WorldWideScience

Sample records for policy gradient based

  1. Wireless SAW Based Temperature Gradient Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Prime Photonics proposes design and development of a surface acoustic wave (SAW) based temperature gradient sensor for instrumentation of thermal protection systems...

  2. Sound beam manipulation based on temperature gradients

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Feng [Key Laboratory of Modern Acoustics, Institute of Acoustics and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); School of Physics & Electronic Engineering, Changshu Institute of Technology, Changshu 215500 (China); Quan, Li; Liu, Xiaozhou, E-mail: xzliu@nju.edu.cn; Gong, Xiufen [Key Laboratory of Modern Acoustics, Institute of Acoustics and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

    2015-10-28

    Previous research with temperature gradients has shown the feasibility of controlling airborne sound propagation. Here, we present a temperature gradients based airborne sound manipulation schemes: a cylindrical acoustic omnidirectional absorber (AOA). The proposed AOA has high absorption performance which can almost completely absorb the incident wave. Geometric acoustics is used to obtain the refractive index distributions with different radii, which is then utilized to deduce the desired temperature gradients. Since resonant units are not applied in the scheme, its working bandwidth is expected to be broadband. The scheme is temperature-tuned and easy to realize, which is of potential interest to fields such as noise control or acoustic cloaking.

  3. Sound beam manipulation based on temperature gradients

    International Nuclear Information System (INIS)

    Qian, Feng; Quan, Li; Liu, Xiaozhou; Gong, Xiufen

    2015-01-01

    Previous research with temperature gradients has shown the feasibility of controlling airborne sound propagation. Here, we present a temperature gradients based airborne sound manipulation schemes: a cylindrical acoustic omnidirectional absorber (AOA). The proposed AOA has high absorption performance which can almost completely absorb the incident wave. Geometric acoustics is used to obtain the refractive index distributions with different radii, which is then utilized to deduce the desired temperature gradients. Since resonant units are not applied in the scheme, its working bandwidth is expected to be broadband. The scheme is temperature-tuned and easy to realize, which is of potential interest to fields such as noise control or acoustic cloaking

  4. Gradient based filtering of digital elevation models

    DEFF Research Database (Denmark)

    Knudsen, Thomas; Andersen, Rune Carbuhn

    We present a filtering method for digital terrain models (DTMs). The method is based on mathematical morphological filtering within gradient (slope) defined domains. The intention with the filtering procedure is to improbé the cartographic quality of height contours generated from a DTM based on ...

  5. Infrared image detail enhancement based on the gradient field specification.

    Science.gov (United States)

    Zhao, Wenda; Xu, Zhijun; Zhao, Jian; Zhao, Fan; Han, Xizhen

    2014-07-01

    Human vision is sensitive to the changes of local image details, which are actually image gradients. To enhance faint infrared image details, this article proposes a gradient field specification algorithm. First we define the image gradient field and gradient histogram. Then, by analyzing the characteristics of the gradient histogram, we construct a Gaussian function to obtain the gradient histogram specification and therefore obtain the transform gradient field. In addition, subhistogram equalization is proposed based on the histogram equalization to improve the contrast of infrared images. The experimental results show that the algorithm can effectively improve image contrast and enhance weak infrared image details and edges. As a result, it can give qualified image information for different applications of an infrared image. In addition, it can also be applied to enhance other types of images such as visible, medical, and lunar surface.

  6. Evidence-based policy

    DEFF Research Database (Denmark)

    Vohnsen, Nina Holm

    2013-01-01

    A current ambition in welfare states as diverse as Denmark, the UK, and in the USA is to base political decision making on rigorous research (Cartwright et al 2009; Mulgan 2009; Bason 2010). Sound as this might seem the ambition has nevertheless been problematized by both policy-makers and the re......A current ambition in welfare states as diverse as Denmark, the UK, and in the USA is to base political decision making on rigorous research (Cartwright et al 2009; Mulgan 2009; Bason 2010). Sound as this might seem the ambition has nevertheless been problematized by both policy......-makers and the research community (e.g. Boden & Epstein 2006; House of Commons 2006; Cartwright et al 2009; Rod 2010; Vohnsen 2011). This article intends to draw out some general pitfalls in the curious meeting of science and politics by focusing on a particular attempt to make evidence-based legislation in Denmark (for...... a full account, see Vohnsen 2011). These insights will be relevant for the anthropological researcher of legislative processes who wishes to move beyond a merely discursive approach to the study of policy and politics....

  7. Gradient waveform pre-emphasis based on the gradient system transfer function.

    Science.gov (United States)

    Stich, Manuel; Wech, Tobias; Slawig, Anne; Ringler, Ralf; Dewdney, Andrew; Greiser, Andreas; Ruyters, Gudrun; Bley, Thorsten A; Köstler, Herbert

    2018-02-25

    The gradient system transfer function (GSTF) has been used to describe the distorted k-space trajectory for image reconstruction. The purpose of this work was to use the GSTF to determine the pre-emphasis for an undistorted gradient output and intended k-space trajectory. The GSTF of the MR system was determined using only standard MR hardware without special equipment such as field probes or a field camera. The GSTF was used for trajectory prediction in image reconstruction and for a gradient waveform pre-emphasis. As test sequences, a gradient-echo sequence with phase-encoding gradient modulation and a gradient-echo sequence with a spiral read-out trajectory were implemented and subsequently applied on a structural phantom and in vivo head measurements. Image artifacts were successfully suppressed by applying the GSTF-based pre-emphasis. Equivalent results are achieved with images acquired using GSTF-based post-correction of the trajectory as a part of image reconstruction. In contrast, the pre-emphasis approach allows reconstruction using the initially intended trajectory. The artifact suppression shown for two sequences demonstrates that the GSTF can serve for a novel pre-emphasis. A pre-emphasis based on the GSTF information can be applied to any arbitrary sequence type. © 2018 International Society for Magnetic Resonance in Medicine.

  8. Scattering-angle based filtering of the waveform inversion gradients

    KAUST Repository

    Alkhalifah, Tariq Ali

    2014-11-22

    Full waveform inversion (FWI) requires a hierarchical approach to maneuver the complex non-linearity associated with the problem of velocity update. In anisotropic media, the non-linearity becomes far more complex with the potential trade-off between the multiparameter description of the model. A gradient filter helps us in accessing the parts of the gradient that are suitable to combat the potential non-linearity and parameter trade-off. The filter is based on representing the gradient in the time-lag normalized domain, in which the low scattering angle of the gradient update is initially muted out in the FWI implementation, in what we may refer to as a scattering angle continuation process. The result is a low wavelength update dominated by the transmission part of the update gradient. In this case, even 10 Hz data can produce vertically near-zero wavenumber updates suitable for a background correction of the model. Relaxing the filtering at a later stage in the FWI implementation allows for smaller scattering angles to contribute higher-resolution information to the model. The benefits of the extended domain based filtering of the gradient is not only it\\'s ability in providing low wavenumber gradients guided by the scattering angle, but also in its potential to provide gradients free of unphysical energy that may correspond to unrealistic scattering angles.

  9. Scattering angle base filtering of the inversion gradients

    KAUST Repository

    Alkhalifah, Tariq Ali

    2014-01-01

    Full waveform inversion (FWI) requires a hierarchical approach based on the availability of low frequencies to maneuver the complex nonlinearity associated with the problem of velocity inversion. I develop a model gradient filter to help us access the parts of the gradient more suitable to combat this potential nonlinearity. The filter is based on representing the gradient in the time-lag normalized domain, in which low scattering angles of the gradient update are initially muted. The result are long-wavelength updates controlled by the ray component of the wavefield. In this case, even 10 Hz data can produce near zero wavelength updates suitable for a background correction of the model. Allowing smaller scattering angle to contribute provides higher resolution information to the model.

  10. Regularized image denoising based on spectral gradient optimization

    International Nuclear Information System (INIS)

    Lukić, Tibor; Lindblad, Joakim; Sladoje, Nataša

    2011-01-01

    Image restoration methods, such as denoising, deblurring, inpainting, etc, are often based on the minimization of an appropriately defined energy function. We consider energy functions for image denoising which combine a quadratic data-fidelity term and a regularization term, where the properties of the latter are determined by a used potential function. Many potential functions are suggested for different purposes in the literature. We compare the denoising performance achieved by ten different potential functions. Several methods for efficient minimization of regularized energy functions exist. Most are only applicable to particular choices of potential functions, however. To enable a comparison of all the observed potential functions, we propose to minimize the objective function using a spectral gradient approach; spectral gradient methods put very weak restrictions on the used potential function. We present and evaluate the performance of one spectral conjugate gradient and one cyclic spectral gradient algorithm, and conclude from experiments that both are well suited for the task. We compare the performance with three total variation-based state-of-the-art methods for image denoising. From the empirical evaluation, we conclude that denoising using the Huber potential (for images degraded by higher levels of noise; signal-to-noise ratio below 10 dB) and the Geman and McClure potential (for less noisy images), in combination with the spectral conjugate gradient minimization algorithm, shows the overall best performance

  11. A Gradient Analysis-Based Study of Aeromagnetic Anomalies of ...

    African Journals Online (AJOL)

    An aeromagnetic intensity contour map of a part of Nupe Basin of Nigeria was acquired, digitized and analysed. This work was carried out for a better understanding of the study area using the Gradient analysis-based technique to calculate depth to basement and to interpret the aeromagnetic anomaly map of the area.

  12. Climate policy decisions require policy-based lifecycle analysis.

    Science.gov (United States)

    Bento, Antonio M; Klotz, Richard

    2014-05-20

    Lifecycle analysis (LCA) metrics of greenhouse gas emissions are increasingly being used to select technologies supported by climate policy. However, LCAs typically evaluate the emissions associated with a technology or product, not the impacts of policies. Here, we show that policies supporting the same technology can lead to dramatically different emissions impacts per unit of technology added, due to multimarket responses to the policy. Using a policy-based consequential LCA, we find that the lifecycle emissions impacts of four US biofuel policies range from a reduction of 16.1 gCO2e to an increase of 24.0 gCO2e per MJ corn ethanol added by the policy. The differences between these results and representative technology-based LCA measures, which do not account for the policy instrument driving the expansion in the technology, illustrate the need for policy-based LCA measures when informing policy decision making.

  13. A study of gradient strengthening based on a finite-deformation gradient crystal-plasticity model

    Science.gov (United States)

    Pouriayevali, Habib; Xu, Bai-Xiang

    2017-11-01

    A comprehensive study on a finite-deformation gradient crystal-plasticity model which has been derived based on Gurtin's framework (Int J Plast 24:702-725, 2008) is carried out here. This systematic investigation on the different roles of governing components of the model represents the strength of this framework in the prediction of a wide range of hardening behaviors as well as rate-dependent and scale-variation responses in a single crystal. The model is represented in the reference configuration for the purpose of numerical implementation and then implemented in the FEM software ABAQUS via a user-defined subroutine (UEL). Furthermore, a function of accumulation rates of dislocations is employed and viewed as a measure of formation of short-range interactions. Our simulation results reveal that the dissipative gradient strengthening can be identified as a source of isotropic-hardening behavior, which may represent the effect of irrecoverable work introduced by Gurtin and Ohno (J Mech Phys Solids 59:320-343, 2011). Here, the variation of size dependency at different magnitude of a rate-sensitivity parameter is also discussed. Moreover, an observation of effect of a distinctive feature in the model which explains the effect of distortion of crystal lattice in the reference configuration is reported in this study for the first time. In addition, plastic flows in predefined slip systems and expansion of accumulation of GNDs are distinctly observed in varying scales and under different loading conditions.

  14. Spatial wavefield gradient-based seismic wavefield separation

    Science.gov (United States)

    Van Renterghem, C.; Schmelzbach, C.; Sollberger, D.; Robertsson, J. OA

    2018-03-01

    Measurements of the horizontal and vertical components of particle motion combined with estimates of the spatial gradients of the seismic wavefield enable seismic data to be acquired and processed using single dedicated multicomponent stations (e.g. rotational sensors) and/or small receiver groups instead of large receiver arrays. Here, we present seismic wavefield decomposition techniques that use spatial wavefield gradient data to separate land and ocean bottom data into their upgoing/downgoing and P/S constituents. Our method is based on the elastodynamic representation theorem with the derived filters requiring local measurements of the wavefield and its spatial gradients only. We demonstrate with synthetic data and a land seismic field data example that combining translational measurements with spatial wavefield gradient estimates allows separating seismic data recorded either at the Earth's free-surface or at the sea bottom into upgoing/downgoing and P/S wavefield constituents for typical incidence angle ranges of body waves. A key finding is that the filter application only requires knowledge of the elastic properties exactly at the recording locations and is valid for a wide elastic property range.

  15. Gradient-based methods for production optimization of oil reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Suwartadi, Eka

    2012-07-01

    Production optimization for water flooding in the secondary phase of oil recovery is the main topic in this thesis. The emphasis has been on numerical optimization algorithms, tested on case examples using simple hypothetical oil reservoirs. Gradientbased optimization, which utilizes adjoint-based gradient computation, is used to solve the optimization problems. The first contribution of this thesis is to address output constraint problems. These kinds of constraints are natural in production optimization. Limiting total water production and water cut at producer wells are examples of such constraints. To maintain the feasibility of an optimization solution, a Lagrangian barrier method is proposed to handle the output constraints. This method incorporates the output constraints into the objective function, thus avoiding additional computations for the constraints gradient (Jacobian) which may be detrimental to the efficiency of the adjoint method. The second contribution is the study of the use of second-order adjoint-gradient information for production optimization. In order to speedup convergence rate in the optimization, one usually uses quasi-Newton approaches such as BFGS and SR1 methods. These methods compute an approximation of the inverse of the Hessian matrix given the first-order gradient from the adjoint method. The methods may not give significant speedup if the Hessian is ill-conditioned. We have developed and implemented the Hessian matrix computation using the adjoint method. Due to high computational cost of the Newton method itself, we instead compute the Hessian-timesvector product which is used in a conjugate gradient algorithm. Finally, the last contribution of this thesis is on surrogate optimization for water flooding in the presence of the output constraints. Two kinds of model order reduction techniques are applied to build surrogate models. These are proper orthogonal decomposition (POD) and the discrete empirical interpolation method (DEIM

  16. Gradient-based model calibration with proxy-model assistance

    Science.gov (United States)

    Burrows, Wesley; Doherty, John

    2016-02-01

    Use of a proxy model in gradient-based calibration and uncertainty analysis of a complex groundwater model with large run times and problematic numerical behaviour is described. The methodology is general, and can be used with models of all types. The proxy model is based on a series of analytical functions that link all model outputs used in the calibration process to all parameters requiring estimation. In enforcing history-matching constraints during the calibration and post-calibration uncertainty analysis processes, the proxy model is run for the purposes of populating the Jacobian matrix, while the original model is run when testing parameter upgrades; the latter process is readily parallelized. Use of a proxy model in this fashion dramatically reduces the computational burden of complex model calibration and uncertainty analysis. At the same time, the effect of model numerical misbehaviour on calculation of local gradients is mitigated, this allowing access to the benefits of gradient-based analysis where lack of integrity in finite-difference derivatives calculation would otherwise have impeded such access. Construction of a proxy model, and its subsequent use in calibration of a complex model, and in analysing the uncertainties of predictions made by that model, is implemented in the PEST suite.

  17. Large Airborne Full Tensor Gradient Data Inversion Based on a Non-Monotone Gradient Method

    Science.gov (United States)

    Sun, Yong; Meng, Zhaohai; Li, Fengting

    2018-03-01

    Following the development of gravity gradiometer instrument technology, the full tensor gravity (FTG) data can be acquired on airborne and marine platforms. Large-scale geophysical data can be obtained using these methods, making such data sets a number of the "big data" category. Therefore, a fast and effective inversion method is developed to solve the large-scale FTG data inversion problem. Many algorithms are available to accelerate the FTG data inversion, such as conjugate gradient method. However, the conventional conjugate gradient method takes a long time to complete data processing. Thus, a fast and effective iterative algorithm is necessary to improve the utilization of FTG data. Generally, inversion processing is formulated by incorporating regularizing constraints, followed by the introduction of a non-monotone gradient-descent method to accelerate the convergence rate of FTG data inversion. Compared with the conventional gradient method, the steepest descent gradient algorithm, and the conjugate gradient algorithm, there are clear advantages of the non-monotone iterative gradient-descent algorithm. Simulated and field FTG data were applied to show the application value of this new fast inversion method.

  18. Environment based innovation: policy questions

    Directory of Open Access Journals (Sweden)

    Mario Rui Silva

    2009-12-01

    Full Text Available Natural resources and physical cultural resources, referred to in this paper as “Environmental Resources”, can be important assets for regional competitiveness and innovation. In recent years, these types of assets have been increasingly taken into consideration in the design and implementation of regional development strategies, as a consequence of their potential role as a source of differentiation and of new competitive advantages. However, in contrast to environmental policies, which usually focus on the protection of the environment, innovation policies and their instruments are largely shaped by, and geared towards, knowledge-based innovation.In this paper, we discuss the role played by environmental resources in the context of regional innovation policies. We begin by discussing the relationship between environmental resources and regional development, and by emphasizing some contrasting views with regard to the function of environmental resources in regional development. Then, we address the relationship between regional competitive advantages and innovation strategies. The specific issues and problems that arise whenever the aim is to attain competitive advantages through the valorisation of environmental resources constitute the core of section III. In that section, we highlight the specific characteristics of environmental resources and we discuss the applicability of the “natural resource curse” argument to the dynamics based on the valorisation of environmental resources. The reasons that justify public interventionas well as the difficulties concerning the adequate level of intervention (local / regional / national are also examined. The paper ends with some conclusions and policy implications.

  19. Gradient Evolution-based Support Vector Machine Algorithm for Classification

    Science.gov (United States)

    Zulvia, Ferani E.; Kuo, R. J.

    2018-03-01

    This paper proposes a classification algorithm based on a support vector machine (SVM) and gradient evolution (GE) algorithms. SVM algorithm has been widely used in classification. However, its result is significantly influenced by the parameters. Therefore, this paper aims to propose an improvement of SVM algorithm which can find the best SVMs’ parameters automatically. The proposed algorithm employs a GE algorithm to automatically determine the SVMs’ parameters. The GE algorithm takes a role as a global optimizer in finding the best parameter which will be used by SVM algorithm. The proposed GE-SVM algorithm is verified using some benchmark datasets and compared with other metaheuristic-based SVM algorithms. The experimental results show that the proposed GE-SVM algorithm obtains better results than other algorithms tested in this paper.

  20. Gradient-based MCMC samplers for dynamic causal modelling.

    Science.gov (United States)

    Sengupta, Biswa; Friston, Karl J; Penny, Will D

    2016-01-15

    In this technical note, we derive two MCMC (Markov chain Monte Carlo) samplers for dynamic causal models (DCMs). Specifically, we use (a) Hamiltonian MCMC (HMC-E) where sampling is simulated using Hamilton's equation of motion and (b) Langevin Monte Carlo algorithm (LMC-R and LMC-E) that simulates the Langevin diffusion of samples using gradients either on a Euclidean (E) or on a Riemannian (R) manifold. While LMC-R requires minimal tuning, the implementation of HMC-E is heavily dependent on its tuning parameters. These parameters are therefore optimised by learning a Gaussian process model of the time-normalised sample correlation matrix. This allows one to formulate an objective function that balances tuning parameter exploration and exploitation, furnishing an intervention-free inference scheme. Using neural mass models (NMMs)-a class of biophysically motivated DCMs-we find that HMC-E is statistically more efficient than LMC-R (with a Riemannian metric); yet both gradient-based samplers are far superior to the random walk Metropolis algorithm, which proves inadequate to steer away from dynamical instability. Copyright © 2015. Published by Elsevier Inc.

  1. Implementing risk-based policies

    International Nuclear Information System (INIS)

    Barill, T.

    1992-01-01

    The principle of risk-based policy is that the protection of human health and the environment is best determined on a case-by-case basis, rather than by a set level of contamination. This paper discusses common techniques used by environmental professionals to effectively implement risk-based policy. Once understood, these principles can be easily applied to provide flexibility in terms of cleanup levels, operations levels and permitting/reporting requirements. Regulations at all levels currently refer to or require assessments of health risk. including RCRA Corrective Action, the Clean Air Act, the Clean Water Act and the Toxics Substances Control Act. A fundamental problem with quantitative risk assessments is that they are based on extrapolating data from a set of laboratory conditions to the real world. A set limit, while easier to handle, allows less contaminated areas to become more contaminated and may require an excessively low cleanup level for more contaminated areas. By using relative risk in assessing a site, factors such as background levels, current and future land use, and health risk can be taken into account

  2. Democratic Population Decisions Result in Robust Policy-Gradient Learning: A Parametric Study with GPU Simulations

    Science.gov (United States)

    Richmond, Paul; Buesing, Lars; Giugliano, Michele; Vasilaki, Eleni

    2011-01-01

    High performance computing on the Graphics Processing Unit (GPU) is an emerging field driven by the promise of high computational power at a low cost. However, GPU programming is a non-trivial task and moreover architectural limitations raise the question of whether investing effort in this direction may be worthwhile. In this work, we use GPU programming to simulate a two-layer network of Integrate-and-Fire neurons with varying degrees of recurrent connectivity and investigate its ability to learn a simplified navigation task using a policy-gradient learning rule stemming from Reinforcement Learning. The purpose of this paper is twofold. First, we want to support the use of GPUs in the field of Computational Neuroscience. Second, using GPU computing power, we investigate the conditions under which the said architecture and learning rule demonstrate best performance. Our work indicates that networks featuring strong Mexican-Hat-shaped recurrent connections in the top layer, where decision making is governed by the formation of a stable activity bump in the neural population (a “non-democratic” mechanism), achieve mediocre learning results at best. In absence of recurrent connections, where all neurons “vote” independently (“democratic”) for a decision via population vector readout, the task is generally learned better and more robustly. Our study would have been extremely difficult on a desktop computer without the use of GPU programming. We present the routines developed for this purpose and show that a speed improvement of 5x up to 42x is provided versus optimised Python code. The higher speed is achieved when we exploit the parallelism of the GPU in the search of learning parameters. This suggests that efficient GPU programming can significantly reduce the time needed for simulating networks of spiking neurons, particularly when multiple parameter configurations are investigated. PMID:21572529

  3. Democratic population decisions result in robust policy-gradient learning: a parametric study with GPU simulations.

    Directory of Open Access Journals (Sweden)

    Paul Richmond

    2011-05-01

    Full Text Available High performance computing on the Graphics Processing Unit (GPU is an emerging field driven by the promise of high computational power at a low cost. However, GPU programming is a non-trivial task and moreover architectural limitations raise the question of whether investing effort in this direction may be worthwhile. In this work, we use GPU programming to simulate a two-layer network of Integrate-and-Fire neurons with varying degrees of recurrent connectivity and investigate its ability to learn a simplified navigation task using a policy-gradient learning rule stemming from Reinforcement Learning. The purpose of this paper is twofold. First, we want to support the use of GPUs in the field of Computational Neuroscience. Second, using GPU computing power, we investigate the conditions under which the said architecture and learning rule demonstrate best performance. Our work indicates that networks featuring strong Mexican-Hat-shaped recurrent connections in the top layer, where decision making is governed by the formation of a stable activity bump in the neural population (a "non-democratic" mechanism, achieve mediocre learning results at best. In absence of recurrent connections, where all neurons "vote" independently ("democratic" for a decision via population vector readout, the task is generally learned better and more robustly. Our study would have been extremely difficult on a desktop computer without the use of GPU programming. We present the routines developed for this purpose and show that a speed improvement of 5x up to 42x is provided versus optimised Python code. The higher speed is achieved when we exploit the parallelism of the GPU in the search of learning parameters. This suggests that efficient GPU programming can significantly reduce the time needed for simulating networks of spiking neurons, particularly when multiple parameter configurations are investigated.

  4. Democratic population decisions result in robust policy-gradient learning: a parametric study with GPU simulations.

    Science.gov (United States)

    Richmond, Paul; Buesing, Lars; Giugliano, Michele; Vasilaki, Eleni

    2011-05-04

    High performance computing on the Graphics Processing Unit (GPU) is an emerging field driven by the promise of high computational power at a low cost. However, GPU programming is a non-trivial task and moreover architectural limitations raise the question of whether investing effort in this direction may be worthwhile. In this work, we use GPU programming to simulate a two-layer network of Integrate-and-Fire neurons with varying degrees of recurrent connectivity and investigate its ability to learn a simplified navigation task using a policy-gradient learning rule stemming from Reinforcement Learning. The purpose of this paper is twofold. First, we want to support the use of GPUs in the field of Computational Neuroscience. Second, using GPU computing power, we investigate the conditions under which the said architecture and learning rule demonstrate best performance. Our work indicates that networks featuring strong Mexican-Hat-shaped recurrent connections in the top layer, where decision making is governed by the formation of a stable activity bump in the neural population (a "non-democratic" mechanism), achieve mediocre learning results at best. In absence of recurrent connections, where all neurons "vote" independently ("democratic") for a decision via population vector readout, the task is generally learned better and more robustly. Our study would have been extremely difficult on a desktop computer without the use of GPU programming. We present the routines developed for this purpose and show that a speed improvement of 5x up to 42x is provided versus optimised Python code. The higher speed is achieved when we exploit the parallelism of the GPU in the search of learning parameters. This suggests that efficient GPU programming can significantly reduce the time needed for simulating networks of spiking neurons, particularly when multiple parameter configurations are investigated.

  5. A time domain phase-gradient based ISAR autofocus algorithm

    CSIR Research Space (South Africa)

    Nel, W

    2011-10-01

    Full Text Available Autofocus is a well known required step in ISAR (and SAR) processing to compensate translational motion. This research proposes a time domain autofocus algorithm and discusses its relation to the well known phase gradient autofocus (PGA) technique...

  6. Design of LED projector based on gradient-index lens

    Science.gov (United States)

    Qian, Liyong; Zhu, Xiangbing; Cui, Haitian; Wang, Yuanhang

    2018-01-01

    In this study, a new type of projector light path is designed to eliminate the deficits of existing projection systems, such as complex structure and low collection efficiency. Using a three-color LED array as the lighting source, by means of the special optical properties of a gradient-index lens, the complex structure of the traditional projector is simplified. Traditional components, such as the color wheel, relay lens, and mirror, become unnecessary. In this way, traditional problems, such as low utilization of light energy and loss of light energy, are solved. With the help of Zemax software, the projection lens is optimized. The optimized projection lens, LED, gradient-index lens, and digital micromirror device are imported into Tracepro. The ray tracing results show that both the utilization of light energy and the uniformity are improved significantly.

  7. Gradient-based selective excitation schemes in NMR

    Energy Technology Data Exchange (ETDEWEB)

    Adell, P.; Parella, T.; Sanchez-Ferranda, F.; Virgili, A. [Departament de Quimica, Universitat Autonoma de Barcelona, Bellaterra, (Spain)

    1996-10-01

    The behaviour of several recently proposed frequency-selective NMR excitation methods was monitored using brucine as a test sample. for each method the results were compared in terms of selectivity, sensitivity, phase properties and J-coupling refocussing. Methods using pulsed field gradients gave better overall results than shaped pulses alone. A slight modification of the WATERGATE method, incorporating the exclusive use of Gaussian pulses and the insertion of a final refocussing delay, gave the most satisfactory results.

  8. ADAPTIVE ANT COLONY OPTIMIZATION BASED GRADIENT FOR EDGE DETECTION

    Directory of Open Access Journals (Sweden)

    Febri Liantoni

    2014-08-01

    Full Text Available Ant Colony Optimization (ACO is a nature-inspired optimization algorithm which is motivated by ants foraging behavior. Due to its favorable advantages, ACO has been widely used to solve several NP-hard problems, including edge detection. Since ACO initially distributes ants at random, it may cause imbalance ant distribution which later affects path discovery process. In this paper an adaptive ACO is proposed to optimize edge detection by adaptively distributing ant according to gradient analysis. Ants are adaptively distributed according to gradient ratio of each image regions. Region which has bigger gradient ratio, will have bigger number of ant distribution. Experiments are conducted using images from various datasets. Precision and recall are used to quantitatively evaluate performance of the proposed algorithm. Precision and recall of adaptive ACO reaches 76.98 % and 96.8 %. Whereas highest precision and recall for standard ACO are 69.74 % and 74.85 %. Experimental results show that the adaptive ACO outperforms standard ACO which randomly distributes ants.

  9. Directory Enabled Policy Based Networking; TOPICAL

    International Nuclear Information System (INIS)

    KELIIAA, CURTIS M.

    2001-01-01

    This report presents a discussion of directory-enabled policy-based networking with an emphasis on its role as the foundation for securely scalable enterprise networks. A directory service provides the object-oriented logical environment for interactive cyber-policy implementation. Cyber-policy implementation includes security, network management, operational process and quality of service policies. The leading network-technology vendors have invested in these technologies for secure universal connectivity that transverses Internet, extranet and intranet boundaries. Industry standards are established that provide the fundamental guidelines for directory deployment scalable to global networks. The integration of policy-based networking with directory-service technologies provides for intelligent management of the enterprise network environment as an end-to-end system of related clients, services and resources. This architecture allows logical policies to protect data, manage security and provision critical network services permitting a proactive defense-in-depth cyber-security posture. Enterprise networking imposes the consideration of supporting multiple computing platforms, sites and business-operation models. An industry-standards based approach combined with principled systems engineering in the deployment of these technologies allows these issues to be successfully addressed. This discussion is focused on a directory-based policy architecture for the heterogeneous enterprise network-computing environment and does not propose specific vendor solutions. This document is written to present practical design methodology and provide an understanding of the risks, complexities and most important, the benefits of directory-enabled policy-based networking

  10. Pilot projects in Evidence Based Policy Making

    NARCIS (Netherlands)

    Vreugdenhil, H.S.I.; Ker Rault, P.A.

    2010-01-01

    In Evidence Based Policy Making, pilot projects have been recognized as important tools to develop ‘evidence’ of policy innovations. This paper presents a theoretical and empirical study of three water management pilot projects in the Rhine basin to deepen understanding of how they can contri-bute

  11. Algorithm for image retrieval based on edge gradient orientation statistical code.

    Science.gov (United States)

    Zeng, Jiexian; Zhao, Yonggang; Li, Weiye; Fu, Xiang

    2014-01-01

    Image edge gradient direction not only contains important information of the shape, but also has a simple, lower complexity characteristic. Considering that the edge gradient direction histograms and edge direction autocorrelogram do not have the rotation invariance, we put forward the image retrieval algorithm which is based on edge gradient orientation statistical code (hereinafter referred to as EGOSC) by sharing the application of the statistics method in the edge direction of the chain code in eight neighborhoods to the statistics of the edge gradient direction. Firstly, we construct the n-direction vector and make maximal summation restriction on EGOSC to make sure this algorithm is invariable for rotation effectively. Then, we use Euclidean distance of edge gradient direction entropy to measure shape similarity, so that this method is not sensitive to scaling, color, and illumination change. The experimental results and the algorithm analysis demonstrate that the algorithm can be used for content-based image retrieval and has good retrieval results.

  12. Cohort-based income gradients in obesity among U.S. adults.

    Science.gov (United States)

    Heo, Jongho; Beck, Audrey N; Lin, Shih-Fan; Marcelli, Enrico; Lindsay, Suzanne; Karl Finch, Brian

    2018-03-01

    No studies have focused on socioeconomic disparities in obesity within and between cohorts. Our objectives were to examine income gradients in obesity between birth-cohorts (inter-cohort variations) and within each birth-cohort (intra-cohort variations) by gender and race/ethnicity. Our sample includes 56,820 white and black adults from pooled, cross-sectional National Health and Nutrition Examination Surveys (1971-2012). We fit a series of logistic hierarchical Age-Period-Cohort models to control for the effects of age and period, simultaneously. Predicted probabilities of obesity by poverty-to-income ratio were estimated and graphed for 5-year cohort groups from 1901-1990. We also stratified this relationship for four gender and racial/ethnic subgroups. Obesity disparities due to income were weaker for post-World War I and II generations, specifically the mid-1920s and the mid-1940s to 1950s cohorts, than for other cohorts. In contrast, we found greater income gradients in obesity among cohorts from the 1930s to mid-1940s and mid-1960s to 1970s. Moreover, obesity disparities due to income across cohorts vary markedly by gender and race/ethnicity. White women with higher income consistently exhibited a lower likelihood of obesity than those with lower income since early 1900s cohorts; whereas, black men with higher income exhibited higher risks of obesity than those with lower income in most cohorts. Our findings suggest that strategies that address race and/or gender inequalities in obesity should be cognizant of significant historical factors that may be unique to cohorts. Period-based approaches that ignore life-course experiences captured in significant cohort-based experiences may limit the utility of policies and interventions. © 2017 Wiley Periodicals, Inc.

  13. Time-domain full waveform inversion using the gradient preconditioning based on transmitted waves energy

    KAUST Repository

    Zhang, Xiao-bo

    2017-06-01

    The gradient preconditioning approach based on seismic wave energy can effectively avoid the huge storage consumption in the gradient preconditioning algorithms based on Hessian matrices in time-domain full waveform inversion (FWI), but the accuracy is affected by the energy of reflected waves when strong reflectors are present in velocity model. To address this problem, we propose a gradient preconditioning method, which scales the gradient based on the energy of the “approximated transmitted wavefield” simulated by the nonreflecting acoustic wave equation. The method does not require computing or storing the Hessian matrix or its inverse. Furthermore, it can effectively eliminate the effects caused by geometric diffusion and non-uniformity illumination on gradient. The results of model experiments confirm that the time-domain FWI using the gradient preconditioning based on transmitted waves energy can achieve higher inversion precision for high-velocity body and the deep strata below when compared with using the gradient preconditioning based on seismic waves energy.

  14. UPM: unified policy-based network management

    Science.gov (United States)

    Law, Eddie; Saxena, Achint

    2001-07-01

    Besides providing network management to the Internet, it has become essential to offer different Quality of Service (QoS) to users. Policy-based management provides control on network routers to achieve this goal. The Internet Engineering Task Force (IETF) has proposed a two-tier architecture whose implementation is based on the Common Open Policy Service (COPS) protocol and Lightweight Directory Access Protocol (LDAP). However, there are several limitations to this design such as scalability and cross-vendor hardware compatibility. To address these issues, we present a functionally enhanced multi-tier policy management architecture design in this paper. Several extensions are introduced thereby adding flexibility and scalability. In particular, an intermediate entity between the policy server and policy rule database called the Policy Enforcement Agent (PEA) is introduced. By keeping internal data in a common format, using a standard protocol, and by interpreting and translating request and decision messages from multi-vendor hardware, this agent allows a dynamic Unified Information Model throughout the architecture. We have tailor-made this unique information system to save policy rules in the directory server and allow executions of policy rules with dynamic addition of new equipment during run-time.

  15. Variational infrared image enhancement based on adaptive dual-threshold gradient field equalization

    Science.gov (United States)

    Zhao, Wenda; Xu, Zhijun; Zhao, Jian; Zhao, Fan; Han, Xizhen

    2014-09-01

    Infrared images are characterized by low signal to noise ratio (SNR) and fuzzy texture edges. This article introduces the variational infrared image enhancement algorithm based on gradient field equalization with adaptive dual thresholds. Firstly, we transform the image into gradient domain and get the gradient histogram. Then, we do the gradient histogram equalization. By setting adaptive dual thresholds to qualify the gradients, the image is prevented from over enhancement. The total variation (TV) model is adopted in the reconstruction of the enhanced image to suppress noise. It is shown from experimental results that the image edge details are significantly enhanced, and therefore the algorithm is qualified for enhancement of infrared images in different applications.

  16. An inverse problem strategy based on forward model evaluations: Gradient-based optimization without adjoint solves

    Energy Technology Data Exchange (ETDEWEB)

    Aguilo Valentin, Miguel Alejandro [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-07-01

    This study presents a new nonlinear programming formulation for the solution of inverse problems. First, a general inverse problem formulation based on the compliance error functional is presented. The proposed error functional enables the computation of the Lagrange multipliers, and thus the first order derivative information, at the expense of just one model evaluation. Therefore, the calculation of the Lagrange multipliers does not require the solution of the computationally intensive adjoint problem. This leads to significant speedups for large-scale, gradient-based inverse problems.

  17. A gradient-based method for segmenting FDG-PET images: methodology and validation

    International Nuclear Information System (INIS)

    Geets, Xavier; Lee, John A.; Gregoire, Vincent; Bol, Anne; Lonneux, Max

    2007-01-01

    A new gradient-based method for segmenting FDG-PET images is described and validated. The proposed method relies on the watershed transform and hierarchical cluster analysis. To allow a better estimation of the gradient intensity, iteratively reconstructed images were first denoised and deblurred with an edge-preserving filter and a constrained iterative deconvolution algorithm. Validation was first performed on computer-generated 3D phantoms containing spheres, then on a real cylindrical Lucite phantom containing spheres of different volumes ranging from 2.1 to 92.9 ml. Moreover, laryngeal tumours from seven patients were segmented on PET images acquired before laryngectomy by the gradient-based method and the thresholding method based on the source-to-background ratio developed by Daisne (Radiother Oncol 2003;69:247-50). For the spheres, the calculated volumes and radii were compared with the known values; for laryngeal tumours, the volumes were compared with the macroscopic specimens. Volume mismatches were also analysed. On computer-generated phantoms, the deconvolution algorithm decreased the mis-estimate of volumes and radii. For the Lucite phantom, the gradient-based method led to a slight underestimation of sphere volumes (by 10-20%), corresponding to negligible radius differences (0.5-1.1 mm); for laryngeal tumours, the segmented volumes by the gradient-based method agreed with those delineated on the macroscopic specimens, whereas the threshold-based method overestimated the true volume by 68% (p = 0.014). Lastly, macroscopic laryngeal specimens were totally encompassed by neither the threshold-based nor the gradient-based volumes. The gradient-based segmentation method applied on denoised and deblurred images proved to be more accurate than the source-to-background ratio method. (orig.)

  18. Policy administration in tag-based authorization

    NARCIS (Netherlands)

    Etalle, Sandro; Hinrichs, Timothy L.; Lee, Adam J.; Trivellato, Daniel; Zannone, Nicola

    2013-01-01

    Tag-Based Authorization (TBA) is a hybrid access control model that combines the ease of use of extensional access control models with the expressivity of logic-based formalisms. The main limitation of TBA is that it lacks support for policy administration. More precisely, it does not allow

  19. Poblano v1.0 : a Matlab toolbox for gradient-based optimization.

    Energy Technology Data Exchange (ETDEWEB)

    Dunlavy, Daniel M.; Acar, Evrim (Sandia National Laboratories, Livermore, CA); Kolda, Tamara Gibson (Sandia National Laboratories, Livermore, CA)

    2010-03-01

    We present Poblano v1.0, a Matlab toolbox for solving gradient-based unconstrained optimization problems. Poblano implements three optimization methods (nonlinear conjugate gradients, limited-memory BFGS, and truncated Newton) that require only first order derivative information. In this paper, we describe the Poblano methods, provide numerous examples on how to use Poblano, and present results of Poblano used in solving problems from a standard test collection of unconstrained optimization problems.

  20. Policy-Based Management Natural Language Parser

    Science.gov (United States)

    James, Mark

    2009-01-01

    The Policy-Based Management Natural Language Parser (PBEM) is a rules-based approach to enterprise management that can be used to automate certain management tasks. This parser simplifies the management of a given endeavor by establishing policies to deal with situations that are likely to occur. Policies are operating rules that can be referred to as a means of maintaining order, security, consistency, or other ways of successfully furthering a goal or mission. PBEM provides a way of managing configuration of network elements, applications, and processes via a set of high-level rules or business policies rather than managing individual elements, thus switching the control to a higher level. This software allows unique management rules (or commands) to be specified and applied to a cross-section of the Global Information Grid (GIG). This software embodies a parser that is capable of recognizing and understanding conversational English. Because all possible dialect variants cannot be anticipated, a unique capability was developed that parses passed on conversation intent rather than the exact way the words are used. This software can increase productivity by enabling a user to converse with the system in conversational English to define network policies. PBEM can be used in both manned and unmanned science-gathering programs. Because policy statements can be domain-independent, this software can be applied equally to a wide variety of applications.

  1. Time dependent policy-based access control

    DEFF Research Database (Denmark)

    Vasilikos, Panagiotis; Nielson, Flemming; Nielson, Hanne Riis

    2017-01-01

    Access control policies are essential to determine who is allowed to access data in a system without compromising the data's security. However, applications inside a distributed environment may require those policies to be dependent on the actual content of the data, the flow of information, while...... also on other attributes of the environment such as the time. In this paper, we use systems of Timed Automata to model distributed systems and we present a logic in which one can express time-dependent policies for access control. We show how a fragment of our logic can be reduced to a logic...... that current model checkers for Timed Automata such as UPPAAL can handle and we present a translator that performs this reduction. We then use our translator and UPPAAL to enforce time-dependent policy-based access control on an example application from the aerospace industry....

  2. Model-reduced gradient-based history matching

    NARCIS (Netherlands)

    Kaleta, M.P.

    2011-01-01

    Since the world's energy demand increases every year, the oil & gas industry makes a continuous effort to improve fossil fuel recovery. Physics-based petroleum reservoir modeling and closed-loop model-based reservoir management concept can play an important role here. In this concept measured data

  3. Bidirectional composition on lie groups for gradient-based image alignment.

    Science.gov (United States)

    Mégret, Rémi; Authesserre, Jean-Baptiste; Berthoumieu, Yannick

    2010-09-01

    In this paper, a new formulation based on bidirectional composition on Lie groups (BCL) for parametric gradient-based image alignment is presented. Contrary to the conventional approaches, the BCL method takes advantage of the gradients of both template and current image without combining them a priori. Based on this bidirectional formulation, two methods are proposed and their relationship with state-of-the-art gradient based approaches is fully discussed. The first one, i.e., the BCL method, relies on the compositional framework to provide the minimization of the compensated error with respect to an augmented parameter vector. The second one, the projected BCL (PBCL), corresponds to a close approximation of the BCL approach. A comparative study is carried out dealing with computational complexity, convergence rate and frequence of convergence. Numerical experiments using a conventional benchmark show the performance improvement especially for asymmetric levels of noise, which is also discussed from a theoretical point of view.

  4. A gradient based algorithm to solve inverse plane bimodular problems of identification

    Science.gov (United States)

    Ran, Chunjiang; Yang, Haitian; Zhang, Guoqing

    2018-02-01

    This paper presents a gradient based algorithm to solve inverse plane bimodular problems of identifying constitutive parameters, including tensile/compressive moduli and tensile/compressive Poisson's ratios. For the forward bimodular problem, a FE tangent stiffness matrix is derived facilitating the implementation of gradient based algorithms, for the inverse bimodular problem of identification, a two-level sensitivity analysis based strategy is proposed. Numerical verification in term of accuracy and efficiency is provided, and the impacts of initial guess, number of measurement points, regional inhomogeneity, and noisy data on the identification are taken into accounts.

  5. Design and Additive Manufacturing of 3D Phononic Band Gap Structures Based on Gradient Based Optimization

    Directory of Open Access Journals (Sweden)

    Maximilian Wormser

    2017-09-01

    Full Text Available We present a novel approach for gradient based maximization of phononic band gaps. The approach is a geometry projection method combining parametric shape optimization with density based topology optimization. By this approach, we obtain, in a two dimension setting, cellular structures exhibiting relative and normalized band gaps of more than 8 and 1.6, respectively. The controlling parameter is the minimal strut size, which also corresponds with the obtained stiffness of the structure. The resulting design principle is manually interpreted into a three dimensional structure from which cellular metal samples are fabricated by selective electron beam melting. Frequency response diagrams experimentally verify the numerically determined phononic band gaps of the structures. The resulting structures have band gaps down to the audible frequency range, qualifying the structures for an application in noise isolation.

  6. Design and Additive Manufacturing of 3D Phononic Band Gap Structures Based on Gradient Based Optimization.

    Science.gov (United States)

    Wormser, Maximilian; Wein, Fabian; Stingl, Michael; Körner, Carolin

    2017-09-22

    We present a novel approach for gradient based maximization of phononic band gaps. The approach is a geometry projection method combining parametric shape optimization with density based topology optimization. By this approach, we obtain, in a two dimension setting, cellular structures exhibiting relative and normalized band gaps of more than 8 and 1.6, respectively. The controlling parameter is the minimal strut size, which also corresponds with the obtained stiffness of the structure. The resulting design principle is manually interpreted into a three dimensional structure from which cellular metal samples are fabricated by selective electron beam melting. Frequency response diagrams experimentally verify the numerically determined phononic band gaps of the structures. The resulting structures have band gaps down to the audible frequency range, qualifying the structures for an application in noise isolation.

  7. Gradient-based optimization in nonlinear structural dynamics

    DEFF Research Database (Denmark)

    Dou, Suguang

    , frequency stabilization, and disk resonator gyroscope. For advanced design of these structures, it is of considerable value to extend current optimization in linear structural dynamics into nonlinear structural dynamics. In this thesis, we present a framework for modelling, analysis, characterization......The intrinsic nonlinearity of mechanical structures can give rise to rich nonlinear dynamics. Recently, nonlinear dynamics of micro-mechanical structures have contributed to developing new Micro-Electro-Mechanical Systems (MEMS), for example, atomic force microscope, passive frequency divider...... coefficients are calculated directly from a nonlinear finite element model. Based on the analysis and the characterization, a new class of optimization problems is studied. In the optimization, design sensitivity analysis is performed by using the adjoint method which is suitable for large-scale structural...

  8. A Nonlocal Damage Model for Elastoplastic Materials based on Gradient Plasticity Theory

    International Nuclear Information System (INIS)

    Chen, J.; Yuan, H.; Kalkhof, D.

    2001-10-01

    Experimental and theoretical studies have shown that size effects in structure deformations and failure become significant as soon as strain gradients are high. For instance as soon as material failure dominates a deformation process, the specimen displays increasingly softening and the finite element computation is significantly affected by the element size. Without considering this effect in the constitutive model one cannot hope a reliable prediction to the ductile material failure process. To give an accurate prediction of the structure integrity and to quantify the material failure process, it is necessary to introduce the strain gradients into constitutive equations. Gradient plasticity models have been discussed extensively in recent years. The mesh-sensitivity in numerical analysis has been successfully eliminated and analytical explanations for size effects were given. In the present work, a general framework for a nonlocal micromechanical damage model based on the gradient-dependent plasticity theory is presented and its finite element algorithm for finite strains is developed and implemented. In the finite element algorithm, equivalent plastic strain and plastic multiplier have been taken as the unknown variables. Due to the implementation of the Lapacian term, the implicit C 1 shape function is applied for equivalent plastic strain and can be transformed to arbitrary quadrilateral elements. Computational analysis of material failure is consistent to the known size effects. By incorporating the Laplacian of plastic strain into the GTN constitutive relationship, the known mesh-dependence is overcome for the simulation of ductile damage processes and numerical results correlate uniquely with the given material parameters. In the chapters of applications, we discuss simulations of micro-indentation tests based on the gradient plasticity model. The role of intrinsic material length parameters in the gradient plasticity model is investigated. The

  9. Application of the thermodynamic-based strain gradient plasticity theory in high velocity impact problems

    Science.gov (United States)

    Voyiadjis, George; Song, Yooseob

    In this work, a thermodynamic-based framework of the higher-order strain gradient plasticity is presented to investigate the thermo-mechanical material response of the metallic volumes at extreme conditions such as high velocity impact related problems. The need of the plastic strain gradients and their corresponding rates is discussed along with the mechanism associated with geometrically necessary dislocations. One of the major issues in the strain gradient plasticity is the determination of the intrinsic material length scales that scale with the gradient of the plastic strain. Explicit and implicit microstructural length scales, which preserve the well-posed nature of the differential equations, are introduced through the use of the viscosity and gradient localization limiters. Numerical simulations of the dynamic deformation response of tantalum hat-shaped specimens, subjected to compressive loading at the ambient initial temperatures and three different strain rates, are carried out and the comparisons of the numerical results to experimental measurements are also made. Another numerical application of a blunt projectile impacting a target is examined and the direct comparison between numerical and experimental results is presented.

  10. Interaction of rate- and size-effect using a dislocation density based strain gradient viscoplasticity model

    Science.gov (United States)

    Nguyen, Trung N.; Siegmund, Thomas; Tomar, Vikas; Kruzic, Jamie J.

    2017-12-01

    Size effects occur in non-uniform plastically deformed metals confined in a volume on the scale of micrometer or sub-micrometer. Such problems have been well studied using strain gradient rate-independent plasticity theories. Yet, plasticity theories describing the time-dependent behavior of metals in the presence of size effects are presently limited, and there is no consensus about how the size effects vary with strain rates or whether there is an interaction between them. This paper introduces a constitutive model which enables the analysis of complex load scenarios, including loading rate sensitivity, creep, relaxation and interactions thereof under the consideration of plastic strain gradient effects. A strain gradient viscoplasticity constitutive model based on the Kocks-Mecking theory of dislocation evolution, namely the strain gradient Kocks-Mecking (SG-KM) model, is established and allows one to capture both rate and size effects, and their interaction. A formulation of the model in the finite element analysis framework is derived. Numerical examples are presented. In a special virtual creep test with the presence of plastic strain gradients, creep rates are found to diminish with the specimen size, and are also found to depend on the loading rate in an initial ramp loading step. Stress relaxation in a solid medium containing cylindrical microvoids is predicted to increase with decreasing void radius and strain rate in a prior ramp loading step.

  11. An algorithm for gradient-based dynamic optimization of UV flash processes

    DEFF Research Database (Denmark)

    Ritschel, Tobias Kasper Skovborg; Capolei, Andrea; Gaspar, Jozsef

    2017-01-01

    This paper presents a novel single-shooting algorithm for gradient-based solution of optimal control problems with vapor-liquid equilibrium constraints. Such optimal control problems are important in several engineering applications, for instance in control of distillation columns, in certain two...

  12. Gradient for the acoustic VTI full waveform inversion based on the instantaneous traveltime sensitivity kernels

    KAUST Repository

    Djebbi, Ramzi

    2015-08-19

    The instantaneous traveltime is able to reduce the non-linearity of full waveform inversion (FWI) that originates from the wrapping of the phase. However, the adjoint state method in this case requires a total of 5 modeling calculations to compute the gradient. Also, considering the larger modeling cost for anisotropic wavefield extrapolation and the necessity to use a line-search algorithm to estimate a step length that depends on the parameters scale, we propose to calculate the gradient based on the instantaneous traveltime sensitivity kernels. We, specifically, use the sensitivity kernels computed using dynamic ray-tracing to build the gradient. The resulting update is computed using a matrix decomposition and accordingly the computational cost is reduced. We consider a simple example where an anomaly is embedded into a constant background medium and we compute the update for the VTI wave equation parameterized using vh, η and ε.

  13. Infrared small target detection based on local intensity and gradient properties

    Science.gov (United States)

    Zhang, Hong; Zhang, Lei; Yuan, Ding; Chen, Hao

    2018-03-01

    Infrared small target detection is a challenging task for computer vision due to the factors such as scale variations of the targets and strong clutters. Inspired by the Gaussian-like shape of the small target, we characterize two local properties of the small target from the perspective of intensity and gradient to address this problem. The two properties are that the intensity value of the target pixels is greater than the value of its locally neighboring pixels, and the gradients towards the target center often distribute regularly around the target. First, based on the two properties, the local intensity and gradient (LIG) map is calculated from the original infrared image in order to enhance the targets and suppress clutters. Next, we can obtain the targets conveniently via segmentation from the LIG map. Extensive evaluations on real data demonstrate that the proposed algorithm has satisfactory results in terms of clutter suppression and robustness.

  14. Aircraft Detection in High-Resolution SAR Images Based on a Gradient Textural Saliency Map

    Directory of Open Access Journals (Sweden)

    Yihua Tan

    2015-09-01

    Full Text Available This paper proposes a new automatic and adaptive aircraft target detection algorithm in high-resolution synthetic aperture radar (SAR images of airport. The proposed method is based on gradient textural saliency map under the contextual cues of apron area. Firstly, the candidate regions with the possible existence of airport are detected from the apron area. Secondly, directional local gradient distribution detector is used to obtain a gradient textural saliency map in the favor of the candidate regions. In addition, the final targets will be detected by segmenting the saliency map using CFAR-type algorithm. The real high-resolution airborne SAR image data is used to verify the proposed algorithm. The results demonstrate that this algorithm can detect aircraft targets quickly and accurately, and decrease the false alarm rate.

  15. Aircraft Detection in High-Resolution SAR Images Based on a Gradient Textural Saliency Map.

    Science.gov (United States)

    Tan, Yihua; Li, Qingyun; Li, Yansheng; Tian, Jinwen

    2015-09-11

    This paper proposes a new automatic and adaptive aircraft target detection algorithm in high-resolution synthetic aperture radar (SAR) images of airport. The proposed method is based on gradient textural saliency map under the contextual cues of apron area. Firstly, the candidate regions with the possible existence of airport are detected from the apron area. Secondly, directional local gradient distribution detector is used to obtain a gradient textural saliency map in the favor of the candidate regions. In addition, the final targets will be detected by segmenting the saliency map using CFAR-type algorithm. The real high-resolution airborne SAR image data is used to verify the proposed algorithm. The results demonstrate that this algorithm can detect aircraft targets quickly and accurately, and decrease the false alarm rate.

  16. Accelerated gradient methods for total-variation-based CT image reconstruction

    DEFF Research Database (Denmark)

    Jørgensen, Jakob Heide; Jensen, Tobias Lindstrøm; Hansen, Per Christian

    2011-01-01

    incorporates several heuristics from the optimization literature such as Barzilai-Borwein (BB) step size selection and nonmonotone line search. The latter uses a cleverly chosen sequence of auxiliary points to achieve a better convergence rate. The methods are memory efficient and equipped with a stopping...... reconstruction can in principle be found by any optimization method, but in practice the large scale of the systems arising in CT image reconstruction preclude the use of memory-demanding methods such as Newton’s method. The simple gradient method has much lower memory requirements, but exhibits slow convergence....... In the present work we address the question of how to reduce the number of gradient method iterations needed to achieve a high-accuracy TV reconstruction. We consider the use of two accelerated gradient-based methods, GPBB and UPN, to solve the 3D-TV minimization problem in CT image reconstruction. The former...

  17. The Urban-Rural Gradient In Asthma: A Population-Based Study in Northern Europe

    Directory of Open Access Journals (Sweden)

    Signe Timm

    2015-12-01

    Full Text Available The early life environment appears to have a persistent impact on asthma risk. We hypothesize that environmental factors related to rural life mediate lower asthma prevalence in rural populations, and aimed to investigate an urban-rural gradient, assessed by place of upbringing, for asthma. The population-based Respiratory Health In Northern Europe (RHINE study includes subjects from Denmark, Norway, Sweden, Iceland and Estonia born 1945–1973. The present analysis encompasses questionnaire data on 11,123 RHINE subjects. Six categories of place of upbringing were defined: farm with livestock, farm without livestock, village in rural area, small town, city suburb and inner city. The association of place of upbringing with asthma onset was analysed with Cox regression adjusted for relevant confounders. Subjects growing up on livestock farms had less asthma (8% than subjects growing up in inner cities (11% (hazard ratio 0.72 95% CI 0.57–0.91, and a significant urban-rural gradient was observed across six urbanisation levels (p = 0.02. An urban-rural gradient was only evident among women, smokers and for late-onset asthma. Analyses on wheeze and place of upbringing revealed similar results. In conclusion, this study suggests a protective effect of livestock farm upbringing on asthma development and an urban-rural gradient in a Northern European population.

  18. Constructing regional advantage: platform policies based on related variety and differentiated knowledge bases.

    NARCIS (Netherlands)

    Asheim, B.T.; Boschma, R.A.; Cooke, P.

    2011-01-01

    Constructing regional advantage: platform policies based on related variety and differentiated knowledge bases, Regional Studies. This paper presents a regional innovation policy model based on the idea of constructing regional advantage. This policy model brings together concepts like related

  19. Implementing evidence-based policy in a network setting: road safety policy in the Netherlands.

    Science.gov (United States)

    Bax, Charlotte; de Jong, Martin; Koppenjan, Joop

    2010-01-01

    In the early 1990s, in order to improve road safety in The Netherlands, the Institute for Road Safety Research (SWOV) developed an evidence-based "Sustainable Safety" concept. Based on this concept, Dutch road safety policy, was seen as successful and as a best practice in Europe. In The Netherlands, the policy context has now changed from a sectoral policy setting towards a fragmented network in which safety is a facet of other transport-related policies. In this contribution, it is argued that the implementation strategy underlying Sustainable Safety should be aligned with the changed context. In order to explore the adjustments needed, two perspectives of policy implementation are discussed: (1) national evidence-based policies with sectoral implementation; and (2) decentralized negotiation on transport policy in which road safety is but one aspect. We argue that the latter approach matches the characteristics of the newly evolved policy context best, and conclude with recommendations for reformulating the implementation strategy.

  20. Topographic gradient based site characterization in India complemented by strong ground-motion spectral attributes

    KAUST Repository

    Nath, Sankar Kumar

    2013-12-01

    We appraise topographic-gradient approach for site classification that employs correlations between 30. m column averaged shear-wave velocity and topographic gradients. Assessments based on site classifications reported from cities across India indicate that the approach is reasonably viable at regional level. Additionally, we experiment three techniques for site classification based on strong ground-motion recordings, namely Horizontal-to-Vertical Spectral Ratio (HVSR), Response Spectra Shape (RSS), and Horizontal-to-Vertical Response Spectral Ratio (HVRSR) at the strong motion stations located across the Himalayas and northeast India. Statistical tests on the results indicate that these three techniques broadly differentiate soil and rock sites while RSS and HVRSR yield better signatures. The results also support the implemented site classification in the light of strong ground-motion spectral attributes observed in different parts of the globe. © 2013 Elsevier Ltd.

  1. The Adjoint Method for Gradient-based Dynamic Optimization of UV Flash Processes

    DEFF Research Database (Denmark)

    Ritschel, Tobias Kasper Skovborg; Capolei, Andrea; Jørgensen, John Bagterp

    2017-01-01

    This paper presents a novel single-shooting algorithm for gradient-based solution of optimal control problems with vapor-liquid equilibrium constraints. Dynamic optimization of UV flash processes is relevant in nonlinear model predictive control of distillation columns, certain two-phase flow......-component flash process which demonstrate the importance of the optimization solver, the compiler, and the linear algebra software for the efficiency of dynamic optimization of UV flash processes....

  2. An Empirical Investigation of Catastrophic Forgetting in Gradient-Based Neural Networks

    OpenAIRE

    Goodfellow, Ian J.; Mirza, Mehdi; Xiao, Da; Courville, Aaron; Bengio, Yoshua

    2013-01-01

    Catastrophic forgetting is a problem faced by many machine learning models and algorithms. When trained on one task, then trained on a second task, many machine learning models "forget" how to perform the first task. This is widely believed to be a serious problem for neural networks. Here, we investigate the extent to which the catastrophic forgetting problem occurs for modern neural networks, comparing both established and recent gradient-based training algorithms and activation functions. ...

  3. Quantification of pH Gradients and Implications in Insulator-Based Dielectrophoresis of Biomolecules

    OpenAIRE

    Gencoglu, Aytug; Camacho-Alanis, Fernanda; Nguyen, Vi Thanh; Nakano, Asuka; Ros, Alexandra; Minerick, Adrienne

    2011-01-01

    Direct current (DC) insulator-based dielectrophoretic (iDEP) microdevices have the potential to replace traditional alternating current (AC) dielectrophoretic devices for many cellular and biomolecular separation applications. The use of large DC fields suggest that electrode reactions and ion transport mechanisms can become important and impact ion distributions in the nanoliters of fluid in iDEP microchannels. This work tracked natural pH gradient formation in a 100 μm wide, 1 cm long micro...

  4. Integrating policy-based management and SLA performance monitoring

    Science.gov (United States)

    Liu, Tzong-Jye; Lin, Chin-Yi; Chang, Shu-Hsin; Yen, Meng-Tzu

    2001-10-01

    Policy-based management system provides the configuration capability for the system administrators to focus on the requirements of customers. The service level agreement performance monitoring mechanism helps system administrators to verify the correctness of policies. However, it is difficult for a device to process the policies directly because the policies are the management concept. This paper proposes a mechanism to decompose a policy into rules that can be efficiently processed by a device. Thus, the device may process the rule and collect the performance statistics information efficiently; and the policy-based management system may collect these performance statistics information and report the service-level agreement performance monitoring information to the system administrator. The proposed policy-based management system achieves both the policy configuration and service-level agreement performance monitoring requirements. A policy consists of a condition part and an action part. The condition part is a Boolean expression of a source host IP group, a destination host IP group, etc. The action part is the parameters of services. We say that an address group is compact if it only consists of a range of IP address that can be denoted by a pair of IP address and corresponding IP mask. If the condition part of a policy only consists of the compact address group, we say that the policy is a rule. Since a device can efficiently process a compact address and a system administrator prefers to define a range of IP address, the policy-based management system has to translate policy into rules and supplements the gaps between policy and rules. The proposed policy-based management system builds the relationships between VPN and policies, policy and rules. Since the system administrator wants to monitor the system performance information of VPNs and policies, the proposed policy-based management system downloads the relationships among VPNs, policies and rules to the

  5. Zwitterionic silica-based monolithic capillary columns for isocratic and gradient hydrophilic interaction liquid chromatography.

    Science.gov (United States)

    Moravcová, Dana; Planeta, Josef; Kahle, Vladislav; Roth, Michal

    2012-12-28

    This study introduces zwitterionic monolithic capillary columns intended for isocratic and gradient HILIC separations. Silica-based monolithic capillary columns (100 μm × 150 mm) prepared by acidic hydrolysis of tetramethoxysilane in the presence of polyethylene glycol and urea were modified by a sulfoalkylbetaine zwitterion ([2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl)-ammonium hydroxide) to HILIC stationary phase. The prepared columns were evaluated under the isocratic and gradient separation conditions using a standard mixture containing nucleic acid bases, nucleosides, and 2-deoxynucleosides. Mobile phases contained high concentration of acetonitrile (95-85%, v/v) and 5-50mM ammonium acetate or ammonium formate in the pH range of 3-6. The synthesized columns showed a long-term stability under the separation conditions while the high permeability and efficiency originating from dual structure of the silica monolith were preserved. The relative standard deviations (RSDs) for the retention times of tested solutes were lower than 2% under the isocratic conditions and lower than 3.5% under the gradient conditions. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Ionospheric forecasting model using fuzzy logic-based gradient descent method

    Directory of Open Access Journals (Sweden)

    D. Venkata Ratnam

    2017-09-01

    Full Text Available Space weather phenomena cause satellite to ground or satellite to aircraft transmission outages over the VHF to L-band frequency range, particularly in the low latitude region. Global Positioning System (GPS is primarily susceptible to this form of space weather. Faulty GPS signals are attributed to ionospheric error, which is a function of Total Electron Content (TEC. Importantly, precise forecasts of space weather conditions and appropriate hazard observant cautions required for ionospheric space weather observations are limited. In this paper, a fuzzy logic-based gradient descent method has been proposed to forecast the ionospheric TEC values. In this technique, membership functions have been tuned based on the gradient descent estimated values. The proposed algorithm has been tested with the TEC data of two geomagnetic storms in the low latitude station of KL University, Guntur, India (16.44°N, 80.62°E. It has been found that the gradient descent method performs well and the predicted TEC values are close to the original TEC measurements.

  7. Research on n-γ discrimination method based on spectrum gradient analysis of signals

    International Nuclear Information System (INIS)

    Luo Xiaoliang; Liu Guofu; Yang Jun; Wang Yueke

    2013-01-01

    Having discovered that there are distinct differences between the spectrum gradient of the output neutron and γ-ray signal from liquid scintillator detectors, this paper presented a n-γ discrimination method called spectrum gradient analysis (SGA) based on frequency-domain features of the pulse signals. The basic principle and feasibility of SGA method were discussed and the validity of n-γ discrimination results of SGA was verified by the associated particle neutron flight experiment. The discrimination performance of SGA was evaluated under different conditions of sampling rates ranging from 5 G/s to 250 M/s. The results show that SGA method exhibits insensitivity to noise, strong anti-interference ability, stable discrimination performance and lower amount of calculation in contrast with time-domain n-γ discrimination methods. (authors)

  8. Ultrasound image edge detection based on a novel multiplicative gradient and Canny operator.

    Science.gov (United States)

    Zheng, Yinfei; Zhou, Yali; Zhou, Hao; Gong, Xiaohong

    2015-07-01

    To achieve the fast and accurate segmentation of ultrasound image, a novel edge detection method for speckle noised ultrasound images was proposed, which was based on the traditional Canny and a novel multiplicative gradient operator. The proposed technique combines a new multiplicative gradient operator of non-Newtonian type with the traditional Canny operator to generate the initial edge map, which is subsequently optimized by the following edge tracing step. To verify the proposed method, we compared it with several other edge detection methods that had good robustness to noise, with experiments on the simulated and in vivo medical ultrasound image. Experimental results showed that the proposed algorithm has higher speed for real-time processing, and the edge detection accuracy could be 75% or more. Thus, the proposed method is very suitable for fast and accurate edge detection of medical ultrasound images. © The Author(s) 2014.

  9. Subpixel displacement measurement method based on the combination of particle swarm optimization and gradient algorithm

    Science.gov (United States)

    Guang, Chen; Qibo, Feng; Keqin, Ding; Zhan, Gao

    2017-10-01

    A subpixel displacement measurement method based on the combination of particle swarm optimization (PSO) and gradient algorithm (GA) was proposed for accuracy and speed optimization in GA, which is a subpixel displacement measurement method better applied in engineering practice. An initial integer-pixel value was obtained according to the global searching ability of PSO, and then gradient operators were adopted for a subpixel displacement search. A comparison was made between this method and GA by simulated speckle images and rigid-body displacement in metal specimens. The results showed that the computational accuracy of the combination of PSO and GA method reached 0.1 pixel in the simulated speckle images, or even 0.01 pixels in the metal specimen. Also, computational efficiency and the antinoise performance of the improved method were markedly enhanced.

  10. Mitigating illumination gradients in a SAR image based on the image data and antenna beam pattern

    Science.gov (United States)

    Doerry, Armin W.

    2013-04-30

    Illumination gradients in a synthetic aperture radar (SAR) image of a target can be mitigated by determining a correction for pixel values associated with the SAR image. This correction is determined based on information indicative of a beam pattern used by a SAR antenna apparatus to illuminate the target, and also based on the pixel values associated with the SAR image. The correction is applied to the pixel values associated with the SAR image to produce corrected pixel values that define a corrected SAR image.

  11. A novel retinal vessel extraction algorithm based on matched filtering and gradient vector flow

    Science.gov (United States)

    Yu, Lei; Xia, Mingliang; Xuan, Li

    2013-10-01

    The microvasculature network of retina plays an important role in the study and diagnosis of retinal diseases (age-related macular degeneration and diabetic retinopathy for example). Although it is possible to noninvasively acquire high-resolution retinal images with modern retinal imaging technologies, non-uniform illumination, the low contrast of thin vessels and the background noises all make it difficult for diagnosis. In this paper, we introduce a novel retinal vessel extraction algorithm based on gradient vector flow and matched filtering to segment retinal vessels with different likelihood. Firstly, we use isotropic Gaussian kernel and adaptive histogram equalization to smooth and enhance the retinal images respectively. Secondly, a multi-scale matched filtering method is adopted to extract the retinal vessels. Then, the gradient vector flow algorithm is introduced to locate the edge of the retinal vessels. Finally, we combine the results of matched filtering method and gradient vector flow algorithm to extract the vessels at different likelihood levels. The experiments demonstrate that our algorithm is efficient and the intensities of vessel images exactly represent the likelihood of the vessels.

  12. A downstream algorithm based on extended gradient vector flow field for object segmentation.

    Science.gov (United States)

    Chuang, Cheng-Hung; Lie, Wen-Nung

    2004-10-01

    For object segmentation, traditional snake algorithms often require human interaction; region growing methods are considerably dependent on the selected homogeneity criterion and initial seeds; watershed algorithms, however, have the drawback of over segmentation. A new downstream algorithm based on a proposed extended gradient vector flow (E-GVF) field model is presented in this paper for multiobject segmentation. The proposed flow field, on one hand, diffuses and propagates gradients near object boundaries to provide an effective guiding force and, on the other hand, presents a higher resolution of direction than traditional GVF field. The downstream process starts with a set of seeds scored and selected by considering local gradient direction information around each pixel. This step is automatic and requires no human interaction, making our algorithm more suitable for practical applications. Experiments show that our algorithm is noise resistant and has the advantage of segmenting objects that are separated from the background, while ignoring the internal structures of them. We have tested the proposed algorithm with several realistic images (e.g., medical and complex background images) and gained good results.

  13. Phase gradient metasurface with broadband anomalous reflection based on cross-shaped units

    Science.gov (United States)

    Chen, Zhaobin; Deng, Hui; Xiong, Qingxu; Liu, Chen

    2018-03-01

    It has been pointed out by many documents that a phase gradient metasurface with wideband characteristics can be designed by the unit with a low-quality factor ( Q value). In this paper, a cross-shaped unit with a low-quality factor Q is proposed. By changing the variable parameters of the unit, it is found that the reflection phase of the unit can achieve a stable distribution of phase gradient in the frequency range of 8.0-20.0 GHz. we analyze variation of the electromagnetic field distribution on the unit with frequency and find that the size along electrical field polarization of electromagnetic field distribution area changes with frequency. Based on our design, effective size of electromagnetic field distribution area keeps meeting the subwavelength condition, thus stable phase distribution is gained across broadened bandwidth. It is found by the analysis of the phase gradient metasurface composed of seven units that the metasurface can exhibit anomalous reflection in the wide frequency band of 8.0-20.0 GHz, and the efficiency of abnormal reflection is higher in the range of 10.0-18.0 GHz. The error between the simulation results of abnormal reflection angle and the theoretical result is only - 1.5° to 0.5° after the work of comparison. Therefore, the metasurface designed by the new cross-shaped unit has a good control on the deflection direction of the reflected wave, and shows obvious advantages in widening the bandwidth.

  14. Extrusion-based 3D printing of poly(propylene fumarate) scaffolds with hydroxyapatite gradients.

    Science.gov (United States)

    Trachtenberg, Jordan E; Placone, Jesse K; Smith, Brandon T; Fisher, John P; Mikos, Antonios G

    2017-04-01

    The primary focus of this work is to present the current challenges of printing scaffolds with concentration gradients of nanoparticles with an aim to improve the processing of these scaffolds. Furthermore, we address how print fidelity is related to material composition and emphasize the importance of considering this relationship when developing complex scaffolds for bone implants. The ability to create complex tissues is becoming increasingly relevant in the tissue engineering community. For bone tissue engineering applications, this work demonstrates the ability to use extrusion-based printing techniques to control the spatial deposition of hydroxyapatite (HA) nanoparticles in a 3D composite scaffold. In doing so, we combined the benefits of synthetic, degradable polymers, such as poly(propylene fumarate) (PPF), with osteoconductive HA nanoparticles that provide robust compressive mechanical properties. Furthermore, the final 3D printed scaffolds consisted of well-defined layers with interconnected pores, two critical features for a successful bone implant. To demonstrate a controlled gradient of HA, thermogravimetric analysis was carried out to quantify HA on a per-layer basis. Moreover, we non-destructively evaluated the tendency of HA particles to aggregate within PPF using micro-computed tomography (μCT). This work provides insight for proper fabrication and characterization of composite scaffolds containing particle gradients and has broad applicability for future efforts in fabricating complex scaffolds for tissue engineering applications.

  15. Extrusion-based 3D printing of poly(propylene fumarate) scaffolds with hydroxyapatite gradients

    Science.gov (United States)

    Trachtenberg, Jordan E.; Placone, Jesse K.; Smith, Brandon T.; Fisher, John P.; Mikos, Antonios G.

    2017-01-01

    The primary focus of this work is to present the current challenges of printing scaffolds with concentration gradients of nanoparticles with an aim to improve the processing of these scaffolds. Furthermore, we address how print fidelity is related to material composition and emphasize the importance of considering this relationship when developing complex scaffolds for bone implants. The ability to create complex tissues is becoming increasingly relevant in the tissue engineering community. For bone tissue engineering applications, this work demonstrates the ability to use extrusion-based printing techniques to control the spatial deposition of hydroxyapatite (HA) nanoparticles in a 3D composite scaffold. In doing so, we combined the benefits of synthetic, degradable polymers, such as poly(propylene fumarate) (PPF), with osteoconductive HA nanoparticles that provide robust compressive mechanical properties. Furthermore, the final 3D printed scaffolds consisted of well-defined layers with interconnected pores, two critical features for a successful bone implant. To demonstrate a controlled gradient of HA, thermogravimetric analysis was carried out to quantify HA on a per-layer basis. Moreover, we non-destructively evaluated the tendency of HA particles to aggregate within PPF using micro-computed tomography (µCT). This work provides insight for proper fabrication and characterization of composite scaffolds containing particle gradients and has broad applicability for future efforts in fabricating complex scaffolds for tissue engineering applications. PMID:28125380

  16. Segmentasi Pembuluh Darah Retina Pada Citra Fundus Menggunakan Gradient Based Adaptive Thresholding Dan Region Growing

    Directory of Open Access Journals (Sweden)

    Deni Sutaji

    2016-07-01

    Full Text Available AbstrakSegmentasi pembuluh darah pada citra fundus retina menjadi hal yang substansial dalam dunia kedokteran, karena dapat digunakan untuk mendeteksi penyakit, seperti: diabetic retinopathy, hypertension, dan cardiovascular. Dokter membutuhkan waktu sekitar dua jam untuk mendeteksi pembuluh darah retina, sehingga diperlukan metode yang dapat membantu screening agar lebih cepat.Penelitian sebelumnya mampu melakukan segmentasi pembuluh darah yang sensitif terhadap variasi ukuran lebar pembuluh darah namun masih terjadi over-segmentasi pada area patologi. Oleh karena itu, penelitian ini bertujuan untuk mengembangkan metode segmentasi pembuluh darah pada citra fundus retina yang dapat mengurangi over-segmentasi pada area patologi menggunakan Gradient Based Adaptive Thresholding dan Region Growing.Metode yang diusulkan terdiri dari 3 tahap, yaitu segmentasi pembuluh darah utama, deteksi area patologi dan segmentasi pembuluh darah tipis. Tahap segmentasi pembuluh darah utama menggunakan high-pass filtering dan tophat reconstruction pada kanal hijau citra yang sudah diperbaiki kontrasnya sehingga lebih jelas perbedaan antara pembuluh darah dan background. Tahap deteksi area patologi menggunakan metode Gradient Based Adaptive Thresholding. Tahap segmentasi pembuluh darah tipis menggunakan Region Growing berdasarkan informasi label pembuluh darah utama dan label area patologi. Hasil segmentasi pembuluh darah utama dan pembuluh darah tipis kemudian digabungkan sehingga menjadi keluaran sistem berupa citra biner pembuluh darah. Berdasarkan hasil uji coba, metode ini mampu melakukan segmentasi pembuluh darah retina dengan baik pada citra fundus DRIVE, yaitu dengan akurasi rata-rata 95.25% dan nilai Area Under Curve (AUC pada kurva Relative Operating Characteristic (ROC sebesar 74.28%.                           Kata Kunci: citra fundus retina, gradient based adaptive thresholding, patologi, pembuluh darah retina, region growing

  17. Longitudinal base to apex perfusion gradients by dipyridamole positron emission tomography indicate diffuse coronary atherosclerosis

    International Nuclear Information System (INIS)

    Nakagawa, Yuko

    2001-01-01

    Diffuse coronary atherosclerosis is clinically important and often associated with localized stenosis but is not detected or quantified by current methods including coronary arteriography. Accordingly, I quantified the longitudinal base to apex distribution of N-13 ammonia on positron emission tomography (PET) after dipyridamole stress for 17 normal volunteers and 30 patients with abnormal coronary arteriograms. Heart images were divided into 32 short axis tomographic slices along the long axis, and each slice was divided into anterior, septal, lateral and inferior quadrant. Average relative activity for each slice in each quadrant was graphed against slice number and a third order polynomial curve was best fit to the longitudinal distribution of activity. In the patients group, average relative activity in each quadrant, except septum in mild to moderate disease group, progressively and significantly decreased from base to apex slices compared to normal group, and perfusion decreasing was more progressed in severe disease group. In 12 of the patients with one- or two-vessel disease, longitudinal base to apex perfusion gradient was observed in angiographically stenosis-free quadrant. Thus, patients with segmental coronary artery disease by arteriography have abnormal longitudinal base to apex perfusion gradients on dipyridamole PET images indicating diffuse coronary atherosclerosis. (author)

  18. An optical flow algorithm based on gradient constancy assumption for PIV image processing

    Science.gov (United States)

    Zhong, Qianglong; Yang, Hua; Yin, Zhouping

    2017-05-01

    Particle image velocimetry (PIV) has matured as a flow measurement technique. It enables the description of the instantaneous velocity field of the flow by analyzing the particle motion obtained from digitally recorded images. Correlation based PIV evaluation technique is widely used because of its good accuracy and robustness. Although very successful, correlation PIV technique has some weakness which can be avoided by optical flow based PIV algorithms. At present, most of the optical flow methods applied to PIV are based on brightness constancy assumption. However, some factors of flow imaging technology and the nature property of the fluids make the brightness constancy assumption less appropriate in real PIV cases. In this paper, an implementation of a 2D optical flow algorithm (GCOF) based on gradient constancy assumption is introduced. The proposed GCOF assumes the edges of the illuminated PIV particles are constant during motion. It comprises two terms: a combined local-global gradient data term and a first-order divergence and vorticity smooth term. The approach can provide accurate dense motion fields. The approach are tested on synthetic images and on two experimental flows. The comparison of GCOF with other optical flow algorithms indicates the proposed method is more accurate especially in conditions of illumination variation. The comparison of GCOF with correlation PIV technique shows that the proposed GCOF has advantages on preserving small divergence and vorticity structures of the motion field and getting less outliers. As a consequence, the GCOF acquire a more accurate and better topological description of the turbulent flow.

  19. An optical flow algorithm based on gradient constancy assumption for PIV image processing

    International Nuclear Information System (INIS)

    Zhong, Qianglong; Yang, Hua; Yin, Zhouping

    2017-01-01

    Particle image velocimetry (PIV) has matured as a flow measurement technique. It enables the description of the instantaneous velocity field of the flow by analyzing the particle motion obtained from digitally recorded images. Correlation based PIV evaluation technique is widely used because of its good accuracy and robustness. Although very successful, correlation PIV technique has some weakness which can be avoided by optical flow based PIV algorithms. At present, most of the optical flow methods applied to PIV are based on brightness constancy assumption. However, some factors of flow imaging technology and the nature property of the fluids make the brightness constancy assumption less appropriate in real PIV cases. In this paper, an implementation of a 2D optical flow algorithm (GCOF) based on gradient constancy assumption is introduced. The proposed GCOF assumes the edges of the illuminated PIV particles are constant during motion. It comprises two terms: a combined local-global gradient data term and a first-order divergence and vorticity smooth term. The approach can provide accurate dense motion fields. The approach are tested on synthetic images and on two experimental flows. The comparison of GCOF with other optical flow algorithms indicates the proposed method is more accurate especially in conditions of illumination variation. The comparison of GCOF with correlation PIV technique shows that the proposed GCOF has advantages on preserving small divergence and vorticity structures of the motion field and getting less outliers. As a consequence, the GCOF acquire a more accurate and better topological description of the turbulent flow. (paper)

  20. Structuring AHP-based maintenance policy selection

    NARCIS (Netherlands)

    Goossens, Adriaan; Basten, Robertus Johannes Ida; Hummel, J. Marjan; van der Wegen, Leonardus L.M.

    2015-01-01

    We aim to structure the maintenance policy selection process for ships, using the Analytic Hierarchy Process (AHP). Maintenance is an important contributor to reach the intended life-time of capital technical assets, and it is gaining increasing interest and relevance. A maintenance policy is a

  1. Block-Based Gradient Descent for Local Backlight Dimming and Flicker Reduction

    DEFF Research Database (Denmark)

    Burini, Nino; Mantel, Claire; Nadernejad, Ehsan

    2014-01-01

    Local backlight dimming technology is a two-fold improvement for LED backlit LCD screens that allows to reduce power consumption and increase visual quality. This paper presents a fast version of an iterative backlight dimming algorithm based on gradient descent search. The speed is increased...... by exploiting the local uniformity of backlight to reduce the complexity for determining the optimal backlight of a given image. The algorithm is adapted to video sequences by using the backlight of the previous frame as a starting point to calculate the backlight for the current frame. Fast variations...

  2. Analyze the optimal solutions of optimization problems by means of fractional gradient based system using VIM

    Directory of Open Access Journals (Sweden)

    Firat Evirgen

    2016-04-01

    Full Text Available In this paper, a class of Nonlinear Programming problem is modeled with gradient based system of fractional order differential equations in Caputo's sense. To see the overlap between the equilibrium point of the fractional order dynamic system and theoptimal solution of the NLP problem in a longer timespan the Multistage Variational İteration Method isapplied. The comparisons among the multistage variational iteration method, the variationaliteration method and the fourth order Runge-Kutta method in fractional and integer order showthat fractional order model and techniques can be seen as an effective and reliable tool for finding optimal solutions of Nonlinear Programming problems.

  3. Stochastic parallel gradient descent based adaptive optics used for a high contrast imaging coronagraph

    International Nuclear Information System (INIS)

    Dong Bing; Ren Deqing; Zhang Xi

    2011-01-01

    An adaptive optics (AO) system based on a stochastic parallel gradient descent (SPGD) algorithm is proposed to reduce the speckle noises in the optical system of a stellar coronagraph in order to further improve the contrast. The principle of the SPGD algorithm is described briefly and a metric suitable for point source imaging optimization is given. The feasibility and good performance of the SPGD algorithm is demonstrated by an experimental system featured with a 140-actuator deformable mirror and a Hartmann-Shark wavefront sensor. Then the SPGD based AO is applied to a liquid crystal array (LCA) based coronagraph to improve the contrast. The LCA can modulate the incoming light to generate a pupil apodization mask of any pattern. A circular stepped pattern is used in our preliminary experiment and the image contrast shows improvement from 10 -3 to 10 -4.5 at an angular distance of 2λ/D after being corrected by SPGD based AO.

  4. Dose gradient analyses in linac-based intracranial stereotactic radiosurgery using paddick's gradient index. Consideration of the optimal method for plan evaluation

    International Nuclear Information System (INIS)

    Ohtakara, Kazuhiro; Hayashi, Shinya; Hoshi, Hiroaki

    2011-01-01

    The objective of our study was to describe the dose gradient characteristics of Linac-based stereotactic radiosurgery using Paddick's gradient index (GI) and to elucidate the factors influencing the GI value. Seventy-three plans for brain metastases using the dynamic conformal arcs were reviewed. The GI values were calculated at the 80% and 90% isodose surfaces (IDSs) and at the different target coverage IDSs (D99, D95, D90, and D85). The GI values significantly decreased as the target coverage of the reference IDS increased (the percentage of the IDS decreased). There was a significant inverse correlation between the GI values and target volume. The plans generated with the addition of a 1-mm leaf margin had worse GI values both at the D99 and D95 relative to those without leaf margin. The number and arrangement of arcs also affected the GI value. The GI values are highly sensitive to the IDS selection variability for dose prescription or evaluation, the target volume, and the planning method. To objectively compare the quality of dose gradient between rival plans, it would be preferable to employ the GI defined at the reference IDS indicating the specific target coverage (exempli gratia (e.g.), D95), irrespective of the intended marginal dose. The modified GI (mGI), defined in this study, substituting the denominator of the original GI with the target volume, would be useful to compensate for the false superior GI value in cases of target over-coverage with the reference IDS and to objectively evaluate the dose gradient outside the target boundary. (author)

  5. Volume based vs. time based chromatograms: reproducibility of data for gradient separations under high and low pressure conditions.

    Science.gov (United States)

    Stankovich, Joseph J; Gritti, Fabrice; Stevenson, Paul G; Vajda, Péter; Beaver, Lois Ann; Guiochon, Georges

    2014-05-23

    A critical aspect in fast gradient separations carried out under constant pressure, in the very high pressure liquid chromatography (VHPLC) mode is that time-based chromatograms may not yield highly reproducible separations. A proposed solution to improve the reproducibility of these separations involves plotting the chromatograms as functions of the volume eluted vs. UV absorbance instead of time vs. UV. To study the consequences of using the volume-based rather than the time-based chromatograms, separations were first performed under low pressures that do not generate significant amounts of heat and for which the variations of the eluent density along the columns are negligible. Secondly, they were performed under very high pressures that do generate heat and measurable variations of the local retention factor and eluent density along the column. Comparison of the results provides estimates of the improvements obtained when volume based chromatograms are used in gradient analyses. Using a column packed with fully porous particles, four different types of methods and several sets for each method were used to perform the gradient elution runs: two sets of constant flow rate operations, four sets of constant pressure operations, two sets of constant pressure operations with programmed flow rate, and one set using the constant heat loss approach. The differences between time-based and volume-based chromatograms are demonstrated by using eight replicates of early, middle, and last eluting peaks. The results show that volume-based chromatograms improve the retention time reproducibility of the four constant pressure methods by a factor of 3.7 on average. If the column is not thermally conditioned prior to performing a long series of separations, flow controlled methods (constant flow rate, programmed constant pressure, and constant wall heat approaches) are more precise. If one gradient run is used to bring the column to a relatively stable temperature, constant

  6. Adaptive optics correction based on stochastic parallel gradient descent technique using Zernike polynomials

    Science.gov (United States)

    Ma, Huimin; Qiao, Yan; Shen, Chunshan

    2017-10-01

    Adaptive optics systems based on stochastic parallel gradient descent optimization (SPGD) have yet shown great potential on compensation of phase distortions induced by wave propagation through atmosphere turbulence. One of the key technique is increasing the converge rate of SPGD correction system. In the present study, it is shown that the convergence rate of the algorithm will be greatly reduced with the increase of the number of corrector units. In this paper, an improved SPGD optimization process which is based on Zernike-mode is developed. The optimized object is changed from the voltage to Zernike coefficient. Adaptive optics correction system simulation model base on SPGD for a laser beam projecting system, and the numerical simulation of compensation process of random atmosphere turbulence is proposed. To improve the converge speed, we explore to ameliorate the correction system by controlling the perturbation considering atmosphere aberration proportion. The results show that the system converges smoothly and increasingly after considering the aberration proportion by Zernike correction.

  7. Genetically based differentiation in growth of multiple non-native plant species along a steep environmental gradient.

    Science.gov (United States)

    Haider, Sylvia; Kueffer, Christoph; Edwards, Peter J; Alexander, Jake M

    2012-09-01

    A non-native plant species spreading along an environmental gradient may need to adjust its growth to the prevailing conditions that it encounters by a combination of phenotypic plasticity and genetic adaptation. There have been several studies of how non-native species respond to changing environmental conditions along latitudinal gradients, but much less is known about elevational gradients. We conducted a climate chamber experiment to investigate plastic and genetically based growth responses of 13 herbaceous non-native plants along an elevational gradient from 100 to 2,000 m a.s.l. in Tenerife. Conditions in the field ranged from high anthropogenic disturbance but generally favourable temperatures for plant growth in the lower half of the gradient, to low disturbance but much cooler conditions in the upper half. We collected seed from low, mid and high elevations and grew them in climate chambers under the characteristic temperatures at these three elevations. Growth of all species was reduced under lower temperatures along both halves of the gradient. We found consistent genetically based differences in growth over the upper elevational gradient, with plants from high-elevation sites growing more slowly than those from mid-elevation ones, while the pattern in the lower part of the gradient was more mixed. Our data suggest that many non-native plants might respond to climate along elevational gradients by genetically based changes in key traits, especially at higher elevations where low temperatures probably impose a stronger selection pressure. At lower elevations, where anthropogenic influences are greater, higher gene flow and frequent disturbance might favour genotypes with broad ecological amplitudes. Thus the importance of evolutionary processes for invasion success is likely to be context-dependent.

  8. 3D printed scaffolds with gradient porosity based on a cellulose nanocrystal hydrogel.

    Science.gov (United States)

    Sultan, Sahar; Mathew, Aji P

    2018-03-01

    3-Dimensional (3D) printing provides a unique methodology for the customization of biomedical scaffolds with respect to size, shape, pore structure and pore orientation useful for tissue repair and regeneration. 3D printing was used to fabricate fully bio-based porous scaffolds of a double crosslinked interpenetrating polymer network (IPN) from a hydrogel ink of sodium alginate and gelatin (SA/G) reinforced with cellulose nanocrystals (CNCs). CNCs provided favorable rheological properties required for 3D printing. The 3D printed scaffolds were crosslinked sequentially via covalent and ionic reactions resulting in dimensionally stable hydrogel scaffolds with pore sizes of 80-2125 μm and nanoscaled pore wall roughness (visible from scanning electron microscopy) favorable for cell interaction. The 2D wide angle X-ray scattering studies showed that the nanocrystals orient preferably in the printing direction; the degree of orientation varied between 61-76%. The 3D printing pathways were optimised successfully to achieve 3-dimensional scaffolds (Z axis up to 20 mm) with uniform as well as gradient pore structures. This study demonstrates the potential of 3D printing in developing bio-based scaffolds with controlled pore sizes, gradient pore structures and alignment of nanocrystals for optimal tissue regeneration.

  9. Gradient distribution of radial structure of PAN-based carbon fiber treated by high temperature

    Directory of Open Access Journals (Sweden)

    Haitao Wang

    2014-02-01

    Full Text Available High-performance graphite fibers were prepared and analyzed. The gradient distribution of radial structure of PAN-based carbon fibers was characterized by two different Raman test methods (incident laser beam perpendicular to and parallel to the fiber axis and studied by the distribution of graphitization degree. Meanwhile difference between the two Raman test methods was used to describe the orientation of the graphite crystallite along the fiber axis. The results showed that the radial structure of PAN-based carbon fiber presented different gradient distribution states at different heat treatment temperatures, and the graphitization degree in the skin region changed more rapidly compared with the core region since the skin region was more affected by temperature which resulted in the obvious difference between skin and core structures. The difference of graphitization degree (Δg characterized by two different Raman test methods increased with heat treatment temperature, indicating that the high temperature treatment (HTT promoted further stacking of graphite crystallite, and the orientation degree of the graphite crystallite along the fiber axis was continuously increased.

  10. Variational Level Set Method for Two-Stage Image Segmentation Based on Morphological Gradients

    Directory of Open Access Journals (Sweden)

    Zemin Ren

    2014-01-01

    Full Text Available We use variational level set method and transition region extraction techniques to achieve image segmentation task. The proposed scheme is done by two steps. We first develop a novel algorithm to extract transition region based on the morphological gradient. After this, we integrate the transition region into a variational level set framework and develop a novel geometric active contour model, which include an external energy based on transition region and fractional order edge indicator function. The external energy is used to drive the zero level set toward the desired image features, such as object boundaries. Due to this external energy, the proposed model allows for more flexible initialization. The fractional order edge indicator function is incorporated into the length regularization term to diminish the influence of noise. Moreover, internal energy is added into the proposed model to penalize the deviation of the level set function from a signed distance function. The results evolution of the level set function is the gradient flow that minimizes the overall energy functional. The proposed model has been applied to both synthetic and real images with promising results.

  11. Game Algorithm for Resource Allocation Based on Intelligent Gradient in HetNet

    Directory of Open Access Journals (Sweden)

    Fang Ye

    2017-02-01

    Full Text Available In order to improve system performance such as throughput, heterogeneous network (HetNet has become an effective solution in Long Term Evolution-Advanced (LET-A. However, co-channel interference leads to degradation of the HetNet throughput, because femtocells are always arranged to share the spectrum with the macro base station. In this paper, in view of the serious cross-layer interference in double layer HetNet, the Stackelberg game model is adopted to analyze the resource allocation methods of the network. Unlike the traditional system models only focusing on macro base station performance improvement, we take into account the overall system performance and build a revenue function with convexity. System utility functions are defined as the average throughput, which does not adopt frequency spectrum trading method, so as to avoid excessive signaling overhead. Due to the value scope of continuous Nash equilibrium of the built game model, the gradient iterative algorithm is introduced to reduce the computational complexity. As for the solution of Nash equilibrium, one kind of gradient iterative algorithm is proposed, which is able to intelligently choose adjustment factors. The Nash equilibrium can be quickly solved; meanwhile, the step of presetting adjustment factors is avoided according to network parameters in traditional linear iterative model. Simulation results show that the proposed algorithm enhances the overall performance of the system.

  12. Illicit Drugs, Policing and the Evidence-Based Policy Paradigm

    Science.gov (United States)

    Ritter, Alison; Lancaster, Kari

    2013-01-01

    The mantra of evidence-based policy (EBP) suggests that endeavours to implement evidence-based policing will produce better outcomes. However there is dissonance between the rhetoric of EBP and the actuality of policing policy. This disjuncture is critically analysed using the case study of illicit drugs policing. The dissonance may be ameliorated…

  13. Base stock policies with degraded service to large orders

    DEFF Research Database (Denmark)

    Du, Bisheng; Larsen, Christian

    2011-01-01

    We study an inventory system controlled by a base stock policy assuming a compound renewal demand process. We extend the base stock policy by incorporating rules for degrading the service of larger orders. Two specific rules are considered, denoted as Postpone(q,t) and Split(q), respectively...

  14. Base stock policies with degraded service to larger orders

    DEFF Research Database (Denmark)

    Du, Bisheng; Larsen, Christian

    We study an inventory system controlled by a base stock policy assuming a compound renewal demand process. We extend the base stock policy by incorporating rules for degrading the service of larger orders. Two specific rules are considered, denoted Postpone(q,t) and Split(q), respectively. The aim...

  15. Thickness filters for gradient based multi-material and thickness optimization of laminated composite structures

    DEFF Research Database (Denmark)

    Sørensen, Rene; Lund, Erik

    2015-01-01

    This paper presents a new gradient based method for performing discrete material and thickness optimization of laminated composite structures. The novelty in the new method lies in the application of so-called casting constraints, or thickness filters in this context, to control the thickness...... variation throughout the laminate. The filters replace the layerwise density variables with a single continuous through-the-thickness design variable. Consequently, the filters eliminate the need for having explicit constraints for preventing intermediate void through the thickness of the laminate....... Therefore, the filters reduce both the number of constraints and design variables in the optimization problem. Based upon a continuous approximation of a unit step function, the thickness filters are capable of projecting discrete 0/1 values to the underlying layerwise or ”physical” density variables which...

  16. Full Waveform Inversion Using an Energy-Based Objective Function with Efficient Calculation of the Gradient

    KAUST Repository

    Choi, Yun Seok

    2017-05-26

    Full waveform inversion (FWI) using an energy-based objective function has the potential to provide long wavelength model information even without low frequency in the data. However, without the back-propagation method (adjoint-state method), its implementation is impractical for the model size of general seismic survey. We derive the gradient of the energy-based objective function using the back-propagation method to make its FWI feasible. We also raise the energy signal to the power of a small positive number to properly handle the energy signal imbalance as a function of offset. Examples demonstrate that the proposed FWI algorithm provides a convergent long wavelength structure model even without low-frequency information, which can be used as a good starting model for the subsequent conventional FWI.

  17. Method and means for a spatial and temporal probe for laser-generated plumes based on density gradients

    Science.gov (United States)

    Yeung, E.S.; Chen, G.

    1990-05-01

    A method and means are disclosed for a spatial and temporal probe for laser generated plumes based on density gradients includes generation of a plume of vaporized material from a surface by an energy source. The probe laser beam is positioned so that the plume passes through the probe laser beam. Movement of the probe laser beam caused by refraction from the density gradient of the plume is monitored. Spatial and temporal information, correlated to one another, is then derived. 15 figs.

  18. Automated Facial Expression Recognition Using Gradient-Based Ternary Texture Patterns

    Directory of Open Access Journals (Sweden)

    Faisal Ahmed

    2013-01-01

    Full Text Available Recognition of human expression from facial image is an interesting research area, which has received increasing attention in the recent years. A robust and effective facial feature descriptor is the key to designing a successful expression recognition system. Although much progress has been made, deriving a face feature descriptor that can perform consistently under changing environment is still a difficult and challenging task. In this paper, we present the gradient local ternary pattern (GLTP—a discriminative local texture feature for representing facial expression. The proposed GLTP operator encodes the local texture of an image by computing the gradient magnitudes of the local neighborhood and quantizing those values in three discrimination levels. The location and occurrence information of the resulting micropatterns is then used as the face feature descriptor. The performance of the proposed method has been evaluated for the person-independent face expression recognition task. Experiments with prototypic expression images from the Cohn-Kanade (CK face expression database validate that the GLTP feature descriptor can effectively encode the facial texture and thus achieves improved recognition performance than some well-known appearance-based facial features.

  19. An Improved GPSR Algorithm Based on Energy Gradient and APIT Grid

    Directory of Open Access Journals (Sweden)

    Zhuang Liu

    2016-01-01

    Full Text Available We investigate GPSR algorithms of WSN and propose an improved routing algorithm based on energy gradient and APIT grid to solve the problem of high and unbalanced energy consumption of GPSR. In GPSR, network uses greedy algorithm and right-hand rule to establish routing paths, and the path keeps running till some nodes within the path are invalid because energy is exhausted, which would lead to the high energy consumption of some nodes in the path and the low energy consumption of others nearby the nodes not in the path as well as bringing high and unbalanced energy consumption of the network. Regarding these problems, we use APIT localization algorithm and APIT grid to query and establish routing paths and establish the corresponding energy gradient when messages are transmitted along the routing paths. When some nodes are approaching the threshold status, we use right-hand rule and recursion greedy algorithm in advance to plan a new routing path towards the target area. When query messages arrive at the event area, the network uses a different method to transmit data according to the density of sensor nodes. Simulation experiments show that the improved routing algorithm is capable of reducing the energy consumption of network and extending the lifecycle of network.

  20. Reactive Power Optimization for Distribution Network Based on Distributed Random Gradient-Free Algorithm

    Directory of Open Access Journals (Sweden)

    Jun Xie

    2018-03-01

    Full Text Available The increasing penetration of distributed energy resources in distribution systems has brought a number of network management and operational challenges; reactive power variation has been identified as one of the dominant effects. Enormous growth in a variety of controllable devices that have complex control requirements are integrated in distribution networks. The operation modes of traditional centralized control are difficult to tackle these problems with central controller. When considering the non-linear multi-objective functions with discrete and continuous optimization variables, the proposed random gradient-free algorithm is employed to the optimal operation of controllable devices for reactive power optimization. This paper presents a distributed reactive power optimization algorithm that can obtain the global optimum solution based on random gradient-free algorithm for distribution network without requiring a central coordinator. By utilizing local measurements and local communications among capacitor banks and distributed generators (DGs, the proposed reactive power control strategy can realize the overall network voltage optimization and power loss minimization simultaneously. Simulation studies on the modified IEEE-69 bus distribution systems demonstrate the effectiveness and superiority of the proposed reactive power optimization strategy.

  1. THE IMAGE REGISTRATION OF FOURIER-MELLIN BASED ON THE COMBINATION OF PROJECTION AND GRADIENT PREPROCESSING

    Directory of Open Access Journals (Sweden)

    D. Gao

    2017-09-01

    Full Text Available Image registration is one of the most important applications in the field of image processing. The method of Fourier Merlin transform, which has the advantages of high precision and good robustness to change in light and shade, partial blocking, noise influence and so on, is widely used. However, not only this method can’t obtain the unique mutual power pulse function for non-parallel image pairs, even part of image pairs also can’t get the mutual power function pulse. In this paper, an image registration method based on Fourier-Mellin transformation in the view of projection-gradient preprocessing is proposed. According to the projection conformational equation, the method calculates the matrix of image projection transformation to correct the tilt image; then, gradient preprocessing and Fourier-Mellin transformation are performed on the corrected image to obtain the registration parameters. Eventually, the experiment results show that the method makes the image registration of Fourier-Mellin transformation not only applicable to the registration of the parallel image pairs, but also to the registration of non-parallel image pairs. What’s more, the better registration effect can be obtained

  2. The Image Registration of Fourier-Mellin Based on the Combination of Projection and Gradient Preprocessing

    Science.gov (United States)

    Gao, D.; Zhao, X.; Pan, X.

    2017-09-01

    Image registration is one of the most important applications in the field of image processing. The method of Fourier Merlin transform, which has the advantages of high precision and good robustness to change in light and shade, partial blocking, noise influence and so on, is widely used. However, not only this method can't obtain the unique mutual power pulse function for non-parallel image pairs, even part of image pairs also can't get the mutual power function pulse. In this paper, an image registration method based on Fourier-Mellin transformation in the view of projection-gradient preprocessing is proposed. According to the projection conformational equation, the method calculates the matrix of image projection transformation to correct the tilt image; then, gradient preprocessing and Fourier-Mellin transformation are performed on the corrected image to obtain the registration parameters. Eventually, the experiment results show that the method makes the image registration of Fourier-Mellin transformation not only applicable to the registration of the parallel image pairs, but also to the registration of non-parallel image pairs. What's more, the better registration effect can be obtained

  3. Evaluation of stress gradient by x-ray stress measurement based on change in angle phi

    International Nuclear Information System (INIS)

    Sasaki, Toshihiko; Kuramoto, Makoto; Yoshioka, Yasuo.

    1985-01-01

    A new principle of X-ray stress evaluation for a sample with steep stress gradient has been prosed. The feature of this method is that the stress is determined by using so-called phi-method based on the change of phi-angle and thus has no effect on the penetration depth of X-rays. The procedure is as follows; firstly, an average stress within the penetration depth of X-rays is determined by changing only phi-angle under a fixed psi-angle, and then a distribution of the average stress vs. the penetration depth of X-rays is detected by repeating the similar procedure at different psi-angles. The following conclusions were found out as the result of residual stress measurements on a carbon steel of type S 55 C polished by emery paper. This method is practical enough to use for a plane stress problem. And the assumption of a linear stress gradient adopted in the authors' previous investigations is valid. In case of a triaxial stress analysis, this method is effective for the solution of three shearing stresses. However, three normal stresses can not be solved perfectly except particular psi-angles. (author)

  4. Image defog algorithm based on open close filter and gradient domain recursive bilateral filter

    Science.gov (United States)

    Liu, Daqian; Liu, Wanjun; Zhao, Qingguo; Fei, Bowen

    2017-11-01

    To solve the problems of fuzzy details, color distortion, low brightness of the image obtained by the dark channel prior defog algorithm, an image defog algorithm based on open close filter and gradient domain recursive bilateral filter, referred to as OCRBF, was put forward. The algorithm named OCRBF firstly makes use of weighted quad tree to obtain more accurate the global atmospheric value, then exploits multiple-structure element morphological open and close filter towards the minimum channel map to obtain a rough scattering map by dark channel prior, makes use of variogram to correct the transmittance map,and uses gradient domain recursive bilateral filter for the smooth operation, finally gets recovery images by image degradation model, and makes contrast adjustment to get bright, clear and no fog image. A large number of experimental results show that the proposed defog method in this paper can be good to remove the fog , recover color and definition of the fog image containing close range image, image perspective, the image including the bright areas very well, compared with other image defog algorithms,obtain more clear and natural fog free images with details of higher visibility, what's more, the relationship between the time complexity of SIDA algorithm and the number of image pixels is a linear correlation.

  5. Strain gradient plasticity-based modeling of hydrogen environment assisted cracking

    DEFF Research Database (Denmark)

    Martínez Pañeda, Emilio; Niordson, Christian Frithiof; P. Gangloff, Richard

    2016-01-01

    to predict hydrogen environment assisted crack growth properties. SGP elevates crack tip geometrically necessary dislocation density and flow stress, with enhancement declining with increasing alloy strength. Elevated hydrostatic stress promotes high-trapped H concentration for crack tip damage......Finite element analysis of stress about a blunt crack tip, emphasizing finite strain and phenomenologicaland mechanism-based strain gradient plasticity (SGP) formulations, is integrated with electrochemical assessment of occluded-crack tip hydrogen (H) solubility and two H-decohesion models......; it is imperative to account for SGP in H cracking models. Predictions of the threshold stress intensity factor and H-diffusion limited Stage II crack growth rate agree with experimental data for a high strength austenitic Ni-Cusuperalloy (Monel®K-500) and two modern ultra-high strength martensitic steels (Aer...

  6. Gradient based structural optimization with fatigue constraints of jacket structures for offshore wind turbines

    DEFF Research Database (Denmark)

    Oest, Jacob; Overgaard, Lars Christian; Lund, Erik

    2015-01-01

    without the need for extensive manual post-processing. Ultimately, the optimized design may be lighter and thus reduce both production and installation cost. The aim of this work is to present such a gradient based optimization method with fatigue constraints of jacket structures for the preliminary......Investigating the fatigue life of support structures of offshore wind turbines is imperative to avoid unexpected failure. Therefore, in the context of structural optimization, including fatigue constraints is crucial, as the optimized design will meet the design criteria early in the design process...... design phase. The key challenge is to efficiently deal with the very large number of non-linear fatigue constraints and the very large time-history loads that are used in the design of offshore support structures. In this paper main emphasis will be on the analytical design sensitivity analysis used...

  7. Drawing for Traffic Marking Using Bidirectional Gradient-Based Detection with MMS LIDAR Intensity

    Science.gov (United States)

    Takahashi, G.; Takeda, H.; Nakamura, K.

    2016-06-01

    Recently, the development of autonomous cars is accelerating on the integration of highly advanced artificial intelligence, which increases demand for a digital map with high accuracy. In particular, traffic markings are required to be precisely digitized since automatic driving utilizes them for position detection. To draw traffic markings, we benefit from Mobile Mapping Systems (MMS) equipped with high-density Laser imaging Detection and Ranging (LiDAR) scanners, which produces large amount of data efficiently with XYZ coordination along with reflectance intensity. Digitizing this data, on the other hand, conventionally has been dependent on human operation, which thus suffers from human errors, subjectivity errors, and low reproductivity. We have tackled this problem by means of automatic extraction of traffic marking, which partially accomplished to draw several traffic markings (G. Takahashi et al., 2014). The key idea of the method was extracting lines using the Hough transform strategically focused on changes in local reflection intensity along scan lines. However, it failed to extract traffic markings properly in a densely marked area, especially when local changing points are close each other. In this paper, we propose a bidirectional gradient-based detection method where local changing points are labelled with plus or minus group. Given that each label corresponds to the boundary between traffic markings and background, we can identify traffic markings explicitly, meaning traffic lines are differentiated correctly by the proposed method. As such, our automated method, a highly accurate and non-human-operator-dependent method using bidirectional gradient-based algorithm, can successfully extract traffic lines composed of complex shapes such as a cross walk, resulting in minimizing cost and obtaining highly accurate results.

  8. DRAWING FOR TRAFFIC MARKING USING BIDIRECTIONAL GRADIENT-BASED DETECTION WITH MMS LIDAR INTENSITY

    Directory of Open Access Journals (Sweden)

    G. Takahashi

    2016-06-01

    Full Text Available Recently, the development of autonomous cars is accelerating on the integration of highly advanced artificial intelligence, which increases demand for a digital map with high accuracy. In particular, traffic markings are required to be precisely digitized since automatic driving utilizes them for position detection. To draw traffic markings, we benefit from Mobile Mapping Systems (MMS equipped with high-density Laser imaging Detection and Ranging (LiDAR scanners, which produces large amount of data efficiently with XYZ coordination along with reflectance intensity. Digitizing this data, on the other hand, conventionally has been dependent on human operation, which thus suffers from human errors, subjectivity errors, and low reproductivity. We have tackled this problem by means of automatic extraction of traffic marking, which partially accomplished to draw several traffic markings (G. Takahashi et al., 2014. The key idea of the method was extracting lines using the Hough transform strategically focused on changes in local reflection intensity along scan lines. However, it failed to extract traffic markings properly in a densely marked area, especially when local changing points are close each other. In this paper, we propose a bidirectional gradient-based detection method where local changing points are labelled with plus or minus group. Given that each label corresponds to the boundary between traffic markings and background, we can identify traffic markings explicitly, meaning traffic lines are differentiated correctly by the proposed method. As such, our automated method, a highly accurate and non-human-operator-dependent method using bidirectional gradient-based algorithm, can successfully extract traffic lines composed of complex shapes such as a cross walk, resulting in minimizing cost and obtaining highly accurate results.

  9. Accelerated gradient-based free form deformable registration for online adaptive radiotherapy

    International Nuclear Information System (INIS)

    Yu, Gang; Yang, Guanyu; Shu, Huazhong; Li, Baosheng; Liang, Yueqiang; Yin, Yong; Li, Dengwang

    2015-01-01

    The registration of planning fan-beam computed tomography (FBCT) and daily cone-beam CT (CBCT) is a crucial step in adaptive radiation therapy. The current intensity-based registration algorithms, such as Demons, may fail when they are used to register FBCT and CBCT, because the CT numbers in CBCT cannot exactly correspond to the electron densities. In this paper, we investigated the effects of CBCT intensity inaccuracy on the registration accuracy and developed an accurate gradient-based free form deformation algorithm (GFFD). GFFD distinguishes itself from other free form deformable registration algorithms by (a) measuring the similarity using the 3D gradient vector fields to avoid the effect of inconsistent intensities between the two modalities; (b) accommodating image sampling anisotropy using the local polynomial approximation-intersection of confidence intervals (LPA-ICI) algorithm to ensure a smooth and continuous displacement field; and (c) introducing a ‘bi-directional’ force along with an adaptive force strength adjustment to accelerate the convergence process. It is expected that such a strategy can decrease the effect of the inconsistent intensities between the two modalities, thus improving the registration accuracy and robustness. Moreover, for clinical application, the algorithm was implemented by graphics processing units (GPU) through OpenCL framework. The registration time of the GFFD algorithm for each set of CT data ranges from 8 to 13 s. The applications of on-line adaptive image-guided radiation therapy, including auto-propagation of contours, aperture-optimization and dose volume histogram (DVH) in the course of radiation therapy were also studied by in-house-developed software. (paper)

  10. A Robust Gradient Based Method for Building Extraction from LiDAR and Photogrammetric Imagery

    Directory of Open Access Journals (Sweden)

    Fasahat Ullah Siddiqui

    2016-07-01

    Full Text Available Existing automatic building extraction methods are not effective in extracting buildings which are small in size and have transparent roofs. The application of large area threshold prohibits detection of small buildings and the use of ground points in generating the building mask prevents detection of transparent buildings. In addition, the existing methods use numerous parameters to extract buildings in complex environments, e.g., hilly area and high vegetation. However, the empirical tuning of large number of parameters reduces the robustness of building extraction methods. This paper proposes a novel Gradient-based Building Extraction (GBE method to address these limitations. The proposed method transforms the Light Detection And Ranging (LiDAR height information into intensity image without interpolation of point heights and then analyses the gradient information in the image. Generally, building roof planes have a constant height change along the slope of a roof plane whereas trees have a random height change. With such an analysis, buildings of a greater range of sizes with a transparent or opaque roof can be extracted. In addition, a local colour matching approach is introduced as a post-processing stage to eliminate trees. This stage of our proposed method does not require any manual setting and all parameters are set automatically from the data. The other post processing stages including variance, point density and shadow elimination are also applied to verify the extracted buildings, where comparatively fewer empirically set parameters are used. The performance of the proposed GBE method is evaluated on two benchmark data sets by using the object and pixel based metrics (completeness, correctness and quality. Our experimental results show the effectiveness of the proposed method in eliminating trees, extracting buildings of all sizes, and extracting buildings with and without transparent roof. When compared with current state

  11. A Robust Gradient Based Method for Building Extraction from LiDAR and Photogrammetric Imagery.

    Science.gov (United States)

    Siddiqui, Fasahat Ullah; Teng, Shyh Wei; Awrangjeb, Mohammad; Lu, Guojun

    2016-07-19

    Existing automatic building extraction methods are not effective in extracting buildings which are small in size and have transparent roofs. The application of large area threshold prohibits detection of small buildings and the use of ground points in generating the building mask prevents detection of transparent buildings. In addition, the existing methods use numerous parameters to extract buildings in complex environments, e.g., hilly area and high vegetation. However, the empirical tuning of large number of parameters reduces the robustness of building extraction methods. This paper proposes a novel Gradient-based Building Extraction (GBE) method to address these limitations. The proposed method transforms the Light Detection And Ranging (LiDAR) height information into intensity image without interpolation of point heights and then analyses the gradient information in the image. Generally, building roof planes have a constant height change along the slope of a roof plane whereas trees have a random height change. With such an analysis, buildings of a greater range of sizes with a transparent or opaque roof can be extracted. In addition, a local colour matching approach is introduced as a post-processing stage to eliminate trees. This stage of our proposed method does not require any manual setting and all parameters are set automatically from the data. The other post processing stages including variance, point density and shadow elimination are also applied to verify the extracted buildings, where comparatively fewer empirically set parameters are used. The performance of the proposed GBE method is evaluated on two benchmark data sets by using the object and pixel based metrics (completeness, correctness and quality). Our experimental results show the effectiveness of the proposed method in eliminating trees, extracting buildings of all sizes, and extracting buildings with and without transparent roof. When compared with current state-of-the-art building

  12. Policy-Based Negotiation Engine for Cross-Domain Interoperability

    Science.gov (United States)

    Vatan, Farrokh; Chow, Edward T.

    2012-01-01

    A successful policy negotiation scheme for Policy-Based Management (PBM) has been implemented. Policy negotiation is the process of determining the "best" communication policy that all of the parties involved can agree on. Specifically, the problem is how to reconcile the various (and possibly conflicting) communication protocols used by different divisions. The solution must use protocols available to all parties involved, and should attempt to do so in the best way possible. Which protocols are commonly available, and what the definition of "best" is will be dependent on the parties involved and their individual communications priorities.

  13. The Knowledge Base for State Policy: Status, Needs, and Trends.

    Science.gov (United States)

    Tushnet, Naida C.

    A task of regional educational laboratories is to provide information to state and local education policy makers. The new focus on policy reflects a change in the labs' knowledge base and audience. The subsequent move into the political arena has created risks for the labs, which have responded to the new task in different ways. The nature of the…

  14. Strengthening Research Capacity and Evidence-Based Policy ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... wider Central Asian region lack capacity to conduct empirical analysis and create policies based on research evidence. To address government priorities, the region needs quality research driven by local demands and analytical skills that can inform effective development responses through policy. This 39-month project, ...

  15. A weighted mean shift, normalized cuts initialized color gradient based geodesic active contour model: applications to histopathology image segmentation

    Science.gov (United States)

    Xu, Jun; Janowczyk, Andrew; Chandran, Sharat; Madabhushi, Anant

    2010-03-01

    While geodesic active contours (GAC) have become very popular tools for image segmentation, they are sensitive to model initialization. In order to get an accurate segmentation, the model typically needs to be initialized very close to the true object boundary. Apart from accuracy, automated initialization of the objects of interest is an important pre-requisite to being able to run the active contour model on very large images (such as those found in digitized histopathology). A second limitation of GAC model is that the edge detector function is based on gray scale gradients; color images typically being converted to gray scale prior to computing the gradient. For color images, however, the gray scale gradient results in broken edges and weak boundaries, since the other channels are not exploited for the gradient determination. In this paper we present a new geodesic active contour model that is driven by an accurate and rapid object initialization scheme-weighted mean shift normalized cuts (WNCut). WNCut draws its strength from the integration of two powerful segmentation strategies-mean shift clustering and normalized cuts. WNCut involves first defining a color swatch (typically a few pixels) from the object of interest. A multi-scale mean shift coupled normalized cuts algorithm then rapidly yields an initial accurate detection of all objects in the scene corresponding to the colors in the swatch. This detection result provides the initial boundary for GAC model. The edge-detector function of the GAC model employs a local structure tensor based color gradient, obtained by calculating the local min/max variations contributed from each color channel (e.g. R,G,B or H,S,V). Our color gradient based edge-detector function results in more prominent boundaries compared to classical gray scale gradient based function. We evaluate segmentation results of our new WNCut initialized color gradient based GAC (WNCut-CGAC) model against a popular region-based model (Chan

  16. Modified Convolutional Neural Network Based on Dropout and the Stochastic Gradient Descent Optimizer

    Directory of Open Access Journals (Sweden)

    Jing Yang

    2018-03-01

    Full Text Available This study proposes a modified convolutional neural network (CNN algorithm that is based on dropout and the stochastic gradient descent (SGD optimizer (MCNN-DS, after analyzing the problems of CNNs in extracting the convolution features, to improve the feature recognition rate and reduce the time-cost of CNNs. The MCNN-DS has a quadratic CNN structure and adopts the rectified linear unit as the activation function to avoid the gradient problem and accelerate convergence. To address the overfitting problem, the algorithm uses an SGD optimizer, which is implemented by inserting a dropout layer into the all-connected and output layers, to minimize cross entropy. This study used the datasets MNIST, HCL2000, and EnglishHand as the benchmark data, analyzed the performance of the SGD optimizer under different learning parameters, and found that the proposed algorithm exhibited good recognition performance when the learning rate was set to [0.05, 0.07]. The performances of WCNN, MLP-CNN, SVM-ELM, and MCNN-DS were compared. Statistical results showed the following: (1 For the benchmark MNIST, the MCNN-DS exhibited a high recognition rate of 99.97%, and the time-cost of the proposed algorithm was merely 21.95% of MLP-CNN, and 10.02% of SVM-ELM; (2 Compared with SVM-ELM, the average improvement in the recognition rate of MCNN-DS was 2.35% for the benchmark HCL2000, and the time-cost of MCNN-DS was only 15.41%; (3 For the EnglishHand test set, the lowest recognition rate of the algorithm was 84.93%, the highest recognition rate was 95.29%, and the average recognition rate was 89.77%.

  17. HydrogeoEstimatorXL: an Excel-based tool for estimating hydraulic gradient magnitude and direction

    Science.gov (United States)

    Devlin, J. F.; Schillig, P. C.

    2017-05-01

    HydrogeoEstimatorXL is a free software tool for the interpretation of flow systems based on spatial hydrogeological field data from multi-well networks. It runs on the familiar Excel spreadsheet platform. The program accepts well location coordinates and hydraulic head data, and returns an analysis of the area flow system in two dimensions based on (1) a single best fit plane of the potentiometric surface and (2) three-point estimators, i.e., well triplets assumed to bound planar sections of the potentiometric surface. The software produces graphical outputs including histograms of hydraulic gradient magnitude and direction, groundwater velocity (based on a site average hydraulic properties), as well as mapped renditions of the estimator triangles and the velocity vectors associated with them. Within the software, a transect can be defined and the mass discharge of a groundwater contaminant crossing the transect can be estimated. This kind of analysis is helpful in gaining an overview of a site's hydrogeology, for problem definition, and as a review tool to check the reasonableness of other independent calculations.

  18. Fuzzy logic-based assessment for mapping potential infiltration areas in low-gradient watersheds.

    Science.gov (United States)

    Quiroz Londoño, Orlando Mauricio; Romanelli, Asunción; Lima, María Lourdes; Massone, Héctor Enrique; Martínez, Daniel Emilio

    2016-07-01

    This paper gives an account of the design a logic-based approach for identifying potential infiltration areas in low-gradient watersheds based on remote sensing data. This methodological framework is applied in a sector of the Pampa Plain, Argentina, which has high level of agricultural activities and large demands for groundwater supplies. Potential infiltration sites are assessed as a function of two primary topics: hydrologic and soil conditions. This model shows the state of each evaluated subwatershed respecting to its potential contribution to infiltration mainly based on easily measurable and commonly used parameters: drainage density, geomorphologic units, soil media, land-cover, slope and aspect (slope orientation). Mapped outputs from the logic model displayed 42% very low-low, 16% moderate, 41% high-very high contribution to potential infiltration in the whole watershed. Subwatersheds in the upper and lower section were identified as areas with high to very high potential infiltration according to the following media features: low drainage density (<1.5 km/km(2)), arable land and pastures as the main land-cover categories, sandy clay loam to loam - clay loam soils and with the geomorphological units named poorly drained plain, channelized drainage plain and, dunes and beaches. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. A Novel Gradient Vector Flow Snake Model Based on Convex Function for Infrared Image Segmentation.

    Science.gov (United States)

    Zhang, Rui; Zhu, Shiping; Zhou, Qin

    2016-10-21

    Infrared image segmentation is a challenging topic because infrared images are characterized by high noise, low contrast, and weak edges. Active contour models, especially gradient vector flow, have several advantages in terms of infrared image segmentation. However, the GVF (Gradient Vector Flow) model also has some drawbacks including a dilemma between noise smoothing and weak edge protection, which decrease the effect of infrared image segmentation significantly. In order to solve this problem, we propose a novel generalized gradient vector flow snakes model combining GGVF (Generic Gradient Vector Flow) and NBGVF (Normally Biased Gradient Vector Flow) models. We also adopt a new type of coefficients setting in the form of convex function to improve the ability of protecting weak edges while smoothing noises. Experimental results and comparisons against other methods indicate that our proposed snakes model owns better ability in terms of infrared image segmentation than other snakes models.

  20. A Gradient-Based Multistart Algorithm for Multimodal Aerodynamic Shape Optimization Problems Based on Free-Form Deformation

    Science.gov (United States)

    Streuber, Gregg Mitchell

    Environmental and economic factors motivate the pursuit of more fuel-efficient aircraft designs. Aerodynamic shape optimization is a powerful tool in this effort, but is hampered by the presence of multimodality in many design spaces. Gradient-based multistart optimization uses a sampling algorithm and multiple parallel optimizations to reliably apply fast gradient-based optimization to moderately multimodal problems. Ensuring that the sampled geometries remain physically realizable requires manually developing specialized linear constraints for each class of problem. Utilizing free-form deformation geometry control allows these linear constraints to be written in a geometry-independent fashion, greatly easing the process of applying the algorithm to new problems. This algorithm was used to assess the presence of multimodality when optimizing a wing in subsonic and transonic flows, under inviscid and viscous conditions, and a blended wing-body under transonic, viscous conditions. Multimodality was present in every wing case, while the blended wing-body was found to be generally unimodal.

  1. Comparative analysis of gradient-field-based orientation estimation methods and regularized singular-value decomposition for fringe pattern processing.

    Science.gov (United States)

    Sun, Qi; Fu, Shujun

    2017-09-20

    Fringe orientation is an important feature of fringe patterns and has a wide range of applications such as guiding fringe pattern filtering, phase unwrapping, and abstraction. Estimating fringe orientation is a basic task for subsequent processing of fringe patterns. However, various noise, singular and obscure points, and orientation data degeneration lead to inaccurate calculations of fringe orientation. Thus, to deepen the understanding of orientation estimation and to better guide orientation estimation in fringe pattern processing, some advanced gradient-field-based orientation estimation methods are compared and analyzed. At the same time, following the ideas of smoothing regularization and computing of bigger gradient fields, a regularized singular-value decomposition (RSVD) technique is proposed for fringe orientation estimation. To compare the performance of these gradient-field-based methods, quantitative results and visual effect maps of orientation estimation are given on simulated and real fringe patterns that demonstrate that the RSVD produces the best estimation results at a cost of relatively less time.

  2. Performance analysis of a microfluidic mixer based on high gradient magnetic separation principles

    Science.gov (United States)

    Liu, Mengyu; Han, Xiaotao; Cao, Quanliang; Li, Liang

    2017-09-01

    To achieve a rapid mixing between a water-based ferrofluid and DI water in a microfluidic environment, a magnetically actuated mixing system based on high gradient magnetic separation principles is proposed in this work. The microfluidic system consists of a T-shaped mirochannel and an array of integrated soft-magnetic elements at the sidewall of the channel. With the aid of an external magnetic bias field, these elements are magnetized to produce a magnetic volume force acting on the fluids containing magnetic nanoparticles, and then to induce additional flows for improving the mixing performance. The mixing process is numerically investigated through analyzing the concentration distribution of magnetic nanoparticles using a coupled particle-fluid transport model, and mixing performances under different parametrical conditions are investigated in detail. Numerical results show that a high mixing efficiency around 97.5% can be achieved within 2 s under an inlet flow rate of 1 mm s-1 and a relatively low magnetic bias field of 50 mT. Meanwhile, it has been found that there is an optimum number of magnetic elements used for obtaining the best mixing performance. These results show the potential of the proposed mixing method in lab-on-a-chip system and could be helpful in designing and optimizing system performance.

  3. Activated charcoal based diffusive gradients in thin films for in situ monitoring of bisphenols in waters.

    Science.gov (United States)

    Zheng, Jian-Lun; Guan, Dong-Xing; Luo, Jun; Zhang, Hao; Davison, William; Cui, Xin-Yi; Wang, Lian-Hong; Ma, Lena Q

    2015-01-06

    Widespread use of bisphenols (BPs) in our daily life results in their elevated concentrations in waters and the need to study their environmental impact, which demands reliable and robust measurement techniques. Diffusive gradients in thin films (DGT) is an in situ passive sampling approach which provides time-integrated data. In this study we developed a new methodology, based on DGT with activated charcoal (AC) as a binding agent, for measuring three BPs (BPA, BPB, and BPF) which incorporated and tested its performance characteristics. Consistent elution efficiencies were obtained using methanol when concentrations of BPs were low and a methanol-NaOH mixture at high concentrations. The diffusion coefficients of BPA, BPB, and BPF in the diffusive gel, measured using an independent diffusion cell, were 5.03 × 10(-6), 5.64 × 10(-6), and 4.44 × 10(-6) cm(2) s(-1) at 25 °C, respectively. DGT with an AC binding gel had a high capacity for BPA, BPB, and BPF at 192, 140, and 194 μg/binding gel disk, respectively, and the binding performance did not deteriorate with time, up to 254 d after production. Time-integrated concentrations of BPs measured in natural waters using DGT devices with AC gels deployed in situ for 7 d were comparable to concentrations measured by an active sampling method. This study demonstrates that AC-based DGT is an effective tool for in situ monitoring of BPs in waters.

  4. 3D DC Resistivity Inversion with Topography Based on Regularized Conjugate Gradient Method

    Directory of Open Access Journals (Sweden)

    Jian-ke Qiang

    2013-01-01

    Full Text Available During the past decades, we observed a strong interest in 3D DC resistivity inversion and imaging with complex topography. In this paper, we implemented 3D DC resistivity inversion based on regularized conjugate gradient method with FEM. The Fréchet derivative is assembled with the electric potential in order to speed up the inversion process based on the reciprocity theorem. In this study, we also analyzed the sensitivity of the electric potential on the earth’s surface to the conductivity in each cell underground and introduced an optimized weighting function to produce new sensitivity matrix. The synthetic model study shows that this optimized weighting function is helpful to improve the resolution of deep anomaly. By incorporating topography into inversion, the artificial anomaly which is actually caused by topography can be eliminated. As a result, this algorithm potentially can be applied to process the DC resistivity data collected in mountain area. Our synthetic model study also shows that the convergence and computation speed are very stable and fast.

  5. Nonlinear behavior of capacitive micro-beams based on strain gradient theory

    International Nuclear Information System (INIS)

    Fathalilou, Mohammad; Sadeghi, Morteza; Rezazadeh, Ghader

    2014-01-01

    This paper studies the size dependent behavior of materials in MEMS structures. This behavior becomes noticeable for a structure when the characteristic size such as thickness or diameter is close to its internal length-scale parameter and is insignificant for the high ratio of the characteristic size to the length-scale parameter, which is the case of the silicon base micro-beams. However, in some types of micro-beams like gold or nickel bases, the size dependent effect cannot be overlooked. In such cases, ignoring this behavior in modeling will lead to incorrect results. Some previous researchers have applied classic beam theory on their models and imposed a considerable hypothetical value of residual stress to match their theoretical results with the experimental ones. The equilibrium positions or fixed points of the gold and nickel micro-beams are obtained and shown that for a given DC voltage, there is a considerable difference between the obtained fixed points using classic beam theory, modified couple stress theory, and modified strain gradient theory. In addition, it is shown that the calculated static and dynamic pull-in voltages using higher order theories are much closer to the experimental results and are higher several times than those obtained by classic beam theory.

  6. An online supervised learning method based on gradient descent for spiking neurons.

    Science.gov (United States)

    Xu, Yan; Yang, Jing; Zhong, Shuiming

    2017-09-01

    The purpose of supervised learning with temporal encoding for spiking neurons is to make the neurons emit a specific spike train encoded by precise firing times of spikes. The gradient-descent-based (GDB) learning methods are widely used and verified in the current research. Although the existing GDB multi-spike learning (or spike sequence learning) methods have good performance, they work in an offline manner and still have some limitations. This paper proposes an online GDB spike sequence learning method for spiking neurons that is based on the online adjustment mechanism of real biological neuron synapses. The method constructs error function and calculates the adjustment of synaptic weights as soon as the neurons emit a spike during their running process. We analyze and synthesize desired and actual output spikes to select appropriate input spikes in the calculation of weight adjustment in this paper. The experimental results show that our method obviously improves learning performance compared with the offline learning manner and has certain advantage on learning accuracy compared with other learning methods. Stronger learning ability determines that the method has large pattern storage capacity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. 3D printing for the design and fabrication of polymer-based gradient scaffolds.

    Science.gov (United States)

    Bracaglia, Laura G; Smith, Brandon T; Watson, Emma; Arumugasaamy, Navein; Mikos, Antonios G; Fisher, John P

    2017-07-01

    To accurately mimic the native tissue environment, tissue engineered scaffolds often need to have a highly controlled and varied display of three-dimensional (3D) architecture and geometrical cues. Additive manufacturing in tissue engineering has made possible the development of complex scaffolds that mimic the native tissue architectures. As such, architectural details that were previously unattainable or irreproducible can now be incorporated in an ordered and organized approach, further advancing the structural and chemical cues delivered to cells interacting with the scaffold. This control over the environment has given engineers the ability to unlock cellular machinery that is highly dependent upon the intricate heterogeneous environment of native tissue. Recent research into the incorporation of physical and chemical gradients within scaffolds indicates that integrating these features improves the function of a tissue engineered construct. This review covers recent advances on techniques to incorporate gradients into polymer scaffolds through additive manufacturing and evaluate the success of these techniques. As covered here, to best replicate different tissue types, one must be cognizant of the vastly different types of manufacturing techniques available to create these gradient scaffolds. We review the various types of additive manufacturing techniques that can be leveraged to fabricate scaffolds with heterogeneous properties and discuss methods to successfully characterize them. Additive manufacturing techniques have given tissue engineers the ability to precisely recapitulate the native architecture present within tissue. In addition, these techniques can be leveraged to create scaffolds with both physical and chemical gradients. This work offers insight into several techniques that can be used to generate graded scaffolds, depending on the desired gradient. Furthermore, it outlines methods to determine if the designed gradient was achieved. This review

  8. Operating Policies and Procedures of Computer Data-Base Systems.

    Science.gov (United States)

    Anderson, David O.

    Speaking on the operating policies and procedures of computer data bases containing information on students, the author divides his remarks into three parts: content decisions, data base security, and user access. He offers nine recommended practices that should increase the data base's usefulness to the user community: (1) the cost of developing…

  9. Contour Detection and Completion for Inpainting and Segmentation Based on Topological Gradient and Fast Marching Algorithms

    Directory of Open Access Journals (Sweden)

    Didier Auroux

    2011-01-01

    Full Text Available We combine in this paper the topological gradient, which is a powerful method for edge detection in image processing, and a variant of the minimal path method in order to find connected contours. The topological gradient provides a more global analysis of the image than the standard gradient and identifies the main edges of an image. Several image processing problems (e.g., inpainting and segmentation require continuous contours. For this purpose, we consider the fast marching algorithm in order to find minimal paths in the topological gradient image. This coupled algorithm quickly provides accurate and connected contours. We present then two numerical applications, to image inpainting and segmentation, of this hybrid algorithm.

  10. Parameter estimation with a novel gradient-based optimization method for biological lattice-gas cellular automaton models.

    Science.gov (United States)

    Mente, Carsten; Prade, Ina; Brusch, Lutz; Breier, Georg; Deutsch, Andreas

    2011-07-01

    Lattice-gas cellular automata (LGCAs) can serve as stochastic mathematical models for collective behavior (e.g. pattern formation) emerging in populations of interacting cells. In this paper, a two-phase optimization algorithm for global parameter estimation in LGCA models is presented. In the first phase, local minima are identified through gradient-based optimization. Algorithmic differentiation is adopted to calculate the necessary gradient information. In the second phase, for global optimization of the parameter set, a multi-level single-linkage method is used. As an example, the parameter estimation algorithm is applied to a LGCA model for early in vitro angiogenic pattern formation.

  11. Tropospheric Gradient Estimation at CODE : Results from Global Solutions (1.Ground-Based GPS Meteorology)

    OpenAIRE

    Micheal, MEINDL; Stefan, SCHAER; Urs, HUGENTOBLER; Gerhard, BEUTLER; Astronomical Institute, University of Berne; Astronomical Institute, University of Berne; Astronomical Institute, University of Berne; Astronomical Institute, University of Berne

    2004-01-01

    Observations at low elevation angles are gathered and used for high accuracy GPS analyses. Introducing tropospheric gradient parameters in the estimation process allows it to take into account of azimuthal variations of tropospheric refraction. This measure significantly improves the repeatability of station coordinates. Most of the mean gradients for stations in the northern and the southern hemisphere show a similar behavior. By combining several years of data from a global solution results...

  12. A morphological perceptron with gradient-based learning for Brazilian stock market forecasting.

    Science.gov (United States)

    Araújo, Ricardo de A

    2012-04-01

    Several linear and non-linear techniques have been proposed to solve the stock market forecasting problem. However, a limitation arises from all these techniques and is known as the random walk dilemma (RWD). In this scenario, forecasts generated by arbitrary models have a characteristic one step ahead delay with respect to the time series values, so that, there is a time phase distortion in stock market phenomena reconstruction. In this paper, we propose a suitable model inspired by concepts in mathematical morphology (MM) and lattice theory (LT). This model is generically called the increasing morphological perceptron (IMP). Also, we present a gradient steepest descent method to design the proposed IMP based on ideas from the back-propagation (BP) algorithm and using a systematic approach to overcome the problem of non-differentiability of morphological operations. Into the learning process we have included a procedure to overcome the RWD, which is an automatic correction step that is geared toward eliminating time phase distortions that occur in stock market phenomena. Furthermore, an experimental analysis is conducted with the IMP using four complex non-linear problems of time series forecasting from the Brazilian stock market. Additionally, two natural phenomena time series are used to assess forecasting performance of the proposed IMP with other non financial time series. At the end, the obtained results are discussed and compared to results found using models recently proposed in the literature. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Application of L1-norm regularization to epicardial potential reconstruction based on gradient projection

    Energy Technology Data Exchange (ETDEWEB)

    Wang Liansheng; Qin Jing; Wong, Tien Tsin; Heng, Pheng Ann, E-mail: lswang@cse.cuhk.edu.hk [Department of Computer Science and Engineering, Chinese University of Hong Kong (Hong Kong)

    2011-10-07

    The epicardial potential (EP)-targeted inverse problem of electrocardiography (ECG) has been widely investigated as it is demonstrated that EPs reflect underlying myocardial activity. It is a well-known ill-posed problem as small noises in input data may yield a highly unstable solution. Traditionally, L2-norm regularization methods have been proposed to solve this ill-posed problem. But the L2-norm penalty function inherently leads to considerable smoothing of the solution, which reduces the accuracy of distinguishing abnormalities and locating diseased regions. Directly using the L1-norm penalty function, however, may greatly increase computational complexity due to its non-differentiability. We propose an L1-norm regularization method in order to reduce the computational complexity and make rapid convergence possible. Variable splitting is employed to make the L1-norm penalty function differentiable based on the observation that both positive and negative potentials exist on the epicardial surface. Then, the inverse problem of ECG is further formulated as a bound-constrained quadratic problem, which can be efficiently solved by gradient projection in an iterative manner. Extensive experiments conducted on both synthetic data and real data demonstrate that the proposed method can handle both measurement noise and geometry noise and obtain more accurate results than previous L2- and L1-norm regularization methods, especially when the noises are large.

  14. Probability density based gradient projection method for inverse kinematics of a robotic human body model.

    Science.gov (United States)

    Lura, Derek; Wernke, Matthew; Alqasemi, Redwan; Carey, Stephanie; Dubey, Rajiv

    2012-01-01

    This paper presents the probability density based gradient projection (GP) of the null space of the Jacobian for a 25 degree of freedom bilateral robotic human body model (RHBM). This method was used to predict the inverse kinematics of the RHBM and maximize the similarity between predicted inverse kinematic poses and recorded data of 10 subjects performing activities of daily living. The density function was created for discrete increments of the workspace. The number of increments in each direction (x, y, and z) was varied from 1 to 20. Performance of the method was evaluated by finding the root mean squared (RMS) of the difference between the predicted joint angles relative to the joint angles recorded from motion capture. The amount of data included in the creation of the probability density function was varied from 1 to 10 subjects, creating sets of for subjects included and excluded from the density function. The performance of the GP method for subjects included and excluded from the density function was evaluated to test the robustness of the method. Accuracy of the GP method varied with amount of incremental division of the workspace, increasing the number of increments decreased the RMS error of the method, with the error of average RMS error of included subjects ranging from 7.7° to 3.7°. However increasing the number of increments also decreased the robustness of the method.

  15. Quaternion-Based Kalman Filter for AHRS Using an Adaptive-Step Gradient Descent Algorithm

    Directory of Open Access Journals (Sweden)

    Li Wang

    2015-09-01

    Full Text Available This paper presents a quaternion-based Kalman filter for real-time estimation of the orientation of a quadrotor. Quaternions are used to represent rotation relationship between navigation frame and body frame. Processing of a 3-axis accelerometer using Adaptive-Step Gradient Descent (ASGD produces a computed quaternion input to the Kalman filter. The step-size in GD is set in direct proportion to the physical orientation rate. Kalman filter combines 3-axis gyroscope and computed quaternion to determine pitch and roll angles. This combination overcomes linearization error of the measurement equations and reduces the calculation cost. 3-axis magnetometer is separated from ASGD to independently calculate yaw angle for Attitude Heading Reference System (AHRS. This AHRS algorithm is able to remove the magnetic distortion impact. Experiments are carried out in the small-size flight controller and the real world flying test shows the proposed AHRS algorithm is adequate for the real-time estimation of the orientation of a quadrotor.

  16. Urban Link Travel Time Prediction Based on a Gradient Boosting Method Considering Spatiotemporal Correlations

    Directory of Open Access Journals (Sweden)

    Faming Zhang

    2016-11-01

    Full Text Available The prediction of travel times is challenging because of the sparseness of real-time traffic data and the intrinsic uncertainty of travel on congested urban road networks. We propose a new gradient–boosted regression tree method to accurately predict travel times. This model accounts for spatiotemporal correlations extracted from historical and real-time traffic data for adjacent and target links. This method can deliver high prediction accuracy by combining simple regression trees with poor performance. It corrects the error found in existing models for improved prediction accuracy. Our spatiotemporal gradient–boosted regression tree model was verified in experiments. The training data were obtained from big data reflecting historic traffic conditions collected by probe vehicles in Wuhan from January to May 2014. Real-time data were extracted from 11 weeks of GPS records collected in Wuhan from 5 May 2014 to 20 July 2014. Based on these data, we predicted link travel time for the period from 21 July 2014 to 25 July 2014. Experiments showed that our proposed spatiotemporal gradient–boosted regression tree model obtained better results than gradient boosting, random forest, or autoregressive integrated moving average approaches. Furthermore, these results indicate the advantages of our model for urban link travel time prediction.

  17. Gradient-Based Optimization of Wind Farms with Different Turbine Heights

    Energy Technology Data Exchange (ETDEWEB)

    Stanley, Andrew P. J.; Thomas, Jared; Ning, Andrew; Annoni, Jennifer; Dykes, Katherine; Fleming, Paul

    2017-01-09

    Turbine wakes reduce power production in a wind farm. Current wind farms are generally built with turbines that are all the same height, but if wind farms included turbines with different tower heights, the cost of energy (COE) may be reduced. We used gradient-based optimization to demonstrate a method to optimize wind farms with varied hub heights. Our study includes a modified version of the FLORIS wake model that accommodates three-dimensional wakes integrated with a tower structural model. Our purpose was to design a process to minimize the COE of a wind farm through layout optimization and varying turbine hub heights. Results indicate that when a farm is optimized for layout and height with two separate height groups, COE can be lowered by as much as 5%-9%, compared to a similar layout and height optimization where all the towers are the same. The COE has the best improvement in farms with high turbine density and a low wind shear exponent.

  18. Gradient-Based Optimization of Wind Farms with Different Turbine Heights: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Stanley, Andrew P. J.; Thomas, Jared; Ning, Andrew; Annoni, Jennifer; Dykes, Katherine; Fleming, Paul

    2017-05-08

    Turbine wakes reduce power production in a wind farm. Current wind farms are generally built with turbines that are all the same height, but if wind farms included turbines with different tower heights, the cost of energy (COE) may be reduced. We used gradient-based optimization to demonstrate a method to optimize wind farms with varied hub heights. Our study includes a modified version of the FLORIS wake model that accommodates three-dimensional wakes integrated with a tower structural model. Our purpose was to design a process to minimize the COE of a wind farm through layout optimization and varying turbine hub heights. Results indicate that when a farm is optimized for layout and height with two separate height groups, COE can be lowered by as much as 5%-9%, compared to a similar layout and height optimization where all the towers are the same. The COE has the best improvement in farms with high turbine density and a low wind shear exponent.

  19. Carotid artery B-mode ultrasound image segmentation based on morphology, geometry and gradient direction

    Science.gov (United States)

    Sunarya, I. Made Gede; Yuniarno, Eko Mulyanto; Purnomo, Mauridhi Hery; Sardjono, Tri Arief; Sunu, Ismoyo; Purnama, I. Ketut Eddy

    2017-06-01

    Carotid Artery (CA) is one of the vital organs in the human body. CA features that can be used are position, size and volume. Position feature can used to determine the preliminary initialization of the tracking. Examination of the CA features can use Ultrasound. Ultrasound imaging can be operated dependently by an skilled operator, hence there could be some differences in the images result obtained by two or more different operators. This can affect the process of determining of CA. To reduce the level of subjectivity among operators, it can determine the position of the CA automatically. In this study, the proposed method is to segment CA in B-Mode Ultrasound Image based on morphology, geometry and gradient direction. This study consists of three steps, the data collection, preprocessing and artery segmentation. The data used in this study were taken directly by the researchers and taken from the Brno university's signal processing lab database. Each data set contains 100 carotid artery B-Mode ultrasound image. Artery is modeled using ellipse with center c, major axis a and minor axis b. The proposed method has a high value on each data set, 97% (data set 1), 73 % (data set 2), 87% (data set 3). This segmentation results will then be used in the process of tracking the CA.

  20. A fast noise-tolerant ECG feature recognition algorithm based on probabilistic analysis of gradient discontinuity.

    Science.gov (United States)

    Watterson, Peter A

    Improvement in real-time electrocardiogram (ECG) interpretation is still needed, especially for QT estimation. This paper proposes a fast algorithm for ECG feature recognition, based on locating turning points in the waveform gradient. The algorithm places the fiducial point at the maximal value of a probabilistic decision function, assessing line intervals of best fit before and after the point and the point location relative to R-wave peaks already found. Fiducial points were successfully located for the 30 heartbeats annotated by a cardiologist of all 10 normal sinus rhythm records from the PhysioNet QT Database. For a given subject, the algorithm's QT estimation had superior repeatability, with intrasubject QT standard deviation just 5.42ms, 60% lower than the cardiologist's 13.57ms. Initial tests suggest immunity to noise of standard deviation up to about 9% of the signal, depending on noise type. The proposed algorithm is fast to calculate and noise-tolerant, and has shown improved repeatability in its QT estimation compared to a cardiologist. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Cooperative and Adaptive Network Coding for Gradient Based Routing in Wireless Sensor Networks with Multiple Sinks

    Directory of Open Access Journals (Sweden)

    M. E. Migabo

    2017-01-01

    Full Text Available Despite its low computational cost, the Gradient Based Routing (GBR broadcast of interest messages in Wireless Sensor Networks (WSNs causes significant packets duplications and unnecessary packets transmissions. This results in energy wastage, traffic load imbalance, high network traffic, and low throughput. Thanks to the emergence of fast and powerful processors, the development of efficient network coding strategies is expected to enable efficient packets aggregations and reduce packets retransmissions. For multiple sinks WSNs, the challenge consists of efficiently selecting a suitable network coding scheme. This article proposes a Cooperative and Adaptive Network Coding for GBR (CoAdNC-GBR technique which considers the network density as dynamically defined by the average number of neighbouring nodes, to efficiently aggregate interest messages. The aggregation is performed by means of linear combinations of random coefficients of a finite Galois Field of variable size GF(2S at each node and the decoding is performed by means of Gaussian elimination. The obtained results reveal that, by exploiting the cooperation of the multiple sinks, the CoAdNC-GBR not only improves the transmission reliability of links and lowers the number of transmissions and the propagation latency, but also enhances the energy efficiency of the network when compared to the GBR-network coding (GBR-NC techniques.

  2. Arbitrary magnetic field gradient waveform correction using an impulse response based pre-equalization technique.

    Science.gov (United States)

    Goora, Frédéric G; Colpitts, Bruce G; Balcom, Bruce J

    2014-01-01

    The time-varying magnetic fields used in magnetic resonance applications result in the induction of eddy currents on conductive structures in the vicinity of both the sample under investigation and the gradient coils. These eddy currents typically result in undesired degradations of image quality for MRI applications. Their ubiquitous nature has resulted in the development of various approaches to characterize and minimize their impact on image quality. This paper outlines a method that utilizes the magnetic field gradient waveform monitor method to directly measure the temporal evolution of the magnetic field gradient from a step-like input function and extracts the system impulse response. With the basic assumption that the gradient system is sufficiently linear and time invariant to permit system theory analysis, the impulse response is used to determine a pre-equalized (optimized) input waveform that provides a desired gradient response at the output of the system. An algorithm has been developed that calculates a pre-equalized waveform that may be accurately reproduced by the amplifier (is physically realizable) and accounts for system limitations including system bandwidth, amplifier slew rate capabilities, and noise inherent in the initial measurement. Significant improvements in magnetic field gradient waveform fidelity after pre-equalization have been realized and are summarized. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Phase gradient algorithm based on co-axis two-step phase-shifting interferometry and its application

    Science.gov (United States)

    Wang, Yawei; Zhu, Qiong; Xu, Yuanyuan; Xin, Zhiduo; Liu, Jingye

    2017-12-01

    A phase gradient method based on co-axis two-step phase-shifting interferometry, is used to reveal the detailed information of a specimen. In this method, the phase gradient distribution can only be obtained by calculating both the first-order derivative and the radial Hilbert transformation of the intensity difference between two phase-shifted interferograms. The feasibility and accuracy of this method were fully verified by the simulation results for a polystyrene sphere and a red blood cell. The empirical results demonstrated that phase gradient is sensitive to changes in the refractive index and morphology. Because phase retrieval and tedious phase unwrapping are not required, the calculation speed is faster. In addition, co-axis interferometry has high spatial resolution.

  4. Damping vibration analysis of smart piezoelectric polymeric nanoplates on viscoelastic substrate based on nonlocal strain gradient theory

    Science.gov (United States)

    Ebrahimi, Farzad; Barati, Mohammad Reza

    2017-06-01

    This paper develops a nonlocal strain gradient plate model for damping vibration analysis of smart piezoelectric polymeric nanoplates resting on visco-Pasternak medium. For more accurate analysis of piezoelectric nanoplate, the proposed theory contains two scale parameters related to the nonlocal and strain gradient effects. Viscoelastic effect is considered based on Kelvin-Voit model. Governing equations of a nonlocal strain gradient smart nanoplate on viscoelastic substrate are derived via Hamilton’s principle. Galerkin’s method is implemented to solve the governing equations. Effects of different factors such as viscoelasticity, nonlocal parameter, length scale parameter, applied voltage and Winkler-Pasternak parameters on damping vibration characteristics of a nanoplate are studied.

  5. Dynamic motion planning of 3D human locomotion using gradient-based optimization.

    Science.gov (United States)

    Kim, Hyung Joo; Wang, Qian; Rahmatalla, Salam; Swan, Colby C; Arora, Jasbir S; Abdel-Malek, Karim; Assouline, Jose G

    2008-06-01

    Since humans can walk with an infinite variety of postures and limb movements, there is no unique solution to the modeling problem to predict human gait motions. Accordingly, we test herein the hypothesis that the redundancy of human walking mechanisms makes solving for human joint profiles and force time histories an indeterminate problem best solved by inverse dynamics and optimization methods. A new optimization-based human-modeling framework is thus described for predicting three-dimensional human gait motions on level and inclined planes. The basic unknowns in the framework are the joint motion time histories of a 25-degree-of-freedom human model and its six global degrees of freedom. The joint motion histories are calculated by minimizing an objective function such as deviation of the trunk from upright posture that relates to the human model's performance. A variety of important constraints are imposed on the optimization problem, including (1) satisfaction of dynamic equilibrium equations by requiring the model's zero moment point (ZMP) to lie within the instantaneous geometrical base of support, (2) foot collision avoidance, (3) limits on ground-foot friction, and (4) vanishing yawing moment. Analytical forms of objective and constraint functions are presented and discussed for the proposed human-modeling framework in which the resulting optimization problems are solved using gradient-based mathematical programming techniques. When the framework is applied to the modeling of bipedal locomotion on level and inclined planes, acyclic human walking motions that are smooth and realistic as opposed to less natural robotic motions are obtained. The aspects of the modeling framework requiring further investigation and refinement, as well as potential applications of the framework in biomechanics, are discussed.

  6. Microsphere-Based Scaffolds Carrying Opposing Gradients of Chondroitin Sulfate and Tricalcium Phosphate

    Directory of Open Access Journals (Sweden)

    Vineet eGupta

    2015-07-01

    Full Text Available Extracellular matrix (ECM components such as chondroitin sulfate (CS and tricalcium phosphate (TCP serve as raw materials and thus spatial patterning of these raw materials may be leveraged to mimic the smooth transition of physical, chemical and mechanical properties at the bone-cartilage interface. We hypothesized that encapsulation of opposing gradients of these raw materials in high molecular weight poly(D,L-lactic-co-glycolic acid (PLGA microsphere-based scaffolds would enhance differentiation of rat bone marrow stromal cells (rBMSCs. The raw material encapsulation altered the microstructure of the microspheres and also influenced the cellular morphology that depended on the type of material encapsulated. Moreover, the mechanical properties of the raw material encapsulating microsphere-based scaffolds initially relied on the composition of the scaffolds and later on were primarily governed by the degradation of the polymer phase and newly synthesized extracellular matrix by the seeded cells. Furthermore, raw materials had a mitogenic effect on the seeded cells and led to increased glycosaminoglycan (GAG, collagen, and calcium content. Interestingly, the initial effects of raw material encapsulation on a per-cell basis might have been overshadowed by medium-regulated environment that appeared to favor osteogenesis. However, it is to be noted that in vivo, differentiation of the cells would be governed by the surrounding native environment. Thus, the results of this study demonstrated the potential of the raw materials in facilitating neo-tissue synthesis in microsphere-based scaffolds and perhaps in combination with bioactive signals, these raw materials may be able to achieve intricate cell differentiation profiles required for regenerating the osteochondral interface.

  7. Router Agent Technology for Policy-Based Network Management

    Science.gov (United States)

    Chow, Edward T.; Sudhir, Gurusham; Chang, Hsin-Ping; James, Mark; Liu, Yih-Chiao J.; Chiang, Winston

    2011-01-01

    This innovation can be run as a standalone network application on any computer in a networked environment. This design can be configured to control one or more routers (one instance per router), and can also be configured to listen to a policy server over the network to receive new policies based on the policy- based network management technology. The Router Agent Technology transforms the received policies into suitable Access Control List syntax for the routers it is configured to control. It commits the newly generated access control lists to the routers and provides feedback regarding any errors that were faced. The innovation also automatically generates a time-stamped log file regarding all updates to the router it is configured to control. This technology, once installed on a local network computer and started, is autonomous because it has the capability to keep listening to new policies from the policy server, transforming those policies to router-compliant access lists, and committing those access lists to a specified interface on the specified router on the network with any error feedback regarding commitment process. The stand-alone application is named RouterAgent and is currently realized as a fully functional (version 1) implementation for the Windows operating system and for CISCO routers.

  8. Age replacement policy based on imperfect repair with random probability

    International Nuclear Information System (INIS)

    Lim, J.H.; Qu, Jian; Zuo, Ming J.

    2016-01-01

    In most of literatures of age replacement policy, failures before planned replacement age can be either minimally repaired or perfectly repaired based on the types of failures, cost for repairs and so on. In this paper, we propose age replacement policy based on imperfect repair with random probability. The proposed policy incorporates the case that such intermittent failure can be either minimally repaired or perfectly repaired with random probabilities. The mathematical formulas of the expected cost rate per unit time are derived for both the infinite-horizon case and the one-replacement-cycle case. For each case, we show that the optimal replacement age exists and is finite. - Highlights: • We propose a new age replacement policy with random probability of perfect repair. • We develop the expected cost per unit time. • We discuss the optimal age for replacement minimizing the expected cost rate.

  9. Worship Discourse and White Race-based Policy Attitudes

    Science.gov (United States)

    Brown, R. Khari; Kaiser, Angela; Jackson, James S.

    2014-01-01

    The current study relies upon the 2004 National Politics Study to examine the association between exposure to race-based messages within places of worship and White race-based policy attitudes. The present study challenges the notion that, for White Americans, religiosity inevitably leads to racial prejudice. Rather, we argue, as others have, that religion exists on a continuum that spans from reinforcing to challenging the status quo of social inequality. Our findings suggests that the extent to which Whites discuss race along with the potential need for public policy solutions to address racial inequality within worship spaces, worship attendance contributes to support for public policies aimed at reducing racial inequality. On the other hand, apolitical and non-structural racial discussions within worship settings do seemingly little to move many Whites to challenge dominant idealistic perceptions of race that eschews public policy interventions as solutions to racial inequality. PMID:25324579

  10. Application of an online ion-chromatography-based instrument for gradient flux measurements of speciated nitrogen and sulfur

    Science.gov (United States)

    Rumsey, Ian C.; Walker, John T.

    2016-06-01

    The dry component of total nitrogen and sulfur atmospheric deposition remains uncertain. The lack of measurements of sufficient chemical speciation and temporal extent make it difficult to develop accurate mass budgets and sufficient process level detail is not available to improve current air-surface exchange models. Over the past decade, significant advances have been made in the development of continuous air sampling measurement techniques, resulting with instruments of sufficient sensitivity and temporal resolution to directly quantify air-surface exchange of nitrogen and sulfur compounds. However, their applicability is generally restricted to only one or a few of the compounds within the deposition budget. Here, the performance of the Monitor for AeRosols and GAses in ambient air (MARGA 2S), a commercially available online ion-chromatography-based analyzer is characterized for the first time as applied for air-surface exchange measurements of HNO3, NH3, NH4+, NO3-, SO2 and SO42-. Analytical accuracy and precision are assessed under field conditions. Chemical concentrations gradient precision are determined at the same sampling site. Flux uncertainty measured by the aerodynamic gradient method is determined for a representative 3-week period in fall 2012 over a grass field. Analytical precision and chemical concentration gradient precision were found to compare favorably in comparison to previous studies. During the 3-week period, percentages of hourly chemical concentration gradients greater than the corresponding chemical concentration gradient detection limit were 86, 42, 82, 73, 74 and 69 % for NH3, NH4+, HNO3, NO3-, SO2 and SO42-, respectively. As expected, percentages were lowest for aerosol species, owing to their relatively low deposition velocities and correspondingly smaller gradients relative to gas phase species. Relative hourly median flux uncertainties were 31, 121, 42, 43, 67 and 56 % for NH3, NH4+, HNO3, NO3-, SO2 and SO42-, respectively. Flux

  11. Energy harvesting from vibration of Timoshenko nanobeam under base excitation considering flexoelectric and elastic strain gradient effects

    Science.gov (United States)

    Managheb, S. A. M.; Ziaei-Rad, S.; Tikani, R.

    2018-05-01

    The coupling between polarization and strain gradients is called flexoelectricity. This phenomenon exists in all dielectrics with any symmetry. In this paper, energy harvesting from a Timoshenko beam is studied by considering the flexoelectric and strain gradient effects. General governing equations and related boundary conditions are derived using Hamilton's principle. The flexoelectric effects are defined by gradients of normal and shear strains which lead to a more general model. The developed model also covers the classical Timoshenko beam theory by ignoring the flexoelectric effect. Based on the developed model, flexoelectricity effect on dielectric beams and energy harvesting from cantilever beam under harmonic base excitation is investigated. A parametric study was conducted to evaluate the effects of flexoelectric coefficients, strain gradient constants, base acceleration and the attaching tip mass on the energy harvested from a cantilever Timoshenko beam. Results show that the flexoelectricity has a significant effect on the energy harvester performance, especially in submicron and nano scales. In addition, this effect makes the beam to behave softer than before and also it changes the harvester first resonance frequency. The present study provides guidance for flexoelectric nano-beam analysis and a method to evaluate the performance of energy harvester in nano-dielectric devices.

  12. Quantification of pH gradients and implications in insulator-based dielectrophoresis of biomolecules.

    Science.gov (United States)

    Gencoglu, Aytug; Camacho-Alanis, Fernanda; Nguyen, Vi Thanh; Nakano, Asuka; Ros, Alexandra; Minerick, Adrienne R

    2011-09-01

    Direct current (DC) insulator-based dielectrophoretic (iDEP) microdevices have the potential to replace traditional alternating current dielectrophoretic devices for many cellular and biomolecular separation applications. The use of large DC fields suggest that electrode reactions and ion transport mechanisms can become important and impact ion distributions in the nanoliters of fluid in iDEP microchannels. This work tracked natural pH gradient formation in a 100 μm wide, 1 cm-long microchannel under applicable iDEP protein manipulation conditions. Using fluorescence microscopy with the pH-sensitive dye FITC Isomer I and the pH-insensitive dye TRITC as a reference, pH was observed to drop drastically in the microchannels within 1 min in a 3000 V/cm electric field; pH drops were observed in the range of 6-10 min within a 100 V/cm electric field and varied based on the buffer conductivity. To address concerns of dye transport impacting intensity data, electrokinetic mobilities of FITC were carefully examined and found to be (i) toward the anode and (ii) 1 to 2 orders of magnitude smaller than H⁺ transport which is responsible for pH drops from the anode toward the cathode. COMSOL simulations of ion transport showed qualitative agreement with experimental results. The results indicate that pH changes are severe enough and rapid enough to influence the net charge of a protein or cause aggregation during iDEP experiments. The results also elucidate reasonable time periods over which the phosphate buffering capacity can counter increases in H⁺ and OH⁻ for unperturbed iDEP manipulations. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Improved incorporation of strain gradient elasticity in the flexoelectricity based energy harvesting from nanobeams

    Science.gov (United States)

    Zhou, Yarong; Yang, Xu; Pan, Dongmei; Wang, Binglei

    2018-04-01

    Flexoelectricity, the coupling of strain gradient and polarization, exists in all the dielectric materials and numerous models have been proposed to study this mechanism. However, the contribution of strain gradient elasticity has typically been underestimated. In this work, inspired by the one-length scale parameter model developed by Deng et al. [19], we incorporate three length-scale parameters to carefully capture the contribution of the purely mechanical strain gradients on flexoelectricity. This three-parameter model is more flexible and could be applied to investigate the flexoelectricity in a wide range of complicated deformations. Accordingly, we carry out our analysis by studying a dielectric nanobeam under different boundary conditions. We show that the strain gradient elasticity and flexoelectricity have apparent size effects and significant influence on the electromechanical response. In particular, the strain gradient effects could significantly reduce the energy efficiency, indicating their importance and necessity. This work may be helpful in understanding the mechanism of flexoelectricity at the nanoscale and sheds light on the flexoelectricity energy harvesting.

  14. Evaluation of extreme ionospheric total electron content gradient associated with plasma bubbles for GNSS Ground-Based Augmentation System

    Science.gov (United States)

    Saito, S.; Yoshihara, T.

    2017-08-01

    Associated with plasma bubbles, extreme spatial gradients in ionospheric total electron content (TEC) were observed on 8 April 2008 at Ishigaki (24.3°N, 124.2°E, +19.6° magnetic latitude), Japan. The largest gradient was 3.38 TECU km-1 (total electron content unit, 1 TECU = 1016 el m-2), which is equivalent to an ionospheric delay gradient of 540 mm km-1 at the GPS L1 frequency (1.57542 GHz). This value is confirmed by using multiple estimating methods. The observed value exceeds the maximum ionospheric gradient that has ever been observed (412 mm km-1 or 2.59 TECU km-1) to be associated with a severe magnetic storm. It also exceeds the assumed maximum value (500 mm km-1 or 3.08 TECU km-1) which was used to validate the draft international standard for Global Navigation Satellite System (GNSS) Ground-Based Augmentation Systems (GBAS) to support Category II/III approaches and landings. The steepest part of this extreme gradient had a scale size of 5.3 km, and the front-normal velocities were estimated to be 71 m s-1 with a wavefront-normal direction of east-northeastward. The total width of the transition region from outside to inside the plasma bubble was estimated to be 35.3 km. The gradient of relatively small spatial scale size may fall between an aircraft and a GBAS ground subsystem and may be undetectable by both aircraft and ground.

  15. Market-Based Policies for Pollution Control in Latin America

    OpenAIRE

    Sarah West; Ann Wolverton

    2003-01-01

    Rapid urbanization and increased industrialization have led to high pollution levels throughout Latin America. Economists tout policies based on market-based economic incentives as the most cost-effective methods for addressing a wide variety of environmental problems. This chapter examines market-based incentives and their applicability to Latin America. We first review the market-based incentives traditionally used to address pollution – emissions taxes, environmental subsidies, tax and sub...

  16. A condition-based maintenance policy for stochastically deteriorating systems

    International Nuclear Information System (INIS)

    Grall, A.; Berenguer, C.; Dieulle, L.

    2002-01-01

    We focus on the analytical modeling of a condition-based inspection/replacement policy for a stochastically and continuously deteriorating single-unit system. We consider both the replacement threshold and the inspection schedule as decision variables for this maintenance problem and we propose to implement the maintenance policy using a multi-level control-limit rule. In order to assess the performance of the proposed maintenance policy and to minimize the long run expected maintenance cost per unit time, a mathematical model for the maintained system cost is derived, supported by the existence of a stationary law for the maintained system state. Numerical experiments illustrate the performance of the proposed policy and confirm that the maintenance cost rate on an infinite horizon can be minimized by a joint optimization of the maintenance structure thresholds, or equivalently by a joint optimization of a system replacement threshold and the aperiodic inspection schedule

  17. Estimating Surface Downward Shortwave Radiation over China Based on the Gradient Boosting Decision Tree Method

    Directory of Open Access Journals (Sweden)

    Lu Yang

    2018-01-01

    Full Text Available Downward shortwave radiation (DSR is an essential parameter in the terrestrial radiation budget and a necessary input for models of land-surface processes. Although several radiation products using satellite observations have been released, coarse spatial resolution and low accuracy limited their application. It is important to develop robust and accurate retrieval methods with higher spatial resolution. Machine learning methods may be powerful candidates for estimating the DSR from remotely sensed data because of their ability to perform adaptive, nonlinear data fitting. In this study, the gradient boosting regression tree (GBRT was employed to retrieve DSR measurements with the ground observation data in China collected from the China Meteorological Administration (CMA Meteorological Information Center and the satellite observations from the Advanced Very High Resolution Radiometer (AVHRR at a spatial resolution of 5 km. The validation results of the DSR estimates based on the GBRT method in China at a daily time scale for clear sky conditions show an R2 value of 0.82 and a root mean square error (RMSE value of 27.71 W·m−2 (38.38%. These values are 0.64 and 42.97 W·m−2 (34.57%, respectively, for cloudy sky conditions. The monthly DSR estimates were also evaluated using ground measurements. The monthly DSR estimates have an overall R2 value of 0.92 and an RMSE of 15.40 W·m−2 (12.93%. Comparison of the DSR estimates with the reanalyzed and retrieved DSR measurements from satellite observations showed that the estimated DSR is reasonably accurate but has a higher spatial resolution. Moreover, the proposed GBRT method has good scalability and is easy to apply to other parameter inversion problems by changing the parameters and training data.

  18. Novel gradient echo sequence-based amide proton transfer magnetic resonance imaging in hyperacute cerebral infarction

    Science.gov (United States)

    HUANG, DEXIAO; LI, SHENKAI; DAI, ZHUOZHI; SHEN, ZHIWEI; YAN, GEN; WU, RENHUA

    2015-01-01

    In the progression of ischemia, pH is important and is essential in elucidating the association between metabolic disruption, lactate formation, acidosis and tissue damage. Chemical exchange-dependent saturation transfer (CEST) imaging can be used to detect tissue pH and, in particular, a specific form of CEST magnetic resonance imaging (MRI), termed amide proton transfer (APT) MRI, which is sensitive to pH and can detect ischemic lesions, even prior to diffusion abnormalities. The critical parameter governing the ability of CEST to detect pH is the sequence. In the present study, a novel strategy was used, based on the gradient echo sequence (GRE), which involved the insertion of a magnetization transfer pulse in each repetition time (TR) and minimizing the TR for in vivo APT imaging. The proposed GRE-APT MRI method was initially verified using a tissue-like pH phantom and optimized MRI parameters for APT imaging. In order to assess the range of acute cerebral infarction, rats (n=4) were subjected to middle cerebral artery occlusion (MCAO) and MRI scanning at 7 telsa (T). Hyperacute ischemic tissue damage was characterized using multiparametric imaging techniques, including diffusion, APT and T2-Weighted MRI. By using a magnetization transfer pulse and minimizing TR, GRE-APT provided high spatial resolution and a homogeneous signal, with clearly distinguished cerebral anatomy. The GRE-APT and diffusion MRI were significantly correlated with lactate content and the area of cerebral infarction in the APT and apparent diffusion coefficient (ADC) maps matched consistently during the hyperacute period. In addition, compared with the infarction area observed on the ADC MRI map, the APT map contained tissue, which had not yet been irreversibly damaged. Therefore, GRE-APT MRI waa able to detect ischemic lactic acidosis with sensitivity and spatiotemporal resolution, suggesting the potential use of pH MRI as a surrogate imaging marker of impaired tissue metabolism for the

  19. Novel gradient echo sequence‑based amide proton transfer magnetic resonance imaging in hyperacute cerebral infarction.

    Science.gov (United States)

    Huang, Dexiao; Li, Shenkai; Dai, Zhuozhi; Shen, Zhiwei; Yan, Gen; Wu, Renhua

    2015-05-01

    In the progression of ischemia, pH is important and is essential in elucidating the association between metabolic disruption, lactate formation, acidosis and tissue damage. Chemical exchange‑dependent saturation transfer (CEST) imaging can be used to detect tissue pH and, in particular, a specific form of CEST magnetic resonance imaging (MRI), termed amide proton transfer (APT) MRI, which is sensitive to pH and can detect ischemic lesions, even prior to diffusion abnormalities. The critical parameter governing the ability of CEST to detect pH is the sequence. In the present study, a novel strategy was used, based on the gradient echo sequence (GRE), which involved the insertion of a magnetization transfer pulse in each repetition time (TR) and minimizing the TR for in vivo APT imaging. The proposed GRE‑APT MRI method was initially verified using a tissue‑like pH phantom and optimized MRI parameters for APT imaging. In order to assess the range of acute cerebral infarction, rats (n=4) were subjected to middle cerebral artery occlusion (MCAO) and MRI scanning at 7 telsa (T). Hyperacute ischemic tissue damage was characterized using multiparametric imaging techniques, including diffusion, APT and T2‑Weighted MRI. By using a magnetization transfer pulse and minimizing TR, GRE‑APT provided high spatial resolution and a homogeneous signal, with clearly distinguished cerebral anatomy. The GRE‑APT and diffusion MRI were significantly correlated with lactate content and the area of cerebral infarction in the APT and apparent diffusion coefficient (ADC) maps matched consistently during the hyperacute period. In addition, compared with the infarction area observed on the ADC MRI map, the APT map contained tissue, which had not yet been irreversibly damaged. Therefore, GRE‑APT MRI waa able to detect ischemic lactic acidosis with sensitivity and spatiotemporal resolution, suggesting the potential use of pH MRI as a surrogate imaging marker of impaired tissue

  20. School Improvement Policy--Site-Based Management

    Directory of Open Access Journals (Sweden)

    C. Kenneth Tanner

    1998-03-01

    Full Text Available Have administrative functions of principals changed in schools practicing site-based management (SBM with shared governance? To deal with this issue we employed the Delphi technique and a panel of 24 experts from 14 states. The experts, which included educational specialists, researchers, writers, and elementary school principals, agreed that the implementation of SBM dramatically influences the roles of the principal in management/administration and leadership. Data revealed that the elementary principal's leadership role requires specialized skills to support shared governance, making it necessary to form professional development programs that adapt to innovations evolving from the implementation of SBM.

  1. Full waveform inversion based on the optimized gradient and its spectral implementation

    KAUST Repository

    Wu, Zedong

    2014-01-01

    Full waveform inversion (FWI) despite it\\'s potential suffers from the ability to converge to the desired solution due to the high nonlinearity of the objective function at conventional seismic frequencies. Even if frequencies necessary for the convergence are available, the high number of iterations required to approach a solution renders FWI as very expensive (especially in 3D). A spectral implementation in which the wavefields are extrapolated and gradients are calculated in the wavenumber domain allows for a cleaner more efficient implementation (no finite difference dispersion errors). In addition, we use not only an up and down going wavefield decomposition of the gradient to access the smooth background update, but also a right and left propagation decomposition to allow us to do that for large dips. To insure that the extracted smooth component of the gradient has the right decent direction, we solve an optimization problem to search for the smoothest component that provides a negative (decent) gradient. Application to the Marmousi model shows that this approach works well with linear increasing initial velocity model and data with frequencies above 2Hz.

  2. Pilling evaluation of patterned fabrics based on a gradient field method

    Czech Academy of Sciences Publication Activity Database

    Techniková, L.; Tunák, M.; Janáček, Jiří

    2016-01-01

    Roč. 41, č. 1 (2016), s. 97-101 ISSN 0971-0426 Institutional support: RVO:67985823 Keywords : 3D surface reconstruction * fabric pilling * gradient field method * patterned fabric * pills detection Subject RIV: JS - Reliability ; Quality Management, Testing Impact factor: 0.430, year: 2016

  3. Performance of Gradient-Based Solutions versus Genetic Algorithms in the Correlation of Thermal Mathematical Models of Spacecrafts

    Directory of Open Access Journals (Sweden)

    Eva Anglada

    2017-01-01

    Full Text Available The correlation of the thermal mathematical models (TMMs of spacecrafts with the results of the thermal test is a demanding task in terms of time and effort. Theoretically, it can be automatized by means of optimization techniques, although this is a challenging task. Previous studies have shown the ability of genetic algorithms to perform this task in several cases, although some limitations have been detected. In addition, gradient-based methods, although also presenting some limitations, have provided good solutions in other technical fields. For this reason, the performance of genetic algorithms and gradient-based methods in the correlation of TMMs is discussed in this paper to compare the pros and cons of them. The case of study used in the comparison is a real space instrument flown aboard the International Space Station.

  4. A dual justification for science-based policy-making

    DEFF Research Database (Denmark)

    Pedersen, David Budtz

    2014-01-01

    Science-based policy-making has grown ever more important in recent years, in parallel with the dramatic increase in the complexity and uncertainty of the ways in which science and technology interact with society and economy at the national, regional and global level. Installing a proper framewo...

  5. Strengthening Science-based Environmental Policy Development in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Strengthening Science-based Environmental Policy Development in Burma's Democratic Transition. For decades, it was very difficult to complete, share or access development research in Burma. However, in the past two years, the Burmese political landscape has seen far-reaching changes. The military junta has ...

  6. Survey-Based Measurement of Public Management and Policy Networks

    Science.gov (United States)

    Henry, Adam Douglas; Lubell, Mark; McCoy, Michael

    2012-01-01

    Networks have become a central concept in the policy and public management literature; however, theoretical development is hindered by a lack of attention to the empirical properties of network measurement methods. This paper compares three survey-based methods for measuring organizational networks: the roster, the free-recall name generator, and…

  7. Evidence-based ICT Policy for Development and Innovation | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Evidence-based ICT Policy for Development and Innovation. The cost of access to information and communication technologies (ITCs) in Africa remains the major impediment to the participation of Africans in the networked society. While Africa is the region with the fastest growing number of mobile phone subscribers in the ...

  8. A Novel Ship Detection Method Based on Gradient and Integral Feature for Single-Polarization Synthetic Aperture Radar Imagery

    Directory of Open Access Journals (Sweden)

    Hao Shi

    2018-02-01

    Full Text Available With the rapid development of remote sensing technologies, SAR satellites like China’s Gaofen-3 satellite have more imaging modes and higher resolution. With the availability of high-resolution SAR images, automatic ship target detection has become an important topic in maritime research. In this paper, a novel ship detection method based on gradient and integral features is proposed. This method is mainly composed of three steps. First, in the preprocessing step, a filter is employed to smooth the clutters and the smoothing effect can be adaptive adjusted according to the statistics information of the sub-window. Thus, it can retain details while achieving noise suppression. Second, in the candidate area extraction, a sea-land segmentation method based on gradient enhancement is presented. The integral image method is employed to accelerate computation. Finally, in the ship target identification step, a feature extraction strategy based on Haar-like gradient information and a Radon transform is proposed. This strategy decreases the number of templates found in traditional Haar-like methods. Experiments were performed using Gaofen-3 single-polarization SAR images, and the results showed that the proposed method has high detection accuracy and rapid computational efficiency. In addition, this method has the potential for on-board processing.

  9. Strong source heat transfer simulations based on a GalerKin/Gradient - least - squares method

    International Nuclear Information System (INIS)

    Franca, L.P.; Carmo, E.G.D. do.

    1989-05-01

    Heat conduction problems with temperature-dependent strong sources are modeled by an equation with a laplacian term, a linear term and a given source distribution term. When the linear-temperature-dependent source term is much larger than the laplacian term, we have a singular perturbation problem. In this case, boundary layers are formed to satisfy the Dirichlet boundary conditions. Although this is an elliptic equation, the standard Galerkin method solution is contaminated by spurious oscillations in the neighborhood of the boundary layers. Herein we employ a Galerkin/Gradient-least-squares method which eliminates all pathological phenomena of the Galerkin method. The method is constructed by adding to the Galerkin method a mesh-dependent term obtained by the least-squares form of the gradient of the Euler-Lagrange equation. Error estimates, numerical simulations in one-and multi-dimensions are given that attest the good stability and accuracy properties of the method [pt

  10. PROSPECTS OF THE REGIONAL INTEGRATION POLICY BASED ON CLUSTER FORMATION

    Directory of Open Access Journals (Sweden)

    Elena Tsepilova

    2018-01-01

    Full Text Available The purpose of this article is to develop the theoretical foundations of regional integration policy and to determine its prospects on the basis of cluster formation. The authors use such research methods as systematization, comparative and complex analysis, synthesis, statistical method. Within the framework of the research, the concept of regional integration policy is specified, and its integration core – cluster – is allocated. The authors work out an algorithm of regional clustering, which will ensure the growth of economy and tax income. Measures have been proposed to optimize the organizational mechanism of interaction between the participants of the territorial cluster and the authorities that allow to ensure the effective functioning of clusters, including taxation clusters. Based on the results of studying the existing methods for assessing the effectiveness of cluster policy, the authors propose their own approach to evaluating the consequences of implementing the regional integration policy, according to which the list of quantitative and qualitative indicators is defined. The present article systematizes the experience and results of the cluster policy of certain European countries, that made it possible to determine the prospects and synergetic effect from the development of clusters as an integration foundation of regional policy in the Russian Federation. The authors carry out the analysis of activity of cluster formations using the example of the Rostov region – a leader in the formation of conditions for the cluster policy development in the Southern Federal District. 11 clusters and cluster initiatives are developing in this region. As a result, the authors propose measures for support of the already existing clusters and creation of the new ones.

  11. Study of flow instability in a centrifugal fan based on energy gradient theory

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Meina; Dou, Hua-Shu; Ma, Xiaoyang [Zhejiang Sci-Tech University, Hangzhou (China); Xiao, Qing [University of Strathclyde, Glasgow (United Kingdom); Chen, Yongning; He, Haijiang; Ye, Xinxue [Zhejiang Yilida Ventilator Co. Ltd, Taizhou (China)

    2016-02-15

    Flow instability in a centrifugal fan was studied using energy gradient theory. Numerical simulation was performed for the three dimensional turbulent flow field in a centrifugal fan. The flow is governed by the three-dimensional incompressible Navier-Stokes equations coupled with the RNG k-ε turbulent model. The finite volume method was used to discretize the governing equations and the Semiimplicit method for pressure linked equation (SIMPLE) algorithm is employed to iterate the system of the equations. The interior flow field in the centrifugal fan and the distribution of the energy gradient function K are obtained at different flow rates. According to the energy gradient method, the area with larger value of K is the place where the flow loses stability easier. The results show that instability is easier to generate in the regions of impeller outlet and volute tongue. The air flow near the hub is more stable than that near the shroud. That is due to the influences of variations of the velocity and the inlet angle along the axial direction. With the decrease of the flow rate, instability zone in a blade channel moves to the impeller inlet from the outlet and the unstable regions in different channels develop in opposite direction to the rotation of impeller.

  12. INVESTIGATION OF FISCAL AND BUDGETARY POLICIES BASED ON ECONOMIC THEORIES

    Directory of Open Access Journals (Sweden)

    EMILIA CAMPEANU

    2011-04-01

    Full Text Available Empirical analysis of fiscal and budgetary policies cannot be achieved without first knowing how they are viewed in the economic theories. This approach is important to indicate the position and implications of fiscal and budgetary policy tools in the economic theory considering their major differences. Therefore, the paper aims is to investigate the fiscal and budgetary policies based on economic theories such as neoclassical, Keynesian and neo-Keynesian theory in order to indicate their divergent points. Once known these approaches at the economic theory level is easier to establish the appropriate measures taking into consideration the framing of a country economy in a certain pattern. This work was supported from the European Social Fund through Sectoral Operational Programme Human Resources Development 2007-2013, project number POSDRU/89/1.5/S/59184 „Performance and excellence in postdoctoral research in Romanian economics science domain” (contract no. 0501/01.11.2010.

  13. Time-domain full waveform inversion using the gradient preconditioning based on seismic wave energy: Application to the South China Sea

    KAUST Repository

    Mengxuan, Zhong

    2017-06-01

    The gradient preconditioning algorithms based on Hessian matrices in time-domain full waveform inversion (FWI) are widely used now, but consume a lot of memory and do not fit the FWI of large models or actual seismic data well. To avoid the huge storage consumption, the gradient preconditioning approach based on seismic wave energy has been proposed it simulates the “approximated wave field” with the acoustic wave equation and uses the energy of the simulated wavefield to precondition the gradient. The method does not require computing and storing the Hessian matrix or its inverse and can effectively eliminate the effect caused by geometric diffusion and uneven illumination on gradient. The result of experiments in this article with field data from South China Sea confirms that the time-domain FWI using the gradient preconditioning based on seismic wave energy (GPWE) can achieve higher inversion accuracy for the deep high-velocity model and its underlying strata.

  14. Voxel Spread Function (VSF) Method for Correction of Magnetic Field Inhomogeneity Effects in Quantitative Gradient-Echo-Based MRI

    Science.gov (United States)

    Yablonskiy, Dmitriy A; Sukstanskii, Alexander L; Luo, Jie; Wang, Xiaoqi

    2012-01-01

    Purpose Macroscopic magnetic field inhomogeneities adversely affect different aspects of MRI images. In quantitative MRI when the goal is to quantify biological tissue parameters, they bias and often corrupt such measurements. The goal of this paper is to develop a method for correction of macroscopic field inhomogeneities that can be applied to a variety of quantitative gradient-echo-based MRI techniques. Methods We have re-analyzed a basic theory of gradient echo (GE) MRI signal formation in the presence of background field inhomogeneities and derived equations that allow for correction of magnetic field inhomogeneity effects based on the phase and magnitude of GE data. We verified our theory by mapping R2* relaxation rate in computer simulated, phantom, and in vivo human data collected with multi-GE sequences. Results The proposed technique takes into account voxel spread function (VSF) effects and allowed obtaining virtually free from artifacts R2* maps for all simulated, phantom and in vivo data except of the edge areas with very steep field gradients. Conclusion The VSF method, allowing quantification of tissue specific R2*-related tissue properties, has a potential to breed new MRI biomarkers serving as surrogates for tissue biological properties similar to R1 and R2 relaxation rate constants widely used in clinical and research MRI. PMID:23233445

  15. Development of a New Gradient Based Strain-Criterion for Prediction of Bendability in Quality Assurance and FEA

    Science.gov (United States)

    Denninger, Ralf; Liewald, Mathias; Sindel, Manfred

    2011-08-01

    Numerical simulation systems are more and more used in process development of car bodies. Nowadays, also the hemming process is optimised in FEA. Thus, the analysing of process robustness calls for a failure criterion for the specific bending and hemming load condition. For that purpose the experimental determination of bendability under various pre-load conditions that occur in real production, e.g. during deep drawing in press shop, is content of this contribution. Using these experimental results, a new approach for a strain-gradient based failure criterion for bending operations is presented to optimise bendability prediction. The bending-strain-gradient approach can be used both in production related departments of quality assurance as well as for simulative process design or process validation for vehicle manufacturing planning.

  16. Sustainable development based energy policy making frameworks, a critical review

    International Nuclear Information System (INIS)

    Meyar-Naimi, H.; Vaez-Zadeh, S.

    2012-01-01

    This paper, in the first step, presents an overview of the origination and formulation of sustainable development (SD) concept and the related policy making frameworks. The frameworks include Pressure–State–Response (PSR), Driving Force–State–Response (DSR), Driving Force–Pressure–State–Impact–Response (DPSIR), Driving Force–Pressure–State–Effect–Action (DPSEA) and Driving Force-Pressure-State-Exposure-Effect-Action (DPSEEA). In this regard, 40 case studies using the reviewed frameworks reported during 1994–2011 are surveyed. Then, their application area and application intensity are investigated. It is concluded that PSR, and DPSEA and DPSEEA have the higher and lower application intensities, respectively. Moreover, using Analytical Hierarchy Process (AHP) with a set of criteria, it is shown that PSR and DPSIR have the highest and lowest priorities. Finally, the shortcomings of frameworks applications are discussed. The paper is helpful in selecting appropriate policy making frameworks and presents some hints for future research in the area for developing more comprehensive models especially for sustainable electric energy policy making. - Highlights: ► The origination and formulation of sustainable development (SD) concept is reviewed. ► SD based frameworks (PSR, DSR, DPSIR, DPSEA and DPSEEA) are also reviewed. ► Then, the frameworks application area and intensity in recent years are investigated. ► Finally, the SD concept and the SD based frameworks are criticized. ► It will be helpful for developing more comprehensive energy policy making models.

  17. Curve Evolution in Subspaces and Exploring the Metameric Class of Histogram of Gradient Orientation based Features using Nonlinear Projection Methods

    DEFF Research Database (Denmark)

    Tatu, Aditya Jayant

    tracking interfaces, active contour based segmentation methods and others. It can also be used to study shape spaces, as deforming a shape can be thought of as evolving its boundary curve. During curve evolution a curve traces out a path in the infinite dimensional space of curves. Due to application...... defined subspace, the N-links bicycle chain space, i.e. the space of curves with equidistant neighboring landmark points. This in itself is a useful shape space for medical image analysis applications. The Histogram of Gradient orientation based features are many in number and are widely used...

  18. Gradient-based estimation of Manning's friction coefficient from noisy data

    KAUST Repository

    Calo, Victor M.

    2013-01-01

    We study the numerical recovery of Manning\\'s roughness coefficient for the diffusive wave approximation of the shallow water equation. We describe a conjugate gradient method for the numerical inversion. Numerical results for one-dimensional models are presented to illustrate the feasibility of the approach. Also we provide a proof of the differentiability of the weak form with respect to the coefficient as well as the continuity and boundedness of the linearized operator under reasonable assumptions using the maximal parabolic regularity theory. © 2012 Elsevier B.V. All rights reserved.

  19. Automatic differentiation for gradient-based optimization of radiatively heated microelectronics manufacturing equipment

    Energy Technology Data Exchange (ETDEWEB)

    Moen, C.D.; Spence, P.A.; Meza, J.C.; Plantenga, T.D.

    1996-12-31

    Automatic differentiation is applied to the optimal design of microelectronic manufacturing equipment. The performance of nonlinear, least-squares optimization methods is compared between numerical and analytical gradient approaches. The optimization calculations are performed by running large finite-element codes in an object-oriented optimization environment. The Adifor automatic differentiation tool is used to generate analytic derivatives for the finite-element codes. The performance results support previous observations that automatic differentiation becomes beneficial as the number of optimization parameters increases. The increase in speed, relative to numerical differences, has a limited value and results are reported for two different analysis codes.

  20. A physics-based model for maintenance of the pH gradient in the gastric mucus layer.

    Science.gov (United States)

    Lewis, Owen L; Keener, James P; Fogelson, Aaron L

    2017-12-01

    It is generally accepted that the gastric mucus layer provides a protective barrier between the lumen and the mucosa, shielding the mucosa from acid and digestive enzymes and preventing autodigestion of the stomach epithelium. However, the precise mechanisms that contribute to this protective function are still up for debate. In particular, it is not clear what physical processes are responsible for transporting hydrogen protons, secreted within the gastric pits, across the mucus layer to the lumen without acidifying the environment adjacent to the epithelium. One hypothesis is that hydrogen may be bound to the mucin polymers themselves as they are convected away from the mucosal surface and eventually degraded in the stomach lumen. It is also not clear what mechanisms prevent hydrogen from diffusing back toward the mucosal surface, thereby lowering the local pH. In this work we investigate a physics-based model of ion transport within the mucosal layer based on a Nernst-Planck-like equation. Analysis of this model shows that the mechanism of transporting protons bound to the mucus gel is capable of reproducing the trans-mucus pH gradients reported in the literature. Furthermore, when coupled with ion exchange at the epithelial surface, our analysis shows that bicarbonate secretion alone is capable of neutralizing the epithelial pH, even in the face of enormous diffusive gradients of hydrogen. Maintenance of the pH gradient is found to be robust to a wide array of perturbations in both physiological and phenomenological model parameters, suggesting a robust physiological control mechanism. NEW & NOTEWORTHY This work combines modeling techniques based on physical principles, as well as novel numerical simulations to test the plausibility of one hypothesized mechanism for proton transport across the gastric mucus layer. Results show that this mechanism is able to maintain the extreme pH gradient seen in in vivo experiments and suggests a highly robust regulation

  1. Thermal vibration analysis of nanoplates based on the higher-order nonlocal strain gradient theory by an analytical approach

    Science.gov (United States)

    Nematollahi, Mohammad Sadegh; Mohammadi, Hossein; Nematollahi, Mohammad Ali

    2017-11-01

    In this paper, a new formulation for analyzing free vibration of thin rectangular nanoplates under different thermal conditions is obtained based on the higher-order nonlocal strain gradient theory. Governing equations and non-classical boundary conditions of the nanoplate are derived by using the variational approach. The exact solution is obtained as a function of higher-order and lower-order nonlocal parameters, strain gradient length scale and temperature difference using Navier solution procedure. The influences of small-scale parameters on the vibrational behavior of the nanoplate are investigated for various thermal conditions. High and low temperature conditions are considered to study the effects of changes in temperature and small-scale parameters. It has been shown that increasing the nonlocal parameters decrease the natural frequency of the nanoplate, while increasing the strain gradient length scale will increase it. Also, the natural frequency of the nanoplate will increase by increasing the temperature difference in low temperature conditions, but it will decrease by increasing the temperature difference in high temperature conditions. Non-uniform behaviors are reported for some cases and softening effect and hardening effect are studied. To validate the solutions, the results are compared with previous researches.

  2. Influence of Rotor-Stator Interaction on Flow Stability in Centrifugal Pump Based on Energy Gradient Method

    Science.gov (United States)

    Zheng, Lu-Lu; Dou, Hua-Shu; Jiang, Wei; Chen, Xiaoping; Zhu, Zuchao; Cui, Baoling

    2016-12-01

    Numerical simulation is performed for the three-dimensional turbulent flow field in a centrifugal pump by solving the Reynolds-averaged Navier-Stokes equations and the RNG k-epsilon turbulent model. The finite volume method and the SIMPLE algorithm are employed for the solution of the system. All the parameters in the centrifugal pump at different blade angular positions are obtained by simulation. The flow structure is analyzed and the distributions of the energy gradient function K are calculated at different blade angular positions based on the energy gradient method. According to the energy gradient method, the location which has larger value of K is easier to cause instability and to be of high turbulence intensity. The result shows that the flow instability is easier to be excited nearing the tongue where the value of K is large. The unstable flow area nearing the tongue is also in agreement with the zone where the velocity decreases rapidly. The sudden variation of velocity contributes to the large value of K. The research result also indicates that the tongue has large impact only on the impeller passages passing the tongue.

  3. Decolonizing the Evidence-Based Education and Policy Movement: Revealing the Colonial Vestiges in Educational Policy, Research, and Neoliberal Reform

    Science.gov (United States)

    Shahjahan, Riyad Ahmed

    2011-01-01

    There is a growing body of literature discussing evidence-based education, practice, policy, and decision-making from a critical perspective. In this article, drawing on the literature and policy documents related to evidence-based education in the USA, Britain, and Canada, I join this critique and offer an anticolonial perspective. I argue that…

  4. Nonlocal strain gradient based wave dispersion behavior of smart rotating magneto-electro-elastic nanoplates

    Science.gov (United States)

    Ebrahimi, Farzad; Dabbagh, Ali

    2017-02-01

    Main object of the present research is an exact investigation of wave propagation responses of smart rotating magneto-electro-elastic (MEE) graded nanoscale plates. In addition, effective material properties of functionally graded (FG) nanoplate are presumed to be calculated using the power-law formulations. Also, it has been tried to cover both softening and stiffness-hardening behaviors of nanostructures by the means of employing nonlocal strain gradient theory (NSGT). Due to increasing the accuracy of the presented model in predicting shear deformation effects, a refined higher-order plate theory is introduced. In order to cover the most enormous circumstances, maximum amount of load generated by plate’s rotation is considered. Furthermore, utilizing a developed form of Hamilton’s principle, containing magneto-electric effects, the nonlocal governing equations of MEE-FG rotating nanoplates are derived. An analytical solution is obtained to solve the governing equations and validity of the solution method is proven by comparing results from present method with those of former attempts. At last, outcomes are plotted in the framework of some figures to show the influences of various parameters such as wave number, nonlocality, length scale parameter, magnetic potential, electric voltage, gradient index and angular velocity on wave frequency, phase velocity and escape frequency of the examined nanoplate.

  5. Visible and infrared image registration algorithm based on NSCT and gradient mirroring

    Science.gov (United States)

    Huang, Qingqing; Gao, Qiong; Yang, Jian; Chen, Jiansheng; Song, Zhanjie

    2014-11-01

    Multi-sensor image registration is an important part of the remote sensing image processing. The gray property of the same object would have large differences in infrared and visible imaging mode, so it could get less matching points by using traditional SIFT algorithm directly in registration. However, NSCT decomposition can represent the structural information of the image very well and extract more SIFT feature points in its high frequency decomposed image. In addition, traditional SIFT descriptors' gradient is affected by gray contrast, which could get less feature matching points during the similarity search in the matching procedure. Gradient mirroring (GM) is a method that can modify the direction of the feature points, which can reduce the contrast impact on the similarity matching. Therefore, a novel method combining NSCT and GM is proposed in this article. The experiments prove that, comparing with the traditional SIFT algorithm, the new method can get more matching points, better distributing and higher matching rate in infrared and visible image registration.

  6. The cell based therapy and the policy implications in India.

    Science.gov (United States)

    Mukhopadhyay, Bratati; Basak, Saroj K; Ganguly, Nirmal K

    2011-01-01

    The recent scientific development using stem or other differentiated cells has generated great hopes for treatment of various diseases. Major thrust has been given to formulate country specific laws and regulations considering international guidelines to conduct research and clinical applications of "Cell Based Therapy" (CBT) all over the world. Attempts have made in this review to discuss the current policies that are practiced by various countries in the areas related to CBT with special emphasis on CBT related research and development in India. The two major funding agencies of Government of India e.g. Department of Biotechnology (DBT) and Indian Council of Medical Research (ICMR), have jointly formulated the "Guidelines for Stem Cell Research and Therapy" in 2007 which requires update and revision. Based on the review of the current world scenario of CBT research and development, suggestions have been made for the development of a new CBT policy that will help in progress of research and patient treatment in India.

  7. Confidence-Based Robot Policy Learning from Demonstration

    Science.gov (United States)

    2009-03-05

    Development of a small biped entertainment robot QRIO. In Micro- Nanomechatronics and Human Science, 2004, pages 23–28, 2004. [45] Odest Chadwicke Jenkins...adaptation of biped locomotion. Robotics and Autonomous Systems, 47:79–91, 2004. [60] Ulrich Nehmzow, Otar Akanyeti, Cristoph Weinrich, Theocharis...Confidence-Based Robot Policy Learning from Demonstration Sonia Chernova CMU-CS-09-105 March 5, 2009 School of Computer Science Computer Science

  8. Assessing of energy policies based on Turkish agriculture:

    International Nuclear Information System (INIS)

    Sayin, Cengiz; Nisa Mencet, M.; Ozkan, Burhan

    2005-01-01

    In this study, the current energy status of Turkey and the effects of national energy policies on Turkish agricultural support policies are discussed for both current and future requirements. Turkey is an energy-importing country producing 30 mtoe (million tons of oil equivalent) energy but consuming 80 mtoe. The energy import ratio of Turkey is 65-70% and the majority of this import is based on petroleum and natural gas. Furthermore, while world energy demand increases by 1.8% annually, Turkey's energy demand increases by about 8%. Although energy consumption in agriculture is much lower than the other sectors in Turkey, energy use as both input and output of agricultural sector is a very important issue due to its large agricultural potential and rural area. Total agricultural land area is 27.8 million hectares and about 66.5% of this area is devoted for cereal production. On the other hand, Turkey has over 4 million agricultural farm holdings of which 70-75% is engaged in cereal production. Machinery expenses, mainly diesel, constitute 30-50% of total variable expenses in cereal production costs. It is observed that energy policies pursued in agriculture have been directly affected by diesel prices in Turkey. Therefore, support policy tools for using diesel and electricity in agriculture are being pursued by the Turkish government

  9. Far-Infrared Based Pedestrian Detection for Driver-Assistance Systems Based on Candidate Filters, Gradient-Based Feature and Multi-Frame Approval Matching

    Directory of Open Access Journals (Sweden)

    Guohua Wang

    2015-12-01

    Full Text Available Far-infrared pedestrian detection approaches for advanced driver-assistance systems based on high-dimensional features fail to simultaneously achieve robust and real-time detection. We propose a robust and real-time pedestrian detection system characterized by novel candidate filters, novel pedestrian features and multi-frame approval matching in a coarse-to-fine fashion. Firstly, we design two filters based on the pedestrians’ head and the road to select the candidates after applying a pedestrian segmentation algorithm to reduce false alarms. Secondly, we propose a novel feature encapsulating both the relationship of oriented gradient distribution and the code of oriented gradient to deal with the enormous variance in pedestrians’ size and appearance. Thirdly, we introduce a multi-frame approval matching approach utilizing the spatiotemporal continuity of pedestrians to increase the detection rate. Large-scale experiments indicate that the system works in real time and the accuracy has improved about 9% compared with approaches based on high-dimensional features only.

  10. Far-Infrared Based Pedestrian Detection for Driver-Assistance Systems Based on Candidate Filters, Gradient-Based Feature and Multi-Frame Approval Matching.

    Science.gov (United States)

    Wang, Guohua; Liu, Qiong

    2015-12-21

    Far-infrared pedestrian detection approaches for advanced driver-assistance systems based on high-dimensional features fail to simultaneously achieve robust and real-time detection. We propose a robust and real-time pedestrian detection system characterized by novel candidate filters, novel pedestrian features and multi-frame approval matching in a coarse-to-fine fashion. Firstly, we design two filters based on the pedestrians' head and the road to select the candidates after applying a pedestrian segmentation algorithm to reduce false alarms. Secondly, we propose a novel feature encapsulating both the relationship of oriented gradient distribution and the code of oriented gradient to deal with the enormous variance in pedestrians' size and appearance. Thirdly, we introduce a multi-frame approval matching approach utilizing the spatiotemporal continuity of pedestrians to increase the detection rate. Large-scale experiments indicate that the system works in real time and the accuracy has improved about 9% compared with approaches based on high-dimensional features only.

  11. Nonlocal strain gradient theory calibration using molecular dynamics simulation based on small scale vibration of nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Mehralian, Fahimeh [Mechanical Engineering Department, Shahrekord University, Shahrekord (Iran, Islamic Republic of); Tadi Beni, Yaghoub, E-mail: tadi@eng.sku.ac.ir [Faculty of Engineering, Shahrekord University, Shahrekord (Iran, Islamic Republic of); Karimi Zeverdejani, Mehran [Mechanical Engineering Department, Shahrekord University, Shahrekord (Iran, Islamic Republic of)

    2017-06-01

    Featured by two small length scale parameters, nonlocal strain gradient theory is utilized to investigate the free vibration of nanotubes. A new size-dependent shell model formulation is developed by using the first order shear deformation theory. The governing equations and boundary conditions are obtained using Hamilton's principle and solved for simply supported boundary condition. As main purpose of this study, since the values of two small length scale parameters are still unknown, they are calibrated by the means of molecular dynamics simulations (MDs). Then, the influences of different parameters such as nonlocal parameter, scale factor, length and thickness on vibration characteristics of nanotubes are studied. It is also shown that increase in thickness and decrease in length parameters intensify the effect of nonlocal parameter and scale factor.

  12. An automatic and accurate method of full heart segmentation from CT image based on linear gradient model

    Science.gov (United States)

    Yang, Zili

    2017-07-01

    Heart segmentation is an important auxiliary method in the diagnosis of many heart diseases, such as coronary heart disease and atrial fibrillation, and in the planning of tumor radiotherapy. Most of the existing methods for full heart segmentation treat the heart as a whole part and cannot accurately extract the bottom of the heart. In this paper, we propose a new method based on linear gradient model to segment the whole heart from the CT images automatically and accurately. Twelve cases were tested in order to test this method and accurate segmentation results were achieved and identified by clinical experts. The results can provide reliable clinical support.

  13. Assessment of Gradient-Based Similarity Functions in the Stable Boundary Layer Derived from a Large-Eddy Simulation

    Science.gov (United States)

    Sorbjan, Zbigniew

    2017-06-01

    Gradient-based similarity functions, evaluated based on data generated by a large-eddy simulation model of the stably stratified boundary layer, are compared with analogous similarity functions, derived from field observations in the surface layer during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment in the Arctic. The comparison is performed in terms of explicit and implicit local scaling systems, for the temperature and momentum fluxes, standard deviations of the vertical velocity and of temperature, as well as dissipation rates for the turbulent kinetic energy and for the temperature variance. The comparison shows the best agreement of the SHEBA-based similarity functions with analogous functions evaluated using the large-eddy simulation data in the range of the Richardson number 0.01<{ Ri}< 0.1.

  14. What Is the Best Way to Contour Lung Tumors on PET Scans? Multiobserver Validation of a Gradient-Based Method Using a NSCLC Digital PET Phantom

    International Nuclear Information System (INIS)

    Werner-Wasik, Maria; Nelson, Arden D.; Choi, Walter; Arai, Yoshio; Faulhaber, Peter F.; Kang, Patrick; Almeida, Fabio D.; Xiao, Ying; Ohri, Nitin; Brockway, Kristin D.; Piper, Jonathan W.; Nelson, Aaron S.

    2012-01-01

    Purpose: To evaluate the accuracy and consistency of a gradient-based positron emission tomography (PET) segmentation method, GRADIENT, compared with manual (MANUAL) and constant threshold (THRESHOLD) methods. Methods and Materials: Contouring accuracy was evaluated with sphere phantoms and clinically realistic Monte Carlo PET phantoms of the thorax. The sphere phantoms were 10–37 mm in diameter and were acquired at five institutions emulating clinical conditions. One institution also acquired a sphere phantom with multiple source-to-background ratios of 2:1, 5:1, 10:1, 20:1, and 70:1. One observer segmented (contoured) each sphere with GRADIENT and THRESHOLD from 25% to 50% at 5% increments. Subsequently, seven physicians segmented 31 lesions (7–264 mL) from 25 digital thorax phantoms using GRADIENT, THRESHOLD, and MANUAL. Results: For spheres 20 mm (p < 0.065) and <20 mm (p < 0.015). For digital thorax phantoms, GRADIENT was the most accurate (p < 0.01), with a mean absolute % error in volume of 10.99% (11.9% SD), followed by 25% THRESHOLD at 17.5% (29.4% SD), and MANUAL at 19.5% (17.2% SD). GRADIENT had the least systematic bias, with a mean % error in volume of –0.05% (16.2% SD) compared with 25% THRESHOLD at –2.1% (34.2% SD) and MANUAL at –16.3% (20.2% SD; p value <0.01). Interobserver variability was reduced using GRADIENT compared with both 25% THRESHOLD and MANUAL (p value <0.01, Levene’s test). Conclusion: GRADIENT was the most accurate and consistent technique for target volume contouring. GRADIENT was also the most robust for varying imaging conditions. GRADIENT has the potential to play an important role for tumor delineation in radiation therapy planning and response assessment.

  15. The productive techniques and constitutive effects of 'evidence-based policy' and 'consumer participation' discourses in health policy processes.

    Science.gov (United States)

    Lancaster, K; Seear, K; Treloar, C; Ritter, A

    2017-03-01

    For over twenty years there have been calls for greater 'consumer' participation in health decision-making. While it is recognised by governments and other stakeholders that 'consumer' participation is desirable, barriers to meaningful involvement nonetheless remain. It has been suggested that the reifying of 'evidence-based policy' may be limiting opportunities for participation, through the way this discourse legitimates particular voices to the exclusion of others. Others have suggested that assumptions underpinning the very notion of the 'affected community' or 'consumers' as fixed and bounded 'policy publics' need to be problematised. In this paper, drawing on interviews (n = 41) with individuals closely involved in Australian drug policy discussions, we critically interrogate the productive techniques and constitutive effects of 'evidence-based policy' and 'consumer participation' discourses in the context of drug policy processes. To inform our analysis, we draw on and combine a number of critical perspectives including Foucault's concept of subjugated knowledges, the work of feminist theorists, as well as recent work regarding conceptualisations of emergent policy publics. First, we explore how the subject position of 'consumer' might be seen as enacted in the material-discursive practices of 'evidence-based policy' and 'consumer participation' in drug policy processes. Secondly, we consider the centralising power-effects of the dominant 'evidence-based policy' paradigm, and how resistance may be thought about in this context. We suggest that such interrogation has potential to recast the call for 'consumer' participation in health policy decision-making and drug policy processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. To what extent are Canadian second language policies evidence-based? Reflections on the intersections of research and policy.

    Science.gov (United States)

    Cummins, Jim

    2014-01-01

    THE PAPER ADDRESSES THE INTERSECTIONS BETWEEN RESEARCH FINDINGS AND CANADIAN EDUCATIONAL POLICIES FOCUSING ON FOUR MAJOR AREAS: (a) core and immersion programs for the teaching of French to Anglophone students, (b) policies concerning the learning of English and French by students from immigrant backgrounds, (c) heritage language teaching, and (d) the education of Deaf and hard-of hearing students. With respect to the teaching of French, policy-makers have largely ignored the fact that most core French programs produce meager results for the vast majority of students. Only a small proportion of students (languages, preferring instead to leave uncorrected the proposition that acquisition of languages such as American Sign Language by young children (with or without cochlear implants) will impede children's language and academic development. The paper reviews the kinds of policies, programs, and practices that could be implemented (at no additional cost) if policy-makers and educators pursued evidence-based educational policies.

  17. To what extent are Canadian second language policies evidence-based? Reflections on the intersections of research and policy

    Science.gov (United States)

    Cummins, Jim

    2014-01-01

    The paper addresses the intersections between research findings and Canadian educational policies focusing on four major areas: (a) core and immersion programs for the teaching of French to Anglophone students, (b) policies concerning the learning of English and French by students from immigrant backgrounds, (c) heritage language teaching, and (d) the education of Deaf and hard-of hearing students. With respect to the teaching of French, policy-makers have largely ignored the fact that most core French programs produce meager results for the vast majority of students. Only a small proportion of students (languages, preferring instead to leave uncorrected the proposition that acquisition of languages such as American Sign Language by young children (with or without cochlear implants) will impede children’s language and academic development. The paper reviews the kinds of policies, programs, and practices that could be implemented (at no additional cost) if policy-makers and educators pursued evidence-based educational policies. PMID:24847289

  18. New technology based on clamping for high gradient radio frequency photogun

    Directory of Open Access Journals (Sweden)

    David Alesini

    2015-09-01

    Full Text Available High gradient rf photoguns have been a key development to enable several applications of high quality electron beams. They allow the generation of beams with very high peak current and low transverse emittance, satisfying the tight demands for free-electron lasers, energy recovery linacs, Compton/Thomson sources and high-energy linear colliders. In the present paper we present the design of a new rf photogun recently developed in the framework of the SPARC_LAB photoinjector activities at the laboratories of the National Institute of Nuclear Physics in Frascati (LNF-INFN, Italy. This design implements several new features from the electromagnetic point of view and, more important, a novel technology for its realization that does not involve any brazing process. From the electromagnetic point of view the gun presents high mode separation, low peak surface electric field at the iris and minimized pulsed heating on the coupler. For the realization, we have implemented a novel fabrication design that, avoiding brazing, strongly reduces the cost, the realization time and the risk of failure. Details on the electromagnetic design, low power rf measurements and high power radiofrequency and beam tests performed at the University of California in Los Angeles (UCLA are discussed in the paper.

  19. Versatile van der Waals Density Functional Based on a Meta-Generalized Gradient Approximation

    Directory of Open Access Journals (Sweden)

    Haowei Peng

    2016-10-01

    Full Text Available A “best-of-both-worlds” van der Waals (vdW density functional is constructed, seamlessly supplementing the strongly constrained and appropriately normed (SCAN meta-generalized gradient approximation for short- and intermediate-range interactions with the long-range vdW interaction from rVV10, the revised Vydrov–van Voorhis nonlocal correlation functional. The resultant SCAN+rVV10 is the only vdW density functional to date that yields excellent interlayer binding energies and spacings, as well as intralayer lattice constants in 28 layered materials. Its versatility for various kinds of bonding is further demonstrated by its good performance for 22 interactions between molecules; the cohesive energies and lattice constants of 50 solids; the adsorption energy and distance of a benzene molecule on coinage-metal surfaces; the binding energy curves for graphene on Cu(111, Ni(111, and Co(0001 surfaces; and the rare-gas solids. We argue that a good semilocal approximation should (as SCAN does capture the intermediate-range vdW through its exchange term. We have found an effective range of the vdW interaction between 8 and 16 Å for systems considered here, suggesting that this interaction is negligibly small at the larger distances where it reaches its asymptotic power-law decay.

  20. Grammars for Games: A Gradient-Based Framework for Optimization in Deep Learning

    Directory of Open Access Journals (Sweden)

    David eBalduzzi

    2016-01-01

    Full Text Available Deep learning is currently the subject of intensive study. However, fundamental concepts such as representations are not formally defined -- researchers know them when they see them -- and there is no common language for describing and analyzing algorithms. This essay proposes an abstract framework that identifies the essential features of current practice and may provide a foundation for future developments. The backbone of almost all deep learning algorithms is backpropagation, which is simply a gradient computation distributed over a neural network. The main ingredients of the framework are thus, unsurprisingly: (i game theory, to formalize distributed optimization; and (ii communication protocols, to track the flow of zeroth and first-order information. The framework allows natural definitions of semantics (as the meaning encoded in functions, representations (as functions whose semantics is chosen to optimized a criterion and grammars (as communication protocols equipped with first-order convergence guarantees. Much of the essay is spent discussing examples taken from the literature. The ultimate aim is to develop a graphical language for describing the structure of deep learning algorithms that backgrounds the details of the optimization procedure and foregrounds how the components interact. Inspiration is taken from probabilistic graphical models and factor graphs, which capture the essential structural features of multivariate distributions.

  1. Providing Climate Policy Makers With a Strong Scientific Base (Invited)

    Science.gov (United States)

    Struzik, E.

    2009-12-01

    Scientists can and should inform public policy decisions in the Arctic. But the pace of climate change in the polar world has been occurring far more quickly than most scientists have been able to predict. This creates problems for decision-makers who recognize that difficult management decisions have to be made in matters pertaining to wildlife management, cultural integrity and economic development. With sea ice melting, glaciers receding, permafrost thawing, forest fires intensifying, and disease and invasive species rapidly moving north, the challenge for scientists to provide climate policy makers with a strong scientific base has been daunting. Clashing as this data sometimes does with the “traditional knowledge” of indigenous peoples in the north, it can also become very political. As a result the need to effectively communicate complex data is more imperative now than ever before. Here, the author describes how the work of scientists can often be misinterpreted or exploited in ways that were not intended. Examples include the inappropriate use of scientific data in decision-making on polar bears, caribou and other wildlife populations; the use of scientific data to debunk the fact that greenhouse gases are driving climate change, and the use of scientific data to position one scientist against another when there is no inherent conflict. This work will highlight the need for climate policy makers to increase support for scientists working in the Arctic, as well as illustrate why it is important to find new and more effective ways of communicating scientific data. Strategies that might be considered by granting agencies, scientists and climate policy decision-makers will also be discussed.

  2. Constitutionally-Legal Policy as Base Type of Legal Policy of Russia

    Science.gov (United States)

    Anichkin, Eugene S.

    2016-01-01

    The article deals with reasons for formation, nature and specifics of the constitutionally legal policy of modern Russia. The special attention is spared to the exposure of the aim, long-term and short-term tasks, and principles of national constitutionally legal policy. The functions of constitutionally legal policy are separately considered:…

  3. A Global-best Harmony Search based Gradient Descent Learning FLANN (GbHS-GDL-FLANN for data classification

    Directory of Open Access Journals (Sweden)

    Bighnaraj Naik

    2016-03-01

    Full Text Available While dealing with real world data for classification using ANNs, it is often difficult to determine the optimal ANN classification model with fast convergence. Also, it is laborious to adjust the set of weights of ANNs by using appropriate learning algorithm to obtain better classification accuracy. In this paper, a variant of Harmony Search (HS, called Global-best Harmony Search along with Gradient Descent Learning is used with Functional Link Artificial Neural Network (FLANN for classification task in data mining. The Global-best Harmony Search (GbHS uses the concepts of Particle Swarm Optimization from Swarm Intelligence to improve the qualities of harmonies. The problem solving strategies of Global-best Harmony Search along with searching capabilities of Gradient Descent Search are used to obtain optimal set of weight for FLANN. The proposed method (GbHS-GDL-FLANN is implemented in MATLAB and compared with other alternatives (FLANN, GA based FLANN, PSO based FLANN, HS based FLANN, Improved HS based FLANN, Self Adaptive HS based FLANN, MLP, SVM and FSN. The GbHS-GDL-FLANN is tested on benchmark datasets from UCI Machine Learning repository by using 5-fold cross validation technique. The proposed method is analyzed under null-hypothesis by using Friedman Test, Holm and Hochberg Procedure and Post-Hoc ANOVA Statistical Analysis (Tukey Test & Dunnett Test for statistical analysis and validity of results. Simulation results reveal that the performance of the proposed GbHS-GDL-FLANN is better and statistically significant from other alternatives.

  4. Centrality and Flow Vergence gradient based Path analysis of scientific literature: A case study of Biotechnology for Engineering

    Science.gov (United States)

    Lathabai, Hiran H.; Prabhakaran, Thara; Changat, Manoj

    2015-07-01

    Biotechnology, ever since its inception has had a huge impact on the society and its various applications have been intricately woven into the human web of life. Its evolution amidst all the other research realms vital to mankind is remarkable. In this paper, we intend to identify the radical innovations in Biotechnology for Engineering using network analyses. Centrality analysis and Path analysis are used for identifying important works. Existence of Flow Vergence effect in the scientific literature is revealed. Flow Vergence gradient, an arc metric derived from FV model, is utilised for Path analysis which detects pivotal papers of paradigm shift more accurately. A major paradigm shift has been identified in the business models of Biotechnology for Engineering - 'Capability to Connectivity' model. Evidence towards the adoption of business practices in BT firms by nanotechnology start-ups is also identified. The notion of critical divergence is introduced and the exhibition of interdisciplinary interaction in emerging fields due to critical divergence is discussed. Implications of above analyses which target: (i) Science and technology policy makers, (ii) industrialists and investors, (iii) researchers in academia as well as industry, are also discussed.

  5. Black Box Traceable Ciphertext Policy Attribute-Based Encryption Scheme

    Directory of Open Access Journals (Sweden)

    Xingbing Fu

    2015-08-01

    Full Text Available In the existing attribute-based encryption (ABE scheme, the authority (i.e., private key generator (PKG is able to calculate and issue any user’s private key, which makes it completely trusted, which severely influences the applications of the ABE scheme. To mitigate this problem, we propose the black box traceable ciphertext policy attribute-based encryption (T-CP-ABE scheme in which if the PKG re-distributes the users’ private keys for malicious uses, it might be caught and sued. We provide a construction to realize the T-CP-ABE scheme in a black box model. Our scheme is based on the decisional bilinear Diffie-Hellman (DBDH assumption in the standard model. In our scheme, we employ a pair (ID, S to identify a user, where ID denotes the identity of a user and S denotes the attribute set associated with her.

  6. Area-based initiatives - Engines of planning and policy innovation?

    DEFF Research Database (Denmark)

    Agger, Annika; Norvig Larsen, Jacob

    a broader perspective on the achievements and outcomes of place-based initiatives. Many of these have functioned as important experimental seedbeds in which innovations in urban policy and organization of public decision-making have been tested. The papers seeks to clarify whether, in the long run, change......Area-based initiatives addressing issues of physical degradation, social exclusion, economic deprivation and lack of cohesion in urban regeneration areas have been promoted widely across Europe in the past two or three decades. Following this many evaluation studies have been completed....... Nevertheless, there is still considerable uncertainty as to the most important outcomes of place-based initiatives. Evaluations have mostly focussed on direct quantitative socio-economic indicators. These have often been quite insignificant, while other effects have been largely neglected. This paper proposes...

  7. A temporal subtraction method for thoracic CT images based on generalized gradient vector flow

    International Nuclear Information System (INIS)

    Miyake, Noriaki; Kim, H.; Maeda, Shinya; Itai, Yoshinori; Tan, J.K.; Ishikawa, Seiji; Katsuragawa, Shigehiko

    2010-01-01

    A temporal subtraction image, which is obtained by subtraction of a previous image from a current one, can be used for enhancing interval changes (such as formation of new lesions and changes in existing abnormalities) on medical images by removing most of the normal structures. If image registration is incorrect, not only the interval changes but also the normal structures would be appeared as some artifacts on the temporal subtraction image. In a temporal subtraction technique for 2-D X-ray image, the effectiveness is shown through a lot of clinical evaluation experiments, and practical use is advancing. Moreover, the MDCT (Multi-Detector row Computed Tomography) can easily introduced on medical field, the development of a temporal subtraction for thoracic CT Images is expected. In our study, a temporal subtraction technique for thoracic CT Images is developed. As the technique, the vector fields are described by use of GGVF (Generalized Gradient Vector Flow) from the previous and current CT images. Afterwards, VOI (Volume of Interest) are set up on the previous and current CT image pairs. The shift vectors are calculated by using nearest neighbor matching of the vector fields in these VOIs. The search kernel on previous CT image is set up from the obtained shift vector. The previous CT voxel which resemble standard the current voxel is detected by voxel value and vector of the GGVF in the kernel. And, the previous CT image is transformed to the same coordinate of standard voxel. Finally, temporal subtraction image is made by subtraction of a warping image from a current one. To verify the proposal method, the result of application to 7 cases and the effectiveness are described. (author)

  8. arXiv Interferometer-based high-accuracy white light measurement of neutral rubidium density and gradient at AWAKE

    CERN Document Server

    Batsch, Fabian; Oez, Erdem; Moody, Joshua; Gschwendtner, Edda; Caldwell, Allen; Muggli, Patric

    The AWAKE experiment requires an automated online rubidium (Rb) plasma density and gradient diagnostic for densities between 1 and 10$\\cdot$10$^{14}$ cm$^{-3}$. A linear density gradient along the plasma source at the percent level may be useful to improve the electron acceleration process. Because of full laser ionization of Rb vapor to Rb$^{+}$ within a radius of 1 mm, the plasma density equals the vapor density. We measure the Rb vapor densities at both ends of the source, with high precision using, white light interferometry. At either source end, broadband laser light passes a remotely controlled Mach-Zehnder interferometer built out of single mode fibers. The resulting interference signal, influenced by dispersion in the vicinity of the Rb D1 and D2 transitions, is dispersed in wavelength by a spectrograph. Fully automated Fourier-based signal conditioning and a fit algorithm yield the density with an uncertainty between the measurements at both ends of 0.11 to 0.46 $\\%$ over the entire density range. T...

  9. Pump-free gradient-based micro-device enables quantitative and high-throughput bacterial growth inhibition analysis.

    Science.gov (United States)

    Ran, Min; Wang, Ying; Wang, Sida; Luo, Chunxiong

    2015-08-01

    Antibiotic susceptibility testing is very important in antibiotic therapy. Traditional methods to determine antibiotic susceptibility include disk diffusion and broth dilution. However, these tests are always labor intensive, time-consuming, and need large amounts of reagents. In this paper, we demonstrated a novel pump-free micro-device that enables quantitative and high-throughput bacterial growth inhibition analysis. This device consists of a series of wells and diffusion-based antibiotic gradient channels. The wells serve as antibiotic sources and buffer sinks, and we could easily observe the bacterial growth in the gradient channels .The design of the multi-wells is adapted to the commercialized multi-channel pipette, which makes it very convenient for loading reagents into the wells. For each assay, only about 20 μL antibiotic solution is needed. As a demonstration, we used both fluorescence images and dark-field images to quantify the bacterial growth inhibition effect under different antibiotics. The quantitative data of bacterial growth inhibition under different antibiotics can be obtained within 3 to 4 h. Considering the simple operation process and the high-throughput and quantitative result this device can offer, it has great potential to be widely used in clinics and may be useful for the study of the kinetics of bacterial growth.

  10. A comprehensive assessment of ionospheric gradients observed in Ecuador during 2013 and 2014 for ground based augmentation systems

    Science.gov (United States)

    Sánchez-Naranjo, S.; Rincón, W.; Ramos-Pollán, R.; González, F. A.; Soley, S.

    2017-04-01

    Ground Based Augmentation Systems GBAS provide differential corrections to approaching and landing aircrafts in the vicinities of an airport. The ionosphere can introduce an error not accountable by those differential corrections, and a threat model for the Conterminous United States region CONUS was developed in order to consider the highest gradients measured. This study presents the first extensive analysis of ionospheric gradients for Ecuador, from data fully covering 2013 and 2014 collected by their national Global Navigation Satellite System GNSS monitoring network (REGME). In this work it is applied an automated methodology adapted for low latitudes for processing data from dual frequency receivers networks, by considering data from all available days in the date range of the study regardless the geomagnetic indices values. The events found above the CONUS threat model occurred during days of nominal geomagnetic indices, confirming: (1) the higher bounds required for an ionospheric threat model for Ecuador, and (2) that geomagnetic indices are not enough to indicate relevant ionospheric anomalies in low latitude regions, reinforcing the necessity of a continuous monitoring of ionosphere. As additional contribution, the events database is published online, making it available to other researchers.

  11. A test for community saturation along the Himalayan bird diversity gradient, based on within-species geographical variation.

    Science.gov (United States)

    Ghosh-Harihar, Mousumi; Price, Trevor D

    2014-05-01

    The idea that ecological communities are unsaturated is central to many explanations for regional gradients in species diversity. We describe a test for differing degrees of saturation across a regional diversity gradient, based on within-species geographical variation in ecological attributes. If communities in species-poor regions are less saturated than communities in species-rich regions, species that straddle both regions should have broader niches in species-poor regions, exploiting resources that are consumed by other species in species-rich regions. We studied 10 species of Old World leaf warblers that range across the Himalayas. Elevational range and feeding method showed niche contractions in the species-poor north-west Himalayas with respect to the species-rich south-east Himalayas, whereas prey size did not vary geographically. Niche contractions are contrary to the expectation of character release in depauperate environments, as has been shown, for example in mainland-island comparisons. We show that arthropod abundances are likely a limiting resource, and that niche contractions are consistent with measurements of a narrowing of resource availability. Results suggest that north-western warbler communities are at least as saturated as the south-east and that lower resource diversity drives reduced species numbers. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

  12. Designing Waveform Sets with Good Correlation and Stopband Properties for MIMO Radar via the Gradient-Based Method

    Directory of Open Access Journals (Sweden)

    Liang Tang

    2017-05-01

    Full Text Available Waveform sets with good correlation and/or stopband properties have received extensive attention and been widely used in multiple-input multiple-output (MIMO radar. In this paper, we aim at designing unimodular waveform sets with good correlation and stopband properties. To formulate the problem, we construct two criteria to measure the correlation and stopband properties and then establish an unconstrained problem in the frequency domain. After deducing the phase gradient and the step size, an efficient gradient-based algorithm with monotonicity is proposed to minimize the objective function directly. For the design problem without considering the correlation weights, we develop a simplified algorithm, which only requires a few fast Fourier transform (FFT operations and is more efficient. Because both of the algorithms can be implemented via the FFT operations and the Hadamard product, they are computationally efficient and can be used to design waveform sets with a large waveform number and waveform length. Numerical experiments show that the proposed algorithms can provide better performance than the state-of-the-art algorithms in terms of the computational complexity.

  13. Designing Waveform Sets with Good Correlation and Stopband Properties for MIMO Radar via the Gradient-Based Method.

    Science.gov (United States)

    Tang, Liang; Zhu, Yongfeng; Fu, Qiang

    2017-05-01

    Waveform sets with good correlation and/or stopband properties have received extensive attention and been widely used in multiple-input multiple-output (MIMO) radar. In this paper, we aim at designing unimodular waveform sets with good correlation and stopband properties. To formulate the problem, we construct two criteria to measure the correlation and stopband properties and then establish an unconstrained problem in the frequency domain. After deducing the phase gradient and the step size, an efficient gradient-based algorithm with monotonicity is proposed to minimize the objective function directly. For the design problem without considering the correlation weights, we develop a simplified algorithm, which only requires a few fast Fourier transform (FFT) operations and is more efficient. Because both of the algorithms can be implemented via the FFT operations and the Hadamard product, they are computationally efficient and can be used to design waveform sets with a large waveform number and waveform length. Numerical experiments show that the proposed algorithms can provide better performance than the state-of-the-art algorithms in terms of the computational complexity.

  14. An individual-based forest model links canopy dynamics and shade tolerances along a soil moisture gradient.

    Science.gov (United States)

    Liénard, Jean; Strigul, Nikolay

    2016-02-01

    Understanding how forested ecosystems respond to climatic changes is a challenging problem as forest self-organization occurs simultaneously across multiple scales. Here, we explore the hypothesis that soil water availability shapes above-ground competition and gap dynamics, and ultimately alters the dominance of shade tolerant and intolerant species along the moisture gradient. We adapt a spatially explicit individual-based model with simultaneous crown and root competitions. Simulations show that the transition from xeric to mesic soils is accompanied by an increase in shade-tolerant species similar to the patterns documented in the North American forests. This transition is accompanied by a change from water to sunlight competitions, and happens at three successive stages: (i) mostly water-limited parkland, (ii) simultaneously water- and sunlight-limited closed canopy forests featuring a very sparse understory, and (iii) mostly sunlight-limited forests with a populated understory. This pattern is caused by contrasting successional dynamics that favour either shade-tolerant or shade-intolerant species, depending on soil moisture and understory density. This work demonstrates that forest patterns along environmental gradients can emerge from spatial competition without physiological trade-offs between shade and growth tolerance. Mechanistic understanding of population processes involved in the forest-parkland-desert transition will improve our ability to explain species distributions and predict forest responses to climatic changes.

  15. Inferred pressure gradient and fluid flow in a condensing sessile droplet based on the measured thickness profile

    Science.gov (United States)

    Gokhale, Shripad J.; Plawsky, Joel L.; Wayner, Peter C.; DasGupta, Sunando

    2004-06-01

    The thickness and curvature profiles of partially wetting condensing drops of 2-propanol on a quartz surface were measured using image analyzing interferometry and a new data analysis procedure. The profiles give fundamental insight into the phenomena of phase change, pressure gradient, fluid flow and spreading in a condensing drop, and the physics of interfacial phenomena in the contact line region of a polar fluid. The precursor adsorbed film and interfacial slope (a measure of the contact angle) and curvature profiles are consistent with previous concepts based on interfacial models. The curvature profiles, which were obtained using a new data reduction procedure, clearly demonstrate the convex nature of the drop near the thicker part (negative value of curvature), whereas, in the thinner region, the drop is concave (positive curvature) where the partially wetting liquid merges with a flat adsorbed film. The pressure profiles inside the drop are calculated from the augmented Young-Laplace equation showing that the pressure gradient increases with an increase in the spreading velocity (rates of condensation) to support the higher liquid flow rates associated with the growth of the drop. Internal flow is towards the point of maximum positive curvature from both the thin film and convex regions. Apolar and polar components of the spreading coefficient help describe the interfacial phenomena occurring. The experimental techniques are relatively simple but very revealing.

  16. The gravity field model IGGT_R1 based on the second invariant of the GOCE gravitational gradient tensor

    Science.gov (United States)

    Lu, Biao; Luo, Zhicai; Zhong, Bo; Zhou, Hao; Flechtner, Frank; Förste, Christoph; Barthelmes, Franz; Zhou, Rui

    2017-11-01

    Based on tensor theory, three invariants of the gravitational gradient tensor (IGGT) are independent of the gradiometer reference frame (GRF). Compared to traditional methods for calculation of gravity field models based on the gravity field and steady-state ocean circulation explorer (GOCE) data, which are affected by errors in the attitude indicator, using IGGT and least squares method avoids the problem of inaccurate rotation matrices. The IGGT approach as studied in this paper is a quadratic function of the gravity field model's spherical harmonic coefficients. The linearized observation equations for the least squares method are obtained using a Taylor expansion, and the weighting equation is derived using the law of error propagation. We also investigate the linearization errors using existing gravity field models and find that this error can be ignored since the used a-priori model EIGEN-5C is sufficiently accurate. One problem when using this approach is that it needs all six independent gravitational gradients (GGs), but the components V_{xy} and V_{yz} of GOCE are worse due to the non-sensitive axes of the GOCE gradiometer. Therefore, we use synthetic GGs for both inaccurate gravitational gradient components derived from the a-priori gravity field model EIGEN-5C. Another problem is that the GOCE GGs are measured in a band-limited manner. Therefore, a forward and backward finite impulse response band-pass filter is applied to the data, which can also eliminate filter caused phase change. The spherical cap regularization approach (SCRA) and the Kaula rule are then applied to solve the polar gap problem caused by GOCE's inclination of 96.7° . With the techniques described above, a degree/order 240 gravity field model called IGGT_R1 is computed. Since the synthetic components of V_{xy} and V_{yz} are not band-pass filtered, the signals outside the measurement bandwidth are replaced by the a-priori model EIGEN-5C. Therefore, this model is practically a

  17. Polyhedral shape model for terrain correction of gravity and gravity gradient data based on an adaptive mesh

    Science.gov (United States)

    Guo, Zhikui; Chen, Chao; Tao, Chunhui

    2016-04-01

    Since 2007, there are four China Da yang cruises (CDCs), which have been carried out to investigate polymetallic sulfides in the southwest Indian ridge (SWIR) and have acquired both gravity data and bathymetry data on the corresponding survey lines(Tao et al., 2014). Sandwell et al. (2014) published a new global marine gravity model including the free air gravity data and its first order vertical gradient (Vzz). Gravity data and its gradient can be used to extract unknown density structure information(e.g. crust thickness) under surface of the earth, but they contain all the mass effect under the observation point. Therefore, how to get accurate gravity and its gradient effect of the existing density structure (e.g. terrain) has been a key issue. Using the bathymetry data or ETOPO1 (http://www.ngdc.noaa.gov/mgg/global/global.html) model at a full resolution to calculate the terrain effect could spend too much computation time. We expect to develop an effective method that takes less time but can still yield the desired accuracy. In this study, a constant-density polyhedral model is used to calculate the gravity field and its vertical gradient, which is based on the work of Tsoulis (2012). According to gravity field attenuation with distance and variance of bathymetry, we present an adaptive mesh refinement and coarsening strategies to merge both global topography data and multi-beam bathymetry data. The local coarsening or size of mesh depends on user-defined accuracy and terrain variation (Davis et al., 2011). To depict terrain better, triangular surface element and rectangular surface element are used in fine and coarse mesh respectively. This strategy can also be applied to spherical coordinate in large region and global scale. Finally, we applied this method to calculate Bouguer gravity anomaly (BGA), mantle Bouguer anomaly(MBA) and their vertical gradient in SWIR. Further, we compared the result with previous results in the literature. Both synthetic model

  18. An efficient impedance method for induced field evaluation based on a stabilized Bi-conjugate gradient algorithm

    International Nuclear Information System (INIS)

    Wang Hua; Liu Feng; Crozier, Stuart; Xia Ling

    2008-01-01

    This paper presents a stabilized Bi-conjugate gradient algorithm (BiCGstab) that can significantly improve the performance of the impedance method, which has been widely applied to model low-frequency field induction phenomena in voxel phantoms. The improved impedance method offers remarkable computational advantages in terms of convergence performance and memory consumption over the conventional, successive over-relaxation (SOR)-based algorithm. The scheme has been validated against other numerical/analytical solutions on a lossy, multilayered sphere phantom excited by an ideal coil loop. To demonstrate the computational performance and application capability of the developed algorithm, the induced fields inside a human phantom due to a low-frequency hyperthermia device is evaluated. The simulation results show the numerical accuracy and superior performance of the method.

  19. Feedback-Based Projected-Gradient Method For Real-Time Optimization of Aggregations of Energy Resources: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Dall-Anese, Emiliano [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bernstein, Andrey [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Simonetto, Andrea [IBM Research Center Ireland

    2017-11-27

    This paper develops an online optimization method to maximize the operational objectives of distribution-level distributed energy resources (DERs) while adjusting the aggregate power generated (or consumed) in response to services requested by grid operators. The design of the online algorithm is based on a projected-gradient method, suitably modified to accommodate appropriate measurements from the distribution network and the DERs. By virtue of this approach, the resultant algorithm can cope with inaccuracies in the representation of the AC power, it avoids pervasive metering to gather the state of noncontrollable resources, and it naturally lends itself to a distributed implementation. Optimality claims are established in terms of tracking of the solution of a well-posed time-varying optimization problem.

  20. Method and apparatus for producing a carbon based foam article having a desired thermal-conductivity gradient

    Science.gov (United States)

    Klett, James W [Knoxville, TN; Cameron, Christopher Stan [Sanford, NC

    2010-03-02

    A carbon based foam article is made by heating the surface of a carbon foam block to a temperature above its graphitizing temperature, which is the temperature sufficient to graphitize the carbon foam. In one embodiment, the surface is heated with infrared pulses until heat is transferred from the surface into the core of the foam article such that the graphitizing temperature penetrates into the core to a desired depth below the surface. The graphitizing temperature is maintained for a time sufficient to substantially entirely graphitize the portion of the foam article from the surface to the desired depth below the surface. Thus, the foam article is an integral monolithic material that has a desired conductivity gradient with a relatively high thermal conductivity in the portion of the core that was graphitized and a relatively low thermal conductivity in the remaining portion of the foam article.

  1. Hygrothermal wave propagation in viscoelastic graphene under in-plane magnetic field based on nonlocal strain gradient theory

    Science.gov (United States)

    Karami, Behrouz; Shahsavari, Davood; Li, Li

    2018-03-01

    A size-dependent model is developed for the hygrothermal wave propagation analysis of an embedded viscoelastic single layer graphene sheet (SLGS) under the influence of in-plane magnetic field. The bi-Helmholtz nonlocal strain gradient theory involving three small scale parameters is introduced to account for the size-dependent effects. The size-dependent model is deduced based on Hamilton's principle. The closed-form solution of eigenfrequency relation between wave number and phase velocity is achieved. By studying the size-dependent effects on the flexural wave of SLGS, the dispersion relation predicted by the developed size-dependent model can show a good match with experimental data. The influence of in-plane magnetic field, temperature and moisture of environs, structural damping, damped substrate, lower and higher order nonlocal parameters and the material characteristic parameter on the phase velocity of SLGS is explored.

  2. The Evolution of Policy Enactment on Gender-Based Violence in Schools

    Science.gov (United States)

    Parkes, Jenny

    2016-01-01

    This article examines how policies and strategies to address school-related gender-based violence have evolved since 2000, when gender-based violence within education was largely invisible. Through an exploration of policy enactment in three countries--Liberia, South Africa, and Brazil--it traces remarkable progress in policy, programmes, and…

  3. A diatom-based biological condition gradient (BCG) approach for assessing impairment and developing nutrient criteria for streams.

    Science.gov (United States)

    Hausmann, Sonja; Charles, Donald F; Gerritsen, Jeroen; Belton, Thomas J

    2016-08-15

    Over-enrichment leading to excess algal growth is a major problem in rivers and streams. Regulations to protect streams typically incorporate nutrient criteria, concentrations of phosphorus and nitrogen that should not be exceeded in order to protect biological communities. A major challenge has been to develop an approach for both categorizing streams based on their biological conditions and determining scientifically defensible nutrient criteria to protect the biotic integrity of streams in those categories. To address this challenge, we applied the Biological Condition Gradient (BCG) approach to stream diatom assemblages to develop a system for categorizing sites by level of impairment, and then examined the related nutrient concentrations to identify potential nutrient criteria. The six levels of the BCG represent a range of ecological conditions from natural (1) to highly disturbed (6). A group of diatom experts developed a set of rules and a model to assign sites to these levels based on their diatom assemblages. To identify potential numeric nutrient criteria, we explored the relation of assigned BCG levels to nutrient concentrations, other anthropogenic stressors, and possible confounding variables using data for stream sites in New Jersey (n=42) and in surrounding Mid-Atlantic states, USA (n=1443). In both data sets, BCG levels correlated most strongly with total phosphorus and the percentage of forest in the watershed, but were independent of pH. We applied Threshold Indicator Taxa Analysis (TITAN) to determine change-points in the diatom assemblages along the BCG gradient. In both data sets, statistically significant diatom changes occurred between BCG levels 3 and 4. Sites with BCG levels 1 to 3 were dominated by species that grow attached to surfaces, while sites with BCG scores of 4 and above were characterized by motile diatoms. The diatom change-point corresponded with a total phosphorus concentration of about 50μg/L. Copyright © 2016 Elsevier B

  4. The institutional economics of market-based climate policy

    International Nuclear Information System (INIS)

    Woerdman, E.

    2005-01-01

    The objective of this book is to analyze the institutional barriers to implementing market-based climate policy, as well as to provide some opportunities to overcome them. The approach is that of institutional economics, with special emphasis on political transaction costs and path dependence. Instead of rejecting the neoclassical approach, this book uses it where fruitful and shows when and why it is necessary to employ a new or neo-institutionalist approach. The result is that equity is considered next to efficiency, that the evolution and possible lock-in of both formal and informal climate institutions are studied, and that attention is paid to the politics and law of economic instruments for climate policy, including some new empirical analyses. The research topics of this book include the set-up costs of a permit trading system, the risk that credit trading becomes locked-in, the potential legal problem of grandfathering in terms of actional subsidies under WTO law or state aid under EC law, and the changing attitudes of various European officials towards restricting the use of the Kyoto Mechanisms

  5. Econometric Model of Rice Policy Based On Presidential Instruction

    Science.gov (United States)

    Abadi Sembiring, Surya; Hutauruk, Julia

    2018-01-01

    The objective of research is to build an econometric model based on Presidential Instruction rice policy. The data was monthly time series from March 2005 to September 2009. Rice policy model specification using simultaneous equation, consisting of 14 structural equations and four identity equation, which was estimated using Two Stages Least Squares (2SLS) method. The results show that: (1) an increase of government purchasing price of dried harvest paddy has a positive impact on to increase in total rice production and community rice stock, (2) an increase community rice stock lead to decrease the rice imports, (3) an increase of the realization of the distribution of subsidized ZA fertilizers and the realization of the distribution of subsidized NPK fertilizers has a positive impact on to increase in total rice production and community rice stock and to reduce rice imports, (4) the price of the dried harvest paddy is highly responsive to the water content of dried harvest paddy both the short run and long run, (5) the quantity of rice imported is highly responsive to the imported rice price, both short run and long run.

  6. Combining Correlation-Based and Reward-Based Learning in Neural Control for Policy Improvement

    DEFF Research Database (Denmark)

    Manoonpong, Poramate; Kolodziejski, Christoph; Wörgötter, Florentin

    2013-01-01

    associations. Based on these biological findings, we propose a new learning model to achieve successful control policies for artificial systems. This model combines correlation-based learning using input correlation learning (ICO learning) and reward-based learning using continuous actor–critic reinforcement...... learning (RL), thereby working as a dual learner system. The model performance is evaluated by simulations of a cart-pole system as a dynamic motion control problem and a mobile robot system as a goal-directed behavior control problem. Results show that the model can strongly improve pole balancing control...... policy, i.e., it allows the controller to learn stabilizing the pole in the largest domain of initial conditions compared to the results obtained when using a single learning mechanism. This model can also find a successful control policy for goal-directed behavior, i.e., the robot can effectively learn...

  7. A Path-Based Gradient Projection Algorithm for the Cost-Based System Optimum Problem in Networks with Continuously Distributed Value of Time

    Directory of Open Access Journals (Sweden)

    Wen-Xiang Wu

    2014-01-01

    Full Text Available The cost-based system optimum problem in networks with continuously distributed value of time is formulated as a path-based form, which cannot be solved by the Frank-Wolfe algorithm. In light of magnitude improvement in the availability of computer memory in recent years, path-based algorithms have been regarded as a viable approach for traffic assignment problems with reasonably large network sizes. We develop a path-based gradient projection algorithm for solving the cost-based system optimum model, based on Goldstein-Levitin-Polyak method which has been successfully applied to solve standard user equilibrium and system optimum problems. The Sioux Falls network tested is used to verify the effectiveness of the algorithm.

  8. Opportunity-based age replacement policy with minimal repair

    International Nuclear Information System (INIS)

    Jhang, J.P.; Sheu, S.H.

    1999-01-01

    This paper proposes an opportunity-based age replacement policy with minimal repair. The system has two types of failures. Type I failures (minor failures) are removed by minimal repairs, whereas type II failures are removed by replacements. Type I and type II failures are age-dependent. A system is replaced at type II failure (catastrophic failure) or at the opportunity after age T, whichever occurs first. The cost of the minimal repair of the system at age z depends on the random part C(z) and the deterministic part c(z). The opportunity arises according to a Poisson process, independent of failures of the component. The expected cost rate is obtained. The optimal T * which would minimize the cost rate is discussed. Various special cases are considered. Finally, a numerical example is given

  9. Policy-Based mobility Management for Heterogeneous Networks

    DEFF Research Database (Denmark)

    Mihovska, Albena D.

    2007-01-01

    Next generation communications will be composed of flexible, scalable and context-aware, secure and resilient architectures and technologies that allow full mobility of the user and enable dynamic management policies that ensure end-to-end secure transmission of data and services across...... heterogeneous infrastructures and networks. This paper investigates the policybased mobility management scheme proposed for the WINNER system. The scheme is based on previously developed cooperation radio resource management (RRM) algorithms including mobility management, for the successful interworking...... of WINNER with new and legacy systems. The paper describes the cooperation architecture and mobility management functionalities and the rules that are applied for the support of mobility within the above scenarios. The rules are applied to solve problems such as: who and what can access which resources...

  10. Irradiance gradients

    International Nuclear Information System (INIS)

    Ward, G.J.; Heckbert, P.S.; Technische Hogeschool Delft

    1992-04-01

    A new method for improving the accuracy of a diffuse interreflection calculation is introduced in a ray tracing context. The information from a hemispherical sampling of the luminous environment is interpreted in a new way to predict the change in irradiance as a function of position and surface orientation. The additional computation involved is modest and the benefit is substantial. An improved interpolation of irradiance resulting from the gradient calculation produces smoother, more accurate renderings. This result is achieved through better utilization of ray samples rather than additional samples or alternate sampling strategies. Thus, the technique is applicable to a variety of global illumination algorithms that use hemicubes or Monte Carlo sampling techniques

  11. Fully automated prostate segmentation in 3D MR based on normalized gradient fields cross-correlation initialization and LOGISMOS refinement

    Science.gov (United States)

    Yin, Yin; Fotin, Sergei V.; Periaswamy, Senthil; Kunz, Justin; Haldankar, Hrishikesh; Muradyan, Naira; Cornud, François; Turkbey, Baris; Choyke, Peter

    2012-02-01

    Manual delineation of the prostate is a challenging task for a clinician due to its complex and irregular shape. Furthermore, the need for precisely targeting the prostate boundary continues to grow. Planning for radiation therapy, MR-ultrasound fusion for image-guided biopsy, multi-parametric MRI tissue characterization, and context-based organ retrieval are examples where accurate prostate delineation can play a critical role in a successful patient outcome. Therefore, a robust automated full prostate segmentation system is desired. In this paper, we present an automated prostate segmentation system for 3D MR images. In this system, the prostate is segmented in two steps: the prostate displacement and size are first detected, and then the boundary is refined by a shape model. The detection approach is based on normalized gradient fields cross-correlation. This approach is fast, robust to intensity variation and provides good accuracy to initialize a prostate mean shape model. The refinement model is based on a graph-search based framework, which contains both shape and topology information during deformation. We generated the graph cost using trained classifiers and used coarse-to-fine search and region-specific classifier training. The proposed algorithm was developed using 261 training images and tested on another 290 cases. The segmentation performance using mean DSC ranging from 0.89 to 0.91 depending on the evaluation subset demonstrates state of the art performance. Running time for the system is about 20 to 40 seconds depending on image size and resolution.

  12. Sampling conditions for gradient-magnitude sparsity based image reconstruction algorithms

    DEFF Research Database (Denmark)

    Sidky, Emil Y.; Jørgensen, Jakob Heide; Pan, Xiaochuan

    2012-01-01

    in the compressive sensing (CS) community for this type of sparsity. The preliminary finding here, based on simulations using images of realistic sparsity levels, is that necessary sampling can go as low as N/4 views for an NxN pixel array. This work sets the stage for fixed-exposure studies where the number...

  13. Designing and implementing science-based methane policies

    Science.gov (United States)

    George, F.

    2017-12-01

    The phenomenal growth in shale gas production across the U.S. has significantly improved the energy security and economic prospects of the country. Natural gas is a "versatile" fuel that has application in every major end-use sector of the economy, both as a fuel and a feedstock. Natural gas has also played a significant role in reducing CO2 emissions from the power sector by displacing more carbon intensive fossil fuels. However, emissions of natural gas (predominantly methane) from the wellhead to the burner tip can erode this environmental benefit. Preserving the many benefits of America's natural gas resources requires smart, science-based policies to optimize the energy delivery efficiency of the natural gas supply chain and ensure that natural gas remains a key pillar in our transition to a low-carbon economy. Southwestern Energy (SWN) is the third largest natural gas producer in the United States. Over the last several years, SWN has participated in a number of scientific studies with regulatory agencies, academia and non-governmental entities that have led to over a dozen peer-reviewed papers on methane emissions from oil and gas operations. This presentation will review how our participation in these studies has informed our internal policies and procedures, as well as our external programs, including the ONE Future coalition (ONE Future). In particular, the presentation will highlight the impact of such studies on our Leak Detection and Repair (LDAR) program, designing new methane research and on the ONE Future initiatives - all with the focus of improving the delivery efficiency of oil and gas operations. Our experience supports continued research in the detection and mitigation of methane emissions, with emphasis on longer duration characterization of methane emissions from oil and gas facilities and further development of cost-effective methane detection and mitigation techniques. We conclude from our scientific and operational experiences that a

  14. Circulatory osmotic desalination driven by a mild temperature gradient based on lower critical solution temperature (LCST) phase transition materials.

    Science.gov (United States)

    Mok, Yeongbong; Nakayama, Daichi; Noh, Minwoo; Jang, Sangmok; Kim, Taeho; Lee, Yan

    2013-11-28

    Abrupt changes in effective concentration and osmotic pressure of lower critical solution temperature (LCST) mixtures facilitate the design of a continuous desalination method driven by a mild temperature gradient. We propose a prototype desalination system by circulating LCST mixtures between low and high temperature (low T and high T) units. Water molecules could be drawn from a high-salt solution to the LCST mixture through a semipermeable membrane at a temperature lower than the phase transition temperature, at which the effective osmotic pressure of the LCST mixture is higher than the high-salt solution. After transfer of water to the high T unit where the LCST mixture is phase-separated, the water-rich phase could release the drawn water into a well-diluted solution through the second membrane due to the significant decrease in effective concentration. The solute-rich phase could be recovered in the low T unit via a circulation process. The molar mass, phase transition temperature, and aqueous solubility of the LCST solute could be tuneable for the circulatory osmotic desalination system in which drawing, transfer, release of water, and the separation and recovery of the solutes could proceed simultaneously. Development of a practical desalination system that draws water molecules directly from seawater and produces low-salt water with high purity by mild temperature gradients, possibly induced by sunlight or waste heat, could be attainable by a careful design of the molecular structure and combination of the circulatory desalination systems based on low- and high-molar-mass LCST draw solutes.

  15. Zwitterionic silica-based monolithic capillary columns for isocratic and gradient hydrophilic interaction liquid chromatography

    Czech Academy of Sciences Publication Activity Database

    Moravcová, Dana; Planeta, Josef; Kahle, Vladislav; Roth, Michal

    2012-01-01

    Roč. 1270, DEC 28 (2012), s. 178-185 ISSN 0021-9673 R&D Projects: GA MV VG20112015021; GA ČR(CZ) GAP206/11/0138; GA ČR(CZ) GAP106/12/0522 Institutional support: RVO:68081715 Keywords : HILIC * Monolithic silica column * Nucleoside separation * Nucleic acid base Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.612, year: 2012

  16. Structural kinematics based damage zone prediction in gradient structures using vibration database

    Science.gov (United States)

    Talha, Mohammad; Ashokkumar, Chimpalthradi R.

    2014-05-01

    To explore the applications of functionally graded materials (FGMs) in dynamic structures, structural kinematics based health monitoring technique becomes an important problem. Depending upon the displacements in three dimensions, the health of the material to withstand dynamic loads is inferred in this paper, which is based on the net compressive and tensile displacements that each structural degree of freedom takes. These net displacements at each finite element node predicts damage zones of the FGM where the material is likely to fail due to a vibration response which is categorized according to loading condition. The damage zone prediction of a dynamically active FGMs plate have been accomplished using Reddy's higher-order theory. The constituent material properties are assumed to vary in the thickness direction according to the power-law behavior. The proposed C0 finite element model (FEM) is applied to get net tensile and compressive displacement distributions across the structures. A plate made of Aluminum/Ziconia is considered to illustrate the concept of structural kinematics-based health monitoring aspects of FGMs.

  17. Correlation of acidic and basic carrier ampholyte and immobilized pH gradient two-dimensional gel electrophoresis patterns based on mass spectrometric protein identification

    DEFF Research Database (Denmark)

    Nawrocki, A; Larsen, Martin Røssel; Podtelejnikov, A V

    1998-01-01

    Separation of proteins on either carrier ampholyte-based or immobilized pH gradient-based two-dimensional (2-D) gels gives rise to electrophoretic patterns that are difficult to compare visually. In this paper we have used matrix-assisted laser desorption/ionization mass spectrometry (MALDI...

  18. Detection of bacteria in normal adult nasal cavity based on polymerase chain reaction-denaturing gradient gel electrophoresis.

    Science.gov (United States)

    Cho, Jae Hoon; Jung, Min Young; Kim, Jin Kook; Chang, Young-Hyo

    2011-01-01

    This study investigated the bacterial diversity in a normal adult nasal cavity using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) of 16S ribosomal RNA (rRNA) gene fragments and compared the results with those of a culture-based method. We swabbed the inferior turbinate from 19 normal volunteers. The transport media was divided by two, one for bacterial culture and another direct extraction for bacterial DNA. PCR-DGGE was performed from the bacterial DNA and all of the sequences were compared with the reference organism by using the BLAST program (a genome database of GenBank in the National Center for Biotechnology Information, Bethesda, MD). All 224 colonies were obtained from 19 samples by using a culture-based method; however, only 9 kinds of bacteria were detected. Staphylococcus epidermidis was the most frequently detected bacteria, and Staphylococcus aureus was the second most. The detection rates of other bacteria were very low. On the other hand, the PCR-DGGE from direct DNA extraction revealed 34 different bands that corresponded to 23 different kinds of bacteria. There were nine genera, viz., Staphylococcus, Bacillus, Enterobacter, Corynebacterium, Actinobacterium, Hafnia, Moraxella, Dolosigranulum, and Clostridium. Among them, unspecific Staphylococcus species and Enterobacter aerogenes were detected most frequently. Compared with the previous culture-based method, PCR-DGGE can detect much more diversity of bacteria in the nasal cavity.

  19. Ecosystem Services Management Based on Differentiation and Regionalization along Vertical Gradient in Taihang Mountain, China

    Directory of Open Access Journals (Sweden)

    Hui Gao

    2018-03-01

    Full Text Available The regulation and management of ecosystem services are fundamental for sustainable development in mountain areas. Although no obvious vertical band spectrum exists in Taihang Mountain region, vertical differentiation of ecological characteristics in the region is obvious. The ecosystem characteristics of vertical differentiation were analyzed using 4 typical ecological indices (land use, temperature, net primary productivity, and water yield. The ecosystem service functional pattern was determined based on analysis of the ecosystem services value per unit area. The 2 ecosystem critical zones of vertical differentiation (500–600 m and 1400–1500 m were determined. The mountain area was divided into 3 ecological zones—sub-alpine zone (>1500 m, mid-mountain zone (600–1400 m and hilly zone (<500 m. The ecosystem services functional pattern was as follows: provisioning services was the main ecosystem services function in the hilly zone, 4 ecosystem service functions were equally important in the mid-mountain zone, regulating, supporting and cultural services were the main ecosystem service functions in the sub-alpine zone. The model of ecosystem service regulation and management in 3 ecological zones was built based on the functional patterns to promote sustainable development.

  20. A quinhydrone biofuel cell based on an enzyme-induced pH gradient

    Energy Technology Data Exchange (ETDEWEB)

    Giroud, Fabien; Gondran, Chantal; Gorgy, Karine; Cosnier, Serge [Departement de Chimie Moleculaire, UMR CNRS 5250 ICMG-FR-2607, Universite Joseph Fourier, BP-53, 38041 Grenoble Cedex 9 (France); Pellissier, Aymeric [Departement de Chimie Moleculaire, UMR CNRS 5250 ICMG-FR-2607, Universite Joseph Fourier, BP-53, 38041 Grenoble Cedex 9 (France); Techniques de l' Ingenierie Medicale et de la Complexite - Informatique, Mathematiques Appliquees Grenoble, UMR CNRS 5525, IFRT-IpV 130, IN3S INstitut de l' INgenierie et de l' INformation de Sante, Faculte de Medecine, Universite Joseph Fourier, 38706 La Tronche cedex (France); Lenouvel, Francois; Cinquin, Philippe [Techniques de l' Ingenierie Medicale et de la Complexite - Informatique, Mathematiques Appliquees Grenoble, UMR CNRS 5525, IFRT-IpV 130, IN3S INstitut de l' INgenierie et de l' INformation de Sante, Faculte de Medecine, Universite Joseph Fourier, 38706 La Tronche cedex (France)

    2011-02-01

    We report on an alternative concept of biofuel cell functioning based on the unconventional use of enzymes to create a pH difference generating a potential difference between electrodes soaked in quinhydrone solutions. The electrode and quinhydrone solution were confined in a dialysis bag placed into a compartment containing either glucose oxidase and catalase for the biocathode or urease for the bioanode. In presence of 0.4 mol L{sup -1} glucose and urea, the enzyme reactions generate a pH difference of 3.55, both compartments being separated by an agar-agar wall. The resulting biofuel cell exhibits an open-circuit voltage and maximum power of 208 mV and 30.6 {mu}W, respectively, without immobilization and electrical connection of the involved enzymes. In addition, this biofuel cell was able to provide continuously10 {mu}A during 23 h, producing 0.133 J and 0.828 C. A similar biofuel cell configuration based only on dialysis bags was also developed. A graphite disk electrode elaborated by mechanical compression of graphite particles and quinhydrone, was placed in a dialysis bag itself confined into another dialysis bag containing enzyme solution. The resulting power and open-circuit voltage at saturating substrate conditions are 7.6 {mu}W and 157 mV, respectively. (author)

  1. Dissipation function and adaptive gradient reconstruction based smoke detection in video

    Science.gov (United States)

    Li, Bin; Zhang, Qiang; Shi, Chunlei

    2017-11-01

    A method for smoke detection in video is proposed. The camera monitoring the scene is assumed to be stationary. With the atmospheric scattering model, dissipation function is reflected transmissivity between the background objects in the scene and the camera. Dark channel prior and fast bilateral filter are used for estimating dissipation function which is only the function of the depth of field. Based on dissipation function, visual background extractor (ViBe) can be used for detecting smoke as a result of smoke's motion characteristics as well as detecting other moving targets. Since smoke has semi-transparent parts, the things which are covered by these parts can be recovered by poisson equation adaptively. The similarity between the recovered parts and the original background parts in the same position is calculated by Normalized Cross Correlation (NCC) and the original background's value is selected from the frame which is nearest to the current frame. The parts with high similarity are considered as smoke parts.

  2. Automated morphological classification of galaxies based on projection gradient nonnegative matrix factorization algorithm

    Science.gov (United States)

    Selim, I. M.; Abd El Aziz, Mohamed

    2017-04-01

    The development of automated morphological classification schemes can successfully distinguish between morphological types of galaxies and can be used for studies of the formation and subsequent evolution of galaxies in our universe. In this paper, we present a new automated machine supervised learning astronomical classification scheme based on the Nonnegative Matrix Factorization algorithm. This scheme is making distinctions between all types roughly corresponding to Hubble types such as elliptical, lenticulars, spiral, and irregular galaxies. The proposed algorithm is performed on two examples with different number of image (small dataset contains 110 image and large dataset contains 700 images). The experimental results show that galaxy images from EFIGI catalog can be classified automatically with an accuracy of ˜93% for small and ˜92% for large number. These results are in good agreement when compared with the visual classifications.

  3. A novel wideband optical absorber based on all-metal 2D gradient nanostructures

    Science.gov (United States)

    Gong, Jianhao; Yang, Fulong; Zhang, Xiaoping

    2017-11-01

    Recently, all-metal nanostructures for perfect absorption of light have attracted much attention due to their excellent plasmonic and photonic properties, but only narrow absorption bands were obtained in previous studies. In this paper, a new kind of metallic metasurface with wideband absorption of visible light is designed, which consists only of a gold nanotriangle array on the opaque metal substrate. By combining different resonant modes in the gradual-changed triangular nanostructure, the wide absorption waveband in visible region from 378 to 626 nm is achieved with more than 90% absorptivity. We demonstrate that the absorption property of the nanostructure can be controlled by tuning the cell size and incident angle. In addition, a metallic trapezoidal grating structure is proposed which can also realize wideband light absorption. This research provides a novel strategy in designing wideband metamaterial absorbers for visible light based on all-metal nanostructures which have great potential applications in light energy harvesting and photoelectric conversion.

  4. Wave propagation analysis of embedded nanoplates based on a nonlocal strain gradient-based surface piezoelectricity theory

    Science.gov (United States)

    Ebrahimi, Farzad; Dabbagh, Ali

    2017-11-01

    The present paper deals with the smart characteristics of waves propagating in a piezoelectric nanosize plate rested on an elastic medium whenever surface effects are included. A more realistic simulation about the elastic medium is presented by utilizing a three-parameter medium containing Winkler, Pasternak and damping coefficients. Furthermore, both of the decreasing and increasing impacts of small scale influences are covered in the framework of a nonlocal strain gradient theory (NSGT). The electric potential is approximated by a function possessing linear and trigonometric parts. Also, by developing the surface elasticity theory of Gurtin-Murdoch for piezoelectric solids, influences of surface layers are considered. Kinematic relations are derived employing the Kirchhoff plate theory. Afterwards, Hamilton's principle is introduced in order to achieve Euler-Lagrange equations of piezoelectric nanoplates. The final part consists of an analytical approach to obtain the wave frequency value. The accuracy of the presented model is verified by organizing a comparison of the presented results with previous ones. Finally, some parametric case studies are rendered to clarify the influence of different parameters such as wave number, nonlocal and length scale parameters, foundation parameters and applied voltage.

  5. Model-based inflation forecasts and monetary policy rules

    OpenAIRE

    Wouters, Raf; Dombrecht, Michel

    2000-01-01

    In this paper, the interaction between inflation and monetary policy rules is analysed within the framework of a dynamic general equilibrium model derived from optimising behaviour and rational expectations. Using model simulations, it is illustrated that the control of monetary policy over the inflation process is strongly dependent on the role of forward looking expectations in the price and wage setting process and on the credibility of monetary policy in the expectation formation process ...

  6. Dengue transmission based on urban environmental gradients in different cities of Pakistan.

    Science.gov (United States)

    Khalid, Bushra; Ghaffar, Abdul

    2015-03-01

    This study focuses on the dengue transmission in different regions of Pakistan. For this purpose, the data of dengue cases for 2009-2012 from four different cities (Rawalpindi, Islamabad, Lahore, and Karachi) of the country is collected, evaluated, and compiled. To identify the reasons and regions of higher risk of Dengue transmission, land use classification, analysis of climate covariates and drainage patterns was done. Analysis involves processing of SPOT 5 10 m, Landsat TM 30 m data sets, and SRTM 90 m digital elevation models by using remote sensing and GIS techniques. The results are based on the change in urbanization and population density, analysis of temperature, rainfall, and wind speed; calculation of drainage patterns including stream features, flow accumulation, and drainage density of the study areas. Results suggest that the low elevation areas with calm winds and minimum temperatures higher than the normal, rapid increase in unplanned urbanization, low flow accumulation, and higher drainage density areas favor the dengue transmission.

  7. Evidence based educational policy and practice: the case of applying the educational effectiveness knowledge base

    NARCIS (Netherlands)

    Scheerens, Jaap

    2014-01-01

    Evidence based educational policy and practice means, first of all, that new programs use relevant scientific knowledge for design purposes, or for critical review of initial program ideas (ex ante evaluation). Secondly, before programs are implemented on a large scale it is considered desirable to

  8. To What Extent Are Canadian Second Language Policies Evidence-Based? Reflections on the Intersections of Research and Policy

    Directory of Open Access Journals (Sweden)

    Jim eCummins

    2014-05-01

    Full Text Available The paper addresses the intersections between research, ideology, and Canadian educational policies focusing on four major areas: (a core and immersion programs for the teaching of French to Anglophone students, (b policies concerning the learning of English and French by students from immigrant backgrounds, (c heritage language teaching, and (d the education of Deaf and hard-of hearing students. With respect to the teaching of French, policy-makers have largely ignored the fact that most core French programs produce meager results for the vast majority of students. Only a small proportion of students (< 10% attend more effective alternatives (e.g. French immersion and Intensive French programs. With respect to immigrant-background students, a large majority of teachers and administrators have not had opportunities to access the knowledge base regarding effective instruction for these students nor have they had opportunities for pre-service or in-service professional development regarding effective instructional practices. Educational policies have also treated the linguistic resources that children bring to school with, at best, benign neglect. In some cases (e.g., Ontario school systems have been explicitly prohibited from instituting enrichment bilingual programs that would promote students’ bilingualism and biliteracy. Finally, with respect to Deaf students, policy-makers have ignored overwhelming research on the positive relationship between academic success and the development of proficiency in natural sign languages, preferring instead to perpetuate the falsehood that acquisition of languages such as American Sign Language by young children (with or without cochlear implants will impede children’s language and academic development. The paper reviews the kinds of policies, programs, and practices that could be implemented (at no additional cost if policy-makers and educators pursued evidence-based educational policies.

  9. Analyses of Spring Barley Evapotranspiration Rates Based on Gradient Measurements and Dual Crop Coefficient Model

    Directory of Open Access Journals (Sweden)

    Gabriela Pozníková

    2014-01-01

    Full Text Available The yield of agricultural crops depends on water availability to a great extent. According some projections, the likelihood of stress caused by drought is increasing in future climates expected for the Central Europe. Therefore, in order to manage agro-ecosystems properly, it is necessary to know water demand of particular crops as precisely as possible. Evapotranspiration (ET is the main part of water balance which takes the water from agro-ecosystems away. The ET consists of evaporation from the soil (E and transpiration (T through the stomata of plants. In this study, we investigated ET of spring barley 1-ha field (Domanínek, Czech Republic measured by Bowen ratio/energy balance method during growing period 2013 (May 8 to July 31. Special focus was dedicated to comparison of barley ET with the reference grass ETo calculated according FAO-56 model, i.e. the determination of barley crop coefficient (Kc. This crop coefficient was subsequently separated into soil evaporation (Ke and transpiration fraction (Kcb by adjusting soil and phenological parameters of dual crop coefficient model to minimize the root mean square error between measured and modelled ET. The resulting Kcb of barley was 0.98 during mid-growing period and 0.05 during initial and end periods. According to FAO-56, typical values are 1.10 and 0.15 for Kcb mid and Kcb end, respectively. Modelled and measured ET show satisfactory agreement with root mean square error equal 0.41 mm. Based on the sums of ET and E for the whole growing season of the spring barley, ET partitioning by FAO-56 dual crop coefficient model resulted in E/ET ratio being 0.24.

  10. Focus measure method based on the modulus of the gradient of the color planes for digital microscopy

    Science.gov (United States)

    Hurtado-Pérez, Román; Toxqui-Quitl, Carina; Padilla-Vivanco, Alfonso; Aguilar-Valdez, J. Félix; Ortega-Mendoza, Gabriel

    2018-02-01

    The modulus of the gradient of the color planes (MGC) is implemented to transform multichannel information to a grayscale image. This digital technique is used in two applications: (a) focus measurements during autofocusing (AF) process and (b) extending the depth of field (EDoF) by means of multifocus image fusion. In the first case, the MGC procedure is based on an edge detection technique and is implemented in over 15 focus metrics that are typically handled in digital microscopy. The MGC approach is tested on color images of histological sections for the selection of in-focus images. An appealing attribute of all the AF metrics working in the MGC space is their monotonic behavior even up to a magnification of 100×. An advantage of the MGC method is its computational simplicity and inherent parallelism. In the second application, a multifocus image fusion algorithm based on the MGC approach has been implemented on graphics processing units (GPUs). The resulting fused images are evaluated using a nonreference image quality metric. The proposed fusion method reveals a high-quality image independently of faulty illumination during the image acquisition. Finally, the three-dimensional visualization of the in-focus image is shown.

  11. Optimization of Simple Monetary Policy Rules on the Base of Estimated DSGE-model

    OpenAIRE

    Shulgin, A.

    2015-01-01

    Optimization of coefficients in monetary policy rules is performed on the base of the DSGE-model with two independent monetary policy instruments estimated on the Russian data. It was found that welfare maximizing policy rules lead to inadequate result and pro-cyclical monetary policy. Optimal coefficients in Taylor rule and exchange rate rule allow to decrease volatility estimated on Russian data of 2001-2012 by about 20%. The degree of exchange rate flexibility parameter was found to be low...

  12. Agile: a problem-based model of regulatory policy making

    NARCIS (Netherlands)

    Boer, A.; van Engers, T.

    2013-01-01

    We understand regulatory policy problems against the backdrop of existing implementations of a regulatory framework. There are argument schemes for proposing a policy and for criticising a proposal, rooted in a shared understanding that there is an existing regulatory framework which is implemented

  13. Functional reduced graphene oxide-based membranes with selective ion transport channels for zwitterionic ions separation based on the pH gradient.

    Science.gov (United States)

    Wu, Yu; Ji, Hongyun; Yang, Feng; Meng, Yan; Wang, Yujue; Dai, Jianyuan; Ren, Haisheng; Tan, Guangqun; Xiao, Dan

    2018-01-18

    In this work, we report a method for the fabrication of a functional free-standing graphene membrane (FFGM) with high mechanical strength, enlarged interlayer spacing and ion channels for zwitterionic ions separation. To obtain the FFGM, the anionic dye Eosin Y (EY) was introduced into a graphene oxide (GO) and hydroquinone (HQ) mixture to prepare functional graphene-based membranes on Cu foil using simply a drop-casting method. In comparison with a GO membrane, the molar flux and the mechanical strength of the FFGM were dramatically increased. The FFGM was then equipped on custom-built glass reservoirs for zwitterionic amino acids (AAs) separation based on the inner pH gradient, which was formed by controlling H + and OH - (in the feed and receiver solution) migration in rGO/GO sheets via an external electric field. With the help of the inner pH gradient and external electric field, AAs could change their charge behaviors. The ionized AAs transport through the FFGM and finally separation was realized.

  14. Bone marrow-derived cells for cardiovascular cell therapy: an optimized GMP method based on low-density gradient improves cell purity and function.

    Science.gov (United States)

    Radrizzani, Marina; Lo Cicero, Viviana; Soncin, Sabrina; Bolis, Sara; Sürder, Daniel; Torre, Tiziano; Siclari, Francesco; Moccetti, Tiziano; Vassalli, Giuseppe; Turchetto, Lucia

    2014-09-27

    Cardiovascular cell therapy represents a promising field, with several approaches currently being tested. The advanced therapy medicinal product (ATMP) for the ongoing METHOD clinical study ("Bone marrow derived cell therapy in the stable phase of chronic ischemic heart disease") consists of fresh mononuclear cells (MNC) isolated from autologous bone marrow (BM) through density gradient centrifugation on standard Ficoll-Paque. Cells are tested for safety (sterility, endotoxin), identity/potency (cell count, CD45/CD34/CD133, viability) and purity (contaminant granulocytes and platelets). BM-MNC were isolated by density gradient centrifugation on Ficoll-Paque. The following process parameters were optimized throughout the study: gradient medium density; gradient centrifugation speed and duration; washing conditions. A new manufacturing method was set up, based on gradient centrifugation on low density Ficoll-Paque, followed by 2 washing steps, of which the second one at low speed. It led to significantly higher removal of contaminant granulocytes and platelets, improving product purity; the frequencies of CD34+ cells, CD133+ cells and functional hematopoietic and mesenchymal precursors were significantly increased. The methodological optimization described here resulted in a significant improvement of ATMP quality, a crucial issue to clinical applications in cardiovascular cell therapy.

  15. Smart City Mobility Application—Gradient Boosting Trees for Mobility Prediction and Analysis Based on Crowdsourced Data

    Science.gov (United States)

    Semanjski, Ivana; Gautama, Sidharta

    2015-01-01

    Mobility management represents one of the most important parts of the smart city concept. The way we travel, at what time of the day, for what purposes and with what transportation modes, have a pertinent impact on the overall quality of life in cities. To manage this process, detailed and comprehensive information on individuals’ behaviour is needed as well as effective feedback/communication channels. In this article, we explore the applicability of crowdsourced data for this purpose. We apply a gradient boosting trees algorithm to model individuals’ mobility decision making processes (particularly concerning what transportation mode they are likely to use). To accomplish this we rely on data collected from three sources: a dedicated smartphone application, a geographic information systems-based web interface and weather forecast data collected over a period of six months. The applicability of the developed model is seen as a potential platform for personalized mobility management in smart cities and a communication tool between the city (to steer the users towards more sustainable behaviour by additionally weighting preferred suggestions) and users (who can give feedback on the acceptability of the provided suggestions, by accepting or rejecting them, providing an additional input to the learning process). PMID:26151209

  16. Smart City Mobility Application--Gradient Boosting Trees for Mobility Prediction and Analysis Based on Crowdsourced Data.

    Science.gov (United States)

    Semanjski, Ivana; Gautama, Sidharta

    2015-07-03

    Mobility management represents one of the most important parts of the smart city concept. The way we travel, at what time of the day, for what purposes and with what transportation modes, have a pertinent impact on the overall quality of life in cities. To manage this process, detailed and comprehensive information on individuals' behaviour is needed as well as effective feedback/communication channels. In this article, we explore the applicability of crowdsourced data for this purpose. We apply a gradient boosting trees algorithm to model individuals' mobility decision making processes (particularly concerning what transportation mode they are likely to use). To accomplish this we rely on data collected from three sources: a dedicated smartphone application, a geographic information systems-based web interface and weather forecast data collected over a period of six months. The applicability of the developed model is seen as a potential platform for personalized mobility management in smart cities and a communication tool between the city (to steer the users towards more sustainable behaviour by additionally weighting preferred suggestions) and users (who can give feedback on the acceptability of the provided suggestions, by accepting or rejecting them, providing an additional input to the learning process).

  17. Adaptive estimation of nonlinear parameters of a nonholonomic spherical robot using a modified fuzzy-based speed gradient algorithm

    Science.gov (United States)

    Roozegar, Mehdi; Mahjoob, Mohammad J.; Ayati, Moosa

    2017-05-01

    This paper deals with adaptive estimation of the unknown parameters and states of a pendulum-driven spherical robot (PDSR), which is a nonlinear in parameters (NLP) chaotic system with parametric uncertainties. Firstly, the mathematical model of the robot is deduced by applying the Newton-Euler methodology for a system of rigid bodies. Then, based on the speed gradient (SG) algorithm, the states and unknown parameters of the robot are estimated online for different step length gains and initial conditions. The estimated parameters are updated adaptively according to the error between estimated and true state values. Since the errors of the estimated states and parameters as well as the convergence rates depend significantly on the value of step length gain, this gain should be chosen optimally. Hence, a heuristic fuzzy logic controller is employed to adjust the gain adaptively. Simulation results indicate that the proposed approach is highly encouraging for identification of this NLP chaotic system even if the initial conditions change and the uncertainties increase; therefore, it is reliable to be implemented on a real robot.

  18. Smart City Mobility Application—Gradient Boosting Trees for Mobility Prediction and Analysis Based on Crowdsourced Data

    Directory of Open Access Journals (Sweden)

    Ivana Semanjski

    2015-07-01

    Full Text Available Mobility management represents one of the most important parts of the smart city concept. The way we travel, at what time of the day, for what purposes and with what transportation modes, have a pertinent impact on the overall quality of life in cities. To manage this process, detailed and comprehensive information on individuals’ behaviour is needed as well as effective feedback/communication channels. In this article, we explore the applicability of crowdsourced data for this purpose. We apply a gradient boosting trees algorithm to model individuals’ mobility decision making processes (particularly concerning what transportation mode they are likely to use. To accomplish this we rely on data collected from three sources: a dedicated smartphone application, a geographic information systems-based web interface and weather forecast data collected over a period of six months. The applicability of the developed model is seen as a potential platform for personalized mobility management in smart cities and a communication tool between the city (to steer the users towards more sustainable behaviour by additionally weighting preferred suggestions and users (who can give feedback on the acceptability of the provided suggestions, by accepting or rejecting them, providing an additional input to the learning process.

  19. BASES OF PUBLIC POLICY FORMATION DIRECTED AT ENSURING BUDGET SECURITY

    Directory of Open Access Journals (Sweden)

    S. Onishchenko

    2015-03-01

    Full Text Available In the article the priorities and public policies that can improve the safety level of the budget of Ukraine have been grounded. Attention on the problems of imbalance and deficiency trends accumulation of public debt has been focused. The detailed analysis of the budget deficit of the European community to further research the main problems of fiscal security has been carried out. The formation of the concept of budget policy should include long-term and medium-term priorities of the state priorities areas have been concluded. Budget policy on public debt must deal with interrelated issues of debt bondage and effective use of public credit, promote economic growth with respect safe level and structure of public debt have been emphasized by author. Debt policy as part of fiscal policy under certain conditions can be a powerful tool to intensify investment and innovation processes in society, promote economic and social development. The reorientation of fiscal policy to address current problems through debt and use it as the basis of investment and innovation development provides an effective public debt management is designed to reduce state budget expenditures on its servicing and repayment, optimizing the scope and structure of debt according to economic growth. The role of debt policy in modern terms increases is clearly subordinate to and consistent with long-term goals and priorities of fiscal policy. There is an urgent development and implementation of effective mechanisms for investing borrowed resources, increasing the efficiency of public investment, including the improvement of organizational, financial, legal and controls. Strategically budget security guarantees only competitive economy, which can be constructed only by recovery and accelerated development of promising sectors of the national economy in the presence of a balanced budget policy. Now there is a tendency to implement only measures to stabilize the political and socio

  20. Supporting Evidence-Based Policy on Biodiversity and Ecosystem Services: Recommendations for Effective Policy Briefs

    Science.gov (United States)

    Balian, Estelle V.; Drius, Liza; Eggermont, Hilde; Livoreil, Barbara; Vandewalle, Marie; Vandewoestjine, Sofie; Wittmer, Heidi; Young, Juliette

    2016-01-01

    Knowledge brokerage on biodiversity and ecosystem services can apply communication tools such as policy briefs to facilitate the dialogue between scientists and policymakers. There is currently considerable debate on how to go beyond the linear communication model, outdated in theoretical debate but still often implicitly leading interaction with…

  1. Three-dimension Cole-Cole model inversion of induced polarization data based on regularized conjugate gradient method

    Science.gov (United States)

    Xu, Zhengwei

    Modeling of induced polarization (IP) phenomena is important for developing effective methods for remote sensing of subsurface geology and is widely used in mineral exploration. However, the quantitative interpretation of IP data in a complex 3D environment is still a challenging problem of applied geophysics. In this dissertation I use the regularized conjugate gradient method to determine the 3D distribution of the four parameters of the Cole-Cole model based on surface induced polarization (IP) data. This method takes into account the nonlinear nature of both electromagnetic induction (EMI) and IP phenomena. The solution of the 3D IP inverse problem is based on the regularized smooth inversion only. The method was tested on synthetic models with DC conductivity, intrinsic chargeability, time constant, and relaxation parameters, and it was also applied to the practical 3D IP survey data. I demonstrate that the four parameters of the Cole-Cole model, DC electrical resistivity, rho 0 , chargeability, eta time constant, tau and the relaxation parameter, C, can be recovered from the observed IP data simultaneously. There are four Cole-Cole parameters involved in the inversion, in other words, within each cell, there are DC conductivity (sigma0 ), chargeability (eta), time parameters (tau), and relaxation parameters (C) compared to conductivity only, used in EM only inversion. In addition to more inversion parameters used in IP survey, dipole-dipole configuration which requires more sources and receivers. One the other hand, calculating Green tensor and Frechet matrix time consuming and storing them requires a lot of memory. So, I develop parallel computation using MATLAB parallel tool to speed up the calculation.

  2. Advancing team-based primary health care: a comparative analysis of policies in western Canada.

    Science.gov (United States)

    Suter, Esther; Mallinson, Sara; Misfeldt, Renee; Boakye, Omenaa; Nasmith, Louise; Wong, Sabrina T

    2017-07-17

    We analyzed and compared primary health care (PHC) policies in British Columbia, Alberta and Saskatchewan to understand how they inform the design and implementation of team-based primary health care service delivery. The goal was to develop policy imperatives that can advance team-based PHC in Canada. We conducted comparative case studies (n = 3). The policy analysis included: Context review: We reviewed relevant information (2007 to 2014) from databases and websites. Policy review and comparative analysis: We compared and contrasted publically available PHC policies. Key informant interviews: Key informants (n = 30) validated narratives prepared from the comparative analysis by offering contextual information on potential policy imperatives. Advisory group and roundtable: An expert advisory group guided this work and a key stakeholder roundtable event guided prioritization of policy imperatives. The concept of team-based PHC varies widely across and within the three provinces. We noted policy gaps related to team configuration, leadership, scope of practice, role clarity and financing of team-based care; few policies speak explicitly to monitoring and evaluation of team-based PHC. We prioritized four policy imperatives: (1) alignment of goals and policies at different system levels; (2) investment of resources for system change; (3) compensation models for all members of the team; and (4) accountability through collaborative practice metrics. Policies supporting team-based PHC have been slow to emerge, lacking a systematic and coordinated approach. Greater alignment with specific consideration of financing, reimbursement, implementation mechanisms and performance monitoring could accelerate systemic transformation by removing some well-known barriers to team-based care.

  3. Enacting Sustainable School-Based Health Initiatives: A Communication-Centered Approach to Policy and Practice

    Science.gov (United States)

    Canary, Heather E.

    2011-01-01

    Communication plays an important role in all aspects of the development and use of policy. We present a communication-centered perspective on the processes of enacting public health policies. Our proposed conceptual framework comprises 4 communication frames: orientation, amplification, implementation, and integration. Empirical examples from 2 longitudinal studies of school-based health policies show how each frame includes different communication processes that enable sustainable public health policy practices in school-based health initiatives. These 4 frames provide unique insight into the capacity of school-based public health policy to engage youths, parents, and a broader community of stakeholders. Communication is often included as an element of health policy; however, our framework demonstrates the importance of communication as a pivotal resource in sustaining changes in public health practices. PMID:21233442

  4. Support Mechanisms for Evidence-Based Policy-Making in Education. Eurydice Report

    Science.gov (United States)

    Riiheläinen, Jari Matti; Böhm, Franziska

    2017-01-01

    The report describes the mechanisms and practices that support evidence-based policy-making in the education sector in Europe. It comparatively looks at institutions and practices in evidence-based policy-making, as well as the accessibility, and mediation, of evidence. The report presents more detailed information on each individual country, with…

  5. Evidence-based policy? The use of mobile phones in hospital

    NARCIS (Netherlands)

    Ettelt, Stefanie; Nolte, Ellen; McKee, Martin; Haugen, Odd Arild; Karlberg, Ingvar; Klazinga, Niek; Ricciardi, Walter; Teperi, Juha

    2006-01-01

    BACKGROUND: Evidence-based policies have become increasingly accepted in clinical practice. However, policies on many of the non-clinical activities that take place in health care facilities may be less frequently evidence based. METHODS: We carried out a review of literature on safety of mobile

  6. Consulting, Mediating, Conducting, and Supporting: How Community-Based Organizations Engage with Research to Influence Policy

    Science.gov (United States)

    Winton, Sue; Evans, Michael P.

    2016-01-01

    Grounded in critical policy theories and democratic conceptions of research, case studies of three community-based organizations, one in Canada and two in the U.S., were analyzed to determine if and how the groups engaged with research in their efforts to influence education policy. The findings demonstrate that the community-based organizations…

  7. Base-stock policies for lost-sales models: Aggregation and asymptotics

    NARCIS (Netherlands)

    J.J. Arts (Joachim); R. Levi (Retsef); G.J.J.A.N. van Houtum (Geert-Jan); A.P. Zwart (Bert)

    2015-01-01

    textabstractThis paper considers the optimization of the base-stock level for the classical periodic review lost-sales inventory system. The optimal policy for this system is not fully understood and computationally expensive to obtain. Base-stock policies for this system are asymptotically

  8. Design and fabrication of integrated micro/macrostructure for 3D functional gradient systems based on additive manufacturing

    Science.gov (United States)

    Yin, Ming; Xie, Luofeng; Jiang, Weifeng; Yin, Guofu

    2018-05-01

    Functional gradient systems have important applications in many areas. Although a 2D dielectric structure that serves as the gradient index medium for controlling electromagnetic waves is well established, it may not be suitable for application in 3D case. In this paper, we present a method to realize functional gradient systems with 3D integrated micro/macrostructure. The homogenization of the structure is studied in detail by conducting band diagram analysis. The analysis shows that the effective medium approximation is valid even when periodicity is comparable to wavelength. The condition to ensure the polarization-invariant, isotropic, and frequency-independent property is investigated. The scheme for the design and fabrication of 3D systems requiring spatial material property distribution is presented. By using the vat photopolymerization process, a large overall size of macrostructure at the system level and precise fine features of microstructure at the unit cell level are realized, thus demonstrating considerable scalability of the system for wave manipulation.

  9. On the Implications of Knowledge Bases for Regional Innovation Policies in Germany

    Directory of Open Access Journals (Sweden)

    Hassink Robert

    2014-12-01

    Full Text Available Regional innovation policies have been criticised for being too standardised, one-size-fits-all and place-neutral in character. Embedded in these debates, this paper has two aims: first, to analyse whether industries with different knowledge bases in regions in Germany have different needs for regional innovation policies, and secondly, to investigate whether knowledge bases can contribute to the fine-tuning of regional innovation policies in particular and to a modern, tailor-made, place-based regional innovation policy in general. It concludes that although needs differ due to differences in knowledge bases, those bases are useful only to a limited extent in fine-tuning regional innovation policies

  10. Strengthening Science-based Environmental Policy Development in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Given this new and rapidly evolving situation, IDRC is providing funding to Simon Fraser University to support a network of young Burmese environmentalists to complete research that contributes to development policy and environmental practice in the ... IDRC and DHSC partner to fight antimicrobial resistance in animals.

  11. A Semantic Based Policy Management Framework for Cloud Computing Environments

    Science.gov (United States)

    Takabi, Hassan

    2013-01-01

    Cloud computing paradigm has gained tremendous momentum and generated intensive interest. Although security issues are delaying its fast adoption, cloud computing is an unstoppable force and we need to provide security mechanisms to ensure its secure adoption. In this dissertation, we mainly focus on issues related to policy management and access…

  12. The power and pain of market-based carbon policies

    NARCIS (Netherlands)

    Henderson, B.; Golub, A.; Pambudi, D.; Hertel, T.; Godde, C.; Herrero, M.; Cacho, O.; Gerber, P.

    2018-01-01

    The objectives of this research are to assess the greenhouse gas mitigation potential of carbon policies applied to the ruminant livestock sector [inclusive of the major ruminant species—cattle (Bos Taurus and Bos indicus), sheep (Ovis aries), and goats (Capra hircus)]—with particular emphasis on

  13. Strengthening Evidence-based Policy Research and Advocacy for ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    The Alliance for a Green Revolution in Africa (AGRA) has launched a vast program for increasing agricultural productivity and improving food security in Africa. To have a sustainable impact on food and nutritional security, however, agricultural technologies must be accompanied by appropriate and equitable policies.

  14. Tomographic reconstruction of the refractive index with hard X-rays: an efficient method based on the gradient vector-field approach.

    Science.gov (United States)

    Gasilov, Sergei; Mittone, Alberto; Brun, Emmanuel; Bravin, Alberto; Grandl, Susanne; Mirone, Alessandro; Coan, Paola

    2014-03-10

    The refractive-index gradient vector field approach establishes a connection between a tomographic data set of differential phase contrast images and the distribution of the partial spatial derivatives of the refractive index in an object. The reconstruction of the refractive index in a plane requires the integration of its gradient field. This work shows how this integration can be efficiently performed by converting the problem to the Poisson equation, which can be accurately solved even in the case of noisy and large datasets. The performance of the suggested method is discussed and demonstrated experimentally by computing the refractive index distribution in both a simple plastic phantom and a complex biological sample. The quality of the reconstruction is evaluated through the direct comparison with other commonly used methods. To this end, the refractive index is retrieved from the same data set using also (1) the filtered backprojection algorithm for gradient projections, and (2) the regularized phase-retrieval procedure. Results show that the gradient vector field approach combined with the developed integration technique provides a very accurate depiction of the sample internal structure. Contrary to the two other techniques, the considered method does not require a preliminary phase-retrieval and can be implemented with any advanced computer tomography algorithm. In this work, analyzer-based phase contrast images are used for demonstration. Results, however, are generally valid and can be applied for processing differential phase-contrast tomographic data sets obtained with other phase-contrast imaging techniques.

  15. Monitoring of the spatio-temporal change in the interplate coupling at northeastern Japan subduction zone based on the spatial gradients of surface velocity field

    Science.gov (United States)

    Iinuma, Takeshi

    2018-04-01

    A monitoring method to grasp the spatio-temporal change in the interplate coupling in a subduction zone based on the spatial gradients of surface displacement rate fields is proposed. I estimated the spatio-temporal change in the interplate coupling along the plate boundary in northeastern (NE) Japan by applying the proposed method to the surface displacement rates based on global positioning system observations. The gradient of the surface velocities is calculated in each swath configured along the direction normal to the Japan Trench for time windows such as 0.5, 1, 2, 3 and 5 yr being shifted by one week during the period of 1997-2016. The gradient of the horizontal velocities is negative and has a large magnitude when the interplate coupling at the shallow part (less than approximately 50 km in depth) beneath the profile is strong, and the sign of the gradient of the vertical velocity is sensitive to the existence of the coupling at the deep part (greater than approximately 50 km in depth). The trench-parallel variation of the spatial gradients of a displacement rate field clearly corresponds to the trench-parallel variation of the amplitude of the interplate coupling on the plate interface, as well as the rupture areas of previous interplate earthquakes. Temporal changes in the trench-parallel variation of the spatial gradient of the displacement rate correspond to the strengthening or weakening of the interplate coupling. We can monitor the temporal change in the interplate coupling state by calculating the spatial gradients of the surface displacement rate field to some extent without performing inversion analyses with applying certain constraint conditions that sometimes cause over- and/or underestimation at areas of limited spatial resolution far from the observation network. The results of the calculation confirm known interplate events in the NE Japan subduction zone, such as the post-seismic slip of the 2003 M8.0 Tokachi-oki and 2005 M7.2 Miyagi

  16. Bryophyte and vascular plant responses to base-richness and water level gradients in Western Carpathian Sphagnum-rich mires

    Czech Academy of Sciences Publication Activity Database

    Hájková, Petra; Hájek, Michal

    2004-01-01

    Roč. 39, č. 4 (2004), s. 335-351 ISSN 1211-9520 R&D Projects: GA ČR(CZ) GA206/02/0568 Institutional research plan: CEZ:AV0Z6005908 Keywords : fen * poor-rich gradient * water table Subject RIV: EF - Botanics Impact factor: 0.968, year: 2004

  17. On computing quadrature-based bounds for the A-norm of the error in conjugate gradients

    Czech Academy of Sciences Publication Activity Database

    Meurant, G.; Tichý, Petr

    2013-01-01

    Roč. 62, č. 2 (2013), s. 163-191 ISSN 1017-1398 R&D Projects: GA AV ČR IAA100300802 Institutional research plan: CEZ:AV0Z10300504 Keywords : conjugate gradients * norm of the error * bounds for the error norm Subject RIV: BA - General Mathematics Impact factor: 1.005, year: 2013

  18. A Model-Based Exploration and Policy Analysis Related to Prostitution and Human Trafficking

    OpenAIRE

    András Kővári; Erik Pruyt

    2014-01-01

    This paper presents a model-based exploration and policy analysis related to prostitution and prostitution-related human trafficking. After a brief introduction to prostitution and prostitution-related human trafficking, the paper zooms in on the Dutch situation. A System Dynamics simulation model related to the Dutch situation developed to explore and provide policy insights is subsequently presented. Using the simulation model, policies are first of all tested, and preliminary conclusions a...

  19. A social relational approach to community-based ecotourism development: Policy intervention strategies

    OpenAIRE

    Rith, Sam Ol

    2010-01-01

    This study examines how policy intervention strategies facilitate or constrain the construction of positive social capital in a community-based ecotourism (CBET) context. It investigates CBET development policies in a specific Cambodian case study, explores implementation processes, assesses the level of social capital created, identifies the connections between social capital construction and development outcomes, and suggests how the policies contribute to social capital construction. The ...

  20. An Agenda for a Reformed Cohesion Policy A place-based approach to meeting European Union challenges and expectations

    OpenAIRE

    Fabrizio Barca

    2008-01-01

    EU regional policy is an investment policy. It supports job creation, competitiveness, economic growth, improved quality of life and sustainable development. These investments support the delivery of the Europe 2020 strategy. The present paper analysis two strategically different options of EU regional policy: place-neutral versus place-based policies for economic development. Our results suggest that in many EU regions the place-neutral policies may no be the best policy response to facing n...

  1. Knickzone Extraction Tool (KET) - A new ArcGIS toolset for automatic extraction of knickzones from a DEM based on multi-scale stream gradients

    Science.gov (United States)

    Zahra, Tuba; Paudel, Uttam; Hayakawa, Yuichi S.; Oguchi, Takashi

    2017-04-01

    Extraction of knickpoints or knickzones from a Digital Elevation Model (DEM) has gained immense significance owing to the increasing implications of knickzones on landform development. However, existing methods for knickzone extraction tend to be subjective or require time-intensive data processing. This paper describes the proposed Knickzone Extraction Tool (KET), a new raster-based Python script deployed in the form of an ArcGIS toolset that automates the process of knickzone extraction and is both fast and more user-friendly. The KET is based on multi-scale analysis of slope gradients along a river course, where any locally steep segment (knickzone) can be extracted as an anomalously high local gradient. We also conducted a comparative analysis of the KET and other contemporary knickzone identification techniques. The relationship between knickzone distribution and its morphometric characteristics are also examined through a case study of a mountainous watershed in Japan.

  2. Validation for 2D/3D registration. II: The comparison of intensity- and gradient-based merit functions using a new gold standard data set.

    Science.gov (United States)

    Gendrin, Christelle; Markelj, Primoz; Pawiro, Supriyanto Ardjo; Spoerk, Jakob; Bloch, Christoph; Weber, Christoph; Figl, Michael; Bergmann, Helmar; Birkfellner, Wolfgang; Likar, Bostjan; Pernus, Franjo

    2011-03-01

    A new gold standard data set for validation of 2D/3D registration based on a porcine cadaver head with attached fiducial markers was presented in the first part of this article. The advantage of this new phantom is the large amount of soft tissue, which simulates realistic conditions for registration. This article tests the performance of intensity- and gradient-based algorithms for 2D/3D registration using the new phantom data set. Intensity-based methods with four merit functions, namely, cross correlation, rank correlation, correlation ratio, and mutual information (MI), and two gradient-based algorithms, the backprojection gradient-based (BGB) registration method and the reconstruction gradient-based (RGB) registration method, were compared. Four volumes consisting of CBCT with two fields of view, 64 slice multidetector CT, and magnetic resonance-T1 weighted images were registered to a pair of kV x-ray images and a pair of MV images. A standardized evaluation methodology was employed. Targets were evenly spread over the volumes and 250 starting positions of the 3D volumes with initial displacements of up to 25 mm from the gold standard position were calculated. After the registration, the displacement from the gold standard was retrieved and the root mean square (RMS), mean, and standard deviation mean target registration errors (mTREs) over 250 registrations were derived. Additionally, the following merit properties were computed: Accuracy, capture range, number of minima, risk of nonconvergence, and distinctiveness of optimum for better comparison of the robustness of each merit. Among the merit functions used for the intensity-based method, MI reached the best accuracy with an RMS mTRE down to 1.30 mm. Furthermore, it was the only merit function that could accurately register the CT to the kV x rays with the presence of tissue deformation. As for the gradient-based methods, BGB and RGB methods achieved subvoxel accuracy (RMS mTRE down to 0.56 and 0.70 mm

  3. Proper orthogonal decomposition-based estimations of the flow field from particle image velocimetry wall-gradient measurements in the backward-facing step flow

    International Nuclear Information System (INIS)

    Nguyen, Thien Duy; Wells, John Craig; Mokhasi, Paritosh; Rempfer, Dietmar

    2010-01-01

    In this paper, particle image velocimetry (PIV) results from the recirculation zone of a backward-facing step flow, of which the Reynolds number is 2800 based on bulk velocity upstream of the step and step height (h = 16.5 mm), are used to demonstrate the capability of proper orthogonal decomposition (POD)-based measurement models. Three-component PIV velocity fields are decomposed by POD into a set of spatial basis functions and a set of temporal coefficients. The measurement models are built to relate the low-order POD coefficients, determined from an ensemble of 1050 PIV fields by the 'snapshot' method, to the time-resolved wall gradients, measured by a near-wall measurement technique called stereo interfacial PIV. These models are evaluated in terms of reconstruction and prediction of the low-order temporal POD coefficients of the velocity fields. In order to determine the estimation coefficients of the measurement models, linear stochastic estimation (LSE), quadratic stochastic estimation (QSE), principal component regression (PCR) and kernel ridge regression (KRR) are applied. We denote such approaches as LSE-POD, QSE-POD, PCR-POD and KRR-POD. In addition to comparing the accuracy of measurement models, we introduce multi-time POD-based estimations in which past and future information of the wall-gradient events is used separately or combined. The results show that the multi-time estimation approaches can improve the prediction process. Among these approaches, the proposed multi-time KRR-POD estimation with an optimized window of past wall-gradient information yields the best prediction. Such a multi-time KRR-POD approach offers a useful tool for real-time flow estimation of the velocity field based on wall-gradient data

  4. Towards Proactive Policies supporting Event-based Task Delegation

    OpenAIRE

    Gaaloul, Khaled; Miseldine, Philip; Charoy, François

    2009-01-01

    International audience; Delegation mechanisms are receiving increasing interest from the research community. Task delegation is a mechanism that supports organisational flexibility in the human-centric workflow systems, and ensures delegation of authority in access control systems. In this paper, we consider task delegation as an advanced security mechanism supporting policy decision. We define an approach to support dynamic delegation of authority within an access control framework. The nove...

  5. Do PISA data justify PISA-based education policy?

    OpenAIRE

    DE SOUSA LOBO BORGES DE ARAUJO LUISA; SALTELLI ANDREA; SCHNEPF SYLKE

    2015-01-01

    Purpose – Since the publication of its first results in 2000, the Programme for International Student Assessment (PISA) implemented by the OECD has repeatedly been the subject of heated debate. In late 2014 controversy flared up anew, with the most severe critics going so far as to call for a halt to the programme. The purpose of this paper is to discuss the methodological design of PISA and the ideological basis of scientific and policy arguments invoked for and against it. De...

  6. A Rights-Based Approach to Internet Policy and Governance for the ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    A Rights-Based Approach to Internet Policy and Governance for the Advancement of Economic, Social, and Cultural Rights. The debate on Internet freedom has intensified over the last few years as governments and civil society organizations explore policies to safeguard online civil liberties and online security. Civil society ...

  7. Policy based traffic light control – Balancing weights of user groups

    NARCIS (Netherlands)

    Vreeswijk, Jacob Dirk; Wismans, Luc Johannes Josephus; Tutert, Bas

    2013-01-01

    On the basis of policy-based target groups, we developed a prioritization strategy for traffic streams and applied it with the adaptive urban traffic control (UTC) ImFlow. Our main aim was to gain understanding of the possibilities of a policy driven prioritization in an urban context. We conclude

  8. Data-Based Decision Making at the Policy, Research, and Practice Levels

    NARCIS (Netherlands)

    Schildkamp, Kim; Ebbeler, J.

    2015-01-01

    Data-based decision making (DBDM) can lead to school improvement. However, schools struggle with the implementation of DBDM. In this symposium, we will discuss research and the implementation of DBDM at the national and regional policy level and the classroom level. We will discuss policy issues

  9. Towards a Demand-Driven Agenda for Place-Based Policies in the EU

    DEFF Research Database (Denmark)

    Jensen, Camilla

    This policy study is the second report on the policy implications of the EU funded project Policy Incentives for the Creation of Knowledge – Methods and Evidence (PICK-ME). All contributions in the project related with place-based policy and cluster building are summarized and reviewed (Work......-term viability through the emergence of new and related industries over time. Labor market policies are an important area of research with respect to the study of innovation in clusters and how to create incentives for clusters that combine related types of knowledge. The policy review also showed...... and creating institutions to achieve coordination mechanisms that use principles of market forces and lead firms towards creating the same ends....

  10. A clear urban-rural gradient of allergic rhinitis in a population-based study in Northern Europe

    DEFF Research Database (Denmark)

    Christensen, Stine Holmegaard; Timm, Signe; Janson, Christer

    2016-01-01

    categories of place of upbringing were defined: farm with livestock, farm without livestock, village in rural area, small town, city suburb, and inner city. Pets in the home at birth and during childhood were recorded. Data were analysed using adjusted logistic regression models. RESULTS: Livestock farm...... upbringing predicted less adult allergic rhinitis [odds ratio (OR) 0.68, 0.54-0.85] and nasal symptoms (OR 0.82, 0.68-0.99) than city upbringing, and an urban-rural gradient with decreasing risk per level of urbanisation was observed (OR 0.92, 0.88-0.94). Pets in the home at birth (OR 0.78, 0...... upbringing. Pets at birth decreased the risk further, but did not explain the urban-rural gradient. Persistent beneficial effects of microbial diversity in early life might be an explanation for the findings....

  11. A new macroscopically anisotropic pressure dependent yield function for metal matrix composite based on strain gradient plasticity for the microstructure

    DEFF Research Database (Denmark)

    Azizi, Reza; Legarth, Brian Nyvang; Niordson, Christian Frithiof

    2013-01-01

    in addition to the elastic strain. Hill's classical anisotropic yield criterion is extended to cover the composite such that hydrostatic pressure dependency, Bauschinger stress and size-effects are considered. It is found that depending on the fiber volume fraction, the anisotropic yield surface......Metal matrix composites with long aligned elastic fibers are studied using an energetic rate independent strain gradient plasticity theory with an isotropic pressure independent yield function at the microscale. The material response is homogenized to obtain a conventional macroscopic model...... that exhibits anisotropic yield properties with a pressure dependence. At the microscale free energy includes both elastic strains and plastic strain gradients, and the theory demands higher order boundary conditions in terms of plastic strain or work conjugate higher order tractions. The mechanical response...

  12. Geothermal Resource/Reservoir Investigations Based on Heat Flow and Thermal Gradient Data for the United States

    Energy Technology Data Exchange (ETDEWEB)

    D. D. Blackwell; K. W. Wisian; M. C. Richards; J. L. Steele

    2000-04-01

    Several activities related to geothermal resources in the western United States are described in this report. A database of geothermal site-specific thermal gradient and heat flow results from individual exploration wells in the western US has been assembled. Extensive temperature gradient and heat flow exploration data from the active exploration of the 1970's and 1980's were collected, compiled, and synthesized, emphasizing previously unavailable company data. Examples of the use and applications of the database are described. The database and results are available on the world wide web. In this report numerical models are used to establish basic qualitative relationships between structure, heat input, and permeability distribution, and the resulting geothermal system. A series of steady state, two-dimensional numerical models evaluate the effect of permeability and structural variations on an idealized, generic Basin and Range geothermal system and the results are described.

  13. Research-Based Knowledge: Researchers' Contribution to Evidence-Based Practice and Policy Making in Career Guidance

    Science.gov (United States)

    Haug, Erik Hagaseth; Plant, Peter

    2016-01-01

    To present evidence for the outcomes of career guidance is increasingly seen as pivotal for a further professionalization of policy making and service provision. This paper puts an emphasis on researchers' contribution to evidence-based practice and policy making in career guidance. We argue for a broader and more pluralistic research strategy to…

  14. A controlled community-based trial to promote smoke-free policy in rural communities.

    Science.gov (United States)

    Hahn, Ellen J; Rayens, Mary Kay; Adkins, Sarah; Begley, Kathy; York, Nancy

    2015-01-01

    Rural, tobacco-growing areas are disproportionately affected by tobacco use, secondhand smoke, and weak tobacco control policies. The purpose was to test the effects of a stage-specific, tailored policy-focused intervention on readiness for smoke-free policy, and policy outcomes in rural underserved communities. A controlled community-based trial including 37 rural counties. Data were collected annually with community advocates (n = 330) and elected officials (n = 158) in 19 intervention counties and 18 comparison counties over 5 years (average response rate = 68%). Intervention communities received policy development strategies from community advisors tailored to their stage of readiness and designed to build capacity, build demand, and translate and disseminate science. Policy outcomes were tracked over 5 years. Communities receiving the stage-specific, tailored intervention had higher overall community readiness scores and better policy outcomes than the comparison counties, controlling for county-level smoking rate, population size, and education. Nearly one-third of the intervention counties adopted smoke-free laws covering restaurants, bars, and all workplaces compared to none of the comparison counties. The stage-specific, tailored policy-focused intervention acted as a value-added resource to local smoke-free campaigns by promoting readiness for policy, as well as actual policy change in rural communities. Although actual policy change and percent covered by the policies were modest, these areas need additional resources and efforts to build capacity, build demand, and translate and disseminate science in order to accelerate smoke-free policy change and reduce the enormous toll from tobacco in these high-risk communities. © 2014 National Rural Health Association.

  15. Eocene high-latitude temperature gradients over time and space based on d18O values of fossil shark teeth

    Science.gov (United States)

    Zeichner, S. S.; Kim, S.; Colman, A. S.

    2015-12-01

    Early-Mid Eocene (56.0-33.9Mya) is characterized by a temperate Antarctic climate and shallower latitudinal temperature gradients than those in present day. The warmer waters off the coast of the Antarctic Peninsula provided suitable habitats for taxa (i.e., sharks) that live today at lower latitudes. Stable isotope analysis of Eocene shark teeth provides a proxy to understand high latitude temperature gradients. However, shark ecology, in particular migration and occupation of tidal versus pelagic habitats, must be considered in the interpretation of stable isotope data. In this study, we analyze d18OPO4 values from the enameloid of Striatolamia (synonymized with Carcharias) shark teeth from the La Meseta formation (Seymour Island, Antarctica) to estimate paleotemperature in Early-Mid Eocene Antarctica, and assess the impact of ecology versus environmental signals on d18OPO4 values. We compare the ranges and offsets between our measured shark tooth d18OPO4 and published bivalve d18OCO3 values to test whether shark teeth record signals of migration across latitudinal temperature gradients, or instead reflect seasonal and long-term temporal variation across La Meseta stratigraphic units.

  16. Science-based regulatory and policy considerations in nutrition.

    Science.gov (United States)

    Schneeman, Barbara

    2015-05-01

    Scientific evidence is necessary for the development of effective and enforceable regulations and government policy. To use scientific information appropriately, a systematic approach is needed for review and evaluation of the evidence. Federal agencies in the United States have developed useful approaches for such a review and evaluation to develop nutrition labeling, including health claims, and for updating of the Dietary Guidelines for Americans. The WHO is using a systematic evaluation process to update its recommendations on diet and health. The results of such reviews also highlight research needs to address relevant gaps in our knowledge. © 2015 American Society for Nutrition.

  17. Priority Queue Based Reactive Buffer Management Policy for Delay Tolerant Network under City Based Environments

    Science.gov (United States)

    Ngadi, Asri; Rashid, Sulma; Habib, Hafiz Adnan

    2018-01-01

    Delay Tolerant Network (DTN) multi-copy routing protocols are privileged to create and transmit multiple copies of each message that causes congestion and some messages are dropped. This process is known as reactive drop because messages were dropped re-actively to overcome buffer overflows. The existing reactive buffer management policies apply a single metric to drop source, relay and destine messages. Hereby, selection to drop a message is dubious because each message as source, relay or destine may have consumed dissimilar magnitude of network resources. Similarly, DTN has included time to live (ttl) parameter which defines lifetime of message. Hence, when ttl expires then message is automatically destroyed from relay nodes. However, time-to-live (ttl) is not applicable on messages reached at their destinations. Moreover, nodes keep replicating messages till ttl expires even-though large number of messages has already been dispersed. In this paper, we have proposed Priority Queue Based Reactive Buffer Management Policy (PQB-R) for DTN under City Based Environments. The PQB-R classifies buffered messages into source, relay and destine queues. Moreover, separate drop metric has been applied on individual queue. The experiment results prove that proposed PQB-R has reduced number of messages transmissions, message drop and increases delivery ratio. PMID:29438438

  18. Priority Queue Based Reactive Buffer Management Policy for Delay Tolerant Network under City Based Environments.

    Directory of Open Access Journals (Sweden)

    Qaisar Ayub

    Full Text Available Delay Tolerant Network (DTN multi-copy routing protocols are privileged to create and transmit multiple copies of each message that causes congestion and some messages are dropped. This process is known as reactive drop because messages were dropped re-actively to overcome buffer overflows. The existing reactive buffer management policies apply a single metric to drop source, relay and destine messages. Hereby, selection to drop a message is dubious because each message as source, relay or destine may have consumed dissimilar magnitude of network resources. Similarly, DTN has included time to live (ttl parameter which defines lifetime of message. Hence, when ttl expires then message is automatically destroyed from relay nodes. However, time-to-live (ttl is not applicable on messages reached at their destinations. Moreover, nodes keep replicating messages till ttl expires even-though large number of messages has already been dispersed. In this paper, we have proposed Priority Queue Based Reactive Buffer Management Policy (PQB-R for DTN under City Based Environments. The PQB-R classifies buffered messages into source, relay and destine queues. Moreover, separate drop metric has been applied on individual queue. The experiment results prove that proposed PQB-R has reduced number of messages transmissions, message drop and increases delivery ratio.

  19. Tobacco plain packaging: Evidence based policy or public health advocacy?

    Science.gov (United States)

    McKeganey, Neil; Russell, Christopher

    2015-06-01

    In December 2012, Australia became the first country to require all tobacco products be sold solely in standardised or 'plain' packaging, bereft of the manufacturers' trademarked branding and colours, although retaining large graphic and text health warnings. Following the publication of Sir Cyril Chantler's review of the evidence on the effects of plain tobacco packaging, the Ministers of the United Kingdom Parliament voted in March 2015 to implement similar legislation. Support for plain packaging derives from the belief that tobacco products sold in plain packs have reduced appeal and so are more likely to deter young people and non-smokers from starting tobacco use, and more likely to motivate smokers to quit and stay quit. This article considers why support for the plain packaging policy has grown among tobacco control researchers, public health advocates and government ministers, and reviews Australian survey data that speak to the possible introductory effect of plain packaging on smoking prevalence within Australia. The article concludes by emphasising the need for more detailed research to be undertaken before judging the capacity of the plain packaging policy to deliver the multitude of positive effects that have been claimed by its most ardent supporters. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Dog ownership has unknown risks but known health benefits: we need evidence based policy

    OpenAIRE

    Orritt, Rachel

    2014-01-01

    Politically driven UK legislation that targets “dangerous dogs” has not been shown to reduce dog bites, writes Rachel Orritt, who calls for policy to be based on robust evidence of incidence and risk assessment of ownership

  1. Stochastic Gradient Monomial Gamma Sampler

    OpenAIRE

    Zhang, Yizhe; Chen, Changyou; Gan, Zhe; Henao, Ricardo; Carin, Lawrence

    2017-01-01

    Recent advances in stochastic gradient techniques have made it possible to estimate posterior distributions from large datasets via Markov Chain Monte Carlo (MCMC). However, when the target posterior is multimodal, mixing performance is often poor. This results in inadequate exploration of the posterior distribution. A framework is proposed to improve the sampling efficiency of stochastic gradient MCMC, based on Hamiltonian Monte Carlo. A generalized kinetic function is leveraged, delivering ...

  2. Study on Logistics Industry Development Policy of Beijing Based on System Dynamic

    Directory of Open Access Journals (Sweden)

    Shuihai Dou

    2014-05-01

    Full Text Available Purpose: This paper is committed to design a logistics industry development policy model based on system dynamic to simulate the policy measures which promote region economic and logistics efficiency. The interaction between logistic industry development policy and economy needs to be investigated and the influence degree of logistic efficiency affected by industry policy needs to be identified too. Design/methodology/approach: In order to achieve the objective, it makes a system analysis from industry perspective to divide system into economic growth subsystem, logistics demand subsystem and logistics supply subsystem. Then the hypothesis and the boundaries are defined, and the causal diagram and system flow diagrams are drawn. The paper designs parameters and structural equation by the sample of Beijing using the econometrics model and takes model validation. Taking Beijing as an example, logistics industry development policy is simulated from the aspect of technological progress, increasing fixed assets investment, adjusting the industrial structure proportion and comprehensive policy by changing the parameters using Vensim-PLE. Findings?After logistics development policy is highly simulated by system dynamic model of logistics industry development policy, it is found that the policies of technological progress, fixed assets investment increasing, the industrial structure proportion adjustment and the comprehensive policy have different function to affect GDP, logistics demand, supply capacity and actual logistics costs. Originality/value: Compared with the previous research, this paper analyzes the interactive mechanism between logistics industry policy and region economy from a system perspective and establishes system dynamics model of logistics industry development policy to make up for the limitation of previous research.

  3. School-based obesity policy, social capital, and gender differences in weight control behaviors.

    Science.gov (United States)

    Zhu, Ling; Thomas, Breanca

    2013-06-01

    We examined the associations among school-based obesity policies, social capital, and adolescents' self-reported weight control behaviors, focusing on how the collective roles of community and adopted policies affect gender groups differently. We estimated state-level ecologic models using 1-way random effects seemingly unrelated regressions derived from panel data for 43 states from 1991 to 2009, which we obtained from the Centers for Disease Control and Prevention's Youth Risk Behavior Surveillance System. We used multiplicative interaction terms to assess how social capital moderates the effects of school-based obesity policies. School-based obesity policies in active communities were mixed in improving weight control behaviors. They increased both healthy and unhealthy weight control behaviors among boys but did not increase healthy weight control behaviors among girls. Social capital is an important contextual factor that conditions policy effectiveness in large contexts. Heterogeneous behavioral responses are associated with both school-based obesity policies and social capital. Building social capital and developing policy programs to balance outcomes for both gender groups may be challenging in managing childhood obesity.

  4. Realizing IoT service's policy privacy over publish/subscribe-based middleware.

    Science.gov (United States)

    Duan, Li; Zhang, Yang; Chen, Shiping; Wang, Shiyao; Cheng, Bo; Chen, Junliang

    2016-01-01

    The publish/subscribe paradigm makes IoT service collaborations more scalable and flexible, due to the space, time and control decoupling of event producers and consumers. Thus, the paradigm can be used to establish large-scale IoT service communication infrastructures such as Supervisory Control and Data Acquisition systems. However, preserving IoT service's policy privacy is difficult in this paradigm, because a classical publisher has little control of its own event after being published; and a subscriber has to accept all the events from the subscribed event type with no choice. Few existing publish/subscribe middleware have built-in mechanisms to address the above issues. In this paper, we present a novel access control framework, which is capable of preserving IoT service's policy privacy. In particular, we adopt the publish/subscribe paradigm as the IoT service communication infrastructure to facilitate the protection of IoT services policy privacy. The key idea in our policy-privacy solution is using a two-layer cooperating method to match bi-directional privacy control requirements: (a) data layer for protecting IoT events; and (b) application layer for preserving the privacy of service policy. Furthermore, the anonymous-set-based principle is adopted to realize the functionalities of the framework, including policy embedding and policy encoding as well as policy matching. Our security analysis shows that the policy privacy framework is Chosen-Plaintext Attack secure. We extend the open source Apache ActiveMQ broker by building into a policy-based authorization mechanism to enforce the privacy policy. The performance evaluation results indicate that our approach is scalable with reasonable overheads.

  5. Moving an Evidence-Based Policy Agenda Forward: Leadership Tips From the Field.

    Science.gov (United States)

    Garrett, Teresa

    2018-05-01

    Advancing evidence-based policy change is a leadership challenge that nurses should embrace. Key tips to ensure that evidence-based policy changes are successful at the individual, community, and population levels are offered to help nurses through the change process. The public trust in the nursing profession is a leverage point that should be used to advance the use of evidence, expedite change, and improve health for students and across communities.

  6. The Purification Method Using Iodixanol (Optiprep)-Based Density Gradient Significantly Reduces Cytokine/Chemokine Production from Human Islet Preparations, Leading to Prolong β-Cell Survival During Culture

    Science.gov (United States)

    Mita, Atsuyoshi; Ricordi, Camillo; Miki, Atsushi; Barker, Scott; Khan, Aisha; Alvarez, Alejandro; Hashikura, Yasuhiko; Miyagawa, Shin-ichi; Ichii, Hirohito

    2009-01-01

    Improved islet isolation has still been important to obtain adequate islet numbers for islet transplantation. Although Ficol-based density gradient is widely used for purification in most islet processing centers, OptiPrep-based density gradient is recently used in the limited centers and their clinical outcomes are excellent. Cytokine/chemokine production from islet preparations for transplantation widely varies. Some cytokines/chemokines have been reported to cause apoptosis in human islet preparations after isolation. Reducing cytokine/chemokine production is a key to improve islet numbers after isolation and islet transplantation outcome. The aim of current study is to investigate the variability of pro-inflammatory cytokine/chemokine production from islet preparations purified by different density gradient. After digestion of human pancreata, pre-purification digests were devided into two groups and purified using semi-automated cell processor with Ficoll-based and OptiPrep-based density gradient. Islet preparations were cultured for 2 days and assessed regarding islet cell viability (FDA/PI), fractional β-cell viability and β-cell content. Cytokine/chemokine production from islet preparations was also examined. After purification, purity, post-purification IEQ and islet recovery rate were comparable between two groups. Although FDA/PI and fractional β-cell viability showed no significant differences, β-cell survival during culture significantly increased in OptiPrep-based density gradient group when compared to Ficoll-based density gradient group. TNF-α, IL-1β, IFN-γ, IL-6 and MIP-1β production from OptiPrep-based density gradient group significantly decreased. OptiPrep-based density gradient can reduce cytokine-production when compared to Ficoll-based density gradient, resulting in improvement of quantity of β-cell mass. Cytokine profiling could spot new light on assessment of islet preparations before transplantation. PMID:19249543

  7. Temporal and spatial evaluation of satellite-based rainfall estimates across the complex topographical and climatic gradients of Chile

    Science.gov (United States)

    Zambrano-Bigiarini, Mauricio; Nauditt, Alexandra; Birkel, Christian; Verbist, Koen; Ribbe, Lars

    2017-03-01

    Accurate representation of the real spatio-temporal variability of catchment rainfall inputs is currently severely limited. Moreover, spatially interpolated catchment precipitation is subject to large uncertainties, particularly in developing countries and regions which are difficult to access. Recently, satellite-based rainfall estimates (SREs) provide an unprecedented opportunity for a wide range of hydrological applications, from water resources modelling to monitoring of extreme events such as droughts and floods.This study attempts to exhaustively evaluate - for the first time - the suitability of seven state-of-the-art SRE products (TMPA 3B42v7, CHIRPSv2, CMORPH, PERSIANN-CDR, PERSIAN-CCS-Adj, MSWEPv1.1, and PGFv3) over the complex topography and diverse climatic gradients of Chile. Different temporal scales (daily, monthly, seasonal, annual) are used in a point-to-pixel comparison between precipitation time series measured at 366 stations (from sea level to 4600 m a.s.l. in the Andean Plateau) and the corresponding grid cell of each SRE (rescaled to a 0.25° grid if necessary). The modified Kling-Gupta efficiency was used to identify possible sources of systematic errors in each SRE. In addition, five categorical indices (PC, POD, FAR, ETS, fBIAS) were used to assess the ability of each SRE to correctly identify different precipitation intensities.Results revealed that most SRE products performed better for the humid South (36.4-43.7° S) and Central Chile (32.18-36.4° S), in particular at low- and mid-elevation zones (0-1000 m a.s.l.) compared to the arid northern regions and the Far South. Seasonally, all products performed best during the wet seasons (autumn and winter; MAM-JJA) compared to summer (DJF) and spring (SON). In addition, all SREs were able to correctly identify the occurrence of no-rain events, but they presented a low skill in classifying precipitation intensities during rainy days. Overall, PGFv3 exhibited the best performance everywhere

  8. The brain MRI image sparse representation based on the gradient information and the non-symmetry and anti-packing model.

    Science.gov (United States)

    Liang, Hu; Zhao, Shengrong; Dong, Xiangjun

    2017-12-01

    Nowadays, sparse representation has been widely used in Magnetic Resonance Imaging (MRI). The commonly used sparse representation methods are based on symmetrical partition, which have not considered the complex structure of MRI image. In this paper, we proposed a sparse representation method for the brain MRI image, called GNAMlet transform, which is based on the gradient information and the non-symmetry and anti-packing model. The proposed sparse representation method can reduce the lost detail information, improving the reconstruction accuracy. The experiment results show the superiority of the proposed transform for the brain MRI image representation in comparison with some state-of-the-art sparse representation methods.

  9. Trait-Based Community Assembly along an Elevational Gradient in Subalpine Forests: Quantifying the Roles of Environmental Factors in Inter- and Intraspecific Variability.

    Directory of Open Access Journals (Sweden)

    Ya-Huang Luo

    Full Text Available Understanding how communities respond to environmental variation is a central goal in ecology. Plant communities respond to environmental gradients via intraspecific and/or interspecific variation in plant functional traits. However, the relative contribution of these two responses to environmental factors remains poorly tested. We measured six functional traits (height, leaf thickness, specific leaf area (SLA, leaf carbon concentration (LCC, leaf nitrogen concentration (LNC and leaf phosphorus concentration (LPC for 55 tree species occurring at five elevations across a 1200 m elevational gradient of subalpine forests in Yulong Mountain, Southwest China. We examined the relative contribution of interspecific and intraspecific traits variability based on community weighted mean trait values and functional diversity, and tested how different components of trait variation respond to different environmental axes (climate and soil variables. Species turnover explained the largest amount of variation in leaf morphological traits (leaf thickness and SLA across the elevational gradient. However, intraspecific variability explained a large amount of variation (49.3%-76.3% in three other traits (height, LNC and LPC despite high levels of species turnover. The detection of limiting similarity in community assembly was improved when accounting for both intraspecific and interspecific variability. Different components of trait variation respond to different environmental axes, especially soil water content and climatic variables. Our results indicate that intraspecific variation is critical for understanding community assembly and evaluating community response to environmental change.

  10. Trait-Based Community Assembly along an Elevational Gradient in Subalpine Forests: Quantifying the Roles of Environmental Factors in Inter- and Intraspecific Variability.

    Science.gov (United States)

    Luo, Ya-Huang; Liu, Jie; Tan, Shao-Lin; Cadotte, Marc William; Wang, Yue-Hua; Xu, Kun; Li, De-Zhu; Gao, Lian-Ming

    2016-01-01

    Understanding how communities respond to environmental variation is a central goal in ecology. Plant communities respond to environmental gradients via intraspecific and/or interspecific variation in plant functional traits. However, the relative contribution of these two responses to environmental factors remains poorly tested. We measured six functional traits (height, leaf thickness, specific leaf area (SLA), leaf carbon concentration (LCC), leaf nitrogen concentration (LNC) and leaf phosphorus concentration (LPC)) for 55 tree species occurring at five elevations across a 1200 m elevational gradient of subalpine forests in Yulong Mountain, Southwest China. We examined the relative contribution of interspecific and intraspecific traits variability based on community weighted mean trait values and functional diversity, and tested how different components of trait variation respond to different environmental axes (climate and soil variables). Species turnover explained the largest amount of variation in leaf morphological traits (leaf thickness and SLA) across the elevational gradient. However, intraspecific variability explained a large amount of variation (49.3%-76.3%) in three other traits (height, LNC and LPC) despite high levels of species turnover. The detection of limiting similarity in community assembly was improved when accounting for both intraspecific and interspecific variability. Different components of trait variation respond to different environmental axes, especially soil water content and climatic variables. Our results indicate that intraspecific variation is critical for understanding community assembly and evaluating community response to environmental change.

  11. Effects of evidence-based strategies to reduce the socioeconomic gradient of uptake in the English NHS Bowel Cancer Screening Programme (ASCEND): four cluster-randomised controlled trials

    Science.gov (United States)

    Wardle, Jane; von Wagner, Christian; Kralj-Hans, Ines; Halloran, Stephen P; Smith, Samuel G; McGregor, Lesley M; Vart, Gemma; Howe, Rosemary; Snowball, Julia; Handley, Graham; Logan, Richard F; Rainbow, Sandra; Smith, Steve; Thomas, Mary C; Counsell, Nicholas; Morris, Steve; Duffy, Stephen W; Hackshaw, Allan; Moss, Sue; Atkin, Wendy; Raine, Rosalind

    2016-01-01

    Summary Background Uptake in the national colorectal cancer screening programme in England varies by socioeconomic status. We assessed four interventions aimed at reducing this gradient, with the intention of improving the health benefits of screening. Methods All people eligible for screening (men and women aged 60–74 years) across England were included in four cluster-randomised trials. Randomisation was based on day of invitation. Each trial compared the standard information with the standard information plus the following supplementary interventions: trial 1 (November, 2012), a supplementary leaflet summarising the gist of the key information; trial 2 (March, 2012), a supplementary narrative leaflet describing people's stories; trial 3 (June, 2013), general practice endorsement of the programme on the invitation letter; and trial 4 (July–August, 2013) an enhanced reminder letter with a banner that reiterated the screening offer. Socioeconomic status was defined by the Index of Multiple Deprivation score for each home address. The primary outcome was the socioeconomic status gradient in uptake across deprivation quintiles. This study is registered, number ISRCTN74121020. Findings As all four trials were embedded in the screening programme, loss to follow-up was minimal (less than 0·5%). Trials 1 (n=163 525) and 2 (n=150 417) showed no effects on the socioeconomic gradient of uptake or overall uptake. Trial 3 (n=265 434) showed no effect on the socioeconomic gradient but was associated with increased overall uptake (adjusted odds ratio [OR] 1·07, 95% CI 1·04–1·10, pscreening uptake, but further reducing inequalities in screening uptake through written materials alone will be challenging. Funding National Institute for Health Research. PMID:26680217

  12. Intervention in gene regulatory networks via greedy control policies based on long-run behavior

    Directory of Open Access Journals (Sweden)

    Ghaffari Noushin

    2009-06-01

    Full Text Available Abstract Background A salient purpose for studying gene regulatory networks is to derive intervention strategies, the goals being to identify potential drug targets and design gene-based therapeutic intervention. Optimal stochastic control based on the transition probability matrix of the underlying Markov chain has been studied extensively for probabilistic Boolean networks. Optimization is based on minimization of a cost function and a key goal of control is to reduce the steady-state probability mass of undesirable network states. Owing to computational complexity, it is difficult to apply optimal control for large networks. Results In this paper, we propose three new greedy stationary control policies by directly investigating the effects on the network long-run behavior. Similar to the recently proposed mean-first-passage-time (MFPT control policy, these policies do not depend on minimization of a cost function and avoid the computational burden of dynamic programming. They can be used to design stationary control policies that avoid the need for a user-defined cost function because they are based directly on long-run network behavior; they can be used as an alternative to dynamic programming algorithms when the latter are computationally prohibitive; and they can be used to predict the best control gene with reduced computational complexity, even when one is employing dynamic programming to derive the final control policy. We compare the performance of these three greedy control policies and the MFPT policy using randomly generated probabilistic Boolean networks and give a preliminary example for intervening in a mammalian cell cycle network. Conclusion The newly proposed control policies have better performance in general than the MFPT policy and, as indicated by the results on the mammalian cell cycle network, they can potentially serve as future gene therapeutic intervention strategies.

  13. [Diffusing information to promote population policies based on N'Djamena's Plan of Action].

    Science.gov (United States)

    Gueye, M

    1990-03-01

    From November 28-30, 1989, the Centre D'Etudes et de Recherche sur la Population pour le Developpement (CERPOD) sponsored the Selingue Retreat (SR), outside of Bamako, Mali to discuss the role of population policy development among the 9 Sahelian countries following the adoption of the N'Djamena Program of Action (PAN) the year before. The key questions discussed were: 1) state of the art regarding implementation of population policy development among Sahelian countries; 2) strategies of technical assistance to support CERPOD for population policy development; 3) organizational matters; and 4) evaluation strategies to evaluate population policy development and CERPOD's programs. The SR recommended that due to the lack of an adequate information base for population policy development that collaboration continue between CERPOD and the Futures Group. The new project will begin with a detailed plan of action for Mali and Guinee-Bissau, followed by Niger and Burkina Faso.

  14. Evidence-Based Policy Making and the Implementation of Regulatory Impact Assessment in Croatia

    Directory of Open Access Journals (Sweden)

    Zdravko Petak

    2015-06-01

    Full Text Available Purpose: This study is dealing with the application of evidence-based policy-making in Croatian public administration and the general role of applied policy analysis in the Croatian system of governance. Methodology: This development is illustrated by the peculiarities of introducing regulatory impact assessment (RIA tools in Croatian public administrative structures. Findings: The author is pointing out various limitations in the usage of policy analysis tools in formulating, implementing and evaluating public policies in Croatia. The crucial role of RIA for enhancing executive capacity of governance structures is particularly stressed in the study. The final part of the article is devoted to the prospects of further development of RIA as an applied policy analysis tool within the Croatian system of governance.

  15. Highly efficient separation of surfactant stabilized water-in-oil emulsion based on surface energy gradient and flame retardancy.

    Science.gov (United States)

    Long, Mengying; Peng, Shan; Deng, Wanshun; Miao, Xinrui; Wen, Ni; Zhou, Qiannan; Deng, Wenli

    2018-06-15

    Surface energy gradient would generate an imbalance force to drive tiny water droplets in dry air from the hydrophilic bumps to superhydrophobic domains, which has found on the Stenocara beetle's back. Inspired by this phenomenon, we introduced a pristine superhydrophilic filter paper on the lower surface energy superhydrophobic filter paper. ZnSn(OH) 6 particles and polydimethylsiloxane were mixed to prepare the superhydrophobic coating, and the coating was spray-coated on the poly(dialkyldimethylammonium chloride) covered filter paper to separate the span 80 stabilized water-in-isooctane emulsion. A pristine filter paper was added on the superhydrophobic filter paper to fabricate another membrane for separation. The results revealed that with a pristine filter paper, the membrane performed higher efficiency and more recyclability, and it could separate the emulsions with higher surfactant concentrations. The stabilized water droplets passed the superamphiphilic surface, and hindered by the superhydrophobic surface, generating a surface energy gradient for better separation. In addition, the superhydrophobic membrane could be protected from fire to some degree due to the introduced ZnSn(OH) 6 particles with excellent flame retardancy. This easy and efficient approach via simply bringing in pristine superhydrophilic membrane has great potential applications for water-in-oil emulsion separation or oil purification. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Improving a maximum horizontal gradient algorithm to determine geological body boundaries and fault systems based on gravity data

    Science.gov (United States)

    Van Kha, Tran; Van Vuong, Hoang; Thanh, Do Duc; Hung, Duong Quoc; Anh, Le Duc

    2018-05-01

    The maximum horizontal gradient method was first proposed by Blakely and Simpson (1986) for determining the boundaries between geological bodies with different densities. The method involves the comparison of a center point with its eight nearest neighbors in four directions within each 3 × 3 calculation grid. The horizontal location and magnitude of the maximum values are found by interpolating a second-order polynomial through the trio of points provided that the magnitude of the middle point is greater than its two nearest neighbors in one direction. In theoretical models of multiple sources, however, the above condition does not allow the maximum horizontal locations to be fully located, and it could be difficult to correlate the edges of complicated sources. In this paper, the authors propose an additional condition to identify more maximum horizontal locations within the calculation grid. This additional condition will improve the method algorithm for interpreting the boundaries of magnetic and/or gravity sources. The improved algorithm was tested on gravity models and applied to gravity data for the Phu Khanh basin on the continental shelf of the East Vietnam Sea. The results show that the additional locations of the maximum horizontal gradient could be helpful for connecting the edges of complicated source bodies.

  17. Cryptography, Information Operations and the Industrial Base: A Policy Dilemma

    National Research Council Canada - National Science Library

    Horner, Stephen

    1997-01-01

    .... The explosive force of information technology places the Global Information Infrastructure, the worldwide industrial base and the various world governments in both mutually supporting and somewhat adversarial positions...

  18. Self-Adaptive Gradient-Based Thresholding Method for Coal Fire Detection Using ASTER Thermal Infrared Data, Part I: Methodology and Decadal Change Detection

    Directory of Open Access Journals (Sweden)

    Xiaomin Du

    2015-05-01

    Full Text Available Coal fires that are induced by natural spontaneous combustion or result from human activities occurring on the surface and in underground coal seams destroy coal resources and cause serious environmental degradation. Thermal infrared image data, which directly measure surface temperature, can be an important tool to map coal fires over large areas. As the first of two parts introducing our coal fire detection method, this paper proposes a self-adaptive threshold-based approach for coal fire detection using ASTER thermal infrared data: the self-adaptive gradient-based thresholding method (SAGBT. This method is based on an assumption that the attenuation of temperature along the coal fire’s boundaries generates considerable numbers of spots with extremely high gradient values. The SAGBT method applied mathematical morphology thinning to skeletonize the potential high gradient buffers into the extremely high gradient lines, which provides a self-adaptive mechanism to generate thresholds according to the thermal spatial patterns of the images. The final threshold was defined as an average temperature value reading from the high temperature buffers (segmented by 1.0 σ from the mean and along a sequence of extremely high gradient lines (thinned from the potential high gradient buffers and segmented within the lower bounds, ranging from 0.5 σ to 1.5 σ and with an upper bound of 3.2 σ, where σ is the standard deviation, marking the coal fire areas. The SAGBT method used the basic outer boundary of the coal-bearing strata to simply exclude false alarms. The intermediate thresholds reduced the coupling with the temperature and converged by changing the potential high gradient buffers. This simple approach can be economical and accurate in identifying coal fire areas. In addition, it allows for the identification of thresholds using multiple ASTER TIR scenes in a consistent and uniform manner, and supports long-term coal fire change analyses using

  19. Shutdown Policies for MEMS-Based Storage Devices -- Analytical Models

    NARCIS (Netherlands)

    Khatib, M.G.; Engelen, Johannes Bernardus Charles; Hartel, Pieter H.

    MEMS-based storage devices should be energy ecient for deployment in mobile systems. Since MEMS-based storage devices have a moving me- dia sled, they should be shut down during periods of inactivity. However, shutdown costs energy, limiting the applicability of aggressive shutdown decisions. The

  20. Community-Based Wildlife Management In Tanzania: The Policy ...

    African Journals Online (AJOL)

    Community-based wildlife management (CWM) approach – known to others as community-based conservation – was first introduced in Tanzania in 1987/88. The approach intends to reconcile wildlife conservation and rural economic development. In the 1990s Tanzanians witnessed a rush by government Ministries and ...

  1. Using knowledge brokering to promote evidence-based policy-making: The need for support structures.

    Science.gov (United States)

    van Kammen, Jessika; de Savigny, Don; Sewankambo, Nelson

    2006-08-01

    Knowledge brokering is a promising strategy to close the "know-do gap" and foster greater use of research findings and evidence in policy-making. It focuses on organizing the interactive process between the producers and users of knowledge so that they can co-produce feasible and research-informed policy options. We describe a recent successful experience with this novel approach in the Netherlands and discuss the requirements for effective institutionalization of knowledge brokering. We also discuss the potential of this approach to assist health policy development in low-income countries based on the experience of developing the Regional East-African Health (REACH)-Policy Initiative. We believe that intermediary organizations, such as regional networks, dedicated institutional mechanisms and funding agencies, can play key roles in supporting knowledge brokering. We recommend the need to support and learn from the brokerage approach to strengthen the relationship between the research and policy communities and hence move towards a stronger culture of evidence-based policy and policy-relevant research.

  2. Combining rate-based and cap-and-trade emissions policies

    International Nuclear Information System (INIS)

    Fischer, Carolyn

    2003-12-01

    Rate-based emissions policies (like tradable performance standards, TPS) fix average emissions intensity, while cap-and-trade (CAT) policies fix total emissions. This paper shows that unfettered trade between rate-based and cap-and-trade programs always raises combined emissions, except when product markets are related in particular ways. Gains from trade are fully passed on to consumers in the rate-based sector, resulting in more output and greater emissions allocations. We consider several policy options to offset the expansion, including a tax, an 'exchange rate' to adjust for relative permit values, output-based allocation (OBA) for the rate-based sector, and tightening the cap. A range of combinations of tighter allocations could improve situations in both sectors with trade while holding emissions constant

  3. Food Availability in School Stores in Seoul, South Korea after Implementation of Food- and Nutrient-Based Policies

    Science.gov (United States)

    Choi, Seul Ki; Frongillo, Edward A.; Blake, Christine E.; Thrasher, James F.

    2017-01-01

    Background: To improve school store food environments, the South Korean government implemented 2 policies restricting unhealthy food sales in school stores. A food-based policy enacted in 2007 restricts specific food sales (soft drinks); and a nutrient-based policy enacted in 2009 restricts energy-dense and nutrient-poor (EDNP) food sales. The…

  4. Air pollution assessment based on elemental concentration of leaves tissue and foliage dust along an urbanization gradient in Vienna.

    Science.gov (United States)

    Simon, Edina; Braun, Mihály; Vidic, Andreas; Bogyó, Dávid; Fábián, István; Tóthmérész, Béla

    2011-05-01

    Foliage dust contains heavy metal that may have harmful effects on human health. The elemental contents of tree leaves and foliage dust are especially useful to assess air environmental pollution. We studied the elemental concentrations in foliage dust and leaves of Acer pseudoplatanus along an urbanization gradient in Vienna, Austria. Samples were collected from urban, suburban and rural areas. We analysed 19 elements in both kind of samples: aluminium, barium, calcium, copper, iron, potassium, magnesium, sodium, phosphor, sulphur, strontium and zinc. We found that the elemental concentrations of foliage dust were significantly higher in the urban area than in the rural area for aluminium, barium, iron, lead, phosphor and selenium. Elemental concentrations of leaves were significantly higher in urban than in rural area for manganese and strontium. Urbanization changed significantly the elemental concentrations of foliage dust and leaves and the applied method can be useful for monitoring the environmental load. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Socioeconomic Gradient in Childhood Obesity and Hypertension: A Multilevel Population-Based Study in a Chinese Community.

    Directory of Open Access Journals (Sweden)

    Patrick Ip

    Full Text Available This study aims to assess evidence for any socioeconomic gradients in childhood obesity and hypertension in a population-representative sample in Hong Kong, China.The data of a stratified random sampled growth survey collected in 2005-2006 was matched with a population by-census. Obesity was defined using the International Obesity Task Force standard and hypertension was defined using the Hong Kong norm table. Family socioeconomic status (SES was measured by maternal education level. Neighbourhood SES was measured by median household income of the neighbourhood. Multilevel Poisson regression models with robust standard error were used to test the association. Body mass indices of children's parents were included as potential confounders. Intra-school/neighbourhood correlations were adjusted using random factors.Totally 14842 children (age 6-19 years included in the analysis, in which 16.6% of them were overweight or obese. Children whose mother only completed secondary school or below had higher risk of childhood obesity (RR 1.41, 95% CI 1.13-1.76, p = 0.003 and hypertension (RR 1.18, 95% CI 1.01-1.36, p = 0.03. Meanwhile, children in the lowest neighbourhood SES group had higher risk of childhood underweight (RR 1.61, 95% CI 1.04-2.49, p = 0.03, overweight (RR 1.35, 95% CI 1.05-1.72, p = 0.02, and obesity (RR 2.07, 95% CI 1.11-3.88, p = 0.02.Socioeconomic gradient in childhood obesity and hypertension existed in Hong Kong, one of the most developed cities in China. These results have implications for policymakers and public health experts and highlight the need to monitor trends in other parts of China.

  6. Informing principal policy reforms in South Africa through data-based evidence

    OpenAIRE

    Gabrielle Wills

    2015-01-01

    In the past decade there has been a notable shift in South African education policy that raises the value of school leadership as a lever for learning improvements. Despite a growing discourse on school leadership, there has been a lack of empirical based evidence on principals to inform, validate or debate the efficacy of proposed policies in raising the calibre of school principals. Drawing on findings from a larger study to understand the labour market for school principals in South Africa...

  7. Economic transition policies in Chinese resource-based cities: An overview of government efforts

    International Nuclear Information System (INIS)

    Li, Huijuan; Long, Ruyin; Chen, Hong

    2013-01-01

    Resource-based cities in China have made momentous contributions to the development of the national economy for decades. However, with the depletion of natural resources, their sustainable development is challenging and transition is important. The Chinese government has made great efforts to help resource-based cities. The purpose of this study is to investigate transition policies and their implementation. Firstly, we reviewed previous studies and summarized the essential elements of some successful resource-based cities, which are useful experiences for Chinese resource-based cities. Secondly, we studied the development of resource-based cities over the past 10 years with a focus on economic development, industrial structure, government revenue and environmental conditions. We found that resource-based cities were less developed compared to other cities. The main reasons are the after-effects of a planned economy, an unreasonable tax system, planning mistakes and misguided resources exploitation policies. Thirdly, we analyzed several aspects of the policy responses after the introduction of transition policies, including designating 69 resource-exhausted cities, supporting cities with funds and projects, formulating transition plans and evaluating transition performance. However, there are some deficiencies in the process of policy implementation. Finally, some recommendations were provided to improve transition performance and sustainable development for resource-based cities. - Highlights: ► Analyze the development of Chinese resource-based cities from four aspects. ► Analyze the causes of less development in resource-based cities. ► Investigate policies and their responses to transformation. ► Provide recommendations to improve transformation performance and sustainable development

  8. STOCHASTIC GRADIENT METHODS FOR UNCONSTRAINED OPTIMIZATION

    Directory of Open Access Journals (Sweden)

    Nataša Krejić

    2014-12-01

    Full Text Available This papers presents an overview of gradient based methods for minimization of noisy functions. It is assumed that the objective functions is either given with error terms of stochastic nature or given as the mathematical expectation. Such problems arise in the context of simulation based optimization. The focus of this presentation is on the gradient based Stochastic Approximation and Sample Average Approximation methods. The concept of stochastic gradient approximation of the true gradient can be successfully extended to deterministic problems. Methods of this kind are presented for the data fitting and machine learning problems.

  9. Developing Moral Sport Policies Through Act-Utilitarianism Based on Bentham’s Hedonic Calculus

    Directory of Open Access Journals (Sweden)

    ROBERT C. SCHNEIDER

    2010-01-01

    Full Text Available Moral policy can be developed and maintained in sport organizations through an approach that incorporates act-utilitarianism (AU based on Jeremy Bentham’s hedonic calculus (HC. Sport managers’ effective application of AU based on HC takes on the form of a holistic approach to moral policy development and maintenance and requires an under-standing of the parts and process of a strict adherence to AU based on HC. The traits of common sense, habits, and past experience are supported by the utilitarian views held by Bentham and Mill to accurately predict happiness and un-happiness that result from actions (Beauchamp, 1982 and are also necessary to drive a holistic approach of AU based on HC that develops and maintains moral policy in sport organizations.

  10. Policy-Aware Sender Anonymity in Location-Based Services

    Science.gov (United States)

    Vyas, Avinash

    2011-01-01

    Sender anonymity in Location-based services (LBS) refers to hiding the identity of a mobile device user who sends requests to the LBS provider for services in her proximity (e.g. "find the nearest gas station etc."). The goal is to keep the requester's interest private even from attackers who (via hacking or subpoenas) gain access to the LBS…

  11. HIV testing for pregnant women: a rights-based analysis of national policies.

    Science.gov (United States)

    King, Elizabeth J; Maman, Suzanne; Wyckoff, Sarah C; Pierce, Matthew W; Groves, Allison K

    2013-01-01

    Ethical and human rights concerns have been expressed regarding the global shift in policies on HIV testing of pregnant women. The main purpose of this research was to conduct a policy analysis using a human rights-based approach of national policies for HIV testing of pregnant women. We collected HIV testing policies from 19 countries including: Cambodia, China, Guyana, Haiti, India, Jamaica, Kenya, Moldova, Papua New Guinea, Russian Federation, South Africa, Sudan, Swaziland, Tanzania, Ukraine, United States, Uzbekistan, Zambia and Zimbabwe. We analysed the HIV testing policies using a standardised framework that focused on government obligations to respect, protect and fulfil. Our results highlight the need for more attention to issues of pregnant women's autonomy in consenting to HIV testing, confidentiality in antenatal care settings and provision of counselling and care services. We conclude with a discussion about potential implications of the current testing policies and provide recommendations for ways that HIV testing policies can more effectively uphold the human rights of pregnant women.

  12. Policy design and performance of emissions trading markets: an adaptive agent-based analysis.

    Science.gov (United States)

    Bing, Zhang; Qinqin, Yu; Jun, Bi

    2010-08-01

    Emissions trading is considered to be a cost-effective environmental economic instrument for pollution control. However, the pilot emissions trading programs in China have failed to bring remarkable success in the campaign for pollution control. The policy design of an emissions trading program is found to have a decisive impact on its performance. In this study, an artificial market for sulfur dioxide (SO2) emissions trading applying the agent-based model was constructed. The performance of the Jiangsu SO2 emissions trading market under different policy design scenario was also examined. Results show that the market efficiency of emissions trading is significantly affected by policy design and existing policies. China's coal-electricity price system is the principal factor influencing the performance of the SO2 emissions trading market. Transaction costs would also reduce market efficiency. In addition, current-level emissions discharge fee/tax and banking mechanisms do not distinctly affect policy performance. Thus, applying emissions trading in emission control in China should consider policy design and interaction with other existing policies.

  13. An Object-Oriented Information Model for Policy-based Management of Distributed Applications

    NARCIS (Netherlands)

    Diaz, G.; Gay, V.C.J.; Horlait, E.; Hamza, M.H.

    2002-01-01

    This paper presents an object-oriented information model to support a policy-based management for distributed multimedia applications. The information base contains application-level information about the users, the applications, and their profile. Our Information model is described in details and

  14. Effects-based integrated assessment modelling for the support of European air pollution abatement policies

    NARCIS (Netherlands)

    Hettelingh, J.P.; Posch, M.; Slootweg, J.; Reinds, G.J.; Vries, de W.; Gall, Le A.; Maas, R.

    2015-01-01

    Critical load and exceedance based indicators for effects of air pollution are used to define and compare air pollution abatement scenarios, thus assisting in the framing of policies and strategies, of emission abatement options. In this chapter the effects-based support of European air pollution

  15. IMPACTS OF GROUP-BASED SIGNAL CONTROL POLICY ON DRIVER BEHAVIOR AND INTERSECTION SAFETY

    Directory of Open Access Journals (Sweden)

    Keshuang TANG

    2008-01-01

    Full Text Available Unlike the typical stage-based policy commonly applied in Japan, the group-based control (often called movement-based in the traffic control industry in Japan refers to such a control pattern that the controller is capable of separately allocating time to each signal group instead of stage based on traffic demand. In order to investigate its applicability at signalized intersections in Japan, an intersection located in Yokkaichi City of Mie Prefecture was selected as an experimental application site by the Japan Universal Traffic Management Society (UTMS. Based on the data collected at the intersection before and after implementing the group-based control policy respectively, this study evaluated the impacts of such a policy on driver behavior and intersection safety. To specify those impacts, a few models utilizing cycle-based data were first developed to interpret the occurrence probability and rate of red-light-running (RLR. Furthermore, analyses were performed on the yellow-entry time (Ye of the last cleared vehicle and post encroachment time (PET during the phase switching. Conclusions supported that the group-based control policy, along with certain other factors, directly or indirectly influenced the RLR behavior of through and right-turn traffics. Meanwhile, it has potential safety benefits as well, indicated by the declined Ye and increased PET values.

  16. Robust Allocation of Reserve Policies for a Multiple-Cell Based Power System

    DEFF Research Database (Denmark)

    Hu, Junjie; Lan, Tian; Heussen, Kai

    2018-01-01

    This paper applies a robust optimization technique for coordinating reserve allocations in multiple-cell based power systems. The linear decision rules (LDR)-based policies were implemented to achieve the reserve robustness, and consist of a nominal power schedule with a series of linear modifica...... in real time operation to make a trade off....

  17. Globalization, migration and labour: imperatives for a rights based policy

    OpenAIRE

    Taran, Patrick

    2011-01-01

    Migration has always been an essential component of economic development and social progress in many countries. Labour migration becomes one of the most important sources of regional integration, where regulation of labour migration is implemented at the regional level, for only such large integration unions that exploit the advantages of markets, resource bases and labour potentials amalgamation, can hold out against increasing competition within globalizing world. However, if migration is n...

  18. Improving societal acceptance of rad waste management policy decisions: an approach based on complex intelligence

    International Nuclear Information System (INIS)

    Rao, Suman

    2008-01-01

    In today's context elaborate public participation exercises are conducted around the world to elicit and incorporate societal risk perceptions into nuclear policy Decision-Making. However, on many occasions, such as in the case of rad waste management, the society remains unconvinced about these decisions. This naturally leads to the questions: are techniques for incorporating societal risk perceptions into the rad waste policy decision making processes sufficiently mature? How could societal risk perceptions and legal normative principles be better integrated in order to render the decisions more equitable and convincing to society? Based on guidance from socio-psychological research this paper postulates that a critical factor for gaining/improving societal acceptance is the quality and adequacy of criteria for option evaluation that are used in the policy decision making. After surveying three rad waste public participation cases, the paper identifies key lacunae in criteria abstraction processes as currently practiced. A new policy decision support model CIRDA: Complex Intelligent Risk Discourse Abstraction model that is based on the heuristic of Risk-Risk Analysis is proposed to overcome these lacunae. CIRDA's functionality of rad waste policy decision making is modelled as a policy decision-making Abstract Intelligent Agent and the agent program/abstraction mappings are presented. CIRDA is then applied to a live (U.K.) rad waste management case and the advantages of this method as compared to the Value Tree Method as practiced in the GB case are demonstrated. (author)

  19. Combining agent-based modeling and life cycle assessment for the evaluation of mobility policies.

    Science.gov (United States)

    Florent, Querini; Enrico, Benetto

    2015-02-03

    This article presents agent-based modeling (ABM) as a novel approach for consequential life cycle assessment (C-LCA) of large scale policies, more specifically mobility-related policies. The approach is validated at the Luxembourgish level (as a first case study). The agent-based model simulates the car market (sales, use, and dismantling) of the population of users in the period 2013-2020, following the implementation of different mobility policies and available electric vehicles. The resulting changes in the car fleet composition as well as the hourly uses of the vehicles are then used to derive consistent LCA results, representing the consequences of the policies. Policies will have significant environmental consequences: when using ReCiPe2008, we observe a decrease of global warming, fossil depletion, acidification, ozone depletion, and photochemical ozone formation and an increase of metal depletion, ionizing radiations, marine eutrophication, and particulate matter formation. The study clearly shows that the extrapolation of LCA results for the circulating fleet at national scale following the introduction of the policies from the LCAs of single vehicles by simple up-scaling (using hypothetical deployment scenarios) would be flawed. The inventory has to be directly conducted at full scale and to this aim, ABM is indeed a promising approach, as it allows identifying and quantifying emerging effects while modeling the Life Cycle Inventory of vehicles at microscale through the concept of agents.

  20. Policy-Based Approach to Emergency Bio-Data Management for Mobile Healthcare

    Directory of Open Access Journals (Sweden)

    Seung-Man Chun

    2014-01-01

    Full Text Available In m-healthcare service, accurate detection and notification of emergency situation are critical to chronic patients' life. Since they are usually performed by a limited number of medical staff, it is difficult to simultaneously support many patients in real-time. This article presents an architecture to support the emergency bio-data management for m-healthcare service using personalized emergency policy. The salient feature of the proposed architecture is that the decision on emergency is made using personalized emergency policy. Specifically, the structure of the detailed system components has also been designed. The emergency condition of the individual bio-data collected from wireless body area network is detected automatically using personalized emergency policy. The message flow diagram based on the personalized emergency policy is described. This enables quick emergency rescue service provided to the patient both accurately and immediately. The prototype of proposed system has been built to demonstrate the design concept.

  1. Seasonal variation in communities of ammonia-oxidizing bacteria based on polymerase chain reaction - denaturing gradient gel electrophoresis in a biofilm reactor for drinking water pretreatment.

    Science.gov (United States)

    Zhang, Xiao-Wen; Qin, Ying-Ying; Ren, Hong-Qiang; Li, Dao-Tang; Yang, Hong

    2008-05-01

    The diversity and variation of total and active ammonia-oxidizing bacteria in a full-scale aerated submerged biofilm reactor for drinking water pretreatment were characterized by clone libraries and denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA and its gene during a whole year. Sequences obtained from clone libraries affiliated with the Nitrosomonas oligotropha lineage and the Nitrosomonas communis lineage. An uncultured subgroup of Nitrosomonas communis lineage was also detected. Seasonal variations in both total and active ammonia-oxidizing bacteria communities were observed in the DGGE profiles, but an RNA-based analysis reflected more obvious dynamic changes in ammonia-oxidizer community than a DNA-based approach. Statistical study based on canonical correspondence analysis showed that a community shift of active ammonia oxidizers was significantly influenced by temperature and pH, but no significant correlation was found between environmental variables and total ammonia-oxidizer community shift.

  2. Size-Dependent Bending, Buckling and Free Vibration Analyses of Microscale Functionally Graded Mindlin Plates Based on the Strain Gradient Elasticity Theory

    Directory of Open Access Journals (Sweden)

    R. Ansari

    Full Text Available Abstract In this paper, a size-dependent microscale plate model is developed to describe the bending, buckling and free vibration behaviors of microplates made of functionally graded materials (FGMs. The size effects are captured based on the modified strain gradient theory (MSGT, and the formulation of the paper is on the basis of Mindlin plate theory. The presented model accommodates the models based upon the classical theory (CT and the modified couple stress theory (MCST if all or two scale parameters are set to zero, respectively. By using Hamilton's principle, the governing equations and related boundary conditions are derived. The bending, buckling and free vibration problems are considered and are solved through the generalized differential quadrature (GDQ method. A detailed parametric and comparative study is conducted to evaluate the effects of length scale parameter, material gradient index and aspect ratio predicted by the CT, MCST and MSGT on the deflection, critical buckling load and first natural frequency of the microplate. The numerical results indicate that the model developed herein is significantly size-dependent when the thickness of the microplate is on the order of the material scale parameters.

  3. The effect of meter-scale lateral oxygen gradients at the sediment-water interface on selected organic matter based alteration, productivity and temperature proxies

    Science.gov (United States)

    Bogus, K. A.; Zonneveld, K. A. F.; Fischer, D.; Kasten, S.; Bohrmann, G.; Versteegh, G. J. M.

    2012-04-01

    A valid assessment of selective aerobic degradation on organic matter (OM) and its impact on OM-based proxies is vital to produce accurate environmental reconstructions. However, most studies investigating these effects suffer from inherent environmental heterogeneities. In this study, we used surface samples collected along two meter-scale transects and one longer transect in the northeastern Arabian Sea to constrain initial OM heterogeneity, in order to evaluate selective aerobic degradation on temperature, productivity and alteration indices at the sediment-water interface. All of the studied alteration indices, the higher plant alkane index, alcohol preservation index, and diol oxidation index, demonstrated that they are sensitive indicators for changes in the oxygen regime. Several export production indices, a cholesterol-based stanol/stenol index and dinoflagellate lipid- and cyst-based ratios, showed significant (more than 20%) change only over the lateral oxygen gradients. Therefore, these compounds do not exclusively reflect surface water productivity, but are significantly altered after deposition. Two of the proxies, glycerol dibiphytanyl glycerol tetraether-based TEX86 sea surface temperature indices and indices based on phytol, phytane and pristane, did not show any trends related to oxygen. Nevertheless, unrealistic sea surface temperatures were obtained after application of the TEX86, TEX86L, and TEX86H proxies. The phytol-based ratios were likely affected by the sedimentary production of pristane. Our results demonstrate the selective impact of aerobic organic matter degradation on the lipid and palynomorph composition of surface sediments along a short lateral oxygen gradient and suggest that some of the investigated proxies may be useful tracers of changing redox conditions at the sediment-water interface.

  4. The effect of meter-scale lateral oxygen gradients at the sediment-water interface on selected organic matter based alteration, productivity and temperature proxies

    Directory of Open Access Journals (Sweden)

    K. A. Bogus

    2012-04-01

    Full Text Available A valid assessment of selective aerobic degradation on organic matter (OM and its impact on OM-based proxies is vital to produce accurate environmental reconstructions. However, most studies investigating these effects suffer from inherent environmental heterogeneities. In this study, we used surface samples collected along two meter-scale transects and one longer transect in the northeastern Arabian Sea to constrain initial OM heterogeneity, in order to evaluate selective aerobic degradation on temperature, productivity and alteration indices at the sediment-water interface. All of the studied alteration indices, the higher plant alkane index, alcohol preservation index, and diol oxidation index, demonstrated that they are sensitive indicators for changes in the oxygen regime. Several export production indices, a cholesterol-based stanol/stenol index and dinoflagellate lipid- and cyst-based ratios, showed significant (more than 20% change only over the lateral oxygen gradients. Therefore, these compounds do not exclusively reflect surface water productivity, but are significantly altered after deposition. Two of the proxies, glycerol dibiphytanyl glycerol tetraether-based TEX86 sea surface temperature indices and indices based on phytol, phytane and pristane, did not show any trends related to oxygen. Nevertheless, unrealistic sea surface temperatures were obtained after application of the TEX86, TEX86L, and TEX86H proxies. The phytol-based ratios were likely affected by the sedimentary production of pristane. Our results demonstrate the selective impact of aerobic organic matter degradation on the lipid and palynomorph composition of surface sediments along a short lateral oxygen gradient and suggest that some of the investigated proxies may be useful tracers of changing redox conditions at the sediment-water interface.

  5. A simulation model for reliability-based appraisal of an energy policy: The case of Lebanon

    International Nuclear Information System (INIS)

    Hamdan, H.A.; Ghajar, R.F.; Chedid, R.B.

    2012-01-01

    The Lebanese Electric Power System (LEPS) has been suffering from technical and financial deficiencies for decades and mirrors the problems encountered in many developing countries suffering from inadequate or no power systems planning resulting in incomplete and ill-operating infrastructure, and suffering from effects of political instability, huge debts, unavailability of financing desired projects and inefficiency in operation. The upgrade and development of the system necessitate the adoption of a comprehensive energy policy that introduces solutions to a diversity of problems addressing the technical, financial, administrative and governance aspects of the system. In this paper, an energy policy for Lebanon is proposed and evaluated based on integration between energy modeling and financial modeling. The paper utilizes the Load Modification Technique (LMT) as a probabilistic tool to assess the impact of policy implementation on energy production, overall cost, technical/commercial losses and reliability. Scenarios reflecting implementation of policy projects are assessed and their impacts are compared with business-as-usual scenarios which assume no new investment is to take place in the sector. Conclusions are drawn on the usefulness of the proposed evaluation methodology and the effectiveness of the adopted energy policy for Lebanon and other developing countries suffering from similar power system problems. - Highlights: ► Evaluation methodology based on a probabilistic simulation tool is proposed. ► A business-as-usual scenario for a given study period of the LEPS was modeled. ► Mitigation scenarios reflecting implementation of the energy policy are modeled. ► Policy simulated and compared with business-as-usual scenarios of the LEPS. ► Results reflect usefulness of proposed methodology and the adopted energy policy.

  6. Size-dependent dynamic stability analysis of microbeams actuated by piezoelectric voltage based on strain gradient elasticity theory

    Energy Technology Data Exchange (ETDEWEB)

    Sahmani, Saeid; Bahrami, Mohsen [Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2015-01-15

    In the current paper, dynamic stability analysis of microbeams subjected to piezoelectric voltage is presented in which the microbeam is integrated with piezoelectric layers on the lower and upper surfaces. Both of the flutter and divergence instabilities of microbeams with clamped-clamped and clamped-free boundary conditions are predicted corresponding to various values of applied voltage. To take size effect into account, the classical Timoshenko beam theory in conjunction with strain gradient elasticity theory is utilized to develop nonclassical beam model containing three additional internal length scale parameters. By using Hamilton's principle, the higher-order governing differential equations and associated boundary conditions are derived. Afterward, generalized differential quadrature method is employed to discretize the size-dependent governing differential equations along with clamped-clamped and clamped-free end supports. The critical piezoelectric voltages corresponding to various values dimensionless length scale parameter are evaluated and compared with those predicted by the classical beam theory. It is revealed that in the case of clamped-free boundary conditions, the both of flutter and divergence instabilities occur. However, for the clamped-clamped microbeams, only divergence instability takes place.

  7. Vibration analysis of bonded double-FGM viscoelastic nanoplate systems based on a modified strain gradient theory incorporating surface effects

    Science.gov (United States)

    Jamalpoor, Ali; Kiani, Ali

    2017-03-01

    On the basis of the modified strain gradient theory, the present paper deals with the theoretical analysis of the free vibration of coupled double-FGM viscoelastic nanoplates by Kelvin-Voigt visco-Pasternak medium. To establish static equilibrium of atoms on the each nanoplate surface, the effects of the surface layers are considered. The properties of material in the thickness direction vary according to the power low distribution. Kirchhoff plate assumption and Hamilton's variational principle are employed to achieve the partial differential equations for three different cases of vibration (out-of-phase, in-phase, and one nanoplate of the system being stationary) and corresponding boundary conditions. Navier's approach which satisfies the simply supported boundary conditions applied to analytically investigate the size effect on the natural frequencies of double-FGM viscoelastic nanoplate systems. Numerical studies are carried out to illustrate the influence of viscoelastic damping structural of the nanoplates, damping coefficient of the visco-Pasternak medium, independent length scale parameter, aspect ratio, surface properties, and other factors on the frequency behavior system. Some numerical results of this research illustrate that the frequencies may increase or decrease with respect to the sign of the surface properties of FGMs.

  8. Analytical gradients for subsystem density functional theory within the slater-function-based amsterdam density functional program.

    Science.gov (United States)

    Schlüns, Danny; Franchini, Mirko; Götz, Andreas W; Neugebauer, Johannes; Jacob, Christoph R; Visscher, Lucas

    2017-02-05

    We present a new implementation of analytical gradients for subsystem density-functional theory (sDFT) and frozen-density embedding (FDE) into the Amsterdam Density Functional program (ADF). The underlying theory and necessary expressions for the implementation are derived and discussed in detail for various FDE and sDFT setups. The parallel implementation is numerically verified and geometry optimizations with different functional combinations (LDA/TF and PW91/PW91K) are conducted and compared to reference data. Our results confirm that sDFT-LDA/TF yields good equilibrium distances for the systems studied here (mean absolute deviation: 0.09 Å) compared to reference wave-function theory results. However, sDFT-PW91/PW91k quite consistently yields smaller equilibrium distances (mean absolute deviation: 0.23 Å). The flexibility of our new implementation is demonstrated for an HCN-trimer test system, for which several different setups are applied. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Highly transparent, stable, and superhydrophobic coatings based on gradient structure design and fast regeneration from physical damage

    Science.gov (United States)

    Chen, Zao; Liu, Xiaojiang; Wang, Yan; Li, Jun; Guan, Zisheng

    2015-12-01

    Optical transparency, mechanical flexibility, and fast regeneration are important factors to expand the application of superhydrophobic surfaces. Herein, we fabricated highly transparent, stable, and superhydrophobic coatings through a novel gradient structure design by versatile dip-coating of silica colloid particles (SCPs) and diethoxydimethysiliane cross-linked silica nanoparticles (DDS-SNPs) on polyethylene terephthalate (PET) film and glass, followed by the modification of octadecyltrichlorosiliane (OTCS). When the DDS concentration reached 5 wt%, the modified SCPs/DDS-SNPs coating exhibited a water contact angle (WCA) of 153° and a sliding angle (SA) superhydrophobic coating on PET film and glass was increased by 2.7% and 1% in the visible wavelength, respectively. This superhydrophobic coating also showed good robustness and stability against water dropping impact, ultrasonic damage, and acid solution. Moreover, the superhydrophobic PET film after physical damage can quickly regain the superhydrophobicity by one-step spray regenerative solution of dodecyltrichlorosilane (DTCS) modified silica nanoparticles at room temperature. The demonstrated method for the preparation and regeneration of superhydrophobic coating is available for different substrates and large-scale production at room temperature.

  10. Optimal Allocation of Thermal-Electric Decoupling Systems Based on the National Economy by an Improved Conjugate Gradient Method

    Directory of Open Access Journals (Sweden)

    Shuang Rong

    2015-12-01

    Full Text Available Aiming to relieve the large amount of wind power curtailment during the heating period in the North China region, a thermal-electric decoupling (TED approach is proposed to both bring down the constraint of forced power output of combined heat and power plants and increase the electric load level during valley load times that assist the power grid in consuming more wind power. The operating principles of the thermal-electric decoupling approach is described, the mathematical model of its profits is developed, the constraint conditions of its operation are listed, also, an improved parallel conjugate gradient is utilized to bypass the saddle problem and accelerate the optimal speed. Numerical simulations are implemented and reveal an optimal allocation of TED which with a rated power of 280 MW and 185 MWh heat storage capacity are possible. This allocation of TED could bring approximately 16.9 billion Yuan of economic profit and consume more than 80% of the surplus wind energy which would be curtailed without the participation of TED. The results in this article verify the effectiveness of this method that could provide a referential guidance for thermal-electric decoupling system allocation in practice.

  11. Geometric-Process-Based Battery Management Optimizing Policy for the Electric Bus

    OpenAIRE

    Li, Yan; Wang, Jin-kuan; Han, Peng; Han, Ying-hua

    2015-01-01

    With the rapid development of the electric vehicle industry and promotive policies worldwide, the electric bus (E-bus) has been adopted in many major cities around the world. One of the most important factors that restrain the widespread application of the E-bus is the high operating cost due to the deficient battery management. This paper proposes a geometric-process-based (GP-based) battery management optimizing policy which aims to minimize the average cost of the operation on the premise ...

  12. Flexible Multi-Authority Attribute-Based Signature Schemes for Expressive Policy

    Directory of Open Access Journals (Sweden)

    Dan Cao

    2012-01-01

    Full Text Available Attribute-based signature (ABS is a new cryptographic primitive, in which a signer can sign a message with his attributes, and the verifier can only known whether the signer owns attributes satisfying his policy. Moreover, the signature cannot be forged by any user not having attributes satisfying the policy. ABS has many applications, such as anonymous authentication, and attribute-based messaging systems. But many applications may require a user obtaining attributes from different authorities, which calls for multi-authority ABS schemes.

  13. From theory based policy evaluation to SMART Policy Design: Lessons learned from 20 ex-post evaluations of energy efficiency instruments

    International Nuclear Information System (INIS)

    Harmelink, Mirjam; Harmsen, Robert; Nilsson, Lars

    2007-01-01

    This article presents the results of an in-depth ex-post analysis of 20 energy efficiency policy instruments applied across different sectors and countries. Within the AID-EE project, we reconstructed and analysed the implementation process of energy efficiency policy instruments with the aim to identify key factors behind successes and failures. The analysis was performed using a uniform methodology called 'theory based policy evaluation'. With this method the whole implementation process is assessed with the aim to identify: (i) the main hurdles in each step of the implementation process, (ii) key success factors for different types of instruments and (iii) the key indicators that need to be monitored to enable a sound evaluation of the energy efficiency instruments. Our analysis shows that: Energy efficiency policies often lack quantitative targets and clear timeframes; Often policy instruments have multiple and/or unclear objectives; The need for monitoring information does often not have priority in the design phase; For most instruments, monitoring information is collected on a regular basis. However, this information is often insufficient to determine the impact on energy saving, cost-effectiveness and target achievement of an instrument; Monitoring and verification of actual energy savings have a relatively low priority for most of the analyzed instruments. There is no such thing as the 'best' policy instrument. However, typical circumstances in which to apply different types of instruments and generic characteristics that determine success or failure can be identified. Based on the assessments and the experience from applying theory based policy evaluation ex-post, we suggest that this should already be used in the policy formulation and design phase of instruments. We conclude that making policy theory an integral and mandated part of the policy process would facilitate more efficient and effective energy efficiency instruments

  14. Sources of variation in innate immunity in great tit nestlings living along a metal pollution gradient: An individual-based approach

    International Nuclear Information System (INIS)

    Vermeulen, Anke; Müller, Wendt; Matson, Kevin D.; Irene Tieleman, B.; Bervoets, Lieven; Eens, Marcel

    2015-01-01

    Excessive deposition of metals in the environment is a well-known example of pollution worldwide. Chronic exposure of organisms to metals can have a detrimental effect on reproduction, behavior, health and survival, due to the negative effects on components of the immune system. However, little is known about the effects of chronic sublethal metal exposure on immunity, especially for wildlife. In our study, we examined the constitutive innate immunity of great tit (Parus major) nestlings (N = 234) living in four populations along a metal pollution gradient. For each nestling, we determined the individual metal concentrations (lead, cadmium, arsenic) present in the red blood cells and measured four different innate immune parameters (agglutination, lysis, haptoglobin concentrations and nitric oxide concentrations) to investigate the relationship between metal exposure and immunological condition. While we found significant differences in endogenous metal concentrations among populations with the highest concentrations closest to the pollution source, we did not observe corresponding patterns in our immune measures. However, when evaluating relationships between metal concentrations and immune parameters at the individual level, we found negative effects of lead and, to a lesser extent, arsenic and cadmium on lysis. In addition, high arsenic concentrations appear to elicit inflammation, as reflected by elevated haptoglobin concentrations. Thus despite the lack of a geographic association between pollution and immunity, this type of association was present at the individual level at a very early life stage. The high variation in metal concentrations and immune measures observed within populations indicates a high level of heterogeneity along an existing pollution gradient. Interestingly, we also found substantial within nest variation, for which the sources remain unclear, and which highlights the need of an individual-based approach. - Highlights: • Innate immunity

  15. Sources of variation in innate immunity in great tit nestlings living along a metal pollution gradient: An individual-based approach

    Energy Technology Data Exchange (ETDEWEB)

    Vermeulen, Anke, E-mail: anke.vermeulen@uantwerpen.be [Department of Biology — Ethology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Müller, Wendt, E-mail: wendt.mueller@uantwerpen.be [Department of Biology — Ethology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Matson, Kevin D., E-mail: k.d.matson@rug.nl [Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, P.O. Box 11103, 9700 CC Groningen (Netherlands); The Resource Ecology Group, Department of Environmental Sciences, Wageningen University, Droevendaalsesteeg 3a, 6708PB Wageningen (Netherlands); Irene Tieleman, B., E-mail: b.i.tieleman@rug.nl [Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, P.O. Box 11103, 9700 CC Groningen (Netherlands); Bervoets, Lieven, E-mail: lieven.bervoets@uantwerpen.be [Department of Biology — SPHERE, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Eens, Marcel, E-mail: marcel.eens@uantwerpen.be [Department of Biology — Ethology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium)

    2015-03-01

    Excessive deposition of metals in the environment is a well-known example of pollution worldwide. Chronic exposure of organisms to metals can have a detrimental effect on reproduction, behavior, health and survival, due to the negative effects on components of the immune system. However, little is known about the effects of chronic sublethal metal exposure on immunity, especially for wildlife. In our study, we examined the constitutive innate immunity of great tit (Parus major) nestlings (N = 234) living in four populations along a metal pollution gradient. For each nestling, we determined the individual metal concentrations (lead, cadmium, arsenic) present in the red blood cells and measured four different innate immune parameters (agglutination, lysis, haptoglobin concentrations and nitric oxide concentrations) to investigate the relationship between metal exposure and immunological condition. While we found significant differences in endogenous metal concentrations among populations with the highest concentrations closest to the pollution source, we did not observe corresponding patterns in our immune measures. However, when evaluating relationships between metal concentrations and immune parameters at the individual level, we found negative effects of lead and, to a lesser extent, arsenic and cadmium on lysis. In addition, high arsenic concentrations appear to elicit inflammation, as reflected by elevated haptoglobin concentrations. Thus despite the lack of a geographic association between pollution and immunity, this type of association was present at the individual level at a very early life stage. The high variation in metal concentrations and immune measures observed within populations indicates a high level of heterogeneity along an existing pollution gradient. Interestingly, we also found substantial within nest variation, for which the sources remain unclear, and which highlights the need of an individual-based approach. - Highlights: • Innate immunity

  16. Age gradients in the stellar populations of massive star forming regions based on a new stellar chronometer

    Energy Technology Data Exchange (ETDEWEB)

    Getman, Konstantin V.; Feigelson, Eric D.; Kuhn, Michael A.; Broos, Patrick S.; Townsley, Leisa K.; Luhman, Kevin L. [Department of Astronomy and Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802 (United States); Naylor, Tim [School of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, EX4 4QL (United Kingdom); Povich, Matthew S. [Department of Physics and Astronomy, California State Polytechnic University, 3801 West Temple Avenue, Pomona, CA 91768 (United States); Garmire, Gordon P. [Huntingdon Institute for X-ray Astronomy, LLC, 10677 Franks Road, Huntingdon, PA 16652 (United States)

    2014-06-01

    A major impediment to understanding star formation in massive star-forming regions (MSFRs) is the absence of a reliable stellar chronometer to unravel their complex star formation histories. We present a new estimation of stellar ages using a new method that employs near-infrared (NIR) and X-ray photometry, Age {sub JX} . Stellar masses are derived from X-ray luminosities using the L{sub X} -M relation from the Taurus cloud. J-band luminosities are compared to mass-dependent pre-main-sequence (PMS) evolutionary models to estimate ages. Age {sub JX} is sensitive to a wide range of evolutionary stages, from disk-bearing stars embedded in a cloud to widely dispersed older PMS stars. The Massive Young Star-Forming Complex Study in Infrared and X-ray (MYStIX) project characterizes 20 OB-dominated MSFRs using X-ray, mid-infrared, and NIR catalogs. The Age {sub JX} method has been applied to 5525 out of 31,784 MYStIX Probable Complex Members. We provide a homogeneous set of median ages for over 100 subclusters in 15 MSFRs; median subcluster ages range between 0.5 Myr and 5 Myr. The important science result is the discovery of age gradients across MYStIX regions. The wide MSFR age distribution appears as spatially segregated structures with different ages. The Age {sub JX} ages are youngest in obscured locations in molecular clouds, intermediate in revealed stellar clusters, and oldest in distributed populations. The NIR color index J – H, a surrogate measure of extinction, can serve as an approximate age predictor for young embedded clusters.

  17. Generalized conjugate gradient squared

    Energy Technology Data Exchange (ETDEWEB)

    Fokkema, D.R.; Sleijpen, G.L.G. [Utrecht Univ. (Netherlands)

    1994-12-31

    In order to solve non-symmetric linear systems of equations, the Conjugate Gradient Squared (CGS) is a well-known and widely used iterative method. In practice the method converges fast, often twice as fast as the Bi-Conjugate Gradient method. This is what you may expect, since CGS uses the square of the BiCG polynomial. However, CGS may suffer from its erratic convergence behavior. The method may diverge or the approximate solution may be inaccurate. BiCGSTAB uses the BiCG polynomial and a product of linear factors in an attempt to smoothen the convergence. In many cases, this has proven to be very effective. Unfortunately, the convergence of BiCGSTAB may stall when a linear factor (nearly) degenerates. BiCGstab({ell}) is designed to overcome this degeneration of linear factors. It generalizes BiCGSTAB and uses both the BiCG polynomial and a product of higher order factors. Still, CGS may converge faster than BiCGSTAB or BiCGstab({ell}). So instead of using a product of linear or higher order factors, it may be worthwhile to look for other polynomials. Since the BiCG polynomial is based on a three term recursion, a natural choice would be a polynomial based on another three term recursion. Possibly, a suitable choice of recursion coefficients would result in method that converges faster or as fast as CGS, but less erratic. It turns out that an algorithm for such a method can easily be formulated. One particular choice for the recursion coefficients leads to CGS. Therefore one could call this algorithm generalized CGS. Another choice for the recursion coefficients leads to BiCGSTAB. It is therefore possible to mix linear factors and some polynomial based on a three term recursion. This way one may get the best of both worlds. The authors will report on their findings.

  18. Improving the evidence base for energy policy: The role of systematic reviews

    International Nuclear Information System (INIS)

    Sorrell, Steve

    2007-01-01

    The concept of evidence-based policy and practice (EBPP) has gained increasing prominence in the UK over the last 10 years and now plays a dominant role in a number of policy areas, including healthcare, education, social work, criminal justice and urban regeneration. But despite this substantial, influential and growing activity, the concept remains largely unknown to policymakers and researchers within the energy field. This paper defines EBPP, identifies its key features and examines the potential role of systematic reviews of evidence in a particular area of policy. It summarises the methods through which systematic reviews are achieved; discusses their advantages and limitations; identifies the particular challenges they face in the energy policy area; and assesses whether and to what extent they can usefully be applied to contemporary energy policy questions. The concept is illustrated with reference to a proposed review of evidence for a 'rebound effect' from improved energy efficiency. The paper concludes that systematic reviews may only be appropriate for a subset of energy policy questions and that research-funding priorities may need to change if their use is to become more widespread

  19. Prediction of the chromatographic retention of acid-base compounds in pH buffered methanol-water mobile phases in gradient mode by a simplified model.

    Science.gov (United States)

    Andrés, Axel; Rosés, Martí; Bosch, Elisabeth

    2015-03-13

    Retention of ionizable analytes under gradient elution depends on the pH of the mobile phase, the pKa of the analyte and their evolution along the programmed gradient. In previous work, a model depending on two fitting parameters was recommended because of its very favorable relationship between accuracy and required experimental work. It was developed using acetonitrile as the organic modifier and involves pKa modeling by means of equations that take into account the acidic functional group of the compound (carboxylic acid, protonated amine, etc.). In this work, the two-parameter predicting model is tested and validated using methanol as the organic modifier of the mobile phase and several compounds of higher pharmaceutical relevance and structural complexity as testing analytes. The results have been quite good overall, showing that the predicting model is applicable to a wide variety of acid-base compounds using mobile phases prepared with acetonitrile or methanol. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Protecting aquatic biodiversity in Europe: How much do EU environmental policies support ecosystem-based management?

    Science.gov (United States)

    Rouillard, Josselin; Lago, Manuel; Abhold, Katrina; Röschel, Lina; Kafyeke, Terri; Mattheiß, Verena; Klimmek, Helen

    2018-02-01

    The sustainable management of aquatic ecosystems requires better coordination between policies span-ning freshwater, coastal and marine environments. Ecosystem-based management (EBM) has been promoted as a holistic and integrative approach for the safekeeping and protection of aquatic biodiversity. The paper assesses the degree to which key European environmental policies for the aquatic environment, namely the Birds and Habitats Directives, Water Framework Directive and Marine Strategy Framework Directive, individually support EBM and can work synergistically to implement EBM. This assessment is based on a review of legal texts, EU guidance and implementation documents. The paper concludes that EBM can be made operational by implementing these key environmental directives. Opportunities for improving the integration of EU environmental policies are highlighted.

  1. Consumers’ evaluation of national new energy vehicle policy in China: An analysis based on a four paradigm model

    International Nuclear Information System (INIS)

    Li, Wenbo; Long, Ruyin; Chen, Hong

    2016-01-01

    The Chinese government has issued numerous policies to promote the development and adoption of new energy vehicles (NEVs) to address the problem of excessive energy consumption and environmental pollution. In this study we divided these policies into seven categories: macroscopic, demonstration, subsidization, preferential tax, technical support, industry management, and infrastructure. Since consumers’ opinions affect the policy choices of government, based on questionnaire data we use a four paradigm model to analyze the consumers’ evaluation of each policy in terms of perceptions of importance and satisfaction. The results show that macroscopic policies are perceived to be of high importance and satisfaction, whereas for industry management policies they are perceived to be of low importance and satisfaction. The importance perceptions of preferential tax and demonstration policies are low, whereas perceptions of their satisfaction are high. Perceptions of the importance of subsidization, technical support, and infrastructure policies are high, whereas perceptions of their satisfaction are low. We find that the subsidization, technical support, and infrastructure policies need urgent improvement. Finally, we put forward several suggestions to improve the current policies and increase the consumers’ intention to adopt NEVs. - Highlights: • This study divided Chinese NEV-related policies into seven types. • This study analyzed consumers’ evaluation of NEV-related policies. • Consumers’ evaluations about NEV-related policies were diverse. • Subsidization, technical support, and infrastructure policies need improvement.

  2. The role of the media in the science-policy nexus. Some critical reflections based on an analysis of the Belgian drug policy debate (1996-2003).

    Science.gov (United States)

    Tieberghien, Julie

    2014-03-01

    Drug policy is one of the most polarised subjects of public debate and media coverage, which frequently tend to be dramatic and event-centred. Although the role of the media in directing the drug discourse is widely acknowledged, limited research has been conducted in examining the particular role of the media in the science-policy nexus. We sought to determine how the (mis)representation of scientific knowledge in the media may, or may not, have an impact on the contribution of scientific knowledge to the drug-policy making process. Using a case study of the Belgian drug-policy debates between 1996 and 2003, we conducted a discourse analysis of specially selected 1067 newspaper articles and 164 policy documents. Our analysis focused on: textual elements that feature intra-discourse differences, how players and scientific knowledge are represented in the text, the arguments used and claims made, and the various types of research utilisation. Media discourse strongly influenced the public's and policy makers' understanding as well as the content of the Belgian drug policy debate between 1996 and 2003. As a major source of scientific knowledge, media coverage supported the 'enlightenment' role of scientific knowledge in the policy-making process by broadening and even determining frames of reference. However, as the presentation of scientific knowledge in the media was often inaccurate or distorted due to the lack of contextual information or statistical misinformation, the media may also support the selective utilisation of scientific knowledge. Many challenges as well as opportunities lie ahead for researchers who want to influence the policy-making process since most research fails to go beyond academic publications. Although media is a valuable linking mechanism between science and policy, by no means does it provide scientists with a guarantee of a more 'evidence-based' drug policy. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. New directions in evidence-based policy research: a critical analysis of the literature.

    Science.gov (United States)

    Oliver, Kathryn; Lorenc, Theo; Innvær, Simon

    2014-07-14

    Despite 40 years of research into evidence-based policy (EBP) and a continued drive from both policymakers and researchers to increase research uptake in policy, barriers to the use of evidence are persistently identified in the literature. However, it is not clear what explains this persistence - whether they represent real factors, or if they are artefacts of approaches used to study EBP. Based on an updated review, this paper analyses this literature to explain persistent barriers and facilitators. We critically describe the literature in terms of its theoretical underpinnings, definitions of 'evidence', methods, and underlying assumptions of research in the field, and aim to illuminate the EBP discourse by comparison with approaches from other fields. Much of the research in this area is theoretically naive, focusing primarily on the uptake of research evidence as opposed to evidence defined more broadly, and privileging academics' research priorities over those of policymakers. Little empirical data analysing the processes or impact of evidence use in policy is available to inform researchers or decision-makers. EBP research often assumes that policymakers do not use evidence and that more evidence - meaning research evidence - use would benefit policymakers and populations. We argue that these assumptions are unsupported, biasing much of EBP research. The agenda of 'getting evidence into policy' has side-lined the empirical description and analysis of how research and policy actually interact in vivo. Rather than asking how research evidence can be made more influential, academics should aim to understand what influences and constitutes policy, and produce more critically and theoretically informed studies of decision-making. We question the main assumptions made by EBP researchers, explore the implications of doing so, and propose new directions for EBP research, and health policy.

  4. Computational Strain Gradient Crystal Plasticity

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Kysar, Jeffrey W.

    2011-01-01

    element solution method is presented, which delivers the slip-rate field and the velocity-field based on two minimum principles. Some plane deformation problems relevant for certain specific orientations of a face centered cubic crystal under plane loading conditions are studied, and effective in......A model for strain gradient crystal visco-plasticity is formulated along the lines proposed by Fleck andWillis (2009) for isotropic plasticity. Size-effects are included in the model due to the addition of gradient terms in both the free energy as well as through a dissipation potential. A finite...

  5. Recent changes in school-based policies on physical activity and nutrition in Spain.

    Science.gov (United States)

    Gallego, Pilar; Galán, Iñaki; José Medrano, María; Ramos, Pilar; Rivera, Francisco; Moreno, Carmen

    2014-12-01

    This study evaluates the changes in Spain between 2006 and 2012, of school-based policies encouraging healthy eating and the undertaking of physical activity (PA). A longitudinal study was undertaken comprising 277 representative schools from all the regions of Spain. The questionnaires were completed by the school management board. An indicator for school policies on PA was constructed (score 0-4) from the following indicators: (i) participation in PA programmes, (ii) existence of written PA guidelines, (iii) training of teachers about PA and (iv) organization of extracurricular PA activities. For nutrition, indicators similar to the first three for PA were evaluated, together with access to healthy foods (score 0-4). In addition to comparing the scores for 2006 and 2012, multivariate linear regression was used to study the association between the characteristics of the schools and the changes in the scores. The indicators for school-based policies on nutrition and PA improved between 2006 and 2012: the average score for PA increased from 1.33 to 1.79 (P policies on nutrition (P policies on PA and nutrition, although there is still room for improvement. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  6. Informing principal policy reforms in South Africa through data-based evidence

    Directory of Open Access Journals (Sweden)

    Gabrielle Wills

    2015-12-01

    Full Text Available In the past decade there has been a notable shift in South African education policy that raises the value of school leadership as a lever for learning improvements. Despite a growing discourse on school leadership, there has been a lack of empirical based evidence on principals to inform, validate or debate the efficacy of proposed policies in raising the calibre of school principals. Drawing on findings from a larger study to understand the labour market for school principals in South Africa, this paper highlights four overarching characteristics of this market with implications for informing principal policy reforms. The paper notes that improving the design and implementation of policies guiding the appointment process for principals is a matter of urgency. A substantial and increasing number of principal replacements are taking place across South African schools given a rising age profile of school principals. In a context of low levels of principal mobility and high tenure, the leadership trajectory of the average school is established for nearly a decade with each principal replacement. Evidence-based policy making has a strong role to play in getting this right.

  7. Value-based Q(s,S) policy for joint replenishments

    DEFF Research Database (Denmark)

    Johansen, Søren Glud; Thorstenson, Anders

    set of 12-item numerical examples from the literature, the long-run average cost of the best known solution is reduced by approximately 1%. Further examples are also investigated and in some cases for which the cost structure implies a high service level, the cost reduction exceeds 10% of the cost......We improve the previously proposed Q(s, S) policy for the stochastic joint replenishment problem. In our value-based Q(s, S) policy, item inventories are reviewed after each demand instant when the total demand since the last replenishment is close to Q. At each such review instance a new...... replenishment order is issued, if the expected cost of ordering immediately according to the (s, S) policy is less than the expected cost of deferring the order until the next demand or until the level Q is reached. We use simulation to evaluate our policy. Applying the value-based Q(s, S) policy to a standard...

  8. Evidence-based medicine - an appropriate tool for evidence-based health policy? A case study from Norway.

    Science.gov (United States)

    Malterud, Kirsti; Bjelland, Anne Karen; Elvbakken, Kari Tove

    2016-03-05

    Evidence-based policy (EBP), a concept modelled on the principles of evidence-based medicine (EBM), is widely used in different areas of policymaking. Systematic reviews (SRs) with meta-analyses gradually became the methods of choice for synthesizing research evidence about interventions and judgements about quality of evidence and strength of recommendations. Critics have argued that the relation between research evidence and service policies is weak, and that the notion of EBP rests on a misunderstanding of policy processes. Having explored EBM standards and knowledge requirements for health policy decision-making, we present an empirical point of departure for discussing the relationship between EBM and EBP. In a case study exploring the Norwegian Knowledge Centre for the Health Services (NOKC), an independent government unit, we first searched for information about the background and development of the NOKC to establish a research context. We then identified, selected and organized official NOKC publications as an empirical sample of typical top-of-the-line knowledge delivery adhering to EBM standards. Finally, we explored conclusions in this type of publication, specifically addressing their potential as policy decision tools. From a total sample of 151 SRs published by the NOKC in the period 2004-2013, a purposive subsample from 2012 (14 publications) advised major caution about their conclusions because of the quality or relevance of the underlying documentation. Although the case study did not include a systematic investigation of uptake and policy consequences, SRs were found to be inappropriate as universal tools for health policy decision-making. The case study demonstrates that EBM is not necessarily suited to knowledge provision for every kind of policy decision-making. Our analysis raises the question of whether the evidence-based movement, represented here by an independent government organization, undertakes too broad a range of commissions using

  9. An institutional framework for designing and monitoring ecosystem-based fisheries management policy experiments

    NARCIS (Netherlands)

    Rudd, M.A.

    2004-01-01

    Indicator systems are seen as central tools for ecosystem-based fisheries management, helping to steer fisheries towards sustainability by providing timely and useful information to decision-makers. Without testing hypotheses about the links between policies and outcomes, however, indicator systems

  10. Evidence-based policy for environmental sustainability: a path forward for South Africa

    CSIR Research Space (South Africa)

    Funke, Nicola S

    2009-03-01

    Full Text Available This handbook summarises the background behind, format of and lessons learned from a Collaborative Workshop on Evidence-based Policy-making that was held in November 2008. The workshop was organised by CSIR and funded by the UK's Department of Food...

  11. 78 FR 54623 - Effects of Foreign Policy-Based Export Controls

    Science.gov (United States)

    2013-09-05

    ... Nuclear Non-Proliferation Act of 1978 (42 U.S.C. 2139a). Under the provisions of section 6 of the EAA... proliferation controls. BIS is also interested in industry information relating to the following: 1. Information on the effect of foreign policy-based export controls on sales of U.S. products to third countries (i...

  12. Modernizing Schools in Mexico: The Rise of Teacher Assessment and School-Based Management Policies

    Science.gov (United States)

    Echávarri, Jaime; Peraza, Cecilia

    2017-01-01

    In this paper we analyze the evolution of the teacher assessment policy and the origins of school-based management initiatives in the Mexican education context from the late 1980s until the last 2012-2013 Education Reform (RE2012-2013). Mexico joined the Global Education Reform Movement during the 1990s through the National Agreement for the…

  13. The Development and Application of Policy-Based Tools for Institutional Green Buildings

    Science.gov (United States)

    Cupido, Anthony F.

    2010-01-01

    In 2008, APPA forwarded a Web-based survey on the author's behalf to all designated representatives of APPA member institutions. The purpose of the survey was to determine if institutional policies are an important criterion for an institution's sustainable building practices and the use of Leadership in Energy and Environmental Design (LEED[R]).…

  14. An Exploration of the System Dynamics Field : A Model-Based Policy Analysis

    NARCIS (Netherlands)

    Rose, A.C.

    2014-01-01

    This report presents a first look study at the field of System Dynamics. The objective of the study is to perform a model-based policy analysis in order to investigate the future advancement of the System Dynamics field. The aim of this investigation is to determine what this advancement should look

  15. Policy Change and Its Effect on Australian Community-Based Natural Resource Management Practices

    Science.gov (United States)

    Cooke, Penelope R.; Hemmings, Brian C.

    2016-01-01

    The authors of this article report on a qualitative study of Australian community-based natural resource management groups known as Landcare groups. They discuss how four Landcare groups contributed to sustainability practices and how a policy change implemented in 2003 influenced the efforts of the groups to remain active in their activities.…

  16. 76 FR 54426 - Effects of Foreign Policy-Based Export Controls

    Science.gov (United States)

    2011-09-01

    ... (Embargoes and Other Special Controls). These controls apply to a range of countries, items, activities and..., production, or overhaul of commercial aircraft engines, components, and systems (Sec. 742.14); Encryption... Foreign Policy-Based Export Controls AGENCY: Bureau of Industry and Security, Commerce. ACTION: Request...

  17. 75 FR 54540 - Effects of Foreign Policy-Based Export Controls

    Science.gov (United States)

    2010-09-08

    ... and Other Special Controls). These controls apply to a range of countries, items, activities and..., production, or overhaul of commercial aircraft engines, components, and systems (Sec. 742.14); encryption.... 100719301-0303-02] Effects of Foreign Policy-Based Export Controls AGENCY: Bureau of Industry and Security...

  18. 77 FR 55183 - Effects of Foreign Policy-Based Export Controls

    Science.gov (United States)

    2012-09-07

    ... and Other Special Controls). These controls apply to a range of countries, items, activities and..., production, or overhaul of commercial aircraft engines, components, and systems (Sec. 742.14); Encryption... Foreign Policy-Based Export Controls AGENCY: Bureau of Industry and Security, Commerce. ACTION: Request...

  19. Place-Based Policies, Firm Productivity and Displacement Effects: Evidence from Shenzhen, China

    NARCIS (Netherlands)

    H.R.A. Koster (Hans); F.F. Cheng (Fang); M.J.A. Gerritse (Michiel); F.G. van Oort (Frank)

    2016-01-01

    textabstractWe analyse the economic impacts of place-based policies that aim to enhance economic development by stimulating growth and productivity of firms in designated areas. We use unique panel data from China with information on manufacturing firms’ production factors, productivity and

  20. A First-Order Policy Language for History-Based Transaction Monitoring

    Science.gov (United States)

    Bauer, Andreas; Goré, Rajeev; Tiu, Alwen

    Online trading invariably involves dealings between strangers, so it is important for one party to be able to judge objectively the trustworthiness of the other. In such a setting, the decision to trust a user may sensibly be based on that user’s past behaviour. We introduce a specification language based on linear temporal logic for expressing a policy for categorising the behaviour patterns of a user depending on its transaction history. We also present an algorithm for checking whether the transaction history obeys the stated policy. To be useful in a real setting, such a language should allow one to express realistic policies which may involve parameter quantification and quantitative or statistical patterns. We introduce several extensions of linear temporal logic to cater for such needs: a restricted form of universal and existential quantification; arbitrary computable functions and relations in the term language; and a “counting” quantifier for counting how many times a formula holds in the past. We then show that model checking a transaction history against a policy, which we call the history-based transaction monitoring problem, is PSPACE-complete in the size of the policy formula and the length of the history, assuming that the underlying interpreted functions and relations are polynomially computable. The problem becomes decidable in polynomial time when the policies are fixed. We also consider the problem of transaction monitoring in the case where not all the parameters of actions are observable. We formulate two such “partial observability” monitoring problems, and show their decidability under certain restrictions.

  1. The Quality of Education: Some Policy Suggestions Based on a Survey of Schools--Zanzibar. SACMEQ Policy Research Report.

    Science.gov (United States)

    Nassor, Sebtuu; Mohammed, Khadija Ali

    The Southern Africa Consortium for Monitoring Educational Quality (SACMEQ) is a consortium of ministries of education in southern Africa. This bound report--one of seven--presents the research results and policy suggestions that emerged from implementation of initial educational policy research project. The report looks broadly at five areas of…

  2. The safety at home study: an evidence base for policy and practice change.

    Science.gov (United States)

    Doran, Diane; Blais, Régis; Baker, G Ross; Harrison, Margaret B; Lang, Ariella; Macdonald, Marilyn; McShane, Julie; Killackey, Tieghan

    2014-01-01

    This paper explores the policies and practices that are needed to improve the safety of home care in light of the most recent evidence about home care safety in Canada. Four areas for policy and practice change are addressed: 1) the promotion of effective communication processes in home care through cross-sector collaboration, case management and technology innovations; 2) screening for safety risk factors; 3) standardizing care processes, packaging and equipment; and 4) supporting family/caregivers and strengthening clients' ability to engage in therapeutic self-care. Evidence-based strategies for change are presented within the context of the evidence about home care safety issues. Copyright © 2014 Longwoods Publishing.

  3. Written institutional ethics policies on euthanasia: an empirical-based organizational-ethical framework.

    Science.gov (United States)

    Lemiengre, Joke; Dierckx de Casterlé, Bernadette; Schotsmans, Paul; Gastmans, Chris

    2014-05-01

    As euthanasia has become a widely debated issue in many Western countries, hospitals and nursing homes especially are increasingly being confronted with this ethically sensitive societal issue. The focus of this paper is how healthcare institutions can deal with euthanasia requests on an organizational level by means of a written institutional ethics policy. The general aim is to make a critical analysis whether these policies can be considered as organizational-ethical instruments that support healthcare institutions to take their institutional responsibility for dealing with euthanasia requests. By means of an interpretative analysis, we conducted a process of reinterpretation of results of former Belgian empirical studies on written institutional ethics policies on euthanasia in dialogue with the existing international literature. The study findings revealed that legal regulations, ethical and care-oriented aspects strongly affected the development, the content, and the impact of written institutional ethics policies on euthanasia. Hence, these three cornerstones-law, care and ethics-constituted the basis for the empirical-based organizational-ethical framework for written institutional ethics policies on euthanasia that is presented in this paper. However, having a euthanasia policy does not automatically lead to more legal transparency, or to a more professional and ethical care practice. The study findings suggest that the development and implementation of an ethics policy on euthanasia as an organizational-ethical instrument should be considered as a dynamic process. Administrators and ethics committees must take responsibility to actively create an ethical climate supporting care providers who have to deal with ethical dilemmas in their practice.

  4. A cluster analysis of Croatian counties as the base for an active demographic policy

    Directory of Open Access Journals (Sweden)

    Elza Jurun

    2017-01-01

    Full Text Available This paper deals with Croatian counties cluster analysis as the base for developing a proactive demographic policy. Unfortunately, Croatia has no national demographic strategy and no national population policy is carried out. Some local governments are taking isolated policy measures but due to an unsystematic and distressed network at the national level it has to date given no significant effects. The Croatian nation is currently experiencing the initial process of demographic extinction. This process began even before the great emigration wave that started about a year and half ago. Since there are no financial resources for the simultaneous and complete implementation of an active demographic policy across the entire Croatian territory, this paper proposes a new approach. Namely, the main demographic indicators have been calculated and analyzed for each Croatian county. After that, using a multivariate methodology, fifteen demographic indicators that significantly differ from county to county were selected as criteria for clustering Croatian counties by k-means method. Clustering output defines several clusters consisting of a smaller number of counties with similar demographic characteristics. These clusters form a spatial county unit in which appropriate measures of an active demographic policy should be urgently implemented. In this way the process of active demographic policy can start with less financial resources and can be limited maybe only to spaces with poorest demographic characteristics. Moreover, the results of this study might very well stimulate "richer” government units to carry out the appropriate active demographic policy measures in their areas without waiting for the adoption of laws and regulations at the national state level.

  5. A CoD-based stationary control policy for intervening in large gene regulatory networks.

    Science.gov (United States)

    Ghaffari, Noushin; Ivanov, Ivan; Qian, Xiaoning; Dougherty, Edward R

    2011-10-18

    One of the most important goals of the mathematical modeling of gene regulatory networks is to alter their behavior toward desirable phenotypes. Therapeutic techniques are derived for intervention in terms of stationary control policies. In large networks, it becomes computationally burdensome to derive an optimal control policy. To overcome this problem, greedy intervention approaches based on the concept of the Mean First Passage Time or the steady-state probability mass of the network states were previously proposed. Another possible approach is to use reduction mappings to compress the network and develop control policies on its reduced version. However, such mappings lead to loss of information and require an induction step when designing the control policy for the original network. In this paper, we propose a novel solution, CoD-CP, for designing intervention policies for large Boolean networks. The new method utilizes the Coefficient of Determination (CoD) and the Steady-State Distribution (SSD) of the model. The main advantage of CoD-CP in comparison with the previously proposed methods is that it does not require any compression of the original model, and thus can be directly designed on large networks. The simulation studies on small synthetic networks shows that CoD-CP performs comparable to previously proposed greedy policies that were induced from the compressed versions of the networks. Furthermore, on a large 17-gene gastrointestinal cancer network, CoD-CP outperforms other two available greedy techniques, which is precisely the kind of case for which CoD-CP has been developed. Finally, our experiments show that CoD-CP is robust with respect to the attractor structure of the model. The newly proposed CoD-CP provides an attractive alternative for intervening large networks where other available greedy methods require size reduction on the network and an extra induction step before designing a control policy.

  6. Effect of depletion layer width on electrical properties of semiconductive thin film gas sensor: a numerical study based on the gradient-distributed oxygen vacancy model

    Science.gov (United States)

    Liu, Jianqiao; Lu, Yiting; Cui, Xiao; Jin, Guohua; Zhai, Zhaoxia

    2016-03-01

    The effects of depletion layer width on the semiconductor gas sensors were investigated based on the gradient-distributed oxygen vacancy model, which provided numerical descriptions for the sensor properties. The potential barrier height, sensor resistance, and response to target gases were simulated to reveal their dependences on the depletion layer width. According to the simulation, it was possible to improve the sensor response by enlarging the width of depletion layer without changing the resistance of the gas sensor under the special circumstance. The different performances between resistance and response could provide a bright expectation that the design and fabrication of gas sensing devices could be economized. The simulation results were validated by the experimental performances of SnO2 thin film gas sensors, which were prepared by the sol-gel technique. The dependences of sensor properties on depletion layer width were observed to be in agreement with the simulations.

  7. Testing the limits of gradient sensing.

    Directory of Open Access Journals (Sweden)

    Vinal Lakhani

    2017-02-01

    Full Text Available The ability to detect a chemical gradient is fundamental to many cellular processes. In multicellular organisms gradient sensing plays an important role in many physiological processes such as wound healing and development. Unicellular organisms use gradient sensing to move (chemotaxis or grow (chemotropism towards a favorable environment. Some cells are capable of detecting extremely shallow gradients, even in the presence of significant molecular-level noise. For example, yeast have been reported to detect pheromone gradients as shallow as 0.1 nM/μm. Noise reduction mechanisms, such as time-averaging and the internalization of pheromone molecules, have been proposed to explain how yeast cells filter fluctuations and detect shallow gradients. Here, we use a Particle-Based Reaction-Diffusion model of ligand-receptor dynamics to test the effectiveness of these mechanisms and to determine the limits of gradient sensing. In particular, we develop novel simulation methods for establishing chemical gradients that not only allow us to study gradient sensing under steady-state conditions, but also take into account transient effects as the gradient forms. Based on reported measurements of reaction rates, our results indicate neither time-averaging nor receptor endocytosis significantly improves the cell's accuracy in detecting gradients over time scales associated with the initiation of polarized growth. Additionally, our results demonstrate the physical barrier of the cell membrane sharpens chemical gradients across the cell. While our studies are motivated by the mating response of yeast, we believe our results and simulation methods will find applications in many different contexts.

  8. A New Regulatory Policy for FTTx-Based Next-Generation Access Networks

    Science.gov (United States)

    Makarovič, Boštjan

    2013-07-01

    This article critically assesses the latest European Commission policies in relation to next-generation access investment that put focus on regulated prices and relaxing of wholesale access obligations. Pointing at the vital socio-legal and economic arguments, it further challenges the assumptions of the current EU regulatory framework and calls for a more contractual utility-based model of regulation instead of the current system that overly relies on market-driven infrastructure-based competition.

  9. Place-Based Policies, Firm Productivity and Displacement Effects: Evidence from Shenzhen, China

    OpenAIRE

    Koster, Hans; Cheng, Fang; Gerritse, Michiel; Oort, Frank

    2016-01-01

    textabstractWe analyse the economic impacts of place-based policies that aim to enhance economic development by stimulating growth and productivity of firms in designated areas. We use unique panel data from China with information on manufacturing firms’ production factors, productivity and location, and we exploit temporal and spatial variation in place-based interventions due to the opening of science parks in the metropolitan area of Shenzhen. The identification strategy enables us to addr...

  10. Health: Policy or Law? A Population-Based Analysis of the Supreme Court's ACA Cases.

    Science.gov (United States)

    Parmet, Wendy E

    2016-12-01

    This essay argues that it matters for the fate of health policies challenged in court whether courts consider health merely as a policy goal that must be subordinate to law, or as a legal norm warranting legal weight and consideration. Applying population-based legal analysis, this article demonstrates that courts have traditionally treated health as a legal norm. However, this norm appears to have weakened in recent years, a trend evident in the Supreme Court's first two decisions concerning the Affordable Care Act, NFIB v. Sebelius and Burwell v. Hobby Lobby However, in its more recent Affordable Care Act decision, King v. Burwell , the health legal norm is once again evident. Whether the Court will continue to treat health as a legal norm will prove critical to the deference and weight it grants health policies in the future. Copyright © 2016 by Duke University Press.

  11. ASN guide project. Safety policy and management in INBs (base nuclear installations)

    International Nuclear Information System (INIS)

    2010-01-01

    This guide presents the recommendations of the French Nuclear Safety Authority (ASN) in the field of safety policy and management (PMS) for base nuclear installations (INBs). It gives an overview and comments of some prescriptions of the so-called INB order and PMS decision. These regulatory texts define a framework for provisions any INB operator must implement to establish his safety policy, to define and implement a system which allows the safety to be maintained, the improvement of his INB safety to be permanently looked for. The following issues are addressed: operator's safety policy, identification of elements important for safety, of activities pertaining to safety, and of associated requirements, safety management organization and system, management of activities pertaining to safety, documentation and archiving

  12. Place-based innovation in Cohesion Policy: meeting and measuring the challenges

    Directory of Open Access Journals (Sweden)

    Alys Solly

    2016-01-01

    Full Text Available This paper, prepared in conjunction with the European Union’s Open Days 2015, examines current Cohesion Policy in terms of its place-based logic, a key aspect of the new Smart Specialisation strategy platform. After discussing changing notions of urbanization and governance, which seem to be shifting Cohesion Policy towards a more performance-oriented analysis of its outcomes, the paper focuses on the question of identifying an appropriate set of indicators and measuring framework. It suggests that measurements of Cohesion Policy performance should analyse the outcomes and indicators, as well as the European and national data sources and statistics, through the lens of effectiveness and well-being.

  13. A Proposed Intelligent Policy-Based Interface for a Mobile eHealth Environment

    Science.gov (United States)

    Tavasoli, Amir; Archer, Norm

    Users of mobile eHealth systems are often novices, and the learning process for them may be very time consuming. In order for systems to be attractive to potential adopters, it is important that the interface should be very convenient and easy to learn. However, the community of potential users of a mobile eHealth system may be quite varied in their requirements, so the system must be able to adapt easily to suit user preferences. One way to accomplish this is to have the interface driven by intelligent policies. These policies can be refined gradually, using inputs from potential users, through intelligent agents. This paper develops a framework for policy refinement for eHealth mobile interfaces, based on dynamic learning from user interactions.

  14. Policy in management based on corruption growth of resources agropolitan in the Gorontalo Province

    Science.gov (United States)

    Wantu, S. M.; Moonti, U.; Wantu, A.

    2018-02-01

    Gorontalo was formed as a new province in Indonesia as a producer of national maize, but until now the agropolitan-based agricultural development condition is still inadequate and needs to be developed well. Thus, it is necessary to conduct a governance-related study on empowering farmers in order to increase their capacity in exploring the agricultural sector. This study aims to see the need for local government policies in managing human resources in the agricultural sector in this case the potential and contribution of farmers in creating new jobs in rural areas. This study uses a qualitative approach to the use of secondary data and primary data as a basis for tracing or researching local government management policies in empowering farmers to improve their welfare and also how this policy is expected to organize effective market mechanisms for farmers.

  15. Efficient Attribute-Based Secure Data Sharing with Hidden Policies and Traceability in Mobile Health Networks

    Directory of Open Access Journals (Sweden)

    Changhee Hahn

    2016-01-01

    Full Text Available Mobile health (also written as mHealth provisions the practice of public health supported by mobile devices. mHealth systems let patients and healthcare providers collect and share sensitive information, such as electronic and personal health records (EHRs at any time, allowing more rapid convergence to optimal treatment. Key to achieving this is securely sharing data by providing enhanced access control and reliability. Typically, such sharing follows policies that depend on patient and physician preferences defined by a set of attributes. In mHealth systems, not only the data but also the policies for sharing it may be sensitive since they directly contain sensitive information which can reveal the underlying data protected by the policy. Also, since the policies usually incur linearly increasing communication costs, mHealth is inapplicable to resource-constrained environments. Lastly, access privileges may be publicly known to users, so a malicious user could illegally share his access privileges without the risk of being traced. In this paper, we propose an efficient attribute-based secure data sharing scheme in mHealth. The proposed scheme guarantees a hidden policy, constant-sized ciphertexts, and traces, with security analyses. The computation cost to the user is reduced by delegating approximately 50% of the decryption operations to the more powerful storage systems.

  16. When to base clinical policies on observational versus randomized trial data.

    Science.gov (United States)

    Hornberger, J; Wrone, E

    1997-10-15

    Physicians must decide when the evidence is sufficient to adopt a new clinical policy. Analysis of large clinical and administrative databases is becoming an important source of evidence for changing clinical policies. Because such analysis cannot control for the effects of all potential confounding variables, physicians risk drawing the wrong conclusion about the cause-and-effect relation between a change in clinical policy and outcomes. Randomized studies offer protection against drawing a conclusion that would lead to adoption of an inferior policy. However, a randomized study may be difficult to justify because of the extra costs of collecting data for a randomized study and concerns that a study will not directly benefit the patients enrolled in the study. This article reviews the advantages and disadvantages of basing clinical policy on analysis of large databases compared with conducting a randomized study. A technique is described and illustrated for accessing the potential costs and benefits of conducting such a study. This type of analysis formed the basis for a physician-managed health care organization deciding to sponsor a randomized study among patients with end-stage renal disease as part of a quality-improvement initiative.

  17. Designing a climate change policy for the international maritime transport sector: Market-based measures and technological options for global and regional policy actions

    International Nuclear Information System (INIS)

    Miola, A.; Marra, M.; Ciuffo, B.

    2011-01-01

    The international maritime transport sector has a significant abatement potential and some technical improvements that reduce GHG emissions would already be profitable without any policy in place. This paper analyses in-depth the limits and opportunities of policy options currently under consideration at the international level to stimulate the sector to reduce its GHG emissions. In particular, in order for the maritime transport sector to become more environmentally friendly, the flexible nature of international market-based measures and the European Union Emission Trading Scheme provide a definite window of opportunity without placing unnecessary high burden on the sector. However, the development of a regional policy, such as at European level, for the international maritime transport sector faces several obstacles: allocation of emissions, carbon leakage, permit allocation, treatment of the great variety in ship type, size and usage, and transaction cost. Global market-based policies could overcome most of these challenges. This paper provides an in-depth analysis of the policy instruments currently under discussion to reduce the sector's burden on the environment, and focuses on economic theory, legal principles, technological options, and the political framework that together make up the basis of decision-making regarding the international maritime transport sector's climate change policies. - Highlights: → Technologies for a more environmental friendly maritime transport sector and their cost-effectiveness. → How to combine ambitious CO 2 reduction goals with a sector-wide market-based policy. → Permits should be auctioned frequently and small emitters have to be excluded. → Inclusion of shipping in the EU ETS causes carbon leakage, so the policy should aim at expansion.

  18. Implementing evidence based policy in a network-setting. Dutch Road Safety Policy in a shift from a Home to an Away Match

    NARCIS (Netherlands)

    Ch. Bax (Charlotte); M. de Jong (Martin); J.F.M. Koppenjan (Joop)

    2010-01-01

    textabstractAbstract In order to improve road safety in the Netherlands, in 1992 the Institute for Road Safety Research (SWOV) developed the evidence-based ‘Sustainable Safety’ concept. Dutch road safety policy, based on this concept, was quite successful and seen as a best practice in Europe.

  19. National Drought Policy: Shifting the Paradigm from Crisis to Risk-based Management

    Science.gov (United States)

    Wilhite, D. A.; Sivakumar, M. K.; Stefanski, R.

    2011-12-01

    Drought is a normal part of climate for virtually all of the world's climatic regimes. To better address the risks associated with this hazard and societal vulnerability, there must be a dramatic paradigm shift in our approach to drought management in the coming decade in the light of the increasing frequency of droughts and projections of increased severity and duration of these events in the future for many regions, especially in the developing world. Addressing this challenge will require an improved awareness of drought as a natural hazard, the establishment of integrated drought monitoring and early warning systems, a higher level of preparedness that fully incorporates risk-based management, and the adoption of national drought policies that are directed at increasing the coping capacity and resilience of populations to future drought episodes. The World Meteorological Organization (WMO), in partnership with other United Nations' agencies, the National Drought Mitigation Center at the University of Nebraska, NOAA, the U.S. Department of Agriculture, and other partners, is currently launching a program to organize a High Level Meeting on National Drought Policy (HMNDP) in March 2013 to encourage the development of national drought policies through the development of a compendium of key policy elements. The key objectives of a national drought policy are to: (1) encourage vulnerable economic sectors and population groups to adopt self-reliant measures that promote risk management; (2) promote sustainable use of the agricultural and natural resource base; and (3) facilitate early recovery from drought through actions consistent with national drought policy objectives. The key elements of a drought policy framework are policy and governance, including political will; addressing risk and improving early warnings, including vulnerability analysis, impact assessment, and communication; mitigation and preparedness, including the application of effective and

  20. The challenges of changing national malaria drug policy to artemisinin-based combinations in Kenya

    Directory of Open Access Journals (Sweden)

    Otieno Dorothy N

    2007-05-01

    Full Text Available Abstract Backgound Sulphadoxine/sulphalene-pyrimethamine (SP was adopted in Kenya as first line therapeutic for uncomplicated malaria in 1998. By the second half of 2003, there was convincing evidence that SP was failing and had to be replaced. Despite several descriptive investigations of policy change and implementation when countries moved from chloroquine to SP, the different constraints of moving to artemisinin-based combination therapy (ACT in Africa are less well documented. Methods A narrative description of the process of anti-malarial drug policy change, financing and implementation in Kenya is assembled from discussions with stakeholders, reports, newspaper articles, minutes of meetings and email correspondence between actors in the policy change process. The narrative has been structured to capture the timing of events, the difficulties and hurdles faced and the resolutions reached to the final implementation of a new treatment policy. Results Following a recognition that SP was failing there was a rapid technical appraisal of available data and replacement options resulting in a decision to adopt artemether-lumefantrine (AL as the recommended first-line therapy in Kenya, announced in April 2004. Funding requirements were approved by the Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM and over 60 million US$ were agreed in principle in July 2004 to procure AL and implement the policy change. AL arrived in Kenya in May 2006, distribution to health facilities began in July 2006 coincidental with cascade in-service training in the revised national guidelines. Both training and drug distribution were almost complete by the end of 2006. The article examines why it took over 32 months from announcing a drug policy change to completing early implementation. Reasons included: lack of clarity on sustainable financing of an expensive therapeutic for a common disease, a delay in release of funding, a lack of comparative efficacy data

  1. An Extended EPQ-Based Problem with a Discontinuous Delivery Policy, Scrap Rate, and Random Breakdown

    Directory of Open Access Journals (Sweden)

    Singa Wang Chiu

    2015-01-01

    Full Text Available In real supply chain environments, the discontinuous multidelivery policy is often used when finished products need to be transported to retailers or customers outside the production units. To address this real-life production-shipment situation, this study extends recent work using an economic production quantity- (EPQ- based inventory model with a continuous inventory issuing policy, defective items, and machine breakdown by incorporating a multiple delivery policy into the model to replace the continuous policy and investigates the effect on the optimal run time decision for this specific EPQ model. Next, we further expand the scope of the problem to combine the retailer’s stock holding cost into our study. This enhanced EPQ-based model can be used to reflect the situation found in contemporary manufacturing firms in which finished products are delivered to the producer’s own retail stores and stocked there for sale. A second model is developed and studied. With the help of mathematical modeling and optimization techniques, the optimal run times that minimize the expected total system costs comprising costs incurred in production units, transportation, and retail stores are derived, for both models. Numerical examples are provided to demonstrate the applicability of our research results.

  2. Using a Participatory Approach to the Development of a School-Based Physical Activity Policy in an Indigenous Community

    Science.gov (United States)

    Hogan, Lindsay; Bengoechea, Enrique García; Salsberg, Jon; Jacobs, Judi; King, Morrison; Macaulay, Ann C.

    2014-01-01

    Background: This study is part of a larger community-based participatory research (CBPR) project to develop, implement, and evaluate the physical activity component of a school-based wellness policy. The policy intervention is being carried out by community stakeholders and academic researchers within the Kahnawake Schools Diabetes Prevention…

  3. A Case Study of Policies and Procedures to Address Cyberbullying at a Technology-Based Middle School

    Science.gov (United States)

    Tate, Bettina Polite

    2017-01-01

    This qualitative case study explored the policies and procedures used to effectively address cyberbullying at a technology-based middle school. The purpose of the study was to gain an in-depth understanding of policies and procedures used to address cyberbullying at a technology-based middle school in the southern United States. The study sought…

  4. Deciding Who Decides Questions at the Intersection of School Finance Reform Litigation and Standards-Based Accountability Policies

    Science.gov (United States)

    Superfine, Benjamin Michael

    2009-01-01

    Courts hearing school finance reform cases have recently begun to consider several issues related to standards-based accountability policies. This convergence of school finance reform litigation and standards-based accountability policies represents a chance for the courts to reallocate decision-making authority for each type of reform across the…

  5. Gradient decent based multi-objective cultural differential evolution for short-term hydrothermal optimal scheduling of economic emission with integrating wind power and photovoltaic power

    International Nuclear Information System (INIS)

    Zhang, Huifeng; Yue, Dong; Xie, Xiangpeng; Dou, Chunxia; Sun, Feng

    2017-01-01

    With the integration of wind power and photovoltaic power, optimal operation of hydrothermal power system becomes great challenge due to its non-convex, stochastic and complex-coupled constrained characteristics. This paper extends short-term hydrothermal system optimal model into short-term hydrothermal optimal scheduling of economic emission while considering integrated intermittent energy resources (SHOSEE-IIER). For properly solving SHOSEE-IIER problem, a gradient decent based multi-objective cultural differential evolution (GD-MOCDE) is proposed to improve the optimal efficiency of SHOSEE-IIER combined with three designed knowledge structures, which mainly enhances search ability of differential evolution in the shortest way. With considering those complex-coupled and stochastic constraints, a heuristic constraint-handling measurement is utilized to tackle with them both in coarse and fine tuning way, and probability constraint-handling procedures are taken to properly handle those stochastic constraints combined with their probability density functions. Ultimately, those approaches are implemented on five test systems, which testify the optimization efficiency of proposed GD-MOCDE and constraint-handling efficiency for system load balance, water balance and stochastic constraint-handling measurements, those obtained results reveal that the proposed GD-MOCDE can properly solve the SHOSEE-IIER problem combined with those constraint-handling approaches. - Highlights: • Gradient decent method is proposed to improve mutation operator. • Hydrothermal system is extended to hybrid energy system. • The uncertainty constraint is converted into deterministic constraint. • The results show the viability and efficiency of proposed algorithm.

  6. Culture-based and denaturing gradient gel electrophoresis analysis of the bacterial community from Chungkookjang, a traditional Korean fermented soybean food.

    Science.gov (United States)

    Hong, Sung Wook; Choi, Jae Young; Chung, Kun Sub

    2012-10-01

    The bacterial community of Chungkookjang and raw rice-straw collected from various areas in South Korea was investigated using both culture-dependent and culture-independent methods. Pure cultures were isolated from Chungkookjang and raw rice-straw on tryptic soy agar plates with 72 to 121 colonies and identified by 16S rDNA gene sequence analysis, respectively. The traditional culture-based method and denaturing gradient gel electrophoresis analysis of PCR-amplified 16S rDNA confirmed that Pantoea agglomerans and B. subtilis were identified as predominant in the raw rice-straw and Chungkookjang, respectively, from Iljuk district of Gyeonggi province, P. ananatis and B. licheniformis were identified as predominant in the raw rice-straw and Chungkookjang from Wonju district of Gangwon province, and Microbacterium sp. and B. licheniformis were identified as predominant in the raw rice-straw and Chungkookjang from Sunchang district of Jeolla province. Other strains, such as Bacillus, Enterococcus, Pseudomonas, Rhodococcus, and uncultured bacteria were also present in raw rice-straw and Chungkookjang. A comprehensive analysis of these microorganisms would provide a more detailed understanding of the biologically active components of Chungkookjang and help improve its quality. Polymerase chain reaction-denaturing gradient gel electrophoresis analysis can be successfully applied to a fermented food to detect unculturable or more species than the culture-dependent method. This technique is an effective and convenient culture-independent method for studying the bacterial community in Chungkookjang. In this study, the bacterial community of Chungkookjang collected from various areas in South Korea was investigated using both culture-dependent and culture-independent methods. © 2012 Institute of Food Technologists®

  7. Evidence Based Weighing Policy during the First Week to Prevent Neonatal Hypernatremic Dehydration while Breastfeeding.

    Science.gov (United States)

    Boer, Suzanne; Unal, Sevim; van Wouwe, Jacobus P; van Dommelen, Paula

    2016-01-01

    Neonatal hypernatremic dehydration is prevented by daily neonatal weight monitoring. We aim to provide evidence-based support of this universally promoted weighing policy and to establish the most crucial days of weighing. Weight measurements of 2,359 healthy newborns and of 271 newborns with clinical hypernatremic dehydration were used within the first seven days of life to simulate various weighting policies to prevent hypernatremic dehydration; its sensitivity, specificity and positive predictive value (PPV) of these policies were calculated. Various referral criteria were also evaluated. A policy of daily weighing with a cut-off value of -2.5 Standard Deviation Score (SDS) on the growth chart for weight loss, had a 97.6% sensitivity, 97.6% specificity and a PPV of 2.80%. Weighing at birth and only at days two, four and seven with the same -2.5 SDS cut-off, resulted in 97.3% sensitivity, 98.5% specificity and a PPV of 4.43%. A weighing policy with measurements restricted to birth and day two, four and seven applying the -2.5 SDS cut-off seems an optimal policy to detect hypernatremic dehydration. Therefore we recommend to preferably weigh newborns at least on day two (i.e. ~48h), four and seven, and refer them to clinical pediatric care if their weight loss increases below -2.5 SDS. We also suggest lactation support for the mother, full clinical assessment of the infant and weighing again the following day in all newborns reaching a weight loss below -2.0 SDS.

  8. Dynamic UAV-based traffic monitoring under uncertainty as a stochastic arc-inventory routing policy

    Directory of Open Access Journals (Sweden)

    Joseph Y.J. Chow

    2016-10-01

    Full Text Available Given the rapid advances in unmanned aerial vehicles, or drones, and increasing need to monitor at a city level, one of the current research gaps is how to systematically deploy drones over multiple periods. We propose a real-time data-driven approach: we formulate the first deterministic arc-inventory routing problem and derive its stochastic dynamic policy. The policy is expected to be of greatest value in scenarios where uncertainty is highest and costliest, such as city monitoring during major events. The Bellman equation for an approximation of the proposed inventory routing policy is formulated as a selective vehicle routing problem. We propose an approximate dynamic programming algorithm based on Least Squares Monte Carlo simulation to find that policy. The algorithm has been modified so that the least squares dependent variable is defined to be the “expected stock out cost upon the next replenishment”. The new algorithm is tested on 30 simulated instances of real time trajectories over 5 time periods of the selective vehicle routing problem to evaluate the proposed policy and algorithm. Computational results on the selected instances show that the algorithm on average outperforms the myopic policy by 23–28%, depending on the parametric design. Further tests are conducted on classic benchmark arc routing problem instances. The 11-link instance gdb19 (Golden et al., 1983 is expanded into a sequential 15-period stochastic dynamic example and used to demonstrate why a naïve static multi-period deployment plan would not be effective in real networks.

  9. Approximate error conjugation gradient minimization methods

    Science.gov (United States)

    Kallman, Jeffrey S

    2013-05-21

    In one embodiment, a method includes selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, calculating an approximate error using the subset of rays, and calculating a minimum in a conjugate gradient direction based on the approximate error. In another embodiment, a system includes a processor for executing logic, logic for selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, logic for calculating an approximate error using the subset of rays, and logic for calculating a minimum in a conjugate gradient direction based on the approximate error. In other embodiments, computer program products, methods, and systems are described capable of using approximate error in constrained conjugate gradient minimization problems.

  10. Base Stock Policy in a Join-Type Production Line with Advanced Demand Information

    Science.gov (United States)

    Hiraiwa, Mikihiko; Tsubouchi, Satoshi; Nakade, Koichi

    Production control such as the base stock policy, the kanban policy and the constant work-in-process policy in a serial production line has been studied by many researchers. Production lines, however, usually have fork-type, join-type or network-type figures. In addition, in most previous studies on production control, a finished product is required at the same time as arrival of demand at the system. Demand information is, however, informed before due date in practice. In this paper a join-type (assembly) production line under base stock control with advanced demand information in discrete time is analyzed. The recursive equations for the work-in-process are derived. The heuristic algorithm for finding appropriate base stock levels of all machines at short time is proposed and the effect of advanced demand information is examined by simulation with the proposed algorithm. It is shown that the inventory cost can decreases with little backlogs by using the appropriate amount of demand information and setting appropriate base stock levels.

  11. Defining Emergency Department Necessary Policies Based on Clinical Governance Accreditation Scores

    Directory of Open Access Journals (Sweden)

    Mehrdad Esmailian

    2015-05-01

    Full Text Available Introduction: The role of accreditation scheme in quality improvement of emergency departments (ED has not been thoroughly evaluated in studies. Therefore, this study was designed to appraise the effects of policies defined based on clinical governance accreditation scores, on improvement of the procedures in ED. Methods: The present cohort study was carried out in the ED of Alzahra University Hospital, Isfahan, Iran in 2012-2013. In 2012 the deficiencies in ED of this hospital was determined based on clinical governance indicators. Then the deficiencies were classified based on their importance and changes were made in the ED. Finally, the effects of the changes were evaluated in August 2013. Results: The evaluation made in 2012 showed that 23 clinical and non-clinical procedures were carried out with deficiencies. Over the mentioned period, 6 (26.1% procedures were not done at all, while 17 (73.9% were done without a policy and irregularly. The overall score for clinical and non-clinical procedures in the ED before carrying out the accreditation scheme was 43 / 230 (18.7% of the maximum possible score. The score was raised to 222 equal to 96.5% of the maximum possible score after carrying out the scheme. This increase was statistically significant (p < 0.001. Conclusion: The findings of the present study showed that defining policies for improving the procedures carried out in ED based on accreditation scheme leads to improvement of medical services in ED.

  12. Denaturing gradient gel electrophoresis

    International Nuclear Information System (INIS)

    Kocherginskaya, S.A.; Cann, I.K.O.; Mackie, R.I.

    2005-01-01

    It is worthwhile considering that only some 30 species make up the bulk of the bacterial population in human faeces at any one time based on the classical cultivation-based approach. The situation in the rumen is similar. Thus, it is practical to focus on specific groups of interest within the complex community. These may be the predominant or the most active species, specific physiological groups or readily identifiable (genetic) clusters of phylogenetically related organisms. Several 16S rDNA fingerprinting techniques can be invaluable for selecting and monitoring sequences or phylogenetic groups of interest and are described below. Over the past few decades, considerable attention was focussed on the identification of pure cultures of microbes on the basis of genetic polymorphisms of DNA encoding rRNA such as ribotyping, amplified fragment length polymorphism and randomly amplified polymorphic DNA. However, many of these methods require prior cultivation and are less suitable for use in analysis of complex mixed populations although important in describing cultivated microbial diversity in molecular terms. Much less attention was given to molecular characterization of complex communities. In particular, research into diversity and community structure over time has been revolutionized by the advent of molecular fingerprinting techniques for complex communities. Denaturing or temperature gradient gel electrophoresis (DGGE/TGGE) methods have been successfully applied to the analysis of human, pig, cattle, dog and rodent intestinal populations

  13. Buckling and free vibration of shallow curved micro/nano-beam based on strain gradient theory under thermal loading with temperature-dependent properties

    Science.gov (United States)

    Rahmani, O.; Hosseini, S. A. H.; Ghoytasi, I.; Golmohammadi, H.

    2017-01-01

    In this study, influences of a uniform thermomechanical loading in buckling and free vibration of a curved FG microbeam have been investigated, based on strain gradient theory (SGT) theory and Timoshenko beam model. Distribution of structural materials varies continuously in thickness direction due to power-law exponent. Unlike classical models, this novel model employs three length scale parameters which can capture the size effect. This work is based on SGT theory and Timoshenko beam model. Governing equation of motion and associated boundary condition have been developed based on Hamilton's principle, which is the specified case of virtual work theorem. In continuance, final differential equations were solved by Navier's solution method and the results have been presented. Moreover, influences of dimensionless length-to-thickness ratio (aspect ratio), dimensionless length scale parameter, power-law exponent, temperature difference and arc angle for various values of mode numbers on natural frequency and critical temperature by considering temperature-dependent material properties have been investigated. In order to validate accomplished study, some of the results were compared with those of previous works. It has been concluded that applying a thermomechanical loading on a FG microbeam causes the natural frequency to become more sensitive about variations of geometrical, physical and mechanical properties and characteristics.

  14. Social gradients in child and adolescent antisocial behavior: a systematic review protocol

    Directory of Open Access Journals (Sweden)

    Piotrowska Patrycja J

    2012-08-01

    Full Text Available Abstract Background The relationship between social position and physical health is well-established across a range of studies. The evidence base regarding social position and mental health is less well developed, particularly regarding the development of antisocial behavior. Some evidence demonstrates a social gradient in behavioral problems, with children from low-socioeconomic backgrounds experiencing more behavioral difficulties than children from high-socioeconomic families. Antisocial behavior is a heterogeneous concept that encompasses behaviors as diverse as physical fighting, vandalism, stealing, status violation and disobedience to adults. Whether all forms of antisocial behavior show identical social gradients is unclear from previous published research. The mechanisms underlying social gradients in antisocial behavior, such as neighborhood characteristics and family processes, have not been fully elucidated. This review will synthesize findings on the social gradient in antisocial behavior, considering variation across the range of antisocial behaviors and evidence regarding the mechanisms that might underlie the identified gradients. Methods In this review, an extensive manual and electronic literature search will be conducted for papers published from 1960 to 2011. The review will include empirical and quantitative studies of children and adolescents ( Discussion This systematic review has been proposed in order to synthesize cross-disciplinary evidence of the social gradient in antisocial behavior and mechanisms underlying this effect. The results of the review will inform social policies aiming to reduce social inequalities and levels of antisocial behavior, and identify gaps in the present literature to guide further research.

  15. Model-Based Comprehensive Analysis of School Closure Policies for Mitigating Influenza Epidemics and Pandemics.

    Science.gov (United States)

    Fumanelli, Laura; Ajelli, Marco; Merler, Stefano; Ferguson, Neil M; Cauchemez, Simon

    2016-01-01

    School closure policies are among the non-pharmaceutical measures taken into consideration to mitigate influenza epidemics and pandemics spread. However, a systematic review of the effectiveness of alternative closure policies has yet to emerge. Here we perform a model-based analysis of four types of school closure, ranging from the nationwide closure of all schools at the same time to reactive gradual closure, starting from class-by-class, then grades and finally the whole school. We consider policies based on triggers that are feasible to monitor, such as school absenteeism and national ILI surveillance system. We found that, under specific constraints on the average number of weeks lost per student, reactive school-by-school, gradual, and county-wide closure give comparable outcomes in terms of optimal infection attack rate reduction, peak incidence reduction or peak delay. Optimal implementations generally require short closures of one week each; this duration is long enough to break the transmission chain without leading to unnecessarily long periods of class interruption. Moreover, we found that gradual and county closures may be slightly more easily applicable in practice as they are less sensitive to the value of the excess absenteeism threshold triggering the start of the intervention. These findings suggest that policy makers could consider school closure policies more diffusely as response strategy to influenza epidemics and pandemics, and the fact that some countries already have some experience of gradual or regional closures for seasonal influenza outbreaks demonstrates that logistic and feasibility challenges of school closure strategies can be to some extent overcome.

  16. The evolution of HIV policy in Vietnam: from punitive control measures to a more rights-based approach

    Directory of Open Access Journals (Sweden)

    Pham Nguyen Ha

    2010-08-01

    Full Text Available Aim: Policymaking in Vietnam has traditionally been the preserve of the political elite, not open to the scrutiny of those outside the Communist Party. This paper aims to analyse Vietnam's HIV policy development in order to describe and understand the policy content, policy-making processes, actors and obstacles to policy implementation. Methods: Nine policy documents on HIV were analysed and 17 key informant interviews were conducted in Hanoi and Quang Ninh Province, based on a predesigned interview guide. Framework analysis, a type of qualitative content analysis, was applied for data analysis. Results: Our main finding was that during the last two decades, developments in HIV policy in Vietnam were driven in a top-down way by the state organs, with support and resources coming from international agencies. Four major themes were identified: HIV policy content, the policy-making processes, the actors involved and human resources for policy implementation. Vietnam's HIV policy has evolved from one focused on punitive control measures to a more rights-based approach, encompassing harm reduction and payment of health insurance for medical costs of patients with HIV-related illness. Low salaries and staff reluctance to work with patients, many of whom are drug users and female sex workers, were described as the main barriers to low health staff motivation. Conclusion: Health policy analysis approaches can be applied in a traditional one party state and can demonstrate how similar policy changes take place, as those found in pluralistic societies, but through more top-down and somewhat hidden processes. Enhanced participation of other actors, like civil society in the policy process, is likely to contribute to policy formulation and implementation that meets the diverse needs and concerns of its population.

  17. Regulatory, institutional, and market-based approaches towards achieving comprehensive chemical policy reform.

    Science.gov (United States)

    Welker-Hood, Kristen; Condon, Marian; Wilburn, Susan

    2007-05-31

    The purpose of this article is to inform nurses and other health care professionals about the nexus between the environment and health and present approaches in which they can be involved so as to support comprehensive reform of chemicals management in the United States. It discusses the health impact of hazardous chemicals and the environmental regulatory failures within the U.S. to protect the public. It also reports on international chemical management initiatives and key elements of chemical policy reform that can guide the U.S. regulatory, market-based, and institutional-based approaches to a comprehensive, chemical policy reform. The role of nursing in advocating for these reforms will be presented.

  18. Status of costing hospital nursing work within Australian casemix activity-based funding policy.

    Science.gov (United States)

    Heslop, Liza

    2012-02-01

    Australia has a long history of patient level costing initiated when casemix funding was implemented in several states in the early 1990s. Australia includes, to some extent, hospital payment based on nursing intensity adopted within casemix funding policy and the Diagnostic Related Group system. Costing of hospital nursing services in Australia has not changed significantly in the last few decades despite widespread introduction of casemix funding policy at the state level. Recent Commonwealth of Australia National Health Reform presents change to the management of the delivery of health care including health-care costing. There is agreement for all Australian jurisdictions to progress to casemix-based activity funding. Within this context, nurse costing infrastructure presents contemporary issues and challenges. An assessment is made of the progress of costing nursing services within casemix funding models in Australian hospitals. Valid and reliable Australian-refined nursing service weights might overcome present cost deficiencies and limitations. © 2012 Blackwell Publishing Asia Pty Ltd.

  19. Population-based learning of load balancing policies for a distributed computer system

    Science.gov (United States)

    Mehra, Pankaj; Wah, Benjamin W.

    1993-01-01

    Effective load-balancing policies use dynamic resource information to schedule tasks in a distributed computer system. We present a novel method for automatically learning such policies. At each site in our system, we use a comparator neural network to predict the relative speedup of an incoming task using only the resource-utilization patterns obtained prior to the task's arrival. Outputs of these comparator networks are broadcast periodically over the distributed system, and the resource schedulers at each site use these values to determine the best site for executing an incoming task. The delays incurred in propagating workload information and tasks from one site to another, as well as the dynamic and unpredictable nature of workloads in multiprogrammed multiprocessors, may cause the workload pattern at the time of execution to differ from patterns prevailing at the times of load-index computation and decision making. Our load-balancing policy accommodates this uncertainty by using certain tunable parameters. We present a population-based machine-learning algorithm that adjusts these parameters in order to achieve high average speedups with respect to local execution. Our results show that our load-balancing policy, when combined with the comparator neural network for workload characterization, is effective in exploiting idle resources in a distributed computer system.

  20. European Union research in support of environment and health: Building scientific evidence base for policy.

    Science.gov (United States)

    Karjalainen, Tuomo; Hoeveler, Arnd; Draghia-Akli, Ruxandra

    2017-06-01

    Opinion polls show that the European Union citizens are increasingly concerned about the impact of environmental factors on their health. In order to respond and provide solid scientific evidence for the numerous policies related to the protection of human health and the environment managed at the Union level, the European Union made a substantial investment in research and innovation in the past two decades through its Framework Programmes for Research and Technological Development, including the current programme, Horizon 2020, which started in 2014. This policy review paper analysed the portfolio of forty collaborative projects relevant to environment and health, which received a total amount of around 228 million euros from the EU. It gives details on their contents and general scientific trends observed, the profiles of the participating countries and institutions, and the potential policy implications of the results obtained. The increasing knowledge base is needed to make informed policy decisions in Europe and beyond, and should be useful to many stakeholders including the scientific community and regulatory authorities. Copyright © 2017. Published by Elsevier Ltd.

  1. Assessing Risk-Based Policies for Pretrial Release and Split Sentencing in Los Angeles County Jails.

    Directory of Open Access Journals (Sweden)

    Mericcan Usta

    Full Text Available Court-mandated downsizing of the CA prison system has led to a redistribution of detainees from prisons to CA county jails, and subsequent jail overcrowding. Using data that is representative of the LA County jail system, we build a mathematical model that tracks the flow of individuals during arraignment, pretrial release or detention, case disposition, jail sentence, and possible recidivism during pretrial release, after a failure to appear in court, during non-felony probation and during felony supervision. We assess 64 joint pretrial release and split-sentencing (where low-level felon sentences are split between jail time and mandatory supervision policies that are based on the type of charge (felony or non-felony and the risk category as determined by the CA Static Risk Assessment tool, and compare their performance to that of the policy LA County used in early 2014, before split sentencing was in use. In our model, policies that offer split sentences to all low-level felons optimize the key tradeoff between public safety and jail congestion by, e.g., simultaneously reducing the rearrest rate by 7% and the mean jail population by 20% relative to the policy LA County used in 2014. The effectiveness of split sentencing is due to two facts: (i convicted felony offenders comprised ≈ 45% of LA County's jail population in 2014, and (ii compared to pretrial release, split sentencing exposes offenders to much less time under recidivism risk per saved jail day.

  2. Validation of measured poleward TEC gradient using multi-station GPS with Artificial Neural Network based TEC model in low latitude region for developing predictive capability of ionospheric scintillation

    Science.gov (United States)

    Sur, D.; Paul, A.

    2017-12-01

    The equatorial ionosphere shows sharp diurnal and latitudinal Total Electron Content (TEC) variations over a major part of the day. Equatorial ionosphere also exhibits intense post-sunset ionospheric irregularities. Accurate prediction of TEC in these low latitudes is not possible from standard ionospheric models. An Artificial Neural Network (ANN) based Vertical TEC (VTEC) model has been designed using TEC data in low latitude Indian longitude sector for accurate prediction of VTEC. GPS TEC data from the stations Calcutta (22.58°N, 88.38°E geographic, magnetic dip 32°), Baharampore (24.09°N, 88.25°E geographic, magnetic dip 35°) and Siliguri (26.72°N, 88.39°E geographic; magnetic dip 40°) are used as training dataset for the duration of January 2007-September 2011. Poleward VTEC gradients from northern EIA crest to region beyond EIA crest have been calculated from measured VTEC and compared with that obtained from ANN based VTEC model. TEC data from Calcutta and Siliguri are used to compute VTEC gradients during April 2013 and August-September 2013. It has been observed that poleward VTEC gradient computed from ANN based TEC model has shown good correlation with measured values during vernal and autumnal equinoxes of high solar activity periods of 2013. Possible correlation between measured poleward TEC gradients and post-sunset scintillations (S4 ≥ 0.4) from northern crest of EIA has been observed in this paper. From the observation, a suitable threshold poleward VTEC gradient has been proposed for possible occurrence of post-sunset scintillations at northern crest of EIA along 88°E longitude. Poleward VTEC gradients obtained from ANN based VTEC model are used to forecast possible ionospheric scintillation after post-sunset period using the threshold value. It has been observed that these predicted VTEC gradients obtained from ANN based VTEC model can forecast post-sunset L-band scintillation with an accuracy of 67% to 82% in this dynamic low latitude

  3. Possible Patient Early Diagnosis by Ultrasonic Noninvasive Estimation of Thermal Gradients into Tissues Based on Spectral Changes Modeling

    Directory of Open Access Journals (Sweden)

    I. Bazan

    2012-01-01

    Full Text Available To achieve a precise noninvasive temperature estimation, inside patient tissues, would open promising research fields, because its clinic results would provide early-diagnosis tools. In fact, detecting changes of thermal origin in ultrasonic echo spectra could be useful as an early complementary indicator of infections, inflammations, or cancer. But the effective clinic applications to diagnosis of thermometry ultrasonic techniques, proposed previously, require additional research. Before their implementations with ultrasonic probes and real-time electronic and processing systems, rigorous analyses must be still made over transient echotraces acquired from well-controlled biological and computational phantoms, to improve resolutions and evaluate clinic limitations. It must be based on computing improved signal-processing algorithms emulating tissues responses. Some related parameters in echo-traces reflected by semiregular scattering tissues must be carefully quantified to get a precise processing protocols definition. In this paper, approaches for non-invasive spectral ultrasonic detection are analyzed. Extensions of author's innovations for ultrasonic thermometry are shown and applied to computationally modeled echotraces from scattered biological phantoms, attaining high resolution (better than 0.1°C. Computer methods are provided for viability evaluation of thermal estimation from echoes with distinct noise levels, difficult to be interpreted, and its effectiveness is evaluated as possible diagnosis tool in scattered tissues like liver.

  4. Possible patient early diagnosis by ultrasonic noninvasive estimation of thermal gradients into tissues based on spectral changes modeling.

    Science.gov (United States)

    Bazan, I; Ramos, A; Calas, H; Ramirez, A; Pintle, R; Gomez, T E; Negreira, C; Gallegos, F J; Rosales, A J

    2012-01-01

    To achieve a precise noninvasive temperature estimation, inside patient tissues, would open promising research fields, because its clinic results would provide early-diagnosis tools. In fact, detecting changes of thermal origin in ultrasonic echo spectra could be useful as an early complementary indicator of infections, inflammations, or cancer. But the effective clinic applications to diagnosis of thermometry ultrasonic techniques, proposed previously, require additional research. Before their implementations with ultrasonic probes and real-time electronic and processing systems, rigorous analyses must be still made over transient echotraces acquired from well-controlled biological and computational phantoms, to improve resolutions and evaluate clinic limitations. It must be based on computing improved signal-processing algorithms emulating tissues responses. Some related parameters in echo-traces reflected by semiregular scattering tissues must be carefully quantified to get a precise processing protocols definition. In this paper, approaches for non-invasive spectral ultrasonic detection are analyzed. Extensions of author's innovations for ultrasonic thermometry are shown and applied to computationally modeled echotraces from scattered biological phantoms, attaining high resolution (better than 0.1 °C). Computer methods are provided for viability evaluation of thermal estimation from echoes with distinct noise levels, difficult to be interpreted, and its effectiveness is evaluated as possible diagnosis tool in scattered tissues like liver.

  5. A new approach to mixed H2/H infinity controller synthesis using gradient-based parameter optimization methods

    Science.gov (United States)

    Ly, Uy-Loi; Schoemig, Ewald

    1993-01-01

    In the past few years, the mixed H(sub 2)/H-infinity control problem has been the object of much research interest since it allows the incorporation of robust stability into the LQG framework. The general mixed H(sub 2)/H-infinity design problem has yet to be solved analytically. Numerous schemes have considered upper bounds for the H(sub 2)-performance criterion and/or imposed restrictive constraints on the class of systems under investigation. Furthermore, many modern control applications rely on dynamic models obtained from finite-element analysis and thus involve high-order plant models. Hence the capability to design low-order (fixed-order) controllers is of great importance. In this research a new design method was developed that optimizes the exact H(sub 2)-norm of a certain subsystem subject to robust stability in terms of H-infinity constraints and a minimal number of system assumptions. The derived algorithm is based on a differentiable scalar time-domain penalty function to represent the H-infinity constraints in the overall optimization. The scheme is capable of handling multiple plant conditions and hence multiple performance criteria and H-infinity constraints and incorporates additional constraints such as fixed-order and/or fixed structure controllers. The defined penalty function is applicable to any constraint that is expressible in form of a real symmetric matrix-inequity.

  6. Magnetoelectric Transverse Gradient Sensor with High Detection Sensitivity and Low Gradient Noise

    OpenAIRE

    Zhang, Mingji; Or, Siu Wing

    2017-01-01

    We report, theoretically and experimentally, the realization of a high detection performance in a novel magnetoelectric (ME) transverse gradient sensor based on the large ME effect and the magnetic field gradient (MFG) technique in a pair of magnetically-biased, electrically-shielded, and mechanically-enclosed ME composites having a transverse orientation and an axial separation. The output voltage of the gradient sensor is directly obtained from the transverse MFG-induced difference in ME vo...

  7. Travelling gradient thermocouple calibration

    International Nuclear Information System (INIS)

    Broomfield, G.H.

    1975-01-01

    A short discussion of the origins of the thermocouple EMF is used to re-introduce the idea that the Peltier and Thompson effects are indistinguishable from one another. Thermocouples may be viewed as devices which generate an EMF at junctions or as integrators of EMF's developed in thermal gradients. The thermal gradient view is considered the more appropriate, because of its better accord with theory and behaviour, the correct approach to calibration, and investigation of service effects is immediately obvious. Inhomogeneities arise in thermocouples during manufacture and in service. The results of travelling gradient measurements are used to show that such effects are revealed with a resolution which depends on the length of the gradient although they may be masked during simple immersion calibration. Proposed tests on thermocouples irradiated in a nuclear reactor are discussed

  8. Gradient-Based Quantitative Image Reconstruction in Ultrasound-Modulated Optical Tomography: First Harmonic Measurement Type in a Linearised Diffusion Formulation.

    Science.gov (United States)

    Powell, Samuel; Arridge, Simon R; Leung, Terence S

    2016-02-01

    Ultrasound-modulated optical tomography is an emerging biomedical imaging modality which uses the spatially localised acoustically-driven modulation of coherent light as a probe of the structure and optical properties of biological tissues. In this work we begin by providing an overview of forward modelling methods, before deriving a linearised diffusion-style model which calculates the first-harmonic modulated flux measured on the boundary of a given domain. We derive and examine the correlation measurement density functions of the model which describe the sensitivity of the modality to perturbations in the optical parameters of interest. Finally, we employ said functions in the development of an adjoint-assisted gradient based image reconstruction method, which ameliorates the computational burden and memory requirements of a traditional Newton-based optimisation approach. We validate our work by performing reconstructions of optical absorption and scattering in two- and three-dimensions using simulated measurements with 1% proportional Gaussian noise, and demonstrate the successful recovery of the parameters to within ±5% of their true values when the resolution of the ultrasound raster probing the domain is sufficient to delineate perturbing inclusions.

  9. T2*-based MR imaging (gradient echo or susceptibility-weighted imaging) in midline and off-midline intracranial germ cell tumors. A pilot study

    International Nuclear Information System (INIS)

    Morana, Giovanni; Tortora, Domenico; Severino, Mariasavina; Rossi, Andrea; Alves, Cesar Augusto; Finlay, Jonathan L.; Nozza, Paolo; Ravegnani, Marcello; Pavanello, Marco; Milanaccio, Claudia; Garre, Maria Luisa; Maghnie, Mohamad

    2018-01-01

    The role of T2*-based MR imaging in intracranial germ cell tumors (GCTs) has not been fully elucidated. The aim of this study was to evaluate the susceptibility-weighted imaging (SWI) or T2* gradient echo (GRE) features of germinomas and non-germinomatous germ cell tumors (NGGCTs) in midline and off-midline locations. We retrospectively evaluated all consecutive pediatric patients referred to our institution between 2005 and 2016, for newly diagnosed, treatment-naive intracranial GCT, who underwent MRI, including T2*-based MR imaging (T2* GRE sequences or SWI). Standard pre- and post-contrast T1- and T2-weighted imaging characteristics along with T2*-based MR imaging features of all lesions were evaluated. Diagnosis was performed in accordance with the SIOP CNS GCT protocol criteria. Twenty-four subjects met the inclusion criteria (17 males and 7 females). There were 17 patients with germinomas, including 5 basal ganglia primaries, and 7 patients with secreting NGGCT. All off-midline germinomas presented with SWI or GRE hypointensity; among midline GCT, all NGGCTs showed SWI or GRE hypointensity whereas all but one pure germinoma were isointense or hyperintense to normal parenchyma. A significant difference emerged on T2*-based MR imaging among midline germinomas, NGGCTs, and off-midline germinomas (p < 0.001). Assessment of the SWI or GRE characteristics of intracranial GCT may potentially assist in differentiating pure germinomas from NGGCT and in the characterization of basal ganglia involvement. T2*-based MR imaging is recommended in case of suspected intracranial GCT. (orig.)

  10. Sector-based political analysis of energy transition: Green shift in the forest policy regime in France

    International Nuclear Information System (INIS)

    Sergent, Arnaud

    2014-01-01

    This article examines energy transition political process from a sector-based approach, through the analysis of recent shift in the French forest policy regime. We demonstrate that, since 2007, energy transition policies have led to a harvesting turn within the French forest policy framework, meaning that priority is given to wood mobilisation, mainly for biomass uses. In addition, our findings suggest that the political authority wielded by the state over forest policy has shifted from forest administrative services to energy agencies and local authorities. Finally, we show that, although implementation of the harvesting turn is a cause of sectoral and inter-sectoral tensions, energy transition challenge also contributes to a process of (re)institutionalisation of mediation relationships among forestry stakeholders and wood-based industries representatives. The article concludes by arguing that sectors should retain relevant institutional frameworks for actors when choosing political arrangements required for implementing energy transition policy. - Highlights: • Implementing energy transition policy potentially challenges sector-based politics. • We propose a policy regime framework and socio-political investigations. • We analyse the political impact of energy transition policy on French forest sector. • Shifts occur in sectoral policy framework, authority, and mediation relationships

  11. Influential Factors of Evidence-Based Energy Policy-making: Government Regulation on Targeting Renewable Energy in Indonesia

    Directory of Open Access Journals (Sweden)

    Wati Hermawati

    2016-07-01

    Full Text Available The paper is based on research identifying lessons and approaches in making energy policy and scrutinizes whether empirical evidence–based energy policy exists in Indonesia. Empirical evidence–based energy policy has the potential to reduce poverty as well as have a greater impact on the economic performance of individuals, communities and the government. In this study, we used document analysis and key informant interviews to explore empirical evidence input in energy policy-making. The results of the analysis revealed the following three points. First, there are a range of limitations in the process of energy policy-making as well as in getting an evidence inputs from concerned institutions such as universities, R&D institutions, and industries. Second, the process in making energy policy went through several stages and was not always in sequences, starting from problem identification, needs identification, advocacy, information gathering, policy drafting, and approval obtainment from the institutions concerned. Third, the most influential factor in the formulation of this energy policy is the factor of power and authority instead of knowledge and evidence. The limitations have demonstrated insufficient evidence in the policy-making. Finally, the paper suggests that a working group for data and information gathering should be created.

  12. Climate-based policies may increase life-cycle social costs of vehicle fleet operation

    International Nuclear Information System (INIS)

    Emery, Isaac; Mbonimpa, Eric; Thal, Alfred E.

    2017-01-01

    Sustainability guidelines and regulations in the United States often focus exclusively on carbon or petroleum reductions. Though some of these policies have resulted in substantial progress toward their goals, the effects of these efforts on other social and environmental externalities are often ignored. In this study, we examine the life-cycle air pollutant emissions for alternative fuel and vehicle purchase scenarios at a military installation near a typical urban area in the United States (U.S.). We find that scenarios which minimize petroleum use or greenhouse gas emissions do not concomitantly minimize criteria air pollutant emissions. We also employ social cost methodologies to quantify economic externalities due to climate change and health-related air pollutant impacts. Accounting for the social costs of climate change and air pollution from vehicle use reveals that criteria air pollutants may have a greater total impact than greenhouse gas emissions in locations similar to the urban area examined in this study. Use of first-generation biofuels, particularly corn grain ethanol, may reduce net petroleum use at the cost of increased total health impacts. More comprehensive policies may be needed to ensure that sustainability policies result in a net benefit to society. - Highlights: • U.S. energy and transportation policies focus on petroleum use and greenhouse gases. • Use of corn ethanol at a military base in Ohio, U.S. increases total social costs vs. gasoline. • Renewable electricity provides cost-effective climate and health protection. • DOD strategy to improve energy security may damage Americans' health. • More inclusive policies needed to protect health and climate.

  13. Project-Based Market Competition and Policy Implications for Sustainable Developments in Building and Construction Sectors

    Directory of Open Access Journals (Sweden)

    Min-Ren Yan

    2015-11-01

    Full Text Available Building and construction sectors are significant contributors to the global economy, but their energy consumption necessitates greater commitment to sustainable developments. There is therefore a growing demand for green innovation in the form of cleaner production and policies to meet the modern requirements of sustainability. However, the nature in which public work is undertaken is in an environment of project-based market competition, whereby contractors routinely bid for contracts under specific project awarding systems, and variations are accompanied with the unique scope of individual projects before the final goods or services are delivered. A comprehensive understanding of the characteristics and contractors’ behavior in systems could help to identify the leverage points of policies. This paper proposes a system dynamics model, with quantitative analysis and simulations, to demonstrate the problems of a system with different project awarding systems and ineffective market performance. The framework of market efficiency and performance measures has been proposed to evaluate the project-based competition mechanism. Managerial policy implications for market efficiency and sustainable developments can thus be systematically discussed and compared through iterative computer simulations and scenario analysis.

  14. Gradient Alloy for Optical Packaging

    Data.gov (United States)

    National Aeronautics and Space Administration — Advances in additive manufacturing, such as Laser Engineered Net Shaping (LENS), enables the fabrication of compositionally gradient microstructures, i.e. gradient...

  15. Biodiversity and Habitat Markets—Policy, Economic, and Ecological implications of Market-Based Conservation

    Science.gov (United States)

    Pindilli, Emily; Casey, Frank

    2015-10-26

    This report is a primer on market-like and market-based mechanisms designed to conserve biodiversity and habitat. The types of markets and market-based approaches that were implemented or are emerging to benefit biodiversity and habitat in the United States are examined. The central approaches considered in this report include payments for ecosystem services, conservation banks, habitat exchanges, and eco-labels. Based on literature reviews and input from experts and practitioners, the report characterizes each market-based approach including policy context and structure; the theoretical basis for applying market-based approaches; the ecological effectiveness of practices and tools for measuring performance; and the future outlook for biodiversity and habitat markets. This report draws from previous research and serves as a summary of pertinent information associated with biodiversity and habitat markets while providing references to materials that go into greater detail on specific topics.

  16. Ageing and Learning in Australia: Arguing an Evidence Base for Informed and Equitable Policy.

    Science.gov (United States)

    Cuthill, Michael; Buys, Laurie; Wilson, Bruce; Kimberley, Helen; Reghenzani, Denise; Kearns, Peter; Thompson, Sally; Golding, Barry; Root, Jo; Weston, Rhonda

    2016-01-01

    Given Australia's population ageing and predicted impacts related to health, productivity, equity and enhancing quality of life outcomes for senior Australians, lifelong learning has been identified as a pathway for addressing the risks associated with an ageing population. To date Australian governments have paid little attention to addressing these needs and thus, there is an urgent need for policy development for lifelong learning as a national priority. The purpose of this article is to explore the current lifelong learning context in Australia and to propose a set of factors that are most likely to impact learning in later years. Evidence based policy that understands and incorporates learning opportunities for all citizens is required to meet emerging global challenges. Providing appropriate learning opportunities to seniors is one clear pathway for achieving diverse health, social and economic outcomes.

  17. Should the strategic trade policy be considered obsolete or should it be redefined based on the current circumstances?

    Directory of Open Access Journals (Sweden)

    Julián Salinas Ventura

    2014-08-01

    Full Text Available This paper discusses the relevance of the strategic trade policy in the economies in Latin American countries, who have signed several trade agreements bilaterally and multilaterally. These agreements limit the policies that can be implemented and mostly do not consider the countries’ specific circumstances. However, it is important to discuss the problem of dependency and its specific manifestations, especially when talking about the Latin American countries’ integration into international trade.The strategic trade policy really needs to be redefined to take global context into consideration and to implement policies that have trade impact on strategic economic sectors, based on a deliberate development strategy. 

  18. New environmental policy instruments to realize forest expansion in Flanders (northern Belgium): A base for smart regulation?

    NARCIS (Netherlands)

    Gossum, Van P.; Ledene, L.; Arts, B.J.M.; Vreese, De R.; Langenhove, Van G.; Verheyen, K.

    2009-01-01

    This paper evaluates the current instrument mix, designs options for smart regulation and estimates the support base of new instruments for the forest expansion policy in Flanders (northern Belgium). The framework applied is a combination of theories on instrument choice (ICT), policy transfer and

  19. Students, Learning, and Race-Based Public Policy: A Look at Diversity Curriculum and Co-Curriculum.

    Science.gov (United States)

    DeAngelo, Linda

    This study is an attempt to bring together research examining diversity initiatives in curriculum and co-curriculum with research on race-based policies, specifically the policy of affirmative action in college admissions. The study attempted to identify and confirm unique background characteristics, beliefs, and predispositions that students…

  20. Phylogenetic analyses and detection of viridans streptococci based on sequences and denaturing gradient gel electrophoresis of the rod shape-determining protein gene

    Science.gov (United States)

    Konishi, Ikuri; Hoshino, Tomonori; Kondo, Yoshio; Saito, Kan; Nishiguchi, Miyuki; Sato, Kyoko; Fujiwara, Taku

    2009-01-01

    Background Population analysis of viridans streptococci is important because these species are associated with dental caries, bacteremia, and subacute endocarditis, in addition to being important members of the human oral commensal microbiota. Design In this study, we phylogenetically analyzed the rod shape-determining protein gene (rodA), which is associated with cellular morphology, cell division, and sensitivity for antibiotics, and demonstrated that the diversity of the rodA gene is sufficient to identify viridans streptococci at the species level. Moreover, we developed a more convenient denaturing gradient gel electrophoresis (DGGE) method based on the diversity of the rodA gene (rodA-DGGE) for detecting nine dominant streptococcal species in human saliva, namely, Streptococcus sanguinis, Streptococcus oralis, Streptococcus mitis, Streptococcus parasanguinis, Streptococcus gordonii, Streptococcus vestibularis, Streptococcus salivarius, Streptococcus mutans, and Streptococcus sobrinus. Results This rodA-DGGE method proved useful in detecting viridans streptococci without cultivation, isolation, and phenotypic characterization. Conclusion Analysis of the oral microbiota by rodA-DGGE offers a higher resolution than the conventional DGGE using 16S rDNA and may be an alternative in the microbial diagnosis of streptococcal infection. PMID:21523207

  1. Reducing the Social Gradient in Uptake of the NHS Colorectal Cancer Screening Programme Using a Narrative-Based Information Leaflet: A Cluster-Randomised Trial

    Directory of Open Access Journals (Sweden)

    Lesley M. McGregor

    2016-01-01

    Full Text Available Objective. To test the effectiveness of adding a narrative leaflet to the current information material delivered by the NHS English colorectal cancer (CRC screening programme on reducing socioeconomic inequalities in uptake. Participants. 150,417 adults (59–74 years routinely invited to complete the guaiac Faecal Occult Blood test (gFOBt in March 2013. Design. A cluster randomised controlled trial (ISRCTN74121020 to compare uptake between two arms. The control arm received the standard NHS CRC screening information material (SI and the intervention arm received the standard information plus a supplementary narrative leaflet, which had previously been shown to increase screening intentions (SI + N. Between group comparisons were made for uptake overall and across socioeconomic status (SES. Results. Uptake was 57.7% and did not differ significantly between the two trial arms (SI: 58.5%; SI + N: 56.7%; odds ratio = 0.93; 95% confidence interval: 0.81–1.06; p=0.27. There was no interaction between group and SES quintile (p=0.44. Conclusions. Adding a narrative leaflet to existing information materials does not reduce the SES gradient in uptake. Despite the benefits of using a pragmatic trial design, the need to add to, rather than replace, existing information may have limited the true value of an evidence-based intervention on behaviour.

  2. Phylogenetic analyses and detection of viridans streptococci based on sequences and denaturing gradient gel electrophoresis of the rod shape-determining protein gene.

    Science.gov (United States)

    Konishi, Ikuri; Hoshino, Tomonori; Kondo, Yoshio; Saito, Kan; Nishiguchi, Miyuki; Sato, Kyoko; Fujiwara, Taku

    2009-08-28

    Population analysis of viridans streptococci is important because these species are associated with dental caries, bacteremia, and subacute endocarditis, in addition to being important members of the human oral commensal microbiota. In this study, we phylogenetically analyzed the rod shape-determining protein gene (rodA), which is associated with cellular morphology, cell division, and sensitivity for antibiotics, and demonstrated that the diversity of the rodA gene is sufficient to identify viridans streptococci at the species level. Moreover, we developed a more convenient denaturing gradient gel electrophoresis (DGGE) method based on the diversity of the rodA gene (rodA-DGGE) for detecting nine dominant streptococcal species in human saliva, namely, Streptococcus sanguinis, Streptococcus oralis, Streptococcus mitis, Streptococcus parasanguinis, Streptococcus gordonii, Streptococcus vestibularis, Streptococcus salivarius, Streptococcus mutans, and Streptococcus sobrinus. This rodA-DGGE method proved useful in detecting viridans streptococci without cultivation, isolation, and phenotypic characterization. Analysis of the oral microbiota by rodA-DGGE offers a higher resolution than the conventional DGGE using 16S rDNA and may be an alternative in the microbial diagnosis of streptococcal infection.

  3. Diversity and taphonomic gradients from shoreface to deep water: Case studies based on sea urchin assemblages from the Miocene of Sardinia

    Science.gov (United States)

    Nebelsick, James; Mancosu, Andrea

    2016-04-01

    Echinoid faunas from Miocene sediments from Sardinia allow diversity to be correlated to variations in depositional environments as well as taphonomic pathways. Taxonomic richness and preservation potentials vary among both carbonate and siliciclastic dominated shelf environments. Studies include detailed investigation of stratigraphy, sedimentology, palaeontology and taphonomy in both the field and in the laboratory. Environmental Interpretations are based on composition and diversity of taxa, functional morphological interpretation of life habits as well as taphonomic signatures. These investigations have revealed: 1) various mass accumulations of clypeasteroid echinoids ranging from autochthonous assemblages to multiple in situ reworked accumulations in shore face environments, 2) the distribution of morphotypes of the common genus Clypeaster, 3) echinoid assemblages dominated by both irregular and regular echinoids in siliciclastic and carbonate shelf environments, 4) spatangoid assemblages in heavily bioturbated coarse sands, and 5) monotypic shell beds of well-preserved regular echinoids and spatangoid from deeper siliciclastic environments. Variations in the diversity of echinoid taxa are correlated to biotic and abiotic ecological factors in specific depositional environments. Preservation potentials vary highly as determined by ambient environmental conditions and skeletal architectures. A synthesis of faunal diversities and preservation potentials along shelf gradient ranging from shoreface to deep water is presented.

  4. A TLBO based gradient descent learning-functional link higher order ANN: An efficient model for learning from non-linear data

    Directory of Open Access Journals (Sweden)

    Bighnaraj Naik

    2018-01-01

    Full Text Available All the higher order ANNs (HONNs including functional link ANN (FLANN are sensitive to random initialization of weight and rely on the learning algorithms adopted. Although a selection of efficient learning algorithms for HONNs helps to improve the performance, on the other hand, initialization of weights with optimized weights rather than random weights also play important roles on its efficiency. In this paper, the problem solving approach of the teaching learning based optimization (TLBO along with learning ability of the gradient descent learning (GDL is used to obtain the optimal set of weight of FLANN learning model. TLBO does not require any specific parameters rather it requires only some of the common independent parameters like number of populations, number of iterations and stopping criteria, thereby eliminating the intricacy in selection of algorithmic parameters for adjusting the set of weights of FLANN model. The proposed TLBO-FLANN is implemented in MATLAB and compared with GA-FLANN, PSO-FLANN and HS-FLANN. The TLBO-FLANN is tested on various 5-fold cross validated benchmark data sets from UCI machine learning repository and analyzed under the null-hypothesis by using Friedman test, Holm’s procedure and post hoc ANOVA statistical analysis (Tukey test & Dunnett test.

  5. Bacterial Diversity in the Digestive Tracts of Four Indian Air-Breathing Fish Species Investigated by PCR Based Denaturing Gradient Gel Electrophoresis

    Directory of Open Access Journals (Sweden)

    Suxu He

    Full Text Available ABSTRACT An investigation was conducted to identify the allochthonous microbiota (entire intestine and the autochthonous microbiota in proximal intestine (PI and distal intestine (DI of four species of Indian air-breathing fish (climbing perch; Anabas testudineus, murrel; Channa punctatus, walking catfish; Clarias batrachus and stinging catfish; Heteropneustes fossilis by PCR based denaturing gradient gel electrophoresis (DGGE. High similarities of the allochthonous microbiota were observed between climbing perch and murrel, walking catfish and stinging catfish, indicating similar food behavior. The autochthonous microbiota of PI and DI from climbing perch and murrel revealed more similarity, than the result obtained from walking catfish and stinging catfish. The autochthonous microbiota of climbing perch and murrel were similar with regard to the allochthonous microbiota, but no such similarity was observed in case of walking catfish and stinging catfish. The fish genotype and intestinal bacteria are well matched and show co-evolutionary relationship. Three fish species has its unique bacteria; autochthonous Enterobacter cloacae, Edwardsiella tarda and Sphingobium sp. in DI of climbing perch, Pseudomonas sp.; allochthonous and autochthonous in PI of walking catfish and uncultured bacterium (EU697160.1, uncultured bacterium (JF018065.1 and uncultured bacterium (EU697160.1 for stinging catfish. In murrel, no unique bacteria were detected.

  6. Implementation of Analytical Energy Gradient of Spin-Dependent General Hartree-Fock Method Based on the Infinite-Order Douglas-Kroll-Hess Relativistic Hamiltonian with Local Unitary Transformation.

    Science.gov (United States)

    Nakajima, Yuya; Seino, Junji; Nakai, Hiromi

    2016-05-10

    An analytical energy gradient for the spin-dependent general Hartree-Fock method based on the infinite-order Douglas-Kroll-Hess (IODKH) method was developed. To treat realistic systems, the local unitary transformation (LUT) scheme was employed both in energy and energy gradient calculations. The present energy gradient method was numerically assessed to investigate the accuracy in several diatomic molecules containing fifth- and sixth-period elements and to examine the efficiency in one-, two-, and three-dimensional silver clusters. To arrive at a practical calculation, we also determined the geometrical parameters of fac-tris(2-phenylpyridine)iridium and investigated the efficiency. The numerical results confirmed that the present method describes a highly accurate relativistic effect with high efficiency. The present method can be a powerful scheme for determining geometries of large molecules, including heavy-element atoms.

  7. Flux-based Enrichment Ratios of Throughfall and Stemflow Found to Vary Significantly within Urban Fragments and Along an Urban-to-Rural Gradient

    Science.gov (United States)

    Dowtin, A. L.; Levia, D. F., Jr.

    2017-12-01

    Throughfall and stemflow are important inputs of water and solutes to forest soils in both rural and urban forests. In metropolitan wooded ecosystems, a number of factors can affect flux-based enrichment ratios, including combustion of fossil fuels and proximity to industry. Use of flux-based enrichment ratios provides a means by which this modification of net precipitation chemistry can be quantified for both throughfall and stemflow, and allows for a characterization of the relative contributions of stemflow and throughfall in the delivery of nutrients and pollutants to forest soils. This study utilizes five mixed deciduous forest stands along an urban-to-rural gradient (3 urban fragments, 1 suburban fragment, and a portion of 1 contiguous rural forest) within a medium-sized metropolitan region of the United States' Northeast megalopolis, to determine how the size, shape, structure, and geographic context of remnant forest fragments determine hydrologic and solute fluxes within them. In situ observations of throughfall and stemflow (the latter of which is limited to Quercus rubra and Quercus alba) within each study plot allow for an identification and characterization of the spatial variability in solute fluxes within and between the respective sites. Preliminary observations indicate significant intra-site variability in solute concentrations as observed in both throughfall and stemflow, with higher concentrations along the respective windward edges of the study plots than at greater depths into their interiors. Higher flux-based stemflow enrichment ratios, for both Q. rubra and Q. alba, were also evident for certain ions (i.e., S2-, NO3-) in the urban forest fragments, with significantly lower ratios observed at the suburban and rural sites. Findings from this research are intended to aid in quantifying the spatial variability of the hydrologic and hydrochemical ecosystem service provisions of remnant metropolitan forest fragments. This research is supported in

  8. Adaptive Measurement-Based Policy-Driven QoS Management with Fuzzy-Rule-based Resource Allocation

    Directory of Open Access Journals (Sweden)

    Philip J. Morrow

    2012-07-01

    Full Text Available Fixed and wireless networks are increasingly converging towards common connectivity with IP-based core networks. Providing effective end-to-end resource and QoS management in such complex heterogeneous converged network scenarios requires unified, adaptive and scalable solutions to integrate and co-ordinate diverse QoS mechanisms of different access technologies with IP-based QoS. Policy-Based Network Management (PBNM is one approach that could be employed to address this challenge. Hence, a policy-based framework for end-to-end QoS management in converged networks, CNQF (Converged Networks QoS Management Framework has been proposed within our project. In this paper, the CNQF architecture, a Java implementation of its prototype and experimental validation of key elements are discussed. We then present a fuzzy-based CNQF resource management approach and study the performance of our implementation with real traffic flows on an experimental testbed. The results demonstrate the efficacy of our resource-adaptive approach for practical PBNM systems.

  9. Developing an effective policy for home hygiene: a risk-based approach.

    Science.gov (United States)

    Bloomfield, S F; Scott, E A

    2003-06-01

    Evaluation of the infection potential in the home suggests that improved hygiene practice could significantly reduce the impact of infectious diseases. Fundamental to developing infection prevention policy for the home is the need to recognise that people live in an environment where all human activities occur, including food and water hygiene, hand hygiene, and hygiene related to care of vulnerable groups. In all these situations, reducing infection risks is based on the same underlying microbiological principles. In developing countries, disposal of human and animal excreta and other waste is often also the responsibility of the family and community. Adopting a holistic approach provides the opportunity for a rational approach to home hygiene based on risk assessment. The International Scientific Forum on Home Hygiene (IFH) believes that to deliver hygiene policy with real health benefits, a risk-based approach must be developed and promoted for the home. A risk-based approach starts from the principle that pathogens are introduced continually into homes on people, food and water, pets, insects and air. Inadequate disposal of human and animal excreta serves to increase this risk. Additionally, sites where stagnant water accumulates, such as sinks, toilets and cleaning cloths can support microbial growth and become a source of infection. By assessing the frequency occurrence of pathogens and potential pathogens on hands, hand and food contact surfaces, laundry, reservoir and reservoir/disseminator sites, together with the potential for transfer in the home, the exposure risk can be assessed.

  10. Leveraging school-based research to inform bullying prevention and policy.

    Science.gov (United States)

    Espelage, Dorothy L

    2016-11-01

    School-based bullying and other forms of school violence have been the topic of over 40 years of research in the U.S. and internationally. Within the last 2 decades, research has increasingly informed bullying prevention, policy, and legislative efforts. The purpose of this article is to highlight several critical research areas on bullying and other forms of school violence that have shaped prevention efforts and policy over the last 2 decades. As the recipient of the 2016 Award for Distinguished Contributions to Research in Public Policy , the discussion here will focus largely on research findings from The Espelage Lab and collaborators, but these studies and findings will be situated in the larger literature. Topics covered include conceptualization of bullying from a social-ecological framework, developmental considerations of bullying and associated forms of aggression, identification of populations at heightened risk for bullying, and efficacy of bullying prevention programs. Recommendations are provided for the next generation of scholars, practitioners, and policymakers focused on bullying prevention. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  11. Paper Fish and Policy Conflict: Catch Shares and Ecosystem-Based Management in Maine's Groundfishery

    Directory of Open Access Journals (Sweden)

    Jennifer F. Brewer

    2011-03-01

    Full Text Available The National Oceanic and Atmospheric Administration professes support for ecosystem-based fisheries management, as mandated by Congress in the Fishery Conservation and Management Act, and as endorsed by the Obama Administration's national ocean policy. Nonetheless, driving agency policies, including catch shares and fishing quotas, focus principally on individual species, diverting attention from ecosystem considerations such as habitat, migratory patterns, trophic relationships, fishing gear, and firm-level decision making. Environmental non-governmental organization (ENGO agendas manifest similar inconsistencies. A case study of Maine's groundfishery demonstrates implications of this policy conflict at the local level. There, multigenerational fishing villages have historically pursued diversified and adaptive livelihood strategies, supported by local ecological knowledge. This tradition is increasingly eroded by regulatory constraints, including catch shares. Field observation, interviews, survey data, and archival review reveal that industry-supported, ecosystem-focused proposals have been rejected by the New England Fishery Management Council, despite the apparent failure of single-species approaches to sustain fish populations, fished ecosystems, and fishing-dependent communities. The creation of groundfishery catch share sectors is likely to perpetuate industry consolidation and political entrenchment under more mobile capital, following precedent set by days-at-sea, and making area protections and gear restrictions less likely. Pending marine spatial planning efforts could enhance social-ecological resilience by creating new opportunities for transdisciplinary decision support, and broader public participation and accountability.

  12. Gradient-based optimization with B-splines on sparse grids for solving forward-dynamics simulations of three-dimensional, continuum-mechanical musculoskeletal system models.

    Science.gov (United States)

    Valentin, J; Sprenger, M; Pflüger, D; Röhrle, O

    2018-02-10

    Investigating the interplay between muscular activity and motion is the basis to improve our understanding of healthy or diseased musculoskeletal systems. To be able to analyze the musculoskeletal systems, computational models are employed. Albeit some severe modeling assumptions, almost all existing musculoskeletal system simulations appeal to multi-body simulation frameworks. Although continuum-mechanical musculoskeletal system models can compensate for some of these limitations, they are essentially not considered due to their computational complexity and cost. The proposed framework is the first activation-driven musculoskeletal system model, in which the exerted skeletal muscle forces are computed using three-dimensional, continuum-mechanical skeletal muscle models and in which muscle activations are determined based on a constraint optimization problem. Numerical feasibility is achieved by computing sparse grid surrogates with hierarchical B-splines, and adaptive sparse grid refinement further reduces the computational effort. The choice of B-splines allows the use of all existing gradient-based optimization techniques without further numerical approximation. This paper demonstrates that the resulting surrogates have low relative errors (less than 0.76%) and can be used within forward simulations that are subject to constraint optimization. To demonstrate this, we set up several different test scenarios in which an upper limb model consisting of the elbow joint, the biceps and triceps brachii and an external load is subjected to different optimization criteria. Even though this novel method has only been demonstrated for a two-muscle system, it can easily be extended to musculoskeletal systems with three or more muscles. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Immobilized pH gradient-driven paper-based IEF: a new method for fractionating complex peptide mixtures before MS analysis

    Directory of Open Access Journals (Sweden)

    Seshi Beerelli

    2011-06-01

    Full Text Available Abstract Introduction The vast difference in the abundance of different proteins in biological samples limits the determination of the complete proteome of a cell type, requiring fractionation of proteins and peptides before MS analysis. Methods We present a method consisting of electrophoresis of complex mixtures of peptides using a strip of filter paper cut into 20 sections laid end to end over a 24-cm-long IPG strip, the pH gradient of which would drive the electrophoresis. Peptides absorbed onto individual paper pads after electrophoresis are subsequently recovered into a buffer solution, thus dividing a complex peptide mixture according to pI into 20 liquid fractions. This paper-based IEF method (PIEF was compared side-by-side with a similar but liquid-based Offgel electrophoresis (OGE by analyzing iTRAQ-labeled peptide mixtures of membrane proteins from four different cell types. Results PIEF outperformed OGE in resolving acidic peptides, whereas OGE did a better job in recovering relatively basic peptides. OGE and PIEF were quite comparable in their coverage, identifying almost equal number of distinct proteins (PIEF =1174; OGE = 1080. Interestingly, however, only 675 were identified by both of them, each method identifying many unique proteins (PIEF = 499; OGE = 415. Thus, the two methods uncovered almost 40% more proteins compared to what is obtained by only one method. Conclusion: This initial investigation demonstrates the technical feasibility of PIEF for complementing OGE. PIEF uses standard IPG IEF equipment, requires no specialized apparatus (e.g., OGE fractionator and may be integrated into peptide mapping strategies for clinical samples.

  14. On fracture in finite strain gradient plasticity

    DEFF Research Database (Denmark)

    Martínez Pañeda, Emilio; Niordson, Christian Frithiof

    2016-01-01

    predictions. These differences increase significantly when large strains are taken into account, as a consequence of the contribution of strain gradients to the work hardening of the material. The magnitude of stress elevation at the crack tip and the distance ahead of the crack where GNDs significantly alter......In this work a general framework for damage and fracture assessment including the effect of strain gradients is provided. Both mechanism-based and phenomenological strain gradient plasticity (SGP) theories are implemented numerically using finite deformation theory and crack tip fields...

  15. Exploring policy impacts for servicising in product-based markets : A generic agent-based model

    NARCIS (Netherlands)

    van der Veen, R.A.C.; Kisjes, K.H.; Nikolic, I.

    2017-01-01

    The shift to markets based on servicising, i.e. market-level transitions from product-based to service-based production and consumption patterns, may contribute to achieve absolute decoupling, i.e. the combined development of economic growth and environmental impact reduction. However, the

  16. Strengthening vaccination policies in Latin America: an evidence-based approach.

    Science.gov (United States)

    Tapia-Conyer, Roberto; Betancourt-Cravioto, Miguel; Saucedo-Martínez, Rodrigo; Motta-Murguía, Lourdes; Gallardo-Rincón, Héctor

    2013-08-20

    Despite many successes in the region, Latin American vaccination policies have significant shortcomings, and further work is needed to maintain progress and prepare for the introduction of newly available vaccines. In order to address the challenges facing Latin America, the Commission for the Future of Vaccines in Latin America (COFVAL) has made recommendations for strengthening evidence-based policy-making and reducing regional inequalities in immunisation. We have conducted a comprehensive literature review to assess the feasibility of these recommendations. Standardisation of performance indicators for disease burden, vaccine coverage, epidemiological surveillance and national health resourcing can ensure comparability of the data used to assess vaccination programmes, allowing deeper analysis of how best to provide services. Regional vaccination reference schemes, as used in Europe, can be used to develop best practice models for vaccine introduction and scheduling. Successful models exist for the continuous training of vaccination providers and decision-makers, with a new Latin American diploma aiming to contribute to the successful implementation of vaccination programmes. Permanent, independent vaccine advisory committees, based on the US Advisory Committee on Immunization Practices (ACIP), could facilitate the uptake of new vaccines and support evidence-based decision-making in the administration of national immunisation programmes. Innovative financing mechanisms for the purchase of new vaccines, such as advance market commitments and cost front-loading, have shown potential for improving vaccine coverage. A common regulatory framework for vaccine approval is needed to accelerate delivery and pool human, technological and scientific resources in the region. Finally, public-private partnerships between industry, government, academia and non-profit sectors could provide new investment to stimulate vaccine development in the region, reducing prices in the

  17. Uniform gradient expansions

    Directory of Open Access Journals (Sweden)

    Massimo Giovannini

    2015-06-01

    Full Text Available Cosmological singularities are often discussed by means of a gradient expansion that can also describe, during a quasi-de Sitter phase, the progressive suppression of curvature inhomogeneities. While the inflationary event horizon is being formed the two mentioned regimes coexist and a uniform expansion can be conceived and applied to the evolution of spatial gradients across the protoinflationary boundary. It is argued that conventional arguments addressing the preinflationary initial conditions are necessary but generally not sufficient to guarantee a homogeneous onset of the conventional inflationary stage.

  18. Uniform gradient expansions

    CERN Document Server

    Giovannini, Massimo

    2015-01-01

    Cosmological singularities are often discussed by means of a gradient expansion that can also describe, during a quasi-de Sitter phase, the progressive suppression of curvature inhomogeneities. While the inflationary event horizon is being formed the two mentioned regimes coexist and a uniform expansion can be conceived and applied to the evolution of spatial gradients across the protoinflationary boundary. It is argued that conventional arguments addressing the preinflationary initial conditions are necessary but generally not sufficient to guarantee a homogeneous onset of the conventional inflationary stage.

  19. High gradient superconducting quadrupoles

    International Nuclear Information System (INIS)

    Lundy, R.A.; Brown, B.C.; Carson, J.A.; Fisk, H.E.; Hanft, R.H.; Mantsch, P.M.; McInturff, A.D.; Remsbottom, R.H.

    1987-07-01

    Prototype superconducting quadrupoles with a 5 cm aperture and gradient of 16 kG/cm have been built and tested as candidate magnets for the final focus at SLC. The magnets are made from NbTi Tevatron style cable with 10 inner and 14 outer turns per quadrant. Quench performance and multipole data are presented. Design and data for a low current, high gradient quadrupole, similar in cross section but wound with a cable consisting of five insulated conductors are also discussed

  20. Market power and output-based refunding of environmental policy revenues

    International Nuclear Information System (INIS)

    Fischer, Carolyn

    2011-01-01

    Output-based refunding of environmental policy revenues combines a tax on emissions with a production subsidy, typically in a revenue-neutral fashion. With imperfect competition, subsidies can alleviate output underprovision. However, when market shares are significant, endogenous refunding reduces abatement incentives and the marginal net tax or subsidy. If market shares differ, marginal abatement costs will not be equalized, and production is shifted among participants. In an asymmetric Cournot duopoly, endogenous refunding leads to higher output, emissions, and overall costs compared with a fixed rebate program targeting the same emissions intensity. These results hold whether emissions rates are determined simultaneously with output or strategically in a two-stage model. (author)

  1. A Proposal of Protocol and Policy-Based Intrusion Detection System

    Directory of Open Access Journals (Sweden)

    Tatsuya Baba

    2004-06-01

    Full Text Available Currently, intrusion detection systems (IDSs are widely deployed in enterprise networks for detecting network attacks. Most existing commercial IDSs are based on misuse detection model. In misuse detection, although known attacks can be detected, unknown ones cannot be detected because attack signatures for unknown attacks cannot be generated. In this paper, we propose a method for detecting network attacks including unknown ones against servers such as web servers, mail servers, FTP servers, and DNS servers, using protocol specifications and site access policy. Furthermore, we propose a method to predict damage from detected attacks using neural networks.

  2. Multi-Agent Auction Based Simulation Tool for an Insurance Policy Market

    Directory of Open Access Journals (Sweden)

    Lavendelis Egons

    2014-07-01

    Full Text Available The paper presents a simulation tool for automated interactions between insurance companies and their clients during the travel insurance buying process. Insurance deal evaluation model using price and insured risks has been developed based on the study of the Latvian insurance market. The proposed model is used together with well-known agent auction protocols, thus providing a multi-agent negotiation protocol. It allows automating one-to-many negotiations between client and insurance companies simulating electronic insurance policy marketplace. The simulation tool has been developed using the MASITS methodology and tool, thus providing a case study for the methodology and tool for a new type of systems

  3. The relevance of a rules-based maize marketing policy: an experimental case study of Zambia.

    Science.gov (United States)

    Abbink, Klaus; Jayne, Thomas S; Moller, Lars C

    2011-01-01

    Strategic interaction between public and private actors is increasingly recognised as an important determinant of agricultural market performance in Africa and elsewhere. Trust and consultation tends to positively affect private activity while uncertainty of government behaviour impedes it. This paper reports on a laboratory experiment based on a stylised model of the Zambian maize market. The experiment facilitates a comparison between discretionary interventionism and a rules-based policy in which the government pre-commits itself to a future course of action. A simple precommitment rule can, in theory, overcome the prevailing strategic dilemma by encouraging private sector participation. Although this result is also borne out in the economic experiment, the improvement in private sector activity is surprisingly small and not statistically significant due to irrationally cautious choices by experimental governments. Encouragingly, a rules-based policy promotes a much more stable market outcome thereby substantially reducing the risk of severe food shortages. These results underscore the importance of predictable and transparent rules for the state's involvement in agricultural markets.

  4. Spatial Planning and Policy Evaluation in an Urban Conurbation: a Regional Agent-Based Economic Model

    Directory of Open Access Journals (Sweden)

    Luzius Stricker

    2017-03-01

    Full Text Available This paper studies different functions and relations between 45 agglomerated municipalities in southern Switzerland (Ticino, using a territorial agent-based model. Our research adopts a bottom-up approach to urban systems, considering the agglomeration mechanism and effects of different regional and urban policies, and simulates the individual actions of diverse agents on a real city using an Agent-based model (ABM. Simulating the individual actions of diverse agents on a real city and measuring the resulting system behaviour and outcomes over time, they effectively provide a good test bed for evaluating the impact of different policies. The database is created merging the Swiss official secondary data for one reference year (2011 with Eurostat and OECD-Regpat. The results highlight that the understanding of municipalities’ functions on the territory appears to be essential for designing a solid institutional agglomeration (or city. From a methodological point of view, we contribute to improve the application of territorial ABM. Finally, our results provide a robust base to evaluate in a dynamic way various political interventions, in order to ensure a sustainable development of the agglomeration and the surrounding territories. Applying the analyses and the model on a larger scale, including further regions and conurbations, and including more indicators and variables, to obtain a more detailed and characteristic model, will constitute a further step of the research.

  5. A preventive maintenance policy based on dependent two-stage deterioration and external shocks

    International Nuclear Information System (INIS)

    Yang, Li; Ma, Xiaobing; Peng, Rui; Zhai, Qingqing; Zhao, Yu

    2017-01-01

    This paper proposes a preventive maintenance policy for a single-unit system whose failure has two competing and dependent causes, i.e., internal deterioration and sudden shocks. The internal failure process is divided into two stages, i.e. normal and defective. Shocks arrive according to a non-homogeneous Poisson process (NHPP), leading to the failure of the system immediately. The occurrence rate of a shock is affected by the state of the system. Both an age-based replacement and finite number of periodic inspections are schemed simultaneously to deal with the competing failures. The objective of this study is to determine the optimal preventive replacement interval, inspection interval and number of inspections such that the expected cost per unit time is minimized. A case study on oil pipeline maintenance is presented to illustrate the maintenance policy. - Highlights: • A maintenance model based on two-stage deterioration and sudden shocks is developed. • The impact of internal system state on external shock process is studied. • A new preventive maintenance strategy combining age-based replacements and periodic inspections is proposed. • Postponed replacement of a defective system is provided by restricting the number of inspections.

  6. Multicriteria-based decision aiding technique for assessing energy policy elements-demonstration to a case in Bangladesh

    International Nuclear Information System (INIS)

    Rahman, Md. Mizanur; Paatero, Jukka V.; Lahdelma, Risto; Wahid, Mazlan A.

    2016-01-01

    Highlights: • A multicriteria technique for assessing energy policy elements has been proposed. • Energy policy elements have been examined based on assigned criteria. • This assessment gives results which are representative of all stakeholders. • Policy elements which are chosen by this method promote sustainability. - Abstract: The adverse environmental consequences and diminishing trend of fossil fuel reserves indicate a serious need for vibrant and judicious energy policy. Energy policy involves a number of stakeholders, and needs to incorporate the interests and requirements of all the key stakeholder groups. This paper presents a methodological technique to assist with formulating, evaluating, and promoting the energy policy of a country in a transparent and representative way with clear scientific justifications and balanced assessments. The multicriteria decision analysis approach has been a widely used technique for evaluating different alternatives based on the interests of a multitude of stakeholders, and goals. This paper utilizes the SMAA (Stochastic Multicriteria Acceptability Analysis) tool, which can evaluate different alternatives by incorporating multiple criteria, in order to examine the preferences of different policy elements. We further extend this technique by incorporating the LEAP model (Long-range Energy Alternatives Planning system) to assess the emission impacts of different policy elements. We demonstrate the application of this evaluation technique by an analysis of four hypothetical policy elements namely Business-as usual (BAU), Renewables (REN), Renewable-biomass only (REN-b), and Energy conservation and efficient technologies (ECET). These are applied to the case of sharing fuel sources for power generation for the Bangladesh power sector. We found that the REN-b and REN policy elements were the best and second best alternatives with 41% and 32% acceptability respectively. This technique gives transparent information for

  7. Area-based initiatives – engines of innovation in planning and policy?

    DEFF Research Database (Denmark)

    Larsen, Jacob Norvig; Agger, Annika

    a broader perspective on the achievements and outcomes of place-based initiatives. Many of these have functioned as important experimental seedbeds in which innovations in urban policy and organization of public decision-making have been tested. The papers seeks to clarify whether, in the long run, change......Area-based initiatives addressing issues of physical degradation, social exclusion, economic deprivation and lack of cohesion in urban regeneration areas have been promoted widely across Europe in the past two or three decades. Following this many evaluation studies have been completed....... Nevertheless, there is still considerable uncertainty as to the most important outcomes of place-based initiatives. Evaluations have mostly focussed on direct quantitative socio-economic indicators. These have often been quite insignificant, while other effects have been largely neglected. This paper proposes...

  8. Ultimate gradient in solid-state accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Whittum, D.H.

    1998-08-01

    The authors recall the motivation for research in high-gradient acceleration and the problems posed by a compact collider. They summarize the phenomena known to appear in operation of a solid-state structure with large fields, and research relevant to the question of the ultimate gradient. They take note of new concepts, and examine one in detail, a miniature particle accelerator based on an active millimeter-wave circuit and parallel particle beams.

  9. Ultimate gradient in solid-state accelerators

    International Nuclear Information System (INIS)

    Whittum, D.H.

    1998-08-01

    The authors recall the motivation for research in high-gradient acceleration and the problems posed by a compact collider. They summarize the phenomena known to appear in operation of a solid-state structure with large fields, and research relevant to the question of the ultimate gradient. They take note of new concepts, and examine one in detail, a miniature particle accelerator based on an active millimeter-wave circuit and parallel particle beams

  10. Satellite gravity gradient grids for geophysics.

    Science.gov (United States)

    Bouman, Johannes; Ebbing, Jörg; Fuchs, Martin; Sebera, Josef; Lieb, Verena; Szwillus, Wolfgang; Haagmans, Roger; Novak, Pavel

    2016-02-11

    The Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite aimed at determining the Earth's mean gravity field. GOCE delivered gravity gradients containing directional information, which are complicated to use because of their error characteristics and because they are given in a rotating instrument frame indirectly related to the Earth. We compute gravity gradients in grids at 225 km and 255 km altitude above the reference ellipsoid corresponding to the GOCE nominal and lower orbit phases respectively, and find that the grids may contain additional high-frequency content compared with GOCE-based global models. We discuss the gradient sensitivity for crustal depth slices using a 3D lithospheric model of the North-East Atlantic region, which shows that the depth sensitivity differs from gradient to gradient. In addition, the relative signal power for the individual gradient component changes comparing the 225 km and 255 km grids, implying that using all components at different heights reduces parameter uncertainties in geophysical modelling. Furthermore, since gravity gradients contain complementary information to gravity, we foresee the use of the grids in a wide range of applications from lithospheric modelling to studies on dynamic topography, and glacial isostatic adjustment, to bedrock geometry determination under ice sheets.

  11. Addressing Health Disparities from Within the Community: Community-Based Participatory Research and Community Health Worker Policy Initiatives Using a Gender-Based Approach.

    Science.gov (United States)

    Simonsen, Sara E; Ralls, Brenda; Guymon, Anna; Garrett, Teresa; Eisenman, Patricia; Villalta, Jeannette; Tavake-Pasi, O Fahina; Mukundente, Valentine; Davis, France A; Digre, Kathleen; Hayes, Stephen; Alexander, Stephanie

    2017-10-17

    The Coalition for a Healthier Community for Utah Women and Girls (CHC-UWAG) focused on addressing obesity-related health disparities impacting Utah women of color using community-based participatory research, a gender-based approach, and culturally sensitive health promotion activities delivered through community health workers (CHWs). A randomized trial of low vs. high intensity wellness coaching by CHWs was initiated. During this process, numerous policy issues emerged and were tracked. We present a case study illustrating how we identified, tracked, and engaged with emerging policy initiatives. Between September 2011 and August 2017, policy initiatives addressing obesity-related disparities among Utah women and girls were identified, tracked in a shared document, and updated regularly. Policies were classified by level (organizational, local, and statewide) and by focus (healthy eating, active living, and promotion of community health workers). CHC-UWAG engagement with policy work was also documented and tracked. Broad dissemination of study findings generated interest in the role of CHWs in addressing obesity. Partnering community-based organizations implemented policies focused on healthy eating and physical activity. Barriers to the broader use of CHWs in Utah were addressed in policy initiatives including the formation of a Utah Public Health Association Section for CHWs and a statewide CHW Coalition with involvement of CHC-UWAG members. The regular solicitation of information about policy initiatives resulted in successful policy tracking and engagement in policy work. The utilization of a gender-based approach helped illuminate the impact of emerging policies on the health of women and girls. Published by Elsevier Inc.

  12. Unproven stem cell-based interventions and achieving a compromise policy among the multiple stakeholders.

    Science.gov (United States)

    Matthews, Kirstin R W; Iltis, Ana S

    2015-11-04

    In 2004, patient advocate groups were major players in helping pass and implement significant public policy and funding initiatives in stem cells and regenerative medicine. In the following years, advocates were also actively engaged in Washington DC, encouraging policy makers to broaden embryonic stem cell research funding, which was ultimately passed after President Barack Obama came into office. Many advocates did this because they were told stem cell research would lead to cures. After waiting more than 10 years, many of these same patients are now approaching clinics around the world offering experimental stem cell-based interventions instead of waiting for scientists in the US to complete clinical trials. How did the same groups who were once (and often still are) the strongest supporters of stem cell research become stem cell tourists? And how can scientists, clinicians, and regulators work to bring stem cell patients back home to the US and into the clinical trial process? In this paper, we argue that the continued marketing and use of experimental stem cell-based interventions is problematic and unsustainable. Central problems include the lack of patient protection, US liability standards, regulation of clinical sites, and clinician licensing. These interventions have insufficient evidence of safety and efficacy; patients may be wasting money and time, and they may be forgoing other opportunities for an intervention that has not been shown to be safe and effective. Current practices do not contribute to scientific progress because the data from the procedures are unsuitable for follow-up research to measure outcomes. In addition, there is no assurance for patients that they are receiving the interventions promised or of what dosage they are receiving. Furthermore, there is inconsistent or non-existent follow-up care. Public policy should be developed to correct the current situation. The current landscape of stem cell tourism should prompt a re

  13. Developing evidence-based ethical policies on the migration of health workers: conceptual and practical challenges

    Directory of Open Access Journals (Sweden)

    Adams Orvill

    2003-10-01

    Full Text Available Abstract It is estimated that in 2000 almost 175 million people, or 2.9% of the world's population, were living outside their country of birth, compared to 100 million, or 1.8% of the total population, in 1995. As the global labour market strengthens, it is increasingly highly skilled professionals who are migrating. Medical practitioners and nurses represent a small proportion of highly skilled workers who migrate, but the loss of health human resources for developing countries can mean that the capacity of the health system to deliver health care equitably is compromised. However, data to support claims on both the extent and the impact of migration in developing countries is patchy and often anecdotal, based on limited databases with highly inconsistent categories of education and skills. The aim of this paper is to examine some key issues related to the international migration of health workers in order to better understand its impact and to find entry points to developing policy options with which migration can be managed. The paper is divided into six sections. In the first, the different types of migration are reviewed. Some global trends are depicted in the second section. Scarcity of data on health worker migration is one major challenge and this is addressed in section three, which reviews and discusses different data sources. The consequences of health worker migration and the financial flows associated with it are presented in section four and five, respectively. To illustrate the main issues addressed in the previous sections, a case study based mainly on the United Kingdom is presented in section six. This section includes a discussion on policies and ends by addressing the policy options from a broader perspective.

  14. VolHOG: a volumetric object recognition approach based on bivariate histograms of oriented gradients for vertebra detection in cervical spine MRI.

    Science.gov (United States)

    Daenzer, Stefan; Freitag, Stefan; von Sachsen, Sandra; Steinke, Hanno; Groll, Mathias; Meixensberger, Jürgen; Leimert, Mario

    2014-08-01

    The automatic recognition of vertebrae in volumetric images is an important step toward automatic spinal diagnosis and therapy support systems. There are many applications such as the detection of pathologies and segmentation which would benefit from automatic initialization by the detection of vertebrae. One possible application is the initialization of local vertebral segmentation methods, eliminating the need for manual initialization by a human operator. Automating the initialization process would optimize the clinical workflow. However, automatic vertebra recognition in magnetic resonance (MR) images is a challenging task due to noise in images, pathological deformations of the spine, and image contrast variations. This work presents a fully automatic algorithm for 3D cervical vertebra detection in MR images. We propose a machine learning method for cervical vertebra detection based on new features combined with a linear support vector machine for classification. An algorithm for bivariate gradient orientation histogram generation from three-dimensional raster image data is introduced which allows us to describe three-dimensional objects using the authors' proposed bivariate histograms. A detailed performance evaluation on 21 T2-weighted MR images of the cervical vertebral region is given. A single model for cervical vertebrae C3-C7 is generated and evaluated. The results show that the generic model performs equally well for each of the cervical vertebrae C3-C7. The algorithm's performance is also evaluated on images containing various levels of artificial noise. The results indicate that the proposed algorithm achieves good results despite the presence of severe image noise. The proposed detection method delivers accurate locations of cervical vertebrae in MR images which can be used in diagnosis and therapy. In order to achieve absolute comparability with the results of future work, the authors are following an open data approach by making the image dataset

  15. From the bottom up: tracing the impact of four health-based social movements on health and social policies.

    Science.gov (United States)

    Keefe, Robert H; Lane, Sandra D; Swarts, Heidi J

    2006-01-01

    Although health-based social movements organized by grassroots activists have a rich history in impacting health and social policy, few systematic studies have addressed their policy change efforts or effectiveness. In this article, the authors trace how four health-based social movements-the women's health movement, ACT UP, breast cancer, and needle exchange-influenced health and social policy legislation. The activists' efforts wrested control of "authoritative knowledge" that had once been the sole domain of "experts" with advanced medical training. They used this knowledge to empower "average" people with medical information, promote self help and engage in civil disobedience, which led to changes in healthcare delivery, drug testing and approval, and increased research funds for HIV/AIDS, breast cancer, and needle exchange. The activists' efforts led to other health-based social movements that are currently, or will become, issues for health and social policy analysts in the future.

  16. Modeling urban expansion policy scenarios using an agent-based approach for Guangzhou Metropolitan Region of China

    Directory of Open Access Journals (Sweden)

    Guangjin Tian

    2014-09-01

    Full Text Available Policy makers and the human decision processes of urban planning have an impact on urban expansion. The behaviors and decision modes of regional authority, real estate developer, resident, and farmer agents and their interactions can be simulated by the analytical hierarchy process (AHP method. The driving factors are regressed with urban dynamics instead of static land-use types. Agents' behaviors and decision modes have an impact on the urban dynamic pattern by adjusting parameter weights. We integrate an agent-based model (ABM with AHP to investigate a complex decision-making process and future urban dynamic processes. Three policy scenarios for baseline development, rapid development, and green land protection have been applied to predict the future development patterns of the Guangzhou metropolitan region. A future policy scenario analysis can help policy makers to understand the possible results. These individuals can adjust their policies and decisions according to their different objectives.

  17. Evidence based policy making in the European Union. The role of the scientific community

    International Nuclear Information System (INIS)

    Majcen, Spela

    2017-01-01

    In the times when the acquis of the European Union (EU) has developed so far as to reach a high level of technical complexity, in particular in certain policy fields such as environmental legislation, it is important to look at what kind of information and data policy decisions are based on. This position paper looks at the extent to which evidence-based decision-making process is being considered in the EU institutions when it comes to adopting legislation in the field of environment at the EU level. The paper calls for closer collaboration between scientists and decision-makers in view of ensuring that correct data is understood and taken into consideration when drafting, amending, negotiating and adopting new legal texts at all levels of the EU decision-making process. It concludes that better awareness of the need for such collaboration among the decision-makers as well as the scientific community would benefit the process and quality of the final outcomes (legislation).

  18. Evidence based policy making in the European Union. The role of the scientific community

    Energy Technology Data Exchange (ETDEWEB)

    Majcen, Spela [Euro-Mediterranean Univ. (EMUNI), Portoroz (Slovenia)

    2017-03-15

    In the times when the acquis of the European Union (EU) has developed so far as to reach a high level of technical complexity, in particular in certain policy fields such as environmental legislation, it is important to look at what kind of information and data policy decisions are based on. This position paper looks at the extent to which evidence-based decision-making process is being considered in the EU institutions when it comes to adopting legislation in the field of environment at the EU level. The paper calls for closer collaboration between scientists and decision-makers in view of ensuring that correct data is understood and taken into consideration when drafting, amending, negotiating and adopting new legal texts at all levels of the EU decision-making process. It concludes that better awareness of the need for such collaboration among the decision-makers as well as the scientific community would benefit the process and quality of the final outcomes (legislation).

  19. Study of Evaluation OSH Management System Policy Based On Safety Culture Dimensions in Construction Project

    Science.gov (United States)

    Latief, Yusuf; Armyn Machfudiyanto, Rossy; Arifuddin, Rosmariani; Mahendra Fira Setiawan, R.; Yogiswara, Yoko

    2017-07-01

    Safety Culture in the construction industry is very influential on the socio economic conditions that resulted in the country’s competitiveness. Based on the data, the accident rate of construction projects in Indonesia is very high. In the era of the Asian Economic Community (AEC) Indonesian contractor is required to improve competitiveness, one of which is the implementation of the project without zero accident. Research using primary and secondary data validated the results of the literature experts and questionnaire respondents were analyzed using methods SmartPLS, obtained pattern of relationships between dimensions of safety culture to improve the performance of Safety. The results showed that the behaviors and Cost of Safety into dimensions that significantly affect the performance of safety. an increase in visible policy-based on Regulation of Public Work and Housing No 5/PRT/M/2014 to improve to lower the accident rate.

  20. Application of theory-based evaluation for the critical analysis of national biofuel policy: A case study in Malaysia.

    Science.gov (United States)

    Abdul-Manan, Amir F N; Baharuddin, Azizan; Chang, Lee Wei

    2015-10-01

    Theory-based evaluation (TBE) is an effectiveness assessment technique that critically analyses the theory underlying an intervention. Whilst its use has been widely reported in the area of social programmes, it is less applied in the field of energy and climate change policy evaluations. This paper reports a recent study that has evaluated the effectiveness of the national biofuel policy (NBP) for the transport sector in Malaysia by adapting a TBE approach. Three evaluation criteria were derived from the official goals of the NBP, those are (i) improve sustainability and environmental friendliness, (ii) reduce fossil fuel dependency, and (iii) enhance stakeholders' welfare. The policy theory underlying the NBP has been reconstructed through critical examination of the policy and regulatory documents followed by a rigorous appraisal of the causal link within the policy theory through the application of scientific knowledge. This study has identified several weaknesses in the policy framework that may engender the policy to be ineffective. Experiences with the use of a TBE approach for policy evaluations are also shared in this report. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Comprehensive optimisation of China’s energy prices, taxes and subsidy policies based on the dynamic computable general equilibrium model

    International Nuclear Information System (INIS)

    He, Y.X.; Liu, Y.Y.; Du, M.; Zhang, J.X.; Pang, Y.X.

    2015-01-01

    Highlights: • Energy policy is defined as a complication of energy price, tax and subsidy policies. • The maximisation of total social benefit is the optimised objective. • A more rational carbon tax ranges from 10 to 20 Yuan/ton under the current situation. • The optimal coefficient pricing is more conducive to maximise total social benefit. - Abstract: Under the condition of increasingly serious environmental pollution, rational energy policy plays an important role in the practical significance of energy conservation and emission reduction. This paper defines energy policies as the compilation of energy prices, taxes and subsidy policies. Moreover, it establishes the optimisation model of China’s energy policy based on the dynamic computable general equilibrium model, which maximises the total social benefit, in order to explore the comprehensive influences of a carbon tax, the sales pricing mechanism and the renewable energy fund policy. The results show that when the change rates of gross domestic product and consumer price index are ±2%, ±5% and the renewable energy supply structure ratio is 7%, the more reasonable carbon tax ranges from 10 to 20 Yuan/ton, and the optimal coefficient pricing mechanism is more conducive to the objective of maximising the total social benefit. From the perspective of optimising the overall energy policies, if the upper limit of change rate in consumer price index is 2.2%, the existing renewable energy fund should be improved

  2. HIV/AIDS Policy Making Process in Iran: Analysis of HIV/AIDS Agenda Setting Based on Kingdon's Framework

    Directory of Open Access Journals (Sweden)

    Rahim Khodayari Zarnaq

    2016-12-01

    Full Text Available Background and Objectives : Agenda setting is the process by which certain issues come onto the policy agenda from the much larger number of issues potentially worthy of attention by policy makers. The aim of this study was to deeply understand about how AIDS entered to health policy agenda in Iran. Material and Methods: An exploratory qualitative retrospective study based on multiple streams framework to analyze AIDS agenda setting process, 32 semi-structured interviews were conducted with key informants and stakeholders in Iran and 30 policy documents were reviewed. Data were analyzed using framework analysis method and MAXQDA software. Results : Problem, policy and politics, the three streams of HIV/AIDS in context of Iran were identified and the advent and continuity of multiple streams and their interactions and combination by policy entrepreneurs in couple of streams in policy windows were explained. Conclusion: In this study, the assumption of independence of three streams from each other was doubted. Also, framework has ambiguities in explaining entrepreneurs' act when opening policy windows. Other researchers can modify the framework by learning-by-doing.

  3. Flexoelectricity: strain gradient effects in ferroelectrics

    Energy Technology Data Exchange (ETDEWEB)

    Ma Wenhui [Department of Physics, Shantou Unversity, Shantou, Guangdong 515063 (China)

    2007-12-15

    Mechanical strain gradient induced polarization effect or flexoelectricity in perovskite-type ferroelectric and relaxor ferroelectric ceramics was investigated. The flexoelectric coefficients measured at room temperature ranged from about 1 {mu} C m{sup -1} for lead zirconate titanate to 100 {mu} C m{sup -1} for barium strontium titanate. Flexoelectric effects were discovered to be sensitive to chemical makeup, phase symmetry, and domain structures. Based on phenomenological discussion and experimental data on flexoelectricity, the present study proposed that mechanical strain gradient field could influence polarization responses in a way analogous to electric field. Flexoelectric coefficients were found to be nonlinearly enhanced by dielectric permittivity and strain gradient. Interfacial mismatch in epitaxial thin films can give rise to high strain gradients, enabling flexoelectric effects to make a significant impact in properly engineered ferroelectric heterostructure systems.

  4. Flexoelectricity: strain gradient effects in ferroelectrics

    International Nuclear Information System (INIS)

    Ma Wenhui

    2007-01-01

    Mechanical strain gradient induced polarization effect or flexoelectricity in perovskite-type ferroelectric and relaxor ferroelectric ceramics was investigated. The flexoelectric coefficients measured at room temperature ranged from about 1 μ C m -1 for lead zirconate titanate to 100 μ C m -1 for barium strontium titanate. Flexoelectric effects were discovered to be sensitive to chemical makeup, phase symmetry, and domain structures. Based on phenomenological discussion and experimental data on flexoelectricity, the present study proposed that mechanical strain gradient field could influence polarization responses in a way analogous to electric field. Flexoelectric coefficients were found to be nonlinearly enhanced by dielectric permittivity and strain gradient. Interfacial mismatch in epitaxial thin films can give rise to high strain gradients, enabling flexoelectric effects to make a significant impact in properly engineered ferroelectric heterostructure systems

  5. Unimodal and crossmodal gradients of spatial attention

    DEFF Research Database (Denmark)

    Föcker, J.; Hötting, K.; Gondan, Matthias

    2010-01-01

    Behavioral and event-related potential (ERP) studies have shown that spatial attention is gradually distributed around the center of the attentional focus. The present study compared uni- and crossmodal gradients of spatial attention to investigate whether the orienting of auditory and visual...... spatial attention is based on modality specific or supramodal representations of space. Auditory and visual stimuli were presented from five speaker locations positioned in the right hemifield. Participants had to attend to the innermost or outmost right position in order to detect either visual...... or auditory deviant stimuli. Detection rates and event-related potentials (ERPs) indicated that spatial attention is distributed as a gradient. Unimodal spatial ERP gradients correlated with the spatial resolution of the modality. Crossmodal spatial gradients were always broader than the corresponding...

  6. Fast Fourier-based simulation of off-resonance artifacts in steady-state gradient echo MRI applied to metal object localization

    NARCIS (Netherlands)

    Zijlstra, Frank; Bouwman, Job G; Braškute, I; Viergever, Max A; Seevinck, PR

    2017-01-01

    PURPOSE: To accelerate simulation of off-resonance artifacts in steady-state gradient echo MRI by using fast Fourier transforms and demonstrate its applicability to metal object localization. THEORY AND METHODS: By exploiting the repetitive nature of steady-state pulse sequences it is possible to

  7. Wavelet based analysis of TanDEM-X and LiDAR DEMs across a tropical vegetation heterogeneity gradient driven by fire disturbance in Indonesia

    NARCIS (Netherlands)

    Grandi, De Elsa Carla; Mitchard, Edward; Hoekman, Dirk

    2016-01-01

    Three-dimensional information provided by TanDEM-X interferometric phase and airborne Light Detection and Ranging (LiDAR) Digital ElevationModels (DEMs) were used to detect differences in vegetation heterogeneity through a disturbance gradient in Indonesia. The range of vegetation types developed

  8. School-Based Obesity-Prevention Policies and Practices and Weight-Control Behaviors among Adolescents.

    Science.gov (United States)

    Larson, Nicole; Davey, Cynthia S; Caspi, Caitlin E; Kubik, Martha Y; Nanney, Marilyn S

    2017-02-01

    The promotion of healthy eating and physical activity within school settings is an important component of population-based strategies to prevent obesity; however, adolescents may be vulnerable to weight-related messages, as rapid development during this life stage often leads to preoccupation with body size and shape. This study examines secular trends in secondary school curricula topics relevant to the prevention of unhealthy weight-control behaviors; describes cross-sectional associations between weight-related curricula content and students' use of weight-control behaviors; and assesses whether implementation of school-based obesity-prevention policies/practices is longitudinally related to students' weight-control behaviors. The Minnesota School Health Profiles and Minnesota Student Survey (grades 9 and 12) data were used along with National Center for Education Statistics data to examine secular trends, cross-sectional associations (n=141 schools), and longitudinal associations (n=42 schools). Students self-reported their height and weight along with past-year use of healthy (eg, exercise), unhealthy (eg, fasting), and extreme (eg, use laxatives) weight-control behaviors. Descriptive statistics, generalized estimating equations, and generalized linear regression models accounting for school-level demographics. There was no observable pattern during the years 2008 to 2014 in the mean number of curricula topics addressing unhealthy weight-control behaviors, despite an increase in the prevalence of curricula addressing acceptance of body-size differences. Including three vs fewer weight-control topics and specifically including the topic of eating disorders in the curricula was related to a lower school-level percent of students using any extreme weight-control behaviors. In contrast, an overall measure of implementing school-based obesity-prevention policies/practices (eg, prohibited advertising) was unrelated to use of unhealthy or extreme behaviors

  9. Policy Actions to Address Weight-Based Bullying and Eating Disorders in Schools: Views of Teachers and School Administrators.

    Science.gov (United States)

    Puhl, Rebecca M; Neumark-Sztainer, Dianne; Bryn Austin, S; Suh, Young; Wakefield, Dorothy B

    2016-07-01

    Weight-related bullying is prevalent among youth and associated with adverse health consequences, including increased risk for body dissatisfaction and disordered eating behaviors, which are risk factors for eating disorders. Although concerns about these problems have stimulated calls for broader intervention efforts in schools, actions thus far have been limited. This study examined educators' perspectives about potential policy actions to address these issues in schools. Educators (N = 240) completed an online questionnaire assessing their support for 11 potential school-based policy actions to address weight-related bullying and eating disorders. Participants also rated policies according to their feasibility and potential for positive impact. Forty-eight percent of participants observed weight-related bullying in their school and 99% expressed the importance of intervening in such incidents. A large majority (75%-94%) supported 8 of the 11 policies, especially actions requiring school-based health curriculum to include content on eating disorder prevention (94%), and addressing weight-bullying through antibullying policies (92%), staff training (89%), and school curriculum (89%). Strongly supported policies were viewed by participants as being the most impactful and feasible to implement. Educators recognize weight-related bullying and eating disorders as problems in their schools that warrant improved prevention and intervention efforts at the policy level. © 2016, American School Health Association.

  10. Assessing the impact of policy interventions on the adoption of plug-in electric vehicles: An agent-based model

    International Nuclear Information System (INIS)

    Silvia, Chris; Krause, Rachel M.

    2016-01-01

    Heightened concern regarding climate change and energy independence has increased interest in plug-in electric vehicles as one means to address these challenges and governments at all levels have considered policy interventions to encourage their adoption. This paper develops an agent-based model that simulates the introduction of four policy scenarios aimed at promoting electric vehicle adoption in an urban community and compares them against a baseline. These scenarios include reducing vehicle purchase price via subsidies, expanding the local public charging network, increasing the number and visibility of fully battery electric vehicles (BEVs) on the roadway through government fleet purchases, and a hybrid mix of these three approaches. The results point to the effectiveness of policy options that increased awareness of BEV technology. Specifically, the hybrid policy alternative was the most successful in encouraging BEV adoption. This policy increases the visibility and familiarity of BEV technology in the community and may help counter the idea that BEVs are not a viable alternative to gasoline-powered vehicles. - Highlights: •Various policy interventions to encourage electric vehicle adoption are examined. •An agent based model is used to simulate individual adoption decisions. •Policies that increase the familiarity of electric vehicles are most effective.

  11. Struggling between resources-based and sustainable development schemes-An analysis of Egypt's recent energy policy

    International Nuclear Information System (INIS)

    Suding, Paul H.

    2011-01-01

    This paper discusses Egypt's recent energy sector and policy developments against objectives and issues of the energy policy strategy adopted in 2007. It reviews energy supply and demand, pricing and subsidies as well as institutional arrangements and respective reform projects from the perspective of assessing achievements. It identifies the consequences of the policy and the long-term outlook and reports on the internal policy struggle. The policy strategy of 2007 is directed at energy security, social and industrial development. Environmental or climate objectives play no role. Energy efficiency is at best considered an instrument. The implementation of the strategy has been successful on the supply side, but not on the demand side. Price reform, refocusing subsidies and sector reform were not achieved. This has negatively affected energy efficiency and diversification, energy availability and supply security, the State budget and the sector's financial capacity. It causes rising energy import requirements and increasing risks to the current account balance. In spite of that, 'old guard' and industrial establishment favour the resource-based development based on cheap energy and protract price reform, whereas another group of businessmen wants a sustainable development concept and monetize the oil and gas production to invest in Egypt's competitiveness. - Research Highlights: → Egyptian energy policy has not delivered demand side results and institutional reform. → The consequences are disparities in supply, external balance, financing and subsidies. →The prevailing interest groups succeed in protracting the implementation of the policy.

  12. Shape reconstruction from gradient data.

    Science.gov (United States)

    Ettl, Svenja; Kaminski, Jürgen; Knauer, Markus C; Häusler, Gerd

    2008-04-20

    We present a generalized method for reconstructing the shape of an object from measured gradient data. A certain class of optical sensors does not measure the shape of an object but rather its local slope. These sensors display several advantages, including high information efficiency, sensitivity, and robustness. For many applications, however, it is necessary to acquire the shape, which must be calculated from the slopes by numerical integration. Existing integration techniques show drawbacks that render them unusable in many cases. Our method is based on an approximation employing radial basis functions. It can be applied to irregularly sampled, noisy, and incomplete data, and it reconstructs surfaces both locally and globally with high accuracy.

  13. Risk Policies in the United States: Definition and Characteristics Based on a Scoping Review of the Literature.

    Science.gov (United States)

    Jacob, Steve; Schiffino, Nathalie

    2015-05-01

    The concept of "risk policy" is used with increasing frequency by decisionmakers, researchers, and the media. However, there is no precise, generally accepted definition of what is covered by policies in this area. Based on a scoping review of the literature published in key journals in the sector, we have identified the main characteristics of public risk policies drawn up and implemented in the United States. The sample comprised 21 articles published in six multidisciplinary journals between 2000 and 2010. © 2014 Society for Risk Analysis.

  14. Resource management and scheduling policy based on grid for AIoT

    Science.gov (United States)

    Zou, Yiqin; Quan, Li

    2017-07-01

    This paper has a research on resource management and scheduling policy based on grid technology for Agricultural Internet of Things (AIoT). Facing the situation of a variety of complex and heterogeneous agricultural resources in AIoT, it is difficult to represent them in a unified way. But from an abstract perspective, there are some common models which can express their characteristics and features. Based on this, we proposed a high-level model called Agricultural Resource Hierarchy Model (ARHM), which can be used for modeling various resources. It introduces the agricultural resource modeling method based on this model. Compared with traditional application-oriented three-layer model, ARHM can hide the differences of different applications and make all applications have a unified interface layer and be implemented without distinction. Furthermore, it proposes a Web Service Resource Framework (WSRF)-based resource management method and the encapsulation structure for it. Finally, it focuses on the discussion of multi-agent-based AG resource scheduler, which is a collaborative service provider pattern in multiple agricultural production domains.

  15. Providing Evidence-Based, Intelligent Support for Flood Resilient Planning and Policy: The PEARL Knowledge Base

    Directory of Open Access Journals (Sweden)

    George Karavokiros

    2016-09-01

    Full Text Available While flood risk is evolving as one of the most imminent natural hazards and the shift from a reactive decision environment to a proactive one sets the basis of the latest thinking in flood management, the need to equip decision makers with necessary tools to think about and intelligently select options and strategies for flood management is becoming ever more pressing. Within this context, the Preparing for Extreme and Rare Events in Coastal Regions (PEARL intelligent knowledge-base (PEARL KB of resilience strategies is presented here as an environment that allows end-users to navigate from their observed problem to a selection of possible options and interventions worth considering within an intuitive visual web interface assisting advanced interactivity. Incorporation of real case studies within the PEARL KB enables the extraction of (evidence-based lessons from all over the word, while the KB’s collection of methods and tools directly supports the optimal selection of suitable interventions. The Knowledge-Base also gives access to the PEARL KB Flood Resilience Index (FRI tool, which is an online tool for resilience assessment at a city level available to authorities and citizens. We argue that the PEARL KB equips authorities with tangible and operational tools that can improve strategic and operational flood risk management by assessing and eventually increasing resilience, while building towards the strengthening of risk governance. The online tools that the PEARL KB gives access to were demonstrated and tested in the city of Rethymno, Greece.

  16. Knowledge-based changes to health systems: the Thai experience in policy development.

    Science.gov (United States)

    Tangcharoensathien, Viroj; Wibulpholprasert, Suwit; Nitayaramphong, Sanguan

    2004-01-01

    Over the past two decades the government in Thailand has adopted an incremental approach to extending health-care coverage to the population. It first offered coverage to government employees and their dependents, and then introduced a scheme under which low-income people were exempt from charges for health care. This scheme was later extended to include elderly people, children younger than 12 years of age and disabled people. A voluntary public insurance scheme was implemented to cover those who could afford to pay for their own care. Private sector employees were covered by the Social Health Insurance scheme, which was implemented in 1991. Despite these efforts, 30% of the population remained uninsured in 2001. In October of that year, the new government decided to embark on a programme to provide universal health-care coverage. This paper describes how research into health systems and health policy contributed to the move towards universal coverage. Data on health systems financing and functioning had been gathered before and after the founding of the Health Systems Research Institute in early 1990. In 1991, a contract capitation model had been used to launch the Social Health Insurance scheme. The advantages of using a capitation model are that it contains costs and provides an acceptable quality of service as opposed to the cost escalation and inefficiency that occur under fee-for-service reimbursement models, such as the one used to provide medical benefits to civil servants. An analysis of the implementation of universal coverage found that politics moved universal coverage onto the policy agenda during the general election campaign in January 2001. The capacity for research on health systems and policy to generate evidence guided the development of the policy and the design of the system at a later stage. Because the reformists who sought to bring about universal coverage (who were mostly civil servants in the Ministry of Public Health and members of

  17. Knowledge-based changes to health systems: the Thai experience in policy development.

    Science.gov (United States)

    Tangcharoensathien, Viroj; Wibulpholprasert, Suwit; Nitayaramphong, Sanguan

    2004-10-01

    Over the past two decades the government in Thailand has adopted an incremental approach to extending health-care coverage to the population. It first offered coverage to government employees and their dependents, and then introduced a scheme under which low-income people were exempt from charges for health care. This scheme was later extended to include elderly people, children younger than 12 years of age and disabled people. A voluntary public insurance scheme was implemented to cover those who could afford to pay for their own care. Private sector employees were covered by the Social Health Insurance scheme, which was implemented in 1991. Despite these efforts, 30% of the population remained uninsured in 2001. In October of that year, the new government decided to embark on a programme to provide universal health-care coverage. This paper describes how research into health systems and health policy contributed to the move towards universal coverage. Data on health systems financing and functioning had been gathered before and after the founding of the Health Systems Research Institute in early 1990. In 1991, a contract capitation model had been used to launch the Social Health Insurance scheme. The advantages of using a capitation model are that it contains costs and provides an acceptable quality of service as opposed to the cost escalation and inefficiency that occur under fee-for-service reimbursement models, such as the one used to provide medical benefits to civil servants. An analysis of the implementation of universal coverage found that politics moved universal coverage onto the policy agenda during the general election campaign in January 2001. The capacity for research on health systems and policy to generate evidence guided the development of the policy and the design of the system at a later stage. Because the reformists who sought to bring about universal coverage (who were mostly civil servants in the Ministry of Public Health and members of

  18. Addressing the systems-based practice requirement with health policy content and educational technology.

    Science.gov (United States)

    Nagler, Alisa; Andolsek, Kathryn; Dossary, Kristin; Schlueter, Joanne; Schulman, Kevin

    2010-01-01

    Duke University Hospital Office of Graduate Medical Education and Duke University's Fuqua School of Business collaborated to offer a Health Policy lecture series to residents and fellows across the institution, addressing the "Systems-based Practice" competency.During the first year, content was offered in two formats: live lecture and web/podcast. Participants could elect the modality which was most convenient for them. In Year Two, the format was changed so that all content was web/podcast and a quarterly live panel discussion was led by module presenters or content experts. Lecture evaluations, qualitative focus group feedback, and post-test data were analyzed.A total of 77 residents and fellows from 8 (of 12) Duke Graduate Medical Education departments participated. In the first year, post-test results were the same for those who attended the live lectures and those who participated via web/podcast. A greater number of individuals participated in Year Two. Participants from both years expressed the need for health policy content in their training programs. Participants in both years valued a hybrid format for content delivery, recognizing a desire for live interaction with the convenience of accessing web/podcasts at times and locations convenient for them. A positive unintended consequence of the project was participant networking with residents and fellows from other specialties.

  19. Configuration model of partial repairable spares under batch ordering policy based on inventory state

    Directory of Open Access Journals (Sweden)

    Ruan Minzhi

    2014-06-01

    Full Text Available Rational planning of spares configuration project is an effective approach to improve equipment availability as well as reduce life cycle cost (LCC. With an analysis of various impacts on support system, the spares demand rate forecast model is constructed. According to systemic analysis method, spares support effectiveness evaluation indicators system is built, and then, initial spares configuration and optimization method is researched. To the issue of discarding and consumption for incomplete repairable items, its expected backorders function is approximated by Laplace demand distribution. Combining the (s−1, s and (R, Q inventory policy, the spares resupply model is established under the batch ordering policy based on inventory state, and the optimization analysis flow for spares configuration is proposed. Through application on shipborne equipment spares configuration, the given scenarios are analyzed under two constraint targets: one is the support effectiveness, and the other is the spares cost. Analysis reveals that the result is consistent with practical regulation; therefore, the model’s correctness, method’s validity as well as optimization project’s rationality are proved to a certain extent.

  20. The science, policy and practice of nature-based solutions: An interdisciplinary perspective.

    Science.gov (United States)

    Nesshöver, Carsten; Assmuth, Timo; Irvine, Katherine N; Rusch, Graciela M; Waylen, Kerry A; Delbaere, Ben; Haase, Dagmar; Jones-Walters, Lawrence; Keune, Hans; Kovacs, Eszter; Krauze, Kinga; Külvik, Mart; Rey, Freddy; van Dijk, Jiska; Vistad, Odd Inge; Wilkinson, Mark E; Wittmer, Heidi

    2017-02-01

    In this paper, we reflect on the implications for science, policy and practice of the recently introduced concept of Nature-Based Solutions (NBS), with a focus on the European context. First, we analyse NBS in relation to similar concepts, and reflect on its relationship to sustainability as an overarching framework. From this, we derive a set of questions to be addressed and propose a general framework for how these might be addressed in NBS projects by funders, researchers, policy-makers and practitioners. We conclude that: To realise their full potential, NBS must be developed by including the experience of all relevant stakeholders such that 'solutions' contribute to achieving all dimensions of sustainability. As NBS are developed, we must also moderate the expectations placed on them since the precedent provided by other initiatives whose aim was to manage nature sustainably demonstrates that we should not expect NBS to be cheap and easy, at least not in the short-term. Copyright © 2016 British Geological Survey, NERC. Published by Elsevier B.V. All rights reserved.