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Sample records for nonlinear process involving

  1. Non-linear optical processes involving excited subbands in laser-dressed quantum wires with triangular cross-section

    Science.gov (United States)

    Radu, A.; Duque, C. A.

    2015-08-01

    The conduction subband structure of a triangular cross-section GaAs/AlGaAs quantum well wire under intense laser field is theoretically investigated by taking into account a finite confining potential. The calculation of the subband energy levels is based on a two-dimensional finite element method within the effective mass approximation. It is shown that a transversally polarized laser field non-uniformly shifts the subband energy levels and could be used for tuning the intersubband transitions and altering the related optical susceptibilities. We found that the non-resonant laser field allows the magnification and the red- or blueshift of the third-order non-linear susceptibility peaks for particular polarizations of the pump light and proper laser parameter values. The effects of the laser dressing field on the intersubband third harmonic generation and quadratic electro-optical process are discussed.

  2. Nonlinear filtering for LIDAR signal processing

    Directory of Open Access Journals (Sweden)

    D. G. Lainiotis

    1996-01-01

    Full Text Available LIDAR (Laser Integrated Radar is an engineering problem of great practical importance in environmental monitoring sciences. Signal processing for LIDAR applications involves highly nonlinear models and consequently nonlinear filtering. Optimal nonlinear filters, however, are practically unrealizable. In this paper, the Lainiotis's multi-model partitioning methodology and the related approximate but effective nonlinear filtering algorithms are reviewed and applied to LIDAR signal processing. Extensive simulation and performance evaluation of the multi-model partitioning approach and its application to LIDAR signal processing shows that the nonlinear partitioning methods are very effective and significantly superior to the nonlinear extended Kalman filter (EKF, which has been the standard nonlinear filter in past engineering applications.

  3. CMOS Nonlinear Signal Processing Circuits

    OpenAIRE

    2010-01-01

    The chapter describes various nonlinear signal processing CMOS circuits, including a high reliable WTA/LTA, simple MED cell, and low-voltage arbitrary order extractor. We focus the discussion on CMOS analog circuit design with reliable, programmable capability, and low voltage operation. It is a practical problem when the multiple identical cells are required to match and realized within a single chip using a conventional process. Thus, the design of high-reliable circuit is indeed needed. Th...

  4. Nonlinear Process Fault Diagnosis Based on Serial Principal Component Analysis.

    Science.gov (United States)

    Deng, Xiaogang; Tian, Xuemin; Chen, Sheng; Harris, Chris J

    2016-12-22

    Many industrial processes contain both linear and nonlinear parts, and kernel principal component analysis (KPCA), widely used in nonlinear process monitoring, may not offer the most effective means for dealing with these nonlinear processes. This paper proposes a new hybrid linear-nonlinear statistical modeling approach for nonlinear process monitoring by closely integrating linear principal component analysis (PCA) and nonlinear KPCA using a serial model structure, which we refer to as serial PCA (SPCA). Specifically, PCA is first applied to extract PCs as linear features, and to decompose the data into the PC subspace and residual subspace (RS). Then, KPCA is performed in the RS to extract the nonlinear PCs as nonlinear features. Two monitoring statistics are constructed for fault detection, based on both the linear and nonlinear features extracted by the proposed SPCA. To effectively perform fault identification after a fault is detected, an SPCA similarity factor method is built for fault recognition, which fuses both the linear and nonlinear features. Unlike PCA and KPCA, the proposed method takes into account both linear and nonlinear PCs simultaneously, and therefore, it can better exploit the underlying process's structure to enhance fault diagnosis performance. Two case studies involving a simulated nonlinear process and the benchmark Tennessee Eastman process demonstrate that the proposed SPCA approach is more effective than the existing state-of-the-art approach based on KPCA alone, in terms of nonlinear process fault detection and identification.

  5. Nonlinear second order elliptic equations involving measures

    CERN Document Server

    Marcus, Moshe

    2013-01-01

    This book presents a comprehensive study of boundary value problems for linear and semilinear second order elliptic equations with measure data,especially semilinear equations with absorption. The interactions between the diffusion operator and the absorption term give rise to a large class of nonlinear phenomena in the study of which singularities and boundary trace play a central role.

  6. Multiorder nonlinear diffraction in frequency doubling processes

    DEFF Research Database (Denmark)

    Saltiel, Solomon M.; Neshev, Dragomir N.; Krolikowski, Wieslaw

    2009-01-01

    We analyze experimentally light scattering from 2 nonlinear gratings and observe two types of second-harmonic frequency-scattering processes. The first process is identified as Raman–Nath type nonlinear diffraction that is explained by applying only transverse phase-matching conditions. The angular...... position of this type of diffraction is defined by the ratio of the second-harmonic wavelength and the grating period. In contrast, the second type of nonlinear scattering process is explained by the longitudinal phase matching only, being insensitive to the nonlinear grating...

  7. Digital signal processing for fiber nonlinearities [Invited

    DEFF Research Database (Denmark)

    Cartledge, John C.; Guiomar, Fernando P.; Kschischang, Frank R.

    2017-01-01

    This paper reviews digital signal processing techniques that compensate, mitigate, and exploit fiber nonlinearities in coherent optical fiber transmission systems......This paper reviews digital signal processing techniques that compensate, mitigate, and exploit fiber nonlinearities in coherent optical fiber transmission systems...

  8. Input saturation in nonlinear multivariable processes resolved by nonlinear decoupling

    Directory of Open Access Journals (Sweden)

    Jens G. Balchen

    1995-04-01

    Full Text Available A new method is presented for the resolution of the problem of input saturation in nonlinear multivariable process control by means of elementary nonlinear decoupling (END. Input saturation can have serious consequences particularly in multivariable control because it may lead to very undesirable system behaviour and quite often system instability. Many authors have searched for systematic techniques for designing multivariable control systems in which saturation may occur in any of the control variables (inputs, manipulated variables. No generally accepted method seems to have been presented so far which gives a solution in closed form. The method of elementary nonlinear decoupling (END can be applied directly to the case of saturation control variables by deriving as many control strategies as there are combinations of saturating control variables. The method is demonstrated by the multivariable control of a simulated Fluidized Catalytic Cracker (FCC with very convincing results.

  9. Modeling of nonlinear responses for reciprocal transducers involving polarization switching

    DEFF Research Database (Denmark)

    Willatzen, Morten; Wang, Linxiang

    2007-01-01

    Nonlinearities and hysteresis effects in a reciprocal PZT transducer are examined by use of a dynamical mathematical model on the basis of phase-transition theory. In particular, we consider the perovskite piezoelectric ceramic in which the polarization process in the material can be modeled....... We present numerical results for the reciprocal-transducer system and identify the influence of nonlinearities on the system dynamics at high and low frequency as well as electrical impedance effects due to tuning by a series inductance. It is found that nonlinear effects are not important at high...... by Landau theory for the first-order phase transformation, in which each polarization state is associated with a minimum of the Landau free-energy function. Nonlinear constitutive laws are obtained by using thermodynamical equilibrium conditions, and hysteretic behavior of the material can be modeled...

  10. Sensor Network Design for Nonlinear Processes

    Institute of Scientific and Technical Information of China (English)

    李博; 陈丙珍

    2003-01-01

    This paper presents a method to design a cost-optimal nonredundant sensor network to observe all variables in a general nonlinear process. A mixed integer linear programming model was used to minimize the cost with data classification to check the observability of all unmeasured variables. This work is a starting point for designing sensor networks for general nonlinear processes based on various criteria, such as reliability and accuracy.

  11. Central Limit Theorem for Nonlinear Hawkes Processes

    CERN Document Server

    Zhu, Lingjiong

    2012-01-01

    Hawkes process is a self-exciting point process with clustering effect whose jump rate depends on its entire past history. It has wide applications in neuroscience, finance and many other fields. Linear Hawkes process has an immigration-birth representation and can be computed more or less explicitly. It has been extensively studied in the past and the limit theorems are well understood. On the contrary, nonlinear Hawkes process lacks the immigration-birth representation and is much harder to analyze. In this paper, we obtain a functional central limit theorem for nonlinear Hawkes process.

  12. Broadband Nonlinear Signal Processing in Silicon Nanowires

    DEFF Research Database (Denmark)

    Yvind, Kresten; Pu, Minhao; Hvam, Jørn Märcher;

    The fast non-linearity of silicon allows Tbit/s optical signal processing. By choosing suitable dimensions of silicon nanowires their dispersion can be tailored to ensure a high nonlinearity at power levels low enough to avoid significant two-photon abso We have fabricated low insertion and propa......The fast non-linearity of silicon allows Tbit/s optical signal processing. By choosing suitable dimensions of silicon nanowires their dispersion can be tailored to ensure a high nonlinearity at power levels low enough to avoid significant two-photon abso We have fabricated low insertion...... and propagation loss silicon nanowires and use them to demonstrate the broadband capabilities of silicon....

  13. The maximal process of nonlinear shot noise

    Science.gov (United States)

    Eliazar, Iddo; Klafter, Joseph

    2009-05-01

    In the nonlinear shot noise system-model shots’ statistics are governed by general Poisson processes, and shots’ decay-dynamics are governed by general nonlinear differential equations. In this research we consider a nonlinear shot noise system and explore the process tracking, along time, the system’s maximal shot magnitude. This ‘maximal process’ is a stationary Markov process following a decay-surge evolution; it is highly robust, and it is capable of displaying both a wide spectrum of statistical behaviors and a rich variety of random decay-surge sample-path trajectories. A comprehensive analysis of the maximal process is conducted, including its Markovian structure, its decay-surge structure, and its correlation structure. All results are obtained analytically and in closed-form.

  14. Ultrafast Nonlinear Signal Processing in Silicon Waveguides

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Mulvad, Hans Christian Hansen; Hu, Hao;

    2012-01-01

    We describe recent demonstrations of exploiting highly nonlinear silicon waveguides for ultrafast optical signal processing. We describe wavelength conversion and serial-to-parallel conversion of 640 Gbit/s data signals and 1.28 Tbit/s demultiplexing and all-optical sampling.......We describe recent demonstrations of exploiting highly nonlinear silicon waveguides for ultrafast optical signal processing. We describe wavelength conversion and serial-to-parallel conversion of 640 Gbit/s data signals and 1.28 Tbit/s demultiplexing and all-optical sampling....

  15. DHA involvement in neurotransmission process

    Directory of Open Access Journals (Sweden)

    Vancassel Sylvie

    2007-05-01

    Full Text Available The very high enrichment of the nervous system in the polyunsaturated fatty acids, arachidonic (AA, 20: 4n-6 and docosahexaenoic acids (DHA, 22: 6n-3, is dependant of the dietary availability of their respective precursors, linoleic (18: 2n-6 and_-linolenic acids (18: 3n-3. Inadequate amounts of DHA in brain membranes have been linked to a wide variety of abnormalities ranging from visual acuity and learning irregularities, to psychopathologies. However, the molecular mechanisms involved remain unknown. Several years ago, we hypothesized that a modification of DHA contents of neuronal membranes by dietary modulation could change the neurotransmission function and then underlie inappropriate behavioural response. We showed that, in parallel to a severe loss of brain DHA concomitant to a compensatory substitution by 22:5n-6, the dietary lack of α-linolenic acid during development induced important changes in the release of neurotransmitters (dopamine, serotonin, acetylcholine in cerebral areas specifically involved in learning, memory and reward processes. Data suggested alteration of presynaptic storage process and dysregulations of reciprocal functional interactions between monoaminergic and cholinergic pathways. Moreover, we showed that recovery of these neurochemical changes was possible when the deficient diet was switched to a diet balanced in n-3 and n-6 PUFA before weaning. The next step is to understand the mechanism involved. Particularly, we focus on the study of the metabolic cooperation between the endothelial cell, the astrocyte and the neuron which regulate synaptic transmission.These works could contribute to the understanding of the link between some neuropsychiatric disorders and the metabolism of n-3 PUFA, through their action on neurotransmission.

  16. Recent advances in nonlinear speech processing

    CERN Document Server

    Faundez-Zanuy, Marcos; Esposito, Antonietta; Cordasco, Gennaro; Drugman, Thomas; Solé-Casals, Jordi; Morabito, Francesco

    2016-01-01

    This book presents recent advances in nonlinear speech processing beyond nonlinear techniques. It shows that it exploits heuristic and psychological models of human interaction in order to succeed in the implementations of socially believable VUIs and applications for human health and psychological support. The book takes into account the multifunctional role of speech and what is “outside of the box” (see Björn Schuller’s foreword). To this aim, the book is organized in 6 sections, each collecting a small number of short chapters reporting advances “inside” and “outside” themes related to nonlinear speech research. The themes emphasize theoretical and practical issues for modelling socially believable speech interfaces, ranging from efforts to capture the nature of sound changes in linguistic contexts and the timing nature of speech; labors to identify and detect speech features that help in the diagnosis of psychological and neuronal disease, attempts to improve the effectiveness and performa...

  17. Quantum Information Processing using Nonlinear Optical Effects

    DEFF Research Database (Denmark)

    Andersen, Lasse Mejling

    of the converted idler depends on the other pump. This allows for temporal-mode-multiplexing. When the effects of nonlinear phase modulation (NPM) are included, the phases of the natural input and output modes are changed, reducing the separability. These effects are to some degree mediated by pre......This PhD thesis treats applications of nonlinear optical effects for quantum information processing. The two main applications are four-wave mixing in the form of Bragg scattering (BS) for quantum-state-preserving frequency conversion, and sum-frequency generation (SFG) in second-order nonlinear...... to obtain a 100 % conversion efficiency is to use multiple stages of frequency conversion, but this setup suffers from the combined effects of NPM. This problem is circumvented by using asymmetrically pumped BS, where one pump is continuous wave. For this setup, NPM is found to only lead to linear phase...

  18. Internal Decoupling in Nonlinear Process Control

    Directory of Open Access Journals (Sweden)

    Jens G. Balchen

    1988-07-01

    Full Text Available A simple method has been investigated for the total or partial removal of the effect of non-linear process phenomena in multi-variable feedback control systems. The method is based upon computing the control variables which will drive the process at desired rates. It is shown that the effect of model errors in the linearization of the process can be partly removed through the use of large feedback gains. In practice there will be limits on how large gains can he used. The sensitivity to parameter errors is less pronounced and the transient behaviour is superior to that of ordinary PI controllers.

  19. Processing Approach of Non-linear Adjustment Models in the Space of Non-linear Models

    Institute of Scientific and Technical Information of China (English)

    LI Chaokui; ZHU Qing; SONG Chengfang

    2003-01-01

    This paper investigates the mathematic features of non-linear models and discusses the processing way of non-linear factors which contributes to the non-linearity of a nonlinear model. On the basis of the error definition, this paper puts forward a new adjustment criterion, SGPE.Last, this paper investigates the solution of a non-linear regression model in the non-linear model space and makes the comparison between the estimated values in non-linear model space and those in linear model space.

  20. Nonlinearly perturbed semi-Markov processes

    CERN Document Server

    Silvestrov, Dmitrii

    2017-01-01

    The book presents new methods of asymptotic analysis for nonlinearly perturbed semi-Markov processes with a finite phase space. These methods are based on special time-space screening procedures for sequential phase space reduction of semi-Markov processes combined with the systematical use of operational calculus for Laurent asymptotic expansions. Effective recurrent algorithms are composed for getting asymptotic expansions, without and with explicit upper bounds for remainders, for power moments of hitting times, stationary and conditional quasi-stationary distributions for nonlinearly perturbed semi-Markov processes. These results are illustrated by asymptotic expansions for birth-death-type semi-Markov processes, which play an important role in various applications. The book will be a useful contribution to the continuing intensive studies in the area. It is an essential reference for theoretical and applied researchers in the field of stochastic processes and their applications that will cont...

  1. Process and meaning: nonlinear dynamics and psychology in visual art.

    Science.gov (United States)

    Zausner, Tobi

    2007-01-01

    Creating and viewing visual art are both nonlinear experiences. Creating a work of art is an irreversible process involving increasing levels of complexity and unpredictable events. Viewing art is also creative with collective responses forming autopoietic structures that shape cultural history. Artists work largely from the chaos of the unconscious and visual art contains elements of chaos. Works of art by the author are discussed in reference to nonlinear dynamics. "Travelogues" demonstrates continued emerging interpretations and a deterministic chaos. "Advice to the Imperfect" signifies the resolution of paradox in the nonlinear tension of opposites. "Quanah" shows the nonlinear tension of opposites as an ongoing personal evolution. "The Mother of All Things" depicts seemingly separate phenomena arising from undifferentiated chaos. "Memories" refers to emotional fixations as limit cycles. "Compassionate Heart," "Wind on the Lake," and "Le Mal du Pays" are a series of works in fractal format focusing on the archetype of the mother and child. "Sameness, Depth of Mystery" addresses the illusion of hierarchy and the dynamics of symbols. In "Chasadim" the origin of worlds and the regeneration of individuals emerge through chaos. References to chaos in visual art mirror the nonlinear complexity of life.

  2. On a shock problem involving a nonlinear viscoelastic bar

    Directory of Open Access Journals (Sweden)

    Tran Ngoc Diem

    2005-11-01

    Full Text Available We treat an initial boundary value problem for a nonlinear wave equation utt−uxx+K|u|αu+λ|ut|βut=f(x,t in the domain 0involves a time convolution term of the boundary value of u at x=0, whereas the boundary condition at the other boundary point is of the form ux(1,t+K1u(1,t+λ1ut(1,t=0 with K1 and λ1 given nonnegative constants. We prove existence of a unique solution of such a problem in classical Sobolev spaces. The proof is based on a Galerkin-type approximation, various energy estimates, and compactness arguments. In the case of α=β=0, the regularity of solutions is studied also. Finally, we obtain an asymptotic expansion of the solution (u,P of this problem up to order N+1 in two small parameters K, λ.

  3. Nonlinear Markov Control Processes and Games

    Science.gov (United States)

    2012-11-15

    further research we indicated possible extensions to state spaces with nontrivial geometry, to the controlled nonlinear quantum dynamic semigroups and...space nonlinear Markov semigroup is a one-parameter semigroup of (possibly nonlinear) transformations of the unit simplex in n-dimensional Euclidean...certain mixing property of nonlinear transition probabilities. In case of the semigroup parametrized by continuous time one defines its generator as the

  4. Nonlinear biochemical signal processing via noise propagation.

    Science.gov (United States)

    Kim, Kyung Hyuk; Qian, Hong; Sauro, Herbert M

    2013-10-14

    Single-cell studies often show significant phenotypic variability due to the stochastic nature of intra-cellular biochemical reactions. When the numbers of molecules, e.g., transcription factors and regulatory enzymes, are in low abundance, fluctuations in biochemical activities become significant and such "noise" can propagate through regulatory cascades in terms of biochemical reaction networks. Here we develop an intuitive, yet fully quantitative method for analyzing how noise affects cellular phenotypes based on identifying a system's nonlinearities and noise propagations. We observe that such noise can simultaneously enhance sensitivities in one behavioral region while reducing sensitivities in another. Employing this novel phenomenon we designed three biochemical signal processing modules: (a) A gene regulatory network that acts as a concentration detector with both enhanced amplitude and sensitivity. (b) A non-cooperative positive feedback system, with a graded dose-response in the deterministic case, that serves as a bistable switch due to noise-induced ultra-sensitivity. (c) A noise-induced linear amplifier for gene regulation that requires no feedback. The methods developed in the present work allow one to understand and engineer nonlinear biochemical signal processors based on fluctuation-induced phenotypes.

  5. Recombination Processes and Nonlinear Markov Chains.

    Science.gov (United States)

    Pirogov, Sergey; Rybko, Alexander; Kalinina, Anastasia; Gelfand, Mikhail

    2016-09-01

    Bacteria are known to exchange genetic information by horizontal gene transfer. Since the frequency of homologous recombination depends on the similarity between the recombining segments, several studies examined whether this could lead to the emergence of subspecies. Most of them simulated fixed-size Wright-Fisher populations, in which the genetic drift should be taken into account. Here, we use nonlinear Markov processes to describe a bacterial population evolving under mutation and recombination. We consider a population structure as a probability measure on the space of genomes. This approach implies the infinite population size limit, and thus, the genetic drift is not assumed. We prove that under these conditions, the emergence of subspecies is impossible.

  6. Global satisfactory control for nonlinear integrator processes with long delay

    Institute of Scientific and Technical Information of China (English)

    Yiqun YANG; Guobo XIANG

    2007-01-01

    Integrator processes with long delay are difficult to control. Nonlinear characteristics of actuators make the control problem more challenging. A technique is proposed in this paper for global satisfactory control (GSC) of such processes with relay-type nonlinearity. An oscillatory control signal is injected into the nonlinear process; the amplitude and frequency of the oscillatory signal are designed to linearise the nonlinear process in the sense of harmonic analysis; and a state feedback controller is configured to implement GSC over the linearised process. An illustrative example is given to demonstrate the effectiveness of the proposed method.

  7. Ground state solutions for nonlinear fractional Schrodinger equations involving critical growth

    Directory of Open Access Journals (Sweden)

    Hua Jin

    2017-03-01

    Full Text Available This article concerns the ground state solutions of nonlinear fractional Schrodinger equations involving critical growth. We obtain the existence of ground state solutions when the potential is not a constant and not radial. We do not use the Ambrosetti-Rabinowitz condition, or the monotonicity condition on the nonlinearity.

  8. Generalized Mass Action Law and Thermodynamics of Nonlinear Markov Processes

    CERN Document Server

    Gorban, A N

    2015-01-01

    The nonlinear Markov processes are the measure-valued dynamical systems which preserve positivity. They can be represented as the law of large numbers limits of general Markov models of interacting particles. In physics, the kinetic equations allow Lyapunov functionals (entropy, free energy, etc.). This may be considered as a sort of inheritance of the Lyapunov functionals from the microscopic master equations. We study nonlinear Markov processes that inherit thermodynamic properties from the microscopic linear Markov processes. We develop the thermodynamics of nonlinear Markov processes and analyze the asymptotic assumption, which are sufficient for this inheritance.

  9. Nonlinear spectral unmixing of hyperspectral images using Gaussian processes

    CERN Document Server

    Altmann, Yoann; McLaughlin, Steve; Tourneret, Jean-Yves

    2012-01-01

    This paper presents an unsupervised algorithm for nonlinear unmixing of hyperspectral images. The proposed model assumes that the pixel reflectances result from a nonlinear function of the abundance vectors associated with the pure spectral components. We assume that the spectral signatures of the pure components and the nonlinear function are unknown. The first step of the proposed method consists of the Bayesian estimation of the abundance vectors for all the image pixels and the nonlinear function relating the abundance vectors to the observations. The endmembers are subsequently estimated using Gaussian process regression. The performance of the unmixing strategy is evaluated with simulations conducted on synthetic and real data.

  10. A double eigenvalue problem for Schrodinger equations involving sublinear nonlinearities at infinity

    Directory of Open Access Journals (Sweden)

    Alexandru Kristaly

    2007-03-01

    Full Text Available We present some multiplicity results concerning parameterized Schrodinger type equations which involve nonlinearities with sublinear growth at infinity. Some stability properties of solutions with respect to the parameters are also established in an appropriate Sobolev space.

  11. Spin versus helicity in processes involving transversity

    CERN Document Server

    Mekhfi, Mustapha

    2011-01-01

    We construct the spin formalism in order to deal in a direct and natural way with processes involving transversity which are now of increasing popularity. The helicity formalism which is more appropriate for collision processes of definite helicity has been so far used also to manage processes with transversity, but at the price of computing numerous helicity amplitudes generally involving unnecessary kinematical variables.In a second step we work out the correspondence between both formalisms and retrieve in another way all results of the helicity formalism but in simpler forms.We then compute certain processes for comparison.A special process:the quark dipole magnetic moment is shown to be exclusively treated within the spin formalism as it is directly related to the transverse spin of the quark inside the baryon.

  12. Bubble nonlinear dynamics and stimulated scattering process

    Science.gov (United States)

    Jie, Shi; De-Sen, Yang; Sheng-Guo, Shi; Bo, Hu; Hao-Yang, Zhang; Shi-Yong, Hu

    2016-02-01

    A complete understanding of the bubble dynamics is deemed necessary in order to achieve their full potential applications in industry and medicine. For this purpose it is first needed to expand our knowledge of a single bubble behavior under different possible conditions including the frequency and pressure variations of the sound field. In addition, stimulated scattering of sound on a bubble is a special effect in sound field, and its characteristics are associated with bubble oscillation mode. A bubble in liquid can be considered as a representative example of nonlinear dynamical system theory with its resonance, and its dynamics characteristics can be described by the Keller-Miksis equation. The nonlinear dynamics of an acoustically excited gas bubble in water is investigated by using theoretical and numerical analysis methods. Our results show its strongly nonlinear behavior with respect to the pressure amplitude and excitation frequency as the control parameters, and give an intuitive insight into stimulated sound scattering on a bubble. It is seen that the stimulated sound scattering is different from common dynamical behaviors, such as bifurcation and chaos, which is the result of the nonlinear resonance of a bubble under the excitation of a high amplitude acoustic sound wave essentially. The numerical analysis results show that the threshold of stimulated sound scattering is smaller than those of bifurcation and chaos in the common condition. Project supported by the Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT1228) and the Young Scientists Fund of the National Natural Science Foundation of China (Grant Nos. 11204050 and 11204049).

  13. A nonlinear wave equation with a nonlinear integral equation involving the boundary value

    Directory of Open Access Journals (Sweden)

    Thanh Long Nguyen

    2004-09-01

    Full Text Available We consider the initial-boundary value problem for the nonlinear wave equation $$displaylines{ u_{tt}-u_{xx}+f(u,u_{t}=0,quad xin Omega =(0,1,; 0nonlinear integral equation $$ P(t=g(t+H(u(0,t-int_0^t K(t-s,u(0,sds, $$ where $g$, $K$, $H$ are given functions. We prove the existence and uniqueness of weak solutions to this problem, and discuss the stability of the solution with respect to the functions $g$, $K$, and $H$. For the proof, we use the Galerkin method.

  14. Glial cells are involved in itch processing

    DEFF Research Database (Denmark)

    Andersen, Hjalte H.; Arendt-Nielsen, Lars; Gazerani, Parisa

    2016-01-01

    Recent discoveries in itch neurophysiology include itch-selective neuronal pathways, the clinically relevant non-histaminergic pathway, and elucidation of the notable similarities and differences between itch and pain. Potential involvement of glial cells in itch processing and the possibility...

  15. NONLINEAR MODEL PREDICTIVE CONTROL OF CHEMICAL PROCESSES

    Directory of Open Access Journals (Sweden)

    R. G. SILVA

    1999-03-01

    Full Text Available A new algorithm for model predictive control is presented. The algorithm utilizes a simultaneous solution and optimization strategy to solve the model's differential equations. The equations are discretized by equidistant collocation, and along with the algebraic model equations are included as constraints in a nonlinear programming (NLP problem. This algorithm is compared with the algorithm that uses orthogonal collocation on finite elements. The equidistant collocation algorithm results in simpler equations, providing a decrease in computation time for the control moves. Simulation results are presented and show a satisfactory performance of this algorithm.

  16. Coupled parametric processes in binary nonlinear photonic structures

    CERN Document Server

    Saygin, M Yu

    2016-01-01

    We study parametric interactions in a new type of nonlinear photonic structures, which is realized in the vicinity of a pair of nonlinear crystals. In this kind of structure, which we call binary, multiple nonlinear optical processes can be implemented simultaneously, owing to multiple phase-matching conditions, fulfilled separately in the constituent crystals. The coupling between the nonlinear processes by means of modes sharing similar frequency is attained by the spatially-broadband nature of the parametric fields. We investigate the spatial properties of the fields generated in the binary structure constructed from periodically poled crystals for the two examples: 1) single parametric down-conversion, and 2) coupled parametric down-conversion and up-conversion processes. The efficacy of the fields' generation in these examples is analyzed through comparison with the cases of traditional single periodically poled crystal and aperiodic photonic structure, respectively. It has been shown that the relative s...

  17. NONLINEAR OPTICS: Nonlinear optical processes in planar waveguides and excitation of surface polaritons

    Science.gov (United States)

    Yashkir, O. V.; Yashkir, Yu N.

    1987-11-01

    An investigation is made of nonlinear optical interaction of light propagating in a planar waveguide with surface polaritons. Reduced wave equations for the amplitudes of the waveguide modes and surface polaritons are used to study the characteristics of generation of surface polaritons of difference frequency, parametric frequency up-conversion of the polaritons, and stimulated Raman scattering by the polaritons. An analysis is made of the characteristic properties of the investigated nonlinear optical processes.

  18. Si-rich Silicon Nitride for Nonlinear Signal Processing Applications.

    Science.gov (United States)

    Lacava, Cosimo; Stankovic, Stevan; Khokhar, Ali Z; Bucio, T Dominguez; Gardes, F Y; Reed, Graham T; Richardson, David J; Petropoulos, Periklis

    2017-02-02

    Nonlinear silicon photonic devices have attracted considerable attention thanks to their ability to show large third-order nonlinear effects at moderate power levels allowing for all-optical signal processing functionalities in miniaturized components. Although significant efforts have been made and many nonlinear optical functions have already been demonstrated in this platform, the performance of nonlinear silicon photonic devices remains fundamentally limited at the telecom wavelength region due to the two photon absorption (TPA) and related effects. In this work, we propose an alternative CMOS-compatible platform, based on silicon-rich silicon nitride that can overcome this limitation. By carefully selecting the material deposition parameters, we show that both of the device linear and nonlinear properties can be tuned in order to exhibit the desired behaviour at the selected wavelength region. A rigorous and systematic fabrication and characterization campaign of different material compositions is presented, enabling us to demonstrate TPA-free CMOS-compatible waveguides with low linear loss (~1.5 dB/cm) and enhanced Kerr nonlinear response (Re{γ} = 16 Wm(-1)). Thanks to these properties, our nonlinear waveguides are able to produce a π nonlinear phase shift, paving the way for the development of practical devices for future optical communication applications.

  19. Positive Solution of a Nonlinear Fractional Differential Equation Involving Caputo Derivative

    Directory of Open Access Journals (Sweden)

    Changyou Wang

    2012-01-01

    Full Text Available This paper is concerned with a nonlinear fractional differential equation involving Caputo derivative. By constructing the upper and lower control functions of the nonlinear term without any monotone requirement and applying the method of upper and lower solutions and the Schauder fixed point theorem, the existence and uniqueness of positive solution for the initial value problem are investigated. Moreover, the existence of maximal and minimal solutions is also obtained.

  20. Innovative Pedagogical Processes Involving Educational Technology

    DEFF Research Database (Denmark)

    Weitze, Charlotte Lærke

    it experimented with gamified learning designs. This involved the students designing digital games while implementing learning goals from their curriculum. The project thus created knowledge about which learning designs and competence development models were possible in this environment, which learning designs...... about how design and learning processes can support continuous pedagogical innovation and competence development. The objective of the learning designs was to create motivating learning experiences for the students in the hybrid synchronous video-mediated learning environment, to which end...

  1. Saturation process of nonlinear standing waves

    Institute of Scientific and Technical Information of China (English)

    马大猷; 刘克

    1996-01-01

    The sound pressure of the nonlinear standing waves is distorted as expected, but also tends to saturate as being found in standing-wave tube experiments with increasing sinusoidal excitation. Saturation conditions were not actually reached, owing to limited excitation power, but the evidence of tendency to saturation is without question. It is the purpose of this investigation to find the law of saturation from the existing experimental data. The results of curve fitting indicate that negative feedback limits the growth of sound pressure with increasing excitation, the growth of the fundamental and the second harmonic by the negative feedback of their sound pressures, and the growth of the third and higher harmonics, however, by their energies (sound pressures squared). The growth functions of all the harmonics are derived, which are confirmed by the experiments. The saturation pressures and their properties are found.

  2. Adaptive control method for nonlinear time-delay processes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Two complex properties,varying time-delay and block-oriented nonlinearity,are very common in chemical engineering processes and not easy to be controlled by routine control methods.Aimed at these two complex properties,a novel adaptive control algorithm the basis of nonlinear OFS(orthonormal functional series) model is proposed.First,the hybrid model which combines OFS and Volterra series is introduced.Then,a stable state feedback strategy is used to construct a nonlinear adaptive control algorithm that can guarantee the closed-loop stability and can track the set point curve without steady-state errors.Finally,control simulations and experiments on a nonlinear process with varying time-delay are presented.A number of experimental results validate the efficiency and superiority of this algorithm.

  3. Nonlinear fiber applications for ultrafast all-optical signal processing

    Science.gov (United States)

    Kravtsov, Konstantin

    In the present dissertation different aspects of all-optical signal processing, enabled by the use of nonlinear fibers, are studied. In particular, we focus on applications of a novel heavily GeO2-doped (HD) nonlinear fiber, that appears to be superior to many other types of nonlinear fibers because of its high nonlinearity and suitability for the use in nonlinear optical loop mirrors (NOLMs). Different functions, such as all-optical switching, thresholding, and wavelength conversion, are demonstrated with the HD fibers in the NOLM configuration. These basic functions are later used for realization of ultrafast time-domain demultiplexers, clock recovery, detectors of short pulses in stealth communications, and primitive elements for analog computations. Another important technology that benefits from the use of nonlinear fiber-based signal processing is optical code-division multiple access (CDMA). It is shown in both theory and experiment that all-optical thresholding is a unique way of improving existing detection methods for optical CDMA. Also, it is the way of implementation of true asynchronous optical spread-spectrum networks, which allows full realization of optical CDMA potential. Some aspects of quantum signal processing and manipulation of quantum states are also studied in this work. It is shown that propagation and collisions of Thirring solitons lead to a substantial squeezing of quantum states, which may find applications for generation of squeezed light.

  4. Nonlinear Statistical Process Monitoring and Fault Detection Using Kernel ICA

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xi; YAN Wei-wu; ZHAO Xu; SHAO Hui-he

    2007-01-01

    A novel nonlinear process monitoring and fault detection method based on kernel independent component analysis (ICA) is proposed. The kernel ICA method is a two-phase algorithm: whitened kernel principal component (KPCA) plus ICA. KPCA spheres data and makes the data structure become as linearly separable as possible by virtue of an implicit nonlinear mapping determined by kernel. ICA seeks the projection directions in the KPCA whitened space, making the distribution of the projected data as non-gaussian as possible. The application to the fluid catalytic cracking unit (FCCU) simulated process indicates that the proposed process monitoring method based on kernel ICA can effectively capture the nonlinear relationship in process variables. Its performance significantly outperforms monitoring method based on ICA or KPCA.

  5. Neural Generalized Predictive Control of a non-linear Process

    DEFF Research Database (Denmark)

    Sørensen, Paul Haase; Nørgård, Peter Magnus; Ravn, Ole

    1998-01-01

    qualities. The controller is a non-linear version of the well-known generalized predictive controller developed in linear control theory. It involves minimization of a cost function which in the present case has to be done numerically. Therefore, we develop the numerical algorithms necessary in substantial...

  6. Modeling and stability analysis of the nonlinear reactive sputtering process

    Directory of Open Access Journals (Sweden)

    György Katalin

    2011-12-01

    Full Text Available The model of the reactive sputtering process has been determined from the dynamic equilibrium of the reactive gas inside the chamber and the dynamic equilibrium of the sputtered metal atoms which form the compound with the reactive gas atoms on the surface of the substrate. The analytically obtained dynamical model is a system of nonlinear differential equations which can result in a histeresis-type input/output nonlinearity. The reactive sputtering process has been simulated by integrating these differential equations. Linearization has been applied for classical analysis of the sputtering process and control system design.

  7. An Agent Interaction Based Method for Nonlinear Process Plan Scheduling

    Institute of Scientific and Technical Information of China (English)

    GAO Qinglu; WU Bo; GUO Guang

    2006-01-01

    This article puts forward a scheduling method for nonlinear process plan shop floor. Task allocation and load balance are realized by bidding mechanism. Though the agent interaction process, the execution of tasks is determined and the coherence of manufacturing decision is verified. The employment of heuristic index can help to optimize the system performance.

  8. Innovation as a Nonlinear Process and the Scientometric Perspective

    NARCIS (Netherlands)

    Leydesdorff, L.; Rotolo, D.; de Nooy, W.; Archambault, E.; Gingras, Y.; Larivière, V.

    2012-01-01

    The process of innovation follows non-linear patterns across the domains of science, technology, and the economy. Novel bibliometric mapping techniques can be used to investigate and represent distinctive, but complementary perspectives on the innovation process (e.g., "demand" and "supply") as well

  9. Innovative Pedagogical Processes Involving Educational Technology

    DEFF Research Database (Denmark)

    Weitze, Charlotte Lærke

    it experimented with gamified learning designs. This involved the students designing digital games while implementing learning goals from their curriculum. The project thus created knowledge about which learning designs and competence development models were possible in this environment, which learning designs......This design-based research project investigates the elements, methods, processes and practices that can contribute to the creation of reflected, innovative and motivating learning designs for teachers and students in a hybrid synchronous video-mediated teaching context, with a focus on how...... to create motivating learning for the students. This was done by examining the three actors in the educational institution (students, teachers and the surrounding organisation) individually and relationally. The design-based research project developed knowledge in co-design processes with the three actors...

  10. High-Order Volterra Model Predictive Control and Its Application to a Nonlinear Polymerisation Process

    Institute of Scientific and Technical Information of China (English)

    Yun Li; Hiroshi Kashiwagi

    2005-01-01

    Model Predictive Control (MPC) has recently found wide acceptance in the process industry, but existing design and implementation methods are restricted to linear process models. A chemical process, however, involves severe nonlinearity which cannot be ignored in practice. This paper aims to solve this nonlinear control problem by extending MPC to accommodate nonlinear models. It develops an analytical framework for nonlinear model predictive control (NMPC). It also offers a third-order Volterra series based nonparametric nonlinear modelling technique for NMPC design, which relieves practising engineers from the need for deriving a physical-principles based model first. An on-line realisation technique for implementing NMPC is then developed and applied to a Mitsubishi Chemicals polymerisation reaction process. Results show that this nonlinear MPC technique is feasible and very effective. It considerably outperforms linear and low-order Volterra model based methods. The advantages of the developed approach lie not only in control performance superior to existing NMPC methods, but also in eliminating the need for converting an analytical model and then convert it to a Volterra model obtainable only up to the second order.

  11. Nonlinear partial least squares with Hellinger distance for nonlinear process monitoring

    KAUST Repository

    Harrou, Fouzi

    2017-02-16

    This paper proposes an efficient data-based anomaly detection method that can be used for monitoring nonlinear processes. The proposed method merges advantages of nonlinear projection to latent structures (NLPLS) modeling and those of Hellinger distance (HD) metric to identify abnormal changes in highly correlated multivariate data. Specifically, the HD is used to quantify the dissimilarity between current NLPLS-based residual and reference probability distributions. The performances of the developed anomaly detection using NLPLS-based HD technique is illustrated using simulated plug flow reactor data.

  12. Positive Solutions for Nonlinear Singular Differential Systems Involving Parameter on the Half-Line

    Directory of Open Access Journals (Sweden)

    Lishan Liu

    2012-01-01

    Full Text Available By using the upper-lower solutions method and the fixed-point theorem on cone in a special space, we study the singular boundary value problem for systems of nonlinear second-order differential equations involving two parameters on the half-line. Some results for the existence, nonexistence and multiplicity of positive solutions for the problem are obtained.

  13. Involvement of youth in Impact Assessment processes

    DEFF Research Database (Denmark)

    Skjervedal, Anna-Sofie Hurup; Hansen, Anne Merrild

    2017-01-01

    Initial studies of the current public participation (PP) forms, public consultations and workshops, applied in Greenland in relation to Impact Assessments (IAs) of oil-gas and mineral projects, have revealed a narrow representation of the local communities. The local representatives involved...... in the PP processes comprise primarily elder men, whereas the youth remain absent. The fast growing development in the natural resource area has already sparked societal change among the widespread communities in Greenland; changes that set high demands for a greater higher educated workforce among...... complementary alternative methods to the current PP forms. Through combining social media and the visual anthropological method of photo-interviewing, this paper seeks to give voice to the absent voice of the young Greenlanders, encouraging them to engage and have their say in these important matters regarding...

  14. Nonlinear Dynamic Characteristics of Combustion Wave in SHS Process

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The characteristic of combustion wave and its change were analyzed by numerical value calculation and computer simulation,based on the combustion dynamical model of SHS process. It is shown that with the change of condition parameters in SHS process various time-space order combustion waves appear.It is concluded from non-liner dynamical mechanism analysis that the strong coupling of two non-linear dynamical processes is the dynamical mechanism causing the time-space order dissipation structures.

  15. Relaxation Processes in Nonlinear Optical Polymer Films

    Directory of Open Access Journals (Sweden)

    S.N. Fedosov

    2010-01-01

    Full Text Available Dielectric properties of the guest-host polystyrene/DR1 system have been studied by the AC dielectric spectroscopy method at frequencies from 1 Hz to 0,5 MHz and by the thermally stimulated depolarization current (TSDC method from – 160 to 0 °C. The relaxation peaks at infra-low frequencies from 10 – 5to 10–2 Hz were also calculated using the Hamon’s approximation. Three relaxation processes, namely, α, β and δ ones were identified from the TSDC peaks, while the ε''(fdependence showed a non-Debye ρ-peak narrowing with temperature. The activation energy of the α-relaxation appeared to be 2,57 eV, while that of the γ-process was 0,52 eV. Temperature dependence of the relaxation time is agreed with the Williams-Landel-Ferry model. The ε''(fpeaks were fitted to Havriliak-Negami’s expression and the corresponding distribution parameters were obtained.

  16. Ultra-Fast Optical Signal Processing in Nonlinear Silicon Waveguides

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Galili, Michael; Pu, Minhao;

    2011-01-01

    We describe recent demonstrations of exploiting highly nonlinear silicon nanowires for processing Tbit/s optical data signals. We perform demultiplexing and optical waveform sampling of 1.28 Tbit/s and wavelength conversion of 640 Gbit/s data signals....

  17. Nonlinear Evolutions of Stimulated Raman and Brillouin Scattering Processes in Partially Stripped-Ion Plasmas

    Institute of Scientific and Technical Information of China (English)

    胡业民; 胡希伟

    2001-01-01

    Numerical analyses for the nonlinear evolutions of stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) processes are given. Various effects of the second- and third-order nonlinear susceptibilities on the SRS and SBS processes are studied. The nonlinear evolutions of SRS and SBS processes are atfected more efficiently than their linear growth rates by the nonlinear susceptibility.

  18. Modeling Autoregressive Processes with Moving-Quantiles-Implied Nonlinearity

    Directory of Open Access Journals (Sweden)

    Isao Ishida

    2015-01-01

    Full Text Available We introduce and investigate some properties of a class of nonlinear time series models based on the moving sample quantiles in the autoregressive data generating process. We derive a test fit to detect this type of nonlinearity. Using the daily realized volatility data of Standard & Poor’s 500 (S&P 500 and several other indices, we obtained good performance using these models in an out-of-sample forecasting exercise compared with the forecasts obtained based on the usual linear heterogeneous autoregressive and other models of realized volatility.

  19. New CMOS Compatible Platforms for Integrated Nonlinear Optical Signal Processing

    CERN Document Server

    Moss, D J

    2014-01-01

    Nonlinear photonic chips have succeeded in generating and processing signals all-optically with performance far superior to that possible electronically - particularly with respect to speed. Although silicon-on-insulator has been the leading platform for nonlinear optics, its high two-photon absorption at telecommunications wavelengths poses a fundamental limitation. This paper reviews some of the recent achievements in CMOS-compatible platforms for nonlinear optics, focusing on amorphous silicon and Hydex glass, highlighting their potential future impact as well as the challenges to achieving practical solutions for many key applications. These material systems have opened up many new capabilities such as on-chip optical frequency comb generation and ultrafast optical pulse generation and measurement.

  20. Homodyne laser interferometer involving minimal quadrature phase error to obtain subnanometer nonlinearity.

    Science.gov (United States)

    Cui, Junning; He, Zhangqiang; Jiu, Yuanwei; Tan, Jiubin; Sun, Tao

    2016-09-01

    The demand for minimal cyclic nonlinearity error in laser interferometry is increasing as a result of advanced scientific research projects. Research shows that the quadrature phase error is the main effect that introduces cyclic nonlinearity error, and polarization-mixing cross talk during beam splitting is the main error source that causes the quadrature phase error. In this paper, a new homodyne quadrature laser interferometer configuration based on nonpolarization beam splitting and balanced interference between two circularly polarized laser beams is proposed. Theoretical modeling indicates that the polarization-mixing cross talk is elaborately avoided through nonpolarizing and Wollaston beam splitting, with a minimum number of quadrature phase error sources involved. Experimental results show that the cyclic nonlinearity error of the interferometer is up to 0.6 nm (peak-to-valley value) without any correction and can be further suppressed to 0.2 nm with a simple gain and offset correction method.

  1. Linear and Nonlinear MHD Wave Processes in Plasmas. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Tataronis, J. A.

    2004-06-01

    This program treats theoretically low frequency linear and nonlinear wave processes in magnetized plasmas. A primary objective has been to evaluate the effectiveness of MHD waves to heat plasma and drive current in toroidal configurations. The research covers the following topics: (1) the existence and properties of the MHD continua in plasma equilibria without spatial symmetry; (2) low frequency nonresonant current drive and nonlinear Alfven wave effects; and (3) nonlinear electron acceleration by rf and random plasma waves. Results have contributed to the fundamental knowledge base of MHD activity in symmetric and asymmetric toroidal plasmas. Among the accomplishments of this research effort, the following are highlighted: Identification of the MHD continuum mode singularities in toroidal geometry. Derivation of a third order ordinary differential equation that governs nonlinear current drive in the singular layers of the Alfvkn continuum modes in axisymmetric toroidal geometry. Bounded solutions of this ODE implies a net average current parallel to the toroidal equilibrium magnetic field. Discovery of a new unstable continuum of the linearized MHD equation in axially periodic circular plasma cylinders with shear and incompressibility. This continuum, which we named “accumulation continuum” and which is related to ballooning modes, arises as discrete unstable eigenfrequency accumulate on the imaginary frequency axis in the limit of large mode numbers. Development of techniques to control nonlinear electron acceleration through the action of multiple coherent and random plasmas waves. Two important elements of this program aye student participation and student training in plasma theory.

  2. Nonlinear Processes in Magnetic Nanodots under Perpendicular Pumping: Micromagnetic Simulations

    Directory of Open Access Journals (Sweden)

    D.V. Slobodiainuk

    2013-03-01

    Full Text Available Processes that take place in permalloy nanodots under external electromagnetic pumping are considered. It is shown that in such system similar to bulk samples Suhl and kinetic instability processes are possible. Using micromagnetic simulations approach key features of mode excitation with an external pumping power increase were revealed. Results of the simulations were compared with published experimental data dedicated to investigation of magnetic nanodotes in nonlinear regime.

  3. A fuzzy model based adaptive PID controller design for nonlinear and uncertain processes.

    Science.gov (United States)

    Savran, Aydogan; Kahraman, Gokalp

    2014-03-01

    We develop a novel adaptive tuning method for classical proportional-integral-derivative (PID) controller to control nonlinear processes to adjust PID gains, a problem which is very difficult to overcome in the classical PID controllers. By incorporating classical PID control, which is well-known in industry, to the control of nonlinear processes, we introduce a method which can readily be used by the industry. In this method, controller design does not require a first principal model of the process which is usually very difficult to obtain. Instead, it depends on a fuzzy process model which is constructed from the measured input-output data of the process. A soft limiter is used to impose industrial limits on the control input. The performance of the system is successfully tested on the bioreactor, a highly nonlinear process involving instabilities. Several tests showed the method's success in tracking, robustness to noise, and adaptation properties. We as well compared our system's performance to those of a plant with altered parameters with measurement noise, and obtained less ringing and better tracking. To conclude, we present a novel adaptive control method that is built upon the well-known PID architecture that successfully controls highly nonlinear industrial processes, even under conditions such as strong parameter variations, noise, and instabilities.

  4. A non-linear model of economic production processes

    Science.gov (United States)

    Ponzi, A.; Yasutomi, A.; Kaneko, K.

    2003-06-01

    We present a new two phase model of economic production processes which is a non-linear dynamical version of von Neumann's neoclassical model of production, including a market price-setting phase as well as a production phase. The rate of an economic production process is observed, for the first time, to depend on the minimum of its input supplies. This creates highly non-linear supply and demand dynamics. By numerical simulation, production networks are shown to become unstable when the ratio of different products to total processes increases. This provides some insight into observed stability of competitive capitalist economies in comparison to monopolistic economies. Capitalist economies are also shown to have low unemployment.

  5. Optoelectronic and nonlinear optical processes in low dimensional semiconductors

    Indian Academy of Sciences (India)

    B P Singh

    2006-11-01

    Spatial confinement of quantum excitations on their characteristic wavelength scale in low dimensional materials offers unique possibilities to engineer the electronic structure and thereby control their physical properties by way of simple manipulation of geometrical parameters. This has led to an overwhelming interest in quasi-zero dimensional semiconductors or quantum dots as tunable materials for multitude of exciting applications in optoelectronic and nonlinear optical devices and quantum information processing. Large nonlinear optical response and high luminescence quantum yield expected in these systems is a consequence of huge enhancement of transition probabilities ensuing from quantum confinement. High quantum efficiency of photoluminescence, however, is not usually realized in the case of bare semiconductor nanoparticles owing to the presence of surface states. In this talk, I will focus on the role of quantum confinement and surface states in ascertaining nonlinear optical and optoelectronic properties of II–VI semiconductor quantum dots and their nanocomposites. I will also discuss the influence of nonlinear optical processes on their optoelectronic characteristics.

  6. Submodels of model of nonlinear diffusion in the inhomogeneous medium involving absorption

    Energy Technology Data Exchange (ETDEWEB)

    Chirkunov, Yu. A., E-mail: chr101@mail.ru [Novosibirsk State Technical University, Marks Avenue 20, Novosibirsk 630073 (Russian Federation)

    2015-10-15

    We study the five-parameter model, describing the process of nonlinear diffusion in an inhomogeneous medium in the presence of absorption, for which the differential equation of the model admits a continuous Lie group of transformations, acting on the set of its solutions. We found six submodels of the original model of nonlinear diffusion, with different symmetry properties. Of these six submodels, the five submodels with transient absorption, for which the absorption coefficient depends on time according to a power law, represent the greatest interest with a mathematical point of view and with the point of view of physical applications. For each of these nonlinear submodels, we obtained formulas for producing new solutions that contain arbitrary constants, and we found all invariant submodels. All essentially distinct invariant solutions describing these invariant submodels are found in an explicit form or are reduced to finding the solution of nonlinear integral equations. The presence of the arbitrary constants in the integral equations that determine these solutions provide new opportunities for analytical and numerical study of boundary value problems for the received submodels and, thus, for the original model of nonlinear diffusion. For the received invariant submodels, we studied diffusion processes for which at the initial moment of the time at a fixed point is specified as a concentration and its gradient or as a concentration and its velocity. Solving of boundary value problems describing these processes is reduced to the solving of nonlinear integral equations. We established the existence and uniqueness of solutions of these boundary value problems under some additional conditions. The obtained results can be used to study the diffusion of substances, diffusion of conduction electrons and other particles, diffusion of physical fields and propagation of heat in inhomogeneous medium, and also to study a turbulence (Leith model, differential

  7. Hybrid transfinite element modeling/analysis of nonlinear heat conduction problems involving phase change

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1988-01-01

    The present paper describes the applicability of hybrid transfinite element modeling/analysis formulations for nonlinear heat conduction problems involving phase change. The methodology is based on application of transform approaches and classical Galerkin schemes with finite element formulations to maintain the modeling versatility and numerical features for computational analysis. In addition, in conjunction with the above, the effects due to latent heat are modeled using enthalpy formulations to enable a physically realistic approximation to be dealt computationally for materials exhibiting phase change within a narrow band of temperatures. Pertinent details of the approach and computational scheme adapted are described in technical detail. Numerical test cases of comparative nature are presented to demonstrate the applicability of the proposed formulations for numerical modeling/analysis of nonlinear heat conduction problems involving phase change.

  8. Involving Program Constituencies in the Evaluation Process.

    Science.gov (United States)

    Deshler, David

    1984-01-01

    Two case studies provide examples of citizen and program participant involvement in program evaluation. The Reflective Appraisal of Programs at Cornell Cooperative Extension involves volunteer interviewers of participants; the Lancaster County (Pennsylvania) Office of Mental Health/Mental Retardation is reviewed by a volunteer citizens' committee.…

  9. Defining stakeholder involvement in participatory design processes

    NARCIS (Netherlands)

    Vink, P.; Imada, A.S.; Zink, K.J.

    2008-01-01

    A participatory approach could be used to implement work place or organizational improvements. However, the question is which participants should be involved and how. In this paper the theoretical involvement in different steps of a linear stepwise approach is described and compared with the latest

  10. Defining stakeholder involvement in participatory design processes

    NARCIS (Netherlands)

    Vink, P.; Imada, A.S.; Zink, K.J.

    2008-01-01

    A participatory approach could be used to implement work place or organizational improvements. However, the question is which participants should be involved and how. In this paper the theoretical involvement in different steps of a linear stepwise approach is described and compared with the latest

  11. Maximal Saddle Solution of a Nonlinear Elliptic Equation Involving the -Laplacian

    Indian Academy of Sciences (India)

    Huahui Yan; Zhuoran Du

    2014-02-01

    A saddle solution is called maximal saddle solution if its absolute value is not smaller than those absolute values of any solutions that vanish on the Simons cone $\\mathcal{C} = \\{s = t\\}$ and have the same sign as - . We prove the existence of a maximal saddle solution of the nonlinear elliptic equation involving the -Laplacian, by using the method of monotone iteration, $$-_{p^u}=f(u) \\quad \\text{in} \\quad R^{2m},$$ where $2m≥ p > 2$.

  12. NON-LINEAR FINITE ELEMENT MODELING OF DEEP DRAWING PROCESS

    Directory of Open Access Journals (Sweden)

    Hasan YILDIZ

    2004-03-01

    Full Text Available Deep drawing process is one of the main procedures used in different branches of industry. Finding numerical solutions for determination of the mechanical behaviour of this process will save time and money. In die surfaces, which have complex geometries, it is hard to determine the effects of parameters of sheet metal forming. Some of these parameters are wrinkling, tearing, and determination of the flow of the thin sheet metal in the die and thickness change. However, the most difficult one is determination of material properties during plastic deformation. In this study, the effects of all these parameters are analyzed before producing the dies. The explicit non-linear finite element method is chosen to be used in the analysis. The numerical results obtained for non-linear material and contact models are also compared with the experiments. A good agreement between the numerical and the experimental results is obtained. The results obtained for the models are given in detail.

  13. Nonlinear Silicon Photonic Signal Processing Devices for Future Optical Networks

    Directory of Open Access Journals (Sweden)

    Cosimo Lacava

    2017-01-01

    Full Text Available In this paper, we present a review on silicon-based nonlinear devices for all optical nonlinear processing of complex telecommunication signals. We discuss some recent developments achieved by our research group, through extensive collaborations with academic partners across Europe, on optical signal processing using silicon-germanium and amorphous silicon based waveguides as well as novel materials such as silicon rich silicon nitride and tantalum pentoxide. We review the performance of four wave mixing wavelength conversion applied on complex signals such as Differential Phase Shift Keying (DPSK, Quadrature Phase Shift Keying (QPSK, 16-Quadrature Amplitude Modulation (QAM and 64-QAM that dramatically enhance the telecom signal spectral efficiency, paving the way to next generation terabit all-optical networks.

  14. Preface "Nonlinear processes in oceanic and atmospheric flows"

    Directory of Open Access Journals (Sweden)

    E. García-Ladona

    2010-05-01

    Full Text Available Nonlinear phenomena are essential ingredients in many oceanic and atmospheric processes, and successful understanding of them benefits from multidisciplinary collaboration between oceanographers, meteorologists, physicists and mathematicians. The present Special Issue on "Nonlinear Processes in Oceanic and Atmospheric Flows" contains selected contributions from attendants to the workshop which, in the above spirit, was held in Castro Urdiales, Spain, in July 2008. Here we summarize the Special Issue contributions, which include papers on the characterization of ocean transport in the Lagrangian and in the Eulerian frameworks, generation and variability of jets and waves, interactions of fluid flow with plankton dynamics or heavy drops, scaling in meteorological fields, and statistical properties of El Niño Southern Oscillation.

  15. Preface "Nonlinear processes in oceanic and atmospheric flows"

    CERN Document Server

    Mancho, A M; Turiel, A; Hernandez-Garcia, E; Lopez, C; Garcia-Ladona, E; 10.5194/npg-17-283-2010

    2010-01-01

    Nonlinear phenomena are essential ingredients in many oceanic and atmospheric processes, and successful understanding of them benefits from multidisciplinary collaboration between oceanographers, meteorologists, physicists and mathematicians. The present Special Issue on ``Nonlinear Processes in Oceanic and Atmospheric Flows'' contains selected contributions from attendants to the workshop which, in the above spirit, was held in Castro Urdiales, Spain, in July 2008. Here we summarize the Special Issue contributions, which include papers on the characterization of ocean transport in the Lagrangian and in the Eulerian frameworks, generation and variability of jets and waves, interactions of fluid flow with plankton dynamics or heavy drops, scaling in meteorological fields, and statistical properties of El Ni\\~no Southern Oscillation.

  16. High-speed signal processing using highly nonlinear optical fibres

    DEFF Research Database (Denmark)

    Peucheret, Christophe; Oxenløwe, Leif Katsuo; Mulvad, Hans Christian Hansen

    2009-01-01

    relying on the phase of the optical field. Topics covered include all-optical switching of 640 Gbit/s and 1.28 Tbit/s serial data, wavelength conversion at 640 Gbit/s, optical amplitude regeneration of differential phase shift keying (DPSK) signals, as well as midspan spectral inversion for differential 8......We review recent progress in all-optical signal processing techniques making use of conventional silica-based highly nonlinear fibres. In particular, we focus on recent demonstrations of ultra-fast processing at 640 Gbit/s and above, as well as on signal processing of novel modulation formats...

  17. Double resonant processes in $\\chi^{(2)}$ nonlinear periodic media

    OpenAIRE

    Konotop, V. V.; Kuzmiak, V.

    2000-01-01

    In a one-dimensional periodic nonlinear $\\chi^{(2)}$ medium, by choosing a proper material and geometrical parameters of the structure, it is possible to obtain two matching conditions for simultaneous generation of second and third harmonics. This leads to new diversity of the processes of the resonant three-wave interactions, which are discussed within the framework of slowly varying envelope approach. In particular, we concentrate on the fractional conversion of the frequency $\\omega \\to (...

  18. SAR processing with non-linear FM chirp waveforms.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2006-12-01

    Nonlinear FM (NLFM) waveforms offer a radar matched filter output with inherently low range sidelobes. This yields a 1-2 dB advantage in Signal-to-Noise Ratio over the output of a Linear FM (LFM) waveform with equivalent sidelobe filtering. This report presents details of processing NLFM waveforms in both range and Doppler dimensions, with special emphasis on compensating intra-pulse Doppler, often cited as a weakness of NLFM waveforms.

  19. A comparison of nonlinear media for parametric all-optical signal processing

    DEFF Research Database (Denmark)

    Martinez Diaz, Jordi; Bohigas Nadal, Jaume; Vukovic, Dragana;

    2013-01-01

    We systematically compare nonlinear media for parametric signal processing by determining the minimum pump power that is required for a given conversion efficiency in a degenerate four-wave mixing process, including the effect of nonlinear loss....

  20. Nonlinear Statistical Signal Processing: A Particle Filtering Approach

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J

    2007-09-19

    A introduction to particle filtering is discussed starting with an overview of Bayesian inference from batch to sequential processors. Once the evolving Bayesian paradigm is established, simulation-based methods using sampling theory and Monte Carlo realizations are discussed. Here the usual limitations of nonlinear approximations and non-gaussian processes prevalent in classical nonlinear processing algorithms (e.g. Kalman filters) are no longer a restriction to perform Bayesian inference. It is shown how the underlying hidden or state variables are easily assimilated into this Bayesian construct. Importance sampling methods are then discussed and shown how they can be extended to sequential solutions implemented using Markovian state-space models as a natural evolution. With this in mind, the idea of a particle filter, which is a discrete representation of a probability distribution, is developed and shown how it can be implemented using sequential importance sampling/resampling methods. Finally, an application is briefly discussed comparing the performance of the particle filter designs with classical nonlinear filter implementations.

  1. Predicting speech intelligibility in conditions with nonlinearly processed noisy speech

    DEFF Research Database (Denmark)

    Jørgensen, Søren; Dau, Torsten

    2013-01-01

    The speech-based envelope power spectrum model (sEPSM; [1]) was proposed in order to overcome the limitations of the classical speech transmission index (STI) and speech intelligibility index (SII). The sEPSM applies the signal-tonoise ratio in the envelope domain (SNRenv), which was demonstrated...... to successfully predict speech intelligibility in conditions with nonlinearly processed noisy speech, such as processing with spectral subtraction. Moreover, a multiresolution version (mr-sEPSM) was demonstrated to account for speech intelligibility in various conditions with stationary and fluctuating...... from computational auditory scene analysis and further support the hypothesis that the SNRenv is a powerful metric for speech intelligibility prediction....

  2. Involvement of Women In Community Development Process In ...

    African Journals Online (AJOL)

    Involvement of Women In Community Development Process In Ikeduru Local Government Area Of Imo State. ... between 31 and 40 years majority (47%) had primary education, majority (73.64%) were not involved in decision making process ...

  3. Bayesian framework for modeling diffusion processes with nonlinear drift based on nonlinear and incomplete observations.

    Science.gov (United States)

    Wu, Hao; Noé, Frank

    2011-03-01

    Diffusion processes are relevant for a variety of phenomena in the natural sciences, including diffusion of cells or biomolecules within cells, diffusion of molecules on a membrane or surface, and diffusion of a molecular conformation within a complex energy landscape. Many experimental tools exist now to track such diffusive motions in single cells or molecules, including high-resolution light microscopy, optical tweezers, fluorescence quenching, and Förster resonance energy transfer (FRET). Experimental observations are most often indirect and incomplete: (1) They do not directly reveal the potential or diffusion constants that govern the diffusion process, (2) they have limited time and space resolution, and (3) the highest-resolution experiments do not track the motion directly but rather probe it stochastically by recording single events, such as photons, whose properties depend on the state of the system under investigation. Here, we propose a general Bayesian framework to model diffusion processes with nonlinear drift based on incomplete observations as generated by various types of experiments. A maximum penalized likelihood estimator is given as well as a Gibbs sampling method that allows to estimate the trajectories that have caused the measurement, the nonlinear drift or potential function and the noise or diffusion matrices, as well as uncertainty estimates of these properties. The approach is illustrated on numerical simulations of FRET experiments where it is shown that trajectories, potentials, and diffusion constants can be efficiently and reliably estimated even in cases with little statistics or nonequilibrium measurement conditions.

  4. Nonlinear processes in the strong wave-plasma interaction

    Science.gov (United States)

    Pegoraro, Francesco; Califano, Francesco; Attico, Nicola; Bulanov, Sergei

    2000-10-01

    Nonlinear interactions in hot laboratory and/or astrophysical plasmas are a very efficient mechanism able to transfer the energy from the large to the small spatial scales of the system. As a result, kinetic processes are excited and play a key role in the plasma dynamics since the typical fluid dissipative length scales (where the nonlinear cascade is stopped) are (much) smaller then the kinetic length scales. Then, the key point is the role of the kinetic effects in the global plasma dynamics, i.e. whether the kinetic effects remains confined to the small scales of the system or whether there is a significant feedback on the large scales. Here we will address this problem by discussing the nonlinear kinetic evolution of the electromagnetic beam plasma instability where phase space vortices, as well as large scale vortex like magnetic structures in the physical space, are generated by wave - particle interactions. The role and influence of kinetic effects on the large scale plasma dynamics will be also discussed by addressing the problem of collisionless magnetic reconection.

  5. Experimental characterization of nonlinear processes of whistler branch waves

    Science.gov (United States)

    Tejero, E. M.; Crabtree, C.; Blackwell, D. D.; Amatucci, W. E.; Ganguli, G.; Rudakov, L.

    2016-05-01

    Experiments in the Space Physics Simulation Chamber at the Naval Research Laboratory isolated and characterized important nonlinear wave-wave and wave-particle interactions that can occur in the Earth's Van Allen radiation belts by launching predominantly electrostatic waves in the intermediate frequency range with wave normal angle greater than 85 ° and measuring the nonlinearly generated electromagnetic scattered waves. The scattered waves have a perpendicular wavelength that is nearly an order of magnitude larger than that of the pump wave. Calculations of scattering efficiency from experimental measurements demonstrate that the scattering efficiency is inversely proportional to the damping rate and trends towards unity as the damping rate approaches zero. Signatures of both wave-wave and wave-particle scatterings are also observed in the triggered emission process in which a launched wave resonant with a counter-propagating electron beam generates a large amplitude chirped whistler wave. The possibility of nonlinear scattering or three wave decay as a saturation mechanism for the triggered emission is suggested. The laboratory experiment has inspired the search for scattering signatures in the in situ data of chorus emission in the radiation belts.

  6. Recent Advances in Graphene-Assisted Nonlinear Optical Signal Processing

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2016-01-01

    Full Text Available Possessing a variety of remarkable optical, electronic, and mechanical properties, graphene has emerged as an attractive material for a myriad of optoelectronic applications. The wonderful optical properties of graphene afford multiple functions of graphene based polarizers, modulators, transistors, and photodetectors. So far, the main focus has been on graphene based photonics and optoelectronics devices. Due to the linear band structure allowing interband optical transitions at all photon energies, graphene has remarkably large third-order optical susceptibility χ(3, which is only weakly dependent on the wavelength in the near-infrared frequency range. The graphene-assisted four-wave mixing (FWM based wavelength conversions have been experimentally demonstrated. So, we believe that the potential applications of graphene also lie in nonlinear optical signal processing, where the combination of its unique large χ(3 nonlinearities and dispersionless over the wavelength can be fully exploited. In this review article, we give a brief overview of our recent progress in graphene-assisted nonlinear optical device and their applications, including degenerate FWM based wavelength conversion of quadrature phase-shift keying (QPSK signal, phase conjugated wavelength conversion by degenerate FWM and transparent wavelength conversion by nondegenerate FWM, two-input and three-input high-base optical computing, and high-speed gate-tunable terahertz coherent perfect absorption (CPA using a split-ring graphene.

  7. Generation of large fifth-order nonlinear phase shifts by use of lossless χ(2) cascaded nonlinear processes

    Institute of Scientific and Technical Information of China (English)

    XU Guang; QIAN Liejia; WANG Tao; FAN Dianyuan; LI Fuming

    2004-01-01

    It is shown that the cascaded fifth-order nonlinear phase shifts will increase with energy loss in the cascaded processes. Essentially different from the multi-photon absorption accompanied with inherent material nonlinearities, the loss of fundamental wave in a cascaded process is controllable and suppressible. By introducing difference frequencies generated from the reaction between the fundamental and its second harmonic after the cascaded processes, the fundamental wave can be free of energy loss, while the large cascaded fifth-order nonlinear phase shift is maintained.

  8. Preconditioned steepest descent methods for some nonlinear elliptic equations involving p-Laplacian terms

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Wenqiang, E-mail: wfeng1@vols.utk.edu [Department of Mathematics, The University of Tennessee, Knoxville, TN 37996 (United States); Salgado, Abner J., E-mail: asalgad1@utk.edu [Department of Mathematics, The University of Tennessee, Knoxville, TN 37996 (United States); Wang, Cheng, E-mail: cwang1@umassd.edu [Department of Mathematics, The University of Massachusetts, North Dartmouth, MA 02747 (United States); Wise, Steven M., E-mail: swise1@utk.edu [Department of Mathematics, The University of Tennessee, Knoxville, TN 37996 (United States)

    2017-04-01

    We describe and analyze preconditioned steepest descent (PSD) solvers for fourth and sixth-order nonlinear elliptic equations that include p-Laplacian terms on periodic domains in 2 and 3 dimensions. The highest and lowest order terms of the equations are constant-coefficient, positive linear operators, which suggests a natural preconditioning strategy. Such nonlinear elliptic equations often arise from time discretization of parabolic equations that model various biological and physical phenomena, in particular, liquid crystals, thin film epitaxial growth and phase transformations. The analyses of the schemes involve the characterization of the strictly convex energies associated with the equations. We first give a general framework for PSD in Hilbert spaces. Based on certain reasonable assumptions of the linear pre-conditioner, a geometric convergence rate is shown for the nonlinear PSD iteration. We then apply the general theory to the fourth and sixth-order problems of interest, making use of Sobolev embedding and regularity results to confirm the appropriateness of our pre-conditioners for the regularized p-Lapacian problems. Our results include a sharper theoretical convergence result for p-Laplacian systems compared to what may be found in existing works. We demonstrate rigorously how to apply the theory in the finite dimensional setting using finite difference discretization methods. Numerical simulations for some important physical application problems – including thin film epitaxy with slope selection and the square phase field crystal model – are carried out to verify the efficiency of the scheme.

  9. Preconditioned steepest descent methods for some nonlinear elliptic equations involving p-Laplacian terms

    Science.gov (United States)

    Feng, Wenqiang; Salgado, Abner J.; Wang, Cheng; Wise, Steven M.

    2017-04-01

    We describe and analyze preconditioned steepest descent (PSD) solvers for fourth and sixth-order nonlinear elliptic equations that include p-Laplacian terms on periodic domains in 2 and 3 dimensions. The highest and lowest order terms of the equations are constant-coefficient, positive linear operators, which suggests a natural preconditioning strategy. Such nonlinear elliptic equations often arise from time discretization of parabolic equations that model various biological and physical phenomena, in particular, liquid crystals, thin film epitaxial growth and phase transformations. The analyses of the schemes involve the characterization of the strictly convex energies associated with the equations. We first give a general framework for PSD in Hilbert spaces. Based on certain reasonable assumptions of the linear pre-conditioner, a geometric convergence rate is shown for the nonlinear PSD iteration. We then apply the general theory to the fourth and sixth-order problems of interest, making use of Sobolev embedding and regularity results to confirm the appropriateness of our pre-conditioners for the regularized p-Lapacian problems. Our results include a sharper theoretical convergence result for p-Laplacian systems compared to what may be found in existing works. We demonstrate rigorously how to apply the theory in the finite dimensional setting using finite difference discretization methods. Numerical simulations for some important physical application problems - including thin film epitaxy with slope selection and the square phase field crystal model - are carried out to verify the efficiency of the scheme.

  10. The Processes Involved in Designing Software.

    Science.gov (United States)

    1980-08-01

    body of relevant knowledge. There has been a limited amount of research on the process of design or on problems that are difficult enough to require the...refinement of those subproblems. Our results are therefore potentially limited to similar straightforward problems. In tasks for which the...They first break the problem Into Its major constituents, thus forming a solution moodl . During each Iteration, subproblems from the previous cycle are

  11. Artificial concurrent catalytic processes involving enzymes.

    Science.gov (United States)

    Köhler, Valentin; Turner, Nicholas J

    2015-01-11

    The concurrent operation of multiple catalysts can lead to enhanced reaction features including (i) simultaneous linear multi-step transformations in a single reaction flask (ii) the control of intermediate equilibria (iii) stereoconvergent transformations (iv) rapid processing of labile reaction products. Enzymes occupy a prominent position for the development of such processes, due to their high potential compatibility with other biocatalysts. Genes for different enzymes can be co-expressed to reconstruct natural or construct artificial pathways and applied in the form of engineered whole cell biocatalysts to carry out complex transformations or, alternatively, the enzymes can be combined in vitro after isolation. Moreover, enzyme variants provide a wider substrate scope for a given reaction and often display altered selectivities and specificities. Man-made transition metal catalysts and engineered or artificial metalloenzymes also widen the range of reactivities and catalysed reactions that are potentially employable. Cascades for simultaneous cofactor or co-substrate regeneration or co-product removal are now firmly established. Many applications of more ambitious concurrent cascade catalysis are only just beginning to appear in the literature. The current review presents some of the most recent examples, with an emphasis on the combination of transition metal with enzymatic catalysis and aims to encourage researchers to contribute to this emerging field.

  12. Nonlinear Optical Microscopy Signal Processing Strategies in Cancer

    Science.gov (United States)

    Adur, Javier; Carvalho, Hernandes F; Cesar, Carlos L; Casco, Víctor H

    2014-01-01

    This work reviews the most relevant present-day processing methods used to improve the accuracy of multimodal nonlinear images in the detection of epithelial cancer and the supporting stroma. Special emphasis has been placed on methods of non linear optical (NLO) microscopy image processing such as: second harmonic to autofluorescence ageing index of dermis (SAAID), tumor-associated collagen signatures (TACS), fast Fourier transform (FFT) analysis, and gray level co-occurrence matrix (GLCM)-based methods. These strategies are presented as a set of potential valuable diagnostic tools for early cancer detection. It may be proposed that the combination of NLO microscopy and informatics based image analysis approaches described in this review (all carried out on free software) may represent a powerful tool to investigate collagen organization and remodeling of extracellular matrix in carcinogenesis processes. PMID:24737930

  13. Nonlinear software sensor for monitoring genetic regulation processes with noise and modeling errors

    CERN Document Server

    Ibarra-Junquera, V; Rosu, H C; Arguello, G; Collado-Vides, J

    2004-01-01

    Nonlinear control techniques by means of a software sensor that are commonly used in chemical engineering could be also applied to genetic regulation processes. We provide here a realistic formulation of this procedure by introducing an additive white Gaussian noise, which is usually found in experimental data. Besides, we include model errors, meaning that we assume we do not know the nonlinear regulation function of the process. In order to illustrate this procedure, we employ the Goodwin dynamics of the concentrations (1963) in the simple form recently discussed by De Jong (2002), which involves the dynamics of the mRNA a, given protein A, and metabolite K concentrations. However instead of considering their full dynamics, we use only the data of metabolite K and a designed software sensor. We also show, more generally, that it is possible to rebuild the complete set of n concentrations despite the uncertainties in the regulation function and the perturbation due to the additive white Gaussian noise

  14. A simple nonlinear PD controller for integrating processes.

    Science.gov (United States)

    Dey, Chanchal; Mudi, Rajani K; Simhachalam, Dharmana

    2014-01-01

    Many industrial processes are found to be integrating in nature, for which widely used Ziegler-Nichols tuned PID controllers usually fail to provide satisfactory performance due to excessive overshoot with large settling time. Although, IMC (Internal Model Control) based PID controllers are capable to reduce the overshoot, but little improvement is found in the load disturbance response. Here, we propose an auto-tuning proportional-derivative controller (APD) where a nonlinear gain updating factor α continuously adjusts the proportional and derivative gains to achieve an overall improved performance during set point change as well as load disturbance. The value of α is obtained by a simple relation based on the instantaneous values of normalized error (eN) and change of error (ΔeN) of the controlled variable. Performance of the proposed nonlinear PD controller (APD) is tested and compared with other PD and PID tuning rules for pure integrating plus delay (IPD) and first-order integrating plus delay (FOIPD) processes. Effectiveness of the proposed scheme is verified on a laboratory scale servo position control system.

  15. Processing Time for Initial Disability Cases Involving the Processing Centers

    Data.gov (United States)

    Social Security Administration — The dataset includes annual data for average processing time and counts of initial disability claims in which there was a medical determination made broken out by...

  16. Neural networks involved in mathematical thinking: evidence from linear and non-linear analysis of electroencephalographic activity.

    Science.gov (United States)

    Micheloyannis, Sifis; Sakkalis, Vagelis; Vourkas, Michalis; Stam, Cornelis J; Simos, Panagiotis G

    2005-01-20

    Using linear and non-linear methods, electroencephalographic (EEG) signals were measured at various brain regions to provide information regarding patterns of local and coordinated activity during performance of three arithmetic tasks (number comparison, single-digit multiplication, and two-digit multiplication) and two control tasks that did not require arithmetic operations. It was hypothesized that these measures would reveal the engagement of local and increasingly complex cortical networks as a function of task specificity and complexity. Results indicated regionally increased neuronal signalling as a function of task complexity at frontal, temporal and parietal brain regions, although more robust task-related changes in EEG-indices of activation were derived over the left hemisphere. Both linear and non-linear indices of synchronization among EEG signals recorded from over different brain regions were consistent with the notion of more "local" processing for the number comparison task. Conversely, multiplication tasks were associated with a widespread pattern of distant signal synchronizations, which could potentially indicate increased demands for neural networks cooperation during performance of tasks that involve a greater number of cognitive operations.

  17. Nonlinear calibration and data processing of the solar radio burst

    Institute of Scientific and Technical Information of China (English)

    颜毅华; 谭程明; 徐龙; 姬慧荣; 傅其骏; 宋国乡

    2002-01-01

    The processes of the sudden energy release and energy transfer, and particle accelerations are the most challenge fundamental problems in solar physics as well as in astrophysics. Nowadays, there has been no direct measurement of the plasma parameters and magnetic fields at the coronal energy release site. Under the certain hypothesis of radiation mechanism and transmission process, radio measurement is almost the only method to diagnose coronal magnetic field. The broadband dynamic solar radio spectrometer that has been finished recently in China has higher time and frequency resolutions. Thus it plays an important role during the research of the 23rd solar cycle in China. Sometimes when there were very large bursts, the spectrometer will be overflowed. It needs to take some special process to discriminate the instrument and interference effects from solar burst signals. According to the characteristic of the solar radio broadband dynamic spectrometer, we developed a nonlinear calibration method to deal with the overflow of instrument, and introduced channel-modification method to deal with images. Finally the interference is eliminated with the help of the wavelet method. Here we take the analysis of the well-known solar-terrestrial event on July 14th, 2000 as the example. It shows the feasibility and validity of the method mentioned above. These methods can also be applied to other issues.

  18. Inferring Instantaneous, Multivariate and Nonlinear Sensitivities for the Analysis of Feedback Processes in a Dynamical System: Lorenz Model Case Study

    Science.gov (United States)

    Aires, Filipe; Rossow, William B.; Hansen, James E. (Technical Monitor)

    2001-01-01

    A new approach is presented for the analysis of feedback processes in a nonlinear dynamical system by observing its variations. The new methodology consists of statistical estimates of the sensitivities between all pairs of variables in the system based on a neural network modeling of the dynamical system. The model can then be used to estimate the instantaneous, multivariate and nonlinear sensitivities, which are shown to be essential for the analysis of the feedbacks processes involved in the dynamical system. The method is described and tested on synthetic data from the low-order Lorenz circulation model where the correct sensitivities can be evaluated analytically.

  19. Nonlinear closure relations theory for transport processes in nonequilibrium systems.

    Science.gov (United States)

    Sonnino, Giorgio

    2009-05-01

    A decade ago, a macroscopic theory for closure relations has been proposed for systems out of Onsager's region. This theory is referred to as the thermodynamic field theory (TFT). The aim of this work was to determine the nonlinear flux-force relations that respect the thermodynamic theorems for systems far from equilibrium. We propose a formulation of the TFT where one of the basic restrictions, namely, the closed-form solution for the skew-symmetric piece of the transport coefficients, has been removed. In addition, the general covariance principle is replaced by the De Donder-Prigogine thermodynamic covariance principle (TCP). The introduction of TCP requires the application of an appropriate mathematical formalism, which is referred to as the entropy-covariant formalism. By geometrical arguments, we prove the validity of the Glansdorff-Prigogine universal criterion of evolution. A new set of closure equations determining the nonlinear corrections to the linear ("Onsager") transport coefficients is also derived. The geometry of the thermodynamic space is non-Riemannian. However, it tends to be Riemannian for high values of the entropy production. In this limit, we recover the transport equations found by the old theory. Applications of our approach to transport in magnetically confined plasmas, materials submitted to temperature, and electric potential gradients or to unimolecular triangular chemical reactions can be found at references cited herein. Transport processes in tokamak plasmas are of particular interest. In this case, even in the absence of turbulence, the state of the plasma remains close to (but, it is not in) a state of local equilibrium. This prevents the transport relations from being linear.

  20. Adaptive optimal control of highly dissipative nonlinear spatially distributed processes with neuro-dynamic programming.

    Science.gov (United States)

    Luo, Biao; Wu, Huai-Ning; Li, Han-Xiong

    2015-04-01

    Highly dissipative nonlinear partial differential equations (PDEs) are widely employed to describe the system dynamics of industrial spatially distributed processes (SDPs). In this paper, we consider the optimal control problem of the general highly dissipative SDPs, and propose an adaptive optimal control approach based on neuro-dynamic programming (NDP). Initially, Karhunen-Loève decomposition is employed to compute empirical eigenfunctions (EEFs) of the SDP based on the method of snapshots. These EEFs together with singular perturbation technique are then used to obtain a finite-dimensional slow subsystem of ordinary differential equations that accurately describes the dominant dynamics of the PDE system. Subsequently, the optimal control problem is reformulated on the basis of the slow subsystem, which is further converted to solve a Hamilton-Jacobi-Bellman (HJB) equation. HJB equation is a nonlinear PDE that has proven to be impossible to solve analytically. Thus, an adaptive optimal control method is developed via NDP that solves the HJB equation online using neural network (NN) for approximating the value function; and an online NN weight tuning law is proposed without requiring an initial stabilizing control policy. Moreover, by involving the NN estimation error, we prove that the original closed-loop PDE system with the adaptive optimal control policy is semiglobally uniformly ultimately bounded. Finally, the developed method is tested on a nonlinear diffusion-convection-reaction process and applied to a temperature cooling fin of high-speed aerospace vehicle, and the achieved results show its effectiveness.

  1. Nonlinear Acoustic Experiments Involving Landmine Detection: Connections with Mesoscopic Elasticity and Slow Dynamics in Geomaterials

    Science.gov (United States)

    Korman, Murray S.; Sabatier, James M.

    2006-05-01

    The vibration interaction between the top-plate of a buried VS 2.2 plastic, anti-tank landmine and the soil above it appears to exhibit similar characteristics to the nonlinear mesoscopic/nanoscale effects that are observed in geomaterials like rocks or granular materials. [J. Acoust. Soc. Am. 116, 3354-3369 (2004)]. When airborne sound at two primary frequencies f1 and f2 (closely spaced near resonance) undergo acoustic-to-seismic coupling, (A/S), interactions with the mine and soil generate combination frequencies | n f1 ± m f2 | which affect the surface vibration velocity. Profiles at f1, f2, f1 -(f2 - f1) and f2 +(f2 - f1) exhibit single peaks whereas other combination frequencies may involve higher order modes. A family of increasing amplitude tuning curves, involving the surface vibration over the landmine, exhibits a linear relationship between the peak particle velocity and corresponding resonant frequency. Subsequent decreasing amplitude tuning curves exhibit hysteresis effects. New experiments for a buried VS 1.6 anti-tank landmine and a "plastic drum head" mine simulant behave similarly. Slow dynamics explains the amplitude difference in tuning curves for first sweeping upward and then downward through resonance, provided the soil modulus drops after periods of high strain. [Support by U.S. Army RDECOM CERDEC, NVESD, Fort Belvoir, VA.

  2. Nonlinear properties of and nonlinear processing in hydrogenated amorphous silicon waveguides

    DEFF Research Database (Denmark)

    Kuyken, B.; Ji, Hua; Clemmen, S.

    2011-01-01

    We propose hydrogenated amorphous silicon nanowires as a platform for nonlinear optics in the telecommunication wavelength range. Extraction of the nonlinear parameter of these photonic nanowires reveals a figure of merit larger than 2. It is observed that the nonlinear optical properties...... of these waveguides degrade with time, but that this degradation can be reversed by annealing the samples. A four wave mixing conversion efficiency of + 12 dB is demonstrated in a 320 Gbit/s serial optical waveform data sampling experiment in a 4 mm long photonic nanowire....

  3. Nonlinear quantum electrodynamic and electroweak processes in strong laser fields

    Energy Technology Data Exchange (ETDEWEB)

    Meuren, Sebastian

    2015-06-24

    Various nonlinear electrodynamic and electroweak processes in strong plane-wave laser fields are considered with an emphasis on short-pulse effects. In particular, the momentum distribution of photoproduced electron-positron pairs is calculated numerically and a semiclassical interpretation of its characteristic features is established. By proving the optical theorem, compact double-integral expressions for the total pair-creation probability are obtained and numerically evaluated. The exponential decay of the photon wave function in a plane wave is included by solving the Schwinger-Dyson equations to leading-order in the quasistatic approximation. In this respect, the polarization operator in a plane wave is investigated and its Ward-Takahashi identity verified. A classical analysis indicates that a photoproduced electron-positron pair recollides for certain initial conditions. The contributions of such recollision processes to the polarization operator are identified and calculated both analytically and numerically. Furthermore, the existence of nontrivial electron-spin dynamics induced by quantum fluctuations is verified for ultra-short laser pulses. Finally, the exchange of weak gauge bosons is considered, which is essential for neutrino-photon interactions. In particular, the axial-vector-vector coupling tensor is calculated and the so-called Adler-Bell-Jackiw (ABJ) anomaly investigated.

  4. Democratizing Process Innovation? On Citizen Involvement in Public Sector BPM

    Science.gov (United States)

    Niehaves, Björn; Malsch, Robert

    ‘Open Innovation’ has been heavily discussed for product innovations; however, an information systems (IS) perspective on ‘process innovation’ has not yet been taken. Analyzing the example of the public sector in Germany, the paper seeks to investigate the factors that hinder and support ‘open process innovation’, a concept we define as the involvement of citizens in business process management (BPM) activities. With the help of a quantitative study (n=358), six factors are examined for their impact on citizen involvement in local government BPM initiatives. The results show that citizen involvement in reform processes is not primarily motivated by the aim of cost reduction, but rather related to legitimacy reasons and the intent to increase employee motivation. Based on these findings, implications for (design) theory and practice are discussed: Instead of detailed collaborative business processes modeling, the key of citizen involvement in public sector BPM lies in communication and mutual understanding.

  5. The Appropriateness Of Parental Involvement In The Job Search Process

    Directory of Open Access Journals (Sweden)

    Gary S. Insch

    2011-01-01

    Full Text Available This paper explores millennial job seekers and their parental involvement in the job search process. Preliminary work on a scale to measure the “appropriateness” of certain job search behaviors is reported. Ten parental job search behaviors are identified.  The appropriateness constructs of “mentoring” and “meddling” are developed and empirically tested. Results indicate that both meddling and mentoring are valid and initially useful constructs in examining the suitability of parental involvement in the job search process. The possible impact of parental involvement in the job search process is then discussed along with possible managerial responses.

  6. All-optical signal processing in quadratic nonlinear materials

    DEFF Research Database (Denmark)

    Johansen, Steffen Kjær

    2002-01-01

    of materials with a second order nonlinearity, the so-called X(2) materials, is faster and stronger than that of more conventional materials with a cubic nonlinearity. The X(2) materials support spatial solitons consisting of two coupled components, the fundamental wave (FW) and its second harmonic (SH......). During this project the interaction between such spatial solitons has been investigated theoretically through perturbation theory and experimentally via numerical simulations. The outcome of this research isnew theoretical tools for quantitatively predicting the escape angle, i.e. the angle of incidence...... and exploitation of these cubic nonlinearities in two-period QPM wave-guides has been another area of investigation. Introducing the second period might make practical engineering of the nonlinearities possible. A major result is the discovery that cubic nonlinearities leads to an enhancement of the bandwidth...

  7. Kenyan nurses involvement in national policy development processes.

    Science.gov (United States)

    Juma, Pamela Atieno; Edwards, Nancy; Spitzer, Denise

    2014-01-01

    The aim of this study was to critically examine how nurses have been involved in national policy processes in the Kenyan health sector. The paper reports qualitative results from a larger mixed method study. National nonnursing decision-makers and nurse leaders, and provincial managers as well as frontline nurse managers from two Kenyan districts were purposefully selected for interviews. Interviews dealt with nurses' involvement in national policy processes, factors hindering nurses' engagement in policy processes, and ways to enhance nurses' involvement in policy processes. Critical theory and feminist perspectives guided the study process. Content analysis of data was conducted. Findings revealed that nurses' involvement in policy processes in Kenya was limited. Only a few nurse leaders were involved in national policy committees as a result of their positions in the sector. Critical analysis of the findings revealed that hierarchies and structural factors as well as nursing professional issues were the primary barriers constraining nurses' involvement in policy processes. Thus, there is need to address these factors both by nurses themselves and by nonnursing decision makers, in order to enhance nurses engagement in policy making and further the contribution to quality of services to the communities.

  8. New Algorithm Model for Processing Generalized Dynamic Nonlinear Data Derived from Deformation Monitoring Network

    Institute of Scientific and Technical Information of China (English)

    LIN Xiangguo; LIANG Yong

    2005-01-01

    The processing of nonlinear data was one of hot topics in surveying and mapping field in recent years.As a result, many linear methods and nonlinear methods have been developed.But the methods for processing generalized nonlinear surveying and mapping data, especially for different data types and including unknown parameters with random or nonrandom, are seldom noticed.A new algorithm model is presented in this paper for processing nonlinear dynamic multiple-period and multiple-accuracy data derived from deformation monitoring network.

  9. Processes Involved in Chinese and English Writing: A Study of Chinese University Students

    Directory of Open Access Journals (Sweden)

    Meihua Liu

    2013-11-01

    Full Text Available The present study examined the writing processes of 20 L1 writers and 20 L2 writers on a course task of writing a narrative in a Chinese university naturalistic setting, as well as the challenges they encountered and their coping strategies during the processes. Analyses of the data collected via questionnaire, journal and semi-structured interviews revealed that (1 both L1 and L2 writing processes were nonlinear and cyclical, involving a constant interplay of thinking, writing, and revising throughout the process, (2 though having a lot in common, the two groups differed in many aspects regarding the foci of concern during the process of writing the narrative, (3 both groups encountered common challenges as well as those peculiar of their own writing during the composing process, and (4 both groups were resourceful learners. Based on these findings, some suggestions are discussed. Keywords: writing process; narrative; L1; L2; challenge; strategy

  10. Constraints on the Higgs Sector from Processes Involving Photons

    OpenAIRE

    Krawczyk,Maria

    1998-01-01

    The Higgs sector of the Standard Model and of the Two Higgs Doublet Extensions of SM, MSSM and the general 2HDM, can be tested in processes involving photons. A short review of the corresponding results is presented.

  11. System Identification and Filtering of Nonlinear Controlled Markov Processes by Canonical Variate Analysis

    Science.gov (United States)

    1989-10-30

    In this Phase I SBIR study, new methods are developed for the system identification and stochastic filtering of nonlinear controlled Markov processes...state space Markov process models and canonical variate analysis (CVA) for obtaining optimal nonlinear procedures for system identification and stochastic

  12. Application of Novel Nonlinear Optical Materials to Optical Processing

    Science.gov (United States)

    Banerjee, Partha P.

    1999-01-01

    We describe wave mixing and interactions in nonlinear photorefractive polymers and disodium flourescein. Higher diffracted orders yielding forward phase conjugation can be generated in a two-wave mixing geometry in photorefractive polymers, and this higher order can be used for image edge enhancement and correlation. Four-wave mixing and phase conjugation is studied using nonlinear disodium floureschein, and the nature and properties of gratings written in this material are investigated.

  13. Development of a robust calibration model for nonlinear in-line process data

    Science.gov (United States)

    Despagne; Massart; Chabot

    2000-04-01

    A comparative study involving a global linear method (partial least squares), a local linear method (locally weighted regression), and a nonlinear method (neural networks) has been performed in order to implement a calibration model on an industrial process. The models were designed to predict the water content in a reactor during a distillation process, using in-line measurements from a near-infrared analyzer. Curved effects due to changes in temperature and variations between the different batches make the problem particularly challenging. The influence of spectral range selection and data preprocessing has been studied. With each calibration method, specific procedures have been applied to promote model robustness. In particular, the use of a monitoring set with neural networks does not always prevent overfitting. Therefore, we developed a model selection criterion based on the determination of the median of monitoring error over replicate trials. The back-propagation neural network models selected were found to outperform the other methods on independent test data.

  14. Nonlinear Model Algorithmic Control of a pH Neutralization Process

    Institute of Scientific and Technical Information of China (English)

    ZOU Zhiyun; YU Meng; WANG Zhizhen; LIU Xinghong; GUO Yuqing; ZHANG Fengbo; GUO Ning

    2013-01-01

    Control of pH neutralization processes is challenging in the chemical process industry because of their inherent strong nonlinearity.In this paper,the model algorithmic control (MAC) strategy is extended to nonlinear processes using Hammerstein model that consists of a static nonlinear polynomial function followed in series by a linear impulse response dynamic element.A new nonlinear Hammerstein MAC algorithm (named NLH-MAC) is presented in detail.The simulation control results of a pH neutralization process show that NLH-MAC gives better control performance than linear MAC and the commonly used industrial nonlinear propotional plus integral plus derivative (PID) controller.Further simulation experiment demonstrates that NLH-MAC not only gives good control response,but also possesses good stability and robustness even with large modeling errors.

  15. THE EXISTENCE OF SOLUTIONS OF NONLINEAR BOUNDARY VALUE PROBLEMS INVOLVING THE p-LAPLACIAN OPERATOR IN Ls-SPACES

    Institute of Scientific and Technical Information of China (English)

    WEI Li; ZHOU Haiyun

    2005-01-01

    By using the perturbation theories on sums of ranges of nonlinear accretive mappings of Calvert and Gupta, we study the abstract results on the existence of a solution u ∈ Ls (Ω) of nonlinear boundary value problems involving the p-Laplacian operator, where2 ≤ s < +∞, and 2N/N+1 < p ≤ 2 for N(≥ 1) which denotes the dimension of RN. To obtain the result, some new techniques are used in this paper. The equation discussed in this paper and our methods here are extension and complement to the corresponding results of L. Wei and Z. He.

  16. Nonlinear PDEs

    OpenAIRE

    2015-01-01

    From the Back Cover: The emphasis throughout the present volume is on the practical application of theoretical mathematical models helping to unravel the underlying mechanisms involved in processes from mathematical physics and biosciences. It has been conceived as a unique collection of abstract methods dealing especially with nonlinear partial differential equations (either stationary or evolutionary) that are applied to understand concrete processes involving some important applications re...

  17. Femtosecond Fiber Lasers Based on Dissipative Processes for Nonlinear Microscopy

    Science.gov (United States)

    Wise, Frank W.

    2012-01-01

    Recent progress in the development of femtosecond-pulse fiber lasers with parameters appropriate for nonlinear microscopy is reviewed. Pulse-shaping in lasers with only normal-dispersion components is briefly described, and the performance of the resulting lasers is summarized. Fiber lasers based on the formation of dissipative solitons now offer performance competitive with that of solid-state lasers, but with the benefits of the fiber medium. Lasers based on self-similar pulse evolution in the gain section of a laser also offer a combination of short pulse duration and high pulse energy that will be attractive for applications in nonlinear bioimaging. PMID:23869163

  18. Nonlinear Schrodinger elliptic systems involving exponential critical growth in R^2

    Directory of Open Access Journals (Sweden)

    Francisco S. B. Albuquerque Albuquerque

    2014-02-01

    Full Text Available This article concerns the existence and multiplicity of solutions for elliptic systems with weights, and nonlinearities having exponential critical growth. Our approach is based on the Trudinger-Moser inequality and on a minimax theorem.

  19. Nonlinear software sensor for monitoring genetic regulation processes with noise and modeling errors

    Science.gov (United States)

    Ibarra-Junquera, V.; Torres, L. A.; Rosu, H. C.; Argüello, G.; Collado-Vides, J.

    2005-07-01

    Nonlinear control techniques by means of a software sensor that are commonly used in chemical engineering could be also applied to genetic regulation processes. We provide here a realistic formulation of this procedure by introducing an additive white Gaussian noise, which is usually found in experimental data. Besides, we include model errors, meaning that we assume we do not know the nonlinear regulation function of the process. In order to illustrate this procedure, we employ the Goodwin dynamics of the concentrations [B. C. Goodwin, Temporal Oscillations in Cells (Academic, New York, 1963)] in the simple form recently applied to single gene systems and some operon cases [H. De Jong, J. Comput. Biol. 9, 67 (2002)], which involves the dynamics of the mRNA, given protein and metabolite concentrations. Further, we present results for a three gene case in coregulated sets of transcription units as they occur in prokaryotes. However, instead of considering their full dynamics, we use only the data of the metabolites and a designed software sensor. We also show, more generally, that it is possible to rebuild the complete set of nonmeasured concentrations despite the uncertainties in the regulation function or, even more, in the case of not knowing the mRNA dynamics. In addition, the rebuilding of concentrations is not affected by the perturbation due to the additive white Gaussian noise and also we managed to filter the noisy output of the biological system.

  20. Mathematical models of non-linear phenomena, processes and systems: from molecular scale to planetary atmosphere

    CERN Document Server

    2013-01-01

    This book consists of twenty seven chapters, which can be divided into three large categories: articles with the focus on the mathematical treatment of non-linear problems, including the methodologies, algorithms and properties of analytical and numerical solutions to particular non-linear problems; theoretical and computational studies dedicated to the physics and chemistry of non-linear micro-and nano-scale systems, including molecular clusters, nano-particles and nano-composites; and, papers focused on non-linear processes in medico-biological systems, including mathematical models of ferments, amino acids, blood fluids and polynucleic chains.

  1. Nonlinear giant magnetoimpedance and the asymmetric circumferential magnetization process in soft magnetic wires

    Science.gov (United States)

    Gómez-Polo, C.; Duque, J. G. S.; Knobel, M.

    2004-07-01

    The magnetoimpedance effect and its nonlinear terms are analysed for a (Co0.94Fe0.06)72.5Si12.5B15 amorphous wire. In order to enhance the nonlinear contribution the sample was previously subjected to current annealing (Joule heating) to induce a circumferential anisotropy. The effect of the application of a torsional strain on the nonlinear magnetoimpedance is analysed in terms of the torsional dependence of the magnetic permeability, evaluated through experimental circumferential hysteresis loops. The results obtained clearly confirm the direct correlation between the asymmetric circumferential magnetization process and the occurrence of nonlinear second-harmonic terms in the magnetoimpedance voltage.

  2. Publication process involving the discovery of artemisinin (qinghaosu) before 1985

    Institute of Scientific and Technical Information of China (English)

    Man-Yuan Wang

    2016-01-01

    All the original references were provided by the Nobel Laureate Youyou Tu. The publication process involving the discovery of artemisinin was collected and sorted by her first Ph D student, Associate Professor Man-Yuan Wang. Through the publication of this article, the journal expects to provide a reference to the scientists who dedicated to the research of artemisinin, especially those who are interested in the discovery process of artemisinin.

  3. Low Doses of Traditional Nanophytomedicines for Clinical Treatment: Manufacturing Processes and Nonlinear Response Patterns.

    Science.gov (United States)

    Bell, Iris R; Sarter, Barbara; Standish, Leanna J; Banerji, Prasanta; Banerji, Pratip

    2015-06-01

    The purpose of the present paper is to (a) summarize evidence for the nanoparticle nature and biological effects of traditional homeopathically-prepared medicines at low and ultralow doses; (b) provide details of historically-based homeopathic green manufacturing materials and methods, relating them to top-down mechanical attrition and plant-based biosynthetic processes in modern nanotechnology; (c) outline the potential roles of nonlinear dose-responses and dynamical interactions with complex adaptive systems in generating endogenous amplification processes during low dose treatment. Possible mechanisms of low dose effects, for which there is evidence involving nanoparticles and/or homeopathically-manufactured medicines, include hormesis, time-dependent sensitization, and stochastic resonance. All of the proposed mechanisms depend upon endogenous nonlinear amplification processes in the recipient organism in interaction with the salient, albeit weak signal properties of the medicine. Conventional ligand-receptor mechanisms relevant to higher doses are less likely involved. Effects, especially for homeopathically-prepared nanophytomedicines, include bidirectional host state-dependent changes in function. Homeopathic clinicians report successful treatment of serious infections and cancers. Preclinical biological evidence is consistent with such claims. Controlled biological data on homeopathically-prepared medicines indicate modulation of gene expression and biological signaling pathways regulating cell cycles, immune reactions, and central nervous system function from studies on cells, animals, and human subjects. As a 200-year old system of traditional medicine used by millions of people worldwide, homeopathy offers a pulsed low dose treatment strategy and strong safety record to facilitate progress in translational nanomedicine with plants and other natural products. In turn, modern nanotechnology methods can improve homeopathic manufacturing procedures

  4. Involvement of external stakeholders in local Health policymaking process

    DEFF Research Database (Denmark)

    Eklund Karlsson, Leena; Jakobsen, Mette Winge; Winblad Heiberg, Malin

    2017-01-01

    Collaboration between research and policy is an essential element for knowledge-based public health. However, only half of the Danish municipalities have experience with collaborating with researchers or other stakeholders. Through content analysis of interviews and policy documents the study exp...... influence on the involvement of external stakeholders, allowing only a few to contribute in a closed policymaking process....

  5. Analysis of bilinear stochastic systems. [involving multiplicative noise processes

    Science.gov (United States)

    Willsky, A. S.; Marcus, S. I.; Martin, D. N.

    1974-01-01

    Analysis of stochastic dynamical systems that involve multiplicative (bilinear) noise processes is considered. After defining the systems of interest, the evolution of the moments of such systems, the question of stochastic stability, and estimation for bilinear stochastic systems are discussed. Both exact and approximate methods of analysis are introduced, and, in particular, the uses of Lie-theoretic concepts and harmonic analysis are discussed.

  6. Solvability of Nonlinear Langevin Equation Involving Two Fractional Orders with Dirichlet Boundary Conditions

    Directory of Open Access Journals (Sweden)

    Bashir Ahmad

    2010-01-01

    Full Text Available We study a Dirichlet boundary value problem for Langevin equation involving two fractional orders. Langevin equation has been widely used to describe the evolution of physical phenomena in fluctuating environments. However, ordinary Langevin equation does not provide the correct description of the dynamics for systems in complex media. In order to overcome this problem and describe dynamical processes in a fractal medium, numerous generalizations of Langevin equation have been proposed. One such generalization replaces the ordinary derivative by a fractional derivative in the Langevin equation. This gives rise to the fractional Langevin equation with a single index. Recently, a new type of Langevin equation with two different fractional orders has been introduced which provides a more flexible model for fractal processes as compared with the usual one characterized by a single index. The contraction mapping principle and Krasnoselskii's fixed point theorem are applied to prove the existence of solutions of the problem in a Banach space.

  7. Nonlinear Systems.

    Science.gov (United States)

    Seider, Warren D.; Ungar, Lyle H.

    1987-01-01

    Describes a course in nonlinear mathematics courses offered at the University of Pennsylvania which provides an opportunity for students to examine the complex solution spaces that chemical engineers encounter. Topics include modeling many chemical processes, especially those involving reaction and diffusion, auto catalytic reactions, phase…

  8. A Process Model of Organizational Commitment and Job Involvement.

    Science.gov (United States)

    1982-09-01

    AD-A123 043 A PROCESS MODEL OF ORGANIZATIONAL COMMITMENT AND JOB I INVOLVEMENT(U) AIR FORCE INST OF TECH WR IGHT PATTERSON AFB OH SCHOL OF SYSTEMS...Appo @1 inu pubo 01004 Aocesston For NTIS CRA&I DTIC TAB Unannounced 0I Justfication - gI, Distr" ’ut ioi / Af t A PROCESS MODEL OF ORGANIZATIONAL...GOVT ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER LSSR 76-82 1,3b - 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED A PROCESS MODEL OF

  9. Nonlinear analysis and control of a continuous fermentation process

    DEFF Research Database (Denmark)

    Szederkényi, G.; Kristensen, Niels Rode; Hangos, K.M

    2002-01-01

    open-loop system properties, to explore the possible control difficulties and to select the system output to be used in the control structure. A wide range of controllers are tested including pole placement and LQ controllers, feedback and input–output linearization controllers and a nonlinear...... controller based on direct passivation. The comparison is based on time-domain performance and on investigating the stability region, robustness and tuning possibilities of the controllers. Controllers using partial state feedback of the substrate concentration and not directly depending on the reaction rate...... are recommended for the simple fermenter. Passivity based controllers have been found to be globally stable, not very sensitive to the uncertainties in the reaction rate and controller parameter but they require full nonlinear state feedback....

  10. Photonic Crystal Nanocavity Devices for Nonlinear Signal Processing

    DEFF Research Database (Denmark)

    Yu, Yi

    , membranization of InP/InGaAs structure and wet etching. Experimental investigation of the switching dynamics of InP photonic crystal nanocavity structures are carried out using short-pulse homodyne pump-probe techniques, both in the linear and nonlinear region where the cavity is perturbed by a relatively small......This thesis deals with the investigation of InP material based photonic crystal cavity membrane structures, both experimentally and theoretically. The work emphasizes on the understanding of the physics underlying the structures’ nonlinear properties and their applications for all-optical signal...... and large pump power. The experimental results are compared with coupled mode equations developed based on the first order perturbation theory, and carrier rate equations we established for the dynamics of the carrier density governing the cavity properties. The experimental observations show a good...

  11. Neural Generalized Predictive Control of a non-linear Process

    DEFF Research Database (Denmark)

    Sørensen, Paul Haase; Nørgård, Peter Magnus; Ravn, Ole

    1998-01-01

    The use of neural network in non-linear control is made difficult by the fact the stability and robustness is not guaranteed and that the implementation in real time is non-trivial. In this paper we introduce a predictive controller based on a neural network model which has promising stability...... detail and discuss the implementation difficulties. The neural generalized predictive controller is tested on a pneumatic servo sys-tem....

  12. Positive Solutions for Nonlinear Fractional Differential Equations with Boundary Conditions Involving Riemann-Stieltjes Integrals

    Directory of Open Access Journals (Sweden)

    Jiqiang Jiang

    2012-01-01

    Full Text Available We consider the existence of positive solutions for a class of nonlinear integral boundary value problems for fractional differential equations. By using some fixed point theorems, the existence and multiplicity results of positive solutions are obtained. The results obtained in this paper improve and generalize some well-known results.

  13. Nonlinear modeling of activated sludge process using the Hammerstein-Wiener structure

    Directory of Open Access Journals (Sweden)

    Frącz Paweł

    2016-01-01

    Full Text Available The paper regards to physical model of the Activated Sludge Process, which is a part of the wastewater treatment. The aim of the study was to describe nitrogen transformation process and the demand of chemical fractions, involved in the ASP process. Moreover, the non-linear relationship between the flow of wastewater and the consumed electrical energy, used by the blowers, was determined. Such analyses are important from the economical and environmental point of view. Assuming that the total power does not change the blower is charging during a year an energy amount of approx. 613 MW. This illustrates in particular the scale of the demand for energy consumption in the biological aeration unit. The aim is to minimize the energy consumption through first building a model of ASP and then through optimization of the overall process by modifying chosen parameter in numerical simulations. In this paper example measurement and analysis results of nitrite and ammonium nitrogen concentrations in the aeration reactor and the active power consumed by blowers for the aeration process were presented. Further the ASP modeling procedure, which uses the Hammerstein-Wiener structure and example verification results were presented. Based on the achieved results it was stated that the developed set of methodologies may be used to improve and expand the overriding control system for system for wastewater treatment plant.

  14. Real-Time Implementation of Nonlinear Optical Processing Functions.

    Science.gov (United States)

    1986-09-30

    demonstrating that the memory is nonlinear and selective. The recording medium could be replaced with real-time media such as photorefractive crystals. Thicker...recording media Fi4 4. Schematic of experiment that d,.non* trated ,,pera have the added advantage of higher angular selectiv- "" . e e r aity. thus... geometrica snapes in contact ’A,.n a c-:’:ser ’Figure 51a’ ., and a spher:cal 4:verg.ng reference -eam Upion :"um’latlon of t -" c-’gram by the object beam

  15. Investigating Individuals' Intention to be Involved in Knowledge Management Process

    Directory of Open Access Journals (Sweden)

    M. J.M. Razi

    2011-01-01

    Full Text Available Problem statement: Implementation of Knowledge Management (KM process in organizations is considered as essential to be competitive in the present competitive world. Though the modern KM practices highly depend on technology, individuals (‘organizational members’ intention to be involved in KM process plays a major role in the success. Hence, the evaluation of individuals’ intention is deemed as significant before the actual implementation of KM process in organizations. Nevertheless, inadequate information is presented in this regard; as a result, a wide research gap prevails in the literature. In this context, the present study focuses on developing a research frame work that can be used to measure the individual intention to be involved in KM process. Approach: Subsequent to a critical analysis of the research gaps, a basic research model has been developed based on knowledge creation theory, KM enablers, and individual acceptance model. Measurers and questionnaire items were identified for each variable from relevant literature. Consequently, the reliability of the instrument was tested among academic staff of a Malaysian university. Results: The Cronbach’s alpha for each variable is more than 0.800 that exhibits the reliability of the instruments. Conclusion: The presented research framework might be a doorstep for future study in this area of KM. Moreover, practitioners may use the proposed framework to measure the intention of individuals to be involved in KM process before actually embarking to it. However, the framework and the model should be tested in different socio cultural and organizational climate to make it robust.

  16. Approaches to handle nonlinearities and nonnormalities in process chemometrics

    NARCIS (Netherlands)

    Thissen, Uwe Maria Johannes

    2004-01-01

    For every industrial process, it is of paramount interest to online monitor the performance of the process and to assess the quality of the products made. In order to meet these goals, the field of process control works on understanding and improving industrial processes. Process chemometrics can be

  17. EARLY READING ASSESSMENT INSTRUMENTS: ABILITIES AND PROCESSES INVOLVED

    Directory of Open Access Journals (Sweden)

    Ana Cláudia de Souza

    2017-04-01

    Full Text Available This study investigates the following early reading assessment instruments: “Bateria de Recepção e Produção da Linguagem Verbal” (SCLIAR-CABRAL, 2003a and “Teste de Competência de Leitura de Palavras e Pseudopalavras” (SEABRA; CAPOVILLA, 2010. The main research goal is to analyze in each one of these reading assessment instruments some of the multiple cognitive processes and basic low-level abilities involved in reading. In this sense, decoding, word recognition, lexical access, syntactic and textual processing, and comprehension are the cognitive processes taken into account. With regard to the basic reading abilities, accuracy and fluency (rhythm, prosody and speed are considered. The results indicate that each one of the analyzed reading assessment instruments assesses different aspects of the reading processes and abilities, mainly through off-line measures. ScliarCabral’s assessment battery allows the researcher or the teacher to evaluate the following processes: perception of the grapheme opposition in minimal pairs of words and in sentences, difficulties in sentence processing, skills in decoding the graphemic-phonemic relationship, and textual comprehension. In its turn, the reading assessment instrument proposed by Seabra e Capovilla allows one to evaluate student’s reading development level, by classifying the kind of processing as logographic, alphabetic or orthographic.

  18. Multiple positive solutions for Kirchhoff type problems involving concave and convex nonlinearities in R^3

    Directory of Open Access Journals (Sweden)

    Xiaofei Cao

    2016-11-01

    Full Text Available In this article, we consider the multiplicity of positive solutions for a class of Kirchhoff type problems with concave and convex nonlinearities. Under appropriate assumptions, we prove that the problem has at least two positive solutions, moreover, one of which is a positive ground state solution. Our approach is mainly based on the Nehari manifold, Ekeland variational principle and the theory of Lagrange multipliers.

  19. A nonlinear optoelectronic filter for electronic signal processing

    Science.gov (United States)

    Loh, William; Yegnanarayanan, Siva; Ram, Rajeev J.; Juodawlkis, Paul W.

    2014-01-01

    The conversion of electrical signals into modulated optical waves and back into electrical signals provides the capacity for low-loss radio-frequency (RF) signal transfer over optical fiber. Here, we show that the unique properties of this microwave-photonic link also enable the manipulation of RF signals beyond what is possible in conventional systems. We achieve these capabilities by realizing a novel nonlinear filter, which acts to suppress a stronger RF signal in the presence of a weaker signal independent of their separation in frequency. Using this filter, we demonstrate a relative suppression of 56 dB for a stronger signal having a 1-GHz center frequency, uncovering the presence of otherwise undetectable weaker signals located as close as 3.5 Hz away. The capabilities of the optoelectronic filter break the conventional limits of signal detection, opening up new possibilities for radar and communication systems, and for the field of precision frequency metrology. PMID:24402418

  20. Nonlinear model predictive control for chemical looping process

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Abhinaya; Lei, Hao; Lou, Xinsheng

    2017-08-22

    A control system for optimizing a chemical looping ("CL") plant includes a reduced order mathematical model ("ROM") that is designed by eliminating mathematical terms that have minimal effect on the outcome. A non-linear optimizer provides various inputs to the ROM and monitors the outputs to determine the optimum inputs that are then provided to the CL plant. An estimator estimates the values of various internal state variables of the CL plant. The system has one structure adapted to control a CL plant that only provides pressure measurements in the CL loops A and B, a second structure adapted to a CL plant that provides pressure measurements and solid levels in both loops A, and B, and a third structure adapted to control a CL plant that provides full information on internal state variables. A final structure provides a neural network NMPC controller to control operation of loops A and B.

  1. Optical pulse engineering and processing using optical nonlinearities of nanostructured waveguides made of silicon

    Science.gov (United States)

    Lavdas, Spyros; You, Jie; Osgood, Richard M.; Panoiu, Nicolae C.

    2015-08-01

    We present recent results pertaining to pulse reshaping and optical signal processing using optical nonlinearities of silicon-based tapered photonic wires and photonic crystal waveguides. In particular, we show how nonlinearity and dispersion engineering of tapered photonic wires can be employed to generate optical similaritons and achieve more than 10× pulse compression. We also discuss the properties of four-wave mixing pulse amplification and frequency conversion efficiency in long-period Bragg waveguides and photonic crystal waveguides. Finally, the influence of linear and nonlinear optical effects on the transmission bit-error rate in uniform photonic wires and photonic crystal waveguides made of silicon is discussed.

  2. Blind Image Deblurring Driven by Nonlinear Processing in the Edge Domain

    Directory of Open Access Journals (Sweden)

    Stefania Colonnese

    2004-12-01

    Full Text Available This work addresses the problem of blind image deblurring, that is, of recovering an original image observed through one or more unknown linear channels and corrupted by additive noise. We resort to an iterative algorithm, belonging to the class of Bussgang algorithms, based on alternating a linear and a nonlinear image estimation stage. In detail, we investigate the design of a novel nonlinear processing acting on the Radon transform of the image edges. This choice is motivated by the fact that the Radon transform of the image edges well describes the structural image features and the effect of blur, thus simplifying the nonlinearity design. The effect of the nonlinear processing is to thin the blurred image edges and to drive the overall blind restoration algorithm to a sharp, focused image. The performance of the algorithm is assessed by experimental results pertaining to restoration of blurred natural images.

  3. Slow and fast light using nonlinear processes in semiconductor optical amplifiers

    Science.gov (United States)

    Pesala, Bala Subrahmanyam

    optical and electrical control of phase shifts near 1 GHz using four wave mixing (FWM) process. By operating the SOA in the gain region, the refractive index change achievable using four wave mixing processes can be greatly enhanced. Using this, we demonstrate both slowing down (by a factor of 150) and speeding up of light (by a factor of 40). For RF applications, we show electrically controllable phase shift of 1.8n at 0.5 GHz bandwidth. Control of RF phase using FWM has the advantage of achieving true time delays (TTDs) which not only avoids the problem of squinting but also allows steering of beam at faster speeds in a phased array antenna system. The same scheme can be used to construct tunable RE filters. For all-optical networking applications, control of velocity of light at bandwidths greater than 100 Gb/sec is required. The second half of this work investigates utilizing ultra-fast nonlinear processes (including spectral hole burning and carrier heating) in semiconductor optical amplifiers to control optical signals at THz bandwidth. An ultra-short light pulse travelling through the SOA experiences a change in refractive index due to these nonlinear processes. This refractive index change is dependent on the gain of the amplifier. Hence, the group velocity can be controlled electrically by changing the applied current to the device. Quantifying the refractive index change induced by the nonlinear processes involves solving the density-matrix equations for a semiconductor which is extremely complicated and requires the knowledge of the detailed band structure. One usually resorts to the numerical methods for these reasons. We develop simplified analytical frame work to understand the contributions of various nonlinear process and present analytical expressions for the refractive index change induced by spectral hole burning and carried heating. Further, we experimentally demonstrate temporal control of the light pulses to more than 3.7 times the input pulse width

  4. Data Analysis Techniques for Resolving Nonlinear Processes in Plasmas : a Review

    OpenAIRE

    de Wit, T. Dudok

    1996-01-01

    The growing need for a better understanding of nonlinear processes in plasma physics has in the last decades stimulated the development of new and more advanced data analysis techniques. This review lists some of the basic properties one may wish to infer from a data set and then presents appropriate analysis techniques with some recent applications. The emphasis is put on the investigation of nonlinear wave phenomena and turbulence in space plasmas.

  5. Simulations of the Ocean Response to a Hurricane: Nonlinear Processes

    KAUST Repository

    Zedler, Sarah E.

    2009-10-01

    Superinertial internal waves generated by a tropical cyclone can propagate vertically and laterally away from their local generation site and break, contributing to turbulent vertical mixing in the deep ocean and maintenance of the stratification of the main thermocline. In this paper, the results of a modeling study are reported to investigate the mechanism by which superinertial fluctuations are generated in the deep ocean. The general properties of the superinertial wave wake were also characterized as a function of storm speed and central latitude. The Massachusetts Institute of Technology (MIT) Ocean General Circulation Model (OGCM) was used to simulate the open ocean response to realistic westward-tracking hurricane-type surface wind stress and heat and net freshwater buoyancy forcing for regions representative of midlatitudes in the Atlantic, the Caribbean, and low latitudes in the eastern Pacific. The model had high horizontal [Δ(x, y) = 1/6°] and vertical (Δz = 5 m in top 100 m) resolution and employed a parameterization for vertical mixing induced by shear instability. In the horizontal momentum equation, the relative size of the nonlinear advection terms, which had a dominant frequency near twice the inertial, was large only in the upper 200 m of water. Below 200 m, the linear momentum equations obeyed a linear balance to 2%. Fluctuations at nearly twice the inertial frequency (2f) were prevalent throughout the depth of the water column, indicating that these nonlinear advection terms in the upper 200 m forced a linear mode below at nearly twice the inertial frequency via vorticity conservation. Maximum variance at 2f in horizontal velocity occurred on the south side of the track. This was in response to vertical advection of northward momentum, which in the north momentum equation is an oscillatory positive definite term that constituted a net force to the south at a frequency near 2f. The ratio of this term to the Coriolis force was larger on the

  6. Nonlinearities in the quantum measurement process of superconducting qubits

    Energy Technology Data Exchange (ETDEWEB)

    Serban, Ioana

    2008-05-15

    The work described in this thesis focuses on the investigation of decoherence and measurement backaction, on the theoretical description of measurement schemes and their improvement. The study presented here is centered around quantum computing implementations using superconducting devices and most important, the Josephson effect. The measured system is invariantly a qubit, i. e. a two-level system. The objective is to study detectors with increasing nonlinearity, e. g. coupling of the qubit to the frequency a driven oscillator, or to the bifurcation amplifier, to determine the performance and backaction of the detector on the measured system and to investigate the importance of a strong qubit-detector coupling for the achievement of a quantum non-demolition type of detection. The first part gives a very basic introduction to quantum information, briefly reviews some of the most promising physical implementations of a quantum computer before focusing on the superconducting devices. The second part presents a series of studies of different qubit measurements, describing the backaction of the measurement onto the measured system and the internal dynamics of the detector. Methodology adapted from quantum optics and chemical physics (master equations, phase-space analysis etc.) combined with the representation of a complex environment yielded a tool capable of describing a nonlinear, non-Markovian environment, which couples arbitrarily strongly to the measured system. This is described in chapter 3. Chapter 4 focuses on the backaction on the qubit and presents novel insights into the qubit dephasing in the strong coupling regime. Chapter 5 uses basically the same system and technical tools to explore the potential of a fast, strong, indirect measurement, and determine how close such a detection would ideally come to the quantum non-demolition regime. Chapter 6 focuses on the internal dynamics of a strongly driven Josephson junction. The analytical results are based on

  7. Correntropy-based partial directed coherence for testing multivariate Granger causality in nonlinear processes

    Science.gov (United States)

    Kannan, Rohit; Tangirala, Arun K.

    2014-06-01

    Identification of directional influences in multivariate systems is of prime importance in several applications of engineering and sciences such as plant topology reconstruction, fault detection and diagnosis, and neurosciences. A spectrum of related directionality measures, ranging from linear measures such as partial directed coherence (PDC) to nonlinear measures such as transfer entropy, have emerged over the past two decades. The PDC-based technique is simple and effective, but being a linear directionality measure has limited applicability. On the other hand, transfer entropy, despite being a robust nonlinear measure, is computationally intensive and practically implementable only for bivariate processes. The objective of this work is to develop a nonlinear directionality measure, termed as KPDC, that possesses the simplicity of PDC but is still applicable to nonlinear processes. The technique is founded on a nonlinear measure called correntropy, a recently proposed generalized correlation measure. The proposed method is equivalent to constructing PDC in a kernel space where the PDC is estimated using a vector autoregressive model built on correntropy. A consistent estimator of the KPDC is developed and important theoretical results are established. A permutation scheme combined with the sequential Bonferroni procedure is proposed for testing hypothesis on absence of causality. It is demonstrated through several case studies that the proposed methodology effectively detects Granger causality in nonlinear processes.

  8. Solving method of generalized nonlinear dynamic least squares for data processing in building of digital mine

    Institute of Scientific and Technical Information of China (English)

    TAO Hua-xue (陶华学); GUO Jin-yun (郭金运)

    2003-01-01

    Data are very important to build the digital mine. Data come from many sources, have different types and temporal states. Relations between one class of data and the other one, or between data and unknown parameters are more nonlinear. The unknown parameters are non-random or random, among which the random parameters often dynamically vary with time. Therefore it is not accurate and reliable to process the data in building the digital mine with the classical least squares method or the method of the common nonlinear least squares. So a generalized nonlinear dynamic least squares method to process data in building the digital mine is put forward. In the meantime, the corresponding mathematical model is also given. The generalized nonlinear least squares problem is more complex than the common nonlinear least squares problem and its solution is more difficultly obtained because the dimensions of data and parameters in the former are bigger. So a new solution model and the method are put forward to solve the generalized nonlinear dynamic least squares problem. In fact, the problem can be converted to two sub-problems, each of which has a single variable. That is to say, a complex problem can be separated and then solved. So the dimension of unknown parameters can be reduced to its half, which simplifies the original high dimensional equations. The method lessens the calculating load and opens up a new way to process the data in building the digital mine, which have more sources, different types and more temporal states.

  9. Modeling supercritical fluid extraction process involving solute-solid interaction

    Energy Technology Data Exchange (ETDEWEB)

    Goto, M.; Roy, B. Kodama, A.; Hirose, T. [Kumamoto Univ., Kumamoto (Japan)

    1998-04-01

    Extraction or leaching of solute from natural solid material is a mass transfer process involving dissolution or release of solutes from a solid matrix. Interaction between the solute and solid matrix often influences the supercritical fluid extraction process. A model accounting for the solute-solid interaction as well as mass transfer is developed. The BET equation is used to incorporate the interaction and the solubility of solutes into the local equilibrium in the model. Experimental data for the supercritical extraction of essential oil and cuticular wax from peppermint leaves are successfully analyzed by the model. The effects of parameters on the extraction behavior are demonstrated to illustrate the concept of the model. 18 refs., 5 figs., 1 tab.

  10. Understanding the cognitive processes involved in writing to learn.

    Science.gov (United States)

    Arnold, Kathleen M; Umanath, Sharda; Thio, Kara; Reilly, Walter B; McDaniel, Mark A; Marsh, Elizabeth J

    2017-06-01

    Writing is often used as a tool for learning. However, empirical support for the benefits of writing-to-learn is mixed, likely because the literature conflates diverse activities (e.g., summaries, term papers) under the single umbrella of writing-to-learn. Following recent trends in the writing-to-learn literature, the authors focus on the underlying cognitive processes. They draw on the largely independent writing-to-learn and cognitive psychology learning literatures to identify important cognitive processes. The current experiment examines learning from 3 writing tasks (and 1 nonwriting control), with an emphasis on whether or not the tasks engaged retrieval. Tasks that engaged retrieval (essay writing and free recall) led to better final test performance than those that did not (note taking and highlighting). Individual differences in structure building (the ability to construct mental representations of narratives; Gernsbacher, Varner, & Faust, 1990) modified this effect; skilled structure builders benefited more from essay writing and free recall than did less skilled structure builders. Further, more essay-like responses led to better performance, implicating the importance of additional cognitive processes such as reorganization and elaboration. The results highlight how both task instructions and individual differences affect the cognitive processes involved when writing-to-learn, with consequences for the effectiveness of the learning strategy. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  11. Aggression proneness: Transdiagnostic processes involving negative valence and cognitive systems.

    Science.gov (United States)

    Verona, Edelyn; Bresin, Konrad

    2015-11-01

    Aggressive behavior is observed in persons with various mental health problems and has been studied from the perspectives of neuroscience and psychophysiology. The present research reviews some of the extant experimental literature to help clarify the interplay between domains of functioning implicated in aggression proneness. We then convey a process-oriented model that elucidates how the interplay of the Negative Valence and Cognitive System domains of NIMH's Research Domain Criteria (RDoC) helps explain aggression proneness, particularly reactive aggression. Finally, we report on a study involving event-related potential (ERP) indices of emotional and inhibitory control processing during an emotional-linguistic go/no-go task among 67 individuals with histories of violence and criminal offending (30% female, 44% African-American) who reported on their aggressive tendencies using the Buss-Perry Aggression Questionnaire. Results provide evidence that tendencies toward angry and aggressive behavior relate to reduced inhibitory control processing (no-go P3) specifically during relevant threat-word blocks, suggesting deterioration of cognitive control by acute or sustained threat sensitivity. These findings highlight the value of ERP methodologies for clarifying the interplay of Negative Valence and Cognitive System processes in aggression proneness.

  12. The Nature of Parental Involvement in Middle School: Examining Nonlinear Associations

    Science.gov (United States)

    Wehrspann, Elizabeth; Dotterer, Aryn M.; Lowe, Katie

    2016-01-01

    Parental educational involvement during middle school has received increased attention from researchers and policymakers because of its links to a variety of academic outcomes. Despite this increased attention, parental involvement has been inconsistently linked to academic outcomes among adolescents, indicating different types and levels of…

  13. Nonlinear enhancement in photonic crystal slow light waveguides fabricated using CMOS-compatible process.

    Science.gov (United States)

    Shinkawa, Mizuki; Ishikura, Norihiro; Hama, Yosuke; Suzuki, Keijiro; Baba, Toshihiko

    2011-10-24

    We have studied low-dispersion slow light and its nonlinear enhancement in photonic crystal waveguides. In this work, we fabricated the waveguides using Si CMOS-compatible process. It enables us to integrate spotsize converters, which greatly simplifies the optical coupling from fibers as well as demonstration of the nonlinear enhancement. Two-photon absorption, self-phase modulation and four-wave mixing were observed clearly for picosecond pulses in a 200-μm-long device. In comparison with Si wire waveguides, a 60-120 fold higher nonlinearity was evaluated for a group index of 51. Unique intensity response also occurred due to the specific transmission spectrum and enhanced nonlinearities. Such slow light may add various functionalities in Si photonics, while loss reduction is desired for ensuring the advantage of slow light.

  14. Nonlinear Transport Processes in Tokamak Plasmas. Part I: The Collisional Regimes

    CERN Document Server

    Sonnino, Giorgio

    2008-01-01

    An application of the thermodynamic field theory (TFT) to transport processes in L-mode tokamak plasmas is presented. The nonlinear corrections to the linear (Onsager) transport coefficients in the collisional regimes are derived. A quite encouraging result is the appearance of an asymmetry between the Pfirsch-Schlueter (P-S) ion and electron transport coefficients: the latter presents a nonlinear correction, which is absent for the ions, and makes the radial electron coefficients much larger than the former. Explicit calculations and comparisons between the neoclassical results and the TFT predictions for JET plasmas are also reported. We found that the nonlinear electron P-S transport coefficients exceed the values provided by neoclassical theory by a factor, which may be of the order 100. The nonlinear classical coefficients exceed the neoclassical ones by a factor, which may be of order 2. The expressions of the ion transport coefficients, determined by the neoclassical theory in these two regimes, remain...

  15. Polarization dependent dispersion and its impact on optical parametric process in high nonlinear microstructure fibre

    Institute of Scientific and Technical Information of China (English)

    Xiao Li; Zhang Wei; Huang Yi-Dong; Peng Jiang-De

    2008-01-01

    High nonlinear microstructure fibre (HNMF) is preferred in nonlinear fibre optics, especially in the applications of optical parametric effects, due to its high optical nonlinear coefficient. However, polarization dependent dispersion will impact the nonlinear optical parametric process in HNMFs. In this paper, modulation instability (MI) method is used to measure the polarization dependent dispersion of a piece of commercial HNMF, including the group velocity dispersion, the dispersion slope, the fourth-order dispersion and group birefringence. It also experimentally demonstrates the impact of the polarization dependent dispersion on the continuous wave supercontinuum (SC) generation. On one axis MI sidebands with symmetric frequency dctunings are generated, while on the other axis with larger MI frequency detuning, SC is generated by soliton self-frequency shift.

  16. Innovation as a nonlinear process, the scientometric perspective, and the specification of an 'innovation opportunities explorer'

    NARCIS (Netherlands)

    Leydesdorff, L.; Rotolo, D.; de Nooy, W.

    2013-01-01

    The process of innovation follows nonlinear patterns across the domains of science, technology, and the economy. Novel bibliometric mapping techniques can be used to investigate and represent distinctive, but complementary perspectives on the innovation process (e.g. ‘demand’ and ‘supply’) as well

  17. Study of nonlinear processes of a large experimental thermoacoustic-Stirling heat engine by using computational fluid dynamics

    Science.gov (United States)

    Yu, G. Y.; Luo, E. C.; Dai, W.; Hu, J. Y.

    2007-10-01

    This article focuses on using computational fluid dynamics (CFD) method to study several important nonlinear phenomenon and processes of a large experimental thermoacoustic-Stirling heat engine. First, the simulated physical model was introduced, and the suitable numerical scheme and algorithm for the time-dependent compressible thermoacoustic system was determined through extensive numerical tests. Then, the simulation results of the entire evolution process of self-excited thermoacoustic oscillation and the acoustical characteristics of pressure and velocity waves were presented and analyzed. Especially, the onset temperature and the saturation process of dynamic pressure were captured by the CFD simulation. In addition, another important nonlinear phenomenon accompanying the acoustic wave, which is the steady mass flow through the traveling-wave loop inside the thermoacoustic engine, was studied. To suppress the steady mass flow numerically, a fan model was adopted in the simulation. Finally, the multidimensional effects of vortex formation in the thermal buffer tube and other components were displayed numerically. Most importantly, a substantial comparison between the simulation and experiments was made, which demonstrated well the validity and powerfulness of the CFD simulation for characterizing several complicated nonlinear phenomenon involved in the self-excited thermoacoustic heat engine.

  18. Sensing Magnetic Directions in Birds: Radical Pair Processes Involving Cryptochrome

    Directory of Open Access Journals (Sweden)

    Roswitha Wiltschko

    2014-07-01

    Full Text Available Birds can use the geomagnetic field for compass orientation. Behavioral experiments, mostly with migrating passerines, revealed three characteristics of the avian magnetic compass: (1 it works spontaneously only in a narrow functional window around the intensity of the ambient magnetic field, but can adapt to other intensities, (2 it is an “inclination compass”, not based on the polarity of the magnetic field, but the axial course of the field lines, and (3 it requires short-wavelength light from UV to 565 nm Green. The Radical Pair-Model of magnetoreception can explain these properties by proposing spin-chemical processes in photopigments as underlying mechanism. Applying radio frequency fields, a diagnostic tool for radical pair processes, supports an involvement of a radical pair mechanism in avian magnetoreception: added to the geomagnetic field, they disrupted orientation, presumably by interfering with the receptive processes. Cryptochromes have been suggested as receptor molecules. Cry1a is found in the eyes of birds, where it is located at the membranes of the disks in the outer segments of the UV-cones in chickens and robins. Immuno-histochemical studies show that it is activated by the wavelengths of light that allow magnetic compass orientation in birds.

  19. Sensing magnetic directions in birds: radical pair processes involving cryptochrome.

    Science.gov (United States)

    Wiltschko, Roswitha; Wiltschko, Wolfgang

    2014-09-01

    Birds can use the geomagnetic field for compass orientation. Behavioral experiments, mostly with migrating passerines, revealed three characteristics of the avian magnetic compass: (1) it works spontaneously only in a narrow functional window around the intensity of the ambient magnetic field, but can adapt to other intensities, (2) it is an "inclination compass", not based on the polarity of the magnetic field, but the axial course of the field lines, and (3) it requires short-wavelength light from UV to 565 nm Green. The Radical Pair-Model of magnetoreception can explain these properties by proposing spin-chemical processes in photopigments as underlying mechanism. Applying radio frequency fields, a diagnostic tool for radical pair processes, supports an involvement of a radical pair mechanism in avian magnetoreception: added to the geomagnetic field, they disrupted orientation, presumably by interfering with the receptive processes. Cryptochromes have been suggested as receptor molecules. Cry1a is found in the eyes of birds, where it is located at the membranes of the disks in the outer segments of the UV-cones in chickens and robins. Immuno-histochemical studies show that it is activated by the wavelengths of light that allow magnetic compass orientation in birds.

  20. Existence of Solutions to Nonlinear Langevin Equation Involving Two Fractional Orders with Boundary Value Conditions

    Directory of Open Access Journals (Sweden)

    Chen Yi

    2011-01-01

    Full Text Available We study a boundary value problem to Langevin equation involving two fractional orders. The Banach fixed point theorem and Krasnoselskii's fixed point theorem are applied to establish the existence results.

  1. Quasilinear Extreme Learning Machine Model Based Internal Model Control for Nonlinear Process

    Directory of Open Access Journals (Sweden)

    Dazi Li

    2015-01-01

    Full Text Available A new strategy for internal model control (IMC is proposed using a regression algorithm of quasilinear model with extreme learning machine (QL-ELM. Aimed at the chemical process with nonlinearity, the learning process of the internal model and inverse model is derived. The proposed QL-ELM is constructed as a linear ARX model with a complicated nonlinear coefficient. It shows some good approximation ability and fast convergence. The complicated coefficients are separated into two parts. The linear part is determined by recursive least square (RLS, while the nonlinear part is identified through extreme learning machine. The parameters of linear part and the output weights of ELM are estimated iteratively. The proposed internal model control is applied to CSTR process. The effectiveness and accuracy of the proposed method are extensively verified through numerical results.

  2. The nature of parental involvement in middle school: Examining nonlinear associations

    OpenAIRE

    Wehrspann, Elizabeth A

    2014-01-01

    Middle school is a time during which the importance of school performance and academic motivation increases, yet actual adolescent achievement and motivation tend to decline during this period. Extent research and theory highlight the importance of parental involvement in education for adolescents, as most work shows that parent involvement is positively related to academic achievement and motivation. However, there are also many mixed findings regarding the link between specific types of inv...

  3. Discretisation of the non-linear heat transfer equation for food freezing processes using orthogonal collocation on finite elements

    Directory of Open Access Journals (Sweden)

    E. D. Resende

    2007-09-01

    Full Text Available The freezing process is considered as a propagation problem and mathematically classified as an "initial value problem." The mathematical formulation involves a complex situation of heat transfer with simultaneous changes of phase and abrupt variation in thermal properties. The objective of the present work is to solve the non-linear heat transfer equation for food freezing processes using orthogonal collocation on finite elements. This technique has not yet been applied to freezing processes and represents an alternative numerical approach in this area. The results obtained confirmed the good capability of the numerical method, which allows the simulation of the freezing process in approximately one minute of computer time, qualifying its application in a mathematical optimising procedure. The influence of the latent heat released during the crystallisation phenomena was identified by the significant increase in heat load in the early stages of the freezing process.

  4. [Proteins of human milk involved in immunological processes].

    Science.gov (United States)

    Lis, Jolanta; Orczyk-Pawiłowicz, Magdalena; Kątnik-Prastowska, Iwona

    2013-05-31

    Human milk contains a lot of components (i.e. proteins, carbohydrates, lipids, inorganic elements) which provide basic nutrients for infants during the first period of their lives. Qualitative composition of milk components of healthy mothers is similar, but their levels change during lactation stages. Colostrum is the fluid secreted during the first days postpartum by mammary epithelial cells. Colostrum is replaced by transitional milk during 5-15 days postpartum and from 15 days postpartum mature milk is produced. Human milk, apart from nutritional components, is a source of biologically active molecules, i.e. immunoglobulins, growth factors, cytokines, acute phase proteins, antiviral and antibacterial proteins. Such components of human milk are responsible for specific biological activities of human milk. This secretion plays an important role in growth and development of newborns. Bioactive molecules present in the milk support the immature immune system of the newborn and also protect against the development of infection. In this article we describe the pathways involved in the production and secretion of human milk, the state of knowledge on the proteome of human milk, and the contents of components of milk during lactation. Moreover, some growth factors and proteins involved in innate and specific immunity, intercellular communication, immunomodulation, and inflammatory processes have been characterized.

  5. Proteins of human milk involved in immunological processes 

    Directory of Open Access Journals (Sweden)

    Jolanta Lis

    2013-05-01

    Full Text Available Human milk contains a lot of components (i.e. proteins, carbohydrates, lipids, inorganic elements which provide basic nutrients for infants during the first period of their lives. Qualitative composition of milk components of healthy mothers is similar, but their levels change during lactation stages. Colostrum is the fluid secreted during the first days postpartum by mammary epithelial cells. Colostrum is replaced by transitional milk during 5-15 days postpartum and from 15 days postpartum mature milk is produced. Human milk, apart from nutritional components, is a source of biologically active molecules, i.e. immunoglobulins, growth factors, cytokines, acute phase proteins, antiviral and antibacterial proteins. Such components of human milk are responsible for specific biological activities of human milk. This secretion plays an important role in growth and development of newborns. Bioactive molecules present in the milk support the immature immune system of the newborn and also protect against the development of infection. In this article we describe the pathways involved in the production and secretion of human milk, the state of knowledge on the proteome of human milk, and the contents of components of milk during lactation. Moreover, some growth factors and proteins involved in innate and specific immunity, intercellular communication, immunomodulation, and inflammatory processes have been characterized.

  6. Non-linear thermodynamic laws application to soil processes

    Directory of Open Access Journals (Sweden)

    Ilgiz Khabirov

    2013-01-01

    Full Text Available An attempt has been made to analyze the possibility to use nonequilibrium thermodynamics for the soil dynamic open systemstreatment. Entropy change of such a system and the entropy coming from or going into the outer sphere. In the steady state, dynamic soil-formation processes occur within an organized structure and are characterized by stable parameters close to equilibrium. Accordingly, when examining soil, one can proceed from the conventional thermodynamic equilibrium. However, the matter of Onzager-Prigozhin general phenomenological theory applicability to soil processes is more complicated. To study soil stability it is necessary to go beyond the limits of linear thermodynamics.

  7. Nonlinear processes upon two-photon interband picosecond excitation of PbWO4 crystal

    Science.gov (United States)

    Lukanin, V. I.; Karasik, A. Ya

    2016-09-01

    A new experimental method is proposed to study the dynamics of nonlinear processes occurring upon two-photon interband picosecond excitation of a lead tungstate crystal and upon its excitation by cw probe radiation in a temporal range from several nanoseconds to several seconds. The method is applied to the case of crystal excitation by a sequence of 25 high-power picosecond pulses with a wavelength of 523.5 nm and 633-nm cw probe radiation. Measuring the probe beam transmittance during crystal excitation, one can investigate the influence of two-photon interband absorption and the thermal nonlinearity of the refractive index on the dynamics of nonlinear processes in a wide range of times (from several nanoseconds to several seconds). The time resolution of the measuring system makes it possible to distinguish fast and slow nonlinear processes of electronic or thermal nature, including the generation of a thermal lens and thermal diffusion. An alternative method is proposed to study the dynamics of induced absorption transformation and, therefore, the dynamics of the development of nonlinear rocesses upon degenerate two-photon excitation of the crystal in the absence of external probe radiation.

  8. Nonlinear Optical Signal Processing for Tbit/s Ethernet Applications

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Galili, Michael; Mulvad, Hans Christian Hansen;

    2012-01-01

    We review recent experimental demonstrations of Tbaud optical signal processing. In particular, we describe a successful 1.28 Tbit/s serial data generation based on single polarization 1.28 Tbaud symbol rate pulses with binary data modulation (OOK) and subsequent all-optical demultiplexing. We also...

  9. Linear and nonlinear optical processing of polymer matrix nanocomposites

    Science.gov (United States)

    DeJournett, Travis J.; Han, Karen; Olasov, Lauren R.; Zeng, Fan W.; Lee, Brennan; Spicer, James B.

    2015-08-01

    This work focuses on the scalable synthesis and processing of nanostructures in polymer matrix nanocomposites (PMNCs) for applications that require photochemical functionality of these nanostructures. An in situ vapor deposition process using various metal and metal oxide precursors has been used to create a range of nanocomposites that display photochromic and photocatalytic behaviors. Under specific processing conditions, these composites consist of discrete nanoparticles distributed uniformly throughout the bulk of an optically transparent polymer matrix. Incorporating other chemical species as supplementary deposition agents in the synthesis process can modify these particles and produce complicated nanostructures with enhanced properties. In particular, work has been carried out to structure nanoparticles using laser irradiation. Starting with metallic or metal oxide nanoparticles in the polymer matrix, localized chemical vapor deposition in the near-particle environment has been carried out using laser irradiation to decompose chemical precursors leading to the formation of secondary structures surrounding the seed nanoparticles. Control of the spatial and temporal characteristics of the excitation source allows for synthesis of nanocomposites with a high degree of control over the location, composition and size of nanoparticles in the matrix and presents the opportunity to produce patterned materials with spatially varying properties.

  10. A Kernel Time Structure Independent Component Analysis Method for Nonlinear Process Monitoring☆

    Institute of Scientific and Technical Information of China (English)

    Lianfang Cai; Xuemin Tian; Ni Zhang

    2014-01-01

    Kernel independent component analysis (KICA) is a newly emerging nonlinear process monitoring method, which can extract mutually independent latent variables cal ed independent components (ICs) from process var-iables. However, when more than one IC have Gaussian distribution, it cannot extract the IC feature effectively and thus its monitoring performance will be degraded drastical y. To solve such a problem, a kernel time struc-ture independent component analysis (KTSICA) method is proposed for monitoring nonlinear process in this paper. The original process data are mapped into a feature space nonlinearly and then the whitened data are calculated in the feature space by the kernel trick. Subsequently, a time structure independent component analysis algorithm, which has no requirement for the distribution of ICs, is proposed to extract the IC feature. Finally, two monitoring statistics are built to detect process faults. When some fault is detected, a nonlinear fault identification method is developed to identify fault variables based on sensitivity analysis. The proposed monitoring method is applied in the Tennessee Eastman benchmark process. Applications demonstrate the superiority of KTSICA over KICA.

  11. Nonlinear Statistical Process Monitoring Based on Control Charts with Memory Effect and Kernel Independent Component Analysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel nonlinear combination process monitoring method was proposed based on techniques with memory effect (multivariate exponentially weighted moving average (MEWMA)) and kernel independent component analysis (KICA). The method was developed for dealing with nonlinear issues and detecting small or moderate drifts in one or more process variables with autocorrelation. MEWMA charts use additional information from the past history of the process for keeping the memory effect of the process behavior trend. KICA is a recently developed statistical technique for revealing hidden, nonlinear statistically independent factors that underlie sets of measurements and it is a two-phase algorithm: whitened kernel principal component analysis (KPCA) plus independent component analysis (ICA). The application to the fluid catalytic cracking unit (FCCU) simulated process indicates that the proposed combined method based on MEWMA and KICA can effectively capture the nonlinear relationship and detect small drifts in process variables. Its performance significantly outperforms monitoring method based on ICA, MEWMA-ICA and KICA, especially for long-term performance deterioration.

  12. Electrically controlled nonlinear optical generation and signal processing in plasmonic metamaterials (Conference Presentation)

    Science.gov (United States)

    Cai, Wenshan

    2016-09-01

    Metamaterials have offered not only the unprecedented opportunity to generate unconventional electromagnetic properties that are not found in nature, but also the exciting potential to create customized nonlinear media with tailored high-order effects. Two particularly compelling directions of current interests are active metamaterials, where the optical properties can be purposely manipulated by external stimuli, and nonlinear metamaterials, which enable intensity-dependent frequency conversion of light. By exploring the interaction of these two directions, we leverage the electrical and optical functions simultaneously supported in nanostructured metals and demonstrate electrically-controlled nonlinear processes from photonic metamaterials. We show that a variety of nonlinear optical phenomena, including the wave mixing and the optical rectification, can be purposely modulated by applied voltage signals. In addition, electrically-induced and voltage-controlled nonlinear effects facilitate us to demonstrate the backward phase matching in a negative index material, a long standing prediction in nonlinear metamaterials. Other results to be covered in this talk include photon-drag effect in plasmonic metamaterials and ion-assisted nonlinear effects from metamaterials in electrolytes. Our results reveal a grand opportunity to exploit optical metamaterials as self-contained, dynamic electrooptic systems with intrinsically embedded electrical functions and optical nonlinearities. Reference: L. Kang, Y. Cui, S. Lan, S. P. Rodrigues, M. L. Brongersma, and W. Cai, Nature Communications, 5, 4680 (2014). S. P. Rodrigues and W.Cai, Nature Nanotechnology, 10, 387 (2015). S. Lan, L. Kang, D. T. Schoen, S. P. Rodrigues, Y. Cui, M. L. Brongersma, and W. Cai, Nature Materials, 14, 807 (2015).

  13. The effect of process delay on dynamical behaviors in a self-feedback nonlinear oscillator

    Science.gov (United States)

    Yao, Chenggui; Ma, Jun; Li, Chuan; He, Zhiwei

    2016-10-01

    The delayed feedback loops play a crucial role in the stability of dynamical systems. The effect of process delay in feedback is studied numerically and theoretically in the delayed feedback nonlinear systems including the neural model, periodic system and chaotic oscillator. The process delay is of key importance in determining the evolution of systems, and the rich dynamical phenomena are observed. By introducing a process delay, we find that it can induce bursting electric activities in the neural model. We demonstrate that this novel regime of amplitude death also exists in the parameter space of feedback strength and process delay for the periodic system and chaotic oscillator. Our results extend the effect of process delay in the paper of Zou et al.(2013) where the process delay can eliminate the amplitude death of the coupled nonlinear systems.

  14. Nonlinear signal processing of electroencephalograms for automated sleep monitoring

    Science.gov (United States)

    Wilson, D.; Rowlands, D. D.; James, Daniel A.; Cutmore, T.

    2005-02-01

    An automated classification technique is desirable to identify the different stages of sleep. In this paper a technique for differentiating the characteristics of each sleep phase has been developed. This is an ideal pre-processor stage for classifying systems such as neural networks. A wavelet based continuous Morlet transform was developed to analyse the EEG signal in both the time and frequency domain. Test results using two 100 epoch EEG test data sets from pre-recorded EEG data are presented. Key rhythms in the EEG signal were identified and classified using the continuous wavelet transform. The wavelet results indicated each sleep phase contained different rhythms and artefacts (noise from muscle movement in the EEG); providing proof that an EEG can be classified accordingly. The coefficients founded by the wavelet transform have been emphasised by statistical techniques. Hypothesis testing was used to highlight major differences between adjacent sleep stages. Various signal processing methods such as power spectrum density and the discrete wavelet transform have been used to emphasise particular characteristics in an EEG. By implementing signal processing methods on an EEG data set specific rules for each sleep stage have been developed suitable for a neural network classification solution.

  15. Non-linear, adaptive array processing for acoustic interference suppression.

    Science.gov (United States)

    Hoppe, Elizabeth; Roan, Michael

    2009-06-01

    A method is introduced where blind source separation of acoustical sources is combined with spatial processing to remove non-Gaussian, broadband interferers from space-time displays such as bearing track recorder displays. This differs from most standard techniques such as generalized sidelobe cancellers in that the separation of signals is not done spatially. The algorithm performance is compared to adaptive beamforming techniques such as minimum variance distortionless response beamforming. Simulations and experiments using two acoustic sources were used to verify the performance of the algorithm. Simulations were also used to determine the effectiveness of the algorithm under various signal to interference, signal to noise, and array geometry conditions. A voice activity detection algorithm was used to benchmark the performance of the source isolation.

  16. Age and Creative Productivity: Nonlinear Estimation of an Information-Processing Model.

    Science.gov (United States)

    Simonton, Dean Keith

    1989-01-01

    Applied two-step cognitive model to relationship between age and creative productivity. Selected ideation and elaboration rates as information-processing parameters that define mathematical function which describes age curves and specifies their variance across disciplines. Applied non-linear estimation program to further validate model. Despite…

  17. Ultrafast nonlinear all-optical processes in silicon-on-insulator waveguides

    NARCIS (Netherlands)

    Dekker, R.; Usechak, N.; Först, M.; Driessen, A.

    2007-01-01

    In this review we present an overview of the progress made in recent years in the field of integrated silicon-on-insulator (SOI) waveguide photonics with a strong emphasis on third-order nonlinear optical processes. Although the focus is on simple waveguide structures the utilization of complex stru

  18. Scene matching based on non-linear pre-processing on reference image and sensed image

    Institute of Scientific and Technical Information of China (English)

    Zhong Sheng; Zhang Tianxu; Sang Nong

    2005-01-01

    To solve the heterogeneous image scene matching problem, a non-linear pre-processing method for the original images before intensity-based correlation is proposed. The result shows that the proper matching probability is raised greatly. Especially for the low S/N image pairs, the effect is more remarkable.

  19. Experimental observations of the characteristics of hot electron and nonlinear processes produced in special material

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Making use of disk targets composed of several peculiar materials (foam Au, foam C8H8)and hohlraum with a special structure, experiments have been done at"Xing Guang - II" laser facility,which study the characteristics of hot electrons and therelated nonlinear processes such as StimulatedRaman Scattering (SRS), Two Plasma Decay (TPD), StimulatedBrillouin Scattering (SBS), etc.

  20. Compound Cue Processing within the Fast and Frugal Heuristics Approach in Nonlinearly Separable Environments

    Science.gov (United States)

    Garcia-Retamero, Rocio; Hoffrage, Ulrich; Dieckmann, Anja; Ramos, Manuel

    2007-01-01

    Three experiments investigated whether participants used Take The Best (TTB) Configural, a fast and frugal heuristic that processes configurations of cues when making inferences concerning which of two alternatives has a higher criterion value. Participants were presented with a compound cue that was nonlinearly separable from its elements. The…

  1. Characterizing time dependent anomalous diffusion process: A survey on fractional derivative and nonlinear models

    Science.gov (United States)

    Wei, Song; Chen, Wen; Hon, Y. C.

    2016-11-01

    This paper investigates the temporal effects in the modeling of flows through porous media and particles transport. Studies will be made among the time fractional diffusion model and two classical nonlinear diffusion models. The effects of the parameters upon the mentioned models have been studied. By simulating the sub-diffusion processes and comparing the numerical results of these models under different boundary conditions, we can conclude that the time fractional diffusion model is more suitable for simulating the sub-diffusion with steady diffusion rate; whereas the nonlinear models are more appropriate for depicting the sub-diffusion under changing diffusion rate.

  2. Analytical investigation of machining chatter by considering the nonlinearity of process damping

    Science.gov (United States)

    Ahmadi, Keivan

    2017-04-01

    In this paper, the well-established problem of self-excited vibrations in machining is revisited to include the nonlinearity of process damping at the tool and workpiece interface. Machining dynamics is modeled using a time-delayed system with nonlinear damping, and the method of averaging is used to obtain the amplitude of the resulting limit cycles. As a result, an analytical relationship is presented to establish the stability charts corresponding with arbitrary limit cycles in machining systems. The presented analytical solutions are verified using experiments and numerical solutions.

  3. 2-D nonlinear IIR-filters for image processing - An exploratory analysis

    Science.gov (United States)

    Bauer, P. H.; Sartori, M.

    1991-01-01

    A new nonlinear IIR filter structure is introduced and its deterministic properties are analyzed. It is shown to be better suited for image processing applications than its linear shift-invariant counterpart. The new structure is obtained from causality inversion of a 2D quarterplane causal linear filter with respect to the two directions of propagation. It is demonstrated, that by using this design, a nonlinear 2D lowpass filter can be constructed, which is capable of effectively suppressing Gaussian or impulse noise without destroying important image information.

  4. PREPARATION AND SECOND-ORDER OPTICAL NONLINEARITY OF NOVEL PHENOXYSILICON NETWORKS BY SOL-GEL PROCESS

    Institute of Scientific and Technical Information of China (English)

    Xiao Huang; Jian Wang; Ling-zhi Zhang; Zhi-gang Cai; Zhao-xi Lianga

    2001-01-01

    Four phenoxysilicon networks for nonlinear optical (NLO) applications were designed and prepared by an extended sol-gel process without additional H20 and catalyst. All poled polymer network films possess high second-order nonlinear optical coefficients (d33) of 10-?~10-8 esu. The investigation of NLO temporal stability at room temperature and elevated temperature (120°C) indicated that these films exhibit high d33 stability because the orientation of the chromophores are locked in the phenoxysilicon organic/inorganic networks.

  5. 2-D nonlinear IIR-filters for image processing - An exploratory analysis

    Science.gov (United States)

    Bauer, P. H.; Sartori, M.

    1991-01-01

    A new nonlinear IIR filter structure is introduced and its deterministic properties are analyzed. It is shown to be better suited for image processing applications than its linear shift-invariant counterpart. The new structure is obtained from causality inversion of a 2D quarterplane causal linear filter with respect to the two directions of propagation. It is demonstrated, that by using this design, a nonlinear 2D lowpass filter can be constructed, which is capable of effectively suppressing Gaussian or impulse noise without destroying important image information.

  6. CONTROL OF NONLINEAR PROCESS USING NEURAL NETWORK BASED MODEL PREDICTIVE CONTROL

    Directory of Open Access Journals (Sweden)

    Dr.A.TRIVEDI

    2011-04-01

    Full Text Available This paper presents a Neural Network based Model Predictive Control (NNMPC strategy to control nonlinear process. Multilayer Perceptron Neural Network (MLP is chosen to represent a Nonlinear Auto Regressive with eXogenous signal (NARX model of a nonlinear system. NARX dynamic model is based on feed-forward architecture and offers good approximation capabilities along with robustness and accuracy. Based on the identified neural model, a generalized predictive control (GPC algorithm is implemented to control the composition in acontinuous stirred tank reactor (CSTR, whose parameters are optimally determined by solving quadratic performance index using well known Levenberg-Marquardt and Quasi-Newton algorithm. NNMPC is tuned by selecting few horizon parameters and weighting factor. The tracking performance of the NNMPC is tested using different amplitude function as a reference signal on CSTR application. Also the robustness and performance is tested in the presence of disturbance on random reference signal.

  7. Hydex Glass and Amorphous Silicon for Integrated Nonlinear Optical Signal Processing

    CERN Document Server

    Morandotti, Roberto

    2015-01-01

    Photonic integrated circuits that exploit nonlinear optics in order to generate and process signals all-optically have achieved performance far superior to that possible electronically - particularly with respect to speed. Although silicon-on-insulator has been the leading platform for nonlinear optics for some time, its high two-photon absorption at telecommunications wavelengths poses a fundamental limitation. We review the recent achievements based in new CMOS-compatible platforms that are better suited than SOI for nonlinear optics, focusing on amorphous silicon and Hydex glass. We highlight their potential as well as the challenges to achieving practical solutions for many key applications. These material systems have opened up many new capabilities such as on-chip optical frequency comb generation and ultrafast optical pulse generation and measurement.

  8. The method of varying amplitudes for solving (non)linear problems involving strong parametric excitation

    DEFF Research Database (Denmark)

    Sorokin, Vladislav; Thomsen, Jon Juel

    2015-01-01

    Parametrically excited systems appear in many fields of science and technology, intrinsically or imposed purposefully; e.g. spatially periodic structures represent an important class of such systems [4]. When the parametric excitation can be considered weak, classical asymptotic methods like...... the method of averaging [2] or multiple scales [6] can be applied. However, with many practically important applications this simplification is inadequate, e.g. with spatially periodic structures it restricts the possibility to affect their effective dynamic properties by a structural parameter modulation...... of considerable magnitude. Approximate methods based on Floquet theory [4] for analyzing problems involving parametric excitation, e.g. the classical Hill’s method of infinite determinants [3,4], can be employed also in cases of strong excitation; however, with Floquet theory being applicable only for linear...

  9. Nonlinear Pulse Shaping in Fibres for Pulse Generation and Optical Processing

    Directory of Open Access Journals (Sweden)

    Sonia Boscolo

    2012-01-01

    Full Text Available The development of new all-optical technologies for data processing and signal manipulation is a field of growing importance with a strong potential for numerous applications in diverse areas of modern science. Nonlinear phenomena occurring in optical fibres have many attractive features and great, but not yet fully explored, potential in signal processing. Here, we review recent progress on the use of fibre nonlinearities for the generation and shaping of optical pulses and on the applications of advanced pulse shapes in all-optical signal processing. Amongst other topics, we will discuss ultrahigh repetition rate pulse sources, the generation of parabolic shaped pulses in active and passive fibres, the generation of pulses with triangular temporal profiles, and coherent supercontinuum sources. The signal processing applications will span optical regeneration, linear distortion compensation, optical decision at the receiver in optical communication systems, spectral and temporal signal doubling, and frequency conversion.

  10. Heterogeneous recurrence representation and quantification of dynamic transitions in continuous nonlinear processes

    Science.gov (United States)

    Chen, Yun; Yang, Hui

    2016-06-01

    Many real-world systems are evolving over time and exhibit dynamical behaviors. In order to cope with system complexity, sensing devices are commonly deployed to monitor system dynamics. Online sensing brings the proliferation of big data that are nonlinear and nonstationary. Although there is rich information on nonlinear dynamics, significant challenges remain in realizing the full potential of sensing data for system control. This paper presents a new approach of heterogeneous recurrence analysis for online monitoring and anomaly detection in nonlinear dynamic processes. A partition scheme, named as Q-tree indexing, is firstly introduced to delineate local recurrence regions in the multi-dimensional continuous state space. Further, we design a new fractal representation of state transitions among recurrence regions, and then develop new measures to quantify heterogeneous recurrence patterns. Finally, we develop a multivariate detection method for on-line monitoring and predictive control of process recurrences. Case studies show that the proposed approach not only captures heterogeneous recurrence patterns in the transformed space, but also provides effective online control charts to monitor and detect dynamical transitions in the underlying nonlinear processes.

  11. Brain signal variability as a window into the bidirectionality between music and language processing: moving from a linear to a nonlinear model.

    Science.gov (United States)

    Hutka, Stefanie; Bidelman, Gavin M; Moreno, Sylvain

    2013-12-30

    There is convincing empirical evidence for bidirectional transfer between music and language, such that experience in either domain can improve mental processes required by the other. This music-language relationship has been studied using linear models (e.g., comparing mean neural activity) that conceptualize brain activity as a static entity. The linear approach limits how we can understand the brain's processing of music and language because the brain is a nonlinear system. Furthermore, there is evidence that the networks supporting music and language processing interact in a nonlinear manner. We therefore posit that the neural processing and transfer between the domains of language and music are best viewed through the lens of a nonlinear framework. Nonlinear analysis of neurophysiological activity may yield new insight into the commonalities, differences, and bidirectionality between these two cognitive domains not measurable in the local output of a cortical patch. We thus propose a novel application of brain signal variability (BSV) analysis, based on mutual information and signal entropy, to better understand the bidirectionality of music-to-language transfer in the context of a nonlinear framework. This approach will extend current methods by offering a nuanced, network-level understanding of the brain complexity involved in music-language transfer.

  12. Complex Nonlinear Behavior in Metabolic Processes: Global Bifurcation Analysis of Escherichia coli Growth on Multiple Substrates

    Directory of Open Access Journals (Sweden)

    Hyun-Seob Song

    2013-09-01

    Full Text Available The nonlinear behavior of metabolic systems can arise from at least two different sources. One comes from the nonlinear kinetics of chemical reactions in metabolism and the other from nonlinearity associated with regulatory processes. Consequently, organisms at a constant growth rate (as experienced in a chemostat could display multiple metabolic states or display complex oscillatory behavior both with potentially serious implications to process operation. This paper explores the nonlinear behavior of a metabolic model of Escherichia coli growth on mixed substrates with sufficient detail to include regulatory features through the cybernetic postulate that metabolic regulation is the consequence of a dynamic objective function ensuring the organism’s survival. The chief source of nonlinearity arises from the optimal formulation with the metabolic state determined by a convex combination of reactions contributing to the objective function. The model for anaerobic growth of E. coli was previously examined for multiple steady states in a chemostat fed by a mixture of glucose and pyruvate substrates under very specific conditions and experimentally verified. In this article, we explore the foregoing model for nonlinear behavior over the full range of parameters, γ (the fractional concentration of glucose in the feed mixture and D (the dilution rate. The observed multiplicity is in the cybernetic variables combining elementary modes. The results show steady-state multiplicity up to seven. No Hopf bifurcation was encountered, however. Bifurcation analysis of cybernetic models is complicated by the non-differentiability of the cybernetic variables for enzyme activities. A methodology is adopted here to overcome this problem, which is applicable to more complicated metabolic networks.

  13. Circuits and systems based on delta modulation linear, nonlinear and mixed mode processing

    CERN Document Server

    Zrilic, Djuro G

    2005-01-01

    This book is intended for students and professionals who are interested in the field of digital signal processing of delta-sigma modulated sequences. The overall focus is on the development of algorithms and circuits for linear, non-linear, and mixed mode processing of delta-sigma modulated pulse streams. The material presented here is directly relevant to applications in digital communication, DSP, instrumentation, and control.

  14. Experimental photonic generation of chirped pulses using nonlinear dispersion-based incoherent processing.

    Science.gov (United States)

    Rius, Manuel; Bolea, Mario; Mora, José; Ortega, Beatriz; Capmany, José

    2015-05-18

    We experimentally demonstrate, for the first time, a chirped microwave pulses generator based on the processing of an incoherent optical signal by means of a nonlinear dispersive element. Different capabilities have been demonstrated such as the control of the time-bandwidth product and the frequency tuning increasing the flexibility of the generated waveform compared to coherent techniques. Moreover, the use of differential detection improves considerably the limitation over the signal-to-noise ratio related to incoherent processing.

  15. Staff Involvement and the Public Library Planning Process.

    Science.gov (United States)

    Stephens, Annabel K.

    1989-01-01

    Reports the results of a study of two library systems' differing approaches to staff involvement in library planning. The systems' attempts to prepare staff members, keep them informed, and encourage staff participation are described, and the resulting benefits are contrasted. Suggestions for successful staff involvement are offered. (34…

  16. Systematic Integrated Process Design and Control of Reactive Distillation Processes Involving Multi-elements

    DEFF Research Database (Denmark)

    Mansouri, Seyed Soheil; Sales-Cruz, Mauricio; Huusom, Jakob Kjøbsted

    2016-01-01

    In this work, integrated process design and control of reactive distillation processes that involve multiple elements (more than two) is addressed through a computer-aided hierarchical decomposition-based framework. Multiple elements are encountered for reactive systems when four or more compounds...... (including inert compounds) are encountered. The reactive distillation design methods and tools which are similar in concept to design of binary non-reactive distillations and binary reactive distillations are used for design of multi-element reactive distillation processes, such as driving force approach...

  17. Real time remaining useful life prediction based on nonlinear Wiener based degradation processes with measurement errors

    Institute of Scientific and Technical Information of China (English)

    唐圣金; 郭晓松; 于传强; 周志杰; 周召发; 张邦成

    2014-01-01

    Real time remaining useful life (RUL) prediction based on condition monitoring is an essential part in condition based maintenance (CBM). In the current methods about the real time RUL prediction of the nonlinear degradation process, the measurement error is not considered and forecasting uncertainty is large. Therefore, an approximate analytical RUL distribution in a closed-form of a nonlinear Wiener based degradation process with measurement errors was proposed. The maximum likelihood estimation approach was used to estimate the unknown fixed parameters in the proposed model. When the newly observed data are available, the random parameter is updated by the Bayesian method to make the estimation adapt to the item’s individual characteristic and reduce the uncertainty of the estimation. The simulation results show that considering measurement errors in the degradation process can significantly improve the accuracy of real time RUL prediction.

  18. Soft sensor modeling based on variable partition ensemble method for nonlinear batch processes

    Science.gov (United States)

    Wang, Li; Chen, Xiangguang; Yang, Kai; Jin, Huaiping

    2017-01-01

    Batch processes are always characterized by nonlinear and system uncertain properties, therefore, the conventional single model may be ill-suited. A local learning strategy soft sensor based on variable partition ensemble method is developed for the quality prediction of nonlinear and non-Gaussian batch processes. A set of input variable sets are obtained by bootstrapping and PMI criterion. Then, multiple local GPR models are developed based on each local input variable set. When a new test data is coming, the posterior probability of each best performance local model is estimated based on Bayesian inference and used to combine these local GPR models to get the final prediction result. The proposed soft sensor is demonstrated by applying to an industrial fed-batch chlortetracycline fermentation process.

  19. Design and implementation of non-linear image processing functions for CMOS image sensor

    Science.gov (United States)

    Musa, Purnawarman; Sudiro, Sunny A.; Wibowo, Eri P.; Harmanto, Suryadi; Paindavoine, Michel

    2012-11-01

    Today, solid state image sensors are used in many applications like in mobile phones, video surveillance systems, embedded medical imaging and industrial vision systems. These image sensors require the integration in the focal plane (or near the focal plane) of complex image processing algorithms. Such devices must meet the constraints related to the quality of acquired images, speed and performance of embedded processing, as well as low power consumption. To achieve these objectives, low-level analog processing allows extracting the useful information in the scene directly. For example, edge detection step followed by a local maxima extraction will facilitate the high-level processing like objects pattern recognition in a visual scene. Our goal was to design an intelligent image sensor prototype achieving high-speed image acquisition and non-linear image processing (like local minima and maxima calculations). For this purpose, we present in this article the design and test of a 64×64 pixels image sensor built in a standard CMOS Technology 0.35 μm including non-linear image processing. The architecture of our sensor, named nLiRIC (non-Linear Rapid Image Capture), is based on the implementation of an analog Minima/Maxima Unit. This MMU calculates the minimum and maximum values (non-linear functions), in real time, in a 2×2 pixels neighbourhood. Each MMU needs 52 transistors and the pitch of one pixel is 40×40 mu m. The total area of the 64×64 pixels is 12.5mm2. Our tests have shown the validity of the main functions of our new image sensor like fast image acquisition (10K frames per second), minima/maxima calculations in less then one ms.

  20. A novel thermodynamic state recursion method for description of nonideal nonlinear chromatographic process of frontal analysis.

    Science.gov (United States)

    Liu, Qian; OuYang, Liangfei; Liang, Heng; Li, Nan; Geng, Xindu

    2012-06-01

    A novel thermodynamic state recursion (TSR) method, which is based on nonequilibrium thermodynamic path described by the Lagrangian-Eulerian representation, is presented to simulate the whole chromatographic process of frontal analysis using the spatial distribution of solute bands in time series like as a series of images. TSR differs from the current numerical methods using the partial differential equations in Eulerian representation. The novel method is used to simulate the nonideal, nonlinear hydrophobic interaction chromatography (HIC) processes of lysozyme and myoglobin under the discrete complex boundary conditions. The results show that the simulated breakthrough curves agree well with the experimental ones. The apparent diffusion coefficient and the Langmuir isotherm parameters of the two proteins in HIC are obtained by the state recursion inverse method. Due to its the time domain and Markov characteristics, TSR is applicable to the design and online control of the nonlinear multicolumn chromatographic systems.

  1. Photonic Damascene Process for Integrated High-Q Microresonator Based Nonlinear Photonics

    CERN Document Server

    Pfeiffer, Martin H P; Brasch, Victor; Zervas, Michael; Geiselmann, Michael; Jost, John D; Kippenberg, Tobias J

    2015-01-01

    High confinement, integrated silicon nitride (SiN) waveguides have recently emerged as attractive platform for on-chip nonlinear optical devices. The fabrication of high-Q SiN microresonators with anomalous group velocity dispersion (GVD) has enabled broadband nonlinear optical frequency comb generation. Such frequency combs have been successfully applied in coherent communication and ultrashort pulse generation. However, the reliable fabrication of high confinement waveguides from stoichiometric, high stress SiN remains challenging. Here we present a novel photonic Damascene fabrication process enabling the use of substrate topography for stress control and thin film crack prevention. With close to unity sample yield we fabricate microresonators with $1.35\\,\\mu\\mathrm{m}$ thick waveguides and optical Q factors of $3.7\\times10^{6}$ and demonstrate single temporal dissipative Kerr soliton (DKS) based coherent optical frequency comb generation. Our newly developed process is interesting also for other material ...

  2. The SPH approach to the process of container filling based on non-linear constitutive models

    Institute of Scientific and Technical Information of China (English)

    Tao Jiang; Jie Ouyang; Lin Zhang; Jin-Lian Ren

    2012-01-01

    In this work,the transient free surface of container filling with non-linear constitutive equation's fluids is numerically investigated by the smoothed particle hydrodynamics (SPH) method.Specifically,the filling process of a square container is considered for non-linear polymer fluids based on the Cross model.The validity of the presented SPH is first verified by solving the Newtonian fluid and OldroydB fluid jet.Various phenomena in the filling process are shown,including the jet buckling,jet thinning,splashing or spluttering,steady filling.Moreover,a new phenomenon of vortex whirling is more evidently observed for the Cross model fluid compared with the Newtonian fluid case.

  3. High-Accuracy Pneumatic Position Control by Applying Nonlinear Control and Arranging Transient Process

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-bo; BAO Gang

    2008-01-01

    By applying a nonlinear control and arranging a transient process, the initiative error of the pneumatic servo positioning system is reduced largely, and a larger gain of the controller is used to improve the responding speed of the system at the same damping ratio. Therefore, a compromise is made among the responding speed, overshoot, robustness, adaptability and stability. In addition, a dynamic output feedback controller, including position velocity and acceleration (PVA) feedback, is designed to improve the performance of the system. And a nonlinear controller is reconstructed based on the linear output feedback controller to decrease noises and disturbances. The dynamic responses of the system are simulated and tested. Results show that the error is kept within 0.02 mm under different mass loads and the positioning transient process is smooth, without overshoot and speedy.

  4. Interactive methods to involve users into workspace design process

    DEFF Research Database (Denmark)

    Souza da Conceição, Carolina; Broberg, Ole; Banke, Palle

    2013-01-01

    This paper addresses the question of whether the use of a combination of interactive methods involving workers can lead to a useful input to the (re)design of their workspace. The workbook and the layout design game methods were tested, and a comparison between their use and the ergonomic analysis...

  5. Effects of non-linear rheology on the electrospinning process: a model study

    CERN Document Server

    Pontrelli, Giuseppe; Coluzza, Ivan; Pisignano, Dario; Succi, Sauro

    2014-01-01

    We develop an analytical bead-spring model to investigate the role of non-linear rheology on the dynamics of electrified jets in the early stage of the electrospinning process. Qualitative arguments, parameter studies as well as numerical simulations, show that the elongation of the charged jet filament is significantly reduced in the presence of a non-zero yield stress. This may have beneficial implications for the optimal design of future electrospinning experiments.

  6. Modern meta-heuristics based on nonlinear physics processes: A review of models and design procedures

    Science.gov (United States)

    Salcedo-Sanz, S.

    2016-10-01

    Meta-heuristic algorithms are problem-solving methods which try to find good-enough solutions to very hard optimization problems, at a reasonable computation time, where classical approaches fail, or cannot even been applied. Many existing meta-heuristics approaches are nature-inspired techniques, which work by simulating or modeling different natural processes in a computer. Historically, many of the most successful meta-heuristic approaches have had a biological inspiration, such as evolutionary computation or swarm intelligence paradigms, but in the last few years new approaches based on nonlinear physics processes modeling have been proposed and applied with success. Non-linear physics processes, modeled as optimization algorithms, are able to produce completely new search procedures, with extremely effective exploration capabilities in many cases, which are able to outperform existing optimization approaches. In this paper we review the most important optimization algorithms based on nonlinear physics, how they have been constructed from specific modeling of a real phenomena, and also their novelty in terms of comparison with alternative existing algorithms for optimization. We first review important concepts on optimization problems, search spaces and problems' difficulty. Then, the usefulness of heuristics and meta-heuristics approaches to face hard optimization problems is introduced, and some of the main existing classical versions of these algorithms are reviewed. The mathematical framework of different nonlinear physics processes is then introduced as a preparatory step to review in detail the most important meta-heuristics based on them. A discussion on the novelty of these approaches, their main computational implementation and design issues, and the evaluation of a novel meta-heuristic based on Strange Attractors mutation will be carried out to complete the review of these techniques. We also describe some of the most important application areas, in

  7. Molecular Optics Nonlinear Optical Processes in Organic and Polymeric Crystals and Films. Part 2

    Science.gov (United States)

    1991-11-01

    susceptibility gamma ijkl(-omega 4; omega 1, omega 2, omega 3 ) demonstrate that the microscopic origin of the nonresonant third order nonlinear optical...interaction calculations of gamma jkl(-omega 4; omega 1, omega 2, omega 3 ) for the archetypal class of quasi-one dimensional conjugated structures...largest of the two dominant, competing virtual excitation processes that determine gamma ijkl(- omega 4; omega 1, omega 2, omega 3 ). It is also found in

  8. Data-driven design of fault diagnosis systems nonlinear multimode processes

    CERN Document Server

    Haghani Abandan Sari, Adel

    2014-01-01

    In many industrial applications early detection and diagnosis of abnormal behavior of the plant is of great importance. During the last decades, the complexity of process plants has been drastically increased, which imposes great challenges in development of model-based monitoring approaches and it sometimes becomes unrealistic for modern large-scale processes. The main objective of Adel Haghani Abandan Sari is to study efficient fault diagnosis techniques for complex industrial systems using process historical data and considering the nonlinear behavior of the process. To this end, different methods are presented to solve the fault diagnosis problem based on the overall behavior of the process and its dynamics. Moreover, a novel technique is proposed for fault isolation and determination of the root-cause of the faults in the system, based on the fault impacts on the process measurements. Contents Process monitoring Fault diagnosis and fault-tolerant control Data-driven approaches and decision making Target...

  9. Development of coherent tunable source in 2–16 m region using nonlinear frequency mixing processes

    Indian Academy of Sciences (India)

    Udit Chatterjee

    2014-01-01

    A very convenient way to obtain widely tunable source of coherent radiation in the infrared region is through nonlinear frequency mixing processes like second harmonic generation (SHG), difference-frequency mixing (DFM) or optical parametric oscillation (OPO). Using commonly available Nd:YAG laser and its harmonic pumped dye laser radiation as parent beams, we have been able to generate coherent tunable infrared radiation (IR) in 2–16 m region using different nonlinear crystals by DFM and OPO. We have also generated such IR source in the 4–5 m region through SHG of CO2 laser in different infrared crystals. In the process we have characterized a large number of nonlinear crystals like different borate group of crystals, KTP, KTA, LiIO3, MgO:LiNbO3, GaSe, AgGaSe2, ZnGeP2, AgGa1−InSe2, HgGa2S4 etc. To improve the conversion efficiencies of such frequency conversion processes, we have developed some novel schemes, like multipass configuration (MC) and positive optical feedback (POF). The significance of the obtained results lies in the fact that to get the same conversion in SHG or DFM, one now requires fundamental input radiation with much lower intensity.

  10. Nonlinear Optical Properties of Organic and Polymeric Thin Film Materials of Potential for Microgravity Processing Studies

    Science.gov (United States)

    Abdeldayem, Hossin; Frazier, Donald O.; Paley, Mark S.; Penn, Benjamin; Witherow, William K.; Bank, Curtis; Shields, Angela; Hicks, Rosline; Ashley, Paul R.

    1996-01-01

    In this paper, we will take a closer look at the state of the art of polydiacetylene, and metal-free phthalocyanine films, in view of the microgravity impact on their optical properties, their nonlinear optical properties and their potential advantages for integrated optics. These materials have many attractive features with regard to their use in integrated optical circuits and optical switching. Thin films of these materials processed in microgravity environment show enhanced optical quality and better molecular alignment than those processed in unit gravity. Our studies of these materials indicate that microgravity can play a major role in integrated optics technology. Polydiacetylene films are produced by UV irradiation of monomer solution through an optical window. This novel technique of forming polydiacetylene thin films has been modified for constructing sophisticated micro-structure integrated optical patterns using a pre-programmed UV-Laser beam. Wave guiding through these thin films by the prism coupler technique has been demonstrated. The third order nonlinear parameters of these films have been evaluated. Metal-free phthalocyanine films of good optical quality are processed in our laboratories by vapor deposition technique. Initial studies on these films indicate that they have excellent chemical, laser, and environmental stability. They have large nonlinear optical parameters and show intrinsic optical bistability. This bistability is essential for optical logic gates and optical switching applications. Waveguiding and device making investigations of these materials are underway.

  11. Soft Sensor for Inputs and Parameters Using Nonlinear Singular State Observer in Chemical Processes

    Institute of Scientific and Technical Information of China (English)

    许锋; 汪晔晔; 罗雄麟

    2013-01-01

    Chemical processes are usually nonlinear singular systems. In this study, a soft sensor using nonlinear singular state observer is established for unknown inputs and uncertain model parameters in chemical processes, which are augmented as state variables. Based on the observability of the singular system, this paper presents a simplified observability criterion under certain conditions for unknown inputs and uncertain model parameters. When the observability is satisfied, the unknown inputs and the uncertain model parameters are estimated online by the soft sensor using augmented nonlinear singular state observer. The riser reactor of fluid catalytic cracking unit is used as an example for analysis and simulation. With the catalyst circulation rate as the only unknown input without model error, one temperature sensor at the riser reactor outlet will ensure the correct estimation for the catalyst cir-culation rate. However, when uncertain model parameters also exist, additional temperature sensors must be used to ensure correct estimation for unknown inputs and uncertain model parameters of chemical processes.

  12. The Interaction between Personality, Social Network Position and Involvement in Innovation Process

    NARCIS (Netherlands)

    E. Dolgova; W. van Olffen (Woody); F.A.J. van den Bosch (Frans); H.W. Volberda (Henk)

    2010-01-01

    textabstractAbstract This dissertation proposal investigates how personality and individuals’ social network position affect individuals’ involvement into the innovation process. It posits that people would feel inclined to become involved into the different phases of the innovation process dependin

  13. Across frequency processes involved in auditory detection of coloration

    DEFF Research Database (Denmark)

    Buchholz, Jörg; Kerketsos, P

    2008-01-01

    When an early wall reflection is added to a direct sound, a spectral modulation is introduced to the signal's power spectrum. This spectral modulation typically produces an auditory sensation of coloration or pitch. Throughout this study, auditory spectral-integration effects involved in coloration...... detection are investigated. Coloration detection thresholds were therefore measured as a function of reflection delay and stimulus bandwidth. In order to investigate the involved auditory mechanisms, an auditory model was employed that was conceptually similar to the peripheral weighting model [Yost, JASA......, 1982, 416-425]. When a “classical” gammatone filterbank was applied within this spectrum-based model, the model largely underestimated human performance at high signal frequencies. However, this limitation could be resolved by employing an auditory filterbank with narrower filters. This novel...

  14. Green functions and Langevin equations for nonlinear diffusion equations: A comment on ‘Markov processes, Hurst exponents, and nonlinear diffusion equations’ by Bassler et al.

    Science.gov (United States)

    Frank, T. D.

    2008-02-01

    We discuss two central claims made in the study by Bassler et al. [K.E. Bassler, G.H. Gunaratne, J.L. McCauley, Physica A 369 (2006) 343]. Bassler et al. claimed that Green functions and Langevin equations cannot be defined for nonlinear diffusion equations. In addition, they claimed that nonlinear diffusion equations are linear partial differential equations disguised as nonlinear ones. We review bottom-up and top-down approaches that have been used in the literature to derive Green functions for nonlinear diffusion equations and, in doing so, show that the first claim needs to be revised. We show that the second claim as well needs to be revised. To this end, we point out similarities and differences between non-autonomous linear Fokker-Planck equations and autonomous nonlinear Fokker-Planck equations. In this context, we raise the question whether Bassler et al.’s approach to financial markets is physically plausible because it necessitates the introduction of external traders and causes. Such external entities can easily be eliminated when taking self-organization principles and concepts of nonextensive thermostatistics into account and modeling financial processes by means of nonlinear Fokker-Planck equations.

  15. Research Education: Perspectives and subjective processes involved in educational research

    Directory of Open Access Journals (Sweden)

    Harm H. Tillema

    2009-10-01

    Full Text Available Educational research acknowledges that researcher’s beliefs and training play a role in framing the outcomes of any study. Research not only consists of defining objectives and following certain methods (search but also of making decisions over the steps taking during the inquiry process (research.Establishing a conceptual framework to guide actions on the subjective processes in research is then crucial to control them. With that purpose in mind we offer researchers and Teacher Educators a heuristic tool to be conscious on the risks that can be taken when immersed in research interpretative process. This instrument could be utilised in PhD programs, masters and research projects.

  16. Ultrafast nonlinear optical processes in metal-dielectric nanocomposites and nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kwang-Hyon

    2012-04-13

    This work reports results of a theoretical study of nonlinear optical processes in metal-dielectric nanocomposites used for the increase of the nonlinear coefficients and for plasmonic field enhancement. The main results include the study of the transient saturable nonlinearity in dielectric composites doped with metal nanoparticles, its physical mechanism as well its applications in nonlinear optics. For the study of the transient response, a time-depending equation for the dielectric function of the nanocomposite using the semi-classical two-temperature model is derived. By using this approach, we study the transient nonlinear characteristics of these materials in comparison with preceding experimental measurements. The results show that these materials behave as efficient saturable absorbers for passive mode-locking of lasers in the spectral range from the visible to near IR. We present results for the modelocked dynamics in short-wavelength solid-state and semiconductor disk lasers; in this spectral range other efficient saturable absorbers do not exist. We suggest a new mechanism for the realization of slow light phenomenon by using glasses doped with metal nanoparticles in a pump-probe regime near the plasmonic resonance. Furthermore, we study femtosecond plasmon generation by mode-locked surface plasmon polariton lasers with Bragg reflectors and metal-gain-absorber layered structures. In the final part of the thesis, we present results for high-order harmonic generation near a metallic fractal rough surface. The results show a possible reduction of the pump intensities by three orders of magnitudes and two orders of magnitudes higher efficiency compared with preceding experimental results by using bow-tie nanostructures.

  17. Multivariable adaptive control and estimation of a nonlinear wastewater treatment process

    Energy Technology Data Exchange (ETDEWEB)

    Ben Youssef, C.; Dahhou, B. [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France)]|[Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France)

    1995-12-31

    In this paper, an approach for estimating biological state and parameter variables and for controlling a non linear wastewater treatment process is developed. Combination of a nonlinear estimation procedure and a multivariable reference model control law provides favourable performances for tracking a given model-based reference model despite disturbances and system parameter uncertainties. Convergence of both estimation and control scheme are demonstrated via Lyapunov`s method. Simulation study with additive measurements noises and parameter jumps shows the efficiency and significant robustness of the control methodology developed for this non linear process. (author) 13 refs.

  18. Hamiltonian models of multiphoton processes and four--photon squeezed states via nonlinear canonical transformations

    CERN Document Server

    De Siena, S; Illuminati, F; Siena, Silvio De; Lisi, Antonio Di; Illuminati, Fabrizio

    2002-01-01

    We introduce nonlinear canonical transformations that yield effective Hamiltonians of multiphoton down conversion processes, and we define the associated non-Gaussian multiphoton squeezed states as the coherent states of the multiphoton Hamiltonians. We study in detail the four-photon processes and the associated non-Gaussian four-photon squeezed states. The realization of squeezing, the behavior of the field statistics, and the structure of the phase space distributions show that these states realize a natural four-photon generalization of the two-photon squeezed states.

  19. Improving industrial designers work process by involving user research

    DEFF Research Database (Denmark)

    Dai, Zheng; Ómarsson, Ólafur

    2011-01-01

    With changing times, new technologies and more opinionated consumers, the modern industrial designer has found himself in need of fresher and more up to date approaches in his daily work. In a fast moving industry, the designer needs to keep a thinking process of dynamic and subjective attitude...

  20. Nonlinear tracking in a diffusion process with a Bayesian filter and the finite element method

    DEFF Research Database (Denmark)

    Pedersen, Martin Wæver; Thygesen, Uffe Høgsbro; Madsen, Henrik

    2011-01-01

    A new approach to nonlinear state estimation and object tracking from indirect observations of a continuous time process is examined. Stochastic differential equations (SDEs) are employed to model the dynamics of the unobservable state. Tracking problems in the plane subject to boundaries...... become complicated using SMC because Monte Carlo randomness is introduced. The finite element (FE) method solves the Kolmogorov equations of the SDE numerically on a triangular unstructured mesh for which boundary conditions to the state-space are simple to incorporate. The FE approach to nonlinear state...... estimation is suited for off-line data analysis because the computed smoothed state densities, maximum a posteriori parameter estimates and state sequence are deterministic conditional on the finite element mesh and the observations. The proposed method is conceptually similar to existing point...

  1. Nonlinear dynamics of three-magnon process driven by ferromagnetic resonance in yttrium iron garnet

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, R. O. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Centro Interdisciplinar de Ciências da Natureza, Universidade Federal da Integração Latino-Americana, 85867-970 Foz do Iguaçu, PR (Brazil); Holanda, J.; Azevedo, A.; Rezende, S. M., E-mail: rezende@df.ufpe.br [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Vilela-Leão, L. H. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Centro Acadêmico do Agreste, Universidade Federal de Pernambuco, 55002-970 Caruaru, PE (Brazil); Rodríguez-Suárez, R. L. [Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago (Chile)

    2015-05-11

    We report an investigation of the dynamics of the three-magnon splitting process associated with the ferromagnetic resonance (FMR) in films of the insulating ferrimagnet yttrium iron garnet (YIG). The experiments are performed with a 6 μm thick YIG film close to a microstrip line fed by a microwave generator operating in the 2–6 GHz range. The magnetization precession is driven by the microwave rf magnetic field perpendicular to the static magnetic field, and its dynamics is observed by monitoring the amplitude of the FMR absorption peak. The time evolution of the amplitude reveals that if the frequency is lowered below a critical value of 3.3 GHz, the FMR mode pumps two magnons with opposite wave vectors that react back on the FMR, resulting in a nonlinear dynamics of the magnetization. The results are explained by a model with coupled nonlinear equations describing the time evolution of the magnon modes.

  2. Three-dimensional multispecies nonlinear perturbative particle simulations of collective processes in intense particle beams

    Directory of Open Access Journals (Sweden)

    Hong Qin

    2000-08-01

    Full Text Available Collective processes in intense charged particle beams described self-consistently by the Vlasov-Maxwell equations are studied using a 3D multispecies nonlinear perturbative particle simulation method. The newly developed beam equilibrium, stability, and transport (BEST code is used to simulate the nonlinear stability properties of intense beam propagation, surface eigenmodes in a high-intensity beam, and the electron-proton (e-p two-stream instability observed in the Proton Storage Ring (PSR experiment. Detailed simulations in a parameter regime characteristic of the PSR experiment show that the dipole-mode two-stream instability is stabilized by a modest spread (about 0.1% in axial momentum of the beam particles.

  3. Numerical simulation of nonlinear processes in a beam-plasma system

    Energy Technology Data Exchange (ETDEWEB)

    Efimova, A. A., E-mail: anna.an.efimova@gmail.com; Berendeev, E. A.; Vshivkov, V. A. [Institute of Computational Mathematics and Mathematical Geophysics SB RAS 6 Acad. Lavrentyev Ave., Novosibirsk 630090 (Russian Federation); Dudnikova, G. I. [University of Maryland, College Park, MD 20742 (United States); Institute of Computational Technologies SB RAS, 6 Acad. Lavrentyev Ave., Novosibirsk 630090 (Russian Federation)

    2015-10-28

    In the present paper we consider the efficiency of the electromagnetic radiation generation due to various nonlinear processes in the beam-plasma system. The beam and plasma parameters were chosen close to the parameters in the experiment on the GOL-3 facility (BINP SB RAS). The model of the collisionless plasma is described by system of the Vlasov-Maxwell equations with periodic boundary conditions. The parallel numerical algorithm is based on the particles-in-cell method (PIC) with mixed Euler-Lagrangian domain decomposition. Various scenarios of nonlinear evolution in the beam-plasma system under the influence of an external magnetic field in case of a low density beam were studied. The energy transfer from one unstable mode to the others modes was observed.

  4. Linear and Nonlinear Impairment Compensation in Coherent Optical Transmission with Digital Signal Processing

    DEFF Research Database (Denmark)

    Porto da Silva, Edson

    Digital signal processing (DSP) has become one of the main enabling technologies for the physical layer of coherent optical communication networks. The DSP subsystems are used to implement several functionalities in the digital domain, from synchronization to channel equalization. Flexibility...... nonlinearity compensation, (II) spectral shaping, and (III) adaptive equalization. For (I), original contributions are presented to the study of the nonlinearity compensation (NLC) with digital backpropagation (DBP). Numerical and experimental performance investigations are shown for different application...... scenarios. Concerning (II), it is demonstrated how optical and electrical (digital) pulse shaping can be allied to improve the spectral confinement of a particular class of optical time-division multiplexing (OTDM) signals that can be used as a building block for fast signaling single-carrier transceivers...

  5. Anticipation and the Non-linear Dynamics of Meaning-Processing in Social Systems

    CERN Document Server

    Leydesdorff, Loet

    2009-01-01

    Social order does not exist as a stable phenomenon, but can be considered as "an order of reproduced expectations." When anticipations operate upon one another, they can generate a non-linear dynamics which processes meaning. Although specific meanings can be stabilized, for example in social institutions, all meaning arises from a global horizon of possible meanings. Using Luhmann's (1984) social systems theory and Rosen's (1985) theory of anticipatory systems, I submit algorithms for modeling the non-linear dynamics of meaning in social systems. First, a self-referential system can use a model of itself for the anticipation. Under the condition of functional differentiation, the social system can be expected to entertain a set of models; each model can also contain a model of the other models. Two anticipatory mechanisms are then possible: a transversal one between the models, and a longitudinal one providing the system with a variety of meanings. A system containing two anticipatory mechanisms can become h...

  6. Improving industrial designers work process by involving user research

    DEFF Research Database (Denmark)

    Dai, Zheng; Ómarsson, Ólafur

    2011-01-01

    With changing times, new technologies and more opinionated consumers, the modern industrial designer has found himself in need of fresher and more up to date approaches in his daily work. In a fast moving industry, the designer needs to keep a thinking process of dynamic and subjective attitude....... User research is part of user centered design (UCD). UCD has a reputation for subjective and reflective practice. In this paper there are two example cases. One is conducted by a classical industrial design process, and another is costing half of energy and time in user research. These examples...... will give the grounding for believing that the industrial designer needs to adopt user research methods to a level where he can still continue to work under the very nature of industrial design that has made it a successful practice for the last century. The combing of the approaches and attitude will help...

  7. Issues involved in the process of developing a medical food.

    Science.gov (United States)

    Ochoa, Juan B; McClave, Stephen A; Saavedra, Jose

    2011-09-01

    The creation of a medical food with potential health benefits for a particular patient population is a surprisingly complex process. Fortunately, the developmental process for a specific medical food is not as rigorous or as tightly regulated as that of a pharmaceutical agent. However, numerous factors unique to the enteral formulation of a new product come into play, such as physical/chemical compatibility, pH, stability, bioavailability, decay, and even palatability. Additional considerations such as strength of health benefit claims, packaging or presentation, and marketability determine the ultimate commercialization and whether a product ends up being released to the public. A full understanding of the development, substantiation, and commercialization of a medical food is necessary for important physiologic concepts in nutrition therapy to end up as part of the therapeutic regimen at the bedside of the critically ill obese patient.

  8. State and parameter estimation based on a nonlinear filter applied to an industrial process control of ethanol production

    Directory of Open Access Journals (Sweden)

    Meleiro L.A.C.

    2000-01-01

    Full Text Available Most advanced computer-aided control applications rely on good dynamics process models. The performance of the control system depends on the accuracy of the model used. Typically, such models are developed by conducting off-line identification experiments on the process. These experiments for identification often result in input-output data with small output signal-to-noise ratio, and using these data results in inaccurate model parameter estimates [1]. In this work, a multivariable adaptive self-tuning controller (STC was developed for a biotechnological process application. Due to the difficulties involving the measurements or the excessive amount of variables normally found in industrial process, it is proposed to develop "soft-sensors" which are based fundamentally on artificial neural networks (ANN. A second approach proposed was set in hybrid models, results of the association of deterministic models (which incorporates the available prior knowledge about the process being modeled with artificial neural networks. In this case, kinetic parameters - which are very hard to be accurately determined in real time industrial plants operation - were obtained using ANN predictions. These methods are especially suitable for the identification of time-varying and nonlinear models. This advanced control strategy was applied to a fermentation process to produce ethyl alcohol (ethanol in industrial scale. The reaction rate considered for substratum consumption, cells and ethanol productions are validated with industrial data for typical operating conditions. The results obtained show that the proposed procedure in this work has a great potential for application.

  9. Kinetic processes in solid helium involving impurities and vacancies (Review)

    Science.gov (United States)

    Maidanov, V. A.; Rudavskii, E. Ya.; Sokolov, S. S.

    2017-01-01

    A brief review is given of the kinetic behavior of impurities and vacancies in solid helium, which Andreev and Lifshitz predicted should be delocalized and converted into unique quasiparticles. Primary attention is devoted to the unusual diffusion processes in solid 3He-4He solutions as they undergo phase separation. Because mechanical stresses develop in the crystal during separation, the diffusive flow is substantially reduced and the effective diffusion coefficient becomes smaller than the coherent quantum diffusion coefficient. During the inverse transition from a separated mixture into the homogeneous state, anomalously rapid mass transfer is observed which can be explained qualitatively in terms of a model in which 3He inclusions are dissolved in three stages. Experimental data on the kinetics of phase separation are compared with a diffusive description of the process that takes into account the difference between diffusion processes outside and inside a nucleus of the new phase. Good agreement is obtained between a theoretical calculation and the experimental data. A homogeneous nucleation model is used to estimate the concentration of nuclei. For the first time, the coefficient of mass diffusion is estimated over the entire range of the concentration of the solutions. The behavior of delocalized vacancies in 4He and 3He solid solutions is studied near the separation temperature. The observed features of the pressure in this kind of system during repeated temperature cycling are explained by the formation of pure 4He vacancy clusters. Although the crystal itself has no strict periodicity owing to the random separation of 3He and 4He atoms at the lattice sites, a periodic structure is realized within a cluster and vacancies become delocalized.

  10. High-speed nonlinear finite element analysis for surgical simulation using graphics processing units.

    Science.gov (United States)

    Taylor, Z A; Cheng, M; Ourselin, S

    2008-05-01

    The use of biomechanical modelling, especially in conjunction with finite element analysis, has become common in many areas of medical image analysis and surgical simulation. Clinical employment of such techniques is hindered by conflicting requirements for high fidelity in the modelling approach, and fast solution speeds. We report the development of techniques for high-speed nonlinear finite element analysis for surgical simulation. We use a fully nonlinear total Lagrangian explicit finite element formulation which offers significant computational advantages for soft tissue simulation. However, the key contribution of the work is the presentation of a fast graphics processing unit (GPU) solution scheme for the finite element equations. To the best of our knowledge, this represents the first GPU implementation of a nonlinear finite element solver. We show that the present explicit finite element scheme is well suited to solution via highly parallel graphics hardware, and that even a midrange GPU allows significant solution speed gains (up to 16.8 x) compared with equivalent CPU implementations. For the models tested the scheme allows real-time solution of models with up to 16,000 tetrahedral elements. The use of GPUs for such purposes offers a cost-effective high-performance alternative to expensive multi-CPU machines, and may have important applications in medical image analysis and surgical simulation.

  11. Effect of alpha and Gaussian refractive index profiles on the design of highly nonlinear optical fibre for efficient nonlinear optical signal processing

    Science.gov (United States)

    Selvendran, S.; Sivanantharaja, A.; Arivazhagan, S.; Kannan, M.

    2016-09-01

    We propose an index profiled, highly nonlinear ultraflattened dispersion fibre (HN-UFF) with appreciable values of fibre parameters such as dispersion, dispersion slope, effective area, nonlinearity, bending loss and splice loss. The designed fibre has normal zero flattened dispersion over S, C, L, U bands and extends up to 1.9857 μm. The maximum dispersion variation observed for this fibre is as low as 1.61 ps km-1 nm-1 over the 500-nm optical fibre transmission spectrum. This fibre also has two zero dispersion wavelengths at 1.487 and 1.9857 μm and the respective dispersion slopes are 0.02476 and 0.0068 ps nm-2 km-1. The fibre has a very low ITU-T cutoff wavelength of 1.2613 μm and a virtuous nonlinear coefficient of 9.43 W-1 km-1. The wide spectrum of zero flattened dispersion and a good nonlinear coefficient make the designed fibre very promising for different nonlinear optical signal processing applications.

  12. Non-equilibrium condensation process in holographic superconductor with nonlinear electrodynamics

    CERN Document Server

    Liu, Yunqi; Wang, Bin

    2015-01-01

    We study the non-equilibrium condensation process in a holographic superconductor with nonlinear corrections to the U(1) gauge field. We start with an asymptotic Anti-de-Sitter(AdS) black hole against a complex scalar perturbation at the initial time, and solve the dynamics of the gravitational systems in the bulk. When the black hole temperature T is smaller than a critical value Tc, the scalar perturbation grows exponentially till saturation, the final state of spacetime approaches to a hairy black hole. In the bulk theory, we find the clue of the influence of nonlinear corrections in the gauge field on the process of the scalar field condensation. We show that the bulk dynamics in the non-equilibrium process is completely consistent with the observations on the boundary order parameter. Furthermore we examine the time evolution of horizons in the bulk non-equilibrium transformation process from the bald AdS black hole to the AdS hairy hole. Both the evolution of apparent and event horizons show that the or...

  13. Generation of photon pairs through parametric processes in nonlinear waveguides with the account of losses

    Science.gov (United States)

    Vavulin, D. N.; Sukhorukov, A. A.

    2016-08-01

    We present an analytical description of the process of spontaneous four-wave mixing in a cubic nonlinear fiber with linear losses. We consider the generation of photon pairs in the fiber when in the input of fiber is fed the pumping wave and single signal photon. The focus of attention is on three cases: when the signal photon propagates in the fiber without generating of biphotons; when the photon pair is generated; and when the photon is lost in the fiber. We also consider the cascade processes, but do not give them an analytical description because of their smallness. Description of the biphotons generation process we provide using the Schrodinger-type equation, and take into account the losses in the fiber through the introduction of the virtual beam splitters. We demonstrate the effectiveness of the generation of photon pairs through parametric processes.

  14. Definition of distance for nonlinear time series analysis of marked point process data

    Energy Technology Data Exchange (ETDEWEB)

    Iwayama, Koji, E-mail: koji@sat.t.u-tokyo.ac.jp [Research Institute for Food and Agriculture, Ryukoku Univeristy, 1-5 Yokotani, Seta Oe-cho, Otsu-Shi, Shiga 520-2194 (Japan); Hirata, Yoshito; Aihara, Kazuyuki [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)

    2017-01-30

    Marked point process data are time series of discrete events accompanied with some values, such as economic trades, earthquakes, and lightnings. A distance for marked point process data allows us to apply nonlinear time series analysis to such data. We propose a distance for marked point process data which can be calculated much faster than the existing distance when the number of marks is small. Furthermore, under some assumptions, the Kullback–Leibler divergences between posterior distributions for neighbors defined by this distance are small. We performed some numerical simulations showing that analysis based on the proposed distance is effective. - Highlights: • A new distance for marked point process data is proposed. • The distance can be computed fast enough for a small number of marks. • The method to optimize parameter values of the distance is also proposed. • Numerical simulations indicate that the analysis based on the distance is effective.

  15. Intrinsic Nonlinearities and Layout Impacts of 100 V Integrated Power MOSFETs in Partial SOI Process

    DEFF Research Database (Denmark)

    Fan, Lin; Knott, Arnold; Jørgensen, Ivan Harald Holger

    Parasitic capacitances of power semiconductors are a part of the key design parameters of state-of-the-art very high frequency (VHF) power supplies. In this poster, four 100 V integrated power MOSFETs with different layout structures are designed, implemented, and analyzed in a 0.18 ȝm partial...... Silicon-on-Insulator (SOI) process with a die area 2.31 mm2.  A small-signal model of power MOSFETs is proposed to systematically analyze the nonlinear parasitic capacitances in different transistor states: off-state, sub-threshold region, and on-state in the linear region. 3D plots are used to summarize...

  16. Time-ordering effects in the generation of entangled photons using nonlinear optical processes.

    Science.gov (United States)

    Quesada, Nicolás; Sipe, J E

    2015-03-06

    We study the effects of time ordering in photon generation processes such as spontaneous parametric down-conversion (SPDC) and four wave mixing (SFWM). The results presented here are used to construct an intuitive picture that allows us to predict when time-ordering effects significantly modify the joint spectral amplitude (JSA) of the photons generated in SPDC and SFWM. These effects become important only when the photons being generated lie with the pump beam that travels through the nonlinear material for a significant amount of time. Thus sources of spectrally separable photons are ideal candidates for the observation of modifications of the JSA due to time ordering.

  17. Imitation learning of Non-Linear Point-to-Point Robot Motions using Dirichlet Processes

    DEFF Research Database (Denmark)

    Krüger, Volker; Tikhanoff, Vadim; Natale, Lorenzo

    2012-01-01

    In this paper we discuss the use of the infinite Gaussian mixture model and Dirichlet processes for learning robot movements from demonstrations. Starting point of this work is an earlier paper where the authors learn a non-linear dynamic robot movement model from a small number of observations....... The model in that work is learned using a classical finite Gaussian mixture model (FGMM) where the Gaussian mixtures are appropriately constrained. The problem with this approach is that one needs to make a good guess for how many mixtures the FGMM should use. In this work, we generalize this approach...

  18. ADI splitting schemes for a fourth-order nonlinear partial differential equation from image processing

    KAUST Repository

    Calatroni, Luca

    2013-08-01

    We present directional operator splitting schemes for the numerical solution of a fourth-order, nonlinear partial differential evolution equation which arises in image processing. This equation constitutes the H -1-gradient flow of the total variation and represents a prototype of higher-order equations of similar type which are popular in imaging for denoising, deblurring and inpainting problems. The efficient numerical solution of this equation is very challenging due to the stiffness of most numerical schemes. We show that the combination of directional splitting schemes with implicit time-stepping provides a stable and computationally cheap numerical realisation of the equation.

  19. A process fault estimation strategy for non-linear dynamic systems

    Science.gov (United States)

    Pazera, Marcin; Korbicz, Józef

    2017-01-01

    The paper deals with the problem of simultaneous state and process fault estimation for non-linear dynamic systems. Instead of estimating the fault directly, its product with state and the state itself are estimated. To derive the fault from the product, a simple algebraic approach is proposed. The estimation strategy is based on the quadratic boundedness approach. The final part of the paper presents an illustrative example concerning a laboratory multi-tank system. The real data experiments clearly exhibit the performance of the proposed approach.

  20. [The decision to abort: the process and feelings involved].

    Science.gov (United States)

    Costa, R G; Hardy, E; Osis, M J; Faúndes, A

    1995-01-01

    In Brazil, induced abortion is considered a crime in the majority of cases, the result being that there is little official data on the subject. Little is known about the conditions under which abortions are induced This research was designed to shed light on the characteristics of the women who had had an abortion and to study the reasons why and conditions under which it occurred. The sample consisted of all employees (7,359) and students (2,231) in a university program in S o Paulo who were mailed a self-administered survey. Accompanying the questionnaire was a letter and self-addressed stamped envelope. 27% of the employees and 42% of the students returned the questionnaires. Of these, 1,314 employees and 138 students had had at least one pregnancy. The results presented in this study show that 465 of the employees and students ar some point had thought of having an abortion. They were divided into two groups: those who had had an abortion and those who had nos. The objective was to analyze the association of some characteristics of the women with their decision to have/not have an abortion and how they felt when faced with this decision. The proportion of women who had had an abortion was significantly lower among married women than singles. A larger percentage of women who had talked with a friend and/or husband/partner/boyfriend had decided to have an abortion than those who had talked to a parent or had not talked to anyone. More women who said they were not prepared to raise/educate a child had had an abortion as compared to those giving other reasons. Almost half of the women undergoing an abortion said that they felt bad emotionally and physically afterwards. Among those who had not had an abortion, almost two-fifths reported that they felt good, were happy, relieved, and did not regret their decision. The conclusion drawn from the population studied was that emotional and social factors played a significant role in the decision-making process for women

  1. Estimation and filtering of nonlinear systems application to a waste-water treatment process

    Energy Technology Data Exchange (ETDEWEB)

    Ben Youssef, C.; Dahhou, B. [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France). Lab. d`Automatique et d`Analyse des Systemes]|[Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France); Zeng, F.Y.; Rols, J.L. [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France)

    1994-04-01

    A fundamental task in design and control of biotechnological processes is system modelling. This task is made difficult by the scarceness of on-line direct sensors for some key variables and by the fact that identifiability of models including Michaelis-Menten type of nonlinearities is not straightforward. The use of adaptive estimation approaches constitutes an interesting alternative to circumvent these kind of problems. This paper discusses an identification technique derived to solve the problem of estimating simultaneously inaccessible state variables and time-varying parameters of a nonlinear wastewater treatment process. An extended linearization technique using Kronecker`s calculation provides the error model of the joint observer-estimator procedure which convergence is proved via Lyapunov`s method. Sufficient conditions for stability of this joint identification scheme are given and discussed according to the persistence excitation conditions of the signals. A simulation study with measurement noises and abrupt jumps of the process parameters shows the feasibility and significant robustness of the proposed adaptive estimation methodologies. (author). (author). 10 refs., 3 figs.

  2. A new cellular nonlinear network emulation on FPGA for EEG signal processing in epilepsy

    Science.gov (United States)

    Müller, Jens; Müller, Jan; Tetzlaff, Ronald

    2011-05-01

    For processing of EEG signals, we propose a new architecture for the hardware emulation of discrete-time Cellular Nonlinear Networks (DT-CNN). Our results show the importance of a high computational accuracy in EEG signal prediction that cannot be achieved with existing analogue VLSI circuits. The refined architecture of the processing elements and its resource schedule, the cellular network structure with local couplings, the FPGA-based embedded system containing the DT-CNN, and the data flow in the entire system will be discussed in detail. The proposed DT-CNN design has been implemented and tested on an Xilinx FPGA development platform. The embedded co-processor with a multi-threading kernel is utilised for control and pre-processing tasks and data exchange to the host via Ethernet. The performance of the implemented DT-CNN has been determined for a popular example and compared to that of a conventional computer.

  3. Sub-diffraction imaging on standard microscopes through photobleaching microscopy with non-linear processing.

    Science.gov (United States)

    Munck, Sebastian; Miskiewicz, Katarzyna; Sannerud, Ragna; Menchon, Silvia A; Jose, Liya; Heintzmann, Rainer; Verstreken, Patrik; Annaert, Wim

    2012-05-01

    Visualization of organelles and molecules at nanometer resolution is revolutionizing the biological sciences. However, such technology is still limited for many cell biologists. We present here a novel approach using photobleaching microscopy with non-linear processing (PiMP) for sub-diffraction imaging. Bleaching of fluorophores both within the single-molecule regime and beyond allows visualization of stochastic representations of sub-populations of fluorophores by imaging the same region over time. Our method is based on enhancing the probable positions of the fluorophores underlying the images. The random nature of the bleached fluorophores is assessed by calculating the deviation of the local actual bleached fluorescence intensity to the average bleach expectation as given by the overall decay of intensity. Subtracting measured from estimated decay images yields differential images. Non-linear enhancement of maxima in these diffraction-limited differential images approximates the positions of the underlying structure. Summing many such processed differential images yields a super-resolution PiMP image. PiMP allows multi-color, three-dimensional sub-diffraction imaging of cells and tissues using common fluorophores and can be implemented on standard wide-field or confocal systems.

  4. Nonlinear modeling and dynamic analysis of a hydro-turbine governing system in the process of sudden load increase transient

    Science.gov (United States)

    Li, Huanhuan; Chen, Diyi; Zhang, Hao; Wang, Feifei; Ba, Duoduo

    2016-12-01

    In order to study the nonlinear dynamic behaviors of a hydro-turbine governing system in the process of sudden load increase transient, we establish a novel nonlinear dynamic model of the hydro-turbine governing system which considers the elastic water-hammer model of the penstock and the second-order model of the generator. The six nonlinear dynamic transfer coefficients of the hydro-turbine are innovatively proposed by utilizing internal characteristics and analyzing the change laws of the characteristic parameters of the hydro-turbine governing system. Moreover, from the point of view of engineering, the nonlinear dynamic behaviors of the above system are exhaustively investigated based on bifurcation diagrams and time waveforms. More importantly, all of the above analyses supply theoretical basis for allowing a hydropower station to maintain a stable operation in the process of sudden load increase transient.

  5. Pole-placement self-tuning control of nonlinear Hammerstein system and its application to pH process control

    Institute of Scientific and Technical Information of China (English)

    Zhiyun Zou; Dandan Zhao; Xinghong Liu; Yuqing Guo; Chen Guan; Wenqiang Feng; Ning Guo

    2015-01-01

    By taking advantage of the separation characteristics of nonlinear gain and dynamic sector inside a Hammerstein model, a novel pole placement self tuning control scheme for nonlinear Hammerstein system was put forward based on the linear system pole placement self tuning control algorithm. And the nonlinear Hammerstein system pole placement self tuning control (NL-PP-STC) algorithm was presented in detail. The identification ability of its parameter estimation algorithm of NL-PP-STC was analyzed, which was always identifiable in closed loop. Two particular problems including the selection of poles and the on-line estimation of model parameters, which may be met in applications of NL-PP-STC to real process control, were discussed. The control simulation of a strong nonlinear pH neutralization process was carried out and good control performance was achieved.

  6. Separating iterative solution model of generalized nonlinear dynamic least squares for data processing in building of digital earth

    Institute of Scientific and Technical Information of China (English)

    陶华学; 郭金运

    2003-01-01

    Data coming from different sources have different types and temporal states. Relations between one type of data and another ones, or between data and unknown parameters are almost nonlinear. It is not accurate and reliable to process the data in building the digital earth with the classical least squares method or the method of the common nonlinear least squares. So a generalized nonlinear dynamic least squares method was put forward to process data in building the digital earth. A separating solution model and the iterative calculation method were used to solve the generalized nonlinear dynamic least squares problem. In fact, a complex problem can be separated and then solved by converting to two sub-problems, each of which has a single variable. Therefore the dimension of unknown parameters can be reduced to its half, which simplifies the original high dimensional equations.

  7. Global Existence and Blow-up of Solutions for Parabolic Systems Involving Cross-Diffusions and Nonlinear Boundary Conditions

    Institute of Scientific and Technical Information of China (English)

    Xiu Hui YANG; Fu Cai LI; Chun Hong XIE

    2005-01-01

    In this paper, we investigate the positive solutions of strongly coupled nonlinear parabolic systems with nonlinear boundary conditions:({ut-α(u,v)△u=g(u,v),vt-b(u,v)△v=h(u,v),(e)u/(e)(g)=d(u,v),(e)u/(e)(g)=f(u,v),)Under appropriate hypotheses on the functions a, b, g, h, d and f, we obtain that the solutions may exist globally or blow up in finite time by utilizing upper and lower solution techniques.

  8. On Critical Exponent for the Existence and Stability Properties of Positive Weak Solutions for some Nonlinear Elliptic Systems Involving the (, )-Laplacian and Indefinite Weight Function

    Indian Academy of Sciences (India)

    G A Afrouzi; J Vahidi

    2011-02-01

    This paper deals with the existence and stability properties of positive weak solutions to classes of nonlinear systems involving the $(p,q)$-Laplacian of the form \\begin{equation*}\\begin{cases}-_p u= a(x)v^-c, < x\\in,\\\\ -_qv= b(x)u^-c, < x\\in,\\\\ u=0=v, < x\\in,\\end{cases}\\end{equation*} where $_p$ denotes the -Laplacian operator defined by $_pz=\\mathrm{div}(|\

  9. Sensor fault diagnosis of nonlinear processes based on structured kernel principal component analysis

    Institute of Scientific and Technical Information of China (English)

    Kechang FU; Liankui DAI; Tiejun WU; Ming ZHU

    2009-01-01

    A new sensor fault diagnosis method based on structured kernel principal component analysis (KPCA) is proposed for nonlinear processes.By performing KPCA on subsets of variables,a set of structured residuals,i.e.,scaled powers of KPCA,can be obtained in the same way as partial PCA.The structured residuals are utilized in composing an isolation scheme for sensor fault diagnosis,according to a properly designed incidence matrix.Sensor fault sensitivity and critical sensitivity are defined,based on which an incidence matrix optimization algorithm is proposed to improve the performance of the structured KPCA.The effectiveness of the proposed method is demonstrated on the simulated continuous stirred tank reactor (CSTR) process.

  10. Nonlinear mechanisms to Rogue events in the process of interaction between optical filaments

    CERN Document Server

    Kovachev, L M

    2015-01-01

    We investigate two types of nonlinear interaction between collinear femtosecond laser pulses with power slightly above the critical for self-focusing $P_{cr}$. In the first case we study energy exchange between filaments. The model describes this process through degenerate four-photon parametric mixing (FPPM) scheme and requests initial phase difference between the waves. When there are no initial phase difference between the pulses, the FPPM process does not work. In this case it is obtained the second type of interaction as merging between two, three or four filaments in a single filament with higher power. It is found that in the second case the interflow between the filaments has potential of interaction due to cross-phase modulation (CPM).

  11. Improved Kernel PLS-based Fault Detection Approach for Nonlinear Chemical Processes

    Institute of Scientific and Technical Information of China (English)

    王丽; 侍洪波

    2014-01-01

    In this paper, an improved nonlinear process fault detection method is proposed based on modified ker-nel partial least squares (KPLS). By integrating the statistical local approach (SLA) into the KPLS framework, two new statistics are established to monitor changes in the underlying model. The new modeling strategy can avoid the Gaussian distribution assumption of KPLS. Besides, advantage of the proposed method is that the kernel latent variables can be obtained directly through the eigen value decomposition instead of the iterative calculation, which can improve the computing speed. The new method is applied to fault detection in the simulation benchmark of the Tennessee Eastman process. The simulation results show superiority on detection sensitivity and accuracy in com-parison to KPLS monitoring.

  12. Innovation as a Nonlinear Process, the Scientometric Perspective, and the Specification of an "Innovation Opportunities Explorer"

    CERN Document Server

    Leydesdorff, Loet; de Nooy, Wouter

    2012-01-01

    The process of innovation follows non-linear patterns across the domains of science, technology, and the economy. Novel bibliometric mapping techniques can be used to investigate and represent distinctive, but complementary perspectives on the innovation process (e.g., "demand" and "supply") as well as the interactions among these perspectives. The perspectives can be represented as "continents" of data related to varying extents over time. For example, the different branches of Medical Subject Headings (MeSH) in the Medline database provide sources of such perspectives (e.g., "Diseases" versus "Drugs and Chemicals"). The multiple-perspective approach enables us to reconstruct facets of the dynamics of innovation, in terms of selection mechanisms shaping localizable trajectories and/or resulting in more globalized regimes. By expanding the data with patents and scholarly publications, we demonstrate the use of this multi-perspective approach in the case of RNA Interference (RNAi). The possibility to develop a...

  13. Automated System of Study Nonlinear Processes in Electro-vacuum Devices with Open Resonant Periodic Structures

    Directory of Open Access Journals (Sweden)

    G.S. Vorobyov

    2014-04-01

    Full Text Available The article describes the experimental equipment and the results of investigations of nonlinear processes occurring during the excitation of electromagnetic oscillations in the resonant electron beam devices such as an orotron-generator of diffraction radiation. These devices are finding wide application in physics and microwave technology, now. A technique for experimental research, which bases on the using of the universal electro vacuum equipment diffraction radiation analyzer and the microprocessor system for collecting and processing data. The experimental investigations results of the energy and frequency characteristics for the most common modes of the excitation oscillations in the open resonant systems such as an orotron. The implementations on the optimum modes for the oscillations excitation in such devices were recommended.

  14. Nonlinear optical signal processing for high-speed, spectrally efficient fiber optic systems and networks

    Science.gov (United States)

    Zhang, Bo

    The past decade has witnessed astounding boom in telecommunication network traffic. With the emergence of multimedia over Internet, the high-capacity optical transport systems have started to shift focus from the core network towards the end users. This trend leads to diverse optical networks with transparency and reconfigurability requirement. As single channel data rate continues to increase and channel spacing continues to shrink for high capacity, high spectral efficiency, the workload on conventional electronic signal processing elements in the router nodes continues to build up. Performing signal processing functions in the optical domain can potentially alleviate the speed bottleneck if the unique optical properties are efficiently leveraged to assist electronic processing methodologies. Ultra-high bandwidth capability along with the promise for multi-channel and format-transparent operation make optical signal processing an attractive technology which is expected to have great impact on future optical networks. For optical signal processing applications in fiber-optic network and systems, a laudable goal would be to explore the unique nonlinear optical processes in novel photonic devices. This dissertation investigates novel optical signal processing techniques through simulations and experimental demonstrations, analyzes limitations of these nonlinear processing elements and proposes techniques to enhance the system performance or designs for functional photonic modules. Two key signal-processing building blocks for future optical networks, namely slow-light-based tunable optical delay lines and SOA-based high-speed wavelength converters, are presented in the first part of the dissertation. Phase preserving and spectrally efficient slow light are experimentally demonstrated using advanced modulation formats. Functional and novel photonic modules, such as multi-channel synchronizer and variable-bit-rate optical time division multiplexer are designed and

  15. Modeling and Compensatory Processes Underlying Involvement in Child Care among Kibbutz-Reared Fathers

    Science.gov (United States)

    Gaunt, Ruth; Bassi, Liat

    2012-01-01

    This study examined modeling and compensatory processes underlying the effects of an early paternal model on father involvement in child care. Drawing on social learning theory, it was hypothesized that father-son relationships would moderate the association between a father's involvement and his own father's involvement. A sample of 136 kibbutz…

  16. Accelerated Degradation Process Analysis Based on the Nonlinear Wiener Process with Covariates and Random Effects

    Directory of Open Access Journals (Sweden)

    Li Sun

    2016-01-01

    Full Text Available It is assumed that the drift parameter is dependent on the acceleration variables and the diffusion coefficient remains the same across the whole accelerated degradation test (ADT in most of the literature based on Wiener process. However, the diffusion coefficient variation would also become obvious in some applications with the stress increasing. Aiming at the phenomenon, the paper concludes that both the drift parameter and the diffusion parameter depend on stress variables based on the invariance principle of failure mechanism and Nelson assumption. Accordingly, constant stress accelerated degradation process (CSADP and step stress accelerated degradation process (SSADP with random effects are modeled. The unknown parameters in the established model are estimated based on the property of degradation and degradation increment, separately for CASDT and SSADT, by the maximum likelihood estimation approach with measurement error. In addition, the simulation steps of accelerated degradation data are provided and simulated step stress accelerated degradation data is designed to validate the proposed model compared to other models. Finally, a case study of CSADT is conducted to demonstrate the benefits of our model in the practical engineering.

  17. Phonon-assisted nonlinear optical processes in ultrashort-pulse pumped optical parametric amplifiers

    Science.gov (United States)

    Isaienko, Oleksandr; Robel, István

    2016-03-01

    Optically active phonon modes in ferroelectrics such as potassium titanyl phosphate (KTP) and potassium titanyl arsenate (KTA) in the ~7-20 THz range play an important role in applications of these materials in Raman lasing and terahertz wave generation. Previous studies with picosecond pulse excitation demonstrated that the interaction of pump pulses with phonons can lead to efficient stimulated Raman scattering (SRS) accompanying optical parametric oscillation or amplification processes (OPO/OPA), and to efficient polariton-phonon scattering. In this work, we investigate the behavior of infrared OPAs employing KTP or KTA crystals when pumped with ~800-nm ultrashort pulses of duration comparable to the oscillation period of the optical phonons. We demonstrate that under conditions of coherent impulsive Raman excitation of the phonons, when the effective χ(2) nonlinearity cannot be considered instantaneous, the parametrically amplified waves (most notably, signal) undergo significant spectral modulations leading to an overall redshift of the OPA output. The pump intensity dependence of the redshifted OPA output, the temporal evolution of the parametric gain, as well as the pump spectral modulations suggest the presence of coupling between the nonlinear optical polarizations PNL of the impulsively excited phonons and those of parametrically amplified waves.

  18. Tracking instantaneous entropy in heartbeat dynamics through inhomogeneous point-process nonlinear models.

    Science.gov (United States)

    Valenza, Gaetano; Citi, Luca; Scilingo, Enzo Pasquale; Barbieri, Riccardo

    2014-01-01

    Measures of entropy have been proved as powerful quantifiers of complex nonlinear systems, particularly when applied to stochastic series of heartbeat dynamics. Despite the remarkable achievements obtained through standard definitions of approximate and sample entropy, a time-varying definition of entropy characterizing the physiological dynamics at each moment in time is still missing. To this extent, we propose two novel measures of entropy based on the inho-mogeneous point-process theory. The RR interval series is modeled through probability density functions (pdfs) which characterize and predict the time until the next event occurs as a function of the past history. Laguerre expansions of the Wiener-Volterra autoregressive terms account for the long-term nonlinear information. As the proposed measures of entropy are instantaneously defined through such probability functions, the proposed indices are able to provide instantaneous tracking of autonomic nervous system complexity. Of note, the distance between the time-varying phase-space vectors is calculated through the Kolmogorov-Smirnov distance of two pdfs. Experimental results, obtained from the analysis of RR interval series extracted from ten healthy subjects during stand-up tasks, suggest that the proposed entropy indices provide instantaneous tracking of the heartbeat complexity, also allowing for the definition of complexity variability indices.

  19. Nonlinear supratransmission

    Energy Technology Data Exchange (ETDEWEB)

    Geniet, F; Leon, J [Physique Mathematique et Theorique, CNRS-UMR 5825, 34095 Montpellier (France)

    2003-05-07

    A nonlinear system possessing a natural forbidden band gap can transmit energy of a signal with a frequency in the gap, as recently shown for a nonlinear chain of coupled pendulums (Geniet and Leon 2002 Phys. Rev. Lett. 89 134102). This process of nonlinear supratransmission, occurring at a threshold that is exactly predictable in many cases, is shown to have a simple experimental realization with a mechanical chain of pendulums coupled by a coil spring. It is then analysed in more detail. First we go to different (nonintegrable) systems which do sustain nonlinear supratransmission. Then a Josephson transmission line (a one-dimensional array of short Josephson junctions coupled through superconducting wires) is shown to also sustain nonlinear supratransmission, though being related to a different class of boundary conditions, and despite the presence of damping, finiteness, and discreteness. Finally, the mechanism at the origin of nonlinear supratransmission is found to be a nonlinear instability, and this is briefly discussed here.

  20. Polyhedral-based nonlinear optical materials. 2. Theoretical investigation of some new high nonlinear optical response compounds involving polyhedral bridges with charged aromatic donors and acceptors.

    Science.gov (United States)

    Allis, D G; Spencer, J T

    2001-07-02

    A theoretical study of several new classes of polyhedral-based molecules has shown that these species display large calculated nonlinear optical responses. These new classes of molecules are based on charged aromatic subunits connected through polyhedral cluster bridges, such as closo-[1-(C(7)H(6))-12-(C(5)Me(4))C(2)B(10)H(10)]. These compounds show calculated first hyperpolarizabilities (beta) ranging from 6.5 to 8413.9 x 10(-30) cm(5) esu(-1). A basis for understanding the origin of these large responses is proposed based on the two-state model and consideration of the orbital and electronic features of the molecules. In general, the highest occupied molecular orbitals for these species are localized on the aromatic donor rings, such as the cyclopentadienyl system, while the lowest unoccupied molecular orbitals are largely on the aromatic acceptor rings, such as the tropylium system. The electronic properties of these polyhedral-based systems appear to be significantly different from the analogous organic [5.6.7]quinarene system (tropyliumcyclopentadienylbenzene). The organic quinarene appears to behave as a completely electron-delocalized system over all three rings while the polyhedral-based compounds can best be described as consisting of two relatively independent, highly polarized regions.

  1. Parametric Phase-sensitive and Phase-insensitive All-optical Signal Processing on Multiple Nonlinear Platforms - Invited talk

    DEFF Research Database (Denmark)

    Peucheret, Christophe; Da Ros, Francesco; Vukovic, Dragana;

    - compatible fabrication process, degrees of freedom in dispersion engineering, and high nonlinear coecient. However, the detrimental eect of free-carrier absorption induced by two-photon absorp- tion has so far prevented them from being used for the demonstration of phase-sensitive processing. Thanks...

  2. Dataset on coherent control of fields and induced currents in nonlinear multiphoton processes in a nanosphere.

    Science.gov (United States)

    McArthur, Duncan; Hourahine, Ben; Papoff, Francesco

    2015-11-24

    We model a scheme for the coherent control of light waves and currents in metallic nanospheres which applies independently of the nonlinear multiphoton processes at the origin of waves and currents. Using exact mathematical formulae, we calculate numerically with a custom fortran code the effect of an external control field which enable us to change the radiation pattern and suppress radiative losses or to reduce absorption, enabling the particle to behave as a perfect scatterer or as a perfect absorber. Data are provided in tabular, comma delimited value format and illustrate narrow features in the response of the particles that result in high sensitivity to small variations in the local environment, including subwavelength spatial shifts.

  3. Nonlinear Sagnac interferometer based on the four-wave mixing process.

    Science.gov (United States)

    Xin, Jun; Liu, Jinming; Jing, Jietai

    2017-01-23

    A new nonlinear Sagnac interferometer (NSI) is proposed by replacing the beam-splitter in the traditional Sagnac interferometer (TSI) with a four-wave mixing process. Such a NSI has better angular velocity sensitivity than the one of the TSI. The standard quantum limit can be beaten and the Heisenberg Limit can even be reached for the ideal case by the NSI. We study the effect of the losses on the angular velocity sensitivity of the NSI and find that the optimal angular velocity, where the best angular velocity sensitivity can be obtained, of the NSI may be dependent on the losses inside the interferometer. Such a NSI has its advantages compared with the TSI and may find its potential applications in quantum metrology.

  4. Nonlinear Transient Dynamics of Photoexcited Silicon Nanoantenna for Ultrafast All-Optical Signal Processing

    CERN Document Server

    Baranov, Denis G; Milichko, Valentin A; Kudryashov, Sergey I; Krasnok, Alexander E; Belov, Pavel A

    2016-01-01

    Optically generated electron-hole plasma in high-index dielectric nanostructures was demonstrated as a means of tuning of their optical properties. However, until now an ultrafast operation regime of such plasma driven nanostructures has not been attained. Here, we perform pump-probe experiments with resonant silicon nanoparticles and report on dense optical plasma generation near the magnetic dipole resonance with ultrafast (about 2.5 ps) relaxation rate. Basing on experimental results, we develop an analytical model describing transient response of a nanocrystalline silicon nanoparticle to an intense laser pulse and show theoretically that plasma induced optical nonlinearity leads to ultrafast reconfiguration of the scattering power pattern. We demonstrate 100 fs switching to unidirectional scattering regime upon irradiation of the nanoparticle by an intense femtosecond pulse. Our work lays the foundation for developing ultracompact and ultrafast all-optical signal processing devices.

  5. Nonlinear color-image decomposition for image processing of a digital color camera

    Science.gov (United States)

    Saito, Takahiro; Aizawa, Haruya; Yamada, Daisuke; Komatsu, Takashi

    2009-01-01

    This paper extends the BV (Bounded Variation) - G and/or the BV-L1 variational nonlinear image-decomposition approaches, which are considered to be useful for image processing of a digital color camera, to genuine color-image decomposition approaches. For utilizing inter-channel color cross-correlations, this paper first introduces TV (Total Variation) norms of color differences and TV norms of color sums into the BV-G and/or BV-L1 energy functionals, and then derives denoising-type decomposition-algorithms with an over-complete wavelet transform, through applying the Besov-norm approximation to the variational problems. Our methods decompose a noisy color image without producing undesirable low-frequency colored artifacts in its separated BV-component, and they achieve desirable high-quality color-image decomposition, which is very robust against colored random noise.

  6. Identification of Input Nonlinear Control Autoregressive Systems Using Fractional Signal Processing Approach

    Directory of Open Access Journals (Sweden)

    Naveed Ishtiaq Chaudhary

    2013-01-01

    Full Text Available A novel algorithm is developed based on fractional signal processing approach for parameter estimation of input nonlinear control autoregressive (INCAR models. The design scheme consists of parameterization of INCAR systems to obtain linear-in-parameter models and to use fractional least mean square algorithm (FLMS for adaptation of unknown parameter vectors. The performance analyses of the proposed scheme are carried out with third-order Volterra least mean square (VLMS and kernel least mean square (KLMS algorithms based on convergence to the true values of INCAR systems. It is found that the proposed FLMS algorithm provides most accurate and convergent results than those of VLMS and KLMS under different scenarios and by taking the low-to-high signal-to-noise ratio.

  7. Identification of Input Nonlinear Control Autoregressive Systems Using Fractional Signal Processing Approach

    Science.gov (United States)

    Chaudhary, Naveed Ishtiaq; Raja, Muhammad Asif Zahoor; Khan, Junaid Ali; Aslam, Muhammad Saeed

    2013-01-01

    A novel algorithm is developed based on fractional signal processing approach for parameter estimation of input nonlinear control autoregressive (INCAR) models. The design scheme consists of parameterization of INCAR systems to obtain linear-in-parameter models and to use fractional least mean square algorithm (FLMS) for adaptation of unknown parameter vectors. The performance analyses of the proposed scheme are carried out with third-order Volterra least mean square (VLMS) and kernel least mean square (KLMS) algorithms based on convergence to the true values of INCAR systems. It is found that the proposed FLMS algorithm provides most accurate and convergent results than those of VLMS and KLMS under different scenarios and by taking the low-to-high signal-to-noise ratio. PMID:23853538

  8. Nonlinear control of an activated sludge aeration process: use of fuzzy techniques for tuning PID controllers.

    Science.gov (United States)

    Rodrigo, M A; Seco, A; Ferrer, J; Penya-roja, J M; Valverde, J L

    1999-01-01

    In this paper, several tuning algorithms, specifically ITAE, IMC and Cohen and Coon, were applied in order to tune an activated sludge aeration PID controller. Performance results of these controllers were compared by simulation with those obtained by using a nonlinear fuzzy PID controller. In order to design this controller, a trial and error procedure was used to determine, as a function of error at current time and at a previous time, sets of parameters (including controller gain, integral time and derivative time) which achieve satisfactory response of a PID controller actuating over the aeration process. Once these sets of data were obtained, neural networks were used to obtain fuzzy membership functions and fuzzy rules of the fuzzy PID controller.

  9. Non-linear multivariable predictive control of an alcoholic fermentation process using functional link networks

    Directory of Open Access Journals (Sweden)

    Luiz Augusto da Cruz Meleiro

    2005-06-01

    Full Text Available In this work a MIMO non-linear predictive controller was developed for an extractive alcoholic fermentation process. The internal model of the controller was represented by two MISO Functional Link Networks (FLNs, identified using simulated data generated from a deterministic mathematical model whose kinetic parameters were determined experimentally. The FLN structure presents as advantages fast training and guaranteed convergence, since the estimation of the weights is a linear optimization problem. Besides, the elimination of non-significant weights generates parsimonious models, which allows for fast execution in an MPC-based algorithm. The proposed algorithm showed good potential in identification and control of non-linear processes.Neste trabalho um controlador preditivo não linear multivariável foi desenvolvido para um processo de fermentação alcoólica extrativa. O modelo interno do controlador foi representado por duas redes do tipo Functional Link (FLN, identificadas usando dados de simulação gerados a partir de um modelo validado experimentalmente. A estrutura FLN apresenta como vantagem o treinamento rápido e convergência garantida, já que a estimação dos seus pesos é um problema de otimização linear. Além disso, a eliminação de pesos não significativos gera modelos parsimoniosos, o que permite a rápida execução em algoritmos de controle preditivo baseado em modelo. Os resultados mostram que o algoritmo proposto tem grande potencial para identificação e controle de processos não lineares.

  10. In-TFT-Array-Process Micro Defect Inspection Using Nonlinear Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    Zhi-Hao Kang

    2009-10-01

    Full Text Available Defect inspection plays a critical role in thin film transistor liquid crystal display (TFT-LCD manufacture, and has received much attention in the field of automatic optical inspection (AOI. Previously, most focus was put on the problems of macro-scale Mura-defect detection in cell process, but it has recently been found that the defects which substantially influence the yield rate of LCD panels are actually those in the TFT array process, which is the first process in TFT-LCD manufacturing. Defect inspection in TFT array process is therefore considered a difficult task. This paper presents a novel inspection scheme based on kernel principal component analysis (KPCA algorithm, which is a nonlinear version of the well-known PCA algorithm. The inspection scheme can not only detect the defects from the images captured from the surface of LCD panels, but also recognize the types of the detected defects automatically. Results, based on real images provided by a LCD manufacturer in Taiwan, indicate that the KPCA-based defect inspection scheme is able to achieve a defect detection rate of over 99% and a high defect classification rate of over 96% when the imbalanced support vector machine (ISVM with 2-norm soft margin is employed as the classifier. More importantly, the inspection time is less than 1 s per input image.

  11. Active and Purely Dissipative Nambu Systems in General Thermostatistical Settings Described by Nonlinear Partial Differential Equations Involving Generalized Entropy Measures

    Directory of Open Access Journals (Sweden)

    T. D. Frank

    2016-12-01

    Full Text Available In physics, several attempts have been made to apply the concepts and tools of physics to the life sciences. In this context, a thermostatistic framework for active Nambu systems is proposed. The so-called free energy Fokker–Planck equation approach is used to describe stochastic aspects of active Nambu systems. Different thermostatistic settings are considered that are characterized by appropriately-defined entropy measures, such as the Boltzmann–Gibbs–Shannon entropy and the Tsallis entropy. In general, the free energy Fokker–Planck equations associated with these generalized entropy measures correspond to nonlinear partial differential equations. Irrespective of the entropy-related nonlinearities occurring in these nonlinear partial differential equations, it is shown that semi-analytical solutions for the stationary probability densities of the active Nambu systems can be obtained provided that the pumping mechanisms of the active systems assume the so-called canonical-dissipative form and depend explicitly only on Nambu invariants. Applications are presented both for purely-dissipative and for active systems illustrating that the proposed framework includes as a special case stochastic equilibrium systems.

  12. Intelligent non-linear modelling of an industrial winding process using recurrent local linear neuro-fuzzy networks

    Institute of Scientific and Technical Information of China (English)

    Hasan ABBASI NOZARI; Hamed DEHGHAN BANADAKI; Mohammad MOKHTARE; Somaveh HEKMATI VAHED

    2012-01-01

    This study deals with the neuro-fuzzy (NF) modelling of a real industrial winding process in which the acquired NF model can be exploited to improve control performance and achieve a robust fault-tolerant system.A new simulator model is proposed for a winding process using non-linear identification based on a recurrent local linear neuro-fuzzy (RLLNF) network trained by local linear model tree (LOLIMOT),which is an incremental tree-based learning algorithm.The proposed NF models are compared with other known intelligent identifiers,namely multilayer perceptron (MLP) and radial basis function (RBF).Comparison of our proposed non-linear models and associated models obtained through the least square error (LSE) technique (the optimal modelling method for linear systems) confirms that the winding process is a non-linear system.Experimental results show the effectiveness of our proposed NF modelling approach.

  13. A Model Predictive Algorithm for Active Control of Nonlinear Noise Processes

    Directory of Open Access Journals (Sweden)

    Qi-Zhi Zhang

    2005-01-01

    Full Text Available In this paper, an improved nonlinear Active Noise Control (ANC system is achieved by introducing an appropriate secondary source. For ANC system to be successfully implemented, the nonlinearity of the primary path and time delay of the secondary path must be overcome. A nonlinear Model Predictive Control (MPC strategy is introduced to deal with the time delay in the secondary path and the nonlinearity in the primary path of the ANC system. An overall online modeling technique is utilized for online secondary path and primary path estimation. The secondary path is estimated using an adaptive FIR filter, and the primary path is estimated using a Neural Network (NN. The two models are connected in parallel with the two paths. In this system, the mutual disturbances between the operation of the nonlinear ANC controller and modeling of the secondary can be greatly reduced. The coefficients of the adaptive FIR filter and weight vector of NN are adjusted online. Computer simulations are carried out to compare the proposed nonlinear MPC method with the nonlinear Filter-x Least Mean Square (FXLMS algorithm. The results showed that the convergence speed of the proposed nonlinear MPC algorithm is faster than that of nonlinear FXLMS algorithm. For testing the robust performance of the proposed nonlinear ANC system, the sudden changes in the secondary path and primary path of the ANC system are considered. Results indicated that the proposed nonlinear ANC system can rapidly track the sudden changes in the acoustic paths of the nonlinear ANC system, and ensure the adaptive algorithm stable when the nonlinear ANC system is time variable.

  14. Schwinger-Dyson equations in large-N quantum field theories and nonlinear random processes

    CERN Document Server

    Buividovich, P V

    2010-01-01

    We study stochastic methods for solving Schwinger-Dyson equations in large-N quantum field theories. Expectation values of single-trace operators are sampled by stationary probability distributions of so-called nonlinear random processes. The set of all histories of such processes corresponds to the set of all planar diagrams in the perturbative expansion of the theory. We describe stochastic algorithms for summation of planar diagrams in matrix-valued scalar field theory and in the Weingarten model of random planar surfaces on the lattice. For compact field variables, the method does not converge in the physically most interesting weak-coupling limit. In this case one can absorb the divergences into the self-consistent redefinition of expansion parameters. Stochastic solution of the self-consistency conditions can be implemented as a random process with memory. We illustrate this idea on the example of two-dimensional O(N) sigma-model. Extension to non-Abelian lattice gauge theories is discussed.

  15. Mild solutions for a problem involving fractional derivatives in the nonlinearity and in the non-local conditions

    Directory of Open Access Journals (Sweden)

    Tatar Nasser-eddine

    2011-01-01

    Full Text Available Abstract A second-order abstract problem of neutral type with derivatives of non-integer order in the nonlinearity as well as in the nonlocal conditions is investigated. This model covers many of the existing models in the literature. It extends the integer order case to the fractional case in the sense of Caputo. A fixed point theorem is used to prove existence of mild solutions. AMS Subject Classification 26A33, 34K40, 35L90, 35L70, 35L15, 35L07

  16. Reading for Repetition and Reading for Translation: Do They Involve the Same Processes?

    Science.gov (United States)

    Macizo, Pedro; Bajo, M. Teresa

    2006-01-01

    Theories of translation differ in the role assigned to the reformulation process. One view, the ''horizontal'' approach, considers that translation involves on-line searches for matches between linguistic entries in the two languages involved [Gerver, D. (1976). Empirical studies of simultaneous interpretation: A review and a model. In R. W.…

  17. The Nature of Parental Involvement in the Schooling Process in Katsina State

    Science.gov (United States)

    Ibrahim, Ahmed Tijjani; Jamil, Hazri Bin

    2012-01-01

    Parental involvement in the schooling process of their children seems to be a neglected research area especially in primary schools of Katsina state in Nigeria. Parental involvement as envisaged by Donald, Lazarus and Lolwana (2006) for purposes of transformation cannot be overemphasized by both parents and teachers in schools. Therefore, parents…

  18. EGS Richardson AGU Chapman NVAG3 Conference: Nonlinear Variability in Geophysics: scaling and multifractal processes

    Science.gov (United States)

    Schertzer, D.; Lovejoy, S.

    1. The conference The third conference on "Nonlinear VAriability in Geophysics: scaling and multifractal processes" (NVAG 3) was held in Cargese, Corsica, Sept. 10-17, 1993. NVAG3 was joint American Geophysical Union Chapman and European Geophysical Society Richardson Memorial conference, the first specialist conference jointly sponsored by the two organizations. It followed NVAG1 (Montreal, Aug. 1986), NVAG2 (Paris, June 1988; Schertzer and Lovejoy, 1991), five consecutive annual sessions at EGS general assemblies and two consecutive spring AGU meeting sessions. As with the other conferences and workshops mentioned above, the aim was to develop confrontation between theories and experiments on scaling/multifractal behaviour of geophysical fields. Subjects covered included climate, clouds, earthquakes, atmospheric and ocean dynamics, tectonics, precipitation, hydrology, the solar cycle and volcanoes. Areas of focus included new methods of data analysis (especially those used for the reliable estimation of multifractal and scaling exponents), as well as their application to rapidly growing data bases from in situ networks and remote sensing. The corresponding modelling, prediction and estimation techniques were also emphasized as were the current debates about stochastic and deterministic dynamics, fractal geometry and multifractals, self-organized criticality and multifractal fields, each of which was the subject of a specific general discussion. The conference started with a one day short course of multifractals featuring four lectures on a) Fundamentals of multifractals: dimension, codimensions, codimension formalism, b) Multifractal estimation techniques: (PDMS, DTM), c) Numerical simulations, Generalized Scale Invariance analysis, d) Advanced multifractals, singular statistics, phase transitions, self-organized criticality and Lie cascades (given by D. Schertzer and S. Lovejoy, detailed course notes were sent to participants shortly after the conference). This

  19. EGS Richardson AGU Chapman NVAG3 Conference: Nonlinear Variability in Geophysics: scaling and multifractal processes

    Directory of Open Access Journals (Sweden)

    D. Schertzer

    1994-01-01

    Full Text Available 1. The conference The third conference on "Nonlinear VAriability in Geophysics: scaling and multifractal processes" (NVAG 3 was held in Cargese, Corsica, Sept. 10-17, 1993. NVAG3 was joint American Geophysical Union Chapman and European Geophysical Society Richardson Memorial conference, the first specialist conference jointly sponsored by the two organizations. It followed NVAG1 (Montreal, Aug. 1986, NVAG2 (Paris, June 1988; Schertzer and Lovejoy, 1991, five consecutive annual sessions at EGS general assemblies and two consecutive spring AGU meeting sessions. As with the other conferences and workshops mentioned above, the aim was to develop confrontation between theories and experiments on scaling/multifractal behaviour of geophysical fields. Subjects covered included climate, clouds, earthquakes, atmospheric and ocean dynamics, tectonics, precipitation, hydrology, the solar cycle and volcanoes. Areas of focus included new methods of data analysis (especially those used for the reliable estimation of multifractal and scaling exponents, as well as their application to rapidly growing data bases from in situ networks and remote sensing. The corresponding modelling, prediction and estimation techniques were also emphasized as were the current debates about stochastic and deterministic dynamics, fractal geometry and multifractals, self-organized criticality and multifractal fields, each of which was the subject of a specific general discussion. The conference started with a one day short course of multifractals featuring four lectures on a Fundamentals of multifractals: dimension, codimensions, codimension formalism, b Multifractal estimation techniques: (PDMS, DTM, c Numerical simulations, Generalized Scale Invariance analysis, d Advanced multifractals, singular statistics, phase transitions, self-organized criticality and Lie cascades (given by D. Schertzer and S. Lovejoy, detailed course notes were sent to participants shortly after the

  20. Extreme-Point Symmetric Mode Decomposition Method for Nonlinear and Non-Stationary Signal Processing

    CERN Document Server

    Wang, Jin-Liang

    2013-01-01

    To process nonlinear and non-stationary signals, an extreme-point symmetric mode decomposition (ESMD) method is developed. It can be seen as a new alternate of the well-known Hilbert-Huang transform (HHT) method which is widely used nowadays. There are two parts for it. The first part is the decomposition approach which yields a series of intrinsic mode functions (IMFs) together with an optimal adaptive global mean (AGM) curve, the second part is the direct interpolating (DI) approach which yields instantaneous amplitudes and frequencies for the IMFs together with a time-varying energy. Relative to the HHT method it has five characteristics as follows: (1) Different from constructing 2 outer envelopes, its sifting process is implemented by the aid of 1, 2 or 3 inner interpolating curves; (2) It does not decompose the signal to the last trend curve with at most one extreme point, it optimizes the residual component to be an optimal AGM curve which possesses a certain number of extreme points; (3) Its symmetry ...

  1. Fundamental nonlinearities of the reactor-settler interaction in the activated sludge process.

    Science.gov (United States)

    Diehl, Stefan; Farås, Sebastian

    2012-01-01

    The activated sludge process can be modelled by ordinary and partial differential equations for the biological reactors and secondary settlers, respectively. Because of the complexity of such a system, simulation models are most often used to investigate them. However, simulation models cannot give general rules on how to control a complex nonlinear process. For a reduced-order model with only two components, soluble substrate and particulate biomass, general results on steady-state solutions have recently been obtained, such as existence, uniqueness and stability of solutions. The aim of the present paper is to utilize those results to formulate some implications of practical importance. In particular, strategies are described for the manual control of the effluent substrate concentration subject to the constraint that the settler is maintained in normal operation (with a sludge blanket in the thickening zone) in steady state. Such strategies contain how the two control parameters, the recycle and waste volumetric flow ratios, should be chosen for any (steady-state) values of the input variables.

  2. Towards information processing from nonlinear physical chemistry: a synthetic electrochemical cognitive system.

    Science.gov (United States)

    Sadeghi, Saman; Thompson, Michael

    2010-01-01

    It is evident that complex animate materials, which operate far from equilibrium, exhibit sensory responses to the environment through emergent patterns. Formation of such patterns is often the underlying mechanism of an active response to environmental changes and can be interpreted as a result of the distributed parallel information processing taking place within the material. Such emergent patterns are not limited to biological entities; indeed there is a wide range of complex nonlinear dissipative systems which exhibit interesting emergent patterns within a range of parameters. As one example, the present paper describes the detection of emergent phenomena associated with surface electrochemical processes that allow the system to respond to input information through evolving patterns in space and time. Associative mapping of this sort offers the opportunity to devise an electrochemical cognitive system (ECS), where pattern formation can be looked at as a macroscopic phenomenon resulting from the extensive distributive computing that occurs at the microscopic level. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  3. Growth of single crystals of organic salts with large second-order optical nonlinearities by solution processes for devices

    Science.gov (United States)

    Leslie, Thomas M.

    1995-01-01

    Data obtained from the electric field induced second harmonic generation (EFISH) and Kurtz Powder Methods will be provided to MSFC for further refinement of their method. A theoretical model for predicting the second-order nonlinearities of organic salts is being worked on. Another task is the synthesis of a number of salts with various counterions. Several salts with promising SHG activities and new salts will be tested for the presence of two crystalline forms. The materials will be recrystallized from dry and wet solvents and compared for SHG efficiency. Salts that have a high SHG efficiency and no tendency to form hydrates will be documented. The synthesis of these materials are included in this report. A third task involves method to aid in the growth of large, high quality single crystals by solution processes. These crystals will be characterized for their applicability in the fabrication of devices that will be incorporated into optical computers in future programs. Single crystals of optimum quality may be obtained by crystal growth in low-gravity. The final task is the design of a temperature lowering single crystal growth apparatus for ground based work. At least one prototype will be built.

  4. Nonlinear PI Control with Adaptive Interaction Algorithm for Multivariable Wastewater Treatment Process

    Directory of Open Access Journals (Sweden)

    S. I. Samsudin

    2014-01-01

    Full Text Available The wastewater treatment plant (WWTP is highly known with the nonlinearity of the control parameters, thus it is difficult to be controlled. In this paper, the enhancement of nonlinear PI controller (ENon-PI to compensate the nonlinearity of the activated sludge WWTP is proposed. The ENon-PI controller is designed by cascading a sector-bounded nonlinear gain to linear PI controller. The rate variation of the nonlinear gain kn is automatically updated based on adaptive interaction algorithm. Initiative to simplify the ENon-PI control structure by adapting kn has been proved by significant improvement under various dynamic influents. More than 30% of integral square error and 14% of integral absolute error are reduced compared to benchmark PI for DO control and nitrate in nitrogen removal control. Better average effluent qualities, less number of effluent violations, and lower aeration energy consumption resulted.

  5. ELF Nonlinear Noise Processing Experimental Measurements, Part 2 - Synoptic Sample of Diurnal and Seasonal Noise Variation in Norway

    Science.gov (United States)

    1976-10-29

    clipping level. The nonlinear processing method described in this report provides at least 10 dB of S/N improvement over the performance obtained without...0001s Ii 0110 151 to-, ,n o 151. 1 iK) Il O( M I ( lf clipper performance was also eviden -t in the January 1974 data. Table 7 contains statisti- cal

  6. A Physics-driven Neural Networks-based Simulation System (PhyNNeSS) for multimodal interactive virtual environments involving nonlinear deformable objects.

    Science.gov (United States)

    De, Suvranu; Deo, Dhannanjay; Sankaranarayanan, Ganesh; Arikatla, Venkata S

    2011-08-01

    BACKGROUND: While an update rate of 30 Hz is considered adequate for real time graphics, a much higher update rate of about 1 kHz is necessary for haptics. Physics-based modeling of deformable objects, especially when large nonlinear deformations and complex nonlinear material properties are involved, at these very high rates is one of the most challenging tasks in the development of real time simulation systems. While some specialized solutions exist, there is no general solution for arbitrary nonlinearities. METHODS: In this work we present PhyNNeSS - a Physics-driven Neural Networks-based Simulation System - to address this long-standing technical challenge. The first step is an off-line pre-computation step in which a database is generated by applying carefully prescribed displacements to each node of the finite element models of the deformable objects. In the next step, the data is condensed into a set of coefficients describing neurons of a Radial Basis Function network (RBFN). During real-time computation, these neural networks are used to reconstruct the deformation fields as well as the interaction forces. RESULTS: We present realistic simulation examples from interactive surgical simulation with real time force feedback. As an example, we have developed a deformable human stomach model and a Penrose-drain model used in the Fundamentals of Laparoscopic Surgery (FLS) training tool box. CONCLUSIONS: A unique computational modeling system has been developed that is capable of simulating the response of nonlinear deformable objects in real time. The method distinguishes itself from previous efforts in that a systematic physics-based pre-computational step allows training of neural networks which may be used in real time simulations. We show, through careful error analysis, that the scheme is scalable, with the accuracy being controlled by the number of neurons used in the simulation. PhyNNeSS has been integrated into SoFMIS (Software Framework for Multimodal

  7. The approaches to the definition of involvement and to types of companies-customers involvement in decision-making process

    Directory of Open Access Journals (Sweden)

    M.Yu. Troian

    2011-10-01

    Full Text Available The approaches to the definition of involvement and toits basic types classification are developed. The classification of types of companies-customers involvement is supplemented. The concept of connotative involvement is defined and scientifically proven. The basic properties of the involvement: the intensity, directionandstability are developed.

  8. 3D modelling of non-linear visco-elasto-plastic crustal and lithospheric processes using LaMEM

    Science.gov (United States)

    Popov, Anton; Kaus, Boris

    2016-04-01

    LaMEM (Lithosphere and Mantle Evolution Model) is a three-dimensional thermo-mechanical numerical code to simulate crustal and lithospheric deformation. The code is based on a staggered finite difference (FDSTAG) discretization in space, which is a stable and very efficient technique to solve the (nearly) incompressible Stokes equations that does not suffer from spurious pressure modes or artificial compressibility (a typical feature of low-order finite element techniques). Higher order finite element methods are more accurate than FDSTAG methods under idealized test cases where the jump in viscosity is exactly aligned with the boundaries of the elements. Yet, geodynamically more realistic cases involve evolving subduction zones, nonlinear rheologies or localized plastic shear bands. In these cases, the viscosity pattern evolves spontaneously during a simulation or even during nonlinear iterations, and the advantages of higher order methods disappear and they all converge with approximately first order accuracy, similar to that of FDSTAG [1]. Yet, since FDSTAG methods have considerably less degrees of freedom than quadratic finite element methods, they require about an order of magnitude less memory for the same number of nodes in 3D which also implies that every matrix-vector multiplication is significantly faster. LaMEM is build on top of the PETSc library and uses the particle-in-cell technique to track material properties, history variables which makes it straightforward to incorporate effects like phase changes or chemistry. An internal free surface is present, together with (simple) erosion and sedimentation processes, and a number of methods are available to import complex geometries into the code (e.g, http://geomio.bitbucket.org). Customized Galerkin coupled geometric multigrid preconditioners are implemented which resulted in a good parallel scalability of the code (we have tested LaMEM on 458'752 cores [2]). Yet, the drawback of using FDSTAG

  9. Grid Size Selection for Nonlinear Least-Squares Optimization in Spectral Estimation and Array Processing

    DEFF Research Database (Denmark)

    Nielsen, Jesper Kjær; Jensen, Tobias Lindstrøm; Jensen, Jesper Rindom;

    2016-01-01

    time. Additionally, we show via three common examples how the grid size depends on parameters such as the number of data points or the number of sensors in DOA estimation. We also demonstrate that the computation time can potentially be lowered by several orders of magnitude by combining a coarse grid......In many spectral estimation and array processing problems, the process of finding estimates of model parameters often involves the optimisation of a cost function containing multiple peaks and dips. Such non-convex problems are hard to solve using traditional optimisation algorithms developed...

  10. Growth of thin films of organic nonlinear optical materials by vapor growth processes - An overview and examination of shortfalls

    Science.gov (United States)

    Frazier, D. O.; Penn, B. G.; Witherow, W. K.; Paley, M. S.

    1991-01-01

    Research on the growth of second- and third-order nonlinear optical (NLO) organic thin film by vapor deposition is reviewed. Particular attention is given to the experimental methods for growing thin films of p-chlorophenylurea, diacetylenes, and phthalocyanines; characteristics of the resulting films; and approaches for advancing thin film technology. It is concluded that the growth of NLO thin films by vapor processes is a promising method for the fabrication of planar waveguides for nonlinear optical devices. Two innovative approaches are proposed including a method of controlling the input beam frequency to maximize nonlinear effects in thin films and single crystals, and the alternate approach to the molecular design of organic NLO materials by increasing the transition dipole moment between ground and excited states of the molecule.

  11. Optimal Constant-Stress Accelerated Degradation Test Plans Using Nonlinear Generalized Wiener Process

    Directory of Open Access Journals (Sweden)

    Zhen Chen

    2016-01-01

    Full Text Available Accelerated degradation test (ADT has been widely used to assess highly reliable products’ lifetime. To conduct an ADT, an appropriate degradation model and test plan should be determined in advance. Although many historical studies have proposed quite a few models, there is still room for improvement. Hence we propose a Nonlinear Generalized Wiener Process (NGWP model with consideration of the effects of stress level, product-to-product variability, and measurement errors for a higher estimation accuracy and a wider range of use. Then under the constraints of sample size, test duration, and test cost, the plans of constant-stress ADT (CSADT with multiple stress levels based on the NGWP are designed by minimizing the asymptotic variance of the reliability estimation of the products under normal operation conditions. An optimization algorithm is developed to determine the optimal stress levels, the number of units allocated to each level, inspection frequency, and measurement times simultaneously. In addition, a comparison based on degradation data of LEDs is made to show better goodness-of-fit of the NGWP than that of other models. Finally, optimal two-level and three-level CSADT plans under various constraints and a detailed sensitivity analysis are demonstrated through examples in this paper.

  12. New Space Weather and Nonlinear Waves and Processes Prize announced for 2013

    Science.gov (United States)

    Thompson, Victoria

    2012-01-01

    At the 2011 Fall Meeting in San Francisco, Calif., AGU announced the creation of a new award: the Space Weather and Nonlinear Waves and Processes Prize. The prize, which is being made possible by a generous contribution from longtime AGU members and NASA Jet Propulsion Laboratory (JPL), California Institute of Technology, scientists Bruce Tsurutani and Olga Verkhoglyadova, will recognize an AGU member scientist and will come with a $10,000 award. Tsurutani has served as a researcher with JPL since 1972 and is currently a senior research scientist. He was also the president of AGU's Space Physics and Aeronomy section from 1990 to 1992 and is a recipient of AGU's John Adam Fleming Medal, given “for original research and technical leadership in geomagnetism, atmospheric electricity, aeronomy, space physics, and related sciences.” Verkhoglyadova served as a professor of space physics in the Department of Astrophysics and Space Physics at Taras Shevchenko National University of Kyiv, in the Ukraine, prior to coming to the United States. Their leadership and dedication to AGU and to their field are apparent in their passion for this prize.

  13. Three novel high-resolution nonlinear methods for fast signal processing

    Science.gov (United States)

    Belkić, Dž.; Dando, P. A.; Main, J.; Taylor, H. S.

    2000-10-01

    Three novel nonlinear parameter estimators are devised and implemented for accurate and fast processing of experimentally measured or theoretically generated time signals of arbitrary length. The new techniques can also be used as powerful tools for diagonalization of large matrices that are customarily encountered in quantum chemistry and elsewhere. The key to the success and the common denominator of the proposed methods is a considerably reduced dimensionality of the original data matrix. This is achieved in a preprocessing stage called beamspace windowing or band-limited decimation. The methods are decimated signal diagonalization (DSD), decimated linear predictor (DLP), and decimated Padé approximant (DPA). Their mutual equivalence is shown for the signals that are modeled by a linear combination of time-dependent damped exponentials with stationary amplitudes. The ability to obtain all the peak parameters first and construct the required spectra afterwards enables the present methods to phase correct the absorption mode. Additionally, a new noise reduction technique, based upon the stabilization method from resonance scattering theory, is proposed. The results obtained using both synthesized and experimental time signals show that DSD/DLP/DPA exhibit an enhanced resolution power relative to the standard fast Fourier transform. Of the three methods, DPA is found to be the most efficient computationally.

  14. Energy conversion in isothermal nonlinear irreversible processes - struggling for higher efficiency

    Science.gov (United States)

    Ebeling, W.; Feistel, R.

    2017-06-01

    First we discuss some early work of Ulrike Feudel on structure formation in nonlinear reactions including ions and the efficiency of the conversion of chemical into electrical energy. Then we give some survey about isothermal energy conversion from chemical to higher forms of energy like mechanical, electrical and ecological energy. Isothermal means here that there are no temperature gradients within the model systems. We consider examples of energy conversion in several natural processes and in some devices like fuel cells. Further, as an example, we study analytically the dynamics and efficiency of a simple "active circuit" converting chemical into electrical energy and driving currents which is roughly modeling fuel cells. Finally we investigate an analogous ecological system of Lotka-Volterra type consisting of an "active species" consuming some passive "chemical food". We show analytically for both these models that the efficiency increases with the load, reaches values higher then 50 percent in a narrow regime of optimal load and goes beyond some maximal load abruptly to zero.

  15. Does the cerebral cortex exploit high dimensional, non-linear dynamics for information processing?

    Directory of Open Access Journals (Sweden)

    Wolf Singer

    2016-09-01

    Full Text Available The discovery of stimulus induced synchronisation in the visual cortex suggested the possibility that the relations among low-level stimulus features are encoded by the temporal relationship between neuronal discharges. In this framework, temporal coherence is considered a signature of perceptual grouping. This insight triggered a large number of experimental studies which sought to investigate the relationship between temporal coordination and cognitive functions. While some core predictions derived from the initial hypothesis were confirmed, these studies, also revealed a rich dynamical landscape beyond simple coherence whose role in signal processing is still poorly understood. In this paper a framework is presented which establishes links between the various manifestations of cortical dynamics by assigning specific coding functions to low dimensional dynamic features such as synchronized oscillations and phase shifts on the one hand and high dimensional non-linear, non-stationary dynamics on the other. The data serving as basis for this synthetic approach have been obtained with chronic multisite recordings from the visual cortex of anesthetized cats and from monkeys trained to solve cognitive tasks. It is proposed that the low dimensional dynamics characterized by synchronized oscillations and large-scale correlations are sub-states that represent the results of computations performed in the high dimensional state space provided by recurrently coupled networks.

  16. Nonlinear Dynamics of Photonics for Optical Signal Processing - Optical Frequency Conversion and Optical DSB-to-SSB Conversion

    Science.gov (United States)

    2015-09-17

    processing - optical frequency conversion and optical DSB -to-SSB conversion 5a. CONTRACT NUMBER FA2386-14-1-0006 5b. GRANT NUMBER Grant 134113...nonlinear dynamics of semiconductor lasers for certain optical signal processing functionalities, including optical DSB -to-SSB conversion, photonic...conversion and optical DSB -to-SSB conversion Performance Period May 30, 2014 ~ May 29, 2015 Principal Investigator Name: Sheng-Kwang Hwang Position

  17. The Longitudinal Process of Early Parent Involvement on Student Achievement: A Path Analysis.

    Science.gov (United States)

    Hayakawa, Momoko; Englund, Michelle M; Warner-Richter, Mallory N; Reynolds, Arthur J

    2013-01-01

    This longitudinal study investigated the process whereby early parent involvement in preschool effects student achievement from kindergarten through 6(th) grade. Participants were 1,539 low-income, mainly African American children and their mothers, in the Chicago Longitudinal Study. Program children (N = 989) received one or two years of the Child-Parent Center (CPC) program - a preschool intervention that strongly promoted parents' development of parent involvement skills within the school and at home. Children from similar backgrounds who did not attend the CPC, but participated in available local resources (e.g. day care), were obtained as a comparison group (N = 550). Path analysis revealed an interactive process between parent involvement, academic achievement, and children's motivation. Early parent involvement directly influenced kindergarten achievement, which in turn influenced first grade student motivation. Highly motivated children then encouraged parents to continue involvement. The cyclic nature of this process across elementary school was observed. The model accounted for 61% of the variance in 6(th) grade achievement. Findings suggest that early parent involvement promoted in the CPC program, sets the stage for subsequent parent involvement, student motivation, and academic achievement throughout early and middle childhood.

  18. 基于核PLS方法的非线性过程在线监控%Online nonlinear process monitoring using kernel partial least squares

    Institute of Scientific and Technical Information of China (English)

    胡益; 王丽; 马贺贺; 侍洪波

    2011-01-01

    针对过程监控数据的非线性特点,提出了一种基于核偏最小二乘(KPLS)的监控方法.KPLS方法是将原始输入数据通过核函数映射到高维特征空间,然后在高维特征空间再进行偏最小二乘(PLS)运算.与线性PIS相比,KPLS方法能充分利用样本空间信息,建立起输入输出变量之间的非线性关系.与其他非线性PLS方法不同,KPLS方法只需要进行线性运算,从而避免非线性优化问题.在对过程进行监控时,首先采用KPLS方法建立模型,得到得分向量,然后计算出T2和SPE统计量及其相应的控制限.Tennessee Eastman (TE)模型上的仿真研究结果表明,所提方法比线性PLS方法具有更好的过程监控性能.%To handle the nonlinear problem for process monitoring, a new technique based on kernel partial least squares (KPLS) is developed. KPLS is an improved partial least squares (PLS) method, and its main idea is to first map the input space into a high-dimensional feature space via a nonlinear kernel function and then to use the standard PLS in that feature space. Compared to linear PLS, KPLS can make full use of the sample space information, and effectively capture the nonlinear relationship between input variables and output variables. Different from other nonlinear PLS, KPLS requires only linear algebra and does not involve any nonlinear optimization. For process data, firstly KPLS was used to derive regression model and got the score vectors, and then two statistics, T2 and SPE, and corresponding control limits were calculated. A case study of the Tennessee-Eastman (TE) process illustrated that the proposed approach showed superior process monitoring performance compared to linear PLS.

  19. [Non-equilibrium thermodynamic separation theory of nonlinear chromatography. II. The 0-1 model for nonlinear-mass transfer kinetic processes].

    Science.gov (United States)

    Liang, Heng; Jia, Zhenbin

    2007-11-01

    In the optimal design and control of preparative chromatographic processes, the obstacles appear when one tries to link the Wilson' s framework of chromatographic theories based on partial differential equations (PDEs) with the Eulerian presentation to optimal control approaches based on discrete time states, such as Markov decision processes (MDP) or Model predictive control (MPC). In this paper, the 0-1 model is presented to overcome the obstacles for nonlinear transport chromatography (NTC). With the Lagrangian-Eulerian description (L-ED), one solute cell unit is split into two solute cells, one (SCm) in the mobile phase with the linear velocity of the mobile phase, and the other (SCs) in the stationary phase with zero-velocity. The thermodynamic state vector, S(k), which comprises four vector components, i.e., the sequence number, the position and the local solute concentrations in both SCms and SCses, is introduced to describe the local thermodynamic path (LTP) and the macroscopical thermodynamic path (MTP). For the NTC, the LTP is designed for a solute zone to evolve from the state, S(k), to the virtual migration state, S(M), undergoing the virtual net migration sub-process, and then to the state, S(k+1), undergoing the virtual net inter phase mass transfer sub-process in a short time interval. Complete thermodynamic state iterations with the Markov characteristics are derived by using the local equilibrium isotherm and the local lumped mass transfer coefficient. When the local thermodynamic equilibrium is retained, excellent properties, such as consistency, stability, conservation, accuracy, etc., of the numerical solution of the 0-1 model are observed in the theoretical analysis and in the numerical experiments of the nonlinear ideal chromatography. It is found that the 0-1 model could properly link up with the MDP or optimal control approaches based on discrete time states.

  20. The Expansion of Dynamic Solving Process About a Class of Non-linear Programming Problems

    Institute of Scientific and Technical Information of China (English)

    ZANG Zhen-chun

    2001-01-01

    In this paper, we research non-linear programming problems which have a given specialstructure, some simple forms of this kind structure have been solved in some papers, here we focus on othercomplex ones.

  1. Identification of damage in a suspension component using narrowband and broadband nonlinear signal processing techniques

    Science.gov (United States)

    Haroon, Muhammad; Adams, Douglas E.

    2007-04-01

    Fatigue tests on a stabilizer bar link of an automotive suspension system are used to initiate a crack and grow the crack size. During these tests, slow sine sweeps are used to extract narrowband restoring forces across the stabilizer bar link. The restoring forces are shown to characterize the nonlinear changes in component internal forces due to crack growth. Broadband frequency response domain techniques are used to analyze the durability response data. Nonlinear frequency domain models of the dynamic transmissibility across the cracked region are shown to change as a function of crack growth. Higher order spectra are used to show the increase in nonlinear coupling of response frequency components with the appearance and growth of the crack. It is shown that crack growth can be detected and characterized by the changes in nonlinear indicators.

  2. The amount of ergonomics and user involvement in 151 design processes.

    Science.gov (United States)

    Kok, Barbara N E; Slegers, Karin; Vink, Peter

    2012-01-01

    Ergonomics, usability and user-centered design are terms that are well known among designers. Yet, products often seem to fail to meet the users' needs, resulting in a gap between expected and experienced usability. To understand the possible causes of this gap the actions taken by the designer during the design process are studied in this paper. This can show whether and how certain actions influence the user-friendliness of the design products. The aim of this research was to understand whether ergonomic principles and methods are included in the design process, whether users are involved in this process and whether the experience of the designer (in ergonomics/user involvement) has an effect on the end product usability. In this study the design processes of 151 tangible products of students in design were analyzed. It showed that in 75% of the cases some ergonomic principles were applied. User involvement was performed in only 1/3 of the design cases. Hardly any correlation was found between the designers' experience in ergonomic principles and the way they applied it and no correlations were found between the designers' experience in user involvement and the users' involvement in the design process.

  3. Discriminating Non-Linearity from Linearity: Its Cognitive Foundations in Five-Year-Olds

    Science.gov (United States)

    Ebersbach, Mirjam; Van Dooren, Wim; Goudriaan, Margje N.; Verschaffel, Lieven

    2010-01-01

    People often have difficulties in understanding situations that involve non-linear processes. Also, the topic of non-linear functions is introduced relatively late in the curriculum. Previous research has nevertheless shown that already children aged 6 years and older are able to discriminate non-linear from linear processes. Within the present…

  4. Uncovering Molecular Relaxation Processes with Nonlinear Spectroscopies in the Deep UV

    Science.gov (United States)

    West, Brantley Andrew

    Conical intersections mediate internal conversion dynamics that compete with even the fastest nuclear motions in molecular systems. Traditional kinetic models do not apply in this regime of commensurate electronic and nuclear motion because the surroundings do not maintain equilibrium throughout the relaxation process. This dissertation focuses on uncovering the physics associated with vibronic interactions at conical intersections. Of particular interest are coherent nuclear motions driven by steep excited state potential energy gradients. Technical advances have only recently made these dynamics accessible in many systems including DNA nucleobases and cyclic polyene molecules. Optical analogues of multidimensional NMR spectroscopies have recently yielded transformative insight in relaxation processes ranging from energy transfer in photosynthesis to bond making and breaking in liquids. Prior to the start of this research, such experiments had only been conducted at infrared and visible wavelengths. Applications in the ultraviolet were motivated by studies of numerous biological systems (e.g., DNA, proteins), but had been challenged by technical issues. The work presented in this dissertation combines pulse generation techniques developed in the optical physics community with spectroscopic techniques largely pioneered by physical chemists to implement two-dimensional ultraviolet spectroscopy (2DUV). This technique is applied at the shortest wavelengths and with the best signal-to-noise ratios reported to date. Sub-picosecond excited state deactivation processes provide photo stability to the DNA double helix. Vibrational energy transfer from the solute to surrounding solvent enables relaxation of the highly non-equilibrium ground state produced by fast internal conversion. In this dissertation, nonlinear spectroscopies carried out at cryogenic temperatures are used to uncover the particular nuclear modes in the solvent that primarily accept vibrational energy from

  5. The Longitudinal Process of Early Parent Involvement on Student Achievement: A Path Analysis

    OpenAIRE

    Hayakawa, Momoko; Englund, Michelle M.; Warner-Richter, Mallory N.; Reynolds, Arthur J.

    2013-01-01

    This longitudinal study investigated the process whereby early parent involvement in preschool effects student achievement from kindergarten through 6th grade. Participants were 1,539 low-income, mainly African American children and their mothers, in the Chicago Longitudinal Study. Program children (N = 989) received one or two years of the Child-Parent Center (CPC) program – a preschool intervention that strongly promoted parents' development of parent involvement skills within the school an...

  6. The purchase decision process and involvement of the elderly regarding nonprescription products.

    Science.gov (United States)

    Reisenwitz, T H; Wimbish, G J

    1997-01-01

    The elderly or senior citizen is a large and growing market segment that purchases a disproportionate amount of health care products, particularly nonprescription products. This study attempts to examine the elderly's level of involvement (high versus low) and their purchase decision process regarding nonprescription or over-the-counter (OTC) products. Frequencies and percentages are calculated to indicate level of involvement as well as purchase decision behavior. Previous research is critiqued and managerial implications are discussed.

  7. Nonlinear solution for radiation boundary condition of heat transfer process in human eye.

    Science.gov (United States)

    Dehghani, A; Moradi, A; Dehghani, M; Ahani, A

    2011-01-01

    In this paper we propose a new method based on finite element method for solving radiation boundary condition of heat equation inside the human eye and other applications. Using this method, we can solve heat equation inside human eye without need to model radiation boundary condition to a robin boundary condition. Using finite element method we can obtain a nonlinear equation, and finally we use nonlinear algorithm to solve it. The human eye is modeled as a composition of several homogeneous regions. The Ritz method in the finite element method is used for solving heat differential equation. Applying the boundary conditions, the heat radiation condition and the robin condition on the cornea surface of the eye and on the outer part of sclera are used, respectively. Simulation results of solving nonlinear boundary condition show the accuracy of the proposed method.

  8. Nonlinear reflection process of linearly-polarized, broadband Alfv\\'en waves in the fast solar wind

    CERN Document Server

    Shoda, Munehito

    2016-01-01

    Using one-dimensional numerical simulations, we study the elementary process of Alfv\\'{e}n wave reflection in a uniform medium, including nonlinear effects. In the linear regime, Alfv\\'{e}n wave reflection is triggered only by the inhomogeneity of the medium, whereas in the nonlinear regime, it can occur via nonlinear wave-wave interactions. Such nonlinear reflection (backscattering) is typified by decay instability. In most studies of decay instabilities, the initial condition has been a circularly polarized Alfv\\'{e}n wave. In this study we consider a linearly polarized Alfv\\'en wave, which drives density fluctuations by its magnetic pressure force. For generality, we also assume a broadband wave with a red-noise spectrum. In the data analysis, we decompose the fluctuations into characteristic variables using local eigenvectors, thus revealing the behaviors of the individual modes. Different from circular-polarization case, we find that the wave steepening produces a new energy channel from the parent Alfv\\...

  9. Observation of nonlinear wave decay processes in the solar wind by the AMPTE IRM plasma wave experiment

    Science.gov (United States)

    Koons, H. C.; Roeder, J. L.; Bauer, O. H.; Haerendel, G.; Treumann, R.

    1987-01-01

    Nonlinear wave decay processes have been detected in the solar wind by the plasma wave experiment aboard the Active Magnetospheric Particle Tracer Explorers (AMPTE) IRM spacecraft. The main process is the generation of ultralow-frequency ion acoustic waves from the decay of Langmuir waves near the electron plasma frequency. Frequently, this is accompanied by an enhancement of emissions near twice the plasma frequency. This enhancement is most likely due to the generation of electromagnetic waves from the coalescence of two Langmuir waves. These processes occur within the electron foreshock in front of the earth's bow shock.

  10. [Medical certification in workers involved in logging and wood-processing].

    Science.gov (United States)

    Romankow, Jacek

    2007-01-01

    Activities involved in forestry and woodworking industry are associated with workers being exposed to numerous environmental and technology-related factors that are detrimental to their health. Such hazards include working in changeable climatic conditions, in the vicinity of heavy equipment, exposure to noise, chainsaw vibrations, enforced body positioning, hard physical work, the effect of exhaust gases, potential effects of biological factors, including epizootic diseases. Wood processing involves performing mechanical activities employing tools and machines, as well as processes utilizing various chemical substances. Forestry and woodworking industry workers may deal both with timber and with wood products. In medical certification, the following issues are of significance: work in the vicinity of rotational elements, noise, effects of chemicals or biological factors, including carcinogenic substances. For this reason, the procedures involved in medical examinations of such workers are complex.

  11. Decentralisation by Devolution: Reflections on Community Involvement in Planning Process in Tanzania

    Science.gov (United States)

    Norman, A. S.; Massoi, L.

    2010-01-01

    This paper provides reflections on Decentralization-by-Devolution in planning process at grassroots level by investigating the manner in which grassroots level is involved in preparing the three years strategic plan; and its implications towards solving socio-economic problems at grassroots level. The study employed a combined research design…

  12. Decentralisation by Devolution: Reflections on Community Involvement in Planning Process in Tanzania

    Science.gov (United States)

    Norman, A. S.; Massoi, L.

    2010-01-01

    This paper provides reflections on Decentralization-by-Devolution in planning process at grassroots level by investigating the manner in which grassroots level is involved in preparing the three years strategic plan; and its implications towards solving socio-economic problems at grassroots level. The study employed a combined research design…

  13. Reduced cortical thickness of brain areas involved in pain processing in patients with chronic pancreatitis.

    NARCIS (Netherlands)

    Frokjaer, J.B.; Bouwense, S.A.W.; Olesen, S.S.; Lundager, F.H.; Eskildsen, S.F.; Goor, H. van; Wilder-Smith, O.H.G.; Drewes, A.M.

    2012-01-01

    BACKGROUND & AIMS: Patients with painful chronic pancreatitis (CP) might have abnormal brain function. We assessed cortical thickness in brain areas involved in visceral pain processing. METHODS: We analyzed brain morphologies of 19 patients with painful CP and compared them with 15 healthy individu

  14. Stakeholder involvement in stages of a participatory process illustrated in interior design cases

    DEFF Research Database (Denmark)

    Vink, Peter; van Rhijn, Gu; Seim, Rikke

    2008-01-01

    In a previous study (Vink et al., 2008) an overview was made of the involvement of different stakeholders in a participatory design process. In this paper this overview was used to describe four participatory design cases focused on improvising productivity, health, and comfort by interior design...

  15. Investigation of heat transfer processes involved liquid impingement jets: a review

    Directory of Open Access Journals (Sweden)

    M. Molana

    2013-09-01

    Full Text Available This review reports research on liquid impingement jets and the abilities, limitations and features of this method of heat transfer. Some available and important correlations for Nusselt number are collected here. Also we demonstrate the capability of nanofluids to be applied in heat transfer processes involved liquid impingement jets.

  16. Potential processes involved in the initiation and maintenance of whiplash-associated disorders : discussion paper 3

    NARCIS (Netherlands)

    Sterling, Michele; McLean, Samuel A.; Sullivan, Michael J. L.; Elliott, James M.; Buitenhuis, Jan; Kamper, Steven J.

    2011-01-01

    Study Design. Nonsystematic review and discussion of the etiological processes involved in whiplash-associated disorders (WAD). Objective. To summarize the research and identify priorities for future research. Summary of Background Data. Although there is convergent evidence of a peripheral lesion i

  17. Music Educators' Involvement in the Individual Education Program Process and Their Knowledge of Assistive Technology

    Science.gov (United States)

    McCord, Kimberly A.; Watts, Emily H.

    2010-01-01

    In 1997, the Individuals With Disabilities Education Act of 1990 was amended to require that assistive technology be considered when preparing an individual education program (IEP). This study explored involvement of Midwestern music educators in the IEP development process as well as their knowledge and attitudes regarding use of assistive…

  18. Reflections on Practical Approaches to Involving Children and Young People in the Data Analysis Process

    Science.gov (United States)

    Coad, Jane; Evans, Ruth

    2008-01-01

    This article reflects on key methodological issues emerging from children and young people's involvement in data analysis processes. We outline a pragmatic framework illustrating different approaches to engaging children, using two case studies of children's experiences of participating in data analysis. The article highlights methods of…

  19. Parent Involvement in the College Recruiting Process: To What Extent? CERI Research Brief 2-2007

    Science.gov (United States)

    Gardner, Phil

    2010-01-01

    Parents' increasing involvement in their children's transition from college to work has grabbed the attention of the media. Every time the author talks with employer groups, he hears similar stories about the pervasive presence of parents in the recruiting process. At the same time, numerous employers questioned the presence of parents in the…

  20. Overview of mechanisms involved during the quenching and partitioning process in steels

    NARCIS (Netherlands)

    Santofimia, M.J.; Zhao, L.; Sietsma, J.

    2011-01-01

    The application of the quenching and partitioning (Q&P) process in steels involves a microstructural evolution that is more complex than just the formation of martensite followed by carbon partitioning from martensite to austenite. Examples of this complexity are the formation of epitaxial ferrite

  1. Educational Support System for Experiments Involving Construction of Sound Processing Circuits

    Science.gov (United States)

    Takemura, Atsushi

    2012-01-01

    This paper proposes a novel educational support system for technical experiments involving the production of practical electronic circuits for sound processing. To support circuit design and production, each student uses a computer during the experiments, and can learn circuit design, virtual circuit making, and real circuit making. In the…

  2. Reflections on Practical Approaches to Involving Children and Young People in the Data Analysis Process

    Science.gov (United States)

    Coad, Jane; Evans, Ruth

    2008-01-01

    This article reflects on key methodological issues emerging from children and young people's involvement in data analysis processes. We outline a pragmatic framework illustrating different approaches to engaging children, using two case studies of children's experiences of participating in data analysis. The article highlights methods of…

  3. Tightening the Purchasing Process: Superintendents Get More Involved in Buying Policies

    Science.gov (United States)

    Rivero, Victor

    2009-01-01

    Over the last 18 months, school district purchasing offices across the country have been tightening the reins like never before while more top-level administrators get involved in the budget process. "When the economy really hit the skids, states got hit hard, so a lot of school districts were forced to make severe budget cuts," says John Musso,…

  4. TRAINING DURING ISO 9001 IMPLEMENTATION AND WORKERS INVOLVEMENT INTO THE QUALITY MANAGEMENT PROCESS IN MONTENEGRO

    Directory of Open Access Journals (Sweden)

    Marc-Arthur Diaye

    2009-03-01

    Full Text Available According to several researchers, workers involvement into the implementation of a quality system in a firm is a key of its success. Since training can improve workers involvement during the implementation of a quality system in a firm, we try in this paper to evaluate quantitatively in the case of Montenegro, the impact of training of workers' involvement. Using an original data set about two leading firms from Montenegro, we show that the coefficient associated with the training variable is on average about -1.44 and is significant at a level of 1%. That is workers who are not trained during the ISO 9001 implementation are strongly less involved into the quality management process of their firms.

  5. Consumer involvement: effects on information processing from over-the-counter medication labels.

    Science.gov (United States)

    Sansgiry, S S; Cady, P S; Sansgiry, S

    2001-01-01

    The objective of this study was to evaluate the effects of consumer involvement on information processing from over-the-counter (OTC) medication labels. A sample of 256 students evaluated simulated OTC product labels for two product categories (headache and cold) in random order. Each participant evaluated labels after reading a scenario to simulate high and low involvement respectively. A questionnaire was used to collect data on variables such as label comprehension, attitude-towards-product label, product evaluation, and purchase intention. The results indicate that when consumers are involved in their purchase of OTC medications they are significantly more likely to understand information from the label and evaluate it accordingly. However, involvement does not affect attitude-towards-product label nor does it enhance purchase intention.

  6. Efficient conversion from infrared to red light by cascaded nonlinear optical processes using an aperiodically poled lithium niobate crystal

    Directory of Open Access Journals (Sweden)

    Juan Eduardo González

    2015-12-01

    Full Text Available We present a scheme for conversion of pulsed light from the infrared to the red spectral region, using an aperiodically poled ferroelectric crystal within a resonant cavity in which two cascaded nonlinear optical processes occur when pumped with a pulsed Nd:YAG laser. This device emits 9 ns pulses of over 1 mJ at 710 nm and is a viable source for future biomedical applications.

  7. Verification of nonlinear dynamic structural test results by combined image processing and acoustic analysis

    Science.gov (United States)

    Tene, Yair; Tene, Noam; Tene, G.

    1993-08-01

    An interactive data fusion methodology of video, audio, and nonlinear structural dynamic analysis for potential application in forensic engineering is presented. The methodology was developed and successfully demonstrated in the analysis of heavy transportable bridge collapse during preparation for testing. Multiple bridge elements failures were identified after the collapse, including fracture, cracks and rupture of high performance structural materials. Videotape recording by hand held camcorder was the only source of information about the collapse sequence. The interactive data fusion methodology resulted in extracting relevant information form the videotape and from dynamic nonlinear structural analysis, leading to full account of the sequence of events during the bridge collapse.

  8. A 3-D nonlinear recursive digital filter for video image processing

    Science.gov (United States)

    Bauer, P. H.; Qian, W.

    1991-01-01

    This paper introduces a recursive 3-D nonlinear digital filter, which is capable of performing noise suppression without degrading important image information such as edges in space or time. It also has the property of unnoticeable bandwidth reduction immediately after a scene change, which makes the filter an attractive preprocessor to many interframe compression algorithms. The filter consists of a nonlinear 2-D spatial subfilter and a 1-D temporal filter. In order to achieve the required computational speed and increase the flexibility of the filter, all of the linear shift-variant filter modules are of the IIR type.

  9. On the stability and dynamics of stochastic spiking neuron models: Nonlinear Hawkes process and point process GLMs

    Science.gov (United States)

    Truccolo, Wilson

    2017-01-01

    Point process generalized linear models (PP-GLMs) provide an important statistical framework for modeling spiking activity in single-neurons and neuronal networks. Stochastic stability is essential when sampling from these models, as done in computational neuroscience to analyze statistical properties of neuronal dynamics and in neuro-engineering to implement closed-loop applications. Here we show, however, that despite passing common goodness-of-fit tests, PP-GLMs estimated from data are often unstable, leading to divergent firing rates. The inclusion of absolute refractory periods is not a satisfactory solution since the activity then typically settles into unphysiological rates. To address these issues, we derive a framework for determining the existence and stability of fixed points of the expected conditional intensity function (CIF) for general PP-GLMs. Specifically, in nonlinear Hawkes PP-GLMs, the CIF is expressed as a function of the previous spike history and exogenous inputs. We use a mean-field quasi-renewal (QR) approximation that decomposes spike history effects into the contribution of the last spike and an average of the CIF over all spike histories prior to the last spike. Fixed points for stationary rates are derived as self-consistent solutions of integral equations. Bifurcation analysis and the number of fixed points predict that the original models can show stable, divergent, and metastable (fragile) dynamics. For fragile models, fluctuations of the single-neuron dynamics predict expected divergence times after which rates approach unphysiologically high values. This metric can be used to estimate the probability of rates to remain physiological for given time periods, e.g., for simulation purposes. We demonstrate the use of the stability framework using simulated single-neuron examples and neurophysiological recordings. Finally, we show how to adapt PP-GLM estimation procedures to guarantee model stability. Overall, our results provide a

  10. Cochlear Implant: the complexity involved in the decision making process by the family

    Directory of Open Access Journals (Sweden)

    Sheila de Souza Vieira

    2014-06-01

    Full Text Available OBJECTIVE: to understand the meanings the family attributes to the phases of the decision-making process on a cochlear implant for their child.METHOD: qualitative research, using Symbolic Interactionism and Grounded Theory as the theoretical and methodological frameworks, respectively. Data collection instrument: semistructured interview. Nine families participated in the study (32 participants.RESULTS: knowledge deficit, difficulties to contextualize benefits and risks and fear are some factors that make this process difficult. Experiences deriving from interactions with health professionals, other cochlear implant users and their relatives strengthen decision making in favor of the implant.CONCLUSION: deciding on whether or not to have the implant involves a complex process, in which the family needs to weigh gains and losses, experience feelings of accountability and guilt, besides overcoming the risk aversion. Hence, this demands cautious preparation and knowledge from the professionals involved in this intervention.

  11. Mathematical modeling suggests that periodontitis behaves as a non-linear chaotic dynamical process

    NARCIS (Netherlands)

    Papantonopoulos, G.H.; Takahashi, K.; Bountis, T.; Loos, B.G.

    2013-01-01

    Background: This study aims to expand on a previously presented cellular automata model and further explore the non-linear dynamics of periodontitis. Additionally the authors investigated whether their mathematical model could predict the two known types of periodontitis, aggressive (AgP) and

  12. The Nonlinear Interaction Process in the Wave Assimilation Model and Its Experiments

    Institute of Scientific and Technical Information of China (English)

    杨永增; 纪永刚; 袁业立

    2003-01-01

    This paper presents a composite interaction formula based on the discrete-interactionoperator of wave-wave nonlinear interaction for deriving its adjoint source function in the wave assimilation model. Assimilation experiments were performed using the significant wave heights observed by the TOPES/POSEIDON satellite, and the gradient distribution in the physical space wasalso analyzed preliminarily.

  13. Mathematical modeling suggests that periodontitis behaves as a non-linear chaotic dynamical process

    NARCIS (Netherlands)

    Papantonopoulos, G.H.; Takahashi, K.; Bountis, T.; Loos, B.G.

    2013-01-01

    Background: This study aims to expand on a previously presented cellular automata model and further explore the non-linear dynamics of periodontitis. Additionally the authors investigated whether their mathematical model could predict the two known types of periodontitis, aggressive (AgP) and chroni

  14. Analysis of a distributed neural system involved in spatial information, novelty, and memory processing.

    Science.gov (United States)

    Menon, V; White, C D; Eliez, S; Glover, G H; Reiss, A L

    2000-10-01

    Perceiving a complex visual scene and encoding it into memory involves a hierarchical distributed network of brain regions, most notably the hippocampus (HIPP), parahippocampal gyrus (PHG), lingual gyrus (LNG), and inferior frontal gyrus (IFG). Lesion and imaging studies in humans have suggested that these regions are involved in spatial information processing as well as novelty and memory encoding; however, the relative contributions of these regions of interest (ROIs) are poorly understood. This study investigated regional dissociations in spatial information and novelty processing in the context of memory encoding using a 2 x 2 factorial design with factors Novelty (novel vs. repeated) and Stimulus (viewing scenes with rich vs. poor spatial information). Greater activation was observed in the right than left hemisphere; however, hemispheric effects did not differ across regions, novelty, or stimulus type. Significant novelty effects were observed in all four regions. A significant ROI x Stimulus interaction was observed - spatial information processing effects were largest effects in the LNG, significant in the PHG and HIPP and nonsignificant in the IFG. Novelty processing was stimulus dependent in the LNG and stimulus independent in the PHG, HIPP, and IFG. Analysis of the profile of Novelty x Stimulus interaction across ROIs provided evidence for a hierarchical independence in novelty processing characterized by increased dissociation from spatial information processing. Despite these differences in spatial information processing, memory performance for novel scenes with rich and poor spatial information was not significantly different. Memory performance was inversely correlated with right IFG activation, suggesting the involvement of this region in strategically flawed encoding effort. Stepwise regression analysis revealed that memory encoding accounted for only a small fraction of the variance (temporal lobe activation. The implications of these results for

  15. Final report on the public involvement process phase 1, Monitored Retrievable Storage Facility Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Moore, L.; Shanteau, C.

    1992-12-01

    This report summarizes the pubic involvement component of Phase 1 of the Monitored Retrievable Storage Facility (NM) Feasibility Study in San Juan County, Utah. Part of this summary includes background information on the federal effort to locate a voluntary site for temporary storage of nuclear waste, how San Juan County came to be involved, and a profile of the county. The heart of the report, however, summarizes the activities within the public involvement process, and the issues raised in those various forums. The authors have made every effort to reflect accurately and thoroughly all the concerns and suggestions expressed to us during the five month process. We hope that this report itself is a successful model of partnership with the citizens of the county -- the same kind of partnership the county is seeking to develop with its constituents. Finally, this report offers some suggestions to both county officials and residents alike. These suggestions concern how decision-making about the county`s future can be done by a partnership of informed citizens and listening decision-makers. In the Appendix are materials relating to the public involvement process in San Juan County.

  16. Final report on the public involvement process phase 1, Monitored Retrievable Storage Facility Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Moore, L.; Shanteau, C.

    1992-12-01

    This report summarizes the pubic involvement component of Phase 1 of the Monitored Retrievable Storage Facility (NM) Feasibility Study in San Juan County, Utah. Part of this summary includes background information on the federal effort to locate a voluntary site for temporary storage of nuclear waste, how San Juan County came to be involved, and a profile of the county. The heart of the report, however, summarizes the activities within the public involvement process, and the issues raised in those various forums. The authors have made every effort to reflect accurately and thoroughly all the concerns and suggestions expressed to us during the five month process. We hope that this report itself is a successful model of partnership with the citizens of the county -- the same kind of partnership the county is seeking to develop with its constituents. Finally, this report offers some suggestions to both county officials and residents alike. These suggestions concern how decision-making about the county's future can be done by a partnership of informed citizens and listening decision-makers. In the Appendix are materials relating to the public involvement process in San Juan County.

  17. RESEARCH OF LINEAR AND NONLINEAR PROCESSES AT FEMTOSECOND LASER RADIATION PROPAGATION IN THE MEDIUM SIMULATING THE HUMAN EYE VITREOUS

    Directory of Open Access Journals (Sweden)

    P. Y. Rogov

    2015-09-01

    Full Text Available The paper deals with mathematical model of linear and nonlinear processes occurring at the propagation of femtosecond laser pulses in the vitreous of the human eye. Methods of computing modeling are applied for the nonlinear spectral equation solution describing the dynamics of a two-dimensional TE-polarized radiation in a homogeneous isotropic medium with cubic fast-response nonlinearity without the usage of slowly varying envelope approximation. Environments close to the optical media parameters of the eye were used for the simulation. The model of femtosecond radiation propagation takes into account the process dynamics for dispersion broadening of pulses in time and the occurence of the self-focusing near the retina when passing through the vitreous body of the eye. Dependence between the pulse duration on the retina has been revealed and the duration of the input pulse and the values of power density at which there is self-focusing have been found. It is shown that the main mechanism of radiation damage with the use of titanium-sapphire laser is photoionization. The results coincide with those obtained by the other scientists, and are usable for creation Russian laser safety standards for femtosecond laser systems.

  18. Considering Process Nonlinearity in Dual-Point Composition Control of a High-Purity Ideal Heat Integrated Distillation Column

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Dual-point composition control for a high-purity ideal heat integrated distillation column (HIDiC) is addressed in this work. Three measures are suggested and combined for overcoming process inherent nonlinearities:(1) variable scaling; (2) multi-model representation of process dynamics and (3) feedforward compensation. These strategies can offer the developed control systems with several distinct advantages: (1) capability of dealing with severe disturbances; (2) tight tuning of controller parameters and (3) high robustness with respect to variation of operating conditions. Simulation results demonstrate the effectiveness of the proposed methodology.

  19. Microscopic study of muon-capture transitions in nuclei involved in double-beta-decay processes

    CERN Document Server

    Kortelainen, M

    2003-01-01

    Total and partial ordinary muon-capture (OMC) rates to 1 sup + and 2 sup - states are calculated in the framework of the proton-neutron quasiparticle random-phase approximation (pnQRPA) for several nuclei involved in double-beta-decay processes. The aim is to obtain information on intermediate states involved in double-beta-decay transitions having these nuclei as either daughter or parent nuclei. It is found that the OMC observables, just like the 2 nu beta beta-decay amplitudes, strongly depend on the particle-particle part of the proton-neutron interaction. First experiments measuring the partial OMC rates for nuclei involved in double beta decays have recently been performed.

  20. Nonlinear analysis on the coupling process of electromagnetic vibrator and earth

    Institute of Scientific and Technical Information of China (English)

    CHEN; Zubin; TENG; Jiwen; LIN; Jun; ZHANG; Linhang; JIANG

    2005-01-01

    The linear model based on the hydraulic pressure vibrator has been no longer adaptable to the electromagnetic vibrator. In order to realize the effective transmission of the limited energy from the vibrator to the ground, it is important to study the coupling model of the electromagnetic vibrator and the earth. In this paper, a nonlinear restore term was introduced to the coupling model because of the existence of a large amount of harmonics in the vibrator baseplate. The nonlinear vibration analysis was applied to the model by the multiscale method. In the course of energy transmission from the vibrator to the ground, ultraharmonic resonance was used to explain the generation of harmonics. An improved scheme was advanced to select the cross correlation reference signal in the vibrator seismic exploration. Good application results were obtained in field experiments.

  1. Non-linear processes in thin titanium nitride transmission lines for parametric amplification

    Science.gov (United States)

    Vissers, Michael; Gao, Jiansong; Chaudhuri, Suptarshi; Bockstiegel, Clint; Sandberg, Martin; Pappas, David P.

    2013-03-01

    Nitride superconductors, such as titanium nitride and niobium titanium nitride, are a non-linear, low dissipation medium at microwave frequencies. The lossless nonlinearity may be probed and utilized. Important applications include generation of higher harmonics, e.g. 3f, and a microwave version of the optical paramagnetic amplifier, i.e. the degenerate-pump case of four-photon mixing (FPM). An amplifier based on these principles should allow for very wide bandwidth, low noise (quantum limited) and high dynamic range devices. These measurements are performed via a single layer, 3 meter long TiN spiral and measured at temperatures below 100 mK. Initial results of the design, fabrication, testing, and impedance optimization of a titanium nitride based parametric amplifier are presented.

  2. Partial and total actuator faults accommodation for input-affine nonlinear process plants.

    Science.gov (United States)

    Mihankhah, Amin; Salmasi, Farzad R; Salahshoor, Karim

    2013-05-01

    In this paper, a new fault-tolerant control system is proposed for input-affine nonlinear plants based on Model Reference Adaptive System (MRAS) structure. The proposed method has the capability to accommodate both partial and total actuator failures along with bounded external disturbances. In this methodology, the conventional MRAS control law is modified by augmenting two compensating terms. One of these terms is added to eliminate the nonlinear dynamic, while the other is reinforced to compensate the distractive effects of the total actuator faults and external disturbances. In addition, no Fault Detection and Diagnosis (FDD) unit is needed in the proposed method. Moreover, the control structure has good robustness capability against the parameter variation. The performance of this scheme is evaluated using a CSTR system and the results were satisfactory.

  3. Involving the elderly in the design process: a participatory design model for usability, safety and attractiveness

    OpenAIRE

    Demirbilek, Oya

    1999-01-01

    Ankara : Institute of Economics and Social Sciences of Bilkent University, 1999. Thesis (Ph.D.) -- Bilkent University, 1999 Includes bibliographical references leaves 113-131 This work presents a conceptual model involving the elderly users into the design process by means of participatory design sessions, where the expertise of designers and the real requirements and opinions of elderly end-users, related to how objects, environments and equipment should be designed to allow ageing ...

  4. Influence of independent risk factors on health status of persons involved in the process of education

    Directory of Open Access Journals (Sweden)

    Guriev A.V.

    2013-03-01

    Full Text Available The research goal is to increase efficiency of health education for subjects involved in the process of education. Materials: 498 questionnaires have been worked out for respondents. Methods: They have included supervision, questioning, free interviewing and methods for statistical processing of results of research. Results: The following factors have been revealed: peculiarity of leisure-time; bad quality of interaction between subjects of educational system and health care system. The characteristic of extra-curriculum risk factors has been done. Conclusion: It is stressed that the survey has determined the basic directions of training for teachers and adults to form healthy way of life.

  5. Individual reactions to high involvement work processes: investigating the role of empowerment and perceived organizational support.

    Science.gov (United States)

    Butts, Marcus M; Vandenberg, Robert J; DeJoy, David M; Schaffer, Bryan S; Wilson, Mark G

    2009-04-01

    This study sought to understand how high involvement work processes (HIWP) are processed at the employee level. Using structural equation modeling techniques, the authors tested and supported a model in which psychological empowerment mediated the effects of HIWP on job satisfaction, organizational commitment, job performance, and job stress. Furthermore, perceived organizational support (POS) was hypothesized to moderate the relationships between empowerment and these outcomes. With exception for the empowerment-job satisfaction association, support was found for our predictions. Future directions for research and the practical implications of our findings for both employees and organizations are discussed.

  6. Novel essential gene Involved in 16S rRNA processing in Escherichia coli.

    Science.gov (United States)

    Kurata, Tatsuaki; Nakanishi, Shinobu; Hashimoto, Masayuki; Taoka, Masato; Yamazaki, Yukiko; Isobe, Toshiaki; Kato, Jun-ichi

    2015-02-27

    Biogenesis of ribosomes is a complex process mediated by many factors. While its transcription proceeds, ribosomal RNA (rRNA) folds itself into a characteristic three-dimensional structure through interaction with ribosomal proteins, during which its ends are processed. Here, we show that the essential protein YqgF, a RuvC family protein with an RNase-H-like motif, is involved in the processing of pre-16S rRNA during ribosome maturation. Indeed, pre-16S rRNA accumulated in cells of a temperature-sensitive yqgF mutant (yqgF(ts)) cultured at a non-permissive temperature. In addition, purified YqgF was shown to process the 5' end of pre-16S rRNA within 70S ribosomes in vitro. Mass spectrometry analysis of the total proteins in the yqgF(ts) mutant cells showed that the expression of genes containing multiple Shine-Dalgarno-like sequences was observed to be lower than in wild type. These results are interpreted to indicate that YqgF is involved in a novel enzymic activity necessary for the processing of pre-16S rRNA, thereby affecting elongation of translation.

  7. Physiological processes non-linearly affect electrophysiological recordings during transcranial electric stimulation.

    Science.gov (United States)

    Noury, Nima; Hipp, Joerg F; Siegel, Markus

    2016-10-15

    Transcranial electric stimulation (tES) is a promising tool to non-invasively manipulate neuronal activity in the human brain. Several studies have shown behavioral effects of tES, but stimulation artifacts complicate the simultaneous investigation of neural activity with EEG or MEG. Here, we first show for EEG and MEG, that contrary to previous assumptions, artifacts do not simply reflect stimulation currents, but that heartbeat and respiration non-linearly modulate stimulation artifacts. These modulations occur irrespective of the stimulation frequency, i.e. during both transcranial alternating and direct current stimulations (tACS and tDCS). Second, we show that, although at first sight previously employed artifact rejection methods may seem to remove artifacts, data are still contaminated by non-linear stimulation artifacts. Because of their complex nature and dependence on the subjects' physiological state, these artifacts are prone to be mistaken as neural entrainment. In sum, our results uncover non-linear tES artifacts, show that current techniques fail to fully remove them, and pave the way for new artifact rejection methods.

  8. Limitations of Feedback, Feedforward and IMC Controller for a First Order Non-Linear Process with Dead Time

    Directory of Open Access Journals (Sweden)

    Maruthai Suresh

    2010-10-01

    Full Text Available A nonlinear process, the heat exchanger whose parameters vary with respect to the process variable, is considered. The time constant and gain of the chosen process vary as a function of temperature. The limitations of the conventional feedback controller tuned using Ziegler-Nichols settings for the chosen process are brought out. The servo and regulatory responses through simulation and experimentation for various magnitudes of set-point changes and load changes at various operating points with the controller tuned only at a chosen nominal operating point are obtained and analyzed. Regulatory responses for output load changes are studied. The efficiency of feedforward controller and the effects of modeling error have been brought out. An IMC based system is presented to understand clearly how variations of system parameters affect the performance of the controller. The present work illustrates the effectiveness of Feedforward and IMC controller.

  9. The Thatcher illusion reveals orientation dependence in brain regions involved in processing facial expressions.

    Science.gov (United States)

    Psalta, Lilia; Young, Andrew W; Thompson, Peter; Andrews, Timothy J

    2014-01-01

    Although the processing of facial identity is known to be sensitive to the orientation of the face, it is less clear whether orientation sensitivity extends to the processing of facial expressions. To address this issue, we used functional MRI (fMRI) to measure the neural response to the Thatcher illusion. This illusion involves a local inversion of the eyes and mouth in a smiling face-when the face is upright, the inverted features make it appear grotesque, but when the face is inverted, the inversion is no longer apparent. Using an fMRI-adaptation paradigm, we found a release from adaptation in the superior temporal sulcus-a region directly linked to the processing of facial expressions-when the images were upright and they changed from a normal to a Thatcherized configuration. However, this release from adaptation was not evident when the faces were inverted. These results show that regions involved in processing facial expressions display a pronounced orientation sensitivity.

  10. Has patients’ involvement in the decision‐making process changed over time?

    Science.gov (United States)

    Van Den Brink‐Muinen, Atie; Van Dulmen, Sandra M.; De Haes, Hanneke C.J.M.; Visser, Adriaan Ph.; Schellevis, François G.; Bensing, Jozien M.

    2006-01-01

    Abstract Objective  To get insight into the changes over time of patients’ involvement in the decision‐making process, and into the factors contributing to patients’ involvement and general practitioners’ (GPs) communication related to the Medical Treatment Act (MTA) issues: information about treatment, other available treatments and side‐effects; informed decision making; asking consent for treatment. Background  Societal developments have changed the doctor–patient relationship recently. Informed decision making has become a central topic. Patients’ informed consent was legalized by the MTA (1995). Design  Data of two cross‐sectional studies, the First (1987) and Second (2001) Dutch National Survey of General Practice, were compared. Setting and participants  General practice consultations; 16 GPs and 442 patients in 1987; 142 GPs and 2784 patients in 2001. Methods  Consultations were videotaped and rated using Roter's Interaction Analysis System and observer questionnaires; pre‐ and post‐consultation patient questionnaires; and GP questionnaires. Descriptive analyses and multivariate, multilevel analysis were applied. Main results  Most patients reported to have received the information they had considered as important prior to the consultation. There were discrepancies in involvement in treatment decisions and in giving information about other available treatments, side‐effects and risks. GPs who were more affective and gave more information, more often involved their patients, especially younger patients, in decision making. In 2001, more informed decision making was observed and the GPs asked consent for a treatment more often, but they less often asked for the patients’ understanding. Conclusion  Patients’ involvement in decision making has increased over time, but not in every respect. However, this does not apply for all patients, especially the older ones. It should be questioned whether they are willing or capable

  11. Stakeholders and public involvement in river management: heterogeneous acceptance of participatory processes among Swiss institutions.

    Science.gov (United States)

    Buletti, Nora; Utz, Stephan; Ejderyan, Olivier; Graefe, Olivier; Lane, Stuart; Reynard, Emmanuel

    2014-05-01

    This research explores participatory processes in the domain of river management in Switzerland. The main objective is to better understand how participatory processes are incorporated into river management practice. Switzerland being a federal state, river management is a cantonal (regional) responsibility, under the supervision (and co-funding) of the State (a Confederation). The federal funding includes the opportunity to fund additional participatory activities to aid river management, not least because the federal authorities consider the involvement of wider stakeholders and the public in decision-making as a means of aiding the progression of projects. This is a particularly important goal in a Swiss setting where direct democracy (the possibility of calling the decision of any level of government into question through a popular vote) means that a reasonable level of project acceptance is a necessary element of project progression. River management in Switzerland now includes both flood protection and river restoration objectives, which has served to increase its controversy: river corridors contain competing interests with different objectives (e.g. ecological enhancement, protection of agricultural land, flood risk reduction). We were asked by the Confederation to evaluate participatory processes it sponsored and one element of this evaluation aimed to develop a typology of stakeholder participation. We conducted interviews with the 26 cantonal officers in charge of river management. These interviews were based upon thematically structured open ended questions, with the responses analyzed qualitatively. We have identified significant divergence in the implementation of participatory processes between the cantons. These appear to be related to two factors: (1) the canton's historical experience of river management; and (2) the methods used to select stakeholders for inclusion in the decisional process. Cantons that refer to guidelines or pre

  12. Sulfomethylated lignosulfonates as additives in oil recovery processes involving chemical recovery agents

    Energy Technology Data Exchange (ETDEWEB)

    Kalfoglou, G.

    1979-10-30

    A process for producing petroleum from subterranean formations is disclosed wherein production from the formation is obtained by driving a fluid from an injection well to a production well. The process involves injecting via the injection well into the formation an aqueous solution of sulfomethylated lignosulfonate salt as a sacrificial agent to inhibit the deposition of surfactant and/or polymer on the reservoir matrix. The process may best be carried out by injecting the sulfomethylated lignosulfonates into the formation through the injection well mixed with either a polymer, a surfactant solution and/or a micellar dispersion. This mixture would then be followed by a drive fluid such as water to push the chemicals to the production well.

  13. Sulfomethylated lignosulfonates as additives in oil recovery processes involving chemical recovery agents

    Energy Technology Data Exchange (ETDEWEB)

    Kalfoglou, G.

    1981-05-26

    A process for producing petroleum from subterranean formations is disclosed wherein production from the formation is obtained by driving a fluid from an injection well to a production well. The process involves injecting via the injection well into the formation an aqueous solution of sulfomethylated lignosulfonate salt as a sacrificial agent to inhibit the deposition of surfactant and/or polymer on the reservoir matrix. The process may best be carried out by injecting the sulfomethylated lignosulfonates into the formation through the injection well mixed with either a polymer, a surfactant solution and/or a micellar dispersion. This mixture would then be followed by a drive fluid such as water to push the chemicals to the production well.

  14. System Dynamics Modelling of the Processes Involving the Maintenance of the Naive T Cell Repertoire

    CERN Document Server

    Figueredo, Grazziela P; Whitbrook, Amanda

    2010-01-01

    The study of immune system aging, i.e. immunosenescence, is a relatively new research topic. It deals with understanding the processes of immunodegradation that indicate signs of functionality loss possibly leading to death. Even though it is not possible to prevent immunosenescence, there is great benefit in comprehending its causes, which may help to reverse some of the damage done and thus improve life expectancy. One of the main factors influencing the process of immunosenescence is the number and phenotypical variety of naive T cells in an individual. This work presents a review of immunosenescence, proposes system dynamics modelling of the processes involving the maintenance of the naive T cell repertoire and presents some preliminary results.

  15. Effects of noninstantaneous nonlinear processes on photon-pair generation by spontaneous four-wave mixing

    DEFF Research Database (Denmark)

    Koefoed, Jacob Gade; Christensen, Jesper Bjerge; Rottwitt, Karsten

    2017-01-01

    We present a general model, based on a Hamiltonian approach, for the joint quantum state of photon pairs generated through pulsed spontaneous four-wave mixing, including nonlinear phase modulation and a finite material response time. For the case of a silica fiber, it is found that the pair......-dependent change in quantum-mechanical purity may be observed in silica. This shows that Raman scattering not only introduces noise, but can also drastically change the spectral correlations in photon pairs when pumped with short pulses....

  16. Nonlinear Deformation Processes and Damage Modes of Super Carbon Nanotubes with Armchair-Armchair Topology

    Institute of Scientific and Technical Information of China (English)

    CHEN Yu-Li; LIU Bin; YIN Ya-Jun; HUANG Yong-Gang; HWUANG Keh-Chih

    2008-01-01

    The tensile deformations and fractures of super carbon nanotubes (SCNTs) with armchair-armchair topology are investigated by using the atomic-scale finite element method. SCNTs generated from carbon nanotubes (CNTs) with different characteristic aspect ratios are found to have different nonlinear behaviours under uniaxiai tensions. Specifically, an SCNT with higher aspect ratio has three distinct stages: rotation, stretch and rupture, while an SCNT with lower aspect ratio has only two stages. This information may compensate for previous work and enrich our knowledge about Y-branched CNTs and SCNTs.

  17. EMPLOYEE INVOLVEMENT IN A CHANGE PROCESS - A CASE STUDY FOR ROMANIAN ORGANIZATIONS

    Directory of Open Access Journals (Sweden)

    Prediscan Mariana

    2015-07-01

    Full Text Available Innovation, competitive advantage, change are some concepts that should be on every organization's agenda, due to the fact the global market leads to global competition so in order to increase the market share, turnover or profit organizations have to incorporate those concepts in their strategies. The outside environment is very unstable and things are evolving very fast so managers from all levels have to acknowledge the importance of change and to identify as soon as possible several new ideas that should be the subject of different change processes. Openness to organizational change has become a mandatory feature for those organizations that want to survive and adapt to the external pressure, helping them to be efficient. Even if in many cases managers are the initiators of change, this process is very complex and needs support and involvement from all the members of the organization, so the employee's attitude and commitment to change is crucial. In many cases employees have a negative attitude towards change and manifest a strong resistance, due to the fact that they are not consulted and are not involved in the process of the identification for the need of change. Without understanding and knowing very well what it is expected from them, employees are afraid of the unknown and prefer to perform their tasks as they did before. Creating a climate and a culture for change is very important, because like this change will be something normal, continuous and people will feel comfortable with any change initiatives, without being surprised, confused or scared. Even if any change process should improve the current state of the organization, sometimes change efforts fail because the ones that resist change are stronger than the ones supporting change. The purpose of this paper is to analyze how often are Romanian employees involved in the processes of change and how important is the role they play. We have also tried to see the Romanian manager

  18. Relevant Factors in the Process of Socialization, Involvement and Belonging of Descendants in Family Businesses

    Directory of Open Access Journals (Sweden)

    Melquicedec Lozano-Posso

    2016-12-01

    Full Text Available This research works toward the identification of the factors that comprise the process of socialization, involvement and initial belonging of descendants in family businesses and the key relationships between them. By means of a qualitative detailed study of four cases, complemented by a quantitative survey of 274 Colombian family businesses, the authors generate a new model that takes into account both factors explored in previous research as well as others identified in this study. Findings confirm the specific dependency of each stage on the subsequent ones; socialization influences involvement, which in turn influences the belonging of the descendants to the family business, with a strong presence of factors such as knowledge, leadership, mode, timing, and motivation. Those responsible for the orientation of potential successors may examine these findings in order to optimize their preparation efforts and support of family human resources for the continuity of the business.

  19. APP processing and the APP-KPI domain involvement in the amyloid cascade.

    Science.gov (United States)

    Menéndez-González, M; Pérez-Pinera, P; Martínez-Rivera, M; Calatayud, M T; Blázquez Menes, B

    2005-01-01

    Alternative APP mRNA splicing can generate isoforms of APP containing a Kunitz protease inhibitor (KPI) domain. KPI is one of the main serine protease inhibitors. Protein and mRNA KPI(+)APP levels are elevated in Alzheimer's disease (AD) brain and are associated with increased amyloid beta deposition. In the last years increasing evidence on multiple points in the amyloid cascade where KPI(+)APP is involved has been accumulated, admitting an outstanding position in the pathogenesis of AD to the KPI domain. This review focuses on the APP processing, the molecular activity of KPI and its physiological and pathological roles and the KPI involvement in the amyloid cascade through the nerve growth factor, the lipoprotein receptor-related protein, the tumor necrosis factor-alpha converting enzyme and the Notch1 protein.

  20. [Gender centrality in the process of identity construction of women involved in drug trafficking].

    Science.gov (United States)

    Barcinski, Mariana

    2009-01-01

    The present article aims to discuss the specificities of crimes perpetrated by women, especially the female participation in drug trafficking in Rio de Janeiro, Brazil. In addition to that, it intends to distinguish female from male criminality. The study is based on reflections made through interviews conducted with eight women presenting a history of involvement in drug trafficking in the slums of Rio de Janeiro. Through a systemic discursive approach(1), the analysis investigates the micro and macro elements involved in the process of the construction of the participants' identity. Results show that women's motivations to enter, remain and drop drug trafficking are in great part determined by gender, which along with color and class shapes the roles performed and the places occupied by men and women in society.

  1. Nonlinear model-based control of the Czochralski process III: Proper choice of manipulated variables and controller parameter scheduling

    Science.gov (United States)

    Neubert, M.; Winkler, J.

    2012-12-01

    This contribution continues an article series [1,2] about the nonlinear model-based control of the Czochralski crystal growth process. The key idea of the presented approach is to use a sophisticated combination of nonlinear model-based and conventional (linear) PI controllers for tracking of both, crystal radius and growth rate. Using heater power and pulling speed as manipulated variables several controller structures are possible. The present part tries to systematize the properties of the materials to be grown in order to get unambiguous decision criteria for a most profitable choice of the controller structure. For this purpose a material specific constant M called interface mobility and a more process specific constant S called system response number are introduced. While the first one summarizes important material properties like thermal conductivity and latent heat the latter one characterizes the process by evaluating the average axial thermal gradients at the phase boundary and the actual growth rate at which the crystal is grown. Furthermore these characteristic numbers are useful for establishing a scheduling strategy for the PI controller parameters in order to improve the controller performance. Finally, both numbers give a better understanding of the general thermal system dynamics of the Czochralski technique.

  2. Effects of injection timing on nonlinear dynamics of the combustion process in the lean-burn premixed natural gas engine

    Science.gov (United States)

    Ding, Shun-Liang; Song, En-Zhe; Yang, Li-Ping; Yao, Chong; Ma, Xiu-Zhen

    2017-02-01

    The nonlinear dynamics of the combustion process in the lean-burn premixed natural gas engine are studied in this paper. Based on nonlinear dynamic theory, the complexity of the combustion process is analyzed under different injection timing conditions. The phase spaces are reconstructed for the experimentally obtained in-cylinder pressure real-time series and the return maps are plotted for the IMEP time series. The results of phase space reconstruction manifest that the attractors are limited to the finite range in the reconstructed phase space. The attractors have a folded and twist geometry structure. The attractors under medium injection timing conditions are looser and more complex. The return maps indicate the coexistence of the stochastic and deterministic components in the patterns combustion process. With the injection timing increasing, there are both a transition from stochastic to deterministic and a transition from deterministic to stochastic, forming the region of deterministic behavior. The largest Lyapunov exponents (LLE) for in-cylinder pressure time series are calculated and the coefficients of variations (COV) of IMEP are also analyzed. The results express that the LLE values are positive. There are a "steep increase" and a "steep decrease" for the LLE and COV values as the injection timing increasing.

  3. Patient involvement in a scientific advisory process: setting the research agenda for medical products.

    Science.gov (United States)

    Elberse, Janneke Elisabeth; Pittens, Carina Anna Cornelia Maria; de Cock Buning, Tjard; Broerse, Jacqueline Elisabeth Willy

    2012-10-01

    Patient involvement in scientific advisory processes could lead to more societally relevant advice. This article describes a case study wherein the Health Council of the Netherlands involved patient groups in an advisory process with a predefined focus: setting a research agenda for medical products development. A four-phase approach was developed to stimulate needs-articulation concerning future medical products for a broad range of patient groups covering 15 disease domains. 119 (expert) patients and 92 non-patient representatives were consulted using interviews and focus groups. In a facilitated way, patients appeared capable and willing to provide input useful for an advisory process. A broad range of medical products was defined serving different purposes. This study showed two dilemmas: first, finding a balance between a predefined focus and being sufficiently broad to enable patients and patient representatives to contribute, and second, finding a balance between relevance for many patients groups and saturation of data for a lower number of patient groups. By taking the context of patients' daily life as starting point patient groups provided new insights. The predefined focus was sometimes perceived as constraining. The GR considered the articulated needs constructive and incorporated patients' input in their advice to the Minister of Health.

  4. Finite-dimensional constrained fuzzy control for a class of nonlinear distributed process systems.

    Science.gov (United States)

    Wu, Huai-Ning; Li, Han-Xiong

    2007-10-01

    This correspondence studies the problem of finite-dimensional constrained fuzzy control for a class of systems described by nonlinear parabolic partial differential equations (PDEs). Initially, Galerkin's method is applied to the PDE system to derive a nonlinear ordinary differential equation (ODE) system that accurately describes the dynamics of the dominant (slow) modes of the PDE system. Subsequently, a systematic modeling procedure is given to construct exactly a Takagi-Sugeno (T-S) fuzzy model for the finite-dimensional ODE system under state constraints. Then, based on the T-S fuzzy model, a sufficient condition for the existence of a stabilizing fuzzy controller is derived, which guarantees that the state constraints are satisfied and provides an upper bound on the quadratic performance function for the finite-dimensional slow system. The resulting fuzzy controllers can also guarantee the exponential stability of the closed-loop PDE system. Moreover, a local optimization algorithm based on the linear matrix inequalities is proposed to compute the feedback gain matrices of a suboptimal fuzzy controller in the sense of minimizing the quadratic performance bound. Finally, the proposed design method is applied to the control of the temperature profile of a catalytic rod.

  5. Rapid prediction method for nonlinear expansion process of medical vascular stent

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A neural network model with high nonlinear recognition capability was constructed to describe the relationship between the deformation impact factors and the deformation results of vascular stent.Then,using the weighted correction method with the attached momentum term,the network training algorithm was optimized by introducing learning factor η and momentum factor ψ,so the speed of the network training and the system robustness were enhanced.The network was trained by some practi-cal cases,and the statistical hypothesis validation was made for the predictive errors.It was shown that the average difference between the intelligent predictive result of vascular stent deformation neu-ral network and the nonlinear finite element analysis result was less than 0.03%,and the trained net-work could perfectly predict the vascular stent deformation.Further more,the rapid evaluation tool for the vascular stent mechanics performance was established using the Pro/Toolkit and the intelligent neural network predictive model of vascular stent expansion.The proposed tool system with strong practicality and high efficiency can significantly shorten the product development cycle of vascular stent.

  6. Genes involved in complex adaptive processes tend to have highly conserved upstream regions in mammalian genomes

    Directory of Open Access Journals (Sweden)

    Kohane Isaac

    2005-11-01

    Full Text Available Abstract Background Recent advances in genome sequencing suggest a remarkable conservation in gene content of mammalian organisms. The similarity in gene repertoire present in different organisms has increased interest in studying regulatory mechanisms of gene expression aimed at elucidating the differences in phenotypes. In particular, a proximal promoter region contains a large number of regulatory elements that control the expression of its downstream gene. Although many studies have focused on identification of these elements, a broader picture on the complexity of transcriptional regulation of different biological processes has not been addressed in mammals. The regulatory complexity may strongly correlate with gene function, as different evolutionary forces must act on the regulatory systems under different biological conditions. We investigate this hypothesis by comparing the conservation of promoters upstream of genes classified in different functional categories. Results By conducting a rank correlation analysis between functional annotation and upstream sequence alignment scores obtained by human-mouse and human-dog comparison, we found a significantly greater conservation of the upstream sequence of genes involved in development, cell communication, neural functions and signaling processes than those involved in more basic processes shared with unicellular organisms such as metabolism and ribosomal function. This observation persists after controlling for G+C content. Considering conservation as a functional signature, we hypothesize a higher density of cis-regulatory elements upstream of genes participating in complex and adaptive processes. Conclusion We identified a class of functions that are associated with either high or low promoter conservation in mammals. We detected a significant tendency that points to complex and adaptive processes were associated with higher promoter conservation, despite the fact that they have emerged

  7. Involvement of cortical midline structures in the processing of autobiographical information

    Science.gov (United States)

    Kaplan, Jonas; Damasio, Hanna; Damasio, Antonio

    2014-01-01

    The term autobiographical self has been used to refer to a mental state that permits reflection on self-identity and personality and the answer to related questions (Damasio, 1998). It requires the retrieval and integrated assembly of memories of facts and events that define an individual’s biography. The neural mechanisms behind this state have not been fully elucidated, but it has been suggested that cortical midline structures (CMSs) are critically involved in processing self-related information. To date, the investigation of the involvement of CMSs in autobiographical-self processes has largely focused on the comparison between self and other in relation to one domain of information, personality traits, and has yielded conflicting results. Here, we investigated how activity in CMSs varies with (1) the target of the information (self versus an acquaintance), (2) the domain of information (personality traits versus facts), and (3) differences across individuals regarding how descriptive and how important/relevant the information targeted by the questions was, and regarding the amount of memory retrieved in order to answer the questions. We used an fMRI block-design in which 19 participants answered questions about traits and biographic facts, in relation to themselves and a distant acquaintance. In addition, the participants rated the descriptiveness and importance of the information targeted by the questions, and estimated the amount of memory retrieved to answer the questions. Our results showed that CMSs were active for both facts and traits and for both self and other, and that the level of activity in the posteromedial cortices was generally higher for other than for self. Moreover, the activity in CMSs also varied with the amount of memory retrieved to answer the questions and with descriptiveness and importance of the information. These findings suggest that involvement of CMSs during the evaluation of information is not specific for self, and depends on

  8. Processing of laminin α chains generates peptides involved in wound healing and host defense.

    Science.gov (United States)

    Senyürek, Ilknur; Kempf, Wolfgang E; Klein, Gerd; Maurer, Andreas; Kalbacher, Hubert; Schäfer, Luisa; Wanke, Ines; Christ, Christina; Stevanovic, Stefan; Schaller, Martin; Rousselle, Patricia; Garbe, Claus; Biedermann, Tilo; Schittek, Birgit

    2014-01-01

    Laminins play a fundamental role in basement membrane architecture and function in human skin. The C-terminal laminin G domain-like (LG) modules of laminin α chains are modified by proteolysis to generate LG1-3 and secreted LG4-5 tandem modules. In this study, we provide evidence that skin-derived cells process and secrete biologically active peptides from the LG4-5 module of the laminin α3, α4 and α5 chain in vitro and in vivo. We show enhanced expression and processing of the LG4-5 module of laminin α3 in keratinocytes after infection and in chronic wounds in which the level of expression and further processing of the LG4-5 module correlated with the speed of wound healing. Furthermore, bacterial or host-derived proteases promote processing of laminin α3 LG4-5. On a functional level, we show that LG4-5-derived peptides play a role in wound healing. Moreover, we demonstrate that LG4-derived peptides from the α3, α4 and α5 chains have broad antimicrobial activity and possess strong chemotactic activity to mononuclear cells. Thus, the data strongly suggest a novel multifunctional role for laminin LG4-5-derived peptides in human skin and its involvement in physiological processes and pathological conditions such as inflammation, chronic wounds and skin infection.

  9. Reflective processes and competencies involved in teaching practice at university: a case study

    Directory of Open Access Journals (Sweden)

    Caetano da Costa

    2010-01-01

    Full Text Available Founded on practical rationality, this qualitative case study aimed to explore the teaching practice at university, focusing on teacher's reflections and competencies. To this end, teaching practices were described, analyzed, and interpreted. These interactions with students on a course in the pharmacy program, brought about situations involving dilemmas and learning opportunities for problem-solving and decision-making skills. Throughout the study, students were encouraged to use knowledge-in-action, reflection-in-action, and reflection-on-action, and these processes were also experienced by the teacher. Analysis of the records from classroom observation and the interviews with students and the teacher showed the fundamental role of such reflective processes, which led to attainment of the intended objectives. In this sense, the teacher's reflective practice was essential for supporting the application of each curricular component of the course.

  10. A Traveller Information System: Minimisation of the Number of Graphs’ Nodes Involved When Processing Route Requests

    Directory of Open Access Journals (Sweden)

    Bendaoud Zakaria

    2014-12-01

    Full Text Available The number of people using public transport is continuously increasing. Transport companies want to fulfil travellers’ expectations wherever possible. However, the great number of public transport companies operating in the same area can sometimes confuse travellers as to which route they should take and how to obtain the information relative to their journey. In this paper we suggest integrating several traveller information systems from different companies into the same multimodal information system, offering companies the choice not to share their data. This encourages them to join the system. Additionally, we have minimised the number of nodes involved when processing travellers’ requests in order to simplify the calculation process. To put our plan into action, we have opted for a multi-agent system coupled with the Voronoi decomposition for managing the network.

  11. Qualified public involvement in the decision making process of siting a waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Danielle Monegalha [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Coordenacao-Geral de Recursos Humanos], e-mail: drodrigues@cnen.gov.br; Almeida, Ivan Pedro Salati de [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Coordenacao-Geral de Assuntos Internacionais], e-mail: ivsalati@cnen.gov.br

    2009-07-01

    The main objective of this paper is to identify the most important characteristics required for the qualification of local communities for participating in the process of defining a specific site for a radioactive waste repository. It also compares the strategies used by Hungary, United Kingdom and Belgium to stimulate the public participation in the decision-making process of building and operating a radioactive waste repository, considering both the stepwise process and the spontaneous candidacy. Two main aspects are discussed as prerequisites to constitute a qualified public. The first aspect is how well the person or entity can be considered an effective representative of the community affected by the repository. This means the conditions the representative has to speak on behalf of the community and participate in the decision making process as its voice. The second characteristic is the level and quality of the information that the community and its representatives must have to participate actively in the decision-making process and what can be done to improve this status. Referring to the strategy to public involvement, this paper discusses the importance of transparency in the process, aiming the credibility of the entrepreneur as the first pace to gaining the confidence of the public affected by the project. Implementing an open dialog and listening to the needs and claims of the population are the first steps to being accepted as a true partner of the community. Preliminary discussions and explanations are important to introduce the subject and to reduce beliefs of false threats in the affected community. The constitution of a local committee is suggested, to act as a legal and formal channel to facilitate the partnership between local community, neighbors and the entrepreneur in order to achieve a positive result in the whole process. (author)

  12. Variation in genes involved in epigenetic processes offers insights into tropically adapted cattle diversity

    Directory of Open Access Journals (Sweden)

    Laercio R Porto-Neto

    2014-04-01

    Full Text Available We evaluated the relevance of the BovineHD Illumina SNP chip with respect to genes involved in epigenetic processes. Genotypes for 729,068 SNP on two tropical cattle breeds of Australia were used: Brahman (n = 2,112 and Tropical Composite (n = 2,550. We used data mining approaches to compile a list of bovine protein-coding genes involved in epigenetic processes. These genes represent 9 functional categories that contain between one (histone demethylases and 99 (chromatin remodelling factors genes. A total of 3,091 SNP mapped to positions within 3,000 bp of the 193 coding regions of those genes, including 113 SNP in transcribed regions, 2,738 in intronic regions and 240 in up- or down-stream regions. For all these SNP categories, we observed differences in the allelic frequencies between Brahman and Tropical Composite cattle. These differences were larger than those observed for the entire set of 729,068 SNP (P = 1.79 x 10-5. A multidimensional scaling analysis using only the 113 SNP in transcribed regions allowed for the separation of the two populations and this separation was comparable to the one obtained with a random set of 113 SNP (Principal Component 1 r2 > 0.84. To further characterise the differences between the breeds we defined a gene-differentiation metric based on the average genotypic frequencies of SNP connected to each gene and compared both cattle populations. The 10% most differentiated genes were distributed across 10 chromosomes, with significant (P < 0.05 enrichment on BTA 3 and 10. The 10% most conserved genes were located in 12 chromosomes. We conclude that there is variation between cattle populations in genes connected to epigenetic processes, and this variation can be used to differentiate cattle breeds. More research is needed to fully characterise the use of these SNP and its potential as means to further our understanding of biological variation and epigenetic processes.

  13. Variation in genes involved in epigenetic processes offers insights into tropically adapted cattle diversity

    Science.gov (United States)

    Porto-Neto, Laercio R.; Fortes, Marina R. S.; McWilliam, Sean M.; Lehnert, Sigrid A.; Reverter, Antonio

    2014-01-01

    We evaluated the relevance of the BovineHD Illumina SNP chip with respect to genes involved in epigenetic processes. Genotypes for 729,068 SNP on two tropical cattle breeds of Australia were used: Brahman (n = 2112) and Tropical Composite (n = 2550). We used data mining approaches to compile a list of bovine protein-coding genes involved in epigenetic processes. These genes represent 9 functional categories that contain between one (histone demethylases) and 99 (chromatin remodeling factors) genes. A total of 3091 SNP mapped to positions within 3000 bp of the 193 coding regions of those genes, including 113 SNP in transcribed regions, 2738 in intronic regions and 240 in up- or down-stream regions. For all these SNP categories, we observed differences in the allelic frequencies between Brahman and Tropical Composite cattle. These differences were larger than those observed for the entire set of 729,068 SNP (P = 1.79 x 10−5). A multidimensional scaling analysis using only the 113 SNP in transcribed regions allowed for the separation of the two populations and this separation was comparable to the one obtained with a random set of 113 SNP (Principal Component 1 r2 > 0.84). To further characterize the differences between the breeds we defined a gene-differentiation metric based on the average genotypic frequencies of SNP connected to each gene and compared both cattle populations. The 10% most differentiated genes were distributed across 10 chromosomes, with significant (P < 0.05) enrichment on BTA 3 and 10. The 10% most conserved genes were located in 12 chromosomes. We conclude that there is variation between cattle populations in genes connected to epigenetic processes, and this variation can be used to differentiate cattle breeds. More research is needed to fully characterize the use of these SNP and its potential as means to further our understanding of biological variation and epigenetic processes. PMID:24795751

  14. A comparison of form processing involved in the perception of biological and nonbiological movements

    Science.gov (United States)

    Thurman, Steven M.; Lu, Hongjing

    2016-01-01

    Although there is evidence for specialization in the human brain for processing biological motion per se, few studies have directly examined the specialization of form processing in biological motion perception. The current study was designed to systematically compare form processing in perception of biological (human walkers) to nonbiological (rotating squares) stimuli. Dynamic form-based stimuli were constructed with conflicting form cues (position and orientation), such that the objects were perceived to be moving ambiguously in two directions at once. In Experiment 1, we used the classification image technique to examine how local form cues are integrated across space and time in a bottom-up manner. By comparing with a Bayesian observer model that embodies generic principles of form analysis (e.g., template matching) and integrates form information according to cue reliability, we found that human observers employ domain-general processes to recognize both human actions and nonbiological object movements. Experiments 2 and 3 found differential top-down effects of spatial context on perception of biological and nonbiological forms. When a background does not involve social information, observers are biased to perceive foreground object movements in the direction opposite to surrounding motion. However, when a background involves social cues, such as a crowd of similar objects, perception is biased toward the same direction as the crowd for biological walking stimuli, but not for rotating nonbiological stimuli. The model provided an accurate account of top-down modulations by adjusting the prior probabilities associated with the internal templates, demonstrating the power and flexibility of the Bayesian approach for visual form perception. PMID:26746875

  15. Nonlinear Memory Capacity of Parallel Time-Delay Reservoir Computers in the Processing of Multidimensional Signals.

    Science.gov (United States)

    Grigoryeva, Lyudmila; Henriques, Julie; Larger, Laurent; Ortega, Juan-Pablo

    2016-07-01

    This letter addresses the reservoir design problem in the context of delay-based reservoir computers for multidimensional input signals, parallel architectures, and real-time multitasking. First, an approximating reservoir model is presented in those frameworks that provides an explicit functional link between the reservoir architecture and its performance in the execution of a specific task. Second, the inference properties of the ridge regression estimator in the multivariate context are used to assess the impact of finite sample training on the decrease of the reservoir capacity. Finally, an empirical study is conducted that shows the adequacy of the theoretical results with the empirical performances exhibited by various reservoir architectures in the execution of several nonlinear tasks with multidimensional inputs. Our results confirm the robustness properties of the parallel reservoir architecture with respect to task misspecification and parameter choice already documented in the literature.

  16. THz Generation by Optical Rectification and Competition with Other Nonlinear Processes

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhen-Yu; HAMEAU Sophie; TIGNON Jér(o)me

    2008-01-01

    We present a study of the competition between tera-hertz (THz) generation by optical rectification in (110)Zn Te crystals,two-photon absorption,second harmonic generation and flee-carrier absorption.The two-photon nonlinear absorption coefficient,second harmonic generation efficiency and flee-carrier absorption coefficient in the THz range are measured independently.The incident pump field is shown to be depleted by two-photon absorption and the THz radiation is shown to be reduced,upon focusing,by free-carrier absorption.The reduction of the generated THz radiation upon tight focusing is explained,provided that one also takes into account diffraction effects from the sub-wavelength THz source.

  17. Modelling and prediction of complex non-linear processes by using Pareto multi-objective genetic programming

    Science.gov (United States)

    Jamali, A.; Khaleghi, E.; Gholaminezhad, I.; Nariman-zadeh, N.

    2016-05-01

    In this paper, a new multi-objective genetic programming (GP) with a diversity preserving mechanism and a real number alteration operator is presented and successfully used for Pareto optimal modelling of some complex non-linear systems using some input-output data. In this study, two different input-output data-sets of a non-linear mathematical model and of an explosive cutting process are considered separately in three-objective optimisation processes. The pertinent conflicting objective functions that have been considered for such Pareto optimisations are namely, training error (TE), prediction error (PE), and the length of tree (complexity of the network) (TL) of the GP models. Such three-objective optimisation implementations leads to some non-dominated choices of GP-type models for both cases representing the trade-offs among those objective functions. Therefore, optimal Pareto fronts of such GP models exhibit the trade-off among the corresponding conflicting objectives and, thus, provide different non-dominated optimal choices of GP-type models. Moreover, the results show that no significant optimality in TE and PE may occur when the TL of the corresponding GP model exceeds some values.

  18. Science-Grade Observing Systems as Process Observatories: Mapping and Understanding Nonlinearity and Multiscale Memory with Models and Observations

    Science.gov (United States)

    Barros, A. P.; Wilson, A. M.; Miller, D. K.; Tao, J.; Genereux, D. P.; Prat, O.; Petersen, W. A.; Brunsell, N. A.; Petters, M. D.; Duan, Y.

    2015-12-01

    Using the planet as a study domain and collecting observations over unprecedented ranges of spatial and temporal scales, NASA's EOS (Earth Observing System) program was an agent of transformational change in Earth Sciences over the last thirty years. The remarkable space-time organization and variability of atmospheric and terrestrial moist processes that emerged from the analysis of comprehensive satellite observations provided much impetus to expand the scope of land-atmosphere interaction studies in Hydrology and Hydrometeorology. Consequently, input and output terms in the mass and energy balance equations evolved from being treated as fluxes that can be used as boundary conditions, or forcing, to being viewed as dynamic processes of a coupled system interacting at multiple scales. Measurements of states or fluxes are most useful if together they map, reveal and/or constrain the underlying physical processes and their interactions. This can only be accomplished through an integrated observing system designed to capture the coupled physics, including nonlinear feedbacks and tipping points. Here, we first review and synthesize lessons learned from hydrometeorology studies in the Southern Appalachians and in the Southern Great Plains using both ground-based and satellite observations, physical models and data-assimilation systems. We will specifically focus on mapping and understanding nonlinearity and multiscale memory of rainfall-runoff processes in mountainous regions. It will be shown that beyond technical rigor, variety, quantity and duration of measurements, the utility of observing systems is determined by their interpretive value in the context of physical models to describe the linkages among different observations. Second, we propose a framework for designing science-grade and science-minded process-oriented integrated observing and modeling platforms for hydrometeorological studies.

  19. Aspects of Information Architecture involved in process mapping in Military Organizations under the semiotic perspective

    Directory of Open Access Journals (Sweden)

    Mac Amaral Cartaxo

    2016-04-01

    Full Text Available Introduction: The description of the processes to represent the activities in an organization has important call semiotic, It is the flowcharts of uses, management reports and the various forms of representation of the strategies used. The subsequent interpretation of the organization's employees involved in learning tasks and the symbols used to translate the meanings of management practices is essential role for the organization. Objective: The objective of this study was to identify evidence of conceptual and empirical, on aspects of information architecture involved in the mapping process carried out in military organizations under the semiotic perspective. Methodology: The research is characterized as qualitative, case study and the data collection technique was the semi-structured interview, applied to management advisors. Results: The main results indicate that management practices described with the use of pictorial symbols and different layouts have greater impact to explain the relevance of management practices and indicators. Conclusion: With regard to the semiotic appeal, it was found that the impact of a management report is significant due to the use of signs and layout that stimulate further reading by simplifying complex concepts in tables, diagrams summarizing lengthy descriptions.

  20. On the constituent counting rules for hard exclusive processes involving multiquark states

    CERN Document Server

    Guo, Feng-Kun; Wang, Wei

    2016-01-01

    At high energies, the cross section of a hard exclusive process at finite scattering angle falls off as a negative power of the center-of-mass energy $\\sqrt{s}$. If all involved quark-gluon compositions undergo hard momentum transfers, the scaling of the fall-off is determined by the underlying valence structures of the initial and final states, known as the constituent counting rules. It was argued in the literature that the counting rules are a powerful tool to determine the valence degrees of freedom inside multiquark states when applied to exclusive production processes. However, we demonstrate that for hadrons with hidden flavors the naive application of the constituent counting rules is problematic, since it is not mandatory for all components to participate the hard scattering at the scale $\\sqrt{s}$. The correct scaling rules can be obtained easily by using effective field theory. A few examples involving the $Z_c(3900)^\\pm$ and $X(3872)$ are discussed.

  1. Diurnal rhythmicity in biological processes involved in bioavailability of functional food factors.

    Science.gov (United States)

    Tsurusaki, Takashi; Sakakibara, Hiroyuki; Aoshima, Yoshiki; Yamazaki, Shunsuke; Sakono, Masanobu; Shimoi, Kayoko

    2013-05-01

    In the past few decades, many types of functional factors have been identified in dietary foods; for example, flavonoids are major groups widely distributed in the plant kingdom. However, the absorption rates of the functional food factors are usually low, and many of these are difficult to be absorbed in the intact forms because of metabolization by biological processes during absorption. To gain adequate beneficial effects, it is therefore mandatory to know whether functional food factors are absorbed in sufficient quantity, and then reach target organs while maintaining beneficial effects. These are the reasons why the bioavailability of functional food factors has been well investigated using rodent models. Recently, many of the biological processes have been reported to follow diurnal rhythms recurring every 24 h. Therefore, absorption and metabolism of functional food factors influenced by the biological processes may vary with time of day. Consequently, the evaluation of the bioavailability of functional food factors using rodent models should take into consideration the timing of consumption. In this review, we provide a perspective overview of the diurnal rhythm of biological processes involved in the bioavailability of functional food factors, particularly flavonoids.

  2. Involvement of the endocannabinoid system in reward processing in the human brain.

    Science.gov (United States)

    van Hell, Hendrika H; Jager, Gerry; Bossong, Matthijs G; Brouwer, Annelies; Jansma, J Martijn; Zuurman, Lineke; van Gerven, Joop; Kahn, René S; Ramsey, Nick F

    2012-02-01

    Disturbed reward processing in humans has been associated with a number of disorders, such as depression, addiction, and attention-deficit hyperactivity disorder. The endocannabinoid (eCB) system has been implicated in reward processing in animals, but in humans, the relation between eCB functioning and reward is less clear. The current study uses functional magnetic resonance imaging (fMRI) to investigate the role of the eCB system in reward processing in humans by examining the effect of the eCB agonist Δ(9)-tetrahydrocannabinol (THC) on reward-related brain activity. Eleven healthy males participated in a randomized placebo-controlled pharmacological fMRI study with administration of THC to challenge the eCB system. We compared anticipatory and feedback-related brain activity after placebo and THC, using a monetary incentive delay task. In this task, subjects are notified before each trial whether a correct response is rewarded ("reward trial") or not ("neutral trial"). Subjects showed faster reaction times during reward trials compared to neutral trials, and this effect was not altered by THC. THC induced a widespread attenuation of the brain response to feedback in reward trials but not in neutral trials. Anticipatory brain activity was not affected. These results suggest a role for the eCB system in the appreciation of rewards. The involvement of the eCB system in feedback processing may be relevant for disorders in which appreciation of natural rewards may be affected such as addiction.

  3. Numerical simulations of industrial processes involving fluid dynamics, combustion and radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ducrocq, J. [Air Liquide, Centre de Recherche Claude-Delorme, Jouy-en-Josas (France)

    1997-12-31

    Moving out of the scientific community research laboratories, computational fluid dynamics (CFD) software packages are now allowing industrials to analyse and optimize industrial processes involving the use of gases, liquids and even some two-phase fluids. Their attractiveness and their impact stems out from the opportunity they offer to bring insight into an existing unit, or even at the design stage, by displaying the spatial distribution of process relevant variables such as temperature, concentration. The filling of the spacing in between a two-layer window is a simple example. This new opportunity of visualisation is at times an unique way, when the process environment is an opaque one, such as liquid metal flowing into a tundish or when measurements of flows may be a long and tedious work, such as flows within water treatment basins. This environment we are to investigate in order to optimize can also be a harsh one, due to its high temperature level for example. Such are burners. But then pure fluid flow analysis, such as cold flow water models, has too many shortcomings. The description of combustion processes and of radiation become a necessary feature in order to describe thermal heat transfer or to locate `hot spots`. Such numerical models showing our oxycombustion expertise in glass melting will be presented. (author)

  4. A Grounded Theory Study of the Mentoring Process Involved With Undergraduate Athletic Training Students.

    Science.gov (United States)

    Pitney, William A; Ehlers, Greg G

    2004-12-01

    OBJECTIVE: To gain insight regarding the mentoring processes involving students enrolled in athletic training education programs and to create a mentoring model. DESIGN AND SETTING: We conducted a grounded theory study with students and mentors currently affiliated with 1 of 2 of the athletic training education programs accredited by the Commission on Accreditation of Allied Health Education Programs. PARTICIPANTS: Sixteen interviews were conducted, 13 with athletic training students and 3 with individuals identified as mentors. The students ranged in age from 20 to 24 years, with an average of 21.6 years. The mentors ranged from 24 to 38 years of age, with an average of 33.3 years. Participants were purposefully selected based on theoretic sampling and availability. DATA ANALYSIS: The transcribed interviews were analyzed using open-, axial-, and selective-coding procedures. Member checks, peer debriefings, and triangulation were used to ensure trustworthiness. RESULTS: Students who acknowledged having a mentor overwhelmingly identified their clinical instructor in this role. The open-coding procedures produced 3 categories: (1) mentoring prerequisites, (2) interpersonal foundations, and (3) educational dimensions. Mentoring prerequisites included accessibility, approachability, and protege initiative. Interpersonal foundations involved the mentor and protege having congruent values, trust, and a personal relationship. The educational dimensions category involved the mentor facilitating knowledge and skill development, encouraging professional perspectives, and individualizing learning. Although a student-certified athletic trainer relationship can be grounded in either interpersonal or educational aspects, the data support the occurrence of an authentic mentoring relationship when the dimensions coalesced. CONCLUSIONS: Potential mentors must not only be accessible but also approachable by a prospective protege. Mentoring takes initiative on behalf of a student and

  5. Public Involvement in Repository Site Selection for Nuclear Waste: Towards a more Dynamic View in Decision-Making Processes

    Energy Technology Data Exchange (ETDEWEB)

    Kruetli, Pius; Stauffacher, Michael; Flueeler, Thomas; Scholz, Roland W. [ETH Zuerich (Switzerland). lnst. for Human-Environment Systems (HES)

    2006-09-15

    This paper discusses possibilities of public involvement in radioactive waste management. A general overview of the radioactive waste issue is presented referring to a proposed model of the respective decision-making process. Based on the well known participation ladder by Arnstein, we differentiate various intensities of public involvement. A matrix with public involvement and the decision-making process is introduced and three prototypical patterns are discussed. We conclude that time frame, the level of public involvement and the mission have to be considered as well as techniques and the overarching context - all in all, a systematic and dynamic approach for public involvement is needed.

  6. Processes and parameters involved in modeling radionuclide transport from bedded salt repositories. Final report. Technical memorandum

    Energy Technology Data Exchange (ETDEWEB)

    Evenson, D.E.; Prickett, T.A.; Showalter, P.A.

    1979-07-01

    The parameters necessary to model radionuclide transport in salt beds are identified and described. A proposed plan for disposal of the radioactive wastes generated by nuclear power plants is to store waste canisters in repository sites contained in stable salt formations approximately 600 meters below the ground surface. Among the principal radioactive wastes contained in these canisters will be radioactive isotopes of neptunium, americium, uranium, and plutonium along with many highly radioactive fission products. A concern with this form of waste disposal is the possibility of ground-water flow occurring in the salt beds and endangering water supplies and the public health. Specifically, the research investigated the processes involved in the movement of radioactive wastes from the repository site by groundwater flow. Since the radioactive waste canisters also generate heat, temperature is an important factor. Among the processes affecting movement of radioactive wastes from a repository site in a salt bed are thermal conduction, groundwater movement, ion exchange, radioactive decay, dissolution and precipitation of salt, dispersion and diffusion, adsorption, and thermomigration. In addition, structural changes in the salt beds as a result of temperature changes are important. Based upon the half-lives of the radioactive wastes, he period of concern is on the order of a million years. As a result, major geologic phenomena that could affect both the salt bed and groundwater flow in the salt beds was considered. These phenomena include items such as volcanism, faulting, erosion, glaciation, and the impact of meteorites. CDM reviewed all of the critical processes involved in regional groundwater movement of radioactive wastes and identified and described the parameters that must be included to mathematically model their behavior. In addition, CDM briefly reviewed available echniques to measure these parameters.

  7. Development of PUNDA (Parametric Universal Nonlinear Dynamics Approximator) Models for Self-Validating Knowledge-Guided Modelling of Nonlinear Processes in Particle Accelerators \\& Industry

    Energy Technology Data Exchange (ETDEWEB)

    Sayyar-Rodsari, Bijan; Schweiger, Carl; Hartman, Eric

    2007-10-07

    The difficult problems being tackled in the accelerator community are those that are nonlinear, substantially unmodeled, and vary over time. Such problems are ideal candidates for model-based optimization and control if representative models of the problem can be developed that capture the necessary mathematical relations and remain valid throughout the operation region of the system, and through variations in system dynamics. The goal of this proposal is to develop the methodology and the algorithms for building high-fidelity mathematical representations of complex nonlinear systems via constrained training of combined first-principles and neural network models.

  8. Involvement of cortical midline structures in the processing of autobiographical information

    Directory of Open Access Journals (Sweden)

    Helder F. Araujo

    2014-07-01

    Full Text Available The term autobiographical self has been used to refer to a mental state that permits reflection on self-identity and personality and the answer to related questions (Damasio, 1998. It requires the retrieval and integrated assembly of memories of facts and events that define an individual’s biography. The neural mechanisms behind this state have not been fully elucidated, but it has been suggested that cortical midline structures (CMSs are critically involved in processing self-related information. To date, the investigation of the involvement of CMSs in autobiographical-self processes has largely focused on the comparison between self and other in relation to one domain of information, personality traits, and has yielded conflicting results. Here, we investigated how activity in CMSs varies with (1 the target of the information (self versus an acquaintance, (2 the domain of information (personality traits versus facts, and (3 differences across individuals regarding how descriptive and how important/relevant the information targeted by the questions was, and regarding the amount of memory retrieved in order to answer the questions. We used an fMRI block-design in which 19 participants answered questions about traits and biographic facts, in relation to themselves and a distant acquaintance. In addition, the participants rated the descriptiveness and importance of the information targeted by the questions, and estimated the amount of memory retrieved to answer the questions. Our results showed that CMSs were active for both facts and traits and for both self and other, and that the level of activity in the posteromedial cortices was generally higher for other than for self. Moreover, the activity in CMSs also varied with the amount of memory retrieved to answer the questions and with descriptiveness and importance of the information. These findings suggest that involvement of CMSs during the evaluation of information is not specific for self

  9. Neuronal processes involved in subjective feeling emergence: oscillatory activity during an emotional monitoring task.

    Science.gov (United States)

    Dan Glauser, Elise S; Scherer, Klaus R

    2008-06-01

    Subjective feeling, defined as the conscious experience of emotion and measured by self-report, is generally used as a manipulation check in studying emotional processes, rather than being the primary focus of research. In this paper, we report a first investigation into the processes involved in the emergence of a subjective feeling. We hypothesized that the oscillatory brain activity presumed to underlie the emergence of a subjective feeling can be measured by electroencephalographic (EEG) frequency band activity, similar to what has been shown in the literature for the conscious representation of objects. Emotional reactions were induced in participants using static visual stimuli. Episodes for which participants reported a subjective feeling were compared to those that did not lead to a conscious emotional experience, in order to identify potential differences between these two kinds of reactions at the oscillatory level. Discrete wavelet transforms of the EEG signal in gamma (31-63 Hz) and beta (15-31 Hz) bands showed significant differences between these two types of reactions. In addition, whereas beta band activities were widely distributed, differences in gamma band activity were predominantly observed in the frontal and prefrontal regions. The results are interpreted and discussed in terms of the complexity of the processes required to perform the affective monitoring task. It is suggested that future work on coherent mental representation of multimodal reaction patterns leading to the emergence of conscious emotional experience should include modifications in the time window examined and an extension of the frequency range to be considered.

  10. Non-linear dynamics of inlet film thickness during unsteady rolling process

    Science.gov (United States)

    Fu, Kuo; Zang, Yong; Gao, Zhiying; Qin, Qin; Wu, Diping

    2016-05-01

    The inlet film thickness directly affects film and stress distribution of rolling interfaces. Unsteady factors, such as unsteady back tension, may disturb the inlet film thickness. However, the current models of unsteady inlet film thickness lack unsteady disturbance factors and do not take surface topography into consideration. In this paper, based on the hydrodynamic analysis of inlet zone an unsteady rolling film model which concerns the direction of surface topography is built up. Considering the small fluctuation of inlet angle, absolute reduction, reduction ratio, inlet strip thickness and roll radius as the input variables and the fluctuation of inlet film thickness as the output variable, the non-linear relationship between the input and output is discussed. The discussion results show that there is 180° phase difference between the inlet film thickness and the input variables, such as the fluctuant absolute reduction, the fluctuant reduction ratio and non-uniform inlet strip thickness, but there is no phase difference between unsteady roll radius and the output. The inlet angle, the steady roll radius and the direction of surface topography have significant influence on the fluctuant amplitude of unsteady inlet film thickness. This study proposes an analysis method for unsteady inlet film thickness which takes surface topography and new disturbance factors into consideration.

  11. Localized surface plasmons modulated nonlinear optical processes in metal film-coupled and upconversion nanocrystals-coated nanoparticles (Conference Presentation)

    Science.gov (United States)

    Lei, Dangyuan

    2016-09-01

    In the first part of this talk, I will show our experimental investigation on the linear and nonlinear optical properties of metal film-coupled nanosphere monomers and dimers both with nanometric gaps. We have developed a new methodology - polarization resolved spectral decomposition and color decoding to "visualizing" unambiguously the spectral and radiation properties of the complex plasmonic gap modes in these hybrid nanostructures. Single-particle spectroscopic measurements indicate that these hybrid nanostructures can simultaneously enhance several nonlinear optical processes, such as second harmonic generation, two-photon absorption induced luminescence, and hyper-Raman scattering. In the second part, I will show how the polarization state of the emissions from sub-10 nm upconversion nanocrystals (UCNCs) can be modulated when they form a hybrid complex with a gold nanorod (GNR). Our single-particle scattering experiments expose how an interplay between excitation polarization and GNR orientation gives rise to an extraordinary polarized nature of the upconversion emissions from an individual hybrid nanostructure. We support our results by numerical simulations and, using Förster resonance energy transfer theory, we uncover how an overlap between the UCNC emission and GNR extinction bands as well as the mutual orientation between emission and plasmonic dipoles jointly determine the polarization state of the UC emissions.

  12. Nonlinear optical and multiphoton processes for in situ manipulation and conversion of photons: applications to energy and healthcare (Conference Presentation)

    Science.gov (United States)

    Prasad, Paras N.

    2017-02-01

    Chiral control of nonlinear optical functions holds a great promise for a wide range of applications including optical signal processing, bio-sensing and chiral bio-imaging. In chiral polyfluorene thin films, we demonstrated extremely large chiral nonlinearity. The physics of manipulating excitation dynamics for photon transformation will be discussed, along with nanochemistry control of upconversion in hierarchically built organic chromophore coupled-core-multiple shell nanostructures which enable introduce new, organic-inorganic energy transfer routes for broadband light harvesting and increased upconversion efficiency via multistep cascaded energy transfer. We are pursuing the applications of photon conversion technology in IR harvesting for photovoltaics, high contrast bioimaging, photoacoustic imaging, photodynamic therapy, and optogenetics. An important application is in Brain research and Neurophotonics for functional mapping and modulation of brain activities. Another new direction pursued is magnetic field control of light in in a chiral polymer nanocomposite to achieve large magneto-optic coefficient which can enable sensing of extremely weak magnetic field due to brain waves. Finally, we will consider the thought provoking concept of utilizing photons to quantify, through magneto-optics, and augment - through nanoptogenetics, the cognitive states, thus paving the path way to a quantified human paradigm.

  13. In-Fiber Subpicosecond Pulse Shaping for Nonlinear Optical Telecommunication Data Processing at 640 Gbit/s

    Directory of Open Access Journals (Sweden)

    J. Azaña

    2012-01-01

    Full Text Available We review recent work on all-fiber (long-period fiber grating devices for optical pulse shaping, particularly flat-top pulse generation, down to the subpicosecond range and their application for nonlinear switching (demultiplexing of optical time-division multiplexed (OTDM data signals in fiber-optic telecommunication links operating up to 640 Gbit/s. Experiments are presented demonstrating error-free 640-to-10 Gbit/s demultiplexing of the 64 tributary channels using the generated flat-top pulses for temporal gating in a Kerr-effect-based nonlinear optical loop mirror. The use of flat-top pulses has critical benefits in the demultiplexing process, including a significantly increased timing-jitter tolerance (up to ~500 fs, i.e., 30% of the bit period and the associated improvement in the bit-error-rate performance (e.g., with a sensitivity increase of up to ~13 dB as compared with the use of Gaussian-like gating pulses. Long-period fiber grating pulse shapers with reduced polarization dependence are fabricated and successfully used for polarization-independent 640-to-10 Gbit/s demultiplexing experiments.

  14. Description of Cognitive and Competence Processes Involved in the Levels of Reading Comprehension in College Students

    Directory of Open Access Journals (Sweden)

    Charles Romel Yáñez Botello

    2013-12-01

    Full Text Available This is a descriptive research whose main objective was to describe the cognitive processes involved in reading and its relation to different levels of reading comprehension. For doing so, it was chosen a sample of 124 college students of Bogotá city. Participants- men and women between 16 and 30 years old- were studying first semester of psychology. The Evaluation Test for Reading Comprehension by Arenas (2007 was applied in order to describe cognitive operations. Moreover, results related to comprehension levels were analyzed through the Rasch Model. Besides, the Angof Methodology was used to specify the competence levels. It was concluded that there are five levels of reading comprehension. It must be said that most of the students were classified in the literal and inferential reading levels. Finally, the findings and limitations of the research were discussed.

  15. Space Weather Monitoring for the IHY: Involving Students Worldwide in the Research Process

    Science.gov (United States)

    Scherrer, D.; Burress, B.; Ross, K.

    2008-06-01

    Our project explores how new methods of space weather data collection and networks of instruments can lead to innovative and exciting ways of involving audiences in the research process. We describe our space weather monitors, being distributed to high school students and universities worldwide for the International Heliophysical Year. The project includes a centralized data collection site, accessible to anyone with or without a monitor. Classroom materials, developed in conjunction with the Chabot Space & Science Center in California, are designed to introduce teachers and students to the Sun, space weather, the Earth's ionosphere, and how to use monitor data to encourage students to undertake "hands-on" research and gain experience with real scientific data. For more information, see \\url{http://sid-stanford.edu}.

  16. The SMC5/6 complex is involved in crucial processes during human spermatogenesis.

    Science.gov (United States)

    Verver, Dideke E; Langedijk, Nathalia S M; Jordan, Philip W; Repping, Sjoerd; Hamer, Geert

    2014-07-01

    Genome integrity is crucial for safe reproduction. Therefore, chromatin structure and dynamics should be tightly regulated during germ cell development. Chromatin structure and function are in large part determined by the structural maintenance of chromosomes (SMC) protein complexes, of which SMC5/6 recently has been shown to be involved in both spermatogonial differentiation and meiosis during mouse spermatogenesis. We therefore investigated the role of this complex in human spermatogenesis. We found SMC6 to be expressed in the human testis and present in a subset of type Adark and type Apale spermatogonia, all spermatocytes, and round spermatids. During human meiosis, SMC5/6 is located at the synaptonemal complex (SC), the XY body, and at the centromeres during meiotic metaphases. However, in contrast to mouse spermatogenesis, SMC6 is not located at pericentromeric heterochromatin in human spermatogenic cells, indicating subtle but perhaps important differences in not only SMC5/6 function but maybe also in maintenance of genomic integrity at the repetitive pericentromeric regions. Nonetheless, our data clearly indicate that the SMC5/6 complex, as shown in mice, is involved in numerous crucial processes during human spermatogenesis, such as in spermatogonial development, on the SC between synapsed chromosomes, and in DNA double-strand break repair on unsynapsed chromosomes during pachynema.

  17. RPL1, a Gene Involved in Epigenetic Processes Regulates Phenotypic Plasticity in Rice

    Institute of Scientific and Technical Information of China (English)

    Cui-Cui Zhang; Wen-Ya Yuan; Qi-Fa Zhang

    2012-01-01

    Organisms can adjust their phenotype in response to changing environmental conditions.This phenomenon is termed phenotypic plasticity.Despite its ubiquitous occurrence,there has been very little study on the molecular mechanism of phenotypic plasticity.In this study,we isolated a rice (Oryza sativa L.) mutant,rice plasticity 1 (rpl1),that displayed increased environment-dependent phenotypic variations.RPL1 was expressed in all tissues examined.The protein was localized in the nucleus and its distribution in the nucleus overlapped with heterochromatin.The rpl1 mutation led to an increase in DNA methylation on repetitive sequences and a decrease in overall histone acetylation.In addition,the mutation affected responses of the rice plant to phytohormones such as brassinosteroid,gibberellin,and cytokinin.Analysis of the putative rice brassinosteroid receptor OsBRI1,a key hormone signaling gene,indicated that RPL1 may be involved in the regulation of epigenomic modification of the gene.These data suggest that RPL1 regulated phenotypic plasticity likely through its involvement in epigenetic processes affecting responses of the plant to phytohormones.

  18. Streptomyces lunalinharesii strain 235 shows the potential to inhibit bacteria involved in biocorrosion processes.

    Science.gov (United States)

    Pacheco da Rosa, Juliana; Korenblum, Elisa; Franco-Cirigliano, Marcella Novaes; Abreu, Fernanda; Lins, Ulysses; Soares, Rosângela M A; Macrae, Andrew; Seldin, Lucy; Coelho, Rosalie R R

    2013-01-01

    Four actinomycete strains previously isolated from Brazilian soils were tested for their antimicrobial activity against Bacillus pumilus LF-4 and Desulfovibrio alaskensis NCIMB 13491, bacteria that are well known to be involved in biofilm formation and biocorrosion. Strain 235, belonging to the species Streptomyces lunalinharesii, inhibited the growth of both bacteria. The antimicrobial activity was seen over a wide range of pH, and after treatment with several chemicals and heat but not with proteinase K and trypsin. The antimicrobial substances present in the concentrated supernatant from growth media were partially characterized by SDS-PAGE and extracellular polypeptides were seen. Bands in the size range of 12 to 14.4 kDa caused antimicrobial activity. Transmission electron microscopy of D. alaskensis cells treated with the concentrated supernatant containing the antimicrobial substances revealed the formation of prominent bubbles, the spherical double-layered structures on the cell membrane, and the periplasmic space completely filled with electron-dense material. This is the first report on the production of antimicrobial substances by actinomycetes against bacteria involved in biocorrosion processes, and these findings may be of great relevance as an alternative source of biocides to those currently employed in the petroleum industry.

  19. Streptomyces lunalinharesii Strain 235 Shows the Potential to Inhibit Bacteria Involved in Biocorrosion Processes

    Directory of Open Access Journals (Sweden)

    Juliana Pacheco da Rosa

    2013-01-01

    Full Text Available Four actinomycete strains previously isolated from Brazilian soils were tested for their antimicrobial activity against Bacillus pumilus LF-4 and Desulfovibrio alaskensis NCIMB 13491, bacteria that are well known to be involved in biofilm formation and biocorrosion. Strain 235, belonging to the species Streptomyces lunalinharesii, inhibited the growth of both bacteria. The antimicrobial activity was seen over a wide range of pH, and after treatment with several chemicals and heat but not with proteinase K and trypsin. The antimicrobial substances present in the concentrated supernatant from growth media were partially characterized by SDS-PAGE and extracellular polypeptides were seen. Bands in the size range of 12 to 14.4 kDa caused antimicrobial activity. Transmission electron microscopy of D. alaskensis cells treated with the concentrated supernatant containing the antimicrobial substances revealed the formation of prominent bubbles, the spherical double-layered structures on the cell membrane, and the periplasmic space completely filled with electron-dense material. This is the first report on the production of antimicrobial substances by actinomycetes against bacteria involved in biocorrosion processes, and these findings may be of great relevance as an alternative source of biocides to those currently employed in the petroleum industry.

  20. Fault diagnosis of nonlinear and large-scale processes using novel modified kernel Fisher discriminant analysis approach

    Science.gov (United States)

    Shi, Huaitao; Liu, Jianchang; Wu, Yuhou; Zhang, Ke; Zhang, Lixiu; Xue, Peng

    2016-04-01

    It is pretty significant for fault diagnosis timely and accurately to improve the dependability of industrial processes. In this study, fault diagnosis of nonlinear and large-scale processes by variable-weighted kernel Fisher discriminant analysis (KFDA) based on improved biogeography-based optimisation (IBBO) is proposed, referred to as IBBO-KFDA, where IBBO is used to determine the parameters of variable-weighted KFDA, and variable-weighted KFDA is used to solve the multi-classification overlapping problem. The main contributions of this work are four-fold to further improve the performance of KFDA for fault diagnosis. First, a nonlinear fault diagnosis approach with variable-weighted KFDA is developed for maximising separation between the overlapping fault samples. Second, kernel parameters and features selection of variable-weighted KFDA are simultaneously optimised using IBBO. Finally, a single fitness function that combines erroneous diagnosis rate with feature cost is created, a novel mixed kernel function is introduced to improve the classification capability in the feature space and diagnosis accuracy of the IBBO-KFDA, and serves as the target function in the optimisation problem. Moreover, an IBBO approach is developed to obtain the better quality of solution and faster convergence speed. On the one hand, the proposed IBBO-KFDA method is first used on Tennessee Eastman process benchmark data sets to validate the feasibility and efficiency. On the other hand, IBBO-KFDA is applied to diagnose faults of automation gauge control system. Simulation results demonstrate that IBBO-KFDA can obtain better kernel parameters and feature vectors with a lower computing cost, higher diagnosis accuracy and a better real-time capacity.

  1. On the constituent counting rule for hard exclusive processes involving multi-quark states

    Science.gov (United States)

    Guo, Feng-Kun; Meißner, Ulf-G.; Wang, Wei

    2017-05-01

    At high energy, the cross section at finite scattering angle of a hard exclusive process falls off as a power of the Manderstam variable s. If all involved quark-gluon compositions undergo hard momentum transfers, the fall-off scaling is determined by the underlying valence structures of the initial and final hadrons, known as the constituent counting rule. In spite of the complication due to helicity conservation, it has been argued that when applied to exclusive process with exotic multiquark states, the counting rule is a powerful way to determine the valence degrees of freedom inside hadron exotics. In this work, we demonstrate that for hadrons with hidden flavors, the naive application of the constituent counting rule to exclusive process with hadron exotic multiquark states is problematic, since it is not mandatory for all components to participate in hard scattering at the scale . We illustrate the problems in the viewpoint based on effective field theory. We clarify the misleading results that may be obtained from the constituent counting rule in exclusive processes with exotic candidates such as , , X(3872), etc. Supported in part by DFG and NSFC through funds provided to the Sino-German CRC 110 “Symmetries and the Emergence of Structure in QCD” (NSFC Grant No. 11261130311), Thousand Talents Plan for Young Professionals, Chinese Academy of Sciences (CAS) President’s International Fellowship Initiative (PIFI) (2015VMA076), National Natural Science Foundation of China (11575110, 11655002), Natural Science Foundation of Shanghai (15DZ2272100, 15ZR1423100), Open Project Program of State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, China (Y5KF111CJ1), and by Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education.

  2. Using pulse transit delay in Z-scan to discriminate between excited-state absorption and other nonlinear processes in ZnO nanocones.

    Science.gov (United States)

    Shortell, Matthew P; Jaatinen, Esa A; Chang, Jin; Waclawik, Eric R

    2014-03-24

    We report a new approach that uses the single beam Z-scan technique, to discriminate between excited state absorption (ESA) and two and three photon nonlinear absorption. By measuring the apparent delay or advance of the pulse in reaching the detector, the nonlinear absorption can be unambiguously identified as either instantaneous or transient. The simple method does not require a large range of input fluences or sophisticated pulse-probe experimental apparatus. The technique is easily extended to any absorption process dependent on pulse width and to nonlinear refraction measurements. We demonstrate in particular, that the large nonlinear absorption in ZnO nanocones when exposed to nanosecond 532 nm pulses, is due mostly to ESA, not pure two-photon absorption.

  3. Spectra and Covariances for ’Classical’ Nonlinear Signal Processing Problems Involving Class A Non-Gaussian Noise

    Science.gov (United States)

    1991-05-21

    1 450 Del f=l./(Nf*Delz) 460 FOR t1;=i TO Mf-𔃼 470 F=is* Delf FREQUENCY 480 PLOT LGT(F),10.*LGT(X(Ms)) 490 NEXT lMs 500 PENUP 510 PAUSE 520 END 530 I...440 WINDOW -2,2,-60,0 450 LINE TYPE 3 460 GRID 1,10 470 LINE TYPE 1 480 Derlf:I./(NIf*Delz) 490 FOR Ms=1 T𔃻 MC/2 500 F=Ms* Delf FREQUENCY 510 T=X(Ms...Rdd) 620 F=F*I. I FREQUENCY 630 IF F> Delf THEN 650 640 NEXT Ns 650 PENUP 660 PAUSE 670 END 680 690 DEF FNExp(Xminus) EXP(-X) WITHOUT UNDERFLOW 700 IF

  4. Facilitated workshop method to involve stakeholders and public in decision making process in radiological emergencies

    Energy Technology Data Exchange (ETDEWEB)

    Mustonen, Raimo; Sinkko, Kari [STUK-Radiation and Nuclear Safety Authority, Helsinki (Finland). Research and Environmental Surveillance; Haemaelaeinen, Raimo P. [Helsinki Univ. of Technology, Helsinki (Finland). System Analysis Laboratory

    2006-09-15

    International organisations in radiation protection have for many years recommended that key players, e.g. authorities, expert organisations, industry, producers of foodstuffs and even the public, should be involved in the planning of protective actions in case of a nuclear accident. In this work, we have developed and tested a facilitated workshop method where representatives from various fields of the society aim to identify and evaluate systematically protective actions. Decision analysis techniques have been applied in workshops in order to find out the most feasible countermeasure strategies and to make the decision making-process transparent and auditable. The work builds on case studies where it was assumed that a hypothetical accident had led to a release of considerable amounts of radionuclides and therefore various types of countermeasures should be considered. This paper provides experiences gained in several European countries on how to facilitate this kind of workshops and how modern decision analysis techniques can be applied in the decision-making process.

  5. Heterologous expression of Pycnoporus cinnabarinus cellobiose dehydrogenase in Pichia pastoris and involvement in saccharification processes

    Directory of Open Access Journals (Sweden)

    Bey Mathieu

    2011-12-01

    Full Text Available Abstract Background Cellobiose dehydrogenase (CDH is an extracellular hemoflavoenzyme produced by lignocellulose-degrading fungi including Pycnoporus cinnabarinus. We investigated the cellulolytic system of P. cinnabarinus, focusing on the involvement of CDH in the deconstruction of lignocellulosic biomass. Results First, P. cinnabarinus growth conditions were optimized for CDH production. Following growth under cellulolytic conditions, the main components secreted were cellulases, xylanases and CDH. To investigate the contribution of P. cinnabarinus secretome in saccharification processes, the Trichoderma reesei enzymatic cocktail was supplemented with the P. cinnabarinus secretome. A significant enhancement of the degradation of wheat straw was observed with (i the production of a large amount of gluconic acid, (ii increased hemicellulose degradation, and (iii increased overall degradation of the lignocellulosic material. P. cinnabarinus CDH was heterologously expressed in Pichia pastoris to obtain large amounts of pure enzyme. In a bioreactor, the recombinant CDH (rCDH expression level reached 7800 U/L. rCDH exhibited values of biochemical parameters similar to those of the natural enzyme, and was able to bind cellulose despite the absence of a carbohydrate-binding module (CBM. Following supplementation of purified rCDH to T. reesei enzymatic cocktail, formation of gluconic acid and increased hemicellulose degradation were observed, thus confirming the previous results observed with P. cinnabarinus secretome. Conclusions We demonstrate that CDH offers an attractive tool for saccharification process enhancement due to gluconic acid production from raw lignocellulosic material.

  6. Analysis of the Proteolytic Processing of ABCA3: Identification of Cleavage Site and Involved Proteases.

    Directory of Open Access Journals (Sweden)

    Nicole Hofmann

    Full Text Available ABCA3 is a lipid transporter in the limiting membrane of lamellar bodies in alveolar type II cells. Mutations in the ABCA3 gene cause respiratory distress syndrome in new-borns and childhood interstitial lung disease. ABCA3 is N-terminally cleaved by an as yet unknown protease, a process believed to regulate ABCA3 activity.The exact site where ABCA3 is cleaved was localized using mass spectrometry (MS. Proteases involved in ABCA3 processing were identified using small molecule inhibitors and siRNA mediated gene knockdown. Results were verified by in vitro digestion of a synthetic peptide substrate mimicking ABCA3's cleavage region, followed by MS analysis.We found that cleavage of ABCA3 occurs after Lys174 which is located in the proteins' first luminal loop. Inhibition of cathepsin L and, to a lesser extent, cathepsin B resulted in attenuation of ABCA3 cleavage. Both enzymes showed activity against the ABCA3 peptide in vitro with cathepsin L being more active.We show here that, like some other proteins of the lysosomal membrane, ABCA3 is a substrate of cathepsin L. Therefore, cathepsin L may represent a potential target to therapeutically influence ABCA3 activity in ABCA3-associated lung disease.

  7. Microbial community analysis involved in the aerobic/extended-idle process performing biological phosphorus removal.

    Science.gov (United States)

    Zeng, Tian-jing; Yang, Guo-jing; Wang, Dong-bo; Li, Xiao-ming; Zheng, Wei; Yang, Qi; Zeng, Guang-ming

    2013-01-01

    Recently, it has been found that biological phosphorus removal can be achieved in an aerobic/extended-idle (AEI) process using both glucose and acetate as the sole substrate. However, the microbial consortiums involved in glucose-fed and acetate-fed systems have not yet been characterized. Thus the aims of this paper were to investigate the diversities and dynamics of bacterial communities during the acclimation period, and to quantify polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) in the systems. The phylogenetic analysis showed that the microbial communities were mainly composed of phylum Proteobacteria, Bacteroidetes, Chlorobi and another six kinds of unclassified bacteria. Fluorescence in-situ hybridization (FISH) analysis revealed that PAOs and GAOs accounted for 43 ± 7 and 16 ± 3% of all bacteria in the glucose-fed system, and 19 ± 4 and 35 ± 5% of total bacteria in the acetate-fed system, respectively. The results showed that the conventional PAOs could thrive in the AEI process, and a defined anaerobic zone was not necessarily required for putative PAOs growth.

  8. Transcriptome analysis in Ceratitis capitata to unveil genes involved in ageing-maturation process

    Directory of Open Access Journals (Sweden)

    V. San Andrés

    2013-07-01

    Full Text Available The sterile insect technique (SIT is widely used in integrated programmes against the Mediterranean fruit fly, Ceratitis capitata (Wiedemann (Diptera: Tephritidae. Information on the age distribution of insects, and more particularly, the knowledge of wild female reproductive status (mature or not at the time of the sterile male release is one of the key factors for the success of the SIT. In recent years, sequencing analysis has become an important tool in molecular biology. In this work we present a genome-wide expression analysis based on SSH (substractive sequence hybridization and EST (expressed sequence tag sequencing and macroarray expression analysis to identify signature genes related to the ageing-maturing process in C. capitata, leading to the successful identification of new putative candidate genes of reproductive status in medfly that would serve as molecular markers for ageing. We have sorted out 94 unigenes from 873 single-pass ESTs, of which 57% have homology with known genes. Ageing-maturing process in C. capitata presents a marked expression pattern accompanied by the increase of transcription level of genes involved in reproduction (vitellogenins, chorion proteins and male-specific serum proteins. Other identified cDNAs (43% with a differential expression pattern would be also candidates but deserve further studies, as they belong to the unknown function class.

  9. Are cognitive "insomnia" processes involved in the development and maintenance of delayed sleep wake phase disorder?

    Science.gov (United States)

    Richardson, Cele E; Gradisar, Michael; Barbero, Sebastian C

    2016-04-01

    Although individuals with delayed sleep wake phase disorder (DSWPD) and chronic insomnia disorder (CID) share many of the same phenomenological experiences, theories relating to the development and maintenance of these disorders are distinct in focus. Unlike CID, theory relating to DSWPD is primarily physiologically based and assumes almost no cognitive pathway. However, recent research findings suggest that individuals with DSWPD also display many of the sleep-disordered cognitive processes that were previously assumed to be unique to the insomnia experience. As such, this review aims to summarise current research findings to address the question "Could cognitive processes be involved in the development and maintenance of DSWPD?" In particular, the presence of cognitive and physiological pre-sleep arousal, sleep-related attentional bias, distorted perception of sleep and daytime functioning, dysfunctional beliefs and safety behaviours will be investigated. As this emerging area of research requires a stronger evidence base, we highlight suggestions for future investigation and provide preliminary practice points for clinicians assessing and treating "insomnia" in patients with DSWPD. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Axillary bud and pericycle involved in the thickening process of the rhizophore nodes in Smilax species

    Directory of Open Access Journals (Sweden)

    B Appezzato-da-Glória

    Full Text Available AbstractThe species of the genus Smilax, popularly known as sarsaparilla, are widely used in folk medicine due to the antirheumatic properties of its underground structures. Smilax fluminensis and S. syphilitica occur in forested areas and form thickened stems called rhizophores from which adventitious roots grow. To provide information for more accurate identification of the commercialised product and for elucidating the process of stem thickening, a morphology and anatomy study of the underground organs of the two species was conducted. The adventitious roots differ in colour and diameter depending on the stage of development. They are white and have a larger diameter in the early stages of development, but as they grow, the adventitious roots become brown and have a smaller diameter due to the disintegration of the epidermis and virtually the entire cortex. In brown roots, the covering function is then performed by the lignified endodermis and the remaining walls of the cells from the last parenchyma cortical layer. These results are similar to those found in studies of other Smilax and suggest that the anatomy of the roots can be useful for identifying fraud in commercialised materials. The thickening process of the nodal regions of the rhizophores in both species involves the activity of axillary buds and pericyclic layers.

  11. Axillary bud and pericycle involved in the thickening process of the rhizophore nodes in Smilax species.

    Science.gov (United States)

    Appezzato-da-Glória, B; Silva, J M; Soares, M K M; Soares, A N; Martins, A R

    2015-08-01

    The species of the genus Smilax, popularly known as sarsaparilla, are widely used in folk medicine due to the antirheumatic properties of its underground structures. Smilax fluminensis and S. syphilitica occur in forested areas and form thickened stems called rhizophores from which adventitious roots grow. To provide information for more accurate identification of the commercialised product and for elucidating the process of stem thickening, a morphology and anatomy study of the underground organs of the two species was conducted. The adventitious roots differ in colour and diameter depending on the stage of development. They are white and have a larger diameter in the early stages of development, but as they grow, the adventitious roots become brown and have a smaller diameter due to the disintegration of the epidermis and virtually the entire cortex. In brown roots, the covering function is then performed by the lignified endodermis and the remaining walls of the cells from the last parenchyma cortical layer. These results are similar to those found in studies of other Smilax and suggest that the anatomy of the roots can be useful for identifying fraud in commercialised materials. The thickening process of the nodal regions of the rhizophores in both species involves the activity of axillary buds and pericyclic layers.

  12. Guidelines for inclusion: Ensuring Indigenous peoples' involvement in water planning processes across South Eastern Australia

    Science.gov (United States)

    Saenz Quitian, Alejandra; Rodríguez, Gloria Amparo

    2016-11-01

    Indigenous peoples within the Murray-Darling Basin have traditionally struggled for the recognition of their cultural, social, environmental, spiritual, commercial and economic connection to the waters that they have traditionally used, as well as their right to engage in all stages of water planning processes. Despite Australian national and federal frameworks providing for the inclusion of Indigenous Australians' objectives in planning frameworks, water plans have rarely addressed these objectives in water, or the strategies to achieve them. Indeed, insufficient resources, a lack of institutional capacity in both Indigenous communities and agencies and an inadequate understanding of Indigenous people's objectives in water management have limited the extent to which Indigenous objectives are addressed in water plans within the Murray-Darling Basin. In this context, the adoption of specific guidelines to meet Indigenous requirements in relation to basin water resources is crucial to support Indigenous engagement in water planning processes. Using insights from participatory planning methods and human rights frameworks, this article outlines a set of alternative and collaborative guidelines to improve Indigenous involvement in water planning and to promote sustainable and just water allocations.

  13. Determination of Constitutive Equation for Thermo-mechanical Processing of INCONEL 718 Through Double Multivariate Nonlinear Regression Analysis

    Science.gov (United States)

    Hussain, Mirza Zahid; Li, Fuguo; Wang, Jing; Yuan, Zhanwei; Li, Pan; Wu, Tao

    2015-07-01

    The present study comprises the determination of constitutive relationship for thermo-mechanical processing of INCONEL 718 through double multivariate nonlinear regression, a newly developed approach which not only considers the effect of strain, strain rate, and temperature on flow stress but also explains the interaction effect of these thermo-mechanical parameters on flow behavior of the alloy. Hot isothermal compression experiments were performed on Gleeble-3500 thermo-mechanical testing machine in the temperature range of 1153 to 1333 K within the strain rate range of 0.001 to 10 s-1. The deformation behavior of INCONEL 718 is analyzed and summarized by establishing the high temperature deformation constitutive equation. The calculated correlation coefficient ( R) and average absolute relative error ( AARE) underline the precision of proposed constitutive model.

  14. Modeling of long-range memory processes with inverse cubic distributions by the nonlinear stochastic differential equations

    Science.gov (United States)

    Kaulakys, B.; Alaburda, M.; Ruseckas, J.

    2016-05-01

    A well-known fact in the financial markets is the so-called ‘inverse cubic law’ of the cumulative distributions of the long-range memory fluctuations of market indicators such as a number of events of trades, trading volume and the logarithmic price change. We propose the nonlinear stochastic differential equation (SDE) giving both the power-law behavior of the power spectral density and the long-range dependent inverse cubic law of the cumulative distribution. This is achieved using the suggestion that when the market evolves from calm to violent behavior there is a decrease of the delay time of multiplicative feedback of the system in comparison to the driving noise correlation time. This results in a transition from the Itô to the Stratonovich sense of the SDE and yields a long-range memory process.

  15. Experimental validation of an optimized signal processing method to handle non-linearity in swept-source optical coherence tomography.

    Science.gov (United States)

    Vergnole, Sébastien; Lévesque, Daniel; Lamouche, Guy

    2010-05-10

    We evaluate various signal processing methods to handle the non-linearity in wavenumber space exhibited by most laser sources for swept-source optical coherence tomography. The following methods are compared for the same set of experimental data: non-uniform discrete Fourier transforms with Vandermonde matrix or with Lomb periodogram, resampling with linear interpolation or spline interpolation prior to fast-Fourier transform (FFT), and resampling with convolution prior to FFT. By selecting an optimized Kaiser-Bessel window to perform the convolution, we show that convolution followed by FFT is the most efficient method. It allows small fractional oversampling factor between 1 and 2, thus a minimal computational time, while retaining an excellent image quality. (c) 2010 Optical Society of America.

  16. On the processing of highly nonlinear solitary waves and guided ultrasonic waves for structural health monitoring and nondestructive evaluation

    Science.gov (United States)

    Bagheri, Abdollah

    The in-situ measurement of thermal stress in civil and mechanical structures may prevent structural anomalies such as unexpected buckling. In the first half of the dissertation, we present a study where highly nonlinear solitary waves (HNSWs) were utilized to measure axial stress in slender beams. HNSWs are compact non-dispersive waves that can form and travel in nonlinear systems such as one-dimensional chains of particles. The effect of the axial stress acting in a beam on the propagation of HNSWs was studied. We found that certain features of the solitary waves enable the measurement of the stress. In general, most guided ultrasonic waves (GUWs)-based health monitoring approaches for structural waveguides are based on the comparison of testing data to baseline data. In the second half of the dissertation, we present a study where some baseline-free signal processing algorithms were presented and applied to numerical and experimental data for the structural health monitoring (SHM) of underwater or dry structures. The algorithms are based on one or more of the following: continuous wavelet transform, empirical mode decomposition, Hilbert transform, competitive optimization algorithm, probabilistic methods. Moreover, experimental data were also processed to extract some features from the time, frequency, and joint time-frequency domains. These features were then fed to a supervised learning algorithm based on artificial neural networks to classify the types of defect. The methods were validated using the numerical model of a plate and a pipe, and the experimental study of a plate in water. In experiment, the propagation of ultrasonic waves was induced by means of laser pulses or transducer and detected with an array of immersion transducers. The results demonstrated that the algorithms are effective, robust against noise, and able to localize and classify the damage.

  17. Analysis of acceptable spectral windows of quadratic cascaded nonlinear processes in a periodically poled lithium niobate waveguide.

    Science.gov (United States)

    Lee, Kwang Jo; Liu, Sheng; Gallo, Katia; Petropoulos, Periklis; Richardson, David J

    2011-04-25

    We report a systematic and comparative study of the acceptance bandwidths of two cascaded quadratic nonlinear processes in periodically poled lithium niobate waveguides, namely cascaded second-harmonic generation and difference-frequency generation (cSHG/DFG) and cascaded sum-frequency generation and difference-frequency generation (cSFG/DFG). We first theoretically and experimentally study the acceptance bandwidths of both the individual second-harmonic generation (SHG) and sum-frequency generation (SFG) processes in the continuous wave (CW) and pulsed-pump regimes. Our results show that the SHG bandwidth is approximately half that of the SFG process in the CW regime, whereas the SHG acceptance bandwidth can approach the CW SFG bandwidth limit when pulsed-pump is used. As a consequence we conclude that the tuning bandwidths of both cascaded processes should be similar in the pulsed pump regime once the pump pulse bandwidths approach that of SFG (i.e. the cSHG/DFG bandwidth is not limited by the CW SHG bandwidth). We confirm that this is the case experimentally.

  18. PROCESSES OF ASSIMILATION INVOLVING DENTAL STOP CONSOANTS /t, d/ IN BRASILIAN PORTUGUESE

    Directory of Open Access Journals (Sweden)

    Dermeval da HORA

    2015-06-01

    Full Text Available The major aim of this paper is to present, based on quantitative sociolinguistics, a analyse of the process of progressive assimilation that involve the dental stop consonants. First of all, one overview about the regressive assimilation, which was extensively studied in Brazilian Portuguese, will be present. Then, the contexts of progressive assimilation in the speech community of Itabaiana-PB will be analyzed. The motivation for this paper is the fact that, in the dialect from Itabaiana, the process of progressive assimilation, in words such as muito ‘many/much’ and gosto ‘like”, in which the preceding phonological context exerts influence over the following one, tend to undergo the process of regressive assimilation, such as as pote ‘pot’ and bote ‘boat’, more useful when we think about the Brazilian Portuguese. The theoretical approach underlying the research is the variation theory, or quantitative Sociolinguistics, pioneered by William Labov (1972. The data collected had already been electronically stored in the corpus from Projeto Variação Linguística da Paraíba – VALPB. The sample consists of 36 informants from the community, being stratified according to gender, age group and years of schooling. As result, the computer program Goldvarb (SANKOFF; TAGLIAMONTE; SMITH, 2005 pointed as favorite to the application of the rule: the gender (male gender, the level of schooling (no scholar historic since the primary, the following phonological context (high back vowel, the precedent phonological context (monophthong, and the tonicity (post-stressed syllable.

  19. Nonlinear Krylov acceleration of reacting flow codes

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S.; Rawat, R.; Smith, P.; Pernice, M. [Univ. of Utah, Salt Lake City, UT (United States)

    1996-12-31

    We are working on computational simulations of three-dimensional reactive flows in applications encompassing a broad range of chemical engineering problems. Examples of such processes are coal (pulverized and fluidized bed) and gas combustion, petroleum processing (cracking), and metallurgical operations such as smelting. These simulations involve an interplay of various physical and chemical factors such as fluid dynamics with turbulence, convective and radiative heat transfer, multiphase effects such as fluid-particle and particle-particle interactions, and chemical reaction. The governing equations resulting from modeling these processes are highly nonlinear and strongly coupled, thereby rendering their solution by traditional iterative methods (such as nonlinear line Gauss-Seidel methods) very difficult and sometimes impossible. Hence we are exploring the use of nonlinear Krylov techniques (such as CMRES and Bi-CGSTAB) to accelerate and stabilize the existing solver. This strategy allows us to take advantage of the problem-definition capabilities of the existing solver. The overall approach amounts to using the SIMPLE (Semi-Implicit Method for Pressure-Linked Equations) method and its variants as nonlinear preconditioners for the nonlinear Krylov method. We have also adapted a backtracking approach for inexact Newton methods to damp the Newton step in the nonlinear Krylov method. This will be a report on work in progress. Preliminary results with nonlinear GMRES have been very encouraging: in many cases the number of line Gauss-Seidel sweeps has been reduced by about a factor of 5, and increased robustness of the underlying solver has also been observed.

  20. Nonlinear regime-switching state-space (RSSS) models.

    Science.gov (United States)

    Chow, Sy-Miin; Zhang, Guangjian

    2013-10-01

    Nonlinear dynamic factor analysis models extend standard linear dynamic factor analysis models by allowing time series processes to be nonlinear at the latent level (e.g., involving interaction between two latent processes). In practice, it is often of interest to identify the phases--namely, latent "regimes" or classes--during which a system is characterized by distinctly different dynamics. We propose a new class of models, termed nonlinear regime-switching state-space (RSSS) models, which subsumes regime-switching nonlinear dynamic factor analysis models as a special case. In nonlinear RSSS models, the change processes within regimes, represented using a state-space model, are allowed to be nonlinear. An estimation procedure obtained by combining the extended Kalman filter and the Kim filter is proposed as a way to estimate nonlinear RSSS models. We illustrate the utility of nonlinear RSSS models by fitting a nonlinear dynamic factor analysis model with regime-specific cross-regression parameters to a set of experience sampling affect data. The parallels between nonlinear RSSS models and other well-known discrete change models in the literature are discussed briefly.

  1. Nonlinear Parasitic Capacitance Modelling of High Voltage Power MOSFETs in Partial SOI Process

    DEFF Research Database (Denmark)

    Fan, Lin; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2016-01-01

    : off-state, sub-threshold region, and on-state in the linear region. A high voltage power MOSFET is designed in a partial Silicon on Insulator (SOI) process, with the bulk as a separate terminal. 3D plots and contour plots of the capacitances versus bias voltages for the transistor summarize...

  2. Optimization of Nonlinear Figure-of-Merits of Integrated Power MOSFETs in Partial SOI Process

    DEFF Research Database (Denmark)

    Fan, Lin; Jørgensen, Ivan Harald Holger; Knott, Arnold

    2016-01-01

    different operating conditions. A systematic analysis of the optimization of these FOMs has not been previously established. The optimization methods are verified on a 100 V power MOSFET implemented in a 0.18 µm partial SOI process. Its FOMs are lowered by 1.3-18.3 times and improved by 22...

  3. Modeling human auditory evoked brainstem responses based on nonlinear cochlear processing

    DEFF Research Database (Denmark)

    Harte, James; Rønne, Filip Munch; Dau, Torsten

    2010-01-01

    (ABR) to transient sounds and frequency following responses (FFR) to tones. The model includes important cochlear processing stages (Zilany and Bruce, 2006) such as basilar-membrane (BM) tuning and compression, inner hair-cell (IHC) transduction, and IHC auditory-nerve (AN) synapse adaptation...

  4. Investigation of the nonlinear effects during the sedimentation process of a charged colloidal particle by direct numerical simulation.

    Science.gov (United States)

    Keller, Florian; Feist, Markus; Nirschl, Hermann; Dörfler, Willy

    2010-04-01

    In this article we study the settling process of a colloidal particle under the influence of a gravitational or centrifugal field in an unbounded electrolyte solution. Since particles in aqueous solutions normally carry a non-zero surface charge, a microscopic electric field develops which alters the sedimentation process compared to an uncharged particle. This process can be mathematically modelled via the Stokes-Poisson-Nernst-Planck system, a system of coupled partial differential equations that have to be solved in an exterior domain. After a dimensional analysis we investigate the influence of the various characteristic dimensionless numbers on the sedimentation velocity. Thereby the linear-response (weak-field) approximation that underpins almost all existing theoretical work on classical electrokinetic phenomena is relaxed, such that no additional assumption on the thickness of the double layer as well as on its displacement is needed. We show that there exists a strong influence of the fluid Reynolds number and the ionic strength on the sedimentation velocity. Further we have developed an asymptotic expansion to describe the limit of small values of the surface potential of a single particle. This expansion incorporates all nonlinear effects and extends the well-known results of Booth (1954) [1] and Ohshima et al. (1984) [2] to higher fluid Reynolds numbers.

  5. Modified kernel principal component analysis using double-weighted local outlier factor and its application to nonlinear process monitoring.

    Science.gov (United States)

    Deng, Xiaogang; Wang, Lei

    2017-10-07

    Traditional kernel principal component analysis (KPCA) based nonlinear process monitoring method may not perform well because its Gaussian distribution assumption is often violated in the real industrial processes. To overcome this deficiency, this paper proposes a modified KPCA method based on double-weighted local outlier factor (DWLOF-KPCA). In order to avoid the assumption of specific data distribution, local outlier factor (LOF) is introduced to construct two LOF-based monitoring statistics, which are used to substitute for the traditional T(2) and SPE statistics, respectively. To provide better online monitoring performance, a double-weighted LOF method is further designed, which assigns the weights for each component to highlight the key components with significant fault information, and uses the moving window to weight the historical statistics for reducing the drastic fluctuations in the monitoring results. Finally, simulations on a numerical example and the Tennessee Eastman (TE) benchmark process are used to demonstrate the superiority of the proposed DWLOF-KPCA method. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Development of brain networks involved in spoken word processing of Mandarin Chinese

    Science.gov (United States)

    Cao, Fan; Khaild, Kainat; Lee, Rebecca; Brennan, Christine; Yang, Yanhui; Li, Kuncheng; Bolger, Donald J.; Booth, James R.

    2010-01-01

    Developmental differences in phonological and orthographic processing of Chinese spoken words were examined in 9-year-olds, 11-year-olds and adults using functional magnetic resonance imaging (fMRI). Rhyming and spelling judgments were made to two-character words presented sequentially in the auditory modality. Developmental comparisons between adults and both groups of children combined showed that age-related changes in activation in visuo-orthographic regions depended on task. There were developmental increases in left inferior temporal gyrus and right inferior occipital gyrus in the spelling task, suggesting more extensive visuo-orthographic processing in a task that required access to these representations. Conversely, there were developmental decreases in activation in left fusiform gyrus and left middle occipital gyrus in the rhyming task, suggesting that the development of reading is marked by reduced involvement of orthography in a spoken language task that does not require access to these orthographic representations. Developmental decreases may arise from the existence of extensive homophony (auditory words that have multiple spellings) in Chinese. In addition, we found that 11-year-olds and adults showed similar activation in left superior temporal gyrus across tasks, with both groups showing greater activation than 9-year-olds. This pattern suggests early development of perceptual representations of phonology. In contrast, 11-year-olds and 9-year-olds showed similar activation in left inferior frontal gyrus across tasks, with both groups showing weaker activation than adults. This pattern suggests late development of controlled retrieval and selection of lexical representations. Altogether, this study suggests differential effects of character acquisition on development of components of the language network in Chinese as compared to previous reports on alphabetic languages. PMID:20884355

  7. System Model Bias Processing Approach for Regional Coordinated States Information Involved Filtering

    Directory of Open Access Journals (Sweden)

    Zebo Zhou

    2016-01-01

    Full Text Available In the Kalman filtering applications, the conventional dynamic model which connects the states information of two consecutive epochs by state transition matrix is usually predefined and assumed to be invariant. Aiming to improve the adaptability and accuracy of dynamic model, we propose multiple historical states involved filtering algorithm. An autoregressive model is used as the dynamic model which is subsequently combined with observation model for deriving the optimal window-recursive filter formulae in the sense of minimum mean square error principle. The corresponding test statistics characteristics of system residuals are discussed in details. The test statistics of regional predicted residuals are then constructed in a time-window for model bias testing with two hypotheses, that is, the null and alternative hypotheses. Based on the innovations test statistics, we develop a model bias processing procedure including bias detection, location identification, and state correction. Finally, the minimum detectable bias and bias-to-noise ratio are both computed for evaluating the internal and external reliability of overall system, respectively.

  8. An ENU mutagenesis screen identifies novel and known genes involved in epigenetic processes in the mouse.

    Science.gov (United States)

    Daxinger, Lucia; Harten, Sarah K; Oey, Harald; Epp, Trevor; Isbel, Luke; Huang, Edward; Whitelaw, Nadia; Apedaile, Anwyn; Sorolla, Anabel; Yong, Joan; Bharti, Vandhana; Sutton, Joanne; Ashe, Alyson; Pang, Zhenyi; Wallace, Nathan; Gerhardt, Daniel J; Blewitt, Marnie E; Jeddeloh, Jeffrey A; Whitelaw, Emma

    2013-01-01

    We have used a sensitized ENU mutagenesis screen to produce mouse lines that carry mutations in genes required for epigenetic regulation. We call these lines Modifiers of murine metastable epialleles (Mommes). We report a basic molecular and phenotypic characterization for twenty of the Momme mouse lines, and in each case we also identify the causative mutation. Three of the lines carry a mutation in a novel epigenetic modifier, Rearranged L-myc fusion (Rlf), and one gene, Rap-interacting factor 1 (Rif1), has not previously been reported to be involved in transcriptional regulation in mammals. Many of the other lines are novel alleles of known epigenetic regulators. For two genes, Rlf and Widely-interspaced zinc finger (Wiz), we describe the first mouse mutants. All of the Momme mutants show some degree of homozygous embryonic lethality, emphasizing the importance of epigenetic processes. The penetrance of lethality is incomplete in a number of cases. Similarly ,abnormalities in phenotype seen in the heterozygous individuals of some lines occur with incomplete penetrance. Recent advances in sequencing enhance the power of sensitized mutagenesis screens to identify the function of previously uncharacterized factors and to discover additional functions for previously characterized proteins. The observation of incomplete penetrance of phenotypes in these inbred mutant mice, at various stages of development, is of interest. Overall, the Momme collection of mouse mutants provides a valuable resource for researchers across many disciplines.

  9. Exit of Plasmodium sporozoites from oocysts is an active process that involves the circumsporozoite protein.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available Plasmodium sporozoites develop within oocysts residing in the mosquito midgut. Mature sporozoites exit the oocysts, enter the hemolymph, and invade the salivary glands. The circumsporozoite (CS protein is the major surface protein of salivary gland and oocyst sporozoites. It is also found on the oocyst plasma membrane and on the inner surface of the oocyst capsule. CS protein contains a conserved motif of positively charged amino acids: region II-plus, which has been implicated in the initial stages of sporozoite invasion of hepatocytes. We investigated the function of region II-plus by generating mutant parasites in which the region had been substituted with alanines. Mutant parasites produced normal numbers of sporozoites in the oocysts, but the sporozoites were unable to exit the oocysts. In in vitro as well, there was a profound delay, upon trypsin treatment, in the release of mutant sporozoites from oocysts. We conclude that the exit of sporozoites from oocysts is an active process that involves the region II-plus of CS protein. In addition, the mutant sporozoites were not infective to young rats. These findings provide a new target for developing reagents that interfere with the transmission of malaria.

  10. The role of patient involvement in the diagnostic process in internal medicine: a cognitive approach.

    Science.gov (United States)

    Lucchiari, Claudio; Pravettoni, Gabriella

    2013-07-01

    Much cognitive and clinical research has addressed clinical reasoning, pointing out that physicians often have difficulties in following a linear course when making accurate diagnoses. Some authors suspect that physicians make mistakes because they unknowingly fail to observe the laws of formal logic and that their reasoning becomes influenced by contextual factors. In this paper, we introduce some basic principles of the cognitive approach to medical decision making and we describe the cognitive balanced model. Then we discuss the relationship between construction of mental models, cognitive biases and patient involvement by the use of a clinical vignette. Medical decisions may be considered fundamentally biased since the use of judgment heuristics and a combination of cognitive-related and system-related factors limit physicians' rationality. While traditional understanding of clinical reasoning has failed to consider contextual factors, most techniques designed to avoid biases seem to fail in promoting sound and safer medical practice. In particular, we argue that an unbiased process requires the use of a cognitive balanced model, in which analytical and intuitive mind skills should be properly integrated. In order to improve medical decision making and thereby lessen incidence of adverse events, it is fundamental to include the patient perspective in a balanced model. Physicians and patients should improve their collective intelligence by sharing mental models within a framework of distributed intelligence. Copyright © 2013 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  11. What have we learned about the processes involved in the Iowa Gambling Task from developmental studies?

    Directory of Open Access Journals (Sweden)

    Mathieu eCassotti

    2014-08-01

    Full Text Available Developmental studies using the Iowa Gambling Task (IGT or child-friendly adaptations of the IGT converged in showing that children and adolescents exhibit a strong bias in favor of disadvantageous choices whereas adults learn to decide advantageously during the course of the task. In the present article, we reviewed developmental studies that used the IGT or child-friendly adaptations of the IGT to show how these findings provide a better understanding of the processes involved in decision-making under uncertainty. For instance, developmental studies have underlined that until late adolescence, the dominant strategy is to focus only on the frequency of punishment and to choose among options with infrequent losses. Indeed, school-aged children and adolescents’ choices in the IGT seem to be guided by the loss frequency leading them to fail in distinguishing between advantageous and disadvantageous options. In addition, recent developmental studies revealed that adults switch less often after losses than school-aged children and adolescents. These findings suggest that psychological tolerance to loss may facilitate learning the characteristics of each option, which in turn improves the ability to choose advantageously. In conclusion, developmental studies help us refine our understanding of decision-making.

  12. Measuring cognitive processes involved in the web search: log files, eye-movements and cued rertospective reports

    NARCIS (Netherlands)

    Argelagos, Esther; Jarodzka, Halszka; Pifarre, Manoli

    2011-01-01

    Argelagós, E., Jarodzka, H., & Pifarré, M. (2011, August). Measuring cognitive processes involved in web search: log files, eye-movements and cued retrospective reports compared. Presentation at EARLI, Exeter, UK.

  13. An Investigation into the Involvement of California Central Valley High School Students with Disabilities in the IEP Process

    Science.gov (United States)

    Anderson, Cheryle Ann

    2012-01-01

    The purpose of this study was to investigate the involvement of California Central Valley high school students with disabilities in the Individual Education Plan (IEP) process. Specifically, this study investigated the involvement of students with disabilities in the development of the IEP and IEP meetings. In addition, this study explored the…

  14. An Investigation into the Involvement of California Central Valley High School Students with Disabilities in the IEP Process

    Science.gov (United States)

    Anderson, Cheryle Ann

    2012-01-01

    The purpose of this study was to investigate the involvement of California Central Valley high school students with disabilities in the Individual Education Plan (IEP) process. Specifically, this study investigated the involvement of students with disabilities in the development of the IEP and IEP meetings. In addition, this study explored the…

  15. Equilibrium theory-based analysis of nonlinear waves in separation processes.

    Science.gov (United States)

    Mazzotti, Marco; Rajendran, Arvind

    2013-01-01

    Different areas of engineering, particularly separation process technology, deal with one-dimensional, nonstationary processes that under reasonable assumptions, namely negligible dispersion effects and transport resistances, are described by mathematical models consisting of systems of first-order partial differential equations. Their behavior is characterized by continuous or discontinuous composition (or thermal) fronts that propagate along the separation unit. The equilibrium theory (i.e., the approach discussed here to determine the solution to these model equations) predicts this with remarkable accuracy, despite the simplifications and assumptions. Interesting applications are in adsorption, chromatography and ion-exchange, distillation, gas injection, heat storage, sedimentation, precipitation, and dissolution waves. We show how mathematics can enlighten the engineering aspects, and we guide the researcher not only to reach a synthetic understanding of properties of fundamental and applicative interest but also to discover new, unexpected, and fascinating phenomena. The tools presented here are useful to teachers, researchers, and practitioners alike.

  16. Linear and nonlinear post-processing of numerically forecasted surface temperature

    Directory of Open Access Journals (Sweden)

    M. Casaioli

    2003-01-01

    Full Text Available In this paper we test different approaches to the statistical post-processing of gridded numerical surface air temperatures (provided by the European Centre for Medium-Range Weather Forecasts onto the temperature measured at surface weather stations located in the Italian region of Puglia. We consider simple post-processing techniques, like correction for altitude, linear regression from different input parameters and Kalman filtering, as well as a neural network training procedure, stabilised (i.e. driven into the absolute minimum of the error function over the learning set by means of a Simulated Annealing method. A comparative analysis of the results shows that the performance with neural networks is the best. It is encouraging for systematic use in meteorological forecast-analysis service operations.

  17. New Robust Nonlinear Controller Design Based on Predictive Control for Industrial Processes

    Directory of Open Access Journals (Sweden)

    Hossein Esfroghy

    2007-12-01

    Full Text Available In this paper a new sliding mode controller based on predictive control is used for the first order system, which is a good model for the industrial process. In this method a developed predictive control is used to optimize the sliding mode control including sliding surface and switching function coefficient at every moment. A new smooth function is used to reduce the chattering problems. Simulation results show the high effectiveness of the proposed controller.

  18. Nonlinear mathematical models for simulation modeling of dynamic processes in feed systems of cutter loaders

    Energy Technology Data Exchange (ETDEWEB)

    Gorbatov, P.A.; Plyungin, A.V. (Donetskii Politekhnicheskii Institut (USSR))

    1990-12-01

    Presents calculation methods and mathematical models of dynamic processes that occur in feed systems of cutter loaders with rigid pulling elements. Characteristics of dynamic interactions between driving wheels and the working section of the pulling system are taken into account. Mathematical models are given that describe the dynamic operation of the feed system. A method for calculation of a hydraulic vibration compensating system and its mathematical model is presented. Effectiveness of the vibration compensating system is discussed. 2 refs.

  19. A straightforward approximate analysis of Kerr nonlinear processes in sub-wavelength diameter optical fiber with better accuracy over variational technique

    Science.gov (United States)

    Sadhu, Arunangshu; Sarkar, Somenath

    2016-05-01

    We report a simple and straightforward approximate analysis to investigate the effect of Kerr type nonlinear optical processes in sub-wavelength diameter step index optical fibers based on Marcuse method in single mode region. Optimum core diameters of such fibers, predicted by us, together with relevant core nonlinearity coefficient and effective area are seen to be compatible with the analytical values indicating the validity of this novel application of the elegant approximate method. However, the corresponding values, obtained by earlier variational method, show larger discrepancy with analytical findings in comparison with ours. Also, maximum enhancement of nonlinear processes within single mode region, confirming almost the analytical method, assures less diffraction. Formulations, coupled with simplicity and novelty of the present analysis, should find wide use by system users and experimentalists in this emerging area.

  20. Analog CMOS Nonlinear Cells and Their Applications in VLSI Signal and Information Processing

    Science.gov (United States)

    Khachab, Nabil Ibrahim

    1990-01-01

    The development of reconfigurable analog CMOS building blocks and their applications in analog VLSI is discussed and introduced in much the same way a logic gate is used in digital VLSI. They simultaneously achieve four -quadrant multiplication and division. These applications include multiplication, signal squaring, division, signal inversion, amplitude modulation. New all MOS implementations of the Hopfield like neural networks are developed by using the new cells. In addition new and novel techniques for sensor linearization and for MOSFET-C programmable-Q and omega_{n} filters are introduced. The new designs are simple, versatile, programmable and make effective use of analog CAD tools. Moreover, they are easily extendable to other technologies such as GaAs and BiCMOS. The objective of these designs is to achieve reduction in Silicon area and power consumption and reduce the interconnections between cells. It is also sought to provide a robust design that is CAD-compatible and make effective use of the standard cell library approach. This will offer more versatility and flexibility for analog signal processing systems and neural networks. Some of these new cells and a 3-neuron neural system are fabricated in a 2mum CMOS process. Experimental results of these circuits verify the validity of this new design approach.

  1. Nonlinear electrodynamics in cytoskeletal protein lattices

    Energy Technology Data Exchange (ETDEWEB)

    Hameroff, S.R.; Smith, S.A.; Watt, R.C.

    1983-01-01

    Cytoskeletal lattice proteins including microtubules are particularly involved in dynamic regulation of intracellular movements and activities. This paper considers possibilities and implications of biological information processing due to coupling of Davydov solitons, Frohlich coherent oscillations and other nonlinear electrodynamic phenomena to conformational states of the grid-like polymer subunits of cytoskeletal microtubules. 39 references.

  2. SYNTHESIS AND OPTICAL PROPERTIES OF A NOVEL ORGANIC/INORGANIC HYBRID NONLINEAR OPTICAL POLYMER VIA SOL-GEL PROCESS

    Institute of Scientific and Technical Information of China (English)

    Hong-xia Xi; Zhong Li; Zhao-xi Liang

    2001-01-01

    A new organic/inorganic hybrid nonlinear optical (NLO) material was developed by the sol-gel process of an alkoxysilane dye with tetraethoxysilane. A NLO moiety based on 4-nitro-4′-hydroxy azobenzene was covalently bonded to the triethoxysilane derivative, i.e. γ-isocyanatopropyl triethoxysilane. The preparation process and properties of the sol-gel derived NLO polymer were studied and characterized by SEM, FTIR, 1H-NMR, UV-Vis, DSC and second harmonic generation (SHG) measurement. The results indicated that the chemical bonding of the chromophores to the inorganic SiO2 networks induces Iow dipole alignment relaxation and preferable orientational stability. The SHG measurements also showed that the bonded polymer film containing 75 wt% of the akoxysilane dye has a high electro-optic coefficient (r33) of7. 1 pm/V at 1.1 μm wavelength, and exhibit good SHG stability, the r33 values can maintain about 92.7% of its initial value at room temperature for 90 days, and can maintain about 59.3% at 100℃ for 300 min.``

  3. High-order nonlinear optical processes in ablated carbon-containing materials: Recent approaches in development of the nonlinear spectroscopy using harmonic generation in the extreme ultraviolet range

    Science.gov (United States)

    Ganeev, R. A.

    2017-08-01

    The nonlinear spectroscopy using harmonic generation in the extreme ultraviolet range became a versatile tool for the analysis of the optical, structural and morphological properties of matter. The carbon-contained materials have shown the advanced properties among other studied species, which allowed both the definition of the role of structural properties on the nonlinear optical response and the analysis of the fundamental features of carbon as the attractive material for generation of coherent short-wavelength radiation. We review the studies of the high-order harmonic generation by focusing ultrashort pulses into the plasmas produced during laser ablation of various organic compounds. We discuss the role of ionic transitions of ablated carbon-containing molecules on the harmonic yield. We also show the similarities and distinctions of the harmonic and plasma spectra of organic compounds and graphite. We discuss the studies of the generation of harmonics up to the 27th order (λ = 29.9 nm) of 806 nm radiation in the boron carbide plasma and analyze the advantages and disadvantages of this target compared with the ingredients comprising B4C (solid boron and graphite) by comparing plasma emission and harmonic spectra from three species. We also show that the coincidence of harmonic and plasma emission wavelengths in most cases does not cause the enhancement or decrease of the conversion efficiency of this harmonic.

  4. Multi input single output model predictive control of non-linear bio-polymerization process

    Energy Technology Data Exchange (ETDEWEB)

    Arumugasamy, Senthil Kumar; Ahmad, Z. [School of Chemical Engineering, Univerisiti Sains Malaysia, Engineering Campus, Seri Ampangan,14300 Nibong Tebal, Seberang Perai Selatan, Pulau Pinang (Malaysia)

    2015-05-15

    This paper focuses on Multi Input Single Output (MISO) Model Predictive Control of bio-polymerization process in which mechanistic model is developed and linked with the feedforward neural network model to obtain a hybrid model (Mechanistic-FANN) of lipase-catalyzed ring-opening polymerization of ε-caprolactone (ε-CL) for Poly (ε-caprolactone) production. In this research, state space model was used, in which the input to the model were the reactor temperatures and reactor impeller speeds and the output were the molecular weight of polymer (M{sub n}) and polymer polydispersity index. State space model for MISO created using System identification tool box of Matlab™. This state space model is used in MISO MPC. Model predictive control (MPC) has been applied to predict the molecular weight of the biopolymer and consequently control the molecular weight of biopolymer. The result shows that MPC is able to track reference trajectory and give optimum movement of manipulated variable.

  5. All-Optical Signal processing using Highly Nonlinear Photonic Crystal Fiber

    DEFF Research Database (Denmark)

    Andersen, Peter Andreas

    2006-01-01

    The use of HNL-PCF in optical communication systems has been investigated in this thesis. The investigation has been done with respect to the future of telecommunications in an all-optical system. The PCFs used have all been used for all-optical signal processing as part of an optical component...... and the possibility of large differences between the refractive indices of the core and the cladding by using air-holes, makes PCFs suited for custom made components. By testing a HNL-PCF as a medium for supercontinuum generation at various dispersion values and at the same time using that supercontinuum...... of modulation format of the signal. The modulation format is also dependent on transmission in the optical system and dependent on the pulse source used to generate the supercontinuum. It is believed that by satisfying strict demands on the pulse sources and the fiber design, could the use of a supercontinuum...

  6. Discontinuous Galerkin methods on graphics processing units for nonlinear hyperbolic conservation laws

    CERN Document Server

    Fuhry, Martin; Krivodonova, Lilia

    2016-01-01

    We present a novel implementation of the modal discontinuous Galerkin (DG) method for hyperbolic conservation laws in two dimensions on graphics processing units (GPUs) using NVIDIA's Compute Unified Device Architecture (CUDA). Both flexible and highly accurate, DG methods accommodate parallel architectures well as their discontinuous nature produces element-local approximations. High performance scientific computing suits GPUs well, as these powerful, massively parallel, cost-effective devices have recently included support for double-precision floating point numbers. Computed examples for Euler equations over unstructured triangle meshes demonstrate the effectiveness of our implementation on an NVIDIA GTX 580 device. Profiling of our method reveals performance comparable to an existing nodal DG-GPU implementation for linear problems.

  7. Self-Organized Criticality in Astrophysics The Statistics of Nonlinear Processes in the Universe

    CERN Document Server

    Aschwanden, Markus

    2011-01-01

    The concept of ‘self-organized criticality’ (SOC) has been applied to a variety of problems, ranging from population growth and traffic jams to earthquakes, landslides and forest fires. The technique is now being applied to a wide range of phenomena in astrophysics, such as planetary magnetospheres, solar flares, cataclysmic variable stars, accretion disks, black holes and gamma-ray bursts, and also to phenomena in galactic physics and cosmology. Self-organized Criticality in Astrophysics introduces the concept of SOC and shows that, due to its universality and ubiquity, it is a law of nature. The theoretical framework and specific physical models are described, together with a range of applications in various aspects of astrophyics. The mathematical techniques, including the statistics of random processes, time series analysis, time scale and waiting time distributions, are presented and the results are applied to specific observations of astrophysical phenomena.

  8. Active pharmaceutical ingredient (API) production involving continuous processes – A process system engineering (PSE)-assisted design framework

    DEFF Research Database (Denmark)

    Cervera Padrell, Albert Emili; Skovby, Tommy; Kiil, Søren

    2012-01-01

    A systematic framework is proposed for the design of continuous pharmaceutical manufacturing processes. Specifically, the design framework focuses on organic chemistry based, active pharmaceutical ingredient (API) synthetic processes, but could potentially be extended to biocatalytic and fermenta...

  9. Institutional and strategic choice perspectives on board involvement in the strategic decision process.

    Science.gov (United States)

    Judge, W Q; Zeithaml, C P

    1992-10-01

    The level of a board of directors' involvement in strategic decisions can be viewed as an institutional response or as a strategic adaptation to external pressures for greater board involvement. We examined the antecedents and effects of board involvement from both the institutional and strategic choice perspectives. Data obtained from personal interviews with 114 board members and archival records indicated that board size and levels of diversification and insider representation were negatively related to board involvement, and organizational age was positively related to it. Furthermore, we found board involvement to be positively related to financial performance after controlling for industry and size effects. Overall, the results suggest that both theoretical perspectives are necessary for a comprehensive description of the strategic role of boards.

  10. Integrating Information: An Analysis of the Processes Involved and the Products Generated in a Written Synthesis Task

    Science.gov (United States)

    Sole, Isabel; Miras, Mariana; Castells, Nuria; Espino, Sandra; Minguela, Marta

    2013-01-01

    The case study reported here explores the processes involved in producing a written synthesis of three history texts and their possible relation to the characteristics of the texts produced and the degree of comprehension achieved following the task. The processes carried out by 10 final-year compulsory education students (15 and 16 years old) to…

  11. Rho family GTP binding proteins are involved in the regulatory volume decrease process in NIH3T3 mouse fibroblasts

    DEFF Research Database (Denmark)

    Pedersen, Stine F; Beisner, Kristine H; Willumsen, Berthe M

    2002-01-01

    The role of Rho GTPases in the regulatory volume decrease (RVD) process following osmotic cell swelling is controversial and has so far only been investigated for the swelling-activated Cl- efflux. We investigated the involvement of RhoA in the RVD process in NIH3T3 mouse fibroblasts, using wild-...

  12. X inactivation counting and choice is a stochastic process : evidence for involvement of an X-linked activator

    NARCIS (Netherlands)

    Monkhorst, Kim; Jonkers, Iris; Rentmeester, Eveline; Grosveld, Frank; Gribnau, Joost

    2008-01-01

    Female mammalian cells achieve dosage compensation of X-encoded genes by X chromosome inactivation (XCI). This process is thought to involve X chromosome counting and choice. To explore how this process is initiated, we analyzed XCI in tetraploid XXXX, XXXY, and XXYY embryonic stem cells and found t

  13. Ultrafast and nonlinear optical characterization of optical limiting processes in fullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Kohlman, R.; Klimov, V.; Shi, X. [and others

    1997-10-01

    The authors present recent results of broadband femotosecond (fs) transient absorption (TA) and broadband nanosecond (ns) optical limiting (OL) studies of C{sub 60} and derivatized C{sub 60}. Improvements in measurement techniques for fs TA spectra provide sensitivity to 10{sup {minus}5} in differential transmission, allowing detailed comparison of excited-state spectra with established energy level diagrams, as well as comparison of the ratio of triplet to singlet excited-state absorption cross sections from TA spectra with those obtained by modeling time transients at different wavelengths. For derivatized fullerenes, which provide enhanced solubility and a ground-state absorption extended into the infrared compared with C{sub 60} there is no spectral region where the triplet absorption cross section dominates the singlet as strongly as demonstrating broadband limiting in all 6, 6 mono-adducts and neat C{sub 60}. The authors report new approaches to processing sol-gel encapsulated fullerenes to improve the OL performance of solid-state materials to approach the response of solution limiters.

  14. Active pharmaceutical ingredient (API) production involving continuous processes--a process system engineering (PSE)-assisted design framework.

    Science.gov (United States)

    Cervera-Padrell, Albert E; Skovby, Tommy; Kiil, Søren; Gani, Rafiqul; Gernaey, Krist V

    2012-10-01

    A systematic framework is proposed for the design of continuous pharmaceutical manufacturing processes. Specifically, the design framework focuses on organic chemistry based, active pharmaceutical ingredient (API) synthetic processes, but could potentially be extended to biocatalytic and fermentation-based products. The method exploits the synergic combination of continuous flow technologies (e.g., microfluidic techniques) and process systems engineering (PSE) methods and tools for faster process design and increased process understanding throughout the whole drug product and process development cycle. The design framework structures the many different and challenging design problems (e.g., solvent selection, reactor design, and design of separation and purification operations), driving the user from the initial drug discovery steps--where process knowledge is very limited--toward the detailed design and analysis. Examples from the literature of PSE methods and tools applied to pharmaceutical process design and novel pharmaceutical production technologies are provided along the text, assisting in the accumulation and interpretation of process knowledge. Different criteria are suggested for the selection of batch and continuous processes so that the whole design results in low capital and operational costs as well as low environmental footprint. The design framework has been applied to the retrofit of an existing batch-wise process used by H. Lundbeck A/S to produce an API: zuclopenthixol. Some of its batch operations were successfully converted into continuous mode, obtaining higher yields that allowed a significant simplification of the whole process. The material and environmental footprint of the process--evaluated through the process mass intensity index, that is, kg of material used per kg of product--was reduced to half of its initial value, with potential for further reduction. The case-study includes reaction steps typically used by the pharmaceutical

  15. Socialization Values and Parenting Practices as Predictors of Parental Involvement in Their Children's Educational Process

    NARCIS (Netherlands)

    Kikas, Eve; Tulviste, Tiia; Peets, Kätlin

    2014-01-01

    Research Findings: The purpose of this study was to examine associations between parental socialization values (including inconsistency in values), parenting practices, and parental involvement in their children's education. Altogether 242 Estonian mothers and fathers of first-grade children partici

  16. Socialization Values and Parenting Practices as Predictors of Parental Involvement in Their Children's Educational Process

    NARCIS (Netherlands)

    Kikas, Eve; Tulviste, Tiia; Peets, Kätlin

    2014-01-01

    Research Findings: The purpose of this study was to examine associations between parental socialization values (including inconsistency in values), parenting practices, and parental involvement in their children's education. Altogether 242 Estonian mothers and fathers of first-grade children

  17. Power relations and contrasting conceptions of evidence in patient-involvement processes used to inform health funding decisions in Australia.

    Science.gov (United States)

    Lopes, Edilene; Carter, Drew; Street, Jackie

    2015-06-01

    We collected and analysed views of key stakeholders on the processes used to involve patient organisations in health care funding decision making in Australia. We conducted 12 semi-structured interviews with patient organisation representatives and members of Advisory Committees that provide advice to the Australian Department of Health and employ Health Technology Assessment (HTA) as an evaluation framework. Using two theoretical frameworks, we analysed structural and contextual elements pertaining to the involvement processes. The findings reported in this article relate to interviewees' perspectives on contextual elements, analysed using a Foucauldian lens. These elements include: the perspectives of marginalised voices; the diversity of views on what ought to be considered valid evidence in a HTA setting; and the relationships between stakeholders, along with how these relationships impact on involvement processes and the outcomes of those processes. The findings demonstrate that the involvement processes currently used are deemed inadequate by both patient organisation representatives and Advisory Committee members, but for different reasons connected to how different stakeholders conceptualise evidence. Advisory Committee members viewed evidence as encompassing clinical outcomes and patient preferences, whereas patient organisation representatives tended to view evidence as encompassing aspects not directly related to a disease entity, such as the social and emotional aspects of patients' experiences in living with illness. Patient organisation representatives reported interacting with other stakeholders (especially industry) to increase the influence of their conception of evidence on decision making. The use of this strategy by interviewees illustrates how power struggles occur in government decision-making processes which involve both medical expertise and patients' accounts. Such struggles, and the power differentials they reflect, need to be considered

  18. Strategic Co-Location in a Hybrid Process Involving Desalination and Pressure Retarded Osmosis (PRO)

    OpenAIRE

    Krantz, William B.; Anthony G. Fane; Tzyy Haur Chong; Chuyang Y. Tang; Sim, Victor S.T.; Qianhong She

    2013-01-01

    This paper focuses on a Hybrid Process that uses feed salinity dilution and osmotic power recovery from Pressure Retarded Osmosis (PRO) to achieve higher overall water recovery. This reduces the energy consumption and capital costs of conventional seawater desalination and water reuse processes. The Hybrid Process increases the amount of water recovered from the current 66.7% for conventional seawater desalination and water reuse processes to a potential 80% through the use of reclaimed water...

  19. Topological approximation of the nonlinear Anderson model

    Science.gov (United States)

    Milovanov, Alexander V.; Iomin, Alexander

    2014-06-01

    We study the phenomena of Anderson localization in the presence of nonlinear interaction on a lattice. A class of nonlinear Schrödinger models with arbitrary power nonlinearity is analyzed. We conceive the various regimes of behavior, depending on the topology of resonance overlap in phase space, ranging from a fully developed chaos involving Lévy flights to pseudochaotic dynamics at the onset of delocalization. It is demonstrated that the quadratic nonlinearity plays a dynamically very distinguished role in that it is the only type of power nonlinearity permitting an abrupt localization-delocalization transition with unlimited spreading already at the delocalization border. We describe this localization-delocalization transition as a percolation transition on the infinite Cayley tree (Bethe lattice). It is found in the vicinity of the criticality that the spreading of the wave field is subdiffusive in the limit t →+∞. The second moment of the associated probability distribution grows with time as a power law ∝ tα, with the exponent α =1/3 exactly. Also we find for superquadratic nonlinearity that the analog pseudochaotic regime at the edge of chaos is self-controlling in that it has feedback on the topology of the structure on which the transport processes concentrate. Then the system automatically (without tuning of parameters) develops its percolation point. We classify this type of behavior in terms of self-organized criticality dynamics in Hilbert space. For subquadratic nonlinearities, the behavior is shown to be sensitive to the details of definition of the nonlinear term. A transport model is proposed based on modified nonlinearity, using the idea of "stripes" propagating the wave process to large distances. Theoretical investigations, presented here, are the basis for consistency analysis of the different localization-delocalization patterns in systems with many coupled degrees of freedom in association with the asymptotic properties of the

  20. The theory of active involvement: processes underlying interventions that engage adolescents in message planning and/or production.

    Science.gov (United States)

    Greene, Kathryn

    2013-01-01

    Adolescence is a time of increased risk taking, and recent intervention strategies have included adolescents planning or producing antirisk messages for their peers. Although these projects may generate enthusiasm, we know little about message planning or production as a strategy for changing adolescent decision-making and behavior. This article articulates the Theory of Active Involvement (TAI) to describe and explain the processes through which these active involvement interventions influence adolescents. TAI is based on social cognitive theory's notion of self-regulation and examines multiple perspective taking and activating the self-reflection processes. The theory specifically describes the process of cognitive changes experienced by participants in active involvement interventions. The sequence is conceptualized as starting when engagement with the intervention (arousal and involvement) produces skill and knowledge gains (immediate outcomes) that lead to reflection (perceived discrepancy) and then other cognitions (expectancies, norms, intentions), with the ultimate outcome being behavior change. Engaging the target audience in a process of self-reflection is conceptualized as the crucial ingredient for meaningful and sustainable change in cognitions and behavior. This article provides valuable insight into how active involvement strategies function and how to best design these interventions, particularly those targeting adolescents.

  1. Nonlinear Processes in Plasmas.

    Science.gov (United States)

    1980-02-25

    27. P. N. Guzdar, L. Chen, P. K. Kaw and C. Oberman, "Effect of Magnetic Shear on the Drift Dissipative Instability," Physical Review Letters , 40...1566-1570, 1978. 28. L. Chen, P. N. Guzdar, R. B. White, P. K. Kaw and C. Oberman, "Theory of the Universal Drift Instability," Physical Review Letters 41...34Particle Diffusion by Magnetic Perturbations of Axisymmetric Geometries," Physical Review Letters 43, 1506-1509, 1979. 42. P. K. Kaw, E. 3. Valeo and P. H

  2. Employment of CB models for non-linear dynamic analysis

    Science.gov (United States)

    Klein, M. R. M.; Deloo, P.; Fournier-Sicre, A.

    1990-01-01

    The non-linear dynamic analysis of large structures is always very time, effort and CPU consuming. Whenever possible the reduction of the size of the mathematical model involved is of main importance to speed up the computational procedures. Such reduction can be performed for the part of the structure which perform linearly. Most of the time, the classical Guyan reduction process is used. For non-linear dynamic process where the non-linearity is present at interfaces between different structures, Craig-Bampton models can provide a very rich information, and allow easy selection of the relevant modes with respect to the phenomenon driving the non-linearity. The paper presents the employment of Craig-Bampton models combined with Newmark direct integration for solving non-linear friction problems appearing at the interface between the Hubble Space Telescope and its solar arrays during in-orbit maneuvers. Theory, implementation in the FEM code ASKA, and practical results are shown.

  3. Bacterial populations and processes involved in acetate and propionate consumption in anoxic brackish sediment

    NARCIS (Netherlands)

    Boschker, H.T.S.; De Graaf, W.; Köster, M.; Meyer-Reil, L.A.; Cappenberg, T.E.

    2001-01-01

    Bacterial populations and pathways involved in acetate and propionate consumption were studied in anoxic brackish sediment from the Grosser Jasmunder Bodden, German Baltic Sea. Uptake of acetate and propionate from the porewater was studied using stable carbon isotope-labeled compounds. Labeled acet

  4. Software Quality Perceptions of Stakeholders Involved in the Software Development Process

    Science.gov (United States)

    Padmanabhan, Priya

    2013-01-01

    Software quality is one of the primary determinants of project management success. Stakeholders involved in software development widely agree that quality is important (Barney and Wohlin 2009). However, they may differ on what constitutes software quality, and which of its attributes are more important than others. Although, software quality…

  5. Acculturation and Latino Family Processes: How Cultural Involvement, Biculturalism, and Acculturation Gaps Influence Family Dynamics

    Science.gov (United States)

    Smokowski, Paul R.; Rose, Roderick; Bacallao, Martica L.

    2008-01-01

    This study investigated how adolescent and parent acculturation (culture-of-origin and U.S. cultural involvement, biculturalism, acculturation conflicts, and parent-adolescent acculturation gaps) influenced family dynamics (family cohesion, adaptability, familism, and parent-adolescent conflict) in a sample of 402 Latino families from North…

  6. Software Quality Perceptions of Stakeholders Involved in the Software Development Process

    Science.gov (United States)

    Padmanabhan, Priya

    2013-01-01

    Software quality is one of the primary determinants of project management success. Stakeholders involved in software development widely agree that quality is important (Barney and Wohlin 2009). However, they may differ on what constitutes software quality, and which of its attributes are more important than others. Although, software quality…

  7. Could early septal involvement in the remodeling process be related to the advance hypertensive heart disease?

    Directory of Open Access Journals (Sweden)

    Fatih Yalçin

    2015-06-01

    Conclusions: LV diastolic dysfunction becomes more severe in septal wall than lateral wall in hypertensive LVH. Septal myocardial performance is more dominantly affected by hypertension possibly due to earlier septal involvement in disease course. Septal MPI is correlated moderately with septal wall thickness.

  8. Enhancing Home Involvement to Address Barriers to Learning: A Collaborative Process. A Center Report

    Science.gov (United States)

    Center for Mental Health in Schools at UCLA, 2011

    2011-01-01

    For schools to significantly enhance home involvement will require (1) broadening the focus beyond thinking only in terms of parents and (2) enhancing the range of ways in which schools connect with primary caretakers. Particular attention must be given to outreaching to those who are reluctant to engage with the school, especially if they have a…

  9. Involving Immigrant Parents of Students with Disabilities in the Educational Process.

    Science.gov (United States)

    Al-Hassan, Suha; Gardner, Ralph, III

    2002-01-01

    This article discusses the barriers that limit school participation by immigrant parents of students with disabilities, including language differences, lack of information, negative educational experiences, unfamiliarity with the U.S. educational practices, cultural differences, and differing views regarding involvement in schools. Strategies are…

  10. No Longer a Teacher Monologue--Involving EFL Writing Learners in Teachers' Assessment and Feedback Processes

    Science.gov (United States)

    Huang, Shu-Chen

    2016-01-01

    This paper reports the design of learning-oriented formative assessments in an EFL writing course that involved learners in regularly responding to teacher feedback. Following major assessment and feedback frameworks developed recently, these formative assessments were explicated in three aspects: the scheduling of learning and assessment…

  11. Using Dual-Task Methodology to Dissociate Automatic from Nonautomatic Processes Involved in Artificial Grammar Learning

    Science.gov (United States)

    Hendricks, Michelle A.; Conway, Christopher M.; Kellogg, Ronald T.

    2013-01-01

    Previous studies have suggested that both automatic and intentional processes contribute to the learning of grammar and fragment knowledge in artificial grammar learning (AGL) tasks. To explore the relative contribution of automatic and intentional processes to knowledge gained in AGL, we utilized dual-task methodology to dissociate automatic and…

  12. Non-linear and non-local transport processes in heterogeneous media: from long-range correlated percolation to fracture and materials breakdown

    Science.gov (United States)

    Sahimi, Muhammad

    1998-12-01

    We review and discuss recent progress in modelling non-linear and non-local transport processes in heterogeneous media. The non-locality that we consider is caused by long-range correlations that either exist in the morphology of the media, or are caused by the transport processes themselves. The interplay between the non-linearity and non-locality is discussed in depth with the aim of establishing that, often non-linearity and non-locality are “two sides of the same coin”, such that one may have no meaning without the presence of the other one. First, we discuss linear and scalar, but non-local transport processes and, in particular, consider those in percolation systems with long-range correlations. It appears that there are significant differences between percolative transport processes in which the long-range correlations (or the covariance function) decrease with the distance r between two points, and those in which they increase as r does. Application of this problem to flow and transport in geological formations is discussed. We then consider linear vector percolation, one type of which, the rigidity percolation, provides an example of a non-local vector transport in heterogeneous media. Applications of vector percolation to modelling elastic properties of glasses, composite solids and rock, mechanical and viscoelastic properties of polymers, and vibrations and dynamical properties of heterogeneous materials are discussed. Non-linear and non-local scalar transport processes are discussed next, including various breakdown phenomena in disordered composites, power-law transport, piecewise linear transport characterized by a threshold, and non-linear processes that arise as a result of imposing a large external potential gradient on a heterogeneous medium. Their relevance to flow of non-Newtonian fluids in porous media, to electrical currents and dielectric breakdown in composite solids and doped polycrystalline semiconductors, and several other problems is

  13. Child Involvement, Alliance, and Therapist Flexibility: Process Variables in Cognitive-Behavioural Therapy for Anxiety Disorders in Childhood

    Science.gov (United States)

    Hudson, Jennifer L.; Kendall, Philip C.; Chu, Brian C.; Gosch, Elizabeth; Martin, Erin; Taylor, Alan; Knight, Ashleigh

    2013-01-01

    Background This study examined the relations between treatment process variables and child anxiety outcomes. Method Independent raters watched/listened to taped therapy sessions of 151 anxiety-disordered (6 -14 yr-old; M = 10.71) children (43% boys) and assessed process variables (child alliance, therapist alliance, child involvement, therapist flexibility and therapist functionality) within a manual-based cognitive-behavioral treatment. Latent growth modelling examined three latent variables (intercept, slope, and quadratic) for each process variable. Child age, gender, family income and ethnicity were examined as potential antecedents. Outcome was analyzed using factorially derived clinician, mother, father, child and teacher scores from questionnaire and structured diagnostic interviews at pretreatment, posttreatment and 12-month follow-up. Results Latent growth models demonstrated a concave quadratic curve for child involvement and therapist flexibility over time. A predominantly linear, downward slope was observed for alliance, and functional flexibility remained consistent over time. Increased alliance, child involvement and therapist flexibility showed some albeit inconsistent, associations with positive treatment outcome. Conclusion Findings support the notion that maintaining the initial high level of alliance or involvement is important for clinical improvement. There is some support that progressively increasing alliance/involvement also positively impacts on treatment outcome. These findings were not consistent across outcome measurement points or reporters. PMID:24246476

  14. Strategic Co-Location in a Hybrid Process Involving Desalination and Pressure Retarded Osmosis (PRO

    Directory of Open Access Journals (Sweden)

    William B. Krantz

    2013-07-01

    Full Text Available This paper focuses on a Hybrid Process that uses feed salinity dilution and osmotic power recovery from Pressure Retarded Osmosis (PRO to achieve higher overall water recovery. This reduces the energy consumption and capital costs of conventional seawater desalination and water reuse processes. The Hybrid Process increases the amount of water recovered from the current 66.7% for conventional seawater desalination and water reuse processes to a potential 80% through the use of reclaimed water brine as an impaired water source. A reduction of up to 23% in energy consumption is projected via the Hybrid Process. The attractiveness is amplified by potential capital cost savings ranging from 8.7%–20% compared to conventional designs of seawater desalination plants. A decision matrix in the form of a customizable scorecard is introduced for evaluating a Hybrid Process based on the importance of land space, capital costs, energy consumption and membrane fouling. This study provides a new perspective, looking at processes not as individual systems but as a whole utilizing strategic co-location to unlock the synergies available in the water-energy nexus for more sustainable desalination.

  15. Strategic Co-Location in a Hybrid Process Involving Desalination and Pressure Retarded Osmosis (PRO).

    Science.gov (United States)

    Sim, Victor S T; She, Qianhong; Chong, Tzyy Haur; Tang, Chuyang Y; Fane, Anthony G; Krantz, William B

    2013-07-04

    This paper focuses on a Hybrid Process that uses feed salinity dilution and osmotic power recovery from Pressure Retarded Osmosis (PRO) to achieve higher overall water recovery. This reduces the energy consumption and capital costs of conventional seawater desalination and water reuse processes. The Hybrid Process increases the amount of water recovered from the current 66.7% for conventional seawater desalination and water reuse processes to a potential 80% through the use of reclaimed water brine as an impaired water source. A reduction of up to 23% in energy consumption is projected via the Hybrid Process. The attractiveness is amplified by potential capital cost savings ranging from 8.7%-20% compared to conventional designs of seawater desalination plants. A decision matrix in the form of a customizable scorecard is introduced for evaluating a Hybrid Process based on the importance of land space, capital costs, energy consumption and membrane fouling. This study provides a new perspective, looking at processes not as individual systems but as a whole utilizing strategic co-location to unlock the synergies available in the water-energy nexus for more sustainable desalination.

  16. Nonlinear Maneuver Autopilot

    Science.gov (United States)

    Menon, P. K. A.; Badgett, M. E.; Walker, R. A.

    1992-01-01

    Trajectory-control laws based on singular-perturbation theory and nonlinear dynamical modeling. Nonlinear maneuver autopilot commands flight-test trajectories of F-15 airplane. Underlying theory of controller enables separation of variables processed in fast and slow control loops, reducing amount of computation required.

  17. Titan's GOO-Sphere: Glacial, Permafrost, Evaporite, and Other Familiar Processes Involving Exotic Materials

    Science.gov (United States)

    Kargel, J. S.; Furfaro, R.; Hays, C. C.; Lopes, R. M. C.; Lunine, J. I.; Mitchell, K. L.; Wall, S. D.; Cassini RADAR Team

    2007-03-01

    A new Geologic Operating Organon (GOO) for Titan is based on the cryogenic activity of many hydrocarbon and organic substances. This model derives insight from volcanic, fluvial, lacustrine, permafrost, and glacial processes on Earth and beyond.

  18. The rehabilitation process of children with motor disabilities in the Dutch therapeutic toddler class: main phases and parent involvement.

    NARCIS (Netherlands)

    Hendriks, A.H.C.; Moor, J.M.H. de; Savelberg, M.M.H.W.; Oud, J.H.L.

    2001-01-01

    This study describes the implementation of the main phases of the rehabilitation process of children with motor disabilities who visit Dutch therapeutic toddler classes. Parent involvement, as well as parents' and professionals' satisfaction were also investigated. It was found that in about half of

  19. The rehabilitation process of children with motor disabilities in the Dutch therapeutic toddler class: main phases and parent involvement.

    NARCIS (Netherlands)

    Hendriks, A.H.C.; Moor, J.M.H. de; Savelberg, M.M.H.W.; Oud, J.H.L.

    2001-01-01

    This study describes the implementation of the main phases of the rehabilitation process of children with motor disabilities who visit Dutch therapeutic toddler classes. Parent involvement, as well as parents' and professionals' satisfaction were also investigated. It was found that in about half of

  20. Early Childhood Spaces: Involving Young Children and Practitioners in the Design Process. Working Papers in Early Childhood Development, No. 45

    Science.gov (United States)

    Clark, Alison

    2007-01-01

    This working paper explores the methodology and initial issues raised in seeking to involve young children in the design process. It reports a study concerned with how young children can play an active role in the designing and developing of children's spaces. The focus is on children under 6 years old in early childhood provision. (Contains 2…

  1. Application of Ict and Rubrics to the Assessment Process where Professional Judgement Is Involved: The Features of an Emarking Tool

    Science.gov (United States)

    Campbell, Alistair

    2005-01-01

    This paper describes a new ICT assessment tool that reduces multihandling of marks, comments and scores specifically where professional judgement is involved. Whereas previous ICT applications in most fields of education have focused on student learning, this tool focuses on the lecturer task of the assessment process. Unlike many ICT based…

  2. [Facilitating Processes of Disintegration instead of Occupational Reintegration: A Qualitative Study on Employer-Involvement in Rehabilitation].

    Science.gov (United States)

    Schwarz, Betje; Specht, Timo; Bethge, Matthias

    2017-06-30

    Purpose To explore the patient's perspective on the involvement of employers into rehabilitation. Methods 8 participants of a work-related medical rehabilitation were interviewed by telephone 4 weeks after discharge. Qualitative content analysis was used to analyze generated data. Results Beside a poor employer-involvement, the interviews revealed that the process of returning to work was characterized and hampered by unused measures of supporting vocational reintegration during rehabilitation, intersection problems in the health care and social security system, and a strategy of waiting by all involved actors. Conclusion Beside an improved employer-involvement, systematic intersection management and full usage of existing measures are demanded to support vocational reintegration. © Georg Thieme Verlag KG Stuttgart · New York.

  3. Neural networks involved in adolescent reward processing: An activation likelihood estimation meta-analysis of functional neuroimaging studies.

    Science.gov (United States)

    Silverman, Merav H; Jedd, Kelly; Luciana, Monica

    2015-11-15

    Behavioral responses to, and the neural processing of, rewards change dramatically during adolescence and may contribute to observed increases in risk-taking during this developmental period. Functional MRI (fMRI) studies suggest differences between adolescents and adults in neural activation during reward processing, but findings are contradictory, and effects have been found in non-predicted directions. The current study uses an activation likelihood estimation (ALE) approach for quantitative meta-analysis of functional neuroimaging studies to: (1) confirm the network of brain regions involved in adolescents' reward processing, (2) identify regions involved in specific stages (anticipation, outcome) and valence (positive, negative) of reward processing, and (3) identify differences in activation likelihood between adolescent and adult reward-related brain activation. Results reveal a subcortical network of brain regions involved in adolescent reward processing similar to that found in adults with major hubs including the ventral and dorsal striatum, insula, and posterior cingulate cortex (PCC). Contrast analyses find that adolescents exhibit greater likelihood of activation in the insula while processing anticipation relative to outcome and greater likelihood of activation in the putamen and amygdala during outcome relative to anticipation. While processing positive compared to negative valence, adolescents show increased likelihood for activation in the posterior cingulate cortex (PCC) and ventral striatum. Contrasting adolescent reward processing with the existing ALE of adult reward processing reveals increased likelihood for activation in limbic, frontolimbic, and striatal regions in adolescents compared with adults. Unlike adolescents, adults also activate executive control regions of the frontal and parietal lobes. These findings support hypothesized elevations in motivated activity during adolescence.

  4. The variability of processes involved in transgene dispersal - case studies from Brassica and related genera

    DEFF Research Database (Denmark)

    Bagger Jørgensen, Rikke; Hauser, Thure Pavlo; D'Hertefeldt, T.

    2009-01-01

    Background, aim, and scope We strive to predict consequences of genetically modified plants (GMPs) being cultivated openly in the environment, as human and animal health, biodiversity, agricultural practise and farmers’ economy could be affected. Therefore, it is unfortunate that the risk...... is a valuable tool in identifying key factors in the gene-flow process for which more knowledge is needed, and identifying parameters and processes which are relatively insensitive to change and therefore require less attention in future collections of data. But the interdependence between models...

  5. Processes involved in assisted reproduction technologies significantly increase sperm DNA fragmentation and phosphatidylserine translocation.

    Science.gov (United States)

    Balasuriya, A; Serhal, P; Doshi, A; Harper, J C

    2014-03-01

    Sperm preparation techniques in assisted reproduction technologies (ART) are potential generators of exogenous stresses that cause additional DNA damage. DNA fragmentation tests, such as the sperm chromatin structure assay, involve freezing sperm samples in the absence of cryoprotectant. Thermal, oxidative stress (OS) and freezing are detrimental to sperm DNA fragmentation and phosphatidylserine (PS) translocation. The primary aim of this study was to subject mature sperm to environmental insults that normally occur during ART. We tested the hypotheses that OS, thermal stress and freeze-thawing caused sperm nuclear and membrane damage and that a positive correlation exists between PS translocation and DNA fragmentation. Sperm DNA integrity deteriorates in semen samples from men with advancing age and a sperm concentration of DNA fragmentation at 37 °C after merely 1 h is important clinically as semen liquefaction and short-term sperm storage in an ART cycle involve incubating samples at this temperature. Freezing without a cryoprotectant significantly increases the level of sperm nuclear damage, so it is important not to freeze neat semen prior to DNA fragmentation testing. This study highlights the importance of minimising the production of exogenous stresses during sperm preparation in ART. © 2012 Blackwell Verlag GmbH.

  6. Effects of seasonal temperature variation on nitrification, anammox process, and bacteria involved in a pilot-scale constructed wetland.

    Science.gov (United States)

    Wang, Ling; Li, Tian

    2015-03-01

    Effects of seasonal temperature (especially low temperature) variation on nitrogen removal process and bacteria involved in an experimental domestic wastewater treatment wetland were investigated in this study. Three different functional groups of bacteria, namely anammox bacteria, ammonia-oxidizing bacteria (AOB), and Nitrospira sp., were involved. Anammox process was seriously inhibited with mean temperature lower than 15 °C. However, obvious adaptation of anammox bacteria also appeared after a long time operation under low temperatures. Contrary to anammox bacteria, AOB were more abundant in winter than in summer. Nitrospira sp. was the least prevalent and showed the lowest level of variation. Distinct nitrate accumulation observed under winter temperatures was likely due to inhibition of anammox process, comparative advantage of Nitrospira sp. in winter, and the presence of cold-tolerant AOB species.

  7. Brain regions involved in processing facial identity and expression are differentially selective for surface and edge information.

    Science.gov (United States)

    Harris, Richard J; Young, Andrew W; Andrews, Timothy J

    2014-08-15

    Although different brain regions are widely considered to be involved in the recognition of facial identity and expression, it remains unclear how these regions process different properties of the visual image. Here, we ask how surface-based reflectance information and edge-based shape cues contribute to the perception and neural representation of facial identity and expression. Contrast-reversal was used to generate images in which normal contrast relationships across the surface of the image were disrupted, but edge information was preserved. In a behavioural experiment, contrast-reversal significantly attenuated judgements of facial identity, but only had a marginal effect on judgements of expression. An fMR-adaptation paradigm was then used to ask how brain regions involved in the processing of identity and expression responded to blocks comprising all normal, all contrast-reversed, or a mixture of normal and contrast-reversed faces. Adaptation in the posterior superior temporal sulcus--a region directly linked with processing facial expression--was relatively unaffected by mixing normal with contrast-reversed faces. In contrast, the response of the fusiform face area--a region linked with processing facial identity--was significantly affected by contrast-reversal. These results offer a new perspective on the reasons underlying the neural segregation of facial identity and expression in which brain regions involved in processing invariant aspects of faces, such as identity, are very sensitive to surface-based cues, whereas regions involved in processing changes in faces, such as expression, are relatively dependent on edge-based cues.

  8. Age-Related Changes in Duration Reproduction: Involvement of Working Memory Processes

    Science.gov (United States)

    Baudouin, Alexia; Vanneste, Sandrine; Pouthas, Viviane; Isingrini, Michel

    2006-01-01

    The aim of the present research was to study age-related changes in duration reproduction by differentiating the working memory processes underlying this time estimation task. We compared performances of young and elderly adults in a duration reproduction task performed in simple and concurrent task conditions. Participants were also administered…

  9. A Study of User Involvement in the Military Construction Program Process.

    Science.gov (United States)

    1986-09-01

    sion change). B. Incomplete requirements during programming . C . Poorly defined requirements. D. Other *. E. There was no change in user...requirements during the MCP process. 30. Were you the responsible individual during the programming and design phase? A. Yes B. Only during programming C . Only

  10. Data, analysis and modeling of physical properties for process designof systems involving lipids

    DEFF Research Database (Denmark)

    Cunico, Larissa; Ceriani, Roberta; Sarup, Bent

    2013-01-01

    Pure component and mixture properties are necessary for synthesis, design, and analysis of processes forthe production of edible oils, fats, biodiesel, and other lipids. The lack of measured data for these systemsmakes it necessary to develop reliable predictive models based on limited data. We...

  11. Fantasy Activity and the Televiewing Event: Considerations for an Information Processing Construct of Involvement.

    Science.gov (United States)

    Lindlof, Thomas R.

    The similarities between television viewing and fantasy activity (daydreaming, reverie, mind-wandering, internal dialogue) more than warrant the building of a theoretical construct, especially in the context of recent empirical research on television viewing consequences. A construct of the television viewing process, based on cognitive theories…

  12. Parental Involvement in the Habilitation Process Following Children's Cochlear Implantation: An Action Theory Perspective

    Science.gov (United States)

    Zaidman-Zait, Anat; Young, Richard A.

    2008-01-01

    Action theory and the qualitative action-project method are used in this study to address and illustrate the complexity of parenting children who have received cochlear implants (CIs) as well as the intentionality of parents engaged in that process. "Action" refers to individual and joint goal-directed and intentional behaviors. Action theory has…

  13. Involvement of O-glycosylation defining oncofetal fibronectin in epithelial-mesenchymal transition process

    DEFF Research Database (Denmark)

    Freire-de-Lima, Leonardo; Gelfenbeyn, Kirill; Ding, Yao

    2011-01-01

    The process termed "epithelial-mesenchymal transition" (EMT) was originally discovered in ontogenic development, and has been shown to be one of the key steps in tumor cell progression and metastasis. Recently, we showed that the expression of some glycosphingolipids (GSLs) is down-regulated duri...

  14. Parent Involvement in the Special Education Eligibility Process: Implementation of Legal Mandates and Best Practices

    Science.gov (United States)

    McEvoy, Cathleen K.

    2013-01-01

    School psychologists throughout New York State were surveyed regarding their schools' policies to include parents in the special education eligibility process related to legal mandates and best practices. Differences were found in the implementation of legal mandates compared to implementation of best practices. Location differences were…

  15. GWAS for executive function and processing speed suggests involvement of the CADM2 gene

    NARCIS (Netherlands)

    Ibrahim-Verbaas, C. A.; Bressler, J.; Debette, S.; Schuur, M.; Smith, A. V.; Bis, J. C.; Davies, G.; Trompet, S.; Smith, J. A.; Wolf, C.; Chibnik, L. B.; Liu, Y.; Vitart, V.; Kirin, M.; Petrovic, K.; Polasek, O.; Zgaga, L.; Fawns-Ritchie, C.; Hoffmann, P.; Karjalainen, J.; Lahti, J.; Llewellyn, D. J.; Schmidt, C.O.; Mather, K. A.; Chouraki, V.; Sun, Q.; Resnick, S. M.; Rose, L. M.; Oldmeadow, C.; Stewart, M.; Smith, B.H.; Gudnason, V.; Yang, Q.; Mirza, S. S.; Jukema, J. W.; Dejager, P. L.; Harris, T. B.; Liewald, D. C.; Amin, N.; Coker, L. H.; Stegle, O.; Lopez, O. L.; Schmidt, R.; Teumer, A.; Ford, I.; Karbalai, N.; Becker, J. T.; Jonsdottir, M. K.; Au, R.; Fehrmann, R. S. N.; Herms, S.; Nalls, M.; Zhao, Wei; Turner, S. T.; Yaffe, K.; Lohman, K.; van Swieten, J. C.; Kardia, S. L. R.; Knopman, D. S.; Meeks, W. M.; Heiss, G.; Holliday, E. G.; Schofield, P. W.; Tanaka, T.; Stott, D. J.; Wang, J.; Ridker, P.; Gow, A. J.; Pattie, A.; Starr, J. M.; Hocking, L. J.; Armstrong, N. J.; McLachlan, S.; Shulman, J. M.; Pilling, L. C.; Eiriksdottir, G.; Scott, R. J.; Kochan, N. A.; Palotie, A.; Hsieh, Y-C; Eriksson, J. G.; Penman, A.; Gottesman, R. F.; Oostra, B. A.; Yu, L.; DeStefano, A. L.; Beiser, A.; Garcia, M.; Rotter, J. i; Noethen, M. M.; Hofman, A.; Slagboom, P. E.; Westendorp, R. G. J.; Buckley, B. M.; Wolf, P. A.; Uitterlinden, A. G.; Psaty, B. M.; Grabe, H. J.; Bandinelli, S.; Chasman, D. I.; Grodstein, F.; Roikkonen, K.; Lambert, J-C; Porteous, D. J.; Price, J. F.; Sachdev, P. S.; Ferrucci, L.; Attia, J. R.; Rudan, I.; Hayward, C.; Wright, A. F.; Wilson, James F.; Cichon, S.; Franke, L.; Schmidt, H.; Ding, J.; de Craen, A. J. M.; Fornage, M.; Bennett, D. A.; Deary, I. J.; Ikram, M. A.; Launer, L. J.; Fitzpatrick, A. L.; Seshadri, S.; van Duijn, C. M.; Mosley, T. H.

    2016-01-01

    To identify common variants contributing to normal variation in two specific domains of cognitive functioning, we conducted a genome-wide association study (GWAS) of executive functioning and information processing speed in non-demented older adults from the CHARGE (Cohorts for Heart and Aging Resea

  16. GWAS for executive function and processing speed suggests involvement of the CADM2 gene

    NARCIS (Netherlands)

    C.A. Ibrahim-Verbaas (Carla); J. Bressler; S. Debette (Stéphanie); M. Schuur (Maaike); A.V. Smith; J.C. Bis (Joshua); G. Davies (Gail); S. Trompet (Stella); J.A. Smith; A. Björnsson (Asgeir); L.B. Chibnik (Lori); Y. Liu; V. Vitart (Veronique); M. Kirin (Mirna); K. Petrovic (Katja); O. Polasek (Ozren); L. Zgaga (Lina); C. Fawns-Ritchie; P. Hoffmann (Per); J. Karjalainen (Juha); J. Lahti; D.J. Llewellyn; C.O. Schmidt (Carsten O.); R. Mather; V. Chouraki (Vincent); Q. Sun; S. Resnick (Susan); L.M. Rose (Lynda M.); C. Oldmeadow (Christopher); M. Stewart; B.H. Smith; V. Gudnason (Vilmundur); Q. Yang (Qiong); S.S. Mirza (Saira); J.W. Jukema; P.L. DeJager (Philip L.); T.B. Harris (Tamara); D.C. Liewald (David C.); N. Amin; L.H. Coker (Laura); O. Stegle (Oliver); O.L. Lopez; R. Schmidt; A. Teumer (Alexander); I. Ford; N. Karbalai (Nazanin); J.T. Becker; M.K. Jonsdottir (Maria K.); R. Au; R.S.N. Fehrmann (Rudolf); S. Herms (Stefan); M.A. Nalls (Michael); W. Zhao; S.T. Turner; K. Yaffe; K. Lohman (Kurt); J.C. van Swieten (John); S.L.R. Kardia; D.S. Knopman (David); W.M. Meeks (William); G. Heiss (Gerardo); E.G. Holliday (Elizabeth); P.W. Schofield; T. Tanaka (Toshiko); D.J. Stott (David J.); J. Wang (Jing); P.M. Ridker (Paul); A.J. Gow; A. Pattie (Alison); J.M. Starr (John); L.J. Hocking; N.J. Armstrong (Nicola J.); S. McLachlan (Stela); L. Shulman (Lee); L.C. Pilling (Luke); G. Eiriksdottir (Gudny); R.J. Scott; N.A. Kochan (Nicole A.); A. Palotie; Y.-C. Hsieh; J.G. Eriksson (Johan G.); A.D. Penman (Alan); R.F. Gottesman (Rebecca); B.A. Oostra (Ben); L. Yu; A.L. DeStefano (Anita L.); A. Beiser; M. Garcia; J.I. Rotter; M.M. Nöthen; A. Hofman (Albert); P.E. Slagboom (Eline); R.G.J. Westendorp; B.M. Buckley (Brendan M.); P.A. Wolf; A.G. Uitterlinden (André); B.M. Psaty (Bruce); H.J. Grabe (Hans Jörgen); S. Bandinelli (Stefania); D.I. Chasman (Daniel); F. Grodstein (Francine); K. Räikkönen (Katri); J.-C. Lambert; D.J. Porteous (David J.); J.F. Price (Jackie F.); P.S. Sachdev (Perminder); L. Ferrucci (Luigi); J. Attia (John); I. Rudan (Igor); C. Hayward; A.F. Wright; J.F. Wilson (James F); S. Cichon (Sven); L. Franke (Lude); H. Schmidt; J. Ding; A.J. de Craen (Anton); M. Fornage (Myriam); D.A. Bennett (David); I.J. Deary (Ian); M.A. Ikram (Arfan); L.J. Launer (Lenore); A.L. Fitzpatrick; S. Seshadri (Sudha); C.M. van Duijn (Cock); T.H. Mosley (Thomas H.)

    2016-01-01

    textabstractTo identify common variants contributing to normal variation in two specific domains of cognitive functioning, we conducted a genome-wide association study (GWAS) of executive functioning and information processing speed in non-demented older adults from the CHARGE (Cohorts for Heart and

  17. Parent Involvement in the Special Education Eligibility Process: Implementation of Legal Mandates and Best Practices

    Science.gov (United States)

    McEvoy, Cathleen K.

    2013-01-01

    School psychologists throughout New York State were surveyed regarding their schools' policies to include parents in the special education eligibility process related to legal mandates and best practices. Differences were found in the implementation of legal mandates compared to implementation of best practices. Location differences were…

  18. A Mathematical Experience Involving Defining Processes: In-Action Definitions and Zero-Definitions

    Science.gov (United States)

    Ouvrier-Buffet, Cecile

    2011-01-01

    In this paper, a focus is made on defining processes at stake in an unfamiliar situation coming from discrete mathematics which brings surprising mathematical results. The epistemological framework of Lakatos is questioned and used for the design and the analysis of the situation. The cognitive background of Vergnaud's approach enriches the study…

  19. Parent Involvement in the Special Education Eligibility Process: Implementation of Legal Mandates and Best Practices

    Science.gov (United States)

    McEvoy, Cathleen K.

    2013-01-01

    School psychologists throughout New York State were surveyed regarding their schools' policies to include parents in the special education eligibility process related to legal mandates and best practices. Differences were found in the implementation of legal mandates compared to implementation of best practices. Location differences were…

  20. Nonlinear effects in optical fibers

    CERN Document Server

    Ferreira, Mario F

    2011-01-01

    Cutting-edge coverage of nonlinear phenomena occurring inside optical fibers Nonlinear fiber optics is a specialized part of fiber optics dealing with optical nonlinearities and their applications. As fiber-optic communication systems have become more advanced and complex, the nonlinear effects in optical fibers have increased in importance, as they adversely affect system performance. Paradoxically, the same nonlinear phenomena also offer the promise of addressing the bandwidth bottleneck for signal processing for future ultra-high speed optical networks. Nonlinear Effects in Optical Fiber