayesian approaches integrating external information into genetic evaluations) need to alter both the mean and (co)variance of the prior distributions and, to our knowledge, most software packages available in the animal breeding community do not permit...... different software packages available in animal breeding. The examples showed the possibility of the proposed method to alter both the mean and (co)variance of the prior distributions with currently available software packages through the use of an extended data file and a user-supplied (co)variance matrix....

Conserved linear dynamics of single-molecule Brownian motion

KAUST Repository

Serag, Maged F.

2017-06-06

Macromolecular diffusion in homogeneous fluid at length scales greater than the size of the molecule is regarded as a random process. The mean-squared displacement (MSD) of molecules in this regime increases linearly with time. Here we show that non-random motion of DNA molecules in this regime that is undetectable by the MSD analysis can be quantified by characterizing the molecular motion relative to a latticed frame of reference. Our lattice occupancy analysis reveals unexpected sub-modes of motion of DNA that deviate from expected random motion in the linear, diffusive regime. We demonstrate that a subtle interplay between these sub-modes causes the overall diffusive motion of DNA to appear to conform to the linear regime. Our results show that apparently random motion of macromolecules could be governed by non-random dynamics that are detectable only by their relative motion. Our analytical approach should advance broad understanding of diffusion processes of fundamental relevance.

Conserved linear dynamics of single-molecule Brownian motion

Science.gov (United States)

Serag, Maged F.; Habuchi, Satoshi

2017-06-01

Macromolecular diffusion in homogeneous fluid at length scales greater than the size of the molecule is regarded as a random process. The mean-squared displacement (MSD) of molecules in this regime increases linearly with time. Here we show that non-random motion of DNA molecules in this regime that is undetectable by the MSD analysis can be quantified by characterizing the molecular motion relative to a latticed frame of reference. Our lattice occupancy analysis reveals unexpected sub-modes of motion of DNA that deviate from expected random motion in the linear, diffusive regime. We demonstrate that a subtle interplay between these sub-modes causes the overall diffusive motion of DNA to appear to conform to the linear regime. Our results show that apparently random motion of macromolecules could be governed by non-random dynamics that are detectable only by their relative motion. Our analytical approach should advance broad understanding of diffusion processes of fundamental relevance.

Conserved linear dynamics of single-molecule Brownian motion

KAUST Repository

Serag, Maged F.; Habuchi, Satoshi

2017-01-01

Macromolecular diffusion in homogeneous fluid at length scales greater than the size of the molecule is regarded as a random process. The mean-squared displacement (MSD) of molecules in this regime increases linearly with time. Here we show that non-random motion of DNA molecules in this regime that is undetectable by the MSD analysis can be quantified by characterizing the molecular motion relative to a latticed frame of reference. Our lattice occupancy analysis reveals unexpected sub-modes of motion of DNA that deviate from expected random motion in the linear, diffusive regime. We demonstrate that a subtle interplay between these sub-modes causes the overall diffusive motion of DNA to appear to conform to the linear regime. Our results show that apparently random motion of macromolecules could be governed by non-random dynamics that are detectable only by their relative motion. Our analytical approach should advance broad understanding of diffusion processes of fundamental relevance.

Finite-dimensional linear algebra

CERN Document Server

Gockenbach, Mark S

2010-01-01

Some Problems Posed on Vector SpacesLinear equationsBest approximationDiagonalizationSummaryFields and Vector SpacesFields Vector spaces Subspaces Linear combinations and spanning sets Linear independence Basis and dimension Properties of bases Polynomial interpolation and the Lagrange basis Continuous piecewise polynomial functionsLinear OperatorsLinear operatorsMore properties of linear operatorsIsomorphic vector spaces Linear operator equations Existence and uniqueness of solutions The fundamental theorem; inverse operatorsGaussian elimination Newton's method Linear ordinary differential eq

Effect of Linear Low-Intensity Extracorporeal Shockwave Therapy for Erectile Dysfunction—12-Month Follow-Up of a Randomized, Double-Blinded, Sham-Controlled Study

Directory of Open Access Journals (Sweden)

Grzegorz Lukasz Fojecki, MD

2018-03-01

Fojecki GL, Tiessen S, Osther PJS. Effect of Linear Low-Intensity Extracorporeal Shockwave Therapy for Erectile Dysfunction—12-Month Follow-Up of a Randomized, Double-Blinded, Sham-Controlled Study. Sex Med 2018;6:1–7.

Pseudo-random Aloha for inter-frame soft combining in RFID systems

DEFF Research Database (Denmark)

Castiglione, Paolo; Ricciato, Fabio; Popovski, Petar

2013-01-01

In this work we consider a recently proposed variant of the classical Framed Slotted-ALOHA where slot selection is based on a pseudo-random function of the message to be transmitted and of the frame index. We couple this feature with convolutional encoding, that allows to perform Inter-frame Soft...... cancellation (instead of combining). Numerical simulation results show that the ISoC scheme brings a noticeable throughput gain over traditional schemes in a dense RFID scenario with multiple concurrent Tag transmissions....

Linear mixed-effects models to describe individual tree crown width for China-fir in Fujian Province, southeast China.

Science.gov (United States)

Hao, Xu; Yujun, Sun; Xinjie, Wang; Jin, Wang; Yao, Fu

2015-01-01

A multiple linear model was developed for individual tree crown width of Cunninghamia lanceolata (Lamb.) Hook in Fujian province, southeast China. Data were obtained from 55 sample plots of pure China-fir plantation stands. An Ordinary Linear Least Squares (OLS) regression was used to establish the crown width model. To adjust for correlations between observations from the same sample plots, we developed one level linear mixed-effects (LME) models based on the multiple linear model, which take into account the random effects of plots. The best random effects combinations for the LME models were determined by the Akaike's information criterion, the Bayesian information criterion and the -2logarithm likelihood. Heteroscedasticity was reduced by three residual variance functions: the power function, the exponential function and the constant plus power function. The spatial correlation was modeled by three correlation structures: the first-order autoregressive structure [AR(1)], a combination of first-order autoregressive and moving average structures [ARMA(1,1)], and the compound symmetry structure (CS). Then, the LME model was compared to the multiple linear model using the absolute mean residual (AMR), the root mean square error (RMSE), and the adjusted coefficient of determination (adj-R2). For individual tree crown width models, the one level LME model showed the best performance. An independent dataset was used to test the performance of the models and to demonstrate the advantage of calibrating LME models.

Tools to identify linear combination of prognostic factors which maximizes area under receiver operator curve.

Science.gov (United States)

Todor, Nicolae; Todor, Irina; Săplăcan, Gavril

2014-01-01

The linear combination of variables is an attractive method in many medical analyses targeting a score to classify patients. In the case of ROC curves the most popular problem is to identify the linear combination which maximizes area under curve (AUC). This problem is complete closed when normality assumptions are met. With no assumption of normality search algorithm are avoided because it is accepted that we have to evaluate AUC n(d) times where n is the number of distinct observation and d is the number of variables. For d = 2, using particularities of AUC formula, we described an algorithm which lowered the number of evaluations of AUC from n(2) to n(n-1) + 1. For d > 2 our proposed solution is an approximate method by considering equidistant points on the unit sphere in R(d) where we evaluate AUC. The algorithms were applied to data from our lab to predict response of treatment by a set of molecular markers in cervical cancers patients. In order to evaluate the strength of our algorithms a simulation was added. In the case of no normality presented algorithms are feasible. For many variables computation time could be increased but acceptable.

Linear Text vs. Non-Linear Hypertext in Handheld Computers: Effects on Declarative and Structural Knowledge, and Learner Motivation

Science.gov (United States)

Son, Chanhee; Park, Sanghoon; Kim, Minjeong

2011-01-01

This study compared linear text-based and non-linear hypertext-based instruction in a handheld computer regarding effects on two different levels of knowledge (declarative and structural knowledge) and learner motivation. Forty four participants were randomly assigned to one of three experimental conditions: linear text, hierarchical hypertext,…

Combined use of random access and ELISA analyzers in the microbiological serology laboratory

Directory of Open Access Journals (Sweden)

Alessandra Moroni

2008-09-01

Full Text Available In the last years the trend of centralizing small laboratories in large reference centers led to a careful evaluation of the diagnostic profiles. In the serology laboratory of Microbiology Unit, St. Orsola-Malpighi Hospital, Bologna, Italy the choice has been to combine random access analyzers (ARCHITECT Abbott and ELISA analyzers (BEPIII Dade Behring.

Randomized double-blind comparison of metoprolol, nifedipine, and their combination in chronic stable angina

DEFF Research Database (Denmark)

Egstrup, K

1988-01-01

In a randomized double-blind study, treatment with either metoprolol, nifedipine, or their combination was compared for effects on ischemic variables and heart rate obtained during ambulatory monitoring in 42 patients with chronic stable angina. All patients had severe chronic stable angina...... could be detected during nifedipine monotherapy. It is concluded that metoprolol monotherapy, as well as its combination with nifedipine, effectively reduces total ischemic activity compared with placebo and nifedipine monotherapy. Control of ischemic activity in chronic stable angina may have...

Linear feedback control, adaptive feedback control and their combination for chaos (lag) synchronization of LC chaotic systems

International Nuclear Information System (INIS)

Yan Zhenya; Yu Pei

2007-01-01

In this paper, we study chaos (lag) synchronization of a new LC chaotic system, which can exhibit not only a two-scroll attractor but also two double-scroll attractors for different parameter values, via three types of state feedback controls: (i) linear feedback control; (ii) adaptive feedback control; and (iii) a combination of linear feedback and adaptive feedback controls. As a consequence, ten families of new feedback control laws are designed to obtain global chaos lag synchronization for τ < 0 and global chaos synchronization for τ = 0 of the LC system. Numerical simulations are used to illustrate these theoretical results. Each family of these obtained feedback control laws, including two linear (adaptive) functions or one linear function and one adaptive function, is added to two equations of the LC system. This is simpler than the known synchronization controllers, which apply controllers to all equations of the LC system. Moreover, based on the obtained results of the LC system, we also derive the control laws for chaos (lag) synchronization of another new type of chaotic system

Mixed models, linear dependency, and identification in age-period-cohort models.

Science.gov (United States)

O'Brien, Robert M

2017-07-20

This paper examines the identification problem in age-period-cohort models that use either linear or categorically coded ages, periods, and cohorts or combinations of these parameterizations. These models are not identified using the traditional fixed effect regression model approach because of a linear dependency between the ages, periods, and cohorts. However, these models can be identified if the researcher introduces a single just identifying constraint on the model coefficients. The problem with such constraints is that the results can differ substantially depending on the constraint chosen. Somewhat surprisingly, age-period-cohort models that specify one or more of ages and/or periods and/or cohorts as random effects are identified. This is the case without introducing an additional constraint. I label this identification as statistical model identification and show how statistical model identification comes about in mixed models and why which effects are treated as fixed and which are treated as random can substantially change the estimates of the age, period, and cohort effects. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Combined slope ratio analysis and linear-subtraction: An extension of the Pearce ratio method

Science.gov (United States)

De Waal, Sybrand A.

1996-07-01

A new technique, called combined slope ratio analysis, has been developed by extending the Pearce element ratio or conserved-denominator method (Pearce, 1968) to its logical conclusions. If two stoichiometric substances are mixed and certain chemical components are uniquely contained in either one of the two mixing substances, then by treating these unique components as conserved, the composition of the substance not containing the relevant component can be accurately calculated within the limits allowed by analytical and geological error. The calculated composition can then be subjected to rigorous statistical testing using the linear-subtraction method recently advanced by Woronow (1994). Application of combined slope ratio analysis to the rocks of the Uwekahuna Laccolith, Hawaii, USA, and the lavas of the 1959-summit eruption of Kilauea Volcano, Hawaii, USA, yields results that are consistent with field observations.

Random Linear Network Coding is Key to Data Survival in Highly Dynamic Distributed Storage

DEFF Research Database (Denmark)

Sipos, Marton A.; Fitzek, Frank; Roetter, Daniel Enrique Lucani

2015-01-01

Distributed storage solutions have become widespread due to their ability to store large amounts of data reliably across a network of unreliable nodes, by employing repair mechanisms to prevent data loss. Conventional systems rely on static designs with a central control entity to oversee...... and control the repair process. Given the large costs for maintaining and cooling large data centers, our work proposes and studies the feasibility of a fully decentralized systems that can store data even on unreliable and, sometimes, unavailable mobile devices. This imposes new challenges on the design...... as the number of available nodes varies greatly over time and keeping track of the system's state becomes unfeasible. As a consequence, conventional erasure correction approaches are ill-suited for maintaining data integrity. In this highly dynamic context, random linear network coding (RLNC) provides...

Model-independent separation of poorly resolved hypperfine split spectra by a linear combination method

International Nuclear Information System (INIS)

Nagy, D.L.; Dengler, J.; Ritter, G.

1988-01-01

A model-independent evaluation of the components of poorly resolved Moessbauer spectra based on a linear combination method is possible if there is a parameter as a function of which the shape of the individual components do not but their intensities do change and the dependence of the intensities on this parameter is known. The efficiency of the method is demonstrated on the example of low temperature magnetically split spectra of the high-T c superconductor YBa 2 (Cu 0.9 Fe 0 .1 ) 3 O 7-y . (author)

Non-linear dynamics in Parkinsonism

Directory of Open Access Journals (Sweden)

Olivier eDarbin

2013-12-01

Full Text Available Over the last 30 years, the functions (and dysfunctions of the sensory-motor circuitry have been mostly conceptualized using linear modelizations which have resulted in two main models: the "rate hypothesis" and the "oscillatory hypothesis". In these two models, the basal ganglia data stream is envisaged as a random temporal combination of independent simple patterns issued from its probability distribution of interval interspikes or its spectrum of frequencies respectively.More recently, non-linear analyses have been introduced in the modelization of motor circuitry activities, and they have provided evidences that complex temporal organizations exist in basal ganglia neuronal activities. Regarding movement disorders, these complex temporal organizations in the basal ganglia data stream differ between conditions (i.e. parkinsonism, dyskinesia, healthy control and are responsive to treatments (i.e. L-DOPA,DBS. A body of evidence has reported that basal ganglia neuronal entropy (a marker for complexity/irregularity in time series is higher in hypokinetic state. In line with these findings, an entropy-based model has been recently formulated to introduce basal ganglia entropy as a marker for the alteration of motor processing and a factor of motor inhibition. Importantly, non-linear features have also been identified as a marker of condition and/or treatment effects in brain global signals (EEG, muscular activities (EMG or kinetic of motor symptoms (tremor, gait of patients with movement disorders. It is therefore warranted that the non-linear dynamics of motor circuitry will contribute to a better understanding of the neuronal dysfunctions underlying the spectrum of parkinsonian motor symptoms including tremor, rigidity and hypokinesia.

Multineuron spike train analysis with R-convolution linear combination kernel.

Science.gov (United States)

Tezuka, Taro

2018-06-01

A spike train kernel provides an effective way of decoding information represented by a spike train. Some spike train kernels have been extended to multineuron spike trains, which are simultaneously recorded spike trains obtained from multiple neurons. However, most of these multineuron extensions were carried out in a kernel-specific manner. In this paper, a general framework is proposed for extending any single-neuron spike train kernel to multineuron spike trains, based on the R-convolution kernel. Special subclasses of the proposed R-convolution linear combination kernel are explored. These subclasses have a smaller number of parameters and make optimization tractable when the size of data is limited. The proposed kernel was evaluated using Gaussian process regression for multineuron spike trains recorded from an animal brain. It was compared with the sum kernel and the population Spikernel, which are existing ways of decoding multineuron spike trains using kernels. The results showed that the proposed approach performs better than these kernels and also other commonly used neural decoding methods. Copyright © 2018 Elsevier Ltd. All rights reserved.

Enhancing Security of Double Random Phase Encoding Based on Random S-Box

Science.gov (United States)

Girija, R.; Singh, Hukum

2018-06-01

In this paper, we propose a novel asymmetric cryptosystem for double random phase encoding (DRPE) using random S-Box. While utilising S-Box separately is not reliable and DRPE does not support non-linearity, so, our system unites the effectiveness of S-Box with an asymmetric system of DRPE (through Fourier transform). The uniqueness of proposed cryptosystem lies on employing high sensitivity dynamic S-Box for our DRPE system. The randomness and scalability achieved due to applied technique is an additional feature of the proposed solution. The firmness of random S-Box is investigated in terms of performance parameters such as non-linearity, strict avalanche criterion, bit independence criterion, linear and differential approximation probabilities etc. S-Boxes convey nonlinearity to cryptosystems which is a significant parameter and very essential for DRPE. The strength of proposed cryptosystem has been analysed using various parameters such as MSE, PSNR, correlation coefficient analysis, noise analysis, SVD analysis, etc. Experimental results are conferred in detail to exhibit proposed cryptosystem is highly secure.

Linearity enigmas in ecology

Energy Technology Data Exchange (ETDEWEB)

Patten, B.C.

1983-04-01

Two issues concerning linearity or nonlinearity of natural systems are considered. Each is related to one of the two alternative defining properties of linear systems, superposition and decomposition. Superposition exists when a linear combination of inputs to a system results in the same linear combination of outputs that individually correspond to the original inputs. To demonstrate this property it is necessary that all initial states and inputs of the system which impinge on the output in question be included in the linear combination manipulation. As this is difficult or impossible to do with real systems of any complexity, nature appears nonlinear even though it may be linear. A linear system that displays nonlinear behavior for this reason is termed pseudononlinear. The decomposition property exists when the dynamic response of a system can be partitioned into an input-free portion due to state plus a state-free portion due to input. This is a characteristic of all linear systems, but not of nonlinear systems. Without the decomposition property, it is not possible to distinguish which portions of a system's behavior are due to innate characteristics (self) vs. outside conditions (environment), which is an important class of questions in biology and ecology. Some philosophical aspects of these findings are then considered. It is suggested that those ecologists who hold to the view that organisms and their environments are separate entities are in effect embracing a linear view of nature, even though their belief systems and mathematical models tend to be nonlinear. On the other hand, those who consider that organism-environment complex forms a single inseparable unit are implictly involved in non-linear thought, which may be in conflict with the linear modes and models that some of them use. The need to rectify these ambivalences on the part of both groups is indicated.

Random effect selection in generalised linear models

DEFF Research Database (Denmark)

Denwood, Matt; Houe, Hans; Forkman, Björn

We analysed abattoir recordings of meat inspection codes with possible relevance to onfarm animal welfare in cattle. Random effects logistic regression models were used to describe individual-level data obtained from 461,406 cattle slaughtered in Denmark. Our results demonstrate that the largest...

Is there still a role for additional linear ablation in addition to pulmonary vein isolation in patients with paroxysmal atrial fibrillation? An Updated Meta-analysis of randomized controlled trials.

Science.gov (United States)

Hu, Xiaoliang; Jiang, Jingzhou; Ma, Yuedong; Tang, Anli

2016-04-15

The benefits and risks of additional left atrium (LA) linear ablation in patients with paroxysmal atrial fibrillation (AF) remain unclear. Randomized controlled trials were identified in the PubMed, Web of Science, Embase and Cochrane databases, and the relevant papers were examined. Pooled relative risks (RR) and 95% confidence interval (95% CI) were estimated using random effects models. The primary endpoint was the maintenance of sinus rhythm after a single ablation. Nine randomized controlled trials involving 1138 patients were included in this analysis. Additional LA linear ablation did not improve the maintenance of the sinus rhythm following a single procedure (RR, 1.03; 95% CI, 0.93-1.13; P=0.60). A subgroup analysis demonstrated that all methods of additional linear ablation failed to improve the outcome. Additional linear ablation significantly increased the mean procedural time (166.53±67.7 vs. 139.57±62.44min, Plinear ablation did not exhibit any benefits in terms of sinus rhythm maintenance for paroxysmal AF patients following a single procedure. Additional linear ablation significantly increased the mean procedural, fluoroscopy and RF application times. This additional ablation was not associated with a statistically significant increase in complication rates. This finding must be confirmed by further large, high-quality clinical trials. Copyright © 2016. Published by Elsevier Ireland Ltd.

Fast solution of elliptic partial differential equations using linear combinations of plane waves.

Science.gov (United States)

Pérez-Jordá, José M

2016-02-01

Given an arbitrary elliptic partial differential equation (PDE), a procedure for obtaining its solution is proposed based on the method of Ritz: the solution is written as a linear combination of plane waves and the coefficients are obtained by variational minimization. The PDE to be solved is cast as a system of linear equations Ax=b, where the matrix A is not sparse, which prevents the straightforward application of standard iterative methods in order to solve it. This sparseness problem can be circumvented by means of a recursive bisection approach based on the fast Fourier transform, which makes it possible to implement fast versions of some stationary iterative methods (such as Gauss-Seidel) consuming O(NlogN) memory and executing an iteration in O(Nlog(2)N) time, N being the number of plane waves used. In a similar way, fast versions of Krylov subspace methods and multigrid methods can also be implemented. These procedures are tested on Poisson's equation expressed in adaptive coordinates. It is found that the best results are obtained with the GMRES method using a multigrid preconditioner with Gauss-Seidel relaxation steps.

Markov and semi-Markov switching linear mixed models used to identify forest tree growth components.

Science.gov (United States)

Chaubert-Pereira, Florence; Guédon, Yann; Lavergne, Christian; Trottier, Catherine

2010-09-01

Tree growth is assumed to be mainly the result of three components: (i) an endogenous component assumed to be structured as a succession of roughly stationary phases separated by marked change points that are asynchronous among individuals, (ii) a time-varying environmental component assumed to take the form of synchronous fluctuations among individuals, and (iii) an individual component corresponding mainly to the local environment of each tree. To identify and characterize these three components, we propose to use semi-Markov switching linear mixed models, i.e., models that combine linear mixed models in a semi-Markovian manner. The underlying semi-Markov chain represents the succession of growth phases and their lengths (endogenous component) whereas the linear mixed models attached to each state of the underlying semi-Markov chain represent-in the corresponding growth phase-both the influence of time-varying climatic covariates (environmental component) as fixed effects, and interindividual heterogeneity (individual component) as random effects. In this article, we address the estimation of Markov and semi-Markov switching linear mixed models in a general framework. We propose a Monte Carlo expectation-maximization like algorithm whose iterations decompose into three steps: (i) sampling of state sequences given random effects, (ii) prediction of random effects given state sequences, and (iii) maximization. The proposed statistical modeling approach is illustrated by the analysis of successive annual shoots along Corsican pine trunks influenced by climatic covariates. © 2009, The International Biometric Society.

Statistical Tests for Mixed Linear Models

CERN Document Server

Khuri, André I; Sinha, Bimal K

2011-01-01

An advanced discussion of linear models with mixed or random effects. In recent years a breakthrough has occurred in our ability to draw inferences from exact and optimum tests of variance component models, generating much research activity that relies on linear models with mixed and random effects. This volume covers the most important research of the past decade as well as the latest developments in hypothesis testing. It compiles all currently available results in the area of exact and optimum tests for variance component models and offers the only comprehensive treatment for these models a

Conservative treatment of lateral epicondylitis: brace versus physical therapy or a combination of both: a randomized clinical trial

NARCIS (Netherlands)

Struijs, P. A. A.; Kerkhoffs, G. M. M. J.; Assendelft, W. J. J.; van Dijk, C. N.

2004-01-01

BACKGROUND: The authors evaluated the effectiveness of brace-only treatment, physical therapy, and the combination of these for patients with tennis elbow. METHODS: Patients were randomized over 3 groups: brace-only treatment, physical therapy, and the combination of these. Main outcome measures

Accurate and Efficient Parallel Implementation of an Effective Linear-Scaling Direct Random Phase Approximation Method.

Science.gov (United States)

Graf, Daniel; Beuerle, Matthias; Schurkus, Henry F; Luenser, Arne; Savasci, Gökcen; Ochsenfeld, Christian

2018-05-08

An efficient algorithm for calculating the random phase approximation (RPA) correlation energy is presented that is as accurate as the canonical molecular orbital resolution-of-the-identity RPA (RI-RPA) with the important advantage of an effective linear-scaling behavior (instead of quartic) for large systems due to a formulation in the local atomic orbital space. The high accuracy is achieved by utilizing optimized minimax integration schemes and the local Coulomb metric attenuated by the complementary error function for the RI approximation. The memory bottleneck of former atomic orbital (AO)-RI-RPA implementations ( Schurkus, H. F.; Ochsenfeld, C. J. Chem. Phys. 2016 , 144 , 031101 and Luenser, A.; Schurkus, H. F.; Ochsenfeld, C. J. Chem. Theory Comput. 2017 , 13 , 1647 - 1655 ) is addressed by precontraction of the large 3-center integral matrix with the Cholesky factors of the ground state density reducing the memory requirements of that matrix by a factor of [Formula: see text]. Furthermore, we present a parallel implementation of our method, which not only leads to faster RPA correlation energy calculations but also to a scalable decrease in memory requirements, opening the door for investigations of large molecules even on small- to medium-sized computing clusters. Although it is known that AO methods are highly efficient for extended systems, where sparsity allows for reaching the linear-scaling regime, we show that our work also extends the applicability when considering highly delocalized systems for which no linear scaling can be achieved. As an example, the interlayer distance of two covalent organic framework pore fragments (comprising 384 atoms in total) is analyzed.

Genomic-Enabled Prediction Kernel Models with Random Intercepts for Multi-environment Trials

Science.gov (United States)

Cuevas, Jaime; Granato, Italo; Fritsche-Neto, Roberto; Montesinos-Lopez, Osval A.; Burgueño, Juan; Bandeira e Sousa, Massaine; Crossa, José

2018-01-01

In this study, we compared the prediction accuracy of the main genotypic effect model (MM) without G×E interactions, the multi-environment single variance G×E deviation model (MDs), and the multi-environment environment-specific variance G×E deviation model (MDe) where the random genetic effects of the lines are modeled with the markers (or pedigree). With the objective of further modeling the genetic residual of the lines, we incorporated the random intercepts of the lines (l) and generated another three models. Each of these 6 models were fitted with a linear kernel method (Genomic Best Linear Unbiased Predictor, GB) and a Gaussian Kernel (GK) method. We compared these 12 model-method combinations with another two multi-environment G×E interactions models with unstructured variance-covariances (MUC) using GB and GK kernels (4 model-method). Thus, we compared the genomic-enabled prediction accuracy of a total of 16 model-method combinations on two maize data sets with positive phenotypic correlations among environments, and on two wheat data sets with complex G×E that includes some negative and close to zero phenotypic correlations among environments. The two models (MDs and MDE with the random intercept of the lines and the GK method) were computationally efficient and gave high prediction accuracy in the two maize data sets. Regarding the more complex G×E wheat data sets, the prediction accuracy of the model-method combination with G×E, MDs and MDe, including the random intercepts of the lines with GK method had important savings in computing time as compared with the G×E interaction multi-environment models with unstructured variance-covariances but with lower genomic prediction accuracy. PMID:29476023

[Combination of acupuncture, cupping and medicine for treatment of fibromyalgia syndrome: a multi-central randomized controlled trial].

Science.gov (United States)

Jang, Zhen-Ya; Li, Chang-Du; Qiu, Ling; Guo, Jun-Hua; He, Ling-Na; Yue, Yang; Li, Fang-Ze; Qin, Wen-Yi

2010-04-01

To evaluate the clinical effect of combination of acupuncture, cupping and medicine for treatment of fibromyalgia syndrome. By using multi-central randomized controlled method, 186 cases were randomly divided into an acupuncture combined with cupping and western medicine group (group A), an acupuncture combined with cupping group (group B) and a western medicine group (group C) and treated continuously for 4 weeks. The treatment of acupuncture combined with cupping was produced by acupuncture at five mental points and moving cupping on the Hechelu of the back, once evrey other day, thrice each week, and the western medicine therapy by oral administration of Amitriptyline, once each day. The scores of McGill Pain Questionnaire (MPQ), the amount of tenderness point and the time of producing effect were compared and the therapeutic effects were assessed with the Hamilton Depression Scale (HAMD). The cured and markedly effective rate was 65.0% (39/60) in the group A, which was superior to 15.9% (10/63) in the group B and 16.1% (9/56) in the group C (both P cupping and medicine on fibromyalgia syndrome is superior to that of the simple acupuncture combined with cupping or the simple medicine.

An Improved Isotropic Periodic Sum Method That Uses Linear Combinations of Basis Potentials

KAUST Repository

Takahashi, Kazuaki Z.; Narumi, Tetsu; Suh, Donguk; Yasuoka, Kenji

2012-01-01

Isotropic periodic sum (IPS) is a technique that calculates long-range interactions differently than conventional lattice sum methods. The difference between IPS and lattice sum methods lies in the shape and distribution of remote images for long-range interaction calculations. The images used in lattice sum calculations are identical to those generated from periodic boundary conditions and are discretely positioned at lattice points in space. The images for IPS calculations are "imaginary", which means they do not explicitly exist in a simulation system and are distributed isotropically and periodically around each particle. Two different versions of the original IPS method exist. The IPSn method is applied to calculations for point charges, whereas the IPSp method calculates polar molecules. However, both IPSn and IPSp have their advantages and disadvantages in simulating bulk water or water-vapor interfacial systems. In bulk water systems, the cutoff radius effect of IPSn strongly affects the configuration, whereas IPSp does not provide adequate estimations of water-vapor interfacial systems unless very long cutoff radii are used. To extend the applicability of the IPS technique, an improved IPS method, which has better accuracy in both homogeneous and heterogeneous systems has been developed and named the linear-combination-based isotropic periodic sum (LIPS) method. This improved IPS method uses linear combinations of basis potentials. We performed molecular dynamics (MD) simulations of bulk water and water-vapor interfacial systems to evaluate the accuracy of the LIPS method. For bulk water systems, the LIPS method has better accuracy than IPSn in estimating thermodynamic and configurational properties without the countercharge assumption, which is used for IPSp. For water-vapor interfacial systems, LIPS has better accuracy than IPSp and properly estimates thermodynamic and configurational properties. In conclusion, the LIPS method can successfully estimate

An Improved Isotropic Periodic Sum Method That Uses Linear Combinations of Basis Potentials

KAUST Repository

Takahashi, Kazuaki Z.

2012-11-13

Isotropic periodic sum (IPS) is a technique that calculates long-range interactions differently than conventional lattice sum methods. The difference between IPS and lattice sum methods lies in the shape and distribution of remote images for long-range interaction calculations. The images used in lattice sum calculations are identical to those generated from periodic boundary conditions and are discretely positioned at lattice points in space. The images for IPS calculations are "imaginary", which means they do not explicitly exist in a simulation system and are distributed isotropically and periodically around each particle. Two different versions of the original IPS method exist. The IPSn method is applied to calculations for point charges, whereas the IPSp method calculates polar molecules. However, both IPSn and IPSp have their advantages and disadvantages in simulating bulk water or water-vapor interfacial systems. In bulk water systems, the cutoff radius effect of IPSn strongly affects the configuration, whereas IPSp does not provide adequate estimations of water-vapor interfacial systems unless very long cutoff radii are used. To extend the applicability of the IPS technique, an improved IPS method, which has better accuracy in both homogeneous and heterogeneous systems has been developed and named the linear-combination-based isotropic periodic sum (LIPS) method. This improved IPS method uses linear combinations of basis potentials. We performed molecular dynamics (MD) simulations of bulk water and water-vapor interfacial systems to evaluate the accuracy of the LIPS method. For bulk water systems, the LIPS method has better accuracy than IPSn in estimating thermodynamic and configurational properties without the countercharge assumption, which is used for IPSp. For water-vapor interfacial systems, LIPS has better accuracy than IPSp and properly estimates thermodynamic and configurational properties. In conclusion, the LIPS method can successfully estimate

Implementation and Performance Evaluation of Distributed Cloud Storage Solutions using Random Linear Network Coding

DEFF Research Database (Denmark)

Fitzek, Frank; Toth, Tamas; Szabados, Áron

2014-01-01

This paper advocates the use of random linear network coding for storage in distributed clouds in order to reduce storage and traffic costs in dynamic settings, i.e. when adding and removing numerous storage devices/clouds on-the-fly and when the number of reachable clouds is limited. We introduce...... various network coding approaches that trade-off reliability, storage and traffic costs, and system complexity relying on probabilistic recoding for cloud regeneration. We compare these approaches with other approaches based on data replication and Reed-Solomon codes. A simulator has been developed...... to carry out a thorough performance evaluation of the various approaches when relying on different system settings, e.g., finite fields, and network/storage conditions, e.g., storage space used per cloud, limited network use, and limited recoding capabilities. In contrast to standard coding approaches, our...

Implementation, recruitment and baseline characteristics: A randomized trial of combined treatments for smoking cessation and weight control

Directory of Open Access Journals (Sweden)

Terry Bush

2017-09-01

Full Text Available Background: Two-thirds of treatment-seeking smokers are obese or overweight. Most smokers are concerned about gaining weight after quitting. The average smoker experiences modest post-quit weight gain which discourages many smokers from quitting. Although evidence suggests that combined interventions to help smokers quit smoking and prevent weight gain can be helpful, studies have not been replicated in real world settings. Methods: This paper describes recruitment and participant characteristics of the Best Quit Study, a 3-arm randomized controlled trial testing tobacco cessation treatment alone or combined with simultaneous or sequential weight management. Study participants were recruited via tobacco quitlines from August 5, 2013 to December 15, 2014. Results: Statistical analysis on baseline data was conducted in 2015/2016. Among 5082 potentially eligible callers to a tobacco quitline, 2540 were randomized (50% of eligible. Compared with individuals eligible but not randomized, those randomized were significantly more likely to be female (65.7% vs 54.5%, p < 0.01, overweight or obese (76.3% vs 62.5%, p < 0.01, more confident in quitting (p < 0.01, more addicted (first cigarette within 5 min: 50.0% vs 44.4%, p < 0.01, and have a chronic disease (28.6% vs. 24.4%, p < 0.01. Randomized groups were not statistically significantly different on demographics, tobacco or weight variables. Two-thirds of participants were female and white with a mean age of 43. Conclusions: Adding weight management interventions to tobacco cessation quitlines was feasible and acceptable to smokers. If successful for cessation and weight outcomes, a combined intervention may provide a treatment approach for addressing weight gain with smoking cessation through tobacco quitlines. Trial registration: Clinicaltrials.gov NCT01867983. Keywords: Smoking, Weight gain, Quitlines, Simultaneous, Sequential

Testing concordance of instrumental variable effects in generalized linear models with application to Mendelian randomization

Science.gov (United States)

Dai, James Y.; Chan, Kwun Chuen Gary; Hsu, Li

2014-01-01

Instrumental variable regression is one way to overcome unmeasured confounding and estimate causal effect in observational studies. Built on structural mean models, there has been considerale work recently developed for consistent estimation of causal relative risk and causal odds ratio. Such models can sometimes suffer from identification issues for weak instruments. This hampered the applicability of Mendelian randomization analysis in genetic epidemiology. When there are multiple genetic variants available as instrumental variables, and causal effect is defined in a generalized linear model in the presence of unmeasured confounders, we propose to test concordance between instrumental variable effects on the intermediate exposure and instrumental variable effects on the disease outcome, as a means to test the causal effect. We show that a class of generalized least squares estimators provide valid and consistent tests of causality. For causal effect of a continuous exposure on a dichotomous outcome in logistic models, the proposed estimators are shown to be asymptotically conservative. When the disease outcome is rare, such estimators are consistent due to the log-linear approximation of the logistic function. Optimality of such estimators relative to the well-known two-stage least squares estimator and the double-logistic structural mean model is further discussed. PMID:24863158

Efficient pseudo-random number generation for monte-carlo simulations using graphic processors

Science.gov (United States)

Mohanty, Siddhant; Mohanty, A. K.; Carminati, F.

2012-06-01

A hybrid approach based on the combination of three Tausworthe generators and one linear congruential generator for pseudo random number generation for GPU programing as suggested in NVIDIA-CUDA library has been used for MONTE-CARLO sampling. On each GPU thread, a random seed is generated on fly in a simple way using the quick and dirty algorithm where mod operation is not performed explicitly due to unsigned integer overflow. Using this hybrid generator, multivariate correlated sampling based on alias technique has been carried out using both CUDA and OpenCL languages.

Efficient pseudo-random number generation for Monte-Carlo simulations using graphic processors

International Nuclear Information System (INIS)

Mohanty, Siddhant; Mohanty, A K; Carminati, F

2012-01-01

A hybrid approach based on the combination of three Tausworthe generators and one linear congruential generator for pseudo random number generation for GPU programing as suggested in NVIDIA-CUDA library has been used for MONTE-CARLO sampling. On each GPU thread, a random seed is generated on fly in a simple way using the quick and dirty algorithm where mod operation is not performed explicitly due to unsigned integer overflow. Using this hybrid generator, multivariate correlated sampling based on alias technique has been carried out using both CUDA and OpenCL languages.

Comparative Efficacy of Newer Antidepressants in Combination with Pregabalin for Fibromyalgia Syndrome: A Controlled, Randomized Study.

Science.gov (United States)

Ramzy, Eiad A

2017-01-01

This controlled, randomized study investigated the hypothesis that the combined use of pregabalin plus paroxetine for fibromyalgia management would be associated with comparable Somatic Symptoms Scale-8 (SSS-8) and Center for Epidemiological Studies Depression Scale (CESDS) scores, but higher tolerability than the combined use of pregabalin plus either amitriptyline or venlafaxine. After institutional ethics committee approval, 75 female subjects diagnosed with fibromyalgia and in receipt of pregabalin (75 mg/day) were randomly allocated to concurrently receive amitriptyline (25 mg/day; n = 24), venlafaxine (75 mg/day; n = 25), or paroxetine (25 mg/day; n = 26). All patients were assessed bimonthly for 6 consecutive months for changes in SSS-8 and CESDS scores, life satisfaction, mood, sleep quality, fatigue, medication tolerability, and adverse events. Compared with pregabalin plus amitriptyline or venlafaxine, the combined use of pregabalin plus paroxetine in fibromyalgia patients resulted in significantly lower SSS-8 and CESDS scores from 18 (P life satisfaction, mood, and sleep quality at most observation times (P fibromyalgia and to enhance the quality of life in affected individuals. © 2016 World Institute of Pain.

The theory of a general quantum system interacting with a linear dissipative system

International Nuclear Information System (INIS)

Feynman, R.P.; Vernon, F.L.

2000-01-01

A formalism has been developed, using Feynman's space-time formulation of nonrelativistic quantum mechanics whereby the behavior of a system of interest, which is coupled to other external quantum systems, may be calculated in terms of its own variables only. It is shown that the effect of the external systems in such a formalism can always be included in a general class of functionals (influence functionals) of the coordinates of the system only. The properties of influence functionals for general systems are examined. Then, specific forms of influence functionals representing the effect of definite and random classical forces, linear dissipative systems at finite temperatures, and combinations of these are analyzed in detail. The linear system analysis is first done for perfectly linear systems composed of combinations of harmonic oscillators, loss being introduced by continuous distributions of oscillators. Then approximately linear systems and restrictions necessary for the linear behavior are considered. Influence functionals for all linear systems are shown to have the same form in terms of their classical response functions. In addition, a fluctuation-dissipation theorem is derived relating temperature and dissipation of the linear system to a fluctuating classical potential acting on the system of interest which reduces to the Nyquist-Johnson relation for noise in the case of electric circuits. Sample calculations of transition probabilities for the spontaneous emission of an atom in free space and in a cavity are made. Finally, a theorem is proved showing that within the requirements of linearity all sources of noise or quantum fluctuation introduced by maser-type amplification devices are accounted for by a classical calculation of the characteristics of the maser

Multidisciplinary Inverse Reliability Analysis Based on Collaborative Optimization with Combination of Linear Approximations

Directory of Open Access Journals (Sweden)

Xin-Jia Meng

2015-01-01

Full Text Available Multidisciplinary reliability is an important part of the reliability-based multidisciplinary design optimization (RBMDO. However, it usually has a considerable amount of calculation. The purpose of this paper is to improve the computational efficiency of multidisciplinary inverse reliability analysis. A multidisciplinary inverse reliability analysis method based on collaborative optimization with combination of linear approximations (CLA-CO is proposed in this paper. In the proposed method, the multidisciplinary reliability assessment problem is first transformed into a problem of most probable failure point (MPP search of inverse reliability, and then the process of searching for MPP of multidisciplinary inverse reliability is performed based on the framework of CLA-CO. This method improves the MPP searching process through two elements. One is treating the discipline analyses as the equality constraints in the subsystem optimization, and the other is using linear approximations corresponding to subsystem responses as the replacement of the consistency equality constraint in system optimization. With these two elements, the proposed method realizes the parallel analysis of each discipline, and it also has a higher computational efficiency. Additionally, there are no difficulties in applying the proposed method to problems with nonnormal distribution variables. One mathematical test problem and an electronic packaging problem are used to demonstrate the effectiveness of the proposed method.

Eigenstates of complex linear combinations of J1, J2, J3 for any representation of SU(2)

International Nuclear Information System (INIS)

Bacry, H.; Technion-Israel Inst. of Tech., Haifa. Dept. of Physics)

1977-05-01

The states which minimalize the uncertainty relation ΔJ 1 ΔJ 2 >=1/2/ 3 >/ are eigenstates of complex linear combinations of J 1 and J 2 . This kind of states is shown to have a very simple geometrical interpretation in the constellation formalism. A detailed description is given in the present pap

Communication: An effective linear-scaling atomic-orbital reformulation of the random-phase approximation using a contracted double-Laplace transformation

International Nuclear Information System (INIS)

Schurkus, Henry F.; Ochsenfeld, Christian

2016-01-01

An atomic-orbital (AO) reformulation of the random-phase approximation (RPA) correlation energy is presented allowing to reduce the steep computational scaling to linear, so that large systems can be studied on simple desktop computers with fully numerically controlled accuracy. Our AO-RPA formulation introduces a contracted double-Laplace transform and employs the overlap-metric resolution-of-the-identity. First timings of our pilot code illustrate the reduced scaling with systems comprising up to 1262 atoms and 10 090 basis functions. 

Combined spa-exercise therapy is effective in patients with ankylosing spondylitis: a randomized controlled trial

NARCIS (Netherlands)

van Tubergen, A.; Landewé, R.; van der Heijde, D.; Hidding, A.; Wolter, N.; Asscher, M.; Falkenbach, A.; Genth, E.; Thè, H. G.; van der Linden, S.

2001-01-01

To determine the efficacy of combined spa-exercise therapy in addition to standard treatment with drugs and weekly group physical therapy in patients with ankylosing spondylitis (AS). A total of 120 Dutch outpatients with AS were randomly allocated into 3 groups of 40 patients each. Group 1 (mean

Effectiveness of Shockwave Treatment Combined With Eccentric Training for Patellar Tendinopathy : A Double-Blinded Randomized Study

NARCIS (Netherlands)

Thijs, Karin M; Zwerver, Johannes; Backx, Frank J G; Steeneken, Victor; Rayer, Stephan; Groenenboom, Petra; Moen, Maarten H

OBJECTIVE: To evaluate the effectiveness of a combined treatment of focused shockwave therapy (ESWT) and eccentric training compared with sham-shockwave therapy (placebo) and eccentric training in participants with patellar tendinopathy (PT) after 24 weeks. DESIGN: Randomized controlled trial.

Effectiveness of Shockwave Treatment Combined With Eccentric Training for Patellar Tendinopathy : A Double-Blinded Randomized Study

NARCIS (Netherlands)

Thijs, Karin M.; Zwerver, Johannes; Backx, Frank J. G.; Steeneken, Victor; Rayer, Stephan; Groenenboom, Petra; Moen, Maarten H.

2017-01-01

OBJECTIVE: To evaluate the effectiveness of a combined treatment of focused shockwave therapy (ESWT) and eccentric training compared with sham-shockwave therapy (placebo) and eccentric training in participants with patellar tendinopathy (PT) after 24 weeks. DESIGN: Randomized controlled trial.

Vanishing-Overhead Linear-Scaling Random Phase Approximation by Cholesky Decomposition and an Attenuated Coulomb-Metric.

Science.gov (United States)

Luenser, Arne; Schurkus, Henry F; Ochsenfeld, Christian

2017-04-11

A reformulation of the random phase approximation within the resolution-of-the-identity (RI) scheme is presented, that is competitive to canonical molecular orbital RI-RPA already for small- to medium-sized molecules. For electronically sparse systems drastic speedups due to the reduced scaling behavior compared to the molecular orbital formulation are demonstrated. Our reformulation is based on two ideas, which are independently useful: First, a Cholesky decomposition of density matrices that reduces the scaling with basis set size for a fixed-size molecule by one order, leading to massive performance improvements. Second, replacement of the overlap RI metric used in the original AO-RPA by an attenuated Coulomb metric. Accuracy is significantly improved compared to the overlap metric, while locality and sparsity of the integrals are retained, as is the effective linear scaling behavior.

Multiple linear combination (MLC) regression tests for common variants adapted to linkage disequilibrium structure.

Science.gov (United States)

Yoo, Yun Joo; Sun, Lei; Poirier, Julia G; Paterson, Andrew D; Bull, Shelley B

2017-02-01

By jointly analyzing multiple variants within a gene, instead of one at a time, gene-based multiple regression can improve power, robustness, and interpretation in genetic association analysis. We investigate multiple linear combination (MLC) test statistics for analysis of common variants under realistic trait models with linkage disequilibrium (LD) based on HapMap Asian haplotypes. MLC is a directional test that exploits LD structure in a gene to construct clusters of closely correlated variants recoded such that the majority of pairwise correlations are positive. It combines variant effects within the same cluster linearly, and aggregates cluster-specific effects in a quadratic sum of squares and cross-products, producing a test statistic with reduced degrees of freedom (df) equal to the number of clusters. By simulation studies of 1000 genes from across the genome, we demonstrate that MLC is a well-powered and robust choice among existing methods across a broad range of gene structures. Compared to minimum P-value, variance-component, and principal-component methods, the mean power of MLC is never much lower than that of other methods, and can be higher, particularly with multiple causal variants. Moreover, the variation in gene-specific MLC test size and power across 1000 genes is less than that of other methods, suggesting it is a complementary approach for discovery in genome-wide analysis. The cluster construction of the MLC test statistics helps reveal within-gene LD structure, allowing interpretation of clustered variants as haplotypic effects, while multiple regression helps to distinguish direct and indirect associations. © 2016 The Authors Genetic Epidemiology Published by Wiley Periodicals, Inc.

Generation, combination and extension of random set approximations to coherent lower and upper probabilities

International Nuclear Information System (INIS)

Hall, Jim W.; Lawry, Jonathan

2004-01-01

Random set theory provides a convenient mechanism for representing uncertain knowledge including probabilistic and set-based information, and extending it through a function. This paper focuses upon the situation when the available information is in terms of coherent lower and upper probabilities, which are encountered, for example, when a probability distribution is specified by interval parameters. We propose an Iterative Rescaling Method (IRM) for constructing a random set with corresponding belief and plausibility measures that are a close outer approximation to the lower and upper probabilities. The approach is compared with the discrete approximation method of Williamson and Downs (sometimes referred to as the p-box), which generates a closer approximation to lower and upper cumulative probability distributions but in most cases a less accurate approximation to the lower and upper probabilities on the remainder of the power set. Four combination methods are compared by application to example random sets generated using the IRM

Double-blind, randomized, controlled, pilot study comparing classic ayurvedic medicine, methotrexate, and their combination in rheumatoid arthritis.

Science.gov (United States)

Furst, Daniel E; Venkatraman, Manorama M; McGann, Mary; Manohar, P Ram; Booth-LaForce, Cathryn; Sarin, Reshmi; Sekar, P G; Raveendran, K G; Mahapatra, Anita; Gopinath, Jidesh; Kumar, P R Krishna

2011-06-01

To compare classic Ayurveda, methotrexate (MTX), and their combination in a double-blind, randomized, double-dummy, pilot trial in rheumatoid arthritis (RA) for 36 weeks. Forty-three seropositive RA patients by American College of Rheumatology (ACR) criteria with disease duration of less than 7 years were assigned to the following treatment groups: MTX plus Ayurvedic placebo (n = 14), Ayurveda plus MTX placebo (n = 12), or Ayurveda plus MTX (n = 17). Outcomes included the Disease Activity Score (DAS28-CRP), ACR20/50/70, and Health Assessment Questionnaire--Disability Index. All measures were obtained every 12 weeks for 36 weeks. Analyses included descriptive statistics, analysis of variance, χ², or Student t test. The unique features of this study included the development of placebos for each Ayurvedic pharmacological dosage form and individualization of Ayurvedic therapy. All groups were comparable at baseline in demographics and disease characteristics. There were no statistically significant differences among the 3 groups on the efficacy measures. ACR20 results were MTX 86%, Ayurveda 100%, and combination 82%, and DAS28-CRP response were MTX -2.4, Ayurveda -1.7, and combination -2.4. Differences in adverse events among groups were also not statistically significant, although the MTX groups experienced more adverse event (MTX 174, Ayurveda 112, combination 176). No deaths occurred. In this first-ever, double-blind, randomized, placebo-controlled pilot study comparing Ayurveda, MTX, and their combination, all 3 treatments were approximately equivalent in efficacy, within the limits of a pilot study. Adverse events were numerically fewer in the Ayurveda-only group. This study demonstrates that double-blind, placebo-controlled, randomized studies are possible when testing individualized classic Ayurvedic versus allopathic treatment in ways acceptable to western standards and to Ayurvedic physicians. It also justifies the need for larger studies.

A unified development of several techniques for the representation of random vectors and data sets

Science.gov (United States)

Bundick, W. T.

1973-01-01

Linear vector space theory is used to develop a general representation of a set of data vectors or random vectors by linear combinations of orthonormal vectors such that the mean squared error of the representation is minimized. The orthonormal vectors are shown to be the eigenvectors of an operator. The general representation is applied to several specific problems involving the use of the Karhunen-Loeve expansion, principal component analysis, and empirical orthogonal functions; and the common properties of these representations are developed.

Personalized PageRank Clustering: A graph clustering algorithm based on random walks

Science.gov (United States)

A. Tabrizi, Shayan; Shakery, Azadeh; Asadpour, Masoud; Abbasi, Maziar; Tavallaie, Mohammad Ali

2013-11-01

Graph clustering has been an essential part in many methods and thus its accuracy has a significant effect on many applications. In addition, exponential growth of real-world graphs such as social networks, biological networks and electrical circuits demands clustering algorithms with nearly-linear time and space complexity. In this paper we propose Personalized PageRank Clustering (PPC) that employs the inherent cluster exploratory property of random walks to reveal the clusters of a given graph. We combine random walks and modularity to precisely and efficiently reveal the clusters of a graph. PPC is a top-down algorithm so it can reveal inherent clusters of a graph more accurately than other nearly-linear approaches that are mainly bottom-up. It also gives a hierarchy of clusters that is useful in many applications. PPC has a linear time and space complexity and has been superior to most of the available clustering algorithms on many datasets. Furthermore, its top-down approach makes it a flexible solution for clustering problems with different requirements.

A fast random walk algorithm for computing the pulsed-gradient spin-echo signal in multiscale porous media.

Science.gov (United States)

Grebenkov, Denis S

2011-02-01

A new method for computing the signal attenuation due to restricted diffusion in a linear magnetic field gradient is proposed. A fast random walk (FRW) algorithm for simulating random trajectories of diffusing spin-bearing particles is combined with gradient encoding. As random moves of a FRW are continuously adapted to local geometrical length scales, the method is efficient for simulating pulsed-gradient spin-echo experiments in hierarchical or multiscale porous media such as concrete, sandstones, sedimentary rocks and, potentially, brain or lungs. Copyright © 2010 Elsevier Inc. All rights reserved.

Adaptive Linear and Normalized Combination of Radial Basis Function Networks for Function Approximation and Regression

Directory of Open Access Journals (Sweden)

Yunfeng Wu

2014-01-01

Full Text Available This paper presents a novel adaptive linear and normalized combination (ALNC method that can be used to combine the component radial basis function networks (RBFNs to implement better function approximation and regression tasks. The optimization of the fusion weights is obtained by solving a constrained quadratic programming problem. According to the instantaneous errors generated by the component RBFNs, the ALNC is able to perform the selective ensemble of multiple leaners by adaptively adjusting the fusion weights from one instance to another. The results of the experiments on eight synthetic function approximation and six benchmark regression data sets show that the ALNC method can effectively help the ensemble system achieve a higher accuracy (measured in terms of mean-squared error and the better fidelity (characterized by normalized correlation coefficient of approximation, in relation to the popular simple average, weighted average, and the Bagging methods.

Long-range correlation in synchronization and syncopation tapping: a linear phase correction model.

Directory of Open Access Journals (Sweden)

Didier Delignières

Full Text Available We propose in this paper a model for accounting for the increase in long-range correlations observed in asynchrony series in syncopation tapping, as compared with synchronization tapping. Our model is an extension of the linear phase correction model for synchronization tapping. We suppose that the timekeeper represents a fractal source in the system, and that a process of estimation of the half-period of the metronome, obeying a random-walk dynamics, combines with the linear phase correction process. Comparing experimental and simulated series, we show that our model allows accounting for the experimentally observed pattern of serial dependence. This model complete previous modeling solutions proposed for self-paced and synchronization tapping, for a unifying framework of event-based timing.

EXPALS, Least Square Fit of Linear Combination of Exponential Decay Function

International Nuclear Information System (INIS)

Douglas Gardner, C.

1980-01-01

1 - Description of problem or function: This program fits by least squares a function which is a linear combination of real exponential decay functions. The function is y(k) = summation over j of a(j) * exp(-lambda(j) * k). Values of the independent variable (k) and the dependent variable y(k) are specified as input data. Weights may be specified as input information or set by the program (w(k) = 1/y(k)). 2 - Method of solution: The Prony-Householder iteration method is used. For unequally-spaced data, a number of interpolation options are provided. This revision includes an option to call a differential correction subroutine REFINE to improve the approximation to unequally-spaced data when equal-interval interpolation is faulty. If convergence is achieved, the probable errors in the computed parameters are calculated also. 3 - Restrictions on the complexity of the problem: Generally, it is desirable to have at least 10n observations where n equals the number of terms and to input k+n significant figures if k significant figures are expected

Multi-disease analysis of maternal antibody decay using non-linear mixed models accounting for censoring.

Science.gov (United States)

Goeyvaerts, Nele; Leuridan, Elke; Faes, Christel; Van Damme, Pierre; Hens, Niel

2015-09-10

Biomedical studies often generate repeated measures of multiple outcomes on a set of subjects. It may be of interest to develop a biologically intuitive model for the joint evolution of these outcomes while assessing inter-subject heterogeneity. Even though it is common for biological processes to entail non-linear relationships, examples of multivariate non-linear mixed models (MNMMs) are still fairly rare. We contribute to this area by jointly analyzing the maternal antibody decay for measles, mumps, rubella, and varicella, allowing for a different non-linear decay model for each infectious disease. We present a general modeling framework to analyze multivariate non-linear longitudinal profiles subject to censoring, by combining multivariate random effects, non-linear growth and Tobit regression. We explore the hypothesis of a common infant-specific mechanism underlying maternal immunity using a pairwise correlated random-effects approach and evaluating different correlation matrix structures. The implied marginal correlation between maternal antibody levels is estimated using simulations. The mean duration of passive immunity was less than 4 months for all diseases with substantial heterogeneity between infants. The maternal antibody levels against rubella and varicella were found to be positively correlated, while little to no correlation could be inferred for the other disease pairs. For some pairs, computational issues occurred with increasing correlation matrix complexity, which underlines the importance of further developing estimation methods for MNMMs. Copyright © 2015 John Wiley & Sons, Ltd.

Multi-kW coherent combining of fiber lasers seeded with pseudo random phase modulated light

Science.gov (United States)

Flores, Angel; Ehrehreich, Thomas; Holten, Roger; Anderson, Brian; Dajani, Iyad

2016-03-01

We report efficient coherent beam combining of five kilowatt-class fiber amplifiers with a diffractive optical element (DOE). Based on a master oscillator power amplifier (MOPA) configuration, the amplifiers were seeded with pseudo random phase modulated light. Each non-polarization maintaining fiber amplifier was optically path length matched and provides approximately 1.2 kW of near diffraction-limited output power (measured M2polarization control. A low power sample of the combined beam after the DOE provided an error signal for active phase locking which was performed via Locking of Optical Coherence by Single-Detector Electronic-Frequency Tagging (LOCSET). After phase stabilization, the beams were coherently combined via the 1x5 DOE. A total combined output power of 4.9 kW was achieved with 82% combining efficiency and excellent beam quality (M2splitter loss was 5%. Similarly, losses due in part to non-ideal polarization, ASE content, uncorrelated wavefront errors, and misalignment errors contributed to the efficiency reduction.

Multi-criteria approach with linear combination technique and analytical hierarchy process in land evaluation studies

Directory of Open Access Journals (Sweden)

Orhan Dengiz

2018-01-01

Full Text Available Land evaluation analysis is a prerequisite to achieving optimum utilization of the available land resources. Lack of knowledge on best combination of factors that suit production of yields has contributed to the low production. The aim of this study was to determine the most suitable areas for agricultural uses. For that reasons, in order to determine land suitability classes of the study area, multi-criteria approach was used with linear combination technique and analytical hierarchy process by taking into consideration of some land and soil physico-chemical characteristic such as slope, texture, depth, derange, stoniness, erosion, pH, EC, CaCO3 and organic matter. These data and land mapping unites were taken from digital detailed soil map scaled as 1:5.000. In addition, in order to was produce land suitability map GIS was program used for the study area. This study was carried out at Mahmudiye, Karaamca, Yazılı, Çiçeközü, Orhaniye and Akbıyık villages in Yenişehir district of Bursa province. Total study area is 7059 ha. 6890 ha of total study area has been used as irrigated agriculture, dry farming agriculture, pasture while, 169 ha has been used for non-agricultural activities such as settlement, road water body etc. Average annual temperature and precipitation of the study area are 16.1oC and 1039.5 mm, respectively. Finally after determination of land suitability distribution classes for the study area, it was found that 15.0% of the study area has highly (S1 and moderately (S2 while, 85% of the study area has marginally suitable and unsuitable coded as S3 and N. It was also determined some relation as compared results of linear combination technique with other hierarchy approaches such as Land Use Capability Classification and Suitability Class for Agricultural Use methods.

Burgers' turbulence problem with linear or quadratic external potential

DEFF Research Database (Denmark)

Barndorff-Nielsen, Ole Eiler; Leonenko, N.N.

2005-01-01

We consider solutions of Burgers' equation with linear or quadratic external potential and stationary random initial conditions of Ornstein-Uhlenbeck type. We study a class of limit laws that correspond to a scale renormalization of the solutions.......We consider solutions of Burgers' equation with linear or quadratic external potential and stationary random initial conditions of Ornstein-Uhlenbeck type. We study a class of limit laws that correspond to a scale renormalization of the solutions....

A comparison of random forest regression and multiple linear regression for prediction in neuroscience.

Science.gov (United States)

Smith, Paul F; Ganesh, Siva; Liu, Ping

2013-10-30

Regression is a common statistical tool for prediction in neuroscience. However, linear regression is by far the most common form of regression used, with regression trees receiving comparatively little attention. In this study, the results of conventional multiple linear regression (MLR) were compared with those of random forest regression (RFR), in the prediction of the concentrations of 9 neurochemicals in the vestibular nucleus complex and cerebellum that are part of the l-arginine biochemical pathway (agmatine, putrescine, spermidine, spermine, l-arginine, l-ornithine, l-citrulline, glutamate and γ-aminobutyric acid (GABA)). The R(2) values for the MLRs were higher than the proportion of variance explained values for the RFRs: 6/9 of them were ≥ 0.70 compared to 4/9 for RFRs. Even the variables that had the lowest R(2) values for the MLRs, e.g. ornithine (0.50) and glutamate (0.61), had much lower proportion of variance explained values for the RFRs (0.27 and 0.49, respectively). The RSE values for the MLRs were lower than those for the RFRs in all but two cases. In general, MLRs seemed to be superior to the RFRs in terms of predictive value and error. In the case of this data set, MLR appeared to be superior to RFR in terms of its explanatory value and error. This result suggests that MLR may have advantages over RFR for prediction in neuroscience with this kind of data set, but that RFR can still have good predictive value in some cases. Copyright © 2013 Elsevier B.V. All rights reserved.

The effect of 12 weeks of aerobic, resistance or combination exercise training on cardiovascular risk factors in the overweight and obese in a randomized trial

Directory of Open Access Journals (Sweden)

Ho Suleen S

2012-08-01

Full Text Available Abstract Background Evidence suggests that exercise training improves CVD risk factors. However, it is unclear whether health benefits are limited to aerobic training or if other exercise modalities such as resistance training or a combination are as effective or more effective in the overweight and obese. The aim of this study is to investigate whether 12 weeks of moderate-intensity aerobic, resistance, or combined exercise training would induce and sustain improvements in cardiovascular risk profile, weight and fat loss in overweight and obese adults compared to no exercise. Methods Twelve-week randomized parallel design examining the effects of different exercise regimes on fasting measures of lipids, glucose and insulin and changes in body weight, fat mass and dietary intake. Participants were randomized to either: Group 1 (Control, n = 16; Group 2 (Aerobic, n = 15; Group 3 (Resistance, n = 16; Group 4 (Combination, n = 17. Data was analysed using General Linear Model to assess the effects of the groups after adjusting for baseline values. Within-group data was analyzed with the paired t-test and between-group effects using post hoc comparisons. Results Significant improvements in body weight (−1.6%, p = 0.044 for the Combination group compared to Control and Resistance groups and total body fat compared to Control (−4.4%, p = 0.003 and Resistance (−3%, p = 0.041. Significant improvements in body fat percentage (−2.6%, p = 0.008, abdominal fat percentage (−2.8%, p = 0.034 and cardio-respiratory fitness (13.3%, p = 0.006 were seen in the Combination group compared to Control. Levels of ApoB48 were 32% lower in the Resistance group compared to Control (p = 0.04. Conclusion A 12-week training program comprising of resistance or combination exercise, at moderate-intensity for 30 min, five days/week resulted in improvements in the cardiovascular risk profile in overweight and obese

Fault tolerant linear actuator

Science.gov (United States)

Tesar, Delbert

2004-09-14

In varying embodiments, the fault tolerant linear actuator of the present invention is a new and improved linear actuator with fault tolerance and positional control that may incorporate velocity summing, force summing, or a combination of the two. In one embodiment, the invention offers a velocity summing arrangement with a differential gear between two prime movers driving a cage, which then drives a linear spindle screw transmission. Other embodiments feature two prime movers driving separate linear spindle screw transmissions, one internal and one external, in a totally concentric and compact integrated module.

An asymptotic-preserving stochastic Galerkin method for the radiative heat transfer equations with random inputs and diffusive scalings

Energy Technology Data Exchange (ETDEWEB)

Jin, Shi, E-mail: sjin@wisc.edu [Department of Mathematics, University of Wisconsin-Madison, Madison, WI 53706 (United States); Institute of Natural Sciences, Department of Mathematics, MOE-LSEC and SHL-MAC, Shanghai Jiao Tong University, Shanghai 200240 (China); Lu, Hanqing, E-mail: hanqing@math.wisc.edu [Department of Mathematics, University of Wisconsin-Madison, Madison, WI 53706 (United States)

2017-04-01

In this paper, we develop an Asymptotic-Preserving (AP) stochastic Galerkin scheme for the radiative heat transfer equations with random inputs and diffusive scalings. In this problem the random inputs arise due to uncertainties in cross section, initial data or boundary data. We use the generalized polynomial chaos based stochastic Galerkin (gPC-SG) method, which is combined with the micro–macro decomposition based deterministic AP framework in order to handle efficiently the diffusive regime. For linearized problem we prove the regularity of the solution in the random space and consequently the spectral accuracy of the gPC-SG method. We also prove the uniform (in the mean free path) linear stability for the space-time discretizations. Several numerical tests are presented to show the efficiency and accuracy of proposed scheme, especially in the diffusive regime.

Kernel reconstruction methods for Doppler broadening — Temperature interpolation by linear combination of reference cross sections at optimally chosen temperatures

International Nuclear Information System (INIS)

Ducru, Pablo; Josey, Colin; Dibert, Karia; Sobes, Vladimir; Forget, Benoit; Smith, Kord

2017-01-01

This paper establishes a new family of methods to perform temperature interpolation of nuclear interactions cross sections, reaction rates, or cross sections times the energy. One of these quantities at temperature T is approximated as a linear combination of quantities at reference temperatures (T_j). The problem is formalized in a cross section independent fashion by considering the kernels of the different operators that convert cross section related quantities from a temperature T_0 to a higher temperature T — namely the Doppler broadening operation. Doppler broadening interpolation of nuclear cross sections is thus here performed by reconstructing the kernel of the operation at a given temperature T by means of linear combination of kernels at reference temperatures (T_j). The choice of the L_2 metric yields optimal linear interpolation coefficients in the form of the solutions of a linear algebraic system inversion. The optimization of the choice of reference temperatures (T_j) is then undertaken so as to best reconstruct, in the L∞ sense, the kernels over a given temperature range [T_m_i_n,T_m_a_x]. The performance of these kernel reconstruction methods is then assessed in light of previous temperature interpolation methods by testing them upon isotope "2"3"8U. Temperature-optimized free Doppler kernel reconstruction significantly outperforms all previous interpolation-based methods, achieving 0.1% relative error on temperature interpolation of "2"3"8U total cross section over the temperature range [300 K,3000 K] with only 9 reference temperatures.

On a linear method in bootstrap confidence intervals

Directory of Open Access Journals (Sweden)

Andrea Pallini

2007-10-01

Full Text Available A linear method for the construction of asymptotic bootstrap confidence intervals is proposed. We approximate asymptotically pivotal and non-pivotal quantities, which are smooth functions of means of n independent and identically distributed random variables, by using a sum of n independent smooth functions of the same analytical form. Errors are of order Op(n-3/2 and Op(n-2, respectively. The linear method allows a straightforward approximation of bootstrap cumulants, by considering the set of n independent smooth functions as an original random sample to be resampled with replacement.

Stochastic Reconstruction and Interpolation of Precipitation Fields Using Combined Information of Commercial Microwave Links and Rain Gauges

Science.gov (United States)

Haese, B.; Hörning, S.; Chwala, C.; Bárdossy, A.; Schalge, B.; Kunstmann, H.

2017-12-01

For the reconstruction and interpolation of precipitation fields, we present the application of a stochastic approach called Random Mixing. Generated fields are based on a data set consisting of rain gauge observations and path-averaged rain rates estimated using Commercial Microwave Link (CML) derived information. Precipitation fields are received as linear combination of unconditional spatial random fields, where the spatial dependence structure is described by copulas. The weights of the linear combination are optimized such that the observations and the spatial structure of the precipitation observations are reproduced. The innovation of the approach is that this strategy enables the simulation of ensembles of precipitation fields of any size. Each ensemble member is in concordance with the observed path-averaged CML derived rain rates and additionally reflects the observed rainfall variability along the CML paths. The ensemble spread allows additionally an estimation of the uncertainty of the reconstructed precipitation fields. The method is demonstrated both for a synthetic data set and a real-world data set in South Germany. While the synthetic example allows an evaluation against a known reference, the second example demonstrates the applicability for real-world observations. Generated precipitation fields of both examples reproduce the spatial precipitation pattern in good quality. A performance evaluation of Random Mixing compared to Ordinary Kriging demonstrates an improvement of the reconstruction of the observed spatial variability. Random Mixing is concluded to be a beneficial new approach for the provision of precipitation fields and ensembles of them, in particular when different measurement types are combined.

Linear fixed-field multipass arcs for recirculating linear accelerators

Directory of Open Access Journals (Sweden)

V. S. Morozov

2012-06-01

Full Text Available Recirculating linear accelerators (RLA’s provide a compact and efficient way of accelerating particle beams to medium and high energies by reusing the same linac for multiple passes. In the conventional scheme, after each pass, the different energy beams coming out of the linac are separated and directed into appropriate arcs for recirculation, with each pass requiring a separate fixed-energy arc. In this paper we present a concept of an RLA return arc based on linear combined-function magnets, in which two and potentially more consecutive passes with very different energies are transported through the same string of magnets. By adjusting the dipole and quadrupole components of the constituting linear combined-function magnets, the arc is designed to be achromatic and to have zero initial and final reference orbit offsets for all transported beam energies. We demonstrate the concept by developing a design for a droplet-shaped return arc for a dogbone RLA capable of transporting two beam passes with momenta different by a factor of 2. We present the results of tracking simulations of the two passes and lay out the path to end-to-end design and simulation of a complete dogbone RLA.

Does the bracket–ligature combination affect the amount of orthodontic space closure over three months? A randomized controlled trial

OpenAIRE

Wong, Henry; Collins, Jill; Tinsley, David; Sandler, Jonathan; Benson, Philip

2013-01-01

Objective: To investigate the effect of bracket–ligature combination on the amount of orthodontic space closure over three months. Design: Randomized clinical trial with three parallel groups. Setting: A hospital orthodontic department (Chesterfield Royal Hospital, UK). Participants: Forty-five patients requiring upper first premolar extractions. Methods: Informed consent was obtained and participants were randomly allocated into one of three groups: (1) conventional pre-adjusted edgewise bra...

Patient, Provider, and Combined Interventions for Managing Osteoarthritis in Primary Care: A Cluster Randomized Trial.

Science.gov (United States)

Allen, Kelli D; Oddone, Eugene Z; Coffman, Cynthia J; Jeffreys, Amy S; Bosworth, Hayden B; Chatterjee, Ranee; McDuffie, Jennifer; Strauss, Jennifer L; Yancy, William S; Datta, Santanu K; Corsino, Leonor; Dolor, Rowena J

2017-03-21

A single-site study showed that a combined patient and provider intervention improved outcomes for patients with knee osteoarthritis, but it did not assess separate effects of the interventions. To examine whether patient-based, provider-based, and patient-provider interventions improve osteoarthritis outcomes. Cluster randomized trial with assignment to patient, provider, and patient-provider interventions or usual care. (ClinicalTrials.gov: NCT01435109). 10 Duke University Health System community-based primary care clinics. 537 outpatients with symptomatic hip or knee osteoarthritis. The telephone-based patient intervention focused on weight management, physical activity, and cognitive behavioral pain management. The provider intervention involved electronic delivery of patient-specific osteoarthritis treatment recommendations to providers. The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score at 12 months. Secondary outcomes were objective physical function (Short Physical Performance Battery) and depressive symptoms (Patient Health Questionnaire). Linear mixed models assessed the difference in improvement among groups. No difference was observed in WOMAC score changes from baseline to 12 months in the patient (-1.5 [95% CI, -5.1 to 2.0]; P = 0.40), provider (2.5 [CI, -0.9 to 5.9]; P = 0.152), or patient-provider (-0.7 [CI, -4.2 to 2.8]; P = 0.69) intervention groups compared with usual care. All groups had improvements in WOMAC scores at 12 months (range, -3.7 to -7.7). In addition, no differences were seen in objective physical function or depressive symptoms at 12 months in any of the intervention groups compared with usual care. The study involved 1 health care network. Data on provider referrals were not collected. Contrary to a previous study of a combined patient and provider intervention for osteoarthritis in a Department of Veterans Affairs medical center, this study found no statistically

A New Approach with Combined Stereotactic Trans-multiarc Beams for Radiosurgery Based on the Linear Accelerator : Photon Knife

International Nuclear Information System (INIS)

Choi, Tae Jin; Kim, Jin Hee; Kim, Ok Bae

1996-01-01

Purpose : To get an acute steepness of dose gradients at outside the target volume in intracranial lesion and a less limitation of beam selection avoiding the high dose at normal brain tissue, this Photon Knife Radiosurgery System was developed in order to provide the three-dimensional dose distribution through the reconstruction of CT scan and the combined stereotactic tranmultiarc beam mode based on linear accelerator photon beam. Methods and Materials : This stereotactic radiosurgery, Photon Knife based on linear accelerator photon beam was provided the non-coplanar multiarc and trans-multiarc irradiations. The stereotactic trans-multiarc beam mode can be obtained from the patient position in decubitus. This study has provided the 3-dimensional isodose curve and anatomical structures with the surface rendering technique. Results : In this study, it shows that the dose distributions of stereotactic beam mode are significantly depended on the selected couch and gantry angle in same collimator size. Practical dose distribution of combined stereotactic trans-multiarc beam has shown a more small rim thickness than that of the non-coplanar multiarc beam mode in axial, sagittal and coronal plane in our study. 3-Dimensional dose line displayed with surface rendering of irregular target shape is helpful to determine the target dose and to predict the prognosis in follow-up radiosurgery. Conclusion : 3-Dimensional dose line displayed with surface rendering of irregular target shape is essential in stereotactic radiosurgery. This combined stereotactic trans-multiarc beam has shown a less limitation of the selection couch and gantry beam angles for the target surrounding critical organs. It has shown that the dose distribution of combined trans-multiarc beam greatly depended on the couch and gantry angles. In our experiments. the absorbed dose has been decreased to 27 % /mm in maximum at the interval of 50% to 80% of isodose line

Application of single-step genomic best linear unbiased prediction with a multiple-lactation random regression test-day model for Japanese Holsteins.

Science.gov (United States)

Baba, Toshimi; Gotoh, Yusaku; Yamaguchi, Satoshi; Nakagawa, Satoshi; Abe, Hayato; Masuda, Yutaka; Kawahara, Takayoshi

2017-08-01

This study aimed to evaluate a validation reliability of single-step genomic best linear unbiased prediction (ssGBLUP) with a multiple-lactation random regression test-day model and investigate an effect of adding genotyped cows on the reliability. Two data sets for test-day records from the first three lactations were used: full data from February 1975 to December 2015 (60 850 534 records from 2 853 810 cows) and reduced data cut off in 2011 (53 091 066 records from 2 502 307 cows). We used marker genotypes of 4480 bulls and 608 cows. Genomic enhanced breeding values (GEBV) of 305-day milk yield in all the lactations were estimated for at least 535 young bulls using two marker data sets: bull genotypes only and both bulls and cows genotypes. The realized reliability (R 2 ) from linear regression analysis was used as an indicator of validation reliability. Using only genotyped bulls, R 2 was ranged from 0.41 to 0.46 and it was always higher than parent averages. The very similar R 2 were observed when genotyped cows were added. An application of ssGBLUP to a multiple-lactation random regression model is feasible and adding a limited number of genotyped cows has no significant effect on reliability of GEBV for genotyped bulls. © 2016 Japanese Society of Animal Science.

Pseudo-random number generator based on asymptotic deterministic randomness

Science.gov (United States)

Wang, Kai; Pei, Wenjiang; Xia, Haishan; Cheung, Yiu-ming

2008-06-01

A novel approach to generate the pseudorandom-bit sequence from the asymptotic deterministic randomness system is proposed in this Letter. We study the characteristic of multi-value correspondence of the asymptotic deterministic randomness constructed by the piecewise linear map and the noninvertible nonlinearity transform, and then give the discretized systems in the finite digitized state space. The statistic characteristics of the asymptotic deterministic randomness are investigated numerically, such as stationary probability density function and random-like behavior. Furthermore, we analyze the dynamics of the symbolic sequence. Both theoretical and experimental results show that the symbolic sequence of the asymptotic deterministic randomness possesses very good cryptographic properties, which improve the security of chaos based PRBGs and increase the resistance against entropy attacks and symbolic dynamics attacks.

Pseudo-random number generator based on asymptotic deterministic randomness

International Nuclear Information System (INIS)

Wang Kai; Pei Wenjiang; Xia Haishan; Cheung Yiuming

2008-01-01

A novel approach to generate the pseudorandom-bit sequence from the asymptotic deterministic randomness system is proposed in this Letter. We study the characteristic of multi-value correspondence of the asymptotic deterministic randomness constructed by the piecewise linear map and the noninvertible nonlinearity transform, and then give the discretized systems in the finite digitized state space. The statistic characteristics of the asymptotic deterministic randomness are investigated numerically, such as stationary probability density function and random-like behavior. Furthermore, we analyze the dynamics of the symbolic sequence. Both theoretical and experimental results show that the symbolic sequence of the asymptotic deterministic randomness possesses very good cryptographic properties, which improve the security of chaos based PRBGs and increase the resistance against entropy attacks and symbolic dynamics attacks

Random Numbers and Quantum Computers

Science.gov (United States)

McCartney, Mark; Glass, David

2002-01-01

The topic of random numbers is investigated in such a way as to illustrate links between mathematics, physics and computer science. First, the generation of random numbers by a classical computer using the linear congruential generator and logistic map is considered. It is noted that these procedures yield only pseudo-random numbers since…

Random numbers from vacuum fluctuations

International Nuclear Information System (INIS)

Shi, Yicheng; Kurtsiefer, Christian; Chng, Brenda

2016-01-01

We implement a quantum random number generator based on a balanced homodyne measurement of vacuum fluctuations of the electromagnetic field. The digitized signal is directly processed with a fast randomness extraction scheme based on a linear feedback shift register. The random bit stream is continuously read in a computer at a rate of about 480 Mbit/s and passes an extended test suite for random numbers.

Random numbers from vacuum fluctuations

Energy Technology Data Exchange (ETDEWEB)

Shi, Yicheng; Kurtsiefer, Christian, E-mail: christian.kurtsiefer@gmail.com [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Center for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore); Chng, Brenda [Center for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore)

2016-07-25

We implement a quantum random number generator based on a balanced homodyne measurement of vacuum fluctuations of the electromagnetic field. The digitized signal is directly processed with a fast randomness extraction scheme based on a linear feedback shift register. The random bit stream is continuously read in a computer at a rate of about 480 Mbit/s and passes an extended test suite for random numbers.

Effect of Linear Low-Intensity Extracorporeal Shockwave Therapy for Erectile Dysfunction-12-Month Follow-Up of a Randomized, Double-Blinded, Sham-Controlled Study

DEFF Research Database (Denmark)

Fojecki, Grzegorz Lukasz; Tiessen, Stefan; Sloth Osther, Palle Jørn

2018-01-01

-EF (ΔIIEF-EF score). The secondary outcome measure was an increase in the EHS score to at least 3 in men with a score no higher than 2 at baseline. Data were analyzed by linear and logistic regressions. RESULTS: Linear regression of the ΔIIEF-EF score from baseline to 12 months included 95 patients (dropout......INTRODUCTION: Short-term data on the effect of low-intensity extracorporeal shockwave therapy (Li-ESWT) on erectile dysfunction (ED) have been inconsistent. The suggested mechanisms of action of Li-ESWT on ED include stimulation of cell proliferation, tissue regeneration, and angiogenesis, which...... can be processes with a long generation time. Therefore, long-term data on the effect of Li-ESWT on ED are strongly warranted. AIM: To assess the outcome at 6 and 12 months of linear Li-ESWT on ED from a previously published randomized, double-blinded, sham-controlled trial. METHODS: Subjects with ED...

Toward combining thematic information with hierarchical multiscale segmentations using tree Markov random field model

Science.gov (United States)

Zhang, Xueliang; Xiao, Pengfeng; Feng, Xuezhi

2017-09-01

It has been a common idea to produce multiscale segmentations to represent the various geographic objects in high-spatial resolution remote sensing (HR) images. However, it remains a great challenge to automatically select the proper segmentation scale(s) just according to the image information. In this study, we propose a novel way of information fusion at object level by combining hierarchical multiscale segmentations with existed thematic information produced by classification or recognition. The tree Markov random field (T-MRF) model is designed for the multiscale combination framework, through which the object type is determined as close as the existed thematic information. At the same time, the object boundary is jointly determined by the thematic labels and the multiscale segments through the minimization of the energy function. The benefits of the proposed T-MRF combination model include: (1) reducing the dependence of segmentation scale selection when utilizing multiscale segmentations; (2) exploring the hierarchical context naturally imbedded in the multiscale segmentations. The HR images in both urban and rural areas are used in the experiments to show the effectiveness of the proposed combination framework on these two aspects.

On the design of henon and logistic map-based random number generator

Science.gov (United States)

Magfirawaty; Suryadi, M. T.; Ramli, Kalamullah

2017-10-01

The key sequence is one of the main elements in the cryptosystem. True Random Number Generators (TRNG) method is one of the approaches to generating the key sequence. The randomness source of the TRNG divided into three main groups, i.e. electrical noise based, jitter based and chaos based. The chaos based utilizes a non-linear dynamic system (continuous time or discrete time) as an entropy source. In this study, a new design of TRNG based on discrete time chaotic system is proposed, which is then simulated in LabVIEW. The principle of the design consists of combining 2D and 1D chaotic systems. A mathematical model is implemented for numerical simulations. We used comparator process as a harvester method to obtain the series of random bits. Without any post processing, the proposed design generated random bit sequence with high entropy value and passed all NIST 800.22 statistical tests.

Linear Fixed-Field Multi-Pass Arcs for Recirculating Linear Accelerators

International Nuclear Information System (INIS)

Morozov, V.S.; Bogacz, S.A.; Roblin, Y.R.; Beard, K.B.

2012-01-01

Recirculating Linear Accelerators (RLA's) provide a compact and efficient way of accelerating particle beams to medium and high energies by reusing the same linac for multiple passes. In the conventional scheme, after each pass, the different energy beams coming out of the linac are separated and directed into appropriate arcs for recirculation, with each pass requiring a separate fixed-energy arc. In this paper we present a concept of an RLA return arc based on linear combined-function magnets, in which two and potentially more consecutive passes with very different energies are transported through the same string of magnets. By adjusting the dipole and quadrupole components of the constituting linear combined-function magnets, the arc is designed to be achromatic and to have zero initial and final reference orbit offsets for all transported beam energies. We demonstrate the concept by developing a design for a droplet-shaped return arc for a dog-bone RLA capable of transporting two beam passes with momenta different by a factor of two. We present the results of tracking simulations of the two passes and lay out the path to end-to-end design and simulation of a complete dog-bone RLA.

Semidefinite linear complementarity problems

International Nuclear Information System (INIS)

Eckhardt, U.

1978-04-01

Semidefinite linear complementarity problems arise by discretization of variational inequalities describing e.g. elastic contact problems, free boundary value problems etc. In the present paper linear complementarity problems are introduced and the theory as well as the numerical treatment of them are described. In the special case of semidefinite linear complementarity problems a numerical method is presented which combines the advantages of elimination and iteration methods without suffering from their drawbacks. This new method has very attractive properties since it has a high degree of invariance with respect to the representation of the set of all feasible solutions of a linear complementarity problem by linear inequalities. By means of some practical applications the properties of the new method are demonstrated. (orig.) [de

Combining rational and random strategies in β-glucosidase Zm-p60.1 protein library construction.

Directory of Open Access Journals (Sweden)

Dušan Turek

Full Text Available Saturation mutagenesis is a cornerstone technique in protein engineering because of its utility (in conjunction with appropriate analytical techniques for assessing effects of varying residues at selected positions on proteins' structures and functions. Site-directed mutagenesis with degenerate primers is the simplest and most rapid saturation mutagenesis technique. Thus, it is highly appropriate for assessing whether or not variation at certain sites is permissible, but not necessarily the most time- and cost-effective technique for detailed assessment of variations' effects. Thus, in the presented study we applied the technique to randomize position W373 in β-glucosidase Zm-p60.1, which is highly conserved among β-glucosidases. Unexpectedly, β-glucosidase activity screening of the generated variants showed that most variants were active, although they generally had significantly lower activity than the wild type enzyme. Further characterization of the library led us to conclude that a carefully selected combination of randomized codon-based saturation mutagenesis and site-directed mutagenesis may be most efficient, particularly when constructing and investigating randomized libraries with high fractions of positive hits.

Combining rational and random strategies in β-glucosidase Zm-p60.1 protein library construction.

Science.gov (United States)

Turek, Dušan; Klimeš, Pavel; Mazura, Pavel; Brzobohatý, Břetislav

2014-01-01

Saturation mutagenesis is a cornerstone technique in protein engineering because of its utility (in conjunction with appropriate analytical techniques) for assessing effects of varying residues at selected positions on proteins' structures and functions. Site-directed mutagenesis with degenerate primers is the simplest and most rapid saturation mutagenesis technique. Thus, it is highly appropriate for assessing whether or not variation at certain sites is permissible, but not necessarily the most time- and cost-effective technique for detailed assessment of variations' effects. Thus, in the presented study we applied the technique to randomize position W373 in β-glucosidase Zm-p60.1, which is highly conserved among β-glucosidases. Unexpectedly, β-glucosidase activity screening of the generated variants showed that most variants were active, although they generally had significantly lower activity than the wild type enzyme. Further characterization of the library led us to conclude that a carefully selected combination of randomized codon-based saturation mutagenesis and site-directed mutagenesis may be most efficient, particularly when constructing and investigating randomized libraries with high fractions of positive hits.

Linear methods in band theory

DEFF Research Database (Denmark)

Andersen, O. Krogh

1975-01-01

of Korringa-Kohn-Rostoker, linear-combination-of-atomic-orbitals, and cellular methods; the secular matrix is linear in energy, the overlap integrals factorize as potential parameters and structure constants, the latter are canonical in the sense that they neither depend on the energy nor the cell volume...

Competitive inhibition can linearize dose-response and generate a linear rectifier.

Science.gov (United States)

Savir, Yonatan; Tu, Benjamin P; Springer, Michael

2015-09-23

Many biological responses require a dynamic range that is larger than standard bi-molecular interactions allow, yet the also ability to remain off at low input. Here we mathematically show that an enzyme reaction system involving a combination of competitive inhibition, conservation of the total level of substrate and inhibitor, and positive feedback can behave like a linear rectifier-that is, a network motif with an input-output relationship that is linearly sensitive to substrate above a threshold but unresponsive below the threshold. We propose that the evolutionarily conserved yeast SAGA histone acetylation complex may possess the proper physiological response characteristics and molecular interactions needed to perform as a linear rectifier, and we suggest potential experiments to test this hypothesis. One implication of this work is that linear responses and linear rectifiers might be easier to evolve or synthetically construct than is currently appreciated.

Random-effects linear modeling and sample size tables for two special crossover designs of average bioequivalence studies: the four-period, two-sequence, two-formulation and six-period, three-sequence, three-formulation designs.

Science.gov (United States)

Diaz, Francisco J; Berg, Michel J; Krebill, Ron; Welty, Timothy; Gidal, Barry E; Alloway, Rita; Privitera, Michael

2013-12-01

Due to concern and debate in the epilepsy medical community and to the current interest of the US Food and Drug Administration (FDA) in revising approaches to the approval of generic drugs, the FDA is currently supporting ongoing bioequivalence studies of antiepileptic drugs, the EQUIGEN studies. During the design of these crossover studies, the researchers could not find commercial or non-commercial statistical software that quickly allowed computation of sample sizes for their designs, particularly software implementing the FDA requirement of using random-effects linear models for the analyses of bioequivalence studies. This article presents tables for sample-size evaluations of average bioequivalence studies based on the two crossover designs used in the EQUIGEN studies: the four-period, two-sequence, two-formulation design, and the six-period, three-sequence, three-formulation design. Sample-size computations assume that random-effects linear models are used in bioequivalence analyses with crossover designs. Random-effects linear models have been traditionally viewed by many pharmacologists and clinical researchers as just mathematical devices to analyze repeated-measures data. In contrast, a modern view of these models attributes an important mathematical role in theoretical formulations in personalized medicine to them, because these models not only have parameters that represent average patients, but also have parameters that represent individual patients. Moreover, the notation and language of random-effects linear models have evolved over the years. Thus, another goal of this article is to provide a presentation of the statistical modeling of data from bioequivalence studies that highlights the modern view of these models, with special emphasis on power analyses and sample-size computations.

Stochastic Linear Quadratic Optimal Control Problems

International Nuclear Information System (INIS)

Chen, S.; Yong, J.

2001-01-01

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

Numerical linear algebra theory and applications

CERN Document Server

Beilina, Larisa; Karchevskii, Mikhail

2017-01-01

This book combines a solid theoretical background in linear algebra with practical algorithms for numerical solution of linear algebra problems. Developed from a number of courses taught repeatedly by the authors, the material covers topics like matrix algebra, theory for linear systems of equations, spectral theory, vector and matrix norms combined with main direct and iterative numerical methods, least squares problems, and eigen problems. Numerical algorithms illustrated by computer programs written in MATLAB® are also provided as supplementary material on SpringerLink to give the reader a better understanding of professional numerical software for the solution of real-life problems. Perfect for a one- or two-semester course on numerical linear algebra, matrix computation, and large sparse matrices, this text will interest students at the advanced undergraduate or graduate level.

Some consequences of assuming simple patterns for the treatment effect over time in a linear mixed model.

Science.gov (United States)

Bamia, Christina; White, Ian R; Kenward, Michael G

2013-07-10

Linear mixed models are often used for the analysis of data from clinical trials with repeated quantitative outcomes. This paper considers linear mixed models where a particular form is assumed for the treatment effect, in particular constant over time or proportional to time. For simplicity, we assume no baseline covariates and complete post-baseline measures, and we model arbitrary mean responses for the control group at each time. For the variance-covariance matrix, we consider an unstructured model, a random intercepts model and a random intercepts and slopes model. We show that the treatment effect estimator can be expressed as a weighted average of the observed time-specific treatment effects, with weights depending on the covariance structure and the magnitude of the estimated variance components. For an assumed constant treatment effect, under the random intercepts model, all weights are equal, but in the random intercepts and slopes and the unstructured models, we show that some weights can be negative: thus, the estimated treatment effect can be negative, even if all time-specific treatment effects are positive. Our results suggest that particular models for the treatment effect combined with particular covariance structures may result in estimated treatment effects of unexpected magnitude and/or direction. Methods are illustrated using a Parkinson's disease trial. Copyright © 2012 John Wiley & Sons, Ltd.

Combined Use of Hyperbaric and Hypobaric Ropivacaine Significantly Improves Hemodynamic Characteristics in Spinal Anesthesia for Caesarean Section: A Prospective, Double-Blind, Randomized, Controlled Study

OpenAIRE

Quan, ZheFeng; Tian, Ming; Chi, Ping; Li, Xin; He, HaiLi; Luo, Chao

2015-01-01

Purpose To observe the hemodynamic changes of parturients in the combined use of hyperbaric (4 mg) and hypobaric (6 mg) ropivacaine during spinal anesthesia for caesarean section in this randomized double-blind study. Methods Parturients (n = 136) undergoing elective cesarean delivery were randomly and equally allocated to receive either combined hyperbaric and hypobaric ropivacaine (Group A) or hyperbaric ropivacaine (Group B). Outcome measures were: hemodynamic characteristics, maximum heig...

Half-trek criterion for generic identifiability of linear structural equation models

NARCIS (Netherlands)

Foygel, R.; Draisma, J.; Drton, M.

2012-01-01

A linear structural equation model relates random variables of interest and corresponding Gaussian noise terms via a linear equation system. Each such model can be represented by a mixed graph in which directed edges encode the linear equations, and bidirected edges indicate possible correlations

Half-trek criterion for generic identifiability of linear structural equation models

NARCIS (Netherlands)

Foygel, R.; Draisma, J.; Drton, M.

2011-01-01

A linear structural equation model relates random variables of interest and corresponding Gaussian noise terms via a linear equation system. Each such model can be represented by a mixed graph in which directed edges encode the linear equations, and bidirected edges indicate possible correlations

Specific heat of the Ising linear chain in a Random field

International Nuclear Information System (INIS)

Silva, P.R.; Sa Barreto, F.C. de

1984-01-01

Starting from correlation identities for the Ising model the effect of a random field on the one dimension version of the model is studied. Explicit results for the magnetization, the two-particle correlation function and the specific heat are obtained for an uncorrelated distribution of the random fields. (Author) [pt

Generalized, Linear, and Mixed Models

CERN Document Server

McCulloch, Charles E; Neuhaus, John M

2011-01-01

An accessible and self-contained introduction to statistical models-now in a modernized new editionGeneralized, Linear, and Mixed Models, Second Edition provides an up-to-date treatment of the essential techniques for developing and applying a wide variety of statistical models. The book presents thorough and unified coverage of the theory behind generalized, linear, and mixed models and highlights their similarities and differences in various construction, application, and computational aspects.A clear introduction to the basic ideas of fixed effects models, random effects models, and mixed m

Combining walking and relaxation for stress reduction-A randomized cross-over trial in healthy adults.

Science.gov (United States)

Matzer, Franziska; Nagele, Eva; Lerch, Nikolaus; Vajda, Christian; Fazekas, Christian

2018-04-01

Both physical activity and relaxation have stress-relieving potential. This study investigates their combined impact on the relaxation response while considering participants' initial stress level. In a randomized cross-over trial, 81 healthy adults completed 4 types of short-term interventions for stress reduction, each lasting for 1 hr: (1) physical activity (walking) combined with resting, (2) walking combined with balneotherapy, (3) combined resting and balneotherapy, and (4) resting only. Saliva cortisol, blood pressure, state of mood, and relaxation were measured preintervention and postintervention. Stress levels were determined by validated questionnaires. All interventions were associated with relaxation responses in the variables saliva cortisol, blood pressure, state of mood, and subjective relaxation. No significant differences were found regarding the reduction of salivary cortisol (F = 1.30; p = .281). The systolic blood pressure was reduced best when walking was combined with balneotherapy or resting (F = 7.34; p stress levels (n = 25) felt more alert after interventions including balneotherapy, whereas they reported an increase of tiredness when walking was combined with resting (F = 3.20; p = .044). Results suggest that combining physical activity and relaxation (resting or balneotherapy) is an advantageous short-term strategy for stress reduction as systolic blood pressure is reduced best while similar levels of relaxation can be obtained. Copyright © 2017 John Wiley & Sons, Ltd.

Combinational Optimal Stopping Problems

Science.gov (United States)

2016-04-01

the set of random events, F is the - algebra , and P is a probability measure, a risk measure is defined as a mapping W X 7! R, where X is a linear ...bound- ary conditions by solving a system of linear algebraic equa- tions. In order to guarantee that vectors G j are independent, and therefore...Stochastic Linear Programming: Models, Theory, and Computation. Springer Kantor IL, Solodovnikov AS (1989) Hypercomplex Num- bers: An Elementary

Ranking Forestry Investments With Parametric Linear Programming

Science.gov (United States)

Paul A. Murphy

1976-01-01

Parametric linear programming is introduced as a technique for ranking forestry investments under multiple constraints; it combines the advantages of simple tanking and linear programming as capital budgeting tools.

The Effect of Creative Tasks on Electrocardiogram: Using Linear and Nonlinear Features in Combination with Classification Approaches

Directory of Open Access Journals (Sweden)

Sahar Zakeri

2017-02-01

Full Text Available Objective: Interest in the subject of creativity and its impacts on human life is growing extensively. However, only a few surveys pay attention to the relation between creativity and physiological changes. This paper presents a novel approach to distinguish between creativity states from electrocardiogram signals. Nineteen linear and nonlinear features of the cardiac signal were extracted to detect creativity states. Method: ECG signals of 52 participants were recorded while doing three tasks of Torrance Tests of Creative Thinking (TTCT/ figural B. To remove artifacts, notch filter 50 Hz and Chebyshev II were applied. According to TTCT scores, participants were categorized into the high and low creativity groups: Participants with scores higher than 70 were assigned into the high creativity group and those with scores less than 30 were considered as low creativity group. Some linear and nonlinear features were extracted from the ECGs. Then, Support Vector Machine (SVM and Adaptive Neuro-Fuzzy Inference System (ANFIS were used to classify the groups.Results: Applying the Wilcoxon test, significant differences were observed between rest and each three tasks of creativity. However, better discrimination was performed between rest and the first task. In addition, there were no statistical differences between the second and third task of the test. The results indicated that the SVM effectively detects all the three tasks from the rest, particularly the task 1 and reached the maximum accuracy of 99.63% in the linear analysis. In addition, the high creative group was separated from the low creative group with the accuracy of 98.41%.Conclusion: the combination of SVM classifier with linear features can be useful to show the relation between creativity and physiological changes.

Effectiveness of Shockwave Treatment Combined With Eccentric Training for Patellar Tendinopathy: A Double-Blinded Randomized Study

OpenAIRE

Thijs, Karin M.; Zwerver, Johannes; Backx, Frank J. G.; Steeneken, Victor; Rayer, Stephan; Groenenboom, Petra; Moen, Maarten H.

2017-01-01

OBJECTIVE: To evaluate the effectiveness of a combined treatment of focused shockwave therapy (ESWT) and eccentric training compared with sham-shockwave therapy (placebo) and eccentric training in participants with patellar tendinopathy (PT) after 24 weeks. DESIGN: Randomized controlled trial. SETTING: Sports medicine departments of a university hospital and a general hospital in the Netherlands. PARTICIPANTS: Fifty-two physically active male and female participants with a clinical diagnosis ...

BWIP-RANDOM-SAMPLING, Random Sample Generation for Nuclear Waste Disposal

International Nuclear Information System (INIS)

Sagar, B.

1989-01-01

1 - Description of program or function: Random samples for different distribution types are generated. Distribution types as required for performance assessment modeling of geologic nuclear waste disposal are provided. These are: - Uniform, - Log-uniform (base 10 or natural), - Normal, - Lognormal (base 10 or natural), - Exponential, - Bernoulli, - User defined continuous distribution. 2 - Method of solution: A linear congruential generator is used for uniform random numbers. A set of functions is used to transform the uniform distribution to the other distributions. Stratified, rather than random, sampling can be chosen. Truncated limits can be specified on many distributions, whose usual definition has an infinite support. 3 - Restrictions on the complexity of the problem: Generation of correlated random variables is not included

Combined Effect of Random Transmit Power Control and Inter-Path Interference Cancellation on DS-CDMA Packet Mobile Communications

Science.gov (United States)

Kudoh, Eisuke; Ito, Haruki; Wang, Zhisen; Adachi, Fumiyuki

In mobile communication systems, high speed packet data services are demanded. In the high speed data transmission, throughput degrades severely due to severe inter-path interference (IPI). Recently, we proposed a random transmit power control (TPC) to increase the uplink throughput of DS-CDMA packet mobile communications. In this paper, we apply IPI cancellation in addition to the random TPC. We derive the numerical expression of the received signal-to-interference plus noise power ratio (SINR) and introduce IPI cancellation factor. We also derive the numerical expression of system throughput when IPI is cancelled ideally to compare with the Monte Carlo numerically evaluated system throughput. Then we evaluate, by Monte-Carlo numerical computation method, the combined effect of random TPC and IPI cancellation on the uplink throughput of DS-CDMA packet mobile communications.

Randomized interpolative decomposition of separated representations

Science.gov (United States)

Biagioni, David J.; Beylkin, Daniel; Beylkin, Gregory

2015-01-01

We introduce an algorithm to compute tensor interpolative decomposition (dubbed CTD-ID) for the reduction of the separation rank of Canonical Tensor Decompositions (CTDs). Tensor ID selects, for a user-defined accuracy ɛ, a near optimal subset of terms of a CTD to represent the remaining terms via a linear combination of the selected terms. CTD-ID can be used as an alternative to or in combination with the Alternating Least Squares (ALS) algorithm. We present examples of its use within a convergent iteration to compute inverse operators in high dimensions. We also briefly discuss the spectral norm as a computational alternative to the Frobenius norm in estimating approximation errors of tensor ID. We reduce the problem of finding tensor IDs to that of constructing interpolative decompositions of certain matrices. These matrices are generated via randomized projection of the terms of the given tensor. We provide cost estimates and several examples of the new approach to the reduction of separation rank.

Chinese Massage Combined with Herbal Ointment for Athletes with Nonspecific Low Back Pain: A Randomized Controlled Trial

Directory of Open Access Journals (Sweden)

Ling Jun Kong

2012-01-01

Full Text Available Non-specific low back pain (NLBP is an increasing health problem for athletes. This randomized controlled trial was designed to investigate the effects of Chinese massage combined with herbal ointment for NLBP. 110 athletes with NLBP were randomly assigned to experimental group with Chinese massage combined with herbal ointment or control group with simple massage therapy. The primary outcome was pain by Chinese Short Form McGill Pain Questionnaire (C-SFMPQ. The secondary outcome was local muscle stiffness by Myotonometer. After 4 weeks, the experimental group experienced significant improvements in C-SFMPQ and in local muscle stiffness compared with control group (between-group difference in mean change from baseline, −1.24 points, P=0.005 in sensory scores; −3.14 points, P<0.001 in affective scores; −4.39 points, P<0.001 in total scores; −0.64 points, P=0.002 in VAS; −1.04 points, P=0.005 in local muscle stiffness during relaxation state. The difference remained at one month followup, but it was only significant in affective scores (−2.83 points, P<0.001 at three months followup. No adverse events were observed. These findings suggest that Chinese massage combined with herbal ointment may be a beneficial complementary and alternative therapy for athletes with NLBP.

Surface tensor estimation from linear sections

DEFF Research Database (Denmark)

Kousholt, Astrid; Kiderlen, Markus; Hug, Daniel

From Crofton's formula for Minkowski tensors we derive stereological estimators of translation invariant surface tensors of convex bodies in the n-dimensional Euclidean space. The estimators are based on one-dimensional linear sections. In a design based setting we suggest three types of estimators....... These are based on isotropic uniform random lines, vertical sections, and non-isotropic random lines, respectively. Further, we derive estimators of the specific surface tensors associated with a stationary process of convex particles in the model based setting....

Surface tensor estimation from linear sections

DEFF Research Database (Denmark)

Kousholt, Astrid; Kiderlen, Markus; Hug, Daniel

2015-01-01

From Crofton’s formula for Minkowski tensors we derive stereological estimators of translation invariant surface tensors of convex bodies in the n-dimensional Euclidean space. The estimators are based on one-dimensional linear sections. In a design based setting we suggest three types of estimators....... These are based on isotropic uniform random lines, vertical sections, and non-isotropic random lines, respectively. Further, we derive estimators of the specific surface tensors associated with a stationary process of convex particles in the model based setting....

Analysis of baseline, average, and longitudinally measured blood pressure data using linear mixed models.

Science.gov (United States)

Hossain, Ahmed; Beyene, Joseph

2014-01-01

This article compares baseline, average, and longitudinal data analysis methods for identifying genetic variants in genome-wide association study using the Genetic Analysis Workshop 18 data. We apply methods that include (a) linear mixed models with baseline measures, (b) random intercept linear mixed models with mean measures outcome, and (c) random intercept linear mixed models with longitudinal measurements. In the linear mixed models, covariates are included as fixed effects, whereas relatedness among individuals is incorporated as the variance-covariance structure of the random effect for the individuals. The overall strategy of applying linear mixed models decorrelate the data is based on Aulchenko et al.'s GRAMMAR. By analyzing systolic and diastolic blood pressure, which are used separately as outcomes, we compare the 3 methods in identifying a known genetic variant that is associated with blood pressure from chromosome 3 and simulated phenotype data. We also analyze the real phenotype data to illustrate the methods. We conclude that the linear mixed model with longitudinal measurements of diastolic blood pressure is the most accurate at identifying the known single-nucleotide polymorphism among the methods, but linear mixed models with baseline measures perform best with systolic blood pressure as the outcome.

Contactless and absolute linear displacement detection based upon 3D printed magnets combined with passive radio-frequency identification

Science.gov (United States)

Windl, Roman; Abert, Claas; Bruckner, Florian; Huber, Christian; Vogler, Christoph; Weitensfelder, Herbert; Suess, Dieter

2017-11-01

Within this work a passive and wireless magnetic sensor, to monitor linear displacements, is proposed. We exploit recent advances in 3D printing and fabricate a polymer bonded magnet with a spatially linear magnetic field component corresponding to the length of the magnet. Regulating the magnetic compound fraction during printing allows specific shaping of the magnetic field distribution. A giant magnetoresistance magnetic field sensor is combined with a radio-frequency identification tag in order to passively monitor the exerted magnetic field of the printed magnet. Due to the tailored magnetic field, a displacement of the magnet with respect to the sensor can be detected within the sub-mm regime. The sensor design provides good flexibility by controlling the 3D printing process according to application needs. Absolute displacement detection using low cost components and providing passive operation, long term stability, and longevity renders the proposed sensor system ideal for structural health monitoring applications.

Contactless and absolute linear displacement detection based upon 3D printed magnets combined with passive radio-frequency identification

Directory of Open Access Journals (Sweden)

Roman Windl

2017-11-01

Full Text Available Within this work a passive and wireless magnetic sensor, to monitor linear displacements, is proposed. We exploit recent advances in 3D printing and fabricate a polymer bonded magnet with a spatially linear magnetic field component corresponding to the length of the magnet. Regulating the magnetic compound fraction during printing allows specific shaping of the magnetic field distribution. A giant magnetoresistance magnetic field sensor is combined with a radio-frequency identification tag in order to passively monitor the exerted magnetic field of the printed magnet. Due to the tailored magnetic field, a displacement of the magnet with respect to the sensor can be detected within the sub-mm regime. The sensor design provides good flexibility by controlling the 3D printing process according to application needs. Absolute displacement detection using low cost components and providing passive operation, long term stability, and longevity renders the proposed sensor system ideal for structural health monitoring applications.

Linearly Refined Session Types

Directory of Open Access Journals (Sweden)

Pedro Baltazar

2012-11-01

Full Text Available Session types capture precise protocol structure in concurrent programming, but do not specify properties of the exchanged values beyond their basic type. Refinement types are a form of dependent types that can address this limitation, combining types with logical formulae that may refer to program values and can constrain types using arbitrary predicates. We present a pi calculus with assume and assert operations, typed using a session discipline that incorporates refinement formulae written in a fragment of Multiplicative Linear Logic. Our original combination of session and refinement types, together with the well established benefits of linearity, allows very fine-grained specifications of communication protocols in which refinement formulae are treated as logical resources rather than persistent truths.

CSSI-PRO: a method for secondary structure type editing, assignment and estimation in proteins using linear combination of backbone chemical shifts

International Nuclear Information System (INIS)

Swain, Monalisa; Atreya, Hanudatta S.

2009-01-01

Estimation of secondary structure in polypeptides is important for studying their structure, folding and dynamics. In NMR spectroscopy, such information is generally obtained after sequence specific resonance assignments are completed. We present here a new methodology for assignment of secondary structure type to spin systems in proteins directly from NMR spectra, without prior knowledge of resonance assignments. The methodology, named Combination of Shifts for Secondary Structure Identification in Proteins (CSSI-PRO), involves detection of specific linear combination of backbone 1 H α and 13 C' chemical shifts in a two-dimensional (2D) NMR experiment based on G-matrix Fourier transform (GFT) NMR spectroscopy. Such linear combinations of shifts facilitate editing of residues belonging to α-helical/β-strand regions into distinct spectral regions nearly independent of the amino acid type, thereby allowing the estimation of overall secondary structure content of the protein. Comparison of the predicted secondary structure content with those estimated based on their respective 3D structures and/or the method of Chemical Shift Index for 237 proteins gives a correlation of more than 90% and an overall rmsd of 7.0%, which is comparable to other biophysical techniques used for structural characterization of proteins. Taken together, this methodology has a wide range of applications in NMR spectroscopy such as rapid protein structure determination, monitoring conformational changes in protein-folding/ligand-binding studies and automated resonance assignment

The Impact of Combined Music and Tai Chi on Depressive Symptoms Among Community-Dwelling Older Persons: A Cluster Randomized Controlled Trial.

Science.gov (United States)

Liao, S J; Tan, M P; Chong, M C; Chua, Y P

2018-05-01

The effectiveness of pharmacological treatment may be limited in older persons. Several studies using Tai Chi or music therapy separately confirmed positive effects in the reduction of depressive symptoms. We conducted a cluster randomized controlled trial to evaluate the possible synergistic effect of combined music and Tai Chi on depressive symptoms. One hundred and seven older adults with mild to moderate depressive symptoms were recruited from Ya'an city. Fifty-five participants were cluster randomized to combined music and Tai Chi group for three months, while the other fifty-two individuals were randomized to the control group that entailed routine health education delivered monthly by community nurses. The primary outcome of depressive symptoms was measured with the Geriatric Depression Scale (GDS) at baseline and monthly for three months. At three-month follow-up, a statistically significant improvement in depressive symptoms was found in the intervention group compared with control group (F(3,315) = 69.661, P < 0.001). Following adjustments for socio-demographic data, the true effect of intervention on depressive symptoms was significant (F = 41.725, P < 0.01, η p 2 = 0.574). Combined music and Tai Chi reduced depressive symptoms among community-dwelling older persons. This represents an economically viable solution to the management of depression in highly populous developing nations.

Power and Sample Size Calculations for Testing Linear Combinations of Group Means under Variance Heterogeneity with Applications to Meta and Moderation Analyses

Science.gov (United States)

Shieh, Gwowen; Jan, Show-Li

2015-01-01

The general formulation of a linear combination of population means permits a wide range of research questions to be tested within the context of ANOVA. However, it has been stressed in many research areas that the homogeneous variances assumption is frequently violated. To accommodate the heterogeneity of variance structure, the…

Effect of Combined Use of Calcium and Vitamin B6 on Premenstrual Syndrome Symptoms: a Randomized Clinical Trial

Directory of Open Access Journals (Sweden)

Seyedeh Zahra Masoumi

2016-03-01

Full Text Available Introduction: Premenstrual syndrome is one of the most common disorders in women, which includes a group of psychological and physical symptoms. The aim of this study was to examine the impact of combined use of calcium and vitamin B6 on premenstrual syndrome symptoms. Methods: This double blind randomized controlled was carried out on 76 students of Hamadan University of Medical Sciences. Students were randomly allocated to two groups. (38 people in each group. Student in intervention groups received calcium tablet (500mg and vitamin B6 (40 mg and student in intervention groups received only vitamin B6 twice a day for two consecutive months. The symptoms were assessed by Beck depression inventory (BDI and daily symptom records (DSR questionnaires. Analyses were carried out by test-retest method, Chi-square, Mann-Whitney, Independent t-test, and paired t-test using SPSS software ver.13. Results: The result showed that although the severity of symptoms decreased in both groups, but this reduction was more significant in the combined calcium and vitamin B6 group. Conclusion: According to the result, using of combination of calcium and vitamin B6 leads to better controlling of the premenstrual syndrome symptoms. Therefore it is recommended for women who suffer from these syndromes.

Effect of Linear Low-Intensity Extracorporeal Shockwave Therapy for Erectile Dysfunction-12-Month Follow-Up of a Randomized, Double-Blinded, Sham-Controlled Study.

Science.gov (United States)

Fojecki, Grzegorz Lukasz; Tiessen, Stefan; Osther, Palle Jørn Sloth

2018-03-01

Short-term data on the effect of low-intensity extracorporeal shockwave therapy (Li-ESWT) on erectile dysfunction (ED) have been inconsistent. The suggested mechanisms of action of Li-ESWT on ED include stimulation of cell proliferation, tissue regeneration, and angiogenesis, which can be processes with a long generation time. Therefore, long-term data on the effect of Li-ESWT on ED are strongly warranted. To assess the outcome at 6 and 12 months of linear Li-ESWT on ED from a previously published randomized, double-blinded, sham-controlled trial. Subjects with ED (N = 126) who scored lower than 25 points in the erectile function domain of the International Index of Erectile Function (IIEF-EF) were eligible for the study. They were allocated to 1 of 2 groups: 5 weekly sessions of sham treatment (group A) or linear Li-ESWT (group B). After a 4-week break, the 2 groups received active treatment once a week for 5 weeks. At baseline and 6 and 12 months, subjects were evaluated by the IIEF-EF, the Erectile Hardness Scale (EHS), and the Sexual Quality of Life in Men. The primary outcome measure was an increase of at least 5 points in the IIEF-EF (ΔIIEF-EF score). The secondary outcome measure was an increase in the EHS score to at least 3 in men with a score no higher than 2 at baseline. Data were analyzed by linear and logistic regressions. Linear regression of the ΔIIEF-EF score from baseline to 12 months included 95 patients (dropout rate = 25%). Adjusted for the IIEF-EF score at baseline, the difference between groups B and A was -1.30 (95% CI = -4.37 to 1.77, P = .4). The success rate based on the main outcome parameter (ΔIIEF-EF score ≥ 5) was 54% in group A vs 47% in group B (odds ratio = 0.67, P = .28). Improvement based on changes in the EHS score in groups A and B was 34% and 24%, respectively (odds ratio = 0.47, P = .82). Exposure to 2 cycles of linear Li-ESWT for ED is not superior to 1 cycle at 6- and 12-month follow-ups. Fojecki GL, Tiessen S

Random Decrement

DEFF Research Database (Denmark)

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

This paper demonstrates how to use the Random Decrement (RD) technique for identification of linear structures subjected to ambient excitation. The theory behind the technique will be presented and guidelines how to choose the different variables will be given. This is done by introducing a new...

Random Decrement

DEFF Research Database (Denmark)

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

1998-01-01

This paper demonstrates how to use the Random Decrement (RD) technique for identification of linear structures subjected to ambient excitation. The theory behind the technique will be presented and guidelines how to choose the different variables will be given. This is done by introducing a new...

The study of combining Latin Hypercube Sampling method and LU decomposition method (LULHS method) for constructing spatial random field

Science.gov (United States)

WANG, P. T.

2015-12-01

Groundwater modeling requires to assign hydrogeological properties to every numerical grid. Due to the lack of detailed information and the inherent spatial heterogeneity, geological properties can be treated as random variables. Hydrogeological property is assumed to be a multivariate distribution with spatial correlations. By sampling random numbers from a given statistical distribution and assigning a value to each grid, a random field for modeling can be completed. Therefore, statistics sampling plays an important role in the efficiency of modeling procedure. Latin Hypercube Sampling (LHS) is a stratified random sampling procedure that provides an efficient way to sample variables from their multivariate distributions. This study combines the the stratified random procedure from LHS and the simulation by using LU decomposition to form LULHS. Both conditional and unconditional simulations of LULHS were develpoed. The simulation efficiency and spatial correlation of LULHS are compared to the other three different simulation methods. The results show that for the conditional simulation and unconditional simulation, LULHS method is more efficient in terms of computational effort. Less realizations are required to achieve the required statistical accuracy and spatial correlation.

Dynamic Output Feedback Control for Nonlinear Networked Control Systems with Random Packet Dropout and Random Delay

Directory of Open Access Journals (Sweden)

Shuiqing Yu

2013-01-01

Full Text Available This paper investigates the dynamic output feedback control for nonlinear networked control systems with both random packet dropout and random delay. Random packet dropout and random delay are modeled as two independent random variables. An observer-based dynamic output feedback controller is designed based upon the Lyapunov theory. The quantitative relationship of the dropout rate, transition probability matrix, and nonlinear level is derived by solving a set of linear matrix inequalities. Finally, an example is presented to illustrate the effectiveness of the proposed method.

Enhancement of loss detection capability using a combination of the Kalman Filter/Linear Smoother and controllable unit accounting approach

International Nuclear Information System (INIS)

Pike, D.H.; Morrison, G.W.

1979-01-01

An approach to loss detection is presented which combines the optimal loss detection capability of state estimation techniques with a controllable unit accounting approach. The state estimation theory makes use of a linear system model which is capable of modeling the interaction of various controllable unit areas within a given facility. An example is presented which illustrates the increase in loss detection probability which is realizable with state estimation techniques. Comparisons are made with a Shewhart Control Chart and the CUSUM statistic

Non-Linear Dynamics of Saturn's Rings

Science.gov (United States)

Esposito, L. W.

2016-12-01

Non-linear processes can explain why Saturn's rings are so active and dynamic. Ring systems differ from simple linear systems in two significant ways: 1. They are systems of granular material: where particle-to-particle collisions dominate; thus a kinetic, not a fluid description needed. Stresses are strikingly inhomogeneous and fluctuations are large compared to equilibrium. 2. They are strongly forced by resonances: which drive a non-linear response, that push the system across thresholds that lead to persistent states. Some of this non-linearity is captured in a simple Predator-Prey Model: Periodic forcing from the moon causes streamline crowding; This damps the relative velocity. About a quarter phase later, the aggregates stir the system to higher relative velocity and the limit cycle repeats each orbit, with relative velocity ranging from nearly zero to a multiple of the orbit average. Summary of Halo Results: A predator-prey model for ring dynamics produces transient structures like `straw' that can explain the halo morphology and spectroscopy: Cyclic velocity changes cause perturbed regions to reach higher collision speeds at some orbital phases, which preferentially removes small regolith particles; surrounding particles diffuse back too slowly to erase the effect: this gives the halo morphology; this requires energetic collisions (v ≈ 10m/sec, with throw distances about 200km, implying objects of scale R ≈ 20km).Transform to Duffing Eqn : With the coordinate transformation, z = M2/3, the Predator-Prey equations can be combined to form a single second-order differential equation with harmonic resonance forcing.Ring dynamics and history implications: Moon-triggered clumping explains both small and large particles at resonances. We calculate the stationary size distribution using a cell-to-cell mapping procedure that converts the phase-plane trajectories to a Markov chain. Approximating it as an asymmetric random walk with reflecting boundaries

Combining support vector machines with linear quadratic regulator adaptation for the online design of an automotive active suspension system

International Nuclear Information System (INIS)

Chiou, J-S; Liu, M-T

2008-01-01

As a powerful machine-learning approach to pattern recognition problems, the support vector machine (SVM) is known to easily allow generalization. More importantly, it works very well in a high-dimensional feature space. This paper presents a nonlinear active suspension controller which achieves a high level performance by compensating for actuator dynamics. We use a linear quadratic regulator (LQR) to ensure optimal control of nonlinear systems. An LQR is used to solve the problem of state feedback and an SVM is used to address the question of the estimation and examination of the state. These two are then combined and designed in a way that outputs feedback control. The real-time simulation demonstrates that an active suspension using the combined SVM-LQR controller provides passengers with a much more comfortable ride and better road handling

Laparoscopic Surgical Treatment of Severe Obesity Combined with Gastroesophageal Reflux Disease: A Pilot Randomized Two-Arm Controlled Clinical Study

Science.gov (United States)

Ospanov, Oral B.; Orekeshova, Akzhunis M.; Fursov, Roman A.; Yelemesov, Aset A.

2016-01-01

Obesity and gastroesophageal reflux disease (GERD) are serious medical, social, and economic problems of modern society. A pilot randomized two-arm controlled clinical study was conducted to compare laparoscopic plication of the greater gastric curvature combined with Nissen fundoplication (LFN+LGP) versus only Nissen fundoplication (LFN). The…

Lactobacillus reuteri strain combination in Helicobacter pylori infection: a randomized, double-blind, placebo-controlled study.

Science.gov (United States)

Francavilla, Ruggiero; Polimeno, Lorenzo; Demichina, Antonella; Maurogiovanni, Giovanni; Principi, Beatrice; Scaccianoce, Giuseppe; Ierardi, Enzo; Russo, Francesco; Riezzo, Giuseppe; Di Leo, Alfredo; Cavallo, Luciano; Francavilla, Antonio; Versalovic, James

2014-01-01

The goals of this study were to investigate the role of a new probiotic preparation (Lactobacillus reuteri DSM 17938 and L. reuteri ATCC PTA 6475) in Helicobacter pylori infection. Specific probiotic strains play a role in H. pylori infection for their ability to decrease bacterial load and gastritis, prevent antibiotic-associated side effects, and increase the eradication rate. This is a prospective, double-blind, randomized, placebo-controlled study in a tertiary care setting. A total of 100 H. pylori-positive naive patients received either L. reuteri combination (2×10 Colony Forming Units) or placebo during a 3-phase study (pre-eradication, eradication, and follow-up). All underwent C urea breath test (C-UBT), blood assessments of gastrin-17 (G17), endoscopy, and the Gastrointestinal Symptom Rating Scale. Eradication was confirmed by C-UBT 8 weeks after the completion of therapy. Fifty patients were allocated in each group. During pre-eradication period, C-UBT δ decreased by 13% in L. reuteri combination as compared with a 4% increase in placebo (-13.2±34% vs. 4.3±27%; Preuteri combination (6.8±2.9 vs. 4±3.1; Preuteri combination as compared with placebo-reported side effects (40.9% vs. 62.8%; Preuteri combination (28% vs. 12%; Preuteri combination and 65.9% in placebo (P=NS). L. reuteri combination increased eradication rate by 9.1% (odds ratio: 1.5). L. reuteri combination alone is able to exert an inhibitory effect on H. pylori growth, and when administered with eradication therapy, it determines a significant reduction in antibiotic-associated side effects. Moreover, L. reuteri combination was able to decrease serum G17 levels and to (not significantly) increase the H. pylori-eradication rate.

Jianpi Bushen, a Traditional Chinese Medicine Therapy, Combined with Chemotherapy for Gastric Cancer Treatment: A Meta-Analysis of Randomized Controlled Trials

Science.gov (United States)

Chen, Yunbo; Zhang, Guijuan; Chen, Xiaoping; Jiang, Xuefeng; Yuan, Naijun; Wang, Yurong; Hao, Xiaoqian

2018-01-01

Objective. To investigate the effects of Jianpi Bushen (JPBS), a traditional Chinese medicine that is used to invigorate the spleen and tonify the kidney, combined with chemotherapy for the treatment of gastric cancer. Methods. Literature retrieval was performed in PubMed, EMBASE, Cochrane Library, MEDLINE, CNKI, Wanfang Data Information Site, and VIP from inception to October 2017. Randomized controlled trials to evaluate the effects of JPBS combined with chemotherapy were identified. The primary reported outcomes were KPS (Karnofsky Performance Status), clinical curative efficiency, immune function, blood system, and nonhematologic system. Review Manager 5.3 (RevMan 5.3) was used for data analysis, and the quality of the studies was also appraised. Results. A total of 26 studies were included with 3098 individuals. The results of the meta-analysis indicated that treatment of gastric cancer with the combination of JPBS and chemotherapy resulted in better outcomes compared to chemotherapy alone. Conclusion. Evidence from the meta-analysis suggested that JPBS combined with chemotherapy has a positive effect on gastric cancer treatment. However, additional rigorously designed and large sample randomized controlled trials are required to confirm the efficacy and safety of this treatment. PMID:29675052

The average inter-crossing number of equilateral random walks and polygons

International Nuclear Information System (INIS)

Diao, Y; Dobay, A; Stasiak, A

2005-01-01

In this paper, we study the average inter-crossing number between two random walks and two random polygons in the three-dimensional space. The random walks and polygons in this paper are the so-called equilateral random walks and polygons in which each segment of the walk or polygon is of unit length. We show that the mean average inter-crossing number ICN between two equilateral random walks of the same length n is approximately linear in terms of n and we were able to determine the prefactor of the linear term, which is a = 3ln2/8 ∼ 0.2599. In the case of two random polygons of length n, the mean average inter-crossing number ICN is also linear, but the prefactor of the linear term is different from that of the random walks. These approximations apply when the starting points of the random walks and polygons are of a distance ρ apart and ρ is small compared to n. We propose a fitting model that would capture the theoretical asymptotic behaviour of the mean average ICN for large values of ρ. Our simulation result shows that the model in fact works very well for the entire range of ρ. We also study the mean ICN between two equilateral random walks and polygons of different lengths. An interesting result is that even if one random walk (polygon) has a fixed length, the mean average ICN between the two random walks (polygons) would still approach infinity if the length of the other random walk (polygon) approached infinity. The data provided by our simulations match our theoretical predictions very well

Regularized iterative integration combined with non-linear diffusion filtering for phase-contrast x-ray computed tomography.

Science.gov (United States)

Burger, Karin; Koehler, Thomas; Chabior, Michael; Allner, Sebastian; Marschner, Mathias; Fehringer, Andreas; Willner, Marian; Pfeiffer, Franz; Noël, Peter

2014-12-29

Phase-contrast x-ray computed tomography has a high potential to become clinically implemented because of its complementarity to conventional absorption-contrast.In this study, we investigate noise-reducing but resolution-preserving analytical reconstruction methods to improve differential phase-contrast imaging. We apply the non-linear Perona-Malik filter on phase-contrast data prior or post filtered backprojected reconstruction. Secondly, the Hilbert kernel is replaced by regularized iterative integration followed by ramp filtered backprojection as used for absorption-contrast imaging. Combining the Perona-Malik filter with this integration algorithm allows to successfully reveal relevant sample features, quantitatively confirmed by significantly increased structural similarity indices and contrast-to-noise ratios. With this concept, phase-contrast imaging can be performed at considerably lower dose.

Information content versus word length in random typing

International Nuclear Information System (INIS)

Ferrer-i-Cancho, Ramon; Moscoso del Prado Martín, Fermín

2011-01-01

Recently, it has been claimed that a linear relationship between a measure of information content and word length is expected from word length optimization and it has been shown that this linearity is supported by a strong correlation between information content and word length in many languages (Piantadosi et al 2011 Proc. Nat. Acad. Sci. 108 3825). Here, we study in detail some connections between this measure and standard information theory. The relationship between the measure and word length is studied for the popular random typing process where a text is constructed by pressing keys at random from a keyboard containing letters and a space behaving as a word delimiter. Although this random process does not optimize word lengths according to information content, it exhibits a linear relationship between information content and word length. The exact slope and intercept are presented for three major variants of the random typing process. A strong correlation between information content and word length can simply arise from the units making a word (e.g., letters) and not necessarily from the interplay between a word and its context as proposed by Piantadosi and co-workers. In itself, the linear relation does not entail the results of any optimization process. (letter)

Linear and Nonlinear Rheology Combined with Dielectric Spectroscopy of Hybrid Polymer Nanocomposites for Semiconductive Applications

Science.gov (United States)

Kádár, Roland; Abbasi, Mahdi; Figuli, Roxana; Rigdahl, Mikael; Wilhelm, Manfred

2017-01-01

The linear and nonlinear oscillatory shear, extensional and combined rheology-dielectric spectroscopy of hybrid polymer nanocomposites for semiconductive applications were investigated in this study. The main focus was the influence of processing conditions on percolated poly(ethylene-butyl acrylate) (EBA) nanocomposite hybrids containing graphite nanoplatelets (GnP) and carbon black (CB). The rheological response of the samples was interpreted in terms of dispersion properties, filler distortion from processing, filler percolation, as well as the filler orientation and distribution dynamics inside the matrix. Evidence of the influence of dispersion properties was found in linear viscoelastic dynamic frequency sweeps, while the percolation of the nanocomposites was detected in nonlinearities developed in dynamic strain sweeps. Using extensional rheology, hybrid samples with better dispersion properties lead to a more pronounced strain hardening behavior, while samples with a higher volume percentage of fillers caused a drastic reduction in strain hardening. The rheo-dielectric time-dependent response showed that in the case of nanocomposites containing only GnP, the orientation dynamics leads to non-conductive samples. However, in the case of hybrids, the orientation of the GnP could be offset by the dispersing of the CB to bridge the nanoplatelets. The results were interpreted in the framework of a dual PE-BA model, where the fillers would be concentrated mainly in the BA regions. Furthermore, better dispersed hybrids obtained using mixing screws at the expense of filler distortion via extrusion processing history were emphasized through the rheo-dielectric tests. PMID:28336857

Linear and Nonlinear Rheology Combined with Dielectric Spectroscopy of Hybrid Polymer Nanocomposites for Semiconductive Applications

Directory of Open Access Journals (Sweden)

Roland Kádár

2017-01-01

Full Text Available The linear and nonlinear oscillatory shear, extensional and combined rheology-dielectric spectroscopy of hybrid polymer nanocomposites for semiconductive applications were investigated in this study. The main focus was the influence of processing conditions on percolated poly(ethylene-butyl acrylate (EBA nanocomposite hybrids containing graphite nanoplatelets (GnP and carbon black (CB. The rheological response of the samples was interpreted in terms of dispersion properties, filler distortion from processing, filler percolation, as well as the filler orientation and distribution dynamics inside the matrix. Evidence of the influence of dispersion properties was found in linear viscoelastic dynamic frequency sweeps, while the percolation of the nanocomposites was detected in nonlinearities developed in dynamic strain sweeps. Using extensional rheology, hybrid samples with better dispersion properties lead to a more pronounced strain hardening behavior, while samples with a higher volume percentage of fillers caused a drastic reduction in strain hardening. The rheo-dielectric time-dependent response showed that in the case of nanocomposites containing only GnP, the orientation dynamics leads to non-conductive samples. However, in the case of hybrids, the orientation of the GnP could be offset by the dispersing of the CB to bridge the nanoplatelets. The results were interpreted in the framework of a dual PE-BA model, where the fillers would be concentrated mainly in the BA regions. Furthermore, better dispersed hybrids obtained using mixing screws at the expense of filler distortion via extrusion processing history were emphasized through the rheo-dielectric tests.

An evaluation of the performance of an integrated solar combined cycle plant provided with air-linear parabolic collectors

International Nuclear Information System (INIS)

Amelio, Mario; Ferraro, Vittorio; Marinelli, Valerio; Summaria, Antonio

2014-01-01

An evaluation of the performance of an innovative solar system integrated in a combined cycle plant is presented, in which the heat transfer fluid flowing in linear parabolic collectors is the same oxidant air that is introduced into the combustion chamber of the plant. This peculiarity allows a great simplification of the plant. There is a 22% saving of fossil fuel results in design conditions and 15.5% on an annual basis, when the plant works at nominal volumetric flow rate in the daily hours. The net average year efficiency is 60.9% against the value of 51.4% of a reference combined cycle plant without solar integration. Moreover, an economic evaluation of the plant is carried out, which shows that the extra-cost of the solar part is recovered in about 5 years. - Highlights: • A model to calculate an innovative ISCCS (Integrated solar Combined Cycle Systems) solar plant is presented. • The plant uses air as heat transfer fluid as well as oxidant in the combustor. • The plant presents a very high thermodynamic efficiency. • The plant is very simple in comparison with existing ISCCS

Simultaneous inference for multilevel linear mixed models - with an application to a large-scale school meal study

DEFF Research Database (Denmark)

Ritz, Christian; Laursen, Rikke Pilmann; Damsgaard, Camilla Trab

2017-01-01

of a school meal programme. We propose a novel and versatile framework for simultaneous inference on parameters estimated from linear mixed models that were fitted separately for several outcomes from the same study, but did not necessarily contain the same fixed or random effects. By combining asymptotic...... sizes of practical relevance we studied simultaneous coverage through simulation, which showed that the approach achieved acceptable coverage probabilities even for small sample sizes (10 clusters) and for 2–16 outcomes. The approach also compared favourably with a joint modelling approach. We also...

SYSTEMATIC SAMPLING FOR NON - LINEAR TREND IN MILK YIELD DATA

OpenAIRE

Tanuj Kumar Pandey; Vinod Kumar

2014-01-01

The present paper utilizes systematic sampling procedures for milk yield data exhibiting some non-linear trends. The best fitted mathematical forms of non-linear trend present in the milk yield data are obtained and the expressions of average variances of the estimators of population mean under simple random, usual systematic and modified systematic sampling procedures have been derived for populations showing non-linear trend. A comparative study is made among the three sampli...

Non-linear multivariate and multiscale monitoring and signal denoising strategy using Kernel Principal Component Analysis combined with Ensemble Empirical Mode Decomposition method

Science.gov (United States)

Žvokelj, Matej; Zupan, Samo; Prebil, Ivan

2011-10-01

The article presents a novel non-linear multivariate and multiscale statistical process monitoring and signal denoising method which combines the strengths of the Kernel Principal Component Analysis (KPCA) non-linear multivariate monitoring approach with the benefits of Ensemble Empirical Mode Decomposition (EEMD) to handle multiscale system dynamics. The proposed method which enables us to cope with complex even severe non-linear systems with a wide dynamic range was named the EEMD-based multiscale KPCA (EEMD-MSKPCA). The method is quite general in nature and could be used in different areas for various tasks even without any really deep understanding of the nature of the system under consideration. Its efficiency was first demonstrated by an illustrative example, after which the applicability for the task of bearing fault detection, diagnosis and signal denosing was tested on simulated as well as actual vibration and acoustic emission (AE) signals measured on purpose-built large-size low-speed bearing test stand. The positive results obtained indicate that the proposed EEMD-MSKPCA method provides a promising tool for tackling non-linear multiscale data which present a convolved picture of many events occupying different regions in the time-frequency plane.

Linear response of mutans streptococci to increasing frequency of xylitol chewing gum use: a randomized controlled trial [ISRCTN43479664

Directory of Open Access Journals (Sweden)

Yamaguchi David K

2006-03-01

Full Text Available Abstract Background Xylitol is a naturally occurring sugar substitute that has been shown to reduce the level of mutans streptococci in plaque and saliva and to reduce tooth decay. It has been suggested that the degree of reduction is dependent on both the amount and the frequency of xylitol consumption. For xylitol to be successfully and cost-effectively used in public health prevention strategies dosing and frequency guidelines should be established. This study determined the reduction in mutans streptococci levels in plaque and unstimulated saliva to increasing frequency of xylitol gum use at a fixed total daily dose of 10.32 g over five weeks. Methods Participants (n = 132 were randomized to either active groups (10.32 g xylitol/day or a placebo control (9.828 g sorbitol and 0.7 g maltitol/day. All groups chewed 12 pieces of gum per day. The control group chewed 4 times/day and active groups chewed xylitol gum at a frequency of 2 times/day, 3 times/day, or 4 times/day. The 12 gum pieces were evenly divided into the frequency assigned to each group. Plaque and unstimulated saliva samples were taken at baseline and five-weeks and were cultured on modified Mitis Salivarius agar for mutans streptococci enumeration. Results There were no significant differences in mutans streptococci level among the groups at baseline. At five-weeks, mutans streptococci levels in plaque and unstimulated saliva showed a linear reduction with increasing frequency of xylitol chewing gum use at the constant daily dose. Although the difference observed for the group that chewed xylitol 2 times/day was consistent with the linear model, the difference was not significant. Conclusion There was a linear reduction in mutans streptococci levels in plaque and saliva with increasing frequency of xylitol gum use at a constant daily dose. Reduction at a consumption frequency of 2 times per day was small and consistent with the linear-response line but was not statistically

Non-linearity consideration when analyzing reactor noise statistical characteristics. [BWR

Energy Technology Data Exchange (ETDEWEB)

Kebadze, B V; Adamovski, L A

1975-06-01

Statistical characteristics of boiling water reactor noise in the vicinity of stability threshold are studied. The reactor is considered as a non-linear system affected by random perturbations. To solve a non-linear problem the principle of statistical linearization is used. It is shown that the halfwidth of resonance peak in neutron power noise spectrum density as well as the reciprocal of noise dispersion, which are used in predicting a stable operation theshold, are different from zero both within and beyond the stability boundary the determination of which was based on linear criteria.

Analysis of random response of structure with uncertain parameters. Combination of substructure synthesis method and hierarchy method

International Nuclear Information System (INIS)

Iwatsubo, Takuzo; Kawamura, Shozo; Mori, Hiroyuki.

1995-01-01

In this paper, the method to obtain the random response of a structure with uncertain parameters is proposed. The proposed method is a combination of the substructure synthesis method and the hierarchy method. The concept of the proposed method is that the hierarchy equation of each substructure is obtained using the hierarchy method, and the hierarchy equation of the overall structure is obtained using the substructure synthesis method. Using the proposed method, the reduced order hierarchy equation can be obtained without analyzing the original whole structure. After the calculation of the mean square value of response, the reliability analysis can be carried out based on the first passage problem and Poisson's excursion rate. As a numerical example of structure, a simple piping system is considered. The damping constant of the support is considered as the uncertainty parameter. Then the random response is calculated using the proposed method. As a result, the proposed method is useful to analyze the random response in terms of the accuracy, computer storage and calculation time. (author)

The reliability of linear position transducer, force plate and combined measurement of explosive power-time variables during a loaded jump squat in elite athletes.

Science.gov (United States)

Hansen, Keir T; Cronin, John B; Newton, Michael J

2011-03-01

The purpose of this study was to determine the between day reliability of power-time measures calculated with data collected using the linear position transducer or the force plate independently, or a combination of the two technologies. Twenty-five male rugby union players performed three jump squats on two occasions one week apart. Ground reaction forces were measured via a force plate and position data were collected using a linear position transducer. From these data, a number of power-time variables were calculated for each method. The force plate, linear position transducer and a combined method were all found to be a reliable means of measuring peak power (ICC = 0.87-0.95, CV = 3.4%-8.0%). The absolute consistency of power-time measures varied between methods (CV = 8.0%-53.4%). Relative consistency of power-time measures was generally comparable between methods and measures, and for many variables was at an acceptable level (ICC = 0.77-0.94). Although a number of time-dependent power variables can be reliably calculated from data acquired from the three methods investigated, the reliability of a number of these measures is below that which is acceptable for use in research and for practical applications.

An Efficient Test for Gene-Environment Interaction in Generalized Linear Mixed Models with Family Data.

Science.gov (United States)

Mazo Lopera, Mauricio A; Coombes, Brandon J; de Andrade, Mariza

2017-09-27

Gene-environment (GE) interaction has important implications in the etiology of complex diseases that are caused by a combination of genetic factors and environment variables. Several authors have developed GE analysis in the context of independent subjects or longitudinal data using a gene-set. In this paper, we propose to analyze GE interaction for discrete and continuous phenotypes in family studies by incorporating the relatedness among the relatives for each family into a generalized linear mixed model (GLMM) and by using a gene-based variance component test. In addition, we deal with collinearity problems arising from linkage disequilibrium among single nucleotide polymorphisms (SNPs) by considering their coefficients as random effects under the null model estimation. We show that the best linear unbiased predictor (BLUP) of such random effects in the GLMM is equivalent to the ridge regression estimator. This equivalence provides a simple method to estimate the ridge penalty parameter in comparison to other computationally-demanding estimation approaches based on cross-validation schemes. We evaluated the proposed test using simulation studies and applied it to real data from the Baependi Heart Study consisting of 76 families. Using our approach, we identified an interaction between BMI and the Peroxisome Proliferator Activated Receptor Gamma ( PPARG ) gene associated with diabetes.

[Effects of granisetron/lidocaine combination on propofol injection-induced pain: a double-blind randomized clinical trial].

Science.gov (United States)

Ma, Yu-shan; Lin, Xue-mei; Zhou, Jun

2009-05-01

To investigate the alleviation effect of vein pretreatment and granisetron/lidocaine combination on propofol injection-induced pain. Two hundreds patients scheduled for gynaecological laparoscopic operations were randomly divided into four groups: control group (group I), lidocaine group (group II), granisetron group (group III) and granisetron/lidocaine combination group (group IV), with 50 patients in each group. The patients in the above four groups received placebo (saline), lidocaine 20 mg, granisetron 2 mg and granisetron 2 mg plus lidocaine intravenously respectively. The patients were injected with one-forth of scheduled propofol via a dorsal hand vein after one minute of venous occlusion. The pain during the injection of propofol was evaluated. Pain occurred in 84% of patients in the control group, 46% in the lidocaine group, 52% in the granisetron group and 24% in the granisetron/lidocaine combination group. There was a significant reduction in pain incidence in the three experimental groups compared with the control group (Pgranisetron/lidocaine combination group than in the control group (Pgranisetron/lidocaine may be effective not only in attenuating pains during i.v. injection of propofol, but also in preventing postoperative nausea, vomiting and shivering.

Modelling and Predicting Backstroke Start Performance Using Non-Linear and Linear Models.

Science.gov (United States)

de Jesus, Karla; Ayala, Helon V H; de Jesus, Kelly; Coelho, Leandro Dos S; Medeiros, Alexandre I A; Abraldes, José A; Vaz, Mário A P; Fernandes, Ricardo J; Vilas-Boas, João Paulo

2018-03-01

Our aim was to compare non-linear and linear mathematical model responses for backstroke start performance prediction. Ten swimmers randomly completed eight 15 m backstroke starts with feet over the wedge, four with hands on the highest horizontal and four on the vertical handgrip. Swimmers were videotaped using a dual media camera set-up, with the starts being performed over an instrumented block with four force plates. Artificial neural networks were applied to predict 5 m start time using kinematic and kinetic variables and to determine the accuracy of the mean absolute percentage error. Artificial neural networks predicted start time more robustly than the linear model with respect to changing training to the validation dataset for the vertical handgrip (3.95 ± 1.67 vs. 5.92 ± 3.27%). Artificial neural networks obtained a smaller mean absolute percentage error than the linear model in the horizontal (0.43 ± 0.19 vs. 0.98 ± 0.19%) and vertical handgrip (0.45 ± 0.19 vs. 1.38 ± 0.30%) using all input data. The best artificial neural network validation revealed a smaller mean absolute error than the linear model for the horizontal (0.007 vs. 0.04 s) and vertical handgrip (0.01 vs. 0.03 s). Artificial neural networks should be used for backstroke 5 m start time prediction due to the quite small differences among the elite level performances.

Substituting random forest for multiple linear regression improves binding affinity prediction of scoring functions: Cyscore as a case study.

Science.gov (United States)

Li, Hongjian; Leung, Kwong-Sak; Wong, Man-Hon; Ballester, Pedro J

2014-08-27

State-of-the-art protein-ligand docking methods are generally limited by the traditionally low accuracy of their scoring functions, which are used to predict binding affinity and thus vital for discriminating between active and inactive compounds. Despite intensive research over the years, classical scoring functions have reached a plateau in their predictive performance. These assume a predetermined additive functional form for some sophisticated numerical features, and use standard multivariate linear regression (MLR) on experimental data to derive the coefficients. In this study we show that such a simple functional form is detrimental for the prediction performance of a scoring function, and replacing linear regression by machine learning techniques like random forest (RF) can improve prediction performance. We investigate the conditions of applying RF under various contexts and find that given sufficient training samples RF manages to comprehensively capture the non-linearity between structural features and measured binding affinities. Incorporating more structural features and training with more samples can both boost RF performance. In addition, we analyze the importance of structural features to binding affinity prediction using the RF variable importance tool. Lastly, we use Cyscore, a top performing empirical scoring function, as a baseline for comparison study. Machine-learning scoring functions are fundamentally different from classical scoring functions because the former circumvents the fixed functional form relating structural features with binding affinities. RF, but not MLR, can effectively exploit more structural features and more training samples, leading to higher prediction performance. The future availability of more X-ray crystal structures will further widen the performance gap between RF-based and MLR-based scoring functions. This further stresses the importance of substituting RF for MLR in scoring function development.

Model Selection with the Linear Mixed Model for Longitudinal Data

Science.gov (United States)

Ryoo, Ji Hoon

2011-01-01

Model building or model selection with linear mixed models (LMMs) is complicated by the presence of both fixed effects and random effects. The fixed effects structure and random effects structure are codependent, so selection of one influences the other. Most presentations of LMM in psychology and education are based on a multilevel or…

Quasi-linear score for capturing heterogeneous structure in biomarkers.

Science.gov (United States)

Omae, Katsuhiro; Komori, Osamu; Eguchi, Shinto

2017-06-19

Linear scores are widely used to predict dichotomous outcomes in biomedical studies because of their learnability and understandability. Such approaches, however, cannot be used to elucidate biodiversity when there is heterogeneous structure in target population. Our study was focused on describing intrinsic heterogeneity in predictions. Because heterogeneity can be captured by a clustering method, integrating different information from different clusters should yield better predictions. Accordingly, we developed a quasi-linear score, which effectively combines the linear scores of clustered markers. We extended the linear score to the quasi-linear score by a generalized average form, the Kolmogorov-Nagumo average. We observed that two shrinkage methods worked well: ridge shrinkage for estimating the quasi-linear score, and lasso shrinkage for selecting markers within each cluster. Simulation studies and applications to real data show that the proposed method has good predictive performance compared with existing methods. Heterogeneous structure is captured by a clustering method. Quasi-linear scores combine such heterogeneity and have a better predictive ability compared with linear scores.

Weak randomness in device independent quantum key distribution and the advantage of using high dimensional entanglement

OpenAIRE

Huber, Marcus; Pawlowski, Marcin

2013-01-01

We show that in device independent quantum key distribution protocols the privacy of randomness is of crucial importance. For sublinear test sample sizes even the slightest guessing probability by an eavesdropper will completely compromise security. We show that a combined attack exploiting test sample and measurement choices compromises the security even with a linear size test sample and otherwise device independent security considerations. We explicitly derive the sample size needed to ret...

Lattice Designs in Standard and Simple Implicit Multi-linear Regression

OpenAIRE

Wooten, Rebecca D.

2016-01-01

Statisticians generally use ordinary least squares to minimize the random error in a subject response with respect to independent explanatory variable. However, Wooten shows illustrates how ordinary least squares can be used to minimize the random error in the system without defining a subject response. Using lattice design Wooten shows that non-response analysis is a superior alternative rotation of the pyramidal relationship between random variables and parameter estimates in multi-linear r...

Organization of growing random networks

Energy Technology Data Exchange (ETDEWEB)

Krapivsky, P. L.; Redner, S.

2001-06-01

The organizational development of growing random networks is investigated. These growing networks are built by adding nodes successively, and linking each to an earlier node of degree k with an attachment probability A{sub k}. When A{sub k} grows more slowly than linearly with k, the number of nodes with k links, N{sub k}(t), decays faster than a power law in k, while for A{sub k} growing faster than linearly in k, a single node emerges which connects to nearly all other nodes. When A{sub k} is asymptotically linear, N{sub k}(t){similar_to}tk{sup {minus}{nu}}, with {nu} dependent on details of the attachment probability, but in the range 2{lt}{nu}{lt}{infinity}. The combined age and degree distribution of nodes shows that old nodes typically have a large degree. There is also a significant correlation in the degrees of neighboring nodes, so that nodes of similar degree are more likely to be connected. The size distributions of the in and out components of the network with respect to a given node{emdash}namely, its {open_quotes}descendants{close_quotes} and {open_quotes}ancestors{close_quotes}{emdash}are also determined. The in component exhibits a robust s{sup {minus}2} power-law tail, where s is the component size. The out component has a typical size of order lnt, and it provides basic insights into the genealogy of the network.

Acoustic emission linear pulse holography

Science.gov (United States)

Collins, H.D.; Busse, L.J.; Lemon, D.K.

1983-10-25

This device relates to the concept of and means for performing Acoustic Emission Linear Pulse Holography, which combines the advantages of linear holographic imaging and Acoustic Emission into a single non-destructive inspection system. This unique system produces a chronological, linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. The innovation is the concept of utilizing the crack-generated acoustic emission energy to generate a chronological series of images of a growing crack by applying linear, pulse holographic processing to the acoustic emission data. The process is implemented by placing on a structure an array of piezoelectric sensors (typically 16 or 32 of them) near the defect location. A reference sensor is placed between the defect and the array.

Combined therapy with levothyroxine and liothyronine in two ratios, compared with levothyroxine monotherapy in primary hypothyroidism: a double-blind, randomized, controlled clinical trial

NARCIS (Netherlands)

Appelhof, Bente C.; Fliers, Eric; Wekking, Ellie M.; Schene, Aart H.; Huyser, Jochanan; Tijssen, Jan G. P.; Endert, Erik; van Weert, Henk C. P. M.; Wiersinga, Wilmar M.

2005-01-01

Controversy remains about the value of combined treatment with levothyroxine (LT4) and liothyronine (LT3), compared with LT4 alone in primary hypothyroidism. We compared combined treatment with LT4 and LT3 in a ratio of 5: 1 or 10: 1 with LT4 monotherapy. We conducted a double-blind, randomized,

Tunable random packings

International Nuclear Information System (INIS)

Lumay, G; Vandewalle, N

2007-01-01

We present an experimental protocol that allows one to tune the packing fraction η of a random pile of ferromagnetic spheres from a value close to the lower limit of random loose packing η RLP ≅0.56 to the upper limit of random close packing η RCP ≅0.64. This broad range of packing fraction values is obtained under normal gravity in air, by adjusting a magnetic cohesion between the grains during the formation of the pile. Attractive and repulsive magnetic interactions are found to affect stongly the internal structure and the stability of sphere packing. After the formation of the pile, the induced cohesion is decreased continuously along a linear decreasing ramp. The controlled collapse of the pile is found to generate various and reproducible values of the random packing fraction η

Generalized randomly amplified linear system driven by Gaussian noises: Extreme heavy tail and algebraic correlation decay in plasma turbulence

International Nuclear Information System (INIS)

Steinbrecher, Gyoergy; Weyssow, B.

2004-01-01

The extreme heavy tail and the power-law decay of the turbulent flux correlation observed in hot magnetically confined plasmas are modeled by a system of coupled Langevin equations describing a continuous time linear randomly amplified stochastic process where the amplification factor is driven by a superposition of colored noises which, in a suitable limit, generate a fractional Brownian motion. An exact analytical formula for the power-law tail exponent β is derived. The extremely small value of the heavy tail exponent and the power-law distribution of laminar times also found experimentally are obtained, in a robust manner, for a wide range of input values, as a consequence of the (asymptotic) self-similarity property of the noise spectrum. As a by-product, a new representation of the persistent fractional Brownian motion is obtained

Multivariate covariance generalized linear models

DEFF Research Database (Denmark)

Bonat, W. H.; Jørgensen, Bent

2016-01-01

are fitted by using an efficient Newton scoring algorithm based on quasi-likelihood and Pearson estimating functions, using only second-moment assumptions. This provides a unified approach to a wide variety of types of response variables and covariance structures, including multivariate extensions......We propose a general framework for non-normal multivariate data analysis called multivariate covariance generalized linear models, designed to handle multivariate response variables, along with a wide range of temporal and spatial correlation structures defined in terms of a covariance link...... function combined with a matrix linear predictor involving known matrices. The method is motivated by three data examples that are not easily handled by existing methods. The first example concerns multivariate count data, the second involves response variables of mixed types, combined with repeated...

Conditional Monte Carlo randomization tests for regression models.

Science.gov (United States)

Parhat, Parwen; Rosenberger, William F; Diao, Guoqing

2014-08-15

We discuss the computation of randomization tests for clinical trials of two treatments when the primary outcome is based on a regression model. We begin by revisiting the seminal paper of Gail, Tan, and Piantadosi (1988), and then describe a method based on Monte Carlo generation of randomization sequences. The tests based on this Monte Carlo procedure are design based, in that they incorporate the particular randomization procedure used. We discuss permuted block designs, complete randomization, and biased coin designs. We also use a new technique by Plamadeala and Rosenberger (2012) for simple computation of conditional randomization tests. Like Gail, Tan, and Piantadosi, we focus on residuals from generalized linear models and martingale residuals from survival models. Such techniques do not apply to longitudinal data analysis, and we introduce a method for computation of randomization tests based on the predicted rate of change from a generalized linear mixed model when outcomes are longitudinal. We show, by simulation, that these randomization tests preserve the size and power well under model misspecification. Copyright © 2014 John Wiley & Sons, Ltd.

Testing random number generators for Monte Carlo applications

International Nuclear Information System (INIS)

Sim, L.H.

1992-01-01

Central to any system for modelling radiation transport phenomena using Monte Carlo techniques is the method by which pseudo random numbers are generated. This method is commonly referred to as the Random Number Generator (RNG). It is usually a computer implemented mathematical algorithm which produces a series of numbers uniformly distributed on the interval [0,1]. If this series satisfies certain statistical tests for randomness, then for practical purposes the pseudo random numbers in the series can be considered to be random. Tests of this nature are important not only for new RNGs but also to test the implementation of known RNG algorithms in different computer environments. Six RNGs have been tested using six statistical tests and one visual test. The statistical tests are the moments, frequency (digit and number), serial, gap, and poker tests. The visual test is a simple two dimensional ordered pair display. In addition the RNGs have been tested in a specific Monte Carlo application. This type of test is often overlooked, however it is important that in addition to satisfactory performance in statistical tests, the RNG be able to perform effectively in the applications of interest. The RNGs tested here are based on a variety of algorithms, including multiplicative and linear congruential, lagged Fibonacci, and combination arithmetic and lagged Fibonacci. The effect of the Bays-Durham shuffling algorithm on the output of a known bad RNG has also been investigated. 18 refs., 11 tabs., 4 figs. of

Performance of an Axisymmetric Rocket Based Combined Cycle Engine During Rocket Only Operation Using Linear Regression Analysis

Science.gov (United States)

Smith, Timothy D.; Steffen, Christopher J., Jr.; Yungster, Shaye; Keller, Dennis J.

1998-01-01

The all rocket mode of operation is shown to be a critical factor in the overall performance of a rocket based combined cycle (RBCC) vehicle. An axisymmetric RBCC engine was used to determine specific impulse efficiency values based upon both full flow and gas generator configurations. Design of experiments methodology was used to construct a test matrix and multiple linear regression analysis was used to build parametric models. The main parameters investigated in this study were: rocket chamber pressure, rocket exit area ratio, injected secondary flow, mixer-ejector inlet area, mixer-ejector area ratio, and mixer-ejector length-to-inlet diameter ratio. A perfect gas computational fluid dynamics analysis, using both the Spalart-Allmaras and k-omega turbulence models, was performed with the NPARC code to obtain values of vacuum specific impulse. Results from the multiple linear regression analysis showed that for both the full flow and gas generator configurations increasing mixer-ejector area ratio and rocket area ratio increase performance, while increasing mixer-ejector inlet area ratio and mixer-ejector length-to-diameter ratio decrease performance. Increasing injected secondary flow increased performance for the gas generator analysis, but was not statistically significant for the full flow analysis. Chamber pressure was found to be not statistically significant.

Non-Linear Dynamics of Saturn’s Rings

Science.gov (United States)

Esposito, Larry W.

2015-11-01

Non-linear processes can explain why Saturn’s rings are so active and dynamic. Ring systems differ from simple linear systems in two significant ways: 1. They are systems of granular material: where particle-to-particle collisions dominate; thus a kinetic, not a fluid description needed. We find that stresses are strikingly inhomogeneous and fluctuations are large compared to equilibrium. 2. They are strongly forced by resonances: which drive a non-linear response, pushing the system across thresholds that lead to persistent states.Some of this non-linearity is captured in a simple Predator-Prey Model: Periodic forcing from the moon causes streamline crowding; This damps the relative velocity, and allows aggregates to grow. About a quarter phase later, the aggregates stir the system to higher relative velocity and the limit cycle repeats each orbit.Summary of Halo Results: A predator-prey model for ring dynamics produces transient structures like ‘straw’ that can explain the halo structure and spectroscopy: This requires energetic collisions (v ≈ 10m/sec, with throw distances about 200km, implying objects of scale R ≈ 20km).Transform to Duffing Eqn : With the coordinate transformation, z = M2/3, the Predator-Prey equations can be combined to form a single second-order differential equation with harmonic resonance forcing.Ring dynamics and history implications: Moon-triggered clumping at perturbed regions in Saturn’s rings creates both high velocity dispersion and large aggregates at these distances, explaining both small and large particles observed there. We calculate the stationary size distribution using a cell-to-cell mapping procedure that converts the phase-plane trajectories to a Markov chain. Approximating the Markov chain as an asymmetric random walk with reflecting boundaries allows us to determine the power law index from results of numerical simulations in the tidal environment surrounding Saturn. Aggregates can explain many dynamic aspects

Pregabalin and dexamethasone in combination with paracetamol for postoperative pain control after abdominal hysterectomy. A randomized clinical trial

DEFF Research Database (Denmark)

Rasmussen, M L; Dierking, G; Lech, K

2008-01-01

BACKGROUND: Multimodal analgesia may be important for optimal postoperative pain treatment and facilitation of early mobilization and recovery. We investigated the analgesic effect of pregabalin and dexamethasone in combination with paracetamol after abdominal hysterectomy. METHODS: One hundred...... and sixteen patients were randomly assigned to either group A (paracetamol+placebo x 2), group B (paracetamol+pregabalin+placebo) or group C (paracetamol+pregabalin+dexamethasone). According to randomization and preoperatively, patients received paracetamol 1000 mg, pregabalin 300 mg, dexamethasone 8 mg...... or placebo. General anaesthesia was performed. Postoperative pain treatment was paracetamol 1000 mg x 4 and patient-controlled intravenous morphine, 2.5 mg bolus. Nausea was treated with ondansetron. Morphine consumption, pain score (visual analogue scale) at rest and during mobilization, nausea, sedation...

Subexponential lower bounds for randomized pivoting rules for the simplex algorithm

DEFF Research Database (Denmark)

Friedmann, Oliver; Hansen, Thomas Dueholm; Zwick, Uri

2011-01-01

The simplex algorithm is among the most widely used algorithms for solving linear programs in practice. With essentially all deterministic pivoting rules it is known, however, to require an exponential number of steps to solve some linear programs. No non-polynomial lower bounds were known, prior...... to this work, for randomized pivoting rules. We provide the first subexponential (i.e., of the form 2Ω(nα), for some α>0) lower bounds for the two most natural, and most studied, randomized pivoting rules suggested to date. The first randomized pivoting rule considered is Random-Edge, which among all improving...... pivoting steps (or edges) from the current basic feasible solution (or vertex) chooses one uniformly at random. The second randomized pivoting rule considered is Random-Facet, a more complicated randomized pivoting rule suggested by Kalai and by Matousek, Sharir and Welzl. Our lower bound for the Random...

Visuo-manual tracking: does intermittent control with aperiodic sampling explain linear power and non-linear remnant without sensorimotor noise?

Science.gov (United States)

Gollee, Henrik; Gawthrop, Peter J; Lakie, Martin; Loram, Ian D

2017-11-01

A human controlling an external system is described most easily and conventionally as linearly and continuously translating sensory input to motor output, with the inevitable output remnant, non-linearly related to the input, attributed to sensorimotor noise. Recent experiments show sustained manual tracking involves repeated refractoriness (insensitivity to sensory information for a certain duration), with the temporary 200-500 ms periods of irresponsiveness to sensory input making the control process intrinsically non-linear. This evidence calls for re-examination of the extent to which random sensorimotor noise is required to explain the non-linear remnant. This investigation of manual tracking shows how the full motor output (linear component and remnant) can be explained mechanistically by aperiodic sampling triggered by prediction error thresholds. Whereas broadband physiological noise is general to all processes, aperiodic sampling is associated with sensorimotor decision making within specific frontal, striatal and parietal networks; we conclude that manual tracking utilises such slow serial decision making pathways up to several times per second. The human operator is described adequately by linear translation of sensory input to motor output. Motor output also always includes a non-linear remnant resulting from random sensorimotor noise from multiple sources, and non-linear input transformations, for example thresholds or refractory periods. Recent evidence showed that manual tracking incurs substantial, serial, refractoriness (insensitivity to sensory information of 350 and 550 ms for 1st and 2nd order systems respectively). Our two questions are: (i) What are the comparative merits of explaining the non-linear remnant using noise or non-linear transformations? (ii) Can non-linear transformations represent serial motor decision making within the sensorimotor feedback loop intrinsic to tracking? Twelve participants (instructed to act in three prescribed

Simultaneous and Sequential MS/MS Scan Combinations and Permutations in a Linear Quadrupole Ion Trap.

Science.gov (United States)

Snyder, Dalton T; Szalwinski, Lucas J; Cooks, R Graham

2017-10-17

Methods of performing precursor ion scans as well as neutral loss scans in a single linear quadrupole ion trap have recently been described. In this paper we report methodology for performing permutations of MS/MS scan modes, that is, ordered combinations of precursor, product, and neutral loss scans following a single ion injection event. Only particular permutations are allowed; the sequences demonstrated here are (1) multiple precursor ion scans, (2) precursor ion scans followed by a single neutral loss scan, (3) precursor ion scans followed by product ion scans, and (4) segmented neutral loss scans. (5) The common product ion scan can be performed earlier in these sequences, under certain conditions. Simultaneous scans can also be performed. These include multiple precursor ion scans, precursor ion scans with an accompanying neutral loss scan, and multiple neutral loss scans. We argue that the new capability to perform complex simultaneous and sequential MS n operations on single ion populations represents a significant step in increasing the selectivity of mass spectrometry.

Linear superposition solutions to nonlinear wave equations

International Nuclear Information System (INIS)

Liu Yu

2012-01-01

The solutions to a linear wave equation can satisfy the principle of superposition, i.e., the linear superposition of two or more known solutions is still a solution of the linear wave equation. We show in this article that many nonlinear wave equations possess exact traveling wave solutions involving hyperbolic, triangle, and exponential functions, and the suitable linear combinations of these known solutions can also constitute linear superposition solutions to some nonlinear wave equations with special structural characteristics. The linear superposition solutions to the generalized KdV equation K(2,2,1), the Oliver water wave equation, and the k(n, n) equation are given. The structure characteristic of the nonlinear wave equations having linear superposition solutions is analyzed, and the reason why the solutions with the forms of hyperbolic, triangle, and exponential functions can form the linear superposition solutions is also discussed

Downscaling of surface moisture flux and precipitation in the Ebro Valley (Spain using analogues and analogues followed by random forests and multiple linear regression

Directory of Open Access Journals (Sweden)

G. Ibarra-Berastegi

2011-06-01

Full Text Available In this paper, reanalysis fields from the ECMWF have been statistically downscaled to predict from large-scale atmospheric fields, surface moisture flux and daily precipitation at two observatories (Zaragoza and Tortosa, Ebro Valley, Spain during the 1961–2001 period. Three types of downscaling models have been built: (i analogues, (ii analogues followed by random forests and (iii analogues followed by multiple linear regression. The inputs consist of data (predictor fields taken from the ERA-40 reanalysis. The predicted fields are precipitation and surface moisture flux as measured at the two observatories. With the aim to reduce the dimensionality of the problem, the ERA-40 fields have been decomposed using empirical orthogonal functions. Available daily data has been divided into two parts: a training period used to find a group of about 300 analogues to build the downscaling model (1961–1996 and a test period (1997–2001, where models' performance has been assessed using independent data. In the case of surface moisture flux, the models based on analogues followed by random forests do not clearly outperform those built on analogues plus multiple linear regression, while simple averages calculated from the nearest analogues found in the training period, yielded only slightly worse results. In the case of precipitation, the three types of model performed equally. These results suggest that most of the models' downscaling capabilities can be attributed to the analogues-calculation stage.

Combination therapy versus gemcitabine monotherapy in the treatment of elderly pancreatic cancer: a meta-analysis of randomized controlled trials

Directory of Open Access Journals (Sweden)

Jin JM

2018-03-01

Full Text Available Jiamin Jin, Chunbo Teng, Tao Li College of Life Science, Northeast Forestry University, Harbin, China Purpose: We aimed to compare the efficacy of combination therapy versus gemcitabine monotherapy in the treatment of elderly pancreatic cancer (PC by using a meta-analysis.Materials and methods: Databases were searched to identify relevant clinical trials. Hazard ratios (HRs were used to estimate overall survival (OS and progression-free survival (PFS. Statistical analyses were conducted by using Comprehensive Meta Analysis software (version 2.0.Results: A total of 3,401 elderly PC patients from six randomized controlled trials were included for analysis. In comparison with gemcitabine alone, combination therapy in elderly PC patients did not significantly improve OS (HR 0.93, 95% CI: 0.82–1.06, p=0.29. Sub-group analysis according to treatment regimens showed that combined chemotherapy significantly improved OS in comparison with gemcitabine alone (HR 0.73, 95% CI: 0.56–0.94, p=0.016, while gemcitabine plus targeted agents did not improve OS (HR 1.02, 95% CI: 0.87–1.19, p=0.83. Additionally, gemcitabine plus nab-paclitaxel significantly improved PFS in elderly PC patients (HR 0.69, 95% CI: 0.52–0.91, p=0.009 in comparison with gemcitabine alone. No publication bias was detected by Begg’s and Egger’s tests for OS.Conclusion: The findings of this study suggest that combined chemotherapy, but not for gemcitabine plus targeted agents, could be recommended for elderly PC patients due to its survival benefits. Further studies are still needed to assess the treatment tolerance of combination chemotherapy in these patient populations. Keywords: pancreatic cancer, elderly, randomized controlled trials, meta-analysis, targeted agents

Solid phase microextraction of diclofenac using molecularly imprinted polymer sorbent in hollow fiber combined with fiber optic-linear array spectrophotometry

Science.gov (United States)

Pebdani, Arezou Amiri; Shabani, Ali Mohammad Haji; Dadfarnia, Shayessteh; Khodadoust, Saeid

2015-08-01

A simple solid phase microextraction method based on molecularly imprinted polymer sorbent in the hollow fiber (MIP-HF-SPME) combined with fiber optic-linear array spectrophotometer has been applied for the extraction and determination of diclofenac in environmental and biological samples. The effects of different parameters such as pH, times of extraction, type and volume of the organic solvent, stirring rate and donor phase volume on the extraction efficiency of the diclofenac were investigated and optimized. Under the optimal conditions, the calibration graph was linear (r2 = 0.998) in the range of 3.0-85.0 μg L-1 with a detection limit of 0.7 μg L-1 for preconcentration of 25.0 mL of the sample and the relative standard deviation (n = 6) less than 5%. This method was applied successfully for the extraction and determination of diclofenac in different matrices (water, urine and plasma) and accuracy was examined through the recovery experiments.

Frequency characteristics of coordinate sequences of linear recurrences over Galois rings

Science.gov (United States)

Kamlovskii, O. V.

2013-12-01

We consider some properties of the coordinate sequences of linear recurrences over Galois rings which characterize the possibility of regarding them as pseudo-random sequences. We study the periodicity properties, linear complexity and frequency characteristics of these sequences. Up to now, these parameters have been studied mainly in the case when the linear recurring sequence has maximal possible period. We investigate the coordinate sequences of linear recurrences of not necessarily maximal period. We obtain sharpened and generalized estimates for the number of elements and r-patterns on the cycles and intervals of these sequences.

Frequency characteristics of coordinate sequences of linear recurrences over Galois rings

International Nuclear Information System (INIS)

Certification Research Center, Moscow (Russian Federation))" data-affiliation=" (LLC Certification Research Center, Moscow (Russian Federation))" >Kamlovskii, O V

2013-01-01

We consider some properties of the coordinate sequences of linear recurrences over Galois rings which characterize the possibility of regarding them as pseudo-random sequences. We study the periodicity properties, linear complexity and frequency characteristics of these sequences. Up to now, these parameters have been studied mainly in the case when the linear recurring sequence has maximal possible period. We investigate the coordinate sequences of linear recurrences of not necessarily maximal period. We obtain sharpened and generalized estimates for the number of elements and r-patterns on the cycles and intervals of these sequences

Expressing stochastic unravellings using random evolution operators

International Nuclear Information System (INIS)

Salgado, D; Sanchez-Gomez, J L

2002-01-01

We prove how the form of the most general invariant stochastic unravelling for Markovian (recently given in the literature by Wiseman and Diosi) and non-Markovian but Lindblad-type open quantum systems can be attained by imposing a single mathematical condition upon the random evolution operator of the system, namely a.s. trace preservation (a.s. stands for almost surely). The use of random operators ensures the complete positivity of the density operator evolution and characterizes the linear/non-linear character of the evolution in a straightforward way. It is also shown how three quantum stochastic evolution models - continuous spontaneous localization, quantum state diffusion and quantum mechanics with universal position localization - appear as concrete choices for the noise term of the evolution random operators are assumed. We finally conjecture how these operators may in the future be used in two different directions: both to connect quantum stochastic evolution models with random properties of space-time and to handle noisy quantum logical gates

Linear response theory an analytic-algebraic approach

CERN Document Server

De Nittis, Giuseppe

2017-01-01

This book presents a modern and systematic approach to Linear Response Theory (LRT) by combining analytic and algebraic ideas. LRT is a tool to study systems that are driven out of equilibrium by external perturbations. In particular the reader is provided with a new and robust tool to implement LRT for a wide array of systems. The proposed formalism in fact applies to periodic and random systems in the discrete and the continuum. After a short introduction describing the structure of the book, its aim and motivation, the basic elements of the theory are presented in chapter 2. The mathematical framework of the theory is outlined in chapters 3–5: the relevant von Neumann algebras, noncommutative $L^p$- and Sobolev spaces are introduced; their construction is then made explicit for common physical systems; the notion of isopectral perturbations and the associated dynamics are studied. Chapter 6 is dedicated to the main results, proofs of the Kubo and Kubo-Streda formulas. The book closes with a chapter about...

Effect of Kangaroo care combined with music on the mother–premature neonate attachment: A randomized controlled trial

Directory of Open Access Journals (Sweden)

Maryam Vahdati

2017-01-01

Full Text Available Background: Premature birth may complicate the development and quality of the mother–infant attachment relationship. Music and kangaroo care are two common complementary cares performed in the neonatal intensive care unit (NICU. The present study investigated the effect of kangaroo care combined with music on the mother–premature neonate attachment. Materials and Methods: In this clinical trial, 64 mothers with premature neonates were selected and assigned to the control and study groups through random allocation. In the control group, kangaroo care, and in the study group, kangaroo care combined with music was adopted. The level of mother–premature neonate attachment was measured and compared before and after the intervention in both the groups using Avant's Maternal Attachment Assessment Scale. Results: There was a significant increase in the mean overall score of attachment in the kangaroo care combined with music group (70.72 (11.46 after the intervention compared to the kangaroo care without music group (53.61 (9.76. Conclusions: The mean overall score of mother–neonate attachment in the kangaroo care combined with music group was higher than the kangaroo care group. This difference can be related to the effectiveness of music combined with kangaroo care.

Randomized controlled trial of fish oil and montelukast and their combination on airway inflammation and hyperpnea-induced bronchoconstriction.

Directory of Open Access Journals (Sweden)

Sandra Tecklenburg-Lund

2010-10-01

Full Text Available Both fish oil and montelukast have been shown to reduce the severity of exercise-induced bronchoconstriction (EIB. The purpose of this study was to compare the effects of fish oil and montelukast, alone and in combination, on airway inflammation and bronchoconstriction induced by eucapnic voluntary hyperpnea (EVH in asthmatics.In this model of EIB, twenty asthmatic subjects with documented hyperpnea-induced bronchoconstriction (HIB entered a randomized double-blind trial. All subjects entered on their usual diet (pre-treatment, n = 20 and then were randomly assigned to receive either one active 10 mg montelukast tablet and 10 placebo fish oil capsules (n = 10 or one placebo montelukast tablet and 10 active fish oil capsules totaling 3.2 g EPA and 2.0 g DHA (n = 10 taken daily for 3-wk. Thereafter, all subjects (combination treatment; n = 20 underwent another 3-wk treatment period consisting of a 10 mg active montelukast tablet or 10 active fish oil capsules taken daily.While HIB was significantly inhibited (p0.017 between treatment groups; percent fall in forced expiratory volume in 1-sec was -18.4 ± 2.1%, -9.3±2.8%, -11.6 ± 2.8% and -10.8 ± 1.7% on usual diet (pre-treatment, fish oil, montelukast and combination treatment respectively. All three treatments were associated with a significant reduction (p0.017 in these biomarkers between treatments.While fish oil and montelukast are both effective in attenuating airway inflammation and HIB, combining fish oil with montelukast did not confer a greater protective effect than either intervention alone. Fish oil supplementation should be considered as an alternative treatment for EIB.ClinicalTrials.gov NCT00676468.

Linear combination of auditory steady-state responses evoked by co-modulated tones

DEFF Research Database (Denmark)

Guérit, François; Marozeau, Jeremy; Epp, Bastian

2017-01-01

Up to medium intensities and in the 80–100-Hz region, the auditory steady-state response (ASSR) to a multi-tone carrier is commonly considered to be a linear sum of the dipoles from each tone specific ASSR generator. Here, this hypothesis was investigated when a unique modulation frequency is used...... for all carrier components. Listeners were presented with a co-modulated dual-frequency carrier (1 and 4 kHz), from which the modulator starting phase Ui of the 1-kHz component was systematically varied. The results support the hypothesis of a linear superposition of the dipoles originating from different...

Analytical vs. Simulation Solution Techniques for Pulse Problems in Non-linear Stochastic Dynamics

DEFF Research Database (Denmark)

Iwankiewicz, R.; Nielsen, Søren R. K.

Advantages and disadvantages of available analytical and simulation techniques for pulse problems in non-linear stochastic dynamics are discussed. First, random pulse problems, both those which do and do not lead to Markov theory, are presented. Next, the analytical and analytically-numerical tec......Advantages and disadvantages of available analytical and simulation techniques for pulse problems in non-linear stochastic dynamics are discussed. First, random pulse problems, both those which do and do not lead to Markov theory, are presented. Next, the analytical and analytically...

Electroacupuncture and Rosiglitazone Combined Therapy as a Means of Treating Insulin Resistance and Type 2 Diabetes Mellitus: A Randomized Controlled Trial

Directory of Open Access Journals (Sweden)

Rong-Tsung Lin

2013-01-01

Full Text Available Aims. To evaluate the efficacy of rosiglitazone (TZD and electroacupuncture (EA combined therapy as a treatment for type 2 diabetes mellitus (T2DM patients by randomized single-blind placebo controlled clinical trial. Methods. A total of 31 newly diagnostic T2DM patients, who fulfilled the study's eligibility criteria, were recruited. The individuals were randomly assigned into two groups, the control group (TZD, N=15 and the experimental group (TZD + EA, N=16. Changes in their plasma free fatty acid (FFA, glucose, and insulin levels, together with their homeostasis model assessment (HOMA indices, were statistically compared before and after treatment. Hypoglycemic activity (% was also compared between these two groups. Results. There was no significant difference in hypoglycemic activity between the TZD and TZD + EA group. The effectiveness of the combined therapy seems to derive from an improvement in insulin resistance and a significant lowering of the secreted insulin rather than the effect of TZD alone on T2DM. The combined treatment had no significant adverse effects. A lower plasma FFA concentration is likely to be the mechanism that causes this effect. Conclusion. This combined therapy seems to suppress endogenous insulin secretion by improving insulin resistance via a mechanism involving a reduction in plasma FFA. This trial is registered with ClinicalTrials.gov NCT01577095.

Outcomes of combined cardiovascular risk factor management strategies in type 2 diabetes: the ACCORD randomized trial.

Science.gov (United States)

Margolis, Karen L; O'Connor, Patrick J; Morgan, Timothy M; Buse, John B; Cohen, Robert M; Cushman, William C; Cutler, Jeffrey A; Evans, Gregory W; Gerstein, Hertzel C; Grimm, Richard H; Lipkin, Edward W; Narayan, K M Venkat; Riddle, Matthew C; Sood, Ajay; Goff, David C

2014-06-01

To compare effects of combinations of standard and intensive treatment of glycemia and either blood pressure (BP) or lipids in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial. ACCORD enrolled 10,251 type 2 diabetes patients aged 40-79 years at high risk for cardiovascular disease (CVD) events. Participants were randomly assigned to hemoglobin A1c goals of risk of the primary outcome was lower in the groups intensively treated for glycemia (hazard ratio [HR] 0.67; 95% CI 0.50-0.91), BP (HR 0.74; 95% CI 0.55-1.00), or both (HR 0.71; 95% CI 0.52-0.96) compared with combined standard BP and glycemia treatment. For secondary outcomes, MI was significantly reduced by intensive glycemia treatment and stroke by intensive BP treatment; most other HRs were neutral or favored intensive treatment groups. In the lipid trial, the general pattern of results showed no evidence of benefit of intensive regimens (whether single or combined) compared with combined standard lipid and glycemia treatment. The mortality HR was 1.33 (95% CI 1.02-1.74) in the standard lipid/intensive glycemia group compared with the standard lipid/standard glycemia group. In the ACCORD BP trial, compared with combined standard treatment, intensive BP or intensive glycemia treatment alone improved major CVD outcomes, without additional benefit from combining the two. In the ACCORD lipid trial, neither intensive lipid nor glycemia treatment produced an overall benefit, but intensive glycemia treatment increased mortality. © 2014 by the American Diabetes Association.

Fuzziness and randomness in an optimization framework

International Nuclear Information System (INIS)

Luhandjula, M.K.

1994-03-01

This paper presents a semi-infinite approach for linear programming in the presence of fuzzy random variable coefficients. As a byproduct a way for dealing with optimization problems including both fuzzy and random data is obtained. Numerical examples are provided for the sake of illustration. (author). 13 refs

A Combined Weighting Method Based on Hybrid of Interval Evidence Fusion and Random Sampling

Directory of Open Access Journals (Sweden)

Ying Yan

2017-01-01

Full Text Available Due to the complexity of system and lack of expertise, epistemic uncertainties may present in the experts’ judgment on the importance of certain indices during group decision-making. A novel combination weighting method is proposed to solve the index weighting problem when various uncertainties are present in expert comments. Based on the idea of evidence theory, various types of uncertain evaluation information are uniformly expressed through interval evidence structures. Similarity matrix between interval evidences is constructed, and expert’s information is fused. Comment grades are quantified using the interval number, and cumulative probability function for evaluating the importance of indices is constructed based on the fused information. Finally, index weights are obtained by Monte Carlo random sampling. The method can process expert’s information with varying degrees of uncertainties, which possesses good compatibility. Difficulty in effectively fusing high-conflict group decision-making information and large information loss after fusion is avertible. Original expert judgments are retained rather objectively throughout the processing procedure. Cumulative probability function constructing and random sampling processes do not require any human intervention or judgment. It can be implemented by computer programs easily, thus having an apparent advantage in evaluation practices of fairly huge index systems.

Numerical analysis of non-linear vibrations of a fractionally damped cylindrical shell under the conditions of combinational internal resonance

Directory of Open Access Journals (Sweden)

Rossikhin Yury A.

2018-01-01

Full Text Available Non-linear damped vibrations of a cylindrical shell embedded into a fractional derivative medium are investigated for the case of the combinational internal resonance, resulting in modal interaction, using two different numerical methods with further comparison of the results obtained. The damping properties of the surrounding medium are described by the fractional derivative Kelvin-Voigt model utilizing the Riemann-Liouville fractional derivatives. Within the first method, the generalized displacements of a coupled set of nonlinear ordinary differential equations of the second order are estimated using numerical solution of nonlinear multi-term fractional differential equations by the procedure based on the reduction of the problem to a system of fractional differential equations. According to the second method, the amplitudes and phases of nonlinear vibrations are estimated from the governing nonlinear differential equations describing amplitude-and-phase modulations for the case of the combinational internal resonance. A good agreement in results is declared.

On combining principal components with Fisher's linear discriminants for supervised learning

NARCIS (Netherlands)

Pechenizkiy, M.; Tsymbal, A.; Puuronen, S.

2006-01-01

"The curse of dimensionality" is pertinent to many learning algorithms, and it denotes the drastic increase of computational complexity and classification error in high dimensions. In this paper, principal component analysis (PCA), parametric feature extraction (FE) based on Fisher’s linear

Random effects coefficient of determination for mixed and meta-analysis models.

Science.gov (United States)

Demidenko, Eugene; Sargent, James; Onega, Tracy

2012-01-01

The key feature of a mixed model is the presence of random effects. We have developed a coefficient, called the random effects coefficient of determination, [Formula: see text], that estimates the proportion of the conditional variance of the dependent variable explained by random effects. This coefficient takes values from 0 to 1 and indicates how strong the random effects are. The difference from the earlier suggested fixed effects coefficient of determination is emphasized. If [Formula: see text] is close to 0, there is weak support for random effects in the model because the reduction of the variance of the dependent variable due to random effects is small; consequently, random effects may be ignored and the model simplifies to standard linear regression. The value of [Formula: see text] apart from 0 indicates the evidence of the variance reduction in support of the mixed model. If random effects coefficient of determination is close to 1 the variance of random effects is very large and random effects turn into free fixed effects-the model can be estimated using the dummy variable approach. We derive explicit formulas for [Formula: see text] in three special cases: the random intercept model, the growth curve model, and meta-analysis model. Theoretical results are illustrated with three mixed model examples: (1) travel time to the nearest cancer center for women with breast cancer in the U.S., (2) cumulative time watching alcohol related scenes in movies among young U.S. teens, as a risk factor for early drinking onset, and (3) the classic example of the meta-analysis model for combination of 13 studies on tuberculosis vaccine.

Randomized trial of a combination of natural products (cernitin, saw palmetto, B-sitosterol, vitamin E) on symptoms of benign prostatic hyperplasia (BPH).

Science.gov (United States)

Preuss, H G; Marcusen, C; Regan, J; Klimberg, I W; Welebir, T A; Jones, W A

2001-01-01

Because benign prostatic hyperplasia (BPH) is relatively common, it is important to discover safe and effective means to treat this often debilitating perturbation. Accordingly, we examined the effectiveness of a combination of natural products (cernitin, saw palmetto, B-sitosterol, vitamin E) in treating symptoms of BPH. We undertook a randomized, placebo-controlled, double-blind study. Patients were enrolled from 3 urological practices in the USA. 144 subjects were randomized for study. 17 subjects eventually withdrew, leaving 70 patients in the test group and 57 in the placebo group to complete the study. Inclusion criteria consisted of a diagnosis of BPH, no evidence of cancer, and a maximal urinary flow rate between 5 and 15 ml/second. Patients received either placebo or the combined natural products for 3 months. Evaluations were performed via the American Urological Association (AUA) Symptom Index score, urinary flow rate, PSA measurement, and residual bladder volume. Nocturia showed a markedly significant decrease in severity in patients receiving the combined natural products compared to those taking placebo (p saw palmetto, B-sitosterol, vitamin E) compared to placebo can significantly lessen nocturia and frequency and diminish overall symptomatology of BPH as indicated by an improvement in the total AUA Symptom Index score. The combination of natural products caused no significant adverse side effects.

Outcomes of a pilot hand hygiene randomized cluster trial to reduce communicable infections among US office-based employees.

Science.gov (United States)

Stedman-Smith, Maggie; DuBois, Cathy L Z; Grey, Scott F; Kingsbury, Diana M; Shakya, Sunita; Scofield, Jennifer; Slenkovich, Ken

2015-04-01

To determine the effectiveness of an office-based multimodal hand hygiene improvement intervention in reducing self-reported communicable infections and work-related absence. A randomized cluster trial including an electronic training video, hand sanitizer, and educational posters (n = 131, intervention; n = 193, control). Primary outcomes include (1) self-reported acute respiratory infections (ARIs)/influenza-like illness (ILI) and/or gastrointestinal (GI) infections during the prior 30 days; and (2) related lost work days. Incidence rate ratios calculated using generalized linear mixed models with a Poisson distribution, adjusted for confounders and random cluster effects. A 31% relative reduction in self-reported combined ARI-ILI/GI infections (incidence rate ratio: 0.69; 95% confidence interval, 0.49 to 0.98). A 21% nonsignificant relative reduction in lost work days. An office-based multimodal hand hygiene improvement intervention demonstrated a substantive reduction in self-reported combined ARI-ILI/GI infections.

Paroxetine, Cognitive Therapy or Their Combination in the Treatment of Social Anxiety Disorder with and without Avoidant Personality Disorder: A Randomized Clinical Trial.

Science.gov (United States)

Nordahl, Hans M; Vogel, Patrick A; Morken, Gunnar; Stiles, Tore C; Sandvik, Pål; Wells, Adrian

2016-01-01

The most efficacious treatments for social anxiety disorder (SAD) are the SSRIs and cognitive therapy (CT). Combined treatment is advocated for SAD but has not been evaluated in randomized trials using CT and SSRI. Our aim was to evaluate whether one treatment is more effective than the other and whether combined treatment is more effective than the single treatments. A total of 102 patients were randomly assigned to paroxetine, CT, the combination of CT and paroxetine, or pill placebo. The medication treatment lasted 26 weeks. Of the 102 patients, 54% fulfilled the criteria for an additional diagnosis of avoidant personality disorder. Outcomes were measured at posttreatment and 12-month follow-up assessments. CT was superior to paroxetine alone and to pill placebo at the end of treatment, but it was not superior to the combination treatment. At the 12-month follow-up, the CT group maintained benefits and was significantly better than placebo and paroxetine alone, whereas there were no significant differences among combination treatment, paroxetine alone, and placebo. Recovery rates at 12 months were much higher in the CT group (68%) compared to 40% in the combination group, 24% in the paroxetine group, and 4% in the pill placebo group. CT was the most effective treatment for SAD at both posttreatment and follow-up compared to paroxetine and better than combined treatment at the 12-month follow-up on the Liebowitz Social Anxiety Scale. Combined treatment provided no advantage over single treatments; rather there was less effect of the combined treatment compared to CT alone. © 2016 The Author(s) Published by S. Karger AG, Basel.

Slepian Simulations of Plastic Displacements of Randomly Excited Hysteretic Structures

DEFF Research Database (Denmark)

Lazarov, Boyan Stefanov

2003-01-01

The object of the study is a fast simulation method for generation and analysis of the plastic response of a randomly excited MDOF oscillatro with several potential elements with elasto-plastic constitutive behavior. The oscillator is statically determinate with linear damping. The external...... approximately as a stationary Gaussian process. This requires that the standard deviation of the stationary response is not too large as compared to the plastic yield limits. The Slepian model process for the behavior of the linear response is then simply the conditional mean (linear regression) of the process...... noise excited linear oscillator obtained from the elasto-plastic oscillator by totally removing the plastic domain. Thus the key to the applicability of the method is that the oscillator has a linear domain within which the response stays for a sufficiently long time to make the random response behave...

Multi-index Stochastic Collocation Convergence Rates for Random PDEs with Parametric Regularity

KAUST Repository

Haji Ali, Abdul Lateef; Nobile, Fabio; Tamellini, Lorenzo; Tempone, Raul

2016-01-01

We analyze the recent Multi-index Stochastic Collocation (MISC) method for computing statistics of the solution of a partial differential equation (PDE) with random data, where the random coefficient is parametrized by means of a countable sequence of terms in a suitable expansion. MISC is a combination technique based on mixed differences of spatial approximations and quadratures over the space of random data, and naturally, the error analysis uses the joint regularity of the solution with respect to both the variables in the physical domain and parametric variables. In MISC, the number of problem solutions performed at each discretization level is not determined by balancing the spatial and stochastic components of the error, but rather by suitably extending the knapsack-problem approach employed in the construction of the quasi-optimal sparse-grids and Multi-index Monte Carlo methods, i.e., we use a greedy optimization procedure to select the most effective mixed differences to include in the MISC estimator. We apply our theoretical estimates to a linear elliptic PDE in which the log-diffusion coefficient is modeled as a random field, with a covariance similar to a Matérn model, whose realizations have spatial regularity determined by a scalar parameter. We conduct a complexity analysis based on a summability argument showing algebraic rates of convergence with respect to the overall computational work. The rate of convergence depends on the smoothness parameter, the physical dimensionality and the efficiency of the linear solver. Numerical experiments show the effectiveness of MISC in this infinite dimensional setting compared with the Multi-index Monte Carlo method and compare the convergence rate against the rates predicted in our theoretical analysis. © 2016 SFoCM

Multi-index Stochastic Collocation Convergence Rates for Random PDEs with Parametric Regularity

KAUST Repository

Haji Ali, Abdul Lateef

2016-08-26

We analyze the recent Multi-index Stochastic Collocation (MISC) method for computing statistics of the solution of a partial differential equation (PDE) with random data, where the random coefficient is parametrized by means of a countable sequence of terms in a suitable expansion. MISC is a combination technique based on mixed differences of spatial approximations and quadratures over the space of random data, and naturally, the error analysis uses the joint regularity of the solution with respect to both the variables in the physical domain and parametric variables. In MISC, the number of problem solutions performed at each discretization level is not determined by balancing the spatial and stochastic components of the error, but rather by suitably extending the knapsack-problem approach employed in the construction of the quasi-optimal sparse-grids and Multi-index Monte Carlo methods, i.e., we use a greedy optimization procedure to select the most effective mixed differences to include in the MISC estimator. We apply our theoretical estimates to a linear elliptic PDE in which the log-diffusion coefficient is modeled as a random field, with a covariance similar to a Matérn model, whose realizations have spatial regularity determined by a scalar parameter. We conduct a complexity analysis based on a summability argument showing algebraic rates of convergence with respect to the overall computational work. The rate of convergence depends on the smoothness parameter, the physical dimensionality and the efficiency of the linear solver. Numerical experiments show the effectiveness of MISC in this infinite dimensional setting compared with the Multi-index Monte Carlo method and compare the convergence rate against the rates predicted in our theoretical analysis. © 2016 SFoCM

Development of a sub-nanometer positioning device: combining a new linear motor with linear motion ball guide ways

International Nuclear Information System (INIS)

Otsuka, J; Tanaka, T; Masuda, I

2010-01-01

A new type of linear motor described in this note has some advantages compared with conventional motors. The attractive magnetic force between the stator (permanent magnets) and mover (armature) is diminished almost to zero. The efficiency is better because the magnetic flux leakage is very small, the size of motor is smaller and detent (force ripple) is smaller than for conventional motors. Therefore, we think that this motor is greatly suitable for ultra-precision positioning as an actuator. An ultra-precision positioning device using this motor and linear motion ball guide ways is newly developed by making the device very rigid and using a suitable control method. Moreover, the positioning performance is evaluated by a positioning resolution, and deviation and dispersion errors. As a result of repeated step response tests, the positioning resolution is 0.3 nm, with the deviation error and dispersion error (3σ) being sub-nanometer. Consequently, the positioning device achieves sub-nanometer positioning. (technical design note)

A Comparative Theoretical and Computational Study on Robust Counterpart Optimization: I. Robust Linear Optimization and Robust Mixed Integer Linear Optimization

Science.gov (United States)

Li, Zukui; Ding, Ran; Floudas, Christodoulos A.

2011-01-01

Robust counterpart optimization techniques for linear optimization and mixed integer linear optimization problems are studied in this paper. Different uncertainty sets, including those studied in literature (i.e., interval set; combined interval and ellipsoidal set; combined interval and polyhedral set) and new ones (i.e., adjustable box; pure ellipsoidal; pure polyhedral; combined interval, ellipsoidal, and polyhedral set) are studied in this work and their geometric relationship is discussed. For uncertainty in the left hand side, right hand side, and objective function of the optimization problems, robust counterpart optimization formulations induced by those different uncertainty sets are derived. Numerical studies are performed to compare the solutions of the robust counterpart optimization models and applications in refinery production planning and batch process scheduling problem are presented. PMID:21935263

Effects of Random Values for Particle Swarm Optimization Algorithm

Directory of Open Access Journals (Sweden)

Hou-Ping Dai

2018-02-01

Full Text Available Particle swarm optimization (PSO algorithm is generally improved by adaptively adjusting the inertia weight or combining with other evolution algorithms. However, in most modified PSO algorithms, the random values are always generated by uniform distribution in the range of [0, 1]. In this study, the random values, which are generated by uniform distribution in the ranges of [0, 1] and [−1, 1], and Gauss distribution with mean 0 and variance 1 ( U [ 0 , 1 ] , U [ − 1 , 1 ] and G ( 0 , 1 , are respectively used in the standard PSO and linear decreasing inertia weight (LDIW PSO algorithms. For comparison, the deterministic PSO algorithm, in which the random values are set as 0.5, is also investigated in this study. Some benchmark functions and the pressure vessel design problem are selected to test these algorithms with different types of random values in three space dimensions (10, 30, and 100. The experimental results show that the standard PSO and LDIW-PSO algorithms with random values generated by U [ − 1 , 1 ] or G ( 0 , 1 are more likely to avoid falling into local optima and quickly obtain the global optima. This is because the large-scale random values can expand the range of particle velocity to make the particle more likely to escape from local optima and obtain the global optima. Although the random values generated by U [ − 1 , 1 ] or G ( 0 , 1 are beneficial to improve the global searching ability, the local searching ability for a low dimensional practical optimization problem may be decreased due to the finite particles.

Efficient decoding of random errors for quantum expander codes

OpenAIRE

Fawzi , Omar; Grospellier , Antoine; Leverrier , Anthony

2017-01-01

We show that quantum expander codes, a constant-rate family of quantum LDPC codes, with the quasi-linear time decoding algorithm of Leverrier, Tillich and Z\\'emor can correct a constant fraction of random errors with very high probability. This is the first construction of a constant-rate quantum LDPC code with an efficient decoding algorithm that can correct a linear number of random errors with a negligible failure probability. Finding codes with these properties is also motivated by Gottes...

Combining linear polarization spectroscopy and the Representative Layer Theory to measure the Beer-Lambert law absorbance of highly scattering materials.

Science.gov (United States)

Gobrecht, Alexia; Bendoula, Ryad; Roger, Jean-Michel; Bellon-Maurel, Véronique

2015-01-01

Visible and Near Infrared (Vis-NIR) Spectroscopy is a powerful non destructive analytical method used to analyze major compounds in bulk materials and products and requiring no sample preparation. It is widely used in routine analysis and also in-line in industries, in-vivo with biomedical applications or in-field for agricultural and environmental applications. However, highly scattering samples subvert Beer-Lambert law's linear relationship between spectral absorbance and the concentrations. Instead of spectral pre-processing, which is commonly used by Vis-NIR spectroscopists to mitigate the scattering effect, we put forward an optical method, based on Polarized Light Spectroscopy to improve the absorbance signal measurement on highly scattering samples. This method selects part of the signal which is less impacted by scattering. The resulted signal is combined in the Absorption/Remission function defined in Dahm's Representative Layer Theory to compute an absorbance signal fulfilling Beer-Lambert's law, i.e. being linearly related to concentration of the chemicals composing the sample. The underpinning theories have been experimentally evaluated on scattering samples in liquid form and in powdered form. The method produced more accurate spectra and the Pearson's coefficient assessing the linearity between the absorbance spectra and the concentration of the added dye improved from 0.94 to 0.99 for liquid samples and 0.84-0.97 for powdered samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Multiobjective Two-Stage Stochastic Programming Problems with Interval Discrete Random Variables

Directory of Open Access Journals (Sweden)

S. K. Barik

2012-01-01

Full Text Available Most of the real-life decision-making problems have more than one conflicting and incommensurable objective functions. In this paper, we present a multiobjective two-stage stochastic linear programming problem considering some parameters of the linear constraints as interval type discrete random variables with known probability distribution. Randomness of the discrete intervals are considered for the model parameters. Further, the concepts of best optimum and worst optimum solution are analyzed in two-stage stochastic programming. To solve the stated problem, first we remove the randomness of the problem and formulate an equivalent deterministic linear programming model with multiobjective interval coefficients. Then the deterministic multiobjective model is solved using weighting method, where we apply the solution procedure of interval linear programming technique. We obtain the upper and lower bound of the objective function as the best and the worst value, respectively. It highlights the possible risk involved in the decision-making tool. A numerical example is presented to demonstrate the proposed solution procedure.

Non-fragile observer design for discrete-time genetic regulatory networks with randomly occurring uncertainties

International Nuclear Information System (INIS)

Banu, L Jarina; Balasubramaniam, P

2015-01-01

This paper investigates the problem of non-fragile observer design for a class of discrete-time genetic regulatory networks (DGRNs) with time-varying delays and randomly occurring uncertainties. A non-fragile observer is designed, for estimating the true concentration of mRNAs and proteins from available measurement outputs. One important feature of the results obtained that are reported here is that the parameter uncertainties are assumed to be random and their probabilities of occurrence are known a priori. On the basis of the Lyapunov–Krasovskii functional approach and using a convex combination technique, a delay-dependent estimation criterion is established for DGRNs in terms of linear matrix inequalities (LMIs) that can be efficiently solved using any available LMI solver. Finally numerical examples are provided to substantiate the theoretical results. (paper)

Recipes for stable linear embeddings from Hilbert spaces to R^m

OpenAIRE

Puy, Gilles; Davies, Michael; Gribonval, Remi

2017-01-01

We consider the problem of constructing a linear map from a Hilbert space H (possibly infinite dimensional) to Rm that satisfies a restricted isometry property (RIP) on an arbitrary signal model, i.e., a subset of H. We present a generic framework that handles a large class of low-dimensional subsets but also unstructured and structured linear maps. We provide a simple recipe to prove that a random linear map satisfies a general RIP with high probability. We also describe a generic technique ...

Recipes for stable linear embeddings from Hilbert spaces to R^m

OpenAIRE

Puy, Gilles; Davies, Mike; Gribonval, Rémi

2015-01-01

We consider the problem of constructing a linear map from a Hilbert space $\\mathcal{H}$ (possibly infinite dimensional) to $\\mathbb{R}^m$ that satisfies a restricted isometry property (RIP) on an arbitrary signal model $\\mathcal{S} \\subset \\mathcal{H}$. We present a generic framework that handles a large class of low-dimensional subsets but also unstructured and structured linear maps. We provide a simple recipe to prove that a random linear map satisfies a general RIP on $\\mathcal{S}$ with h...

Effect of progestin vs. combined oral contraceptive pills on lactation: A double-blind randomized controlled trial

Science.gov (United States)

Espey, Eve; Ogburn, Tony; Leeman, Larry; Singh, Rameet; Schrader, Ronald

2013-01-01

Objective To estimate the effect of progestin-only vs. combined hormonal contraceptive pills on rates of breastfeeding continuation in postpartum women. Secondary outcomes include infant growth parameters, contraceptive method continuation and patient satisfaction with breastfeeding and contraceptive method. Methods In this randomized controlled trial, postpartum breastfeeding women who desired oral contraceptives were assigned to progestin-only vs. combined hormonal contraceptive pills. At two and eight weeks postpartum, participants completed in-person questionnaires that assessed breastfeeding continuation and contraceptive use. Infant growth parameters including weight, length and head circumference were assessed at eight weeks postpartum. Telephone questionnaires assessing breastfeeding, contraceptive continuation and satisfaction were completed at 3-7 weeks and 4 and 6 months. Breastfeeding continuation was compared between groups using Cox proportional hazards regression. Differences in baseline demographic characteristics and in variables between the two intervention groups were compared using chi-square tests, Fisher’s Exact test, or two-sample t-tests as appropriate. Results Breastfeeding continuation rates, contraceptive continuation, and infant growth parameters did not differ between users of progestin-only and combined hormonal contraceptive pills. Infant formula supplementation and maternal perception of inadequate milk supply were associated with decreased rates of breastfeeding in both groups. Conclusions Choice of combined or progestin-only birth control pills administered two weeks postpartum did not adversely affect breastfeeding continuation. PMID:22143258

Comparison of Linear and Non-linear Regression Analysis to Determine Pulmonary Pressure in Hyperthyroidism.

Science.gov (United States)

Scarneciu, Camelia C; Sangeorzan, Livia; Rus, Horatiu; Scarneciu, Vlad D; Varciu, Mihai S; Andreescu, Oana; Scarneciu, Ioan

2017-01-01

This study aimed at assessing the incidence of pulmonary hypertension (PH) at newly diagnosed hyperthyroid patients and at finding a simple model showing the complex functional relation between pulmonary hypertension in hyperthyroidism and the factors causing it. The 53 hyperthyroid patients (H-group) were evaluated mainly by using an echocardiographical method and compared with 35 euthyroid (E-group) and 25 healthy people (C-group). In order to identify the factors causing pulmonary hypertension the statistical method of comparing the values of arithmetical means is used. The functional relation between the two random variables (PAPs and each of the factors determining it within our research study) can be expressed by linear or non-linear function. By applying the linear regression method described by a first-degree equation the line of regression (linear model) has been determined; by applying the non-linear regression method described by a second degree equation, a parabola-type curve of regression (non-linear or polynomial model) has been determined. We made the comparison and the validation of these two models by calculating the determination coefficient (criterion 1), the comparison of residuals (criterion 2), application of AIC criterion (criterion 3) and use of F-test (criterion 4). From the H-group, 47% have pulmonary hypertension completely reversible when obtaining euthyroidism. The factors causing pulmonary hypertension were identified: previously known- level of free thyroxin, pulmonary vascular resistance, cardiac output; new factors identified in this study- pretreatment period, age, systolic blood pressure. According to the four criteria and to the clinical judgment, we consider that the polynomial model (graphically parabola- type) is better than the linear one. The better model showing the functional relation between the pulmonary hypertension in hyperthyroidism and the factors identified in this study is given by a polynomial equation of second

Comparison of efficacy and tolerance between combination therapy and monotherapy as first-line chemotherapy in elderly patients with advanced gastric cancer: Study protocol for a randomized controlled trial.

Science.gov (United States)

Lee, Keun-Wook; Zang, Dae Young; Ryu, Min-Hee; Kim, Ki Hyang; Kim, Mi-Jung; Han, Hye Sook; Koh, Sung Ae; Park, Jin Hyun; Kim, Jin Won; Nam, Byung-Ho; Choi, In Sil

2017-12-01

The combination of a fluoropyrimidine [5-fluorouracil (5-FU), capecitabine, or S-1] with a platinum analog (cisplatin or oxaliplatin) is the most widely accepted first-line chemotherapy regimen for metastatic or recurrent advanced gastric cancer (AGC), based on the results of clinical trials. However, there is little evidence to guide chemotherapy for elderly patients with AGC because of under-representation of this age group in clinical trials. Thus, the aim of this study is to determine the optimal chemotherapy regimen for elderly patients with AGC by comparing the efficacies and safeties of combination therapy versus monotherapy as first-line chemotherapy. This study is a randomized, controlled, multicenter, phase III trial. A total of 246 elderly patients (≥70 years old) with metastatic or recurrent AGC who have not received previous palliative chemotherapy will be randomly allocated to a combination therapy group or a monotherapy group. Patients randomized to the combination therapy group will receive fluoropyrimidine plus platinum combination chemotherapy (capecitabine/cisplatin, S-1/cisplatin, capecitabine/oxaliplatin, or 5-FU/oxaliplatin), and those randomized to the monotherapy group will receive fluoropyrimidine monotherapy (capecitabine, S-1, or 5-FU). The primary outcome is the overall survival of patients in each treatment group. The secondary outcomes include progression-free survival, response rate, quality of life, and safety. We are conducting this pragmatic trial to determine whether elderly patients with AGC will obtain the same benefit from chemotherapy as younger patients. We expect that this study will help guide decision-making for the optimal treatment of elderly patients with AGC.

Randomized comparative trial of efficacy of paracetamol, ibuprofen and paracetamol-ibuprofen combination for treatment of febrile children

Directory of Open Access Journals (Sweden)

Falgun Indravadan Vyas

2014-01-01

Full Text Available Objective: Paracetamol and ibuprofen are widely used for fever in children as monotherapy and as combined therapy. None of the treatments is proven clearly superior to others. Hence, the study was planned to compare the efficacy of paracetamol, ibuprofen and paracetamol-ibuprofen combination for treatment of febrile children. Materials and Methods: This was an investigator blind, randomized, comparative, parallel clinical trial conducted in 99 febrile children, 6 months to 12 years of age, allocated to three groups. First group received paracetamol 15 mg/kg, second group received ibuprofen 10 mg/kg and third group received both paracetamol and ibuprofen, all as a single dose by the oral route. Patients were followed-up at intervals of 1, 2, 3 and 4 h post dose by tympanic thermometry. Results: Mean tympanic temperature after 4 h of drug administration was significantly lower in the combination group compared with paracetamol group (P < 0.05; however, the difference was not clinically significant (<1΀C. The rate of fall of temperature was highest in the combination group. Number of afebrile children any time post dose until 4 h was highest in the combination group. Difference between combination and paracetamol was significant for the 1 st h (P = 0.04. Highest fall of temperature was noted in the 1 st h of drug administration in all the groups. No serious adverse events were observed in any of the groups. Conclusion: Paracetamol and ibuprofen combination caused quicker temperature reduction than either paracetamol or ibuprofen alone. If quicker reduction of body temperature is the desired goal of therapy, the use of combination of paracetamol + ibuprofen may be advocated.

Forecast combinations

OpenAIRE

Aiolfi, Marco; Capistrán, Carlos; Timmermann, Allan

2010-01-01

We consider combinations of subjective survey forecasts and model-based forecasts from linear and non-linear univariate specifications as well as multivariate factor-augmented models. Empirical results suggest that a simple equal-weighted average of survey forecasts outperform the best model-based forecasts for a majority of macroeconomic variables and forecast horizons. Additional improvements can in some cases be gained by using a simple equal-weighted average of survey and model-based fore...

Distributed CMOS Bidirectional Amplifiers Broadbanding and Linearization Techniques

CERN Document Server

El-Khatib, Ziad; Mahmoud, Samy A

2012-01-01

This book describes methods to design distributed amplifiers useful for performing circuit functions such as duplexing, paraphrase amplification, phase shifting power splitting and power combiner applications.  A CMOS bidirectional distributed amplifier is presented that combines for the first time device-level with circuit-level linearization, suppressing the third-order intermodulation distortion. It is implemented in 0.13μm RF CMOS technology for use in highly linear, low-cost UWB Radio-over-Fiber communication systems. Describes CMOS distributed amplifiers for optoelectronic applications such as Radio-over-Fiber systems, base station transceivers and picocells; Presents most recent techniques for linearization of CMOS distributed amplifiers; Includes coverage of CMOS I-V transconductors, as well as CMOS on-chip inductor integration and modeling; Includes circuit applications for UWB Radio-over-Fiber networks.

Prediction of retention indices for frequently reported compounds of plant essential oils using multiple linear regression, partial least squares, and support vector machine.

Science.gov (United States)

Yan, Jun; Huang, Jian-Hua; He, Min; Lu, Hong-Bing; Yang, Rui; Kong, Bo; Xu, Qing-Song; Liang, Yi-Zeng

2013-08-01

Retention indices for frequently reported compounds of plant essential oils on three different stationary phases were investigated. Multivariate linear regression, partial least squares, and support vector machine combined with a new variable selection approach called random-frog recently proposed by our group, were employed to model quantitative structure-retention relationships. Internal and external validations were performed to ensure the stability and predictive ability. All the three methods could obtain an acceptable model, and the optimal results by support vector machine based on a small number of informative descriptors with the square of correlation coefficient for cross validation, values of 0.9726, 0.9759, and 0.9331 on the dimethylsilicone stationary phase, the dimethylsilicone phase with 5% phenyl groups, and the PEG stationary phase, respectively. The performances of two variable selection approaches, random-frog and genetic algorithm, are compared. The importance of the variables was found to be consistent when estimated from correlation coefficients in multivariate linear regression equations and selection probability in model spaces. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Combined impact of negative lifestyle factors on cardiovascular risk in children: a randomized prospective study.

Science.gov (United States)

Meyer, Ursina; Schindler, Christian; Bloesch, Tamara; Schmocker, Eliane; Zahner, Lukas; Puder, Jardena J; Kriemler, Susi

2014-12-01

Negative lifestyle factors are known to be associated with increased cardiovascular risk (CVR) in children, but research on their combined impact on a general population of children is sparse. Therefore, we aimed to quantify the combined impact of easily assessable negative lifestyle factors on the CVR scores of randomly selected children after 4 years. Of the 540 randomly selected 6- to 13-year-old children, 502 children participated in a baseline health assessment, and 64% were assessed again after 4 years. Measures included anthropometry, fasting blood samples, and a health assessment questionnaire. Participants scored one point for each negative lifestyle factor at baseline: overweight; physical inactivity; high media consumption; little outdoor time; skipping breakfast; and having a parent who has ever smoked, is inactive, or overweight. A CVR score at follow-up was constructed by averaging sex- and age-related z-scores of waist circumference, blood pressure, glucose, inverted high-density lipoprotein, and triglycerides. The age-, sex-, pubertal stage-, and social class-adjusted probabilities (95% confidence interval) for being in the highest CVR score tertile at follow-up for children who had at most one (n = 48), two (n = 64), three (n = 56), four (n = 41), or five or more (n = 14) risky lifestyle factors were 15.4% (8.9-25.3), 24.3% (17.4-32.8), 36.0% (28.6-44.2), 49.8% (38.6-61.0), and 63.5% (47.2-77.2), respectively. Even in childhood, an accumulation of negative lifestyle factors is associated with higher CVR scores after 4 years. These negative lifestyle factors are easy to assess in clinical practice and allow early detection and prevention of CVR in childhood. Copyright © 2014 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Random Forest Approach to QSPR Study of Fluorescence Properties Combining Quantum Chemical Descriptors and Solvent Conditions.

Science.gov (United States)

Chen, Chia-Hsiu; Tanaka, Kenichi; Funatsu, Kimito

2018-04-22

The Quantitative Structure - Property Relationship (QSPR) approach was performed to study the fluorescence absorption wavelengths and emission wavelengths of 413 fluorescent dyes in different solvent conditions. The dyes included the chromophore derivatives of cyanine, xanthene, coumarin, pyrene, naphthalene, anthracene and etc., with the wavelength ranging from 250 nm to 800 nm. An ensemble method, random forest (RF), was employed to construct nonlinear prediction models compared with the results of linear partial least squares and nonlinear support vector machine regression models. Quantum chemical descriptors derived from density functional theory method and solvent information were also used by constructing models. The best prediction results were obtained from RF model, with the squared correlation coefficients [Formula: see text] of 0.940 and 0.905 for λ abs and λ em , respectively. The descriptors used in the models were discussed in detail in this report by comparing the feature importance of RF.

Stochastic Parameter Estimation of Non-Linear Systems Using Only Higher Order Spectra of the Measured Response

Science.gov (United States)

Vasta, M.; Roberts, J. B.

1998-06-01

Methods for using fourth order spectral quantities to estimate the unknown parameters in non-linear, randomly excited dynamic systems are developed. Attention is focused on the case where only the response is measurable and the excitation is unmeasurable and known only in terms of a stochastic process model. The approach is illustrated through application to a non-linear oscillator with both non-linear damping and stiffness and with excitation modelled as a stationary Gaussian white noise process. The methods have applications in studies of the response of structures to random environmental loads, such as wind and ocean wave forces.

Immediate combined effect of gastrocnemius stretching and sustained talocrural joint mobilization in individuals with limited ankle dorsiflexion: A randomized controlled trial.

Science.gov (United States)

Kang, Min-Hyeok; Oh, Jae-Seop; Kwon, Oh-Yun; Weon, Jong-Hyuk; An, Duk-Hyun; Yoo, Won-Gyu

2015-12-01

Although gastrocnemius stretching and talocrural joint mobilization have been suggested as effective interventions to address limited ankle dorsiflexion passive range of motion (DF PROM), the effects of a combination of the two interventions have not been identified. The aim of the present study was to compare the effects of gastrocnemius stretching combined with joint mobilization and gastrocnemius stretching alone. A randomized controlled trial. In total, 24 individuals with limited ankle DF PROM were randomized to undergo gastrocnemius stretching combined with joint mobilization (12 feet in 12 individuals) or gastrocnemius stretching alone (12 feet in 12 individuals) for 5 min. Ankle kinematics during gait (time to heel-off and ankle DF before heel-off), ankle DF PROM, posterior talar glide, and displacement of the myotendinous junction (MTJ) of the gastrocnemius were assessed before and after the interventions. The groups were compared using two-way repeated measures analysis of variance. Greater increases in the time to heel-off and ankle DF before heel-off during gait and posterior talar glide were observed in the stretching combined with joint mobilization group versus the stretching alone group. Ankle DF PROM and displacement of the MTJ of the gastrocnemius were increased significantly after the interventions in both groups, with no significant difference between them. These findings suggest that gastrocnemius stretching with joint mobilization needs to be considered to improve ankle kinematics during gait. Copyright © 2015 Elsevier Ltd. All rights reserved.

Analysis of blood pressure signal in patients with different ventricular ejection fraction using linear and non-linear methods.

Science.gov (United States)

Arcentales, Andres; Rivera, Patricio; Caminal, Pere; Voss, Andreas; Bayes-Genis, Antonio; Giraldo, Beatriz F

2016-08-01

Changes in the left ventricle function produce alternans in the hemodynamic and electric behavior of the cardiovascular system. A total of 49 cardiomyopathy patients have been studied based on the blood pressure signal (BP), and were classified according to the left ventricular ejection fraction (LVEF) in low risk (LR: LVEF>35%, 17 patients) and high risk (HR: LVEF≤35, 32 patients) groups. We propose to characterize these patients using a linear and a nonlinear methods, based on the spectral estimation and the recurrence plot, respectively. From BP signal, we extracted each systolic time interval (STI), upward systolic slope (BPsl), and the difference between systolic and diastolic BP, defined as pulse pressure (PP). After, the best subset of parameters were obtained through the sequential feature selection (SFS) method. According to the results, the best classification was obtained using a combination of linear and nonlinear features from STI and PP parameters. For STI, the best combination was obtained considering the frequency peak and the diagonal structures of RP, with an area under the curve (AUC) of 79%. The same results were obtained when comparing PP values. Consequently, the use of combined linear and nonlinear parameters could improve the risk stratification of cardiomyopathy patients.

Optimizing Linear Functions with Randomized Search Heuristics - The Robustness of Mutation

DEFF Research Database (Denmark)

Witt, Carsten

2012-01-01

The analysis of randomized search heuristics on classes of functions is fundamental for the understanding of the underlying stochastic process and the development of suitable proof techniques. Recently, remarkable progress has been made in bounding the expected optimization time of the simple (1...

An intervention that reduces stress in people who combine work with informal care: randomized controlled trial results.

Science.gov (United States)

Boezeman, Edwin J; Nieuwenhuijsen, Karen; Sluiter, Judith K

2018-06-01

The aim of the research was to examine whether a role-focused self-help course intervention would decrease caregiver stress and distress, and functioning problems, among people who suffer stress because they combine paid work with informal care. A pre-registered (NTR 5528) randomized controlled design was applied (intervention vs. wait list control). Participants (n = 128) were people who had paid work and were suffering stress due to their involvement in informal care activities. Participants allocated to the intervention group (n = 65) received the role-focused self-help course. Control group members (n = 63) received this intervention after all measurements. Prior to the random allocation (pre-test), and 1 month (post-test 1) and 2 months (post-test 2) after allocation, all participants completed a questionnaire that measured their caregiver stress (primary outcome), distress, work functioning, negative care-to-work interference and negative care-to-social and personal life interference. Mixed model ANOVAs were used to test the effectiveness of the intervention. Two months after allocation, the intervention group participants had lower levels of caregiver stress and distress compared with the control group participants. The intervention did not directly resolve impaired work functioning or interference of care with work and social/personal life. The intervention decreases caregiver stress and distress in people who suffer stress because they combine paid work with informal caring. The intervention (Dutch version) can be downloaded at no cost from www.amc.nl/mantelzorgstress.

Solid phase microextraction of diclofenac using molecularly imprinted polymer sorbent in hollow fiber combined with fiber optic-linear array spectrophotometry.

Science.gov (United States)

Pebdani, Arezou Amiri; Shabani, Ali Mohammad Haji; Dadfarnia, Shayessteh; Khodadoust, Saeid

2015-08-05

A simple solid phase microextraction method based on molecularly imprinted polymer sorbent in the hollow fiber (MIP-HF-SPME) combined with fiber optic-linear array spectrophotometer has been applied for the extraction and determination of diclofenac in environmental and biological samples. The effects of different parameters such as pH, times of extraction, type and volume of the organic solvent, stirring rate and donor phase volume on the extraction efficiency of the diclofenac were investigated and optimized. Under the optimal conditions, the calibration graph was linear (r(2)=0.998) in the range of 3.0-85.0 μg L(-1) with a detection limit of 0.7 μg L(-1) for preconcentration of 25.0 mL of the sample and the relative standard deviation (n=6) less than 5%. This method was applied successfully for the extraction and determination of diclofenac in different matrices (water, urine and plasma) and accuracy was examined through the recovery experiments. Copyright © 2015 Elsevier B.V. All rights reserved.

Linear devices in combined high-level radiation environments

International Nuclear Information System (INIS)

van Vonno, N.W.

1987-01-01

The design of precision analog integrated circuits for use in combined high-level radiation environments has traditionally been on a full-custom basis. The use of semicustom design methods has become prevalent in digital devices, with standard cell libraries and gate arrays readily available from multiple vendors. This paper addresses the application of semicustom design techniques to analog parts. In all cases the emphasis is on bipolar technology, since this provides an optimal combination of precision and radiation hardness. A mixed mode analog/digital (A/D) cell family for implementing semicustom designs is described, together with the fabrication process used. Specific processing and design methods are used to provide circuit hardness against neutron, total gamma dose, and transient gamma environments. Semicustom mixed analog/digital design is seen as an appropriate methodology for implementation of medium-performance mixed mode functions for radiation-hardened applications. This leads to trade-offs in process complexity and performance. Full custom design remains necessary for demanding applications such as high-speed A/D conversion and associated sample/hold functions. An A/D cell family optimized for hardness is described, together with the bipolar process used to implement it

Multicenter, Randomized, Controlled Study Comparing Tafluprost/Timolol Fixed Combination with Latanoprost/Timolol Fixed Combination in Primary Open-Angle Glaucoma and Ocular Hypertension.

Science.gov (United States)

Suzuki, Katsuyoshi; Otsuka, Naomi; Hizaki, Hiroko; Hashimoto, Masayo; Kuwayama, Yasuaki

2018-06-05

This was the first exploratory randomized controlled study to compare the efficacy and safety of a preserved tafluprost/timolol fixed combination (TAF/TIM) with a preserved latanoprost/timolol fixed combination (LAT/TIM). This prospective, randomized, open-label study was conducted in Japanese patients with primary open-angle glaucoma, including normal-tension glaucoma or ocular hypertension. Following a 4-week LAT/TIM run-in period, eligible patients entered a 12-week treatment period, during which they received either LAT/TIM or TAF/TIM. The efficacy endpoint was the change in intraocular pressure (IOP) from baseline to week 12 and the safety endpoints included the changes from baseline to week 12 in superficial punctate keratopathy (SPK) score, tear breakup time (TBUT), and hyperemia score, as well as adverse events (AEs). At week 6, ocular symptoms were evaluated using a questionnaire. In total, 131 patients provided informed consent. Of these, 115 completed the run-in period and were assigned to receive TAF/TIM (n = 60) or LAT/TIM (n = 55). At week 12, there were no significant differences between the TAF/TIM and LAT/TIM groups in the change from baseline in trough IOP and IOP at 4-6 h after instillation. There were no significant differences between the two groups in the change from baseline to week 12 in SPK score, TBUT, and hyperemia score. However, only in the TAF/TIM group, the total SPK score and the inferior cornea SPK score were significantly lower at week 12 compared with baseline. Eye irritation and eye pain were significantly decreased in the TAF/TIM group compared with the LAT/TIM group. Two treatment-related AEs were reported in the TAF/TIM group (3.3%) and none in the LAT/TIM group, while no serious AEs were reported in either group. TAF/TIM is as effective as LAT/TIM in terms of IOP-reducing effect, with fewer ocular symptoms. TAF/TIM was associated with a significant improvement in SPK scores. UMIN Clinical Trials Registry Identifier

SNR Estimation in Linear Systems with Gaussian Matrices

KAUST Repository

Suliman, Mohamed Abdalla Elhag; Alrashdi, Ayed; Ballal, Tarig; Al-Naffouri, Tareq Y.

2017-01-01

This letter proposes a highly accurate algorithm to estimate the signal-to-noise ratio (SNR) for a linear system from a single realization of the received signal. We assume that the linear system has a Gaussian matrix with one sided left correlation. The unknown entries of the signal and the noise are assumed to be independent and identically distributed with zero mean and can be drawn from any distribution. We use the ridge regression function of this linear model in company with tools and techniques adapted from random matrix theory to achieve, in closed form, accurate estimation of the SNR without prior statistical knowledge on the signal or the noise. Simulation results show that the proposed method is very accurate.

SNR Estimation in Linear Systems with Gaussian Matrices

KAUST Repository

Suliman, Mohamed Abdalla Elhag

2017-09-27

This letter proposes a highly accurate algorithm to estimate the signal-to-noise ratio (SNR) for a linear system from a single realization of the received signal. We assume that the linear system has a Gaussian matrix with one sided left correlation. The unknown entries of the signal and the noise are assumed to be independent and identically distributed with zero mean and can be drawn from any distribution. We use the ridge regression function of this linear model in company with tools and techniques adapted from random matrix theory to achieve, in closed form, accurate estimation of the SNR without prior statistical knowledge on the signal or the noise. Simulation results show that the proposed method is very accurate.

Applications of Probabilistic Combiners on Linear Feedback Shift Register Sequences

Science.gov (United States)

2016-12-01

on the resulting output strings show a drastic increase in complexity, while simultaneously passing the stringent randomness tests required by the...a three-variable function. Our tests on the resulting output strings show a drastic increase in complex- ity, while simultaneously passing the...10001101 01000010 11101001 Decryption of a message that has been encrypted using bitwise XOR is quite simple. Since each bit is its own additive inverse

A characterization of linearly repetitive cut and project sets

Science.gov (United States)

Haynes, Alan; Koivusalo, Henna; Walton, James

2018-02-01

For the development of a mathematical theory which can be used to rigorously investigate physical properties of quasicrystals, it is necessary to understand regularity of patterns in special classes of aperiodic point sets in Euclidean space. In one dimension, prototypical mathematical models for quasicrystals are provided by Sturmian sequences and by point sets generated by substitution rules. Regularity properties of such sets are well understood, thanks mostly to well known results by Morse and Hedlund, and physicists have used this understanding to study one dimensional random Schrödinger operators and lattice gas models. A key fact which plays an important role in these problems is the existence of a subadditive ergodic theorem, which is guaranteed when the corresponding point set is linearly repetitive. In this paper we extend the one-dimensional model to cut and project sets, which generalize Sturmian sequences in higher dimensions, and which are frequently used in mathematical and physical literature as models for higher dimensional quasicrystals. By using a combination of algebraic, geometric, and dynamical techniques, together with input from higher dimensional Diophantine approximation, we give a complete characterization of all linearly repetitive cut and project sets with cubical windows. We also prove that these are precisely the collection of such sets which satisfy subadditive ergodic theorems. The results are explicit enough to allow us to apply them to known classical models, and to construct linearly repetitive cut and project sets in all pairs of dimensions and codimensions in which they exist. Research supported by EPSRC grants EP/L001462, EP/J00149X, EP/M023540. HK also gratefully acknowledges the support of the Osk. Huttunen foundation.

TEHRAN AIR POLLUTANTS PREDICTION BASED ON RANDOM FOREST FEATURE SELECTION METHOD

Directory of Open Access Journals (Sweden)

A. Shamsoddini

2017-09-01

Full Text Available Air pollution as one of the most serious forms of environmental pollutions poses huge threat to human life. Air pollution leads to environmental instability, and has harmful and undesirable effects on the environment. Modern prediction methods of the pollutant concentration are able to improve decision making and provide appropriate solutions. This study examines the performance of the Random Forest feature selection in combination with multiple-linear regression and Multilayer Perceptron Artificial Neural Networks methods, in order to achieve an efficient model to estimate carbon monoxide and nitrogen dioxide, sulfur dioxide and PM2.5 contents in the air. The results indicated that Artificial Neural Networks fed by the attributes selected by Random Forest feature selection method performed more accurate than other models for the modeling of all pollutants. The estimation accuracy of sulfur dioxide emissions was lower than the other air contaminants whereas the nitrogen dioxide was predicted more accurate than the other pollutants.

Tehran Air Pollutants Prediction Based on Random Forest Feature Selection Method

Science.gov (United States)

Shamsoddini, A.; Aboodi, M. R.; Karami, J.

2017-09-01

Air pollution as one of the most serious forms of environmental pollutions poses huge threat to human life. Air pollution leads to environmental instability, and has harmful and undesirable effects on the environment. Modern prediction methods of the pollutant concentration are able to improve decision making and provide appropriate solutions. This study examines the performance of the Random Forest feature selection in combination with multiple-linear regression and Multilayer Perceptron Artificial Neural Networks methods, in order to achieve an efficient model to estimate carbon monoxide and nitrogen dioxide, sulfur dioxide and PM2.5 contents in the air. The results indicated that Artificial Neural Networks fed by the attributes selected by Random Forest feature selection method performed more accurate than other models for the modeling of all pollutants. The estimation accuracy of sulfur dioxide emissions was lower than the other air contaminants whereas the nitrogen dioxide was predicted more accurate than the other pollutants.

A Type System for the Vectorial Aspect of the Linear-Algebraic Lambda-Calculus

Directory of Open Access Journals (Sweden)

Pablo Arrighi

2012-07-01

Full Text Available We describe a type system for the linear-algebraic lambda-calculus. The type system accounts for the part of the language emulating linear operators and vectors, i.e. it is able to statically describe the linear combinations of terms resulting from the reduction of programs. This gives rise to an original type theory where types, in the same way as terms, can be superposed into linear combinations. We show that the resulting typed lambda-calculus is strongly normalizing and features a weak subject-reduction.

Linear viscoelastic characterization from filament stretching rheometry

DEFF Research Database (Denmark)

Wingstrand, Sara Lindeblad; Alvarez, Nicolas J.; Hassager, Ole

to measure both linear and nonlinear dynamics on a single apparatus. With a software modification to the FSR motor control, we show that linear viscoelasticity can be measured via small amplitude squeeze flow (SASF). Squeeze flow is a combination of both shear and extensional flow applied by axially......Traditionally, linear viscoelasticity is measured using small amplitude oscillatory shear flow. Due to experimental difficulties, shear flows are predominately confined to the linear and mildly nonlinear regime. On the other hand, extensional flows have proven more practical in measuring...... viscoelasticity well into the nonlinear regime. Therefore at present, complete rheological characterization of a material requires two apparatuses: a shear and an extensional rheometer. This work is focused on developing a linear viscoelastic protocol for the filament stretching rheometer (FSR) in order...

EVOLUTION OF FAST MAGNETOACOUSTIC PULSES IN RANDOMLY STRUCTURED CORONAL PLASMAS

International Nuclear Information System (INIS)

Yuan, D.; Li, B.; Pascoe, D. J.; Nakariakov, V. M.; Keppens, R.

2015-01-01

We investigate the evolution of fast magnetoacoustic pulses in randomly structured plasmas, in the context of large-scale propagating waves in the solar atmosphere. We perform one-dimensional numerical simulations of fast wave pulses propagating perpendicular to a constant magnetic field in a low-β plasma with a random density profile across the field. Both linear and nonlinear regimes are considered. We study how the evolution of the pulse amplitude and width depends on their initial values and the parameters of the random structuring. Acting as a dispersive medium, a randomly structured plasma causes amplitude attenuation and width broadening of the fast wave pulses. After the passage of the main pulse, secondary propagating and standing fast waves appear. Width evolution of both linear and nonlinear pulses can be well approximated by linear functions; however, narrow pulses may have zero or negative broadening. This arises because narrow pulses are prone to splitting, while broad pulses usually deviate less from their initial Gaussian shape and form ripple structures on top of the main pulse. Linear pulses decay at an almost constant rate, while nonlinear pulses decay exponentially. A pulse interacts most efficiently with a random medium with a correlation length of about half of the initial pulse width. This detailed model of fast wave pulses propagating in highly structured media substantiates the interpretation of EIT waves as fast magnetoacoustic waves. Evolution of a fast pulse provides us with a novel method to diagnose the sub-resolution filamentation of the solar atmosphere

Miniature linear cooler development

International Nuclear Information System (INIS)

Pruitt, G.R.

1993-01-01

An overview is presented of the status of a family of miniature linear coolers currently under development by Hughes Aircraft Co. for use in hand held, volume limited or power limited infrared applications. These coolers, representing the latest additions to the Hughes family of TOP trademark [twin-opposed piston] linear coolers, have been fabricated and tested in three different configurations. Each configuration is designed to utilize a common compressor assembly resulting in reduced manufacturing costs. The baseline compressor has been integrated with two different expander configurations and has been operated with two different levels of input power. These various configuration combinations offer a wide range of performance and interface characteristics which may be tailored to applications requiring limited power and size without significantly compromising cooler capacity or cooldown characteristics. Key cooler characteristics and test data are summarized for three combinations of cooler configurations which are representative of the versatility of this linear cooler design. Configurations reviewed include the shortened coldfinger [1.50 to 1.75 inches long], limited input power [less than 17 Watts] for low power availability applications; the shortened coldfinger with higher input power for lightweight, higher performance applications; and coldfingers compatible with DoD 0.4 Watt Common Module coolers for wider range retrofit capability. Typical weight of these miniature linear coolers is less than 500 grams for the compressor, expander and interconnecting transfer line. Cooling capacity at 80K at room ambient conditions ranges from 400 mW to greater than 550 mW. Steady state power requirements for maintaining a heat load of 150 mW at 80K has been shown to be less than 8 Watts. Ongoing reliability growth testing is summarized including a review of the latest test article results

Progress on $e^{+}e^{-}$ linear colliders

CERN Multimedia

CERN. Geneva. Audiovisual Unit; Siemann, Peter

2002-01-01

Physics issues. The physics program will be reviewed for e+e- linear colliders in the TeV energy range. At these prospective facilities central issues of particle physics can be addressed, the problem of mass, unification and structure of space-time. In this context the two lectures will focus on analyses of the Higgs mechanism, supersymmetry and extra space dimensions. Moreover, high-precision studies of the top-quark and the gauge boson sector will be discussed. Combined with LHC results, a comprehensive picture can be developed of physics at the electroweak scale and beyond. Designs and technologies (R. Siemann - 29, 30, 31 May) The physics and technologies of high energy linear colliders will be reviewed. Fundamental concepts of linear colliders will be introduced. They will be discussed in: the context of the Stanford Linear Collider where many ideas changed and new ones were developed in response to operational experience. the requirements for future linear colliders. The different approaches for reac...

Linear morphoea follows Blaschko's lines.

Science.gov (United States)

Weibel, L; Harper, J I

2008-07-01

The aetiology of morphoea (or localized scleroderma) remains unknown. It has previously been suggested that lesions of linear morphoea may follow Blaschko's lines and thus reflect an embryological development. However, the distribution of linear morphoea has never been accurately evaluated. We aimed to identify common patterns of clinical presentation in children with linear morphoea and to establish whether linear morphoea follows the lines of Blaschko. A retrospective chart review of 65 children with linear morphoea was performed. According to clinical photographs the skin lesions of these patients were plotted on to standardized head and body charts. With the aid of Adobe Illustrator a final figure was produced including an overlay of all individual lesions which was used for comparison with the published lines of Blaschko. Thirty-four (53%) patients had the en coup de sabre subtype, 27 (41%) presented with linear morphoea on the trunk and/or limbs and four (6%) children had a combination of the two. In 55 (85%) children the skin lesions were confined to one side of the body, showing no preference for either left or right side. On comparing the overlays of all body and head lesions with the original lines of Blaschko there was an excellent correlation. Our data indicate that linear morphoea follows the lines of Blaschko. We hypothesize that in patients with linear morphoea susceptible cells are present in a mosaic state and that exposure to some trigger factor may result in the development of this condition.

Case studies combined with or without concept maps improve critical thinking in hospital-based nurses: a randomized-controlled trial.

Science.gov (United States)

Huang, Yu-Chuan; Chen, Hsing-Hsia; Yeh, Mei-Ling; Chung, Yu-Chu

2012-06-01

Critical thinking (CT) is essential to the exercise of professional judgment. As nurses face increasingly complex health-care situations, critical thinking can promote appropriate clinical decision-making and improve the quality of nursing care. This study aimed to evaluate the effects of a program of case studies, alone (CS) or combined with concept maps (CSCM), on improving CT in clinical nurses. The study was a randomized controlled trial. The experimental group participated in a 16-week CSCM program, whereas the control group participated in a CS program of equal duration. A randomized-controlled trial with a multistage randomization process was used to select and to assign participants, ultimately resulting in 67 nurses in each group. Data were collected before and after the program using the California Critical Thinking Skill Test (CCTST) and the California Critical Thinking Disposition Inventory (CCTDI). After the programs, there were significant differences between the two groups in the critical thinking skills of analysis, evaluation, inference, deduction, and induction. There was also an overall significant difference, and a significant difference in the specific disposition of open-mindedness. This study supports the application of case studies combined with concept maps as a hospital-based teaching strategy to promote development of critical thinking skills and encourage dispositions for nurses. The CSCM resulted in greater improvements in all critical thinking skills of as well as the overall and open-minded affective dispositions toward critical thinking, compared with the case studies alone. An obvious improvement in the CSCM participants was the analytic skill and disposition. Further longitudinal studies and data collection from multisite evaluations in a range of geographic locales are warranted. Copyright © 2012 Elsevier Ltd. All rights reserved.

Combined Effects of Ezetimibe and Phytosterols on Cholesterol Metabolism: A Randomized, Controlled Feeding Study in Humans

Science.gov (United States)

Lin, Xiaobo; Racette, Susan B.; Lefevre, Michael; Ma, Lina; Spearie, Catherine Anderson; Steger-May, Karen; Ostlund, Richard E.

2011-01-01

Background Both ezetimibe and phytosterols inhibit cholesterol absorption. We tested the hypothesis that ezetimibe combined with phytosterols is more effective than ezetimibe alone in altering cholesterol metabolism. Methods and Results Twenty-one mildly hypercholesterolemic subjects completed a randomized, double-blind, placebo-controlled, triple crossover study. Each subject received a phytosterol-controlled diet plus (1) ezetimibe placebo + phytosterol placebo, (2) 10 mg ezetimibe/day + phytosterol placebo, and (3) 10 mg ezetimibe/day + 2.5 g phytosterols/day, for 3 weeks each. All meals were prepared in a metabolic kitchen. Primary outcomes were intestinal cholesterol absorption, fecal cholesterol excretion, and LDL cholesterol levels. The combined treatment resulted in significantly lower intestinal cholesterol absorption (598 mg/day, 95% CI 368 to 828) relative to control (2161 mg/day, 1112 to 3209) and ezetimibe alone (1054 mg/day, 546 to 1561, both P phytosterols averaged 129 (95% CI: 116 to 142), 108 (97 to 119), and 101 (90 to 112) mg/dL (P phytosterols to ezetimibe significantly enhanced the effects of ezetimibe on whole-body cholesterol metabolism and plasma LDL cholesterol. The large cumulative action of combined dietary and pharmacologic treatment on cholesterol metabolism emphasizes the potential importance of dietary phytosterols as adjunctive therapy for the treatment of hypercholesterolemia. PMID:21768544

Analysis, Simulation and Prediction of Multivariate Random Fields with Package RandomFields

Directory of Open Access Journals (Sweden)

Martin Schlather

2015-02-01

Full Text Available Modeling of and inference on multivariate data that have been measured in space, such as temperature and pressure, are challenging tasks in environmental sciences, physics and materials science. We give an overview over and some background on modeling with cross- covariance models. The R package RandomFields supports the simulation, the parameter estimation and the prediction in particular for the linear model of coregionalization, the multivariate Matrn models, the delay model, and a spectrum of physically motivated vector valued models. An example on weather data is considered, illustrating the use of RandomFields for parameter estimation and prediction.

Combined treatment with oral finasteride and topical minoxidil in male androgenetic alopecia: a randomized and comparative study in Chinese patients.

Science.gov (United States)

Hu, Ruiming; Xu, Feng; Sheng, Youyu; Qi, Sisi; Han, Yumei; Miao, Ying; Rui, Wenlong; Yang, Qinping

2015-01-01

Finasteride at 1 mg/day and 5% topical minoxidil are effective in male androgenetic alopecia (MAGA). However, studies describing their effects in Chinese individuals are scarce. 450 Chinese MAGA patients were randomly assigned to receive finasteride (n = 160), minoxidil (n = 130) and combined medication (n = 160) for 12 months. The patients returned to the clinic every 3 months for efficacy evaluation. And efficacy was evaluated in 428 men at treatment end, including 154, 122, and 152 in the finasteride, 5% minoxidil, and combination groups, respectively. All groups showed similar baseline characteristics, including age at enrollment, and duration and severity of alopecia (p > 0.05). At 12 months, 80.5, 59, and 94.1% men treated with finasteride, 5% minoxidil and the combination therapy showed improvement, respectively. Adverse reactions were rare (finasteride, 1.8%; minoxidil, 6.1%), and disappeared right after drug withdrawal. In conclusion, finasteride is superior to 5% minoxidil, while the combined medication showed the best efficacy. © 2015 Wiley Periodicals, Inc.

LINEAR2007, Linear-Linear Interpolation of ENDF Format Cross-Sections

International Nuclear Information System (INIS)

2007-01-01

1 - Description of program or function: LINEAR converts evaluated cross sections in the ENDF/B format into a tabular form that is subject to linear-linear interpolation in energy and cross section. The code also thins tables of cross sections already in that form. Codes used subsequently need thus to consider only linear-linear data. IAEA1311/15: This version include the updates up to January 30, 2007. Changes in ENDF/B-VII Format and procedures, as well as the evaluations themselves, make it impossible for versions of the ENDF/B pre-processing codes earlier than PREPRO 2007 (2007 Version) to accurately process current ENDF/B-VII evaluations. The present code can handle all existing ENDF/B-VI evaluations through release 8, which will be the last release of ENDF/B-VI. Modifications from previous versions: - Linear VERS. 2007-1 (JAN. 2007): checked against all ENDF/B-VII; increased page size from 60,000 to 600,000 points 2 - Method of solution: Each section of data is considered separately. Each section of File 3, 23, and 27 data consists of a table of cross section versus energy with any of five interpolation laws. LINEAR will replace each section with a new table of energy versus cross section data in which the interpolation law is always linear in energy and cross section. The histogram (constant cross section between two energies) interpolation law is converted to linear-linear by substituting two points for each initial point. The linear-linear is not altered. For the log-linear, linear-log and log- log laws, the cross section data are converted to linear by an interval halving algorithm. Each interval is divided in half until the value at the middle of the interval can be approximated by linear-linear interpolation to within a given accuracy. The LINEAR program uses a multipoint fractional error thinning algorithm to minimize the size of each cross section table

A linear programming approach to max-sum problem: a review.

Science.gov (United States)

Werner, Tomás

2007-07-01

The max-sum labeling problem, defined as maximizing a sum of binary (i.e., pairwise) functions of discrete variables, is a general NP-hard optimization problem with many applications, such as computing the MAP configuration of a Markov random field. We review a not widely known approach to the problem, developed by Ukrainian researchers Schlesinger et al. in 1976, and show how it contributes to recent results, most importantly, those on the convex combination of trees and tree-reweighted max-product. In particular, we review Schlesinger et al.'s upper bound on the max-sum criterion, its minimization by equivalent transformations, its relation to the constraint satisfaction problem, the fact that this minimization is dual to a linear programming relaxation of the original problem, and the three kinds of consistency necessary for optimality of the upper bound. We revisit problems with Boolean variables and supermodular problems. We describe two algorithms for decreasing the upper bound. We present an example application for structural image analysis.

Randomized trial of amino acid mixture combined with physical activity promotion for abdominal fat reduction in overweight adults.

Science.gov (United States)

Ueda, Keisuke; Sasai, Hiroyuki; Tsujimoto, Takehiko; Sanbongi, Chiaki; Ikegami, Shuji; Kobayashi, Hiroyuki; Shioya, Nobuhiko; Suzuki, Satoru; Nakata, Yoshio

2018-01-01

The purpose of this study was to test the efficacy of arginine, alanine, and phenylalanine mixture (A-mix) ingestion at 1,500 mg/day in combination with the promotion of physical activity for abdominal fat reduction in overweight adults. A placebo-controlled, double-blind, parallel-group, randomized trial for 12 weeks combined with a 4-week follow-up period was conducted at a single center in Minato-ku, Tokyo, Japan, between December 2016 and May 2017. Data were analyzed between June and August 2017. The study participants were 200 overweight adults within the age range of 20-64 years. The participants were randomly assigned to the A-mix group (n=100) or a placebo group (n=100) and were administered 500 mL of test beverage containing 1,500 or 0 mg of A-mix, respectively, for 12 weeks. All participants maintained a physically active lifestyle between week 0 and week 12 through monthly sessions of physical activity. The primary outcomes were the 12-week changes in the abdominal total, subcutaneous, and visceral fat areas, as assessed by computed tomography. Of the 200 enrolled participants, 199 (99%) accomplished the 12-week intervention and 4-week follow-up period. The per-protocol-based analysis for 194 participants demonstrated that the abdominal total fat area decreased significantly in the A-mix group compared with that in the placebo group (difference, 10.0 cm 2 ; 95% confidence interval [CI]: 0.4-19.6 cm 2 ; P =0.041). Comparable outcomes were obtained for the abdominal subcutaneous fat area (difference, 7.4 cm 2 ; 95% CI: 0.1-14.7 cm 2 ; P =0.047). No study-related unfavorable events occurred. A-mix supplementation in combination with physical activity promotion facilitated abdominal fat reduction in overweight adults.

A randomized trial of upper limb botulimun toxin versus placebo injection, combined with physiotherapy, in children with hemiplegia.

Science.gov (United States)

Ferrari, Adriano; Maoret, Anna Rosa; Muzzini, Simonetta; Alboresi, Silvia; Lombardi, Francesco; Sgandurra, Giuseppina; Paolicelli, Paola Bruna; Sicola, Elisa; Cioni, Giovanni

2014-10-01

The main goal of this study was to investigate the efficacy of Botulinum Toxin A (BoNT-A), combined with an individualized intensive physiotherapy/orthoses treatment, in improving upper limb activity and competence in daily activity in children with hemiplegia, and to compare its effectiveness with that of non-pharmacological instruments. It was a Randomized Clinical Trial of 27 children with spastic hemiplegic cerebral palsy, outpatients of two high speciality Centres for child rehabilitation. Each child was assigned by simple randomization to experimental group (BoNT-A) or control group (placebo). Assisting Hand Assessment (AHA) was chosen as primary outcome measure; other measures were selected according to ICF dimensions. Participants were assessed at baseline (T0), at T1, T2, T3 (1-3-6 months after injection, respectively). Every patient was given a specific physiotherapeutic treatment, consisting of individualized goal directed exercises, task oriented activities, daily stretching manoeuvres, functional and/or static orthoses. BoNT-A group showed a significant increase of AHA raw scores at T2, compared to control group (T2-T0: p=.025) and functional goals achievement (GAS) was also slightly better in the same group (p=.033). Other measures indicated some improvement in both groups, without significant intergroup differences. Children with intermediate severity of hand function at House scale for upper limb impairment seem to have a better benefit from BoNT-A protocol. BoNT-A was effective in improving manipulation in the activity domain, in association with individualized goal-directed physiotherapy and orthoses; the combined treatment is recommended. The study brings more evidence for the efficacy of a combined treatment botulinum toxin injection-physiotherapy-orthoses, and it gives some suggestions for candidate selection and individualized treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Classical and nonclassical randomness in quantum measurements

International Nuclear Information System (INIS)

Farenick, Douglas; Plosker, Sarah; Smith, Jerrod

2011-01-01

The space POVM H (X) of positive operator-valued probability measures on the Borel sets of a compact (or even locally compact) Hausdorff space X with values in B(H), the algebra of linear operators acting on a d-dimensional Hilbert space H, is studied from the perspectives of classical and nonclassical convexity through a transform Γ that associates any positive operator-valued measure ν with a certain completely positive linear map Γ(ν) of the homogeneous C*-algebra C(X) x B(H) into B(H). This association is achieved by using an operator-valued integral in which nonclassical random variables (that is, operator-valued functions) are integrated with respect to positive operator-valued measures and which has the feature that the integral of a random quantum effect is itself a quantum effect. A left inverse Ω for Γ yields an integral representation, along the lines of the classical Riesz representation theorem for linear functionals on C(X), of certain (but not all) unital completely positive linear maps φ:C(X) x B(H)→B(H). The extremal and C*-extremal points of POVM H (X) are determined.

A simplified method for random vibration analysis of structures with random parameters

International Nuclear Information System (INIS)

Ghienne, Martin; Blanzé, Claude

2016-01-01

Piezoelectric patches with adapted electrical circuits or viscoelastic dissipative materials are two solutions particularly adapted to reduce vibration of light structures. To accurately design these solutions, it is necessary to describe precisely the dynamical behaviour of the structure. It may quickly become computationally intensive to describe robustly this behaviour for a structure with nonlinear phenomena, such as contact or friction for bolted structures, and uncertain variations of its parameters. The aim of this work is to propose a non-intrusive reduced stochastic method to characterize robustly the vibrational response of a structure with random parameters. Our goal is to characterize the eigenspace of linear systems with dynamic properties considered as random variables. This method is based on a separation of random aspects from deterministic aspects and allows us to estimate the first central moments of each random eigenfrequency with a single deterministic finite elements computation. The method is applied to a frame with several Young's moduli modeled as random variables. This example could be expanded to a bolted structure including piezoelectric devices. The method needs to be enhanced when random eigenvalues are closely spaced. An indicator with no additional computational cost is proposed to characterize the ’’proximity” of two random eigenvalues. (paper)

Graph-based linear scaling electronic structure theory

Energy Technology Data Exchange (ETDEWEB)

Niklasson, Anders M. N., E-mail: amn@lanl.gov; Negre, Christian F. A.; Cawkwell, Marc J.; Swart, Pieter J.; Germann, Timothy C.; Bock, Nicolas [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Mniszewski, Susan M.; Mohd-Yusof, Jamal; Wall, Michael E.; Djidjev, Hristo [Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Rubensson, Emanuel H. [Division of Scientific Computing, Department of Information Technology, Uppsala University, Box 337, SE-751 05 Uppsala (Sweden)

2016-06-21

We show how graph theory can be combined with quantum theory to calculate the electronic structure of large complex systems. The graph formalism is general and applicable to a broad range of electronic structure methods and materials, including challenging systems such as biomolecules. The methodology combines well-controlled accuracy, low computational cost, and natural low-communication parallelism. This combination addresses substantial shortcomings of linear scaling electronic structure theory, in particular with respect to quantum-based molecular dynamics simulations.

Pseudo-random properties of a linear congruential generator investigated by b-adic diaphony

Science.gov (United States)

Stoev, Peter; Stoilova, Stanislava

2017-12-01

In the proposed paper we continue the study of the diaphony, defined in b-adic number system, and we extend it in different directions. We investigate this diaphony as a tool for estimation of the pseudorandom properties of some of the most used random number generators. This is done by evaluating the distribution of specially constructed two-dimensional nets on the base of the obtained random numbers. The aim is to see how the generated numbers are suitable for calculations in some numerical methods (Monte Carlo etc.).

Effect of Combined Systematized Behavioral Modification Education Program With Desmopressin in Patients With Nocturia: A Prospective, Multicenter, Randomized, and Parallel Study

Directory of Open Access Journals (Sweden)

Sung Yong Cho

2014-12-01

Full Text Available Purpose The aims of this study were to investigate the efficacy of combining the systematized behavioral modification program (SBMP with desmopressin therapy and to compare this with desmopressin monotherapy in the treatment of nocturnal polyuria (NPU. Methods Patients were randomized at 8 centers to receive desmopressin monotherapy (group A or combination therapy, comprising desmopressin and the SBMP (group B. Nocturia was defined as an average of 2 or more nightly voids. The primary endpoint was a change in the mean number of nocturnal voids from baseline during the 3-month treatment period. The secondary endpoints were changes in the bladder diary parameters and questionnaires scores, and improvements in self-perception for nocturia. Results A total of 200 patients were screened and 76 were excluded from the study, because they failed the screening process. A total of 124 patients were randomized to receive treatment, with group A comprising 68 patients and group B comprising 56 patients. The patients' characteristics were similar between the groups. Nocturnal voids showed a greater decline in group B (-1.5 compared with group A (-1.2, a difference that was not statistically significant. Significant differences were observed between groups A and B with respect to the NPU index (0.37 vs. 0.29, P=0.028, the change in the maximal bladder capacity (-41.3 mL vs. 13.3 mL, P<0.001, and the rate of patients lost to follow up (10.3% [7/68] vs. 0% [0/56], P=0.016. Self-perception for nocturia significantly improved in both groups. Conclusions Combination treatment did not have any additional benefits in relation to reducing nocturnal voids in patients with NPU; however, combination therapy is helpful because it increases the maximal bladder capacity and decreases the NPI. Furthermore, combination therapy increased the persistence of desmopressin in patients with NPU.

Inference for binomial probability based on dependent Bernoulli random variables with applications to meta‐analysis and group level studies

Science.gov (United States)

Bakbergenuly, Ilyas; Morgenthaler, Stephan

2016-01-01

We study bias arising as a result of nonlinear transformations of random variables in random or mixed effects models and its effect on inference in group‐level studies or in meta‐analysis. The findings are illustrated on the example of overdispersed binomial distributions, where we demonstrate considerable biases arising from standard log‐odds and arcsine transformations of the estimated probability p^, both for single‐group studies and in combining results from several groups or studies in meta‐analysis. Our simulations confirm that these biases are linear in ρ, for small values of ρ, the intracluster correlation coefficient. These biases do not depend on the sample sizes or the number of studies K in a meta‐analysis and result in abysmal coverage of the combined effect for large K. We also propose bias‐correction for the arcsine transformation. Our simulations demonstrate that this bias‐correction works well for small values of the intraclass correlation. The methods are applied to two examples of meta‐analyses of prevalence. PMID:27192062

On randomly interrupted diffusion

International Nuclear Information System (INIS)

Luczka, J.

1993-01-01

Processes driven by randomly interrupted Gaussian white noise are considered. An evolution equation for single-event probability distributions in presented. Stationary states are considered as a solution of a second-order ordinary differential equation with two imposed conditions. A linear model is analyzed and its stationary distributions are explicitly given. (author). 10 refs

Random eigenvalue problems revisited

Indian Academy of Sciences (India)

statistical distributions; linear stochastic systems. 1. ... dimensional multivariate Gaussian random vector with mean µ ∈ Rm and covariance ... 5, the proposed analytical methods are applied to a three degree-of-freedom system and the ...... The joint pdf ofω1 andω3 is however close to a bivariate Gaussian density function.

Strong Laws of Large Numbers for Arrays of Rowwise NA and LNQD Random Variables

Directory of Open Access Journals (Sweden)

Jiangfeng Wang

2011-01-01

Full Text Available Some strong laws of large numbers and strong convergence properties for arrays of rowwise negatively associated and linearly negative quadrant dependent random variables are obtained. The results obtained not only generalize the result of Hu and Taylor to negatively associated and linearly negative quadrant dependent random variables, but also improve it.

Genetic parameters for quail body weights using a random ...

African Journals Online (AJOL)

A model including fixed and random linear regressions is described for analyzing body weights at different ages. In this study, (co)variance components, heritabilities for quail weekly weights and genetic correlations among these weights were estimated using a random regression model by DFREML under DXMRR option.

Combined-stent covered technique and single covered stent technique for transjugular intrahepatic porto-systemic shunt: a prospective randomized controlled study

International Nuclear Information System (INIS)

Wang Changming; Li Xuan; Fu Jun; Lu Xianjun; Luan Jingyuan; Li Tianrun; Zhao Jun; Dong Guoxiang

2014-01-01

Objective: To compare the technique of combined stents with that of single stent-graft for the construction of transjugular intrahepatic porto-systemic shunt (TIPS) and to discuss their clinical outcomes. Methods: During the period from April 2011 to Dec. 2012, a total of 30 patients with upper gastrointestinal bleeding due to portal hypertension were admitted to the hospital. TIPS procedure was carried out in all the 30 patients. The patients were randomly allocated into either combined-stent group (n=17) or stent-graft group (control group, n=13) on the basis of a computer-generated randomization sequence. The PSC quality control, the patency rate of portal vein branches and the shunts, the incidence of encephalopathy and the survival rate of the two groups were documented and analyzed. Results: Technical success rate was 100%. After the treatment, in both groups the PSG became significantly lower than the PSG determined before the treatment (P<0.000). According to quality control chart, the of combined stents was superior to stent-graft technique in effectively controlling PSG. Five days after TIPS, the ammonia level in the combined- stent group was significantly decreased (P=0.029), while in the control group the ammonia level showed no significant changes (P=0.065). One patient died shortly after TIPS. The median follow- up time was 181 days. During the follow-up period death occurred in 3 cases in each group. The difference in the survival rate between the two groups was no significant (P=0.906). Of the three patients who developed encephalopathy, two were in the combined-stent group and one was in the control group. After medication the symptoms of encephalopathy were relieved. The patency rate of the shunts was 100% and the re-bleeding rate was 0% for both groups. The patency rate of portal vein branches was significantly higher in the combined-stent group than that in the control group (P=0.039). Conclusion: For the construction of TIPS, the technique of

Light propagation in linear optical media

CERN Document Server

Gillen, Glen D; Guha, Shekhar

2013-01-01

Light Propagation in Linear Optical Media describes light propagation in linear media by expanding on diffraction theories beyond what is available in classic optics books. In one volume, this book combines the treatment of light propagation through various media, interfaces, and apertures using scalar and vector diffraction theories. After covering the fundamentals of light and physical optics, the authors discuss light traveling within an anisotropic crystal and present mathematical models for light propagation across planar boundaries between different media. They describe the propagation o

Linear kinetic theory and particle transport in stochastic mixtures

Energy Technology Data Exchange (ETDEWEB)

Pomraning, G.C. [Univ. of California, Los Angeles, CA (United States)

1995-12-31

We consider the formulation of linear transport and kinetic theory describing energy and particle flow in a random mixture of two or more immiscible materials. Following an introduction, we summarize early and fundamental work in this area, and we conclude with a brief discussion of recent results.

Linear Power-Flow Models in Multiphase Distribution Networks: Preprint

Energy Technology Data Exchange (ETDEWEB)

Bernstein, Andrey; Dall' Anese, Emiliano

2017-05-26

This paper considers multiphase unbalanced distribution systems and develops approximate power-flow models where bus-voltages, line-currents, and powers at the point of common coupling are linearly related to the nodal net power injections. The linearization approach is grounded on a fixed-point interpretation of the AC power-flow equations, and it is applicable to distribution systems featuring (i) wye connections; (ii) ungrounded delta connections; (iii) a combination of wye-connected and delta-connected sources/loads; and, (iv) a combination of line-to-line and line-to-grounded-neutral devices at the secondary of distribution transformers. The proposed linear models can facilitate the development of computationally-affordable optimization and control applications -- from advanced distribution management systems settings to online and distributed optimization routines. Performance of the proposed models is evaluated on different test feeders.

Bayes linear statistics, theory & methods

CERN Document Server

Goldstein, Michael

2007-01-01

Bayesian methods combine information available from data with any prior information available from expert knowledge. The Bayes linear approach follows this path, offering a quantitative structure for expressing beliefs, and systematic methods for adjusting these beliefs, given observational data. The methodology differs from the full Bayesian methodology in that it establishes simpler approaches to belief specification and analysis based around expectation judgements. Bayes Linear Statistics presents an authoritative account of this approach, explaining the foundations, theory, methodology, and practicalities of this important field. The text provides a thorough coverage of Bayes linear analysis, from the development of the basic language to the collection of algebraic results needed for efficient implementation, with detailed practical examples. The book covers:The importance of partial prior specifications for complex problems where it is difficult to supply a meaningful full prior probability specification...

Accuracy of 1H magnetic resonance spectroscopy for quantification of 2-hydroxyglutarate using linear combination and J-difference editing at 9.4T.

Science.gov (United States)

Neuberger, Ulf; Kickingereder, Philipp; Helluy, Xavier; Fischer, Manuel; Bendszus, Martin; Heiland, Sabine

2017-12-01

Non-invasive detection of 2-hydroxyglutarate (2HG) by magnetic resonance spectroscopy is attractive since it is related to tumor metabolism. Here, we compare the detection accuracy of 2HG in a controlled phantom setting via widely used localized spectroscopy sequences quantified by linear combination of metabolite signals vs. a more complex approach applying a J-difference editing technique at 9.4T. Different phantoms, comprised out of a concentration series of 2HG and overlapping brain metabolites, were measured with an optimized point-resolved-spectroscopy sequence (PRESS) and an in-house developed J-difference editing sequence. The acquired spectra were post-processed with LCModel and a simulated metabolite set (PRESS) or with a quantification formula for J-difference editing. Linear regression analysis demonstrated a high correlation of real 2HG values with those measured with the PRESS method (adjusted R-squared: 0.700, pJ-difference editing method (adjusted R-squared: 0.908, pJ-difference editing method however had a significantly higher explanatory value over the regression model with the PRESS method (pJ-difference editing 2HG was discernible down to 1mM, whereas with the PRESS method 2HG values were not discernable below 2mM and with higher systematic errors, particularly in phantoms with high concentrations of N-acetyl-asparate (NAA) and glutamate (Glu). In summary, quantification of 2HG with linear combination of metabolite signals shows high systematic errors particularly at low 2HG concentration and high concentration of confounding metabolites such as NAA and Glu. In contrast, J-difference editing offers a more accurate quantification even at low 2HG concentrations, which outweighs the downsides of longer measurement time and more complex postprocessing. Copyright © 2017. Published by Elsevier GmbH.

Accuracy of 1H magnetic resonance spectroscopy for quantification of 2-hydroxyglutarate using linear combination and J-difference editing at 9.4 T

Energy Technology Data Exchange (ETDEWEB)

Neuberger, Ulf; Fischer, Manuel; Heiland, Sabine [Univ. of Heidelberg Medical Center, Heidelberg (Germany). Dept. of Neuroradiology; Univ. of Heidelberg Medical Center, Heidelberg (Germany). Div. of Experimental Radiology; Kickingereder, Philipp; Bendszus, Martin [Univ. of Heidelberg Medical Center, Heidelberg (Germany). Dept. of Neuroradiology; Helluy, Xavier [Bochum Univ. (Germany). Dept. of Biopsychology

2017-07-01

Non-invasive detection of 2-hydroxyglutarate (2HG) by magnetic resonance spectroscopy is attractive since it is related to tumor metabolism. Here, we compare the detection accuracy of 2HG in a controlled phantom setting via widely used localized spectroscopy sequences quantified by linear combination of metabolite signals vs. a more complex approach applying a J-difference editing technique at 9.4 T. Different phantoms, comprised out of a concentration series of 2HG and overlapping brain metabolites, were measured with an optimized point-resolved-spectroscopy sequence (PRESS) and an in-house developed J-difference editing sequence. The acquired spectra were post-processed with LCModel and a simulated metabolite set (PRESS) or with a quantification formula for J-difference editing. Linear regression analysis demonstrated a high correlation of real 2HG values with those measured with the PRESS method (adjusted R-squared: 0.700, p < 0.001) as well as with those measured with the J-difference editing method (adjusted R-squared: 0.908, p < 0.001). The regression model with the J-difference editing method however had a significantly higher explanatory value over the regression model with the PRESS method (p < 0.0001). Moreover, with J-difference editing 2HG was discernible down to 1 mM, whereas with the PRESS method 2HG values were not discernable below 2 mM and with higher systematic errors, particularly in phantoms with high concentrations of N-acetyl-asparate (NAA) and glutamate (Glu). In summary, quantification of 2HG with linear combination of metabolite signals shows high systematic errors particularly at low 2HG concentration and high concentration of confounding metabolites such as NAA and Glu. In contrast, J-difference editing offers a more accurate quantification even at low 2HG concentrations, which outweighs the downsides of longer measurement time and more complex postprocessing.

An efficient method for generalized linear multiplicative programming problem with multiplicative constraints.

Science.gov (United States)

Zhao, Yingfeng; Liu, Sanyang

2016-01-01

We present a practical branch and bound algorithm for globally solving generalized linear multiplicative programming problem with multiplicative constraints. To solve the problem, a relaxation programming problem which is equivalent to a linear programming is proposed by utilizing a new two-phase relaxation technique. In the algorithm, lower and upper bounds are simultaneously obtained by solving some linear relaxation programming problems. Global convergence has been proved and results of some sample examples and a small random experiment show that the proposed algorithm is feasible and efficient.

Efficient decomposition and linearization methods for the stochastic transportation problem

International Nuclear Information System (INIS)

Holmberg, K.

1993-01-01

The stochastic transportation problem can be formulated as a convex transportation problem with nonlinear objective function and linear constraints. We compare several different methods based on decomposition techniques and linearization techniques for this problem, trying to find the most efficient method or combination of methods. We discuss and test a separable programming approach, the Frank-Wolfe method with and without modifications, the new technique of mean value cross decomposition and the more well known Lagrangian relaxation with subgradient optimization, as well as combinations of these approaches. Computational tests are presented, indicating that some new combination methods are quite efficient for large scale problems. (authors) (27 refs.)

Physics possibilities at a linear collider

Indian Academy of Sciences (India)

Up to now the standard model (SM) has passed all accelerator-based experimental tests. .... Higgs sector and of the MSSM as well as for testing grand unification. ..... SPS1a scenario [33] for a coherent combination of LHC and linear collider.

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

Science.gov (United States)

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

2011-01-01

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

Effects of Combining a Brief Cognitive Intervention with Transcranial Direct Current Stimulation on Pain Tolerance: A Randomized Controlled Pilot Study.

Science.gov (United States)

Powers, Abigail; Madan, Alok; Hilbert, Megan; Reeves, Scott T; George, Mark; Nash, Michael R; Borckardt, Jeffrey J

2018-04-01

Cognitive behavioral therapy has been shown to be effective for treating chronic pain, and a growing literature shows the potential analgesic effects of minimally invasive brain stimulation. However, few studies have systematically investigated the potential benefits associated with combining approaches. The goal of this pilot laboratory study was to investigate the combination of a brief cognitive restructuring intervention and transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex in affecting pain tolerance. Randomized, double-blind, placebo-controlled laboratory pilot. Medical University of South Carolina. A total of 79 healthy adult volunteers. Subjects were randomized into one of six groups: 1) anodal tDCS plus a brief cognitive intervention (BCI); 2) anodal tDCS plus pain education; 3) cathodal tDCS plus BCI; 4) cathodal tDCS plus pain education; 5) sham tDCS plus BCI; and 6) sham tDCS plus pain education. Participants underwent thermal pain tolerance testing pre- and postintervention using the Method of Limits. A significant main effect for time (pre-post intervention) was found, as well as for baseline thermal pain tolerance (covariate) in the model. A significant time × group interaction effect was found on thermal pain tolerance. Each of the five groups that received at least one active intervention outperformed the group receiving sham tDCS and pain education only (i.e., control group), with the exception of the anodal tDCS + education-only group. Cathodal tDCS combined with the BCI produced the largest analgesic effect. Combining cathodal tDCS with BCI yielded the largest analgesic effect of all the conditions tested. Future research might find stronger interactive effects of combined tDCS and a cognitive intervention with larger doses of each intervention. Because this controlled laboratory pilot employed an acute pain analogue and the cognitive intervention did not authentically represent cognitive behavioral

Linear vs non-linear QCD evolution: from HERA data to LHC phenomenology

CERN Document Server

Albacete, J L; Quiroga-Arias, P; Rojo, J

2012-01-01

The very precise combined HERA data provides a testing ground in which the relevance of novel QCD regimes, other than the successful linear DGLAP evolution, in small-x inclusive DIS data can be ascertained. We present a study of the dependence of the AAMQS fits, based on the running coupling BK non-linear evolution equations (rcBK), on the fitted dataset. This allows for the identification of the kinematical region where rcBK accurately describes the data, and thus for the determination of its applicability boundary. We compare the rcBK results with NNLO DGLAP fits, obtained with the NNPDF methodology with analogous kinematical cuts. Further, we explore the impact on LHC phenomenology of applying stringent kinematical cuts to the low-x HERA data in a DGLAP fit.

On the Linear Stability of the Fifth-Order WENO Discretization

KAUST Repository

Motamed, Mohammad

2010-10-03

We study the linear stability of the fifth-order Weighted Essentially Non-Oscillatory spatial discretization (WENO5) combined with explicit time stepping applied to the one-dimensional advection equation. We show that it is not necessary for the stability domain of the time integrator to include a part of the imaginary axis. In particular, we show that the combination of WENO5 with either the forward Euler method or a two-stage, second-order Runge-Kutta method is linearly stable provided very small time step-sizes are taken. We also consider fifth-order multistep time discretizations whose stability domains do not include the imaginary axis. These are found to be linearly stable with moderate time steps when combined with WENO5. In particular, the fifth-order extrapolated BDF scheme gave superior results in practice to high-order Runge-Kutta methods whose stability domain includes the imaginary axis. Numerical tests are presented which confirm the analysis. © Springer Science+Business Media, LLC 2010.

On Combining Language Models: Oracle Approach

National Research Council Canada - National Science Library

Hacioglu, Kadri; Ward, Wayne

2001-01-01

In this paper, we address the of combining several language models (LMs). We find that simple interpolation methods, like log-linear and linear interpolation, improve the performance but fall short of the performance of an oracle...

Modeling of Volatility with Non-linear Time Series Model

OpenAIRE

Kim Song Yon; Kim Mun Chol

2013-01-01

In this paper, non-linear time series models are used to describe volatility in financial time series data. To describe volatility, two of the non-linear time series are combined into form TAR (Threshold Auto-Regressive Model) with AARCH (Asymmetric Auto-Regressive Conditional Heteroskedasticity) error term and its parameter estimation is studied.

A versatile programmable CAMAC random pulse generator

International Nuclear Information System (INIS)

Abdel-Aal, R.E.

1991-01-01

A new technique for generating linear pulses which can be random in both amplitude and time is described. With this technique, desired values for both pulse amplitude and spacing are set for the individual pulses by the software on a pulse-by-pulse basis. The versatility offered by this software programming allows a wide range of distributions to be obtained; with the user having close control on the distribution parameters. A number of such distributions may also be combined into a single output pulse stream. An implementation in a CAMAC module is presented. Both hardware and software aspects are described and typical performance results for amplitude and time distributions of the uniform and Gaussian type are given. Implications of using the pulser in a typical data acquisition environment on both the data acquisition and the pulser performance are considered. Typical applications are discussed together with some of the limitations. (orig.)

Modular Transformations, Order-Chaos Transitions and Pseudo-Random Number Generation

Science.gov (United States)

Bonelli, Antonio; Ruffo, Stefano

Successive pairs of pseudo-random numbers generated by standard linear congruential transformations display ordered patterns of parallel lines. We study the "ordered" and "chaotic" distribution of such pairs by solving the eigenvalue problem for two-dimensional modular transformations over integers. We conjecture that the optimal uniformity for pair distribution is obtained when the slope of linear modular eigenspaces takes the value n opt =maxint (p/√ {p-1}), where p is a prime number. We then propose a new generator of pairs of independent pseudo-random numbers, which realizes an optimal uniform distribution (in the "statistical" sense) of points on the unit square (0, 1] × (0, 1]. The method can be easily generalized to the generation of k-tuples of random numbers (with k>2).

Effect of health education combining diet and exercise supervision in Chinese women with perimenopausal symptoms: a randomized controlled trial.

Science.gov (United States)

Xi, S; Mao, L; Chen, X; Bai, W

2017-04-01

This study aimed to evaluate the effect of health education combining diet and exercise supervision on menopausal symptoms and diet/exercise habits. The randomized controlled study enrolled 60 patients with perimenopausal syndrome (Kupperman Menopause Index (KMI) score ≥15). The participants were randomized into either an intervention group (n = 30) or a control group (n = 30). Women were interviewed with questionnaires about perimenopausal symptoms, diet pattern and exercise habit. Their height and weight were measured. Women in the intervention group received health education, diet supervision and exercise supervision twice a week while those in the control group continued as normal. The total KMI score, scores of individual symptoms, diet pattern and exercise habit were measured after intervention. The total KMI score, the individual KMI scores for paresthesia, irritability, depression/suspicious, fatigue, arthralgia/myalgia, and palpitations of the intervention group were significantly lower compared with the control group after intervention. The intake of cereal, meat, fats and oils of the intervention group were significantly lower at week 12 compared with baseline. The percentage of women with a regular exercise habit was significantly higher in the intervention group than in the control group after intervention. Twelve weeks intervention of health education combining diet and exercise supervision could improve perimenopausal symptoms and help the patients establish good living habits.

Linear and non-linear Modified Gravity forecasts with future surveys

Science.gov (United States)

Casas, Santiago; Kunz, Martin; Martinelli, Matteo; Pettorino, Valeria

2017-12-01

Modified Gravity theories generally affect the Poisson equation and the gravitational slip in an observable way, that can be parameterized by two generic functions (η and μ) of time and space. We bin their time dependence in redshift and present forecasts on each bin for future surveys like Euclid. We consider both Galaxy Clustering and Weak Lensing surveys, showing the impact of the non-linear regime, with two different semi-analytical approximations. In addition to these future observables, we use a prior covariance matrix derived from the Planck observations of the Cosmic Microwave Background. In this work we neglect the information from the cross correlation of these observables, and treat them as independent. Our results show that η and μ in different redshift bins are significantly correlated, but including non-linear scales reduces or even eliminates the correlation, breaking the degeneracy between Modified Gravity parameters and the overall amplitude of the matter power spectrum. We further apply a Zero-phase Component Analysis and identify which combinations of the Modified Gravity parameter amplitudes, in different redshift bins, are best constrained by future surveys. We extend the analysis to two particular parameterizations of μ and η and consider, in addition to Euclid, also SKA1, SKA2, DESI: we find in this case that future surveys will be able to constrain the current values of η and μ at the 2-5% level when using only linear scales (wavevector k < 0 . 15 h/Mpc), depending on the specific time parameterization; sensitivity improves to about 1% when non-linearities are included.

INVERSION SYMMETRY, ARCHITECTURE AND DISPERSITY, AND THEIR EFFECTS ON THERMODYNAMICS IN BULK AND CONFINED REGIONS: FROM RANDOMLY BRANCHED POLYMERS TO LINEAR CHAINS, STARS AND DENDRIMERS

Directory of Open Access Journals (Sweden)

P.D.Gujrati

2002-01-01

Full Text Available Theoretical evidence is presented in this review that architectural aspects can play an important role, not only in the bulk but also in confined geometries by using our recursive lattice theory, which is equally applicable to fixed architectures (regularly branched polymers, stars, dendrimers, brushes, linear chains, etc. and variable architectures, i.e. randomly branched structures. Linear chains possess an inversion symmetry (IS of a magnetic system (see text, whose presence or absence determines the bulk phase diagram. Fixed architectures possess the IS and yield a standard bulk phase diagram in which there exists a theta point at which two critical lines C and C' meet and the second virial coefficient A2 vanishes. The critical line C appears only for infinitely large polymers, and an order parameter is identified for this criticality. The critical line C' exists for polymers of all sizes and represents phase separation criticality. Variable architectures, which do not possess the IS, give rise to a topologically different phase diagram with no theta point in general. In confined regions next to surfaces, it is not the IS but branching and monodispersity, which becomes important in the surface regions. We show that branching plays no important role for polydisperse systems, but become important for monodisperse systems. Stars and linear chains behave differently near a surface.

Accurate determination of interfacial protein secondary structure by combining interfacial-sensitive amide I and amide III spectral signals.

Science.gov (United States)

Ye, Shuji; Li, Hongchun; Yang, Weilai; Luo, Yi

2014-01-29

Accurate determination of protein structures at the interface is essential to understand the nature of interfacial protein interactions, but it can only be done with a few, very limited experimental methods. Here, we demonstrate for the first time that sum frequency generation vibrational spectroscopy can unambiguously differentiate the interfacial protein secondary structures by combining surface-sensitive amide I and amide III spectral signals. This combination offers a powerful tool to directly distinguish random-coil (disordered) and α-helical structures in proteins. From a systematic study on the interactions between several antimicrobial peptides (including LKα14, mastoparan X, cecropin P1, melittin, and pardaxin) and lipid bilayers, it is found that the spectral profiles of the random-coil and α-helical structures are well separated in the amide III spectra, appearing below and above 1260 cm(-1), respectively. For the peptides with a straight backbone chain, the strength ratio for the peaks of the random-coil and α-helical structures shows a distinct linear relationship with the fraction of the disordered structure deduced from independent NMR experiments reported in the literature. It is revealed that increasing the fraction of negatively charged lipids can induce a conformational change of pardaxin from random-coil to α-helical structures. This experimental protocol can be employed for determining the interfacial protein secondary structures and dynamics in situ and in real time without extraneous labels.

Linear Regression with a Randomly Censored Covariate: Application to an Alzheimer's Study.

Science.gov (United States)

Atem, Folefac D; Qian, Jing; Maye, Jacqueline E; Johnson, Keith A; Betensky, Rebecca A

2017-01-01

The association between maternal age of onset of dementia and amyloid deposition (measured by in vivo positron emission tomography (PET) imaging) in cognitively normal older offspring is of interest. In a regression model for amyloid, special methods are required due to the random right censoring of the covariate of maternal age of onset of dementia. Prior literature has proposed methods to address the problem of censoring due to assay limit of detection, but not random censoring. We propose imputation methods and a survival regression method that do not require parametric assumptions about the distribution of the censored covariate. Existing imputation methods address missing covariates, but not right censored covariates. In simulation studies, we compare these methods to the simple, but inefficient complete case analysis, and to thresholding approaches. We apply the methods to the Alzheimer's study.

A computational methodology for a micro launcher engine test bench using a combined linear static and dynamic in frequency response analysis

Directory of Open Access Journals (Sweden)

Ion DIMA

2017-03-01

Full Text Available This article aims to provide a quick methodology to determine the critical values of the forces, displacements and stress function of frequency, under a combined linear static (101 Solution - Linear Static and dynamic load in frequency response (108 Solution - Frequency Response, Direct Method, applied to a micro launcher engine test bench, using NASTRAN 400 Solution - Implicit Nonlinear. NASTRAN/PATRAN software is used. Practically in PATRAN the preprocessor has to define a linear or nonlinear static load at step 1 and a dynamic in frequency response load (time dependent at step 2. In Analyze the following options are chosen: for Solution Type Implicit Nonlinear Solution (SOL 400 is selected, for Subcases Static Load and Transient Dynamic is chosen and for Subcase Select the two cases static and dynamic will be selected. NASTRAN solver will overlap results from static analysis with the dynamic analysis. The running time will be reduced three times if using Krylov solver. NASTRAN SYSTEM (387 = -1 instruction is used in order to activate Krylov option. Also, in Analysis the OP2 Output Format shall be selected, meaning that in bdf NASTRAN input file the PARAM POST 1 instruction shall be written. The structural damping can be defined in two different ways: either at the material card or using the PARAM, G, 0.05 instruction (in this example a damping coefficient by 5% was used. The SDAMPING instruction in pair with TABDMP1 work only for dynamic in frequency response, modal method, or in direct method with viscoelastic material, not for dynamic in frequency response, direct method (DFREQ, with linear elastic material. The Direct method – DFREQ used in this example is more accurate. A set in translation of boundary conditions was used and defined at the base of the test bench.

Effect of upper extremity proprioceptive neuromuscular facilitation combined with elastic resistance bands on respiratory muscle strength: a randomized controlled trial

Directory of Open Access Journals (Sweden)

Guilherme P. T. Areas

2013-12-01

Full Text Available BACKGROUND: Elastic resistance bands (ERB combined with proprioceptive neuromuscular facilitation (PNF are often used in resistance muscle training programs, which have potential effects on peripheral muscle strength. However, the effects of the combination of ERB and PNF on respiratory muscle strength warrant further investigation. OBJECTIVES: The assessment of the effects of PNF combined with ERB on respiratory muscle strength. METHOD: Twenty healthy, right-handed females were included. Subjects were randomized to either the resistance training program group (TG, n=10 or the control group (CG, n=10. Maximal expiratory pressure (MEP and inspiratory pressure (MIP were measured before and after four weeks of an upper extremity resistance training program. The training protocol consisted of upper extremity PNF combined with ERB, with resistance selected from 1 repetition maximum protocol. RESULTS: PNF combined with ERB showed significant increases in MIP and MEP (p<0.05. In addition, there were significant differences between the TG and CG regarding ∆MIP (p=0.01 and ∆MEP (p=0.04. CONCLUSIONS: PNF combined with ERB can have a positive impact on respiratory muscle strength. These results may be useful with respect to cardiopulmonary chronic diseases that are associated with reduced respiratory muscle strength.

Polarized ensembles of random pure states

Science.gov (United States)

Deelan Cunden, Fabio; Facchi, Paolo; Florio, Giuseppe

2013-08-01

A new family of polarized ensembles of random pure states is presented. These ensembles are obtained by linear superposition of two random pure states with suitable distributions, and are quite manageable. We will use the obtained results for two purposes: on the one hand we will be able to derive an efficient strategy for sampling states from isopurity manifolds. On the other, we will characterize the deviation of a pure quantum state from separability under the influence of noise.

MODELS OF COVARIANCE FUNCTIONS OF GAUSSIAN RANDOM FIELDS ESCAPING FROM ISOTROPY, STATIONARITY AND NON NEGATIVITY

Directory of Open Access Journals (Sweden)

Pablo Gregori

2014-03-01

Full Text Available This paper represents a survey of recent advances in modeling of space or space-time Gaussian Random Fields (GRF, tools of Geostatistics at hand for the understanding of special cases of noise in image analysis. They can be used when stationarity or isotropy are unrealistic assumptions, or even when negative covariance between some couples of locations are evident. We show some strategies in order to escape from these restrictions, on the basis of rich classes of well known stationary or isotropic non negative covariance models, and through suitable operations, like linear combinations, generalized means, or with particular Fourier transforms.

Vitamin E and fish oil, separately or in combination, on treatment of primary dysmenorrhea: a double-blind, randomized clinical trial.

Science.gov (United States)

Sadeghi, Narges; Paknezhad, Farnoush; Rashidi Nooshabadi, Mohamadreza; Kavianpour, Maria; Jafari Rad, Sima; Khadem Haghighian, Hossein

2018-03-15

Primary dysmenorrhea is one of the most common complaints of women. The aim of this study was to investigate the adjuvant effect of vitamin E and omega-3 fatty acids, separately or in combination, supplements on pain in the treatment of primary dysmenorrhea. This clinical trial conducted on students of university. Qualified girls completed the VAS before randomization. Arrangement was determined according to the severity of the pain (mild 0-3; moderate 3.1-6; severe 6.1-10). One hundred patients were randomly assigned to four groups receiving omega-3 (n = 25), vitamin E (n = 25), vitamin E- omega-3 (n = 25), or placebo (n = 25). Three hundred milligrams of omega-3 capsules (180 mg EPA and 120 mg DHA) and 200 international units (IU) vitamin E were administered daily. Severity of the pain measured in the beginning and the end of the study. Omega-3 and vitamin E supplements effectively relieved menstrual pain compared with the placebo. But in group with combination of vitamin E + omega-3 has a considerable effect on menstrual pain when compared with other groups (p E are helpful in reducing of dysmenorrhea pain and can be replaced with them.

Solution of the linearly anisotropic neutron transport problem in a infinite cylinder combining the decomposition and HTSN methods

International Nuclear Information System (INIS)

Goncalves, Glenio A.; Bodmann, Bardo; Bogado, Sergio; Vilhena, Marco T.

2008-01-01

Analytical solutions for neutron transport in cylindrical geometry is available for isotropic problems, but to the best of our knowledge for anisotropic problems are not available, yet. In this work, an analytical solution for the neutron transport equation in an infinite cylinder assuming anisotropic scattering is reported. Here we specialize the solution, without loss of generality, for the linearly anisotropic problem using the combined decomposition and HTS N methods. The key feature of this method consists in the application of the decomposition method to the anisotropic problem by virtue of the fact that the inverse of the operator associated to isotropic problem is well know and determined by the HTS N approach. So far, following the idea of the decomposition method, we apply this operator to the integral term, assuming that the angular flux appearing in the integrand is considered to be equal to the HTS N solution interpolated by polynomial considering only even powers. This leads to the first approximation for an anisotropic solution. Proceeding further, we replace this solution for the angular flux in the integral and apply again the inverse operator for the isotropic problem in the integral term and obtain a new approximation for the angular flux. This iterative procedure yields a closed form solution for the angular flux. This methodology can be generalized, in a straightforward manner, for transport problems with any degree of anisotropy. For the sake of illustration, we report numerical simulations for linearly anisotropic transport problems. (author)

Effects of a new combination of nutraceuticals with Morus alba on lipid profile, insulin sensitivity and endotelial function in dyslipidemic subjects. A cross-over, randomized, double-blind trial.

Science.gov (United States)

Trimarco, Valentina; Izzo, Raffaele; Stabile, Eugenio; Rozza, Francesco; Santoro, Mario; Manzi, Maria Virginia; Serino, Federica; Schiattarella, Gabriele Giacomo; Esposito, Giovanni; Trimarco, Bruno

2015-06-01

Nutraceuticals (NUT) are forms of compounds with biological activity commonly used to improve health in dosage largely exceeding those obtainable in food. We compared, in a double blind randomized cross-over trial, the effects of two NUT combinations on the control of glico-lipidic metabolism in patients with hypercholesterolemia not on statins. At study start patients were given dietary counseling and received placebo for 2 weeks. After this run-in period, patients were randomized: (1) Combination A [Policosanol, Red yeast rice (Monakolin K 3 mg), Berberine 500 mg, Astaxantine, Folic Acid and Coenzyme Q10] for 4 weeks followed by 4 weeks of Combination B [Red yeast rice (Monakolin K 3.3 mg), Berberine 531.25 mg and leaf extract of Morus alba]; (2) Combination B for 4 weeks followed by 4 weeks of Combination A. Combination B reduced LDL cholesterol below 130 mg/dl in 56.5 % of the patients, and Cambination A only in 21.7 % of them (p ≤ 0.027). Both treatments reduced plasma levels of triglycerides, total and LDL cholesterol and increased HDL cholesterol (all p Morus alba extract improves the effect on plasma cholesterol and on glucose metabolism of the NUT Combination. These effects may allow the speculation of a more marked improvement in cardiovascular prognosis.

Midportion achilles tendon microcirculation after intermittent combined cryotherapy and compression compared with cryotherapy alone: a randomized trial.

Science.gov (United States)

Knobloch, Karsten; Grasemann, Ruth; Spies, Marcus; Vogt, Peter M

2008-11-01

The effect of combined cryotherapy/compression versus cryotherapy alone on the Achilles tendon is undetermined. Standardized combined cryotherapy/compression changes in midportion Achilles tendon microcirculation are superior to those with cryotherapy during intermittent application. Controlled laboratory study. Sixty volunteers were randomized for either combined cryotherapy/compression (Cryo/Cuff, DJO Inc, Vista, California: n = 30; 32 +/- 11 years) or cryotherapy alone (KoldBlue, TLP Industries, Kent, United Kingdom: n = 30; 33 +/- 12 years) with intermittent 3 x 10-minute application. Midportion Achilles tendon microcirculation was determined (O2C, LEA Medizintechnik, Giessen, Germany). Both Cryo/Cuff and KoldBlue significantly reduced superficial and deep capillary tendon blood flow within the first minute of application (43 +/- 46 arbitrary units [AU] vs 10 +/- 19 AU and 42 +/- 46 AU vs 12 +/- 10 AU; P = .0001) without a significant difference throughout all 3 applications. However, during recovery, superficial and deep capillary blood flow was reestablished significantly faster using Cryo/Cuff (P = .023). Tendon oxygen saturation was reduced in both groups significantly (3 minutes Cryo/Cuff: 36% +/- 20% vs 16% +/- 15%; KoldBlue: 42% +/- 19% vs 28% +/- 20%; P cryotherapy and compression with significantly increased tendon oxygen saturation during recovery in contrast to cryotherapy alone. Both regimens lead to a significant amelioration of tendinous venous outflow. Combined cryotherapy and compression is superior to cryotherapy alone regarding the Achilles tendon microcirculation. Further studies in tendinopathy and tendon rehabilitation are warranted to elucidate its value regarding functional issues.

On the Optimal Location of Sensors for Parametric Identification of Linear Systems

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Brincker, Rune

1994-01-01

. It is assumed most often that the results of the measurements are statistically independent random variables. In an example the importance of considering the measurements as statistically dependent random variables is shown. The covariance of the model parameters expected to be obtained is investigated......An outline of the field of optimal location of sensors for parametric identification of linear structural systems is presented. There are few papers devoted to the case of optimal location of sensors in which the measurements are modeled by a random field with non-trivial covariance function...

First passage times for combinations of random loads

OpenAIRE

Jacobs, Patricia A.

1985-01-01

Structures are subject to changing loads from various sources. In many instances these loads fluctuate in time apparently random fashion. Models are considered for which the stress put on the structure by various loads simultaneously can be described by a regenerative process. The distribution of the first time until the stress on the structure exceeds a given level x is studied. Asymptotic properties of the distribution are given for a large stress level x and for the tail of the distributio...

Damping Estimation of Friction Systems in Random Vibrations

DEFF Research Database (Denmark)

Friis, Tobias; Katsanos, Evangelos; Amador, Sandro

Friction is one of the most efficient and economical mechanisms to reduce vibrations in structural mechanics. However, the estimation of the equivalent linear damping of the friction damped systems in experimental modal analysis and operational modal analysis can be adversely affected by several...... assumptions regarding the definition of the linear damping and the identification methods or may be lacking a meaningful interpretation of the damping. Along these lines, this project focuses on assessing the potential to estimate efficiently the equivalent linear damping of friction systems in random...

Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

Science.gov (United States)

Coffey, Howard T.

1993-01-01

A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle leviation.

Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

Science.gov (United States)

Coffey, H.T.

1993-10-19

A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle levitation. 3 figures.

Dapsone gel 5% in combination with adapalene gel 0.1%, benzoyl peroxide gel 4% or moisturizer for the treatment of acne vulgaris: a 12-week, randomized, double-blind study.

Science.gov (United States)

Fleischer, Alan B; Shalita, Alan; Eichenfield, Lawrence F; Abramovits, William; Lucky, Anne; Garrett, Steven

2010-01-01

To evaluate the safety and efficacy of dapsone gel 5% in the treatment of acne when used in combination with adapalene gel 0.1%, benzoyl peroxide gel 4% or moisturizer. This was a twelve-week, randomized, double-blind study. Patients aged 12 years and older (n=301) applied dapsone gel twice daily and were randomly assigned (1:1:1) to one of three additional treatments, applied once daily. By week 12, dapsone gel combined with any of the three additional treatments reduced the mean number of inflammatory lesions. However, the authors did not detect a significant difference in the reduction of inflammatory lesions when dapsone was used in combination with adapalene gel or with benzoyl peroxide gel compared to the dapsone plus moisturizer combination group (P=0.052 for both versus moisturizer combination). Patients treated with dapsone gel combined with adapalene showed a significantly better response in reduction in non-inflammatory and total acne lesion count than those who received the moisturizer combination. Local adverse reactions in all three treatment groups were minimal and generally mild in severity. Dapsone gel in combination with adapalene gel or benzoyl peroxide gel is safe and well tolerated for the treatment of acne vulgaris.

Continuous-Time Mean-Variance Portfolio Selection with Random Horizon

International Nuclear Information System (INIS)

Yu, Zhiyong

2013-01-01

This paper examines the continuous-time mean-variance optimal portfolio selection problem with random market parameters and random time horizon. Treating this problem as a linearly constrained stochastic linear-quadratic optimal control problem, I explicitly derive the efficient portfolios and efficient frontier in closed forms based on the solutions of two backward stochastic differential equations. Some related issues such as a minimum variance portfolio and a mutual fund theorem are also addressed. All the results are markedly different from those in the problem with deterministic exit time. A key part of my analysis involves proving the global solvability of a stochastic Riccati equation, which is interesting in its own right

Continuous-Time Mean-Variance Portfolio Selection with Random Horizon

Energy Technology Data Exchange (ETDEWEB)

Yu, Zhiyong, E-mail: yuzhiyong@sdu.edu.cn [Shandong University, School of Mathematics (China)

2013-12-15

This paper examines the continuous-time mean-variance optimal portfolio selection problem with random market parameters and random time horizon. Treating this problem as a linearly constrained stochastic linear-quadratic optimal control problem, I explicitly derive the efficient portfolios and efficient frontier in closed forms based on the solutions of two backward stochastic differential equations. Some related issues such as a minimum variance portfolio and a mutual fund theorem are also addressed. All the results are markedly different from those in the problem with deterministic exit time. A key part of my analysis involves proving the global solvability of a stochastic Riccati equation, which is interesting in its own right.

Linear Programming, the Simplex Algorithm and Simple Polytopes

Directory of Open Access Journals (Sweden)

Das Bhusan

2010-09-01

Full Text Available In the first part of the paper we survey some far reaching applications of the basis facts of linear programming to the combinatorial theory of simple polytopes. In the second part we discuss some recent developments concurring the simplex algorithm. We describe sub-exponential randomized pivot roles and upper bounds on the diameter of graphs of polytopes.

Random skew plane partitions with a piecewise periodic back wall

DEFF Research Database (Denmark)

Boutillier, Cedric; Mkrtchyan, Sevak; Reshetikhin, Nicolai

Random skew plane partitions of large size distributed according to an appropriately scaled Schur process develop limit shapes. In the present work we consider the limit of large random skew plane partitions where the inner boundary approaches a piecewise linear curve with non-lattice slopes. Muc...

Evaluation of film dosemeters by linear programming

International Nuclear Information System (INIS)

Kragh, P.; Nitschke, J.

1992-01-01

An evaluation method for multi-component dosemeters is described which uses linear programming in order to decrease the dependence on energy and direction. The results of this method are more accurate than those obtained with the evaluation methods so far applied in film dosimetry. In addition, systematic errors can be given when evaluating individual measurements. Combined linear programming, as a special case of the presented method, is described taking a film dosemeter of particular type as an example. (orig.) [de

Modelos linear e não linear em análises genéticas para sobrevivência de crias de ovinos da raça Santa Inês Linear and nonlinear models in genetic analyses of lamb survival in the Santa Inês hair sheep breed

Directory of Open Access Journals (Sweden)

W.H. Sousa

1999-06-01

Full Text Available Registros de sobrevivência do nascimento ao desmame de 3846 crias de ovinos da raça Santa Inês foram analisados por modelos de reprodutor linear e não linear (modelo de limiar, para estimar componentes de variância e herdabilidade. Os modelos usados para sobrevivência, analisada como característica da cria, incluíram os efeitos fixos de sexo, da combinação tipo de nascimento-criação da cria e da idade da ovelha ao parto, efeito da covariável peso da cria ao nascer e efeitos aleatórios de reprodutor, da classe rebanho-ano-estação e do resíduo. Componentes de variância para o modelo linear foram estimados pelo método da máxima verossimilhança restrita (REML e para o modelo não linear por uma aproximação da máxima verossimilhança marginal (MML, pelo programa CMMAT2. O coeficiente de herdabilidade (h² estimado pelo modelo de limiar foi de 0,29, e pelo modelo linear, 0,14. A correlação de ordem de Spearman entre as capacidades de transmissão dos reprodutores, com base nos dois modelos foi de 0,96. As estimativas de h² obtidas indicam a possibilidade de se obter, por seleção, ganho genético para sobrevivência.Records of 3,846 lambs survival from birth to weaning of Santa Inês hair sheep breed, were analyzed by linear and non linear sire models (threshold model to estimate variance components and heritability (h². The models that were used to analyze survival, considered in this study as a lamb trait, included the fixed effects of sex of the lamb, combination of type of birth-rearing of lamb, and age of ewe, birth weight of lamb as covariate, and random effects of sire, herd-year-season and residual. Variance components were obtained using restricted maximum likelihood (REML, in linear model and marginal maximum likelihood in threshold model through CMMAT2 program. Estimate of heritability (h² obtained by threshold model was 0.29 and by linear model was 0.14. Rank correlation of Spearman, between sire solutions

Polarized ensembles of random pure states

International Nuclear Information System (INIS)

Cunden, Fabio Deelan; Facchi, Paolo; Florio, Giuseppe

2013-01-01

A new family of polarized ensembles of random pure states is presented. These ensembles are obtained by linear superposition of two random pure states with suitable distributions, and are quite manageable. We will use the obtained results for two purposes: on the one hand we will be able to derive an efficient strategy for sampling states from isopurity manifolds. On the other, we will characterize the deviation of a pure quantum state from separability under the influence of noise. (paper)

Effect of fixed-dose combinations of ezetimibe plus rosuvastatin in patients with primary hypercholesterolemia: MRS-ROZE (Multicenter Randomized Study of ROsuvastatin and eZEtimibe).

Science.gov (United States)

Kim, Kyung-Jin; Kim, Sang-Hyun; Yoon, Young Won; Rha, Seung-Woon; Hong, Soon-Jun; Kwak, Choong-Hwan; Kim, Weon; Nam, Chang-Wook; Rhee, Moo-Yong; Park, Tae-Ho; Hong, Taek-Jong; Park, Sungha; Ahn, Youngkeun; Lee, Namho; Jeon, Hui-Kyung; Jeon, Dong-Woon; Han, Kyoo-Rok; Moon, Keon-Woong; Chae, In-Ho; Kim, Hyo-Soo

2016-10-01

We aimed to compare the effects of fixed-dose combinations of ezetimibe plus rosuvastatin to rosuvastatin alone in patients with primary hypercholesterolemia, including a subgroup analysis of patients with diabetes mellitus (DM) or metabolic syndrome (MetS). This multicenter eight-week randomized double-blind phase III study evaluated the safety and efficacy of fixed-dose combinations of ezetimibe 10 mg plus rosuvastatin, compared with rosuvastatin alone in patients with primary hypercholesterolemia. Four hundred and seven patients with primary hypercholesterolemia who required lipid-lowering treatment according to the ATP III guideline were randomized to one of the following six treatments for 8 weeks: fixed-dose combinations with ezetimibe 10 mg daily plus rosuvastatin (5, 10, or 20 mg daily) or rosuvastatin alone (5, 10, or 20 mg daily). Fixed-dose combination of ezetimibe plus rosuvastatin significantly reduced LDL cholesterol, total cholesterol, and triglyceride levels compared with rosuvastatin alone. Depending on the rosuvastatin dose, these fixed-dose combinations of ezetimibe plus rosuvastatin provided LDL cholesterol, total cholesterol, and triglyceride reductions of 56%-63%, 37%-43%, and 19%-24%, respectively. Moreover, the effect of combination treatment on cholesterol levels was more pronounced in patients with DM or MetS than in non-DM or non-MetS patients, respectively, whereas the effect of rosuvastatin alone did not differ between DM vs non-DM or MetS vs non-MetS patients. Fixed-dose combinations of ezetimibe and rosuvastatin provided significantly superior efficacy to rosuvastatin alone in lowering LDL cholesterol, total cholesterol, and triglyceride levels. Moreover, the reduction rate was greater in patients with DM or MetS. © 2016 The Authors Cardiovascular Therapeutics Published by John Wiley & Sons Ltd.

Alternate approaches to future electron-positron linear colliders

International Nuclear Information System (INIS)

Loew, G.A.

1998-01-01

The purpose of this article is two-fold: to review the current international status of various design approaches to the next generation of e + e - linear colliders, and on the occasion of his 80th birthday, to celebrate Richard B. Neal's many contributions to the field of linear accelerators. As it turns out, combining these two tasks is a rather natural enterprise because of Neal's long professional involvement and insight into many of the problems and options which the international e + e - linear collider community is currently studying to achieve a practical design for a future machine

A randomized phase 2 study of combination cediranib and olaparib versus olaparib alone as recurrence therapy in platinum-sensitive ovarian cancer

Science.gov (United States)

Liu, Joyce F.; Barry, William T.; Birrer, Michael; Lee, Jung-Min; Buckanovich, Ronald J.; Fleming, Gini F.; Rimel, BJ; Buss, Mary K.; Nattam, Sreenivasa; Hurteau, Jean; Luo, Weixiu; Quy, Philippa; Whalen, Christin; Obermayer, Lisa; Lee, Hang; Winer, Eric P.; Kohn, Elise C.; Ivy, S. Percy; Matulonis, Ursula A.

2015-01-01

Background Olaparib is an oral poly(ADP-ribose) polymerase inhibitor and cediranib is an oral anti-angiogenic with activity against VEGFR-1, 2, and 3. Both agents have antitumor activity in women with recurrent ovarian cancer, and the combination of these agents was active and had manageable toxicities in a Phase 1 trial. We asked whether the combination of cediranib and olaparib could improve progression-free survival compared to olaparib monotherapy in women with recurrent platinum-sensitive ovarian cancer. Methods We conducted a randomized, open-label, phase 2 study to evaluate the activity of olaparib monotherapy compared with combination cediranib and olaparib in women with ovarian cancer with measurable platinum-sensitive, relapsed, high-grade serous or endometrioid disease or those with deleterious germline BRCA1/2 mutations (gBRCAm). Patients were randomized using permuted blocks within stratum defined by gBRCA status and prior anti-angiogenic therapy to receive olaparib capsules 400mg twice daily or the combination at the recommended phase 2 dose of cediranib 30mg daily and olaparib capsules 200mg twice daily. The primary endpoint was progression-free survival (PFS) analyzed under intention to treat. The trial is registered with ClinicalTrials.gov, NCT01116648. The Phase 2 portion of the trial reported here is no longer accruing patients. Findings Forty-six of 90 randomized patients received olaparib alone, and 44 received cediranib/olaparib. Median PFS was significantly longer with cediranib/olaparib (17.7 vs. 9.0 mos, HR 0.42; p = 0.005). Grade 3 and 4 adverse events were more common with cediranib/olaparib, including fatigue (12 vs. 5), diarrhea (10 vs. 0), and hypertension (18 vs. 0). Subset analysis within stratum defined by BRCA1/2 status demonstrated activity of cediranib/olaparib in both gBRCAm and gBRCAwt/u (wild-type/unknown) patients. Significant improvement in PFS occurred in gBRCAwt/u women receiving cediranib/olaparib (16.5 vs. 5.7 mos, p = 0

Linear b-gauges for open string fields

International Nuclear Information System (INIS)

Kiermaier, Michael; Zwiebach, Barton; Sen, Ashoke

2008-01-01

Motivated by Schnabl's gauge choice, we explore open string perturbation theory in gauges where a linear combination of antighost oscillators annihilates the string field. We find that in these linear b-gauges different gauge conditions are needed at different ghost numbers. We derive the full propagator and prove the formal properties which guarantee that the Feynman diagrams reproduce the correct on-shell amplitudes. We find that these properties can fail due to the need to regularize the propagator, and identify a large class of linear b-gauges for which they hold rigorously. In these gauges the propagator has a non-anomalous Schwinger representation and builds Riemann surfaces by adding strip-like domains. Projector-based gauges, like Schnabl's, are not in this class of gauges but we construct a family of regular linear b-gauges which interpolate between Siegel gauge and Schnabl gauge

The random continued fraction transformation

Science.gov (United States)

Kalle, Charlene; Kempton, Tom; Verbitskiy, Evgeny

2017-03-01

We introduce a random dynamical system related to continued fraction expansions. It uses random combinations of the Gauss map and the Rényi (or backwards) continued fraction map. We explore the continued fraction expansions that this system produces, as well as the dynamical properties of the system.

Combining numerical simulations with time-domain random walk for pathogen risk assessment in groundwater

Science.gov (United States)

Cvetkovic, V.; Molin, S.

2012-02-01

We present a methodology that combines numerical simulations of groundwater flow and advective transport in heterogeneous porous media with analytical retention models for computing the infection risk probability from pathogens in aquifers. The methodology is based on the analytical results presented in [1,2] for utilising the colloid filtration theory in a time-domain random walk framework. It is shown that in uniform flow, the results from the numerical simulations of advection yield comparable results as the analytical TDRW model for generating advection segments. It is shown that spatial variability of the attachment rate may be significant, however, it appears to affect risk in a different manner depending on if the flow is uniform or radially converging. In spite of the fact that numerous issues remain open regarding pathogen transport in aquifers on the field scale, the methodology presented here may be useful for screening purposes, and may also serve as a basis for future studies that would include greater complexity.

Influence of defects on the effective electrical conductivity of a monolayer produced by random sequential adsorption of linear k-mers onto a square lattice

Science.gov (United States)

Tarasevich, Yuri Yu.; Laptev, Valeri V.; Goltseva, Valeria A.; Lebovka, Nikolai I.

2017-07-01

The effect of defects on the behaviour of electrical conductivity, σ, in a monolayer produced by the random sequential adsorption of linear k-mers (particles occupying k adjacent sites) onto a square lattice is studied by means of a Monte Carlo simulation. The k-mers are deposited on the substrate until a jamming state is reached. The presence of defects in the lattice (impurities) and of defects in the k-mers with concentrations of dl and dk, respectively, is assumed. The defects in the lattice are distributed randomly before deposition and these lattice sites are forbidden for the deposition of k-mers. The defects of the k-mers are distributed randomly on the deposited k-mers. The sites filled with k-mers have high electrical conductivity, σk, whereas the empty sites, and the sites filled by either types of defect have a low electrical conductivity, σl, i.e., a high-contrast, σk /σl ≫ 1, is assumed. We examined isotropic (both the possible x and y orientations of a particle are equiprobable) and anisotropic (all particles are aligned along one given direction, y) deposition. To calculate the effective electrical conductivity, the monolayer was presented as a random resistor network and the Frank-Lobb algorithm was used. The effects of the concentrations of defects dl and dk on the electrical conductivity for the values of k =2n, where n = 1 , 2 , … , 5, were studied. Increase of both the dl and dk parameters values resulted in decreases in the value of σ and the suppression of percolation. Moreover, for anisotropic deposition the electrical conductivity along the y direction was noticeably larger than in the perpendicular direction, x. Phase diagrams in the (dl ,dk)-plane for different values of k were obtained.

A randomized controlled study of the efficacy of tamsulosin monotherapy and its combination with mirabegron for overactive bladder induced by benign prostatic obstruction.

Science.gov (United States)

Ichihara, Koji; Masumori, Naoya; Fukuta, Fumimasa; Tsukamoto, Taiji; Iwasawa, Akihiko; Tanaka, Yoshinori

2015-03-01

We evaluated the efficacy and safety of add-on treatment with a β3-adrenoceptor agonist (mirabegron) for overactive bladder symptoms remaining after α1-blocker (tamsulosin) treatment in men with benign prostatic obstruction. Patients with benign prostatic obstruction with urinary urgency at least once per week and a total OABSS of 3 or more points after 8 or more weeks of treatment with tamsulosin were enrolled in the study. They were randomly allocated to receive 0.2 mg tamsulosin daily or 0.2 mg tamsulosin and 50 mg mirabegron daily for 8 weeks. The primary end point was change in total OABSS. Safety assessments included change in post-void residual urine volume and adverse events. From January 2012 through September 2013 a total of 94 patients were randomized. Of these patients 76 completed the protocol treatment. In the full analysis set the change in total OABSS during the treatment period was significantly greater in the combination group than in the monotherapy group (-2.21 vs -0.87, p=0.012). The changes in scores for urinary urgency, daytime frequency, International Prostate Symptom Score storage symptom subscore and quality of life index at 8 weeks were significantly greater in the combination group. The change in post-void residual urine volume was significantly greater in the combination group. Although 6 patients experienced adverse events in the combination group, urinary retention was observed in only 1 patient. Combined tamsulosin and mirabegron treatment is effective and safe for patients with benign prostatic obstruction who have overactive bladder symptoms after tamsulosin monotherapy. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Fault tolerance in parity-state linear optical quantum computing

International Nuclear Information System (INIS)

Hayes, A. J. F.; Ralph, T. C.; Haselgrove, H. L.; Gilchrist, Alexei

2010-01-01

We use a combination of analytical and numerical techniques to calculate the noise threshold and resource requirements for a linear optical quantum computing scheme based on parity-state encoding. Parity-state encoding is used at the lowest level of code concatenation in order to efficiently correct errors arising from the inherent nondeterminism of two-qubit linear-optical gates. When combined with teleported error-correction (using either a Steane or Golay code) at higher levels of concatenation, the parity-state scheme is found to achieve a saving of approximately three orders of magnitude in resources when compared to the cluster state scheme, at a cost of a somewhat reduced noise threshold.

Quantum associative memory with linear and non-linear algorithms for the diagnosis of some tropical diseases.

Science.gov (United States)

Tchapet Njafa, J-P; Nana Engo, S G

2018-01-01

This paper presents the QAMDiagnos, a model of Quantum Associative Memory (QAM) that can be a helpful tool for medical staff without experience or laboratory facilities, for the diagnosis of four tropical diseases (malaria, typhoid fever, yellow fever and dengue) which have several similar signs and symptoms. The memory can distinguish a single infection from a polyinfection. Our model is a combination of the improved versions of the original linear quantum retrieving algorithm proposed by Ventura and the non-linear quantum search algorithm of Abrams and Lloyd. From the given simulation results, it appears that the efficiency of recognition is good when particular signs and symptoms of a disease are inserted given that the linear algorithm is the main algorithm. The non-linear algorithm helps confirm or correct the diagnosis or give some advice to the medical staff for the treatment. So, our QAMDiagnos that has a friendly graphical user interface for desktop and smart-phone is a sensitive and a low-cost diagnostic tool that enables rapid and accurate diagnosis of four tropical diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Premium Pricing of Liability Insurance Using Random Sum Model

Directory of Open Access Journals (Sweden)

Mujiati Dwi Kartikasari

2017-03-01

Full Text Available Premium pricing is one of important activities in insurance. Nonlife insurance premium is calculated from expected value of historical data claims. The historical data claims are collected so that it forms a sum of independent random number which is called random sum. In premium pricing using random sum, claim frequency distribution and claim severity distribution are combined. The combination of these distributions is called compound distribution. By using liability claim insurance data, we analyze premium pricing using random sum model based on compound distribution

Combined application of eicosapentaenoic acid and docosahexaenoic acid on depression in women: a meta-analysis of double-blind randomized controlled trials

Directory of Open Access Journals (Sweden)

Yang JR

2015-08-01

Full Text Available Jia-run Yang, Dong Han, Zheng-xue Qiao, Xue Tian, Dong Qi, Xiao-hui QiuDepartment of Medical Psychology, Public Health Institute of Harbin Medical University, Harbin, Heilongjiang Province, People’s Republic of ChinaObjectives: Previous randomized controlled trials (RCTs suggest that depression can be effectively treated by omega-3 polyunsaturated fatty acids (PUFAs. Therefore, we conducted this meta-analysis to systematically evaluate the clinical applicability of the combination of docosahexaenoic acid (DHA and eicosapentaenoic acid (EPA, which are the two major bioactive types of PUFAs, in depressed women.Methods: RCTs that compared the combination of DHA and EPA to placebo for short-course treatment of depression in women were systematically reviewed up to March 2015. Outcome measurement was the standardized difference in means in clinical measure of depression severity. Random effect model was performed. Meta-regression analysis was performed to assess the effects of baseline depression scores.Results: Data were obtained from eight RCTs. In these RCTs, 182 patients received placebo and 185 patients received DHA and EPA. The pooled standardized difference in mean was 0.65 with 95% CI = [0.18, 1.12]. There was no relation between the efficacy and the baseline depression scores. The sensitivity analysis found that the combination of EPA and DHA as monotherapy yielded a standardized difference in means of 0.65 (95% CI =0.41, 0.90 without heterogeneity.Discussion: These results indicate a beneficial effect of the combination of EPA and DHA on depressed mood in women compared with placebo. The clinical applicability of EPA and DHA showed greater promise and should be further explored.Keywords: depression, omega-3 polyunsaturated fatty acids, PUFAs, docosahexaenoic acid, DHA, eicosapentaenoic acid, EPA

An efficient linear power generator - Linear motor for oscillating piston machines; Effizienter Lineargenerator / Linearmotor fuer Kolbenmaschine - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Lindegger, M.

2008-07-01

When an oscillating piston interacts with an electrical generator or motor, it is obvious that the electrical machine should also have linear motion, eliminating the disadvantage of a crankshaft. This work has two parts: construction of an efficient linear generator for a Stirling engine with a free piston and a theoretical study of the efficiency of linear motors for driving compressors. The Stirling engine and the linear generator have a continuous power of 1.3 kW{sub el}. With thermal peak power the planned 1.5 kW{sub el} are attained. The Project 'Stirling Free Piston Generator' for cogeneration will continue. Smaller linear motors with permanent magnets function without electronic control from single-phase AC net. The theoretical study shows how linear motors can be led out by linking the electric vector diagram with the pressure-volume diagram of the compressor. At a power level exceeding a few kW, a three-phase system with power electronics is more suitable. The frequency of oscillation is variable and lower than 50 Hz. The efficiency of the simulated linear motors lies in the range of efficiency class EFF1 of standard motors. The very high efficiencies of rotating motors with permanent magnets are not attained. The combination of the linear motor with an optimised thermal process leads to advantages regarding the efficiency. If a heat pump with linear drive system can operate with hot lubricating oil the losses in the heat exchangers are reduced. The Competence Center for Thermal Machines at Lucerne University of Applied Sciences and Arts shows great interest to pursue the project of a linear heat pump for small temperature differences. (author)

Randomized trial of amino acid mixture combined with physical activity promotion for abdominal fat reduction in overweight adults

Directory of Open Access Journals (Sweden)

Ueda K

2018-02-01

Full Text Available Keisuke Ueda,1,2 Hiroyuki Sasai,3 Takehiko Tsujimoto,4 Chiaki Sanbongi,1 Shuji Ikegami,1 Hiroyuki Kobayashi,5 Nobuhiko Shioya,6 Satoru Suzuki,7 Yoshio Nakata5 1Food Science and Technology Research Laboratories, Meiji Co., Ltd, Hachiouji, 2Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, 3Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, 4Faculty of Human Sciences, Shimane University, Matsue, 5Faculty of Medicine, University of Tsukuba, Tsukuba, 6KSO Corporation, Tokyo, 7Shinagawa Season Terrace Health Care Clinic, Tokyo, Japan Purpose: The purpose of this study was to test the efficacy of arginine, alanine, and phenylalanine mixture (A-mix ingestion at 1,500 mg/day in combination with the promotion of physical activity for abdominal fat reduction in overweight adults.Methods: A placebo-controlled, double-blind, parallel-group, randomized trial for 12 weeks combined with a 4-week follow-up period was conducted at a single center in Minato-ku, Tokyo, Japan, between December 2016 and May 2017. Data were analyzed between June and August 2017. The study participants were 200 overweight adults within the age range of 20–64 years. The participants were randomly assigned to the A-mix group (n=100 or a placebo group (n=100 and were administered 500 mL of test beverage containing 1,500 or 0 mg of A-mix, respectively, for 12 weeks. All participants maintained a physically active lifestyle between week 0 and week 12 through monthly sessions of physical activity. The primary outcomes were the 12-week changes in the abdominal total, subcutaneous, and visceral fat areas, as assessed by computed tomography.Results: Of the 200 enrolled participants, 199 (99% accomplished the 12-week intervention and 4-week follow-up period. The per-protocol-based analysis for 194 participants demonstrated that the abdominal total fat area decreased significantly in the A-mix group compared with

Effects of repetitive transcranial magnetic stimulation combined with sensory cueing on unilateral neglect in subacute patients with right hemispheric stroke: a randomized controlled study.

Science.gov (United States)

Yang, Nicole Yh; Fong, Kenneth Nk; Li-Tsang, Cecilia Wp; Zhou, D

2017-09-01

To compare the effects of rTMS combined with sensory cueing, rTMS alone, and conventional rehabilitation on unilateral neglect, hemiplegic arm functions and performance of activities of daily living. A single-blinded randomized controlled trial. A convalescent hospital. Sixty inpatients with left unilateral neglect after stroke. Patients were randomly assigned to three groups: rTMS combined with sensory cueing, rTMS, and conventional rehabilitation alone. rTMS at 1 Hz was applied over P5 of the contralesional hemisphere while vibration cueing was emitted using a wristwatch device on the hemiplegic arm, five days per week for two weeks. The first two groups received the same dosage of conventional rehabilitation on top of their experimental interventions. Blinded assessments were administered at baseline, 2 weeks postintervention, and 6 weeks follow-up. Neglect and arm motor performance. Both rTMS combined with sensory cueing (99.6±33.0) and rTMS alone (88.2±28.7) significantly reduced unilateral neglect than conventional rehabilitation (72.7±33.1) when measured using the conventional subtests of the Behavioural Inattention Test, but the combination was better than rTMS alone. Hemiplegic arm functions and activities of daily living improved in all patients across the three groups but no significant differences were found between the groups. The combination of inhibitory P5-rTMS with sensory cueing was better than either rTMS or conventional rehabilitation alone in producing a stronger and long-lasting improvement in unilateral neglect, but the improvement was not associated with improved arm function or independence in activities of daily living.

Practical application of equivalent linearization approaches to nonlinear piping systems

International Nuclear Information System (INIS)

Park, Y.J.; Hofmayer, C.H.

1995-01-01

The use of mechanical energy absorbers as an alternative to conventional hydraulic and mechanical snubbers for piping supports has attracted a wide interest among researchers and practitioners in the nuclear industry. The basic design concept of energy absorbers (EA) is to dissipate the vibration energy of piping systems through nonlinear hysteretic actions of EA exclamation point s under design seismic loads. Therefore, some type of nonlinear analysis needs to be performed in the seismic design of piping systems with EA supports. The equivalent linearization approach (ELA) can be a practical analysis tool for this purpose, particularly when the response approach (RSA) is also incorporated in the analysis formulations. In this paper, the following ELA/RSA methods are presented and compared to each other regarding their practice and numerical accuracy: Response approach using the square root of sum of squares (SRSS) approximation (denoted RS in this paper). Classical ELA based on modal combinations and linear random vibration theory (denoted CELA in this paper). Stochastic ELA based on direct solution of response covariance matrix (denoted SELA in this paper). New algorithms to convert response spectra to the equivalent power spectral density (PSD) functions are presented for both the above CELA and SELA methods. The numerical accuracy of the three EL are studied through a parametric error analysis. Finally, the practicality of the presented analysis is demonstrated in two application examples for piping systems with EA supports

Effect of Combined versus Monotherapy with Deferoxamine and Deferiprone in Iron Overloaded Thalassemia Patients: a Randomized Clinical Trial

Directory of Open Access Journals (Sweden)

Sasan Hejazi

2016-06-01

Full Text Available Background: Patients with transfusional iron overload have depended on iron chelation therapy and improving chelation regimens have been of the highest priority. The aim of this study was to compare effect of combined versus monotherapy with Deferoxamine (DFO and Deferiprone (DFP in iron overloaded beta thalassemia (BT major patients Materials and Methods We studied 36 BT major patients (mean age 7.6±4.6; range 3–16 years attending the Ormieh Motahari hospital for regular transfusional support. Patients were randomly allocated to receive one of the following two treatments: DFO in combination with DFP (n=12, DFO alone (n=12 and DFP alone (n=12. Serum ferritin level, liver enzymes, blood urea nitrogen, and creatinine and side effects were monitored over a 12 months period. Results: After one year, serum ferritin decreased more significantly in patients on DFO+DFP therapy compared to patients who only received DFO or DFP alone (P

Addition of non-invasive ventilatory support to combined aerobic and resistance training improves dyspnea and quality of life in heart failure patients: a randomized controlled trial.

Science.gov (United States)

Bittencourt, Hugo Souza; Cruz, Cristiano Gonçalves; David, Bruno Costa; Rodrigues, Erenaldo; Abade, Camille Magalhães; Junior, Roque Aras; Carvalho, Vitor Oliveira; Dos Reis, Francisco Borges Faria; Gomes Neto, Mansueto

2017-11-01

To test the hypothesis that combined aerobic and resistance training and non-invasive ventilatory support result in additional benefits compared with combined aerobic and resistance training alone in heart failure patients. A randomized, single-blind, controlled study. Cardiac rehabilitation center. A total of 46 patients with New York Heart Association class II/III heart failure were randomly assigned to a 10-week program of combined aerobic and resistance training, plus non-invasive ventilatory support ( n = 23) or combined aerobic and resistance training alone ( n = 23). Before and after intervention, results for the following were obtained: 6-minute walk test, forced vital capacity, forced expiratory volume at one second, maximal inspiratory muscle pressure, and maximal expiratory muscle pressure, with evaluation of dyspnea by the London Chest Activity of Daily Living scale, and quality of life with the Minnesota Living With Heart Failure questionnaire. Of the 46 included patients, 40 completed the protocol. The combined aerobic and resistance training plus non-invasive ventilatory support, as compared with combined aerobic and resistance training alone, resulted in significantly greater benefit for dyspnea (mean change: 4.8 vs. 1.3, p = 0.004), and quality of life (mean change: 19.3 vs. 6.8, p = 0.017 ). In both groups, the 6-minute walk test improved significantly (mean change: 45.7 vs. 44.1, p = 0.924), but without a statistically significant difference. Non-invasive ventilatory support combined with combined aerobic and resistance training provides additional benefits for dyspnea and quality of life in moderate heart failure patients. ClinicalTrials.gov identifier: NCT02384798. Registered 03 April 2015.

Effect of Integral Non-Linearity on Energy Calibration of ...

African Journals Online (AJOL)

The integral non-linearity (INL) of four spectroscopy systems, two integrated (A1 and A2) and two classical (B1 and B2) systems was determined using pulses from a random pulse generator. The effect of INL on the system's energy calibration was also determined. The effect is minimal in the classical system at high ...

Linear Algebra and Smarandache Linear Algebra

OpenAIRE

Vasantha, Kandasamy

2003-01-01

The present book, on Smarandache linear algebra, not only studies the Smarandache analogues of linear algebra and its applications, it also aims to bridge the need for new research topics pertaining to linear algebra, purely in the algebraic sense. We have introduced Smarandache semilinear algebra, Smarandache bilinear algebra and Smarandache anti-linear algebra and their fuzzy equivalents. Moreover, in this book, we have brought out the study of linear algebra and vector spaces over finite p...

Omeprazole-Domperidone Fixed Dose Combination vs Omeprazole Monotherapy: A Phase 4, Open-Label, Comparative, Parallel Randomized Controlled Study in Mild to Moderate Gastroesophageal Reflux Disease

Directory of Open Access Journals (Sweden)

KY Marakhouski

2017-05-01

Full Text Available Aim: To compare the efficacy and safety of omeprazole-domperidone combination vs omeprazole monotherapy in gastroesophageal reflux disease (GERD. Methods: In a comparative, randomized controlled, phase 4 study, outpatients with GERD were randomly allocated to either group 1 (omeprazole 20 mg + domperidone 30 mg or group 2 (omeprazole 20 mg in an equal ratio; 2 capsules daily in the morning were administered for 8 weeks. Results: Sixty patients were enrolled. Esophagitis reversal was observed in 92% patients in group 1 vs 65.2% in group 2. Approximately, 83.3% patients in group 1 vs 43.3% patients in group 2 demonstrated full cupping of reflux symptoms at 8 weeks. Combined therapy resulted in significantly longer period of heartburn-free days (23 vs 12 days on omeprazole. There were no safety concerns. Conclusions: Omeprazole-domperidone combination was more effective than omeprazole alone in providing complete cupping of reflux symptoms and healing of esophagitis in patients with GERD. Both the treatments were well tolerated with few reports of adverse events. Trial registration: This trial is registered with http://clinicaltrials.gov , number NCT02140073.

Inference for binomial probability based on dependent Bernoulli random variables with applications to meta-analysis and group level studies.

Science.gov (United States)

Bakbergenuly, Ilyas; Kulinskaya, Elena; Morgenthaler, Stephan

2016-07-01

We study bias arising as a result of nonlinear transformations of random variables in random or mixed effects models and its effect on inference in group-level studies or in meta-analysis. The findings are illustrated on the example of overdispersed binomial distributions, where we demonstrate considerable biases arising from standard log-odds and arcsine transformations of the estimated probability p̂, both for single-group studies and in combining results from several groups or studies in meta-analysis. Our simulations confirm that these biases are linear in ρ, for small values of ρ, the intracluster correlation coefficient. These biases do not depend on the sample sizes or the number of studies K in a meta-analysis and result in abysmal coverage of the combined effect for large K. We also propose bias-correction for the arcsine transformation. Our simulations demonstrate that this bias-correction works well for small values of the intraclass correlation. The methods are applied to two examples of meta-analyses of prevalence. © 2016 The Authors. Biometrical Journal Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Tracking control of concentration profiles in a fed-batch bioreactor using a linear algebra methodology.

Science.gov (United States)

Rómoli, Santiago; Serrano, Mario Emanuel; Ortiz, Oscar Alberto; Vega, Jorge Rubén; Eduardo Scaglia, Gustavo Juan

2015-07-01

Based on a linear algebra approach, this paper aims at developing a novel control law able to track reference profiles that were previously-determined in the literature. A main advantage of the proposed strategy is that the control actions are obtained by solving a system of linear equations. The optimal controller parameters are selected through Monte Carlo Randomized Algorithm in order to minimize a proposed cost index. The controller performance is evaluated through several tests, and compared with other controller reported in the literature. Finally, a Monte Carlo Randomized Algorithm is conducted to assess the performance of the proposed controller. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Flutamide versus a cyproterone acetate-ethinyl estradiol combination in moderate acne: a pilot randomized clinical trial

Directory of Open Access Journals (Sweden)

Adalatkhah H

2011-07-01

Full Text Available Hassan Adalatkhah1, Farhad Pourfarzi2, Homayoun Sadeghi-Bazargani31Department of Dermatology, 2Department of Social Medicine, Faculty of Medicine, Ardabil University of Medical Sciences, Ardabil; 3Statistics and Epidemiology Department, Faculty of Health and Nutrition, Tabriz University of Medical Sciences, Tabriz, IranBackground: The use of oral flutamide is rarely investigated in acne therapy. The aim of this study was to compare the efficacy of oral flutamide with that of a cyproterone-estradiol combination in treating acne lesions.Methods: A randomized clinical trial enrolled patients with moderate acne into two equal groups to receive either oral flutamide or the cyproterone-estradiol combination for 6 months. Lesion count, Acne Severity Index, and Global Acne Grading system (GAGS scores were used to assess improvement in acne lesions. The dichotomous measurement scale for primary endpoint assessment was defined as improvement from moderate to mild acne based on GAGS score. Patient satisfaction and dermal fat were also assessed. Intention to treat and per protocol analyses were done, reporting related effect sizes.Results: Both treatments resulted in substantial improvement in acne lesions. Although flutamide seemed to have higher efficacy, an intention to treat analysis did not find the two treatment protocols to be different. The relative risk in intention to treat analysis was 1.8 (95% confidence interval [CI] 0.89–1.6, and was 1.33 (95% CI 1.03–1.72 for the per protocol analysis. The number needed to treat for flutamide compared with the cyproterone-estradiol combination was 7.7 and 4.2 in the intention to treat and per protocol analyses, respectively.Conclusion: Flutamide appears to be more effective than a cyproterone-estradiol combination in some aspects of acne treatment, but this requires confirmation in a larger trial.Keywords: acne vulgaris, flutamide, cyproterone acetate, ethinyl estradiol, androgen antagonists

Alternate approaches to future electron-positron linear colliders

Energy Technology Data Exchange (ETDEWEB)

Loew, G.A. [Stanford Univ., CA (United States). Stanford Linear Accelerator Center

1998-07-01

The purpose of this article is two-fold: to review the current international status of various design approaches to the next generation of e{sup +}e{sup {minus}} linear colliders, and on the occasion of his 80th birthday, to celebrate Richard B. Neal`s many contributions to the field of linear accelerators. As it turns out, combining these two tasks is a rather natural enterprise because of Neal`s long professional involvement and insight into many of the problems and options which the international e{sup +}e{sup {minus}} linear collider community is currently studying to achieve a practical design for a future machine.

Premium Pricing of Liability Insurance Using Random Sum Model

OpenAIRE

Kartikasari, Mujiati Dwi

2017-01-01

Premium pricing is one of important activities in insurance. Nonlife insurance premium is calculated from expected value of historical data claims. The historical data claims are collected so that it forms a sum of independent random number which is called random sum. In premium pricing using random sum, claim frequency distribution and claim severity distribution are combined. The combination of these distributions is called compound distribution. By using liability claim insurance data, we ...

Pseudo-random Trees: Multiple Independent Sequence Generators for Parallel and Branching Computations

Science.gov (United States)

Halton, John H.

1989-09-01

A class of families of linear congruential pseudo-random sequences is defined, for which it is possible to branch at any event without changing the sequence of random numbers used in the original random walk and for which the sequences in different branches show properties analogous to mutual statistical independence. This is a hitherto unavailable, and computationally desirable, tool.

On the null distribution of Bayes factors in linear regression

Science.gov (United States)

We show that under the null, the 2 log (Bayes factor) is asymptotically distributed as a weighted sum of chi-squared random variables with a shifted mean. This claim holds for Bayesian multi-linear regression with a family of conjugate priors, namely, the normal-inverse-gamma prior, the g-prior, and...

Equidistant Linear Network Codes with maximal Error-protection from Veronese Varieties

DEFF Research Database (Denmark)

Hansen, Johan P.

2012-01-01

Linear network coding transmits information in terms of a basis of a vector space and the information is received as a basis of a possible altered vectorspace. Ralf Koetter and Frank R. Kschischang in Coding for errors and erasures in random network coding (IEEE Transactions on Information Theory...... construct explicit families of vector-spaces of constant dimension where any pair of distinct vector-spaces are equidistant in the above metric. The parameters of the resulting linear network codes which have maximal error-protection are determined....

Assessing the predictive capability of randomized tree-based ensembles in streamflow modelling

Science.gov (United States)

Galelli, S.; Castelletti, A.

2013-07-01

Combining randomization methods with ensemble prediction is emerging as an effective option to balance accuracy and computational efficiency in data-driven modelling. In this paper, we investigate the prediction capability of extremely randomized trees (Extra-Trees), in terms of accuracy, explanation ability and computational efficiency, in a streamflow modelling exercise. Extra-Trees are a totally randomized tree-based ensemble method that (i) alleviates the poor generalisation property and tendency to overfitting of traditional standalone decision trees (e.g. CART); (ii) is computationally efficient; and, (iii) allows to infer the relative importance of the input variables, which might help in the ex-post physical interpretation of the model. The Extra-Trees potential is analysed on two real-world case studies - Marina catchment (Singapore) and Canning River (Western Australia) - representing two different morphoclimatic contexts. The evaluation is performed against other tree-based methods (CART and M5) and parametric data-driven approaches (ANNs and multiple linear regression). Results show that Extra-Trees perform comparatively well to the best of the benchmarks (i.e. M5) in both the watersheds, while outperforming the other approaches in terms of computational requirement when adopted on large datasets. In addition, the ranking of the input variable provided can be given a physically meaningful interpretation.

Optimal Linear Responses for Markov Chains and Stochastically Perturbed Dynamical Systems

Science.gov (United States)

Antown, Fadi; Dragičević, Davor; Froyland, Gary

2018-03-01

The linear response of a dynamical system refers to changes to properties of the system when small external perturbations are applied. We consider the little-studied question of selecting an optimal perturbation so as to (i) maximise the linear response of the equilibrium distribution of the system, (ii) maximise the linear response of the expectation of a specified observable, and (iii) maximise the linear response of the rate of convergence of the system to the equilibrium distribution. We also consider the inhomogeneous, sequential, or time-dependent situation where the governing dynamics is not stationary and one wishes to select a sequence of small perturbations so as to maximise the overall linear response at some terminal time. We develop the theory for finite-state Markov chains, provide explicit solutions for some illustrative examples, and numerically apply our theory to stochastically perturbed dynamical systems, where the Markov chain is replaced by a matrix representation of an approximate annealed transfer operator for the random dynamical system.

Regional hyperthermia combined with radiotherapy for locally advanced non-small cell lung cancers. A multi-institutional prospective randomized trial of the International Atomic Energy Agency

International Nuclear Information System (INIS)

Mitsumori, Michihide; Hiraoka, Masahiro; Zeng Zhifan; Oliynychenko, P.; Park, Jeong-Ho; Choi, Ihl-Bohng; Tatsuzaki, Hideo; Tanaka, Yoshiaki

2007-01-01

An International Atomic Energy Agency (IAEA)-sponsored, multi-institutional prospective randomized trial was conducted to clarify whether the combination of hyperthermia and radiotherapy improves the local response rate of locally advanced non-small cell lung cancer (NSCLC) compared with that obtained by radiotherapy alone. Between October 1998 and April 2002, 80 patients with locally advanced NSCLC were randomized to receive either standard radiation therapy alone (RT) or radiation therapy combined with hyperthermia (RT+HT). The primary endpoint was the local response rate. The secondary endpoints were local progression-free survival and overall survival. The median follow-up period was 204 days for all patients and 450 days for surviving patients. There were no significant differences between the two arms with regard to local response rate (P=0.49) or overall survival rate (P=0.868). However, local progression-free survival was significantly better in the RT+HT arm (P=0.036). Toxicity was generally mild and no grade 3 late toxicity was observed in either arm. Although improvement of local progression-free survival was observed in the RT+HT arm, this prospective randomized study failed to show any substantial benefit from the addition of hyperthermia to radiotherapy in the treatment of locally advanced NSCLC. (author)

Linear gate with prescaled window

Energy Technology Data Exchange (ETDEWEB)

Koch, J; Bissem, H H; Krause, H; Scobel, W [Hamburg Univ. (Germany, F.R.). 1. Inst. fuer Experimentalphysik

1978-07-15

An electronic circuit is described that combines the features of a linear gate, a single channel analyzer and a prescaler. It allows selection of a pulse height region between two adjustable thresholds and scales the intensity of the spectrum within this window down by a factor 2sup(N) (0<=N<=9), whereas the complementary part of the spectrum is transmitted without being affected.

Apatite fission track analysis: geological thermal history analysis based on a three-dimensional random process of linear radiation damage

International Nuclear Information System (INIS)

Galbraith, R.F.; Laslett, G.M.; Green, P.F.; Duddy, I.R.

1990-01-01

Spontaneous fission of uranium atoms over geological time creates a random process of linearly shaped features (fission tracks) inside an apatite crystal. The theoretical distributions associated with this process are governed by the elapsed time and temperature history, but other factors are also reflected in empirical measurements as consequences of sampling by plane section and chemical etching. These include geometrical biases leading to over-representation of long tracks, the shape and orientation of host features when sampling totally confined tracks, and 'gaps' in heavily annealed tracks. We study the estimation of geological parameters in the presence of these factors using measurements on both confined tracks and projected semi-tracks. Of particular interest is a history of sedimentation, uplift and erosion giving rise to a two-component mixture of tracks in which the parameters reflect the current temperature, the maximum temperature and the timing of uplift. A full likelihood analysis based on all measured densities, lengths and orientations is feasible, but because some geometrical biases and measurement limitations are only partly understood it seems preferable to use conditional likelihoods given numbers and orientations of confined tracks. (author)

Perturbation analysis of linear control problems

International Nuclear Information System (INIS)

Petkov, Petko; Konstantinov, Mihail

2017-01-01

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

[Flying needling therapy combined with clomiphene for ovulation failure in polycystic ovary syndrome:a randomized controlled trial].

Science.gov (United States)

Ma, Hong; Quan, Xiaohong; Chen, Xiuhua; Dong, Ying

2016-11-12

To compare the efficacy among the combined treatment of flying needling therapy and clomiphene, the simple application of flying needling therapy and simple clomiphene in the treatment of ovulation failure in polycystic ovary syndrome (PCOS). Ninety patients of PCOS were randomized into a flying needling therapy group, a medication group and a combined treatment group, 30 cases in each one. In the flying needling therapy group, the flying needling therapy was simply applied to Ganshu (BL 18), Shenshu (BL 23), Zhongwan (CV 12), Shuifen (CV 9), Guanyuan (CV 4) and Zhongji (CV 3). The unilateral back- shu points were used alternatively in each treatment. The needles were inserted rapidly with rotation technique and even-needling manipulation. The needles were retained for 30 min. The treatment was given once every two days, 3 times a week. In the medication group, clomiphene was taken orally on the 5th day of menstruation, continuously for 5 days. In the combined treatment group, the flying needling therapy and clomiphene were used in combination. All of the patients were treated for 3 months and followed up for 1 month. The ovulation rates were compared among the three groups. The levels of androgen testosterone were compared before and after treatment. In the combined treatment group, the ovulation rate was 86.2% (100/116), better than 66.7% (80/120) in the flying needling therapy group and 69.6% (78/112) in the medication group (both P medication group ( P >0.05). After treatment, the level of testosterone was reduced in the three groups (all P medication group (both P medication group ( P >0.05). The adverse reactions in the combined treatment group and the flying needling therapy group were lower than those in the medication group (both P <0.05). The flying needling therapy effectively improves in the ovulation failure of PCOS and its effect is similar to clomiphene. The allied treatment of them apparently improves the clinical efficacy and alleviates the adverse

Effective Perron-Frobenius eigenvalue for a correlated random map

Science.gov (United States)

Pool, Roman R.; Cáceres, Manuel O.

2010-09-01

We investigate the evolution of random positive linear maps with various type of disorder by analytic perturbation and direct simulation. Our theoretical result indicates that the statistics of a random linear map can be successfully described for long time by the mean-value vector state. The growth rate can be characterized by an effective Perron-Frobenius eigenvalue that strongly depends on the type of correlation between the elements of the projection matrix. We apply this approach to an age-structured population dynamics model. We show that the asymptotic mean-value vector state characterizes the population growth rate when the age-structured model has random vital parameters. In this case our approach reveals the nontrivial dependence of the effective growth rate with cross correlations. The problem was reduced to the calculation of the smallest positive root of a secular polynomial, which can be obtained by perturbations in terms of Green’s function diagrammatic technique built with noncommutative cumulants for arbitrary n -point correlations.

Cellular Automata-Based Parallel Random Number Generators Using FPGAs

Directory of Open Access Journals (Sweden)

David H. K. Hoe

2012-01-01

Full Text Available Cellular computing represents a new paradigm for implementing high-speed massively parallel machines. Cellular automata (CA, which consist of an array of locally connected processing elements, are a basic form of a cellular-based architecture. The use of field programmable gate arrays (FPGAs for implementing CA accelerators has shown promising results. This paper investigates the design of CA-based pseudo-random number generators (PRNGs using an FPGA platform. To improve the quality of the random numbers that are generated, the basic CA structure is enhanced in two ways. First, the addition of a superrule to each CA cell is considered. The resulting self-programmable CA (SPCA uses the superrule to determine when to make a dynamic rule change in each CA cell. The superrule takes its inputs from neighboring cells and can be considered itself a second CA working in parallel with the main CA. When implemented on an FPGA, the use of lookup tables in each logic cell removes any restrictions on how the super-rules should be defined. Second, a hybrid configuration is formed by combining a CA with a linear feedback shift register (LFSR. This is advantageous for FPGA designs due to the compactness of the LFSR implementations. A standard software package for statistically evaluating the quality of random number sequences known as Diehard is used to validate the results. Both the SPCA and the hybrid CA/LFSR were found to pass all the Diehard tests.

Cancer-Related Fatigue and Rehabilitation : A Randomized Controlled Multicenter Trial Comparing Physical Training Combined With Cognitive-Behavioral Therapy With Physical Training Only and With No Intervention

NARCIS (Netherlands)

van Weert, E.; May, A.M.; Korstjens, I.; Post, W.J.; van der Schans, C.P.; van den Borne, B.; Mesters, I.; Ros, W.J.G.; Hoekstra-Weebers, J.E.H.M.

2010-01-01

Background. Research suggests that cancer rehabilitation reduces fatigue in survivors of cancer. To date, it is unclear what type of rehabilitation is most beneficial. Objective. This randomized controlled trial compared the effect on cancer-related fatigue of physical training combined with

Cancer-related fatigue and rehabilitation: A randomized controlled multicenter trial comparing physical training combined with cognitive-behavioral therapy with physical training only and with no intervention

NARCIS (Netherlands)

E. van Weert (Ellen); A.M. May (Anne); I. Korstjens (Irene); W.J. Post (Wendy); C.P. van der Schans (Cees); B. van den Borne (Bart); I. Mesters (Ilse); W.J.G. Ros (Wynand); J.E.H.M. Hoekstra-Weebers (Josette)

2010-01-01

textabstractBackground. Research suggests that cancer rehabilitation reduces fatigue in survivors of cancer. To date, it is unclear what type of rehabilitation is most beneficial. Objective. This randomized controlled trial compared the effect on cancerrelated fatigue of physical training combined

Genomic prediction based on data from three layer lines using non-linear regression models.

Science.gov (United States)

Huang, Heyun; Windig, Jack J; Vereijken, Addie; Calus, Mario P L

2014-11-06

Most studies on genomic prediction with reference populations that include multiple lines or breeds have used linear models. Data heterogeneity due to using multiple populations may conflict with model assumptions used in linear regression methods. In an attempt to alleviate potential discrepancies between assumptions of linear models and multi-population data, two types of alternative models were used: (1) a multi-trait genomic best linear unbiased prediction (GBLUP) model that modelled trait by line combinations as separate but correlated traits and (2) non-linear models based on kernel learning. These models were compared to conventional linear models for genomic prediction for two lines of brown layer hens (B1 and B2) and one line of white hens (W1). The three lines each had 1004 to 1023 training and 238 to 240 validation animals. Prediction accuracy was evaluated by estimating the correlation between observed phenotypes and predicted breeding values. When the training dataset included only data from the evaluated line, non-linear models yielded at best a similar accuracy as linear models. In some cases, when adding a distantly related line, the linear models showed a slight decrease in performance, while non-linear models generally showed no change in accuracy. When only information from a closely related line was used for training, linear models and non-linear radial basis function (RBF) kernel models performed similarly. The multi-trait GBLUP model took advantage of the estimated genetic correlations between the lines. Combining linear and non-linear models improved the accuracy of multi-line genomic prediction. Linear models and non-linear RBF models performed very similarly for genomic prediction, despite the expectation that non-linear models could deal better with the heterogeneous multi-population data. This heterogeneity of the data can be overcome by modelling trait by line combinations as separate but correlated traits, which avoids the occasional

Effect of Low-Energy Linear Shockwave Therapy on Erectile Dysfunction

DEFF Research Database (Denmark)

Fojecki, Grzegorz L; Thiessen, Stefan; Osther, Palle Jørn Sloth

2017-01-01

INTRODUCTION: Previous studies have shown that focal low-energy extracorporeal shockwave therapy (Li-ESWT) can have a positive effect in men with erectile dysfunction (ED). Linear Li-ESWT (LLi-ESWT) for ED has not been previously assessed in a randomized trial. AIM: To evaluate the treatment...... MEASURES: The primary outcome measurement was an increase of at least five points on the IIEF-EF score. The secondary outcome measurement was an increased EHS score to at least 3 in men with a score no higher than 2 at baseline. Data were analyzed by linear and logistic regression. RESULTS: Mean IIEF...

Genetic parameters and correlations among linear type traits in the ...

African Journals Online (AJOL)

user

2011-02-28

Feb 28, 2011 ... of Holstein heredity (BLD), respectively. The fixed effect of technician was denoted by TEC, the random effect of animal additive genetic effect and residual effects were shown by A and E, respectively. Each of the fixed effects was investigated via SAS software (proc Generalized Linear Model). In this study,.

Organization of growing random networks

International Nuclear Information System (INIS)

Krapivsky, P. L.; Redner, S.

2001-01-01

The organizational development of growing random networks is investigated. These growing networks are built by adding nodes successively, and linking each to an earlier node of degree k with an attachment probability A k . When A k grows more slowly than linearly with k, the number of nodes with k links, N k (t), decays faster than a power law in k, while for A k growing faster than linearly in k, a single node emerges which connects to nearly all other nodes. When A k is asymptotically linear, N k (t)∼tk -ν , with ν dependent on details of the attachment probability, but in the range 2 -2 power-law tail, where s is the component size. The out component has a typical size of order lnt, and it provides basic insights into the genealogy of the network

Data mining methods in the prediction of Dementia: A real-data comparison of the accuracy, sensitivity and specificity of linear discriminant analysis, logistic regression, neural networks, support vector machines, classification trees and random forests

Directory of Open Access Journals (Sweden)

Santana Isabel

2011-08-01

Full Text Available Abstract Background Dementia and cognitive impairment associated with aging are a major medical and social concern. Neuropsychological testing is a key element in the diagnostic procedures of Mild Cognitive Impairment (MCI, but has presently a limited value in the prediction of progression to dementia. We advance the hypothesis that newer statistical classification methods derived from data mining and machine learning methods like Neural Networks, Support Vector Machines and Random Forests can improve accuracy, sensitivity and specificity of predictions obtained from neuropsychological testing. Seven non parametric classifiers derived from data mining methods (Multilayer Perceptrons Neural Networks, Radial Basis Function Neural Networks, Support Vector Machines, CART, CHAID and QUEST Classification Trees and Random Forests were compared to three traditional classifiers (Linear Discriminant Analysis, Quadratic Discriminant Analysis and Logistic Regression in terms of overall classification accuracy, specificity, sensitivity, Area under the ROC curve and Press'Q. Model predictors were 10 neuropsychological tests currently used in the diagnosis of dementia. Statistical distributions of classification parameters obtained from a 5-fold cross-validation were compared using the Friedman's nonparametric test. Results Press' Q test showed that all classifiers performed better than chance alone (p Conclusions When taking into account sensitivity, specificity and overall classification accuracy Random Forests and Linear Discriminant analysis rank first among all the classifiers tested in prediction of dementia using several neuropsychological tests. These methods may be used to improve accuracy, sensitivity and specificity of Dementia predictions from neuropsychological testing.

A bandwidth correction to the Allegri-Zhang solution for accelerated random vibration testing

Directory of Open Access Journals (Sweden)

Benasciutti Denis

2018-01-01

Full Text Available In 2008, Allegri and Zhang published a study [Int. J. Fatigue. 2008, 30(6:967-977] in which they provided an exact analytical solution to the inverse scaling law for accelerated vibration tests of linear systems submitted to stationary Gaussian excitations By combining finite element analysis with multiaxial spectral methods defined in the frequency-domain, their solution generalised the simple inverse power law model suggested in some standards. The solution adopted the “equivalent von Mises stress” multiaxial criterion combined with the narrow-band damage expression. This work aims to propose a bandwidth correction to the original Allegri-Zhang solution to account for the actual spectral banwidth of the local multiaxial stress. The corrected Allegri-Zhang solution is also extended to another multiaxial spectral method, namely the “Projection-by-Projection” criterion. A numerical example is finally discussed, in which the corrected solution is applied to an L-shaped beam submitted to random accelerations.

Analytic regularity and collocation approximation for elliptic PDEs with random domain deformations

KAUST Repository

Castrillon, Julio; Nobile, Fabio; Tempone, Raul

2016-01-01

In this work we consider the problem of approximating the statistics of a given Quantity of Interest (QoI) that depends on the solution of a linear elliptic PDE defined over a random domain parameterized by N random variables. The elliptic problem

SOME SYSTEMATIC SAMPLING STRATEGIES USING MULTIPLE RANDOM STARTS

OpenAIRE

Sampath Sundaram; Ammani Sivaraman

2010-01-01

In this paper an attempt is made to extend linear systematic sampling using multiple random starts due to Gautschi(1957)for various types of systematic sampling schemes available in literature, namely(i)  Balanced Systematic Sampling (BSS) of  Sethi (1965) and (ii) Modified Systematic Sampling (MSS) of Singh, Jindal, and Garg  (1968). Further, the proposed methods were compared with Yates corrected estimator developed with reference to Gautschi’s Linear systematic samplin...

H∞ control for uncertain linear system over networks with Bernoulli data dropout and actuator saturation.

Science.gov (United States)

Yu, Jimin; Yang, Chenchen; Tang, Xiaoming; Wang, Ping

2018-03-01

This paper investigates the H ∞ control problems for uncertain linear system over networks with random communication data dropout and actuator saturation. The random data dropout process is modeled by a Bernoulli distributed white sequence with a known conditional probability distribution and the actuator saturation is confined in a convex hull by introducing a group of auxiliary matrices. By constructing a quadratic Lyapunov function, effective conditions for the state feedback-based H ∞ controller and the observer-based H ∞ controller are proposed in the form of non-convex matrix inequalities to take the random data dropout and actuator saturation into consideration simultaneously, and the problem of non-convex feasibility is solved by applying cone complementarity linearization (CCL) procedure. Finally, two simulation examples are given to demonstrate the effectiveness of the proposed new design techniques. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Combined Simulation of a Micro Permanent Magnetic Linear Contactless Displacement Sensor

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Jing Gao

2010-09-01

Full Text Available The permanent magnetic linear contactless displacement (PLCD sensor is a new type of displacement sensor operating on the magnetic inductive principle. It has many excellent properties and has already been used for many applications. In this article a Micro-PLCD sensor which can be used for microelectromechanical system (MEMS measurements is designed and simulated with the CST EM STUDIO® software, including building a virtual model, magnetostatic calculations, low frequency calculations, steady current calculations and thermal calculations. The influence of some important parameters such as air gap dimension, working frequency, coil current and eddy currents etc. is studied in depth.

Continuous spinal anesthesia versus combined spinal epidural block for major orthopedic surgery: prospective randomized study

Directory of Open Access Journals (Sweden)

Luiz Eduardo Imbelloni

Full Text Available CONTEXT AND OBJECTIVES: In major orthopedic surgery of the lower limbs, continuous spinal anesthesia (CSA and combined spinal epidural anesthesia (CSE are safe and reliable anesthesia methods. In this prospective randomized clinical study, the blockading properties and side effects of CSA were compared with single interspace CSE, among patients scheduled for major hip or knee surgery. DESIGN AND SETTING: Prospective clinical study conducted at the Institute for Regional Anesthesia, Hospital de Base, São José do Rio Preto. METHODS: 240 patients scheduled for hip arthroplasty, knee arthroplasty or femoral fracture treatment were randomly assigned to receive either CSA or CSE. Blockades were performed in the lateral position at the L3-L4 interspace. Puncture success, technical difficulties, paresthesia, highest level of sensory and motor blockade, need for complementary doses of local anesthetic, degree of technical difficulties, cardiocirculatory changes and postdural puncture headache (PDPH were recorded. At the end of the surgery, the catheter was removed and cerebrospinal fluid leakage was evaluated. RESULTS: Seven patients were excluded (three CSA and four CSE. There was significantly lower incidence of paresthesia in the CSE group. The resultant sensory blockade level was significantly higher with CSE. Complete motor blockade occurred in 110 CSA patients and in 109 CSE patients. Arterial hypotension was observed significantly more often in the CSE group. PDPH was observed in two patients of each group. CONCLUSION: Our results suggest that both CSA and CSE provided good surgical conditions with low incidence of complications. The sensory blockade level and hemodynamic changes were lower with CSA.

Reduction of Linear Programming to Linear Approximation

OpenAIRE

Vaserstein, Leonid N.

2006-01-01

It is well known that every Chebyshev linear approximation problem can be reduced to a linear program. In this paper we show that conversely every linear program can be reduced to a Chebyshev linear approximation problem.

Prevention of post-spinal hypotension using crystalloid, colloid and ephedrine with three different combinations: A double blind randomized study

Directory of Open Access Journals (Sweden)

Mitra Jabalameli

2012-01-01

Full Text Available Background: The benefit of prophylactic combination therapy using crystalloid and colloid preload with ephedrine has not been cleared to prevent maternal hypotension after spinal anesthesia at cesarean delivery. This study evaluated the efficacy of three combinational methods to prevent hypotension following spinal anesthesia. Materials and Methods: In this prospective double blind trial, 150 candidates of elective cesarean delivery under spinal anesthesia were randomly allocated to three treatment groups; 1---Ringer′s Lactate (RL solution (15 ml/kg plus Hemaxel (7 ml/kg preload, 2---RL solution (15 ml/kg preload plus ephedrine (15 mg, IV, bolus, 3---Hemaxel (7 ml/kg preload plus ephedrine (15 mg, IV, bolus. Maternal hemodynamic changes during 60 min after spinal injection, nausea/vomiting, and neonatal condition were compared among the groups. Results: The cumulative incidence of hypotension was 44%, 40%, and 46% in groups 1 to 3, respectively. There were not significant differences in supplementary ephedrine requirement among groups which received or among groups which did not receive prophylactic ephedrine. Groups were not different in the incidence of hypertension and nausea or vomiting. There were no significant differences among groups in Apgar scores at 1 or 5 min and umbilical artery PH. Conclusion: Combination of preventive methods decreased the occurrence of hypotension following spinal anesthesia to an acceptable level. Overall, the most effective method was a combination of crystalloid preload with ephedrine.

Random Forest ensembles for detection and prediction of Alzheimer's disease with a good between-cohort robustness

Directory of Open Access Journals (Sweden)

A.V. Lebedev

2014-01-01

In the ADNI set, the best AD/HC sensitivity/specificity (88.6%/92.0% — test set was achieved by combining cortical thickness and volumetric measures. The Random Forest model resulted in significantly higher accuracy compared to the reference classifier (linear Support Vector Machine. The models trained using parcelled and high-dimensional (HD input demonstrated equivalent performance, but the former was more effective in terms of computation/memory and time costs. The sensitivity/specificity for detecting MCI-to-AD conversion (but not AD/HC classification performance was further improved from 79.5%/75%–83.3%/81.3% by a combination of morphometric measurements with ApoE-genotype and demographics (age, sex, education. When applied to the independent AddNeuroMed cohort, the best ADNI models produced equivalent performance without substantial accuracy drop, suggesting good robustness sufficient for future clinical implementation.

Core seismic behaviour: linear and non-linear models

International Nuclear Information System (INIS)

Bernard, M.; Van Dorsselaere, M.; Gauvain, M.; Jenapierre-Gantenbein, M.

1981-08-01

The usual methodology for the core seismic behaviour analysis leads to a double complementary approach: to define a core model to be included in the reactor-block seismic response analysis, simple enough but representative of basic movements (diagrid or slab), to define a finer core model, with basic data issued from the first model. This paper presents the history of the different models of both kinds. The inert mass model (IMM) yielded a first rough diagrid movement. The direct linear model (DLM), without shocks and with sodium as an added mass, let to two different ones: DLM 1 with independent movements of the fuel and radial blanket subassemblies, and DLM 2 with a core combined movement. The non-linear (NLM) ''CORALIE'' uses the same basic modelization (Finite Element Beams) but accounts for shocks. It studies the response of a diameter on flats and takes into account the fluid coupling and the wrapper tube flexibility at the pad level. Damping consists of one modal part of 2% and one part due to shocks. Finally, ''CORALIE'' yields the time-history of the displacements and efforts on the supports, but damping (probably greater than 2%) and fluid-structures interaction are still to be precised. The validation experiments were performed on a RAPSODIE core mock-up on scale 1, in similitude of 1/3 as to SPX 1. The equivalent linear model (ELM) was developed for the SPX 1 reactor-block response analysis and a specified seismic level (SB or SM). It is composed of several oscillators fixed to the diagrid and yields the same maximum displacements and efforts than the NLM. The SPX 1 core seismic analysis with a diagrid input spectrum which corresponds to a 0,1 g group acceleration, has been carried out with these models: some aspects of these calculations are presented here

Efficacy of an Electromechanical Gait Trainer Poststroke in Singapore: A Randomized Controlled Trial.

Science.gov (United States)

Chua, Joyce; Culpan, Jane; Menon, Edward

2016-05-01

To evaluate the longer-term effects of electromechanical gait trainers (GTs) combined with conventional physiotherapy on health status, function, and ambulation in people with subacute stroke in comparison with conventional physiotherapy given alone. Randomized controlled trial with intention-to-treat analysis. Community hospital in Singapore. Nonambulant individuals (N=106) recruited approximately 1 month poststroke. Both groups received 45 minutes of physiotherapy 6 times per week for 8 weeks as follows: the GT group received 20 minutes of GT training and 5 minutes of stance/gait training in contrast with 25 minutes of stance/gait training for the control group. Both groups completed 10 minutes of standing and 10 minutes of cycling. The primary outcome was the Functional Ambulation Category (FAC). Secondary outcomes were the Barthel Index (BI), gait speed and endurance, and Stroke Impact Scale (SIS). Measures were taken at baseline and 4, 8, 12, 24, and 48 weeks. Generalized linear model analysis showed significant improvement over time (independent of group) for the FAC, BI, and SIS physical and participation subscales. However, no significant group × time or group differences were observed for any of the outcome variables after generalized linear model analysis. The use of GTs combined with conventional physiotherapy can be as effective as conventional physiotherapy applied alone for people with subacute stroke. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Performance of Power Systems under Sustained Random Perturbations

Directory of Open Access Journals (Sweden)

Humberto Verdejo

2014-01-01

Full Text Available This paper studies linear systems under sustained additive random perturbations. The stable operating point of an electric power system is replaced by an attracting stationary solution if the system is subjected to (small random additive perturbations. The invariant distribution of this stationary solution gives rise to several performance indices that measure how well the system copes with the randomness. These indices are introduced, showing how they can be used for the optimal tuning of system parameters in the presence of noise. Results on a four-generator two-area system are presented and discussed.

International linear collider simulations using BDSIM

Indian Academy of Sciences (India)

BDSIM is a Geant4 [1] extension toolkit for the simulation of particle transport in accelerator beamlines. It is a code that combines accelerator-style particle tracking with traditional Geant-style tracking based on Runga–Kutta techniques. A more detailed description of the code can be found in [2]. In an e+e− linear collider ...

Combined use of hyperbaric and hypobaric ropivacaine significantly improves hemodynamic characteristics in spinal anesthesia for caesarean section: a prospective, double-blind, randomized, controlled study.

Science.gov (United States)

Quan, ZheFeng; Tian, Ming; Chi, Ping; Li, Xin; He, HaiLi; Luo, Chao

2015-01-01

To observe the hemodynamic changes of parturients in the combined use of hyperbaric (4 mg) and hypobaric (6 mg) ropivacaine during spinal anesthesia for caesarean section in this randomized double-blind study. Parturients (n = 136) undergoing elective cesarean delivery were randomly and equally allocated to receive either combined hyperbaric and hypobaric ropivacaine (Group A) or hyperbaric ropivacaine (Group B). Outcome measures were: hemodynamic characteristics, maximum height of sensory block, time to achieve T8 sensory blockade level, incidence of complications, Apgar scores at 1 and 5 min, and neonatal blood gas analysis. Group A had a lower level of sensory blockade (T6 [T6-T7]) and longer time to achieve T8 sensory blockade level (8 ± 1.3 min) than did patients in Group B (T3 [T2-T4] and 5 ± 1.0 min, respectively; P hyperbaric (4 mg) and hypobaric (6 mg) ropivacaine significantly decreased the incidences of hypotension and complications in spinal anesthesia for caesarean section by extending induction time and decreasing the level of sensory blockade. Chinese Clinical Trial Register ChiCTR-TRC-13004622.

A randomized 9-month study of blood pressure and body fat responses to aerobic training versus combined aerobic and resistance training in older men.

Science.gov (United States)

Sousa, Nelson; Mendes, Romeu; Abrantes, Catarina; Sampaio, Jaime; Oliveira, José

2013-08-01

This randomized study evaluated the impact of different exercise training modalities on blood pressure and body fat responses in apparently healthy older men. Forty-eight elderly men (aged 65-75 years) were randomly assigned to an aerobic training group (ATG, n=15), a combined aerobic and resistance training group (CTG, n=16), or a control group (n=17). Both exercise training programs were moderate-to-vigorous intensity, three days/week for 9-months. Strength, aerobic endurance, body fat and blood pressure were measured on five different occasions. The data were analyzed using a mixed-model ANOVA, and the independence between systolic blood pressure (SBP), diastolic blood pressure (DBP) and group was tested. A significant main effect of group (pendurance, with higher performance observed in the CTG. A significant main effect of group (ptraining programs reduce resting blood pressure. However, only the combined exercise training was effective at reducing body fat percentage; consequently, there were larger changes in blood pressure, which result in a significant reduction in hypertensive subjects. Copyright © 2013 Elsevier Inc. All rights reserved.

A differential calculus for random matrices with applications to (max,+)-linear stochastic systems

NARCIS (Netherlands)

Heidergott, B.F.

2001-01-01

We introducet he concept of weak differentiabilityf or randomm atricesa nd therebyo btain closedform analytical expressions for derivatives of functions of random matrices. More specifically, we develop a calculus of weak differentiationf or randomm atricest hat resembles the standardc alculus of

Noise Reduction with Optimal Variable Span Linear Filters

DEFF Research Database (Denmark)

Jensen, Jesper Rindom; Benesty, Jacob; Christensen, Mads Græsbøll

2016-01-01

In this paper, the problem of noise reduction is addressed as a linear filtering problem in a novel way by using concepts from subspace-based enhancement methods, resulting in variable span linear filters. This is done by forming the filter coefficients as linear combinations of a number...... included in forming the filter. Using these concepts, a number of different filter designs are considered, like minimum distortion, Wiener, maximum SNR, and tradeoff filters. Interestingly, all these can be expressed as special cases of variable span filters. We also derive expressions for the speech...... demonstrate the advantages and properties of the variable span filter designs, and their potential performance gain compared to widely used speech enhancement methods....

Linear IgA bullous dermatosis in a neonate.

Science.gov (United States)

Hruza, L L; Mallory, S B; Fitzgibbons, J; Mallory, G B

1993-06-01

A newborn black boy had two facial blisters at birth that progressed to bullous lesions over the trunk, genitals, extremities, and oral and tracheal mucosa. A biopsy specimen demonstrated a subepidermal bulla with mixed eosinophilic and neutrophilic, inflammatory infiltrate. Direct immunofluorescence showed linear IgA, IgG, and C3 depositions along the basement membrane zone, consistent with a diagnosis of childhood linear IgA bullous dermatosis (chronic bullous dermatosis of childhood). The skin disease was controlled with combined prednisone and dapsone. This is the youngest reported patient with the disease. Linear IgA bullous dermatosis should be considered in the differential diagnosis of blistering diseases of the newborn, and immunofluorescence should be performed on a skin biopsy specimen.

Correlated continuous time random walks: combining scale-invariance with long-range memory for spatial and temporal dynamics

International Nuclear Information System (INIS)

Schulz, Johannes H P; Chechkin, Aleksei V; Metzler, Ralf

2013-01-01

Standard continuous time random walk (CTRW) models are renewal processes in the sense that at each jump a new, independent pair of jump length and waiting time are chosen. Globally, anomalous diffusion emerges through scale-free forms of the jump length and/or waiting time distributions by virtue of the generalized central limit theorem. Here we present a modified version of recently proposed correlated CTRW processes, where we incorporate a power-law correlated noise on the level of both jump length and waiting time dynamics. We obtain a very general stochastic model, that encompasses key features of several paradigmatic models of anomalous diffusion: discontinuous, scale-free displacements as in Lévy flights, scale-free waiting times as in subdiffusive CTRWs, and the long-range temporal correlations of fractional Brownian motion (FBM). We derive the exact solutions for the single-time probability density functions and extract the scaling behaviours. Interestingly, we find that different combinations of the model parameters lead to indistinguishable shapes of the emerging probability density functions and identical scaling laws. Our model will be useful for describing recent experimental single particle tracking data that feature a combination of CTRW and FBM properties. (paper)

Identification of Nonlinear Dynamic Systems Possessing Some Non-linearities

Directory of Open Access Journals (Sweden)

Y. N. Pavlov

2015-01-01

system of the second-order with nonlinearity of the type "quadratic friction" in combination with nonlinearity of the type "dry friction", was developed a software to simulate a process for providing pseudo experimental data containing random accuracy and to determine the parameters of the system. A conducted computational experiment enabled an estimate of the accuracy with which the proposed algorithm determines the parameters of the system. The illustrative numerical simulation has demonstrated that with using the proposed nonlinear dynamic system identification algorithm in frequency hodograph the accuracy of determining the coefficient values of the frequency transfer function of the second order system with a dry and quadratic friction is comparable with the range of measurement accuracy of experimental samples of this system hodograph. Well-known publications do not mention this identification method of the nonlinear dynamic systems. The nonlinear dynamical systems identification method the article describes can find application when determining parameters of various kinds of actuators. The using method of harmonic linearization and identification of dynamical systems by hodographs is promising for solving the problem of the identification of nonlinear systems with different types of nonlinearities.

The study, design and simulation of a free piston Stirling engine linear alternatorThe study, design and simulation of a free piston Stirling engine linear alternator

Directory of Open Access Journals (Sweden)

Teodora Susana Oros

2014-12-01

Full Text Available This paper presents a study, design and simulation of a Free Piston Stirling Engine Linear Alternator. There are presented the main steps of the magnetic and electric calculations for a permanent magnet linear alternator of fixed coil and moving magnets type. Finally, a detailed thermal, mechanical and electrical model for a Stirling engine linear alternator have been made in SIMULINK simulation program. The linear alternator simulation model uses a controllable DC voltage which simulates the linear alternator combined with a rectifier, a variable load and a DC-DC converter, which compensates for the variable nature of Stirling engine operation, and ensures a constant voltage output regardless of the load.

Premedication with Oral Alprazolam and Melatonin Combination: A Comparison with Either Alone—A Randomized Controlled Factorial Trial

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Krishna Pokharel

2014-01-01

Full Text Available We assessed if the addition of melatonin to alprazolam has superior premedication effects compared to either drug alone. A prospective, double blind placebo controlled trial randomly assigned 80 adult patients (ASA 1&2 with a Visual Analogue Score (VAS for anxiety ≥3 to receive a tablet containing a combination of alprazolam 0.5 mg and melatonin 3 mg, alprazolam 0.5 mg, melatonin 3 mg, or placebo orally 90 min before a standard anesthetic. Primary end points were change in anxiety and sedation score at 15, 30, and 60 min after premedication, and number of patients with loss of memory for the five pictures shown at various time points when assessed after 24 h. One-way ANOVA, Friedman repeated measures analysis of variance, Kruskal Wallis and chi square tests were used as relevant. Combination drug produced the maximum reduction in anxiety VAS (3 (1.0–4.3 from baseline at 60 min (P<0.05. Sedation scores at various time points and number of patients not recognizing the picture shown at 60 min after premedication were comparable between combination drug and alprazolam alone. Addition of melatonin to alprazolam had superior anxiolysis compared with either drugs alone or placebo. Adding melatonin neither worsened sedation score nor the amnesic effect of alprazolam alone. This study was registered, approved, and released from ClinicalTrials.gov. Identifier number: NCT01486615.

Combination therapy with biofeedback, loperamide, and stool-bulking agents is effective for the treatment of fecal incontinence in women - a randomized controlled trial.

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Sjödahl, Jenny; Walter, Susanna A; Johansson, Elin; Ingemansson, Anna; Ryn, Ann-Katrine; Hallböök, Olof

2015-08-01

Biofeedback and medical treatments have been extensively used for moderate fecal incontinence (FI). There is limited data comparing and combining these two treatments. The objective of this study was to evaluate the effect of biofeedback and medical treatments, separately and in combination. Sixty-four consecutive female patients, referred to a tertiary centre for FI, were included. The patients were randomized to start with either biofeedback (4-6 months) or medical treatment with loperamide and stool-bulking agents (2 months). Both groups continued with a combination of treatments, i.e. medical treatment was added to biofeedback and vice versa. A two-week prospective bowel symptom diary and anorectal physiology were evaluated at baseline, after single- and combination treatments. Fifty-seven patients completed the study. Median number of leakage episodes during two weeks decreased from 6 to 3 (p biofeedback and medical treatment is effective for symptom relief in FI. The symptom improvement was associated with improved fecal consistency, reduced urgency, and increased rectal sensory thresholds.

Does Combination Therapy with Tamsulosin and Tolterodine Improve Ureteral Stent Discomfort Compared with Tamsulosin Alone? A Double-Blind, Randomized, Controlled Trial.

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Sivalingam, Sri; Streeper, Necole M; Sehgal, Priyanka D; Sninsky, Brian C; Best, Sara L; Nakada, Stephen Y

2016-02-01

Ureteral stent discomfort is a significant postoperative problem for many patients. Despite the use of narcotics and α-blockers patients often experience bothersome lower urinary tract symptoms and pain, which impair daily activities. We compared combination therapy with an α-blocker and an anticholinergic to monotherapy with an α-blocker. A double-blind, randomized, controlled trial was performed from December 2012 to April 2014. A total of 80 patients were randomized, including 44 to the combination group (tamsulosin 0.4 mg and tolterodine early release 4 mg) and 36 to the monotherapy group (tamsulosin 0.4 mg and placebo). Patients with preexisting ureteral stent placement or current anticholinergic therapy were excluded from study. Patients completed USSQ (Urinary Stent Symptom Questionnaire) before stent placement on the day of surgery, the day after stent placement, the morning of stent removal and the day after stent removal. The questionnaire included questions regarding urinary symptoms, general health, body pain, and work and sexual history. A total of 80 patients (40 males and 40 females) were studied. Mean age was 51.5 vs 51.3 years (p = 0.95) and mean body mass index was 33.6 vs 31.9 kg/m(2) (p = 0.44) in monotherapy group 1 vs combination therapy group 2. Between the 2 groups there was no significant difference in urinary symptoms, body pain and activities of daily living from baseline to just before stent removal (p = 0.95, 0.40 and 0.95, respectively). Although there was no difference between the groups, both showed improvement in urinary symptoms from the time of initial stent insertion to just prior to stent removal (difference -0.50 for combination therapy and -0.40 for monotherapy). The mean stent indwelling time of 9.6 and 8.7 days in the combination and monotherapy groups, respectively, did not differ (p = 0.67). On ANOVA it had no significant impact on results (p = 0.64). Combination therapy with tamsulosin and tolterodine does not

Applications of equivalent linearization approaches to nonlinear piping systems

International Nuclear Information System (INIS)

Park, Y.; Hofmayer, C.; Chokshi, N.

1997-01-01

The piping systems in nuclear power plants, even with conventional snubber supports, are highly complex nonlinear structures under severe earthquake loadings mainly due to various mechanical gaps in support structures. Some type of nonlinear analysis is necessary to accurately predict the piping responses under earthquake loadings. The application of equivalent linearization approaches (ELA) to seismic analyses of nonlinear piping systems is presented. Two types of ELA's are studied; i.e., one based on the response spectrum method and the other based on the linear random vibration theory. The test results of main steam and feedwater piping systems supported by snubbers and energy absorbers are used to evaluate the numerical accuracy and limitations

Linear Motor for Drive of Belt Conveyor

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Milan Krasl

2006-01-01

Full Text Available This paper introduces a novel approach on the design of a linear motor for drive of belt conveyor (LMBC. The motor is a simple combination of asynchronous motor in plane. The electromagnetic forces is one of the most important parameters of electrical machines. This parameter is necessary for the checking of the design. This paper describes several variants: linear motor with slots in platens, slots in one half of platens and optimization of slots. The electromagnetic force can be found with the help of a Finite Elements Method – based program. For solution was used QuickField program.

Combined eating behaviors and overweight: Eating quickly, late evening meals, and skipping breakfast.

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Lee, Jung Su; Mishra, Gita; Hayashi, Kunihiko; Watanabe, Etsuko; Mori, Katsumi; Kawakubo, Kiyoshi

2016-04-01

Various eating behaviors have been linked with body weight management. However, combined effects of major eating behaviors are not fully understood. This study aimed to clarify the association of the combination of eating quickly (EQ), late evening meals (LEM), and skipping breakfast (SB) with being overweight. A cross-sectional study with standardized questions for EQ, LEM, and SB was conducted. Stratified random sampling of 5% of residents aged 20 to 80years was surveyed in a city in northeast Japan in 2011, and 4249 (84.9%) residents were analyzed. Association of combinations of eating behaviors on being overweight (BMI (kg/m(2)≥25.0)) was estimated by using logistic analysis, and odds ratio (OR) and 95% confidential interval were calculated after adjustment for potential covariates. LEM, SB, or a combination of LEM and SB was not significantly associated with being overweight. However, the combination of EQ or only EQ was significantly associated with being overweight. As the number of eating behavior practices increased, there was a linear increase in OR for being overweight. The OR of all three combined eating behaviors was higher than that of any combined two behaviors or of each behavior. This study result supports the evidence that EQ increases the risk of being overweight whether by itself or in combinations with LEM and/or SB. However, only LEM or only SB did not increase the risk of being overweight. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of Combined Physical and Cognitive Exercises on Cognition and Mobility in Patients With Mild Cognitive Impairment: A Randomized Clinical Trial.

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Shimada, Hiroyuki; Makizako, Hyuma; Doi, Takehiko; Park, Hyuntae; Tsutsumimoto, Kota; Verghese, Joe; Suzuki, Takao

2017-11-17

Although participation in physical and cognitive activities is encouraged to reduce the risk of dementia, the preventive efficacy of these activities for patients with mild cognitive impairment is unestablished. To compare the cognitive and mobility effects of a 40-week program of combined cognitive and physical activity with those of a health education program. A randomized, parallel, single-blind controlled trial. A population-based study of participants recruited from Obu, a residential suburb of Nagoya, Japan. Between August 2011 and February 2012, we evaluated 945 adults 65 years or older with mild cognitive impairment, enrolled 308, and randomly assigned them to the combined activity group (n = 154) or the health education control group (n = 154). The combined activity program involved weekly 90-minute sessions for 40 weeks focused on physical and cognitive activities. The control group attended 90-minute health promotion classes thrice during the 40-week trial period. The outcome measures were assessed at the study's beginning and end by personnel blinded to mild cognitive impairment subtype and group. The primary endpoints were postintervention changes in scores on (1) the Mini-Mental State Examination as a measure of general cognitive status and memory, (2) the Wechsler Memory Scale-Revised-Logical Memory II, and (3) the Rey Auditory Verbal Learning Test. We applied mobility assessments and assessed brain atrophy with magnetic resonance imaging. Compared with the control group, the combined activity group showed significantly greater scores on the Mini-Mental State Examination (difference = 0.8 points, P = .012) and Wechsler Memory Scale-Revised-Logical Memory II (difference = 1.0, P = .004), significant improvements in mobility and the nonmemory domains and reduced left medial temporal lobe atrophy in amnestic mild cognitive impairment (Z-score difference = -31.3, P physical and cognitive activity improves or maintains

Chaos as an intermittently forced linear system.

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Brunton, Steven L; Brunton, Bingni W; Proctor, Joshua L; Kaiser, Eurika; Kutz, J Nathan

2017-05-30

Understanding the interplay of order and disorder in chaos is a central challenge in modern quantitative science. Approximate linear representations of nonlinear dynamics have long been sought, driving considerable interest in Koopman theory. We present a universal, data-driven decomposition of chaos as an intermittently forced linear system. This work combines delay embedding and Koopman theory to decompose chaotic dynamics into a linear model in the leading delay coordinates with forcing by low-energy delay coordinates; this is called the Hankel alternative view of Koopman (HAVOK) analysis. This analysis is applied to the Lorenz system and real-world examples including Earth's magnetic field reversal and measles outbreaks. In each case, forcing statistics are non-Gaussian, with long tails corresponding to rare intermittent forcing that precedes switching and bursting phenomena. The forcing activity demarcates coherent phase space regions where the dynamics are approximately linear from those that are strongly nonlinear.The huge amount of data generated in fields like neuroscience or finance calls for effective strategies that mine data to reveal underlying dynamics. Here Brunton et al.develop a data-driven technique to analyze chaotic systems and predict their dynamics in terms of a forced linear model.

Combined use of hyperbaric and hypobaric ropivacaine significantly improves hemodynamic characteristics in spinal anesthesia for caesarean section: a prospective, double-blind, randomized, controlled study.

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ZheFeng Quan

Full Text Available To observe the hemodynamic changes of parturients in the combined use of hyperbaric (4 mg and hypobaric (6 mg ropivacaine during spinal anesthesia for caesarean section in this randomized double-blind study.Parturients (n = 136 undergoing elective cesarean delivery were randomly and equally allocated to receive either combined hyperbaric and hypobaric ropivacaine (Group A or hyperbaric ropivacaine (Group B. Outcome measures were: hemodynamic characteristics, maximum height of sensory block, time to achieve T8 sensory blockade level, incidence of complications, Apgar scores at 1 and 5 min, and neonatal blood gas analysis.Group A had a lower level of sensory blockade (T6 [T6-T7] and longer time to achieve T8 sensory blockade level (8 ± 1.3 min than did patients in Group B (T3 [T2-T4] and 5 ± 1.0 min, respectively; P < 0.001, both. The incidence rates for hypotension, nausea, and vomiting were significantly lower in Group A (13%, 10%, and 3%, respectively than Group B (66%, 31%, and 13%; P < 0.001, P = 0.003, P = 0.028.Combined use of hyperbaric (4 mg and hypobaric (6 mg ropivacaine significantly decreased the incidences of hypotension and complications in spinal anesthesia for caesarean section by extending induction time and decreasing the level of sensory blockade.Chinese Clinical Trial Register ChiCTR-TRC-13004622.

Linear bioconvection in a suspension of randomly swimming, gyrotactic micro-organisms

DEFF Research Database (Denmark)

Bees, Martin Alan; Hill, N.A.

1998-01-01

We have analyzed the initiation of pattern formation in a layer of finite depth for Pedley and Kessler's new model [J. Fluid Mech. 212, 155 (1990)] of bioconvection. This is the first analysis of bioconvection in a realistic geometry using a model that deals with random swimming in a rational...... manner. We have considered the effects of a distribution of swimming speeds, which has not previously received attention in theoretical papers and find that it is important in calculating the diffusivity. Our predictions of initial pattern wavelengths are reasonably close to the observed ones but better...

Management of Facial Synkinesis with a Combination of BTX-A and Biofeedback: A Randomized Trial.

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Pourmomeny, Abbas Ali; Asadi, Sahar; Cheatsaz, Ahmad

2015-11-01

Synkinesis and facial asymmetry due to facial nerve palsy are distressing conditions that affect quality of life. Unfortunately, these sequelae of facial nerve palsy are unresolved. The aim of this study was to investigate the efficacy of a combination of biofeedback therapy and botulinum toxin A (BTX-A) injection for the management of synkinesis and asymmetry of facial muscles. Among referrals from three university hospitals, 34 patients with facial synkinesis were divided randomly into two groups. All participants were evaluated using Photoshop software, videotape, and facial grading system (FGS). The first group received a single dose of BTX-A at the start of treatment, while the second group received normal saline as a control. Both groups received electromyography (EMG) biofeedback three times a week for 4 months. The mean FGS values for the BTX group before and after treatment were 55.17 and 74.17, respectively, and those for the biofeedback group were 66.31 and 81.37, respectively. Moreover, it was shown that in both groups oral-ocular and oculo-oral synkinesis decreased significantly after treatment compared with before treatment (PPhotoshop and videotape, these differences were even greater. Despite the decrease in synkinesis in both groups after treatment, there were no significant differences between the two treatment groups (P>0.05). Biofeedback therapy is as effective as the combination of biofeedback and BTX in reducing synkinesis and recovery of facial symmetry in Bell's palsy.

Comparison of linear, mixed integer and non-linear programming methods in energy system dispatch modelling

DEFF Research Database (Denmark)

Ommen, Torben Schmidt; Markussen, Wiebke Brix; Elmegaard, Brian

2014-01-01

In the paper, three frequently used operation optimisation methods are examined with respect to their impact on operation management of the combined utility technologies for electric power and DH (district heating) of eastern Denmark. The investigation focusses on individual plant operation...... differences and differences between the solution found by each optimisation method. One of the investigated approaches utilises LP (linear programming) for optimisation, one uses LP with binary operation constraints, while the third approach uses NLP (non-linear programming). The LP model is used...... as a benchmark, as this type is frequently used, and has the lowest amount of constraints of the three. A comparison of the optimised operation of a number of units shows significant differences between the three methods. Compared to the reference, the use of binary integer variables, increases operation...

Hyperchaotic encryption based on multi-scroll piecewise linear Systems

Czech Academy of Sciences Publication Activity Database

García-Martínez, M.; Ontanon-García, L.J.; Campos-Cantón, E.; Čelikovský, Sergej

2015-01-01

Roč. 270, č. 1 (2015), s. 413-424 ISSN 0096-3003 R&D Projects: GA ČR GA13-20433S Institutional support: RVO:67985556 Keywords : Hyperchaotic encryption * Piecewise linear systems * Stream cipher * Pseudo-random bit generator * Chaos theory * Multi-scrollattractors Subject RIV: BC - Control Systems Theory Impact factor: 1.345, year: 2015 http://library.utia.cas.cz/separaty/2015/TR/celikovsky-0446895.pdf

An intuitionistic fuzzy multi-objective non-linear programming model for sustainable irrigation water allocation under the combination of dry and wet conditions

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