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Sample records for recurrent multilayer perceptron

  1. Algorithm for Training a Recurrent Multilayer Perceptron

    Parlos, Alexander G.; Rais, Omar T.; Menon, Sunil K.; Atiya, Amir F.

    2004-01-01

    An improved algorithm has been devised for training a recurrent multilayer perceptron (RMLP) for optimal performance in predicting the behavior of a complex, dynamic, and noisy system multiple time steps into the future. [An RMLP is a computational neural network with self-feedback and cross-talk (both delayed by one time step) among neurons in hidden layers]. Like other neural-network-training algorithms, this algorithm adjusts network biases and synaptic-connection weights according to a gradient-descent rule. The distinguishing feature of this algorithm is a combination of global feedback (the use of predictions as well as the current output value in computing the gradient at each time step) and recursiveness. The recursive aspect of the algorithm lies in the inclusion of the gradient of predictions at each time step with respect to the predictions at the preceding time step; this recursion enables the RMLP to learn the dynamics. It has been conjectured that carrying the recursion to even earlier time steps would enable the RMLP to represent a noisier, more complex system.

  2. KLASIFIKASI WEBSITE MENGGUNAKAN ALGORITMA MULTILAYER PERCEPTRON

    Nyoman Purnama

    2014-12-01

    Full Text Available Sistem klasifikasi merupakan proses temu balik informasi yang sangat bergantung dari elemen-elemen penyusunnya.Sistem ini banyak digunakan untuk mengatasi permasalahan segmentasi data. Klasifikasi dapat digunakan pada website sebagaimetode untuk mengelompokkan website. Website merupakan salah satu data yang memiliki informasi yang beraneka-ragam,sehingga pengelompokan data ini penting untuk diteliti. Sistem klasifikasi dimulai dengan melakukan proses pengumpulaninformasi dari halaman website (parsing dan untuk setiap hasil parsing dilakukan proses penghapusan kata henti, stemming,feature selection dengan tf-idf. Hasil dari proses ini berupa fitur yang menjadi inputan algoritma Multilayer Perceptron. Dalamalgoritma ini terjadi proses pembelajaran terhadap pola input masukan dan pembuatan bobot pelatihan. Bobot ini akandigunakan pada proses klasifikasi. Hasil dari penelitian menunjukkan bahwa algoritma Multilayer Perceptron dapatmenghasilkan klasifikasi website dengan akurasi yang bagus. Hal ini dibuktikan dengan beberapa tahapan penelitian yangberbeda dan didapatkan nilai akurasi rata-rata diatas 70%.

  3. Multilayer Potts perceptrons with Levenberg-Marquardt learning.

    Wu, Jiann-Ming

    2008-12-01

    This paper presents learning multilayer Potts perceptrons (MLPotts) for data driven function approximation. A Potts perceptron is composed of a receptive field and a K -state transfer function that is generalized from sigmoid-like transfer functions of traditional perceptrons. An MLPotts network is organized to perform translation from a high-dimensional input to the sum of multiple postnonlinear projections, each with its own postnonlinearity realized by a weighted K-state transfer function. MLPotts networks span a function space that theoretically covers network functions of multilayer perceptrons. Compared with traditional perceptrons, weighted Potts perceptrons realize more flexible postnonlinear functions for nonlinear mappings. Numerical simulations show MLPotts learning by the Levenberg-Marquardt (LM) method significantly improves traditional supervised learning of multilayer perceptrons for data driven function approximation.

  4. Multilayer perceptron, fuzzy sets, and classification

    Pal, Sankar K.; Mitra, Sushmita

    1992-01-01

    A fuzzy neural network model based on the multilayer perceptron, using the back-propagation algorithm, and capable of fuzzy classification of patterns is described. The input vector consists of membership values to linguistic properties while the output vector is defined in terms of fuzzy class membership values. This allows efficient modeling of fuzzy or uncertain patterns with appropriate weights being assigned to the backpropagated errors depending upon the membership values at the corresponding outputs. During training, the learning rate is gradually decreased in discrete steps until the network converges to a minimum error solution. The effectiveness of the algorithm is demonstrated on a speech recognition problem. The results are compared with those of the conventional MLP, the Bayes classifier, and the other related models.

  5. IDENTIFIKASI GORESAN DASAR MANDARIN DENGAN METODE MULTILAYER PERCEPTRON

    Dewi

    2015-02-01

    Full Text Available Mandarin Language is the second international language after English Language. Mandarin Language is different with English Language. Mandarin Language consists of stroke, intonation and pin yin. The basic strokes in Mandarin Language are eleven strokes. In this research, author identifies the basic stroke of Mandarin using Multilayer Perceptron to determine how the accuracy of Multilayer Perceptron to recognize the strokes. Data of the basic stroke of Mandarin that used are strokes from several different people.The data has been saved in image with size 80x80 pixel and changed into black and white image. Then taking the FFT and Mean Citra value from the image. The next step is training the data, determining the target and implementation the multilayer perceptron method. The accuracy that reached by multilayer perceptron method in identifying the basic stroke of Mandarin is 59.09% with 45 node of hidden layer. The node amount of hidden layer very affect the output value.

  6. Optoelectronic implementation of multilayer perceptron and Hopfield neural networks

    Domanski, Andrzej W.; Olszewski, Mikolaj K.; Wolinski, Tomasz R.

    2004-11-01

    In this paper we present an optoelectronic implementation of two networks based on multilayer perceptron and the Hopfield neural network. We propose two different methods to solve a problem of lack of negative optical signals that are necessary for connections between layers of perceptron as well as within the Hopfield network structure. The first method applied for construction of multilayer perceptron was based on division of signals into two channels and next to use both of them independently as positive and negative signals. The second one, applied for implementation of the Hopfield model, was based on adding of constant value for elements of matrix weight. Both methods of compensation of lack negative optical signals were tested experimentally as optoelectronic models of multilayer perceptron and Hopfield neural network. Special configurations of optical fiber cables and liquid crystal multicell plates were used. In conclusion, possible applications of the optoelectronic neural networks are briefly discussed.

  7. Prediction of Parametric Roll Resonance by Multilayer Perceptron Neural Network

    Míguez González, M; López Peña, F.; Díaz Casás, V.

    2011-01-01

    acknowledged in the last few years. This work proposes a prediction system based on a multilayer perceptron (MP) neural network. The training and testing of the MP network is accomplished by feeding it with simulated data of a three degrees-of-freedom nonlinear model of a fishing vessel. The neural network...

  8. Conventional modeling of the multilayer perceptron using polynomial basis functions

    Chen, Mu-Song; Manry, Michael T.

    1993-01-01

    A technique for modeling the multilayer perceptron (MLP) neural network, in which input and hidden units are represented by polynomial basis functions (PBFs), is presented. The MLP output is expressed as a linear combination of the PBFs and can therefore be expressed as a polynomial function of its inputs. Thus, the MLP is isomorphic to conventional polynomial discriminant classifiers or Volterra filters. The modeling technique was successfully applied to several trained MLP networks.

  9. Validation of Infinite Impulse Response Multilayer Perceptron for Modelling Nuclear Dynamics

    F. Cadini

    2008-01-01

    Full Text Available Artificial neural networks are powerful algorithms for constructing nonlinear empirical models from operational data. Their use is becoming increasingly popular in the complex modeling tasks required by diagnostic, safety, and control applications in complex technologies such as those employed in the nuclear industry. In this paper, the nonlinear modeling capabilities of an infinite impulse response multilayer perceptron (IIR-MLP for nuclear dynamics are considered in comparison to static modeling by a finite impulse response multilayer perceptron (FIR-MLP and a conventional static MLP. The comparison is made with respect to the nonlinear dynamics of a nuclear reactor as investigated by IIR-MLP in a previous paper. The superior performance of the locally recurrent scheme is demonstrated.

  10. A Parallel Framework for Multilayer Perceptron for Human Face Recognition

    Bhowmik, M K; Nasipuri, M; Basu, D K; Kundu, M

    2010-01-01

    Artificial neural networks have already shown their success in face recognition and similar complex pattern recognition tasks. However, a major disadvantage of the technique is that it is extremely slow during training for larger classes and hence not suitable for real-time complex problems such as pattern recognition. This is an attempt to develop a parallel framework for the training algorithm of a perceptron. In this paper, two general architectures for a Multilayer Perceptron (MLP) have been demonstrated. The first architecture is All-Class-in-One-Network (ACON) where all the classes are placed in a single network and the second one is One-Class-in-One-Network (OCON) where an individual single network is responsible for each and every class. Capabilities of these two architectures were compared and verified in solving human face recognition, which is a complex pattern recognition task where several factors affect the recognition performance like pose variations, facial expression changes, occlusions, and ...

  11. Implementing Semantic Deduction of Propositional Knowledge in an Extension Multi-layer Perceptron

    HUANGTian-min; PEIZheng

    2003-01-01

    The paper presents an extension multi-layer perceptron model that is capable of representing and reasoning propositional knowledge base. An extended version of propositional calculus is developed,and its some properties is discussed. Formulas of the extended calculus can be expressed in the extension multi-layer perceptron. Naturally, semantic deduction of propositional knowledge base can be imple-ment by the extension multi-layer perceptron, and by learning, an unknown formula set can be found.

  12. Minimizing Hexapod Robot Foot Deviations Using Multilayer Perceptron

    Vytautas Valaitis

    2015-12-01

    Full Text Available Rough-terrain traversability is one of the most valuable characteristics of walking robots. Even despite their slower speeds and more complex control algorithms, walking robots have far wider usability than wheeled or tracked robots. However, efficient movement over irregular surfaces can only be achieved by eliminating all possible difficulties, which in many cases are caused by a high number of degrees of freedom, feet slippage, frictions and inertias between different robot parts or even badly developed inverse kinematics (IK. In this paper we address the hexapod robot-foot deviation problem. We compare the foot-positioning accuracy of unconfigured inverse kinematics and Multilayer Perceptron-based (MLP methods via theory, computer modelling and experiments on a physical robot. Using MLP-based methods, we were able to significantly decrease deviations while reaching desired positions with the hexapod’s foot. Furthermore, this method is able to compensate for deviations of the robot arising from any possible reason.

  13. Classification of fused face images using multilayer perceptron neural network

    Bhattacharjee, Debotosh; Nasipuri, Mita; Basu, Dipak Kumar; Kundu, Mahantapas

    2010-01-01

    This paper presents a concept of image pixel fusion of visual and thermal faces, which can significantly improve the overall performance of a face recognition system. Several factors affect face recognition performance including pose variations, facial expression changes, occlusions, and most importantly illumination changes. So, image pixel fusion of thermal and visual images is a solution to overcome the drawbacks present in the individual thermal and visual face images. Fused images are projected into eigenspace and finally classified using a multi-layer perceptron. In the experiments we have used Object Tracking and Classification Beyond Visible Spectrum (OTCBVS) database benchmark thermal and visual face images. Experimental results show that the proposed approach significantly improves the verification and identification performance and the success rate is 95.07%. The main objective of employing fusion is to produce a fused image that provides the most detailed and reliable information. Fusion of multip...

  14. Forecasting PM10 in Algiers: efficacy of multilayer perceptron networks.

    Abderrahim, Hamza; Chellali, Mohammed Reda; Hamou, Ahmed

    2016-01-01

    Air quality forecasting system has acquired high importance in atmospheric pollution due to its negative impacts on the environment and human health. The artificial neural network is one of the most common soft computing methods that can be pragmatic for carving such complex problem. In this paper, we used a multilayer perceptron neural network to forecast the daily averaged concentration of the respirable suspended particulates with aerodynamic diameter of not more than 10 μm (PM10) in Algiers, Algeria. The data for training and testing the network are based on the data sampled from 2002 to 2006 collected by SAMASAFIA network center at El Hamma station. The meteorological data, air temperature, relative humidity, and wind speed, are used as inputs network parameters in the formation of model. The training patterns used correspond to 41 days data. The performance of the developed models was evaluated on the basis index of agreement and other statistical parameters. It was seen that the overall performance of model with 15 neurons is better than the ones with 5 and 10 neurons. The results of multilayer network with as few as one hidden layer and 15 neurons were quite reasonable than the ones with 5 and 10 neurons. Finally, an error around 9% has been reached.

  15. Parallel multilayer perceptron neural network used for hyperspectral image classification

    Garcia-Salgado, Beatriz P.; Ponomaryov, Volodymyr I.; Robles-Gonzalez, Marco A.

    2016-04-01

    This study is focused on time optimization for the classification problem presenting a comparison of five Artificial Neural Network Multilayer Perceptron (ANN-MLP) architectures. We use the Artificial Neural Network (ANN) because it allows to recognize patterns in data in a lower time rate. Time and classification accuracy are taken into account together for the comparison. According to time comparison, two paradigms in the computational field for each ANN-MLP architecture are analysed with three schemes. Firstly, sequential programming is applied by using a single CPU core. Secondly, parallel programming is employed over a multi-core CPU architecture. Finally, a programming model running on GPU architecture is implemented. Furthermore, the classification accuracy is compared between the proposed five ANN-MLP architectures and a state-of.the-art Support Vector Machine (SVM) with three classification frames: 50%,60% and 70% of the data set's observations are randomly selected to train the classifiers. Also, a visual comparison of the classified results is presented. The Peak Signal to Noise Ratio (PSNR) and Structural Similarity Index Measure (SSIM) criteria are also calculated to characterise visual perception. The images employed were acquired by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), the Reflective Optics System Imaging Spectrometer (ROSIS) and the Hyperion sensor.

  16. Classification of Log-Polar-Visual Eigenfaces using Multilayer Perceptron

    Bhowmik, Mrinal Kanti; Nasipuri, Mita; Kundu, Mahantapas; Basu, Dipak Kumar

    2010-01-01

    In this paper we present a simple novel approach to tackle the challenges of scaling and rotation of face images in face recognition. The proposed approach registers the training and testing visual face images by log-polar transformation, which is capable to handle complicacies introduced by scaling and rotation. Log-polar images are projected into eigenspace and finally classified using an improved multi-layer perceptron. In the experiments we have used ORL face database and Object Tracking and Classification Beyond Visible Spectrum (OTCBVS) database for visual face images. Experimental results show that the proposed approach significantly improves the recognition performances from visual to log-polar-visual face images. In case of ORL face database, recognition rate for visual face images is 89.5% and that is increased to 97.5% for log-polar-visual face images whereas for OTCBVS face database recognition rate for visual images is 87.84% and 96.36% for log-polar-visual face images.

  17. [Research on Early Identification of Bipolar Disorder Based on Multi-layer Perceptron Neural Network].

    Zhang, Haowei; Gao, Yanni; Yuan, Chengmei; Liu, Ying; Ding, Yuqing

    2015-06-01

    Multi-layer perceptron (MLP) neural network belongs to multi-layer feedforward neural network, and has the ability and characteristics of high intelligence. It can realize the complex nonlinear mapping by its own learning through the network. Bipolar disorder is a serious mental illness with high recurrence rate, high self-harm rate and high suicide rate. Most of the onset of the bipolar disorder starts with depressive episode, which can be easily misdiagnosed as unipolar depression and lead to a delayed treatment so as to influence the prognosis. The early identifica- tion of bipolar disorder is of great importance for patients with bipolar disorder. Due to the fact that the process of early identification of bipolar disorder is nonlinear, we in this paper discuss the MLP neural network application in early identification of bipolar disorder. This study covered 250 cases, including 143 cases with recurrent depression and 107 cases with bipolar disorder, and clinical features were statistically analyzed between the two groups. A total of 42 variables with significant differences were screened as the input variables of the neural network. Part of the samples were randomly selected as the learning sample, and the other as the test sample. By choosing different neu- ral network structures, all results of the identification of bipolar disorder were relatively good, which showed that MLP neural network could be used in the early identification of bipolar disorder.

  18. Characterisation of tequila according to their major volatile composition using multilayer perceptron neural networks.

    Ceballos-Magaña, Silvia G; de Pablos, Fernando; Jurado, José Marcos; Martín, María Jesús; Alcázar, Ángela; Muñiz-Valencia, Roberto; Gonzalo-Lumbreras, Raquel; Izquierdo-Hornillos, Roberto

    2013-02-15

    Differentiation of silver, gold, aged and extra-aged tequila using 1-propanol, ethyl acetate, 2-methyl-1-propanol, 3-methyl-1-butanol and 2-methyl-1-butanol and furan derivatives like 5-(hydroxymethyl)-2-furaldehyde and 2-furaldehyde has been carried out. The content of 1-propanol, ethyl acetate, 2-methyl-1-propanol, 3-methyl-1-butanol and 2-methyl-1-butanol was determined by means of head space solid phase microextraction gas chromatography mass-spectrometry. 5-(Hydroxymethyl)-2-furaldehyde and 2-furaldehyde were determined by high performance liquid chromatography with diode array detection. Kruskal-Wallis test was used to highlight significant differences between types of tequila. Principal component analysis was applied as visualisation technique. Linear discriminant analysis and multilayer perceptron artificial neural networks were used to construct classification models. The best classification performance was obtained when multilayer perceptron model was applied.

  19. Classification of non-performing loans portfolio using Multilayer Perceptron artificial neural networks

    Flávio Clésio Silva de Souza

    2014-06-01

    Full Text Available The purpose of the present research is to apply a Multilayer Perceptron (MLP neural network technique to create classification models from a portfolio of Non-Performing Loans (NPLs to classify this type of credit derivative. These credit derivatives are characterized as the amount of loans that were not paid and are already overdue more than 90 days. Since these titles are, because of legislative motives, moved by losses, Credit Rights Investment Funds (FDIC performs the purchase of these debts and the recovery of the credits. Using the Multilayer Perceptron (MLP architecture of Artificial Neural Network (ANN, classification models regarding the posterior recovery of these debts were created. To evaluate the performance of the models, evaluation metrics of classification relating to the neural networks with different architectures were presented. The results of the classifications were satisfactory, given the classification models were successful in the presented economics costs structure.

  20. A multilayer perceptron solution to the match phase problem in rule-based artificial intelligence systems

    Sartori, Michael A.; Passino, Kevin M.; Antsaklis, Panos J.

    1992-01-01

    In rule-based AI planning, expert, and learning systems, it is often the case that the left-hand-sides of the rules must be repeatedly compared to the contents of some 'working memory'. The traditional approach to solve such a 'match phase problem' for production systems is to use the Rete Match Algorithm. Here, a new technique using a multilayer perceptron, a particular artificial neural network model, is presented to solve the match phase problem for rule-based AI systems. A syntax for premise formulas (i.e., the left-hand-sides of the rules) is defined, and working memory is specified. From this, it is shown how to construct a multilayer perceptron that finds all of the rules which can be executed for the current situation in working memory. The complexity of the constructed multilayer perceptron is derived in terms of the maximum number of nodes and the required number of layers. A method for reducing the number of layers to at most three is also presented.

  1. APPLYING PRINCIPAL COMPONENT ANALYSIS, MULTILAYER PERCEPTRON AND SELF-ORGANIZING MAPS FOR OPTICAL CHARACTER RECOGNITION

    Khuat Thanh Tung

    2016-11-01

    Full Text Available Optical Character Recognition plays an important role in data storage and data mining when the number of documents stored as images is increasing. It is expected to find the ways to convert images of typewritten or printed text into machine-encoded text effectively in order to support for the process of information handling effectively. In this paper, therefore, the techniques which are being used to convert image into editable text in the computer such as principal component analysis, multilayer perceptron network, self-organizing maps, and improved multilayer neural network using principal component analysis are experimented. The obtained results indicated the effectiveness and feasibility of the proposed methods.

  2. Generation of hourly irradiation synthetic series using the neural network multilayer perceptron

    Hontoria, L.; Aguilera, J. [Universidad de Jaen, Linares-Jaen (Spain). Dpto. de Electronica; Zufiria, P. [Ciudad Universitaria, Madrid (Spain). Grupo de Redes Neuronales

    2002-05-01

    In this work, a methodology based on the neural network model called multilayer perceptron (MLP) to solve a typical problem in solar energy is presented. This methodology consists of the generation of synthetic series of hourly solar irradiation. The model presented is based on the capacity of the MLP for finding relations between variables for which interrelation is unknown explicitly. The information available can be included progressively at the series generator at different stages. A comparative study with other solar irradiation synthetic generation methods has been done in order to demonstrate the validity of the one proposed. (author)

  3. Experts Fusion and Multilayer Perceptron Based on Belief Learning for Sonar Image Classification

    Martin, Arnaud

    2008-01-01

    The sonar images provide a rapid view of the seabed in order to characterize it. However, in such as uncertain environment, real seabed is unknown and the only information we can obtain, is the interpretation of different human experts, sometimes in conflict. In this paper, we propose to manage this conflict in order to provide a robust reality for the learning step of classification algorithms. The classification is conducted by a multilayer perceptron, taking into account the uncertainty of the reality in the learning stage. The results of this seabed characterization are presented on real sonar images.

  4. Approximating Gaussian mixture model or radial basis function network with multilayer perceptron.

    Patrikar, Ajay M

    2013-07-01

    Gaussian mixture models (GMMs) and multilayer perceptron (MLP) are both popular pattern classification techniques. This brief shows that a multilayer perceptron with quadratic inputs (MLPQ) can accurately approximate GMMs with diagonal covariance matrices. The mapping equations between the parameters of GMM and the weights of MLPQ are presented. A similar approach is applied to radial basis function networks (RBFNs) to show that RBFNs with Gaussian basis functions and Euclidean norm can be approximated accurately with MLPQ. The mapping equations between RBFN and MLPQ weights are presented. There are well-established training procedures for GMMs, such as the expectation maximization (EM) algorithm. The GMM parameters obtained by the EM algorithm can be used to generate a set of initial weights of MLPQ. Similarly, a trained RBFN can be used to generate a set of initial weights of MLPQ. MLPQ training can be continued further with gradient-descent based methods, which can lead to improvement in performance compared to the GMM or RBFN from which it is initialized. Thus, the MLPQ can always perform as well as or better than the GMM or RBFN.

  5. An Intelligent Approach to Educational Data: Performance Comparison of the Multilayer Perceptron and the Radial Basis Function Artificial Neural Networks

    Kayri, Murat

    2015-01-01

    The objective of this study is twofold: (1) to investigate the factors that affect the success of university students by employing two artificial neural network methods (i.e., multilayer perceptron [MLP] and radial basis function [RBF]); and (2) to compare the effects of these methods on educational data in terms of predictive ability. The…

  6. An Analog Multilayer Perceptron Neural Network for a Portable Electronic Nose

    Chih-Heng Pan

    2012-12-01

    Full Text Available This study examines an analog circuit comprising a multilayer perceptron neural network (MLPNN. This study proposes a low-power and small-area analog MLP circuit to implement in an E-nose as a classifier, such that the E-nose would be relatively small, power-efficient, and portable. The analog MLP circuit had only four input neurons, four hidden neurons, and one output neuron. The circuit was designed and fabricated using a 0.18 μm standard CMOS process with a 1.8 V supply. The power consumption was 0.553 mW, and the area was approximately 1.36 × 1.36 mm2. The chip measurements showed that this MLPNN successfully identified the fruit odors of bananas, lemons, and lychees with 91.7% accuracy.

  7. Identification of Determinants for Globalization of SMEs using Multi-Layer Perceptron Neural Networks

    Umar Draz

    2016-01-01

    Full Text Available SMEs (Small and Medium Sized Enterprises sector is facing problems relating to implementation of international quality standards. These SMEs need to identify factors affecting business success abroad for intelligent allocation of resources to the process of internationalization. In this paper, MLP NN (Multi-Layer Perceptron Neural Network has been used for identifying relative importance of key variables related to firm basics, manufacturing, quality inspection labs and level of education in determining the exporting status of Pakistani SMEs. A survey has been conducted for scoring out the pertinent variables in SMEs and coded in MLP NNs. It is found that ?firm registered with OEM (Original Equipment Manufacturer and ?size of firm? are the most important in determining exporting status of SMEs followed by other variables. For internationalization, the results aid policy makers in formulating strategies

  8. Highly Accurate Multi-layer Perceptron Neural Network for Air Data System

    H. S. Krishna

    2009-11-01

    Full Text Available The error backpropagation multi-layer perceptron algorithm is revisited. This algorithm is used to train and validate two models of three-layer neural networks that can be used to calibrate a 5-hole pressure probe. This paper addresses Occam's Razor problem as it describes the adhoc training methodology applied to improve accuracy and sensitivity. The trained outputs from 5-4-3 feed-forward network architecture with jump connection are comparable to second decimal digit (~0.05 accuracy, hitherto unreported in literature.Defence Science Journal, 2009, 59(6, pp.670-674, DOI:http://dx.doi.org/10.14429/dsj.59.1574

  9. Image Binarization Using Multi-Layer Perceptron: A Semi-Supervised Approach

    Amlan Raychaudhuri

    2012-04-01

    Full Text Available In this paper, we have discussed the Image Binarization technique using Multilayer Perceptron (MLP. The purpose of Image Binarization is to extract the lightness (brightness, density as a feature amount from the Image. It converts a gray-scale image of up to 256 gray levels to a black and white image. We use Backpropagation algorithm for training MLP. It is a supervised learning technique. Here Kmeans clustering algorithm has been used for clustering a 256 × 256 gray-level image. The dataset obtained by this is fed to the MLP and processed in a Semi-Supervised way where some training samples are taken as Known patterns (for training and others as Unknown patterns. Finally through this approach a Binarized image is produced.

  10. A Rejection Model Based on Multi-Layer Perceptrons forMandarin Digit Recognition

    钟林; 刘加; 刘润生

    2002-01-01

    High performance Mandarin digit recognition (MDR) is much more difficult to achieve than its English counterpart, especially on inexpensive hardware implementation In this paper, a new Multi-Layer Perceptrons (MLP) based postprocessor, an a posteriori probability estimator, is presented and used for the rejection model of the speaker independent Mandarin digit recognition system based on hidden Markov model (HMM). Poor utterances,which are recognized by HMMs but have low a posteriori probability, will be rejected. After rejecting about 4.9% of the tested utterances, the MLP rejection model can boost the digit recognition accuracy from 97.1% to 99.6%. The performance is better than those rejection models based on linear discrimination, likelihood ratio or anti-digit.

  11. Classification of Polar-Thermal Eigenfaces using Multilayer Perceptron for Human Face Recognition

    Bhowmik, Mrinal Kanti; Nasipuri, Mita; Basu, Dipak Kumar; Kundu, Mahantapas

    2010-01-01

    This paper presents a novel approach to handle the challenges of face recognition. In this work thermal face images are considered, which minimizes the affect of illumination changes and occlusion due to moustache, beards, adornments etc. The proposed approach registers the training and testing thermal face images in polar coordinate, which is capable to handle complicacies introduced by scaling and rotation. Polar images are projected into eigenspace and finally classified using a multi-layer perceptron. In the experiments we have used Object Tracking and Classification Beyond Visible Spectrum (OTCBVS) database benchmark thermal face images. Experimental results show that the proposed approach significantly improves the verification and identification performance and the success rate is 97.05%.

  12. Analysis of (7)Be behaviour in the air by using a multilayer perceptron neural network.

    Samolov, A; Dragović, S; Daković, M; Bačić, G

    2014-11-01

    A multilayer perceptron artificial neural network (ANN) model for the prediction of the (7)Be behaviour in the air as the function of meteorological parameters was developed. The model was optimized and tested using (7)Be activity concentrations obtained by standard gamma-ray spectrometric analysis of air samples collected in Belgrade (Serbia) during 2009-2011 and meteorological data for the same period. Good correlation (r = 0.91) between experimental values of (7)Be activity concentrations and those predicted by ANN was obtained. The good performance of the model in prediction of (7)Be activity concentrations could provide basis for construction of models which would forecast behaviour of other airborne radionuclides.

  13. Digital modulation classification using multi-layer perceptron and time-frequency features

    Yuan Ye; Mei Wenbo

    2007-01-01

    Considering that real communication signals corrupted by noise are generally nonstationary, and time-frequency distributions are especially suitable for the analysis of nonstationary signals, time-frequency distributions are introduced for the modulation classification of communication signals.The extracted time-frequency features have good classification information, and they are insensitive to signal to noise ratio (SNR) variation.According to good classification by the correct rate of a neural network classifier, a multilayer perceptron (MLP) classifier with better generalization, as well as, addition of time-frequency features set for classifying six different modulation types has been proposed.Computer simulations show that the MLP classifier outperforms the decision-theoretic classifier at low SNRs, and the classification experiments for real MPSK signals verify engineering significance of the MLP classifier.

  14. Exchange rate prediction with multilayer perceptron neural network using gold price as external factor

    Mohammad Fathian

    2012-04-01

    Full Text Available In this paper, the problem of predicting the exchange rate time series in the foreign exchange rate market is going to be solved using a time-delayed multilayer perceptron neural network with gold price as external factor. The input for the learning phase of the artificial neural network are the exchange rate data of the last five days plus the gold price in two different currencies of the exchange rate as the external factor for helping the artificial neural network improving its forecast accuracy. The five-day delay has been chosen because of the weekly cyclic behavior of the exchange rate time series with the consideration of two holidays in a week. The result of forecasts are then compared with using the multilayer peceptron neural network without gold price external factor by two most important evaluation techniques in the literature of exchange rate prediction. For the experimental analysis phase, the data of three important exchange rates of EUR/USD, GBP/USD, and USD/JPY are used.

  15. An application of the multilayer perceptron: Solar radiation maps in Spain

    Hontoria, L.; Aguilera, J. [Grupo Investigacion y Desarrollo en Energia Solar y Automatica, Dpto. de Ingenieria Electronica, de Telecomunicaciones y Automatica, Escuela Politecnica Superior de Jaen, Campus de las Lagunillas, Universidad de Jaen, 23071 Jaen (Spain); Zufiria, P. [Grupo de Redes Neuronales, Dpto. de Matematica Aplicada a las Tecnologias de la Informacion, ETSI Telecomunicaciones, UPM Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2005-11-01

    In this work an application of a methodology to obtain solar radiation maps is presented. This methodology is based on a neural network system [Lippmann, R.P., 1987. An introduction to computing with neural nets. IEEE ASSP Magazine, 4-22] called Multi-Layer Perceptron (MLP) [Haykin, S., 1994. Neural Networks. A Comprehensive Foundation. Macmillan Publishing Company; Hornik, K., Stinchcombe, M., White, H., 1989. Multilayer feedforward networks are universal approximators. Neural Networks, 2(5), 359-366]. To obtain a solar radiation map it is necessary to know the solar radiation of many points spread wide across the zone of the map where it is going to be drawn. For most of the locations all over the world the records of these data (solar radiation in whatever scale, daily or hourly values) are non-existent. Only very few locations have the privilege of having good meteorological stations where records of solar radiation have being registered. But even in those locations with historical records of solar data, the quality of these solar series is not as good as it should be for most purposes. In addition, to draw solar radiation maps the number of points on the maps (real sites) that it is necessary to work with makes this problem difficult to solve. Nevertheless, with the application of the methodology proposed in this paper, this problem has been solved and solar radiation maps have been obtained for a small region of Spain: Jaen province, a southern province of Spain between parallels 38{sup o}25' N and 37{sup o}25' N, and meridians 4{sup o}10' W and 2{sup o}10' W, and for a larger region: Andalucia, the most southern region of Spain situated between parallels 38{sup o}40' N and 36{sup o}00' N, and meridians 7{sup o}30' W and 1{sup o}40' W. (author)

  16. Multilayer Perceptron for Robust Nonlinear Interval Regression Analysis Using Genetic Algorithms

    2014-01-01

    On the basis of fuzzy regression, computational models in intelligence such as neural networks have the capability to be applied to nonlinear interval regression analysis for dealing with uncertain and imprecise data. When training data are not contaminated by outliers, computational models perform well by including almost all given training data in the data interval. Nevertheless, since training data are often corrupted by outliers, robust learning algorithms employed to resist outliers for interval regression analysis have been an interesting area of research. Several approaches involving computational intelligence are effective for resisting outliers, but the required parameters for these approaches are related to whether the collected data contain outliers or not. Since it seems difficult to prespecify the degree of contamination beforehand, this paper uses multilayer perceptron to construct the robust nonlinear interval regression model using the genetic algorithm. Outliers beyond or beneath the data interval will impose slight effect on the determination of data interval. Simulation results demonstrate that the proposed method performs well for contaminated datasets. PMID:25110755

  17. Multilayer perceptron for robust nonlinear interval regression analysis using genetic algorithms.

    Hu, Yi-Chung

    2014-01-01

    On the basis of fuzzy regression, computational models in intelligence such as neural networks have the capability to be applied to nonlinear interval regression analysis for dealing with uncertain and imprecise data. When training data are not contaminated by outliers, computational models perform well by including almost all given training data in the data interval. Nevertheless, since training data are often corrupted by outliers, robust learning algorithms employed to resist outliers for interval regression analysis have been an interesting area of research. Several approaches involving computational intelligence are effective for resisting outliers, but the required parameters for these approaches are related to whether the collected data contain outliers or not. Since it seems difficult to prespecify the degree of contamination beforehand, this paper uses multilayer perceptron to construct the robust nonlinear interval regression model using the genetic algorithm. Outliers beyond or beneath the data interval will impose slight effect on the determination of data interval. Simulation results demonstrate that the proposed method performs well for contaminated datasets.

  18. Anaerobic tapered fluidized bed reactor for starch wastewater treatment and modeling using multilayer perceptron neural network

    2007-01-01

    Anaerobic treatability of synthetic sago wastewater was investigated in a laboratory anaerobic tapered fluidized bed reactor (ATFBR) with a mesoporous granular activated carbon (GAC) as a support material. The experimental protocol was defined to examine the effect of the maximum organic loading rate (OLR), hydraulic retention time (HRT), the efficiency of the reactor and to report on its steady-state performance. The reactor was subjected to a steady-state operation over a range of OLR up to 85.44 kg COD/(m3·d). The COD removal efficiency was found to be 92% in the reactor while the biogas produced in the digester reached 25.38 m3/(m3·d) of the reactor. With the increase of OLR from 83.7 kg COD/(m3·d), the COD removal efficiency decreases. Also an artificial neural network (ANN) model using multilayer perceptron (MLP) has been developed for a system of two input variable and five output dependent variables. For the training of the input-output data, the experimental values obtained have been used. The output parameters predicted have been found to be much closer to the corresponding experimental ones and the model was validated for 30% of the untrained data. The mean square error (MSE) was found to be only 0.0146.

  19. Photometric redshifts with the Multilayer Perceptron Neural Network: application to the HDF-S and SDSS

    Vanzella, E; Fontana, A; Nonino, M; Arnouts, S; Giallongo, E; Grazian, A; Fasano, G; Popesso, P; Saracco, P; Zaggia, S R

    2003-01-01

    We present a technique for the estimation of photometric redshifts based on feed-forward neural networks. The Multilayer Perceptron (MLP) Artificial Neural Network is used to predict photometric redshifts in the HDF-S from an ultra deep multicolor catalog. Various possible approaches for the training of the neural network are explored, including the deepest and most complete spectroscopic redshift catalog currently available (the Hubble Deep Field North dataset) and models of the spectral energy distribution of galaxies available in the literature. The MLP can be trained on observed data, theoretical data and mixed samples. The prediction of the method is tested on the spectroscopic sample in the HDF-S (44 galaxies). Over the entire redshift range, $0.1

  20. Multilayer perceptron neural network for downscaling rainfall in arid region: A case study of Baluchistan, Pakistan

    Kamal Ahmed; Shamsuddin Shahid; Sobri Bin Haroon; Wang Xiao-Jun

    2015-08-01

    Downscaling rainfall in an arid region is much challenging compared to wet region due to erratic and infrequent behaviour of rainfall in the arid region. The complexity is further aggregated due to scarcity of data in such regions. A multilayer perceptron (MLP) neural network has been proposed in the present study for the downscaling of rainfall in the data scarce arid region of Baluchistan province of Pakistan, which is considered as one of the most vulnerable areas of Pakistan to climate change. The National Center for Environmental Prediction (NCEP) reanalysis datasets from 20 grid points surrounding the study area were used to select the predictors using principal component analysis. Monthly rainfall data for the time periods 1961–1990 and 1991–2001 were used for the calibration and validation of the MLP model, respectively. The performance of the model was assessed using various statistics including mean, variance, quartiles, root mean square error (RMSE), mean bias error (MBE), coefficient of determination (R2) and Nash–Sutcliffe efficiency (NSE). Comparisons of mean monthly time series of observed and downscaled rainfall showed good agreement during both calibration and validation periods, while the downscaling model was found to underpredict rainfall variance in both periods. Other statistical parameters also revealed good agreement between observed and downscaled rainfall during both calibration and validation periods in most of the stations.

  1. Landslide Occurrence Prediction Using Trainable Cascade Forward Network and Multilayer Perceptron

    Mohammad Subhi Al-batah

    2015-01-01

    Full Text Available Landslides are one of the dangerous natural phenomena that hinder the development in Penang Island, Malaysia. Therefore, finding the reliable method to predict the occurrence of landslides is still the research of interest. In this paper, two models of artificial neural network, namely, Multilayer Perceptron (MLP and Cascade Forward Neural Network (CFNN, are introduced to predict the landslide hazard map of Penang Island. These two models were tested and compared using eleven machine learning algorithms, that is, Levenberg Marquardt, Broyden Fletcher Goldfarb, Resilient Back Propagation, Scaled Conjugate Gradient, Conjugate Gradient with Beale, Conjugate Gradient with Fletcher Reeves updates, Conjugate Gradient with Polakribiere updates, One Step Secant, Gradient Descent, Gradient Descent with Momentum and Adaptive Learning Rate, and Gradient Descent with Momentum algorithm. Often, the performance of the landslide prediction depends on the input factors beside the prediction method. In this research work, 14 input factors were used. The prediction accuracies of networks were verified using the Area under the Curve method for the Receiver Operating Characteristics. The results indicated that the best prediction accuracy of 82.89% was achieved using the CFNN network with the Levenberg Marquardt learning algorithm for the training data set and 81.62% for the testing data set.

  2. Evaluation of multilayer perceptron algorithms for an analysis of network flow data

    Bieniasz, Jedrzej; Rawski, Mariusz; Skowron, Krzysztof; Trzepiński, Mateusz

    2016-09-01

    The volume of exchanged information through IP networks is larger than ever and still growing. It creates a space for both benign and malicious activities. The second one raises awareness on security network devices, as well as network infrastructure and a system as a whole. One of the basic tools to prevent cyber attacks is Network Instrusion Detection System (NIDS). NIDS could be realized as a signature-based detector or an anomaly-based one. In the last few years the emphasis has been placed on the latter type, because of the possibility of applying smart and intelligent solutions. An ideal NIDS of next generation should be composed of self-learning algorithms that could react on known and unknown malicious network activities respectively. In this paper we evaluated a machine learning approach for detection of anomalies in IP network data represented as NetFlow records. We considered Multilayer Perceptron (MLP) as the classifier and we used two types of learning algorithms - Backpropagation (BP) and Particle Swarm Optimization (PSO). This paper includes a comprehensive survey on determining the most optimal MLP learning algorithm for the classification problem in application to network flow data. The performance, training time and convergence of BP and PSO methods were compared. The results show that PSO algorithm implemented by the authors outperformed other solutions if accuracy of classifications is considered. The major disadvantage of PSO is training time, which could be not acceptable for larger data sets or in real network applications. At the end we compared some key findings with the results from the other papers to show that in all cases results from this study outperformed them.

  3. 在一种扩展多层感知器模型中实现命题知识的语义推演%Implementing Semantic Deduction of Propositional Knowledge in an Extension Multi-layer Perceptron

    黄天民; 裴峥

    2003-01-01

    The paper presents an extension multi-layer perceptron model that is capable of representing and reasoning propositional knowledge base. An extended version of propositional calculus is developed, and its some properties is discussed. Formulas of the extended calculus can be expressed in the extension multi-layer perceptron. Naturally, semantic deduction of propositional knowledge base can be implement by the extension multi-layer perceptron, and by learning, an unknown formula set can be found.

  4. Multilayer Perceptron applied to Data Assimilation for the Global FSU Atmospheric Model

    Cocke, S.; Cintra, R. S.; Campos Velho, H. F.

    2015-12-01

    The better quality of forecasts is given the more accurate of the initial conditions. Data assimilation (DA) is the process by which short-forecast and observations are combined to obtain an accurate representation of the state of the modeled system, e.g. is a technique to generate an initial condition to a weather forecasts. This paper shows the results of a DA technique using artificial neural networks (NN) to obtain the analysis to the atmospheric model for the Florida State University. The Local Ensemble Transform Kalman filter (LETKF) is implemented with Florida State University Global Spectral Model (FSUGSM). The ANN data assimilation is made to emulate the initial condition from LETKF to run the FSUGSM. LETKF is a version of Kalman filter with Monte-Carlo ensembles of short-term forecasts to solve the data assimilation problem. The model FSUGSM is a multilevel spectral primitive equation model with vertical sigma coordinates, at resolution T63L27. The data assimilation experiments are based in simulated observations data and FSUGSM 6-hours forecasts. For the NN data assimilation, we use Multilayer Perceptron (MLP) with supervised training algorithm where NN receives input vectors with their corresponding response from LETKF data assimilation. The surface pressure, absolute temperature, zonal component wind, meridional component wind and humidity results are presented. A self-configuration method finds the optimal NN and configures a set of 52 MLPs to DA experiment, referred as MLP-DA. A methodology developed with self-configuration using a meta-heuristic called the Multiple Particle Collision Algorithm to compute the optimal topology for NN. The MLP presents four input nodes, two nodes coordinates vector, one for the 6-hours forecast vector and one node for observation vector; one output node for the analysis vector results. The vector represents the values for one grid model point. The ANNs were trained with data from each month of 2001, 2002, and 2003. The

  5. A Linear Multi-Layer Perceptron for Identifying Harmonic Contents of Biomedical Signals

    Nguyen, Thien; Wira, Patrice

    2013-01-01

    Part 7: Intelligent Signal and Image Processing; International audience; A linear Multi Layer Perceptron (MLP) is proposed as a new approach to identify the harmonic content of biomedical signals and to characterize them. This layered neural network uses only linear neurons. Some synthetic sinusoidal terms are used as inputs and represent a priori knowledge. A measured signal serves as a reference, then a supervised learning allows to adapt the weights and to fit its Fourier series. The ampli...

  6. Recurrent expressions for calculation of reflectivity from multilayer media

    Bagdasaryan, H V

    1992-01-01

    Recurrent expressions for calculations of transmissivity and reflectivity from multilayer media are obtained. A distinctive feature of proposed expressions is the possibility to obtain the distribution of field amplitude in each layer of multilayer medium. 10 refs.

  7. Exploiting Heavy Tails in Training Times of Multilayer Perceptrons. A Case Study with the UCI Thyroid Disease Database

    Cebrian, Manuel

    2007-01-01

    The random initialization of weights of a multilayer perceptron makes it possible to model its training process as a Las Vegas algorithm, i.e. a randomized algorithm which stops when some required training error is obtained, and whose execution time is a random variable. This modelling is used to perform a case study on a well-known pattern recognition benchmark: the UCI Thyroid Disease Database. Empirical evidence is presented of the training time probability distribution exhibiting a heavy tail behavior, meaning a big probability mass of long executions. This fact is exploited to reduce the training time cost by applying two simple restart strategies. The first assumes full knowledge of the distribution yielding a 40% cut down in expected time with respect to the training without restarts. The second, assumes null knowledge, yielding a reduction ranging from 9% to 23%.

  8. Dr. Polopoly - IntelligentSystem Monitoring : An Experimental and Comparative Study ofMultilayer Perceptrons and Random Forests ForError Diagnosis In A Network of Servers

    Djupfeldt, Petter

    2016-01-01

    This thesis explores the potential of using machine learning to superviseand diagnose a computer system by comparing how Multilayer Perceptron(MLP) and Random Forest (RF) perform at this task in a controlledenvironment. The base of comparison is primarily how accurate theyare in their predictions, but some thought is given to how cost effectivethey are regarding time. The specific system used is a content management system (CMS)called Polopoly. The thesis details how training samples were col...

  9. Daily global solar radiation modelling using multi-layer perceptron neural networks in semi-arid region

    Mawloud GUERMOUI

    2016-07-01

    Full Text Available Accurate estimation of Daily Global Solar Radiation (DGSR has been a major goal for solar energy application. However, solar radiation measurements are not a simple task for several reasons. In the cases where data are not available, it is very common the use of computational models to estimate the missing data, which are based mainly of the search for relationships between weather variables, such as temperature, humidity, sunshine duration, etc. In this respect, the present study focuses on the development of artificial neural network (ANN model for estimation of daily global solar radiation on horizontal surface in Ghardaia city (South Algeria. In this analysis back-propagation algorithm is applied. Daily mean air temperature, relative humidity and sunshine duration was used as climatic inputs parameters, while the daily global solar radiation (DGSR was the only output of the ANN. We have evaluated Multi-Layer Perceptron (MLP models to estimate DGSR using three year of measurement (2005-2008. It was found that MLP-model based on sunshine duration and mean air temperature give accurate results in term of Mean Absolute Bias Error, Root Mean Square Error, Relative Square Error and Correlation Coefficient. The obtained values of these indicators are 0.67 MJ/m², 1.28 MJ/m², 6.12%and 98.18%, respectively which shows that MLP is highly qualified for DGSR estimation in semi-arid climates.

  10. Adaptive Weibull Multiplicative Model and Multilayer Perceptron Neural Networks for Dark-Spot Detection from SAR Imagery

    Alireza Taravat

    2014-12-01

    Full Text Available Oil spills represent a major threat to ocean ecosystems and their environmental status. Previous studies have shown that Synthetic Aperture Radar (SAR, as its recording is independent of clouds and weather, can be effectively used for the detection and classification of oil spills. Dark formation detection is the first and critical stage in oil-spill detection procedures. In this paper, a novel approach for automated dark-spot detection in SAR imagery is presented. A new approach from the combination of adaptive Weibull Multiplicative Model (WMM and MultiLayer Perceptron (MLP neural networks is proposed to differentiate between dark spots and the background. The results have been compared with the results of a model combining non-adaptive WMM and pulse coupled neural networks. The presented approach overcomes the non-adaptive WMM filter setting parameters by developing an adaptive WMM model which is a step ahead towards a full automatic dark spot detection. The proposed approach was tested on 60 ENVISAT and ERS2 images which contained dark spots. For the overall dataset, an average accuracy of 94.65% was obtained. Our experimental results demonstrate that the proposed approach is very robust and effective where the non-adaptive WMM & pulse coupled neural network (PCNN model generates poor accuracies.

  11. The prediction of bacteria type and culture growth phase by an electronic nose with a multi-layer perceptron network

    Gardner, J. W.; Craven, M.; Dow, C.; Hines, E. L.

    1998-01-01

    An investigation into the use of an electronic nose to predict the class and growth phase of two potentially pathogenic micro-organisms, Eschericha coli ( E. coli) and Staphylococcus aureus ( S. aureus), has been performed. In order to do this we have developed an automated system to sample, with a high degree of reproducibility, the head space of bacterial cultures grown in a standard nutrient medium. Head spaces have been examined by using an array of six different metal oxide semiconducting gas sensors and classified by a multi-layer perceptron (MLP) with a back-propagation (BP) learning algorithm. The performance of 36 different pre-processing algorithms has been studied on the basis of nine different sensor parameters and four different normalization techniques. The best MLP was found to classify successfully 100% of the unknown S. aureus samples and 92% of the unknown E. coli samples, on the basis of a set of 360 training vectors and 360 test vectors taken from the lag, log and stationary growth phases. The real growth phase of the bacteria was determined from optical cell counts and was predicted from the head space samples with an accuracy of 81%. We conclude that these results show considerable promise in that the correct prediction of the type and growth phase of pathogenic bacteria may help both in the more rapid treatment of bacterial infections and in the more efficient testing of new anti-biotic drugs.

  12. Time series modeling with pruned multi-layer perceptron and 2-stage damped least-squares method

    Voyant, Cyril; Tamas, Wani; Paoli, Christophe; Balu, Aurélia; Muselli, Marc; Nivet, Marie-Laure; Notton, Gilles

    2014-03-01

    A Multi-Layer Perceptron (MLP) defines a family of artificial neural networks often used in TS modeling and forecasting. Because of its "black box" aspect, many researchers refuse to use it. Moreover, the optimization (often based on the exhaustive approach where "all" configurations are tested) and learning phases of this artificial intelligence tool (often based on the Levenberg-Marquardt algorithm; LMA) are weaknesses of this approach (exhaustively and local minima). These two tasks must be repeated depending on the knowledge of each new problem studied, making the process, long, laborious and not systematically robust. In this paper a pruning process is proposed. This method allows, during the training phase, to carry out an inputs selecting method activating (or not) inter-nodes connections in order to verify if forecasting is improved. We propose to use iteratively the popular damped least-squares method to activate inputs and neurons. A first pass is applied to 10% of the learning sample to determine weights significantly different from 0 and delete other. Then a classical batch process based on LMA is used with the new MLP. The validation is done using 25 measured meteorological TS and cross-comparing the prediction results of the classical LMA and the 2-stage LMA.

  13. Data Optimization with Multilayer Perceptron Neural Network and Using New Pattern in Decision Tree Comparatively

    Murat Kayri

    2010-01-01

    Full Text Available Problem statement: The aim of the present study is to exemplify the use of Artificial Neural Networks (ANN for parameter prediction. Missing value or unreal approach to some questions in scale is a problem for unbiased findings. To learn a real pattern with ANN provides robust and unbiased parameter estimation. Approach: To this end, data was collected from 906 students using ?Scale of student views about the expected situations and the current expectations from their families during learning process? for the study entitled ?Student views about the expected situations and the current expectations from their families during learning process?. In the study, first the initial data set gathered using the measurement tool and the new data set produced by Multi-Layer Receptors algorithm, which was considered as the highest predictive level of ANN for the research were individually analyzed by Chaid analysis and the results of the two analyses were compared. Results: The findings showed that as a result of Chaid analysis with the initial data set the variable ?education level of mother? had a considerable effect on total score dependent variable, while ?education level of father? was the influential variable on the attitude level in the data set predicted by ANN, unlike the previous model. Conclusion/Recommendations: The findings of the research show Artificial Neural Networks could be used for parameter estimation in cause-effect based studies. It is also thought the research will contribute to extensive use of advanced statistical methods.

  14. Evaluation of 1-D tracer concentration profile in a small river by means of Multi-Layer Perceptron Neural Networks

    A. Piotrowski

    2007-12-01

    Full Text Available The prediction of temporal concentration profiles of a transported pollutant in a river is still a subject of ongoing research efforts worldwide. The present paper is aimed at studying the possibility of using Multi-Layer Perceptron Neural Networks to evaluate the whole concentration versus time profile at several cross-sections of a river under various flow conditions, using as little information about the river system as possible. In contrast with the earlier neural networks based work on longitudinal dispersion coefficients, this new approach relies more heavily on measurements of concentration collected during tracer tests over a range of flow conditions, but fewer hydraulic and morphological data are needed. The study is based upon 26 tracer experiments performed in a small river in Edinburgh, UK (Murray Burn at various flow rates in a 540 m long reach. The only data used in this study were concentration measurements collected at 4 cross-sections, distances between the cross-sections and the injection site, time, as well as flow rate and water velocity, obtained according to the data measured at the 1st and 2nd cross-sections.

    The four main features of concentration versus time profiles at a particular cross-section, namely the peak concentration, the arrival time of the peak at the cross-section, and the shapes of the rising and falling limbs of the profile are modeled, and for each of them a separately designed neural network was used. There was also a variant investigated in which the conservation of the injected mass was assured by adjusting the predicted peak concentration. The neural network methods were compared with the unit peak attenuation curve concept.

    In general the neural networks predicted the main features of the concentration profiles satisfactorily. The predicted peak concentrations were generally better than those obtained using the unit peak attenuation method, and the method with mass

  15. Improving daily streamflow forecasts in mountainous Upper Euphrates basin by multi-layer perceptron model with satellite snow products

    Uysal, Gökçen; Şensoy, Aynur; Şorman, A. Arda

    2016-12-01

    This paper investigates the contribution of Moderate Resolution Imaging Spectroradiometer (MODIS) satellite Snow Cover Area (SCA) product and in-situ snow depth measurements to Artificial Neural Network model (ANN) based daily streamflow forecasting in a mountainous river basin. In order to represent non-linear structure of the snowmelt process, Multi-Layer Perceptron (MLP) Feed-Forward Backpropagation (FFBP) architecture is developed and applied in Upper Euphrates River Basin (10,275 km2) of Turkey where snowmelt constitutes approximately 2/3 of total annual volume of runoff during spring and early summer months. Snowmelt season is evaluated between March and July; 7 years (2002-2008) seasonal daily data are used during training while 3 years (2009-2011) seasonal daily data are split for forecasting. One of the fastest ANN training algorithms, the Levenberg-Marquardt, is used for optimization of the network weights and biases. The consistency of the network is checked with four performance criteria: coefficient of determination (R2), Nash-Sutcliffe model efficiency (ME), root mean square error (RMSE) and mean absolute error (MAE). According to the results, SCA observations provide useful information for developing of a neural network model to predict snowmelt runoff, whereas snow depth data alone are not sufficient. The highest performance is experienced when total daily precipitation, average air temperature data are combined with satellite snow cover data. The data preprocessing technique of Discrete Wavelet Analysis (DWA) is coupled with MLP modeling to further improve the runoff peak estimates. As a result, Nash-Sutcliffe model efficiency is increased from 0.52 to 0.81 for training and from 0.51 to 0.75 for forecasting. Moreover, the results are compared with that of a conceptual model, Snowmelt Runoff Model (SRM), application using SCA as an input. The importance and the main contribution of this study is to use of satellite snow products and data

  16. Performance comparison between Logistic regression, decision trees, and multilayer perceptron in predicting peripheral neuropathy in type 2 diabetes mellitus

    LI Chang-ping; ZHI Xin-yue; MA Jun; CUI Zhuang; ZHU Zi-long; ZHANG Cui; HU Liang-ping

    2012-01-01

    Background Various methods can be applied to build predictive models for the clinical data with binary outcome variable.This research aims to explore the process of constructing common predictive models,Logistic regression (LR),decision tree (DT) and multilayer perceptron (MLP),as well as focus on specific details when applying the methods mentioned above:what preconditions should be satisfied,how to set parameters of the model,how to screen variables and build accuracy models quickly and efficiently,and how to assess the generalization ability (that is,prediction performance) reliably by Monte Carlo method in the case of small sample size.Methods All the 274 patients (include 137 type 2 diabetes mellitus with diabetic peripheral neuropathy and 137 type 2 diabetes mellitus without diabetic peripheral neuropathy) from the Metabolic Disease Hospital in Tianjin participated in the study.There were 30 variables such as sex,age,glycosylated hemoglobin,etc.On account of small sample size,the classification and regression tree (CART) with the chi-squared automatic interaction detector tree (CHAID) were combined by means of the 100 times 5-7 fold stratified cross-validation to build DT.The MLP was constructed by Schwarz Bayes Criterion to choose the number of hidden layers and hidden layer units,alone with levenberg-marquardt (L-M) optimization algorithm,weight decay and preliminary training method.Subsequently,LR was applied by the best subset method with the Akaike Information Criterion (AIC) to make the best used of information and avoid overfitting.Eventually,a 10 to 100 times 3-10 fold stratified cross-validation method was used to compare the generalization ability of DT,MLP and LR in view of the areas under the receiver operating characteristic (ROC) curves (AUC).Results The AUC of DT,MLP and LR were 0.8863,0.8536 and 0.8802,respectively.As the larger the AUC of a specific prediction model is,the higher diagnostic ability presents,MLP performed optimally,and then

  17. Laser spot detection-based computer interface system using autoassociative multilayer perceptron with input-to-output mapping-sensitive error back propagation learning algorithm

    Jeong, Sungmoon; Jung, Chanwoong; Kim, Cheol-Su; Shim, Jae Hoon; Lee, Minho

    2011-08-01

    This paper presents a new computer interface system based on laser spot detection and moving pattern analysis of the detected laser spots in real-time processing. We propose a systematic method that uses either the frame difference of successive input images or an autoassociative multilayer perceptron (AAMLP) to detect laser spots. The AAMLP is applied only to areas of the input images where the frame difference of the successive images is not effective for detecting laser spots. In order to enhance the detection performance, the AAMLP is trained by a new training algorithm that increases the sensitivity of the input-to-output mapping of the AAMLP allowing a small variation in the input feature of the laser spot image to be successfully indicated. The proposed interface system is also able to keep track of the laser spot and recognize gesture commands. The moving pattern of the laser spot is recognized by using a multilayer perception. It is experimentally shown that the proposed computer interface system is fast enough for real-time operation with reliable accuracy.

  18. [Multi-layer perceptron neural network based algorithm for simultaneous retrieving temperature and emissivity from hyperspectral FTIR data].

    Cheng, Jie; Xiao, Qing; Li, Xiao-Wen; Liu, Qin-Huo; Du, Yong-Ming

    2008-04-01

    The present paper firstly points out the defect of typical temperature and emissivity separation algorithms when dealing with hyperspectral FTIR data: the conventional temperature and emissivity algorithms can not reproduce correct emissivity value when the difference between the ground-leaving radiance and object's blackbody radiation at its true temperature and the instrument random noise are on the same order, and this phenomenon is very prone to occur rence near 714 and 1 250 cm(-1) in the field measurements. In order to settle this defect, a three-layer perceptron neural network has been introduced into the simultaneous inversion of temperature and emissivity from hyperspectral FTIR data. The soil emissivity spectra from the ASTER spectral library were used to produce the training data, the soil emissivity spectra from the MODIS spectral library were used to produce the test data, and the result of network test shows the MLP is robust. Meanwhile, the ISSTES algorithm was used to retrieve the temperature and emissivity form the test data. By comparing the results of MLP and ISSTES, we found the MLP can overcome the disadvantage of typical temperature and emisivity separation, although the rmse of derived emissivity using MLP is lower than the ISSTES as a whole. Hence, the MLP can be regarded as a beneficial complementarity of the typical temperature and emissivity separation.

  19. Modeling Urban Expansion in Bangkok Metropolitan Region Using Demographic–Economic Data through Cellular Automata-Markov Chain and Multi-Layer Perceptron-Markov Chain Models

    Chudech Losiri

    2016-07-01

    Full Text Available Urban expansion is considered as one of the most important problems in several developing countries. Bangkok Metropolitan Region (BMR is the urbanized and agglomerated area of Bangkok Metropolis (BM and its vicinity, which confronts the expansion problem from the center of the city. Landsat images of 1988, 1993, 1998, 2003, 2008, and 2011 were used to detect the land use and land cover (LULC changes. The demographic and economic data together with corresponding maps were used to determine the driving factors for land conversions. This study applied Cellular Automata-Markov Chain (CA-MC and Multi-Layer Perceptron-Markov Chain (MLP-MC to model LULC and urban expansions. The performance of the CA-MC and MLP-MC yielded more than 90% overall accuracy to predict the LULC, especially the MLP-MC method. Further, the annual population and economic growth rates were considered to produce the land demand for the LULC in 2014 and 2035 using the statistical extrapolation and system dynamics (SD. It was evident that the simulated map in 2014 resulting from the SD yielded the highest accuracy. Therefore, this study applied the SD method to generate the land demand for simulating LULC in 2035. The outcome showed that urban occupied the land around a half of the BMR.

  20. Using multilayer perceptron computation to discover ideal insect olfactory receptor combinations in the mosquito and fruit fly for an efficient electronic nose.

    Bachtiar, Luqman R; Unsworth, Charles P; Newcomb, Richard D

    2015-01-01

    The model organism, Drosophila melanogaster, and the mosquito Anopheles gambiae use 60 and 79 odorant receptors, respectively, to sense their olfactory world. However, a commercial "electronic nose" in the form of an insect olfactory biosensor demands very low numbers of receptors at its front end of detection due to the difficulties of receptor/sensor integration and functionalization. In this letter, we demonstrate how computation via artificial neural networks (ANNs), in the form of multilayer perceptrons (MLPs), can be successfully incorporated as the signal processing back end of the biosensor to drastically reduce the number of receptors to three while still retaining 100% performance of odorant detection to that of a full complement of receptors. In addition, we provide a detailed performance comparison between D. melanogaster and A. gambiae odorant receptors and demonstrate that A. gambiae receptors provide superior olfaction detection performance over D. melanogaster for very low receptor numbers. The results from this study present the possibility of using the computation of MLPs to discover ideal biological olfactory receptors for an olfactory biosensor device to provide maximum classification performance of unknown odorants.

  1. A multilayer recurrent neural network for solving continuous-time algebraic Riccati equations.

    Wang, Jun; Wu, Guang

    1998-07-01

    A multilayer recurrent neural network is proposed for solving continuous-time algebraic matrix Riccati equations in real time. The proposed recurrent neural network consists of four bidirectionally connected layers. Each layer consists of an array of neurons. The proposed recurrent neural network is shown to be capable of solving algebraic Riccati equations and synthesizing linear-quadratic control systems in real time. Analytical results on stability of the recurrent neural network and solvability of algebraic Riccati equations by use of the recurrent neural network are discussed. The operating characteristics of the recurrent neural network are also demonstrated through three illustrative examples.

  2. Deep Kernel Mapping Support Vector Machines Based on Multi-layer Perceptron%基于多层感知器的深度核映射支持向量机

    李玉鑑; 张婷; 胡海鹤

    2016-01-01

    为改善支持向量机的性能,从深度学习的角度研究核学习的方法,提出了基于多层感知器的深度核映射支持向量机模型( deep kernel mapping support vector machine,DKMSVM)以及相应的学习算法。该模型首先通过多层感知器学习一个从原始输入空间到合适维度空间的核映射代替传统意义上的核函数,然后直接在合适维度空间使用支持向量机进行分类,而不是采用核技巧进行求解。实验结果验证了DKMSVM的有效性。%To improve the performance of support vector machines ( SVMs ) , from the deep learning ’ s point of view, a kernel learning method was studied and a deep kernel mapping support vector machine ( DKMSVM ) was proposed based on multi-layer perceptron together with the corresponding learning algorithm. Firstly, a kernel mapping from the original input space to a proper dimensional space through a multilayer perceptron instead of a traditional kernel function was researched in this model. Then a SVM was used to classify in the proper dimensional space without kernel tricks. Experimental results demonstrate the effectiveness of DKMSVM.

  3. Identification Simulation for Dynamical System Based on Genetic Algorithm and Recurrent Multilayer Neural Network

    鄢田云; 张翠芳; 靳蕃

    2003-01-01

    Identification simulation for dynamical system which is based on genetic algorithm (GA) and recurrent multilayer neural network (RMNN) is presented. In order to reduce the inputs of the model, RMNN which can remember and store some previous parameters is used for identifier. And for its high efficiency and optimization, genetic algorithm is introduced into training RMNN. Simulation results show the effectiveness of the proposed scheme. Under the same training algorithm, the identification performance of RMNN is superior to that of nonrecurrent multilayer neural network (NRMNN).

  4. Recognition of Text Image Using Multilayer Perceptron

    Vijendra, Singh; Vasudeva, Nisha; Parashar, Hem Jyotsana

    2016-01-01

    The biggest challenge in the field of image processing is to recognize documents both in printed and handwritten format. Optical Character Recognition OCR is a type of document image analysis where scanned digital image that contains either machine printed or handwritten script input into an OCR software engine and translating it into an editable machine readable digital text format. A Neural network is designed to model the way in which the brain performs a particular task or function of int...

  5. Multilayer perceptron neural network for flow prediction.

    Araujo, P; Astray, G; Ferrerio-Lage, J A; Mejuto, J C; Rodriguez-Suarez, J A; Soto, B

    2011-01-01

    Artificial neural networks (ANNs) have proven to be a tool for characterizing, modeling and predicting many of the non-linear hydrological processes such as rainfall-runoff, groundwater evaluation or simulation of water quality. After proper training they are able to generate satisfactory predictive results for many of these processes. In this paper they have been used to predict 1 or 2 days ahead the average and maximum daily flow of a river in a small forest headwaters in northwestern Spain. The inputs used were the flow and climate data (precipitation, temperature, relative humidity, solar radiation and wind speed) as recorded in the basin between 2003 and 2008. Climatic data have been utilized in a disaggregated form by considering each one as an input variable in ANN(1), or in an aggregated form by its use in the calculation of evapotranspiration and using this as input variable in ANN(2). Both ANN(1) and ANN(2), after being trained with the data for the period 2003-2007, have provided a good fit between estimated and observed data, with R(2) values exceeding 0.95. Subsequently, its operation has been verified making use of the data for the year 2008. The correlation coefficients obtained between the data estimated by ANNs and those observed were in all cases superior to 0.85, confirming the capacity of ANNs as a model for predicting average and maximum daily flow 1 or 2 days in advance.

  6. An Adaptive Recurrent Neural Network for Remaining Useful Life Prediction of Lithium-ion Batteries

    2010-10-01

    Oregon on October 10-14, 2010. U.S. Government or Federal Purpose Rights License., The original document contains color images . 14. ABSTRACT Prognostics...current processing . Output Hidden Nodes/Layers InputsPrevious States Z-1 Z-1 Z-1 Z-1 Weights M Weights W Weights V Weights U Adaptive Feedback Recurrent...network output can take any form of multi-layer perceptron (MLP), denoted by ))(()( nygnyo  , (3) where )(g represents the nonlinear mapping of

  7. Based on Perceptron Object Classification Algorithms for Processing of Agricultural Field Images

    Ganchenko, V.; Doudkin, A.; Pawlowski, T.; Petrovsky, A.; Sadykhov, R.

    2012-01-01

    Neural network algorithms of object classification are considered in the paper applying to disease area recognition of agricultural field images. The images are presented as reduced normalized histograms. The classification is carried out for RGB-and HSV-space by using of a multilayer perceptron.

  8. A Multilayer Recurrent Fuzzy Neural Network for Accurate Dynamic System Modeling

    LIU He; HUANG Dao

    2008-01-01

    A muitilayer recurrent fuzzy neural network (MRFNN)is proposed for accurate dynamic system modeling.The proposed MRFNN has six layers combined with T-S fuzzy model.The recurrent structures are formed by local feedback connections in the membership layer and the rule layer.With these feedbacks,the fuzzy sets are time-varying and the temporal problem of dynamic system can he solved well.The parameters of MRFNN are learned by chaotic search(CS)and least square estimation(LSE)simultaneously,where CS is for tuning the premise parameters and LSE is for updating the consequent coefficients accordingly.Results of simulations show the proposed approach is effective for dynamic system modeling with high accuracy.

  9. A Novel Single Neuron Perceptron with Universal Approximation and XOR Computation Properties

    Ehsan Lotfi

    2014-01-01

    Full Text Available We propose a biologically motivated brain-inspired single neuron perceptron (SNP with universal approximation and XOR computation properties. This computational model extends the input pattern and is based on the excitatory and inhibitory learning rules inspired from neural connections in the human brain’s nervous system. The resulting architecture of SNP can be trained by supervised excitatory and inhibitory online learning rules. The main features of proposed single layer perceptron are universal approximation property and low computational complexity. The method is tested on 6 UCI (University of California, Irvine pattern recognition and classification datasets. Various comparisons with multilayer perceptron (MLP with gradient decent backpropagation (GDBP learning algorithm indicate the superiority of the approach in terms of higher accuracy, lower time, and spatial complexity, as well as faster training. Hence, we believe the proposed approach can be generally applicable to various problems such as in pattern recognition and classification.

  10. First steps towards the realization of a double layer perceptron based on organic memristive devices

    A. V. Emelyanov

    2016-11-01

    Full Text Available Memristors are widely considered as promising elements for the efficient implementation of synaptic weights in artificial neural networks (ANNs since they are resistors that keep memory of their previous conductive state. Whereas demonstrations of simple neural networks (e.g., a single-layer perceptron based on memristors already exist, the implementation of more complicated networks is more challenging and has yet to be reported. In this study, we demonstrate linearly nonseparable combinational logic classification (XOR logic task using a network implemented with CMOS-based neurons and organic memrisitive devices that constitutes the first step toward the realization of a double layer perceptron. We also show numerically the ability of such network to solve a principally analogue task which cannot be realized by digital devices. The obtained results prove the possibility to create a multilayer ANN based on memristive devices that paves the way for designing a more complex network such as the double layer perceptron.

  11. First steps towards the realization of a double layer perceptron based on organic memristive devices

    Emelyanov, A. V.; Lapkin, D. A.; Demin, V. A.; Erokhin, V. V.; Battistoni, S.; Baldi, G.; Dimonte, A.; Korovin, A. N.; Iannotta, S.; Kashkarov, P. K.; Kovalchuk, M. V.

    2016-11-01

    Memristors are widely considered as promising elements for the efficient implementation of synaptic weights in artificial neural networks (ANNs) since they are resistors that keep memory of their previous conductive state. Whereas demonstrations of simple neural networks (e.g., a single-layer perceptron) based on memristors already exist, the implementation of more complicated networks is more challenging and has yet to be reported. In this study, we demonstrate linearly nonseparable combinational logic classification (XOR logic task) using a network implemented with CMOS-based neurons and organic memrisitive devices that constitutes the first step toward the realization of a double layer perceptron. We also show numerically the ability of such network to solve a principally analogue task which cannot be realized by digital devices. The obtained results prove the possibility to create a multilayer ANN based on memristive devices that paves the way for designing a more complex network such as the double layer perceptron.

  12. A Deterministic and Polynomial Modified Perceptron Algorithm

    Olof Barr

    2006-01-01

    Full Text Available We construct a modified perceptron algorithm that is deterministic, polynomial and also as fast as previous known algorithms. The algorithm runs in time O(mn3lognlog(1/ρ, where m is the number of examples, n the number of dimensions and ρ is approximately the size of the margin. We also construct a non-deterministic modified perceptron algorithm running in timeO(mn2lognlog(1/ρ.

  13. Classification of Parking Spots Using Multilayer Perceptron Networks

    FALCAO, H. S.; LOVATO, A. V.; SANTOS A. F. DOS; OLIVEIRA, L. S.

    2013-01-01

    This project intends to develop a prototype for the identification of free spots in open air parking area where there is a good aerial view without obstacles, allowing for the identification of occupied and free spots. We used image processing techniques and pattern recognition using Artificial Neural Networks (ANN). In order to help implement the prototype, we used Matlab. In order to simulate the parking area, we created a model so that we could acquire the images using a webcam, process th...

  14. Classification of Parking Spots Using Multilayer Perceptron Networks

    FALCAO, H. S.

    2013-12-01

    Full Text Available This project intends to develop a prototype for the identification of free spots in open air parking area where there is a good aerial view without obstacles, allowing for the identification of occupied and free spots. We used image processing techniques and pattern recognition using Artificial Neural Networks (ANN. In order to help implement the prototype, we used Matlab. In order to simulate the parking area, we created a model so that we could acquire the images using a webcam, process them, train the neural network, classify the spots and finally, show the results. The results show that it is viable to apply pattern recognition through image capture to classify parking spots

  15. Fuzzy and Multilayer Perceptron for Evaluation of HV Bushings

    Dhlamini, Sizwe M; Majozi, Thokozani

    2007-01-01

    The work proposes the application of fuzzy set theory (FST) to diagnose the condition of high voltage bushings. The diagnosis uses dissolved gas analysis (DGA) data from bushings based on IEC60599 and IEEE C57-104 criteria for oil impregnated paper (OIP) bushings. FST and neural networks are compared in terms of accuracy and computational efficiency. Both FST and NN simulations were able to diagnose the bushings condition with 10% error. By using fuzzy theory, the maintenance department can classify bushings and know the extent of degradation in the component.

  16. Identification of Non-Linear Structures using Recurrent Neural Networks

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Hansen, H. I.

    Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure.......Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure....

  17. Identification of Non-Linear Structures using Recurrent Neural Networks

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Hansen, H. I.

    1995-01-01

    Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure.......Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure....

  18. Parameter estimation in space systems using recurrent neural networks

    Parlos, Alexander G.; Atiya, Amir F.; Sunkel, John W.

    1991-01-01

    The identification of time-varying parameters encountered in space systems is addressed, using artificial neural systems. A hybrid feedforward/feedback neural network, namely a recurrent multilayer perception, is used as the model structure in the nonlinear system identification. The feedforward portion of the network architecture provides its well-known interpolation property, while through recurrency and cross-talk, the local information feedback enables representation of temporal variations in the system nonlinearities. The standard back-propagation-learning algorithm is modified and it is used for both the off-line and on-line supervised training of the proposed hybrid network. The performance of recurrent multilayer perceptron networks in identifying parameters of nonlinear dynamic systems is investigated by estimating the mass properties of a representative large spacecraft. The changes in the spacecraft inertia are predicted using a trained neural network, during two configurations corresponding to the early and late stages of the spacecraft on-orbit assembly sequence. The proposed on-line mass properties estimation capability offers encouraging results, though, further research is warranted for training and testing the predictive capabilities of these networks beyond nominal spacecraft operations.

  19. Stochastic resonance in an intracellular genetic perceptron

    Bates, Russell; Blyuss, Oleg; Zaikin, Alexey

    2014-03-01

    Intracellular genetic networks are more intelligent than was first assumed due to their ability to learn. One of the manifestations of this intelligence is the ability to learn associations of two stimuli within gene-regulating circuitry: Hebbian-type learning within the cellular life. However, gene expression is an intrinsically noisy process; hence, we investigate the effect of intrinsic and extrinsic noise on this kind of intracellular intelligence. We report a stochastic resonance in an intracellular associative genetic perceptron, a noise-induced phenomenon, which manifests itself in noise-induced increase of response in efficiency after the learning event under the conditions of optimal stochasticity.

  20. Learning algorithms for perceptrons from statistical physics

    Gordon, Mirta B.; Peretto, Pierre; Berchier, Dominique

    1993-02-01

    Learning algorithms for perceptrons are deduced from statistical mechanics. Thermodynamical quantities are used as cost functions which may be extremalized by gradient dynamics to find the synaptic efficacies that store the learning set of patterns. The learning rules so obtained are classified in two categories, following the statistics used to derive the cost functions, namely, Boltzmann statistics, and Fermi statistics. In the limits of zero or infinite temperatures some of the rules behave like already known algorithms, but new strategies for learning are obtained at finite temperatures, which minimize the number of errors on the training set. Nous déduisons des algorithmes d'apprentissage pour des perceptrons à partir de considérations de mécanique statistique. Des quantités thermodynamiques sont considérées comme des fonctions de coût, dont on obtient, par une dynamique de gradient, les efficacités synaptiques qui apprennent l'ensemble d'apprentissage. Les règles ainsi obtenues sont classées en deux catégories suivant les statistiques, de Boltzmann ou de Fermi, utilisées pour dériver les fonctions de coût. Dans les limites de températures nulle ou infinie, la plupart des règles trouvées tendent vers les algorithmes connus, mais à température finie on trouve des stratégies nouvelles, qui minimisent le nombre d'erreurs dans l'ensemble d'apprentissage.

  1. Optimal properties of analog perceptrons with excitatory weights.

    Claudia Clopath

    Full Text Available The cerebellum is a brain structure which has been traditionally devoted to supervised learning. According to this theory, plasticity at the Parallel Fiber (PF to Purkinje Cell (PC synapses is guided by the Climbing fibers (CF, which encode an 'error signal'. Purkinje cells have thus been modeled as perceptrons, learning input/output binary associations. At maximal capacity, a perceptron with excitatory weights expresses a large fraction of zero-weight synapses, in agreement with experimental findings. However, numerous experiments indicate that the firing rate of Purkinje cells varies in an analog, not binary, manner. In this paper, we study the perceptron with analog inputs and outputs. We show that the optimal input has a sparse binary distribution, in good agreement with the burst firing of the Granule cells. In addition, we show that the weight distribution consists of a large fraction of silent synapses, as in previously studied binary perceptron models, and as seen experimentally.

  2. Analysis and test of efficient methods for building recursive deterministic perceptron neural networks.

    Elizondo, David A; Birkenhead, Ralph; Góngora, Mario; Taillard, Eric; Luyima, Patrick

    2007-12-01

    The Recursive Deterministic Perceptron (RDP) feed-forward multilayer neural network is a generalisation of the single layer perceptron topology. This model is capable of solving any two-class classification problem as opposed to the single layer perceptron which can only solve classification problems dealing with linearly separable sets. For all classification problems, the construction of an RDP is done automatically and convergence is always guaranteed. Three methods for constructing RDP neural networks exist: Batch, Incremental, and Modular. The Batch method has been extensively tested and it has been shown to produce results comparable with those obtained with other neural network methods such as Back Propagation, Cascade Correlation, Rulex, and Ruleneg. However, no testing has been done before on the Incremental and Modular methods. Contrary to the Batch method, the complexity of these two methods is not NP-Complete. For the first time, a study on the three methods is presented. This study will allow the highlighting of the main advantages and disadvantages of each of these methods by comparing the results obtained while building RDP neural networks with the three methods in terms of the convergence time, the level of generalisation, and the topology size. The networks were trained and tested using the following standard benchmark classification datasets: IRIS, SOYBEAN, and Wisconsin Breast Cancer. The results obtained show the effectiveness of the Incremental and the Modular methods which are as good as that of the NP-Complete Batch method but with a much lower complexity level. The results obtained with the RDP are comparable to those obtained with the backpropagation and the Cascade Correlation algorithms.

  3. On-line learning algorithms for locally recurrent neural networks.

    Campolucci, P; Uncini, A; Piazza, F; Rao, B D

    1999-01-01

    This paper focuses on on-line learning procedures for locally recurrent neural networks with emphasis on multilayer perceptron (MLP) with infinite impulse response (IIR) synapses and its variations which include generalized output and activation feedback multilayer networks (MLN's). We propose a new gradient-based procedure called recursive backpropagation (RBP) whose on-line version, causal recursive backpropagation (CRBP), presents some advantages with respect to the other on-line training methods. The new CRBP algorithm includes as particular cases backpropagation (BP), temporal backpropagation (TBP), backpropagation for sequences (BPS), Back-Tsoi algorithm among others, thereby providing a unifying view on gradient calculation techniques for recurrent networks with local feedback. The only learning method that has been proposed for locally recurrent networks with no architectural restriction is the one by Back and Tsoi. The proposed algorithm has better stability and higher speed of convergence with respect to the Back-Tsoi algorithm, which is supported by the theoretical development and confirmed by simulations. The computational complexity of the CRBP is comparable with that of the Back-Tsoi algorithm, e.g., less that a factor of 1.5 for usual architectures and parameter settings. The superior performance of the new algorithm, however, easily justifies this small increase in computational burden. In addition, the general paradigms of truncated BPTT and RTRL are applied to networks with local feedback and compared with the new CRBP method. The simulations show that CRBP exhibits similar performances and the detailed analysis of complexity reveals that CRBP is much simpler and easier to implement, e.g., CRBP is local in space and in time while RTRL is not local in space.

  4. Canonical ensemble approach to graded-response perceptrons

    Bollé, D.; Erichsen, R., Jr.

    1999-03-01

    Perceptrons with graded input-output relations and a limited output precision are studied within the Gardner-Derrida canonical ensemble approach. Soft non-negative error measures are introduced allowing for extended retrieval properties. In particular, the performance of these systems for a linear (quadratic) error measure, corresponding to the perceptron (adaline) learning algorithm, is compared with the performance for a rigid error measure, simply counting the number of errors. Replica-symmetry-breaking effects are evaluated, and the analytic results are compared with numerical simulations.

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

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

    2012-01-01

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

  6. Updating model for land use database based on multi-layer perceptron network and its application%基于多层感知器神经网络的土地利用数据库更新模型及应用

    纪亚洲; 顾和和; 李保杰

    2015-01-01

    layer. Land class polygon is the first and the most important layer for land use database to update, so its updating model is designed on the top of the land use database adaptive updating model. To judge the change type and update strategy, 3 input conditions and 12 neurons are set up in land class polygon updating model, among which 4 neurons are responsible for judging the change type, 6 neurons are responsible for judging the spatial strategy, and 2 neurons are responsible for judging attribute strategy. Compared with land class polygon, linear feature updating model is more complicated. Therefore, linear feature updating model has 6 input conditions and 12 neurons, among which the distribution of neurons is the same as that of neurons in land class polygon updating model. Isolated feature belongs to one-dimensional element, so its updating model is relatively simple. In isolated feature updating model, 4 neurons are arranged to judge the change type, 3 neurons to judge spatial strategy, and 2 neurons to attribute strategy. The same-type neurons of adaptive updating model are organized into a network layer, and all layers are organized into a multi-layer perception network in an all-connected way. In addition, in order to realize the judgment of change type and update strategy, a threshold activation function is arranged in each neuron, and between the neurons connection weight is set up to adjust the input of neuron active function. All kinds of training methods of multi-layer perception neuron network are analyzed in a comprehensive and deep way. Change sample data of each element are collected so that updating model training can be carried out. Spatial and attribute update rules of various land use elements under the conditions of different topological relationships and different properties should be studied. And the knowledge and experience are organized into an update knowledge database. When new change survey data are input into model again, topology, property

  7. The Role of Weight Shrinking in Large Margin Perceptron Learning

    Panagiotakopoulos, Constantinos

    2012-01-01

    We introduce into the classical perceptron algorithm with margin a mechanism that shrinks the current weight vector as a first step of the update. If the shrinking factor is constant the resulting algorithm may be regarded as a margin-error-driven version of NORMA with constant learning rate. In this case we show that the allowed strength of shrinking depends on the value of the maximum margin. We also consider variable shrinking factors for which there is no such dependence. In both cases we obtain new generalizations of the perceptron with margin able to provably attain in a finite number of steps any desirable approximation of the maximal margin hyperplane. The new approximate maximum margin classifiers appear experimentally to be very competitive in 2-norm soft margin tasks involving linear kernels.

  8. Chaotic diagonal recurrent neural network

    Wang Xing-Yuan; Zhang Yi

    2012-01-01

    We propose a novel neural network based on a diagonal recurrent neural network and chaos,and its structure andlearning algorithm are designed.The multilayer feedforward neural network,diagonal recurrent neural network,and chaotic diagonal recurrent neural network are used to approach the cubic symmetry map.The simulation results show that the approximation capability of the chaotic diagonal recurrent neural network is better than the other two neural networks.

  9. Universal perceptron and DNA-like learning algorithm for binary neural networks: non-LSBF implementation.

    Chen, Fangyue; Chen, Guanrong; He, Qinbin; He, Guolong; Xu, Xiubin

    2009-08-01

    Implementing linearly nonseparable Boolean functions (non-LSBF) has been an important and yet challenging task due to the extremely high complexity of this kind of functions and the exponentially increasing percentage of the number of non-LSBF in the entire set of Boolean functions as the number of input variables increases. In this paper, an algorithm named DNA-like learning and decomposing algorithm (DNA-like LDA) is proposed, which is capable of effectively implementing non-LSBF. The novel algorithm first trains the DNA-like offset sequence and decomposes non-LSBF into logic XOR operations of a sequence of LSBF, and then determines the weight-threshold values of the multilayer perceptron (MLP) that perform both the decompositions of LSBF and the function mapping the hidden neurons to the output neuron. The algorithm is validated by two typical examples about the problem of approximating the circular region and the well-known n-bit parity Boolean function (PBF).

  10. Hybrid combination of multi-layer perceptron and neutron activation analysis in cement prediction

    Eftekhari-Zadeh, E.; Feghhi, S. A. H.; Roshani, G. H.

    2017-02-01

    Determination of concentration of major elements such as Ca, Si, Al, and Fe in cement is very important for quality control during its production, correct classification according to the existing standards, and thus for appropriate use in the construction industry. For this purpose, neutron activation analysis is very suitable. In this preliminary theoretical work, the irradiation and consecutive measurement of the percentage of the constituent elements in different cement samples were done using MCNPX with γ-ray spectra as the output. Specific peaks of Ca, Si, Al, and Fe obtained from these spectra were used as input for artificial neural network (18 of them for training and 8 for testing) resulting in the determination of each element in the given sample. The mean absolute errors of the results are less than 0.4%, which is very promising for the future experimental work where the uncertainties are usually one order higher.

  11. Hybrid combination of multi-layer perceptron and neutron activation analysis in cement prediction

    E EFTEKHARI-ZADEH; S A H FEGHHI; G H ROSHANI

    2017-02-01

    Determination of concentration of major elements such as Ca, Si, Al, and Fe in cement is very important for quality control during its production, correct classification according to the existing standards, and thus for appropriate use in the construction industry. For this purpose, neutron activation analysis is verysuitable. In this preliminary theoretical work, the irradiation and consecutive measurement of the percentage of the constituent elements in different cement samples were done using MCNPX with γ -ray spectra as the output. Specific peaks of Ca, Si, Al, and Fe obtained from these spectra were used as input for artificial neural network (18 of them for training and 8 for testing) resulting in the determination of each element in the given sample. The mean absolute errors of the results are less than 0.4%, which is very promising for the future xperimental work where the uncertainties are usually one order higher.

  12. Fast lossless color image compression method using perceptron

    贾克斌; 张延华; 庄新月

    2004-01-01

    The technique of lossless image compression plays an important role in image transmission and storage for high quality. At present, both the compression ratio and processing speed should be considered in a real-time multimedia system. A novel lossless compression algorithm is researched. A low complexity predictive model is proposed using the correlation of pixels and color components. In the meantime, perceptron in neural network is used to rectify the prediction values adaptively. It makes the prediction residuals smaller and in a small dynamic scope. Also a color space transform is used and good decorrelation is obtained in our algorithm. The compared experimental results have shown that our algorithm has a noticeably better performance than traditional algorithms. Compared to the new standard JPEG-LS, this predictive model reduces its computational complexity. And its speed is faster than the JPEG-LS with negligible performance sacrifice.

  13. Handwritten Arabic Numeral Recognition using a Multi Layer Perceptron

    Das, Nibaran; Saha, Sudip; Haque, Syed Sahidul

    2010-01-01

    Handwritten numeral recognition is in general a benchmark problem of Pattern Recognition and Artificial Intelligence. Compared to the problem of printed numeral recognition, the problem of handwritten numeral recognition is compounded due to variations in shapes and sizes of handwritten characters. Considering all these, the problem of handwritten numeral recognition is addressed under the present work in respect to handwritten Arabic numerals. Arabic is spoken throughout the Arab World and the fifth most popular language in the world slightly before Portuguese and Bengali. For the present work, we have developed a feature set of 88 features is designed to represent samples of handwritten Arabic numerals for this work. It includes 72 shadow and 16 octant features. A Multi Layer Perceptron (MLP) based classifier is used here for recognition handwritten Arabic digits represented with the said feature set. On experimentation with a database of 3000 samples, the technique yields an average recognition rate of 94....

  14. Classification of frozen soil blastability by using perceptron neural network

    马芹永; 张志红

    2002-01-01

    Influence factors of frozen soil blastability are analyzed which mainly conclude the strain energy coefficient, tensile strength, compressive strength, longitudinal wave velocity and transverse wave velocity. According to the principle of perceptron neural network, at first the index factors are standardized by the aid of the efficient function theory, then the blastability of frozen sand at -7, -12 and -17 ℃ are classified three categories. Through adjusting the weight value and threshold value, we can obtain that the clay blastability at -7 ℃ is close to the sand blastability at -12 ℃, they belong to the second category, the clay blastability at -12 ℃ is close to the sand blastability at -17 ℃, thus they are divided into the third category.

  15. Multilayer Networks

    Kivelä, Mikko; Barthelemy, Marc; Gleeson, James P; Moreno, Yamir; Porter, Mason A

    2013-01-01

    Most real and engineered systems include multiple subsystems and layers of connectivity, and it is important to take such features into account to try to obtain a complete understanding of these systems. It is thus necessary to generalize "traditional" network theory by developing (and validating) a framework and associated tools to study multilayer systems in a comprehensive fashion. The origins of such efforts occurred several decades ago, but now the study of multilayer networks has become one of the major directions in network science. In this paper, we discuss the history of multilayer networks (and related concepts) and then review the exploding body of work on such networks. To unify the disparate terminology in the large body of recent work, we discuss a general framework for multilayer networks, construct a dictionary of terminology to relate the numerous existing concepts to each other, and provide a thorough discussion that compares, contrasts, and translates between related notions such as multila...

  16. Predicting termination of atrial fibrillation based on the structure and quantification of the recurrence plot.

    Sun, Rongrong; Wang, Yuanyuan

    2008-11-01

    Predicting the spontaneous termination of the atrial fibrillation (AF) leads to not only better understanding of mechanisms of the arrhythmia but also the improved treatment of the sustained AF. A novel method is proposed to characterize the AF based on structure and the quantification of the recurrence plot (RP) to predict the termination of the AF. The RP of the electrocardiogram (ECG) signal is firstly obtained and eleven features are extracted to characterize its three basic patterns. Then the sequential forward search (SFS) algorithm and Davies-Bouldin criterion are utilized to select the feature subset which can predict the AF termination effectively. Finally, the multilayer perceptron (MLP) neural network is applied to predict the AF termination. An AF database which includes one training set and two testing sets (A and B) of Holter ECG recordings is studied. Experiment results show that 97% of testing set A and 95% of testing set B are correctly classified. It demonstrates that this algorithm has the ability to predict the spontaneous termination of the AF effectively.

  17. Quantum perceptron over a field and neural network architecture selection in a quantum computer.

    da Silva, Adenilton José; Ludermir, Teresa Bernarda; de Oliveira, Wilson Rosa

    2016-04-01

    In this work, we propose a quantum neural network named quantum perceptron over a field (QPF). Quantum computers are not yet a reality and the models and algorithms proposed in this work cannot be simulated in actual (or classical) computers. QPF is a direct generalization of a classical perceptron and solves some drawbacks found in previous models of quantum perceptrons. We also present a learning algorithm named Superposition based Architecture Learning algorithm (SAL) that optimizes the neural network weights and architectures. SAL searches for the best architecture in a finite set of neural network architectures with linear time over the number of patterns in the training set. SAL is the first learning algorithm to determine neural network architectures in polynomial time. This speedup is obtained by the use of quantum parallelism and a non-linear quantum operator.

  18. Probability matching in perceptrons: Effects of conditional dependence and linear nonseparability.

    Dawson, Michael R W; Gupta, Maya

    2017-01-01

    Probability matching occurs when the behavior of an agent matches the likelihood of occurrence of events in the agent's environment. For instance, when artificial neural networks match probability, the activity in their output unit equals the past probability of reward in the presence of a stimulus. Our previous research demonstrated that simple artificial neural networks (perceptrons, which consist of a set of input units directly connected to a single output unit) learn to match probability when presented different cues in isolation. The current paper extends this research by showing that perceptrons can match probabilities when presented simultaneous cues, with each cue signaling different reward likelihoods. In our first simulation, we presented up to four different cues simultaneously; the likelihood of reward signaled by the presence of one cue was independent of the likelihood of reward signaled by other cues. Perceptrons learned to match reward probabilities by treating each cue as an independent source of information about the likelihood of reward. In a second simulation, we violated the independence between cues by making some reward probabilities depend upon cue interactions. We did so by basing reward probabilities on a logical combination (AND or XOR) of two of the four possible cues. We also varied the size of the reward associated with the logical combination. We discovered that this latter manipulation was a much better predictor of perceptron performance than was the logical structure of the interaction between cues. This indicates that when perceptrons learn to match probabilities, they do so by assuming that each signal of a reward is independent of any other; the best predictor of perceptron performance is a quantitative measure of the independence of these input signals, and not the logical structure of the problem being learned.

  19. Perancangan Pengenal QR (Quick Response) Code Dengan Jaringan Syaraf Tiruan Metode Perceptron

    Novalia

    2013-01-01

    Quick Response (QR) Code is used to store important information of an item or product. QR Code has a very random pattern and can not be distinguished. QR Code can also be dirty and damaged. Research conducted on the pattern of QR Code in order to find out the information stored in the QR Code. The method used to identify patterns of QR Code is to use Artificial Neural Networks Perceptron method. Perceptron is a neural network method is often used for pattern recognition. The input to the syst...

  20. Recurrent varicocele

    Katherine Rotker

    2016-01-01

    Full Text Available Varicocele recurrence is one of the most common complications associated with varicocele repair. A systematic review was performed to evaluate varicocele recurrence rates, anatomic causes of recurrence, and methods of management of recurrent varicoceles. The PubMed database was evaluated using keywords "recurrent" and "varicocele" as well as MESH criteria "recurrent" and "varicocele." Articles were not included that were not in English, represented single case reports, focused solely on subclinical varicocele, or focused solely on a pediatric population (age <18. Rates of recurrence vary with the technique of varicocele repair from 0% to 35%. Anatomy of recurrence can be defined by venography. Management of varicocele recurrence can be surgical or via embolization.

  1. Magnetic multilayer structure

    Herget, Philipp; O'Sullivan, Eugene J.; Romankiw, Lubomyr T.; Wang, Naigang; Webb, Bucknell C.

    2016-07-05

    A mechanism is provided for an integrated laminated magnetic device. A substrate and a multilayer stack structure form the device. The multilayer stack structure includes alternating magnetic layers and diode structures formed on the substrate. Each magnetic layer in the multilayer stack structure is separated from another magnetic layer in the multilayer stack structure by a diode structure.

  2. Magnetic multilayer structure

    Herget, Philipp; O' Sullivan, Eugene J.; Romankiw, Lubomyr T.; Wang, Naigang; Webb, Bucknell C.

    2017-03-21

    A mechanism is provided for an integrated laminated magnetic device. A substrate and a multilayer stack structure form the device. The multilayer stack structure includes alternating magnetic layers and diode structures formed on the substrate. Each magnetic layer in the multilayer stack structure is separated from another magnetic layer in the multilayer stack structure by a diode structure.

  3. Development of a multi-layer perceptron artificial neural network model to determine haul trucks energy consumption

    Soofastaei Ali; Aminossadati Saiied M.; Arefi Mohammad M.; Kizil Mehmet S.

    2016-01-01

    The mining industry annually consumes trillions of British thermal units of energy, a large part of which is saveable. Diesel fuel is a significant source of energy in surface mining operations and haul trucks are the major users of this energy source. Gross vehicle weight, truck velocity and total resistance have been recognised as the key parameters affecting the fuel consumption. In this paper, an artificial neural net-work model was developed to predict the fuel consumption of haul trucks in surface mines based on the gross vehicle weight, truck velocity and total resistance. The network was trained and tested using real data collected from a surface mining operation. The results indicate that the artificial neural network modelling can accurately predict haul truck fuel consumption based on the values of the haulage param-eters considered in this study.

  4. Modeling of gamma ray energy-absorption buildup factors for thermoluminescent dosimetric materials using multilayer perceptron neural network

    Kucuk, Nil; Manohara, S.R.; Hanagodimath, S.M.

    2013-01-01

    V, and for penetration depths up to 10 mfp (mean-free-path). The MLPNNs have been trained by a Levenberg–Marquardt learning algorithm. The developed model is in 99% agreement with the ANSI/ANS-6.4.3 standard data set. Furthermore, the model is fast and does not require tremendous computational efforts. The estimated BA...

  5. FORECASTING AUTOMOBILE WARRANTY PERFORMANCE IN PRESENCE OF ‘MATURING DATA' PHENOMENA USING MULTILAYER PERCEPTRON NEURAL NETWORK

    Bharatendra RAI; Nanua SINGH

    2005-01-01

    Automobile companies that spend billions of dollars annually towards warranty cost, give high priority to warranty reduction programs. Forecasting of automobile warranty performance plays an important role towards these efforts. The forecasting process involves prediction of not only the specific months-in-service (MIS) warranty performance at certain future time, but also at future MIS values. However, 'maturing data' (also called warranty growth) phenomena that causes warranty performance at specific MIS values to change with time, makes such a forecasting task challenging.Although warranty forecasting methods such as log-log plots and dynamic linear models appear in this paper we use an artificial neural network for the forecasting of warranty performance in presence testing errors using response surface methodology. This application shows the effectiveness of neural phenomena.

  6. Performance analysis of radial basis function networks and multi-layer perceptron networks in modeling urban change: A case study.

    Shafizadeh Moghadam, H; Hagenauer, J; Farajzadeh, M; Helbich, M

    2015-01-01

    The majority of cities are rapidly growing. This makes the monitoring and modeling of urban change’s spatial patterns critical to urban planners, decision makers, and environment protection activists. Although a wide range of methods exists for modeling and simulating urban growth, machine learning

  7. Analisis Perbandingan Neural Network Backpropagation dengan Simple Perceptron dalam Mengenali Image Daun

    Alfina, Ommi

    2012-01-01

    As one of the information processing systems, artificial neural networks (ANN) which resembles biological neural networks has grown rapidly. One application of artificial neural networks is in the field of biology which to categorize plant species. In order to determine the species of a plant, one usually looks at its flowers or its leaves. In this research, two artificial neural networks (ANN) methods which are backpropagation and simple perceptron are applied separately in order to evalua...

  8. Recurrent vulvovaginitis.

    Powell, Anna M; Nyirjesy, Paul

    2014-10-01

    Vulvovaginitis (VV) is one of the most commonly encountered problems by a gynecologist. Many women frequently self-treat with over-the-counter medications, and may present to their health-care provider after a treatment failure. Vulvovaginal candidiasis, bacterial vaginosis, and trichomoniasis may occur as discreet or recurrent episodes, and have been associated with significant treatment cost and morbidity. We present an update on diagnostic capabilities and treatment modalities that address recurrent and refractory episodes of VV.

  9. Noise and randomlike behavior of perceptrons: Theory and applicationto protein structure prediction

    Compiani, M.; Fariselli, P.; Casadio, R.

    1997-06-01

    In the first part of this paper we study the performance of a single-layer perceptron that is expected to classify patterns into classes in the case where the mapping to be learned is corrupted by noise. Extending previous results concerning the statistical behavior of perceptrons, we distinguish two mutually exclusive kinds of noise (I noise and R noise) and study their effect on the statistical information that can be drawn from the output. In the presence of I noise, the learning stage results in the convergence of the output to the probabilities that the input occurs in each class. R noise, on the contrary, perturbs the learning of probabilities to the extent that the performance of the perceptron deteriorates and the network becomes equivalent to a random predictor. We derive an analytical expression for the efficiency of classification of inputs affected by strong R noise. We argue that, from the standpoint of the efficiency score, the network is equivalent to a device performing biased random flights in the space of the weights, which are ruled by the statistical information stored by the network during the learning stage. The second part of the paper is devoted to the application of our model to the prediction of protein secondary structures where one has to deal with the effects of R noise. Our results are shown to be consistent with data drawn from experiments and simulations of the folding process. In particular, the existence of coding and noncoding traits of the protein is properly rationalized in terms of R-noise intensity. In addition, our model provides a justification of the seeming existence of a relationship between the prediction efficiency and the amount of R noise in the sequence-to-structure mapping. Finally, we define an entropylike parameter that is useful as a measure of R noise.

  10. Recurrent fevers.

    Isaacs, David; Kesson, Alison; Lester-Smith, David; Chaitow, Jeffrey

    2013-03-01

    An 11-year-old girl had four episodes of fever in a year, lasting 7-10 days and associated with headache and neck stiffness. She had a long history of recurrent urticaria, usually preceding the fevers. There was also a history of vague pains in her knees and in the small joints of her hands. Her serum C-reactive protein was moderately raised at 41 g/L (normal <8). Her rheumatologist felt the association of recurrent fevers that lasted 7 or more days with headaches, arthralgia and recurrent urticaria suggested one of the periodic fever syndromes. Genetic testing confirmed she had a gene mutation consistent with one of tumour necrosis factor receptor-associated periodic syndrome.

  11. Perceptron system to assist in decision making and monitoring of quality of software development in Information Technology environments

    Chau Sen Shia

    2016-07-01

    Full Text Available - Classical methods for software development require high costs and problems of communication between development teams, project risks and delays in the delivery of its services. In this work, the aim is to develop a perceptron model to demonstrate the ability to control, service quality assessment and decision-making in IT (Information Technology. For this, we used perceptron network techniques, standards of service quality measures and risk analysis model of applied projects in software engineering. With the network perceptron model implementation was possible to simulate the application of development in several requests for applications for software, in order to meet the management of schedules in all phases of the life cycle of the projects carried out. The tests with the perceptron model were applied in it environments to meet service requests from various fields. The results and analyses presented in these projects demonstrate that communication between development teams were more consistent. It was also possible to predict with more accuracy the delivery of services, decision making and risk reduction projects.

  12. Interfacial effects in multilayers

    Barbee, T.W. Jr. [Lawrence Livermore National Lab., CA (United States). Chemistry and Materials Science Dept.

    1998-12-31

    Interfacial structure and the atomic interactions between atoms at interfaces in multilayers or nano-laminates have significant impact on the physical properties of these materials. A technique for the experimental evaluation of interfacial structure and interfacial structure effects is presented and compared to experiment. In this paper the impact of interfacial structure on the performance of x-ray, soft x-ray and extreme ultra-violet multilayer optic structures is emphasized. The paper is concluded with summary of these results and an assessment of their implications relative to multilayer development and the study of buried interfaces in solids in general.

  13. Multilayer Social Networks

    Dickison, Mark; Magnani, Matteo; Rossi, Luca

    research communities, leading to the development of several independent models and methods to deal with the same set of problems. This book unifies and consolidates existing practical and theoretical knowledge on multilayer networks including data collection and analysis, modeling, and mining of multilayer......Multilayer networks, in particular multilayer social networks, where users belong to and interact on different networks at the same time, are an active research area in social network analysis, computer science, and physics. These networks have traditionally been studied within these separate...... social network systems, the evolution of interconnected social networks, and dynamic processes such as information spreading. A single real dataset is used to illustrate the concepts presented throughout the book, demonstrating both the practical utility and the potential shortcomings of the various...

  14. Effective electromagnetic shielding in multilayer printed circuit boards

    Wiles, K. G.; Moe, J. L.

    Multilayer printed circuit boards have proven to be recurrent abettors of electromagnetic coupling problems created by the incessantly faster response times in integrated circuit technologies. Coupling within multilayer boards has not only inhibited meeting certain EMI requirements but has also precipitated 'self-inflicted' malfunctions commonly experienced during development of avionic systems. A recent avionic system, interfacing two asynchronous processors through a fourteen-layer motherboard, permitted coupling through ground plane connector apertures of sufficient amplitude and duration as to cause unintentional intercommunication and system malfunctions. The coupling mechanism and ground plane modifications which reduced this coupling by 40 dB and eliminated the incompatibility are discussed in this paper

  15. Effects of dilation and translation on a perceptron-type learning rule for higher order Hopfield neural networks.

    Lenze, Burkhard; Raddatz, Jörg

    2002-04-01

    In this paper, we will take a further look at a generalized perceptron-like learning rule which uses dilation and translation parameters in order to enhance the recall performance of higher order Hopfield neural networks without significantly increasing their complexity. We will practically study the influence of these parameters on the perceptron learning and recall process, using a generalized version of the Hebbian learning rule for initialization. Our analysis will be based on a pattern recognition problem with random patterns. We will see that in case of a highly correlated set of patterns, there can be gained some improvements concerning the learning and recall performance. On the other hand, we will show that the dilation and translation parameters have to be chosen carefully for a positive result.

  16. The development of a knowledge base in an expert system based on the four-layer perceptron neural network

    2007-01-01

    Owing to continuous production lines with large amount of consecutive controls, various control signals and huge logistic relations, this paper introduced the methods and principles of the development of knowledge base in a fault diagnosis expert system that was based on machine learning by the four-layer perceptron neural network. An example was presented. By combining differential function with not differentia function and back propagation of error with back propagation of expectation, the four-layer perceptron neural network was established. And it was good for solving such a bottleneck problem in knowledge acquisition in expert system and enhancing real-time on-line diagnosis. A method of synthetic back propagation was designed, which broke the limit to non-differentiable function in BP neural network.

  17. Statistical Mechanical Analysis of Online Learning with Weight Normalization in Single Layer Perceptron

    Yoshida, Yuki; Karakida, Ryo; Okada, Masato; Amari, Shun-ichi

    2017-04-01

    Weight normalization, a newly proposed optimization method for neural networks by Salimans and Kingma (2016), decomposes the weight vector of a neural network into a radial length and a direction vector, and the decomposed parameters follow their steepest descent update. They reported that learning with the weight normalization achieves better converging speed in several tasks including image recognition and reinforcement learning than learning with the conventional parameterization. However, it remains theoretically uncovered how the weight normalization improves the converging speed. In this study, we applied a statistical mechanical technique to analyze on-line learning in single layer linear and nonlinear perceptrons with weight normalization. By deriving order parameters of the learning dynamics, we confirmed quantitatively that weight normalization realizes fast converging speed by automatically tuning the effective learning rate, regardless of the nonlinearity of the neural network. This property is realized when the initial value of the radial length is near the global minimum; therefore, our theory suggests that it is important to choose the initial value of the radial length appropriately when using weight normalization.

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

    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.

  19. Control of Multilayer Networks

    Menichetti, Giulia; Bianconi, Ginestra

    2015-01-01

    The controllability of a network is a theoretical problem of relevance in a variety of contexts ranging from financial markets to the brain. Until now, network controllability has been characterized only on isolated networks, while the vast majority of complex systems are formed by multilayer networks. Here we build a theoretical framework for the linear controllability of multilayer networks by mapping the problem into a combinatorial matching problem. We found that correlating the external signals in the different layers can significantly reduce the multiplex network robustness to node removal, as it can be seen in conjunction with a hybrid phase transition occurring in interacting Poisson networks. Moreover we observe that multilayer networks can stabilize the fully controllable multiplex network configuration that can be stable also when the full controllability of the single network is not stable.

  20. Controlling light with plasmonic multilayers

    Orlov, Alexey A.; Zhukovsky, Sergei; Iorsh, Ivan V.

    2014-01-01

    Recent years have seen a new wave of interest in layered media - namely, plasmonic multilayers - in several emerging applications ranging from transparent metals to hyperbolic metamaterials. In this paper, we review the optical properties of such subwavelength metal-dielectric multilayered...... metamaterials and describe their use for light manipulation at the nanoscale. While demonstrating the recently emphasized hallmark effect of hyperbolic dispersion, we put special emphasis to the comparison between multilayered hyperbolic metamaterials and more broadly defined plasmonic-multilayer metamaterials...

  1. A constructive algorithm to solve "convex recursive deletion" (CoRD) classification problems via two-layer perceptron networks.

    Cabrelli, C; Molter, U; Shonkwiler, R

    2000-01-01

    A sufficient condition that a region be classifiable by a two-layer feedforward neural net (a two-layer perceptron) using threshold activation functions is that either it be a convex polytope or that intersected with the complement of a convex polytope in its interior, or that intersected with the complement of a convex polytope in its interior or ... recursively. These have been called convex recursive deletion (CoRD) regions.We give a simple algorithm for finding the weights and thresholds in both layers for a feedforward net that implements such a region. The results of this work help in understanding the relationship between the decision region of a perceptron and its corresponding geometry in input space. Our construction extends in a simple way to the case that the decision region is the disjoint union of CoRD regions (requiring three layers). Therefore this work also helps in understanding how many neurons are needed in the second layer of a general three-layer network. In the event that the decision region of a network is known and is the union of CoRD regions, our results enable the calculation of the weights and thresholds of the implementing network directly and rapidly without the need for thousands of backpropagation iterations.

  2. Multilayer graphene waveguides

    Smirnova, Daria; Shadrivov, Ilya; Kivshar, Yuri

    2014-01-01

    We study dispersion properties of TM-polarized electromagnetic waves guided by a multilayer graphene metamaterial. We demonstrate that both dispersion and localization of the guided modes can be efficiently controlled by changing the number of layers in the structure. Remarkably, we find that in the long wavelength limit, the dispersion of the fundamental mode of the N-layer graphene structure coincides with the dispersion of a plasmon mode supported by a single graphene layer, but with N times larger conductivity. We also compare our exact dispersion relations with the results provided by the effective media model.

  3. Fuzzy recurrence plots

    Pham, T. D.

    2016-12-01

    Recurrence plots display binary texture of time series from dynamical systems with single dots and line structures. Using fuzzy recurrence plots, recurrences of the phase-space states can be visualized as grayscale texture, which is more informative for pattern analysis. The proposed method replaces the crucial similarity threshold required by symmetrical recurrence plots with the number of cluster centers, where the estimate of the latter parameter is less critical than the estimate of the former.

  4. Ultrahard Multilayer Coatings

    Chrzan, D.C.; Dugger, M.; Follstaedt, D.M.; Friedman, Lawrence H.; Friedmann, T.A.; Knapp, J.A.; McCarty, K.F.; Medlin, D.L.; Mirkarimi, P.B.; Missert, N.; Newcomer, P.P.; Sullivan, J.P.; Tallant, D.R.

    1999-05-01

    We have developed a new multilayer a-tC material that is thick stress-free, adherent, low friction, and with hardness and stiffness near that of diamond. The new a-tC material is deposited by J pulsed-laser deposition (PLD) at room temperature, and fully stress-relieved by a short thermal anneal at 600°C. A thick multilayer is built up by repeated deposition and annealing steps. We measured 88 GPa hardness, 1100 GPa Young's modulus, and 0.1 friction coefficient (under high load). Significantly, these results are all well within the range reported for crystalline diamond. In fact, this material, if considered separate from crystalline diamond, is the 2nd hardest material known to man. Stress-free a-tC also has important advantages over thin film diamond; namely, it is smooth, processed at lower temperature, and can be grown on a much broader range of substrates. This breakthrough will enable a host of applications that we are actively pursuing in MEMs, sensors, LIGA, etc.

  5. Magneto-optical multilayers

    Bader, S.D.

    1992-02-01

    Magneto-optical multilayers are of interest to the optical data storage community as a possible second-generation medium of the future. The important Co/Pt-superlattice system is introduced in this respect, and an extensive reference listing is provided to previous research. Magneto-optical modeling studies of Co/Pt are presented, and it is concluded that the interfacial Pt is magnetized and is magneto-optically active at the short wavelengths of interest ({approximately}4 eV) for applications. Magneto-optics in the ultrathin limit are discussed, and an additivity law is presented and verified experimentally utilizing data for epitaxial Fe/Ag(111) superlattices. Finally, the surface magnetic anisotropy that provides the vertical easy axes of magnetization in candidate superlattice systems is discussed and illustrated experimentally using ultrathin epitaxial films of Fe grown on a variety of substrates. It is concluded that magneto-optic multilayers will provide many stimulating basic and applied challenges in the years ahead.

  6. Magnetic metallic multilayers

    Hood, R.Q.

    1994-04-01

    Utilizing self-consistent Hartree-Fock calculations, several aspects of multilayers and interfaces are explored: enhancement and reduction of the local magnetic moments, magnetic coupling at the interfaces, magnetic arrangements within each film and among non-neighboring films, global symmetry of the systems, frustration, orientation of the various moments with respect to an outside applied field, and magnetic-field induced transitions. Magnetoresistance of ferromagnetic-normal-metal multilayers is found by solving the Boltzmann equation. Results explain the giant negative magnetoresistance encountered in these systems when an initial antiparallel arrangement is changed into a parallel configuration by an external magnetic field. The calculation depends on (1) geometric parameters (thicknesses of layers), (2) intrinsic metal parameters (number of conduction electrons, magnetization, and effective masses in layers), (3) bulk sample properties (conductivity relaxation times), (4) interface scattering properties (diffuse scattering versus potential scattering at the interfaces, and (5) outer surface scattering properties (specular versus diffuse surface scattering). It is found that a large negative magnetoresistance requires considerable asymmetry in interface scattering for the two spin orientations. Features of the interfaces that may produce an asymmetrical spin-dependent scattering are studied: varying interfacial geometric random roughness with no lateral coherence, correlated (quasi-periodic) roughness, and varying chemical composition of the interfaces. The interplay between these aspects of the interfaces may enhance or suppress the magnetoresistance, depending on whether it increases or decreases the asymmetry in the spin-dependent scattering of the conduction electrons.

  7. Cloud-based application for rice moisture content measurement using image processing technique and perceptron neural network

    Cruz, Febus Reidj G.; Padilla, Dionis A.; Hortinela, Carlos C.; Bucog, Krissel C.; Sarto, Mildred C.; Sia, Nirlu Sebastian A.; Chung, Wen-Yaw

    2017-02-01

    This study is about the determination of moisture content of milled rice using image processing technique and perceptron neural network algorithm. The algorithm involves several inputs that produces an output which is the moisture content of the milled rice. Several types of milled rice are used in this study, namely: Jasmine, Kokuyu, 5-Star, Ifugao, Malagkit, and NFA rice. The captured images are processed using MATLAB R2013a software. There is a USB dongle connected to the router which provided internet connection for online web access. The GizDuino IOT-644 is used for handling the temperature and humidity sensor, and for sending and receiving of data from computer to the cloud storage. The result is compared to the actual moisture content range using a moisture tester for milled rice. Based on results, this study provided accurate data in determining the moisture content of the milled rice.

  8. Multi-layers castings

    J. Szajnar

    2010-01-01

    Full Text Available In paper is presented the possibility of making of multi-layers cast steel castings in result of connection of casting and welding coating technologies. First layer was composite surface layer on the basis of Fe-Cr-C alloy, which was put directly in founding process of cast carbon steel 200–450 with use of preparation of mould cavity method. Second layer were padding welds, which were put with use of TIG – Tungsten Inert Gas surfacing by welding technology with filler on Ni matrix, Ni and Co matrix with wolfram carbides WC and on the basis on Fe-Cr-C alloy, which has the same chemical composition with alloy, which was used for making of composite surface layer. Usability for industrial applications of surface layers of castings were estimated by criterion of hardness and abrasive wear resistance of type metal-mineral.

  9. Multilayer Multidimensional Extension Set Theory

    CAO Shao-zhong; YANG Guo-wei; TU Xu-yan

    2006-01-01

    In order to study the contradiction problem of multilayer multidimensional complex systems, the concepts of extension field and stable field of intersection and union of multilayer multidimensional extension set are given. Then the related operations and properties are discussed. The results of study expand the concepts of intersection and union of extension set to a general situation, and provide the theoretical basis for production of the concepts of intersection and union of multilayer multidimensional matter element system extension set. In this way, it will be possible that matter element system theory is used to creative designs of complex systems.

  10. Multilayered Magnetic Gelatin Membrane Scaffolds

    Samal, Sangram K.; Goranov, Vitaly; Dash, Mamoni; Russo, Alessandro; Shelyakova, Tatiana; Graziosi, Patrizio; Lungaro, Lisa; Riminucci, Alberto; Uhlarz, Marc; Bañobre-López, Manuel; Rivas, Jose; Herrmannsdörfer, Thomas; Rajadas, Jayakumar; De Smedt, Stefaan; Braeckmans, Kevin; Kaplan, David L.; Dediu, V. Alek

    2016-01-01

    A versatile approach for the design and fabrication of multilayer magnetic scaffolds with tunable magnetic gradients is described. Multilayer magnetic gelatin membrane scaffolds with intrinsic magnetic gradients were designed to encapsulate magnetized bioagents under an externally applied magnetic field for use in magnetic-field-assisted tissue engineering. The temperature of the individual membranes increased up to 43.7 °C under an applied oscillating magnetic field for 70 s by magnetic hyperthermia, enabling the possibility of inducing a thermal gradient inside the final 3D multilayer magnetic scaffolds. On the basis of finite element method simulations, magnetic gelatin membranes with different concentrations of magnetic nanoparticles were assembled into 3D multilayered scaffolds. A magnetic-gradient-controlled distribution of magnetically labeled stem cells was demonstrated in vitro. This magnetic biomaterial–magnetic cell strategy can be expanded to a number of different magnetic biomaterials for various tissue engineering applications. PMID:26451743

  11. Speech Recognition Method Based on Multilayer Chaotic Neural Network

    REN Xiaolin; HU Guangrui

    2001-01-01

    In this paper,speech recognitionusing neural networks is investigated.Especially,chaotic dynamics is introduced to neurons,and a mul-tilayer chaotic neural network (MLCNN) architectureis built.A learning algorithm is also derived to trainthe weights of the network.We apply the MLCNNto speech recognition and compare the performanceof the network with those of recurrent neural net-work (RNN) and time-delay neural network (TDNN).Experimental results show that the MLCNN methodoutperforms the other neural networks methods withrespect to average recognition rate.

  12. Optimal Recurrence Grammars

    Graben, Peter beim; Fröhlich, Flavio

    2015-01-01

    We optimally estimate the recurrence structure of a multivariate time series by Markov chains obtained from recurrence grammars. The goodness of fit is assessed with a utility function derived from the stochastic Markov transition matrix. It assumes a local maximum for the distance threshold of the optimal recurrence grammar. We validate our approach by means of the nonlinear Lorenz system and its linearized stochastic surrogates. Finally we apply our optimization procedure to the segmentation of neurophysiological time series obtained from anesthetized animals. We propose the number of optimal recurrence domains as a statistic for classifying an animals' state of consciousness.

  13. Recurrent intracerebral hemorrhage

    Shen jinsong; Lu jianhong

    2000-01-01

    Objective: In order to study the clinical manifestation and risk factor of recurrent intracerebral hemorrhage(ICH).Methods:The 256 patients were analysed who admitted to our hospital for intracerebral hemorrhage between 1995 and 1997.The 15(5 .86%)patients had a recurrent ICH.There were 9 men and 6 women and the mean age of the patients was 63.5 ± 6.4years at the first bleeding episode and 67.8± 8. 5 years at the second. The mean interval between the two bleeding episodes was 44.6 ± 12.5 months. The 73.3%patients were hypertensive .′The site of the first hemorrhage was ganglionic in 8 patients , ]ohar in six paients and brainstem in one .The recurrent hemorrhage occurred at a different location from the previous ICH.The most common pattern of recurrence was “ganglionic -ganglionic” (7 patients), lobar - ganglionic (3 patients), lobar-lobar(three patients), which was always observed in hypertensive patients. The outcome after the recurrent hemorrhage was usually poor. By comparison with 24 patients followed up to average 47.5± 18.7 months with isolated ICH without recurrence .Only lobar hematoma and a younger age were risk factors for recurrences whereas sex and previous hypertension were not. The mechanism of recurrence of ICH were multiple(hypertension, cerebral amyloid angiopathy).Contral of blood pressure and good living habit after the first hemorrhage may prevent ICH recurrences.

  14. Kinetic Study of anti-HIV drugs by Thermal Decomposition Analysis: A Multilayer Artificial Neural Network Propose

    Ferreira, B D L; Sebastião, R C O; Yoshida, M I; Mussel, W N; Fialho, S L; Barbosa, J

    2016-01-01

    Kinetic study by thermal decomposition of antiretroviral drugs, Efavirenz (EFV) and Lamivudine (3TC), usually present in the HIV cocktail, can be done by individual adjustment of the solid decomposition models. However, in some cases unacceptable errors are found using this methodology. To circumvent this problem, here is proposed to use a multilayer perceptron neural network (MLP), with an appropriate algorithm, which constitutes a linearization of the network by setting weights between the input layer and the intermediate one and the use of Kinetic models as activation functions of neurons in the hidden layer. The interconnection weights between that intermediate layer and output layer determines the contribution of each model in the overall fit of the experimental data. Thus, the decomposition is assumed to be a phenomenon that can occur following different kinetic processes. In the investigated data, the kinetic thermal decomposition process was best described by R1 and D4 model for all temperatures to EF...

  15. Neural networks and chaos: construction, evaluation of chaotic networks, and prediction of chaos with multilayer feedforward networks.

    Bahi, Jacques M; Couchot, Jean-François; Guyeux, Christophe; Salomon, Michel

    2012-03-01

    Many research works deal with chaotic neural networks for various fields of application. Unfortunately, up to now, these networks are usually claimed to be chaotic without any mathematical proof. The purpose of this paper is to establish, based on a rigorous theoretical framework, an equivalence between chaotic iterations according to Devaney and a particular class of neural networks. On the one hand, we show how to build such a network, on the other hand, we provide a method to check if a neural network is a chaotic one. Finally, the ability of classical feedforward multilayer perceptrons to learn sets of data obtained from a dynamical system is regarded. Various boolean functions are iterated on finite states. Iterations of some of them are proven to be chaotic as it is defined by Devaney. In that context, important differences occur in the training process, establishing with various neural networks that chaotic behaviors are far more difficult to learn.

  16. Multilayer optical calculations

    Byrnes, Steven J

    2016-01-01

    When light hits a multilayer planar stack, it is reflected, refracted, and absorbed in a way that can be derived from the Fresnel equations. The analysis is treated in many textbooks, and implemented in many software programs, but certain aspects of it are difficult to find explicitly and consistently worked out in the literature. Here, we derive the formulas underlying the transfer-matrix method of calculating the optical properties of these stacks, including oblique-angle incidence, absorption-vs-position profiles, and ellipsometry parameters. We discuss and explain some strange consequences of the formulas in the situation where the incident and/or final (semi-infinite) medium are absorptive, such as calculating $T>1$ in the absence of gain. We also discuss some implementation details like complex-plane branch cuts. Finally, we derive modified formulas for including one or more "incoherent" layers, i.e. very thick layers in which interference can be neglected. This document was written in conjunction with ...

  17. Multilayer graphene rubber nanocomposites

    Schartel, Bernhard; Frasca, Daniele; Schulze, Dietmar; Wachtendorf, Volker; Krafft, Bernd; Morys, Michael; Böhning, Martin; Rybak, Thomas

    2016-05-01

    Multilayer Graphene (MLG), a nanoparticle with a specific surface of BET = 250 m2/g and thus made of only approximately 10 graphene sheets, is proposed as a nanofiller for rubbers. When homogenously dispersed, it works at low loadings enabling the replacement of carbon black (CB), increase in efficiency, or reduction in filler concentration. Actually the appropriate preparation yielded nanocomposites in which just 3 phr are sufficient to significantly improve the rheological, curing and mechanical properties of different rubbers, as shown for Chlorine-Isobutylene-Isoprene Rubber (CIIR), Nitrile-Butadiene Rubber (NBR), Natural Rubber (NR), and Styrene-Butadiene Rubber (SBR). A mere 3 phr of MLG tripled the Young's modulus of CIIR, an effect equivalent to 20 phr of carbon black. Similar equivalents are observed for MLG/CB mixtures. MLG reduces gas permeability, increases thermal and electrical conductivities, and retards fire behavior. The later shown by the reduction in heat release rate in the cone calorimeter. The higher the nanofiller concentration is (3 phr, 5 phr, and 10 phr was investigated), the greater the improvement in the properties of the nanocomposites. Moreover, the MLG nanocomposites improve stability of mechanical properties against weathering. An increase in UV-absorption as well as a pronounced radical scavenging are proposed and were proved experimentally. To sum up, MLG is interesting as a multifunctional nanofiller and seems to be quite ready for rubber development.

  18. The eternal recurrence today

    Neves, J C S

    2015-01-01

    In this work we have carried out an approach between the nonsingular scientific cosmologies (without the initial singularity, the big bang), specially the cyclic models, and the Nietzsche's thought of the eternal recurrence. Moreover, we have pointed out reasons for the Nietzsche's search for scientific proofs about the eternal recurrence in the decade of 1880's.

  19. Recurrent aphthous stomatitis

    L Preeti

    2011-01-01

    Full Text Available Recurrent aphthous ulcers are common painful mucosal conditions affecting the oral cavity. Despite their high prevalence, etiopathogenesis remains unclear. This review article summarizes the clinical presentation, diagnostic criteria, and recent trends in the management of recurrent apthous stomatitis.

  20. Recurrent Abdominal Pain

    Banez, Gerard A.; Gallagher, Heather M.

    2006-01-01

    The purpose of this article is to provide an empirically informed but clinically oriented overview of behavioral treatment of recurrent abdominal pain. The epidemiology and scope of recurrent abdominal pain are presented. Referral process and procedures are discussed, and standardized approaches to assessment are summarized. Treatment protocols…

  1. Acute recurrent polyhydramnios

    Rode, Line; Bundgaard, Anne; Skibsted, Lillian

    2007-01-01

    Acute recurrent polyhydramnios is a rare occurrence characterized by a poor fetal outcome. This is a case report describing a 34-year-old woman presenting with acute recurrent polyhydramnios. Treatment with non-steroidal anti-inflammatory drugs (NSAID) and therapeutic amniocenteses was initiated ...

  2. Multi-Layer and Recursive Neural Networks for Metagenomic Classification.

    Ditzler, Gregory; Polikar, Robi; Rosen, Gail

    2015-09-01

    Recent advances in machine learning, specifically in deep learning with neural networks, has made a profound impact on fields such as natural language processing, image classification, and language modeling; however, feasibility and potential benefits of the approaches to metagenomic data analysis has been largely under-explored. Deep learning exploits many layers of learning nonlinear feature representations, typically in an unsupervised fashion, and recent results have shown outstanding generalization performance on previously unseen data. Furthermore, some deep learning methods can also represent the structure in a data set. Consequently, deep learning and neural networks may prove to be an appropriate approach for metagenomic data. To determine whether such approaches are indeed appropriate for metagenomics, we experiment with two deep learning methods: i) a deep belief network, and ii) a recursive neural network, the latter of which provides a tree representing the structure of the data. We compare these approaches to the standard multi-layer perceptron, which has been well-established in the machine learning community as a powerful prediction algorithm, though its presence is largely missing in metagenomics literature. We find that traditional neural networks can be quite powerful classifiers on metagenomic data compared to baseline methods, such as random forests. On the other hand, while the deep learning approaches did not result in improvements to the classification accuracy, they do provide the ability to learn hierarchical representations of a data set that standard classification methods do not allow. Our goal in this effort is not to determine the best algorithm in terms accuracy-as that depends on the specific application-but rather to highlight the benefits and drawbacks of each of the approach we discuss and provide insight on how they can be improved for predictive metagenomic analysis.

  3. Unfolding single- and multilayers

    Llorens, Maria-Gema; Bons, Paul D.; Griera, Albert; Gomez-Rivas, Enrique

    2014-05-01

    When planar structures (e.g. sedimentary layers, veins, dykes, cleavages, etc.) are subjected to deformation, they have about equal chances to be shortened or stretched. The most common shortening and stretching structures are folds and boudinage, respectively. However, boudinage requires additional deformation mechanisms apart from viscous flow, like formation of fractures or strain localization. When folded layers are subjected to extension, they could potentially unfold back to straight layers. Although probably not uncommon, this would be difficult to recognize. Open questions are whether folded layers can unfold, what determines their mechanical behaviour and how we can recognize them in the field. In order to approach these questions, we present a series of numerical experiments that simulate stretching of previously folded single- and multi-layers in simple shear, using the two dimensional numerical modelling platform ELLE, including the finite element module BASIL that calculates viscous deformation. We investigate the parameters that affect a fold train once it rotates into the extensional field. The results show that the unfolding process strongly depends on the viscosity contrast between the layer and matrix (Llorens et al., 2013). Layers do not completely unfold when they experience softening before or during the stretching process or when other neighbouring competent layers prevent them from unfolding. The foliation refraction patterns are the main indicators of unfolded folds. Additionally, intrafolial folds and cusp-like folds adjacent to straight layers, as well as variations in fold amplitudes and limb lengths of irregular folds can also be used as indicators of stretching of a layer after shortening and folding. References: Llorens, M-.G., Bons, P.D., Griera, A. and Gomez-Rivas, E. 2013. When do folds unfold during progressive shear?. Geology, 41, 563-566.

  4. Predictors of Recurrent AKI.

    Siew, Edward D; Parr, Sharidan K; Abdel-Kader, Khaled; Eden, Svetlana K; Peterson, Josh F; Bansal, Nisha; Hung, Adriana M; Fly, James; Speroff, Ted; Ikizler, T Alp; Matheny, Michael E

    2016-04-01

    Recurrent AKI is common among patients after hospitalized AKI and is associated with progressive CKD. In this study, we identified clinical risk factors for recurrent AKI present during index AKI hospitalizations that occurred between 2003 and 2010 using a regional Veterans Administration database in the United States. AKI was defined as a 0.3 mg/dl or 50% increase from a baseline creatinine measure. The primary outcome was hospitalization with recurrent AKI within 12 months of discharge from the index hospitalization. Time to recurrent AKI was examined using Cox regression analysis, and sensitivity analyses were performed using a competing risk approach. Among 11,683 qualifying AKI hospitalizations, 2954 patients (25%) were hospitalized with recurrent AKI within 12 months of discharge. Median time to recurrent AKI within 12 months was 64 (interquartile range 19-167) days. In addition to known demographic and comorbid risk factors for AKI, patients with longer AKI duration and those whose discharge diagnosis at index AKI hospitalization included congestive heart failure (primary diagnosis), decompensated advanced liver disease, cancer with or without chemotherapy, acute coronary syndrome, or volume depletion, were at highest risk for being hospitalized with recurrent AKI. Risk factors identified were similar when a competing risk model for death was applied. In conclusion, several inpatient conditions associated with AKI may increase the risk for recurrent AKI. These findings should facilitate risk stratification, guide appropriate patient referral after AKI, and help generate potential risk reduction strategies. Efforts to identify modifiable factors to prevent recurrent AKI in these patients are warranted.

  5. RECURRENT CROUP IN CHILDREN

    S. L. Piskunova

    2014-01-01

    Full Text Available The article presents the results of examination of 1849 children, entering children's infectioushospitalofVladivostokwith the clinical picture of croup of viral etiology. The clinical features of primary and recurrent croup are described. Frequency of recurrent croup inVladivostokis 8%. Children with a recurrent croup had the burdened premorbid background, and also persistent herpetic infections (cytomegalic infection in 42,9% cases, cytomegalic infection in combination with the herpes simplex virus -1. Frequency of croups substantially rose in the period of epidemic of influenza.

  6. Recurrent Intracerebral Hemorrhage

    Schmidt, Linnea Boegeskov; Goertz, Sanne; Wohlfahrt, Jan;

    2016-01-01

    the use of any of the investigated medicines with antithrombotic effect (ATT, SSRI's, NSAID's) and recurrent ICH. CONCLUSIONS: The substantial short-and long-term recurrence risks warrant aggressive management of hypertension following a primary ICH, particularly in patients treated surgically...... treatment and renal insufficiency were associated with increased recurrence risks (RR 1.64, 95% CI 1.39-1.93 and RR 1.72, 95% CI 1.34-2.17, respectively), whereas anti-hypertensive treatment was associated with a reduced risk (RR 0.82, 95% CI 0.74-0.91). We observed non-significant associations between...

  7. Multilayer adsorption on fractal surfaces.

    Vajda, Péter; Felinger, Attila

    2014-01-10

    Multilayer adsorption is often observed in liquid chromatography. The most frequently employed model for multilayer adsorption is the BET isotherm equation. In this study we introduce an interpretation of multilayer adsorption measured on liquid chromatographic stationary phases based on the fractal theory. The fractal BET isotherm model was successfully used to determine the apparent fractal dimension of the adsorbent surface. The nonlinear fitting of the fractal BET equation gives us the estimation of the adsorption equilibrium constants and the monolayer saturation capacity of the adsorbent as well. In our experiments, aniline and proline were used as test molecules on reversed phase and normal phase columns, respectively. Our results suggest an apparent fractal dimension 2.88-2.99 in the case of reversed phase adsorbents, in the contrast with a bare silica column with a fractal dimension of 2.54.

  8. On Concircularly Recurrent Finsler Manifolds

    Youssef, Nabil L

    2013-01-01

    Two special Finsler spaces have been introduced and investigated, namely $R^h$-recurrent Finsler space and consircularly recurrent Finsler space. The defining properties of these spaces are formulated in terms of the first curvature tensor of Cartan connection. The following three results constitute the main object of the present paper: 1. A concircularly flat Finsler manifold is necessarily of constant curvature (Theorem A); 2. Every $R^h$-recurrent Finsler manifold is concirculaly recurrent with the same recurrence form (Theorem B); 3. Every horizontally integrable concircularly recurrent Finsler manifold is $R^h$-recurrent with the same recurrence form (Theorem C). The whole work is formulated in a coordinate-free form.

  9. APLICACIÓN DE LA PERCEPTRÓN EN EL GRÁFICO DE CONTROL DE MEDICIONES INDIVIDUALES // IMPLEMENTATION OF THE PERCEPTRON IN THE CONTROL CHART FOR INDIVIDUAL

    José Antonio Vázquez-López

    2012-06-01

    Full Text Available In this article the Perceptron artificial neural network is applied as a classifier system of out of control points, in the field of contrlol chart for individual measurements. The use of geometric properties of the Perceptron as a training method is introduced, replacing in consequence to the known training methods. Some experiments with numerical databases contaminated with altered data in global average was performed, and the ability of the detection of \\out of control points" of the control chart with the implementation of the Perceptron trained by geometry was compared. The results reveal greater capacity in the Perceptron. This approach can be generalized to other types of control charts and patterns of natural and special variation, not considered in this research. // RESUMEN: En este artículo se aplica la red neuronal artificial Perceptrón como sistema clasificador de puntos fuera de control en el ámbito de la carta de control de mediciones individuales. Se introduce el uso de las propiedades geométricas de la Perceptrón como método de entrenamiento para sustituir, en consecuencia, a los métodos de entrenamiento conocidos. Se experimentó con bases de datos numéricas contaminadas con datos alterados en su media global y se comparó la capacidad de la detección de puntos fuera de control de la carta de control con la aplicación de la Perceptrón entrenada por geometría. Los resultados revelan mayor capacidad en la Perceptrón en diferentes porcentajes de contaminación. Esta propuesta puede ser generalizada a otros tipos de gráficos de control y a patrones de variación especial y natural no considerados en esta investigación.

  10. Recurrent Breast Cancer

    ... that can help you cope with distress include: Art therapy Dance or movement therapy Exercise Meditation Music ... mayoclinic.org/diseases-conditions/recurrent-breast-cancer/basics/definition/CON-20032432 . Mayo Clinic Footer Legal Conditions and ...

  11. Recurrences of strange attractors

    E J Ngamga; A Nandi; R Ramaswamy; M C Romano; M Thiel; J Kurths

    2008-06-01

    The transitions from or to strange nonchaotic attractors are investigated by recurrence plot-based methods. The techniques used here take into account the recurrence times and the fact that trajectories on strange nonchaotic attractors (SNAs) synchronize. The performance of these techniques is shown for the Heagy-Hammel transition to SNAs and for the fractalization transition to SNAs for which other usual nonlinear analysis tools are not successful.

  12. Multifocal recurrent periostitis

    Kozlowski, K.; Anderson, R.; Tink, A.

    1981-11-01

    Two case reports of recurrent multifocal periostitis in two girls aged 15 and 16 are added to the eight cases already reported in the literature. The disease is characterised clinically by recurrent mesomelic swelling of the extremities and radiologically by periosteal thickening and sclerosis of underlying bone. Hyperglobulinaemia is the most constant biochemical finding. The bone biopsy shows no typical features. The possibility of a viral etiology is discussed.

  13. Multilayer Controller for Outdoor Vehicle

    Reske-Nielsen, Anders; Mejnertsen, Asbjørn; Andersen, Nils Axel

    2006-01-01

    A full software and hardware solution has been designed, implemented and tested for control of a small agricultural automatic tractor. The objective was to realise a user-friendly, multi-layer controller architecture for an outdoor platform. The collaborative research work was done as a part...

  14. New developments in Ni/Ti multilayers

    Anderson, I.; Hoghoj, P. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    It is now 20 years since super-mirrors were first used as a neutron optical element. Since then the field of multilayer neutron-optics has matured with multilayers finding their way to application in many neutron scattering instruments. However, there is still room for progress in terms of multilayer quality, performance and application. Along with work on multilayers for neutron polarisation Ni/Ti super-mirrors have been optimised. The state-of-the-art Ni/Ti super-mirror performance and the results obtained in two neutron-optics applications of Ni/Ti multilayers are presented. (author).

  15. Recurrent Fever in Children

    Sofia Torreggiani

    2016-03-01

    Full Text Available Children presenting with recurrent fever may represent a diagnostic challenge. After excluding the most common etiologies, which include the consecutive occurrence of independent uncomplicated infections, a wide range of possible causes are considered. This article summarizes infectious and noninfectious causes of recurrent fever in pediatric patients. We highlight that, when investigating recurrent fever, it is important to consider age at onset, family history, duration of febrile episodes, length of interval between episodes, associated symptoms and response to treatment. Additionally, information regarding travel history and exposure to animals is helpful, especially with regard to infections. With the exclusion of repeated independent uncomplicated infections, many infective causes of recurrent fever are relatively rare in Western countries; therefore, clinicians should be attuned to suggestive case history data. It is important to rule out the possibility of an infectious process or a malignancy, in particular, if steroid therapy is being considered. After excluding an infectious or neoplastic etiology, immune-mediated and autoinflammatory diseases should be taken into consideration. Together with case history data, a careful physical exam during and between febrile episodes may give useful clues and guide laboratory investigations. However, despite a thorough evaluation, a recurrent fever may remain unexplained. A watchful follow-up is thus mandatory because new signs and symptoms may appear over time.

  16. Recurrent Fever in Children.

    Torreggiani, Sofia; Filocamo, Giovanni; Esposito, Susanna

    2016-03-25

    Children presenting with recurrent fever may represent a diagnostic challenge. After excluding the most common etiologies, which include the consecutive occurrence of independent uncomplicated infections, a wide range of possible causes are considered. This article summarizes infectious and noninfectious causes of recurrent fever in pediatric patients. We highlight that, when investigating recurrent fever, it is important to consider age at onset, family history, duration of febrile episodes, length of interval between episodes, associated symptoms and response to treatment. Additionally, information regarding travel history and exposure to animals is helpful, especially with regard to infections. With the exclusion of repeated independent uncomplicated infections, many infective causes of recurrent fever are relatively rare in Western countries; therefore, clinicians should be attuned to suggestive case history data. It is important to rule out the possibility of an infectious process or a malignancy, in particular, if steroid therapy is being considered. After excluding an infectious or neoplastic etiology, immune-mediated and autoinflammatory diseases should be taken into consideration. Together with case history data, a careful physical exam during and between febrile episodes may give useful clues and guide laboratory investigations. However, despite a thorough evaluation, a recurrent fever may remain unexplained. A watchful follow-up is thus mandatory because new signs and symptoms may appear over time.

  17. Recurrent wheezing in children

    Piazza, Michele; Piacentini, Giorgio

    2016-01-01

    Recurrent wheezing have a significant morbidity and it’s estimated that about one third of school-age children manifest the symptom during the first 5 years of life. Proper identification of children at risk of developing asthma at school age may predict long-term outcomes and improve treatment and preventive approach, but the possibility to identify these children at preschool age remains limited. For many years authors focused their studies to identify early children with recurrent wheezing at risk to develop asthma at school age. Different phenotypes have been proposed for a more precise characterization and a personalized plan of treatment. The main criticism concerns the inability to define stable phenotypes with the risk of overestimating or underestimating the characteristics of symptoms in these children. The aim of this review is to report the recent developments on the diagnosis and treatment of recurrent paediatric wheezing. PMID:26835404

  18. Recurrence of angular cheilitis.

    Ohman, S C; Jontell, M; Dahlen, G

    1988-08-01

    The incidence of recurrence of angular cheilitis following a successful antimicrobial treatment was studied in 48 patients. Clinical assessments including a microbial examination were carried out 8 months and 5 yr after termination of treatment. Eighty percent of the patients reported recurrence of their angular cheilitis on one or more occasions during the observation period. Patients with cutaneous disorders associated with dry skin or intraoral leukoplakia had an increased incidence of recrudescence. Neither the presence of denture stomatitis nor the type of microorganisms isolated from the original lesions of angular cheilitis, i.e. Candida albicans and/or Staphylococcus aureus, were associated with the number of recurrences. The present observations indicate that treatment of the majority of patients with angular cheilitis should be considered in a longer perspective than previously supposed, due to the short lasting therapeutic effects of the antimicrobial therapy.

  19. Recurrent Novae - A Review

    Mukai, Koji

    2014-01-01

    In recent years, recurrent nova eruptions are often observed very intensely in wide range of wavelengths from radio to optical to X-rays. Here I present selected highlights from recent multi-wavelength observations. The enigma of T Pyx is at the heart of this paper. While our current understanding of CV and symbiotic star evolution can explain why certain subset of recurrent novae have high accretion rate, that of T Pyx must be greatly elevated compared to the evolutionary mean. At the same time, we have extensive data to be able to estimate how the nova envelope was ejected in T Pyx, and it turns to be a rather complex tale. One suspects that envelope ejection in recurrent and classical novae in general is more complicated than the textbook descriptions. At the end of the review, I will speculate that these two may be connected.

  20. Recurrent parotitis in children

    Bhattarai M

    2006-01-01

    Full Text Available Recurrent parotitis is an uncommon condition in children. Its etiological factors have not been proved till date although causes due to genetic inheritance, local autoimmune manifestation, allergy, viral infection and immunodeficiency have been suggested. The exact management of this disorder is not yet standardized, but a conservative approach is preferred and all affected children should be screened for Sjogren′s syndrome and immune deficiency including human immunodeficiency virus. We report a 12 years female child who presented with 12 episodes of non-painful recurrent swellings of the bilateral parotid gland in the past 3 years.

  1. A Three-Threshold Learning Rule Approaches the Maximal Capacity of Recurrent Neural Networks.

    Alemi, Alireza; Baldassi, Carlo; Brunel, Nicolas; Zecchina, Riccardo

    2015-08-01

    Understanding the theoretical foundations of how memories are encoded and retrieved in neural populations is a central challenge in neuroscience. A popular theoretical scenario for modeling memory function is the attractor neural network scenario, whose prototype is the Hopfield model. The model simplicity and the locality of the synaptic update rules come at the cost of a poor storage capacity, compared with the capacity achieved with perceptron learning algorithms. Here, by transforming the perceptron learning rule, we present an online learning rule for a recurrent neural network that achieves near-maximal storage capacity without an explicit supervisory error signal, relying only upon locally accessible information. The fully-connected network consists of excitatory binary neurons with plastic recurrent connections and non-plastic inhibitory feedback stabilizing the network dynamics; the memory patterns to be memorized are presented online as strong afferent currents, producing a bimodal distribution for the neuron synaptic inputs. Synapses corresponding to active inputs are modified as a function of the value of the local fields with respect to three thresholds. Above the highest threshold, and below the lowest threshold, no plasticity occurs. In between these two thresholds, potentiation/depression occurs when the local field is above/below an intermediate threshold. We simulated and analyzed a network of binary neurons implementing this rule and measured its storage capacity for different sizes of the basins of attraction. The storage capacity obtained through numerical simulations is shown to be close to the value predicted by analytical calculations. We also measured the dependence of capacity on the strength of external inputs. Finally, we quantified the statistics of the resulting synaptic connectivity matrix, and found that both the fraction of zero weight synapses and the degree of symmetry of the weight matrix increase with the number of stored

  2. A Three-Threshold Learning Rule Approaches the Maximal Capacity of Recurrent Neural Networks.

    Alireza Alemi

    2015-08-01

    Full Text Available Understanding the theoretical foundations of how memories are encoded and retrieved in neural populations is a central challenge in neuroscience. A popular theoretical scenario for modeling memory function is the attractor neural network scenario, whose prototype is the Hopfield model. The model simplicity and the locality of the synaptic update rules come at the cost of a poor storage capacity, compared with the capacity achieved with perceptron learning algorithms. Here, by transforming the perceptron learning rule, we present an online learning rule for a recurrent neural network that achieves near-maximal storage capacity without an explicit supervisory error signal, relying only upon locally accessible information. The fully-connected network consists of excitatory binary neurons with plastic recurrent connections and non-plastic inhibitory feedback stabilizing the network dynamics; the memory patterns to be memorized are presented online as strong afferent currents, producing a bimodal distribution for the neuron synaptic inputs. Synapses corresponding to active inputs are modified as a function of the value of the local fields with respect to three thresholds. Above the highest threshold, and below the lowest threshold, no plasticity occurs. In between these two thresholds, potentiation/depression occurs when the local field is above/below an intermediate threshold. We simulated and analyzed a network of binary neurons implementing this rule and measured its storage capacity for different sizes of the basins of attraction. The storage capacity obtained through numerical simulations is shown to be close to the value predicted by analytical calculations. We also measured the dependence of capacity on the strength of external inputs. Finally, we quantified the statistics of the resulting synaptic connectivity matrix, and found that both the fraction of zero weight synapses and the degree of symmetry of the weight matrix increase with the

  3. Thermally induced delamination of multilayers

    Sørensen, Bent F.; Sarraute, S.; Jørgensen, O.

    1998-01-01

    Steady-state delamination of multilayered structures, caused by stresses arising during processing due to thermal expansion mismatch, is analyzed by a fracture mechanics model based on laminate theory. It is found that inserting just a few interlayers with intermediate thermal expansion coefficie...... coefficients may be an effective way of reducing the delamination energy release rate. Uneven layer thickness and increasing elastic mismatch are shown to raise the energy release rate. Experimental work confirms important trends of the model.......Steady-state delamination of multilayered structures, caused by stresses arising during processing due to thermal expansion mismatch, is analyzed by a fracture mechanics model based on laminate theory. It is found that inserting just a few interlayers with intermediate thermal expansion...

  4. XPS Studies of Magnetic Multilayers

    2001-01-01

    NiOx/Ni81Fe19 and Co/AlOx/Co magnetic multilayers were fabri cated by reactive RF/DC magnetron sputtering on clean glass substrates and oxidized Si (100) substrates, respectively. The exchange biasing field (Hex) between NiOx and Ni81Fe19 as a function of oxidation stat es was studied by X-ray photoelectron spectroscopy (XPS). The oxidatio n states and the oxide thickness of Al layers in magnetic multilayer f ilms consisting of Co/AlOx/Co were also analyzed. It is found that the Hex of NiOx/Ni81Fe19 films only depends on Ni2+ but not on Ni3+ or Ni . The bottom Co can be completely covered by depositing an Al layer th icker than 2.0nm. The oxide layer was Al2O3, and its thickness was 1.1 5nm.

  5. Anomalous magnetoresistance in Fibonacci multilayers.

    Machado, L. D.; Bezerra, C. G.; Correa, M. A.; Chesman, C.; Pearson, J. E.; Hoffmann, A. (Materials Science Division); (Universidade Federal do Rio Grande do Norte)

    2012-01-01

    We theoretically investigated magnetoresistance curves in quasiperiodic magnetic multilayers for two different growth directions, namely, [110] and [100]. We considered identical ferromagnetic layers separated by nonmagnetic layers with two different thicknesses chosen based on the Fibonacci sequence. Using parameters for Fe/Cr multilayers, four terms were included in our description of the magnetic energy: Zeeman, cubic anisotropy, bilinear coupling, and biquadratic coupling. The minimum energy was determined by the gradient method and the equilibrium magnetization directions found were used to calculate magnetoresistance curves. By choosing spacers with a thickness such that biquadratic coupling is stronger than bilinear coupling, unusual behaviors for the magnetoresistance were observed: (i) for the [110] case, there is a different behavior for structures based on even and odd Fibonacci generations, and, more interesting, (ii) for the [100] case, we found magnetic field ranges for which the magnetoresistance increases with magnetic field.

  6. Multilayer coating for high gradients

    Kubo, Takayuki

    2016-01-01

    The multilayer coating for high gradients is reviewed. Not only the S-I-S structure, but also the S-S bilayer structure are also treated. This is an incomplete manuscript of an invited article which will be submitted to a journal. I have uploaded this version in order to help the understanding on my talk at the TESLA Technology Collaboration meeting at Saclay, France.

  7. Ultra-thin multilayer capacitors.

    Renk, Timothy Jerome; Monson, Todd C.

    2009-06-01

    The fabrication of ultra-thin lanthanum-doped lead zirconium titanate (PLZT) multilayer ceramic capacitors (MLCCs) using a high-power pulsed ion beam was studied. The deposition experiments were conducted on the RHEPP-1 facility at Sandia National Laboratories. The goal of this work was to increase the energy density of ceramic capacitors through the formation of a multilayer device with excellent materials properties, dielectric constant, and standoff voltage. For successful device construction, there are a number of challenging requirements including achieving correct stoichiometric and crystallographic composition of the deposited PLZT, as well as the creation of a defect free homogenous film. This report details some success in satisfying these requirements, although 900 C temperatures were necessary for PLZT perovskite phase formation. These temperatures were applied to a previously deposited multi-layer film which was then post-annealed to this temperature. The film exhibited mechanical distress attributable to differences in the coefficient of thermal expansion (CTE) of the various layers. This caused significant defects in the deposited films that led to shorts across devices. A follow-on single layer deposition without post-anneal produced smooth layers with good interface behavior, but without the perovskite phase formation. These issues will need to be addressed in order for ion beam deposited MLCCs to become a viable technology. It is possible that future in-situ heating during deposition may address both the CTE issue, and result in lowered processing temperatures, which in turn could raise the probability of successful MLCC formation.

  8. Lung Cancer Indicators Recurrence

    This study describes prognostic factors for lung cancer spread and recurrence, as well as subsequent risk of death from the disease. The investigators observed that regardless of cancer stage, grade, or type of lung cancer, patients in the study were more

  9. Training Recurrent Networks

    Pedersen, Morten With

    1997-01-01

    Training recurrent networks is generally believed to be a difficult task. Excessive training times and lack of convergence to an acceptable solution are frequently reported. In this paper we seek to explain the reason for this from a numerical point of view and show how to avoid problems when...

  10. Recurrent Gliosarcoma in Pregnancy

    2014-01-01

    Gliosarcoma is a rare tumor of the central nervous system and it constitutes about 1 to 8% of all malignant gliomas. In this report we are presenting a recurrent gliosarcoma case during a pregnancy in a 30-year-old woman. This is the first report presenting gliosarcoma in the pregnancy.

  11. Recurrent gallstone ileus.

    Hayes, Nicolas; Saha, Sanjoy

    2012-11-01

    Mechanical small bowel obstructions caused by gallstones account for 1% to 3% of cases. In these patients, 80% to 90% of residual gallstones in these patients will pass through a remaining fistula without consequence. Recurrent gallstone ileus has been reported in 5% of patients. We report the case of a woman, aged 72 years, who presented with mechanical small bowel obstruction caused by gallstone ileus. After successful surgical therapy for gallstone ileus, the patient's symptoms recurred, and she was diagnosed with recurrent gallstone ileus requiring a repeat operation. While management of gallstone ileus can be achieved through a single-stage operation including enterolithotomy and cholecystectomy with repair of biliary-enteric fistula or by enterolithotomy alone, the literature supports enterolithotomy alone as the treatment of choice for gallstone ileus due to decreased mortality and morbidity. However, the latter approach does not obviate potential recurrence. We present this case of recurrent gallstone ileus to elucidate and review the pathogenesis, presentation, diagnosis, and consensus recommendations regarding management of this disorder.

  12. Chronic recurrent multifocal osteomyelitis

    Wedman, Jan; van Weissenbruch, Ranny

    2005-01-01

    We report what is, to our best knowledge, the first case of chronic recurrent multifocal osteomyelitis (CRMO) in which the frontal and sphenoid bones were involved. Characterized by a prolonged and fluctuating course of osteomyelitis at different sites, CRMO is self-limited, although sequelae can oc

  13. Acute Recurrent Pancreatitis

    Glen A Lehman

    2003-01-01

    Full Text Available History, physical examination, simple laboratory and radiological tests, and endoscopic retrograde cholangiopancreatography (ERCP are able to establish the cause of recurrent acute pancreatitis in 70% to 90% of patients. Dysfunction of the biliary and/or pancreatic sphincter, as identified by sphincter of Oddi manometry, accounts for the majority of the remaining cases. The diagnosis may be missed if the pancreatic sphincter is not evaluated. Pancreas divisum is a prevalent congenital abnormality that is usually innocuous but can lead to recurrent attacks of acute pancreatitis or abdominal pain. In select cases, endoscopic sphincterotomy of the minor papilla can provide relief of symptoms and prevent further attacks. A small proportion of patients with idiopathic pancreatitis have tiny stones in the common bile duct (microlithiasis. Crystals can be visualized during microscopic analysis of bile that is aspirated at the time of ERCP. Neoplasia is a rare cause of pancreatitis, and the diagnosis can usually be established by computerized tomography or ERCP. A wide variety of medications can also cause recurrent pancreatitis. ERCP, sphincter of Oddi manometry, and microscopy of aspirated bile should be undertaken in patients with recurrent pancreatitis in whom the diagnosis is not obvious.

  14. Recurrent Spatial Transformer Networks

    Sønderby, Søren Kaae; Sønderby, Casper Kaae; Maaløe, Lars;

    2015-01-01

    We integrate the recently proposed spatial transformer network (SPN) [Jaderberg et. al 2015] into a recurrent neural network (RNN) to form an RNN-SPN model. We use the RNN-SPN to classify digits in cluttered MNIST sequences. The proposed model achieves a single digit error of 1.5% compared to 2...

  15. Evaluación de las Redes Neuronales Artificiales Perceptron Multicapa y Fuzzy-Artmap en la Clasificación de Imágenes Satelitales

    Guillermo Antonio Toro Bayona

    2012-06-01

    Full Text Available Este documento reporta una comparación cuantitativa y cualitativa del desempeño de las redes neuronales artificiales Perceptron Multicapa y Fuzzy-Artmap para clasificación de coberturas del suelo a partir de imágenes satelitales multi-espectrales. Se describen parámetros y condiciones que ayudan a producir imágenes clasificadas con buena exactitud temática. Adicionalmente, se hace una comparación entre los dos modelos de redes neuronales que describen sus ventajas y desventajas.

  16. Multi-layer seal for electrochemical devices

    Chou, Yeong-Shyung [Richland, WA; Meinhardt, Kerry D [Kennewick, WA; Stevenson, Jeffry W [Richland, WA

    2010-09-14

    Multi-layer seals are provided that find advantageous use for reducing leakage of gases between adjacent components of electrochemical devices. Multi-layer seals of the invention include a gasket body defining first and second opposing surfaces and a compliant interlayer positioned adjacent each of the first and second surfaces. Also provided are methods for making and using the multi-layer seals, and electrochemical devices including said seals.

  17. Multi-layer seal for electrochemical devices

    Chou, Yeong-Shyung [Richland, WA; Meinhardt, Kerry D [Kennewick, WA; Stevenson, Jeffry W [Richland, WA

    2010-11-16

    Multi-layer seals are provided that find advantageous use for reducing leakage of gases between adjacent components of electrochemical devices. Multi-layer seals of the invention include a gasket body defining first and second opposing surfaces and a compliant interlayer positioned adjacent each of the first and second surfaces. Also provided are methods for making and using the multi-layer seals, and electrochemical devices including said seals.

  18. Multilayer Analysis and Visualization of Networks

    De Domenico, Manlio; Arenas, Alex

    2014-01-01

    Multilayer relationships among and information about biological entities must be accompanied by the means to analyze, visualize, and obtain insights from such data. We report a methodology and a collection of algorithms for the analysis of multilayer networks in our new open-source software (muxViz). We demonstrate the ability of muxViz to analyze and interactively visualize multilayer data using empirical genetic and neuronal networks.

  19. Imaging of recurrent prostate cancer

    Futterer, J.J.

    2012-01-01

    Approximately 30\\% of patients who underwent radical prostatectomy or radiation therapy will develop biochemical recurrent disease. Biochemical recurrent disease is defined as an increase in the serum value of prostate-specific antigen (PSA) after reaching the nadir. Prostate recurrence can present

  20. Immunomodulators to treat recurrent miscarriage

    Prins, Jelmer R.; Kieffer, Tom E. C.; Scherjon, Sicco A.

    2014-01-01

    Recurrent miscarriage is a reproductive disorder affecting many couples. Although several factors are associated with recurrent miscarriage, in more than 50% of the cases the cause is unknown. Maladaptation of the maternal immune system is associated with recurrent miscarriage and could explain part

  1. Spatial recurrence plots.

    Vasconcelos, D B; Lopes, S R; Viana, R L; Kurths, J

    2006-05-01

    We propose an extension of the recurrence plot concept to perform quantitative analyzes of roughness and disorder of spatial patterns at a fixed time. We introduce spatial recurrence plots (SRPs) as a graphical representation of the pointwise correlation matrix, in terms of a two-dimensional spatial return plot. This technique is applied to the study of complex patterns generated by coupled map lattices, which are characterized by measures of complexity based on SRPs. We show that the complexity measures we propose for SRPs provide a systematic way of investigating the distribution of spatially coherent structures, such as synchronization domains, in lattice profiles. This approach has potential for many more applications, e.g., in surface roughness analyzes.

  2. Modularity promotes epidemic recurrence

    Jesan, T; Sinha, Sitabhra

    2016-01-01

    The long-term evolution of epidemic processes depends crucially on the structure of contact networks. As empirical evidence indicates that human populations exhibit strong community organization, we investigate here how such mesoscopic configurations affect the likelihood of epidemic recurrence. Through numerical simulations on real social networks and theoretical arguments using spectral methods, we demonstrate that highly contagious diseases that would have otherwise died out rapidly can persist indefinitely for an optimal range of modularity in contact networks.

  3. Recurrent Gallstone Ileus

    Hayes, Nicolas; Saha, Sanjoy

    2012-01-01

    Mechanical small bowel obstructions caused by gallstones account for 1% to 3% of cases. In these patients, 80% to 90% of residual gallstones in these patients will pass through a remaining fistula without consequence. Recurrent gallstone ileus has been reported in 5% of patients. We report the case of a woman, aged 72 years, who presented with mechanical small bowel obstruction caused by gallstone ileus. After successful surgical therapy for gallstone ileus, the patient's symptoms recurred, a...

  4. Multilayer Graphene for Waveguide Terahertz Modulator

    Khromova, I.; Andryieuski, Andrei; Lavrinenko, Andrei

    2014-01-01

    We study terahertz to infrared electromagnetic properties of multilayer graphene/dielectric artificial medium and present a novel concept of terahertz modulation at midinfrared wavelengths. This approach allows the realization of high-speed electrically controllable terahertz modulators based...... on hollow waveguide sections filled with multilayer graphene....

  5. Multi-Layer E-Textile Circuits

    Dunne, Lucy E.; Bibeau, Kaila; Mulligan, Lucie; Frith, Ashton; Simon, Cory

    2012-01-01

    Stitched e-textile circuits facilitate wearable, flexible, comfortable wearable technology. However, while stitched methods of e-textile circuits are common, multi-layer circuit creation remains a challenge. Here, we present methods of stitched multi-layer circuit creation using accessible tools and techniques.

  6. Superhard nano-multilayers and nanocomposite coatings

    BAI Xiaoming; ZHENG Weitao; AN Tao

    2005-01-01

    This paper reviews the recent development of nano-multilayers and nanocomposite coatings. The hardening mechanisms and design of hard coating are discussed in details. Recent research on Ti/TiN and nitride/nitride multilayer, Ti-Si-N and Ti-Al-Si-N nanocomposite coatings is described, and the perspectives of the related research are proposed.

  7. Diffusion phenomena in chemically stabilized multilayer structures

    Bruijn, Saskia

    2011-01-01

    Multilayered thin film structures are widely applied as reflective coatings for optical elements in the extreme ultraviolet wavelength regime. In this thesis we investigate the structural and chemical changes that occur in Mo/Si based multilayers as a result of radiation induced thermal loads and ot

  8. Multilayer Nanoporous Graphene Membranes for Water Desalination.

    Cohen-Tanugi, David; Lin, Li-Chiang; Grossman, Jeffrey C

    2016-02-10

    While single-layer nanoporous graphene (NPG) has shown promise as a reverse osmosis (RO) desalination membrane, multilayer graphene membranes can be synthesized more economically than the single-layer material. In this work, we build upon the knowledge gained to date toward single-layer graphene to explore how multilayer NPG might serve as a RO membrane in water desalination using classical molecular dynamic simulations. We show that, while multilayer NPG exhibits similarly promising desalination properties to single-layer membranes, their separation performance can be designed by manipulating various configurational variables in the multilayer case. This work establishes an atomic-level understanding of the effects of additional NPG layers, layer separation, and pore alignment on desalination performance, providing useful guidelines for the design of multilayer NPG membranes.

  9. Figure correction of multilayer coated optics

    Chapman; Henry N. , Taylor; John S.

    2010-02-16

    A process is provided for producing near-perfect optical surfaces, for EUV and soft-x-ray optics. The method involves polishing or otherwise figuring the multilayer coating that has been deposited on an optical substrate, in order to correct for errors in the figure of the substrate and coating. A method such as ion-beam milling is used to remove material from the multilayer coating by an amount that varies in a specified way across the substrate. The phase of the EUV light that is reflected from the multilayer will be affected by the amount of multilayer material removed, but this effect will be reduced by a factor of 1-n as compared with height variations of the substrate, where n is the average refractive index of the multilayer.

  10. Polyelectrolyte Multilayers: Towards Single Cell Studies

    Dmitry Volodkin

    2014-05-01

    Full Text Available Single cell analysis (SCA is nowadays recognized as one of the key tools for diagnostics and fundamental cell biology studies. The Layer-by-layer (LbL polyelectrolyte assembly is a rather new but powerful technique to produce multilayers. It allows to model the extracellular matrix in terms of its chemical and physical properties. Utilization of the multilayers for SCA may open new avenues in SCA because of the triple role of the multilayer film: (i high capacity for various biomolecules; (ii natural mimics of signal molecule diffusion to a cell and (iii cell patterning opportunities. Besides, light-triggered release from multilayer films offers a way to deliver biomolecules with high spatio-temporal resolution. Here we review recent works showing strong potential to use multilayers for SCA and address accordingly the following issues: biomolecule loading, cell patterning, and light-triggered release.

  11. Multiscale recurrence quantification analysis of order recurrence plots

    Xu, Mengjia; Shang, Pengjian; Lin, Aijing

    2017-03-01

    In this paper, we propose a new method of multiscale recurrence quantification analysis (MSRQA) to analyze the structure of order recurrence plots. The MSRQA is based on order patterns over a range of time scales. Compared with conventional recurrence quantification analysis (RQA), the MSRQA can show richer and more recognizable information on the local characteristics of diverse systems which successfully describes their recurrence properties. Both synthetic series and stock market indexes exhibit their properties of recurrence at large time scales that quite differ from those at a single time scale. Some systems present more accurate recurrence patterns under large time scales. It demonstrates that the new approach is effective for distinguishing three similar stock market systems and showing some inherent differences.

  12. Recurrent Miller Fisher syndrome.

    Madhavan, S; Geetha; Bhargavan, P V

    2004-07-01

    Miller Fisher syndrome (MFS) is a variant of Guillan Barre syndrome characterized by the triad of ophthalmoplegia, ataxia and areflexia. Recurrences are exceptional with Miller Fisher syndrome. We are reporting a case with two episodes of MFS within two years. Initially he presented with partial ophthalmoplegia, ataxia. Second episode was characterized by full-blown presentation characterized by ataxia, areflexia and ophthalmoplegia. CSF analysis was typical during both episodes. Nerve conduction velocity study was fairly within normal limits. MRI of brain was within normal limits. He responded to symptomatic measures initially, then to steroids in the second episode. We are reporting the case due to its rarity.

  13. Recurrent Pregnancy Loss

    Véronique Piroux

    1997-01-01

    Full Text Available Antiphospholipid antibodies (APA are associated with thrombosis, thrombocytopenia and fetal loss but they occur in a variety of diseases. Despite many efforts, a correlation between the specificity of particular subgroups of APA and particular clinical situations remains to be established. The antigens at the origin of APA remain to be identified. We discuss here the possible links between cell apoptosis or necrosis, leading to plasma membrane alterations, and the occurrence of APA in response to sustained stimulation. The pathogenic potential of APA is also considered with respect to recurrent pregnancy loss.

  14. Recurrence Relations and Determinants

    Janjic, Milan

    2011-01-01

    We examine relationships between two minors of order n of some matrices of n rows and n+r columns. This is done through a class of determinants, here called $n$-determinants, the investigation of which is our objective. We prove that 1-determinants are the upper Hessenberg determinants. In particular, we state several 1-determinants each of which equals a Fibonacci number. We also derive relationships among terms of sequences defined by the same recurrence equation independently of the initial conditions. A result generalizing the formula for the product of two determinants is obtained. Finally, we prove that the Schur functions may be expressed as $n$-determinants.

  15. Recurrent correlation associative memories.

    Chiueh, T D; Goodman, R M

    1991-01-01

    A model for a class of high-capacity associative memories is presented. Since they are based on two-layer recurrent neural networks and their operations depend on the correlation measure, these associative memories are called recurrent correlation associative memories (RCAMs). The RCAMs are shown to be asymptotically stable in both synchronous and asynchronous (sequential) update modes as long as their weighting functions are continuous and monotone nondecreasing. In particular, a high-capacity RCAM named the exponential correlation associative memory (ECAM) is proposed. The asymptotic storage capacity of the ECAM scales exponentially with the length of memory patterns, and it meets the ultimate upper bound for the capacity of associative memories. The asymptotic storage capacity of the ECAM with limited dynamic range in its exponentiation nodes is found to be proportional to that dynamic range. Design and fabrication of a 3-mm CMOS ECAM chip is reported. The prototype chip can store 32 24-bit memory patterns, and its speed is higher than one associative recall operation every 3 mus. An application of the ECAM chip to vector quantization is also described.

  16. Terbium-based extreme ultraviolet multilayers.

    Windt, David L; Seely, John F; Kjornrattanawanich, Benjawan; Uspenskii, Yu A

    2005-12-01

    We have fabricated periodic multilayers that comprise either Si/Tb or SiC/Tb bilayers, designed to operate as narrowband reflective coatings near 60 nm wavelength in the extreme ultraviolet (EUV). We find peak reflectance values in excess of 20% near normal incidence. The spectral bandpass of the best Si/Tb multilayer was measured to be 6.5 nm full width at half-maximum (FWHM), while SiC/Tb multilayers have a more broad response, of order 9.4 nm FWHM. Transmission electron microscopy analysis of Si/Tb multilayers reveals polycrystalline Tb layers, amorphous Si layers, and relatively large asymmetric amorphous interlayers. Thermal annealing experiments indicate excellent stability to 100 degrees C (1 h) for Si/Tb. These new multilayer coatings have the potential for use in normal incidence instrumentation in a region of the EUV where efficient narrowband multilayers have not been available until now. In particular, reflective Si/Tb multilayers can be used for solar physics applications where the coatings can be tuned to important emission lines such as O V near 63.0 nm and Mg X near 61.0 nm.

  17. Thermal stability of nanoscale metallic multilayers

    Ramos, A.S., E-mail: sofia.ramos@dem.uc.pt [CEMUC, Departamento de Engenharia Mecânica, Universidade de Coimbra, 3030-788 Coimbra (Portugal); Cavaleiro, A.J.; Vieira, M.T. [CEMUC, Departamento de Engenharia Mecânica, Universidade de Coimbra, 3030-788 Coimbra (Portugal); Morgiel, J. [Institute of Metallurgy and Materials Science, Polish Academy of Sciences, Reymonta 25, 30-059 Cracow (Poland); Safran, G. [Research Institute for Technical Physics and Materials Science, Hungarian Academy of Sciences, H-1121 Budapest (Hungary)

    2014-11-28

    Metallic nanolayered thin films/foils, in particular Ni/Al multilayers, have been used to promote joining. The objective of this work is to evaluate the thermal stability of nanoscale metallic multilayers with potential for joining applications. Multilayers thin films with low (Ti/Al and Ni/Ti), medium (Ni/Al) and high (Pd/Al) enthalpies of exothermic reaction were prepared by dual cathode magnetron sputtering. Their thermal stability was studied by: i) differential scanning calorimetry combined with X-ray diffraction (XRD), ii) in-situ XRD using cobalt radiation, and iii) in-situ transmission electron microscopy. It was possible to detect traces of intermetallic or amorphous phases in the as-deposited short period (bilayer thickness) multilayers, except for the Ti/Al films where no reaction products that might be formed during deposition were identified. For short periods (below 20 nm) the equilibrium phases are directly achieved upon annealing, whereas for higher periods intermediate trialuminide phases are present for Ti/Al and Ni/Al multilayers. The formation of B2-NiTi from Ni/Ti multilayers occurs without the formation of intermediate phases. On the contrary, for the Pd–Al system the formation of intermediate phases was never avoided. The viability of nanoscale multilayers as “filler” materials for joining macro or microparts/devices was demonstrated. - Highlights: • Me1 and Me2 (Me—metal) alternated nanolayers deposited by magnetron sputtering • Reactive Me1/Me2 multilayer thin films with nanometric modulation period • By heat treatment the films always evolve to the equilibrium intermetallic phase. • For some Me1–Me2 systems and periods, the formation of intermediate phases occurs. • Me1/Me2 multilayer thin films can be used as filler materials to enhance joining.

  18. The physics of multilayer networks

    De Domenico, Manlio; Porter, Mason A; Arenas, Alex

    2016-01-01

    The study of networks plays a crucial role in investigating the structure, dynamics, and function of a wide variety of complex systems in myriad disciplines. Despite the success of traditional network analysis, standard networks provide a limited representation of these systems, which often includes different types of relationships (i.e., "multiplexity") among their constituent components and/or multiple interacting subsystems. Such structural complexity has a significant effect on both dynamics and function. Throwing away or aggregating available structural information can generate misleading results and provide a major obstacle towards attempts to understand the system under analysis. The recent "multilayer' approach for modeling networked systems explicitly allows the incorporation of multiplexity and other features of realistic networked systems. On one hand, it allows one to couple different structural relationships by encoding them in a convenient mathematical object. On the other hand, it also allows o...

  19. Centrality in Interconnected Multilayer Networks

    De Domenico, Manlio; Omodei, Elisa; Gómez, Sergio; Arenas, Alex

    2013-01-01

    Real-world complex systems exhibit multiple levels of relationships. In many cases, they require to be modeled by interconnected multilayer networks, characterizing interactions on several levels simultaneously. It is of crucial importance in many fields, from economics to biology, from urban planning to social sciences, to identify the most (or the less) influent nodes in a network. However, defining the centrality of actors in an interconnected structure is not trivial. In this paper, we capitalize on the tensorial formalism, recently proposed to characterize and investigate this kind of complex topologies, to show how several centrality measures -- well-known in the case of standard ("monoplex") networks -- can be extended naturally to the realm of interconnected multiplexes. We consider diagnostics widely used in different fields, e.g., computer science, biology, communication and social sciences, to cite only some of them. We show, both theoretically and numerically, that using the weighted monoplex obta...

  20. Magnetic quantization in multilayer graphenes

    Lin, Chiun-Yan; Ou, Yih-Jon; Chiu, Yu-Huang; Lin, Ming-Fa

    2015-01-01

    Essential properties of multilayer graphenes are diversified by the number of layers and the stacking configurations. For an $N$-layer system, Landau levels are divided into $N$ groups, with each identified by a dominant sublattice associated with the stacking configuration. We focus on the main characteristics of Landau levels, including the degeneracy, wave functions, quantum numbers, onset energies, field-dependent energy spectra, semiconductor-metal transitions, and crossing patterns, which are reflected in the magneto-optical spectroscopy, scanning tunneling spectroscopy, and quantum transport experiments. The Landau levels in AA-stacked graphene are responsible for multiple Dirac cones, while in AB-stacked graphene the Dirac properties depend on the number of graphene layers, and in ABC-stacked graphene the low-lying levels are related to surface states. The Landau-level mixing leads to anticrossings patterns in energy spectra, which are seen for intergroup Landau levels in AB-stacked graphene, while in...

  1. Epidemiology of recurrent venous thrombosis

    D.D. Ribeiro

    2012-01-01

    Full Text Available Venous thrombosis, including deep vein thrombosis and pulmonary embolism, is a common disease that frequently recurs. Recurrence can be prevented by anticoagulants, but this comes at the risk of bleeding. Therefore, assessment of the risk of recurrence is important to balance the risks and benefits of anticoagulant treatment. This review briefly outlines what is currently known about the epidemiology of recurrent venous thrombosis, and focuses in more detail on potential new risk factors for venous recurrence. The general implications of these findings in patient management are discussed.

  2. Psychosocial adjustment to recurrent cancer.

    Mahon, S M; Cella, D F; Donovan, M I

    1990-01-01

    This descriptive study of the perceptions and needs of people with recurrent malignancies asks three questions: How do patients describe the meaning of a recurrence of cancer? Do individuals perceive the diagnosis of recurrence and the initial diagnosis of cancer differently? What are the key psychosocial problems associated with recurrent cancer? The theoretical framework was based on Lazarus and Folkman's theory of stress, appraisal, and coping. Subjects completed the Impact of Event Scale (IES), the Psychosocial Adjustment to Illness Scale--Self-Report (PAIS), and a semistructured qualitative interview. The interview elicited perceptions of the event of recurrence and differences between the diagnosis of recurrence and the initial diagnosis. The convenience sample included 40 patients diagnosed with recurrent cancer within the last 30 days. Many subjects (78%) reported that the recurrence was more upsetting than the initial diagnosis. Scores on both the IES and the PAIS were high when compared to normative samples of patients with cancer suggesting that this sample of patients experienced a lot of psychological distress as well as problems at home, work, and in their social lives. These concerns often were unknown to caregivers. Although more research is needed, the authors propose that, with more accurate assessment, more effective intervention could be implemented and the quality of life improved for patients with recurrent cancer.

  3. Recurrent pregnancy loss

    Egerup, P; Kolte, A M; Larsen, E C;

    2016-01-01

    immunoglobulin (IvIg) conducted from 1991 to 2014. No other treatments were given. Patients with documented explained pregnancy losses (ectopic pregnancies and aneuploid miscarriages) were excluded. PARTICIPANTS/MATERIALS, SETTING, METHODS: Of the 168 patients included in the trials, 127 had secondary RPL......STUDY QUESTION: Is there a different prognostic impact for consecutive and non-consecutive early pregnancy losses in women with secondary recurrent pregnancy loss (RPL)? SUMMARY ANSWER: Only consecutive early pregnancy losses after the last birth have a statistically significant negative prognostic...... impact in women with secondary RPL. WHAT IS KNOWN ALREADY: The risk of a new pregnancy loss increases with the number of previous pregnancy losses in patients with RPL. Second trimester losses seem to exhibit a stronger negative impact than early losses. It is unknown whether the sequence of pregnancy...

  4. Recurrent vulvovaginal candidiasis.

    Sobel, Jack D

    2016-01-01

    Recurrent vulvovaginal candidiasis (RVVC) is a common cause of significant morbidity in women in all strata of society affecting millions of women worldwide. Previously, RVVC occurrence was limited by onset of menopause but the widespread use of hormone replacement therapy has extended the at-risk period. Candida albicans remains the dominant species responsible for RVVC, however optimal management of RVVC requires species determination and effective treatment measures are best if species-specific. Considerable progress has been made in understanding risk factors that determine susceptibility to RVVC, particularly genetic factors, as well as new insights into normal vaginal defense immune mechanisms and their aberrations in RVVC. While effective control of RVVC is achievable with the use of fluconazole maintenance suppressive therapy, cure of RVVC remains elusive especially in this era of fluconazole drug resistance. Vaccine development remains a critical challenge and need.

  5. Langmuir Blodgett multilayers and related nanostructures

    S S Major; S S Talwar; R S Srinivasa

    2006-07-01

    Langmuir Blodgett (LB) process is an important route to the development of organized molecular layered structures of a variety of organic molecules with suitably designed architecture and functionality. LB multilayers have also been used as templates and precursors to develop nano-structured thin films. In this article, studies on the molecular packing and three-dimensional structure of prototypic cadmium arachidate (CdA), zinc arachidate (ZnA) and mixed CdA–ZnA LB multilayers are presented. The formation of semiconducting nano-clusters of CdS, ZnS and CdZn1−S alloys within the organic multilayer matrix, using arachidate LB multilayers as precursors is also discussed.

  6. Reverse engineering of multi-layer films

    Effendi Widjaja; Marc Garland

    2011-01-01

    This contribution introduces the combined application of Raman microscopy and band-target entropy minimization (BTEM) in order to successfully reverse-engineer a multi-layer packaging material. Three layers are identified, namely, polyethylene, a paper and talc layer (with two distinct cellulose forms), and a poly-styrene co-polymer composite containing anatase and calcite. This rapid and non-destructive approach provides a unique opportunity for the assessment of multi-layer composites, incl...

  7. [Hygienic evaluation of multilayer carbon nanotubes].

    Haliullin, T O; Zalyalov, R R; Shvedova, A A; Tkachov, A G

    2015-01-01

    The authors demonstrate that traditional methods evaluating work conditions on contemporary innovative enterprises producing nanomaterials assess these conditions as harmless and safe. At the same time, special investigation methods enable to reveal new hazards for workers' health: the study results prove that workers engaged into multilayer carbon nanotubes production are exposed to multilayer carbon nanotubes aerosols in concentrations exceeding internationally acceptable levels of 1 μg/ml (NIOSH)--that can harm the workers' health.

  8. Ordered organic-organic multilayer growth

    Forrest, Stephen R; Lunt, Richard R

    2015-01-13

    An ordered multilayer crystalline organic thin film structure is formed by depositing at least two layers of thin film crystalline organic materials successively wherein the at least two thin film layers are selected to have their surface energies within .+-.50% of each other, and preferably within .+-.15% of each other, whereby every thin film layer within the multilayer crystalline organic thin film structure exhibit a quasi-epitaxial relationship with the adjacent crystalline organic thin film.

  9. Magnetic Surfaces, Thin Films, and Multilayers

    1992-01-01

    PERPENDICULAR MAGNETIC ANISOTROPY AND MAGNETO-OPTICS * PERPENDICULAR MAGNETIC ANISOTROPY OF Pd/Co AND RELATED MULTILAYERS 441 S...THE PERPENDICULAR MAGNETIC ANISOTROPY AND STRUCTURE OF SPUTTERED Ag/Co, Pd/Co, AND AgPd/Co MULTILAYERED FILMS 473 Akira Yamaguchi, We-Hyo Soe, Ryoichi...the magnetic phase transi- tion and magnetic anisotropy, has attracted considerable interest. Theoretical predictions on perpendicular magnetic anisotropy

  10. Atomic mechanisms of interdiffusion in metallic multilayers

    Zotov, N. [Centre of Advanced European Studies and Research (Caesar), Ludwig-Erhard-Allee 2, 53175 Bonn (Germany)], E-mail: zotov@caesar.de; Ludwig, A. [Centre of Advanced European Studies and Research (Caesar), Ludwig-Erhard-Allee 2, 53175 Bonn (Germany); Institute of Materials, Faculty of Mechanical Engineering, Ruhr-Universitaet Bochum, 44780 Bochum (Germany)

    2007-09-15

    Interdiffusion data (activation energies and pre-exponential factors) for different metal-metal multilayers (MLs) published in the literature and our own results on Fe/Pt MLs are reviewed. The analysis of the available data suggests that vacancy diffusion is the main interdiffusion mechanism in metallic MLs. An empirical relation between the activation energy for interdiffusion in metallic multilayers, the average activation energy of vacancy diffusion and the activation energy for in-plane grain-boundary diffusion is proposed.

  11. Recurrent dermatitis from jellyfish envenomation.

    Menahem, S; Shvartzman, P.

    1994-01-01

    Jellyfish envenomation can cause an immediate local skin reaction, which is usually a painful linear vesiculourticarial eruption. Persistent, delayed, or recurrent dermatitis is less common. Because jellyfish sting reactions and their management are unfamiliar to family physicians, we describe a case of recurrent local dermatitis after jellyfish envenomation and suggest appropriate treatment.

  12. Recurrence plots and recurrence quantification analysis of human motion data

    Josiński, Henryk; Michalczuk, Agnieszka; Świtoński, Adam; Szczesna, Agnieszka; Wojciechowski, Konrad

    2016-06-01

    The authors present exemplary application of recurrence plots, cross recurrence plots and recurrence quantification analysis for the purpose of exploration of experimental time series describing selected aspects of human motion. Time series were extracted from treadmill gait sequences which were recorded in the Human Motion Laboratory (HML) of the Polish-Japanese Academy of Information Technology in Bytom, Poland by means of the Vicon system. Analysis was focused on the time series representing movements of hip, knee, ankle and wrist joints in the sagittal plane.

  13. INTERFACE REACTION IN MAGNETIC MULTILAYERS

    G.H. Yu; M.H. Li; F.W. Zhu; X.F. Cui; J.L. Jin

    2001-01-01

    Ta/NiO/NiFe/Ta multilayers were prepared by rf reactive and dc magnetron sputter-ing. The exchange coupling field (Hex) between NiO and NiFe reached 120Oe. Thecomposition and chemical states at the interface region of NiO/NiFe were studied us-ing the x-ray photoelectron spectroscopy (XPS) and peak decomposition technique. Theresults show that there are two thermodynamically favorable reactions at NiO/NiFeinterface: NiO+Fe = Ni+FeO and 3NiO+2Fe 3Ni+Fe2 O3. The thickness of thechemical reaction as estimated by angle-resolved XPS was about 1-1.5nm. These in-terrace reaction products are magnetic defects, and we believe that the Hex and thecoereivity (He) of NiO/NiFe ave affected by these defects. Moreover, the results alsoshow that there is an "intermixing layer" at the Ta/NiO (and NiO/Ta) interface dueto a thermodynamically favorable reaction: 2Ta+5NiO=5Ni+Ta2O5. This interfacereaction has an effect on the exchange coupling as well. The thickness of the "inter-mixing layer" as estimated by XPS depth-profiles was about 8-10nm.

  14. Moisture in multilayer ceramic capacitors

    Donahoe, Daniel Noel

    When both precious metal electrode and base metal electrode (BME) capacitors were subjected to autoclave (120°C/100% RH) testing, it was found that the precious metal capacitors aged according to a well known aging mechanism (less than 3% from their starting values), but the BME capacitors degraded to below the -30% criterion at 500 hours of exposure. The reasons for this new failure mechanism are complex, and there were two theories that were hypothesized. The first was that there could be oxidation or corrosion of the nickel plates. The other hypothesis was that the loss of capacitance was due to molecular changes in the barium titanate. This thesis presents the evaluation of these hypotheses and the physics of the degradation mechanism. It is concluded by proof by elimination that there are molecular changes in the barium titanate. Furthermore, the continuous reduction in capacitor size makes the newer base metal electrode capacitors more vulnerable to moisture degradation than the older generation precious metal capacitors. In addition, standard humidity life testing, such as JESD-22 THB and HAST, will likely not uncover this problem. Therefore, poor reliability due to degradation of base metal electrode multilayer ceramic capacitors may catch manufacturers and consumers by surprise.

  15. Multilayer Piezoelectric Stack Actuator Characterization

    Sherrit, Stewart; Jones, Christopher M.; Aldrich, Jack B.; Blodget, Chad; Bao, Xioaqi; Badescu, Mircea; Bar-Cohen, Yoseph

    2008-01-01

    Future NASA missions are increasingly seeking to use actuators for precision positioning to accuracies of the order of fractions of a nanometer. For this purpose, multilayer piezoelectric stacks are being considered as actuators for driving these precision mechanisms. In this study, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and extreme temperatures and voltages. AC signal testing included impedance, capacitance and dielectric loss factor of each actuator as a function of the small-signal driving sinusoidal frequency, and the ambient temperature. DC signal testing includes leakage current and displacement as a function of the applied DC voltage. The applied DC voltage was increased to over eight times the manufacturers' specifications to investigate the correlation between leakage current and breakdown voltage. Resonance characterization as a function of temperature was done over a temperature range of -180C to +200C which generally exceeded the manufacturers' specifications. In order to study the lifetime performance of these stacks, five actuators from one manufacturer were driven by a 60volt, 2 kHz sine-wave for ten billion cycles. The tests were performed using a Lab-View controlled automated data acquisition system that monitored the waveform of the stack electrical current and voltage. The measurements included the displacement, impedance, capacitance and leakage current and the analysis of the experimental results will be presented.

  16. Multilayer heterostructures and their manufacture

    Hammond, Scott R; Reese, Matthew; Rupert, Benjamin; Miedaner, Alexander; Curtis, Clavin; Olson, Dana; Ginley, David S

    2015-11-04

    A method of synthesizing multilayer heterostructures including an inorganic oxide layer residing on a solid substrate is described. Exemplary embodiments include producing an inorganic oxide layer on a solid substrate by a liquid coating process under relatively mild conditions. The relatively mild conditions include temperatures below 225.degree. C. and pressures above 9.4 mb. In an exemplary embodiment, a solution of diethyl aluminum ethoxide in anhydrous diglyme is applied to a flexible solid substrate by slot-die coating at ambient atmospheric pressure, and the diglyme removed by evaporation. An AlO.sub.x layer is formed by subjecting material remaining on the solid substrate to a relatively mild oven temperature of approximately 150.degree. C. The resulting AlO.sub.x layer exhibits relatively high light transmittance and relatively low vapor transmission rates for water. An exemplary embodiment of a flexible solid substrate is polyethylene napthalate (PEN). The PEN is not substantially adversely affected by exposure to 150.degree. C

  17. Recurrent neural collective classification.

    Monner, Derek D; Reggia, James A

    2013-12-01

    With the recent surge in availability of data sets containing not only individual attributes but also relationships, classification techniques that take advantage of predictive relationship information have gained in popularity. The most popular existing collective classification techniques have a number of limitations-some of them generate arbitrary and potentially lossy summaries of the relationship data, whereas others ignore directionality and strength of relationships. Popular existing techniques make use of only direct neighbor relationships when classifying a given entity, ignoring potentially useful information contained in expanded neighborhoods of radius greater than one. We present a new technique that we call recurrent neural collective classification (RNCC), which avoids arbitrary summarization, uses information about relationship directionality and strength, and through recursive encoding, learns to leverage larger relational neighborhoods around each entity. Experiments with synthetic data sets show that RNCC can make effective use of relationship data for both direct and expanded neighborhoods. Further experiments demonstrate that our technique outperforms previously published results of several collective classification methods on a number of real-world data sets.

  18. [Chronic recurrent multifocal osteomyelitis].

    Schilling, F; Eckardt, A; Kessler, S

    2000-01-01

    The aim of this paper is to give a detailed description of the so-called "chronic recurrent multifocal osteomyelitis" (CRMO). The clinical, radiological and histopathological results of an analysis of 29 cases (15 children/adolescents and 14 adults) are presented and correlated to current data from the literature. We could delinate the following points: 1. CRMO is a systemic aseptic inflammation of the bone marrow (Osteitis), it can occur polytopically and association with pustulous dermatologic symptoms is possible. 2. It is not a rare disease 3. Osteomyelitis is probably "reactive" and a plasma-cell sclerotic process with ist own characteristic histologic three-phase course. 4. We could observe 5 specific types of localization which can be documented by X-ray or bone scan. 5. Accompanying arthritis os often present, especially "sympathetic coxitis". 6. The use of drugs in treatment of CRMO (i.e. azithromycin, calcitonin, and bisphosphonates) is discussed. In conclusion we want to point out, that 1. 99mTC bone scan should always be performed when there is suspicion for CRMO to reveal the pattern of affection, 2. the rheumatologist and dermatologist should be contacted, 3. operation is normally not necessary for treatment of the mostly self-limitin disease, and 4. the term "SAPHO syndrome" should be avoided, further differentiation of the diagnosis is necessary.

  19. Chronic recurrent multifocal osteomyelitis.

    Roderick, Marion R; Ramanan, Athimalaipet V

    2013-01-01

    Chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory bone disease occurring primarily in children and adolescents. Episodes of systemic inflammation occur due to immune dysregulation without autoantibodies, pathogens or antigen-specific T cells. CRMO is characterised by the insidious onset of pain with swelling and tenderness over the affected bones. Clavicular involvement was the classical description; however, the metaphyses and epiphyses of long bones are frequently affected. Lesions may occur in any bone, including vertebrae. Characteristic imaging includes bone oedema, lytic areas, periosteal reaction and soft tissue reaction. Biopsies from affected areas display polymorphonuclear leucocytes with osteoclasts and necrosis in the early stages. Subsequently, lymphocytes and plasma cells predominate followed by fibrosis and signs of reactive new bone forming around the inflammation. Diagnosis is facilitated by the use of STIR MRI scanning, potentially obviating the need for biopsy and unnecessary long-term antibiotics due to incorrect diagnosis. Treatment options include non-steroidal anti-inflammatory drugs and bisphosphonates. Biologics have been tried in resistant cases with promising initial results. Gene identification has not proved easy although research in this area continues. Early descriptions of the disease suggested a benign course; however, longer-term follow up shows that it can cause significant morbidity and longer-term disability. Although it has always been thought of as very rare, the prevalence is likely to be vastly underestimated due to poor recognition of the disease.

  20. Vulvovaginitis candidiasis recurrence during pregnancy.

    Fardiazar, Z; Ronaci, F; Torab, R; Goldust, M

    2012-04-15

    Vulvovaginitis is the most common gynecologic condition seen by practitioners rendering primary care to women. Vulvovaginitis Candidiasis (VVC) is the most common type of vaginitis and this study aimed at specifying VVC recurrence during pregnancy. In this prospective study, 150 pregnant women suffering from vaginal excretion, morsus and itching were studied. Initially, the patients were treated using clotrimazole local cream (5 g) for 7 successive days. After initial treatment, the patients were freely visited once a month until delivery considering vaginitis symptoms and VVC recurrence was examined during pregnancy. Mean age of the understudy mothers was 27.26 +/- 3.76. Mean of recurrence number was 0.17 +/- 0.48 during the first trimester. Mean of recurrence number was 0.92 +/- 0.76 during the second trimester. Mean of recurrence number was 2.16 +/- 0.63 during the third trimester. Statistically significant difference was between recurrences during three trimesters of pregnancy (p < 0.001). There is statistically significant difference between mean number of recurrences during three trimesters of pregnancy.

  1. Recurrent Novae in M31

    Shafter, A W; Rector, T A; Schweizer, F; Hornoch, K; Orio, M; Pietsch, W; Darnley, M J; Williams, S C; Bode, M F; Bryan, J

    2014-01-01

    The reported positions of 964 suspected nova eruptions in M31 recorded through the end of calendar year 2013 have been compared in order to identify recurrent nova candidates. To pass the initial screen and qualify as a recurrent nova candidate two or more eruptions were required to be coincident within 0.1', although this criterion was relaxed to 0.15' for novae discovered on early photographic patrols. A total of 118 eruptions from 51 potential recurrent nova systems satisfied the screening criterion. To determine what fraction of these novae are indeed recurrent the original plates and published images of the relevant eruptions have been carefully compared. This procedure has resulted in the elimination of 27 of the 51 progenitor candidates (61 eruptions) from further consideration as recurrent novae, with another 8 systems (17 eruptions) deemed unlikely to be recurrent. Of the remaining 16 systems, 12 candidates (32 eruptions) were judged to be recurrent novae, with an additional 4 systems (8 eruptions) b...

  2. STDP in recurrent neuronal networks

    Matthieu Gilson

    2010-09-01

    Full Text Available Recent results about spike-timing-dependent plasticity (STDP in recurrently connected neurons are reviewed, with a focus on the relationship between the weight dynamics and the emergence of network structure. In particular, the evolution of synaptic weights in the two cases of incoming connections for a single neuron and recurrent connections are compared and contrasted. A theoretical framework is used that is based upon Poisson neurons with a temporally inhomogeneous firing rate and the asymptotic distribution of weights generated by the learning dynamics. Different network configurations examined in recent studies are discussed and an overview of the current understanding of STDP in recurrently connected neuronal networks is presented.

  3. Base Metal Co-Fired Multilayer Piezoelectrics

    Lisheng Gao

    2016-03-01

    Full Text Available Piezoelectrics have been widely used in different kinds of applications, from the automobile industry to consumer electronics. The novel multilayer piezoelectrics, which are inspired by multilayer ceramic capacitors, not only minimize the size of the functional parts, but also maximize energy efficiency. Development of multilayer piezoelectric devices is at a significant crossroads on the way to achieving low costs, high efficiency, and excellent reliability. Concerning the costs of manufacturing multilayer piezoelectrics, the trend is to replace the costly noble metal internal electrodes with base metal materials. This paper discusses the materials development of metal co-firing and the progress of integrating current base metal chemistries. There are some significant considerations in metal co-firing multilayer piezoelectrics: retaining stoichiometry with volatile Pb and alkaline elements in ceramics, the selection of appropriate sintering agents to lower the sintering temperature with minimum impact on piezoelectric performance, and designing effective binder formulation for low pO2 burnout to prevent oxidation of Ni and Cu base metal.

  4. Disease Localization in Multilayer Networks

    de Arruda, Guilherme Ferraz; Cozzo, Emanuele; Peixoto, Tiago P.; Rodrigues, Francisco A.; Moreno, Yamir

    2017-01-01

    We present a continuous formulation of epidemic spreading on multilayer networks using a tensorial representation, extending the models of monoplex networks to this context. We derive analytical expressions for the epidemic threshold of the susceptible-infected-susceptible (SIS) and susceptible-infected-recovered dynamics, as well as upper and lower bounds for the disease prevalence in the steady state for the SIS scenario. Using the quasistationary state method, we numerically show the existence of disease localization and the emergence of two or more susceptibility peaks, which are characterized analytically and numerically through the inverse participation ratio. At variance with what is observed in single-layer networks, we show that disease localization takes place on the layers and not on the nodes of a given layer. Furthermore, when mapping the critical dynamics to an eigenvalue problem, we observe a characteristic transition in the eigenvalue spectra of the supra-contact tensor as a function of the ratio of two spreading rates: If the rate at which the disease spreads within a layer is comparable to the spreading rate across layers, the individual spectra of each layer merge with the coupling between layers. Finally, we report on an interesting phenomenon, the barrier effect; i.e., for a three-layer configuration, when the layer with the lowest eigenvalue is located at the center of the line, it can effectively act as a barrier to the disease. The formalism introduced here provides a unifying mathematical approach to disease contagion in multiplex systems, opening new possibilities for the study of spreading processes.

  5. Opioids and breast cancer recurrence

    Cronin-Fenton, Deirdre P; Heide-Jørgensen, Uffe; Ahern, Thomas P

    2015-01-01

    BACKGROUND: Opioids may alter immune function, thereby potentially affecting cancer recurrence. The authors investigated the association between postdiagnosis opioid use and breast cancer recurrence. METHODS: Patients with incident, early stage breast cancer who were diagnosed during 1996 through...... 2008 in Denmark were identified from the Danish Breast Cancer Cooperative Group Registry. Opioid prescriptions were ascertained from the Danish National Prescription Registry. Follow-up began on the date of primary surgery for breast cancer and continued until breast cancer recurrence, death......, emigration, 10 years, or July 31, 2013, whichever occurred first. Cox regression models were used to compute hazard ratios and 95% confidence intervals associating breast cancer recurrence with opioid prescription use overall and by opioid type and strength, immunosuppressive effect, chronic use (≥6 months...

  6. Recurrent networks for wave forecasting

    Mandal, S.; Prabaharan, N.

    , merchant vessel routing, nearshore construction, etc. more efficiently and safely. This paper presents an application of the Artificial Neural Network, namely Backpropagation Recurrent Neural Network (BRNN) with rprop update algorithm for wave forecasting...

  7. Recurrence for random dynamical systems

    Marie, Philippe

    2009-01-01

    This paper is a first step in the study of the recurrence behavior in random dynamical systems and randomly perturbed dynamical systems. In particular we define a concept of quenched and annealed return times for systems generated by the composition of random maps. We moreover prove that for super-polynomially mixing systems, the random recurrence rate is equal to the local dimension of the stationary measure.

  8. The recurrent carpal tunnel syndrome.

    Kern, B C; Brock, M; Rudolph, K H; Logemann, H

    1993-01-01

    Sixteen out of 720 patients with carpal tunnel syndrome who had undergone surgery since 1979 were reoperated for a "recurrence" (2.2%). Twelve of these patients had been originally operated on in our department. Thus, our own recurrence rate is 1.7%. Three patients deteriorated following surgery, 6 had an unsatisfactory improvement, and in 7 the symptoms recurred after initial improvement. Eight of the reoperated patients had a predisposing disease (terminal renal insufficiency, insulin-dependent diabetes mellitus, acromegaly). In 10 of the 16 cases the initial operation had been carried out by surgeons in the first three years of training. Reoperation revealed incomplete splitting of the transverse carpal ligament in 10 cases, compression of the median nerve by the scar in 4, injury of the muscular branch in 1, and an anatomical variant as cause of incomplete decompression in 1 patient. "Recurrences" after carpal tunnel surgery are predominantly due to inadequacies of the first procedure. A remarkable number of patients (50%) has predisposing diseases. Interfascicular or epineural neurolysis and complete exposure and neurolysis of the median nerve and its branches is necessary only in cases of recurrence. Their omission at the first surgery does not result in an increased recurrence rate. Our observations indicate that the number of operations for recurrent carpal tunnel syndrome can probably be reduced when the first operation is performed with care and experience. Patients with carpal tunnel syndrome secondary to a systemic disease are particularly at risk.

  9. Multilayer cladding with hyperbolic dispersion for plasmonic waveguides

    Babicheva, Viktoriia; Shalaginov, Mikhail Y.; Ishii, Satoshi;

    2015-01-01

    We study the properties of plasmonic waveguides with a dielectric core and multilayer metal-dielectric claddings that possess hyperbolic dispersion. The waveguides hyperbolic multilayer claddings show better performance in comparison to conventional plasmonic waveguides. © OSA 2015....

  10. Community Detection Using Multilayer Edge Mixture Model

    Zhang, Han; Lai, Jian-Huang; Yu, Philip S

    2016-01-01

    A wide range of complex systems can be modeled as networks with corresponding constraints on the edges and nodes, which have been extensively studied in recent years. Nowadays, with the progress of information technology, systems that contain the information collected from multiple perspectives have been generated. The conventional models designed for single perspective networks fail to depict the diverse topological properties of such systems, so multilayer network models aiming at describing the structure of these networks emerge. As a major concern in network science, decomposing the networks into communities, which usually refers to closely interconnected node groups, extracts valuable information about the structure and interactions of the network. Unlike the contention of dozens of models and methods in conventional single-layer networks, methods aiming at discovering the communities in the multilayer networks are still limited. In order to help explore the community structure in multilayer networks, we...

  11. Performance of multilayer coated silicon pore optics

    Ackermann, M. D.; Collon, M. J.; Cooper-Jensen, Carsten P.;

    2010-01-01

    simultaneously requirements for effective area of 2.5 m2 at 1.25 keV, 0.65 m2 at 6 keV and 150 cm2 at 30 keV. The reflectivity of the bare mirror substrate materials does not allow these requirements to be met. As such the IXO baseline design contains a coating layout that varies as a function of mirror radius...... and in accordance with the variation in grazing incidence angle. The higher energy photon response is enhanced through the use of depth-graded multilayer coatings on the inner radii mirror modules. In this paper we report on the first reflectivity measurements of wedged ribbed silicon pore optics mirror plates...... coated with a depth graded W/Si multilayer. The measurements demonstrate that the deposition and performance of the multilayer coatings is compatible with the SPO production process....

  12. Multilayer Integrated Film Bulk Acoustic Resonators

    Zhang, Yafei

    2013-01-01

    Multilayer Integrated Film Bulk Acoustic Resonators mainly introduces the theory, design, fabrication technology and application of a recently developed new type of device, multilayer integrated film bulk acoustic resonators, at the micro and nano scale involving microelectronic devices, integrated circuits, optical devices, sensors and actuators, acoustic resonators, micro-nano manufacturing, multilayer integration, device theory and design principles, etc. These devices can work at very high frequencies by using the newly developed theory, design, and fabrication technology of nano and micro devices. Readers in fields of IC, electronic devices, sensors, materials, and films etc. will benefit from this book by learning the detailed fundamentals and potential applications of these advanced devices. Prof. Yafei Zhang is the director of the Ministry of Education’s Key Laboratory for Thin Films and Microfabrication Technology, PRC; Dr. Da Chen was a PhD student in Prof. Yafei Zhang’s research group.

  13. Evolutionary games on multilayer networks: A colloquium

    Wang, Zhen; Szolnoki, Attila; Perc, Matjaz

    2015-01-01

    Networks form the backbone of many complex systems, ranging from the Internet to human societies. Accordingly, not only is the range of our interactions limited and thus best described and modeled by networks, it is also a fact that the networks that are an integral part of such models are often interdependent or even interconnected. Networks of networks or multilayer networks are therefore a more apt description of social systems. This colloquium is devoted to evolutionary games on multilayer networks, and in particular to the evolution of cooperation as one of the main pillars of modern human societies. We first give an overview of the most significant conceptual differences between single-layer and multilayer networks, and we provide basic definitions and a classification of the most commonly used terms. Subsequently, we review fascinating and counterintuitive evolutionary outcomes that emerge due to different types of interdependencies between otherwise independent populations. The focus is on coupling th...

  14. Scaling Properties of Multilayer Random Networks

    Méndez-Bermúdez, J A; Rodrigues, Francisco A; Moreno, Yamir

    2016-01-01

    Multilayer networks are widespread in natural and manmade systems. Key properties of these networks are their spectral and eigenfunction characteristics, as they determine the critical properties of many dynamics occurring on top of them. In this paper, we numerically demonstrate that the normalized localization length $\\beta$ of the eigenfunctions of multilayer random networks follows a simple scaling law given by $\\beta=x^*/(1+x^*)$, with $x^*=\\gamma(b_{\\text{eff}}^2/L)^\\delta$, $\\gamma,\\delta\\sim 1$ and $b_{\\text{eff}}$ being the effective bandwidth of the adjacency matrix of the network, whose size is $L=M\\times N$. The reported scaling law for $\\beta$ might help to better understand criticality in multilayer networks as well as to predict the eigenfunction localization properties of them.

  15. Long Range Surface Plasmons in Multilayer Structures

    Delfan, Aida

    2013-01-01

    We present a new strategy, based on a Fresnel coefficient pole analysis, for designing an asymmetric multilayer structure that supports long range surface plasmons (LRSP). We find that the electric field intensity in the metal layer of a multilayer LRSP structure can be even slightly smaller than in the metal layer of the corresponding symmetric LRSP structure, minimizing absorption losses and resulting in LRSP propagation lengths up to 2mm. With a view towards biosensing applications, we also present semi-analytic expressions for a standard surface sensing parameter in arbitrary planar resonant structures, and in particular show that for an asymmetric structure consisting of a gold film deposited on a multilayer of SiO2 and TiO2 a surface sensing parameter G = 1.28(1/nm) can be achieved.

  16. Multilayers Assembly of DNA Probe for Biosensor

    谢文章; 路英杰; 隋森芳

    2002-01-01

    Surface plasmon resonance (SPR) was a sensitive method to study molecular interactions. Based on the specific binding, this paper presented the molecular assembly of protein-nucleic acid multilayers on the surface of a gold film. The first layer was a biotin-lipid (B-DMPE/DMPE) containing a monolayer prepared using the Langmuir-Blodgett (LB) technique. The second and third layers were avidin and DNA labeled biotin, respectively. The fourth layer was anti-DNA antibody extracted from the serum of patients with systemic lupus erythematosus (SLE). These interactions provide stability in the multilayer films of the complexes. The multilayer formation process was detected by SPR spectroscopy. The results show that the chip-based sensor system can be used for functional characterization of protein-protein and protein-DNA interactions.

  17. Using Visualization Techniques in Multilayer Traffic Modeling

    Bragg, Arnold

    We describe visualization techniques for multilayer traffic modeling - i.e., traffic models that span several protocol layers, and traffic models of protocols that cross layers. Multilayer traffic modeling is challenging, as one must deal with disparate traffic sources; control loops; the effects of network elements such as IP routers; cross-layer protocols; asymmetries in bandwidth, session lengths, and application behaviors; and an enormous number of complex interactions among the various factors. We illustrate by using visualization techniques to identify relationships, transformations, and scaling; to smooth simulation and measurement data; to examine boundary cases, subtle effects and interactions, and outliers; to fit models; and to compare models with others that have fewer parameters. Our experience suggests that visualization techniques can provide practitioners with extraordinary insight about complex multilayer traffic effects and interactions that are common in emerging next-generation networks.

  18. Femtosecond damage threshold of multilayer metal films

    Ibrahim, Wael M. G.; Elsayed-Ali, Hani E.; Shinn, Michelle D.; Bonner, Carl E.

    2003-05-01

    With the availability of terawatt laser systems with subpicosecond pulses, laser damage to optical components has become the limiting factor for further increases in the output peak power. Evaluation of different material structures in accordance to their suitability for high-power laser systems is essential. Multi-shot damage experiments, using 110 fs laser pulses at 800 nm, on polycrystalline single layer gold films and multi-layer (gold-vanadium, and gold-titanium) films were conducted. The laser incident fluence was varied, in both cases, from 0.1 to 0.6 J/cm2. No evidence of surface damage was apparent in the gold sample up to a fluence of 0.3 J/cm2. The multilayer sample experienced the onset of surface damage at the lowest fluence value used of 0.1 J/cm2. Damage results are in contrast with the time resolved ultrafast thermoreflectivity measurements that revealed a reduction of the thermoreflectivity signal for the multilayer films. This decrease in the thermoreflectivity signal signifies a reduction in the surface electron temperature that should translate in a lower lattice temperature at the later stage. Hence, one should expect a higher damage threshold for the multilayer samples. Comparison of the experimental results with the predictions of the Two-Temperature Model (TTM) is presented. The damage threshold of the single layer gold film corresponds to the melting threshold predicted by the model. In contrast to the single layer gold film, the multi-layer sample damaged at almost one third the damage threshold predicted by the TTM model. Possible damage mechanisms leading to the early onset of damage for the multilayer films are discussed.

  19. Reverse engineering of multi-layer films

    Effendi Widjaja

    2011-03-01

    Full Text Available This contribution introduces the combined application of Raman microscopy and band-target entropy minimization (BTEM in order to successfully reverse-engineer a multi-layer packaging material. Three layers are identified, namely, polyethylene, a paper and talc layer (with two distinct cellulose forms, and a poly-styrene co-polymer composite containing anatase and calcite. This rapid and non-destructive approach provides a unique opportunity for the assessment of multi-layer composites, including the constitution of the additives present.

  20. Magnetic multilayers : fundamental and practical aspects

    Krishnan, R.

    1992-01-01

    After a brief introduction we describe the preparation of the multilayers by evaporation under ultra high vacuum conditions and their characterisation. We then discuss the magnetic and magneto-optical properties of some multilayer systems such as, Ni/Ag, Fe/Ag, Co/Ag and Co/Pt. The last one is quite interesting and is a potential candidate for magneto-optical information storage, particularly capable of working in the shorter wave length of light. We describe particularly the various anisotro...

  1. Thermal diffusion in Ni/Al multilayer

    Swain, M.; Bhattacharya, D.; Singh, S.; Basu, S. [Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400085 (India); Gupta, M. [UGC-DAE-Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452017 (India)

    2013-02-05

    Two Ni/Al multilayers deposited by ion beam sputtering of nominal design [Ni(200A)/Al(100A)] Multiplication-Sign 5 and [Ni(50A)/Al(227A)] Multiplication-Sign 5 on Si substrates were annealed at 200 Degree-Sign C. As-deposited and annealed samples were characterized by x-ray diffraction (XRD) and x-ray reflectometry (XRR). The effort was to study the path of alloying in the above two multilayers of same elements but of opposite stoichiometric ratio. We find distinct differences in alloying of these samples.

  2. Investigation of periodic Ni–Ti multilayers

    Veres, T., E-mail: veres.tamas@wigner.mta.hu [Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, Budapest H-1121, Konkoly-Thege út 29.-33. (Hungary); Cser, L. [Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, Budapest H-1121, Konkoly-Thege út 29.-33. (Hungary); Bodnarchuck, V.; Ignatovich, V. [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie st. 6, Dubna, Moscow Reg. 141980 (Russian Federation); Horváth, Z.E. [Research Centre for Natural Sciences, Institute for Technical Physics and Materials Science, Budapest H-1121, Konkoly-Thege út 29.-33. (Hungary); Nagy, B. [Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest H-1121, Konkoly-Thege út 29.-33. (Hungary)

    2013-07-01

    In order to improve the quality of neutron supermirrors periodic multilayers of various periods were prepared. The reflectivity properties of these systems were investigated using neutron and X-ray reflectometry. The obtained experimental results were compared with the calculated ones. The deviations from the proposed structure and calculated scattering length densities were investigated. In first approximation, the results proved the main features of the calculations. The roughness of different interfaces was also investigated. - Highlights: • Periodic Ni(Mo)/Ti multilayer samples were prepared by dc sputtering. • X-ray and neutron reflectivity measurements on the samples • Fitting and comparison with the proposed structure.

  3. Multilayer graphene under vertical electric field

    Kumar, S. Bala; GUO, Jing

    2011-01-01

    We study the effect of vertical electric field (E-field) on the electronic properties of multilayer graphene. We show that the effective mass, electron velocity and density-of-state of a bilayer graphene are modified under the E-field. We also study the transformation of the band structure of multilayer graphenes. E-field induces finite (zero) bandgap in the even (odd)-layer ABA-stacking graphene. On the other hand, finite bandgap is induced in all ABC-stacking graphene. We also identify the ...

  4. Piezoelectric multilayer actuator life test.

    Sherrit, Stewart; Bao, Xiaoqi; Jones, Christopher M; Aldrich, Jack B; Blodget, Chad J; Moore, James D; Carson, John W; Goullioud, Renaud

    2011-04-01

    Potential NASA optical missions such as the Space Interferometer Mission require actuators for precision positioning to accuracies of the order of nanometers. Commercially available multilayer piezoelectric stack actuators are being considered for driving these precision mirror positioning mechanisms. These mechanisms have potential mission operational requirements that exceed 5 years for one mission life. To test the feasibility of using these commercial actuators for these applications and to determine their reliability and the redundancy requirements, a life test study was undertaken. The nominal actuator requirements for the most critical actuators on the Space Interferometry Mission (SIM) in terms of number of cycles was estimated from the Modulation Optics Mechanism (MOM) and Pathlength control Optics Mechanism (POM) and these requirements were used to define the study. At a nominal drive frequency of 250 Hz, one mission life is calculated to be 40 billion cycles. In this study, a set of commercial PZT stacks configured in a potential flight actuator configuration (pre-stressed to 18 MPa and bonded in flexures) were tested for up to 100 billion cycles. Each test flexure allowed for two sets of primary and redundant stacks to be mechanically connected in series. The tests were controlled using an automated software control and data acquisition system that set up the test parameters and monitored the waveform of the stack electrical current and voltage. The samples were driven between 0 and 20 V at 2000 Hz to accelerate the life test and mimic the voltage amplitude that is expected to be applied to the stacks during operation. During the life test, 10 primary stacks were driven and 10 redundant stacks, mechanically in series with the driven stacks, were open-circuited. The stroke determined from a strain gauge, the temperature and humidity in the chamber, and the temperature of each individual stack were recorded. Other properties of the stacks, including the

  5. RECURRENT NOVAE IN M31

    Shafter, A. W. [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); Henze, M. [European Space Astronomy Centre, P.O. Box 78, E-28692 Villanueva de la Cañada, Madrid (Spain); Rector, T. A. [Department of Physics and Astronomy, University of Alaska Anchorage, 3211 Providence Dr., Anchorage, AK 99508 (United States); Schweizer, F. [Carnegie Observatories, 813 Santa Barbara St., Pasadena, CA 91101 (United States); Hornoch, K. [Astronomical Institute, Academy of Sciences, CZ-251 65 Ondřejov (Czech Republic); Orio, M. [Astronomical Observatory of Padova (INAF), I-35122 Padova (Italy); Pietsch, W. [Max Planck Institute for Extraterrestrial Physics, P.O. Box 1312, Giessenbachstr., D-85741, Garching (Germany); Darnley, M. J.; Williams, S. C.; Bode, M. F. [Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5RF (United Kingdom); Bryan, J., E-mail: aws@nova.sdsu.edu [McDonald Observatory, Austin, TX 78712 (United States)

    2015-02-01

    The reported positions of 964 suspected nova eruptions in M31 recorded through the end of calendar year 2013 have been compared in order to identify recurrent nova (RN) candidates. To pass the initial screen and qualify as a RN candidate, two or more eruptions were required to be coincident within 0.′1, although this criterion was relaxed to 0.′15 for novae discovered on early photographic patrols. A total of 118 eruptions from 51 potential RN systems satisfied the screening criterion. To determine what fraction of these novae are indeed recurrent, the original plates and published images of the relevant eruptions have been carefully compared. This procedure has resulted in the elimination of 27 of the 51 progenitor candidates (61 eruptions) from further consideration as RNe, with another 8 systems (17 eruptions) deemed unlikely to be recurrent. Of the remaining 16 systems, 12 candidates (32 eruptions) were judged to be RNe, with an additional 4 systems (8 eruptions) being possibly recurrent. It is estimated that ∼4% of the nova eruptions seen in M31 over the past century are associated with RNe. A Monte Carlo analysis shows that the discovery efficiency for RNe may be as low as 10% that for novae in general, suggesting that as many as one in three nova eruptions observed in M31 arise from progenitor systems having recurrence times ≲100 yr. For plausible system parameters, it appears unlikely that RNe can provide a significant channel for the production of Type Ia supernovae.

  6. Transmission fingerprints in quasiperiodic magnonic multilayers

    Coelho, I.P. [Departamento de Ensino Superior, Instituto Federal de Educacao, Ciencia e Tecnologia do Maranhao, Imperatriz-MA 65919-050 (Brazil); Departamento de Fisica, Universidade Federal do Rio Grande do Norte, Natal-RN 59072-970 (Brazil); Vasconcelos, M.S. [Escola de Ciencias e Tecnologia, Universidade Federal do Rio Grande do Norte, Natal-RN 59072-970 (Brazil); Bezerra, C.G., E-mail: cbezerra@dfte.ufrn.br [Departamento de Fisica, Universidade Federal do Rio Grande do Norte, Natal-RN 59072-970 (Brazil)

    2011-12-15

    In this paper we investigated the influence of mirror symmetry on the transmission spectra of quasiperiodic magnonic multilayers arranged according to Fibonacci, Thue-Morse and double period quasiperiodic sequences. We consider that the multilayers composed of two simple cubic Heisenberg ferromagnets with bulk exchange constants J{sub A} and J{sub B} and spin quantum numbers S{sub A} and S{sub B}, respectively. The multilayer structure is surrounded by two semi-infinite slabs of a third Heisenberg ferromagnetic material with exchange constant J{sub C} and spin quantum number S{sub C}. For simplicity, the lattice constant has the same value a in each material, corresponding to epitaxial growth at the interfaces. The transfer matrix treatment was used for the exchange-dominated regime, taking into account the random phase approximation (RPA). Our numerical results illustrate the effects of mirror symmetry on (i) transmission spectra and (ii) transmission fingerprints. - Highlights: > We model quasiperiodic magnetic multilayers presenting mirror symmetry. > We investigated the allowed and forbidden bands of magnonic transmission. > Transmission return maps show the influence of mirror symmetry. > Mirror symmetry has no effect on the Fibonacci case. > Mirror symmetry does have effect on the Thue-Morse and double period cases.

  7. Enhancing Casimir repulsion via topological insulator multilayers

    Zeng, Ran; Chen, Liang; Nie, Wenjie; Bi, Meihua; Yang, Yaping; Zhu, Shiyao

    2016-08-01

    We propose to observe the enhanced Casimir repulsion between two parallel multilayer walls made of alternating layers of a topological insulator (TI) and a normal insulator. Based on the transfer matrix method, the Fresnel coefficients matrix is generalized to apply to the TI multilayer structure. The Casimir repulsion under the influence of the magnetization orientation in the magnetic coatings on TI layer surfaces, the layer thicknesses, and the topological magnetoelectric polarizability, is investigated. We show that, for the multilayer structures with parallel magnetization on the TI layer surfaces, it is possible to enhance the repulsion by increasing the TI layer number, which is due to the accumulation of the contribution to the repulsion from the polarization rotation effect occurring on each TI layer surface. Generally, in the distance region where there is Casimir attraction between semi-infinite TIs, the force may turn into repulsion in TI multilayer structure, and in the region of repulsion for semi-infinite TI, the repulsive force can be enhanced in magnitude, the enhancement tends to a maximum while the structure contains sufficiently many layers.

  8. Single-order lamellar multilayer gratings

    Meer, van der R.

    2013-01-01

    A major challenge in the soft x-ray (SXR) and eXtreme UltraViolet (XUV) spectral ranges is the ability to manipulate the incident radiation using optical elements. By patterning conventional multilayer mirrors with nanoscale structures, novel optical elements with a variety of optical properties can

  9. Josephson plasma resonance in superconducting multilayers

    Pedersen, Niels Falsig; Sakai, S

    1998-01-01

    We derive an analytical solution for the Josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low-T-c systems with magnetic coupling between the superconducting layers. but many features of our results are more general, and thus an application...

  10. Josephson plasma resonance in superconducting multilayers

    Pedersen, Niels Falsig

    1999-01-01

    We derive an analytical solution for the josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low T-c systems with magnetic coupling between the superconducting layers, but many features of our results are more general, and thus an application...

  11. Recurrence Statistics of Great Earthquakes

    Ben-Naim, E; Johnson, P A

    2013-01-01

    We investigate the sequence of great earthquakes over the past century. To examine whether the earthquake record includes temporal clustering, we identify aftershocks and remove those from the record. We focus on the recurrence time, defined as the time between two consecutive earthquakes. We study the variance in the recurrence time and the maximal recurrence time. Using these quantities, we compare the earthquake record with sequences of random events, generated by numerical simulations, while systematically varying the minimal earthquake magnitude Mmin. Our analysis shows that the earthquake record is consistent with a random process for magnitude thresholds 7.0<=Mmin<=8.3, where the number of events is larger. Interestingly, the earthquake record deviates from a random process at magnitude threshold 8.4<=Mmin<= 8.5, where the number of events is smaller; however, this deviation is not strong enough to conclude that great earthquakes are clustered. Overall, the findings are robust both qualitat...

  12. Oncolytic HSV-1716 in Treating Younger Patients With Refractory or Recurrent High Grade Glioma That Can Be Removed By Surgery

    2016-05-26

    Recurrent Childhood Anaplastic Astrocytoma; Recurrent Childhood Anaplastic Oligoastrocytoma; Recurrent Childhood Anaplastic Oligodendroglioma; Recurrent Childhood Giant Cell Glioblastoma; Recurrent Childhood Glioblastoma; Recurrent Childhood Gliomatosis Cerebri; Recurrent Childhood Gliosarcoma

  13. Galactosemia presenting as recurrent sepsis.

    Rathi, Narendra; Rathi, Akanksha

    2011-12-01

    Galactosemia is a treatable metabolic disorder caused by the deficiency of enzyme galactose-1-phosphate uridyl transferase (GALT) and inherited as an autosomal recessive trait. A case of neonate manifesting with recurrent Escherichia coli sepsis is presented here which turned out to be a classic galactosemia. No other common presenting features were observed in this infant except cataract on slit lamp examination. To the best of our knowledge, there is no case of galactosemia reported in literature which presented with recurrent neonatal sepsis without hepatomegaly, hyperbilirubinemia, bleeding disorder, vomiting, diarrhea, failure to thrive, hypoglycemia, coagulopathy, hemolysis or renal tubular acidosis.

  14. Community Extraction in Multilayer Networks with Heterogeneous Community Structure

    Wilson, James D; Bhamidi, Shankar; Nobel, Andrew B

    2016-01-01

    Multilayer networks are a useful way to capture and model multiple, binary relationships among a fixed group of objects. While community detection has proven to be a useful exploratory technique for the analysis of single-layer networks, the development of community detection methods for multilayer networks is still in its infancy. We propose and investigate a procedure, called Multilayer Extraction, that identifies densely connected vertex-layer sets in multilayer networks. Multilayer Extraction makes use of a significance based score that quantifies the connectivity of an observed vertex-layer set by comparison with a multilayer fixed degree random graph model. Unlike existing detection methods, Multilayer Extraction handles networks with heterogeneous layers where community structure may be different from layer to layer. The procedure is able to capture overlapping communities, and it identifies background vertex-layer pairs that do not belong to any community. We establish large-graph consistency of the v...

  15. Perpendicular magnetic anisotropy of Co85Cr15/Pt multilayers

    Pol Hwang; Baohe Li; Tao Yang; Zhonghai Zhai; Fengwu Zhu

    2004-01-01

    The CoCr/Pt bilayers and (CoCr/Pt)20 multilayers with Pt underlayer were prepared by DC magnetron sputtering. The effects of prepared condition on perpendicular magnetic anisotropy were investigated. The results show that the thickness of Pt underlayer has a great effect on the microstructure and perpendicular magnetic anisotropy of CoCr/Pt bilayers and (CoCr/Pt)20 multilayers.When the thickness of Pt underlayer increases, Pt(111) and CoCr(002) peaks of both CoCr/Pt bilayers and (CoCr/Pt)20 multilayers increase and the bilayer periodicity of the multilayers is improved. The effective magnetic anisotropy of (CoCr/Pt)20 multilayers with Pt underlayer was much larger than that of CoCr/Pt bilayers. The (CoCr/Pt)20 multilayers has a stronger perpendicular magnetic anisotropy than that of CoCr/Pt bilayers. This is ascribed to the interface magnetic anisotropy of the multilayers.

  16. A Recurrent Neural Network Approach to Rear Vehicle Detection Which Considered State Dependency

    Kayichirou Inagaki

    2003-08-01

    Full Text Available Experimental vision-based detection often fails in cases when the acquired image quality is reduced by changing optical environments. In addition, the shape of vehicles in images that are taken from vision sensors change due to approaches by vehicle. Vehicle detection methods are required to perform successfully under these conditions. However, the conventional methods do not consider especially in rapidly varying by brightness conditions. We suggest a new detection method that compensates for those conditions in monocular vision-based vehicle detection. The suggested method employs a Recurrent Neural Network (RNN, which has been applied for spatiotemporal processing. The RNN is able to respond to consecutive scenes involving the target vehicle and can track the movements of the target by the effect of the past network states. The suggested method has a particularly beneficial effect in environments with sudden, extreme variations such as bright sunlight and shield. Finally, we demonstrate effectiveness by state-dependent of the RNN-based method by comparing its detection results with those of a Multi Layered Perceptron (MLP.

  17. Supervised Learning of Two-Layer Perceptron under the Existence of External Noise — Learning Curve of Boolean Functions of Two Variables in Tree-Like Architecture —

    Uezu, Tatsuya; Kiyokawa, Shuji

    2016-06-01

    We investigate the supervised batch learning of Boolean functions expressed by a two-layer perceptron with a tree-like structure. We adopt continuous weights (spherical model) and the Gibbs algorithm. We study the Parity and And machines and two types of noise, input and output noise, together with the noiseless case. We assume that only the teacher suffers from noise. By using the replica method, we derive the saddle point equations for order parameters under the replica symmetric (RS) ansatz. We study the critical value αC of the loading rate α above which the learning phase exists for cases with and without noise. We find that αC is nonzero for the Parity machine, while it is zero for the And machine. We derive the exponents barβ of order parameters expressed as (α - α C)bar{β} when α is near to αC. Furthermore, in the Parity machine, when noise exists, we find a spin glass solution, in which the overlap between the teacher and student vectors is zero but that between student vectors is nonzero. We perform Markov chain Monte Carlo simulations by simulated annealing and also by exchange Monte Carlo simulations in both machines. In the Parity machine, we study the de Almeida-Thouless stability, and by comparing theoretical and numerical results, we find that there exist parameter regions where the RS solution is unstable, and that the spin glass solution is metastable or unstable. We also study asymptotic learning behavior for large α and derive the exponents hat{β } of order parameters expressed as α - hat{β } when α is large in both machines. By simulated annealing simulations, we confirm these results and conclude that learning takes place for the input noise case with any noise amplitude and for the output noise case when the probability that the teacher's output is reversed is less than one-half.

  18. Interpretation of Recurrent Neural Networks

    Pedersen, Morten With; Larsen, Jan

    1997-01-01

    This paper addresses techniques for interpretation and characterization of trained recurrent nets for time series problems. In particular, we focus on assessment of effective memory and suggest an operational definition of memory. Further we discuss the evaluation of learning curves. Various nume...

  19. [Local recurrence of paratesticular rhabdomyosarcoma].

    Rabii, R; Moufid, K; Fekak, H; Dassouli, B; Joual, A; Bennani, S; el Mrini, M; Benjelloun, S

    2002-10-01

    We report an uncommon case of scrotal recurrence of embryonal paratesticular rhabdomyosarcoma in 19 year old man after 3 years later. The diagnosis was suspected clinically and confirmed by histopathology study after resection of the scrotal tumor. About this case, the authors discuss the diagnosis and the management of this tumor.

  20. Relativistic phase space dimensional recurrences

    Delbourgo, Robert

    2003-01-01

    We derive recurrence relations between phase space expressions in different dimensions by confining some of the coordinates to tori or spheres of radius $R$ and taking the limit as $R \\to \\infty$. These relations take the form of mass integrals, associated with extraneous momenta (relative to the lower dimension), and produce the result in the higher dimension.

  1. Recurrence Formulas for Fibonacci Sums

    Brandao, Adilson J V

    2008-01-01

    In this article we present a new recurrence formula for a finite sum involving the Fibonacci sequence. Furthermore, we state an algorithm to compute the sum of a power series related to Fibonacci series, without the use of term-by-term differentiation theorem

  2. Design and development of multilayer vascular graft

    Madhavan, Krishna

    2011-07-01

    Vascular graft is a widely-used medical device for the treatment of vascular diseases such as atherosclerosis and aneurysm as well as for the use of vascular access and pediatric shunt, which are major causes of mortality and morbidity in this world. Dysfunction of vascular grafts often occurs, particularly for grafts with diameter less than 6mm, and is associated with the design of graft materials. Mechanical strength, compliance, permeability, endothelialization and availability are issues of most concern for vascular graft materials. To address these issues, we have designed a biodegradable, compliant graft made of hybrid multilayer by combining an intimal equivalent, electrospun heparin-impregnated poly-epsilon-caprolactone nanofibers, with a medial equivalent, a crosslinked collagen-chitosan-based gel scaffold. The intimal equivalent is designed to build mechanical strength and stability suitable for in vivo grafting and to prevent thrombosis. The medial equivalent is designed to serve as a scaffold for the activity of the smooth muscle cells important for vascular healing and regeneration. Our results have shown that genipin is a biocompatible crosslinker to enhance the mechanical properties of collagen-chitosan based scaffolds, and the degradation time and the activity of smooth muscle cells in the scaffold can be modulated by the crosslinking degree. For vascular grafting and regeneration in vivo, an important design parameter of the hybrid multilayer is the interface adhesion between the intimal and medial equivalents. With diametrically opposite affinities to water, delamination of the two layers occurs. Physical or chemical modification techniques were thus used to enhance the adhesion. Microscopic examination and graft-relevant functional characterizations have been performed to evaluate these techniques. Results from characterization of microstructure and functional properties, including burst strength, compliance, water permeability and suture

  3. Clostridium difficile recurrences in Stockholm.

    Sandell, Staffan; Rashid, Mamun-Ur; Jorup-Rönström, Christina; Ellström, Kristina; Nord, Carl Erik; Weintraub, Andrej

    2016-04-01

    Sixty-eight hospital-admitted patients with a first episode of Clostridium difficile infection (CDI) were included and followed up during 1 year. Faeces samples were collected at 1, 2, 6 and 12 months after inclusion and analyzed for the presence of C. difficile toxin B, genes for toxin A, toxin B, binary toxin and TcdC deletion by PCR. All strains were also PCR-ribotyped and the MICs of the isolates were determined against eight antimicrobial agents. In 68 patients initially included, antibiotics, clinical signs and co-morbidities were analyzed and 56 were evaluable for recurrences. The mean number of different antibiotics given during 3 months prior to inclusion was 2.6 (range 0-6). Six patients had not received any antibiotics and three of them had diagnosed inflammatory bowel disease. Thirty-two patients (57%) had either a microbiological or clinical recurrence, 16 of whom had clinical recurrences that were confirmed microbiologically (13, 23%) or unconfirmed by culture (3, 5%). Twenty-nine patients were positive in at least one of the follow-up tests, 16 had the same ribotype in follow-up tests, i.e. relapse, and 13 a different ribotype, i.e., reinfection. Most common ribotypes were 078/126, 020, 023, 026, 014/077, 001 and 005. No strain of ribotype 027 was found. Strains ribotype 078/126 and 023 were positive for binary toxin and were the strains most prone to cause recurrence. All strains were sensitive to vancomycin and metronidazole. Patients with recurrences were significantly older (p = 0.02) and all patients had a high burden of comorbidities, which could explain the high fatality rate, 26 (38%) patients died during the 1-year follow-up.

  4. [Thoracoscopic treatment of recurrent pneumothorax].

    Suter, M; Berner, M; Vandoni, R; Cuttat, J F

    1994-04-01

    Spontaneous pneumothorax (PNO) is usually due to rupture of a small subpleural bleb into the pleural cavity and affects mainly young men. After simple drainage, recurrence occurs in about 50% of cases. The risk of recurrence increases after each new PNO. Secondary PNO complicates an underlying pulmonary disease, especially chronic obstructive pulmonary disease with emphysema. A new form of secondary PNO has emerged in the recent years in AIDS patients with pneumocystis carinii pneumonia. We have shifted to a thoracoscopic therapy of PNO since May 1991. 25 PNO in 24 patients (1 bilateral) have been treated since that time up to April 1993. 19 PNO were primary, whereas 6 were secondary, included 3 iatrogenic PNO. Resection of the leaking parenchymal area was performed in 20 patients, and parietal partial pleurectomy was done in 20 cases. In the remaining cases, fibrin glue was applied on the lesion and in 3 cases, chemical pleurodesis was attempted using silver nitrate or talc. 1 AIDS patient died of ARDS. 3 patients had recurrent PNO and had thoracotomy without complication. 21 patients did well. Partial PNO recurred in one of them 4 months later, and was treated by simple needle aspiration. Thoracoscopy is a useful method to treat recurrent or persistent spontaneous PNO. After only 25 cases, our success rate in primary PNO is 90%. There should be a learning curve. On the basis of our experience, we believe that recognition of the lesion and its resection as well as apical parietal pleurectomy are necessary to obtain good results and a low recurrence rate.

  5. Giant recurrent retroperitoneal liposarcoma presenting as a recurrent inguinal hernia

    Ajay H. Bhandarwar

    2011-11-01

    Full Text Available Retroperitoneal liposarcoma presenting as an inguinal hernia is a rare entity. We present the first case of Giant recurrent liposarcoma presenting as a recurrent inguinal hernia in a 40-year-old male. Physical examination showed an irreducible lump in the right inguinal region and a scar in the right lumbar and right inguinal region. Computed tomography (CT scan of abdomen revealed it to be a retro peritoneal mass extending into the right inguinal region along and involving the cord structures. Wide local excision of the tumour with right orchidectomy and inguinal hernioplasty was performed. Histo-pathology confirmed it to be a liposarcoma. Patient received postoperative radio therapy. Follow up of two years has shown him to be disease free. Retroperitoneal liposarcoma can grow along cord structures into the inguinal canal and mimic an irreducible indirect inguinal hernia.

  6. Fifth International Symposium on Recurrence Plot

    Riley, Michael; Giuliani, Alessandro; Webber, Charles; Jr, Jr; Translational Recurrences : From Mathematical Theory to Real-World Applications

    2014-01-01

    This book features 13 papers presented at the Fifth International Symposium on Recurrence Plots, held August 2013 in Chicago, IL. It examines recent applications and developments in recurrence plots and recurrence quantifi cation analysis (RQA) with special emphasis on biological and cognitive systems and the analysis of coupled systems using cross-recurrence methods. Readers will discover new applications and insights into a range of systems provided by recurrence plot analysis and new theoretical and mathematical developments in recurrence plots. Recurrence plot based analysis is a powerful tool that operates on real-world complex systems that are nonlinear, non-stationary, noisy, of any statistical distribution, free of any particular model type, and not particularly long. Quantitative analyses promote the detection of system state changes, synchronized dynamical regimes, or classifi cation of system states. Th e book will be of interest to an interdisciplinary audience of recurrence plot users and researc...

  7. Temperature, age, and recurrence of febrile seizure

    M. van Stuijvenberg (Margriet); E.W. Steyerberg (Ewout); G. Derksen-Lubsen (Gerarda); H.A. Moll (Henriëtte)

    1998-01-01

    textabstractOBJECTIVE: Prediction of a recurrent febrile seizure during subsequent episodes of fever. DESIGN: Study of the data of the temperatures, seizure recurrences, and baseline patient characteristics that were collected at a randomized placebo controlled trial of ibuprofen s

  8. Prevention of postoperative recurrence of Crohn's disease

    van Loo, E. S.; Dijkstra, G.; Ploeg, R. J.; Nieuwenhuijs, V. B.

    2012-01-01

    Background: Up to 75% of patients with Crohn's disease (CD) will have intestinal resection during their life. Most patients will, however, develop postoperative recurrence (endoscopic, clinical or surgical). Several medical and surgical strategies have been attempted to prevent postoperative recurre

  9. Recurrent facial urticaria following herpes simplex labialis.

    Zawar, Vijay; Godse, Kiran

    2012-03-01

    We describe recurrent acute right-sided facial urticaria associated with herpes labialis infection in a middle-aged female patient. Antiviral medications and antihistamines not only successfully cleared the herpes infection and urticaria but also prevented further recurrences.

  10. Recurrent facial urticaria following herpes simplex labialis

    Vijay Zawar; Kiran Godse

    2012-01-01

    We describe recurrent acute right-sided facial urticaria associated with herpes labialis infection in a middle-aged female patient. Antiviral medications and antihistamines not only successfully cleared the herpes infection and urticaria but also prevented further recurrences.

  11. Recurrent femoral hernia and associated ovarian pathology.

    Gately, Ryan Patrick; Concannon, Elizabeth Sarah; Hogan, A; Ryan, R S; O'Leary, M; Barry, K

    2012-08-27

    The following case describes an ovarian tumour presenting in a highly unusual manner-in the form of a recurrent femoral hernia. Recurrent femoral herniae are unusual and should prompt awareness of underlying pathology causing increased intra-abdominal pressure.

  12. Optics in magnetic multilayers and nanostructures

    Visnovsky, Stefan

    2006-01-01

    In the continuing push toward optical computing, the focus remains on finding and developing the right materials. Characterizing materials, understanding the behavior of light in these materials, and being able to control the light are key players in the search for suitable optical materials. Optics in Magnetic Multilayers and Nanostructures presents an accessible introduction to optics in anisotropic magnetic media.While most of the literature presents only final results of the complicated formulae for the optics in anisotropic media, this book provides detailed explanations and full step-by-step derivations that offer insight into the procedure and reveal any approximations. Based on more than three decades of experimental research on the subject, the author explains the basic concepts of magnetooptics; nonreciprocal wave propagation; the simultaneous effect of crystalline symmetry and arbitrarily oriented magnetization on the form of permittivity tensors; spectral dependence of permittivity; multilayers at...

  13. Mathematical Formulation of Multi-Layer Networks

    De Domenico, Manlio; Cozzo, Emanuele; Kivelä, Mikko; Moreno, Yamir; Porter, Mason A; Gòmez, Sergio; Arenas, Alex

    2013-01-01

    A network representation is useful for describing the structure of a large variety of complex systems. However, most real and engineered systems have multiple subsystems and layers of connectivity, and the data produced by such systems is very rich. Achieving a deep understanding of such systems necessitates generalizing "traditional" network theory, and the newfound deluge of data now makes it possible to test increasingly general frameworks for the study of networks. In particular, although adjacency matrices are useful to describe traditional single-layer networks, such a representation is insufficient for the analysis and description of multiplex and time-dependent networks. One must therefore develop a more general mathematical framework to cope with the challenges posed by multi-layer complex systems. In this paper, we introduce a tensorial framework to study multi-layer networks, and we discuss the generalization of several important network descriptors and dynamical processes ---including degree centr...

  14. Random walk centrality in interconnected multilayer networks

    Solé-Ribalta, Albert; Gómez, Sergio; Arenas, Alex

    2015-01-01

    Real-world complex systems exhibit multiple levels of relationships. In many cases they require to be modeled as interconnected multilayer networks, characterizing interactions of several types simultaneously. It is of crucial importance in many fields, from economics to biology and from urban planning to social sciences, to identify the most (or the less) influential nodes in a network using centrality measures. However, defining the centrality of actors in interconnected complex networks is not trivial. In this paper, we rely on the tensorial formalism recently proposed to characterize and investigate this kind of complex topologies, and extend two well known random walk centrality measures, the random walk betweenness and closeness centrality, to interconnected multilayer networks. For each of the measures we provide analytical expressions that completely agree with numerically results.

  15. Measure of Node Similarity in Multilayer Networks

    Mollgaard, Anders; Dammeyer, Jesper; Jensen, Mogens H; Lehmann, Sune; Mathiesen, Joachim

    2016-01-01

    The weight of links in a network is often related to the similarity of the nodes. Here, we introduce a simple tunable measure for analysing the similarity of nodes across different link weights. In particular, we use the measure to analyze homophily in a group of 659 freshman students at a large university. Our analysis is based on data obtained using smartphones equipped with custom data collection software, complemented by questionnaire-based data. The network of social contacts is represented as a weighted multilayer network constructed from different channels of telecommunication as well as data on face-to-face contacts. We find that even strongly connected individuals are not more similar with respect to basic personality traits than randomly chosen pairs of individuals. In contrast, several socio-demographics variables have a significant degree of similarity. We further observe that similarity might be present in one layer of the multilayer network and simultaneously be absent in the other layers. For a...

  16. Topological edge modes in multilayer graphene systems

    Ge, Lixin

    2015-08-10

    Plasmons can be supported on graphene sheets as the Dirac electrons oscillate collectively. A tight-binding model for graphene plasmons is a good description as the field confinement in the normal direction is strong. With this model, the topological properties of plasmonic bands in multilayer graphene systems are investigated. The Zak phases of periodic graphene sheet arrays are obtained for different configurations. Analogous to Su-Schrieffer-Heeger (SSH) model in electronic systems, topological edge plasmon modes emerge when two periodic graphene sheet arrays with different Zak phases are connected. Interestingly, the dispersion of these topological edge modes is the same as that in the monolayer graphene and is invariant as the geometric parameters of the structure such as the separation and period change. These plasmonic edge states in multilayer graphene systems can be further tuned by electrical gating or chemical doping. © 2015 Optical Society of America.

  17. Information Propagation in Clustered Multilayer Networks

    Zhuang, Yong

    2015-01-01

    In today's world, individuals interact with each other in more complicated patterns than ever. Some individuals engage through online social networks (e.g., Facebook, Twitter), while some communicate only through conventional ways (e.g., face-to-face). Therefore, understanding the dynamics of information propagation among humans calls for a multi-layer network model where an online social network is conjoined with a physical network. In this work, we initiate a study of information diffusion in a clustered multi-layer network model, where all constituent layers are random networks with high clustering. We assume that information propagates according to the SIR model and with different information transmissibility across the networks. We give results for the conditions, probability, and size of information epidemics, i.e., cases where information starts from a single individual and reaches a positive fraction of the population. We show that increasing the level of clustering in either one of the layers increas...

  18. Network Composition from Multi-layer Data

    Lerman, Kristina; Yan, Xiaoran

    2016-01-01

    It is common for people to access multiple social networks, for example, using phone, email, and social media. Together, the multi-layer social interactions form a "integrated social network." How can we extend well developed knowledge about single-layer networks, including vertex centrality and community structure, to such heterogeneous structures? In this paper, we approach these challenges by proposing a principled framework of network composition based on a unified dynamical process. Mathematically, we consider the following abstract problem: Given multi-layer network data and additional parameters for intra and inter-layer dynamics, construct a (single) weighted network that best integrates the joint process. We use transformations of dynamics to unify heterogeneous layers under a common dynamics. For inter-layer compositions, we will consider several cases as the inter-layer dynamics plays different roles in various social or technological networks. Empirically, we provide examples to highlight the usef...

  19. Thermal Residual Stresses in Multilayered Coatings

    Xiancheng ZHANG; Binshi XU; Haidou WANG; Yixiong WU

    2005-01-01

    The mechanical integrity and reliability of coated devices are strongly affected by the residual stresses in thin films and coatings. However, due to the metallurgical complexity of materials, it is rather difficult to obtain a closed-form solution of residual stresses within multilayered coatings (e.g. functionally graded coatings, FGCs). In this paper,an analytical model is developed to predict the distribution of residual stresses within multilayered coatings. The advantage of this model is that the solution of residual stresses is independent of the number of layers. Specific results are obtained by calculating elastic thermal stresses in ZrO2/NiCoCrAIY FGCs, which consist of different material layers. Furthermore, the residual stress distribution near the edges and the stress-induced failure modes of coating are also analyzed. The topics discussed provide some insights into the development of a methodology for designing fail-safe coating systems.

  20. Ferromagnetic Resonance in Gd/Co Multilayers

    A. V. Svalov; V. O. Vas'kovskiy; J. M. Barandiaran; G. V. Kurlyandskaya; L. Lezama; J. Gutiérrez; N. G. Bebenin; D. Schmool

    2001-01-01

    Magnetometric and ferromagnetic resonance (MFR) measurements have been performed on the polycrystalline multilayered structure, [Gd(7.5 nm)/Co(3nm)]20. The temperature dependence of magnetization of the sample suggests a compensation temperature Tcomp in the region of 240K, implying that the Co and Gd layers are antiferromagnetically aligned. The FMR curves are strongly temperature dependent, particularly in the vicinity of Tcomp.

  1. Automation Enhancement of Multilayer Laue Lenses

    Lauer K. R.; Conley R.

    2010-12-01

    X-ray optics fabrication at Brookhaven National Laboratory has been facilitated by a new, state of the art magnetron sputtering physical deposition system. With its nine magnetron sputtering cathodes and substrate carrier that moves on a linear rail via a UHV brushless linear servo motor, the system is capable of accurately depositing the many thousands of layers necessary for multilayer Laue lenses. I have engineered a versatile and automated control program from scratch for the base system and many subsystems. Its main features include a custom scripting language, a fully customizable graphical user interface, wireless and remote control, and a terminal-based interface. This control system has already been successfully used in the creation of many types of x-ray optics, including several thousand layer multilayer Laue lenses.Before reaching the point at which a deposition can be run, stencil-like masks for the sputtering cathodes must be created to ensure the proper distribution of sputtered atoms. Quality of multilayer Laue lenses can also be difficult to measure, given the size of the thin film layers. I employ my knowledge of software and algorithms to further ease these previously painstaking processes with custom programs. Additionally, I will give an overview of an x-ray optic simulator package I helped develop during the summer of 2010. In the interest of keeping my software free and open, I have worked mostly with the multiplatform Python and the PyQt application framework, utilizing C and C++ where necessary.

  2. Evolutionary games on multilayer networks: a colloquium

    Wang, Zhen; Wang, Lin; Szolnoki, Attila; Perc, Matjaž

    2015-05-01

    Networks form the backbone of many complex systems, ranging from the Internet to human societies. Accordingly, not only is the range of our interactions limited and thus best described and modeled by networks, it is also a fact that the networks that are an integral part of such models are often interdependent or even interconnected. Networks of networks or multilayer networks are therefore a more apt description of social systems. This colloquium is devoted to evolutionary games on multilayer networks, and in particular to the evolution of cooperation as one of the main pillars of modern human societies. We first give an overview of the most significant conceptual differences between single-layer and multilayer networks, and we provide basic definitions and a classification of the most commonly used terms. Subsequently, we review fascinating and counterintuitive evolutionary outcomes that emerge due to different types of interdependencies between otherwise independent populations. The focus is on coupling through the utilities of players, through the flow of information, as well as through the popularity of different strategies on different network layers. The colloquium highlights the importance of pattern formation and collective behavior for the promotion of cooperation under adverse conditions, as well as the synergies between network science and evolutionary game theory.

  3. Magnetic remanent states in antiferromagnetically coupled multilayers

    Kiselev, N.S., E-mail: m.kyselov@ifw-dresden.d [IFW Dresden, Postfach 270116, D-01171 Dresden (Germany); Donetsk Institute for Physics and Technology, 83114 Donetsk (Ukraine); Roessler, U.K.; Bogdanov, A.N. [IFW Dresden, Postfach 270116, D-01171 Dresden (Germany); Hellwig, O. [San Jose Research Center, Hitachi Global Storage Technologies, San Jose, CA 95135 (United States)

    2010-05-15

    In antiferromagnetically coupled multilayers with perpendicular anisotropy unusual multidomain textures can be stabilized due to a close competition between long-range demagnetization fields and short-range interlayer exchange coupling. In particular, the formation and evolution of specific topologically stable planar defects within the antiferromagnetic ground state, i.e. wall-like structures with a ferromagnetic configuration extended over a finite width, explain configurational hysteresis phenomena recently observed in [Co/Pt(Pd)]/Ru and [Co/Pt]/NiO multilayers. Within a phenomenological theory, we have analytically derived the equilibrium sizes of these 'ferroband' defects as functions of the antiferromagnetic exchange, a bias magnetic field, and geometrical parameters of the multilayers. In the magnetic phase diagram, the existence region of the ferrobands mediates between the regions of patterns with sharp antiferromagnetic domain walls and regular arrays of ferromagnetic stripes. The theoretical results are supported by magnetic force microscopy images of the remanent states observed in [Co/Pt]/Ru.

  4. Multilayer modal actuator-based piezoelectric transformers.

    Huang, Yao-Tien; Wu, Wen-Jong; Wang, Yen-Chieh; Lee, Chih-Kung

    2007-02-01

    An innovative, multilayer piezoelectric transformer equipped with a full modal filtering input electrode is reported herein. This modal-shaped electrode, based on the orthogonal property of structural vibration modes, is characterized by full modal filtering to ensure that only the desired vibration mode is excited during operation. The newly developed piezoelectric transformer is comprised of three layers: a multilayered input layer, an insulation layer, and a single output layer. The electrode shape of the input layer is derived from its structural vibration modal shape, which takes advantage of the orthogonal property of the vibration modes to achieve a full modal filtering effect. The insulation layer possesses two functions: first, to couple the mechanical vibration energy between the input and output, and second, to provide electrical insulation between the two layers. To meet the two functions, a low temperature, co-fired ceramic (LTCC) was used to provide the high mechanical rigidity and high electrical insulation. It can be shown that this newly developed piezoelectric transformer has the advantage of possessing a more efficient energy transfer and a wider optimal working frequency range when compared to traditional piezoelectric transformers. A multilayer piezoelectric, transformer-based inverter applicable for use in LCD monitors or portable displays is presented as well.

  5. Recurrent cervical cancer : detection and prognosis

    Duyn, A; Van Eijkeren, M; Kenter, G; Zwinderman, K; Ansink, A

    2002-01-01

    Background. Only a small proportion of cervical cancer recurrences is detected during routine follow-up. We investigated which percentage of recurrences is detected during follow-up, which diagnostic tools are helpful to detect recurrent disease and which factors are of prognostic significance once

  6. 14 CFR 135.351 - Recurrent training.

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Recurrent training. 135.351 Section 135.351... AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Training § 135.351 Recurrent training. (a) Each certificate holder must ensure that each crewmember receives recurrent...

  7. 14 CFR 121.427 - Recurrent training.

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Recurrent training. 121.427 Section 121.427..., FLAG, AND SUPPLEMENTAL OPERATIONS Training Program § 121.427 Recurrent training. (a) Recurrent training must ensure that each crew member or dispatcher is adequately trained and currently proficient...

  8. 14 CFR 91.1107 - Recurrent training.

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Recurrent training. 91.1107 Section 91.1107... Management § 91.1107 Recurrent training. (a) Each program manager must ensure that each crewmember receives recurrent training and is adequately trained and currently proficient for the type aircraft and...

  9. An ensemble perspective on multi-layer networks

    Wider, Nicolas; Scholtes, Ingo; Schweitzer, Frank

    2015-01-01

    We study properties of multi-layered, interconnected networks from an ensemble perspective, i.e. we analyze ensembles of multi-layer networks that share similar aggregate characteristics. Using a diffusive process that evolves on a multi-layer network, we analyze how the speed of diffusion depends on the aggregate characteristics of both intra- and inter-layer connectivity. Through a block-matrix model representing the distinct layers, we construct transition matrices of random walkers on multi-layer networks, and estimate expected properties of multi-layer networks using a mean-field approach. In addition, we quantify and explore conditions on the link topology that allow to estimate the ensemble average by only considering aggregate statistics of the layers. Our approach can be used when only partial information is available, like it is usually the case for real-world multi-layer complex systems.

  10. Clopidogrel-Induced Recurrent Polyarthritis

    Harburger, Joseph; Stallings, Gary; Agrawal, Nikhil; Garg, Jalaj

    2013-01-01

    Clopidogrel is an oral thienopyridine and together with aspirin is a component of dual antiplatelet therapy for the prevention of stent thrombosis after intracoronary stent placement. The common adverse effects from its use are an increased risk of bleeding, neutropenia, and rash. Arthralgia and backache are also known to occur with its use. There have been case reports linking arthritis with the use of clopidogrel. We describe the case of a 64-year-old man who reported symptoms of fever and joint pains following initiation of therapy with clopidogrel. Acute-phase reactants were elevated. Laboratory and radiologic testing were unremarkable. Incidentally, he reported experiencing a similar arthritis after he received a loading dose of clopidogrel prior to a diagnostic coronary angiography in the past. The symptoms improved dramatically on discontinuation of clopidogrel. There was no recurrence of symptoms with prasugrel. This describes possibly the second incidence of recurrent arthritis with clopidogrel therapy. PMID:26425581

  11. Clopidogrel-Induced Recurrent Polyarthritis

    Sahil Agrawal MD

    2013-08-01

    Full Text Available Clopidogrel is an oral thienopyridine and together with aspirin is a component of dual antiplatelet therapy for the prevention of stent thrombosis after intracoronary stent placement. The common adverse effects from its use are an increased risk of bleeding, neutropenia, and rash. Arthralgia and backache are also known to occur with its use. There have been case reports linking arthritis with the use of clopidogrel. We describe the case of a 64-year-old man who reported symptoms of fever and joint pains following initiation of therapy with clopidogrel. Acute-phase reactants were elevated. Laboratory and radiologic testing were unremarkable. Incidentally, he reported experiencing a similar arthritis after he received a loading dose of clopidogrel prior to a diagnostic coronary angiography in the past. The symptoms improved dramatically on discontinuation of clopidogrel. There was no recurrence of symptoms with prasugrel. This describes possibly the second incidence of recurrent arthritis with clopidogrel therapy.

  12. Segmentalliverincarcerationthrougha recurrent incisional lumbar hernia

    Nikolaos S. Salemis; Konstantinos Nisotakis; Stavros Gourgiotis; Efstathios Tsohataridis

    2007-01-01

    BACKGROUND: Lumbar hernia is a rare congenital or acquired defect of the posterior abdominal wall. The acquired type is more common and occurs mainly as an incisional defect after lfank surgery. Incarceration or strangulation of hernia contents is uncommon. METHOD: Segmental liver incarceration through a recurrent incisional lumbar defect was diagnosed in a 58 years old woman by magnetic resonance imaging. RESULTS: The patient underwent an open repair of the com-plicated hernia. An expanded polytetralfouoroethylene (e-PTFE) mesh was fashioned as a sublay prosthesis. She had an uncomplicated postoperative course. Follow-up examinations revealed no evidence of recurrence. CONCLUSIONS: Although lumbar hernia rarely results in incarceration or strangulation, early repair is necessary because of the risks of complications and the increasing dififculty in repairment as it enlarges. Surgical repair is often dififcult and challenging.

  13. Training recurrent networks by Evolino.

    Schmidhuber, Jürgen; Wierstra, Daan; Gagliolo, Matteo; Gomez, Faustino

    2007-03-01

    In recent years, gradient-based LSTM recurrent neural networks (RNNs) solved many previously RNN-unlearnable tasks. Sometimes, however, gradient information is of little use for training RNNs, due to numerous local minima. For such cases, we present a novel method: EVOlution of systems with LINear Outputs (Evolino). Evolino evolves weights to the nonlinear, hidden nodes of RNNs while computing optimal linear mappings from hidden state to output, using methods such as pseudo-inverse-based linear regression. If we instead use quadratic programming to maximize the margin, we obtain the first evolutionary recurrent support vector machines. We show that Evolino-based LSTM can solve tasks that Echo State nets (Jaeger, 2004a) cannot and achieves higher accuracy in certain continuous function generation tasks than conventional gradient descent RNNs, including gradient-based LSTM.

  14. Multiperiodicity in plasmonic multilayers: General description and diversity of topologies

    Orlov, Alexey A.; Krylova, Anastasia K.; Zhukovsky, Sergei;

    2014-01-01

    We introduce multiperiodicity in periodicmetal-dielectric multilayers by stacking more than two types of metal and/or dielectric layers into the unit cell. A simple way to characterize arbitrary multiperiodic multilayers using permutation vectors is suggested and employed. Effects of multiperiodi......We introduce multiperiodicity in periodicmetal-dielectric multilayers by stacking more than two types of metal and/or dielectric layers into the unit cell. A simple way to characterize arbitrary multiperiodic multilayers using permutation vectors is suggested and employed. Effects...

  15. Ultrahydrophobicity of Polydimethylsiloxanes-Based Multilayered Thin Films

    Hongyan Gao

    2009-01-01

    Full Text Available The formation of polydimethylsiloxanes (PDMSs-based layer-by-layer multilayer ultrathin films on charged surfaces prepared from water and phosphate buffer solutions has been investigated. The multilayer films prepared under these conditions showed different surface roughness. Nanoscale islands and network structures were observed homogeneously on the multilayer film prepared from pure water solutions, which is attributing to the ultrahydrobic property of the multilayer film. The formation of nanoscale islands and network structures was due to the aggregation of PDMS-based polyelectrolytes in water. This work provides a facile approach for generating ultrahydrophobic thin films on any charged surfaces by PDMS polyelectrolytes.

  16. POINT SOURCE IN THE LAYERED MEDIUM WITH METAMATERIALS: METHOD OF RECURRENT RELATIONS

    K. V. Pravdin

    2014-05-01

    Full Text Available Multilayer systems with metamaterials are studied. A system comprising parallel alternated layers filled with metamaterial and vacuum is considered. The problem of obtaining expressions for electric part of the Green’s function is raised for the NIM situation. A NIM situation is a case when electric and magnetic permeabilities are equal –1 for metamaterial and +1 for vacuum. The Maxwell’s equations for a point source of electromagnetic field are considered. A differential equation for electric p-polarized scalar part of the Green’s function for every layer is obtained with standard boundary conditions. Solution is obtained with the fundamental system of solutions with unknown coefficients. For the unknown coefficients the recurrence relations method is chosen as evident in usage and easy in analysis of obtained solutions. The solutions of the recurrence relations are obtained in general form by the method of generating functions. As a result the formulae for required Green’s function are obtained for every layer in the condition of NIM situation. s-polarized part is obtained in a similar way. It is easy to obtain a vector form of the electric Green’s function with its scalar form and the standard alternations. Obtained results can be used by simulations of superlens systems and multilayer covers with metamaterials.

  17. Erlotinib and Temozolomide in Treating Young Patients With Recurrent or Refractory Solid Tumors

    2013-06-04

    Previously Treated Childhood Rhabdomyosarcoma; Recurrent Childhood Brain Tumor; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Medulloblastoma; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Neuroblastoma; Recurrent Osteosarcoma

  18. Effective theory of rotationally faulted multilayer graphene

    Kindermann, Markus

    2012-02-01

    The crystal structure of graphene multilayers with an interlayer twist is characterized by Moir'e patterns with various commensurabilities. Also the electronic structure of the material, which grows for instance epitaxially on SiC, is remarkably rich. In this talk an effective low-energy description of such multilayers will be discussed. In certain limits the theory reduces to a (single-layer) Dirac model with space-dependent potentials and mass term. The consequences of this theory will be explored and comparison with experiment will be made. The discussion of experimental consequences will focus on the Landau quantization in a magnetic field, where much experimental data is available. For instance, a spatially modulated splitting of the zeroth Landau level in the material has been observed through scanning tunneling spectroscopy [1]. That splitting finds a natural explanation in the space-dependent mass term of the presented theory [2]. Also a large low-field splitting of higher Landau levels recently observed in graphene multilayers [3] will be shown to follow from that theory. Finally, a theoretically expected [4] amplitude modulation of the Landau level wavefunctions on the top layer of the material will be discussed. [4pt] [1] D. L. Miller, K. D. Kubista, G. M. Rutter, M. Ruan, W. A. de Heer, M. Kindermann, P. N. First, and J. A. Stroscio, Nature Physics 6, 811 (2010). [0pt] [2] M. Kindermann and P. N. First, Phys. Rev. B 83, 045425 (2010). [0pt] [3] Y. J. Song, A. F. Otte, Y. Kuk, Y. Hu, D. B. Torrance, P. N. First, W. A. de Heer, H. Min, S. Adam, M. D. Stiles, A. H. MacDonald, and J. A. Stroscio, Nature 467, 185 (2010). [0pt] [4] M. Kindermann and E. G. Mele, Phys. Rev. B 84, 161406(R) (2011).

  19. Tactile display with dielectric multilayer elastomer actuatorsq

    Matysek, Marc; Lotz, Peter; Schlaak, Helmut F.

    2009-03-01

    Tactile perception is the human sensation of surface textures through the vibrations generated by stroking a finger over the surface. The skin responds to several distributed physical quantities. Perhaps the most important are high-frequency vibrations, pressure distributions (static shape) and thermal properties. The integration of tactile displays in man-machine interfaces promises a more intuitive handling. For this reason many tactile displays are developed using different technologies. We present several state-of-the-art tactile displays based on different types of dielectric elastomer actuators to clarify the advantages of our matrix display based on multilayer technology. Using this technology perpendicular and hexagonal arrays of actuator elements (tactile stimulators) can be integrated into a PDMS substrate. Element diameters down to 1 mm allow stimuli at the range of the human two-point-discrimination threshold. Driving the elements by column and row addressing enables various stimulation patterns with a reduced number of feeding lines. The transient analysis determines charging times of the capacitive actuators depending on actuator geometry and material parameters. This is very important to ensure an adequate dynamic characteristic of the actuators to stimulate the human skin by vibrations. The suitability of multilayer dielectric elastomer actuators for actuation in tactile displays has been determined. Beside the realization of a static tactile display - where multilayer DEA are integrated as drives for movable contact pins - we focus on the direct use of DEA as a vibrotactile display. Finally, we present the scenario and achieved results of a recognition threshold test. Even relative low voltages in the range of 800 V generate vibrations with 100% recognition ratio within the group of participants. Furthermore, the frequency dependent characteristic of the determined recognition threshold confirms with established literature.

  20. Optics and multilayer coatings for EUVL systems

    Soufli, R; Bajt, S; Hudyma, R M; Taylor, J S

    2008-03-21

    EUV lithography (EUVL) employs illumination wavelengths around 13.5 nm, and in many aspects it is considered an extension of optical lithography, which is used for the high-volume manufacturing (HVM) of today's microprocessors. The EUV wavelength of illumination dictates the use of reflective optical elements (mirrors) as opposed to the refractive lenses used in conventional lithographic systems. Thus, EUVL tools are based on all-reflective concepts: they use multilayer (ML) coated optics for their illumination and projection systems, and they have a ML-coated reflective mask.

  1. Plasmonic waveguides with hyperbolic multilayer cladding

    Babicheva, Viktoriia E; Ishii, Satoshi; Boltasseva, Alexandra; Kildishev, Alexander V

    2014-01-01

    Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any homogenization, we calculate the resonant eigenmodes of the finite-width cladding layers, and find agreement with the resonant features in the dispersion of the cladded waveguides. We show that at the resonant widths, the propagating modes of the waveguides are coupled to the cladding eigenmodes and hence, are strongly absorbed. By avoiding the resonant widths in the design of the actual waveguides, the strong absorption can be eliminated.

  2. Supervised Learning in Multilayer Spiking Neural Networks

    Sporea, Ioana

    2012-01-01

    The current article introduces a supervised learning algorithm for multilayer spiking neural networks. The algorithm presented here overcomes some limitations of existing learning algorithms as it can be applied to neurons firing multiple spikes and it can in principle be applied to any linearisable neuron model. The algorithm is applied successfully to various benchmarks, such as the XOR problem and the Iris data set, as well as complex classifications problems. The simulations also show the flexibility of this supervised learning algorithm which permits different encodings of the spike timing patterns, including precise spike trains encoding.

  3. Analysis of multi-layer ERBS spectra

    Marmitt, G.G. [Atomic and Molecular Physics Laboratories, Research School of Physics and Engineering, The Australian National University, Canberra 0200 (Australia); Instituto de Fisica da Universidade Federal do Rio Grande do Sul, Avenida Bento Goncalves 9500, 91501-970 Porto Alegre, RS (Brazil); Rosa, L.F.S. [Instituto de Fisica da Universidade Federal do Rio Grande do Sul, Avenida Bento Goncalves 9500, 91501-970 Porto Alegre, RS (Brazil); Nandi, S.K. [Electronic Materials Engineering Department, Research School of Physics and Engineering, The Australian National University, Canberra 0200 (Australia); Research School of Astronomy and Astrophysics, The Australian National University, Canberra, ACT 2611 (Australia); Department of Physics, University of Chittagong, Chittagong 4331 (Bangladesh); Vos, M., E-mail: maarten.vos@anu.edu.au [Atomic and Molecular Physics Laboratories, Research School of Physics and Engineering, The Australian National University, Canberra 0200 (Australia)

    2015-07-15

    Highlights: • Electron Rutherford backscattering (ERBS) spectra are presented. • The spectra are fitted based on physical meaningful quantities. • Very consistent results are obtained for spectra taken under different conditions. • This establishes that ERBS can be used to measure film thicknesses. - Abstract: A systematic way of analysis of multi-layer electron Rutherford backscattering spectra is described. The approach uses fitting in terms of physical meaningful parameters. Simultaneous analysis then becomes possible for spectra taken at different incoming energies and measurement geometries. Examples are given to demonstrate the level of detail that can be resolved by this technique.

  4. Engineering aspects of multilayer piezoceramic actuators

    Golovnin, V. A.; Kaplunov, I. A.; Ivanova, A. I.; Grechishkin, R. M.

    2013-12-01

    With the increasing demand for multilayer ceramic chip components a full understanding of the co-firing of ceramics with metal electrodes becomes important. In the present work the processing of a piezoelectric monolithic actuator by stacking and cofiring Ag-Pd electroded tape cast layers was studied. The inter-diffusion and microstructure of the co-fired interface of PZT ferroelectrics and Ag-Pd metal electrode were examined by scanning electron microscopy (SEM) and energy-dispersive microanalysis. No strong structural distortions and interdiffusion were observed at the co-fired ceramic-electrode interface.

  5. Multimedia Traffic Routing in Multilayer WDM Networks

    Amphawan, Angela; Hasan, Hassanuddin

    2012-01-01

    The advent of real-time multimedia services over the Internet has stimulated new technologies for expanding the information carrying capacity of optical network backbones. Multilayer wavelength division multiplexing (WDM) packet switching is an emerging technology for increasing the bandwidth of optical networks. Two algorithms for the routing of the multimedia traffic flows were applied: (i) Capacitated Shortest Path First (CSPF) routing, which minimizes the distance of each flow linking the given source and destination nodes and satisfying capacity constraints; and (ii) Flow Deviation Algorithm (FDA) routing, which minimizes the network?wide average packet delay.

  6. Fracture mechanics parameters of multilayer pipes

    Šestáková L.

    2007-10-01

    Full Text Available Multilayer pipes consisting of different materials are frequently used in praxis because of partial improvement of the properties of pipe systems. To estimate lifetime of these pipes the basic fracture parameters have to be determined. In this work finite element calculations are applied in order to estimate the stress intensity factor K and T-stress values for a new type of non-homogenous C-shape specimen. The application of calculated K and T values to laboratory estimation of fracture toughness and its transferability to real pipe system is discussed.

  7. Electronic Properties in a Hierarchical Multilayer Structure

    ZHU Chen-Ping; XIONG Shi-Jie

    2001-01-01

    We investigate electronic properties of a hierarchical multilayer structure consisting of stacking of barriers and wells. The structure is formed in a sequence of generations, each of which is constructed with the same pattern but with the previous generation as the basic building blocks. We calculate the transmission spectrum which shows the multifractal behavior for systems with large generation index. From the analysis of the average resistivity and the multifractal structure of the wavefunctions, we show that there exist different types of states exhibiting extended, localized and intermediate characteristics. The degree of localization is sensitive to the variation of the structural parameters.Suggestion of the possible experimental realization is discussed.

  8. Static and dynamic properties of Fibonacci multilayers

    Machado, L. D.; Bezerra, C. G.; Correa, M. A.; Chesman, C.; Pearson, J. E.; Hoffmann, A.

    2013-05-01

    We theoretically investigate static and dynamic properties of quasiperiodic magnetic multilayers. We considered identical ferromagnetic layers separated by non-magnetic spacers with two different thicknesses chosen based on the Fibonacci sequence. Using parameters for Fe/Cr, the minimum energy was determined and the equilibrium magnetization directions found were used to calculate magnetoresistance curves. Regarding dynamic behavior, ferromagnetic resonance (FMR) curves were calculated using an approximation known from the literature. Our numerical results illustrate the effects of quasiperiodicity on the static and dynamic properties of these structures.

  9. Multi-Periodicity Induces Prominent Optical Phenomena in Plasmonic Multilayers

    Orlov, Alexey A.; Krylova, A. K.; Zhukovsky, Sergei;

    2014-01-01

    We introduce multi-periodicity in plasmonic multilayers and develop a general theory for the description of their eigenwaves. We define the order of multi-periodicity as the number of different kinds of plasmonic interfaces present in the multilayer, and investigate the optical effects that arise...

  10. Highly reflecting Y/Mg–Hx multilayered switchable mirrors

    Giebels, I.A.M.E.; Isidorsson, J.; Kooij, E.S.; Remhof, A.; Koeman, N.J.; Rector, J.H.; Gogh, van A.T.M.; Griessen, R.

    2002-01-01

    Optical, structural and thermodynamic properties of Y/Mg–Hx multilayered switchable mirrors are investigated and compared with YMgHx-alloys and pure YHx. Multilayers clearly have superior reflectance in the low-hydrogen state over the whole range of photon energies, 0.72

  11. 78 FR 30329 - Multilayered Wood Flooring from China

    2013-05-22

    ... took effect on November 7, 2011. See 76 FR 61937 (Oct. 6, 2011) and the newly revised Commission... COMMISSION Multilayered Wood Flooring from China AGENCY: United States International Trade Commission. ACTION... and 731-TA-1179 (Final) concerning multilayered wood flooring (``MLWF'') from China. For...

  12. 75 FR 79019 - Multilayered Wood Flooring From China

    2010-12-17

    ... the notice in the Federal Register of October 27, 2010 (75 FR 66126). The conference was held in... COMMISSION Multilayered Wood Flooring From China Determinations On the basis of the record \\1\\ developed in... reason of imports from China of multilayered wood flooring, provided for in subheadings 4409.10,...

  13. 76 FR 76435 - Multilayered Wood Flooring From China

    2011-12-07

    ... Register on June 9, 2011 (76 FR 33782). The hearing was held in Washington, DC, on October 12, 2011, and... COMMISSION Multilayered Wood Flooring From China Determinations On the basis of the record \\1\\ developed in... China of multilayered wood flooring, provided for in subheadings 4409.10, 4409.29, 4412.31,...

  14. Effective thermal conductivity of complicated hierarchic multilayer fabric

    Fan Jie

    2014-01-01

    Full Text Available Warm retention property of fabric is one of the most important factors for clothing comfortability. The worm retention efficiency of a multilayer fabric with hierarchic inner structure was investigated based on its geometric feature. The thermal resistance of the multilayer fabric increases as the layer of the fabric increases.

  15. Spin-dependent Peltier effect in Co /Cu multilayer nanowires

    Gravier, Laurent; Serrano-Guisan, Santiago; Ansermet, J.-Ph.

    2005-05-01

    Heat transport perpendicular to the plane of magnetic multilayers is monitored with ac temperature gradients in the presence of a direct charge current. A very strong dependence on the applied magnetic field of the voltage response to the ac gradient is observed using Co /Cu multilayered nanowires. The effect is interpreted as a Peltier effect for a one-dimensional heat flux.

  16. Stress in tungsten carbide-diamond like carbon multilayer coatings

    Pujada, B.R.; Tichelaar, F.D.; Janssen, G.C.A.M.

    2007-01-01

    Tungsten carbide-diamond like carbon (WC-DLC) multilayer coatings have been prepared by sputter deposition from a tungsten-carbide target and periodic switching on and off of the reactive acetylene gas flow. The stress in the resulting WC-DLC multilayers has been studied by substrate curvature. Peri

  17. Phosphorus-based compounds for EUV multilayer optics materials

    Medvedev, V.V.; Yakshin, A.E.; Kruijs, van de R.W.E.; Bijkerk, F.

    2015-01-01

    We have evaluated the prospects of phosphorus-based compounds in extreme ultraviolet multilayer optics. Boron phosphide (BP) is suggested to be used as a spacer material in reflective multilayer optics operating just above the L-photoabsorption edge of P (λ ≈9.2 nm). Mo, Ag, Ru, Rh, and Pd were cons

  18. Multiple analysis of an unknown optical multilayer coating

    Dobrowolski, J.A.; Ho, F.C.; Waldorf, A.; Mitchell, D.F.; Costich, V.R.; Vincent, S.; Thoeni, W.; Casparis, E.; Pfefferkorn, R.; Bartella, J.

    1985-08-15

    Results are given of the analysis at five different laboratories of an unknown optical multilayer coating. In all, eleven different analytical and laboratory techniques were applied to the problem. The multilayer nominally consisted of three dielectric and two metallic layers. It was demonstrated convincingly that with present day techniques it is possible to determine the basic structure of such a coating.

  19. Structural and magnetic properties of epitaxial Fe/Cu multilayers

    Harada, Y. E-mail: t5101008@iwate-u.ac.jp; Nakanishi, Y.; Yoshimoto, N.; Yamaguchi, A.; Nakamura, M.; Yoshizawa, M

    2004-05-01

    We have grown FCC-Fe/Cu multilayers by molecular beam epitaxy method. The structural and magnetic properties were studied by RHEED, XRD and magnetoresistance measurement (MR). The RHEED images confirmed that Fe/Cu multilayers were epitaxially grown on Cu(1 0 0). Furthermore, a clear negative MR was observed. The buffer layer condition for MR effect will be discussed.

  20. Reversal mechanism of submicron patterned CoNi/Pt multilayers

    Haast, M.A.M.; Schuurhuis, J.R.; Abelmann, L.; Lodder, J.C.; Popma, Th.J.A.

    1998-01-01

    With laser interference lithography Co50Ni50/Pt multilayers with perpendicular magnetic anisotropy have been patterned into regular matrices of submicron sized dots. Their magnetic properties have been studied with Vibrating Sample Magnetometry. Compared to continuous multilayers (Hc=15 kA/m) the co

  1. Power Control in Multi-Layer Cellular Networks

    Davaslioglu, Kemal

    2012-01-01

    We investigate the possible performance gains of power control in multi-layer cellular systems where microcells and picocells are distributed within macrocells. Although multilayers in cellular networks help increase system capacity and coverage, and can reduce total energy consumption; they cause interference, reducing the performance of the network. Therefore, downlink transmit power levels of multi-layer hierarchical cellular networks need to be controlled in order to fully exploit their benefits. In this work, we present an analytical derivation to determine optimum power levels for two-layer cellular networks and generalize our solution to multi-layer cellular networks. We also simulate our results in a typical multi-layer network setup and observe significant power savings compared to single-layer cellular networks.

  2. Synthesis and Characterization of Multilayered Diamond Coatings for Biomedical Implants

    Leigh Booth

    2011-05-01

    Full Text Available With incredible hardness and excellent wear-resistance, nanocrystalline diamond (NCD coatings are gaining interest in the biomedical community as articulating surfaces of structural implant devices. The focus of this study was to deposit multilayered diamond coatings of alternating NCD and microcrystalline diamond (MCD layers on Ti-6Al-4V alloy surfaces using microwave plasma chemical vapor deposition (MPCVD and validate the multilayer coating’s effect on toughness and adhesion. Multilayer samples were designed with varying NCD to MCD thickness ratios and layer numbers. The surface morphology and structural characteristics of the coatings were studied with X-ray diffraction (XRD, Raman spectroscopy, and atomic force microscopy (AFM. Coating adhesion was assessed by Rockwell indentation and progressive load scratch adhesion tests. Multilayered coatings shown to exhibit the greatest adhesion, comparable to single-layered NCD coatings, were the multilayer samples having the lowest average grain sizes and the highest titanium carbide to diamond ratios.

  3. Mechanical properties of glass polymer multilayer composite

    A Seal; N R Bose; S K Dalui; A K Mukhopadhyay; K K Phani; H S Maiti

    2001-04-01

    The preliminary experimental studies on the comparative behaviour of the deformation processes involved in the failure of a commercial, 0.3 mm thick, 18 mm diameter soda–lime–silica glass disks () and multilayered glass disk–epoxy (GE) as well as glass disk–epoxy–-glass fabric (GEF) composite structures are reported. The failure tests were conducted in a biaxial flexure at room temperature. The epoxy was a commercial resin and the -glass fabric was also commercially obtained as a two-dimensional weave of -glass fibres to an area density of about 242 g m–2. The multilayered structures were developed by alternate placement of the glass and reinforcing layers by a hand lay-up technique followed by lamination at an appropriate temperature and pressure. Depending on the number of layers the volume fraction of reinforcement could be varied from about 0.20 for the GE system to about 0.50 for the GEF system. It was observed that the specific failure load (load per unit thickness) was enhanced from a value of about 60 N/mm obtained for the glass to a maximum value of about 100 N/mm for the GE composites and to a maximum of about 70 N/mm for the GEF composite system. Similarly, the displacements at failure () measured with a linear variable differential transformer (LVDT) were also found to be a strongly sensitive function of the type of reinforcement (GE or GEF) as well as the number of layers.

  4. Epidemic model with isolation in multilayer networks

    Zuzek, L G Alvarez; Braunstein, L A

    2014-01-01

    The Susceptible-Infected-Recovered (SIR) model has successfully mimicked the propagation of such airborne diseases as influenza A (H1N1). Although the SIR model has recently been studied in a multilayer networks configuration, in almost all the research the dynamic movement of infected individuals, e.g., how they are often kept in isolation, is disregarded. We study the SIR model in two multilayer networks and use an isolation parameter, indicating time period, to measure the effect of isolating infected individuals from both layers. This isolation reduces the transmission of the disease because the time in which infection can spread is reduced. In this scenario we find that the epidemic threshold increases with the isolation time and the isolation parameter and the impact of the propagation is reduced. We also find that when isolation is total there is a threshold for the isolation parameter above which the disease never becomes an epidemic. We also find that regular epidemic models always overestimate the e...

  5. Multilayer motif analysis of brain networks

    Battiston, Federico; Chavez, Mario; Latora, Vito

    2016-01-01

    In the last decade network science has shed new light on the anatomical connectivity and on correlations in the activity of different areas of the human brain. The study of brain networks has made possible in fact to detect the central areas of a neural system, and to identify its building blocks by looking at overabundant small subgraphs, known as motifs. However, network analysis of the brain has so far mainly focused on structural and functional networks as separate entities. The recently developed mathematical framework of multi-layer networks allows to perform a multiplex analysis of the human brain where the structural and functional layers are considered at the same time. In this work we describe how to classify subgraphs in multiplex networks, and we extend motif analysis to networks with many layers. We then extract multi-layer motifs in brain networks of healthy subjects by considering networks with two layers, respectively obtained from diffusion and functional magnetic resonance imaging. Results i...

  6. Measure of Node Similarity in Multilayer Networks.

    Anders Mollgaard

    Full Text Available The weight of links in a network is often related to the similarity of the nodes. Here, we introduce a simple tunable measure for analysing the similarity of nodes across different link weights. In particular, we use the measure to analyze homophily in a group of 659 freshman students at a large university. Our analysis is based on data obtained using smartphones equipped with custom data collection software, complemented by questionnaire-based data. The network of social contacts is represented as a weighted multilayer network constructed from different channels of telecommunication as well as data on face-to-face contacts. We find that even strongly connected individuals are not more similar with respect to basic personality traits than randomly chosen pairs of individuals. In contrast, several socio-demographics variables have a significant degree of similarity. We further observe that similarity might be present in one layer of the multilayer network and simultaneously be absent in the other layers. For a variable such as gender, our measure reveals a transition from similarity between nodes connected with links of relatively low weight to dis-similarity for the nodes connected by the strongest links. We finally analyze the overlap between layers in the network for different levels of acquaintanceships.

  7. Finite element analysis of multilayer coextrusion.

    Hopkins, Matthew Morgan; Schunk, Peter Randall; Baer, Thomas A. (Proctor & Gamble Company, West Chester, OH); Mrozek, Randy A. (Army Research Laboratory, Adelphi, MD); Lenhart, Joseph Ludlow (Army Research Laboratory, Adelphi, MD); Rao, Rekha Ranjana; Collins, Robert (Oak Ridge National Laboratory); Mondy, Lisa Ann

    2011-09-01

    Multilayer coextrusion has become a popular commercial process for producing complex polymeric products from soda bottles to reflective coatings. A numerical model of a multilayer coextrusion process is developed based on a finite element discretization and two different free-surface methods, an arbitrary-Lagrangian-Eulerian (ALE) moving mesh implementation and an Eulerian level set method, to understand the moving boundary problem associated with the polymer-polymer interface. The goal of this work is to have a numerical capability suitable for optimizing and troubleshooting the coextrusion process, circumventing flow instabilities such as ribbing and barring, and reducing variability in layer thickness. Though these instabilities can be both viscous and elastic in nature, for this work a generalized Newtonian description of the fluid is used. Models of varying degrees of complexity are investigated including stability analysis and direct three-dimensional finite element free surface approaches. The results of this work show how critical modeling can be to reduce build test cycles, improve material choices, and guide mold design.

  8. Polymer multilayer tattooing for enhanced DNA vaccination

    Demuth, Peter C.; Min, Younjin; Huang, Bonnie; Kramer, Joshua A.; Miller, Andrew D.; Barouch, Dan H.; Hammond, Paula T.; Irvine, Darrell J.

    2013-04-01

    DNA vaccines have many potential benefits but have failed to generate robust immune responses in humans. Recently, methods such as in vivo electroporation have demonstrated improved performance, but an optimal strategy for safe, reproducible, and pain-free DNA vaccination remains elusive. Here we report an approach for rapid implantation of vaccine-loaded polymer films carrying DNA, immune-stimulatory RNA, and biodegradable polycations into the immune-cell-rich epidermis, using microneedles coated with releasable polyelectrolyte multilayers. Films transferred into the skin following brief microneedle application promoted local transfection and controlled the persistence of DNA and adjuvants in the skin from days to weeks, with kinetics determined by the film composition. These ‘multilayer tattoo’ DNA vaccines induced immune responses against a model HIV antigen comparable to electroporation in mice, enhanced memory T-cell generation, and elicited 140-fold higher gene expression in non-human primate skin than intradermal DNA injection, indicating the potential of this strategy for enhancing DNA vaccination.

  9. Mo-C Multilayered CVD Coatings

    A. Sagalovych

    2013-12-01

    Full Text Available Production processes of multi-layered Mo-C coatings by the method of chemical vapor deposition (CVD with the use of organometallic compounds were developed. Coatings are applied on technical purpose steel DIN 1.2379 (H12F1 and DIN 1.7709 (25H2MF (ÉI10 heat-treated ball with the high class of surface roughness (> 10. The average deposition rate was 50 μm / h. The optimal conditions of deposition coatings for different technological schemas were defined. Metallographic investigations of the obtained coatings were carried out. Tribological studies of the friction and wear characteristics of sliding friction in conditions of boundary lubrication of Ï-S multilayered CVD coatings shows, that coatings have low friction coefficients (0075-0095 at loads up to 2.0 kN, showed high resistance to wear and are effective in increasing the stability of the pair for precision friction pairs of hydraulical units.

  10. Measure of Node Similarity in Multilayer Networks

    Mollgaard, Anders; Zettler, Ingo; Dammeyer, Jesper; Jensen, Mogens H.; Lehmann, Sune; Mathiesen, Joachim

    2016-01-01

    The weight of links in a network is often related to the similarity of the nodes. Here, we introduce a simple tunable measure for analysing the similarity of nodes across different link weights. In particular, we use the measure to analyze homophily in a group of 659 freshman students at a large university. Our analysis is based on data obtained using smartphones equipped with custom data collection software, complemented by questionnaire-based data. The network of social contacts is represented as a weighted multilayer network constructed from different channels of telecommunication as well as data on face-to-face contacts. We find that even strongly connected individuals are not more similar with respect to basic personality traits than randomly chosen pairs of individuals. In contrast, several socio-demographics variables have a significant degree of similarity. We further observe that similarity might be present in one layer of the multilayer network and simultaneously be absent in the other layers. For a variable such as gender, our measure reveals a transition from similarity between nodes connected with links of relatively low weight to dis-similarity for the nodes connected by the strongest links. We finally analyze the overlap between layers in the network for different levels of acquaintanceships. PMID:27300084

  11. Relaxation dynamics of multilayer triangular Husimi cacti

    Galiceanu, Mircea; Jurjiu, Aurel

    2016-09-01

    We focus on the relaxation dynamics of multilayer polymer structures having, as underlying topology, the Husimi cactus. The relaxation dynamics of the multilayer structures is investigated in the framework of generalized Gaussian structures model using both Rouse and Zimm approaches. In the Rouse type-approach, we determine analytically the complete eigenvalues spectrum and based on it we calculate the mechanical relaxation moduli (storage and loss modulus) and the average monomer displacement. First, we monitor these physical quantities for structures with a fixed generation number and we increase the number of layers, such that the linear topology will smoothly come into play. Second, we keep constant the size of the structures, varying simultaneously two parameters: the generation number of the main layer, G, and the number of layers, c. This fact allows us to study in detail the crossover from a pure Husimi cactus behavior to a predominately linear chain behavior. The most interesting situation is found when the two limiting topologies cancel each other. For this case, we encounter in the intermediate frequency/time domain regions of constant slope for different values of the parameter set (G, c) and we show that the number of layers follows an exponential-law of G. In the Zimm-type approach, which includes the hydrodynamic interactions, the quantities that describe the mechanical relaxation dynamics do not show scaling behavior as in the Rouse model, except the limiting case, namely, a very high number of layers and low generation number.

  12. Dry etching technologies for reflective multilayer

    Iino, Yoshinori; Karyu, Makoto; Ita, Hirotsugu; Kase, Yoshihisa; Yoshimori, Tomoaki; Muto, Makoto; Nonaka, Mikio; Iwami, Munenori

    2012-11-01

    We have developed a highly integrated methodology for patterning Extreme Ultraviolet (EUV) mask, which has been highlighted for the lithography technique at the 14nm half-pitch generation and beyond. The EUV mask is characterized as a reflective-type mask which is completely different compared with conventional transparent-type of photo mask. And it requires not only patterning of absorber layer without damaging the underlying multi reflective layers (40 Si/Mo layers) but also etching multi reflective layers. In this case, the dry etch process has generally faced technical challenges such as the difficulties in CD control, etch damage to quartz substrate and low selectivity to the mask resist. Shibaura Mechatronics ARESTM mask etch system and its optimized etch process has already achieved the maximal etch performance at patterning two-layered absorber. And in this study, our process technologies of multi reflective layers will be evaluated by means of optimal combination of process gases and our optimized plasma produced by certain source power and bias power. When our ARES™ is used for multilayer etching, the user can choose to etch the absorber layer at the same time or etch only the multilayer.

  13. Is acute recurrent pancreatitis a chronic disease?

    Mariani, Alberto; Testoni, Pier Alberto

    2008-01-01

    Whether acute recurrent pancreatitis is a chronic disease is still debated and a consensus is not still reached as demonstrated by differences in the classification of acute recurrent pancreatitis. There is major evidence for considering alcoholic pancreatitis as a chronic disease ab initio while chronic pancreatitis lesions detectable in biliary acute recurrent pancreatitis (ARP) seem a casual association. Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutation, hereditary a...

  14. Recurrent, giant subcutaneous leiomyosarcoma of the thigh

    Gao Chuanping, MD

    2015-10-01

    Full Text Available We present a case of recurrent, massive subcutaneous leiomyosarcoma involving the left thigh in a 29-year-old male from Madagascar. The patient had earlier undergone local resection of subcutaneous leiomyosarcoma a half year before. After surgical intervention, local recurrence developed at this site and was rapidly growing. The patient was surgically treated with a 2-cm-wide margin local excision in our hospital. The patient has remained recurrence free at 1-year follow-up.

  15. Generalised Recurrence Plot Analysis for Spatial Data

    Marwan, Norbert; Kurths, Juergen; Saparin, Peter

    2006-01-01

    Recurrence plot based methods are highly efficient and widely accepted tools for the investigation of time series or one-dimensional data. We present an extension of the recurrence plots and their quantifications in order to study recurrent structures in higher-dimensional spatial data. The capability of this extension is illustrated on prototypical 2D models. Next, the tested and proved approach is applied to assess the bone structure from CT images of human proximal tibia. We find that the ...

  16. Recurrence quantification analysis of chimera states

    Santos, M. S.; Szezech, J. D.; Batista, A. M.; Caldas, I. L.; Viana, R. L.; Lopes, S. R.

    2015-10-01

    Chimera states, characterised by coexistence of coherence and incoherence in coupled dynamical systems, have been found in various physical systems, such as mechanical oscillator networks and Josephson-junction arrays. We used recurrence plots to provide graphical representations of recurrent patterns and identify chimera states. Moreover, we show that recurrence plots can be used as a diagnostic of chimera states and also to identify the chimera collapse.

  17. Faithfulness of Recurrence Plots: A Mathematical Proof

    Hirata, Yoshito; Komuro, Motomasa; Horai, Shunsuke; Aihara, Kazuyuki

    It is practically known that a recurrence plot, a two-dimensional visualization of time series data, can contain almost all information related to the underlying dynamics except for its spatial scale because we can recover a rough shape for the original time series from the recurrence plot even if the original time series is multivariate. We here provide a mathematical proof that the metric defined by a recurrence plot [Hirata et al., 2008] is equivalent to the Euclidean metric under mild conditions.

  18. Recurrence of gestational diabetes in primiparous women

    Kruse, Anne R; Darling, Mette S; Hansen, Mia K L

    2015-01-01

    Introduction Gestational diabetes mellitus (GDM) increases the risk for diabetes in the next pregnancy and later in life. Thus, estimating the risk of GDM in further pregnancies provides a time frame for possible preventive measures. We aimed to calculate the recurrence rate of GDM in primiparous...... and the subsequent pregnancy. Conclusions Recurrence of diet-treated GDM was 47.2% in primiparous women with previous GDM and the recurrence was associated with weight gain between pregnancies....

  19. Generalised recurrence plot analysis for spatial data

    Marwan, Norbert [Institute of Physics, University of Potsdam, 14415 Potsdam (Germany)]. E-mail: marwan@agnld.uni-potsdam.de; Kurths, Juergen [Institute of Physics, University of Potsdam, 14415 Potsdam (Germany); Saparin, Peter [Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam-Golm (Germany)

    2007-01-08

    Recurrence plot based methods are highly efficient and widely accepted tools for the investigation of time series or one-dimensional data. We present an extension of the recurrence plots and their quantifications in order to study recurrent structures in higher-dimensional spatial data. The capability of this extension is illustrated on prototypical 2D models. Next, the tested and proved approach is applied to assess the bone structure from CT images of human proximal tibia. We find that the spatial structures in trabecular bone become more recurrent during the bone loss in osteoporosis.

  20. Recurrent odontogenic keratocyst within the masticatory space

    Lim, Su Yeon; Huh, Kyung Hoe; Yi, Won Jin; Choi, Hyun Bae; Choi, Soon Chul [School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    2008-06-15

    The odontogenic keratocyst (OKC) is a developmental odontogenic cyst typically occurring in the jaws. Since the first description of OKC was published in 1956, the lesion has been of particular interest because of its specific histopathologic features, high recurrence rate, and aggressive behavior. Recurrences most commonly arise within bone at the site of the original cyst. However, as lining cells may find their way into surrounding tissues either from implantation during surgery or from cortical perforation recurrences may arise at a distance from the original cyst. Here, we report a rare case of recurrent OKC which was first developed in mandible and recurred within the masticatory space.

  1. Recurrence and Relapse in Bipolar Mood Disorder

    S Gh Mousavi

    2004-06-01

    Full Text Available Background: Despite the effectiveness of pharmacotherapy in acute phase of bipolar mood disorder, patients often experience relapses or recurrent episodes. Hospitalization of patients need a great deal of financial and humanistic resources which can be saved through understanding more about the rate of relapse and factors affecting this rate. Methods: In a descriptive analytical study, 380 patients with bipolar disorder who were hospitalized in psychiatric emergency ward of Noor hospital, Isfahan, Iran, were followed. Each patient was considered for; the frequency of relapse and recurrence, kind of pharmachotherapy, presence of psychotherapeutic treatments, frequency of visits by psychiatrist and the rank of present episode. Results: The overall prevalence of recurrence was 42.2%. Recurrence was lower in patients using lithium carbonate or sodium valproate or combined therapy (about 40%, compared to those using carbamazepine (80%. Recurrence was higher in patients treated with only pharmacotherapy (44.5% compared to those treated with both pharmacotherapy and psychotherapy (22.2%. Patients who were visited monthy by psychiatrist had lower rate of recurrence compared to those who had irregular visits. Conclusion: The higher rate of recurrence observed in carbamazepine therapy may be due to its adverse reactions and consequently poor compliance to this drug. Lower rates of recurrence with psychotherapy and regular visits may be related to the preventive effects of these procedures and especially to the effective management of stress. Keywords: Bipolar Mood Disorder, Recurrence, Relapse.

  2. Unique double recurrence of cerebral arteriovenous malformation.

    Nagm, Alhusain; Horiuchi, Tetsuyoshi; Ichinose, Shunsuke; Hongo, Kazuhiro

    2015-09-01

    Surgically treated patients with arteriovenous malformations (AVMs) are considered cured when the postoperative angiogram proves complete resection. However, despite no residual nidus or early draining vein on postoperative angiogram, rare instances of AVM recurrence have been reported in adults. In this paper, the authors present a case of a 24-year-old woman with asymptomatic double recurrence of her cerebral AVM after angiographically proven complete resection. To the authors' knowledge, this patient represents the first case with double de novo asymptomatic recurrence of Spetzler-Martin grade I AVM. Also, she represents the first case with unique AVM criteria in each recurrence.

  3. Palbociclib Isethionate in Treating Younger Patients With Recurrent, Progressive, or Refractory Central Nervous System Tumors

    2016-10-19

    Childhood Choroid Plexus Tumor; Childhood Ependymoblastoma; Childhood Grade III Meningioma; Childhood High-grade Cerebellar Astrocytoma; Childhood High-grade Cerebral Astrocytoma; Childhood Medulloepithelioma; Recurrent Childhood Anaplastic Astrocytoma; Recurrent Childhood Anaplastic Oligoastrocytoma; Recurrent Childhood Anaplastic Oligodendroglioma; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Giant Cell Glioblastoma; Recurrent Childhood Glioblastoma; Recurrent Childhood Gliomatosis Cerebri; Recurrent Childhood Gliosarcoma; Recurrent Childhood Medulloblastoma; Recurrent Childhood Pineoblastoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor

  4. Recurrent pregnancy loss and obesity.

    Sugiura-Ogasawara, Mayumi

    2015-05-01

    Recurrent pregnancy loss (RPL) was defined as two or more miscarriages. Antiphospholipid syndrome, uterine anomalies, and parental chromosomal abnormalities, particularly translocation and abnormal embryonic karyotype, are identifiable causes of RPL. Obesity may increase the risk of sporadic miscarriage in pregnancies conceived spontaneously. Obesity with body mass index (BMI)>30 kg/m2 is an independent risk factor for further miscarriage with odds ratio 1.7-3.5 in patients with early RPL. Obesity is associated with euploid miscarriage. Unexplained RPL with euploid embryo might be a common disease caused by both polymorphisms of multiple susceptibility genes and lifestyle factors such as women's age, obesity, and smoking. Patients with a history of RPL were found to have a higher risk of cardiovascular disease, celiac disease, gastric ulcer, gastritis, and atopic dermatitis. No study has examined the effect of weight loss on the prevention of further miscarriage in patients with RPL.

  5. Recurrent Primary Spinal Hydatid Cyst

    Okan Turk

    2015-03-01

    Full Text Available Primary hydatid disease of spine is rare and spinal hydatitosis constitute only 1% of all hydatitosis. We report a case of recurrent primary intraspinal extradural hydatid cyst of the thoracic region causing progressive paraparesis. The patient was operated 16 years ago for primary spinal hydatid disease involvement and was instrumented dorsally for stabilization. The magnetic resonance imaging (MRI of thoracic spine showed a cystic lesion at T11-12 level and compressed spinal cord posterolaterally. Intraspinal cyst was excised through T11-12 laminectomy which made formerly. The early postoperative period showed a progressive improvement of his neurological deficit and he was discharged with antihelmintic treatment consisting of albendazole and amoxicillin-sulbactam combination. [Cukurova Med J 2015; 40(Suppl 1: 84-89

  6. Atypical recurrence of rheumatic chorea

    Gunjan Pankaj Kumar

    2015-05-01

    Full Text Available Syndenhams Chorea in acute rheumatic fever is reported to occur in 20-30% of patients. It is usually late onset, occurring upto 6 months after acute infection but may occasionally be present as presenting symptom of rheumatic fever. It is a self-limiting condition with spontaneous remission lasting from 1 week to 6 months. The risk of recurrence is present in 1st 1-2 years in about 20% of cases. Most of children (two thirds with rheumatic fever are of school age (5-15 years of age. It is common in India and the incidence has not shown the declining trends seen in the developing countries. We report the clinical findings, investigations and the course of clinical development of a 14-year-old girl, who presented with Rheumatic chorea which recurred 3 years after the initial episode. [Int J Res Med Sci 2015; 3(5.000: 1272-1273

  7. Recurrent Glioblastoma: Where we stand

    Sanjoy Roy

    2015-01-01

    Full Text Available Current first-line treatment regimens combine surgical resection and chemoradiation for Glioblastoma that provides a slight increase in overall survival. Age on its own should not be used as an exclusion criterion of glioblastoma multiforme (GBM treatment, but performance should be factored heavily into the decision-making process for treatment planning. Despite aggressive initial treatment, most patients develop recurrent diseases which can be treated with re-resection, systemic treatment with targeted agents or cytotoxic chemotherapy, reirradiation, or radiosurgery. Research into novel therapies is investigating alternative temozolomide regimens, convection-enhanced delivery, immunotherapy, gene therapy, antiangiogenic agents, poly ADP ribose polymerase inhibitors, or cancer stem cell signaling pathways. Given the aggressive and resilient nature of GBM, continued efforts to better understand GBM pathophysiology are required to discover novel targets for future therapy.

  8. Recurrence of neuroleptic malignant syndrome.

    González-Blanco, Leticia; García-Prada, Hilario; Santamarina, Susana; Jiménez-Treviño, Luis; Bobes, Julio

    2013-01-01

    Neuroleptic malignant syndrome (NMS) is a rare idiosyncratic reaction associated with the use of neuroleptics that has an incidence of 0.02 to 3% among patients taking these drugs. This is a very serious complication with a mortality rate that reaches 10-20%. It is therefore very important to have high clinical suspicion and use appropriate criteria to objectify this clinical picture early, stopping the medication causing the picture and to avoid the subsequent complications as much as possible that would be responsible for both its mortality and sequels. We present that case of an 81-year old woman who was admitted to the Psychiatric Hospitalization Unit (PHU) for a depressive episode with psychotic symptoms who developed a neuroleptic malignant syndrome (NMS) when Haloperidol was introduced. After its suspension and subsequent clinical recovery, antipsychotic treatment with Risperidone was reintroduced and she suffered a recurrence of NMS. Finally, significant improvement was achieved with several sessions of electroshock therapy (EST).

  9. Pharmacotherapy of recurrent aphthous ulcers

    J P Angeline Archana

    2011-01-01

    Full Text Available Aphthous ulcer is the most common type of ulcer affecting the oral cavity and is considered to be one of the most painful conditions. Treatment is often unsatisfactory. Newer treatment modalities are therefore being tried. Amlexanox and rebamipide are the approved drugs for painful aphthous ulcers and have been used in painful symptoms of acid peptic disease as prostaglandin enhancers. Safety and efficacy of the drugs used in the treatment of recurrent aphthous ulcers were evaluated and being used widely by most of the treating physicians choosing a modality of treatment of their experience. There is no proper treatment modality available till date. Various drugs and their efficacy with least adverse drug effects while treating the various aphthous ulcers are discussed.

  10. Current management options for recurrent adrenocortical carcinoma

    Glover AR

    2013-06-01

    Full Text Available Anthony R Glover,1 Julian C Y Ip,1 Jing Ting Zhao,1 Patsy S H Soon,1,4 Bruce G Robinson,1,3 Stan B Sidhu1,2 1Kolling Institute of Medical Research, Cancer Genetics Laboratory, 2Endocrine Surgical Unit, 3Department of Endocrinology, Royal North Shore Hospital and University of Sydney, St Leonards, 4Department of Surgery, Bankstown Hospital and University of New South Wales, Bankstown, NSW, Australia Abstract: Adrenal cortical carcinoma (ACC is a rare cancer that poses a number of management challenges due to the limited number of effective systemic treatments. Complete surgical resection offers the best chance of long-term survival. However, despite complete resection, ACC is associated with high recurrence rates. This review will discuss the management of recurrent ACC in adults following complete surgical resection. Management should take place in a specialist center and treatment decisions must consider the individual tumor biology of each case of recurrence. Given the fact that ACC commonly recurs, management to prevent recurrence should be considered from initial diagnosis with the use of adjuvant mitotane. Close follow up with clinical examination and imaging is important for early detection of recurrent disease. Locoregional recurrence may be isolated, and repeat surgical resection should be considered along with mitotane. The use of radiotherapy in ACC remains controversial. Systemic recurrence most often involves liver, pulmonary, and bone metastasis and is usually managed with mitotane, with or without combination chemotherapy. There is a limited role for surgical resection in systemic recurrence in selected patients. In all patients with recurrent disease, control of excessive hormone production is an important part of management. Despite intensive management of recurrent ACC, treatment failure is common and the use of clinical trials and novel treatment is an important part of management. Keywords: recurrence, surgery, chemotherapy

  11. Risk factors for idiopathic optic neuritis recurrence.

    Yi Du

    Full Text Available Approximately 30-50% of idiopathic optic neuritis (ION patients experience one or multiple episodes of recurrence. The aim of this study was to search for risk factors for ION recurrence.Clinical data on hospitalized patients diagnosed with ION between January 2003 and January 2011 at the First Affiliated Hospital of Guangxi Medical University were retrospectively collected. Univariate and multivariate analyses were performed on factors that might cause ION recurrence. In total, 115 ION cases (32 recurrent and 83 non-recurrent cases with complete data were analyzed. The length of the follow-up period ranged from 12 to 108 months (median: 42 months.The univariate analysis showed that the recurrence rate for unilateral ION was higher than that for bilateral ION (40% vs. 12%, p=0.001. Underlying diseases had a significant impact on recurrence (p<0.001: the recurrence rates due to neuromyelitis optica (NMO, multiple sclerosis (MS, demyelinating lesions alone of the central nervous system, and unknown causes were 89%, 70%, 41%, and 8.7%, respectively. The multivariate analysis showed that the factors causing relatively high recurrence rates included NMO (odds ratio [OR], 73.5; 95% confidence interval [CI], 7.3 to 740.9, MS (OR, 33.9; 95% CI, 5.2 to 222.2, and demyelinating lesions alone (OR, 8.9; 95% CI, 2.3 to 34.4, unilateral involvement (OR, 5.7; 95% CI, 1.5 to 21.3, relatively low initial glucocorticoid dosage (equivalent to ≤ 100 mg prednisone/day (OR, 4.3; 95% CI, 1.0 to 17.9.Underlying diseases, laterality (unilateral or bilateral, and initial glucocorticoid dosage are important risk factors of ION recurrence. Clinical physicians are advised to treat ION patients with a sufficient dose of glucocorticoid in the initial treatment stage to reduce the recurrence risk.

  12. Interline power flow controller (IPFC) based damping recurrent neural network controllers for enhancing stability

    Banaei, M.R., E-mail: m.banaei@azaruniv.ed [Electrical Engineering Department, Faculty of Engineering, Azarbaijan University of Tarbiat Moallem, Tabriz (Iran, Islamic Republic of); Kami, A. [Electrical Engineering Department, Faculty of Engineering, Azarbaijan University of Tarbiat Moallem, Tabriz (Iran, Islamic Republic of)

    2011-07-15

    Highlights: {yields} A method is presented to improve power system stability using IPFC. {yields} Recurrent neural network controllers damp oscillations in a power system. {yields} Training is based on back propagation with adaptive training parameters. {yields} Selection of effectiveness damping control signal carried out using SVD method. -- Abstract: This paper presents a method to improve power system stability using IPFC based damping online learning recurrent neural network controllers for damping oscillations in a power system. Parameters of equipped controllers for enhancing dynamical stability at the IPFC are tuned using mathematical methods. Therefore these control parameters are often fixed and are set for particular system configurations or operating points. Multilayer recurrent neural network, which can be tuned for changing system conditions, is used in this paper for effectively damp the oscillations. Training is based on back propagation with adaptive training parameters. This controller is tested to variations in system loading and fault in the power system and its performance is compared with performance of a controller that the phase compensation method is used to set its parameters. Selection of effectiveness damping control signal for the design of robust IPFC damping controller carried out through singular value decomposition (SVD) method. Simulation studies show the superior robustness and stabilizing effect of the proposed controller in comparison with phase compensation method.

  13. Diagonal recurrent neural network based adaptive control of nonlinear dynamical systems using lyapunov stability criterion.

    Kumar, Rajesh; Srivastava, Smriti; Gupta, J R P

    2017-03-01

    In this paper adaptive control of nonlinear dynamical systems using diagonal recurrent neural network (DRNN) is proposed. The structure of DRNN is a modification of fully connected recurrent neural network (FCRNN). Presence of self-recurrent neurons in the hidden layer of DRNN gives it an ability to capture the dynamic behaviour of the nonlinear plant under consideration (to be controlled). To ensure stability, update rules are developed using lyapunov stability criterion. These rules are then used for adjusting the various parameters of DRNN. The responses of plants obtained with DRNN are compared with those obtained when multi-layer feed forward neural network (MLFFNN) is used as a controller. Also, in example 4, FCRNN is also investigated and compared with DRNN and MLFFNN. Robustness of the proposed control scheme is also tested against parameter variations and disturbance signals. Four simulation examples including one-link robotic manipulator and inverted pendulum are considered on which the proposed controller is applied. The results so obtained show the superiority of DRNN over MLFFNN as a controller.

  14. Building a Chaotic Proved Neural Network

    Bahi, Jacques M; Salomon, Michel

    2011-01-01

    Chaotic neural networks have received a great deal of attention these last years. In this paper we establish a precise correspondence between the so-called chaotic iterations and a particular class of artificial neural networks: global recurrent multi-layer perceptrons. We show formally that it is possible to make these iterations behave chaotically, as defined by Devaney, and thus we obtain the first neural networks proven chaotic. Several neural networks with different architectures are trained to exhibit a chaotical behavior.

  15. Final Progress Report on Robust and/or Adaptive Filtering by Neural Networks

    2007-11-02

    Conference on Artificial Neural Networks in Engineering , Nov. 4-7, 2001, St. Louis, Missouri. This paper shows that the risk-averting error criterion is...sensitive estimates, i.e., exhibiting an extremely high level of nonuniqueness . • Recurrent Multilayer Perceptrons for Discrete-Time Dynamic System...Proceedings of the 2001 Conference on Artificial Neural Networks in Engineering , St. Louis, Missouri, November 2001. 7. Avoiding Poor Local Minima in Training

  16. MRCP findings in recurrent pyogenic cholangitis

    Jain, Manoj [Department of Radiology, AMRI Hospitals, Salt Lake, JC-16 and 17 Salt Lake City, Kolkata 700091 (India)], E-mail: jainmanoj70@hotmail.com; Agarwal, Ajay [Department of Radiology, AMRI Hospitals, Salt Lake, JC-16 and 17 Salt Lake City, Kolkata 700091 (India)], E-mail: doctorajay2002@yahoo.co.in

    2008-04-15

    Objective: In this essay, we present the spectrum of intrahepatic and extrahepatic bile duct abnormalities seen on MRCP in patients with recurrent pyogenic cholangitis. Conclusion: MRCP is a promising, noninvasive alternative to more invasive direct cholangiography for evaluating the intrahepatic and extrahepatic bile ducts in patients with recurrent pyogenic cholangitis.

  17. Recurrent takotsubo cardiomyopathy in a child.

    Srivastava, Nayan T; Parent, John J; Hurwitz, Roger A

    2016-02-01

    Takotsubo cardiomyopathy or transient apical ballooning syndrome very rarely presents in children. In all patients with takotsubo, it is estimated that only 3.5% will have recurrence. In this study, we describe a case of recurrent takotsubo cardiomyopathy in a child, likely triggered by status epilepticus.

  18. Examestane in advanced or recurrent endometrial carcinoma

    Lindemann, Kristina; Malander, Susanne; Christensen, René dePont;

    2014-01-01

    We evaluated the efficacy and safety of the aromatase inhibitor exemestane in patients with advanced, persistent or recurrent endometrial carcinoma.......We evaluated the efficacy and safety of the aromatase inhibitor exemestane in patients with advanced, persistent or recurrent endometrial carcinoma....

  19. Recurrence in Major Depression: A Conceptual Analysis

    Monroe, Scott M.; Harkness, Kate L.

    2011-01-01

    Theory and research on major depression have increasingly assumed a recurrent and chronic disease model. Yet not all people who become depressed suffer recurrences, suggesting that depression is also an acute, time-limited condition. However, few if any risk indicators are available to forecast which of the initially depressed will or will not…

  20. Forequarter amputation for recurrent breast cancer

    Krishna N. Pundi

    2015-01-01

    Conclusion: Forequarter amputation can be judiciously used for patients with recurrent or metastatic breast cancer. Patients with recurrent disease without evidence of distant metastases may be considered for curative amputation, while others may receive palliative benefit; disappointingly our patient achieved neither of these outcomes. In the long term, these patients may still have significant psychological problems.

  1. Recurrent facial urticaria following herpes simplex labialis

    Vijay Zawar

    2012-01-01

    Full Text Available We describe recurrent acute right-sided facial urticaria associated with herpes labialis infection in a middle-aged female patient. Antiviral medications and antihistamines not only successfully cleared the herpes infection and urticaria but also prevented further recurrences.

  2. Recurrent respiratory papillomatosis : From diagnosis to treatment

    Tjon-Pian-Gi, Robin Edward Adrianus

    2016-01-01

    Recurrent respiratory papillomatosis (RRP) is a rare, benign, recurrent disease of the airway. Its warty lesions are associated with the Human papilloma virus (HPV) types 6 and 11, with a predisposition in the larynx. Because no curative treatment exists, some patients may require more than 100 surg

  3. ACQUIRED CUTIS LAXA WITH RECURRENT URTICARIA

    Ganaparthi

    2015-05-01

    Full Text Available A 30 year old male patient presented with progressive laxity and wrinkling of skin over the face for past 10 years, patient also gives history of recurrent urticaria since 12 years. Skin biopsy using Verhoff Van Gieson stain suggestive of cutis laxa. We are reporting a rare case of acquired cutis laxa with recurrent urticaria

  4. Plasmon Resonance in Multilayer Graphene Nanoribbons

    Emani, Naresh Kumar; Chung, Ting-Fung; Prokopeva, Ludmila J; Kildishev, Alexander V; Shalaev, Vladimir M; Chen, Yong P; Boltasseva, Alexandra

    2015-01-01

    Plasmon resonance in nanopatterned single layer graphene nanoribbon (SL-GNR), double layer graphene nanoribbon (DL-GNR) and triple layer graphene nanoribbon (TL-GNR) structures is studied both experimentally and by numerical simulations. We use 'realistic' graphene samples in our experiments to identify the key bottle necks in both experiments and theoretical models. The existence of electrical tunable plasmons in such stacked multilayer GNRs was first experimentally verified by infrared microscopy. We find that the strength of the plasmonic resonance increases in DL-GNR when compared to SL-GNRs. However, we do not find a further such increase in TL-GNRs compared to DL-GNRs. We carried out systematic full wave simulations using finite element technique to validate and fit experimental results, and extract the carrier scattering rate as a fitting parameter. The numerical simulations show remarkable agreement with experiments for unpatterned SLG sheet, and a qualitative agreement for patterned graphene sheet. W...

  5. Interface stress in Au/Ni multilayers

    Schweitz, K.O.; Böttiger, J.; Chevallier, J.;

    2000-01-01

    The effect of intermixing on the apparent interface stress is studied in -textured dc-magnetron sputtered Au/Ni multilayers by use of two methods commonly used for determining interface stress. The method using profilometry and in-plane x-ray diffraction does not take intermixing...... into account and yields an apparent interface stress of -8.46 +/- 0.99 J m(-2). However, observed discrepancies between model calculations and measured high-angle x-ray diffractograms indicate intermixing, and by use of the profilometry and sin(2) psi method the real interface stress value of -2.69 +/- 0.43 J...... m(-2) is found. This method also reveals a significant and systematic change of the stress-free lattice parameter of both constituents as a function of modulation period which is shown to account for the difference between the two findings. The method using in-plane diffraction is thus shown...

  6. The polymorphic, multilayered and networked urbanised territory

    Nielsen, Tom

    2015-01-01

    The discussion of the network city has in recent years been supplemented by an increasing interest in reconsidering the notion of territory. Looking into both geographical and urban design theories, we find examples of a focus on how the networks of the city not only connect them irreversibly...... of the main development characteristics of a low-profile example of a developing European urban region, Eastern Jutland in Denmark, the article contributes with a discussion of how concrete urban development perspectives in such a context can help inform the more general conceptualisation efforts developed...... in theory. The concept of The Polymorphic, Multilayered and Networked Urbanised Territory is introduced to grasp the reality experienced in European regions outside the largest and most potent versions of contemporary cities....

  7. Multilayer Network Analysis of Nuclear Reactions

    Zhu, Liang; Ma, Yu-Gang; Chen, Qu; Han, Ding-Ding

    2016-08-01

    The nuclear reaction network is usually studied via precise calculation of differential equation sets, and much research interest has been focused on the characteristics of nuclides, such as half-life and size limit. In this paper, however, we adopt the methods from both multilayer and reaction networks, and obtain a distinctive view by mapping all the nuclear reactions in JINA REACLIB database into a directed network with 4 layers: neutron, proton, 4He and the remainder. The layer names correspond to reaction types decided by the currency particles consumed. This combined approach reveals that, in the remainder layer, the β-stability has high correlation with node degree difference and overlapping coefficient. Moreover, when reaction rates are considered as node strength, we find that, at lower temperatures, nuclide half-life scales reciprocally with its out-strength. The connection between physical properties and topological characteristics may help to explore the boundary of the nuclide chart.

  8. A multilayer surface detector for ultracold neutrons

    Wang, Zhehui; Callahan, N B; Adamek, E R; Bacon, J D; Blatnik, M; Brandt, A E; Broussard, L J; Clayton, S M; Cude-Woods, C; Currie, S; Dees, E B; Ding, X; Gao, J; Gray, F E; Hoffbauer, M A; Holley, A T; Ito, T M; Liu, C -Y; Makela, M; Ramsey, J C; Pattie,, R W; Salvat, D J; Saunders, A; Schmidt, D W; Schulze, R K; Seestrom, S J; Sharapov, E I; Sprow, A; Tang, Z; Wei, W; Wexler, J W; Womack, T L; Young, A R; Zeck, B A

    2015-01-01

    A multilayer surface detector for ultracold neutrons (UCNs) is described. The top $^{10}$B layer is exposed to the vacuum chamber and directly captures UCNs. The ZnS:Ag layer beneath the $^{10}$B layer is a few microns thick, which is sufficient to detect the charged particles from the $^{10}$B(n,$\\alpha$)$^7$Li neutron-capture reaction, while thin enough so that ample light due to $\\alpha$ and $^7$Li escapes for detection by photomultiplier tubes. One-hundred-nm thick $^{10}$B layer gives high UCN detection efficiency, as determined by the mean UCN kinetic energy, detector materials and others. Low background, including negligible sensitivity to ambient neutrons, has also been verified through pulse-shape analysis and comparisons with other existing $^3$He and $^{10}$B detectors. This type of detector has been configured in different ways for UCN flux monitoring, development of UCN guides and neutron lifetime research.

  9. A multilayer surface detector for ultracold neutrons

    Wang, Zhehui, E-mail: zwang@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Hoffbauer, M.A.; Morris, C.L. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Callahan, N.B.; Adamek, E.R. [Indiana University, Bloomington, IN 47405 (United States); Bacon, J.D. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Blatnik, M. [Cleveland State University, Cleveland, OH 44115 (United States); Brandt, A.E. [North Carolina State University, Raleigh, NC 27695 (United States); Broussard, L.J.; Clayton, S.M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Cude-Woods, C. [North Carolina State University, Raleigh, NC 27695 (United States); Currie, S. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Dees, E.B. [North Carolina State University, Raleigh, NC 27695 (United States); Ding, X. [Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Gao, J. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Gray, F.E. [Regis University, Denver, CO 80221 (United States); Hickerson, K.P. [University of California Los Angeles, Los Angeles, CA 90095 (United States); Holley, A.T. [Tennessee Technological University, Cookeville, TN 38505 (United States); Ito, T.M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Liu, C.-Y. [Indiana University, Bloomington, IN 47405 (United States); and others

    2015-10-21

    A multilayer surface detector for ultracold neutrons (UCNs) is described. The top {sup 10}B layer is exposed to vacuum and directly captures UCNs. The ZnS:Ag layer beneath the {sup 10}B layer is a few microns thick, which is sufficient to detect the charged particles from the {sup 10}B(n,α){sup 7}Li neutron-capture reaction, while thin enough that ample light due to α and {sup 7}Li escapes for detection by photomultiplier tubes. A 100-nm thick {sup 10}B layer gives high UCN detection efficiency, as determined by the mean UCN kinetic energy, detector materials, and other parameters. Low background, including negligible sensitivity to ambient neutrons, has also been verified through pulse-shape analysis and comparison with other existing {sup 3}He and {sup 10}B detectors. This type of detector has been configured in different ways for UCN flux monitoring, development of UCN guides and neutron lifetime research.

  10. Multilayer solar cell waveguide structures containing metamaterials

    Hamouche, Houria.; Shabat, Mohammed. M.; Schaadt, Daniel M.

    2017-01-01

    Multilayer antireflection coating structures made from silicon and metamaterials are designed and investigated using the Transfer Matrix Method (TMM). The Transfer Matrix Method is a very useful algorithm for the analysis of periodic structures. We investigate in this paper two anti-reflection coating structures for silicon solar cells with a metamaterial film layer. In the first structure, the metamaterial film layer is sandwiched between a semi-infinite glass cover layer and a semi-infinite silicon substrate layer. The second structure consists of a four layers, a pair of metamaterial-dielectric layer with opposite real part of refractive indices, is placed between the two semi-infinite cover and substrate. We have simulated the absorptivity property of the structures for adjustable thicknesses by using MAPLE software. The absorptivity of the structures achieves greater than 80% for incident electromagnetic wave of transverse magnetic (TM) polarization.

  11. Multilayer Statistical Intrusion Detection in Wireless Networks

    Noureddine Boudriga

    2008-12-01

    Full Text Available The rapid proliferation of mobile applications and services has introduced new vulnerabilities that do not exist in fixed wired networks. Traditional security mechanisms, such as access control and encryption, turn out to be inefficient in modern wireless networks. Given the shortcomings of the protection mechanisms, an important research focuses in intrusion detection systems (IDSs. This paper proposes a multilayer statistical intrusion detection framework for wireless networks. The architecture is adequate to wireless networks because the underlying detection models rely on radio parameters and traffic models. Accurate correlation between radio and traffic anomalies allows enhancing the efficiency of the IDS. A radio signal fingerprinting technique based on the maximal overlap discrete wavelet transform (MODWT is developed. Moreover, a geometric clustering algorithm is presented. Depending on the characteristics of the fingerprinting technique, the clustering algorithm permits to control the false positive and false negative rates. Finally, simulation experiments have been carried out to validate the proposed IDS.

  12. Guided wave propagation in multilayered piezoelectric structures

    2009-01-01

    A general formulation of the method of the reverberation-ray matrix (MRRM) based on the state space formalism and plane wave expansion technique is presented for the analysis of guided waves in multilayered piezoelectric structures. Each layer of the structure is made of an arbitrarily anisotropic piezoelectric material. Since the state equation of each layer is derived from the three-dimensional theory of linear piezoelectricity, all wave modes are included in the formulation. Within the framework of the MRRM, the phase relation is properly established by excluding exponentially growing functions, while the scattering relation is also appropriately set up by avoiding matrix inversion operation. Consequently, the present MRRM is unconditionally numerically stable and free from computational limitations to the total number of layers, the thickness of individual layers, and the frequency range. Numerical examples are given to illustrate the good performance of the proposed formulation for the analysis of the dispersion characteristic of waves in layered piezoelectric structures.

  13. PROACTIVE NETWORK SECURITYAPPROACH FOR MULTILAYERED ARCHITECURE

    Lalitha Kumari R

    2013-06-01

    Full Text Available In order to fulfill the organization goals and objectives, multilayered network architecture and various heterogeneous server environments are used. As the network architectures are complex, there is an increased demand in information security. So each organization needs to provide sufficient network security for the known and the unknown attacks according to its goals, requirements and objectives. Highly skilled hacker’s everyday discovers the new threats in order to break the security bridge in each organization. Hence the organizations are forced to revise their security policies in order to handle the network vulnerabilities that are increasing day by day. So to handle this issue a proactive network strategy is proposed against network vulnerabilities such as fraud, information leakage, denial of service attack and so on. By this approach the network is scanned periodically and the threats are prioritized andevaluated accordingly.

  14. Plasmon resonance in multilayer graphene nanoribbons

    Emani, Naresh Kumar; Wang, Di; Chung, Ting Fung

    2015-01-01

    Plasmon resonances in nanopatterned single-layer graphene nanoribbons (SL-GNRs), double-layer graphene nanoribbons (DL-GNRs) and triple-layer graphene nanoribbons (TL-GNRs) are studied experimentally using 'realistic' graphene samples. The existence of electrically tunable plasmons in stacked...... multilayer graphene nanoribbons was first experimentally verified by infrared microscopy. We find that the strength of the plasmonic resonance increases in DL-GNRs when compared to SL-GNRs. However, further increase was not observed in TL-GNRs when compared to DL-GNRs. We carried out systematic full......-wave simulations using a finite-element technique to validate and fit experimental results, and extract the carrier-scattering rate as a fitting parameter. The numerical simulations show remarkable agreement with experiments for an unpatterned SLG sheet, and a qualitative agreement for a patterned graphene sheet...

  15. An ultra-broadband multilayered graphene absorber

    Amin, Muhammad

    2013-01-01

    An ultra-broadband multilayered graphene absorber operating at terahertz (THz) frequencies is proposed. The absorber design makes use of three mechanisms: (i) The graphene layers are asymmetrically patterned to support higher order surface plasmon modes that destructively interfere with the dipolar mode and generate electromagnetically induced absorption. (ii) The patterned graphene layers biased at different gate voltages backedup with dielectric substrates are stacked on top of each other. The resulting absorber is polarization dependent but has an ultra-broadband of operation. (iii) Graphene\\'s damping factor is increased by lowering its electron mobility to 1000cm 2=Vs. Indeed, numerical experiments demonstrate that with only three layers, bandwidth of 90% absorption can be extended upto 7THz, which is drastically larger than only few THz of bandwidth that can be achieved with existing metallic/graphene absorbers. © 2013 Optical Society of America.

  16. Optical localization in quasi-periodic multilayers

    Vasconcelos, M. S.; Albuquerque, E. L.; Mariz, A. M.

    1998-07-01

    We investigate the optical transmission spectra of quasi-periodic dielectric multilayer slabs arranged in a fashion that exhibits what has been called deterministic disorders. They can be of the so-called substitutional sequences type, and are characterized by the nature of their Fourier spectrum, which can be dense pure point (e.g. a Fibonacci sequence) or singular continuous (e.g. Thue-Morse and double-period sequences). The transmission coefficients are conveniently derived by using a theoretical model based on the transfer-matrix approach. A comparison between the oblique-incidence optical transmission spectrum and the normal-incidence one shows quite a different transmission behaviours over a particular range of frequency.

  17. Transmission fingerprints in quasiperiodic dielectric multilayers

    Vasconcelos, M. S.; Albuquerque, E. L.

    1999-05-01

    We investigate the optical transmission fingerprints in structures that exhibit deterministic disorders. A class of models that has attracted particular attention in this context are the quasiperiodic dielectric multilayers that obey a substitutional sequence. These substitutional sequence are characterized by the nature of their Fourier spectrum, which can be dense pure point (Fibonacci sequences), singular continuous (Thue-Morse and double-period sequences), and absolutely continuous (Rudin-Shapiro sequence). We use a transfer-matrix approach to derive the optical transmission coefficients. Numerical results are presented to illustrate the self-similar aspect of the spectra, as well as to show the optical fingerprint through a return map of the transmission coefficients.

  18. Multilayer network analysis of nuclear reactions

    Zhu, Liang; Chen, Qu; Han, Ding-Ding

    2016-01-01

    The nuclear reaction network is usually studied via precise calculation of differential equation sets, and much research interest has been focused on the characteristics of nuclides, such as half-life and size limit. In this paper, however, we adopt the methods from both multilayer and reaction networks, and obtain a distinctive view by mapping all the nuclear reactions in JINA REACLIB database into a directed network with 4 layers: neutron, proton, $^4$He and the remainder. The layer names correspond to reaction types decided by the currency particles consumed. This combined approach reveals that, in the remainder layer, the $\\beta$-stability has high correlation with node degree difference and overlapping coefficient. Moreover, when reaction rates are considered as node strength, we find that, at lower temperatures, nuclide half-life scales reciprocally with its out-strength. The connection between physical properties and topological characteristics may help to explore the boundary of the nuclide chart.

  19. Design and Performance of Capping Layers for EUV Multilayer Mirrors

    Bajt, S; Chapman, H N; Nuygen, N; Alameda, J; Robinson, J C; Malinowski, M; Gullikson, E; Aquila, A; Tarrio, C; Grantham, S

    2003-03-10

    The reflectance stability of multilayer coatings for extreme ultraviolet lithography (EUVL) in a commercial tool environment is of uttermost importance to ensure continuous exposures with minimum maintenance cost. We have made substantial progress in designing the protective capping layer coatings, understanding their performance and estimating their lifetimes based on accelerated electron beam and EUV exposure studies. Our current capping layer coatings have about 40 times longer lifetimes than Si-capped multilayer optics. Nevertheless, the lifetime of current Ru-capped multilayers is too short to satisfy commercial tool requirements and further improvements are essential.

  20. On degree-degree correlations in multilayer networks

    de Arruda, Guilherme Ferraz; Moreno, Yamir; Rodrigues, Francisco A

    2015-01-01

    We propose a generalization of the concept of assortativity based on the tensorial representation of multilayer networks, covering the definitions given in terms of Pearson and Spearman coefficients. Our approach can also be applied to weighted networks and provides information about correlations considering pairs of layers. By analyzing the multilayer representation of the airport transportation network, we show that contrasting results are obtained when the layers are analyzed independently or as an interconnected system. Finally, we study the impact of the level of assortativity and heterogeneity between layers on the spreading of diseases. Our results highlight the need of studying degree-degree correlations on multilayer systems, instead of on aggregated networks.

  1. Release-rate calorimetry of multilayered materials for aircraft seats

    Fewell, L. L.; Parker, J. A.; Duskin, F.; Speith, H.; Trabold, E.

    1980-01-01

    Multilayered samples of contemporary and improved fire-resistant aircraft seat materials were evaluated for their rates of heat release and smoke generation. Top layers with glass-fiber block cushion were evaluated to determine which materials, based on their minimum contributions to the total heat release of the multilayered assembly, may be added or deleted. The smoke and heat release rates of multilayered seat materials were then measured at heat fluxes of 1.5 and 3.5 W/cm2. Abrasion tests were conducted on the decorative fabric covering and slip sheet to ascertain service life and compatibility of layers

  2. Multilayer optics for coherent EUV/X-ray laser sources

    Delmotte, F.; Dehlinger, M.; Bourassin-Bouchet, Ch.; de Rossi, S.; Jerome, A.; Meltchakov, E.; Varnière, F.

    2015-09-01

    After a brief review of recent results achieved at Laboratoire Charles Fabry concerning high reflectivity mirrors, mirrors with enhanced spectral purity and broadband mirrors, we describe a new approach to design high efficiency multilayer mirrors for application on a broad spectral range. The main idea is to use 2 "spacer" materials (Aluminum and Scandium) in combination with a third material (Boron carbide or Silicon Carbide). We present several examples of design optimization using such multilayers. Finally, we show the first preliminary experimental results with Al/Sc/B4C and Al/Sc/SiC multilayers deposited by ion beam sputtering.

  3. Rheological Properties of Fractal Deformation in Multilayer Folds

    HOU Guiting

    2009-01-01

    The fractal dimensions of foIds are related to layer thickness and viscosity of the multilayer.This paper discusses how the thickness,viscosity,and anisotropic degree affect the rheological deformation of fractal folds in mulfilayers.The number of layers,their thicknesses,viscosities,and anisotropic degree of multilayers cooperate to affect the rheological deformation of folds,which is not controlled by a single rheological factor.A greater anisotropic degree of multilayers is favorable to develop the more complex and disharmonious fractal folds.

  4. On degree-degree correlations in multilayer networks

    de Arruda, Guilherme Ferraz; Cozzo, Emanuele; Moreno, Yamir; Rodrigues, Francisco A.

    2016-06-01

    We propose a generalization of the concept of assortativity based on the tensorial representation of multilayer networks, covering the definitions given in terms of Pearson and Spearman coefficients. Our approach can also be applied to weighted networks and provides information about correlations considering pairs of layers. By analyzing the multilayer representation of the airport transportation network, we show that contrasting results are obtained when the layers are analyzed independently or as an interconnected system. Finally, we study the impact of the level of assortativity and heterogeneity between layers on the spreading of diseases. Our results highlight the need of studying degree-degree correlations on multilayer systems, instead of on aggregated networks.

  5. Design considerations for energy efficient, resilient, multi-layer networks

    Fagertun, Anna Manolova; Hansen, Line Pyndt; Ruepp, Sarah Renée

    2016-01-01

    This work investigates different network design considerations with respect to energy-efficiency, under green-field resilient multi-layer network deployment. The problem of energy efficient, reliable multi-layer network design is known to result in different trade-offs between key performance...... in multi-layer networks and performance measures such as network resource utilization, availability, agility to traffic fluctuations and energy consumption. A green-field network deployment scenario is considered, where different resiliency methods, design methodologies and grooming strategies are applied...

  6. Epidemic spreading and bond percolation in multilayer networks

    Bianconi, Ginestra

    2016-01-01

    The Susceptible-Infected-Recovered (SIR) model is studied in multilayer networks with arbitrary number of links across the layers. By following the mapping to bond percolation we give the exact expression for the epidemic threshold and the fraction of the infected individuals in arbitrary number of layers. The case of a multilayer network formed by two interconnected networks is specifically studied as a function of the degree distribution within and across the layers. We show that the epidemic threshold strongly depends on the degree correlations of the multilayer structure. Finally we relate our results to the results obtained in the annealed approximation for the Susceptible-Infected-Susceptible (SIS) model.

  7. Multilayer Approach for Advanced Hybrid Lithium Battery

    Ming, Jun

    2016-06-06

    Conventional intercalated rechargeable batteries have shown their capacity limit, and the development of an alternative battery system with higher capacity is strongly needed for sustainable electrical vehicles and hand-held devices. Herein, we introduce a feasible and scalable multilayer approach to fabricate a promising hybrid lithium battery with superior capacity and multivoltage plateaus. A sulfur-rich electrode (90 wt % S) is covered by a dual layer of graphite/Li4Ti5O12, where the active materials S and Li4Ti5O12 can both take part in redox reactions and thus deliver a high capacity of 572 mAh gcathode -1 (vs the total mass of electrode) or 1866 mAh gs -1 (vs the mass of sulfur) at 0.1C (with the definition of 1C = 1675 mA gs -1). The battery shows unique voltage platforms at 2.35 and 2.1 V, contributed from S, and 1.55 V from Li4Ti5O12. A high rate capability of 566 mAh gcathode -1 at 0.25C and 376 mAh gcathode -1 at 1C with durable cycle ability over 100 cycles can be achieved. Operando Raman and electron microscope analysis confirm that the graphite/Li4Ti5O12 layer slows the dissolution/migration of polysulfides, thereby giving rise to a higher sulfur utilization and a slower capacity decay. This advanced hybrid battery with a multilayer concept for marrying different voltage plateaus from various electrode materials opens a way of providing tunable capacity and multiple voltage platforms for energy device applications. © 2016 American Chemical Society.

  8. Characterization of stickiness by means of recurrence.

    Zou, Yong; Thiel, Marco; Romano, M Carmen; Kurths, Jürgen

    2007-12-01

    We propose recurrence plots (RPs) to characterize the stickiness of a typical area-preserving map with coexisting chaotic and regular orbits. The difference of the recurrence properties between quasiperiodic and chaotic orbits is revisited, which helps to understand the complex patterns of the corresponding RPs. Moreover, several measures from the recurrence quantification analysis are used to quantify these patterns. Among these measures, the recurrence rate, quantifying the percentage of black points in the plot, is applied to characterize the stickiness of a typical chaotic orbit. The advantage of the recurrence based method in comparison to other standard techniques is that it is possible to distinguish between quasiperiodic and chaotic orbits that are temporarily trapped in a sticky domain, from very short trajectories.

  9. Calcaneal chondroblastoma with pathologic fracture and recurrence.

    Dutt, Laksha; Schade, Valerie L; Manoso, Mark W

    2015-01-01

    Chondroblastomas account for 80% of cases. Local recurrence rates of ≤38% have been reported, most often because of inadequate resection, and have been associated with malignant conversion and metastasis. Adjuvant therapies can help minimize the incidence of local recurrence. Long-term follow-up examinations are recommended, given the protracted interval that can exist between recurrence and the potential for malignant conversion and metastasis. We present the case of a young, healthy, active male with a calcaneal chondroblastoma and associated pathologic fracture whose initial treatment consisted of curettage, hydrogen peroxide lavage, and allogeneic bone grafting. Recurrence developed at 15 months postoperatively and was treated with repeat curettage, high-speed burring, and reconstruction with steel Steinman pins and polymethylmethacrylate, resulting in no pain or recurrence at the 5-month follow-up point.

  10. Recurrent well-differentiated thyroid carcinoma.

    Magarey, Matthew J R; Freeman, Jeremy L

    2013-07-01

    The incidence of Well-differentiated Thyroid Carcinoma (WDTC) has been increasing over the past several decades. Consequently, so has the incidence of recurrence, which ranges from 15% to 30%. Factors leading to increased risk of recurrence are well described. However, the impact of local and regional recurrence is not well understood, but distant recurrence dramatically reduces 10-year survival to 50%. Recurrent WDTC has several established options for treatment; Observation, Radioactive Iodine (RAI), Surgery and External Beam Radiotherapy (EBRT). Novel treatments such as radiofrequency ablation (RFA) and percutaneous ultrasound-guided ethanol injection (PUEI) are beginning to gain popularity and have promising early results. A review of the current literature, outcome measurements and a strategy for revision surgery within the central neck compartment are discussed within this manuscript.

  11. 6th International Symposium on Recurrence Plots

    Jr, Jr; Ioana, Cornel; Marwan, Norbert

    2016-01-01

    The chapters in this book originate from the research work and contributions presented at the Sixth International Symposium on Recurrence Plots held in Grenoble, France in June 2015. Scientists from numerous disciplines gathered to exchange knowledge on recent applications and developments in recurrence plots and recurrence quantification analysis. This meeting was remarkable because of the obvious expansion of recurrence strategies (theory) and applications (practice) into ever-broadening fields of science. It discusses real-world systems from various fields, including mathematics, strange attractors, applied physics, physiology, medicine, environmental and earth sciences, as well as psychology and linguistics. Even readers not actively researching any of these particular systems will benefit from discovering how other scientists are finding practical non-linear solutions to specific problems. The book is of interest to an interdisciplinary audience of recurrence plot users and researchers interested in time...

  12. Recurrence of autoimmune liver diseases after livertransplantation

    2015-01-01

    Liver transplantation (LT) is the most effective treatmentmodality for end stage liver disease caused by manyetiologies including autoimmune processes. That said,the need for transplantation for autoimmune hepatitis(AIH) and primary biliary cirrhosis (PBC), but not forprimary sclerosing cholangitis (PSC), has decreasedover the years due to the availability of effective medicaltreatment. Autoimmune liver diseases have superiortransplant outcomes than those of other etiologies. WhileAIH and PBC can recur after LT, recurrence is of limitedclinical significance in most, but not all cases. RecurrentPSC, however, often progresses over years to a stagerequiring re-transplantation. The exact incidence andthe predisposing factors of disease recurrence remaindebated. Better understanding of the pathogenesis andthe risk factors of recurrent autoimmune liver diseasesis required to develop preventive measures. In thisreview, we discuss the current knowledge of incidence,diagnosis, risk factors, clinical course, and treatmentof recurrent autoimmune liver disease (AIH, PBC, PSC)following LT.

  13. Alisertib in Treating Young Patients With Recurrent or Refractory Solid Tumors or Leukemia

    2016-07-20

    Hepatoblastoma; Previously Treated Childhood Rhabdomyosarcoma; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Childhood Kidney Neoplasm; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Neuroblastoma; Recurrent Osteosarcoma

  14. Experimental Comparison of Extreme-Ultraviolet Multilayers for Solar Physics

    Windt, David L.; Donguy, Soizik; Seely, John; Kjornrattanawanich, Benjawan

    2004-03-01

    We compare the reflectance and stability of multilayers comprising either Si/Mo, Si/Mo2C, Si/B4C, Si/C, or Si/SiC bilayers, designed for use as extreme-ultraviolet (EUV) reflective coatings. The films were deposited by using magnetron sputtering and characterized by both x-ray and EUV reflectometry. We find that the new Si/SiC multilayer offers the greatest spectral selectivity at the longer wavelengths, as well as the greatest thermal stability. We also describe the optimization of multilayers designed for the Solar-B EIS instrument. Finally, we compare experimental reflectance data with calculations and conclude that currently available optical constants cannot be used to adequately model the performance of many of these multilayers.

  15. Physics and technology development of multilayer EUV reflective optics

    Louis, E.

    2012-01-01

    This thesis describes the development of molybdenum/silicon based multilayer reflective elements for the Extreme UV wavelength range, as motivated by their application in photolithography for semiconductor manufacturing. The thesis reflects the basic thin film physics, technological developments, an

  16. Synthesis of Nanostructured Nanoclay-Zirconia Multilayers: a Feasibility Study

    Hao Chen

    2008-01-01

    Full Text Available This paper reports the first effort to synthesize a new class of inorganic nanostructured materials consisting of alternating ultrathin layers of nanoclays and oxide ceramics. A novel solution-based layer-by-layer (LBL deposition technique was developed to prepare multilayers of hydrated Zr cations and nanoclays. This LBL deposition technique is devised by integrating an electrostatic-mediated dip coating method for making nanoclay-polymer multilayers with a successive ionic layer adsorption and reaction method for making ultrathin oxide films. Nanostructured clay-zirconia multilayer composites formed through subsequent annealing. Characterization by scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction confirmed that these films are uniform and crack-free, consist of no detectable impurities, and possess nanoscale-layered structure. The incorporation of nanoclays facilitates the electrostatic-mediated assembling of multilayers, enhances the structural integrity, and provides a generic framework to construct functionally graded materials. Potential applications are envisaged.

  17. Multi-layer Far-Infrared Component Technology Project

    National Aeronautics and Space Administration — This Phase I SBIR will demonstrate the feasibility of a process to create multi-layer thin-film optics for the far-infrared/sub-millimeter wave spectral region. The...

  18. Broad-Band EUV Multilayer Coatings For Solar Physics Project

    National Aeronautics and Space Administration — We propose to develop and commercialize a new class of aperiodic multilayer coating that is designed to provide high normal-incidence reflectance over a wide...

  19. Spectral Resolution Improvement of Mo/Si Multilayers

    WU Wen-Juan; WANG Zhan-Shan; ZHU Jing-Tao; ZHANG Zhong; WANG Feng-Li; CHEN Ling-Yan; ZHOU Hong-Jun; HUO Tong-Lin

    2011-01-01

    @@ Theoretically, the spectral resolution of a multilayer can be improved through a combination of utilizing high reflectance orders and by decreasing the thickness of the scattering layer.We fabricate Mo/Si multilayers in the first, second, third, fourth and fifth reflectance orders with Mo layer thicknesses of 3.Onm and 2.0nm,respectively, using direct current magnetron sputtering.The structure of the multilayers is characterized with a grazing angle x-ray diffractometer(XRD).Then the reflectivity of the multilayers is measured in a synchrotron radiation facility.The results show that the spectral resolution increases with the increasing reflectance order and with the decreasing Mo layer thickness.The highest spectral resolution is improved to 117.5 in the 5th order for dm.=2 nm, where the reflectivity is 18%.

  20. Gadolinium EUV Multilayers for Solar Imaging Near 60 nm Project

    National Aeronautics and Space Administration — We propose to develop and commercialize a new class of extreme ultraviolet (EUV) multilayer coatings containing the rare-earth element gadolinium (Gd), designed as...

  1. Wave transmission prediction of multilayer floating breakwater using neural network

    Mandal, S.; Patil, S.G.; Hegde, A.V.

    In the present study, an artificial neural network method has been applied for wave transmission prediction of multilayer floating breakwater. Two neural network models are constructed based on the parameters which influence the wave transmission...

  2. Multi-layer perception approach to identification of compound information

    孙金玮; 李德胜

    2001-01-01

    Presents a novel approach of multi-layer sensing for perception of high-level environmental information related to many conventional physical quantities, such as temperature, humidity and brightness, which focuses on the processing of multi-functional variables in a multi-layer framework, and consists of multi-functional sensing and multi-layer fusion. Concerning the first aspect, a CdS and Fe3 O4 materials based multi-functionsensor has been developed to measure the three quantities, and provides a possible solution to the sensor multifunctional measurement equations, especially when the sensor processes more than three quantities, and proposes ways to evaluate the concerned environment as degree of comfort, Quantity Creditability Tactics (QCT) of multi-layer data fusion.

  3. Analysis of finite conductivity fractures intercepting multilayer reservoirs

    Bennett, C.; Raghavan, R.; Reynolds, A.C.

    1982-09-01

    This paper presents the analytical and numerical results of an examination into the response of a fractured well in a multi-layered reservoir. The analytical solutions derived are new and served three functions. First, they enabled the verification of the numerical solutions. Second, they provided information on the structure of the solution, and thus increased physical understanding. Third, they suggested a method whereby the authors were able to correlate multi-layer solutions with the single-layer solutions. The authors show that under certain circumstances the well response of wells draining multilayer reservoirs can be correlated with single-layer reservoirs. They also find that the ratio of the fracture height to the fracture length has an influence on well performance. This influence is discussed. The authors also consider the analysis of buildup data following a short producing time. They show that the multi-layer buildup solutions can be correlated with the single-layer buildup solutions.

  4. Analysis of finite conductivity fractures intercepting multilayer reservoirs

    Bennett, C.O.; Reynolds, A.C.; Raghavan, R.

    1982-01-01

    The response of a fractured well in a multilayered reservoir is the primary subject of this study. Both analytic and numeric results are presented. The analytic solutions derived are new and served 3 important functions. First, they enable verification of the numeric solutions used in this study. Second, they provided information on the structure of the solution, and thus increased physical understanding. Third, they suggested a method for correlating multilayer solutions with the single-layer solutions. The well response of wells draining multilayer reservoirs can be correlated with single-layer reservoirs. It also was found that the ratio of the fracture height to fracture length has an influence on well performance. The analysis of buildup data following a short producing time is considered. It is shown that the multilayer buildup solutions can be correlated with the single-layer buildup solutions. 21 references.

  5. CoTaZr/Pd multilayer with perpendicular magnetic anisotropy

    Yong Chang Lau

    2013-08-01

    Full Text Available We report a novel perpendicularly magnetized thin film [Co91.5Ta4.5Zr4/Pd]5 multilayer, which exhibits strong perpendicular magnetic anisotropy when grown on 5 nm of Pd and Ru seed layers. The Pd-seeded multilayer annealed at 300 °C shows an effective uniaxial anisotropy constant, Keff = 1.1 MJ m−3, with an anisotropy field as high as 1.6 T. The perpendicular anisotropy is sustained on annealing at 400 °C for 1 h. X-ray diffraction on multilayers with 30 repeats suggests that the use of amorphous CoTaZr reduces the stress of the stack, compared to [Co/Pd] multilayer.

  6. Determinants of recurrence after intended curative resection for colorectal cancer

    Wilhelmsen, Michael; Kring, Thomas; Jorgensen, Lars N;

    2014-01-01

    in development of recurrence. It is well established that emergency surgery is a major determinant of recurrence. Moreover, anastomotic leakages, postoperative bacterial infections, and blood transfusions increase the recurrence rates although the exact mechanisms still remain obscure. From pathology studies...

  7. Recurrent seizures after lidocaine ingestion

    Hamed Aminiahidashti

    2015-01-01

    Full Text Available Lidocaine has a concentration-dependent effect on seizures. Concentrations above 15 μg/mL frequently result in seizures in laboratory animals and human. We report a case of central nervous system (CNS lidocaine toxicity and recurrent seizure after erroneous ingestion of lidocaine solution. A 4-year-old boy presented to the Emergency Department of Imam Hospital of Sari in December 2013 due to tonic-clonic generalized seizures approximately 30 min ago. 3 h before seizure, his mother gave him 2 spoons (amount 20-25 cc lidocaine hydrochloride 2% solution instead of pediatric gripe by mistake. Seizure with generalized tonic-clonic occurred 3 times in home. Neurological examination was essentially unremarkable except for the depressed level of consciousness. Personal and medical history was unremarkable. There was no evidence of intracranial ischemic or hemorrhagic lesions in computed tomography scan. There were no further seizures, the condition of the patient remained stable, and he was discharged 2 days after admission. The use of viscous lidocaine may result in cardiovascular and CNS toxicity, particularly in children. Conservative management is the best option for treatment of lidocaine induced seizure.

  8. Inguinal hernia recurrence: Classification and approach

    Campanelli Giampiero

    2006-01-01

    Full Text Available The authors reviewed the records of 2,468 operations of groin hernia in 2,350 patients, including 277 recurrent hernias updated to January 2005. The data obtained - evaluating technique, results and complications - were used to propose a simple anatomo-clinical classification into three types which could be used to plan the surgical strategy:Type R1: first recurrence ′high,′ oblique external, reducible hernia with small (< 2 cm defect in non-obese patients, after pure tissue or mesh repairType R2: first recurrence ′low,′ direct, reducible hernia with small (< 2 cm defect in non-obese patients, after pure tissue or mesh repairType R3: all the other recurrences - including femoral recurrences; recurrent groin hernia with big defect (inguinal eventration; multirecurrent hernias; nonreducible, linked with a controlateral primitive or recurrent hernia; and situations compromised from aggravating factors (for example obesity or anyway not easily included in R1 or R2, after pure tissue or mesh repair.

  9. Tumor vaccine against recurrence of hepatocellular carcinoma

    Bao-Gang Peng; Li-Jiang Liang; Qiang He; Ming Kuang; Jia-Ming Lia; Ming-De Lu; Jie-Fu Huang

    2005-01-01

    AIM: To investigate the effects of autologous tumor vaccine on recurrence of hepatocellular carcinoma (HCC).METHODS: Sixty patients with HCC who had undergone curative resection, were randomly divided into HCC vaccine group and control group. Three vaccinations at 2-wk intervals were performed after curative hepatic resection. Delayedtype- hypersensitivity (DTH) test was performed before and after vaccination. Primary endpoints were the time of recurrence.RESULTS: Four patients in control group and 6 patients in HCC vaccine group were withdrawn from the study. The vaccine containing human autologous HCC fragments showed no essential adverse effect in a phase Ⅱ clinical trial and 17 of 24 patients developed a DTH response against the fragments. Three of 17 DTH-positive response patients and 5 of 7 DTH- negative response patients had recurrences after curative resection. After the operation,1-, 2- and 3-year recurrence rates of HCC vaccine groupwere 16.7%, 29.2% and 33.3%, respectively. But, 1-, 2- and3-year recurrence rates of the control group were 30.8%,53.8% and 61.5%, respectively. The time before the first recurrence in the vaccinated patients was significantly longer than that in the control patients (P<0.05).CONCLUSION: Autologous tumor vaccine is of promise in decreasing recurrence of human HCC.

  10. Tea and Recurrent Clostridium difficile Infection.

    Oman Evans Ii, Martin; Starley, Brad; Galagan, Jack Carl; Yabes, Joseph Michael; Evans, Sara; Salama, Joseph John

    2016-01-01

    Background and Aims. Studies have shown effects of diet on gut microbiota. We aimed to identify foods associated with recurrent Clostridium difficile infection (CDI). Methods. In this cross-sectional survey, consecutive patients diagnosed with CDI were identified by electronic medical records. Colitis symptoms and positive Clostridium difficile assay were confirmed. Health-care onset-health-care facility associated CDI was excluded. Food surveys were mailed to 411 patients. Survey responses served as the primary outcome measure. Spearman's rank correlation identified risk factors for CDI recurrence. Results. Surveys were returned by 68 patients. Nineteen patients experienced CDI recurrence. Compared to patients without CDI recurrence, patients with CDI recurrence had more antibiotics prescribed preceding their infection (p = 0.003). Greater numbers of the latter also listed tea (p = 0.002), coffee (p = 0.013), and eggs (p = 0.013), on their 24-hour food recall. Logistic regression identified tea as the only food risk factor for CDI recurrence (adjusted OR: 5.71; 95% CI: 1.26-25.89). Conclusion. The present results indicate a possible association between tea and CDI recurrence. Additional studies are needed to characterize and confirm this association.

  11. Structural and magnetic changes on annealing permalloy/copper multilayers

    Fulthorpe, B.D.; Hase, T.P.A. E-mail: t.p.a.hase@dur.ac.uk; Tanner, B.K.; Marrows, C.H.; Hickey, B.J

    2001-05-01

    Thin-film powder diffraction and in situ grazing incidence X-ray scattering have been used to determine the structural changes that occur during annealing of permalloy/copper multilayers. We show that the enhanced stability in the magnetotransport properties of multilayers doped with cobalt at the interfaces correlates with reduced interdiffusion. The development of a long correlation length conformal roughness during annealing is observed.

  12. Advanced materials for multilayer mirrors for extreme ultraviolet solar astronomy.

    Bogachev, S A; Chkhalo, N I; Kuzin, S V; Pariev, D E; Polkovnikov, V N; Salashchenko, N N; Shestov, S V; Zuev, S Y

    2016-03-20

    We provide an analysis of contemporary multilayer optics for extreme ultraviolet (EUV) solar astronomy in the wavelength ranges: λ=12.9-13.3  nm, λ=17-21  nm, λ=28-33  nm, and λ=58.4  nm. We found new material pairs, which will make new spaceborne experiments possible due to the high reflection efficiencies, spectral resolution, and long-term stabilities of the proposed multilayer coatings. In the spectral range λ=13  nm, Mo/Be multilayer mirrors were shown to demonstrate a better ratio of reflection efficiency and spectral resolution compared with the commonly used Mo/Si. In the spectral range λ=17-21  nm, a new multilayer structure Al/Si was proposed, which had higher spectral resolution along with comparable reflection efficiency compared with the commonly used Al/Zr multilayer structures. In the spectral range λ=30  nm, the Si/B4C/Mg/Cr multilayer structure turned out to best obey reflection efficiency and long-term stability. The B4C and Cr layers prevented mutual diffusion of the Si and Mg layers. For the spectral range λ=58  nm, a new multilayer Mo/Mg-based structure was developed; its reflection efficiency and long-term stability have been analyzed. We also investigated intrinsic stresses inherent for most of the multilayer structures and proposed possibilities for stress elimination.

  13. Estimation of the mean energy of muons in multilayer detectors

    Barnaveli, A T; Khaldeeva, I V; Eristavi, N A

    1995-01-01

    The technique of muon mean energy determination in multilayer detectors is developed. The mean energy is measured by means of average small bursts m i.e. the number of electrons and positrons generated by muons in the detecting layers of device via three basic processes --- creation of e^+e^- pairs, \\delta-electrons and bremsestrahlung. The accuracy of the method is considered. Key words: muon energy, multilayer detectors.

  14. Near-Field Heat Transfer between Multilayer Hyperbolic Metamaterials

    Biehs, Svend-Age; Ben-Abdallah, Philippe

    2017-02-01

    We review the near-field radiative heat flux between hyperbolic materials focusing on multilayer hyperbolic meta-materials. We discuss the formation of the hyperbolic bands, the impact of ordering of the multilayer slabs, as well as the impact of the first single layer on the heat transfer. Furthermore, we compare the contribution of surface modes to that of hyperbolic modes. Finally, we also compare the exact results with predictions from effective medium theory.

  15. Corrosion protected, multi-layer fuel cell interface

    Feigenbaum, Haim; Pudick, Sheldon; Wang, Chiu L.

    1986-01-01

    An improved interface configuration for use between adjacent elements of a fuel cell stack. The interface is impervious to gas and liquid and provides resistance to corrosion by the electrolyte of the fuel cell. The multi-layer configuration for the interface comprises a non-cupreous metal-coated metallic element to which is film-bonded a conductive layer by hot pressing a resin therebetween. The multi-layer arrangement provides bridging electrical contact.

  16. Recurrent acute pancreatitis and its relative factors

    Wei Zhang; Hong-Chao Shan; Yan Gu

    2005-01-01

    AIM: To evaluate the causes and the relative factors of recurrent acute pancreatitis.METHODS: From 1997 to 2000, acute pancreatitis relapsed in 77 of 245 acute pancreatitis patients. By reviewing the clinical treatment results and the follow-up data, we analyzed the recurrent factors of acute pancreatitis using univariate analysis and multivariate analysis.RESULTS: Of the 245 acute pancreatitis patients, 77 were patients with recurrent acute pancreatitis. Of them, 56 patients relapsed two times, 19 relapsed three times, each patient relapsed three and four times. Forty-seven patients relapsed in hospital and the other 30 patients relapsed after discharge. Eighteen patients relapsed in 1 year, eight relapsed in 1-3 years, and four relapsed after 3 years. There were 48 cases of biliary pancreatitis, 3 of alcohol pancreatitis, 5 of hyperlipidemia pancreatitis, 21 of idiopathic pancreatitis. Univariate analysis showed that the patients with local complications of pancreas, obstructive jaundice and hepatic function injury were easy to recur during the treatment period of acute pancreatitis (P = 0.022<0.05, P = 0.012<0.05 and P = 0.002<0.05, respectively). Multivariate analysis showed that there was no single factor related to recurrence. Of the 47 patients who had recurrence in hospital, 16 had recurrence in a fast period, 31 after refeeding. CONCLUSION: Acute pancreatitis is easy to recur even during treatment. The factors such as changes of pancreas structure and uncontrolled systemic inflammatory reaction are responsible for the recurrence of acute pancreatitis. Early refeeding increases the recurrence of acute pancreatitis. Defining the etiology is essential for reducing the recurrence of acute pancreatitis.

  17. Temperature and Humidity Control in Multi-Layered Garments

    Lee, Duck Weon

    2011-12-01

    The purpose of this research is to measure a property of a multilayered fabric system by using heat energy and vapor flow in terms of thermodynamics. By observing change in the heat energy and vapor flow passing through the multilayered fabric system, this research is able to provide precise information about a property of individual fabric layer composing the multilayered fabric system. This new research idea originates from a concept that, when heat energy and vapor flow pass through the layer or membrane, the amount of the heat energy and vapor flow is changed in accordance with a function of the layer or membrane. In particular, the amount of the vapor flow is apparently changed according to the fabric or membranes' structure and material property in a given environmental condition. The research conducts an experiment by using 'the energy source,' which is newly and innovatively developed, measuring temperature and relative humidity in the multilayered system. Through experimental data, the research calculates the amount of heat energy flow in the microclimates and fabric by using Stefan Boltzmann equation, Newton's law of cooling, Fourier's law, and Clausius- Clapeyron Relation. The research explains what properties of the fabric layers influence the energy flow attributable to conduction in the multilayered system consisting individual layers. In addition, the research shows that it is possible to build an optimized multilayered system under a variety of environmental conditions.

  18. Phase-independent multilayer defect repair for EUV photomasks

    Zhao, Shuo; Qi, Zhengqing John

    2016-10-01

    EUV mask repair techniques have primarily focused on absorber biasing to recover the imaging contrast loss originating from multilayer blank defects, while exploratory efforts have investigated local multilayer modification for compensating any through-focus Bossung asymmetry. The work here evaluates these repair techniques and attempts to expand upon them through finite-difference time-domain (FDTD) simulations. In particular, the possibility of local material deposition as an added repair technique is considered, and the interactions between various compensation strategies and illumination modes are explored. A multilayer defect repair methodology that is non-disruptive to the multilayer stack is introduced for the recovery of both the amplitude loss and phase error originating from native blank defects. The effectiveness of the compensation technique is shown to be independent of the defect type, providing a repair solution that is impartial to the phase offset induced by the multilayer defect. Significant lithographic process window improvements are reported, as compared to conventional absorber-based repair, attributed primarily to the restoration of symmetric printing behavior through defocus. This provides an alternative, viable approach to HVM multilayer defect repair.

  19. Magnetic property and interlayer segregation in spin valve metal multilayers

    于广华; 李明华; 朱逢吾; 柴春林; 姜宏伟; 赖武彦

    2002-01-01

    The experimental results show that the exchange coupling field of NiFe/FeMn for Ta/NiFe/FeMn/Ta multilayers is higher than that for the spin valve multilayers Ta/NiFe/Cu/NiFe/FeMn/Ta.In order to find out the reason,the composition and chemical states at the surfaces of Ta(12nm)/NiFe(7nm),Ta(12nm)/NiFe(7nm)/Cu(4nm) and Ta(12nm)/NiFe(7nm)/Cu(3nm)/NiFe(5nm) were studied using the X-ray photoelectron spectroscopy (XPS).The results show that no elements from lower layers float out or segregate to the surface for the first and second samples.However,Cu atoms segregate to the surface of Ta(12nm)/NiFe(7nm)/Cu(3nm)/NiFe(5nm) multilayers,i.e.Cu atoms segregate to the NiFe/FeMn interface for Ta/NiFe/Cu/NiFe/FeMn/Ta multilayers.We believe that the presence of Cu atoms at the interface of NiFe/FeMn is one of the important factors causing the exchange coupling field of Ta/NiFe/FeMn/Ta multilayers to be higher than that of Ta/NiFe/Cu/NiFe/FeMn/Ta multilayers.``

  20. Interlayer Segregation of Cu Atoms in Metal Multilayers

    于广华; 李明华; 朱逢吾; 姜宏伟; 赖武彦; 柴春林

    2001-01-01

    The experimental results show that the exchange coupling field Hex of NiFe/FeMn for Ta/NiFe/FeMn/Ta multilayers is higher than that for the spin valve multilayers Ta/NiFe/Cu/NiFe/FeMn/Ta. The composition and chemical states at the surface of Ta(12 nm)/NiFe( 7 nm), Ta(12 nm)/NiFe(7 nm)/Cu(4 nm) and Ta(12 nm)/NiFe(7 nm)/Cu(3nm)/NiFe(5 nm) were studied by using x-ray photoelectron spectroscopy. The results show that no element from the underlayers floats out or segregates to the surface for Ta(12nm)/NiFe(7nm), Ta(12nm)/NiFe(7nm)/Cu(4nm). However, Cu atoms segregate to the surface of Ta(12nm)/NiFe(7nm)/Cu(3nm)/NiFe(5nm) multilayers, I.e. To the NiFe/FeMn interface for Ta/NiFe/Cu/NiFe/FeMn/Ta multilayers. We believe that the presence of Cu atoms at the interface of NiFe/FeMn is one of the important factors which will cause the exchange coupling field Hex of Ta/NiFe/FeMn/Ta multilayers to be higher than that of Ta/NiFe/Cu/NiFe/FeMn/Ta multilayers.

  1. Characteristics of model polyelectrolyte multilayer films containing laponite clay nanoparticles.

    Elzbieciak, M; Wodka, D; Zapotoczny, S; Nowak, P; Warszynski, P

    2010-01-05

    Polyelectrolyte films structure formed by the "layer-by-layer" (LbL) technique can be enriched by addition of charged nanoparticles like carbon nanotubes and silver or hydroxyapatite nanoparticles, which can improve properties of the polyelectrolyte films or modify their functionality. In our paper we examined the formation and properties of model polyelectrolyte multilayers containing a synthetic layered silicate, Laponite. The Laponite nanoparticles were incorporated into multilayer films, which were formed from weak, branched polycation PEI and strong polyanion PSS. Since charge of PEI is pH-dependent, we build up multilayer films in two deposition conditions: pH = 6 when PEI was strongly charged and pH = 10.5 when charge density of PEI was low. Thicknesses of the films constructed with various numbers of Laponite layers were measured by single wavelength ellipsometry. We also determined the differences in permeability for selected electroactive molecules using cyclic voltamperometry. Properties of the films containing clay nanoparticles were compared with model polyelectrolyte multilayer films PEI/PSS formed at the same conditions. We found that Laponite nanoparticles strongly influenced PEI/PSS multilayer film properties. Replacement of PSS by Laponite eliminated the oscillations of the film thickness in the case when PEI was weakly charged. PSS layer adsorbed on top of PEI/Laponite bilayers increased the thickness of multilayer films and improved their barrier properties so synergistic effects between these properties for polyelectrolytes and Laponite nanoparticles could be observed.

  2. Pain recurrence after shaving of rectovaginal endometriosis

    Heide, Mathias Gottschalck; Forman, Axel

    on the bowel with risk of recurrence. This could motivate a change into more radical surgery. In the present study we therefore assessed recurrence of pain after shaving of rectovaginal endometriosis performed 2001-2009. Methods: Retrospective follow-up study. Questionnaires were sent to 212 women of whom 174...... women (82%) responded. Outcomes were correlated to the involvement of the anterior rectal wall and postoperative hormonal treatment. Results: Recurrence (pain unchanged or worse) of menstrual pain was found in 26 %, intermenstrual pain in 29 %, dyspareunia in 42 % and dyschezia in 41 %. Postoperative...

  3. Discontinuities in recurrent neural networks.

    Gavaldá, R; Siegelmann, H T

    1999-04-01

    This article studies the computational power of various discontinuous real computational models that are based on the classical analog recurrent neural network (ARNN). This ARNN consists of finite number of neurons; each neuron computes a polynomial net function and a sigmoid-like continuous activation function. We introduce arithmetic networks as ARNN augmented with a few simple discontinuous (e.g., threshold or zero test) neurons. We argue that even with weights restricted to polynomial time computable reals, arithmetic networks are able to compute arbitrarily complex recursive functions. We identify many types of neural networks that are at least as powerful as arithmetic nets, some of which are not in fact discontinuous, but they boost other arithmetic operations in the net function (e.g., neurons that can use divisions and polynomial net functions inside sigmoid-like continuous activation functions). These arithmetic networks are equivalent to the Blum-Shub-Smale model, when the latter is restricted to a bounded number of registers. With respect to implementation on digital computers, we show that arithmetic networks with rational weights can be simulated with exponential precision, but even with polynomial-time computable real weights, arithmetic networks are not subject to any fixed precision bounds. This is in contrast with the ARNN that are known to demand precision that is linear in the computation time. When nontrivial periodic functions (e.g., fractional part, sine, tangent) are added to arithmetic networks, the resulting networks are computationally equivalent to a massively parallel machine. Thus, these highly discontinuous networks can solve the presumably intractable class of PSPACE-complete problems in polynomial time.

  4. Recurrence quantification analysis theory and best practices

    Jr, Jr; Marwan, Norbert

    2015-01-01

    The analysis of recurrences in dynamical systems by using recurrence plots and their quantification is still an emerging field.  Over the past decades recurrence plots have proven to be valuable data visualization and analysis tools in the theoretical study of complex, time-varying dynamical systems as well as in various applications in biology, neuroscience, kinesiology, psychology, physiology, engineering, physics, geosciences, linguistics, finance, economics, and other disciplines.   This multi-authored book intends to comprehensively introduce and showcase recent advances as well as established best practices concerning both theoretical and practical aspects of recurrence plot based analysis.  Edited and authored by leading researcher in the field, the various chapters address an interdisciplinary readership, ranging from theoretical physicists to application-oriented scientists in all data-providing disciplines.

  5. Recurrent Omental Hemangiopericytoma: A Therapeutic Challenge

    Sara Jaber

    2016-01-01

    Full Text Available Hemangiopericytomas are vascular tumors with a susceptibility to arise anywhere in the human body. We present a case of a 68-year-old female with primary omental hemangiopericytoma and a two-time recurrence managed with surgery and close follow-up. The first recurrence was at 52 months and the second at 37 months following the prior presentation. No adjuvant chemotherapy or radiation therapy was administered. Given the widespread nature of the cell of origin, routine follow-up postoperatively with interval imaging in order to detect recurrences is imperative. Pathologic tumor characteristics may determine potential for recurrence and may also assist in determining whether adjuvant treatment modalities should be included in the management plan. Review of the English literature reveals a total of 24 cases of omental hemangiopericytomas inclusive of the current report.

  6. Is acute recurrent pancreatitis a chronic disease?

    Alberto Mariani; Pier Alberto Testoni

    2008-01-01

    Whether acute recurrent pancreaUtis is a chronic disease is still debated and a consensus is not still reached as demonstrated by differences in the classification of acute recurrent pancreatitis.There is major evidence for considering alcoholic pancreatitis as a chronic disease ab initio while chronic pancreatitis lesions detectable in biliary acute recurrent pancreatitis (ARP) seem a casual association.Cystic fibrosis transmembrane con ductance regulator (CFTR) gene mutation,hereditary and obstructive pancreatitis seem an acute disease that progress to chronic pancreatitis,likely as a consequence of the activation and proliferation of pancreatic stellate cells that produce and activate collagen and therefore fibrosis.From the diagnostic point of view,in patients with acute recurrent pancreatitis Endoscopic ultrasound (EUS) seems the more reliable technique for an accurate evaluation and follow-up of some ductal and parenchymal abnormalities suspected for early chronic pancreatitis.

  7. Recurrence risk for germinal mosaics revisited

    van der Meulen, M A; te Meerman, G J

    1995-01-01

    A formula to calculate recurrence risk for germline mosaicism published by Hartl in 1971 has been updated to include marker information. For practical genetic counselling new, more elaborate tables are given.

  8. Multiple nodal locoregional recurrence of pheochromocytoma

    César Pablo Ramírez-Plaza

    2015-01-01

    Conclusion: Isolated lymph nodal recurrence is very rare in malignant PCC, with only 7 cases previously published. The role of surgery is essential to get long-term survival because provides clinical and functional control of the disease.

  9. Recurrent acute pancreatitis: From the editor

    Pier Alberto Testoni

    2008-01-01

    @@ This special issue of World Journal of Gastroenterology contains a number of articles focusing on acute recurrent pancreatitis,a clinical entity that still remains a complex diagnostic and therapeutic challenge in clinical practice.

  10. A comprehensive profile of recurrent glioblastoma

    Campos, B.; Olsen, Lars Rønn; Urup, T.;

    2016-01-01

    In spite of relentless efforts to devise new treatment strategies, primary glioblastomas invariably recur as aggressive, therapy-resistant relapses and patients rapidly succumb to these tumors. Many therapeutic agents are first tested in clinical trials involving recurrent glioblastomas. Remarkably......, however, fundamental knowledge on the biology of recurrent glioblastoma is just slowly emerging. Here, we review current knowledge on recurrent glioblastoma and ask whether and how therapies change intra-tumor heterogeneity, molecular traits and growth pattern of glioblastoma, and to which extent...... this information can be exploited for therapeutic decision-making. We conclude that the ability to characterize and predict therapy-induced changes in recurrent glioblastoma will determine, whether, one day, glioblastoma can be contained in a state of chronic disease.Oncogene advance online publication, 4 April...

  11. Recurrence of hypertensive disorders of pregnancy

    van Oostwaard, Miriam F; Langenveld, Josje; Schuit, Ewoud

    2015-01-01

    increased with decreasing gestational age at delivery in the index pregnancy. If the HDP recurred, in general it was milder, regarding maximum diastolic blood pressure, proteinuria, the use of oral antihypertensive and anticonvulsive medication, the delivery of a small-for-gestational-age child, premature...... delivery, and perinatal death. Normotensive women experienced chronic hypertension after pregnancy more often after experiencing recurrence (odds ratio, 3.7; 95% CI, 2.3-6.1). CONCLUSION: Among women that experience hypertension in pregnancy, the recurrence rate in a next pregnancy is relatively low......OBJECTIVE: We performed an individual participant data (IPD) metaanalysis to calculate the recurrence risk of hypertensive disorders of pregnancy (HDP) and recurrence of individual hypertensive syndromes. STUDY DESIGN: We performed an electronic literature search for cohort studies that reported...

  12. Evaluation for postoperative recurrence of Crohn disease.

    Swoger, Jason M; Regueiro, Miguel

    2012-06-01

    Disease recurrence following resective surgery for Crohn disease remains a challenging clinical problem, and more studies are needed to better define risk stratification and treatment recommendations in the postoperative setting. Endoscopy remains the gold standard for the assessment of postoperative disease recurrence, and all Crohn disease patients who undergo surgery should undergo ileocolonoscopy within 6 to 12 months of surgery. The degree of endoscopic recurrence in the neoterminal ileum during this procedure provides prognostic information regarding the severity of the future disease course. WCE, MRE, and SICUS are all promising noninvasive modalities to assess for postoperative Crohn disease activity. However, further studies are needed to better define scoring systems, operating characteristics and variability, and prognostic data for each of these modalities. In patients at risk for early disease recurrence, more aggressive prophylactic therapy should be considered, in hopes of delivering true “top-down” therapy that may offer maximum impact in altering the natural history of Crohn disease.

  13. Recurrence Within 24 Hours of Unprovoked Seizures

    J Gordon Millichap

    2006-09-01

    Full Text Available The incidence and risk factors of acute recurrence of unprovoked seizures within 24 hours of admission to an Emergency Department (ED were analyzed by a retrospective chart review at Schneider Children’s Hospital, New York.

  14. Ocean wave forecasting using recurrent neural networks

    Mandal, S.; Prabaharan, N.

    , merchant vessel routing, nearshore construction, etc. more efficiently and safely. This paper describes an artificial neural network, namely recurrent neural network with rprop update algorithm and is applied for wave forecasting. Measured ocean waves off...

  15. Genetics Home Reference: benign recurrent intrahepatic cholestasis

    ... All Close All Description Benign recurrent intrahepatic cholestasis (BRIC) is characterized by episodes of liver dysfunction called ... a lack of appetite. A common feature of BRIC is the reduced absorption of fat in the ...

  16. EUV testing of multilayer mirrors: critical issues

    Hill, S B; Ermanoski, I; Grantham, S; Tarrio, C; Lucatorto, T B; Madey, T E; Bajt, S; Chandhok, M; Yan, P; Wood, O; Wurn, S; Edwards, N V

    2006-02-24

    Recently, while performing extensive EUV irradiation endurance testing on Ru-capped multilayer mirrors in the presence of elevated partial pressures of water and hydrocarbons, NIST has observed that the amount of EUV-induced damage actually decreases with increasing levels of water vapor above {approx} 5 x 10{sup -7} Torr. It is thought that the admitted water vapor may interact with otherwise stable, condensed carbonaceous species in an UHV vacuum system to increase the background levels of simple gaseous carbon-containing molecules. Some support for this hypothesis was demonstrated by observing the mitigating effect of very small levels of simple hydrocarbons with the intentional introduction of methyl alcohol in addition to the water vapor. It was found that the damage rate decreased by at least an order of magnitude when the partial pressure of methyl alcohol was just one percent of the water partial pressure. These observations indicate that the hydrocarbon components of the vacuum environment under actual testing conditions must be characterized and controlled to 10{sup -11} Torr or better in order to quantify the damage caused by high levels of water vapor. The possible effects of exposure beam size and out-of-band radiation on mirror lifetime testing will also be discussed.

  17. Robust Multilayer Insulation for Cryogenic Systems

    Fesmire, J. E.; Scholtens, B. F.; Augustynowicz, S. D.

    2007-01-01

    New requirements for thermal insulation include robust Multilayer insulation (MU) systems that work for a range of environments from high vacuum to no vacuum. Improved MLI systems must be simple to install and maintain while meeting the life-cycle cost and thermal performance objectives. Performance of actual MLI systems has been previously shown to be much worse than ideal MLI. Spacecraft that must contain cryogens for both lunar service (high vacuum) and ground launch operations (no vacuum) are planned. Future cryogenic spacecraft for the soft vacuum environment of Mars are also envisioned. Industry products using robust MLI can benefit from improved cost-efficiency and system safety. Novel materials have been developed to operate as excellent thermal insulators at vacuum levels that are much less stringent than the absolute high vacuum requirement of current MLI systems. One such robust system, Layered Composite Insulation (LCI), has been developed by the Cryogenics Test Laboratory at NASA Kennedy Space Center. The experimental testing and development of LCI is the focus of this paper. LCI thermal performance under cryogenic conditions is shown to be six times better than MLI at soft vacuum and similar to MLI at high vacuum. The experimental apparent thermal conductivity (k-value) and heat flux data for LCI systems are compared with other MLI systems.

  18. Multilayer material characterization using thermographic signal reconstruction

    Shepard, Steven M.; Beemer, Maria Frendberg

    2016-02-01

    Active-thermography has become a well-established Nondestructive Testing (NDT) method for detection of subsurface flaws. In its simplest form, flaw detection is based on visual identification of contrast between a flaw and local intact regions in an IR image sequence of the surface temperature as the sample responds to thermal stimulation. However, additional information and insight can be obtained from the sequence, even in the absence of a flaw, through analysis of the logarithmic derivatives of individual pixel time histories using the Thermographic Signal Reconstruction (TSR) method. For example, the response of a flaw-free multilayer sample to thermal stimulation can be viewed as a simple transition between the responses of infinitely thick samples of the individual constituent layers over the lifetime of the thermal diffusion process. The transition is represented compactly and uniquely by the logarithmic derivatives, based on the ratio of thermal effusivities of the layers. A spectrum of derivative responses relative to thermal effusivity ratios allows prediction of the time scale and detectability of the interface, and measurement of the thermophysical properties of one layer if the properties of the other are known. A similar transition between steady diffusion states occurs for flat bottom holes, based on the hole aspect ratio.

  19. Cellulose multilayer Membranes manufacture with Ionic liquid

    Livazovic, Sara

    2015-05-09

    Membrane processes are considered energy-efficient for water desalination and treatment. However most membranes are based on polymers prepared from fossil petrochemical sources. The development of multilayer membranes for nanofiltration and ultrafiltration, with thin selective layers of naturally available cellulose has been hampered by the availability of non-aggressive solvents. We propose the manufacture of cellulose membranes based on two approaches: (i) silylation, coating from solutions in tetrahydrofuran, followed by solvent evaporation and cellulose regeneration by acid treatment; (ii) casting from solution in 1-ethyl-3-methylimidazolum acetate ([C2mim]OAc), an ionic liquid, followed by phase inversion in water. By these methods porous supports could be easily coated with semi-crystalline cellulose. The membranes were hydrophilic with contact angles as low as 22.0°, molecular weight cut-off as low as 3000 g mol-1 with corresponding water permeance of 13.8 Lm−2 h−1 bar−1. Self-standing cellulose membranes were also manufactured without porous substrate, using only ionic liquid as green solvent. This membrane was insoluble in water, tetrahydrofuran, hexane, N,N-dimethylformamide, 1-methyl-2-pyrrolidinone and N,N-dimethylacetamide.

  20. Organizing Books and Authors by Multilayer SOM.

    Zhang, Haijun; Chow, Tommy W S; Wu, Q M Jonathan

    2016-12-01

    This paper introduces a new framework for the organization of electronic books (e-books) and their corresponding authors using a multilayer self-organizing map (MLSOM). An author is modeled by a rich tree-structured representation, and an MLSOM-based system is used as an efficient solution to the organizational problem of structured data. The tree-structured representation formulates author features in a hierarchy of author biography, books, pages, and paragraphs. To efficiently tackle the tree-structured representation, we used an MLSOM algorithm that serves as a clustering technique to handle e-books and their corresponding authors. A book and author recommender system is then implemented using the proposed framework. The effectiveness of our approach was examined in a large-scale data set containing 3868 authors along with the 10500 e-books that they wrote. We also provided visualization results of MLSOM for revealing the relevance patterns hidden from presented author clusters. The experimental results corroborate that the proposed method outperforms other content-based models (e.g., rate adapting poisson, latent Dirichlet allocation, probabilistic latent semantic indexing, and so on) and offers a promising solution to book recommendation, author recommendation, and visualization.

  1. Competitive epidemic spreading over arbitrary multilayer networks

    Darabi Sahneh, Faryad; Scoglio, Caterina

    2014-06-01

    This study extends the Susceptible-Infected-Susceptible (SIS) epidemic model for single-virus propagation over an arbitrary graph to an Susceptible-Infected by virus 1-Susceptible-Infected by virus 2-Susceptible (SI1SI2S) epidemic model of two exclusive, competitive viruses over a two-layer network with generic structure, where network layers represent the distinct transmission routes of the viruses. We find analytical expressions determining extinction, coexistence, and absolute dominance of the viruses after we introduce the concepts of survival threshold and absolute-dominance threshold. The main outcome of our analysis is the discovery and proof of a region for long-term coexistence of competitive viruses in nontrivial multilayer networks. We show coexistence is impossible if network layers are identical yet possible if network layers are distinct. Not only do we rigorously prove a region of coexistence, but we can quantitate it via interrelation of central nodes across the network layers. Little to no overlapping of the layers' central nodes is the key determinant of coexistence. For example, we show both analytically and numerically that positive correlation of network layers makes it difficult for a virus to survive, while in a network with negatively correlated layers, survival is easier, but total removal of the other virus is more difficult.

  2. Progress at the ESRF multilayer facility

    Morawe, Ch; Peffen, J. Ch; Friedrich, K.; Osterhoff, M.

    2013-03-01

    The ESRF multilayer (ML) deposition facility is fully operational since 2009. By the end of 2011, almost 50 ML projects were completed using the new machine, bringing the total number to 143 since 1998. Thanks to the new equipment and its improved performance the throughput could be significantly increased. The ESRF upgrade project caused strong demands for new ML optics, in particular dynamically bent KB focusing devices requiring very precise and steeply graded ML coatings. Thanks to this technology, the ESRF nano-imaging end-station ID22NI now provides the users with spot sizes of the order of 50×50 nm2 at a photon flux of 1012 ph/s. Among various in-house research and development activities the study of stress evolution during thin film and ML growth will be highlighted. Additional projects involving a PhD student and a PostDoc fellow cover the fields of wave optical simulations using curved MLs and the exposure of ML based monochromators to the white beam.

  3. Management of Recurrent Rhinosinusitis in Children

    2012-01-01

    Rhinosinusitis is the most common complication of viral upper respiratory tract infections and the fifth most common indication for the prescription for antimicrobial agents in childhood period. In clinical evaluation a persistant nasal discharge or cough (or both) lasting more than ten days are generally seen. Acute rhinosinusitis lasts less than four weeks and chronic rhinosinusitis persists more than 12 weeks. The common causes of recurrent acute and chronic rhinosinusitis are recurrent vi...

  4. Forequarter amputation for recurrent breast cancer

    Pundi, Krishna N.; AlJamal, Yazan N.; Ruparel, Raaj K.; Farley, David R.

    2015-01-01

    Introduction: Localized excision combined with radiation and chemotherapy represents the current standard of care for recurrent breast cancer. However, in certain conditions a forequarter amputation may be employed for these patients. Presentation of case: We present a patient with recurrent breast cancer who had a complicated treatment history including multiple courses of chemotherapy, radiation, and local surgical excision. With diminishing treatment options, she opted for a forequarter...

  5. Current surgery of retinal detachment recurrence. Review

    V. D. Zakharov

    2012-01-01

    Full Text Available this review presents a detailed analysis and an experience of surgical treatment of retinal detachment recurrence associated with light silicone oil tamponade of vitreous cavity. Approaches and variants of treatment were described in the historical aspect and till now. there are considered general and particular issues in case of retinal detachment recurrence appearance, expediency and volume of intraoperative manipulations, time of operation and choice of temporary substitute of vitreous body for a purpose of postoperative tamponade of vitreous cavity.

  6. Current surgery of retinal detachment recurrence. Review

    V. D. Zakharov

    2014-07-01

    Full Text Available this review presents a detailed analysis and an experience of surgical treatment of retinal detachment recurrence associated with light silicone oil tamponade of vitreous cavity. Approaches and variants of treatment were described in the historical aspect and till now. there are considered general and particular issues in case of retinal detachment recurrence appearance, expediency and volume of intraoperative manipulations, time of operation and choice of temporary substitute of vitreous body for a purpose of postoperative tamponade of vitreous cavity.

  7. Solving recurrence relations supported by Wolfram Mathematica

    Enrique Vílchez-Quesada

    2015-01-01

    Full Text Available This paper introduces some algorithms for solving linear relationships, homogeneous and non-homogeneous recurrence with constant and non-constant coefficients, using software as the main resource in solving processes. The Mathematica commercial application has provided the technical support necessary for the implementation of the methods used. It also presents other examples of recurrence relations, showing the effectiveness and limitations of the algorithms created by the author and programmed in Mathematica environment that provides.

  8. Recurrent congenital heart block in neonatal lupus.

    Escobar, Maria C; Gómez-Puerta, José A; Albert, Dimpna; Ferrer, Queralt; Girona, Josep

    2007-07-01

    Congenital heart block (CHB) is the main complication of neonatal lupus (NL) and is strongly associated with the presence of anti-SSA/Ro and anti-SSB/La antibodies. The recurrence of CHB in subsequent pregnancies in mothers with these antibodies is uncommon, occurring in approximately 15% of cases. We describe here a case of recurrent CHB in a previously asymptomatic mother with Sjögren syndrome and discuss the current strategies for the prevention and treatment of CHB in NL.

  9. Family history and recurrence of febrile seizures.

    1994-01-01

    To determine the value of a detailed family history for the assessment of the risk of recurrence of febrile seizures, 115 children who visited the emergency room of an academic children's hospital were studied prospectively. The recurrence risk of febrile seizures was analysed in relation to the child's family history and the proportion of relatives affected by febrile seizures using Kaplan-Meier estimates and Cox proportional hazard models. A first degree family history positive for febrile ...

  10. Recurrence relation for relativistic atomic matrix elements

    Martínez y Romero, R P; Salas-Brito, A L

    2000-01-01

    Recurrence formulae for arbitrary hydrogenic radial matrix elements are obtained in the Dirac form of relativistic quantum mechanics. Our approach is inspired on the relativistic extension of the second hypervirial method that has been succesfully employed to deduce an analogous relationship in non relativistic quantum mechanics. We obtain first the relativistic extension of the second hypervirial and then the relativistic recurrence relation. Furthermore, we use such relation to deduce relativistic versions of the Pasternack-Sternheimer rule and of the virial theorem.

  11. Dupuytren contracture recurrence project: reaching consensus on a definition of recurrence.

    Felici, N; Marcoccio, I; Giunta, R; Haerle, M; Leclercq, C; Pajardi, G; Wilbrand, S; Georgescu, A V; Pess, G

    2014-12-01

    The aim of this study was to determine a definition of recurrence of Dupuytren disease that could be utilized for the comparison of the results independently from the treatment used. 24 hand surgeons from 17 countries met in an international consensus conference. The participants used the Delphi method to evaluate a series of statements: (1) the need for defining recurrence, (2) the concept of recurrence applied to the Tubiana staging system, (3) the concept of recurrence applied to each single treated joint, and (4) the concept of recurrence applied to the finger ray. For each item, the possible answer was given on a scale of 1-5: 1=maximum disagreement; 2=disagreement; 3=agreement; 4=strong agreement; 5=absolute agreement. There was consensus on disagreement if 1 and 2 comprised at least 66% of the recorded answers and consensus on agreement if 3, 4 and 5 comprised at least 66% of the recorded answers. If a threshold of 66% was not reached, the related statement was considered "not defined". A need for a definition of recurrence was established. The presence of nodules or cords without finger contracture was not considered an indication of recurrence. The Tubiana staging system was considered inappropriate for reporting recurrence. Recurrence was best determined by the measurement of a specific joint, rather than a total ray. Time 0 occurred between 6 weeks and 3 months. Recurrence was defined as a PED of more than 20° for at least one of treated joint, in the presence of a palpable cord, compared to the result obtained at time 0. This study determined the need for a standard definition of recurrence and reached consensus on that definition, which we should become the standard for the reporting of recurrence. If utilized in subsequent publications, this will allow surgeons to compare different techniques and make is easier to help patients make an informed choice.

  12. Recurrence interval analysis of trading volumes.

    Ren, Fei; Zhou, Wei-Xing

    2010-06-01

    We study the statistical properties of the recurrence intervals τ between successive trading volumes exceeding a certain threshold q. The recurrence interval analysis is carried out for the 20 liquid Chinese stocks covering a period from January 2000 to May 2009, and two Chinese indices from January 2003 to April 2009. Similar to the recurrence interval distribution of the price returns, the tail of the recurrence interval distribution of the trading volumes follows a power-law scaling, and the results are verified by the goodness-of-fit tests using the Kolmogorov-Smirnov (KS) statistic, the weighted KS statistic and the Cramér-von Mises criterion. The measurements of the conditional probability distribution and the detrended fluctuation function show that both short-term and long-term memory effects exist in the recurrence intervals between trading volumes. We further study the relationship between trading volumes and price returns based on the recurrence interval analysis method. It is found that large trading volumes are more likely to occur following large price returns, and the comovement between trading volumes and price returns is more pronounced for large trading volumes.

  13. Management of recurrent postoperative fungal endophthalmitis

    Anand Vinekar

    2014-01-01

    Full Text Available Aim: To report the management of recurrent postoperative fungal endophthalmitis (POFE after failed pars plana vitrectomy (PPV and antifungal therapy. Settings and Design: Tertiary Care Referral Centre in North India. Retrospective, single institution, interventional case-series. Materials and Methods: Six patients with microbiologically proven recurrent post-operative fungal endophthalmitis refractory to conventional management were included. The final recurrence was managed with intraocular lens (IOL explantation and re-PPV. Main outcome measures included preserved globe anatomy, visual acuity and retinal status. ′Anatomical success′ was defined as preserved anatomy of the globe, and absence of signs of inflammation. ′Functional success′ was defined as an attached retina and a best corrected visual acuity of better than 20/400. Results: Of the six cases of POFE, five were culture positive [Aspergillus flavus (1, Aspergillus fumigatus (2, Candida albicans (1 and Candida glabrata (1] and one was smear positive for yeast. All recurred (mean recurrences, 4 despite a mean of 2.17 PPVs and intravitreal amphotericin B. No recurrences were observed after IOL explantation with re - PPV (median follow-up, 37 months. Pre-study defined criteria for successful ′anatomical′ and ′functional′ outcomes were achieved in 83.3% and 50% respectively. Conclusion: This report highlights the effective role of combined IOL explantation with PPV in managing recurrent POFE.

  14. An evaluation of factors predicting breast recurrence and prognosis after recurrence, on distinguishing intramammary and extramammary recurrence, in breast-conserving surgery

    Nishimura, Reiki; Nagao, Kazuharu; Miyayama, Haruhiko [Kumamoto City Hospital (Japan)] (and others)

    2001-06-01

    Recurrence of cancer in the breast is an important problem in breast-conserving therapy. We evaluated risk factors for recurrence from the viewpoint of recurrence type and outcome after recurrence. Of 533 cases of breast cancer treated with breast-conserving surgery from April 1989 through July 2000, disease in 66 recurred (12.4%) and were classified as 23 cases of breast recurrence only, 16 cases of both breast recurrence and distant metastasis, and 27 cases of distant metastasis only. The clinical factors examined included age, lymphatic invasion, nodal status, extensive intraductal component (EIC), proliferative activity, and estrogen receptor (ER) status. Of the 39 cases of breast recurrence, 19 had intramammary tumors and 20 had extramammary tumors of the skin, subcutaneous tissue, or muscle, including 8 cases with inflammatory breast recurrence. Multivariate analysis showed that factors correlated with breast recurrence were age, ER status, proliferative activity, and surgical margin. EIC-comedo was related to intramammary recurrence, whereas lymphatic invasion and nodal status were related to extramammary recurrence. Postoperative irradiation was an effective treatment for tumors in young women and tumors with positive margins or a comedo component. Outcome after breast recurrence depended on nodal status at primary operation, and survival rates were worst in patients with inflammatory breast recurrence. In conclusion, age, EIC-comedo status, the surgical margin, and negative ER status were correlated with breast recurrence. Countermeasures against these factors should be investigated. (author)

  15. Spectroscopic properties of multilayered gold nanoparticle 2D sheets.

    Yoshida, Akihito; Imazu, Keisuke; Li, Xinheng; Okamoto, Koichi; Tamada, Kaoru

    2012-12-11

    We report the fabrication technique and optical properties of multilayered two-dimensional (2D) gold nanoparticle sheets ("Au nanosheet"). The 2D crystalline monolayer sheet composed of Au nanoparticles shows an absorption peak originating from a localized surface plasmon resonance (LSPR). It was found that the absorption spectra dramatically change when the monolayers are assembled into the multilayers on different substrates (quartz or Au). In the case of the multilayers on Au thin film (d = 200 nm), the LSPR peak is shifted to longer wavelength at the near-IR region by increasing the number of layers. The absorbance also depends on the layer number and shows the nonlinear behavior. On the other hand, the multilayers on quartz substrate show neither such LSPR peak shift nor nonlinear response of absorbance. The layer number dependence on metal surfaces can be interpreted as the combined effects between the near-field coupling of the LSPR and the far-field optics of the stratified metamaterial films, as proposed in our previous study. We also report the spectroscopic properties of hybrid multilayers composed of two kinds of monolayers, i.e., Au nanosheet and Ag nanosheet. The combination of the different metal nanoparticle sheets realizes more flexible plasmonic color tuning.

  16. Structural and electrical properties in tungsten/tungsten oxide multilayers

    Cacucci, Arnaud [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, 9 Avenue Alain Savary, BP47870, F-21078 DIJON Cedex (France); Potin, Valérie, E-mail: valerie.potin@u-bourgogne.fr [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, 9 Avenue Alain Savary, BP47870, F-21078 DIJON Cedex (France); Imhoff, Luc [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, 9 Avenue Alain Savary, BP47870, F-21078 DIJON Cedex (France); Martin, Nicolas [Institut FEMTO-ST, UMR 6174 CNRS, Université de Franche-Comté, ENSMM, UTBM, 32 Avenue de l' observatoire, F-25044, BESANCON Cedex (France)

    2014-02-28

    Tungsten and tungsten oxide periodic nanometric multilayers have been deposited by DC reactive sputtering using the reactive gas pulsing process. Different pulsing periods have been used for each deposition to produce metal-oxide periodic alternations ranging from 3.3 to 71.5 nm. The morphology, crystallinity and chemical composition of these films have been investigated by transmission electron microscopy and energy-dispersive X-ray spectroscopy techniques. The produced multilayers exhibited an amorphous structure and the composition stability of WO{sub 3} sub-layers has been pointed out. Moreover, electrical properties have also been studied by the van der Pauw technique. It revealed a clear stability of resistivity versus temperature for almost all samples and an influence of the multilayered structure on the resistivity behavior. - Highlights: • W/WO{sub 3} multilayers with nanometric periods are produced by gas pulsing. • Multilayers are mainly amorphous and the oxide sub-layers composed of WO{sub 3}. • Crystallized inclusions of β-W and β-W{sub 3}O phases in metallic sub-layers • Metallic-like behavior with low temperature coefficient of resistance.

  17. AN EFFECTIVE NETWORK CONGESTION CONTROL METHOD FOR MULTILAYER NETWORK

    Du Haifeng; Xiao Yang; Lu Lingyun

    2008-01-01

    The congestion control problem in a single node network has been solved by the nonlinear feedback control method, which has been proven to be effective and robust for different router's queue size. However, these control models are based on the single layer network architecture, and the senders and receivers are directly connected by one pair of routers. With the network architecture being more and more complex, it is a serious problem how to cooperate many routers working in the multilayer network simultaneously. In this paper, an effective Active Queue Management (AQM) scheme to guarantee the stability by the nonlinear control of imposing some restrictions on AQM parameter in multilayer network is proposed. The nonlinear control can rely on some heuristics and network traffic controllers that appear to be highly correlated with the multilayer network status. The proposed method is based on the improved classical Random Early Detection (RED) differential equation and a theorem for network congestion control. The theorem proposed in the paper proved that the stability of the fluid model can effectively ensure the convergence of the average rate to its equilibrium point through many routers in multilayer network. Moreover, when the network capacity is larger, the proposed scheme can still approach to the fullest extensibility of utilization and ensure the stability of the fluid model. The paper reveals the reasons of congestion control in multilayer network, provides a theorem for avoiding network congestion, and gives simulations to verify the results.

  18. Self-Propagating Reactive Fronts in Compacts of Multilayered Particles

    Ihab Sraj

    2013-01-01

    Full Text Available Reactive multilayered foils in the form of thin films have gained interest in various applications such as joining, welding, and ignition. Typically, thin film multilayers support self-propagating reaction fronts with speeds ranging from 1 to 20 m/s. In some applications, however, reaction fronts with much smaller velocities are required. This recently motivated Fritz et al. (2011 to fabricate compacts of regular sized/shaped multilayered particles and demonstrate self-sustained reaction fronts having much smaller velocities than thin films with similar layering. In this work, we develop a simplified numerical model to simulate the self-propagation of reactive fronts in an idealized compact, comprising identical Ni/Al multilayered particles in thermal contact. The evolution of the reaction in the compact is simulated using a two-dimensional transient model, based on a reduced description of mixing, heat release, and thermal transport. Computed results reveal that an advancing reaction front can be substantially delayed as it crosses from one particle to a neighboring particle, which results in a reduced mean propagation velocity. A quantitative analysis is thus conducted on the dependence of these phenomena on the contact area between the particles, the thermal contact resistance, and the arrangement of the multilayered particles.

  19. Interaction-induced insulating state in thick multilayer graphene

    Nam, Youngwoo; Ki, Dong-Keun; Koshino, Mikito; McCann, Edward; Morpurgo, Alberto F.

    2016-12-01

    Close to charge neutrality, the low-energy properties of high-quality suspended devices based on atomically thin graphene layers are determined by electron-electron interactions. Bernal-stacked layers, in particular, have shown a remarkable even-odd effect with mono- and tri-layers remaining gapless conductors, and bi- and tetra-layers becoming gapped insulators. These observations—at odds with the established notion that (Bernal) trilayers and thicker multilayers are semi-metals—have resulted in the proposal of a physical scenario leading to a surprising prediction, namely that even-layered graphene multilayers remain insulating irrespective of their thickness. Here, we present data from two devices that conform ideally to this hypothesis, exhibiting the behavior expected for Bernal-stacked hexa- and octa-layer graphene. Despite their large thickness, these multilayers are insulating for carrier density |n| virtually perfect agreement with what is observed in bi- and tetra-layer graphene—and exhibit the expected integer quantum Hall effect. These findings indicate the soundness of our basic insights on the effect of electron interactions in Bernal graphene multilayers, show that graphene multilayers exhibit unusual and interesting physics that remains to be understood, and pose ever more pressing questions as to the microscopic mechanisms behind the semimetallic behavior of bulk graphite.

  20. Multilayer Mg: Stainless Steel Sheets, Microstructure, and Mechanical Properties

    Inoue, Junya; Sadeghi, Alireza; Kyokuta, Nobuhiko; Ohmori, Toshinori; Koseki, Toshihiko

    2017-02-01

    Different multilayer Mg AZ31 and SS304L steel sheet combinations were prepared with different volume fractions of Mg. Isolated stress-strain curves of the Mg layers showed significant improvements in the strength and elongation of multilayer samples. Results indicated that in the most extreme situation with the lowest Mg volume fraction (V f = 0.39), the ultimate strength was increased by 25 pct to 370 MPa and the elongation was improved by 70 pct to 0.34. Investigation of the fracture surface showed that failure occurs by the coalescence of cracks close to the interface region. The improved strength of the multilayer samples was due to the combined effect of surface crack prevention by the steel layer and the higher work-hardening rate caused by the possible increased activity of non-basal systems. It is suggested that the stronger work-hardening behavior and the enhanced activity of non-basal systems in the multilayer samples were due to the formation of new stress components in the transverse direction. The larger the volume fraction of steel in the multilayer, the longer the distance remaining unstrained before the UTS.

  1. Tunable drug loading and release from polypeptide multilayer nanofilms

    Bingbing Jiang

    2009-03-01

    Full Text Available Bingbing Jiang1, Bingyun Li1,2,31Biomaterials, Bioengineering and Nanotechnology Laboratory, Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV, USA; 2WVNano Initiative, WV, USA; 3Department of Chemical Engineering, College of Engineering and Mineral Resources, West Virginia University, Morgantown, WV, USA Abstract: Polypeptide multilayer nanofilms were prepared using electrostatic layer-by-layer self-assembly nanotechnology. Small charged drug molecules (eg, cefazolin, gentamicin, and methylene blue were loaded in polypeptide multilayer nanofilms. Their loading and release were found to be pH-dependent and could also be controlled by changing the number of film layers and drug incubation time, and applying heat-treatment after film formation. Antibiotic-loaded polypeptide multilayer nanofilms showed controllable antibacterial properties against Staphylococcus aureus. The developed biodegradable polypeptide multilayer nanofilms are capable of loading both positively- and negatively-charged drug molecules and promise to serve as drug delivery systems on biomedical devices for preventing biomedical device-associated infection, which is a significant clinical complication for both civilian and military patients.Keywords: polypeptide, self-assembly, polyelectrolyte multilayer, nanofilm, charged molecule, tunable release

  2. High-resolution x-ray analysis with multilayer gratings

    Jonnard, Philippe; André, Jean-Michel; 10.1002/xrs.1128

    2013-01-01

    Periodic multilayers are nowadays widely used to perform x-ray analysis in the soft x-ray range (photon energy lower than 1 keV). However, they do not permit to obtain high-resolution spectra like natural or synthetic crystals. Thus, multilayers cannot resolve interferences between close x-ray lines. It has been shown and demonstrated experimentally that patterning a grating profile within a multilayer structure leads to a diffractive optics with improved resolving power. We illustrate the use of a Mo/B4C multilayer grating in the Fe L and C K spectral ranges, around 700 eV and 280 eV respectively. First, in the Fe L range, the improved spectral resolution enables us to distinguish the Fe L\\alpha and L\\beta emissions (separated by 13 eV). In addition, using a sample made of a mix of LiF and an iron ore, we show that it is possible to easily resolve the F K and Fe L emissions. These examples demonstrate that an improved x-ray analysis can be obtained with multilayer gratings when there is the need to study sam...

  3. Elastic properties of suspended multilayer WSe{sub 2}

    Zhang, Rui, E-mail: rui.zhang@ed.ac.uk; Cheung, Rebecca [Scottish Microelectronics Centre, Alexander Crum Brown Road, The University of Edinburgh, King' s Buildings, Edinburgh EH9 3FF (United Kingdom); Koutsos, Vasileios [Institute for Materials and Processes, School of Engineering, The University of Edinburgh, King' s Buildings, Edinburgh EH9 3FB (United Kingdom)

    2016-01-25

    We report the experimental determination of the elastic properties of suspended multilayer WSe{sub 2}, a promising two-dimensional (2D) semiconducting material combined with high optical quality. The suspended WSe{sub 2} membranes have been fabricated by mechanical exfoliation of bulk WSe{sub 2} and transfer of the exfoliated multilayer WSe{sub 2} flakes onto SiO{sub 2}/Si substrates pre-patterned with hole arrays. Then, indentation experiments have been performed on these membranes with an atomic force microscope. The results show that the 2D elastic modulus of the multilayer WSe{sub 2} membranes increases linearly while the prestress decreases linearly as the number of layers increases. The interlayer interaction in WSe{sub 2} has been observed to be strong enough to prevent the interlayer sliding during the indentation experiments. The Young's modulus of multilayer WSe{sub 2} (167.3 ± 6.7 GPa) is statistically independent of the thickness of the membranes, whose value is about two thirds of other most investigated 2D semiconducting transition metal dichalcogenides, namely, MoS{sub 2} and WS{sub 2}. Moreover, the multilayer WSe{sub 2} can endure ∼12.4 GPa stress and ∼7.3% strain without fracture or mechanical degradation. The 2D WSe{sub 2} can be an attractive semiconducting material for application in flexible optoelectronic devices and nano-electromechanical systems.

  4. Switching between optical bistability and multistability in plasmonic multilayer nanoparticles

    Daneshfar, Nader; Naseri, Tayebeh

    2017-01-01

    We study the nonlinear optical response of multilayer metallic nanoparticles driven by an electromagnetic wave, which can show large field enhancement, hence significantly enhancing optical processes. In addition to optical bistability (OB), we find that optical multistability (OM), which plays a more important role in some applications than OB, is achievable and can be obtained in a multilayer plasmonic nanoparticle. Our results demonstrate that owing to strong localized fields created in the core and each layer of multilayer nanoshells, which occurs in the particles at frequencies close to the surface plasmon resonance, multilayer nanoparticles are promising systems with unique optical characteristics to control the light by light at the nanometer scale. It is demonstrated that OB can be converted to OM via adjusting the wavelength of the applied field and the size of the nanoshell, and the system can manifest optical hysteresis. It is found that the optical bistable or multistable threshold and the shape of hysteresis loops are strongly dependent on the thickness of shells, the incident wavelength, the permittivity of the surrounding medium, and the composition of the core and the inner/outer layers. We also give a discussion on the impact of the exciton-plasmon interaction and the intrinsic size effect on the nonlinear optical response of multilayer spherical nanoparticles.

  5. Rework of multilayer printed wiring board assemblies

    Clement, D.W.

    1976-08-01

    Processes of reworking printed wiring assemblies (PWA) built with multilayer printed wiring boards (MLPWB) were investigated. Because of the MLPWBs added thickness and increased heat absorption potential, assemblies built with these boards are suspected of being more susceptible to damage during component removal than assemblies built with single-layer double-sided boards. There also have been questions raised about the effect that rework has on the internal connections of the MLPWBs. A review and limited evaluation of all known rework methods resulted in selecting ''solder wick'' and ''vacuum extraction'' as the two main rework methods for use in the evaluations. The Appendix defines and describes these rework techniques. Two different groups of units, intended to be representative of a wide range of proposed and presently used MLPWB-component configurations, were fabricated and then reworked by variations of these two techniques. Approximately 16,000 internal connections of MLPWBs were subjected to rework. No internal connections became open or degraded. In addition, 80 PTHs with internal connections were subjected to 10 cycles of rework to examine the effect of rework on MLPWB internal connections. Continuity of the internal connections was measured before and after all rework. Even though the rework did cause extensive external damage to the MLPWBs (blisters, measles, and land damage, for example), there was no indication of internal connection degradation. The information received thus far leads to the conclusion that internal connections of MLPWBs are not likely to be degraded as a result of assembly rework.

  6. Tidal Heating in Multilayered Terrestrial Exoplanets

    Henning, Wade G.; Hurford, Terry

    2014-01-01

    The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R(sub E) is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.

  7. FEBRILE SEIZURE: RECURRENCE AND RISK FACTORS

    A. TALEBIAN

    2006-06-01

    Full Text Available Background:Febrile Convulsion is the most common convulsive disorder in children,occurring in 2 to 4% of the pediatric population and recurring in 30-50% of cases. Considering the varying recurrence rates reported, thisstudy was conducted at the pediatric ward of the Shaheed BeheshtiGeneral Hospital, between 2000-2001 to determine the frequencyof recurrence and related risk factors in children presenting with theirfirst episode of febrile convulsionMaterials & Methods:A two–year cohort study was performed on 50 children presentingwith the first attack of febrile convulsion. Patient demographic dataincluding age, sex, type and duration of seizure, family history offebrile seizure or epilepsy and the interval between fever onset andoccurrence of seizure were recorded in questionnaires. Those patients,for whom prophylactic medication was not administered, werefollowed at three–month intervals for up to one year. Findings werestatistically analyzed using Fisher’s exact testResults:Recurrence was observed in twelve children (24% out of the fifty,being most common in patients aged less than one year (54.4%.Recurrence rates among children with a positive family history offebrile convulsion, presence of complex febrile seizure and positivefamily history of epilepsy were 42.1%, 42.8% and 25% respectively.From among those children with a “less than one hour” intervalbetween fever onset and occurrence of seizure, recurrence occurredin 43-7% of cases, while in those with a “more than one hourinterval”, 14.7% experienced recurrence.Conclusion:Recurrence rates are increased by certain factors including age-belowone year-, positive family history of febrile convulsion, and a “lessthan one hour” interval between time of fever onset and seizureoccurrence.

  8. Finding recurrence networks' threshold adaptively for a specific time series

    Eroglu, D.; Marwan, N.; Prasad, S.; Kurths, J.

    2014-11-01

    Recurrence-plot-based recurrence networks are an approach used to analyze time series using a complex networks theory. In both approaches - recurrence plots and recurrence networks -, a threshold to identify recurrent states is required. The selection of the threshold is important in order to avoid bias of the recurrence network results. In this paper, we propose a novel method to choose a recurrence threshold adaptively. We show a comparison between the constant threshold and adaptive threshold cases to study period-chaos and even period-period transitions in the dynamics of a prototypical model system. This novel method is then used to identify climate transitions from a lake sediment record.

  9. Recurrent Falls in Parkinson’s Disease: A Systematic Review

    Allen, Natalie E.; Allison K. Schwarzel; Canning,Colleen G.

    2013-01-01

    Most people with Parkinson’s disease (PD) fall and many experience recurrent falls. The aim of this review was to examine the scope of recurrent falls and to identify factors associated with recurrent fallers. A database search for journal articles which reported prospectively collected information concerning recurrent falls in people with PD identified 22 studies. In these studies, 60.5% (range 35 to 90%) of participants reported at least one fall, with 39% (range 18 to 65%) reporting recurr...

  10. Thermal radiation antennas made of multilayer structures containing negative index metamaterials

    Maksimovic, M.; Hammer, M.; Jaksic, Z.; Greiner, C.M.; Waechter, C.A.

    2008-01-01

    We investigate the thermal antenna behavior of emissive/absorptive substrates coated by passive optical multilayer systems that contain negative refractive index metamaterials (NIM). Spectral and angular distributions of the thermal radiation emittance for periodic defect-containing multilayer with

  11. Layers over layer-by-layer assemblies: silanization of polyelectrolyte multilayers.

    Dirani, Ali; Fernandes, Antony E; Wong, Diana Ramirez; Lipnik, Pascale; Poleunis, Claude; Nysten, Bernard; Glinel, Karine; Jonas, Alain M

    2014-08-26

    The functionalization of poly(allylamine hydrochloride)/poly(acrylic acid) (PAH/PAA) polyelectrolyte multilayers by silanes reacted from the gas phase is studied depending on reaction time and temperature, pH of multilayer assembly, and nature of the reacting silane group. Whereas monochlorosilanes only diffuse in the multilayer and graft in limited amount, trichloro- and triethoxysilanes form rapidly a continuous gel layer on the surface of the multilayer, with a thickness of ca. 10-20 nm. The reactivity is lower in the strongly paired regime of the multilayers (neutral assembly conditions) but otherwise is not affected by the pH of multilayer assembly. Silanization considerably broadens the range of possible functionalities for (PAH/PAA) multilayers: hydrophobicity, surface-initiated polymerization, and grafting of fluorescent probes by the formation of disulfide bridges are demonstrated. Conversely, our results also broaden the range of substrates that can be functionalized by silanes, using (PAH/PAA) multilayers as ubiquitous anchoring layers.

  12. Multiparametric characterisation of metal-chalcogen atomic multilayer assembly by potentiodynamic electrochemical impedance spectroscopy

    Ragoisha, G.A.; Bondarenko, A.S.; Osipovich, N.P.; Rabchynski, S.M.; Streltsov, E.A.

    2008-01-01

    An approach to multiparametric characterisation of variable electroactive interfaces based on potentiodynamic electrochemical impedance spectroscopy (PDEIS) [G.A. Ragoisha, A.S. Bondarenko, Electrochim. Acta 50 (2005) 1553] has been extended to atomic multilayer assembly monitoring. The multilayers

  13. H pylori recurrence after successful eradication

    Yaron Niv

    2008-01-01

    Recurrence of H pylori after eradication is rare in developed countries and more frequent in developing countries.Recrudescence(recolonization of the same strain within 12 mo after eradication)rather than reinfection(colonization with a new strain,more than 12 mo after eradication)is considered to be responsiblefor most of the cases.This observation was confirmed only in developed countries,while in developing countries a recent meta-analysis demonstrated a high rate of reinfection.The proportion of H pylori annual recurrence was 2.67% and 13.00% in developed and developing countries,respectively.Nested meta-analysis(only cases with a longer follow-up and a negative 13CUBT a year after eradication)revealed annual recurrence rate of 1.45%[relative risk(RR),0.54]and 12.00%(RR,0.92)in developed and developing countries,respectively.These findings support the notion that in developed countries many cases of recurrence are due to recrudescence within the first year after eradication,with a 46% drop in the recurrence rate after the first year post eradication,while in developing countries reinfection is more pronounced,and continue at the same rate since eradication.A different approach for follow-up after H pylori eradication is probably needed in patients of developing countries,since reinfection is highly prevalent.

  14. Generative Benchmark Models for Mesoscale Structures in Multilayer Networks

    Bazzi, Marya; Arenas, Alex; Howison, Sam D; Porter, Mason A

    2016-01-01

    Multilayer networks allow one to represent diverse and interdependent connectivity patterns --- e.g., time-dependence, multiple subsystems, or both --- that arise in many applications and which are difficult or awkward to incorporate into standard network representations. In the study of multilayer networks, it is important to investigate "mesoscale" (i.e., intermediate-scale) structures, such as dense sets of nodes known as "communities" that are connected sparsely to each other, to discover network features that are not apparent at the microscale or the macroscale. A variety of methods and algorithms are available to identify communities in multilayer networks, but they differ in their definitions and/or assumptions of what constitutes a community, and many scalable algorithms provide approximate solutions with little or no theoretical guarantee on the quality of their approximations. Consequently, it is crucial to develop generative models of networks to use as a common test of community-detection tools. I...

  15. In Situ Phase Evolution of Ni/Ti Reactive Multilayers

    Cavaleiro, A. J.; Ramos, A. S.; Martins, R. M. S.; Baetz, C.; Vieira, M. T.; Braz Fernandes, F. M.

    2014-07-01

    Joining shape-memory alloys (SMA) to other materials is strongly required in order to enlarge their fields of application. Fusion welding induces strong compositional and microstructural changes that significantly affect the shape-memory effect and the superelastic behavior of these alloys. The exothermic and in some cases self-propagating character of some nano-multilayer reactions is explored in this study as an alternative for joining SMA. To follow these very fast reactions, high brilliance sources, such as synchrotron radiation, are required. In situ high-resolution x-ray diffraction data, giving the phase evolution sequence with temperature of the Ni/Ti multilayer thin films under study, are presented. A correlation between the multilayer design and the tendency for the sequence of phase formation is established.

  16. Multilayer silver nanoparticles embedded in graded-index dielectric layers

    Shokeen, Poonam; Jain, Amit; Gupta, Vinay; Kapoor, Avinashi

    2017-04-01

    A pulsed laser deposited SiO2/Ag/ZnO/Ag/TiO2 multilayer structure is studied to enhance the light trapping capability of thin-film solar cell. Structural and optical properties of structure are studied with scanning electron microscopy, x-ray diffraction, photoluminescence and UV-visible spectroscopy. Proposed geometry improves the extinction spectra and quenches photoluminescence in comparison to TiO2/Ag and SiO2/Ag/ZnO geometry. Finite-difference time-domain (FDTD) simulations indicate a promising effect of the proposed geometries on thin-film solar cells. Twofold enhancement in total quantum efficiency of an optimized multilayer plasmonic graded-index thin-film solar cell is observed in comparison to the pristine solar cell. Results suggest a more concerted study of multilayer plasmonic nanostructures with graded-index anti-reflection coatings to improve the performance of thin-film photovoltaic devices.

  17. SIW based multilayer transition and power divider in LTCC technology

    Abuzaid, Hattan

    2013-06-01

    A multilayer transition and balanced power divider are presented for millimeter-wave system-on-package (SoP). These two components operate at Ka-band and exploit the substrate integrate waveguide (SIW) technology with its shielding characteristics and the Low-temperature co-fired ceramics (LTCC) technology for its high density integration. A coupling slot has been used to perform vertical integration, which can be easily optimized through its length. The measured input return loss within the bandwidth of interest (32 GHz-38 GHz) is less than -15 dB and -18 dB for the multilayer transition and the power divider, respectively. The lateral dimensions of a multilayer system, such as a feed network of an array, can be greatly reduced by employing these 3D slot-coupled components. © 2013 IEEE.

  18. Multilayer DNA Origami Packed on Hexagonal and Hybrid Lattices

    Ke, Yonggang; Voigt, Niels Vinther; Shih, William M.;

    2012-01-01

    “Scaffolded DNA origami” has been proven to be a powerful and efficient approach to construct two-dimensional or three-dimensional objects with great complexity. Multilayer DNA origami has been demonstrated with helices packing along either honeycomb-lattice geometry or square-lattice geometry....... Here we report successful folding of multilayer DNA origami with helices arranged on a close-packed hexagonal lattice. This arrangement yields a higher density of helical packing and therefore higher resolution of spatial addressing than has been shown previously. We also demonstrate hybrid multilayer...... DNA origami with honeycomb-lattice, square-lattice, and hexagonal-lattice packing of helices all in one design. The availability of hexagonal close-packing of helices extends our ability to build complex structures using DNA nanotechnology....

  19. Multilayer DNA Origami Packed on Hexagonal and Hybrid Lattices

    Ke, Yonggang; Voigt, Niels V.; Gothelf, Kurt V.; Shih, William M.

    2012-01-01

    “Scaffolded DNA origami” has been proven to be a powerful and efficient approach to construct two-dimensional or three-dimensional objects with great complexity. Multilayer DNA origami has been demonstrated with helices packing along either honeycomb-lattice geometry or square-lattice geometry. Here we report successful folding of multilayer DNA origami with helices arranged on a close-packed hexagonal lattice. This arrangement yields a higher density of helical packing and therefore higher resolution of spatial addressing than has been shown previously. We also demonstrate hybrid multilayer DNA origami with honeycomb-lattice, square-lattice, and hexagonal lattice packing of helices all in one design. The availability of hexagonal close packing of helices extends our ability to build complex structures using DNA nanotechnology. PMID:22187940

  20. Amorphization in Gd-Co alloys and multilayers

    Alonso, J.A. [Departamento de Fisica Teorica, Universidad de Valladolid, Valladolid (Spain); Hojvat de Tendler, R. [Instituto de Estudios Nucleares, Centro Atomico Ezeiza, CNEA, Buenos Aires (Argentina); Barbiric, D.A. [Departamento de Quimica Inorganica, Analitica y Quimica Fisica, Universidad de Buenos Aires, Buenos Aires (Argentina); Riveiro, J.M. [Departamento de Fisica Aplicada, Universidad de Castilla-La Mancha, Ciudad Real (Spain)

    2002-10-07

    A semiempirical model is used to analyse the results of published experiments reporting on the solid-state amorphization reactions in bilayers and multilayers formed by Gd and Co. The role of the interfacial effects in raising the free energy of the initial arrangement in a multilayered configuration, and in promoting the amorphization reaction, is studied in detail. The model explains the observation of amorphous alloys over a broad composition range in the bilayer experiments. The preferred composition obtained in the multilayer experiments is discussed critically and the model prediction of a preferred composition Gd{sub 0.46}Co{sub 0.54} is in good agreement with the compositions observed in recent experiments. (author)

  1. Tetragonal and cubic zirconia multilayered ceramic constructs created by EPD.

    Mochales, Carolina; Frank, Stefan; Zehbe, Rolf; Traykova, Tania; Fleckenstein, Christine; Maerten, Anke; Fleck, Claudia; Mueller, Wolf-Dieter

    2013-02-14

    The interest in electrophoretic deposition (EPD) for nanomaterials and ceramics production has widely increased due to the versatility of this technique to effectively combine different materials in unique shapes and structures. We successfully established an EPD layering process with submicrometer sized powders of Y-TZP with different mol percentages of yttrium oxide (3 and 8%) and produced multilayers of alternating tetragonal and cubic phases with a clearly defined interface. The rationale behind the design of these multilayer constructs was to optimize the properties of the final ceramic by combining the high mechanical toughness of the tetragonal phase of zirconia together with the high ionic conductivity of its cubic phase. In this work, a preliminary study of the mechanical properties of these constructs proved the good mechanical integrity of the multilayered constructs obtained as well as crack deflection in the interface between tetragonal and cubic zirconia layers.

  2. MULTILAYER MICROSTRIP ANTENNA QUALITY FACTOR OPTIMIZATION FOR BANDWIDTH ENHANCEMENT

    M.C. SRIVASTAVA

    2012-12-01

    Full Text Available The impedance bandwidth, one of the important characteristics of microstrip patch antennas, can be significantly improved by using a multilayer dielectric configuration. In this paper the focus is on bandwidth enhancement technique of a multilayer patch antenna for X-band applications. In order to enhance the bandwidth, antenna losses are contained by controlling those quality factors which can have a significant impact on the bandwidth for a given permittivity and thickness of the substrate. This has been achieved by conformal transformation of the multidielectric microstrip antenna. For the ease of analysis Wheelers transformation is used to map the complex permittivity of a multilayer substrate to a single layer. Method of Moments and Finite Difference Time Domain approaches are used for the computation of results.

  3. Advances in self-assembled ultrathin polyoxomolybdates multilayers

    Liang-bao YANG; Xiu-fang WANG; An-jian XIE; Gang HU; Yu-bua SHEN

    2009-01-01

    The research on the assembly and function of organized molecular films has gained more and more interest. Electrostatic interactions can be employed to assemble polyoxomolybdates in surface confined multi-layers. Ultrathin multilayer films of polyoxomolybdates and organic molecules by the self-assembly method have been reviewed. At the same time, self-assemblies in aqueous solution are also reported, such as wheel-shaped clusters (Mo154), hollow spherical "blackberry"-like vesicles (Mo72Fe30) and Keggin structures. Polyoxomo-lybdate multilayers are promising candidates for diverse applications including electrocatalytic, photo- and electro-chromic systems. The development in this particular field of materials science may be highlighted in the future.

  4. Rutting Resistance of Asphalt Overlay with Multilayer Wheel Tracking Test

    LIAO Weidong; CHEN Zheng; WU Shaopeng; MO Liantong; LIU Gang

    2006-01-01

    The rutting resistance of multilayer asphalt overlay was researched by using laboratory wheel tracking test. The effects of loading level and test temperature on rutting resistance of asphalt overlay structure were evaluated by means of multilayer specimens .In comparison with multilayer tests, standard specimens of various layers were also conducted to evaluate the rutting resistance. Experimental results indicated that the test temperature and applied load have a significant effect on rutting resistance of asphalt concrete. Higher test temperature and heavier applied load resulted in higher rut depths. In addition, the mutilayer wheel tracking test has been demonstrated to be a more reasonable solution in evaluation on rutting resistance of asphatt pavement structure beasuse it reflects the cumulative permanent deformation in all of asphalt layers.

  5. Stronger multilayer acrylic dielectric elastomer actuators with silicone gel coatings

    Lau, Gih-Keong; La, Thanh-Giang; Sheng-Wei Foong, Ervin; Shrestha, Milan

    2016-12-01

    Multilayer dielectric elastomer actuators (DEA) perform worst off than single-layer DEAs due to higher susceptibility to electro-thermal breakdown. This paper presents a hot-spot model to predict the electro-thermal breakdown field of DEAs and its dependence on thermal insulation. To inhibit the electrothermal breakdown, silicone gel coating was applied as barrier coating to multilayer acrylic DEA. The gel coating helps suppress the electro-thermally induced puncturing of DEA membrane at the hot spot. As a result, the gel-coated DEAs, in either a single layer or a multilayer stack, can produce 30% more isometric stress change as compared to those none-coated. These gel-coated acrylic DEAs show great potential to make stronger artificial muscles.

  6. Tailoring dielectric properties of ferroelectric-dielectric multilayers

    Kesim, M. T.; Zhang, J. [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Cole, M. W. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, Aberdeen Proving Ground, Maryland 21005 (United States); Misirlioglu, I. B. [Faculty of Engineering and Natural Sciences, Sabancı University, Orhanlı/Tuzla, 34956 Istanbul (Turkey); Alpay, S. P., E-mail: p.alpay@ims.uconn.edu [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)

    2014-01-13

    We develop a nonlinear thermodynamic model for multilayer ferroelectric heterostructures that takes into account electrostatic and electromechanical interactions between layers. We concentrate on the effect of relative layer fractions and in-plane thermal stresses on dielectric properties of Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3}-, BaTiO{sub 3}-, and PbZr{sub 0.2}Ti{sub 0.8}O{sub 3} (PZT)-SrTiO{sub 3} (STO) multilayers on Si and c-sapphire. We show that dielectric properties of such multilayers can be significantly enhanced by tailoring the growth/processing temperature and the STO layer fraction. Our computations show that large tunabilities (∼90% at 400 kV/cm) are possible in carefully designed barium strontium titanate-STO and PZT-STO even on Si for which there exist substantially large in-plane strains.

  7. Mechanical Properties and Fracture Behaviour of Multilayer Alumina Composites

    ZHENG Xinguo; ZHAO Fei; ZHANG Jinyong

    2015-01-01

    Adopting a ceramic/polymer multilayer structure design to simulate the structure of nacre is usually believed to be an effective way to increase the toughness of ceramic composites at the expense of the material's bending strength. However, in this study, we found that both the bending strength and the toughness could be improved simultaneously when using a certain Al2O3/Kevlar multilayer composite design compared to pure alumina samples with the same dimensions. The fracture behaviour of the Al2O3/Kevlar multilayer composite was studied to ifnd a reason for this improvement. The results showed that the complex and asymmetrical stresses occurring in the Kevlar-reinforced layers were the main reason for the differences in fracture behaviour. We expect our results to open up new ways for the design of future high performance ceramic composites.

  8. Atomic scale structure investigations of epitaxial Fe/Cr multilayers

    Kąc, M., E-mail: malgorzata.kac@ifj.edu.pl [The Henryk Niewodniczański Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland); Morgiel, J. [Institute of Metallurgy and Materials Science PAN, 25 Reymonta St., 30-059 Kraków (Poland); Polit, A.; Zabila, Y.; Marszałek, M. [The Henryk Niewodniczański Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland)

    2014-06-01

    Fe/Cr multilayers were deposited by molecular beam epitaxy on the MgO(1 0 0) substrate. Structural properties of the samples were analyzed by low energy electron diffraction, high resolution transmission electron microscopy (HRTEM), as well as by X-ray reflectivity, conversion electron Mössbauer spectroscopy (CEMS) and Auger electron spectroscopy. Investigations revealed multilayered system built of well-ordered Fe and Cr thin films with (1 0 0) orientation. A high geometrical perfection of the system, i.e. planar form of interfaces and reproducible thickness of layers, was also proven. Fe/Cr interface roughness was determined to be 2–3 atomic layers. CEMS studies allowed to analyze at atomic scale the structure of buried Fe/Cr interfaces, as well as to distinguish origin of interface roughness. Roughnesses resulting from interface corrugations and from the Fe–Cr interdiffusion at interfaces were observed. Fe/Cr multilayers showed strong antiferromagnetic coupling of Fe layers.

  9. Determination of magnetic properties of multilayer metallic thin films

    Birlikseven, C

    2000-01-01

    and magnetization measurements were taken. In recent year, Giant Magnetoresistance Effect has been attracting an increasingly high interest. High sensitivity magnetic field detectors and high sensitivity read heads of magnetic media can be named as important applications of these films. In this work, magnetic and electrical properties of single layer and thin films were investigated. Multilayer thin films were supplied by Prof. Dr. A. Riza Koeymen from Texas University. Multilayer magnetic thin films are used especially for magnetic reading and magnetic writing. storing of large amount of information into small areas become possible with this technology. Single layer films were prepared using the electron beam evaporation technique. For the exact determination of film thicknesses, a careful calibration of the thicknesses was made. Magnetic properties of the multilayer films were studied using the magnetization, magnetoresistance measurements and ferromagnetic resonance technique. Besides, by fitting the exper...

  10. IONIC SELF-ASSEMBLY AND HUMIDITY SENSITIVITY OF POLYELECTROLYTE MULTILAYERS

    Hai-hu Yu; De-sheng Jiang

    2002-01-01

    Multilayer thin films of alternately adsorbed layers of polyelectrolytes PDDA and PS-119 were formed on both planar silica substrates and optical fibers through the ionic self-assembly technique. Intrinsic Fabry-Perot cavities were fabricated by stepwise assembling the polyelectrolytes onto the ends of optical fibers for the purposes of fiber optical device and sensor development. Ionically assembled polyelectrolyte multilayer thin films, in whichthere are hydrophilic side groups with strong affinity towards water molecules, are a category of humidity-sensitive functional materials. The polyelectrolyte multilayer thin film Fabry-Perot cavity-type fiber optical humidity sensor can work over a wide range from about 0% RH to about 100% RH with a response time less than 1 s.

  11. Medical Image Retrieval Based on Multi-Layer Resampling Template

    WANG Xin-rui; YANG Yun-feng

    2014-01-01

    Medical image application in clinical diagnosis and treatment is becoming more and more widely, How to use a large number of images in the image management system and it is a very important issue how to assist doctors to analyze and diagnose. This paper studies the medical image retrieval based on multi-layer resampling template under the thought of the wavelet decomposition, the image retrieval method consists of two retrieval process which is coarse and fine retrieval. Coarse retrieval process is the medical image retrieval process based on the image contour features. Fine retrieval process is the medical image retrieval process based on multi-layer resampling template, a multi-layer sampling operator is employed to extract image resampling images each layer, then these resampling images are retrieved step by step to finish the process from coarse to fine retrieval.

  12. Phase measurement of soft x-ray multilayer mirrors.

    de Rossi, Sébastien; Bourassin-Bouchet, Charles; Meltchakov, Evgueni; Giglia, Angelo; Nannarone, Stefano; Delmotte, Franck

    2015-10-01

    We propose a new model enabling the extraction of the phase of a multilayer mirror from photocurrent measurements in the soft x rays. In this range, the effects of the mean free path of the electrons inside the stack can no longer be neglected, which prevents the phase reconstruction by conventional photocurrent measurements. The new model takes into account this phenomenon and thus extends up to the x rays the applicability range of the technique. This approach has been validated through a numerical and experimental study of chromium/scandium multilayers used near 360 eV. To our knowledge, this work constitutes the first measurement of the phase of a multilayer mirror in the soft x-ray range.

  13. Electron with arbitrary pseudo-spins in multilayer graphene

    Worasak Prarokijjak; Bumned Soodchomshom

    2015-01-01

    Using the low-energy effective Hamiltonian of the ABC-stacked multilayer graphene, the pseudo-spin coupling to real orbital angular momentum of electrons in multilayer graphene is investigated. We show that the electron wave function in N-layer graphene mimics the behavior of a particle with a spin of N × (}/2), where N={1, 2, 3, . . .}. It is said that for N>1 the low-energy effective Hamiltonian for ABC-stacked graphene cannot be used to describe pseudo-spin-1/2 particles. The wave function of electrons in multilayer graphene may behave like fermionic (or bosonic) particle for N being odd (or even). In this paper, we propose a theory of graphene serving as a host material of electrons with arbitrary pseudo-spins tunable by changing the number of graphene layers.

  14. Multilayer crack-free hybrid coatings for functional devices

    Islam, Shumaila; Bidin, Noriah; Riaz, Saira; Naseem, Shahzad; Marsin Sanagi, Mohd.; Imran, M.

    2016-04-01

    Porous acid catalyzed TiO2 single, SiO2-TiO2 hybrid, and TiO2/SiO2-TiO2/SiO2 multilayer coatings are synthesized and characterized for optical and electro-optical applications. The reflection value is reasonably reduced from the surface of the glass by integrating sol-gel based spin-coated single and multilayer thin films. Structurally, the films show uniform, crack-free, and porous nanofilms with good surface roughness of below 10 nm, which has potential for optical applications. Wide range tunability of refractive index (2.83 to 1.59) with more than 78% optical transparency is observed. The multilayered reflection profile is observed around 0.18%, so these coatings are desirable for optochemical functional devices.

  15. Broad band invisibility cloak made of normal dielectric multilayer

    Xu, Xiaofei; Xiong, Shuai; Fan, Jinlong; Zhao, Jun-Ming; Jiang, Tian

    2011-01-01

    We present the design, fabrication and performance test of a quasi three-dimensional carpet cloak made of normal dielectric in the microwave regime. Taking advantage of a simple linear coordinate transformation we design a carpet cloak with homogeneous anisotropic medium and then practically realize the device with multilayer of alternating normal dielectric slabs based on the effective medium theory. As a proof-of-concept example, we fabricate the carpet cloak with multilayer of FR4 dielectric slabs with air spacing. The performance of the fabricated design is verified through full-wave numerical simulation and measurement of the far-field scattering electromagnetic waves in a microwave anechoic chamber. Experimental results have demonstrated pronounced cloaking effect in a very broad band from 8 GHz to 18 GHz (whole X and Ku band) due to the low loss, non-dispersive feature of the multilayer dielectric structure.

  16. Catalytic Polymer Multilayer Shell Motors for Separation of Organics.

    Lin, Zhihua; Wu, Zhiguang; Lin, Xiankun; He, Qiang

    2016-01-26

    A catalytic polymer multilayer shell motor has been developed, which effects fast motion-based separation of charged organics in water. The shell motors are fabricated by sputtering platinum onto the exposed surface of silica templates embedded in Parafilm, followed by layer-by-layer assembly of polyelectrolyte multilayers to the templates. The catalytic shell motors display high bubble propulsion with speeds of up to 260 μm s(-1) (13 body lengths per second). Moreover, the polyelectrolyte multilayers assembled at high pH (pH>9.0) adsorb approximately 89% of dye molecules from water, owing to the electrostatic interaction between the positively charged polymers and the anionic dye molecules, and subsequently release them at neutral pH in a microfluidic device. The efficient propulsion coupled with the effective adsorption behavior of the catalytic shell motors in a microfluidic device results in accelerated separation of organics in water and thus holds considerable promise for water analysis.

  17. Modeling Macroscopic Shape Distortions during Sintering of Multi-layers

    Tadesse Molla, Tesfaye

    Ceramic multi-layered composites are being used as components in various technologies ranging from electronics to energy conversion devices. Thus, different architectures of multi-layers involving ceramic materials are often required to be produced by powder processing, followed by sintering...... evolutions during co-firing of bi-layers. Optimizations of the co-firing process by controlling the initial geometry of the sample and structural characteristics are also suggested. Furthermore, the multi-scale model has also shown the expected behavior of shape distortions for different bi-layers systems...... involving layers with the same and different sinterabilities. Based on the experimental and simulation results, the following conclusions are reached: during sintering of planar multi-layers, understanding of the effect of gravity on the camber evolution can be used in optimizing the co-sintering process so...

  18. Surface modification of multilayer graphene using Ga ion irradiation

    Wang, Quan, E-mail: wangq@mail.ujs.edu.cn [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Shao, Ying; Ge, Daohan; Ren, Naifei [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Yang, Qizhi [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); State key laboratory of Robotics, Chinese Academy of Sciences, Shengyang 110000 (China)

    2015-04-28

    The effect of Ga ion irradiation intensity on the surface of multilayer graphene was examined. Using Raman spectroscopy, we determined that the irradiation caused defects in the crystal structure of graphene. The density of defects increased with the increase in dwell times. Furthermore, the strain induced by the irradiation changed the crystallite size and the distance between defects. These defects had the effect of doping the multilayer graphene and increasing its work function. The increase in work function was determined using contact potential difference measurements. The surface morphology of the multilayer graphene changed following irradiation as determined by atomic force microscopy. Additionally, the adhesion between the atomic force microscopy tip and sample increased further indicating that the irradiation had caused surface modification, important for devices that incorporate graphene.

  19. Structure of solid monolayers and multilayers of -hexane on graphite

    M Krishnan; S Balasubramanian; S Clarke

    2003-10-01

    We present all-atom molecular dynamics simulations of -hexane on the basal plane of graphite at monolayer and multilayer coverages. In keeping with experimental data, we find the presence of ordered adsorbed layers both at single monolayer coverage and when the adsorbed layer coexists with excess liquid adsorbate. Using a simulation method that does not impose any particular periodicity on the adsorbed layer, we quantitatively compare our results to the results of neutron diffraction experiments and find a structural transition from a uniaxially incommensurate lattice to a fully commensurate structure on increasing the coverage from a monolayer to a multilayer. The zig-zag backbone planes of all the alkane molecules lie parallel to the graphite surface at the multilayer coverage, while a few molecules are observed to attain the perpendicular orientation at monolayer coverage.

  20. Multi-layer boron thin-film detectors for neutrons

    Wang, Zhehui [Los Alamos National Laboratory; Morris, Christopher L [Los Alamos National Laboratory

    2010-01-01

    Intrinsic efficiencies of the multilayer boron detectors have been examined both theoretically and experimentally. It is shown that due to the charge loss in the boron layers, the practical efficiencies of most multi-layer {sup 10}B detectors are limited up to about 42%, much less than 77% of the 2 bar 2-inch diameter {sup 3}He detectors. It is suggested that the same charge loss mechanism will prevent essentially all substrate-based boron detectors from ever reaching the efficiencies of high-pressure {sup 3}He tubes, independent of the substrate geometry and material composition (including silicon). Meanwhile, the experimental data indicate that the multi-layer approach can increase the efficiencies up to the theoretical limit. Good n/{gamma} discrimination has also achieved using the ionization charnber technique.