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Sample records for recurrent multilayer perceptron

  1. Auto-kernel using multilayer perceptron

    Directory of Open Access Journals (Sweden)

    Wei-Chen Cheng

    2012-06-01

    Full Text Available This work presents a constructive method to train the multilayer perceptron layer after layer successively and to accomplish the kernel used in the support vector machine. Data in different classes will be trained to map to distant points in each layer. This will ease the mapping of the next layer. A perfect mapping kernel can be accomplished successively. Those distant mapped points can be discriminated easily by a single perceptron.

  2. Multi-Layer Perceptrons and Symbolic Data

    CERN Document Server

    Rossi, Fabrice

    2008-01-01

    In some real world situations, linear models are not sufficient to represent accurately complex relations between input variables and output variables of a studied system. Multilayer Perceptrons are one of the most successful non-linear regression tool but they are unfortunately restricted to inputs and outputs that belong to a normed vector space. In this chapter, we propose a general recoding method that allows to use symbolic data both as inputs and outputs to Multilayer Perceptrons. The recoding is quite simple to implement and yet provides a flexible framework that allows to deal with almost all practical cases. The proposed method is illustrated on a real world data set.

  3. Multi-Layer Perceptrons and Symbolic Data

    OpenAIRE

    Rossi, Fabrice; Conan-Guez, Brieuc

    2008-01-01

    In some real world situations, linear models are not sufficient to represent accurately complex relations between input variables and output variables of a studied system. Multilayer Perceptrons are one of the most successful non-linear regression tool but they are unfortunately restricted to inputs and outputs that belong to a normed vector space. In this chapter, we propose a general recoding method that allows to use symbolic data both as inputs and outputs to Multilayer ...

  4. KLASIFIKASI WEBSITE MENGGUNAKAN ALGORITMA MULTILAYER PERCEPTRON

    Directory of Open Access Journals (Sweden)

    Nyoman Purnama

    2014-08-01

    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%.

  5. Quaternionic Multilayer Perceptron with Local Analyticity

    Directory of Open Access Journals (Sweden)

    Nobuyuki Matsui

    2012-11-01

    Full Text Available A multi-layered perceptron type neural network is presented and analyzed in this paper. All neuronal parameters such as input, output, action potential and connection weight are encoded by quaternions, which are a class of hypercomplex number system. Local analytic condition is imposed on the activation function in updating neurons’ states in order to construct learning algorithm for this network. An error back-propagation algorithm is introduced for modifying the connection weights of the network.

  6. Wind speed estimation using multilayer perceptron

    International Nuclear Information System (INIS)

    Highlights: • We present a method for determining the average wind speed using neural networks. • We use data from that site in the short term and data from other nearby stations. • The inputs used in the ANN were wind speed and direction data from a station. • The method allows knowing the wind speed without topographical data. - Abstract: Wind speed knowledge is prerequisite in the siting of wind turbines. In consequence the wind energy use requires meticulous and specified knowledge of the wind characteristics at a location. This paper presents a method for determining the annual average wind speed at a complex terrain site by using neural networks, when only short term data are available for that site. This information is useful for preliminary calculations of the wind resource at a remote area having only a short time period of wind measurements measurement in a site. Artificial neural networks are useful for implementing non-linear process variables over time, and therefore are a useful tool for estimating the wind speed. The neural network used is multilayer perceptron with three layers and the supervised learning algorithm used is backpropagation. The inputs used in the neural network were wind speed and direction data from a single station, and the training patterns used correspond to sixty days data. The results obtained by simulating the annual average wind speed at the selected site based on data from nearby stations with correlation coefficients above 0.5 were satisfactory, compared with actual values. Reliable estimations were obtained, with errors below 6%

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

    Directory of Open Access Journals (Sweden)

    N. Pedroni

    2008-03-01

    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.

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

    OpenAIRE

    Bhowmik, Mrinal Kanti; Bhattacharjee, Debotosh; 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 an...

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

    OpenAIRE

    Mita Nasipuri; Mahantapas Kundu; Dipak Kumar Basu; Debotosh Bhattacharjee; Mrinal Kanti Bhowmik

    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 Perce...

  10. Multilayer perceptron-based DFE with lattice structure.

    Science.gov (United States)

    Zerguine, A; Shafi, A; Bettayeb, M

    2001-01-01

    The severely distorting channels limit the use of linear equalizers and the use of the nonlinear equalizers then becomes justifiable. Neural-network-based equalizers, especially the multilayer perceptron (MLP)-based equalizers, are computationally efficient alternative to currently used nonlinear filter realizations, e.g., the Volterra type. The drawback of the MLP-based equalizers is, however, their slow rate of convergence, which limit their use in practical systems. In this work, the effect of whitening the input data in a multilayer perceptron-based decision feedback equalizer (DFE) is evaluated. It is shown from computer simulations that whitening the received data employing adaptive lattice channel equalization algorithms improves the convergence rate and bit error rate performances of multilayer perceptron-based DFE. The adaptive lattice algorithm is a modification to the one developed by Ling and Proakis (1985). The consistency in performance is observed in both time-invariant and time-varying channels. Finally, it is found in this work that, for time-invariant channels, the MLP DFE outperforms the least mean squares (LMS)-based DFE. However, for time-varying channels comparable performance is obtained for the two configurations. PMID:18249886

  11. Efficient training of multilayer perceptrons using principal component analysis

    International Nuclear Information System (INIS)

    A training algorithm for multilayer perceptrons is discussed and studied in detail, which relates to the technique of principal component analysis. The latter is performed with respect to a correlation matrix computed from the example inputs and their target outputs. Typical properties of the training procedure are investigated by means of a statistical physics analysis in models of learning regression and classification tasks. We demonstrate that the procedure requires by far fewer examples for good generalization than traditional online training. For networks with a large number of hidden units we derive the training prescription which achieves, within our model, the optimal generalization behavior

  12. Learning of Multilayer Perceptrons with Piecewise-Linear Activation Functions.

    Czech Academy of Sciences Publication Activity Database

    Kozub, P.; Hole?a, Martin

    Praha : Matfyzpress, 2008 - (Obdržálek, D.; Štanclová, J.; Plátek, M.), s. 27-46 ISBN 978-80-7378-076-0. [MIS 2008. Malý informatický seminá? /25./. Josef?v d?l (CZ), 12.01.2008-19.01.2008] R&D Projects: GA ?R GA201/08/0802; GA ?R GA201/08/1744 Institutional research plan: CEZ:AV0Z10300504 Keywords : artificial neural networks * multilayer perceptrons * activation functions * function approximation * constrained optimization Subject RIV: IN - Informatics, Computer Science

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

    Directory of Open Access Journals (Sweden)

    Mita Nasipuri

    2010-01-01

    Full Text Available 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 most importantly illumination changes. Experimental results show that the proposed OCON structure performs better than the conventional ACON in terms of network training convergence speed and which can be easily exercised in a parallel environment.

  14. Theoretical Properties of Projection Based Multilayer Perceptrons with Functional Inputs

    CERN Document Server

    Rossi, F; Rossi, Fabrice; Conan-Guez, Brieuc

    2006-01-01

    Many real world data are sampled functions. As shown by Functional Data Analysis (FDA) methods, spectra, time series, images, gesture recognition data, etc. can be processed more efficiently if their functional nature is taken into account during the data analysis process. This is done by extending standard data analysis methods so that they can apply to functional inputs. A general way to achieve this goal is to compute projections of the functional data onto a finite dimensional sub-space of the functional space. The coordinates of the data on a basis of this sub-space provide standard vector representations of the functions. The obtained vectors can be processed by any standard method. In our previous work, this general approach has been used to define projection based Multilayer Perceptrons (MLPs) with functional inputs. We study in this paper important theoretical properties of the proposed model. We show in particular that MLPs with functional inputs are universal approximators: they can approximate to ...

  15. Online learning dynamics of multilayer perceptrons with unidentifiable parameters

    International Nuclear Information System (INIS)

    In the over-realizable learning scenario of multilayer perceptrons, in which the student network has a larger number of hidden units than the true or optimal network, some of the weight parameters are unidentifiable. In this case, the teacher network consists of a union of optimal subspaces included in the parameter space. The optimal subspaces, which lead to singularities, are known to affect the estimation performance of neural networks. Using statistical mechanics, we investigate the online learning dynamics of two-layer neural networks in the over-realizable scenario with unidentifiable parameters. We show that the convergence speed strongly depends on the initial parameter conditions. We also show that there is a quasi-plateau around the optimal subspace, which differs from the well-known plateaus caused by permutation symmetry. In addition, we discuss the property of the final learning state, relating this to the singular structures

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

    DEFF Research Database (Denmark)

    Míguez González, M; López Peña, F.

    2011-01-01

    Parametric roll resonance is a ship stability related phenomenon that generates sudden large amplitude oscillations up to 30-40 degrees of roll. This can cause severe damage, and it can put the crew in serious danger. The need for a parametric rolling real time prediction system has been 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 is shown to be capable of forecasting the ship’s roll motion in realistic scenarios.

  17. Multilayer perceptron in damage detection of bridge structures

    Science.gov (United States)

    Pandey, P. C.; Barai, S. V.

    1995-02-01

    Recent developments in artificial neural networks (ANN) have opened up new possibilities in the domain of structural engineering. For inverse problems like structural identification of large civil engineerlng structures such as bridges and buildings where the in situ measured data are expected to be imprecise and often incomplete, the ANN holds greater promise. The detection of structural damage and identification of damaged element in a large complex structure is a challenging task indeed. This paper presents an application of multilayer perceptron in the damage detection of steel bridge structures. The ssues relating to the design of network and learning paradigm are addressed and network architectures have been developed with reference to trussed bridge structures. The training patterns are generated for multiple damaged zones in a structure and performance of the networks with one and two hidden layers are examined. It has been observed that the performance of the network with two hidden layers was better than that of a single-layer architecture in general. The engineering importance of the whole exercise is demonstrated from the fact that measured input at only a few locations in the structure is needed in the identification process using the ANN.

  18. Empirical model development and validation with dynamic learning in the recurrent multilayer perception

    International Nuclear Information System (INIS)

    A nonlinear multivariable empirical model is developed for a U-tube steam generator using the recurrent multilayer perceptron network as the underlying model structure. The recurrent multilayer perceptron is a dynamic neural network, very effective in the input-output modeling of complex process systems. A dynamic gradient descent learning algorithm is used to train the recurrent multilayer perceptron, resulting in an order of magnitude improvement in convergence speed over static learning algorithms. In developing the U-tube steam generator empirical model, the effects of actuator, process,and sensor noise on the training and testing sets are investigated. Learning and prediction both appear very effective, despite the presence of training and testing set noise, respectively. The recurrent multilayer perceptron appears to learn the deterministic part of a stochastic training set, and it predicts approximately a moving average response. Extensive model validation studies indicate that the empirical model can substantially generalize (extrapolate), though online learning becomes necessary for tracking transients significantly different than the ones included in the training set and slowly varying U-tube steam generator dynamics. In view of the satisfactory modeling accuracy and the associated short development time, neural networks based empirical models in some cases appear to provide a serious alternative to first principles models. Caution, however, must be exercised because extensive on-line validation of these models is still warranted

  19. Multilayer Perceptron Neural Networks Model for Meteosat Second Generation SEVIRI Daytime Cloud Masking

    DEFF Research Database (Denmark)

    Proud, Simon Richard

    2015-01-01

    A multilayer perceptron neural network cloud mask for Meteosat Second Generation SEVIRI (Spinning Enhanced Visible and Infrared Imager) images is introduced and evaluated. The model is trained for cloud detection on MSG SEVIRI daytime data. It consists of a multi-layer perceptron with one hidden sigmoid layer, trained with the error back-propagation algorithm. The model is fed by six bands of MSG data (0.6, 0.8, 1.6, 3.9, 6.2 and 10.8 ?m) with 10 hidden nodes. The multiple-layer perceptrons lead to a cloud detection accuracy of 88.96%, when trained to map two predefined values that classify cloud and clear sky. The network was further evaluated using sixty MSG images taken at different dates. The network detected not only bright thick clouds but also thin or less bright clouds. The analysis demonstrated the feasibility of using machine learning models of cloud detection in MSG SEVIRI imagery.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Experiments with Evolutionary and Hybrid Learning of Multi-layer Perceptron Neural Networks.

    Czech Academy of Sciences Publication Activity Database

    Neruda, Roman; Slušný, Stanislav

    Ostrava : VŠB Technická univerzita, 2007 - (Mikulecký, P.; Dvorský, J.; Krátký, M.), s. 75-84 ISBN 978-80-248-1279-3. [Znalosti 2007. Ostrava (CZ), 21.02.2007-23.02.2007] R&D Projects: GA AV ?R 1ET100300414 Institutional research plan: CEZ:AV0Z10300504 Keywords : multilayer perceptron * evolutionary learning * hybrid algorithms Subject RIV: IN - Informatics, Computer Science

  2. Direct optimisation of a multilayer perceptron for the estimation of cepstral mean and variance statistics

    OpenAIRE

    Dines, John; Vepa, Jithendra

    2007-01-01

    We propose an alternative means of training a multilayer perceptron for the task of speech activity detection based on a criterion to minimise the error in the estimation of mean and variance statistics for speech cepstrum based features using the Kullback-Leibler divergence. We present our baseline and proposed speech activity detection approaches for multi-channel meeting room recordings and demonstrate the effectiveness of the new criterion by comparing the two approaches when used to carr...

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

    Science.gov (United States)

    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.

  4. Multilayer Perceptron Neural Networks Model for Meteosat Second Generation SEVIRI Daytime Cloud Masking

    Directory of Open Access Journals (Sweden)

    Alireza Taravat

    2015-02-01

    Full Text Available A multilayer perceptron neural network cloud mask for Meteosat Second Generation SEVIRI (Spinning Enhanced Visible and Infrared Imager images is introduced and evaluated. The model is trained for cloud detection on MSG SEVIRI daytime data. It consists of a multi-layer perceptron with one hidden sigmoid layer, trained with the error back-propagation algorithm. The model is fed by six bands of MSG data (0.6, 0.8, 1.6, 3.9, 6.2 and 10.8 ?m with 10 hidden nodes. The multiple-layer perceptrons lead to a cloud detection accuracy of 88.96%, when trained to map two predefined values that classify cloud and clear sky. The network was further evaluated using sixty MSG images taken at different dates. The network detected not only bright thick clouds but also thin or less bright clouds. The analysis demonstrated the feasibility of using machine learning models of cloud detection in MSG SEVIRI imagery.

  5. A New Approach to Predicting Bankruptcy: Combining DEA and Multi-Layer Perceptron

    Directory of Open Access Journals (Sweden)

    Ayan Mukhopadhyay

    2012-07-01

    Full Text Available The question of financial health and sustenance of a firm is so intriguing that it has spanned numerous studies. For investors,stakeholders and lenders, assessing the risk associated with an enterprise is vital. Several tools have been formulated to deal with predicting the solvency of a firm. This paper attempts to combine Data Envelopment Analysis and Multi-Layer Perceptron (MLP to suggest a new method for prediction of bankruptcy that not only focusses on historical financial data of firms that filed for bankruptcy like other past studies but also takes into account the data of those firms that were likely to do so. This method thus identifies firms that have a high chance of facing bankruptcy along with those that have filed for bankruptcy. The performance of this procedure is compared with MLP. The suggested method outperforms MLP in prediction of bankruptcy.

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

    Directory of Open Access Journals (Sweden)

    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

  7. DISCRETE WAVELET TRANSFORM AND S-TRANSFORM BASED TIME SERIES DATA MINING USING MULTILAYER PERCEPTRON NEURAL NETWORK

    OpenAIRE

    LALIT KUMAR BEHERA; MAYA NAYAK; SAREETA MOHANTY

    2011-01-01

    This paper presents discrete wavelet transform and the S-transform based neural classifier scheme used for time series data mining of power quality events occurring due to power signal disturbances. The DWT and the S –transform are used for feature extraction and then the extracted features are classified with neural classifiers such as multilayered perceptron network (MLP) for pattern classification, data mining and subsequent knowledge discovery.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  9. Phase transitions in the generalization behaviour of multilayer perceptrons; 2, The influence of noise

    CERN Document Server

    Schottky, B

    1997-01-01

    We extend our study of phase transitions in the generalization behaviour of multilayer perceptrons with non-overlapping receptive fields to the problem of the influence of noise, concerning e.g. the input units and/or the couplings between the input units and the hidden units of the second layer (='input noise'), or the final output unit (='output noise'). Without output noise, the output itself is given by a general, permutation-invariant Boolean function of the outputs of the hidden units. As a result we find that the phase transitions, which we found in the deterministic case, mostly persist in the presence of noise. The influence of the noise on the position of the phase transition, as well as on the behaviour in other regimes of the loading parameter $\\alpha$, can often be described by a simple rescaling of $\\alpha$ depending on strength and type of the noise. We then consider the problem of the optimal noise level for Gibbsian and Bayesian learning, looking on replica symmetry breaking as well. Finally ...

  10. Using multilayer perceptron and a satellite image for the estimation of soil salinity

    International Nuclear Information System (INIS)

    Applying the model of the Perceptron multilayer with momentum of an artificial neural network particularly and a multispectral image of high resolution spatial and radiometric, for the first time estimated the salinity of the soil cultivated with sugar cane. The study area is the UBPC 'Lazaro Romero' of the sugar company 'Hector Molina' of the locality San Nicolas de Bari, Havana province, located at 22° 44' North latitude and 81 ° 56' longitude West. The experiments were made in the framework of the El-479 project funded by the Inter universities Council of Flanders, Belgium. 36 samples geo referenced of soils were taken at 3 depths in each of the 4 sugar cane selected blocks, which determined the electrical conductivity of the saturation extract; half of that amount of data was used for the training of the network and the other half for control in a computer program of the artificial neural network created to that effect, together with the reflectance of vegetation indexes for the image, which were maps of electrical conductivity of each block and bands. They were compared with those obtained by simple linear regression between the normalized difference vegetation index and electrical conductivity, Ndv with the approach of the neuronal network, the correlation coefficient was 0.78 to 0.83, while the linear regression was between 0.65 to 0.75

  11. Face Recognition through Multilayer Perceptron (MLP and Learning Vector Quantization (LVQ

    Directory of Open Access Journals (Sweden)

    Dr. Ikvinderpal Singh

    2012-12-01

    Full Text Available Face recognition is challenging problems and there is still a lot of work that needs to be done in this area. Over the past ten years, face recognition has received substantial attention from researchers in biometrics, pattern recognition, computer vision, and cognitive psychology communities. This common interest in facial recognition technology among researchers working in diverse fields is motivated both by the remarkable ability to recognize people and by the increased attention being devoted to security applications. Applications of face recognition can be found in security, tracking, multimedia, and entertainment domains.This paper presents a face recognition system using artificial neural network. Here, we have designed a neural network with some own set network parameters. The results presented here have been obtained using two basic methods: multilayer perceptron (MLP, and learning vector quantization (LVQ. In both cases, two kinds of data have been fed to the classifiers: reduced resolution images (gray level or segmented, and feature vectors. The experimental results also show that, for the approaches considered here, analyzing gray level images produced better results than analyzing geometrical features, either because of the errors introduced during their extraction or because the original images have a richer information content. Furthermore, training times were much shorter for LVQ than for MLP. On the other hand, MLP achieved lower error rates when dealing with geometrical features.

  12. Geomagnetic Dst index forecast using a multilayer perceptrons artificial neural network

    International Nuclear Information System (INIS)

    Complete text of publication follows. The best known manifestations of the impact of solar wind on the magnetosphere are the geomagnetic storms. The prediction of geomagnetic field behavior allows the alert of geomagnetic storms occurrence, as those phenomena can cause many damages in the planet. The Artificial Intelligence tools have been applied in many multidisciplinary studies, covering several areas of knowledge, as a choice of approach to the solution of problems with characteristics like non-linearity, imprecision, and other features that can not be easily solved with conventional computational models. Techniques such as Artificial Neural Networks, Expert Systems and Decision Trees have been used in the Space Weather studies to perform tasks such as forecasting geomagnetic storms and the investigation of rules and parameters related on its occurrence. The main focus of this work is on forecasting the geomagnetic field behavior, represented this time by the Dst index, using for that task, mainly, the interplanetary magnetic field components and solar wind data. The tool chosen here to solve the non-linear problem was a Multi-layer Perceptrons Artificial Neural Network, trained with the backpropagation algorithm. Unlike what was done in other studies, we chose to predict calm and disturbed periods like, for example, a full month of data, for application in a real time forecasting system. It was possible to predict the geomagnetic Dst index one or two hours before with great percentage efficiency.

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

    Indian Academy of Sciences (India)

    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.

  14. On electron and pion identification using a multilayer perceptron in the transition radiation detector of the CBM experiment

    International Nuclear Information System (INIS)

    The problem of pion-electron identification based on their energy losses in the TRD is considered in the frame of the CBM experiment. For particles identification an artificial neural network (ANN) was used, a multilayer perceptron realized in JETNET and ROOT packages. It is demonstrated that, in order to get correct and comparable results, it is important to define the network structure correctly. The recommendations for such a selection are given. In order to achieve an acceptable level of pions suppression, the energy losses need to be transformed to more 'effective' variables. The dependency of ANN output threshold for a fixed portion of electron loss on the particle momentum is presented

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    In this work, multilayered perceptron neural networks (MLPNNs) were presented for the computation of the gamma-ray energy absorption buildup factors (BA) of seven thermoluminescent dosimetric (TLD) materials [LiF, BeO, Na2B4O7, CaSO4, Li2B4O7, KMgF3, Ca3(PO4)2] in the energy region 0.015–15MeV, 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...

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

    CERN Document Server

    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%.

  17. Improving the Multilayer Perceptron Learning by Using a Method to Calculate the Initial Weights with the Similarity Quality Measure Based on Fuzzy Sets and Particle Swarms

    Directory of Open Access Journals (Sweden)

    Lenniet Coello

    2015-01-01

    Full Text Available The most widely used neural network model is Multilayer Perceptron (MLP, in which training of the connection weights is normally completed by a Back Propagation learning algorithm. G ood initial values of weights bear a fast convergence and a better generalization capability even with simple gradient - based error minimization techniques. This work presen ts a method to calculate the initial weights in order to train the Multilayer Perceptron Model. The method named PSO+RST+FUZZY is based on the similarity quality measure proposed within the framework of the extended Rough Set Theory that employs fuzzy sets to characterize the domain of similarity thresholds. Sensitivity of BP to initial weights with PSO+RST+FUZZY was studied experimentally, showing better performance than other methods used to calculate feature weights .

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  2. Multilayer perceptron applied to the estimation of the influence of the solar spectral distribution on thin-film photovoltaic modules

    International Nuclear Information System (INIS)

    Highlights: • Multilayer perceptrons are used to simulate the I–V curve of thin-film PV modules. • APE from the spectral irradiance was added as an input variable to the network. • A self-organised map is used to select the curves used for training the network. • Curve error and maximum power error decrease when using this technique. • This method could provide accurate estimation of the output of a PV plant. - Abstract: In this paper, we propose the use of a methodology to characterise the electrical parameters of several thin-film photovoltaic module technologies. This methodology allows us to use not only solar irradiance and module temperature as classical models do, but also spectral distribution of solar radiation. The methodology is based on the use of neural network models. From all measured I–V curves of a module, a previous selection of them has been used in order to train the neural network model. This selection is performed using a Kohonen self-organising map fed with spectral data. This spectral information has been added as an input to the neural network itself. The results show that the incorporation of spectral measurements to simulate thin-film modules improves significantly both the fitting of the predicted I–V curve to the measured one and the peak power point estimation

  3. Critical heat flux prediction by using radial basis function and multilayer perceptron neural networks: A comparison study

    International Nuclear Information System (INIS)

    Critical heat flux (CHF) is an important parameter for the design of nuclear reactors. Although many experimental and theoretical researches have been performed, there is not a single correlation to predict CHF because it is influenced by many parameters. These parameters are based on fixed inlet, local and fixed outlet conditions. Artificial neural networks (ANNs) have been applied to a wide variety of different areas such as prediction, approximation, modeling and classification. In this study, two types of neural networks, radial basis function (RBF) and multilayer perceptron (MLP), are trained with the experimental CHF data and their performances are compared. RBF predicts CHF with root mean square (RMS) errors of 0.24%, 7.9%, 0.16% and MLP predicts CHF with RMS errors of 1.29%, 8.31% and 2.71%, in fixed inlet conditions, local conditions and fixed outlet conditions, respectively. The results show that neural networks with RBF structure have superior performance in CHF data prediction over MLP neural networks. The parametric trends of CHF obtained by the trained ANNs are also evaluated and results reported

  4. Application of Multi-Layered Perceptron Neural network (MLPNN) to Combined Economic and Emission Dispatch

    OpenAIRE

    Sarakhs branch; Sarakhs, Iran.

    2012-01-01

    This paper presents a multi-layered perceptronneural network (MLPNN) method to solve the combinedeconomic and emission dispatch (CEED) problem. The harmfulecological effects caused by the emission of particulate andgaseous pollutants like sulfur dioxide (SO2) and oxides ofnitrogen ( NOx ) can be reduced by adequate distribution ofload between the plants of a power system. However, this leadsto a noticeable increase in the operating cost of the plants. Thispaper presents the (MLPNN) method app...

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

    Directory of Open Access Journals (Sweden)

    A. Piotrowski

    2007-08-01

    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-conservation assured generally performed better than the method that did not account for mass-conservation. Predictions of peak travel time were also better using the neural networks than the unit peak attenuation method. Including more data into the neural network training set clearly improved the prediction of the shapes of the concentration profiles. Similar improvements in peak concentration were less significant and the travel time prediction appeared to be largely unaffected.

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

    Directory of Open Access Journals (Sweden)

    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-conservation assured generally performed better than the method that did not account for mass-conservation. Predictions of peak travel time were also better using the neural networks than the unit peak attenuation method. Including more data into the neural network training set clearly improved the prediction of the shapes of the concentration profiles. Similar improvements in peak concentration were less significant and the travel time prediction appeared to be largely unaffected.

  7. Generación dinámica de la topología de una red neuronal artificial del tipo perceptron multicapa / Dynamic topology generation of an artificial neural network of the multilayer perceptron type

    Scientific Electronic Library Online (English)

    Héctor, Tabares; John, Branch; Jaime, Valencia.

    2006-09-01

    Full Text Available En este trabajo se aplica un método constructivo aproximado para encontrar ar­quitecturas de redes neuronales artificiales (RNA) de tipo perceptrón multicapa (PMC). El método se complementa con la técnica de la búsqueda forzada de mejores mínimos locales. El entrenamiento de la red se lleva a cabo a [...] través del algoritmo gradiente descendente básico (GDB); se aplican técnicas como la repetición del entrenamiento y la detención temprana (validación cruzada), para mejorar los resultados. El criterio de evaluación se basa en las habilidades de aprendizaje y de generalización de las arquitecturas generadas específicas de un dominio. Se presentan resultados experimentales con los cuales se demuestra la efectividad del método propuesto y comparan con las arquitecturas halladas por otros métodos. Abstract in english This paper deals with an approximate constructive method to find architectures of artificial neuronal network (ANN) of the type MultiLayer Percetron (MLP) which solves a particular problem. This method is supplemented with the technique of the Forced search of better local minima. The training of th [...] e net uses an algorithm basic descending gradient (BDG). Techniques such as repetition of the training and the early stopping (cross validation) are used to improve the results. The evaluation approach is based not only on the learning abilities but also on the generalization of the specific generated architectures of a domain. Experimental results are presented in order to prove the effectiveness of the proposed method. These are compared with architectures found by other methods.

  8. Modeling of gamma ray energy-absorption buildup factors for thermoluminescent dosimetric materials using multilayer perceptron neural network : A comparative study

    DEFF Research Database (Denmark)

    Kucuk, Nil; Manohara, S.R.

    2013-01-01

    In this work, multilayered perceptron neural networks (MLPNNs) were presented for the computation of the gamma-ray energy absorption buildup factors (BA) of seven thermoluminescent dosimetric (TLD) materials [LiF, BeO, Na2B4O7, CaSO4, Li2B4O7, KMgF3, Ca3(PO4)2] in the energy region 0.015–15MeV, 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 data for TLD materials have been given with penetration depth and incident photon energy as comparative to the results of the interpolation method using the Geometrical Progression (G-P) fitting formula.

  9. Discrete perceptrons

    OpenAIRE

    Stojnic, Mihailo

    2013-01-01

    Perceptrons have been known for a long time as a promising tool within the neural networks theory. The analytical treatment for a special class of perceptrons started in seminal work of Gardner \\cite{Gar88}. Techniques initially employed to characterize perceptrons relied on a statistical mechanics approach. Many of such predictions obtained in \\cite{Gar88} (and in a follow-up \\cite{GarDer88}) were later on established rigorously as mathematical facts (see, e.g. \\cite{Sch...

  10. Modeling of gamma ray energy-absorption buildup factors for thermoluminescent dosimetric materials using multilayer perceptron neural network: A comparative study

    International Nuclear Information System (INIS)

    In this work, multilayered perceptron neural networks (MLPNNs) were presented for the computation of the gamma-ray energy absorption buildup factors (BA) of seven thermoluminescent dosimetric (TLD) materials [LiF, BeO, Na2B4O7, CaSO4, Li2B4O7, KMgF3, Ca3(PO4)2] in the energy region 0.015–15 MeV, 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 data for TLD materials have been given with penetration depth and incident photon energy as comparative to the results of the interpolation method using the Geometrical Progression (G-P) fitting formula. - Highlights: ? Gamma-ray energy absorption buildup factors estimation in TLD materials. ? The ANN approach can be alternative to G-P fitting method for BA calculations. ? The applied model is not time-consuming and easily predicted

  11. Optimization of metformin HCl 500 mg sustained release matrix tablets using Artificial Neural Network (ANN) based on Multilayer Perceptrons (MLP) model.

    Science.gov (United States)

    Mandal, Uttam; Gowda, Veeran; Ghosh, Animesh; Bose, Anirbandeep; Bhaumik, Uttam; Chatterjee, Bappaditya; Pal, Tapan Kumar

    2008-02-01

    The aim of the present study was to apply the simultaneous optimization method incorporating Artificial Neural Network (ANN) using Multi-layer Perceptron (MLP) model to the development of a metformin HCl 500 mg sustained release matrix tablets with an optimized in vitro release profile. The amounts of HPMC K15M and PVP K30 at three levels (-1, 0, +1) for each were selected as casual factors. In vitro dissolution time profiles at four different sampling times (1 h, 2 h, 4 h and 8 h) were chosen as output variables. 13 kinds of metformin matrix tablets were prepared according to a 2(3) factorial design (central composite) with five extra center points, and their dissolution tests were performed. Commercially available STATISTICA Neural Network software (Stat Soft, Inc., Tulsa, OK, U.S.A.) was used throughout the study. The training process of MLP was completed until a satisfactory value of root square mean (RSM) for the test data was obtained using feed forward back propagation method. The root mean square value for the trained network was 0.000097, which indicated that the optimal MLP model was reached. The optimal tablet formulation based on some predetermined release criteria predicted by MLP was 336 mg of HPMC K15M and 130 mg of PVP K30. Calculated difference (f(1) 2.19) and similarity (f(2) 89.79) factors indicated that there was no difference between predicted and experimentally observed drug release profiles for the optimal formulation. This work illustrates the potential for an artificial neural network with MLP, to assist in development of sustained release dosage forms. PMID:18239298

  12. Compact yet efficient hardware architecture for multilayer-perceptron neural networks Arquitetura de hardware compacta e eficiente para redes neurais artificiais do tipo múltiplas camadas

    Directory of Open Access Journals (Sweden)

    Rodrigo Martins da Silva

    2011-12-01

    Full Text Available There are several neural network implementations using either software, hardware-based or a hardware/software co-design. This work proposes a hardware architecture to implement an artificial neural network (ANN, whose topology is the multilayer perceptron (MLP. In this paper, we explore the parallelism of neural networks and allow on-thefly changes of the number of inputs, number of layers and number of neurons per layer of the net. This reconfigurability characteristic permits that any application of ANNs may be implemented using the proposed hardware. In order to reduce the processing time that is spent in arithmetic computation, a real number is represented using a fraction of integers. In this way, the arithmetics is limited to integer operations, performed by fast combinational circuits. A simple state machine is required to control sums and products of fractions. Sigmoid is used as the activation function in the proposed implementation. It is approximated by polynomials, whose underlying computation requires only sums and products. A theorem is introduced and proven so as to cover the arithmetic strategy of the computation of the activation function. Thus, the arithmetic circuitry used to implement the neuron weighted sum is reused for computing the sigmoid. this resource sharing decreased drastically the total area of the system. After modeling and simulation for functionality validation, the proposed architecture synthesized using reconfigurable hardware. The results are promising.Em termos computacionais, uma rede neural artificial (RNA pode ser implementada em software ou em hardware, ou ainda de maneira híbrida, combinando ambos os recursos. O presente trabalho propõe uma arquitetura de hardware para a computação de uma rede neural do tipo perceptron com múltiplas camadas (MLP. Soluções em hardware tendem a ser mais eficientes do que soluções em software. O projeto em questão, além de explorar fortemente o paralelismo das redes neurais, permite alterações do número de entradas, número de camadas e de neurônios por camada, de modo que diversas aplicações de RNAs possam ser executadas no hardware proposto. Visando a uma redução de tempo do processamento aritmético, um número real é aproximado por uma fração de inteiros. Dessa forma, as operações aritméticas limitam-se a operações inteiras, executadas por circuitos combinacionais. Uma simples máquina de estados é demandada para controlar somas e produtos de frações. A função de ativação usada neste projeto é a sigmóide. Essa função é aproximada mediante o uso de polinômios, cujas operações são regidas por somas e produtos. Um teorema é introduzido e provado, permitindo a fundamentação da estratégia de cálculo da função de ativação. Dessa forma, reaproveita-se o circuito aritmético da soma ponderada para também computar a sigmóide. Essa re-utilização dos recursos levou a uma redução drástica de área total de circuito. Após modelagem e simulação para validação do bom funcionamento, a arquitetura proposta foi sintetizada utilizando recursos reconfiguráveis, do tipo FPGA. Os resultados são promissores.

  13. Compact yet efficient hardware architecture for multilayer-perceptron neural networks / Arquitetura de hardware compacta e eficiente para redes neurais artificiais do tipo múltiplas camadas

    Scientific Electronic Library Online (English)

    Rodrigo Martins da, Silva; Luiza de Macedo, Mourelle; Nadia, Nedjah.

    2011-12-01

    Full Text Available Em termos computacionais, uma rede neural artificial (RNA) pode ser implementada em software ou em hardware, ou ainda de maneira híbrida, combinando ambos os recursos. O presente trabalho propõe uma arquitetura de hardware para a computação de uma rede neural do tipo perceptron com múltiplas camadas [...] (MLP). Soluções em hardware tendem a ser mais eficientes do que soluções em software. O projeto em questão, além de explorar fortemente o paralelismo das redes neurais, permite alterações do número de entradas, número de camadas e de neurônios por camada, de modo que diversas aplicações de RNAs possam ser executadas no hardware proposto. Visando a uma redução de tempo do processamento aritmético, um número real é aproximado por uma fração de inteiros. Dessa forma, as operações aritméticas limitam-se a operações inteiras, executadas por circuitos combinacionais. Uma simples máquina de estados é demandada para controlar somas e produtos de frações. A função de ativação usada neste projeto é a sigmóide. Essa função é aproximada mediante o uso de polinômios, cujas operações são regidas por somas e produtos. Um teorema é introduzido e provado, permitindo a fundamentação da estratégia de cálculo da função de ativação. Dessa forma, reaproveita-se o circuito aritmético da soma ponderada para também computar a sigmóide. Essa re-utilização dos recursos levou a uma redução drástica de área total de circuito. Após modelagem e simulação para validação do bom funcionamento, a arquitetura proposta foi sintetizada utilizando recursos reconfiguráveis, do tipo FPGA. Os resultados são promissores. Abstract in english There are several neural network implementations using either software, hardware-based or a hardware/software co-design. This work proposes a hardware architecture to implement an artificial neural network (ANN), whose topology is the multilayer perceptron (MLP). In this paper, we explore the parall [...] elism of neural networks and allow on-thefly changes of the number of inputs, number of layers and number of neurons per layer of the net. This reconfigurability characteristic permits that any application of ANNs may be implemented using the proposed hardware. In order to reduce the processing time that is spent in arithmetic computation, a real number is represented using a fraction of integers. In this way, the arithmetics is limited to integer operations, performed by fast combinational circuits. A simple state machine is required to control sums and products of fractions. Sigmoid is used as the activation function in the proposed implementation. It is approximated by polynomials, whose underlying computation requires only sums and products. A theorem is introduced and proven so as to cover the arithmetic strategy of the computation of the activation function. Thus, the arithmetic circuitry used to implement the neuron weighted sum is reused for computing the sigmoid. this resource sharing decreased drastically the total area of the system. After modeling and simulation for functionality validation, the proposed architecture synthesized using reconfigurable hardware. The results are promising.

  14. El uso de perceptrones multicapa para la modelización estadística de series de tiempo no lineales de so2, en Salta Capital, Argentina The use of multilayer perceptrons for statistical modeling so2 non linear time series in Salta Capital, Argentina

    Directory of Open Access Journals (Sweden)

    Haydeé Elena Musso

    2013-01-01

    Full Text Available En este trabajo se realizó un estudio estadístico de variables físico químicas asociadas al fenómeno de contaminación ambiental, en particular concentración media mensual de SO2 , medidas en la ciudad Salta Capital, Argentina, simultáneamente a concentraciones de NO2 y O3 . Las series bajo estudio presentaban comportamientos dinámicos no lineales, datos atípicos y cambios estructurales, lo que hizo imposible modelarlas con tipologías econométricas tradiciones (AR, MA, ARMA, ARIMA, entre otras. Una solución eficiente que se encontró, hace uso de la teoría de los perceptrones multicapa. Mediante el modelo estructural de series de tiempo, esta solución se presenta como un proceso matemático iterativo que permite obtener un modelado final el cual tiene una muy alta confiabilidad (95%, para realizar pronoósticos a futuro sobre el comportamiento de la variable estudiada.In this paper a statistical study of phisical-chemistry variables connected with enviroment pollution, specifically SO2 monthly average concentration, measured in Salta Capital city, Argentina, together with NO2 and O3 concentrations, was made. Time series under study shown non linear dinamic behaviour, outliers and structural changes. Due to these it was impossible to use typical econometric typologies (AR, MA, ARMA, ARIMA, among others. An effective solution which uses multistep perceptrons theory was found. By using structural time series modelling, this solution is presented by an iterative mathematical process that allows us to obtain a final model with a high confidence level (95% in order to do the forecasting step on the studied variable.

  15. El uso de perceptrones multicapa para la modelización estadística de series de tiempo no lineales de so2, en Salta Capital, Argentina / The use of multilayer perceptrons for statistical modeling so2 non linear time series in Salta Capital, Argentina

    Scientific Electronic Library Online (English)

    Haydeé Elena, Musso; Orlando José, Ávila Blas.

    2013-01-01

    Full Text Available En este trabajo se realizó un estudio estadístico de variables físico químicas asociadas al fenómeno de contaminación ambiental, en particular concentración media mensual de SO2 , medidas en la ciudad Salta Capital, Argentina, simultáneamente a concentraciones de NO2 y O3 . Las series bajo estudio p [...] resentaban comportamientos dinámicos no lineales, datos atípicos y cambios estructurales, lo que hizo imposible modelarlas con tipologías econométricas tradiciones (AR, MA, ARMA, ARIMA, entre otras). Una solución eficiente que se encontró, hace uso de la teoría de los perceptrones multicapa. Mediante el modelo estructural de series de tiempo, esta solución se presenta como un proceso matemático iterativo que permite obtener un modelado final el cual tiene una muy alta confiabilidad (95%), para realizar pronoósticos a futuro sobre el comportamiento de la variable estudiada. Abstract in english In this paper a statistical study of phisical-chemistry variables connected with enviroment pollution, specifically SO2 monthly average concentration, measured in Salta Capital city, Argentina, together with NO2 and O3 concentrations, was made. Time series under study shown non linear dinamic behavi [...] our, outliers and structural changes. Due to these it was impossible to use typical econometric typologies (AR, MA, ARMA, ARIMA, among others). An effective solution which uses multistep perceptrons theory was found. By using structural time series modelling, this solution is presented by an iterative mathematical process that allows us to obtain a final model with a high confidence level (95%) in order to do the forecasting step on the studied variable.

  16. Reconocimiento del habla mediante el uso de la correlación cruzada y una perceptrón multicapa / Speech recognition by using cross correlation and a multilayer perceptron

    Scientific Electronic Library Online (English)

    Carlos A., de Luna-Ortega; Miguel, Mora-González; Julio C., Martínez-Romo; Francisco J., Luna-Rosas; Jesús, Muñoz-Maciel.

    Full Text Available En el presente artículo se da a conocer una alternativa algorítimica a los sistemas actuales de reconocimiento automático del habla (ASR), mediante una propuesta en la forma de realizar la caracterización de las palabras basada en una aproximación que usa la extracción de coeficientes de la codifica [...] ción de predicción lineal (LPC) y la correlación cruzada. La implementación consiste en extraer las características fonéticas mediante los coeficientes LPC, después se forman vectores de patrones de la pronunciación conformados por el promedio de los coeficientes LPC de las muestras de las palabras obteniendo un vector característico de cada pronunciación mediante la autocorrelación de las secuencias de coeficientes LPC; estos vectores se utilizan para entrenar un clasificador de tipo perceptrón multicapa (MLP). Se realizaron pruebas de desempeño previo entrenamiento con los diferentes patrones de las palabras a reconocer. Se utilizó la fonética de los dígitos del cero al nueve como vocabulario objetivo, debido a su amplia aplicación, y para estimar el desempeño de este método se utilizaron dos corpus de pronunciaciones: el corpus UPA, que contempla en su base de datos la pronuncación de la región occidente de México, y el corpus Tlatoa, que hace lo propio para la región centro de México. Las señales en ambos corpus fueron adquiridas en el lenguaje español, y a una frecuencia de muestreo de 8kHz. Los porcentajes de reconocimiento obtenidos fueron del 96.7 y 93.3% para las modalidades de mono-locutor para el corpus UPA y múltiple-locutor para el corpus Tlatoa, respectivamente. Asimismo, se realizó una comparación contra dos métodos clásicos del reconocimiento de voz y del habla, Dynamic Time Warping (DTW) y Hidden Markov Models (HMM). Abstract in english It this paper we present an algorithmic alternative to the current Automatic Speech Recognition (ASR) systems by proposing a way to characterize words based on approximations that use an extracted coefficient from Linear Predictive Coding (LPC). The method consists in extracting phonetic characteris [...] tics through the use of LPC coefficients, after which pattern vectors are formed from the LPC coefficient averages taken from the word sampling, thus creating a unique vector for each pronunciation through the auto correlation of the LPC coefficient sequences. These vectors are used to train a Multilayer Perceptron (MLP) classifier. After training performance trials were executed. The sounds from the digits zero through nine where used as a target vocabulary, given its general use, and to estimate the performance of this method two corpus where used: the UPA corpus, which in its vocabulary uses a pronunciation familiar to the western part of Mexico, and the Tlatoa corpus, who's vocabulary presents a pronunciation typical of the central region of Mexico. The signals from both corpus where sampled in the Spanish language, and at a sampling frequency of 8kHz. The recognition rate for the mono-speaker from the UPA corpus and the multiple-speaker from the Tlatoa corpus were 96.7% and 93.3% respectively. Additionally, there where comparisons done against two classic methods used for speech recognition, Dynamic Time Warping (DTW) and Hidden Markov Models (HMM).

  17. Funciones de transferencia en el perceptrón multicapa: efecto de su combinación en entrenamiento local y distribuido / Transfer functions in the multilayer perceptron: effects of its combination on local and distributed training

    Scientific Electronic Library Online (English)

    Yuleidys, Mejías César; Ramón, Carrasco Velar; Isbel, Ochoa Izquierdo; Edel, Moreno Lemus.

    2013-12-01

    Full Text Available El perceptrón multicapa (PMC) figura dentro de los tipos de redes neuronales artificiales (RNA) con resultados útiles en los estudios de relación estructura-actividad. Dado que los volúmenes de datos en proyectos de Bioinformática son eventualmente grandes, se propuso evaluar algoritmos para acortar [...] el tiempo de entrenamiento de la red sin afectar su eficiencia. Se desarrolló un algoritmo para el entrenamiento local y distribuido del PMC con la posibilidad de variar las funciones de transferencias para lo cual se utilizaron el Weka y la Plataforma de Tareas Distribuidas Tarenal para distribuir el entrenamiento del perceptrón multicapa. Se demostró que en dependencia de la muestra de entrenamiento, la variación de las funciones de transferencia pueden reportar resultados mucho más eficientes que los obtenidos con la clásica función Sigmoidal, con incremento de la g-media entre el 4.5 y el 17 %. Se encontró además que en los entrenamientos distribuidos es posible alcanzar eventualmente mejores resultados que los logrados en ambiente local. Abstract in english The multilayer perceptron (PMC) ranks among the types of artificial neural networks (ANN), which has provided better results in studies of structure-activity relationship. As the data volumes in Bioinformatics' projects are eventually big, it was proposed to evaluate algorithms to shorten the traini [...] ng time of the network without affecting its efficiency. There were evaluated different tools that work with ANN and were selected Weka algorithm for extracting the network and the Platform for Distributed Task Tarenal to distribute the training of multilayer perceptron. Finally, it was developed a training algorithm for local and distributed the MLP with the possibility of varying transfer functions. It was shown that depending on the training sample, the change of transfer functions can yield results much more efficient than those obtained with the classic sigmoid function with increased g-media between 4.5 and 17 %. Moreover, it was found that with distributed training can be achieved eventually, better results than those achieved in the local environment.

  18. Simulación del proceso de biodegradación de aguas residuales de la industria de carne mediante una red neuronal artificial perceptrón multicapa / Simulation of biodegradation process of wastewater from meat industry by means of a multilayer perceptron artificial neural network

    Scientific Electronic Library Online (English)

    José C, Cúrvelo Santana; Sidnei A, de Araújo; Joana P, M. Biazus; Roberto R, de Souza.

    2015-04-01

    Full Text Available En este trabajo se propone utilizar una Red Neuronal Artificial (RNA) Perceptrón Multicapa (PMC) para simular la variación de la concentración de proteína de acuerdo con el tiempo y también para determinar la hora final del procedimiento, además de los parámetros óptimos del proceso de biodegradació [...] n de las proteínas de un efluente de matadero. Para eso, han sido utilizadas las papaínas, presentes en el látex de la papaya (Carica papaya) con el objetivo de disminuir la concentración de proteínas de un efluente de matadero a pH (5 y 7) con una temperatura de (25 y 30° C) controlada. Los resultados mostraron que las papaínas redujeron de 82% a 91% la concentración de proteína en 30 y 40 h de proceso. Las simulaciones con la RNA apuntaron que las condiciones perfectas fueron obtenidas a pH 5, con 30 °C y en 35 h, en el cual se ha alcanzado una reducción de 91% de la concentración de proteínas. Abstract in english In this paper, the use of a multilayer perceptron (MLP) artificial neural network (ANN) is proposed to simulate the variation of protein concentration according to the time and also to determine the end and optimal conditions of the biodegradation process of wastewater from meat industry. To reduce [...] the protein concentration, papains from Carica papaya latex have been used at controlled condition of pH (5 and 7) and temperature (25 and 30 °C). Results showed that a reduction of 82 to 91% of protein concentration by the action of papains for 30 to 40 h of process time. Simulations showed that the best condition of the process occurred at pH 5, 30 °C and 35 h, in which a maximum biodegradation of 91% was obtained.

  19. Detección de Latidos Cardiacos Patológicos y Normales Utilizando Transformada por Paquetes Wavelet, Máquinas de Soporte Vectorial y Perceptrón Multicapa / Detection of Pathological and Normal Heartbeat Using Wavelet Packet, Support Vector Machines and Multilayer Perceptron

    Scientific Electronic Library Online (English)

    Alejandro J., Orozco-Naranjo; Pablo A., Muñoz-Gutiérrez.

    2013-12-30

    Full Text Available Este artículo presenta los resultados obtenidos al desarrollar una metodología para la detección de 5 tipos de latidos cardiacos (Normal (N), Bloqueo de Rama Derecha (RBBB), Bloqueo de Rama Izquierda (LBBB), Contracción Auricular Prematura (APC) y Contracción Ventricular Prematura (PVC)) utilizando [...] la transformada por paquetes Wavelet de manera no adaptativa en la extracción de características de las señales cardiacas, empleando la función Shanon para cálculo de la entropía y adicionando una fase de identificación de nodos por cada tipo de señal cardiaca en el árbol Wavelet. La utilización de la transformada por paquetes Wavelet permite acceder a información obtenida de la descomposición tanto de baja como de alta frecuencia proporcionando un análisis más integral que el logrado con la transformada Wavelet discreta. Se evaluaron Wavelets madre de las familias Daubechies, Symlet 5 y Biortogonal inversa; que fueron resultado de una investigación previa en que se identificaron las Wavelet madre que mayor entropía presentaban con las señales cardiacas. Con la modalidad no adaptativa se reduce el costo computacional al utilizar los paquetes Wavelet, coste que representa la mayor desventaja de esta transformada, dando validez a la investigación realizada. Para la clasificación de los patrones cardiacos se emplearon las máquinas de soporte vectorial y el perceptrón multicapa. Con las máquinas de soporte vectorial empleando kernel de función de base radial, se logró un error de clasificación del 2,57 %. Abstract in english This paper presents the results obtained by developing a methodology to detect 5 types of heartbeats (Normal (N), Right bundle branch block (RBBB), Left bundle branch block (LBBB), Premature atrial contraction (APC) and Premature ventricular contraction (PVC)), using Wavelet transform packets with n [...] on-adaptative mode applied on features extraction from heartbeats. It was used the Shannon function to calculate the entropy and It was added an identification nodes stage per every type of cardiac signal in the Wavelet tree. The using of Wavelet packets transform allows the access to information which results of decomposition of low and high frecuency, giving providing a more integral analysis than achieved by the discrete Wavelet transform. Three families of mother Wavelet were evaluated on transformation: Daubechies, Symlet and Reverse Biorthogonal, which were results from a previous research in that were identified the mother Wavelet that had higher entropy with the cardiac signals. With non-adaptive mode, the computational cost is reduced when Wavelet packets are used; this cost represents the most marked disadvantage from the transform. To classify the heartbeats were used Support Vector Machines and Multilayer Perceptron. The best classification error was achieved employing Support Vector Machine and a radial basis function; it was 2.57 %.

  20. The synaptic morphological perceptron

    Science.gov (United States)

    Myers, Daniel S.

    2006-08-01

    In recent years, several researchers have constructed novel neural network models based on lattice algebra. Because of computational similarities to operations in the system of image morphology, these models are often called morphological neural networks. One neural model that has been successfully applied to many pattern recognition problems is the single-layer morphological perceptron with dendritic structure (SLMP). In this model, the fundamental computations are performed at dendrites connected to the body of a single neuron. Current training algorithms for the SLMP work by enclosing the target patterns in a set of hyperboxes orthogonal to the axes of the data space. This work introduces an alternate model of the SLMP, dubbed the synaptic morphological perceptron (SMP). In this model, each dendrite has one or more synapses that receive connections from inputs. The SMP can learn any region of space determined by an arbitrary configuration of hyperplanes, and is not restricted to forming hyperboxes during training. Thus, it represents a more general form of the morphological perceptron than previous architectures.

  1. S\\'election de la structure d'un perceptron multicouches pour la r\\'eduction dun mod\\`ele de simulation d'une scierie

    OpenAIRE

    Thomas, Philippe; Thomas, André

    2008-01-01

    Simulation is often used to evaluate the relevance of a Directing Program of Production (PDP) or to evaluate its impact on detailed sc\\'enarii of scheduling. Within this framework, we propose to reduce the complexity of a model of simulation by exploiting a multilayer perceptron. A main phase of the modeling of one system using a multilayer perceptron remains the determination of the structure of the network. We propose to compare and use various pruning algorithms in order ...

  2. Hybrid Evolutionary Algorithm for Multilayer Perceptron Networks with Competetive Performance.

    Czech Academy of Sciences Publication Activity Database

    Neruda, Roman

    Los Alamitos : IEEE, 2007, s. 1620-1627. ISBN 978-1-4244-1339-3. [CEC 2007. Congress on Evolutionary Computation. Singapore (SG), 25.09.2007-28.09.2007] R&D Projects: GA AV ?R 1ET100300419 Institutional research plan: CEZ:AV0Z10300504 Keywords : hybrid algorithms * evolutionary learning * neural networks Subject RIV: IN - Informatics, Computer Science

  3. Classification of fuels using multilayer perceptron neural networks

    International Nuclear Information System (INIS)

    Electrical impedance data obtained with an array of conducting polymer chemical sensors was used by a neural network (ANN) to classify fuel adulteration. Real samples were classified with accuracy greater than 90% in two groups: approved and adulterated.

  4. FPGA Implementation of Multilayer Perceptron for Modeling of Photovoltaic panel

    International Nuclear Information System (INIS)

    The Number of electronic applications using artificial neural network-based solutions has increased considerably in the last few years. However, their applications in photovoltaic systems are very limited. This paper introduces the preliminary result of the modeling and simulation of photovoltaic panel based on neural network and VHDL-language. In fact, an experimental database of meteorological data (irradiation, temperature) and output electrical generation signals of the PV-panel (current and voltage) has been used in this study. The inputs of the ANN-PV-panel are the daily total irradiation and mean average temperature while the outputs are the current and voltage generated from the panel. Firstly, a dataset of 4x364 have been used for training the network. Subsequently, the neural network (MLP) corresponding to PV-panel is simulated using VHDL language based on the saved weights and bias of the network. Simulation results of the trained MLP-PV panel based on Matlab and VHDL are presented. The proposed PV-panel model based ANN and VHDL permit to evaluate the performance PV-panel using only the environmental factors and involves less computational efforts, and it can be used for predicting the output electrical energy from the PV-panel

  5. A combinatorial approach to understanding perceptron capabilities.

    Science.gov (United States)

    Gibson, G J

    1993-01-01

    This work investigates the classification capabilities of perceptrons which incorporate a single hidden layer of nodes from a theoretical viewpoint. In particular, the question of determining whether a given set can be realized as the decision region of such a network is considered. The main theoretic result demonstrates that the realizability of a set can be determined by restricting attention to any neighborhood of its boundary. This result is then used to identify general classes of realizable sets, and an example is given which shows that even though the realizability of a set might be readily discerned, the construction of an appropriate perceptron architecture may be complicated. PMID:18276529

  6. Chaotic diagonal recurrent neural network

    International Nuclear Information System (INIS)

    We propose a novel neural network based on a diagonal recurrent neural network and chaos, and its structure and learning 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. (interdisciplinary physics and related areas of science and technology)

  7. Handwritten Digit Recognition with Binary Optical Perceptron

    OpenAIRE

    Saxena, Indu; Moerland, Perry; Fiesler, Emile; Pourzand, A. R.

    1997-01-01

    Binary weights are favored in electronic and optical hardware implementations of neural networks as they lead to improved system speeds. Optical neural networks based on fast ferroelectric liquid crystal binary level devices can benefit from the many orders of magnitudes improved liquid crystal response times. An optimized learning algorithm for all-positive perceptrons is simulated on a limited data set of hand-written digits and the resultant network implemented optically. First, gray-scale...

  8. Minimization of Empirical Error over Perceptron Networks.

    Czech Academy of Sciences Publication Activity Database

    K?rková, V?ra

    Wien : Springer-Verlag, 2005 - (Ribiero, B.; Albrecht, R.; Dobnikar, A.; Pearson, D.; Steele, N.), s. 46-49 ISBN 3-211-24934-6. [ICANNGA'2005 /7./. Coimbra (PT), 21.03.2005-23.03.2005] R&D Projects: GA ?R GA201/05/0557 Institutional research plan: CEZ:AV0Z10300504 Keywords : supervised learning * perceptron networks * approximate optimization Subject RIV: BA - General Mathematics

  9. Landscape statistics of the binary perceptron

    OpenAIRE

    Fontanari, J. F.; Köberle, R.

    1990-01-01

    The landscape of the binary perceptron is studied by Simulated Annealing, exhaustive search and performing random walks on the landscape. We find that the number of local minima increases exponentially with the number of bonds, becoming deeper in the vicinity of a global minimum, but more and more shallow as we move away from it. The random walker detects a simple dependence on the size of the mapping, the architecture introducing a nontrivial dependence on the number of steps.

  10. Stochastic resonance in an intracellular genetic perceptron

    Science.gov (United States)

    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.

  11. Representations of Boolean Functions by Perceptron Networks.

    Czech Academy of Sciences Publication Activity Database

    K?rková, V?ra

    Prague : Institute of Computer Science AS CR, 2014 - (K?rková, V.; Bajer, L.; Peška, L.; Vojtáš, R.; Hole?a, M.; Nehéz, M.), s. 68-70 ISBN 978-80-87136-19-5. [ITAT 2014. European Conference on Information Technologies - Applications and Theory /14./. Demänovská dolina (SK), 25.09.2014-29.09.2014] R&D Projects: GA MŠk(CZ) LD13002 Institutional support: RVO:67985807 Keywords : perceptron networks * model complexity * Boolean functions Subject RIV: IN - Informatics, Computer Science

  12. Optimal Capacity of the Blume-Emery-Griffiths perceptron

    OpenAIRE

    Bolle, D.; Castillo, I. Perez; Shim, G. M.

    2002-01-01

    A Blume-Emery-Griffiths perceptron model is introduced and its optimal capacity is calculated within the replica-symmetric Gardner approach, as a function of the pattern activity and the imbedding stability parameter. The stability of the replica-symmetric approximation is studied via the analogue of the Almeida-Thouless line. A comparison is made with other three-state perceptrons.

  13. The Perceptron Algorithm: Image and Signal Decomposition, Compression, and Analysis by Iterative Gaussian Blurring

    CERN Document Server

    Vassiliadis, V S

    2006-01-01

    A novel algorithm for tunable compression to within the precision of reproduction targets, or storage, is proposed. The new algorithm is termed the `Perceptron Algorithm', which utilises simple existing concepts in a novel way, has multiple immediate commercial application aspects as well as it opens up a multitude of fronts in computational science and technology. The aims of this paper are to present the concepts underlying the algorithm, observations by its application to some example cases, and the identification of a multitude of potential areas of applications such as: image compression by orders of magnitude, signal compression including sound as well, image analysis in a multilayered detailed analysis, pattern recognition and matching and rapid database searching (e.g. face recognition), motion analysis, biomedical applications e.g. in MRI and CAT scan image analysis and compression, as well as hints on the link of these ideas to the way how biological memory might work leading to new points of view i...

  14. Multifractals and percolation in the coupling space of perceptrons

    CERN Document Server

    Weigt, M

    1996-01-01

    The coupling space of perceptrons with continuous as well as with binary weights gets partitioned into a disordered multifractal by a set of $p=\\gamma N$ random input patterns. The multifractal spectrum $f(\\alpha)$ can be calculated analytically using the replica formalism. The storage capacity and the generalization behaviour of the perceptron are shown to be related to properties of $f(\\alpha)$ which are correctly described within the replica symmetric ansatz. Replica symmetry breaking is interpreted geometrically as a transition from percolating to non-percolating cells. The existence of empty cells gives rise to singularities in the multifractal spectrum. The relation of these singularities to the Vapnik-Chervonenkis-dimension of the perceptron is discussed. The analytical results for binary couplings are corroborated by numerical studies.

  15. Stability of the replica symmetric solution in diluted perceptron learning

    International Nuclear Information System (INIS)

    We study the role played by dilution in the average behavior of a perceptron model with continuous coupling with the replica method. We analyze the stability of the replica symmetric solution as a function of the dilution field for the generalization and memorization problems. Thanks to a Gardner-like stability analysis we show that at any fixed ratio ? between the number of patterns M and the dimension N of the perceptron (? = M/N), there exists a critical dilution field hc above which the replica symmetric ansatz becomes unstable. (letter)

  16. Estimativa do perfil da concentração de clorofila em águas naturais através de um perceptron de múltiplas camadas

    Scientific Electronic Library Online (English)

    F., Dall Cortivo; E. S., Chalhoub; H. F., Campos Velho.

    2012-12-01

    Full Text Available Estimativa do perfil de concentração de clorofila, em águas naturais, a partir da radiação emergente na superfície de um corpo d'agua, com o uso de rede neural artificial do tipo Perceptron de Múltiplas Camadas. A concentração de clorofila está relacionada com os coeficientes de absorção e espalhame [...] nto via modelos bio-ópticos. O treinamento da rede é formulado como um problema de otimização, no qual a atualização das variáveis livres da rede (pesos, viés e parâmetros de cada função de ativação) é feita através do método quasi-Newton. Abstract in english In this work the average profile of chlorophyll concentration is estimated from the emitted radiation at the surface of natural waters. This is performed through the use an Artificial Neural Network of Multilayer Perceptron type to act as the inverse operator. Bio-optical models are used to correlat [...] e the chlorophyll concentration with the absorption and scattering coefficients. The network training is formulated as an optimization problem, in which the update of the free variables of network (weights, viéses and each slope of the activation functions) is performed through the quasi-Newton method.

  17. A coherent perceptron for all-optical learning

    Energy Technology Data Exchange (ETDEWEB)

    Tezak, Nikolas; Mabuchi, Hideo [Stanford University, Edward L. Ginzton Laboratory, Stanford, CA (United States)

    2015-12-15

    We present nonlinear photonic circuit models for constructing programmable linear transformations and use these to realize a coherent perceptron, i.e., an all-optical linear classifier capable of learning the classification boundary iteratively from training data through a coherent feedback rule. Through extensive semi-classical stochastic simulations we demonstrate that the device nearly attains the theoretical error bound for a model classification problem. (orig.)

  18. A coherent perceptron for all-optical learning

    International Nuclear Information System (INIS)

    We present nonlinear photonic circuit models for constructing programmable linear transformations and use these to realize a coherent perceptron, i.e., an all-optical linear classifier capable of learning the classification boundary iteratively from training data through a coherent feedback rule. Through extensive semi-classical stochastic simulations we demonstrate that the device nearly attains the theoretical error bound for a model classification problem. (orig.)

  19. Sleep snoring detection using multi-layer neural networks.

    Science.gov (United States)

    Nguyen, Tan Loc; Won, Yonggwan

    2015-08-17

    Snoring detection is important for diagnosing obstructive sleep apnea syndrome (OSAS) and other respiratory sleep disorders. In general, audio signal processing such as snoring sound analysis uses the frequency characteristics of the signal. Recently, a correlational filter Multilayer Perceptron neural network (f-MLP) has been proposed, which has the first hidden layer of correlational filter operations in frequency domain. It demonstrated a superior classification performance for the pattern sets; of these, frequency information is the dominant feature for classification. The first hidden layer is implemented with the correlational filter operation; its output is the power spectrum of the filter output, while the other layers are the same as the ordinary multilayer Perceptron (o-MLP). By using the back-propagation learning algorithm for the correlational filter layer, f-MLP was able to self-adapt the filter coefficients to produce its output with more discrimination power for classification in the higher layer. In this research, this f-MLP was applied for sleep snoring signal detection. As a result, the f-MLP achieved an average detection rate of 96% for the test patterns, compared to the conventional multilayer neural network that demonstrates an 82% average detection rate. PMID:26405943

  20. Multilayer perceptron for simulation models reduction: application to a sawmill workshop

    OpenAIRE

    Thomas, Philippe; Thomas, André

    2011-01-01

    Simulation is often used to evaluate supply chain or workshop management. This simulation task needs models, which are difficult to construct. The aim of this work is to reduce the complexity of a simulation model design. The proposed approach combines discrete and continuous approaches in order to construct speeder and simpler reduced model. The simulation model focuses on bottlenecks with a discrete approach according to the theory of constraints. The remaining of the workshop must be taken...

  1. Electron/pion identification in the CBM TRD using a multilayer perceptron

    International Nuclear Information System (INIS)

    The problem of electron/pion identification in the CBM experiment based on the measurements of energy losses and transition radiation in the TRD detector is discussed. A possibility to solve such a problem by applying an artificial neural network (ANN) is considered. As input information for the network we used both the samples of energy losses of pions or electrons in the TRD absorbers and the 'clever' variable obtained on the basis of the original data. We show that usage of this new variable permits one to reach a reliable level of particle recognition no longer than after 10-20 training epochs; there are practically no fluctuations against the trend, and the needed level of pions suppression is obtained under the condition of a minimal loss of electrons

  2. An Automated MR Image Segmentation System Using Multi-layer Perceptron Neural Network

    OpenAIRE

    Amiri, S; Movahedi, M M; K Kazemi; Parsaei, H

    2013-01-01

    Background: Brain tissue segmentation for delineation of 3D anatomical structures from magnetic resonance (MR) images can be used for neuro-degenerative disorders, characterizing morphological differences between subjects based on volumetric analysis of gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF), but only if the obtained segmentation results are correct. Due to image artifacts such as noise, low contrast and intensity non-uniformity, there are some classification errors...

  3. Prediction of Missing Flow Records Using Multilayer Perceptron and Coactive Neurofuzzy Inference System

    OpenAIRE

    Tfwala, Samkele S.; Yu-Min Wang; Yu-Chieh Lin

    2013-01-01

    Hydrological data are often missing due to natural disasters, improper operation, limited equipment life, and other factors, which limit hydrological analysis. Therefore, missing data recovery is an essential process in hydrology. This paper investigates the accuracy of artificial neural networks (ANN) in estimating missing flow records. The purpose is to develop and apply neural networks models to estimate missing flow records in a station when data from adjacent stations is available. Multi...

  4. The reactor safety study with help of artificial neuron networks (multilayer perceptrons)

    International Nuclear Information System (INIS)

    One deals with deposition of insulation large amounts on settling tank components that may result in malfunction of residual heat removal systems. Paper describes briefly simulation of pressure drops in confinement systems by means of an artificial neuron nets and compares the simulation data with the experiment ones

  5. Representations of highly-varying functions by perceptron networks.

    Czech Academy of Sciences Publication Activity Database

    K?rková, V?ra

    North Charleston : CreateSpace Independent Publishing Platform, 2013 - (Vina?, T.; Hole?a, M.; Lexa, M.; Peška, L.; Vojtáš, P.), s. 73-76 ISBN 978-1-4909-5208-6. [ITAT 2013. Conference on Theory and Practice of Information Technologies. Donovaly (SK), 11.09.2013-15.09.2013] R&D Projects: GA ?R GAP202/11/1368 Institutional support: RVO:67985807 Keywords : one-hidden-layer networks * perceptrons * Boolean functions * network complexity Subject RIV: IN - Informatics, Computer Science

  6. Limitations of One-Hidden-Layer Perceptron Networks.

    Czech Academy of Sciences Publication Activity Database

    K?rková, V?ra

    Aachen & Charleston : Technical University & CreateSpace Independent Publishing Platform, 2015 - (Yaghob, J.), s. 167-171 ISBN 978-1515120650. ISSN 1613-0073. - (CEUR Workshop Proceedings. V-1422). [ITAT 2015. Conference on Theory and Practice of Information Technologies /15./. Slovenský Raj (SK), 17.09.2015-21.09.2015] R&D Projects: GA MŠk(CZ) LD13002 Institutional support: RVO:67985807 Keywords : perceptron networks * model complexity * representations of finite mappings by neural networks Subject RIV: IN - Informatics, Computer Science

  7. A Novel Channel Equalizer Using Large Margin Algebraic Perceptron Network

    Directory of Open Access Journals (Sweden)

    Siba P. Panigrahi

    2010-08-01

    Full Text Available This paper proposes a novel control scheme for channel equalization for wireless communication system. The proposed scheme considers channel equalization as a classification problem. For efficient solution of the problem, this paper makes use of a neural network working on Algebraic Perceptron (AP algorithm as a classifier. Also, this paper introduces a method of performance improvement by increasing margin of AP equalizers. Novelty of the proposed scheme is evidenced by its simulation results.

  8. On-line learning of non-monotonic rules by simple perceptron

    CERN Document Server

    Inoue, J; Kabashima, Yoshiyuki; Inoue, Jun-ichi; Nishimori, Hidetoshi; Kabashima, Yoshiyuki

    1997-01-01

    We study the generalization ability of a simple perceptron which learns unlearnable rules. The rules are presented by a teacher perceptron with a non-monotonic transfer function. The student is trained in the on-line mode. The asymptotic behaviour of the generalization error is estimated under various conditions. Several learning strategies are proposed and improved to obtain the theoretical lower bound of the generalization error.

  9. Isomorphisms in Multilayer Networks

    CERN Document Server

    Kivelä, Mikko

    2015-01-01

    We extend the concept of graph isomorphisms to multilayer networks, and we identify multiple types of isomorphisms. For example, in multilayer networks with a single "aspect" (i.e., type of layering), permuting vertex labels, layer labels, and both of types of layers each yield a different type of isomorphism. We discuss how multilayer network isomorphisms naturally lead to defining isomorphisms in any type of network that can be represented as a multilayer network. This thereby yields isomorphisms for multiplex networks, temporal networks, networks with both such features, and more. We reduce each of the multilayer network isomorphism problems to a graph isomorphism problem, and we use this reduction to prove that the multilayer network isomorphism problem is computationally equally hard as the graph isomorphism problem. One can thus use software that has been developed to solve graph isomorphism problems as a practical means for solving multilayer network isomorphism problems.

  10. Perceptron-like computation based on biologically-inspired neurons with heterosynaptic mechanisms

    Science.gov (United States)

    Kaluza, Pablo; Urdapilleta, Eugenio

    2014-10-01

    Perceptrons are one of the fundamental paradigms in artificial neural networks and a key processing scheme in supervised classification tasks. However, the algorithm they provide is given in terms of unrealistically simple processing units and connections and therefore, its implementation in real neural networks is hard to be fulfilled. In this work, we present a neural circuit able to perform perceptron's computation based on realistic models of neurons and synapses. The model uses Wang-Buzsáki neurons with coupling provided by axodendritic and axoaxonic synapses (heterosynapsis). The main characteristics of the feedforward perceptron operation are conserved, which allows to combine both approaches: whereas the classical artificial system can be used to learn a particular problem, its solution can be directly implemented in this neural circuit. As a result, we propose a biologically-inspired system able to work appropriately in a wide range of frequencies and system parameters, while keeping robust to noise and error.

  11. Approximation of Functions by Perceptron Networks with Bounded Number of Hidden Units.

    Czech Academy of Sciences Publication Activity Database

    K?rková, V?ra

    1995-01-01

    Ro?. 8, ?. 5 (1995), s. 745-750. ISSN 0893-6080 R&D Projects: GA ?R GA201/93/0427; GA AV ?R IA23057 Keywords : approximation of function s * one-hidden-layer neural network * heaviside perceptrons * radial - basis - function units * bounded number of hidden units Impact factor: 1.262, year: 1995

  12. Perfect transmission and highly asymmetric light localization in photonic multilayers

    International Nuclear Information System (INIS)

    General principles for the existence of perfect transmission resonances in photonic multilayer structures are formulated in terms of light interference described by recurrent Airy formulas. Mirror symmetry in the multilayer is shown to be a sufficient but not necessary condition for perfect transmission resonances. Asymmetric structures displaying perfect transmission in accordance with the proposed principles are demonstrated. A hybrid Fabry-Perot photonic-crystal structure of the type (BA)k(AB)k(AABB)m is proposed, combining perfect transmission and highly asymmetric electric field localization. Strength and asymmetry of localization can be controlled independently to be of use in tailoring nonreciprocal behavior of nonlinear all-optical diodes.

  13. U-shaped learning and frequency effects in a multi-layered perceptron: implications for child language acquisition.

    OpenAIRE

    PLUNKETT, K; Marchman, V

    1991-01-01

    A three-layer back-propagation network is used to implement a pattern association task in which four types of mapping are learned. These mappings, which are considered analogous to those which characterize the relationship between the stem and past tense forms of English verbs, include arbitrary mappings, identity mappings, vowel changes, and additions of a suffix. The degree of correspondence between parallel distributed processing (PDP) models which learn mappings of this sort (e.g., Rumelh...

  14. Control of Multilayer Networks

    CERN Document Server

    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.

  15. Advances in Artificial Neural Networks – Methodological Development and Application

    OpenAIRE

    Yanbo Huang

    2009-01-01

    Artificial neural networks as a major soft-computing technology have been extensively studied and applied during the last three decades. Research on backpropagation training algorithms for multilayer perceptron networks has spurred development of other neural network training algorithms for other networks such as radial basis function, recurrent network, feedback network, and unsupervised Kohonen self-organizing network. These networks, especially the multilayer perceptron network with a back...

  16. Recurrence in Quantum Mechanics

    OpenAIRE

    Duvenhage, Rocco

    2002-01-01

    We first compare the mathematical structure of quantum and classical mechanics when both are formulated in a C*-algebraic framework. By using finite von Neumann algebras, a quantum mechanical analogue of Liouville's theorem is then proposed. We proceed to study Poincare recurrence in C*-algebras by mimicking the measure theoretic setting. The results are interpreted as recurrence in quantum mechanics, similar to Poincare recurrence in classical mechanics.

  17. Recurrence Tracking Microscope

    OpenAIRE

    Saif, Farhan

    2006-01-01

    In order to probe nanostructures on a surface we present a microscope based on the quantum recurrence phenomena. A cloud of atoms bounces off an atomic mirror connected to a cantilever and exhibits quantum recurrences. The times at which the recurrences occur depend on the initial height of the bouncing atoms above the atomic mirror, and vary following the structures on the surface under investigation. The microscope has inherent advantages over existing techniques of scanni...

  18. Recurrent Escherichia coli bacteremia.

    OpenAIRE

    Maslow, J N; Mulligan, M E; Arbeit, R D

    1994-01-01

    Escherichia coli is the most common gram-negative organism associated with bacteremia. While recurrent E. coli urinary tract infections are well-described, recurrent E. coli bacteremia appears to be uncommon, with no episodes noted in multiple series of patients with gram-negative bacteremias. We report on 5 patients with recurrent bloodstream infections identified from a series of 163 patients with E. coli bacteremia. For each patient, the isolates from each episode were analyzed by pulsed-f...

  19. Optimal Recurrence Grammars

    CERN Document Server

    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.

  20. Diffusion in multilayers

    OpenAIRE

    Piecuch, M.

    1988-01-01

    Diffusion experiments are usually performed at macroscopic length scales, use of multilayers can lower these scale down to the nanometer range. This paper describes the main idea governing atomic transport at such short distance and in such inhomogeneous systems. The basic experimental methods involved are also discussed. Some representative recent works are shortly described.

  1. The eternal recurrence today

    CERN Document Server

    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.

  2. Recurrent pityriasis rosea

    OpenAIRE

    Singh S; Singh Sanjay; Pandey S

    1998-01-01

    A case of recurrent pityriasis rosea in a 25-year old man is reported. He had his first attack 4 years ago and new outbreaks followed every year in winter with last 2 episodes occurring in the same year. All investigations were normal and no explanation for recurrences was found.

  3. Learning by random walks in the weight space of the Ising perceptron

    International Nuclear Information System (INIS)

    Several variants of a stochastic local search process for constructing the synaptic weights of an Ising perceptron are studied. In this process, binary patterns are sequentially presented to the Ising perceptron and are then learned as the synaptic weight configuration is modified through a chain of single- or double-weight flips within the compatible weight configuration space of the earlier learned patterns. This process is able to reach a storage capacity of ??0.63 for pattern length N = 101 and ??0.41 for N = 1001. If in addition a relearning process is exploited, the learning performance is further improved to a storage capacity of ??0.80 for N = 101 and ??0.42 for N = 1001. We found that, for a given learning task, the solutions constructed by the random walk learning process are separated by a typical Hamming distance, which decreases with the constraint density ? of the learning task; at a fixed value of ?, the width of the Hamming distance distribution decreases with N

  4. Learning by random walks in the weight space of the Ising perceptron

    Science.gov (United States)

    Huang, Haiping; Zhou, Haijun

    2010-08-01

    Several variants of a stochastic local search process for constructing the synaptic weights of an Ising perceptron are studied. In this process, binary patterns are sequentially presented to the Ising perceptron and are then learned as the synaptic weight configuration is modified through a chain of single- or double-weight flips within the compatible weight configuration space of the earlier learned patterns. This process is able to reach a storage capacity of ??0.63 for pattern length N = 101 and ??0.41 for N = 1001. If in addition a relearning process is exploited, the learning performance is further improved to a storage capacity of ??0.80 for N = 101 and ??0.42 for N = 1001. We found that, for a given learning task, the solutions constructed by the random walk learning process are separated by a typical Hamming distance, which decreases with the constraint density ? of the learning task; at a fixed value of ?, the width of the Hamming distance distribution decreases with N.

  5. Coping with Fear of Recurrence

    Science.gov (United States)

    ... Recurrence Request Permissions Print to PDF Coping With Fear of Recurrence Approved by the Cancer.Net Editorial ... affects your life. Tips for coping with the fear of recurrence Living with uncertainty is never easy. ...

  6. Mobile Multilayer IPsec protocol

    Directory of Open Access Journals (Sweden)

    T.Gayathri

    2009-08-01

    Full Text Available A mobile user moves around and switches between wireless cells, subnets and domains, it needs to maintain the session continuity. At the same time security of signaling and transport media should not be compromised. A multi-layer security framework involving user authentication, packet based encryption and access control mechanism can provide the desired level of security to the mobile users. Supporting streaming traffic in a mobile wireless Internet is faced with several challenges due to continuous handoff experienced by a mobile user. These challenges include dynamic binding, location management, quality of service and end-to-end security for signaling and transport. Mobile users will use heterogeneous radio access networking technologies. Mobile multilayer IPsec protocol (MML IPSec extends ML-IPSec to deal with mobility and make it suitable for wireless networks. MML-IPSec is integration of ML-IPSec and mobile IP.

  7. Recurrent vaginal candidiasis.

    Science.gov (United States)

    Loh, K Y; Sivalingam, N

    2003-12-01

    Recurrent vaginal candidiasis is one of the most common reasons for patients visiting their primary care doctors. Majority of the cases are caused by Candida albicans. Controlling of risk factors such as diabetes mellitus, used of broad spectrum antibiotics, contraceptive pills and steroid therapy helps in managing recurrent vaginal candidiasis. Initial 14-day course of oral azoles and followed by 6 months maintenance are effective in treating majority of the cases. Failure to treat recurrent vaginal candidiasis can lead to various bio-psycho-social complications. PMID:15190674

  8. Discrete multitime multiple recurrence

    OpenAIRE

    Ghiu, Cristian; Tuliga, Raluca; Udriste, Constantin

    2015-01-01

    The aim of our paper is to formulate and solve problems concerning multitime multiple recurrence equations. We discuss in detail the generic properties and the existence and uniqueness of solutions. Among the general things, we discuss in detail the cases of autonomous and non-autonomous recurrences, highlighting in particular the theorems of existence and uniqueness of solutions. Finally, are given interesting examples which are the analogue of arithmetic progression and th...

  9. Recurrences of strange attractors

    Indian Academy of Sciences (India)

    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.

  10. Generalizing with perceptrons in case of structured phase- and pattern-spaces

    CERN Document Server

    Dirscherl, G; Krey, U

    1998-01-01

    We investigate the influence of different kinds of structure on the learning behaviour of a perceptron performing a classification task defined by a teacher rule. The underlying pattern distribution is permitted to have spatial correlations. The prior distribution for the teacher coupling vectors itself is assumed to be nonuniform. Thus classification tasks of quite different difficulty are included. As learning algorithms we discuss Hebbian learning, Gibbs learning, and Bayesian learning with different priors, using methods from statistics and the replica formalism. We find that the Hebb rule is quite sensitive to the structure of the actual learning problem, failing asymptotically in most cases. Contrarily, the behaviour of the more sophisticated methods of Gibbs and Bayes learning is influenced by the spatial correlations only in an intermediate regime of $\\alpha$, where $\\alpha$ specifies the size of the training set. Concerning the Bayesian case we show, how enhanced prior knowledge improves the performa...

  11. Learning by random walks in the weight space of the Ising perceptron

    CERN Document Server

    Huang, Haiping

    2010-01-01

    The weight space of the Ising perceptron is explored by a random walk process where single weight flips are performed until the new presented pattern is learned. In this learning protocol, patterns are added sequentially and previous learned patterns (constraints) should be kept satisfied. Random walks are carried out until no solutions can be found. By this protocol, we are able to evaluate the overlap distribution of different solutions found on the same learning instance, and we show that solutions are far apart in Hamming distance even at small loading, implying that well-separated clusters form in the weight space. Adding the constraint that the stability of each learned pattern should be maximized before another new pattern is presented, the evolving fraction of frozen weights can be computed and shows that the simple random walk process will get trapped by the exponentially many suboptimal states. However, we suggest an additional rule by which a finite energy barrier involving only the barely learned ...

  12. Hyperhomocysteinemia in Recurrent Miscarriage

    International Nuclear Information System (INIS)

    Objective: An elevated total plasma homocysteine level has been suggested as a possible risk factor in women suffering from recurrent pregnancy loss. The current study was undertaken to assess the association between homocysteine, folate, cobalamin (vitamin B12) and the risk of recurrent pregnancy loss. Design: Case . control study Materials and Methods: The study included 57 non-pregnant Egyptian women. They were classified according to their obstetric history into 2 groups: 32 cases with at least two consecutive miscarriages (Study group), and 25 cases with normal obstetric history (Control group). All cases were tested for plasma total homocysteine, serum folate and cobalamin (vitamin B12). Results: The fasting total homocysteine was significantly higher in the study group as compared to the control group. While the median concentrations for the vitamins studied were significantly lower in women of the study group as compared to the controls. Elevated homocysteine and reduced vitamin B12 can be considered risk factors for recurrent miscarriage with odds ratio (OR) and 95% confidence intervals (95% CI) of 1.839 (1.286, 2.63) and 1.993 (1.346, 2.951) respectively in the group of recurrent miscarriages. The OR (95% CI) in the study population for low serum folate concentrations was 1.23 (0.776, 2.256). Conclusion: Elevated homocysteine and reduced serum vitamin B12 are risk factors for recurrent miscarriage. Low serum folate did not seem a risk factor for recurrent miscarriage. Testing for homocysteine levels in women suffering from unexplained recurrent miscarriage and pre-conceptional supplementation with vitamin B12 might be beneficial to improve pregnancy outcome

  13. Magnetic metallic multilayers

    International Nuclear Information System (INIS)

    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

  14. Ultrahard Multilayer Coatings

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Ultrahard Multilayer Coatings

    International Nuclear Information System (INIS)

    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 ampersand deg;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

  16. Recurrent Novae - A Review

    CERN Document Server

    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.

  17. Recurrent Pneumonia in Children

    Directory of Open Access Journals (Sweden)

    Solmaz Çelebi

    2010-06-01

    Full Text Available Objective: The aim of this study was to determine the relative frequency and describe the predisposing causes of recurrent pneumonia in children. Material and methods: We retrospectively reviewed the medical records of patients with pneumonia at Uludag University Medical Faculty, Department of Pediatrics, between January 1998 and December 2007. Recurrent pneumonia was defined as at least two episodes in a 1 year period or at least three episodes over a lifetime. Patients with recurrent pneumonia were included in this study.Results: During the study period, 1617 children were admitted to hospital with a diagnosis of pneumonia, 185 (11.4% met the criteria for recurrent pneumonia. The mean age of patients was 16±32 months (3 months-14 years and 61% were male. An underlying cause was identified in 143 patients (77%. Of these, the underlying cause was diagnosed prior the pneumonia in 25 patients (17%, during the first episode in 30 (21%, and during recurrence in 88 (62%. Underlying causes included congenital cardiac defects in 32 patients (17.2%, gastroesophageal reflux in 31 patients (16.7%, aspiration syndrome in 27 patients (14.5%, asthma in 16 patients (8.6%, cystic fibrosis in 12 patients (6.4% immune disorders in 10 patients (5.4%, tuberculosis in 9 patients (4.8% and anomalies of the chest and lung in 6 patients (3.2%. No predisposing illness could be demonstrated in 42 patients (33%. Conclusion: Recurrent pneumonia occurred in 11.4% of all children hospitalized for pneumonia. The underlying cause was identified in 77% of the children. The most common causes were congenital cardiac defects, gastroesophageal reflux and aspiration syndrome.

  18. Serially recurrent osteoid osteoma.

    Science.gov (United States)

    Sampath, Srihari C; Sampath, Srinath C; Rosenthal, Daniel I

    2015-06-01

    Osteoid osteoma is a relatively common, benign, painful tumor of bone. It is widely believed to run a course culminating in spontaneous regression. The tumor can usually be eliminated by excision or ablation, although it may recur locally. Although management has classically been surgical, thermocoagulation via percutaneously delivered radiofrequency energy has demonstrated excellent results, typically resulting in durable response following a single treatment. Here, we present an unusual case of serially recurrent pathologically proven pediatric osteoid osteoma, treated by radiofrequency ablation five times over the course of 11 years. Limitations of RF ablation of osteoid osteoma and possible factors predisposing to incomplete treatment or recurrence are discussed. PMID:25503857

  19. Structure and Swelling Behaviour of Polyelectrolyte Multilayers

    OpenAIRE

    Dodoo, Samuel

    2011-01-01

    In this thesis, the relation between structure, growth and swelling in water of polyelectrolyte multilayers are investigated. Polyelectrolyte multilayers are fabricated by alternating adsorption of polyanions and polycations on a silicon substrate. The multilayer is sensitive to external stimuli, which often counteracts the stability of the multilayer. Also the many applications of polyelectrolyte multilayers have made the interphase between the substrate and the film bulk to be of interest. ...

  20. Neutron diffraction by multilayer systems

    International Nuclear Information System (INIS)

    Stract dynamical scattering theory of neutrons by multilayer systems, formed by alternating thin films of two materials, is developed. The statistical distribution of film widths is taken into account. The reflection and transmission coefficients are calculated. The neutron conductivity bands are shown to exist in multilayer systems. For the system of N bilayers a conductivity band consists of N-1 levels. In the absence of absorption such a system becomes completely transparent for neutrons, if the normal component of thear kinetic energy Esub(perpendicular) equals the energy of a conductivity band level. Systems with ferromagnetic films or polarized nuclei polarize neutrons. Multilayer systems can serve as a neutron Fabry-Perot interferometer

  1. Debugging of neural network based on 3-layer perceptron by the example of expert system in ophthalmology

    Directory of Open Access Journals (Sweden)

    Kuzmin Alexey Konstantinovich

    2011-02-01

    Full Text Available The algorithm of development of full set of tests for debugging of neural network expert systems based on threelayer perceptron is considered. The algo-rithm is based on rules extraction from neural network and using of the method of technical diagnostics PODEM. The use of algorithm for testing of expert sys-tem Glaukoma Complaint for prognosis of compliance of ophthalmologic patients is described.

  2. Lung Cancer Indicators Recurrence

    Science.gov (United States)

    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

  3. On Solving Linear Recurrences

    Science.gov (United States)

    Dobbs, David E.

    2013-01-01

    A direct method is given for solving first-order linear recurrences with constant coefficients. The limiting value of that solution is studied as "n to infinity." This classroom note could serve as enrichment material for the typical introductory course on discrete mathematics that follows a calculus course.

  4. Multi-layers castings

    Directory of Open Access Journals (Sweden)

    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.

  5. Multilayer graphene condenser microphone

    Science.gov (United States)

    Todorovi?, Dejan; Matkovi?, Aleksandar; Mili?evi?, Marijana; Jovanovi?, Djordje; Gaji?, Radoš; Salom, Iva; Spasenovi?, Marko

    2015-12-01

    Vibrating membranes are the cornerstone of acoustic technology, forming the backbone of modern loudspeakers and microphones. Acoustic performance of a condenser microphone is derived mainly from the membrane’s size, surface mass and achievable static tension. The widely studied and available nickel has been a dominant membrane material for professional microphones for several decades. In this paper we introduce multilayer graphene as a membrane material for condenser microphones. The graphene device outperforms a high end commercial nickel-based microphone over a significant part of the audio spectrum, with a larger than 10 dB enhancement of sensitivity. Our experimental results are supported with numerical simulations, which also show that a 300 layer thick graphene membrane under maximum tension would offer excellent extension of the frequency range, up to 1 MHz.

  6. Integrated Multilayer Insulation

    Science.gov (United States)

    Dye, Scott

    2009-01-01

    Integrated multilayer insulation (IMLI) is being developed as an improved alternative to conventional multilayer insulation (MLI), which is more than 50 years old. A typical conventional MLI blanket comprises between 10 and 120 metallized polymer films separated by polyester nets. MLI is the best thermal- insulation material for use in a vacuum, and is the insulation material of choice for spacecraft and cryogenic systems. However, conventional MLI has several disadvantages: It is difficult or impossible to maintain the desired value of gap distance between the film layers (and consequently, it is difficult or impossible to ensure consistent performance), and fabrication and installation are labor-intensive and difficult. The development of IMLI is intended to overcome these disadvantages to some extent and to offer some additional advantages over conventional MLI. The main difference between IMLI and conventional MLI lies in the method of maintaining the gaps between the film layers. In IMLI, the film layers are separated by what its developers call a micro-molded discrete matrix, which can be loosely characterized as consisting of arrays of highly engineered, small, lightweight, polymer (typically, thermoplastic) frames attached to, and placed between, the film layers. The term "micro-molded" refers to both the smallness of the frames and the fact that they are fabricated in a process that forms precise small features, described below, that are essential to attainment of the desired properties. The term "discrete" refers to the nature of the matrix as consisting of separate frames, in contradistinction to a unitary frame spanning entire volume of an insulation blanket.

  7. Controlling light with plasmonic multilayers

    DEFF Research Database (Denmark)

    Orlov, Alexey A.; Zhukovsky, Sergei

    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 A number of fundamental electromagnetic effects unique to the latter are identified and demonstrated. Examples include the evolution of isofrequency contour shape from elliptical to hyperbolic, all-angle negative refraction, and nonlocality-induced optical birefringence. Analysis of the underlying physical causes, which are spatial dispersion and optical nonlocality, is also reviewed. These recent results are extremely promising for a number of applications ranging from nanolithography to optical cloaking. © 2014 Elsevier B.V.

  8. Exploring recurrences in quasiperiodic systems

    OpenAIRE

    Zou, Yong

    2007-01-01

    In this work, some new results to exploit the recurrence properties of quasiperiodic dynamical systems are presented by means of a two dimensional visualization technique, Recurrence Plots(RPs). Quasiperiodicity is the simplest form of dynamics exhibiting nontrivial recurrences, which are common in many nonlinear systems. The concept of recurrence was introduced to study the restricted three body problem and it is very useful for the characterization of nonlinear systems. I have analyzed in ...

  9. Risk for Recurrence in Depression

    OpenAIRE

    Burcusa, Stephanie L.; Iacono, William G

    2007-01-01

    Depression is a highly recurrent disorder with significant personal and public health consequences. Prevention of recurrence would be extremely desirable, and thus researchers have begun to identify risk factors that are specific to recurrence, which may be different from risk factors for first-onset of depression. Methodological issues in this area of research are briefly reviewed (e.g., the various definitions of “recurrence” and “depression”), followed by a review of studies on specific ri...

  10. Multicategory nets of single-layer perceptrons: complexity and sample-size issues.

    Science.gov (United States)

    Raudys, Sarunas; Kybartas, Rimantas; Zavadskas, Edmundas Kazimieras

    2010-05-01

    The standard cost function of multicategory single-layer perceptrons (SLPs) does not minimize the classification error rate. In order to reduce classification error, it is necessary to: 1) refuse the traditional cost function, 2) obtain near to optimal pairwise linear classifiers by specially organized SLP training and optimal stopping, and 3) fuse their decisions properly. To obtain better classification in unbalanced training set situations, we introduce the unbalance correcting term. It was found that fusion based on the Kulback-Leibler (K-L) distance and the Wu-Lin-Weng (WLW) method result in approximately the same performance in situations where sample sizes are relatively small. The explanation for this observation is by theoretically known verity that an excessive minimization of inexact criteria becomes harmful at times. Comprehensive comparative investigations of six real-world pattern recognition (PR) problems demonstrated that employment of SLP-based pairwise classifiers is comparable and as often as not outperforming the linear support vector (SV) classifiers in moderate dimensional situations. The colored noise injection used to design pseudovalidation sets proves to be a powerful tool for facilitating finite sample problems in moderate-dimensional PR tasks. PMID:20215067

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

    Science.gov (United States)

    Araújo, Ricardo de A

    2012-04-01

    Several linear and non-linear techniques have been proposed to solve the stock market forecasting problem. However, a limitation arises from all these techniques and is known as the random walk dilemma (RWD). In this scenario, forecasts generated by arbitrary models have a characteristic one step ahead delay with respect to the time series values, so that, there is a time phase distortion in stock market phenomena reconstruction. In this paper, we propose a suitable model inspired by concepts in mathematical morphology (MM) and lattice theory (LT). This model is generically called the increasing morphological perceptron (IMP). Also, we present a gradient steepest descent method to design the proposed IMP based on ideas from the back-propagation (BP) algorithm and using a systematic approach to overcome the problem of non-differentiability of morphological operations. Into the learning process we have included a procedure to overcome the RWD, which is an automatic correction step that is geared toward eliminating time phase distortions that occur in stock market phenomena. Furthermore, an experimental analysis is conducted with the IMP using four complex non-linear problems of time series forecasting from the Brazilian stock market. Additionally, two natural phenomena time series are used to assess forecasting performance of the proposed IMP with other non financial time series. At the end, the obtained results are discussed and compared to results found using models recently proposed in the literature. PMID:22391234

  12. Implementation of a spike-based perceptron learning rule using TiO2-x memristors.

    Science.gov (United States)

    Mostafa, Hesham; Khiat, Ali; Serb, Alexander; Mayr, Christian G; Indiveri, Giacomo; Prodromakis, Themis

    2015-01-01

    Synaptic plasticity plays a crucial role in allowing neural networks to learn and adapt to various input environments. Neuromorphic systems need to implement plastic synapses to obtain basic "cognitive" capabilities such as learning. One promising and scalable approach for implementing neuromorphic synapses is to use nano-scale memristors as synaptic elements. In this paper we propose a hybrid CMOS-memristor system comprising CMOS neurons interconnected through TiO2-x memristors, and spike-based learning circuits that modulate the conductance of the memristive synapse elements according to a spike-based Perceptron plasticity rule. We highlight a number of advantages for using this spike-based plasticity rule as compared to other forms of spike timing dependent plasticity (STDP) rules. We provide experimental proof-of-concept results with two silicon neurons connected through a memristive synapse that show how the CMOS plasticity circuits can induce stable changes in memristor conductances, giving rise to increased synaptic strength after a potentiation episode and to decreased strength after a depression episode. PMID:26483629

  13. Implementation of a spike-based perceptron learning rule using TiO2?x memristors

    Science.gov (United States)

    Mostafa, Hesham; Khiat, Ali; Serb, Alexander; Mayr, Christian G.; Indiveri, Giacomo; Prodromakis, Themis

    2015-01-01

    Synaptic plasticity plays a crucial role in allowing neural networks to learn and adapt to various input environments. Neuromorphic systems need to implement plastic synapses to obtain basic “cognitive” capabilities such as learning. One promising and scalable approach for implementing neuromorphic synapses is to use nano-scale memristors as synaptic elements. In this paper we propose a hybrid CMOS-memristor system comprising CMOS neurons interconnected through TiO2?x memristors, and spike-based learning circuits that modulate the conductance of the memristive synapse elements according to a spike-based Perceptron plasticity rule. We highlight a number of advantages for using this spike-based plasticity rule as compared to other forms of spike timing dependent plasticity (STDP) rules. We provide experimental proof-of-concept results with two silicon neurons connected through a memristive synapse that show how the CMOS plasticity circuits can induce stable changes in memristor conductances, giving rise to increased synaptic strength after a potentiation episode and to decreased strength after a depression episode. PMID:26483629

  14. Paediatric recurrent herpetic whitlow.

    Science.gov (United States)

    Patel, Ramnik; Kumar, Hemant; More, Bharat; Patricolo, Mario

    2013-01-01

    We present a case of recurrent painful blisters of middle phalanx of the left ring finger of a 15-month-old previously healthy and immunocompetent female child. These lesions initially were confused with infective bacterial whitlow, treated with incision and drainage, and later with cigarette burns which led to referral to child protection team. Paediatric dermatologist finally diagnosed after scrapping and virology culture. The patient had recovery following full treatment with topical and systemic acyclovir. She presented again at the age of 4 with recurrence which required topical and systemic acyclovir therapy with good recovery. It is important to be aware of the danger of incorrect diagnosis, raising child protection concerns and management leading to danger of cross infection and serious illness especially in the immunocompromised patients. PMID:23904423

  15. Equine recurrent airway obstruction

    OpenAIRE

    Artur Nied?wied?

    2014-01-01

    Equine Recurrent Airway Obstruction (RAO), also known as heaves or broken wind, is one of the most common disease in middle-aged horses. Inflammation of the airway is inducted by organic dust exposure. This disease is characterized by neutrophilic inflammation, bronchospasm, excessive mucus production and pathologic changes in the bronchiolar walls. Clinical signs are resolved in 3-4 weeks after environmental changes. Horses suffering from RAO are susceptible to allergens throughout their liv...

  16. Recurrent cutaneous leishmaniasis*

    OpenAIRE

    Gomes, Ciro Martins; Damasco, Fabiana dos Santos; de Morais, Orlando Oliveira; de Paula, Carmen Déa Ribeiro; Sampaio, Raimunda Nonata Ribeiro

    2013-01-01

    We present a case of an 18-year-old male patient who, after two years of inappropriate treatment for cutaneous leishmaniasis, began to show nodules arising at the edges of the former healing scar. He was immune competent and denied any trauma. The diagnosis of recurrent cutaneous leishmaniasis was made following positive culture of aspirate samples. The patient was treated with N-methylglucamine associated with pentoxifylline for 30 days. Similar cases require special attention mainly because...

  17. Training Recurrent Networks

    DEFF Research Database (Denmark)

    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 training. In particular we investigate ill-conditioning, the need for and effect of regularization and illustrate the superiority of second-order methods for training

  18. Random entropy and recurrence

    Directory of Open Access Journals (Sweden)

    Ronald Meester

    2003-08-01

    Full Text Available We show that a cocycle, which is nothing but a generalized random walk with index set ℤd, with bounded step sizes is recurrent whenever its associated random entropy is zero, and transient whenever its associated random entropy is positive. This generalizes a well-known one-dimensional result and implies a Polya type dichotomy for this situation.

  19. Discrete diagonal recurrences and discrete minimal submanifolds

    OpenAIRE

    Ghiu, Cristian; Tuliga, Raluca; Udriste, Constantin; Tevy, Ionel

    2015-01-01

    Our original results refer to multivariate recurrences: discrete multitime diagonal recurrence, bivariate recurrence, trivariate recurrence, solutions tailored to particular situations, second order multivariate recurrences, characteristic equation, and multivariate diagonal recurrences of superior order. We find the solutions, we clarify the structural background and provides short, conceptual proofs. The original results include a new point of view on discrete minimal subm...

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

    Science.gov (United States)

    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. PMID:26316190

  1. Irreversible Multilayer Adsorption

    CERN Document Server

    Nielaba, P; Wang, J S

    1993-01-01

    Random sequential adsorption (RSA) models have been studied due to their relevance to deposition processes on surfaces. The depositing particles are represented by hard-core extended objects; they are not allowed to overlap. Numerical Monte Carlo studies and analytical considerations are reported for 1D and 2D models of multilayer adsorption processes. Deposition without screening is investigated, in certain models the density may actually increase away from the substrate. Analytical studies of the late stage coverage behavior show the crossover from exponential time dependence for the lattice case to the power law behavior in the continuum deposition. 2D lattice and continuum simulations rule out some "exact" conjectures for the jamming coverage. For the deposition of dimers on a 1D lattice with diffusional relaxation we find that the limiting coverage (100%) is approached according to the ~1/t**0.5 power-law preceded, for fast diffusion, by the mean-field crossover regime with the intermediate ~1/t behavior...

  2. Equine recurrent airway obstruction

    Directory of Open Access Journals (Sweden)

    Artur Nied?wied?

    2014-10-01

    Full Text Available Equine Recurrent Airway Obstruction (RAO, also known as heaves or broken wind, is one of the most common disease in middle-aged horses. Inflammation of the airway is inducted by organic dust exposure. This disease is characterized by neutrophilic inflammation, bronchospasm, excessive mucus production and pathologic changes in the bronchiolar walls. Clinical signs are resolved in 3-4 weeks after environmental changes. Horses suffering from RAO are susceptible to allergens throughout their lives, therefore they should be properly managed. In therapy the most importanthing is to eliminate dustexposure, administration of corticosteroids and use bronchodilators to improve pulmonary function.

  3. Incarcerated recurrent Amyand's hernia

    OpenAIRE

    Quartey, Benjamin; Ugochukwu, Obinna; Kuehn, Reed; Ospina, Karen

    2012-01-01

    Amyand's hernia is a rarity and a recurrent case is extremely rare. A 71-year-old male with a previous history of right inguinal hernia repair presented to the emergency department with a 1-day history of pain in the right groin. A physical examination revealed a nonreducible right inguinal hernia. A computed tomography scan showed a 1.3-cm appendix with surrounding inflammation within a right inguinal hernia. An emergent right groin exploration revealed an incarcerated and injected non-perfo...

  4. Recurrent Inversion Formulas

    OpenAIRE

    Zhao, Wenhua

    2003-01-01

    Let $F(z)=z-H(z)$ with $o(H(z))\\geq 2$ be a formal map from $\\bC^n$ to $\\bC^n$ and $G(z)$ the formal inverse of $F(z)$. In this paper, we fist study the deformation $F_t(z)=z-tH(z)$ and its formal inverse map $G_t(z)$. We then derive two recurrent formulas for the formal inverse $G(z)$. The first formula in certain situations provides a more efficient method for the calculation of $G(z)$ than other well known inversion formulas. The second one is differential free but only w...

  5. On the conditions for the existence of Perfect Learning and power law in learning from stochastic examples by Ising perceptrons

    CERN Document Server

    Uezu, T

    2001-01-01

    In a previous letter, we studied learning from stochastic examples by perceptrons with Ising weights in the framework of statistical mechanics. Under the one-step replica symmetry breaking ansatz, the behaviours of learning curves were classified according to some local property of the rules by which examples were drawn. Further, the conditions for the existence of the Perfect Learning together with other behaviors of the learning curves were given. In this paper, we give the detailed derivation about these results and further argument about the Perfect Learning together with extensive numerical calculations.

  6. Computing and fabricating multilayer models

    OpenAIRE

    Holroyd, Michael; Baran, Ilya; Lawrence, Jason; Matusik, Wojciech

    2011-01-01

    We present a method for automatically converting a digital 3D model into a multilayer model: a parallel stack of high-resolution 2D images embedded within a semi-transparent medium. Multilayer models can be produced quickly and cheaply and provide a strong sense of an object's 3D shape and texture over a wide range of viewing directions. Our method is designed to minimize visible cracks and other artifacts that can arise when projecting an input model onto a small number of parallel planes, a...

  7. Transfer matrices for multilayer structures

    International Nuclear Information System (INIS)

    We consider four of the transfer matrices defined to deal with multilayer structures. We deduce algorithms to calculate them numerically, in a simple and neat way. We illustrate their application to semi-infinite systems using SGFM formulae. These algorithms are of fast convergence and allow a calculation of bulk-, surface- and inner-layers band structure in good agreement with much more sophisticated calculations. Supermatrices, interfaces and multilayer structures can be calculated in this way with a small computational effort. (author). 10 refs

  8. Elasticity of polyelectrolyte multilayer microcapsules

    CERN Document Server

    Lulevich, V V; Vinogradova, O I

    2003-01-01

    We present a novel approach to probe elastic properties of polyelectrolyte multilayer microcapsules. The method is based on measurements of the capsule load-deformation curves with the atomic force microscope. The experiment suggests that at low applied load deformations of the capsule shell are elastic. Using elastic theory of membranes we relate force, deformation, elastic moduli, and characteristic sizes of the capsule. Fitting to the prediction of the model yields the lower limit for Young's modulus of the polyelectrolyte multilayers of the order of a few MPa. This value corresponds to Young's modulus of a highly elastic polymer.

  9. Recurrence theorems: A unified account

    International Nuclear Information System (INIS)

    I discuss classical and quantum recurrence theorems in a unified manner, treating both as generalisations of the fact that a system with a finite state space only has so many places to go. Along the way, I prove versions of the recurrence theorem applicable to dynamics on linear and metric spaces and make some comments about applications of the classical recurrence theorem in the foundations of statistical mechanics

  10. Linear discrete multitime multiple recurrence

    OpenAIRE

    Ghiu, Cristian; Tuliga, Raluca; Udriste, Constantin

    2015-01-01

    The multitime multiple recurrences are common in analysis of algorithms, computational biology, information theory, queueing theory, filters theory, statistical physics etc. The theoretical part about them is little or not known. That is why, the aim of our paper is to formulate and solve problems concerning nonautonomous multitime multiple recurrence equations. Among other things, we discuss in detail the cases of linear recurrences with constant coefficients, highlighting ...

  11. Endoscopic Cubital Tunnel Recurrence Rates

    OpenAIRE

    Cobb, Tyson K.; Sterbank, Patrick T.; Lemke, Jon H.

    2009-01-01

    Cubital tunnel syndrome is the second most common nerve entrapment in the upper extremity. There are no current publications concerning the recurrence rates after endoscopic cubital tunnel release. The purpose of this study is to evaluate the recurrence rate of endoscopic cubital tunnel release compared to published reports of recurrence following open cubital tunnel procedures. We reviewed 134 consecutive cases of endoscopic cubital tunnel release in 117 patients. There were 104 cases in 94 ...

  12. Evolution of recurrent fuzzy controllers

    OpenAIRE

    Kavka, Carlos; Roggero, Patricia; Apolloni, Javier

    2004-01-01

    The main advantage of a recurrent architecture is the ability to store information from prior system states. A recurrent fuzzy controller includes hidden fuzzy variables which makes the controller more appropriate to deal with dynamic systems. We are currently investigating the effect of evolution of recurrent fuzzy controllers by applying the FV representation, which provides a set of advantages that can signi catively benefit the quality of the knowledge insertion process.

  13. Geospatial scenario based modelling of urban and agricultural intrusions in Ramsar wetland Deepor Beel in Northeast India using a multi-layer perceptron neural network

    Science.gov (United States)

    Mozumder, Chitrini; Tripathi, Nitin K.

    2014-10-01

    In recent decades, the world has experienced unprecedented urban growth which endangers the green environment in and around urban areas. In this work, an artificial neural network (ANN) based model is developed to predict future impacts of urban and agricultural expansion on the uplands of Deepor Beel, a Ramsar wetland in the city area of Guwahati, Assam, India, by 2025 and 2035 respectively. Simulations were carried out for three different transition rates as determined from the changes during 2001-2011, namely simple extrapolation, Markov Chain (MC), and system dynamic (SD) modelling, using projected population growth, which were further investigated based on three different zoning policies. The first zoning policy employed no restriction while the second conversion restriction zoning policy restricted urban-agricultural expansion in the Guwahati Municipal Development Authority (GMDA) proposed green belt, extending to a third zoning policy providing wetland restoration in the proposed green belt. The prediction maps were found to be greatly influenced by the transition rates and the allowed transitions from one class to another within each sub-model. The model outputs were compared with GMDA land demand as proposed for 2025 whereby the land demand as produced by MC was found to best match the projected demand. Regarding the conservation of Deepor Beel, the Landscape Development Intensity (LDI) Index revealed that wetland restoration zoning policies may reduce the impact of urban growth on a local scale, but none of the zoning policies was found to minimize the impact on a broader base. The results from this study may assist the planning and reviewing of land use allocation within Guwahati city to secure ecological sustainability of the wetlands.

  14. Brain scintigraphy in recurrent medulloblastoma

    International Nuclear Information System (INIS)

    Twenty-three patients with previously treated medulloblastoma had brain scintigrams during evaluation for recurrent or metastatic tumor. The scintigrams revealed posterior fossa recurrence in 15 patients and supratentorial metastases in 9; only 1 of the latter was clinically suspected. Two subdural hematomas and one calvarial metastasis were also detected. Comparison with other diagnostic evidence shows agreement in 13 out of 14 cases (93 percent) for posterior fossa recurrence and 8/10 (80 percent) for supratentiorial masses. Brain scintigraphy appears to be a sensitive and specific test for the detection of recurrence and metastasis in patients with treated medulloblastoma

  15. Image quality of figured multilayered optics

    International Nuclear Information System (INIS)

    The reflectivity and resolution of a multilayer structure is strongly affected by the roughness at the interfaces between two successive layers and by the amount that the constituent materials will diffuse into one another at the interfaces. Performance is also affected by the variations in individual layer thicknesses and by inhomogeneities in the materials. These deviations from the ideal multilayer will also affect the quality of the image from a figured multilayer optical element. The theory used to model the effects of non-ideal multilayers on the image quality of figured optics will be discussed. The relationship between image quality and multilayer structure quality will be illustrated with several examples

  16. New developments in Ni/Ti multilayers

    Energy Technology Data Exchange (ETDEWEB)

    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).

  17. Multilayer Controller for Outdoor Vehicle

    DEFF Research Database (Denmark)

    Reske-Nielsen, Anders; Mejnertsen, Asbjørn; Andersen, Nils Axel; Ravn, Ole; Nørremark, Michael; Griepentrog, Hans Werner

    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 of a research project within the field of automated agriculture and precision farming.

  18. Shortest recurrence periods of novae

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Mariko [Department of Astronomy, Keio University, Hiyoshi, Yokohama 223-8521 (Japan); Saio, Hideyuki [Astronomical Institute, Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan); Hachisu, Izumi [Department of Earth Science and Astronomy, College of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Nomoto, Ken' ichi, E-mail: mariko@educ.cc.keio.ac.jp [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan)

    2014-10-01

    Stimulated by the recent discovery of the 1 yr recurrence period nova M31N 2008-12a, we examined the shortest recurrence periods of hydrogen shell flashes on mass-accreting white dwarfs (WDs). We discuss the mechanism that yields a finite minimum recurrence period for a given WD mass. Calculating the unstable flashes for various WD masses and mass accretion rates, we identified a shortest recurrence period of about two months for a non-rotating 1.38 M {sub ?} WD with a mass accretion rate of 3.6 × 10{sup –7} M {sub ?} yr{sup –1}. A 1 yr recurrence period is realized for very massive (? 1.3 M {sub ?}) WDs with very high accretion rates (? 1.5 × 10{sup –7} M {sub ?} yr{sup –1}). We revised our stability limit of hydrogen shell burning, which will be useful for binary evolution calculations toward Type Ia supernovae.

  19. STDP in recurrent neuronal networks

    Directory of Open Access Journals (Sweden)

    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.

  20. $\\omega$-recurrence in cocycles

    CERN Document Server

    Chaika, Jon

    2011-01-01

    After relating the notion of $\\omega$-recurrence in skew products to the range of values taken by partial ergodic sums and Lyapunov exponents, ergodic $\\mathbb{Z}$-valued cocycles over an irrational rotation are presented in detail. First, the generic situation is studied and shown to be $1/n$-recurrent. It is then shown that for any $\\omega(n) 1/2$, there are uncountably many infinite staircases (a certain specific cocycle over a rotation) which are \\textit{not} $\\omega$-recurrent, and therefore have positive Lyapunov exponent. A further section makes brief remarks regarding cocycles over interval exchange transformations of periodic type.

  1. Polyelectrolyte Multilayering in Spherical Geometry

    CERN Document Server

    Messina, R; Kremer, K; Messina, Rene; Holm, Christian; Kremer, Kurt

    2003-01-01

    The adsorption of highly \\textit{oppositely} charged flexible polyelectrolytes onto a charged spherical surface is investigated by means of Monte Carlo simulations in a fashion which resembles the layer-by-layer deposition technique introduced by Decher. Electroneutrality is insured at each step by the presence of monovalent counterions (anions and cations). We study in detail the structure of the \\textit{equilibrium} complex. Our investigations of the first few layer formations strongly suggest that multilayering in spherical geometry is not possible as an equilibrium process with purely electrostatic interactions. We especially focus on the influence of specific (non-electrostatic) short range attractive interactions (e.g., Van der Waals) on the stability of the multilayers.

  2. Metallic multilayers at the nanoscale

    Energy Technology Data Exchange (ETDEWEB)

    Jankowski, A.F.

    1994-11-01

    The development of multilayer structures has been driven by a wide range of commercial applications requiring enhanced material behaviors. Innovations in physical vapor deposition technologies, in particular magnetron sputtering, have enabled the synthesis of metallic-based structures with nanoscaled layer dimensions as small as one-to-two monolayers. Parameters used in the deposition process are paramount to the Formation of these small layer dimensions and the stability of the structure. Therefore, optimization of the desired material properties must be related to assessment of the actual microstructure. Characterization techniques as x-ray diffraction and high resolution microscopy are useful to reveal the interface and layer structure-whether ordered or disordered crystalline, amorphous, compositionally abrupt or graded, and/or lattice strained Techniques for the synthesis of metallic multilayers with subnanometric layers will be reviewed with applications based on enhancing material behaviors as reflectivity and magnetic anisotropy but with emphasis on experimental studies of mechanical properties.

  3. Anomalous magnetoresistance in Fibonacci multilayers.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Recurrent Spatial Transformer Networks

    DEFF Research Database (Denmark)

    SØnderby, SØren Kaae; SØnderby, Casper Kaae

    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 2.9% for a convolutional networks and 2.0% for convolutional networks with SPN layers. The SPN outputs a zoomed, rotated and skewed version of the input image. We investigate different down-sampling factors (ratio of pixel in input and output) for the SPN and show that the RNN-SPN model is able to down-sample the input images without deteriorating performance. The down-sampling in RNN-SPN can be thought of as adaptive down-sampling that minimizes the information loss in the regions of interest. We attribute the superior performance of the RNN-SPN to the fact that it can attend to a sequence of regions of interest.

  5. Centrality in Interconnected Multilayer Networks

    OpenAIRE

    De Domenico, Manlio; Solé-Ribalta, Albert; 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. ...

  6. Mathematical Formulation of Multilayer Networks

    Science.gov (United States)

    De Domenico, Manlio; Solé-Ribalta, Albert; Cozzo, Emanuele; Kivelä, Mikko; Moreno, Yamir; Porter, Mason A.; Gómez, Sergio; Arenas, Alex

    2013-10-01

    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 are 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 multilayer complex systems. In this paper, we introduce a tensorial framework to study multilayer networks, and we discuss the generalization of several important network descriptors and dynamical processes—including degree centrality, clustering coefficients, eigenvector centrality, modularity, von Neumann entropy, and diffusion—for this framework. We examine the impact of different choices in constructing these generalizations, and we illustrate how to obtain known results for the special cases of single-layer and multiplex networks. Our tensorial approach will be helpful for tackling pressing problems in multilayer complex systems, such as inferring who is influencing whom (and by which media) in multichannel social networks and developing routing techniques for multimodal transportation systems.

  7. Localized modes in defective multilayer structures

    OpenAIRE

    Entezar, S. Roshan; Namdar, A.

    2009-01-01

    In this paper, the localized surface modes in a defective multilayer structure has been investigated. It is shown that the defective multilayer structures can support two different kind of localized modes depending on the position and the thickness of the defect layer. One of these modes is localized at the interface between the multilayer structure and a homogeneous medium (the so-called surface mode) and the other one is localized at the defect layer (defect localized mode...

  8. Electrical conductivity of collapsed multilayer graphene tubes

    OpenAIRE

    D. Mendoza

    2011-01-01

    Synthesis of multilayer graphene on copper wires by a chemical vapor deposition method is reported. After copper etching, the multilayer tube collapses forming stripes of graphitic films, their electrical conductance as a function of temperature indicate a semiconductor-like behavior. Using the multilayer graphene stripes, a cross junction is built and owing to its electrical behavior we propose that a tunneling process exists in the device.

  9. Multilayer Analysis and Visualization of Networks

    CERN Document Server

    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.

  10. Polarizability and Screening in Chiral Multilayer Graphene

    OpenAIRE

    Min, Hongki; Hwang, E. H.; Sarma, S. Das

    2012-01-01

    We calculate the static polarizability of multilayer graphene and study the effect of stacking arrangement, carrier density, and onsite energy difference on graphene screening properties. At low densities, the energy spectrum of multilayer graphene is described by a set of chiral two-dimensional electron systems and the associated chiral nature determines the screening properties of multilayer graphene showing very different behavior depending on whether the chirality index ...

  11. Cylindrical x-ray multilayer monochromator

    International Nuclear Information System (INIS)

    This paper reports on a cylindrical grazing incidence monochromator (mirror) for 1.54 Angstrom CuK? x-rays. W/C multilayers were deposited onto thin sheets of mica and then bent into cylindrical shapes. The favorable properties of mica, including monolayer smoothness and malleability when used in very thin sheets, provide an ideal substrate material. X-Ray diffraction measurements indicate a multilayer d spacing of 1.07 nm. Such a small d spacing multilayer can be used in cylindrical optics with focal lengths of 50 cm or less. Experimental results using the cylindrical multilayer optic are compared to code predictions

  12. Recurrent ameloblastoma of the mandible

    OpenAIRE

    Joshi, C P; Vyas, K. C.; Deedwania, Seema; Jain, Sanjeev; Mangal, M. M.

    1999-01-01

    Ameloblastoma is an agressive locally recurring neoplasm of odentogenic epithelium. Here we describe a case of mandibular ameloblastoma with 12 yrs. history of local recurrences followed with history of excision twice (10 yrs. and 7 years back).

  13. Recurrence Quantification of Fractal Structures

    Directory of Open Access Journals (Sweden)

    CharlesWebber

    2012-10-01

    Full Text Available By definition, fractal structures possess recurrent patterns. At different levels repeating patterns can be visualized at higher magnifications. The purpose of this chapter is threefold. First, general characteristics of dynamical systems are addressed from a theoretical mathematical perspective. Second, qualitative and quantitative recurrence analysis is reviewed in brief, but the reader is directed to other sources for explicit details. Third, example mathematical systems that generate strange attractors are explicitly defined, giving the reader the ability to reproduce the rich dynamics of continuous chaotic flows or discrete chaotic iterations. The challenge is then posited for the reader to study for themselves the recurrent structuring of these different dynamics. With a firm appreciation of the power of recurrence analysis, the reader will be prepared to turn their sights on real world systems (physiological, psychological, mechanical, etc..

  14. Recurrent networks for wave forecasting

    Digital Repository Service at National Institute of Oceanography (India)

    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...

  15. Recurrent hemiplegia due to hypoglycaemia

    OpenAIRE

    Penman, W. A.; Johnson, J K

    1982-01-01

    A case of recurrent hemiplegia resulting from hypoglycaemia associated with a large thoracic fibrosarcoma, and the satisfactory response to removal of the tumour, is described. The possible causes of the hypoglycaemia are discussed.

  16. Primary breast lymphoma; disease recurrence

    Directory of Open Access Journals (Sweden)

    Hüseyin KADIO?LU

    2012-01-01

    Full Text Available Primary breast lymphoma (PBL accounts 0.4-0.5% of all breast cancers. The aim is to present the patient diagnosed with recurrency of primary breast lymphoma treated six year ago without radiotherapy. A 63-years-old woman patient admitted to our hospital with a palpabl mass in her left breast. Six years ago she was treated with chemoterapy after local excision for primary left breast lymphoma. Imaging modalities showed multiple lesion in breast and confirmed with biopsy. Pathologic results were similar with first one and the case was accepted as PBL recurrence. Multipl metastases has been determined with staging modalities. Patient started to chemotherapy treatment. PBL is a rare cancer of breast and there is no consensus at the treatment of disease. In the literature addition of radiotherapy to the treatment prevents local recurrence. There were occured recurrence without radiotherapy, mimicked that radiotherapy is an essential modality in PBL treatment.

  17. Recurrence for random dynamical systems

    OpenAIRE

    Marie, Philippe; Rousseau, Jerome

    2011-01-01

    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.

  18. Opioids and breast cancer recurrence

    DEFF Research Database (Denmark)

    Cronin-Fenton, Deirdre P; Heide-Jørgensen, Uffe; Ahern, Thomas P; Lash, Timothy L; Christiansen, Peer M; Ejlertsen, Bent; Sjøgren, Per; Kehlet, Henrik; Sørensen, Henrik T

    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 dat...

  19. Antigen expression on recurrent meningioma cells

    International Nuclear Information System (INIS)

    Meningiomas are intracranial brain tumours that frequently recur. Recurrence rates up to 20% in 20 years for benign meningiomas, up to 80% for atypical meningiomas and up to 100% for malignant meningiomas, have been reported. The most important prognostic factors for meningioma recurrence are meningioma grade, meningioma invasiveness and radicality of neurosurgical resection. The aim of our study was to evaluate the differences in antigenic expression on the surface of meningioma cells between recurrent and non-recurrent meningiomas. 19 recurrent meningiomas and 35 non-recurrent meningiomas were compared regarding the expression of MIB-1 antigen, progesterone receptors, cathepsin B and cathepsin L, using immunohistochemistry. MIB-1 antigen expression was higher in the recurrent meningioma group (p=0.001). No difference in progesterone receptor status between recurrent and non-recurrent meningiomas was confirmed. Immunohistochemical intensity scores for cathepsin B (p= 0.007) and cathepsin L (p<0.001) were both higher in the recurrent than in the non-recurrent meningioma group. MIB-1 antigen expression is higher in recurrent compared to non-recurrent meningiomas. There is no difference in expression of progesterone receptors between recurrent and non-recurrent meningiomas. Cathepsins B and L are expressed more in recurrent meningiomas

  20. On uniform recurrence of a direct product

    OpenAIRE

    Salimov, Pavel Vadimovich

    2010-01-01

    The direct product of two words is a naturally defined word on the alphabet of pairs of symbols. An infinite word is uniformly recurrent if each its subword occurs in it with bounded gaps. An infinite word is strongly recurrent if the direct product of it with each uniformly recurrent word is also uniformly recurrent. We prove that fixed points of the expanding binary symmetric morphisms are strongly recurrent. In particular, such is the Thue-Morse word.

  1. Multi-Layer E-Textile Circuits

    Science.gov (United States)

    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.

  2. Multilayer Graphene for Waveguide Terahertz Modulator

    DEFF Research Database (Denmark)

    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.

  3. Cold neutron interferometry using multilayer mirrors

    International Nuclear Information System (INIS)

    Cold neutron interferometry using multilayer mirrors are discussed. The interferometry includes two kinds of multilayer interferometers, which are analogous optically to the Mach-Zehnder and the Jamin interferometer in classical optics. The Mach-Zehnder multilayer interferometer has been installed at JRR3M reactor of JAERI. We describe the conditions required for the Mach-Zehnder multilayer interferometer and the characteristics of the interferometer. The Jamin multilayer interferometer, called as phase echo interferometer, shows a phase echo effect analogous functionally to the spin echo principle. We describe briefly the first successful performance tests. We propose a precession phase echo interferometer and a phase echo spin interferometer, based on the coherent superposition of spin eigenstates and the phase echo effect. (author)

  4. RECURRENT NOVAE IN M31

    Energy Technology Data Exchange (ETDEWEB)

    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 Ond?ejov (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.

  5. Recurrence in coined quantum walks

    International Nuclear Information System (INIS)

    Recurrence of quantum walks on lattices can be characterized by the generalized Polya number. Its value reflects the difference between a classical and a quantum system. The dimension of the lattice is not a unique parameter in the quantum case; both the coin operator and the initial quantum state of the coin influence the recurrence in a nontrivial way. In addition, the definition of the Polya number involves measurement of the system. Depending on how measurement is included in the definition, the recurrence properties vary. We show that in the limiting case of frequent, strong measurements, one can approach the classical dynamics. Comparing various cases, we have found numerical indication that our previous definition of the Polya number provides an upper limit.

  6. Recurrence in coined quantum walks

    Energy Technology Data Exchange (ETDEWEB)

    Kiss, T; Kecskes, L [Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, Konkoly-Thege M. u. 29-33, H-1121 Budapest (Hungary); Stefanak, M; Jex, I [Department of Physics, FJFI CVUT v Praze, Brehova 7, 115 19 Praha 1-Stare Mesto (Czech Republic)], E-mail: tkiss@szfki.hu

    2009-07-15

    Recurrence of quantum walks on lattices can be characterized by the generalized Polya number. Its value reflects the difference between a classical and a quantum system. The dimension of the lattice is not a unique parameter in the quantum case; both the coin operator and the initial quantum state of the coin influence the recurrence in a nontrivial way. In addition, the definition of the Polya number involves measurement of the system. Depending on how measurement is included in the definition, the recurrence properties vary. We show that in the limiting case of frequent, strong measurements, one can approach the classical dynamics. Comparing various cases, we have found numerical indication that our previous definition of the Polya number provides an upper limit.

  7. Recent advances in etched multilayer X-ray optics

    OpenAIRE

    André, J.; Sammar, A.; Bac, S.; Ouahabi, M.; Idir, M.; Soullié, G.; Barchewitz, R.

    1994-01-01

    We present the recent advances achieved in the Laboratoire de Chimie Physique of Université Paris 6, in the field of the soft X-ray etched multilayer optics. Modellings and characterizations are given for the laminar multilayer amplitude gratings, the highly resolutive X-ray multilayer monochromators, the X-ray polychromators and the Bragg-Fresnel multilayer linear lenses.?

  8. Interpretation of Recurrent Neural Networks

    OpenAIRE

    Pedersen, Morten With; Larsen, Jan

    2006-01-01

    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 numerical experiments on time series prediction problems are used to illustrate the potential of the suggested methods

  9. Nature of the recurrent novae

    International Nuclear Information System (INIS)

    The basic properties of individual recurrent nova systems are reviewed, and the mechanisms of their outbursts are studied. Some general properties associated with accretion events and thermonuclear runaway models are briefly examined, and detailed models for the recurrent novae T CrB, RS Oph, T Pyx, U Sco, and V1017 Sgr and the possible recurrent novae WZ Sge, V616 Mon, VY Aqr, RZ Leo, V1195 Oph, and V529 Ori are discussed. The results suggest that the outbursts of U Sco and T Pyx are caused by thermonuclear runaways on the surface of massive white dwarfs, while the outbursts of T CrB and RS Oph are very probably accretion events, initiated by a burst of mass transferred from a giant companion onto a main sequence star. V1017 Sgr fails the model criteria for a recurrent nova, being more properly considered a symbiotic star. V1195 Oph, RZ Leo, VY Aqr, and WZ Sge are assigned to the class of dwarf novae. No evidence is found that V529 Ori has recurred. 228 references

  10. Interpretation of Recurrent Neural Networks

    DEFF Research Database (Denmark)

    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 numerical experiments on time series prediction problems are used to illustrate the potential of the suggested methods

  11. Recurrence Formulas for Fibonacci Sums

    OpenAIRE

    Brandao, Adilson J. V.; Martins, Joao L.

    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

  12. Ovarian irradiation in recurrent endometriosis

    International Nuclear Information System (INIS)

    We describe a case of a young woman with a history of an aplastic anaemia in which pelvic radiotherapy was used successfully in the management of a recurrent and inoperable endometriosis. The use of therapeutic pelvic or ovarian irradiation in endometriosis may be considered, when surgical and medical treatments have been exhausted and have failed. (authors)

  13. Tunable optical properties of multilayers black phosphorus

    CERN Document Server

    Low, Tony; Carvalho, A; Jiang, Yongjin; Wang, Han; Xia, Fengnian; Neto, A H Castro

    2014-01-01

    We calculated the optical conductivity tensor of multilayers black phosphorus using the Kubo formula within an effective low-energy Hamiltonian. The optical absorption spectra of multilayers black phosphorus are shown to vary sensitively with thickness, doping, and light polarization. In conjunction with experimental spectra obtained from infrared absorption spectroscopy, we discuss the role of interband coupling and disorder on the observed anisotropic absorption spectra. Multilayers black phosphorus might offer attractive alternatives to narrow gap compound semiconductors for optoelectronics across mid- to near-infrared frequencies.

  14. Vibrational properties of acoustic metamaterial multilayers

    Science.gov (United States)

    Terao, Takamichi; Ohnishi, Yoshikazu

    2015-04-01

    The vibrational properties of acoustic metamaterial multilayers, which are made of a periodic arrangement of clusters of mass and mass-in-mass microstructure, were numerically studied. The dispersion relations of one-dimensional multilayers and two-dimensional periodic structures with square lattices were clarified. It was confirmed that flat modes appear in a sonic band gap, and that the number of such in-gap modes can be controlled by changing the structure of a multilayer. The physical origin of the flat modes is also discussed.

  15. Fifth International Symposium on Recurrence Plot

    CERN Document Server

    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...

  16. Irreversible nucleation in multilayer growth

    CERN Document Server

    Politi, P; Politi, Paolo; Castellano, Claudio

    2001-01-01

    The epitaxial growth process of a high symmetry surface occurs because adatoms meet and nucleate new islands, that eventually coalesce and complete atomic layers. During multilayer growth, nucleation usually takes place on top of terraces where the geometry of the diffusion process is well defined: We have studied in detail the spatiotemporal distribution of nucleation events and the resulting nucleation rate, a quantity of primary importance to model experimental results and evaluate diffusion barriers at step-edges. We provide rigorous results for irreversible nucleation and we assess the limits of mean-field theory (MFT): we show that MFT overestimates the correct result by a factor proportional to the number of times an adatom diffusing on the terrace visits an already visited lattice site. In this report we aim at giving a simple physical account of our results.

  17. Magnetic quantization in multilayer graphenes

    CERN Document Server

    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...

  18. Centrality in Interconnected Multilayer Networks

    CERN Document Server

    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...

  19. Lymphatic Vessel Memory Stimulated by Recurrent Inflammation

    OpenAIRE

    Kelley, Philip M.; Connor, Alicia L.; Tempero, Richard M.

    2013-01-01

    Inflammation stimulates new lymphatic vessel growth (inflammatory lymphangiogenesis). One key question is how recurrent inflammation, a common clinical condition, regulates lymphatic vessel remodeling. We show here that recurrent inflammation accelerated the development a functional lymphatic vessel network. This observation suggests a novel program of lymphangiogenesis and identifies a property of lymphatic vessel memory in response to recurrent inflammation. A brief episode of initial infla...

  20. Langmuir Blodgett multilayers and related nanostructures

    Indian Academy of Sciences (India)

    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 Cd$_{x}$Zn$_{1?x}$S alloys within the organic multilayer matrix, using arachidate LB multilayers as precursors is also discussed.

  1. Irradiated multilayer film for primal meat packaging

    International Nuclear Information System (INIS)

    This patent deals with a heat-shrinkable, multilayer film suitable for use in fabricating bags for packaging primal and sub-primal meat cuts and processed meats. The multilayer film has a first outer layer of an ethylene-vinyl acetate copolymer, a core layer of a barrier film comprising vinylidene chloride-methyl acrylate copolymer, and a second outer layer of an ethylene-vinyl acetate copolymer. The multilayer film is preferably made by co-extrusion of the layers, and then it is biaxially stretched. After biaxial stretching, the multilayer film is irradiated to a dosage level of between 1 megarad and 5 megarads and heat-sealed in the form of a bag. The bag has improved storage stability characteristics

  2. Soft X-ray multilayers and filters

    CERN Document Server

    Wang Zhan Shan; Tang Wei Xing; Qin Shuji; Zhou Bing; Chen Ling Ya

    2002-01-01

    The periodic and non-periodic multilayers were designed by using a random number to change each layer and a suitable merit function. Ion beam sputtering and magnetron sputtering were used to fabricate various multilayers and beam splitters in soft X-ray range. The characterization of multilayers by small angle X-ray diffraction, Auger electron spectroscopy, Rutherford back scattering spectroscopy and reflectivity illustrated the multilayers had good structures and smooth interlayers. The reflectivity and transmission of a beam splitter is about 5%. The fabrication and transmission properties of Ag, Zr were studied. The Rutherford back scattering spectroscopy and auger electron spectroscopy were used to investigate the contents and distributions of impurities and influence on qualities of filters. The attenuation coefficients were corrected by the data obtained by measurements

  3. Stress Reduction in Improving Quality of Life in Patients With Recurrent Gynecologic or Breast Cancer

    Science.gov (United States)

    2015-10-08

    Anxiety Disorder; Depression; Fatigue; Leydig Cell Tumor; Ovarian Sarcoma; Ovarian Stromal Cancer; Pain; Peritoneal Carcinomatosis; Pseudomyxoma Peritonei; Recurrent Breast Cancer; Recurrent Cervical Cancer; Recurrent Endometrial Carcinoma; Recurrent Fallopian Tube Cancer; Recurrent Gestational Trophoblastic Tumor; Recurrent Ovarian Epithelial Cancer; Recurrent Ovarian Germ Cell Tumor; Recurrent Primary Peritoneal Cavity Cancer; Recurrent Uterine Sarcoma; Recurrent Vaginal Cancer; Recurrent Vulvar Cancer

  4. Obatoclax and Bortezomib in Treating Patients With Aggressive Relapsed or Recurrent Non-Hodgkin Lymphoma

    Science.gov (United States)

    2013-05-01

    Adult Non-Hodgkin Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma

  5. Atomic mechanisms of interdiffusion in metallic multilayers

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Laterally graded multilayer double-monochromator

    International Nuclear Information System (INIS)

    The authors describe a tunable multilayer monochromator with an adjustable bandpass to be used for reflectivity and grazing incidence diffraction studies on surfaces at energies near 10 keV. Multilayers have a bandpass typically 100 times larger than the Si(111) reflection, and by using multilayers an experimenter can significantly increase data collection rates over those available with a Si monochromator. The transmission through 1 and 2 laterally graded multilayer (LGML) reflections was recorded versus photon energy. The identical LGMLs were comprised of 60 bilayers of W and C on 100 x 25 x 3 mm float glass with a bilayer spacing varying from 35 to 60 angstrom. The average gradient was 0.27 angstrom/mm along the long dimension. The rms deviation of the data for the bilayer spacing from a linear fit was 0.36 angstrom. Data were obtained for a nondispersive (±) double-multilayer arrangement. The relative bandpass width (FWHM) when the two multilayers exposed the same bilayer spacing was measured to be 2.2% with a transmission of 78.7 ± 1.6%. This value is consistent with the transmission of 88.9% that they also measured for a single LGML at HASYLAB beamline D4. The bandpass was tunable in the range 1.1% to 2.2%

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Recurrent gossypiboma in the thigh

    Energy Technology Data Exchange (ETDEWEB)

    Puri, Ajay; Anchan, Chetan; Agarwal, Manish G. [Tata Memorial Hospital, Department of Orthopaedic Oncology, Mumbai (India); Jambhekar, Nirmala A. [Tata Memorial Hospital, Department of Pathology, Mumbai (India); Badwe, Rajendra A. [Tata Memorial Hospital, Department of Surgical Oncology, Mumbai (India)

    2007-06-15

    Gossypiboma, an iatrogenic mass lesion caused by a retained surgical sponge is an extremely rare event following musculoskeletal procedures. This entity is therefore a very unusual experience and can create considerable confusion. Unsuspecting surgeons may thus be caught out by this unlikely presentation. We present our experience with a recurrent gossypiboma in the thigh occurring several years after surgical evacuation of a similar gossypiboma from the same anatomic location with interval resolution of symptoms. The purpose of this case report is to highlight the possibility of a ''recurrent'' soft tissue mass occurring for reasons other than a neoplasm. In the absence of a definitive biopsy diagnosis of tumor in patients who have undergone prior surgical procedures in that area, it may be more prudent to adopt a conservative surgical resection rather than a conventional radical resection as warranted by the dramatic clinical presentation mimicking a soft tissue sarcoma. (orig.)

  9. Recurrent Atypical Fibroxanthoma Versus Malignant Fibrous Histiocytoma.

    Science.gov (United States)

    Branch, Leslie G; Albertini, John G; Leshin, Barry

    2015-06-01

    Atypical fibroxanthoma (AFX) has been characterized variously as a benign noninvasive neoplasm with rare recurrence. We report 2 cases of recurrent AFX. There is ongoing controversy over the diagnosis of AFX versus malignant fibrous histiocytoma (MFH) in the clinical context of recurrent AFX. Histopathologic diagnosis of fibrohistiocytic neoplasms can be quite challenging and small foci of cancer can be easily overlooked. This is particularly problematic when scarring associated with recurrent tumors is present. The utility of en face sections, as utilized in Mohs micrographical surgery, and the employment of immunohistochemical stains may be helpful in diagnosis. Recurrence of AFX can occur but is difficult to distinguish from MFH. PMID:26080249

  10. Recurrence In Turbulent Dynamical Systems.

    Czech Academy of Sciences Publication Activity Database

    Uruba, Václav

    Prague : Institute of Thermomechanics AS CR, v. v. i., 2011 - (P?íhoda, J.; Kozel, K.), s. 129-132 ISBN 978-80-87012-32-1. [Topical Problems of Fluid Mechanics 2011. Praha (CZ), 16.02.2011-17.02.2011] R&D Projects: GA ?R GA101/08/1112; GA ?R GAP101/10/1230 Institutional research plan: CEZ:AV0Z20760514 Keywords : turbulence * recurrence * dynamical systems Subject RIV: BK - Fluid Dynamics

  11. Spatiotemporal recurrences of sandpile avalanches

    Science.gov (United States)

    Tarun, Anjali B.; Paguirigan, Antonino A.; Batac, Rene C.

    2015-10-01

    We study the space and time properties of avalanches in a continuous sandpile model by constructing a temporally directed network linking together the recurrent avalanche events based on their spatial separation. We use two different criteria for network construction: a later event is connected to a previous one if it is either nearest or farthest from it among all the later events. With this, we observe scale-free regimes emerge as characterized by the following power-law exponents: (a) ? = 1.7 for the avalanche size distributions; (b) ?F = 2.1 in the in-degree distribution of farthest recurrences; (c) ? = 1 for the separation distances; and (d) ? = 1 for the temporal separations of recurrences. Our results agree with earlier observations that describe the sandpile avalanches as repulsive events, i.e. the next avalanche is more likely to be physically separated from an earlier one. These observations, which are not captured by usual interoccurrence statistics and by random connection mechanisms, suggest an underlying spatiotemporal organization in the sandpile that makes it useful for modeling real-world systems.

  12. Interference in multilayer relativistic mirrors

    Science.gov (United States)

    Mirzanejhad, Saeed; Sohbatzadeh, Farshad; Babaei, Javad; Taghipour, Meisam; Mohammadzadeh, Zahra

    2015-10-01

    In this paper, reflection coefficient of a relativistic ultra-thin electron multilayer is calculated using electromagnetic interference procedures. The relativistic electron layers are assumed to be formed by nonlinear plasma wake waves that constitute the electron density cusps. It is shown that the interference between successive relativistic mirrors is restricted by the condition, ? p ? ( 2 ? 0 ) 5 / 2 / ? p 0 , where ?p is the laser pulse duration. The results showed that tailoring the pulse amplitude, incident wave frequency value, incidence angle, and plasma density leads to increasing reflection coefficient a few orders of magnitudes. This constructive interference condition can be used for increasing conversion efficiency in the reflected energy from relativistic mirrors for the purpose of generating ultra-short coherence pulses in the extreme ultraviolet and x-ray regions. We also performed reflection from relativistic thin electron layers using relativistic 1D3V electromagnetic particle-in-cell (PIC) simulation. It was found that the results of PIC simulation are in agreement with analytical considerations.

  13. Multi-layered Social Networks

    CERN Document Server

    Bródka, Piotr

    2012-01-01

    It is quite obvious that in the real world, more than one kind of relationship can exist between two actors and that those ties can be so intertwined that it is impossible to analyse them separately [Fienberg 85], [Minor 83], [Szell 10]. Social networks with more than one type of relation are not a completely new concept [Wasserman 94] but they were analysed mainly at the small scale, e.g. in [McPherson 01], [Padgett 93], and [Entwisle 07]. Just like in the case of regular single-layered social network there is no widely accepted definition or even common name. At the beginning such networks have been called multiplex network [Haythornthwaite 99], [Monge 03]. The term is derived from communications theory which defines multiplex as combining multiple signals into one in such way that it is possible to separate them if needed [Hamill 06]. Recently, the area of multi-layered social network has started attracting more and more attention in research conducted within different domains [Kazienko 11a], [Szell 10], [...

  14. Multilayer heterostructures and their manufacture

    Energy Technology Data Exchange (ETDEWEB)

    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

  15. CT manifestations of recurrent thyroid carcinoma

    International Nuclear Information System (INIS)

    Objective: To study the CT manifestations of recurrent thyroid carcinoma, in order to recognize the characteristics of recurrent thyroid carcinoma. Methods: 42 cases of recurrent thyroid carcinoma proved by surgery and pathology were reviewed, including papillary carcinoma (n = 25), follicular carcinoma (n = 9), medullary carcinoma (n = 6) and clear cell carcinoma (n=2). Results: Local recurrence in thyroid bed was found in 23 cases. Invasion of carotid artery (n = 2), trachea and esophagus (n = 17), larynx and hypopharynx (n = 2) was revealed by CT. In 9 cases of follicular carcinoma 8 had local thyroid bed recurrence. All of the 7 cases with contrast administration had enhancement of tumor mass. Recurrence of contralateral lobe was seen in 12 cases, the pathologic types were the same as the primary carcinoma. Cervical lymph node metastases were proved in 31 cases, being the major manifestation of papillary carcinoma (76%). Mediastinal lymph node metastases were found in 7 cases. 75% of patients had more than one type of recurrences. Conclusion: The majority of recurrent thyroid carcinoma were found in cervical lymph node and thyroid bed. Thyroid bed recurrence was most commonly seen in follicular carcinoma while cervical lymph node metastasis were frequent in papillary carcinoma. The adjacent organs or structures was of ten invaded by local recurrent tumor

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

    Science.gov (United States)

    2015-02-19

    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

  17. Sperm DNA fragmentation, recurrent implantation failure and recurrent miscarriage

    Directory of Open Access Journals (Sweden)

    Carol Coughlan

    2015-01-01

    Full Text Available Evidence is increasing that the integrity of sperm DNA may also be related to implantation failure and recurrent miscarriage (RM. To investigate this, the sperm DNA fragmentation in partners of 35 women with recurrent implantation failure (RIF following in vitro fertilization, 16 women diagnosed with RM and seven recent fathers (control were examined. Sperm were examined pre- and post-density centrifugation by the sperm chromatin dispersion (SCD test and the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL assay. There were no significant differences in the age of either partner or sperm concentration, motility or morphology between three groups. Moreover, there were no obvious differences in sperm DNA fragmentation measured by either test. However, whilst on average sperm DNA fragmentation in all groups was statistically lower in prepared sperm when measured by the SCD test, this was not seen with the results from the TUNEL assay. These results do not support the hypothesis that sperm DNA fragmentation is an important cause of RIF or RM, or that sperm DNA integrity testing has value in such patients. It also highlights significant differences between test methodologies and sperm preparation methods in interpreting the data from sperm DNA fragmentation tests.

  18. Recurrent seizures after lidocaine ingestion

    OpenAIRE

    Aminiahidashti, Hamed; Laali, Abolghasem; Nosrati, Nazanin; Jahani, Fatemeh

    2015-01-01

    Lidocaine has a concentration-dependent effect on seizures. Concentrations above 15 ?g/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...

  19. Magnetic damping in magnetic multilayers

    International Nuclear Information System (INIS)

    Full text: Magnetic multilayers provide a special case where dynamic interactions between the itinerant electrons and the magnetic moments in ultrathin films offer new possibilities compared to bulk materials. The precessing magnetization acts as a peristaltic spin pump, which transports the spin momentum away from the ferromagnet (F). In contrast to the well-known oscillatory exchange interaction in the ground state, this coupling is dynamical in nature and long ranged. In magnetic bilayers F/N/F, the transverse component of the spin current in non-magnetic spacer, N, is entirely absorbed at the N/F interface. This means that the N/F interface acts as an ideal spin sink providing an effective spin brake for the opposite ferromagnetic layer F, which results in an additional magnetic interface damping that obeys the Gilbert phenomenology. Experimental studies have been carried out using crystalline Au/Fe/Au/Fe/GaAs(001), Pd/Fe/GaAs(001), and Au/Fe/Au/Pd/Fe/GaAs(001) multilayers. The quantitative comparison with spin pumping theory is very good for Fe/Au/Fe structures. First principles electron band calculations of the spin mixing conductance ??? result in Gilbert damping, which is in a nearly perfect agreement with the measured non-local, interface damping. The spin transport across Pd spacers is different compared to that in Au spacers. The spin current is strongly attenuated by interaction with fluctuating moment in Pd. The propagation of the spin current becomes more complex in heterogeneous Pd/Au spacers. It will be shown that the propagation of the spin current in Pd/Au (001) spacers is affected by a partial reflection of spin current at the Pd/Au interface. The Pd lattice has a large lattice mismatch with respect to Fe. For the Pd layers thicker than 5ML the lattice strain is partially released by a rectangular network of misfit dislocations. It will be shown that the formation of a self-assembled nano network of misfit dislocations leads to a strong extrinsic magnetic damping. The out of plane measurements of the FMR linewidth have revealed that the extrinsic damping is caused by two magnon scattering. This system provides an ideal opportunity to investigate the role of two magnon scattering in a wide range of microwave frequencies. FMR measurements were carried out from 4 GHz to 73 GHz. The contribution to the FMR linewidth from two magnon scattering is strongly anisotropic and follows the rectangular symmetry of the glide planes of the misfit dislocation network. The angular dependence of the FMR linewidth is a consequence of an effective channeling of the scattered spinwaves. The extrinsic damping often results in FMR linewidth above 10GHz that increases linearly with microwave frequency but is accompanied by a zero frequency offset. Two magnon scattering in Pd/Fe systems is no exception. It will be shown that this behavior is not followed in the lower range of microwave frequencies. The FMR linewidth eventually shows a rapid decrease towards zero, resulting in a large effective Gilbert damping which can surpass the intrinsic contribution to Gilbert damping by two orders of magnitude. Corresponding Author: B. Heinrich, bheinrich at sfu.ca, 1 604 2914402

  20. Maximum screening fields of superconducting multilayer structures

    Science.gov (United States)

    Gurevich, Alex

    2015-01-01

    It is shown that a multilayer comprised of alternating thin superconducting and insulating layers on a thick substrate can fully screen the applied magnetic field exceeding the superheating fields Hs of both the superconducting layers and the substrate, the maximum Meissner field is achieved at an optimum multilayer thickness. For instance, a dirty layer of thickness ˜0.1 ?m at the Nb surface could increase Hs ? 240 mT of a clean Nb up to Hs ? 290 mT. Optimized multilayers of Nb3Sn, NbN, some of the iron pnictides, or alloyed Nb deposited onto the surface of the Nb resonator cavities could potentially double the rf breakdown field, pushing the peak accelerating electric fields above 100 MV/m while protecting the cavity from dendritic thermomagnetic avalanches caused by local penetration of vortices.

  1. Maximum screening fields of superconducting multilayer structures

    Directory of Open Access Journals (Sweden)

    Alex Gurevich

    2015-01-01

    Full Text Available It is shown that a multilayer comprised of alternating thin superconducting and insulating layers on a thick substrate can fully screen the applied magnetic field exceeding the superheating fields Hs of both the superconducting layers and the substrate, the maximum Meissner field is achieved at an optimum multilayer thickness. For instance, a dirty layer of thickness ?0.1??m at the Nb surface could increase Hs ? 240 mT of a clean Nb up to Hs ? 290 mT. Optimized multilayers of Nb3Sn, NbN, some of the iron pnictides, or alloyed Nb deposited onto the surface of the Nb resonator cavities could potentially double the rf breakdown field, pushing the peak accelerating electric fields above 100 MV/m while protecting the cavity from dendritic thermomagnetic avalanches caused by local penetration of vortices.

  2. Evolutionary games on multilayer networks: A colloquium

    CERN Document Server

    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...

  3. Multilayer Integrated Film Bulk Acoustic Resonators

    CERN Document Server

    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.

  4. Multilayer neural networks a generalized net perspective

    CERN Document Server

    Krawczak, Maciej

    2013-01-01

    The primary purpose of this book is to show that a multilayer neural network can be considered as a multistage system, and then that the learning of this class of neural networks can be treated as a special sort of the optimal control problem. In this way, the optimal control problem methodology, like dynamic programming, with modifications, can yield a new class of learning algorithms for multilayer neural networks. Another purpose of this book is to show that the generalized net theory can be successfully used as a new description of multilayer neural networks. Several generalized net descriptions of neural networks functioning processes are considered, namely: the simulation process of networks, a system of neural networks and the learning algorithms developed in this book. The generalized net approach to modelling of real systems may be used successfully for the description of a variety of technological and intellectual problems, it can be used not only for representing the parallel functioning of homogen...

  5. Monolayers and Langmuir-Blodgett multilayers of discotic liquid crystals?

    OpenAIRE

    Laschewsky, André

    1989-01-01

    Contents: 1. Discotic Liquid Crystals 2. Monolayers and Langmuir-Blodgett Multilayers 3. Theoretical Considerations on the Molecular Packing of Discotic LCs in Monolayers and Multilayers 4. Spreading Experiments with Discotic LCs 5. LB-Multilayers of Discotic LCs 6. Polymeric Discotic LCs 7. Summary

  6. Calculation of nuclear resonant scattering spectra of magnetic multilayers

    International Nuclear Information System (INIS)

    Calculations of the angle- and time-dependent photon reflectivity of multilayers are presented, using the technique of characteristic matrices. Spectra of 56Fe/57Fe and Cr/57Fe multilayers are calculated under various conditions. The parameters of the multilayers are optimized for suitable test samples of reflectometry measurements. (author) 10 refs.; 6 figs

  7. Chemoradiotherapy response in recurrent rectal cancer

    OpenAIRE

    Yu, Stanley K T; Bhangu, Aneel; Tait, Diana M; Tekkis, Paris; Wotherspoon, Andrew; Brown, Gina

    2013-01-01

    The efficacy of response to preoperative chemoradiotherapy (CRT) in recurrent versus primary rectal cancer has not been investigated. We compared radiological downsizing between primary and recurrent rectal cancers following CRT and determined the optimal size reduction threshold for response validated by survival outcomes. The proportional change in tumor length for primary and recurrent rectal cancers following CRT was compared using the independent sample t-test. Overall survival (OS) was ...

  8. Is acute recurrent pancreatitis a chronic disease?

    OpenAIRE

    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...

  9. Recurrent Stroke: What Have We Learnt?

    OpenAIRE

    EM Khoo; Rabia K

    2007-01-01

    Stroke is the third leading cause of death, a major cause of disability in adults, and is frequently more disabling than fatal. With a decline in mortality from initial cerebral infarction and an increase in the life expectancy of the population, the number of patients with recurrent stroke and ensuing cardiovascular events will become greater. Thus it is important to find out those patients at high risk of stroke recurrence. This case report illustrates the process of recurrent stroke and th...

  10. Intravenous immunoglobulin treatment for secondary recurrent miscarriage

    DEFF Research Database (Denmark)

    Christiansen, Ole Bjarne; Larsen, Elisabeth Clare; Egerup, P; Lunøe, Anne Louise; Egestad, Lisbeth; Nielsen, Henriette Svarre

    2015-01-01

    OBJECTIVE: To determine whether infusions with intravenous immunoglobulin (IVIg) during early pregnancy increase live birth rate in women with secondary recurrent miscarriage compared with placebo. DESIGN: A single-centre, randomised, double-blind, placebo-controlled trial. SETTING: A tertiary centre for recurrent miscarriage in Copenhagen, Denmark. POPULATION: A group of 82 women with unexplained secondary recurrent miscarriage and at least four miscarriages. METHODS: Women were randomly assign...

  11. Recurrence quantification analysis of chimera states

    Science.gov (United 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.

  12. On a family of linear recurrences

    International Nuclear Information System (INIS)

    We concern ourselves with the family of linear recurrence relations aj = aj?1+aj?d with the initial conditions a0 = . . . = ad?1 = 1. We discuss the periodicity evaluation of such recurrences for prime powers d, and demonstrate that a key feature of our evaluation method relates to an instance of Shor's algorithm for factoring. As an application, we discuss how efficient quantum circuit designs may be completely recast as a problem relating to linear recurrence relations.

  13. Morphic Words and Nested Recurrence Relations

    OpenAIRE

    Celaya, Marcel; Ruskey, Frank

    2013-01-01

    We explore a family of nested recurrence relations with arbitrary levels of nesting, which have an interpretation in terms of fixed points of morphisms over a countably infinite alphabet. Recurrences in this family are related to a number of well-known sequences, including Hofstadter's G sequence and the Conolly and Tanny sequences. For a recurrence a(n) in this family with only finitely terms, we provide necessary and sufficient conditions for the limit a(n)/n to exist.

  14. Clinical pattern of recurrent herpes simplex keratitis

    OpenAIRE

    Saini Jagjit; Agarwala Ritu

    1999-01-01

    Purpose: To document the clinical pattern in recurrent herpes simplex disease. Methods: Eyes with clinically documented pattern of corneal manifestation on more than one occasion were analysed. For each eye recruited, the clinical pattern of the disease at each recurrence of herpes simplex corneal disease, age, disease-free intervals, triggering factors, laterality and steroid abuse were noted and evaluated. Results: For an average follow up of 6.9 years, a recurrence rate of 0.6 episodes per...

  15. Statin use and venous thromboembolism recurrence

    DEFF Research Database (Denmark)

    Schmidt, M; Cannegieter, S C; Johannesdottir, S A; Dekkers, O M; Horváth-Puhó, E; Sørensen, H T

    2014-01-01

    BACKGROUND: Data on statins' effect on venous thromboembolism (VTE) recurrence are conflicting. OBJECTIVES: We examined whether statin use was associated with reduced risk of recurrent VTE in a nationwide population-based setting. PATIENTS/METHODS: Using the Danish National Patient Registry, we identified first-time and recurrent VTEs between 1 July 2004 and 31 December 2012 (n = 27,862). VTE diagnoses were validated by medical record review of a subsample of patients. We ascertained nationwide ...

  16. Recurrent intramedullary epidermoid cyst of conus medullaris

    OpenAIRE

    Fleming, Christina; Kaliaperumal, Chandrasekaran; O’Sullivan, Michael

    2011-01-01

    Spinal intramedullary epidermoid cyst is a rare condition. Recurrent epidermoid cyst in the spine cord is known to occur. The authors describe a case of recurrent conus medullaris epidermoid cyst in a 24-year-old female. She initially presented at 7 years of age with bladder disturbance in the form of diurnal enuresis and recurrent urinary tract infection. MRI lumbar spine revealed a 4 cm conus medullaris epidermoid cyst. Since the initial presentation, the cyst had recurred seven times in th...

  17. Multilayer filter design with high K materials

    Science.gov (United States)

    Curtis, Nathaniel, II

    A novel approach to filter design is presented. A high-K multilayer coupled line filter is designed for optimal performance within a dielectric resonator of rectangular cross section. The multilayer filter is shown to have a performance comparable to its planar counterpart as well as the Lange coupler while maintaining the design advantages that come with the multilayer approach to filter design such as increased flexibility in managing parameter constraints. The performance of the rectangular cross sectioned resonator in terms of modal response and resonant frequency has been evaluated through mathematical derivation and simulation. The reader will find the step by step process to designing the resonant structure as well as a MATLAB script that will graphically display the effect changing various parameters may have on resonator size to assist in the design analysis. The resonator has been designed to provide a finite package in terms of space and performance so that it may house the multilayer filter on a printed circuit board for ease of system implementation. The proposed design with analysis will prove useful for all multilayer coupled line filter types that may take advantage of the uniform environment provided by the finite packaging of the dielectric resonator. As with any microwave system, considerable effort must be put forth to maintain signal integrity throughout the delivery process from the signal input to reception at the output. As a result a large amount of effort and research has gone into answering the question of how to efficiently feed both a dielectric resonator filter of rectangular cross section as well as a coupled line filter that would be embedded within the resonators confines. Several methods for feeding have been explored and reported on. Of the feeding methods reported on the most feasible design includes a unique microstrip delivery to the embedded multilayer filter as pictured here.* *Please refer to dissertation for diagram.

  18. Recurrence and Relapse in Bipolar Mood Disorder

    Directory of Open Access Journals (Sweden)

    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.

  19. Physical and chemical characterization of multilayered structures

    International Nuclear Information System (INIS)

    It is important to know the physical and chemical properties of a multilayer if its performance is to be compared to theoretical predictions, or if guidance is needed for the production of superior multilayers. Accurate, nondestructive analytical methods, such as neutron activation analysis, are restricted to certain elements. Certain destructive methods, such as total carbon analysis by combustion, can be sensitive enough for use with very small samples. The method of choice depends upon sensitivity and specificity, both of which are discussed in this paper. 6 refs., 3 figs., 2 tabs

  20. Exchange interactions in Fe/Y multilayers

    International Nuclear Information System (INIS)

    The magnetization of Fe/Y multilayers has been measured as a function of temperature. A bulk-like T 3/2 temperature dependence of the magnetization is observed for all multilayers in the temperature range 5-300 K. The spin-wave constant B is found to decrease inversely with t Fe. A simple theoretical model with exchange interactions only, and with non-interacting magnons, has been used to explain the temperature dependence of the magnetization and the approximate values for the bulk exchange interaction J b, surface exchange interaction J s and the interlayer exchange interaction J I for various Fe layer thicknesses have been obtained

  1. Reverse engineering of multi-layer films

    Directory of Open Access Journals (Sweden)

    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.

  2. Preparation of multi-layer laser targets

    International Nuclear Information System (INIS)

    The author describes the preparation of copper- or gold-Formvar-aluminum-Formvar multi-layer laser targets. First, copper or gold is deposited on a piece of glass, then it is covered with the Formvar film. After the copper or gold layer, together with the Formvar film, is stripped off and fitted in, aluminum is deposited. Because the Formvar is vaporized in the vaporizing chamber only once, the obtained multi-layer target is of high quality and meets the requirements for practical use

  3. Chemoradiotherapy response in recurrent rectal cancer

    International Nuclear Information System (INIS)

    The efficacy of response to preoperative chemoradiotherapy (CRT) in recurrent versus primary rectal cancer has not been investigated. We compared radiological downsizing between primary and recurrent rectal cancers following CRT and determined the optimal size reduction threshold for response validated by survival outcomes. The proportional change in tumor length for primary and recurrent rectal cancers following CRT was compared using the independent sample t-test. Overall survival (OS) was calculated using the Kaplan–Meier product limit method and differences between survival for tumor size reduction thresholds of 30% (response evaluation criteria in solid tumors [RECIST]), 40%, and 50% after CRT in primary and recurrent rectal cancer groups. A total of 385 patients undergoing CRT were analyzed, 99 with recurrent rectal cancer and 286 with primary rectal cancer. The mean proportional reduction in maximum craniocaudal length was significantly higher for primary rectal tumors (33%) compared with recurrent rectal cancer (11%) (P < 0.01). There was no difference in OS for either primary or recurrent rectal cancer when ?30% or ?40% definitions were used. However, for both primary and recurrent tumors, significant differences in median 3-year OS were observed when a RECIST cut-off of 50% was used. OS was 99% versus 77% in primary and 100% versus 42% in recurrent rectal cancer (P = 0.002 and P = 0.03, respectively). Only patients that demonstrated >50% size reduction showed a survival benefit. Recurrent rectal cancer appears radioresistant compared with primary tumors for tumor size after CRT. Further investigation into improving/intensifying chemotherapy and radiotherapy for locally recurrent rectal cancer is justified

  4. Local Recurrence After Uveal Melanoma Proton Beam Therapy: Recurrence Types and Prognostic Consequences

    International Nuclear Information System (INIS)

    Purpose: To study the prognosis of the different types of uveal melanoma recurrences treated by proton beam therapy (PBT). Methods and Materials: This retrospective study analyzed 61 cases of uveal melanoma local recurrences on a total of 1102 patients treated by PBT between June 1991 and December 2010. Survival rates have been determined by using Kaplan-Meier curves. Prognostic factors have been evaluated by using log-rank test or Cox model. Results: Our local recurrence rate was 6.1% at 5 years. These recurrences were divided into 25 patients with marginal recurrences, 18 global recurrences, 12 distant recurrences, and 6 extrascleral extensions. Five factors have been identified as statistically significant risk factors of local recurrence in the univariate analysis: large tumoral diameter, small tumoral volume, low ratio of tumoral volume over eyeball volume, iris root involvement, and safety margin inferior to 1 mm. In the local recurrence-free population, the overall survival rate was 68.7% at 10 years and the specific survival rate was 83.6% at 10 years. In the local recurrence population, the overall survival rate was 43.1% at 10 years and the specific survival rate was 55% at 10 years. The multivariate analysis of death risk factors has shown a better prognosis for marginal recurrences. Conclusion: Survival rate of marginal recurrences is superior to that of the other recurrences. The type of recurrence is a clinical prognostic value to take into account. The influence of local recurrence retreatment by proton beam therapy should be evaluated by novel studies

  5. Atypical recurrence of rheumatic chorea

    Directory of Open Access Journals (Sweden)

    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

  6. Pharmacotherapy of recurrent aphthous ulcers

    Directory of Open Access Journals (Sweden)

    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.

  7. Multilayer film with better layer adhesion

    International Nuclear Information System (INIS)

    A pasteurizable and/or cook-in shrink film is provided with good interlaminar adhesion and good orientability, and characterized by the presence of ethylene alkyl acrylate copolymer in shrink and abuse layers, in adhesive layers, or both. An associated method for making the film is also provided that includes co-extrusion of the multilayer film, optional irradiation, and orientation

  8. Analysis of Fracture Behaviour of Multilayer Pipes.

    Czech Academy of Sciences Publication Activity Database

    Nezbedová, E.; Knésl, Zden?k; Vlach, B.

    2007-01-01

    Ro?. 36, ?. 5 (2007), s. 207-212. ISSN 1465-8011. [Plastic Pipes /13./. Washington, D. C., 02.10.2006-05.10.2006] R&D Projects: GA ?R GA106/07/1284 Institutional research plan: CEZ:AV0Z20410507 Keywords : multi-layer pipes Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.431, year: 2007

  9. Multilayer aerogel for compact RICH detectors

    International Nuclear Information System (INIS)

    This paper covers some of the latest achievements in the testing of multi-index silica aerogel. Optical bench measurements and preliminary results from a recently performed charged particle beam test are presented. This work is part of an effort aimed at assessing the potential of multilayer aerogel as a radiator for compact, proximity focused ring imaging Cherenkov detectors.

  10. Multilayer aerogel for compact RICH detectors

    Energy Technology Data Exchange (ETDEWEB)

    Arnaboldi, C. [INFN Sezione di Milano Bicocca (Italy); Bellunato, T.; Calvi, M. [Universita degli Studi di Milano Bicocca (Italy); Cisbani, E. [Istituto Superiore di Sanita and INFN, Roma (Italy); Dalla Torre, S. [INFN sezione di Trieste (Italy); De Leo, R. [Dipartimento di Fisica and INFN Sezione di Bari, Bari (Italy); Kravchenko, E. [Budker Institute for Nuclear Physics, Novosibirsk (Russian Federation); Lagamba, L.; Marrone, S. [Dipartimento di Fisica and INFN Sezione di Bari, Bari (Italy); Matteuzzi, C. [INFN Sezione di Milano Bicocca (Italy); Nappi, E. [Dipartimento di Fisica and INFN Sezione di Bari, Bari (Italy); Perego, D.L. [Universita degli Studi di Milano Bicocca (Italy); Pessina, G. [INFN Sezione di Milano Bicocca (Italy); Vilardi, I. [Dipartimento di Fisica and INFN Sezione di Bari, Bari (Italy)

    2009-12-15

    This paper covers some of the latest achievements in the testing of multi-index silica aerogel. Optical bench measurements and preliminary results from a recently performed charged particle beam test are presented. This work is part of an effort aimed at assessing the potential of multilayer aerogel as a radiator for compact, proximity focused ring imaging Cherenkov detectors.

  11. Transmission fingerprints in quasiperiodic magnonic multilayers

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Thermal Transport in Graphene and Graphene Multilayers

    OpenAIRE

    Balandin, Alexander A.; Nika, Denis L.

    2015-01-01

    In this paper we review thermal properties of graphene and multilayer graphene and discuss the optothermal technique developed for the thermal conductivity measurements. We also outline different theoretical approaches used for the description of phonon transport in graphene and provide comparison with available experimental thermal conductivity data.

  13. Diffraction Gratings Based on Multilayer Structures

    International Science & Technology Center (ISTC)

    Development of High Efficiency Diffraction Gratings on the Basis of Multilayer Structures for Monochromators and Polychromators of X-Ray Synchrotron Radiation and for Ultra-High Spectral Resolution X-Ray Diagnostics in the 0.1 – 10 Kev Energy Range

  14. Josephson plasma resonance in superconducting multilayers

    DEFF Research Database (Denmark)

    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 to the recently derived plasma resonance phenomena for high T-c superconductors of the BSCCO type is discussed.

  15. Lesson learned from (some) recurrent novae

    OpenAIRE

    Mason, Elena; Walters, Frederick M.

    2013-01-01

    In this talk we present early decline and nebular spectra of the recurrent novae YY Dor and nova LMC 2009. These and a few other recurrent novae of the same type, share similar spectral characteristics and evolution. We will critically discuss those common features suggesting same white dwarf progenitor and post outburst phases for all of them.

  16. Recurrent facial urticaria following herpes simplex labialis

    Directory of Open Access Journals (Sweden)

    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.

  17. A case of seven recurrent ectopic pregnancies.

    OpenAIRE

    Shakeel A. Faiz; Bengt G. Sporrong; Abdulaziz A. Al-Meshari

    2003-01-01

    ABSTRACT If a woman with previous ectopic pregnancy ever gets pregnant again, the risk of a repeat ectopic pregnancy is said to be 4-fold. We present a rare case of 7 recurrent ectopic pregnancies in a 39-year-old Saudi woman, together with a literature review of the reproductive performance after recurrent ectopic pregnancy.

  18. Recurrence plots for diesel engine variability tests

    Energy Technology Data Exchange (ETDEWEB)

    Longwic, Rafal [Technical Univ. of Lublin (Poland). Dept. of Vehicles; Litak, Grzegorz [Technical Univ. of Lublin (Poland). Dept. of Applied Mechanics; Sen, Asok K. [Indiana Univ., Indianapolis, IN (United States). Dept. of Mathematical Sciences

    2009-01-15

    Cycle-to-cycle variations of maximum pressure in a diesel engine are studied by using the methods of recurrence plots and recurrence quantification analysis. The pressure variations are found to exhibit strong periodicities in low frequency bands and intermittent oscillations at higher frequencies. The results are confirmed by wavelet analysis. (orig.)

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

    Science.gov (United States)

    2015-08-31

    Childhood Hepatoblastoma; Previously Treated Childhood Rhabdomyosarcoma; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; 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; Recurrent Wilms Tumor and Other Childhood Kidney Tumors

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

    International Nuclear Information System (INIS)

    Highlights: ? A method is presented to improve power system stability using IPFC. ? Recurrent neural network controllers damp oscillations in a power system. ? Training is based on back propagation with adaptive training parameters. ? 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Evidence-based management of recurrent miscarriages

    Directory of Open Access Journals (Sweden)

    Yadava B Jeve

    2014-01-01

    Full Text Available Recurrent miscarriages are postimplantation failures in natural conception; they are also termed as habitual abortions or recurrent pregnancy losses. Recurrent pregnancy loss is disheartening to the couple and to the treating clinician. There has been a wide range of research from aetiology to management of recurrent pregnancy loss. It is one of the most debated topic among clinicians and academics. The ideal management is unanswered. This review is aimed to produce an evidence-based guidance on clinical management of recurrent miscarriage. The review is structured to be clinically relevant. We have searched electronic databases (PubMed and Embase using different key words. We have combined the searches and arranged them with the hierarchy of evidences. We have critically appraised the evidence to produce a concise answer for clinical practice. We have graded the evidence from level I to V on which these recommendations are based.

  3. MR imaging characteristics of recurrent thyroid tumors

    International Nuclear Information System (INIS)

    MR imaging was used to evaluate 32 patients after partial or total thyroidectomy. Surgical (n = 25) or clinical (n = 7) follow-up was done. Of 23 patients with primary thyroid carcinomas, MR imaging disclosed recurrence in 15 and no recurrence in eight. There were two false-positive diagnoses and one false-negative diagnosis. Nine patients who had undergone surgery for benign disease were studied to assess the appearance of the thyroid bed after thyroidectomy. Local recurrence of carcinoma was characterized by low to medium signal intensity on T1-weighted images and medium to high signal intensity on T2-weighted images. Scar tissue has low intensity. Coronal and sagittal images provided definition of local and mediastinal extension and metastasis. Thus, MR imaging can be used to evaluate recurrence of thyroid tumors and to differentiate recurrence from postoperative fibrosis

  4. CT evaluation of locally recurrent rectal cancer

    International Nuclear Information System (INIS)

    From April 1979 to February 1984, fifty patients with locally recurrent rectal cancer following abdomino-perineal (AP) resection for rectal cancer were reviwed. In order to observe the pelvic anatomy, base-line CT studies were performed immediatly after AP resection in all cases. Signs of local recurrence were seen on CT for all patients The pelivic anatomy following sugical resection of rectal cancer can be clearly imaged by CT. Pelvic recurrence usually, presents as a mass with soft tissue density that is frequently invading adjacent structures, particularly deep pelvic muscles and the posterior wall of the bladder. There are some limitations in the CT evaluation for recurrent mass due to difficulty in differentiating malignancy from granuloma. CT, however, is useful for making a diagnosis of recurrent tumors and for observing the shape, internal structure of the tumor and invasion to the adjacent tissue. (author)

  5. Perceptron Learning of SAT

    OpenAIRE

    Flint, Alex; Blaschko, Matthew,

    2012-01-01

    Boolean satisfiability (SAT) as a canonical NP-complete decision problem is one of the most important problems in computer science. In practice, real-world SAT sentences are drawn from a distribution that may result in efficient algorithms for their solution. Such SAT instances are likely to have shared characteristics and substructures. This work approaches the exploration of a family of SAT solvers as a learning problem. In particular, we relate polynomial time solvability of a SAT subset t...

  6. Inguinal hernia recurrence: Classification and approach

    Directory of Open Access Journals (Sweden)

    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.

  7. Design and development of multilayer vascular graft

    Science.gov (United States)

    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 strength, showed that the multilayer graft possessed properties mimicking those of native vessels. Achieving these FDA-required functional properties is essential because they play critical roles in graft performances in vivo such as thrombus formation, occlusion, healing, and bleeding. In addition, cell studies and animal studies have been performed on the multilayer graft. Our results show that the multilayer graft support mimetic vascular culture of cells and the acellular graft serves as an artery equivalent in vivo to sustain the physiological conditions and promote appropriate cellular activity. In conclusion, the newly-developed hybrid multilayer graft provides a proper balance of biomechanical and biochemical properties and demonstrates the potential for the use of vascular tissue engineering and regeneration.

  8. RECURRENT STROKE: WHAT HAVE WE LEARNT?

    Directory of Open Access Journals (Sweden)

    EM Khoo

    2007-01-01

    Full Text Available Stroke is the third leading cause of death, a major cause of disability in adults, and is frequently more disabling than fatal. With a decline in mortality from initial cerebral infarction and an increase in the life expectancy of the population, the number of patients with recurrent stroke and ensuing cardiovascular events will become greater. Thus it is important to find out those patients at high risk of stroke recurrence. This case report illustrates the process of recurrent stroke and the resulting disabilities and morbidities in a 42-year- old man. The role of integrated stroke rehabilitation programme is described.

  9. Generalised Recurrence Plot Analysis for Spatial Data

    CERN Document Server

    Marwan, N; Saparin, P; 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 spatial structures in trabecular bone become more self-similar during the bone loss in osteoporosis.

  10. Treatment of Recurrent Ovarian Cancer.

    Directory of Open Access Journals (Sweden)

    Neville F. Hacker

    2004-08-01

    Full Text Available Recurrent ovarian cancer is a common clinical problem and the management of eachpatient must be individualized. Diagnosis is usually based on a progressively rising CA-125titre, and a CT scan of the pelvis and abdomen, together with a chest X-ray should be performed.Although there is no study to support immediate treatment in the asymptomaticpatient, our approach is to commence such patients on Tamoxifen. Chemotherapy isreserved for asymptomatic patients or those who progress on Tamoxifen. The longer thetreatment-free interval of 18-24 months. The choice of non-platinum second or subsequentline chemotherapy is based on many factors including likelihood of benefit, potential toxicity,schedule and convenience to the patient, as well as organ function and residual toxicityfrom prior treatment. Aggressive secondary cytoreductive surgery can significantly prolongsurvival in those with a disease-free interval of 24 months or more and in those in whom allmacroscopic disease can be removed. Radiation therapy to the tumour bed following resectionof localized disease may be beneficial in selected patients. Quality of life issues are particularlyimportant for this group of patients and have not been adequately studies.Communication regarding the objectives of therapy is important, and the multidisciplinaryapproach should include palliative care and psycho-social support, in addition to the moretraditional medical options.

  11. Recurrent seizures after lidocaine ingestion.

    Science.gov (United States)

    Aminiahidashti, Hamed; Laali, Abolghasem; Nosrati, Nazanin; Jahani, Fatemeh

    2015-01-01

    Lidocaine has a concentration-dependent effect on seizures. Concentrations above 15 ?g/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. PMID:25709968

  12. Ethanol ablation of predominantly cystic thyroid nodules: Evaluation of recurrence rate and factors related to recurrence

    International Nuclear Information System (INIS)

    Aim: To evaluate recurrence rate and associated risk factors for recurrence after ethanol ablation (EA) in patients with predominantly cystic thyroid nodules. Materials and methods: This observational study was approved by the Ethics Committee of the Institutional Review Board and informed consent for procedures was obtained. From April 2009 to April 2013, 107 consecutive patients with predominantly cystic nodules were treated using EA. Recurrence was defined as nodules showing a residual solid portion with internal vascularity, cosmetic problems remaining, or persistent symptoms, and patients who requested additional therapy to resolve their symptomatic or cosmetic problems. Delayed recurrence was defined as treated nodules that showed no recurrent features at 1 month, but showed newly developed recurrent features during the longer follow-up period. Multivariate analysis was used for variables to demonstrate the independent factors related to volume reduction. Results: One month after EA, 18.7% of patients (20/107) showed recurrence. Among 87 patients with non-recurrence, 24.1% (21/87) showed delayed recurrence. The total recurrence rate was 38.3% (41/107). Patients with recurrence (n = 41) were treated using radiofrequency ablation (n = 28), second EA (n = 4), and refused further treatment (n = 9). These patients responded well to repeat EA and radiofrequency ablation. Multivariate analysis demonstrated that the initial nodule volume (>20 ml; p < 0.036) and vascularity (grade >1; p < 0.049) were independent predictors of volume reduction at last follow-up. Conclusions: The results revealed that although EA seemed to be effective during the initial period, delayed recurrence should be considered during longer-term follow-up. The independent predictors of recurrence were initial volume (>20 ml) and vascularity. - Highlights: • Ethanol ablation showed unsatisfactory results in 18.7% of patient at one month. • Delayed recurrence was observed in 24.1% of patients during the follow-up period. • Total recurrence rate was 38.3% after ethanol ablation. • Our study results revealed that although EA seemed to be effective in the initial period, delayed recurrence should be considered during the longer follow-up period. • The independent predictors of recurrence were initial volume (>20 mL) and vascularity

  13. Mo-C Multilayered CVD Coatings

    Directory of Open Access Journals (Sweden)

    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 ?m / 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.

  14. Soft X-ray multilayer beam splitters

    International Nuclear Information System (INIS)

    A semitransparent Mo/Si multilayer beam splitter with a completely self-standing active area (10 x 10 mm) and a flatness of 1.1 nm (r.m.s) was fabricated. The influence of the roughness of the membrane substrate on the reflectivity of a beam splitter was investigated for different materials and deposition schemes. Precise control of multilayer stress to give a slightly tensile state not only enables the fabrication of a large and flat reflection surface, but also makes it possible to etch away the supporting membrane and obtain a completely self-standing structure. The performance evaluation using synchrotron radiation revealed that the fabricated beam splitter works as a one-to-one beam splitter whose reflectivity and transmittance are both 27% (s-polarization, 45 degrees, ? 13.4 mm)

  15. Multiple wavelength photolithography for preparing multilayer microstructures

    Science.gov (United States)

    Dentinger, Paul Michael (Livermore, CA); Krafcik, Karen Lee (Livermore, CA)

    2003-06-24

    The invention relates to a multilayer microstructure and a method for preparing thereof. The method involves first applying a first photodefinable composition having a first exposure wavelength on a substrate to form a first polymeric layer. A portion of the first photodefinable composition is then exposed to electromagnetic radiation of the first exposure wavelength to form a first pattern in the first polymeric layer. After exposing the first polymeric layer, a second photodefinable composition having a second exposure wavelength is applied on the first polymeric layer to form a second polymeric layer. A portion of the second photodefinable composition is then exposed to electromagnetic radiation of the second exposure wavelength to form a second pattern in the second polymeric layer. In addition, a portion of each layer is removed according to the patterns to form a multilayer microstructure having a cavity having a shape that corresponds to the portions removed.

  16. Random walk centrality in interconnected multilayer networks

    CERN Document Server

    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.

  17. The structure and dynamics of multilayer networks

    Science.gov (United States)

    Boccaletti, S.; Bianconi, G.; Criado, R.; del Genio, C. I.; Gómez-Gardeñes, J.; Romance, M.; Sendiña-Nadal, I.; Wang, Z.; Zanin, M.

    2014-11-01

    In the past years, network theory has successfully characterized the interaction among the constituents of a variety of complex systems, ranging from biological to technological, and social systems. However, up until recently, attention was almost exclusively given to networks in which all components were treated on equivalent footing, while neglecting all the extra information about the temporal- or context-related properties of the interactions under study. Only in the last years, taking advantage of the enhanced resolution in real data sets, network scientists have directed their interest to the multiplex character of real-world systems, and explicitly considered the time-varying and multilayer nature of networks. We offer here a comprehensive review on both structural and dynamical organization of graphs made of diverse relationships (layers) between its constituents, and cover several relevant issues, from a full redefinition of the basic structural measures, to understanding how the multilayer nature of the network affects processes and dynamics.

  18. The structure and dynamics of multilayer networks

    CERN Document Server

    Boccaletti, S; Criado, R; del Genio, C I; Gómez-Gardeñes, J; Romance, M; Sendiña-Nadal, I; Wang, Z; Zanin, M

    2014-01-01

    In the past years, network theory has successfully characterized the interaction among the constituents of a variety of complex systems, ranging from biological to technological, and social systems. However, up until recently, attention was almost exclusively given to networks in which all components were treated on equivalent footing, while neglecting all the extra information about the temporal- or context-related properties of the interactions under study. Only in the last years, taking advantage of the enhanced resolution in real data sets, network scientists have directed their interest to the multiplex character of real-world systems, and explicitly considered the time-varying and multilayer nature of networks. We offer here a comprehensive review on both structural and dynamical organization of graphs made of diverse relationships (layers) between its constituents, and cover several relevant issues, from a full redefinition of the basic structural measures, to understanding how the multilayer nature of...

  19. Multi-layer weighted social network model

    CERN Document Server

    Murase, Yohsuke; Jo, Hang-Hyun; Kaski, Kimmo; Kertész, János

    2014-01-01

    Recent empirical studies using large-scale datasets have validated the Granovetter hypothesis on the structure of the society in that there are strongly wired communities connected by weak ties. However, as interaction between individuals takes place in diverse contexts, these communities turn out to be overlapping. This implies that the society has a multi-layered structure, where the layers represent the different contexts. To model this structure we begin with a single-layer weighted social network (WSN) model showing the Granovetterian structure. We find that when merging such WSN models, sufficient amount of inter-layer correlation is needed to maintain the relationship between topology and link weights but these correlations destroy the enhancement in the community overlap due to multiple layers. To resolve this, we devise a geographic multi-layer WSN model, where the indirect inter-layer correlations due to the geographic constraints of individuals enhance the overlaps between the communities and, at t...

  20. Optics in magnetic multilayers and nanostructures

    CERN Document Server

    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...

  1. Mathematical Formulation of Multi-Layer Networks

    CERN Document Server

    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...

  2. Information Propagation in Clustered Multilayer Networks

    CERN Document Server

    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...

  3. Heterogeneous recurrence monitoring and control of nonlinear stochastic processes

    International Nuclear Information System (INIS)

    Recurrence is one of the most common phenomena in natural and engineering systems. Process monitoring of dynamic transitions in nonlinear and nonstationary systems is more concerned with aperiodic recurrences and recurrence variations. However, little has been done to investigate the heterogeneous recurrence variations and link with the objectives of process monitoring and anomaly detection. Notably, nonlinear recurrence methodologies are based on homogeneous recurrences, which treat all recurrence states in the same way as black dots, and non-recurrence is white in recurrence plots. Heterogeneous recurrences are more concerned about the variations of recurrence states in terms of state properties (e.g., values and relative locations) and the evolving dynamics (e.g., sequential state transitions). This paper presents a novel approach of heterogeneous recurrence analysis that utilizes a new fractal representation to delineate heterogeneous recurrence states in multiple scales, including the recurrences of both single states and multi-state sequences. Further, we developed a new set of heterogeneous recurrence quantifiers that are extracted from fractal representation in the transformed space. To that end, we integrated multivariate statistical control charts with heterogeneous recurrence analysis to simultaneously monitor two or more related quantifiers. Experimental results on nonlinear stochastic processes show that the proposed approach not only captures heterogeneous recurrence patterns in the fractal representation but also effectively monitors the changes in the dynamics of a complex system

  4. Heterogeneous recurrence monitoring and control of nonlinear stochastic processes

    Science.gov (United States)

    Yang, Hui; Chen, Yun

    2014-03-01

    Recurrence is one of the most common phenomena in natural and engineering systems. Process monitoring of dynamic transitions in nonlinear and nonstationary systems is more concerned with aperiodic recurrences and recurrence variations. However, little has been done to investigate the heterogeneous recurrence variations and link with the objectives of process monitoring and anomaly detection. Notably, nonlinear recurrence methodologies are based on homogeneous recurrences, which treat all recurrence states in the same way as black dots, and non-recurrence is white in recurrence plots. Heterogeneous recurrences are more concerned about the variations of recurrence states in terms of state properties (e.g., values and relative locations) and the evolving dynamics (e.g., sequential state transitions). This paper presents a novel approach of heterogeneous recurrence analysis that utilizes a new fractal representation to delineate heterogeneous recurrence states in multiple scales, including the recurrences of both single states and multi-state sequences. Further, we developed a new set of heterogeneous recurrence quantifiers that are extracted from fractal representation in the transformed space. To that end, we integrated multivariate statistical control charts with heterogeneous recurrence analysis to simultaneously monitor two or more related quantifiers. Experimental results on nonlinear stochastic processes show that the proposed approach not only captures heterogeneous recurrence patterns in the fractal representation but also effectively monitors the changes in the dynamics of a complex system.

  5. Control of residual stress in extreme ultraviolet multilayer coatings

    International Nuclear Information System (INIS)

    Study of stress in Mo/Si multilayers is carried out for application of extreme ultraviolet multilayer coatings in the diagnosis of high density plasmas and extreme ultraviolet lithography. Stress generating mechanisms is discussed. Precise measurement of stress is taken by ZYGO interferometer. It is observed that the growth of the Mo component in the multilayers is tensile, while that of the Si component is compressive. The residual stress in a 40-bilayer Mo/Si multilayer coating with high reflectivity is -500 MPa (compressive), stress generation may be attributed to the interfacial diffusion. By varying Mo-to Si thickness ratio (?), the stress in multilayers can be compensated to a certain extent. However, the reflectance of Mo/Si multilayers is reduced correspondently. (authors)

  6. Permeation barrier studies of multilayer films

    OpenAIRE

    Henry, BM; Topping, J.; Assender, HE; Grovenor, CRM; Marras, L

    2005-01-01

    The gas barrier properties of multilayered films fabricated using a new vacuum web coater at the University of Oxford have been investigated. Oxygen and water vapor transmission rates were measured for a range of coated LLDPE film architectures in order to establish the influence of vacuum deposited acrylate layers on the barrier properties. It was found that the addition of an organic interlayer between two aluminum layers results in three order of magnitude decrease in oxygen transmission r...

  7. Methodology for determining multilayered temperature inversions

    OpenAIRE

    Fochesatto, G.J.

    2014-01-01

    The atmospheric boundary layer (ABL) exhibit multilayered thermal structure especially in polar atmosphere during extreme winters. These thermal inversions are originated based on the combined forcing of local and large scale synoptic meteorology. At the local scale the thermal inversion layer forms near the surface and plays a central role in controlling the surface radiative cooling; however, depending upon the large scale synoptic meteorological forcing, an upper level thermal inv...

  8. Methodology for determining multilayered temperature inversions

    OpenAIRE

    Fochesatto, G.J.

    2015-01-01

    Temperature sounding of the atmospheric boundary layer (ABL) and lower troposphere exhibits multilayered temperature inversions specially in high latitudes during extreme winters. These temperature inversion layers are originated based on the combined forcing of local- and large-scale synoptic meteorology. At the local scale, the thermal inversion layer forms near the surface and plays a central role in controlling the surface radiative cooling and air pollution dispersion; ...

  9. Magnetism of Semiconductors and Metallic Multilayers

    OpenAIRE

    Stanciu, Victor

    2005-01-01

    Magnetic properties of diluted magnetic semiconductors and magnetic metallic multilayers are investigated by SQUID magnetometry. By doping GaAs with magnetic Mn2+ ions under well defined growth conditions, one obtains a diluted magnetic semiconductor, (Ga,Mn)As, in which the randomly-distributed magnetic ions act as acceptor centers. At high enough dopant and hole concentration a carrier-induced ferromagnetic state results between the magnetic ions. Due to peculiarities of the growth process ...

  10. Superabsorption of light by multilayer nanowires.

    Science.gov (United States)

    Mirzaei, Ali; Shadrivov, Ilya V; Miroshnichenko, Andrey E; Kivshar, Yuri S

    2015-11-14

    We suggest a new strategy for tailoring and enhancing the absorption of light by multilayered nanowires. We use the multipole expansion method and experimental data for dielectric and plasmonic materials and demonstrate that the absorption for one of the polarizations can be substantially enhanced due to an overlap of different resonant modes in nanowires. We show that our approach can be employed for a design of multiband tunable optical absorption across a wide spectral range for both TE and TM polarizations. PMID:26462974

  11. A Multilayer Model of Computer Networks

    OpenAIRE

    Shchurov, Andrey A.

    2015-01-01

    The fundamental concept of applying the system methodology to network analysis declares that network architecture should take into account services and applications which this network provides and supports. This work introduces a formal model of computer networks on the basis of the hierarchical multilayer networks. In turn, individual layers are represented as multiplex networks. The concept of layered networks provides conditions of top-down consistency of the model. Next,...

  12. Plasmonic waveguides with hyperbolic multilayer cladding

    OpenAIRE

    Babicheva, Viktoriia E.; Shalaginov, Mikhail Y.; 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 th...

  13. Unsupervised model compression for multilayer bootstrap networks

    OpenAIRE

    Zhang, Xiao-Lei

    2015-01-01

    Recently, multilayer bootstrap network (MBN) has demonstrated promising performance in unsupervised dimensionality reduction. It can learn compact representations in standard data sets, i.e. MNIST and RCV1. However, as a bootstrap method, the prediction complexity of MBN is high. In this paper, we propose an unsupervised model compression framework for this general problem of unsupervised bootstrap methods. The framework compresses a large unsupervised bootstrap model into a...

  14. Planar multilayer structure analysis: an educational approach

    Scientific Electronic Library Online (English)

    D.B., Ferreira; A.F., Tinoco Salazar; I., Bianchi; J.C. da S., Lacava.

    2012-06-01

    Full Text Available This paper discusses how symbolic computation combined with a circuit model can be used for analyzing planar multilayer structures, in a manner suitable for educational approach. Working in the Fourier domain, expressions for the transversal spectral Green’s functions are evaluated in compact, close [...] d form using the symbolic computation capability of the Mathematica package. Printed antennas were analyzed through the method of moments. Further validation was achieved with the IE3D and HFSS packages.

  15. Recurrent IVF failure and hereditary thrombophilia

    OpenAIRE

    Safdarian, Leila; Najmi, Zahra; Aleyasin, Ashraf; Aghahosseini, Marzieh; Rashidi, Mandana; Asadollah, Sara

    2014-01-01

    Background: The largest percentage of failed invitro fertilization (IVF (cycles, are due to lack of implantation. As hereditary thrombophilia can cause in placentation failure, it may have a role in recurrent IVF failure.

  16. Chondrosarcoma of the Maxilla-Recurrent

    Directory of Open Access Journals (Sweden)

    Aniece Chowdhary, Parmod Kalsotra, Des Raj Bhagat, Poonam Sharma*, Pervez Katoch**

    2008-04-01

    Full Text Available An uncommon case of recurrent chondrosarcoma of the maxilla is presented. A brief discussion on theradiologic and histologic presentation of the tumor and the treatment modalities of this unusual tumor isdiscussed.

  17. Recurrence quantification analysis theory and best practices

    CERN Document Server

    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.

  18. Evolutionary games on multilayer networks: a colloquium

    Science.gov (United States)

    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.

  19. Quantum spin Hall phase in multilayer graphene

    Science.gov (United States)

    García-Martínez, N. A.; Lado, J. L.; Fernández-Rossier, J.

    2015-06-01

    The so-called quantum spin Hall phase is a topologically nontrivial insulating phase that is predicted to appear in graphene and graphenelike systems. In this paper we address the question of whether this topological property persists in multilayered systems. We consider two situations: purely multilayer graphene and heterostructures where graphene is encapsulated by trivial insulators with a strong spin-orbit coupling. We use a four-orbital tight-binding model that includes full atomic spin-orbit coupling and we calculate the Z2 topological invariant of the bulk states as well as the edge states of semi-infinite crystals with armchair termination. For homogeneous multilayers we find that even when the spin-orbit interaction opens a gap for all possible stackings, only those with an odd number of layers host gapless edge states while those with an even number of layers are trivial insulators. For heterostructures where graphene is encapsulated by trivial insulators, it turns out that interlayer coupling is able to induce a topological gap whose size is controlled by the spin-orbit coupling of the encapsulating materials, indicating that the quantum spin Hall phase can be induced by proximity to trivial insulators.

  20. Technique for etching monolayer and multilayer materials

    Energy Technology Data Exchange (ETDEWEB)

    Bouet, Nathalie C. D.; Conley, Raymond P.; Divan, Ralu; Macrander, Albert

    2015-10-06

    A process is disclosed for sectioning by etching of monolayers and multilayers using an RIE technique with fluorine-based chemistry. In one embodiment, the process uses Reactive Ion Etching (RIE) alone or in combination with Inductively Coupled Plasma (ICP) using fluorine-based chemistry alone and using sufficient power to provide high ion energy to increase the etching rate and to obtain deeper anisotropic etching. In a second embodiment, a process is provided for sectioning of WSi.sub.2/Si multilayers using RIE in combination with ICP using a combination of fluorine-based and chlorine-based chemistries and using RF power and ICP power. According to the second embodiment, a high level of vertical anisotropy is achieved by a ratio of three gases; namely, CHF.sub.3, Cl.sub.2, and O.sub.2 with RF and ICP. Additionally, in conjunction with the second embodiment, a passivation layer can be formed on the surface of the multilayer which aids in anisotropic profile generation.

  1. Automation Enhancement of Multilayer Laue Lenses

    Energy Technology Data Exchange (ETDEWEB)

    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. Performance of multilayer coated silicon pore optics

    DEFF Research Database (Denmark)

    Ackermann, M. D.; Collon, M. J.

    2010-01-01

    The requirements for the IXO (International X-ray Observatory) telescope are very challenging in respect of angular resolution and effective area. Within a clear aperture with 1.7 m > R > 0.25 m that is dictated by the spacecraft envelope, the optics technology must be developed to satisfy 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.

  3. Stress-strain condition for multilayer pipe

    Energy Technology Data Exchange (ETDEWEB)

    Kuksa, L.V.; Slezovsky, A.V.; Pichurin, I.I.; Yaner, V.R.; Sychev, A.V.; Tarasov, V.V.

    1979-05-01

    A multilayer steel pipeline has several advantages over a monolithic pipeline, especially with regard to fracture toughness. To evaluate stress-strain states in layer of multilayer pipe, the USSR's Engineering-Construction Institute studied samples of experimental multilayer pipe of 7-in (180-mm) diameter made at the Volzhsky Pipe Plant from steel tube of 80-mil (2-mm) wall thickness, spirally wound at a 75/sup 0/ angle with four layers of 40-mil (1-mm) thick steel strip 3.9 in (100 mm) wide. Only the ends of the strip were welded to the face of the pipe base; the edges were free. During pressure-testing of the pipe, the stress-strain characteristics were measured for each of the five layers. The stress-strain curves and the calculations showed that preliminary loading of the pipe to the plastic deformation range of each layer changed the stress state of the layers upon repetitive loading. The second, third, and fourth layers developed a plane stress condition, with the ratio of principal plane stresses equal to 1.5 to 1.7. The friction behavior of the layers changed the direction of the principal stresses upon loading.

  4. Neutron diffraction studies of thin film multilayer structures

    Energy Technology Data Exchange (ETDEWEB)

    Majkrzak, C.F.

    1985-01-01

    The application of neutron diffraction methods to the study of the microscopic chemical and magnetic structures of thin film multilayers is reviewed. Multilayer diffraction phenomena are described in general and in particular for the case in which one of the materials of a bilayer is ferromagnetic and the neutron beam polarized. Recent neutron diffraction measurements performed on some interesting multilayer systems are discussed. 70 refs., 5 figs.

  5. Multilayered film monitoring using terahertz reflective time-domain spectroscopy

    Science.gov (United States)

    Choi, Jindoo; Kwon, Won Sik; Kim, Kyung-Soo; Kim, Soohyun

    2015-07-01

    We present qualitative monitoring of multilayered films by noninvasive investigation in the terahertz frequencies. Three multilayered films composed of marine paint are characterized in reflective, non-orthogonal measurements in ambient atmosphere. The spectra of the constituent marine paint layers EH2350, Interthane 989, BEA777, and ENA300 present sufficient spectral information for effective monitoring of the multilayered structures. Our experimental findings show promise in noninvasive monitoring of layered structures in realistic industrial evaluation applications.

  6. Young's modulus of polyelectrolyte multilayers from microcapsule swelling

    CERN Document Server

    Vinogradova, O I; Lulevich, V V; Nordschild, S; Sukhorukov, G B

    2003-01-01

    We measure Young's modulus of a free polyelectrolyte multilayer film by studying osmotically induced swelling of polyelectrolyte multilayer microcapsules filled with the polyelectrolyte solution. Different filling techniques and core templates were used for the capsule preparation. Varying the concentration of the polyelectrolyte inside the capsule, its radius and the shell thickness yielded an estimate of an upper limit for Young's modulus of the order of 100 MPa. This corresponds to an elastomer and reflects strong interactions between polyanions and polycations in the multilayer.

  7. Modeling Macroscopic Shape Distortions during Sintering of Multi-layers

    DEFF Research Database (Denmark)

    Tadesse Molla, Tesfaye

    2014-01-01

    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 (firing). However, unintended features like shape instabilities of samples, cracks or delamination of layers may arise during sintering of multi-layer composites. Among these defects, macroscopic shape disto...

  8. Nanometric multilayers: A new approach for joining TiAl

    OpenAIRE

    Ramos, A S; Vieira, M. T.; Duarte, L. I.; Vieira, M. F.; Viana, F.; Calinas, R.

    2006-01-01

    A novel intermetallic alloy diffusion bonding procedure is being developed. The innovative aspect relies on the use of sputtered nanometallic multilayers made up of the elements present in the bulk intermetallics to enhance the bonding mechanisms. For this purpose a deep knowledge of the multilayer thin films is required, focusing on thermal phase stability and grain size evolution. [gamma]-TiAl was selected for this study and Ti/Al multilayer thin films with nanometric period ([Lambda] = 4 n...

  9. The Sonographic Features of Recurrent Breast Cancer

    International Nuclear Information System (INIS)

    We wanted to evaluate the sonographic findings of recurrent breast cancer in the patients who underwent mastectomy or breast conserving surgery (BCS). We also wanted to evaluate the characteristics of recurrent cancer that's detected on follow up sonography only. We retrospectively reviewed 87 patients with recurrent breast cancer and who were operated on during the previous 10 years. We analyzed the method of detection and the sonographic appearance of tumor, including the location, size, shape, margin, internal echogenicity and BI-RADS categories, in 52 patients who had abnormal sonographic findings. We compared the sonographic findings of the recurrent cancer between the patients who underwent mastectomy and the patients who underwent BCS. We also analyzed the characters of the recurrent cancer that was only detectable on follow-up sonography. Among the 87 patients with recurrent breast cancer, 37 patients had undergone previous mastectomy and 50 patients had undergone previous BCS. The most common mode of detection was a palpable mass on physical examination for the patients who underwent mastectomy (64.9%, 24/37) and the most common mode of detection was the follow-up sonography for the patients who underwent BCS (40%, 20/50). The sonographic appearance of the recurrent cancer was similar for both the patients who underwent mastectomy or BCS. The most common locations were the breast parenchymal layer in 82% (36/44) of the patients who underwent BCS and the subcutaneous fat layer of the operated area in 67% (14/21) of the patients who underwent mastectomy. The type of recurrent cancer detected on sonography only was small nodules in the patients who underwent BCS, and that for the patients who underwent mastectomy was nodules, regardless of size, that were located in the deep muscle layer. Recurrent breast cancer, regardless of size, was frequently detected on a physical examination in the patients who underwent previous mastectomy, and this was detected on sonography in the patients who underwent with previous BCS. Follow up sonography was valuable to evaluate for tumor recurrence after breast cancer surgery, and this detected 16% (6/37), 28% (14/50) of the recurrent cancers that were otherwise occult tumor

  10. Risk factors that affect recurrence in strokes

    Directory of Open Access Journals (Sweden)

    Sevim Bayba?

    2010-01-01

    Full Text Available Introduction: Recurrent stroke is defined as a new cerebrovascular event which occurs after the stabilization of the previous stroke. Recurrence of stroke increases likelihood of disability-mortality associated with stroke. Systematic evaluation of stroke cases can help to reduce the risk of recurrence. Objective: In order to predict strokes which carry the risk of recurrence, we aimed to compare data related to risk factors, stroke type, etiology and disability-mortality rates associated with stroke. Material And Method: Patients with stroke who referred to Bak?rkoy Neurological and Psychiatric Diseases Training and Research State Hospital between June 1, 2002 and February 28, 2003 were recorded into the stroke database in a consecutive and prospective manner. Strokes were classified as ischemic/hemorrhagic and first/recurrent. For recurrent strokes, information about previous strokes was also recorded. Risk factors were classified as hypertension (HT, diabetes mellitus (DM, hyperlipidemia, atrial fibrillation (AF, coronary artery disease (CAD, migraine, transient ischemic accident (TIA, family history of cerebrovascular accident (CVA, oral contraceptive use, PAD, congestive heart failure (CHF, other heart diseases, smoking cigarette and alcohol consumption. Disability-mortality rates associated with stroke were evaluated. All data were compared for first and recurrent strokes. Results: In our study, 631 patients were evaluated, 52.3% of whom were female and 47.7% male. Frequency of stroke was statistically high (p<0.001 in females over 70 years old. Recurrent strokes were of the same type. For the first and recurrent strokes, HT was the highest risk factor. AF frequency increased with age (p<0.001. The rate of disability-mortality was found high in strokes of undetermined and cardioembolic origin. Conclusion: Knowledge of etiologic group can help to predict recurrence of stroke and prevent death. We think that effective treatment of modifiable risk factors identified in stroke groups where recurrence is the highest, and prioritising the investigation of cardioembolic risk factors in elderly women are significant in terms of primary and secondary stroke prevention.

  11. 76 FR 92 - Multilayered Wood Flooring From the People's Republic of China: Postponement of Preliminary...

    Science.gov (United States)

    2011-01-03

    ...Administration [C-570-971] Multilayered Wood Flooring From the People's Republic of...initiated an investigation of multilayered wood flooring from the People's Republic of China (``PRC''). See Multilayered Wood Flooring From the People's Republic...

  12. 77 FR 45336 - Multilayered Wood Flooring From the People's Republic of China: Initiation of Antidumping Duty...

    Science.gov (United States)

    2012-07-31

    ...Administration [A-570-970] Multilayered Wood Flooring From the People's Republic of...antidumping duty order on multilayered wood flooring from the People's Republic of...antidumping duty order on multilayered wood flooring from the PRC was published...

  13. 78 FR 46318 - Multilayered Wood Flooring From the People's Republic of China: Initiation of Antidumping Duty...

    Science.gov (United States)

    2013-07-31

    ...Administration [A-570-970] Multilayered Wood Flooring From the People's Republic of...antidumping duty order on multilayered wood flooring from the People's Republic of...antidumping duty order on multilayered wood flooring from the PRC on December 8,...

  14. 76 FR 13357 - Multilayered Wood Flooring from the People's Republic of China: Postponement of Preliminary...

    Science.gov (United States)

    2011-03-11

    ...Administration [A-570-970] Multilayered Wood Flooring from the People's Republic of...antidumping duty investigation on multilayered wood flooring from the People's Republic of...1\\ See Multilayered Wood Flooring from the People's Republic...

  15. 78 FR 32367 - Multilayered Wood Flooring From the People's Republic of China; Preliminary Results of...

    Science.gov (United States)

    2013-05-30

    ...Administration [A-570-970] Multilayered Wood Flooring From the People's Republic of...antidumping duty order on multilayered wood flooring (``MLWF'') from the People's...Duty New Shipper Review: Multilayered Wood Flooring from the People's Republic...

  16. Recurrent abdominal pain: a psychogenic disorder?

    OpenAIRE

    McGrath, P J; Goodman, J T; Firestone, P; Shipman, R.; Peters, S.

    1983-01-01

    A controlled study of 30 children with recurrent abdominal pain and 30 pain free children failed to show any statistically significant differences between the groups on a variety of psychological variables thought to be associated with psychogenicity. A psychogenic basis has often been assumed as the cause in diagnosis of recurrent abdominal pain when clinical examination and laboratory tests show no organic or medical reason. We emphasise that establishing a psychogenic cause is only indicat...

  17. Does (supragastric belching trigger recurrent hiccups?

    Directory of Open Access Journals (Sweden)

    Wim P Hopman, Mariëtte C van Kouwen, André J Smout

    2010-04-01

    Full Text Available Twenty-four hours multichannel intraesophageal impedance and pH monitoring in a patient who suffered from recurrent hiccups for more than a year revealed frequent supragastric belching and pathological oesophageal acid exposure. Furthermore, a temporal relationship between the start of a hiccup episode and gastric belching was observed. The data support the hypothesis that there is an association between supragastric belching, persistent recurrent hiccups and gastro-oesophageal reflux disease, and that gastric belching may evoke hiccup attacks.

  18. Supervised Sequence Labelling with Recurrent Neural Networks

    OpenAIRE

    Graves, Alexander

    2011-01-01

    Recurrent neural networks are powerful sequence learners. They are able to incorporate context information in a flexible way, and are robust to localised distortions of the input data. These properties make them well suited to sequence labelling, where input sequences are transcribed with streams of labels. The aim of this thesis is to advance the state-of-the-art in supervised sequence labelling with recurrent networks. Its two main contributions are (1) a new type of output layer that allow...

  19. Psychological aspects of recurrent chest pain.

    OpenAIRE

    Kisely, S R; Russell, E. M.; Creed, F H

    1993-01-01

    Of 113 consecutive patients admitted recurrently with chest pain 28% exhibited psychiatric morbidity using the GHQ-28 (General Health Questionnaire). Eighty patients had ischaemic heart disease, 17 had non-specific pain and 13 were excluded because of other organic causes for their pain. Of the non-specific group, seven had been admitted previously with chest pain. In common with previous studies of first admissions with non-specific chest pain, recurrent admissions were younger and predomina...

  20. Autoimmune diseases and breast cancer recurrence

    DEFF Research Database (Denmark)

    Lietzen, Lone Winther; Cronin-Fenton, Deirdre; Christiansen, Peer; Sørensen, Henrik Toft; Lash, Timothy L

    2015-01-01

    Autoimmune diseases (ADs) comprise a large group of heterogeneous diseases in which the immune system attacks healthy organs. Both intrinsic changes in the body and AD treatment can compromise immune function. Impaired immune function could increase the risk of recurrent cancer. We aimed to investigate this hypothesis in a population-based epidemiological study. We examined the risk of breast cancer (BC) recurrence associated with an AD diagnosis among patients with incident stages I-III BC diag...

  1. Glucocorticoid Prescriptions and Breast Cancer Recurrence

    DEFF Research Database (Denmark)

    Lietzen, L W; Ahern, T; Christiansen, P; Jensen, A B; Sørensen, H T; Lash, T L; Cronin-Fenton, D P

    2014-01-01

    BACKGROUND: Treatment with synthetic glucocorticoids (GCs) depresses the immune response and may therefore modify cancer outcomes. We investigated the association between GC use and breast cancer recurrence. MATERIALS AND METHODS: We conducted a population-based cohort study to examine the risk of breast cancer recurrence associated with GC use among incident stage I-III female breast cancer patients aged >18 years diagnosed 1996-2003 in Denmark. Data on patients, clinical and treatment factors,...

  2. Recurrent pituitary ependymoma: a complex clinical problem.

    OpenAIRE

    R. Belcher; Chahal, HS; Evanson, J; Afshar, F; Marino, S; Grossman, AB

    2010-01-01

    Ependymomas rarely arise from the region of the pituitary fossa, with only four cases previously reported in the literature. We present a complex case of a recurrent ependymoma of the parasellar region which has been difficult to clinically manage due to its tendency to recurrence. Our patient has had four operations over the last 28 years, with external beam radiotherapy, but still has residual tumor and is currently panhypopituitary and with significant visual loss. We believe there is cons...

  3. Multiply Recurrent Episodes of Gastric Emphysema

    OpenAIRE

    Haluck, Randy S.; Dye, Charles E.; Tomasko, Jonathan M.; Vishal Jain; Pauli, Eric M.

    2011-01-01

    Introduction. Gastric emphysema can present both a diagnostic challenge and a life-threatening condition for patients and has only once been reported as being recurrent. Background. A 64-year-old male presented with chronic abdominal pain and was found to have gastric pneumatosis on CT scan. The patient was successfully managed conservatively. The cause was attributed to aberrant arterial anatomy and atherosclerosis along with hypotension. The patient has since had 3 episodes of recurrent gas...

  4. Par-4 prevents breast cancer recurrence.

    Science.gov (United States)

    Hebbar, Nikhil; Shrestha-Bhattarai, Tripti; Rangnekar, Vivek M

    2013-01-01

    Therapy resistance and disease recurrence are two of the most challenging aspects in breast cancer treatment. A recent article in Cancer Cell makes a significant contribution toward a better understanding of this therapeutic problem by establishing downregulation of the tumor suppressor Par-4 as the primary determinant of breast cancer recurrence. This viewpoint brings forth the importance of their findings and its implications on future research and therapy. PMID:24164776

  5. Par-4 prevents breast cancer recurrence

    OpenAIRE

    Hebbar, Nikhil; Shrestha-Bhattarai, Tripti; Rangnekar, Vivek M.

    2013-01-01

    Therapy resistance and disease recurrence are two of the most challenging aspects in breast cancer treatment. A recent article in Cancer Cell makes a significant contribution toward a better understanding of this therapeutic problem by establishing downregulation of the tumor suppressor Par-4 as the primary determinant of breast cancer recurrence. This viewpoint brings forth the importance of their findings and its implications on future research and therapy.

  6. Recurrence of suicidal ideation across depressive episodes.

    OpenAIRE

    Williams, JM; CRANE, C; Barnhofer, T; Van der Does, AJ; Segal, ZV

    2006-01-01

    BACKGROUND: In recent years it has become clear that depression is a recurrent disorder, with the risk of recurrence in those with two or more episodes being as high as 90%. This has prompted interest in the consistency of individual depressive symptoms across consecutive episodes, an issue that is important for symptoms such as suicidal ideation, where a past history may give important indicators of future behaviour. METHODS: We prospectively examined 69 individuals with a history of Major D...

  7. Solving recurrence relations supported by Wolfram Mathematica

    Directory of Open Access Journals (Sweden)

    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. Crowding, Patterns, and Recurrent Processing.

    Science.gov (United States)

    Herzog, Michael; Manassi, Mauro; Hermens, Frouke; Francis, Greg

    2015-09-01

    In crowding, target perception deteriorates in the presence of clutter. Crowding is usually explained by pooling models where higher level neurons pool features from both a target and "informationless" flanking elements. Here, we show that such models fail to explain a large body of findings on pattern recognition, thereby undermining the philosophy of this approach. For example, observers judged the offset of a vernier presented in peripheral vision. When the vernier was flanked by eight aligned verniers on each side, strong crowding occurred, as expected. Next, we presented the vernier and the flankers as in the previous condition and, in addition, an aligned vernier at the same location as the target vernier. Crowding did not increase as one might have expected from adding an "informationless" element. Quite to the contrary, crowding strongly decreased. We argue that crowding can be explained by pattern processing and grouping. The aligned vernier complements the two arrays of flanking verniers, by creating a regular pattern of equally spaced, identical elements. Since the aligned vernier groups with the flankers, the target vernier does not group with the flankers anymore, and crowding is weak. When the aligned vernier was longer than both the vernier and flankers, no reduction of crowding occurred because, as we argue, the length difference prohibits the aligned vernier from completing the pattern of the flankers. It is the "good" pattern that matters. When we presented only one flanker to the left and right of the vernier, crowding was as strong as with eight flankers. However, crowding remained strong when we added the aligned vernier. We show by computer simulations how pattern recognition and crowding can be explained by recurrent processing. Meeting abstract presented at VSS 2015. PMID:26326238

  9. The first example of multilayer films with thermochromic properties

    Science.gov (United States)

    Jiang, Min; Wang, Enbo; Xu, Lin; Kang, Zhenhui; Lian, Suoyuan

    2004-04-01

    A novel thermochromic multilayer film containing polyoxometalate cluster K 12.5Na 1.5[NaP 5W 30O 110] has been fabricated by layer-by-layer self-assembly method. In case of the multilayer film, the color changes gradually from yellowish to blue when it is subjected to temperatures between 120°C and 180°C for a period of time, and the multilayer film could be bleached in air at room temperature to recover its initial state. The novel thermochromic multilayer may be of practical benefit in the development of thermosensors, which would represent promising materials for future applications.

  10. The first example of multilayer films with thermochromic properties

    International Nuclear Information System (INIS)

    A novel thermochromic multilayer film containing polyoxometalate cluster K12.5Na1.5[NaP5W30O110] has been fabricated by layer-by-layer self-assembly method. In case of the multilayer film, the color changes gradually from yellowish to blue when it is subjected to temperatures between 120 deg. C and 180 deg. C for a period of time, and the multilayer film could be bleached in air at room temperature to recover its initial state. The novel thermochromic multilayer may be of practical benefit in the development of thermosensors, which would represent promising materials for future applications

  11. Study of immune and haemostatic response induced by protein multilayers.

    OpenAIRE

    Richter, Maja

    2010-01-01

    FibMat2.0 is a fibrinogen multilayer developed by AddBIO. Other proteins such as immunoglobulin G (IgG) and human serum albumin (HSA) can also be used to build multilayers with the same technique. The aim of this study of FibMat2.0 was to investigate if the manufacturing of the protein multilayer would induce an immune or haemostatic response in the body. The multilayers of IgG and HSA were also studied. Methods such as null ellipsometry, imaging of coagulation and the cone-and-plate setup we...

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

    DEFF Research Database (Denmark)

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

    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 as this order increases from one (simple periodic multilayers) to two (bi- periodic multilayers) and beyond. For example, we show the formation of additional photonic bands, multi-refringence of p -polarized light, Dirac and mixed states.

  13. Soft X-UV silver silicon multilayer mirrors

    Science.gov (United States)

    Shao, Jian-Da; Fan, Zhengxiu; Guo, Yong H.; Jin, Lei

    1991-11-01

    In the soft x-ray domain (near 10 nm), the reported optical constants of silver and silicon are sufficiently different to make them attractive for a multilayer design. In this paper, design and fabrication of silver/silicon multilayer to be used as normal-incidence reflectors for 11.4 nm radiation are presented. Characterization of these multilayer structures was accomplished using Auger electron spectroscopy (AES) and little-angle x-ray diffraction (LXD). As a result of our experiments, we came to realize that silver/silicon multilayer can provide high quality structures and reach a certain reflectance.

  14. Management of recurrent postoperative fungal endophthalmitis

    Directory of Open Access Journals (Sweden)

    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.

  15. Radiation therapy for recurrent esophageal carcinoma

    International Nuclear Information System (INIS)

    Between 1980 and 1994, 36 patients with loco-regional recurrent esophageal cancer were treated with radiation therapy (RT) at Kyoto University Hospital. Local response and survival rates of the patients were analyzed. The 2- and 5-year cumulative survival rates of the patients were both 13%. Pretreatment and treatment parameters were evaluated in an univariate analysis for the endpoint of survival rates. Tumor size (?3 cm vs. >3 cm) and initial treatment (surgery vs. RT) were significant variables for survival rates. In addition to the parameters, interval between initial treatment and recurrence (?6 months vs. > 6 months), distant metastasis at the time of recurrence, and recurrent sites (mediastinal lymph nodes, neck lymph nodes vs. esophagus, abdominal lymph nodes) also affected the survival rate, although not significantly. In terms of treatment methods, all three tumors treated with accelerated hyperfractionation showed CR. On the other hand, RT with chemotherapy did not improve the prognosis. In conclusion, aggressive RT is indicated for patients with recurrent esophageal cancer who were initially treated with surgery and had only mediastinal or neck lymph nodes recurrence of ?3 cm in diameter. (author)

  16. Building a Chaotic Proved Neural Network

    CERN Document Server

    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.

  17. Forecasting Iran’s Rice Imports Trend During 2009-2013

    OpenAIRE

    Mohammad Reza Pakravan; Mohammad Kavoosi Kelashemi; Hamid Reza Alipour

    2011-01-01

    In the present study Iran's rice imports trend is forecasted, using artificial neural networks and econometric methods, during 2009 to 2013, and their results are compared. The results showed that feet forward neural network leading with less forecast error and had better performance in comparison to econometric techniques and also, other methods of neural networks, such as Recurrent networks and Multilayer perceptron networks. Moreover, the results showed that the amount of rice import has a...

  18. Building a Chaotic Proved Neural Network

    OpenAIRE

    Bahi, Jacques M.; Guyeux, Christophe; 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 arc...

  19. Recurrent Falls in Parkinson's Disease: A Systematic Review

    OpenAIRE

    Allen, Natalie E; Schwarzel, Allison K.; 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...

  20. Pain recurrence after shaving of rectovaginal endometriosis

    DEFF Research Database (Denmark)

    Heide, Mathias Gottschalck; Forman, Axel

    Background: Surgical treatment of rectovaginal endometriosis varies from shaving of the nodule off the rectal wall without perforation, over discoid excision to routine rectal resection. Of these methods, shaving involves the lowest rate of serious complications but leaves endometriosis tissue 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 OCs and gestagen IUD showed a trend towards a protective effect against menstrual pain (p=0.06). There was foundno significant association between recurrence of pain and anterior rectal wall involvement. Conclusion: Shaving of rectovaginal endometriosis shows a high risk of postoperative pain recurrence, especially for dyspareunia and dyschezia. Routine postoperative hormonal treatment seems of value. Research into new surgical methods is motivated.

  1. Management of recurrent aneurysms following endovascular therapy.

    Science.gov (United States)

    Chen, Kevin S; Wilson, Thomas J; Stetler, William R; Davis, Matthew C; Giles, David A; Kahn, Elyne N; Chaudhary, Neeraj; Gemmete, Joseph J; Thompson, B Gregory; Pandey, Aditya S

    2015-12-01

    The aim of the current study is to describe the complication rates and clinical outcomes in patients who either underwent repeat intervention or conservative management with radiographic surveillance when presenting with aneurysmal recurrence after endovascular treatment. Since publication of the international subarachnoid aneurysm trial (ISAT), an increasing number of patients are treated with endovascular therapy. However, recurrence after endovascular therapy continues to pose a challenge, and there is minimal evidence to guide its management. We performed a retrospective review of all patients who underwent endovascular treatment of an intracranial aneurysm from January 2005 to February 2013. The patients who had an aneurysmal recurrence following the initial endovascular treatment were identified and divided into two groups: those followed with conservative management (n=24), and those who underwent reintervention (n=65). The groups were compared for complications and clinical outcomes. When a reintervention was undertaken, microsurgical clip ligation was associated with a higher rate of occlusion than additional endovascular therapy (psubarachnoid hemorrhage, or had a greater degree of recurrence. We conclude that clinical outcomes and repeat subarachnoid hemorrhage are similar in patients who underwent retreatment versus those who had conservative management for their recurrent cerebral aneurysms. PMID:26256068

  2. CT findings in recurrent pyogenic cholangitis

    International Nuclear Information System (INIS)

    Recurrent pyogenic cholangitis is characterized clinically by recurrent attacks of right upper abdominal pain, fever and jaundice, and pathologically by chronic inflammation of the bile ducts with or without pigment bile duct stones. We analyzed the CT findings of 33 cases with recurrent pyogenic cholangitis. Twenty-four cases were confirmed by operation, and 9 cases were diagnosed clinically and cholangiographically. The CT findings of recurrent pyogenic cholangitis were dilatation of the intrahepatic ducts (n = 30), dilatation of the extrahepatic ducts (n = 24) intrahepatic stones (n = 16), extrahepatic stones (n = 12), stricture of the bile ducts (n = 10), wall enhancement of the bile ducts (n = 8), gallstones (n = 8), segmental atrophy of the liver (n = 7), pneumobilia (n = 4), abscess (n = 3), and segmental enhancement (n = 1) of the liver. A CT is considered helpful when sectional imaging is needed, but sonographic findings are equivocal or not confirmative; space-occupying lesions complicated with recurrent pyogenic cholangitis: hepatic resection is planned; and imaging guidance is needed for complex drainage procedures

  3. Multi-layer laminate structure and manufacturing method

    Science.gov (United States)

    Keenihan, James R.; Cleereman, Robert J.; Eurich, Gerald; Graham, Andrew T.; Langmaid, Joe A.

    2013-01-29

    The present invention is premised upon a multi-layer laminate structure and method of manufacture, more particularly to a method of constructing the multi-layer laminate structure utilizing a laminate frame and at least one energy activated flowable polymer.

  4. Multilayer mirror interferometer for very cold neutrons at KUR

    International Nuclear Information System (INIS)

    Multilayer mirror interferometer for very cold neutrons has been in progress for these years at KUR. This device is a kind of Mach-Zehnder interferometer using multilayer neutron monochromators as optical elements. We describe an adjusting methods of the mirror position with very high precision. (author)

  5. Multilayered iron complexes of [2.2]paracyclophane

    OpenAIRE

    Laganis, Evan D.; Finke, R. G.; Boekelheide, V.

    1981-01-01

    Recent syntheses of ruthenium complexes of [2.2]paracyclophane provided a highly interesting class of compounds, the multilayered transition metal complexes of cyclophanes. The present study discloses that arene-metal exchange procedures with ferrocene derivatives, effected either photochemically or by Lewis acid catalysis, are convenient methods for preparing the analogous multilayered iron complexes of [2.2]paracyclophane.

  6. Superconducting superlattices and multilayers. Proceedings SPIE Volume 2157

    International Nuclear Information System (INIS)

    This book is divided into the following sections: layered superconductors 1; HTSC (high-temperature superconductors) multilayers; HTSC superlattices 1; layered superconductors 2; HTSC superlattices 2; and LTSC (low-temperature superconductor) superlattices and multilayers. Separate abstracts were prepared for 38 papers in this book

  7. Dipole radiation in a multilayer geometry

    International Nuclear Information System (INIS)

    There are several kinds of experiments that can be done with multilayer stacks of dielectric media which require an understanding of light emission by sources within the stack for their analysis. These experiments may involve, for example, light-emitting tunnel junctions, Raman scattering in Kretschmann and other multilayered geometries, and Rayleigh scattering by small amounts of surface or interface roughness, either alone or in combination with other processes. A set of electromagnetic Green's functions for a multilayer stack of isotropic dielectric media [D. L. Mills and A. A. Maradudin, Phys. Rev. B 12, 2943 (1975)] gives the electric fields produced everywhere by a point source of current oscillating at a frequency f. These Green's functions can thus be used to solve this type of problem. In this paper we show how these Green's functions can be written in terms of 2 x 2 transfer matrices of the type commonly used to find the fields in a dielectric stack due to an incident plane wave. With this simplification we can easily evaluate the Green's functions for a stack with an arbitrary number of layers. We further show that, when the electric fields generated by a point source within the stack are evaluated far away, they can be written directly in terms of the electric fields that would be generated at the location of the current source by plane waves incident from the direction of the observation point. We show that this follows from the Lorentz reciprocity theorem. Thus, in this case the formalism of Green's functions is not needed

  8. Multimedia Traffic Routing in Multilayer WDM Networks

    CERN Document Server

    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.

  9. Fractional statistical theory of finite multilayer adsorption

    Science.gov (United States)

    Takara, E. A.; Quiroga, E.; Matoz-Fernandez, D. A.; Ochoa, N. A.; Ramirez-Pastor, A. J.

    2016-01-01

    In the present paper, finite multilayer adsorption is described as a fractional statistics problem, based on Haldane's statistics. In this scheme, the Helmholtz free energy and its derivatives are written in terms of a parameter g, which relates to the configuration of the molecules in the adsorbed state. For values of g ranging between 0 and 1 the formalism is used to model experimental data of bovine serum albumin (BSA) adsorbed onto an ion exchange resin for different values of pH and temperature. Excellent agreement between theory and experiments was found.

  10. Optics and multilayer coatings for EUVL systems

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Optical nutation in multilayered ellipsoidal quantum dots

    Science.gov (United States)

    Sadeghi, E.

    2015-09-01

    The optical nutation signal of two and three ellipsoidal quantum dots (EQD) with finite confinement potential in the presence of polarized laser field is considered. In this regard, the effective-mass approximation within a perturbation scheme is used and the induced effective polarization of atoms in the multilayered ellipsoidal quantum dots is calculated for GaAs/GaAlAs/GaAs structure. The results showed that the optical nutation peak depends not only on the thickness of the intermediate layer but also on the ellipticity constant.

  12. Oscillating magnetocaloric effect of a multilayer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Alisultanov, Z. Z., E-mail: zaur0102@gmail.com [Amirkhanov Institute of Physics, Russian Academy of Sciences, Dagestan Science Centre, Makhachkala (Russian Federation); Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Dagestan State University, Makhachkala (Russian Federation); Paixão, L. S.; Reis, M. S. [Instituto de Física, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza s/n, 24210-346 Niterói, RJ (Brazil)

    2014-12-08

    The oscillating magnetocaloric effect of a multilayer graphene in Bernal and rhombohedral stacking is investigated to extend the previous knowledge of the effect on a single layer graphene. We started from results of a tight-binding model and obtained analytical expressions for the thermodynamic potential and for the entropy change. The last exhibits the same dependence on field and temperature observed for other diamagnetic systems; it oscillates with the inverse magnetic field and presents a maximum value at a given temperature. The amplitude of the oscillating entropy change decreases with the number of layers and the stacking sequence rules the magnetocaloric properties of the system.

  13. Interface stress in Au/Ni multilayers

    DEFF Research Database (Denmark)

    Schweitz, K.O.; Böttiger, J.; Chevallier, J.; Feidenhans'l, Robert Krarup; Nielsen, Martin Meedom; Rasmussen, Frank Berg

    2000-01-01

    The effect of intermixing on the apparent interface stress is studied in < 111 >-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...

  14. Magnetic properties of Dy/Zr multilayers

    International Nuclear Information System (INIS)

    [Dy(xA)/Zr(30A)]n superlattices (x ? 30), were evaporated under ultra-high vacuum on Si(100) substrates. Magnetization measurements indicate that the antiferromagnetic transition occurring at 178K in bulk Dy is suppressed in the multilayers. This phenomenon is attributed to magnetoelastic effects induced by strains at Zr/Dy interfaces. A perpendicular magnetic anisotropy takes place for x ? 15. However, the magnetic anisotropy is found to depend markedly on the technique used for Dy deposition. (author). 11 refs., 4 figs

  15. Electron beam backscattering effect in multilayer materials

    International Nuclear Information System (INIS)

    The dependence of electron backscattering coefficient upon incident electron energy, material thickness and energy loss was reviewed. Effect of electron backscattering coefficient on electron processing was also described. Based on multi-penetration and multi-backscattering of incident electrons in multilayer materials, a program ED410 has been proposed for calculating the depth distribution of electron energy deposition and the dose factor in different substrate materials for different incident energy. By using a substrate and its backscattering effect, irradiation uniformity in electron processing can be greatly improved

  16. Shortest Path Discovery in the Multi-layered Social Network

    CERN Document Server

    Bródka, Piotr; Kazienko, Przemys?aw; 10.1109/ASONAM.2011.67

    2012-01-01

    Multi-layered social networks consist of the fixed set of nodes linked by multiple connections. These connections may be derived from different types of user activities logged in the IT system. To calculate any structural measures for multi-layered networks this multitude of relations should be coped with in the parameterized way. Two separate algorithms for evaluation of shortest paths in the multi-layered social network are proposed in the paper. The first one is based on pre-processing - aggregation of multiple links into single multi-layered edges, whereas in the second approach, many edges are processed 'on the fly' in the middle of path discovery. Experimental studies carried out on the DBLP database converted into the multi-layered social network are presented as well.

  17. Ecological Multilayer Networks: A New Frontier for Network Ecology

    CERN Document Server

    Pilosof, Shai; Kéfi, Sonia

    2015-01-01

    Networks provide a powerful approach to address myriad phenomena across ecology. Ecological systems are inherently 'multilayered'. For instance, species interact with one another in different ways and those interactions vary spatiotemporally. However, ecological networks are typically studied as ordinary (i.e., monolayer) networks. 'Multilayer networks' are currently at the forefront of network science, but ecological multilayer network studies have been sporadic and have not taken advantage of rapidly developing theory. Here we present the latest concepts and tools of multilayer network theory and discuss their application to ecology. This novel framework for the study of ecological multilayer networks encourages ecologists to move beyond monolayer network studies and facilitates ways for doing so. It thereby paves the way for novel, exciting research directions in network ecology.

  18. Enhanced piezoelectric response in the artificial ferroelectric polymer multilayers

    International Nuclear Information System (INIS)

    An actuator with a high piezoelectric response, the ferroelectric polymer multilayer actuator, is described. The ferroelectric polymer multilayers consisting of alternative ferroelectric poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) copolymer and relaxor poly(vinylidene fluoride-trifluoroethylene-chlorofloroethylene) (P(VDF-TrFE-CFE)) terpolymer with different periodicities and fixed total thickness are prepared by the Langmuir-Blodgett technique. Both X-ray diffraction and Raman spectroscopic measurements indicate that the structure of the multilayer with thin alternating layer is similar to that of the ferroelectric copolymer. Compared with that of the copolymer, it is found that the piezoelectric coefficient of the multilayer could be improved by 57%. We attributed the enhanced piezoelectric response of the multilayers to the internal electric fields that arises from the electrostatic couplings between different layers

  19. Clustering Network Layers With the Strata Multilayer Stochastic Block Model

    CERN Document Server

    Stanley, Natalie; Taylor, Dane; Mucha, Peter J

    2015-01-01

    Multilayer networks are a useful data structure for simultaneously capturing multiple types of relationships between a set of nodes. In such networks, each relational definition gives rise to a layer. While each layer provides its own set of information, community structure can be collectively utilized to discover and quantify underlying relational patterns. To most concisely extract information from a multilayer network, we propose to identify and combine sets of layers with meaningful similarities in community structure. In this paper, we describe the strata multilayer stochastic block model (sMLSBM), a probabilistic model for multilayer community structure. The assumption of the model is that there exist groups of layers, that we call strata, with community structure described by a common stochastic block model (SBM). That is, layers in a stratum exhibit similar node-to-community assignments as well as SBM probability parameters. Fitting the sMLSBM to a multilayer network provides a joint clustering of nod...

  20. Enhanced piezoelectric response in the artificial ferroelectric polymer multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, X. L.; Wang, J. L., E-mail: jlwang@mail.sitp.ac.cn, E-mail: lin-tie@mail.sitp.ac.cn; Tian, B. B.; Liu, B. L.; Wang, X. D.; Sun, S.; Zou, Y. H.; Lin, T., E-mail: jlwang@mail.sitp.ac.cn, E-mail: lin-tie@mail.sitp.ac.cn; Sun, J. L.; Meng, X. J.; Chu, J. H. [National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Yu Tian Road 500, Shanghai 200083 (China); University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049 (China)

    2014-12-01

    An actuator with a high piezoelectric response, the ferroelectric polymer multilayer actuator, is described. The ferroelectric polymer multilayers consisting of alternative ferroelectric poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) copolymer and relaxor poly(vinylidene fluoride-trifluoroethylene-chlorofloroethylene) (P(VDF-TrFE-CFE)) terpolymer with different periodicities and fixed total thickness are prepared by the Langmuir-Blodgett technique. Both X-ray diffraction and Raman spectroscopic measurements indicate that the structure of the multilayer with thin alternating layer is similar to that of the ferroelectric copolymer. Compared with that of the copolymer, it is found that the piezoelectric coefficient of the multilayer could be improved by 57%. We attributed the enhanced piezoelectric response of the multilayers to the internal electric fields that arises from the electrostatic couplings between different layers.

  1. RECURRENT SUBCLITORAL ABSCESS TREATED BY MARSUPIALIZATION

    Directory of Open Access Journals (Sweden)

    HORMOZ DABIRASHRAFI

    1986-05-01

    Full Text Available This is a report of a very rare case of recurrent subclitoral abscess. Its etiology and the best treatment of the disease is here in discussed. We, the same as Sur, believe that marsupialization is the most promising treatment. Recurrent periclitoral abscess has been described previously5. s ome of the authors believe that it is part of the pilonidal disease. The first pilonidal cyst in 7 the clitoral region was introduced by Palmer (1957."nAnother case of pilonidal sinus of clitoris was repor-2 ted by Betson . All of the researchers are not in this opinion that the disease is necessarily a pilonidal sinus 1 3,and, sometimes, there is not any hair in the epithelium lining of the cyst. One case of recurrent subclitoral abscess treated by marsupialization is presented here.

  2. Recurrent intramedullary epidermoid cyst of conus medullaris.

    LENUS (Irish Health Repository)

    Fleming, Christina

    2011-01-01

    Spinal intramedullary epidermoid cyst is a rare condition. Recurrent epidermoid cyst in the spine cord is known to occur. The authors describe a case of recurrent conus medullaris epidermoid cyst in a 24-year-old female. She initially presented at 7 years of age with bladder disturbance in the form of diurnal enuresis and recurrent urinary tract infection. MRI lumbar spine revealed a 4 cm conus medullaris epidermoid cyst. Since the initial presentation, the cyst had recurred seven times in the same location and she underwent surgical intervention in the form of exploration and debulking. This benign condition, owing to its anatomical location, has posed a surgical and overall management challenge. This occurrence is better managed in a tertiary-care centre requiring multi-disciplinary treatment approach.

  3. Geometry of $Q$-recurrent maps

    OpenAIRE

    Pérez, Rodrigo A.

    2003-01-01

    Given a critically periodic quadratic map with no secondary renormalizations, we introduce the notion of $Q$-recurrent quadratic polynomials. We show that the pieces of the principal nest of a $Q$-recurrent map $f_c$ converge in shape to the Julia set of $Q$. We use this fact to compute analytic invariants of the nest of $f_c$, to give a complete characterization of complex quadratic Fibonacci maps and to obtain a new auto-similarity result on the Mandelbrot set.

  4. Risk factors of recurrent anal sphincter ruptures

    DEFF Research Database (Denmark)

    Jangö, Hanna; Langhoff-Roos, J; Rosthøj, Steen; Sakse, A

    2012-01-01

    Please cite this paper as: Jangö H, Langhoff-Roos J, Rosthøj S, Sakse A. Risk factors of recurrent anal sphincter ruptures: a population-based cohort study. BJOG 2012;00:000-000 DOI: 10.1111/j.1471-0528.2012.03486.x. Objective? To determine the incidence and risk factors of recurrent anal sphincter rupture (ASR). Design? Population-based retrospective cohort study. Setting? Data were taken from the National Medical Birth Registry, Denmark. Population? Patients with a first and a second vaginal d...

  5. Recurrent breast sparganosis: Clinical and radiological findings

    International Nuclear Information System (INIS)

    We report a case of recurrent sparganosis of the breast within 6 months following surgical removal of worms from the breast. The patient was referred to our hospital with a palpable mass in the right breast. On admission, breast ultrasonography revealed a tortuous tubular hypoechoic lesion with indistinct margins within a surrounding hyperechoic area, which strongly suggested sparganosis. We performed surgical excision and confirmed sparganosis. After 6 months, the patient detected a new mass in her right breast and visited our hospital. Breast ultrasonography revealed similar features in a different area of the same breast. We confirmed recurrent sparganosis surgically

  6. Managing recurrent genital herpes with acyclovir

    Directory of Open Access Journals (Sweden)

    Bedi T

    1995-01-01

    Full Text Available Seventy five patients of recurrent genital herpes (RGH treated with oral or topical acyclovir and placebo were compared and followed for periods ranging 4 to 8 years in a prospective study. Oral acyclovir definitely helps RGH patients; it shortens healing time; postpones recurrences and instills confidence in the patients. There is sufficient evidence that RGH dies a natural death with time as seen after 8 years follow up in placebo group patients. Topical use of acyclovir cream is not as useful as believed.

  7. Mining Recurrent Pattern Identification on Large Database

    OpenAIRE

    Shivangi Srivastava; Ganesh Khadanga; Divya Gupta

    2014-01-01

    Recurrent pattern mining is an important problem in the context of data mining. In this paper data mining algorithms have been discussed and compared. Recurrent pattern mining has been an important area in data mining research and it is the first step in the analysis of data rising in a broad range of applications. The algorithms are compared with respect to the items like methodology and its basic principles in terms of the elements user like support, and scan of the database (full or parti...

  8. Mining Recurrent Pattern Identification on Large Database

    Directory of Open Access Journals (Sweden)

    Shivangi Srivastava

    2014-04-01

    Full Text Available Recurrent pattern mining is an important problem in the context of data mining. In this paper data mining algorithms have been discussed and compared. Recurrent pattern mining has been an important area in data mining research and it is the first step in the analysis of data rising in a broad range of applications. The algorithms are compared with respect to the items like methodology and its basic principles in terms of the elements user like support, and scan of the database (full or partial.

  9. Recurrent stupor due to lysinuric protein intolerance

    Directory of Open Access Journals (Sweden)

    Ahsan Moosa N

    2005-01-01

    Full Text Available Recurrent stupor in children is an uncommon clinical problem with a wide differential diagnosis; inherited metabolic disorders account for a vast majority. We report a 9-year-old girl with recurrent episodes of stupor. Initial episode was treated as viral encephalitis and the second episode was managed as non-convulsive status epilepticus. Hyperammonemia was detected in the last episode. Metabolic work-up after dietary protein challenge revealed classical biochemical features of lysinuric protein intolerance. She was managed with protein-restricted diet, which resulted in marked neurological improvement. LPI is a rare inherited metabolic disorder due to membrane transport defect of cationic amino acids.

  10. On the periods of generalized Fibonacci recurrences

    OpenAIRE

    Brent, Richard P.

    2010-01-01

    We give a simple condition for a linear recurrence (mod 2^w) of degree r to have the maximal possible period 2^(w-1).(2^r-1). It follows that the period is maximal in the cases of interest for pseudo-random number generation, i.e. for 3-term linear recurrences defined by trinomials which are primitive (mod 2) and of degree r > 2. We consider the enumeration of certain exceptional polynomials which do not give maximal period, and list all such polynomials of degree less than 15.

  11. Recurrent cystitis in non-pregnant women

    OpenAIRE

    Sen, Ayan

    2008-01-01

    Cystitis is a bacterial infection of the lower urinary tract which causes pain when passing urine, and causes frequency, urgency, haematuria, and suprapubic pain not associated with passing urine. Recurrent cystitis is usually defined as three episodes of UTI in the previous 12 months, or two episodes in the previous 6 months.It is common in young, healthy women, with one study finding 27% of women developing a second infection within 6 months of the first, and 2.7% having a second recurre...

  12. Recurrent peripheral odontogenic fibroma. Case report.

    Science.gov (United States)

    Patel, Stavan; Vakkas, John; Mandel, Louis

    2011-01-01

    Peripheral odontogenic fibroma (POF), an extraosseous variant of the central odontogenic fibroma, is considered an uncommon benign gingival lesion with a small recurrence rate. Clinically, it mimics a variety of benign neoplasms, metastases and reactive lesions, but it is most commonly confused with the peripheral ossifying fibroma. In this report, we describe a healthy 32-year-old male who was seen with a recurrent POF of the right maxilla. The surgical excision site was repaired using a free palatal graft, leading to a favorable outcome in an esthetic region of the oral cavity. PMID:21894830

  13. RECURRENT SUBCLITORAL ABSCESS TREATED BY MARSUPIALIZATION

    OpenAIRE

    HORMOZ DABIRASHRAFI; SIMIN KAMYAB TEHRANY

    1986-01-01

    This is a report of a very rare case of recurrent subclitoral abscess. Its etiology and the best treatment of the disease is here in discussed. We, the same as Sur, believe that marsupialization is the most promising treatment. Recurrent periclitoral abscess has been described previously5. s ome of the authors believe that it is part of the pilonidal disease. The first pilonidal cyst in 7 the clitoral region was introduced by Palmer (1957)."nAnother case of pilonidal sinus of clitoris wa...

  14. Finite element analysis of multilayer coextrusion.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Epidemic model with isolation in multilayer networks

    CERN Document Server

    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...

  16. Polymer multilayer tattooing for enhanced DNA vaccination

    Science.gov (United States)

    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.

  17. Mechanical properties of glass polymer multilayer composite

    Indian Academy of Sciences (India)

    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.

  18. Guided modes in a uniaxial multilayer

    Science.gov (United States)

    Avrutsky, Ivan

    2003-03-01

    An algorithm is presented for simulation of guided modes in a multilayer uniaxial structure with each layer characterized by its own ellipsoid of refractive indices and direction of optical axis. The proposed approach is based on presenting an electromagnetic field in each layer as a linear combination of ordinary and extraordinary waves coupled through the boundary conditions. The problem is reduced to two dimensions by considering the waves with a given projection of the wave vector on the plane of the waveguide. No a priori assumption about the guided-mode polarization is required in this method. Hybrid polarized modes appear naturally as solutions of a system of linear equations with respect to the amplitudes of the ordinary and extraordinary waves. The proposed approach covers a wide variety of important practical cases including isotropic waveguides, surface waves at the boundary between positive uniaxial crystal and isotropic medium, surface plasmons at metallic interfaces, uniaxial multilayers in a very general form, and leaky modes in such structures.

  19. Magneto-electronic properties of multilayer graphenes.

    Science.gov (United States)

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

    2015-10-21

    This article reviews the rich magneto-electronic properties of multilayer graphene systems. Multilayer graphenes are built from graphene sheets attracting one another by van der Waals forces; the magneto-electronic properties 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 particular, a formation of both intergroup and intragroup anticrossings is observed in ABC-stacked graphene. The aforementioned magneto-electronic properties lead to diverse optical spectra, plasma spectra, and transport properties when the stacking order and the number of layers are varied. The calculations are in agreement with optical and transport experiments, and novel features that have not yet been verified experimentally are presented. PMID:26388455

  20. Scattering cancellation by metamaterial cylindrical multilayers

    Science.gov (United States)

    Tricarico, S.; Bilotti, F.; Vegni, L.

    2009-05-01

    In this paper, we present the theoretical analysis and the design of cylindrical multilayered electromagnetic cloaks based on the scattering cancellation technique. We propose at first the analysis and the design of bi-layered cylindrical shells, made of homogenous and isotropic metamaterials, in order to effectively reduce the scattered field from a dielectric cylindrical object. The single shell and the bi-layered shell cases are compared in terms of scattering reduction and loss effects. The comparison shows that the bi-layered configuration exhibits superior performances. The scattering cancellation approach, is, then, extended to the case of generic multilayered cylindrical shells, considering again homogeneous and isotropic metamaterials. The employment of the proposed technique to the case of cloaking devices working at multiple frequencies is also envisaged and discussed. Finally, some practical layouts of cylindrical electromagnetic cloaks working at optical frequencies are also proposed. In these configurations, the homogenous and isotropic metamaterials are replaced by their actual counterparts, obtained using alternating stacked plasmonic and non-plasmonic layers. The theoretical formulation and the design approaches presented throughout the paper are validated through proper full-wave numerical simulations.

  1. Superconductivity and vortex properties in various multilayers

    International Nuclear Information System (INIS)

    In this thesis three qualitatively different type of superconducting multilayers are studied. We discuss the vortex lattice structure in Nb/NbZr multilayers, a system where both type of constituting layers are superconducting. At certain temperatures and for parallel fields close to Hc2parallel, the Nb/NbZr system has a strongly modulated order parameter, and in this aspect resembles the high-Tc materials. By lowering the field the modulation decreases, having important consequences for the vortex lattice structure. By studying the transport critical currents we show that in the case of strong modulation the vortex lattice has a kinked structure, but at weaker modulations the vortices are straight, and the change in modulation actually results in a vortex lattice transition. Our study confirms the picture of the existence of kinked vortex lattices, but it is rather surprising that these kinked structures can exist in a system which in itself is not at all that anisotropic. It indicates the relevance of other parameters governing the vortex lattice structure. (orig.)

  2. The parallel versus branching recurrences in computability logic

    CERN Document Server

    Xu, Wenyan

    2011-01-01

    This paper shows that the basic logic induced by the parallel recurrence of Computability Logic is a proper superset of the basic logic induced by the branching recurrence. The latter is known to be precisely captured by the cirquent calculus system CL15, conjectured by Japaridze to remain sound---but not complete---with parallel recurrence instead of branching recurrence. The present result is obtained by positively verifying that conjecture. A secondary result of the paper is showing that parallel recurrence is strictly weaker than branching recurrence in the sense that, while the latter logically implies the former, vice versa does not hold.

  3. Use of recurrence plot and recurrence quantification analysis in Taiwan unemployment rate time series

    Science.gov (United States)

    Chen, Wei-Shing

    2011-04-01

    The aim of the article is to answer the question if the Taiwan unemployment rate dynamics is generated by a non-linear deterministic dynamic process. This paper applies a recurrence plot and recurrence quantification approach based on the analysis of non-stationary hidden transition patterns of the unemployment rate of Taiwan. The case study uses the time series data of the Taiwan’s unemployment rate during the period from 1978/01 to 2010/06. The results show that recurrence techniques are able to identify various phases in the evolution of unemployment transition in Taiwan.

  4. Thermally induced structural modification in the Al/Zr multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Qi; Zhang, Zhong; Ma, Shuang; Qi, Runze; Li, Jia [MOE Key Laboratory of Advanced Micro-Structured Materials, Institute of Precision Optical Engineering, Department of Physics, Tongji University, Shanghai 200092 (China); Wang, Zhanshan, E-mail: wangzs@tongji.edu.cn [MOE Key Laboratory of Advanced Micro-Structured Materials, Institute of Precision Optical Engineering, Department of Physics, Tongji University, Shanghai 200092 (China); Jonnard, Philippe; Le Guen, Karine; André, Jean-Michel [Laboratoire de Chimie Physique – Matière Rayonnement, UPMC Univ Paris 06, CNRS UMR 7614, 11 rue Pierre et Marie Curie, F-75231 Paris cedex 05 (France)

    2013-08-15

    The effect of increasing temperature on the structural stability and interactions of two kinds of Al/Zr (Al(1%wtSi)/Zr and Al(Pure)/Zr) multilayer mirrors are investigated. All Al/Zr multilayers annealed from 200 °C to 500 °C were deposited on Si wafers by using direct-current magnetron sputtering technology. A detailed and consistent picture of the thermally induced changes in the microstructure is obtained using an array of complementary measurements including grazing incidence X-ray reflectometry, atomic force microscopy, X-ray diffraction and high-resolution transmission electron microscopy. The first significant structural changes of two systems are observed at 250 °C, characterized by asymmetrical interlayers appearing at interface. At 290 °C, the interface consisting of amorphous Al–Zr alloy is transformed to amorphous Al–Zr alloy and cubic ZrAl{sub 3} in both systems. At 298 °C for Al(1%wtSi)/Zr and 295 °C for Al(Pure)/Zr multilayers, the interfacial phases of Al–Zr alloy transform into polycrystalline mixtures of hcp-ZrAl{sub 2} and cubic-ZrAl{sub 3}, which smooth the interface boundary and lower the surface roughness in the multilayers. Up to 500 °C, the multilayer structure still exists in both systems, and the differences between the asymmetrical interlayers are much larger in the multilayers. Finally, we discuss the transformation from symmetrical to asymmetrical in the annealing process for other multilayer systems.

  5. Advances in polyelectrolyte multilayer nanofilms as tunable drug delivery systems

    Directory of Open Access Journals (Sweden)

    Bingbing Jiang

    2009-08-01

    Full Text Available Bingbing Jiang1, John B Barnett2,3, Bingyun Li1,4,5#1Biomaterials, Bioengineering and Nanotechnology Laboratory, Department of Orthopaedics, School of Medicine, 2Department of Microbiology, Immunology, and Cell Biology, 3Center for Immunopathology and Microbial Pathogenesis, School of Medicine, 5Department of Chemical Engineering, College of Engineering and Mineral Resources, West Virginia University, Morgantown, WV, USA; 4WVNano Initiative, Morgantown, WV, USA; #Aided by a grant from Osteosynthesis and Trauma Care (OTC FoundationAbstract: There has been considerable interest in polyelectrolyte multilayer nanofilms, which have a variety of applications ranging from optical and electrochemical materials to biomedical devices. Polyelectrolyte multilayer nanofilms are constructed from aqueous solutions using electrostatic layer-by-layer self-assembly of oppositely-charged polyelectrolytes on a solid substrate. Multifunctional polyelectrolyte multilayer nanofilms have been studied using charged dyes, metal and inorganic nanoparticles, DNA, proteins, and viruses. In the past few years, there has been increasing attention to developing polyelectrolyte multilayer nanofilms as drug delivery vehicles. In this mini-review, we present recent developments in polyelectrolyte multilayer nanofilms with tunable drug delivery properties, with particular emphasis on the strategies in tuning the loading and release of drugs in polyelectrolyte multilayer nanofilms as well as their applications.Keywords: nanofilm, polyelectrolyte multilayer, drug delivery, electrostatic layer-by-layer self-assembly, biomedical device, surface modification

  6. PET imaging of recurrent medullary thyroid cancer

    International Nuclear Information System (INIS)

    Medullary carcinoma of the thyroid gland is a rare tumor. Its prognosis is mainly linked to surgery, because there is no valid alternative therapy to improve patients outcome. In this report, we discuss the recurrence of such a tumor in a 64-year-old female, focusing on magnetic resonance imaging and positron emission tomography evaluation of this tumor. (orig.)

  7. Recurrence quantification analysis in Liu's attractor

    International Nuclear Information System (INIS)

    Recurrence Quantification Analysis is used to detect transitions chaos to periodical states or chaos to chaos in a new dynamical system proposed by Liu et al. This system contains a control parameter in the second equation and was originally introduced to investigate the forming mechanism of the compound structure of the chaotic attractor which exists when the control parameter is zero

  8. Recurrent septic arthritis due to Pseudomonas sp.

    OpenAIRE

    Dan, M.; Jedwab, M.; Shibolet, S.

    1981-01-01

    Two episodes of Pseudomonas septic arthritis occurred in an 84-year-old diabetic man separated by a 6 year interval. Pseudomonas is an unusual cause of septic arthritis requiring vigorous antibiotic therapy. The recurrence of the infection may be related to the inadequate response to treatment in the first episode, however, the long interval remains unexplained.

  9. Recurrent spinal adhesive arachnoiditis: a case report

    Directory of Open Access Journals (Sweden)

    James Pitágoras de Mattos

    1988-03-01

    Full Text Available Spinal adhesive arachnoiditis is not an uncommon disease, usually having a monophasic course. We studied an atypical patient with recurrent spinal adhesive arachnoiditis nine years after intrathecal anesthesia and the first attack of the disease. Also noteworthy was the favorable evolution after surgery.

  10. Recurrent Sepsis Caused by Streptococcus pyogenes?

    OpenAIRE

    Rasmussen, Magnus

    2011-01-01

    I report that a 75-year-old man with severe atherosclerosis experienced two episodes of bacteremia with Streptococcus pyogenes of type emm87. Recurrent sepsis with S. pyogenes is extremely rare, and a foot ulcer was the suspected point of entry. The patient did not develop opsonizing antibodies to the isolate.

  11. Harris Recurrence and MCMC: A Simplified Approach

    DEFF Research Database (Denmark)

    Asmussen, Søren; Glynn, Peter W.

    2010-01-01

    A key result underlying the theory of MCMC is that any ?-irreducible Markov chain having a transition density with respect to ? and possessing a stationary distribution is automatically positive Harris recurrent. This paper provides a short self-contained proof of this fact.

  12. Recurrent brain tumor with hydrocephalus in pregnancy.

    Science.gov (United States)

    Taylan, Enes; Akdemir, Ali; Zeybek, Burak; Ergenoglu, Ahmet Mete; Yeniel, Ahmet Ozgur

    2015-03-01

    Brain tumors during pregnancy are very rare. Diagnosis of this condition is difficult because the symptoms imitate pregnancy-related ailments. The management of this condition also presents challenges. This case report aims to present a successful treatment and delivery of a patient with recurrent brain tumor during pregnancy with hydrocephalus. PMID:25332049

  13. Recurrent Pneumonia due to Double Aortic Arch

    Directory of Open Access Journals (Sweden)

    I. Sedighi

    2012-04-01

    Full Text Available Introduction: Pneumonia is one of the most common infections during childhood. In children with recurrent bacterial pneumonia complete evaluation for underlying factors is necessary. The most common underlying diseases include: antibody deficiencies , cystic fibrosis , tracheoesophageal fistula and increased pulmonary blood flow. Vascular ring and its pressure effect is a less common cause of stridor and recurrent pneumonia. Congenital abnormalities in aortic arch and main branches which form vascular ring around esophagus and trachea with variable pressure effect cause respiratory symptoms such as stridor , wheezing and recurrent pneumoniaCase Report: A 2 year old boy was admitted in our hospital with respiratory distress and cough . Chest x-Ray demonstrated right lobar pneumonia. He had history of stridor and wheezing from neonatal period and hospitalization due to pneumonia for four times. The patient received appropriate antibiotics. Despite fever and respiratory distress improvement, wheezing continued. Review of his medical documents showed fixed pressure effect on posterior aspect of esophagus in barium swallow. In CT angiography we confirmed double aortic arch.Conclusion: Double aortic arch is one of the causes of persistant respiratory symptom and recurrent pneumonia in children for which fluoroscopic barium swallow is the first non-invasive diagnostic method.(Sci J Hamadan Univ Med Sci 2012;19(1:70-74

  14. Clinical pattern of recurrent herpes simplex keratitis

    Directory of Open Access Journals (Sweden)

    Saini Jagjit

    1999-01-01

    Full Text Available Purpose: To document the clinical pattern in recurrent herpes simplex disease. Methods: Eyes with clinically documented pattern of corneal manifestation on more than one occasion were analysed. For each eye recruited, the clinical pattern of the disease at each recurrence of herpes simplex corneal disease, age, disease-free intervals, triggering factors, laterality and steroid abuse were noted and evaluated. Results: For an average follow up of 6.9 years, a recurrence rate of 0.6 episodes per year was observed. Disease-free intervals of 75.7 months for epithelial herpes simplex disease was considerably longer than the 21.3 months observed for stromal disease. Clinical pattern of recurrence was of the same type following first episode of disciform keratitis, epithelial keratitis and endothelitis in 84%, 72.7%, and 75% of the eyes respectively. Conclusion: Herpes simplex disease often recurs in the same manifest clinical pattern as the first episode. This clinical evidence provides additional support for the potential role of herpes simplex biotypes in determining manifestation of clinical disease pattern.

  15. Recurrent Tuberculosis and Exogenous Reinfection, Shanghai, China

    OpenAIRE

    Shen, Guomiao; Xue, Zhen; Shen, Xin; SUN, Bin; Gui, Xiaohong; SHEN, MEI; Mei, Jian; Gao, Qian

    2006-01-01

    Of 52 patients with recurrent tuberculosis in Shanghai, People's Republic of China, 32 (61.5%) had isolates in which genotype patterns of Mycobacterium tuberculosis differed between first and second episodes. This result indicates that exogenous reinfection is common in an area with a high incidence of tuberculosis.

  16. Recurrent focal segmental glomerulosclerosis after kidney transplantation.

    Science.gov (United States)

    Trachtman, Rebecca; Sran, Simranjeet S; Trachtman, Howard

    2015-10-01

    Focal segmental glomerulosclerosis (FSGS) is an important cause of glomerular disease in children and adolescents and nearly 50 % of affected patients will progress to end-stage kidney disease over a 5 to 10-year period. Unfortunately, there is no established treatment for disease in the native kidney. Moreover, up to 55 % of patients develop recurrent disease after receiving a kidney transplant, with a substantially higher risk in patients who have already experienced recurrent disease in a prior transplant. A number of clinical and laboratory factors have been identified as risk factors for this complication. In addition, new investigations into podocyte biology and circulating permeability factors have shed light on the cause of recurrent the disease. While a number of novel therapeutic agents have been applied in the management of this problem, there still is no proven treatment. In this review, we summarize recent advances in the epidemiology, pathophysiology, and treatment of recurrent FSGS in pediatric patients who have received a kidney transplant. PMID:25690943

  17. Surgical Management of Recurrent Nasopharyngeal Carcinoma

    Directory of Open Access Journals (Sweden)

    Sheng-Po Hao

    2010-08-01

    Full Text Available Current standard treatment of nasopharyngeal carcinoma(NPC is either radiotherapy alone or combined chemoradiotherapy.Surgery in the form of nasopharyngectomy is usuallyonly offered when there is evidence of local recurrence or persistentdisease. Recurrent NPC (rNPC can be detected earlierwith the utilization of Epstein-Barr virus molecular diagnosis.This may result in early management with salvage surgery andhence improved survival. The facial translocation approachenhanced our ability to access the nasopharynx. Through amultidisciplinary approach with the collaboration of neurosurgeons,the surgical indication of salvage surgery is extended.This allowed improved respectability in locally advanced diseaseand involved the skull base and intracranial extensionwith reasonable morbidity and mortality. Endoscopic nasopharyngectomyis a choice for recurrent NPC with central roof orfloor lesions with minimal lateral extension. Multivariate analysis indicated that gender,parapharyngeal space involvement, surgical margin, and the modality of adjuvant therapyimpact significantly on local control. The impact on survival is indicated by the dura orbrain involvement, local recurrence and modality of adjuvant therapy. It is apparent thatrecurrent NPC patients who underwent surgery had a significantly better survival rate thanthe re-radiation therapy group.

  18. Chemoprophylaxis in the vesical tumoral recurrence

    International Nuclear Information System (INIS)

    The superficial bladder tumors are characterized by a high rate of recurrence taking place especially within the first two years that is even higher in the high risk groups. There is an agreement in the usefulness of the Calmette-Guerin Bacillus (CGB) to diminish the tumoral recurrence. The intravesical chemotherapy with other medications have demonstrated its profit or not in decreasing the recurrence of these bladder tumors. Between 1999 and 2008 we studied and treated 110 patients (96 men and 14 women), aged in average 63 years old. They were divided into three groups for the treatment of the tumoral recidivism after the transurethral resection or partial cystectomy, using three different chemoprophylactic agents and inmunomodulators (Thio-Tepa, BCG+Transference Factor, Doxorubicin +Interferon Alpha 2b). The objective of this research was presenting our experience in the treatment of these patients during five years, obtaining better results in the group treated with doxorubicin + interferon alpha 2b, followed by the group treated by means of BCG + transference factor, with a remarked decrease of the recurrence and a limitation in the long term progression of the disease

  19. Risk factors for recurrent vulvovaginal candidiasis

    Directory of Open Access Journals (Sweden)

    Jankovi? Slobodan

    2010-01-01

    Full Text Available Background/Aim. Recurrent vulvovaginal candidiasis is relatively frequent condition, and may have serious health consequences, like chronic vulvovaginal pain syndrome. The aim of our study was to determine possible risk factors for recurrent vulvovaginal candidiasis in non-pregnant females within the reproductive age. Methods. The design of our study was of a case-control type. Case and control patients were selected from the gynecological patients at six primary care facilities in Serbia and in Montenegro. The data on the patients' health condition, concomitant therapy and diseases were taken from their records, and the data on habits were obtained by unstructured interview. For potential risk factors crude odds ratios were calculated, and then adjusted by logistic regression. Results. A total of fifty-one patients had four or more episodes of vulvovaginal candidiasis during the last year (cases, and 132 patients with one to three episodes of vulvovaginal candidiasis were sampled as controls, matched by age. The only two significant associations were found between recurrent vulvovaginal candidiasis and continual wearing of panty liners during the last year (Odds ratio - ORadjusted: 3.97; confidence interval - CI: 1.57-10.02; p = 0.004, and between recurrent vulvovaginal candidiasis and predominant use of vaginal tampons during menstruation in the last year (ORadjusted: 4.25; CI: 1.11-16.27; p = 0.035. The synergistic effect was observed for the concurrent continual wearing of panty liners during the last year and selfmedication with antimycotics. Conclusions. Local factors, like wearing of panty liners or use of tampons during menstruation, may promote recurrence of vulvovaginal candidiasis, especially in patients who practice selfmedication with antimycotics.

  20. Erlotinib in Treating Patients With Recurrent Malignant Glioma or Recurrent or Progressive Meningioma

    Science.gov (United States)

    2014-07-09

    Adult Anaplastic Astrocytoma; Adult Anaplastic Oligodendroglioma; Adult Giant Cell Glioblastoma; Adult Glioblastoma; Adult Gliosarcoma; Adult Grade I Meningioma; Adult Grade II Meningioma; Adult Grade III Meningioma; Adult Mixed Glioma; Recurrent Adult Brain Tumor

  1. A new recurrence formula for generic exceptional orthogonal polynomials

    OpenAIRE

    Miki,Hiroshi; Tsujimoto, Satoshi

    2014-01-01

    A new recurrence relation for exceptional orthogonal polynomials is proposed, which holds for type 1, 2 and 3. As concrete examples, the recurrence relations are given for Xj-Hermite, Laguerre and Jacobi polynomials in j = 1,2 case.

  2. Operative findings in recurrent hernia after a Lichtenstein procedure.

    DEFF Research Database (Denmark)

    Bay-Nielsen, M; Nordin, P

    2001-01-01

    BACKGROUND: Recurrence after inguinal herniorraphy continues to be a problem, although the Lichtenstein technique (anterior, open fixated sheet mesh) is associated with reduced recurrence rates. Recurrence after Lichtenstein repair is suspected to be caused by insufficient fixation and overlap at the pubic tubercle. METHODS: A review was made of 87 records from operations for recurrence after a previous Lichtenstein procedure, based upon national and large area data bases, recording 95% (Denmark) and 50% (Sweden) of all inguinal hernia operations. RESULTS: Direct recurrences were found in 62%, whereas the remaining recurrences were either indirect (17%), femoral (13%), or other/unclassified (8%). CONCLUSION: The most plausible explanation for the development of the direct recurrences is an insufficient medial mesh fixation and overlap over the pubic tubercle. Avoidance of more than half of the recurrences after the Lichtenstein repair may be obtained by increased attention to this specific technical aspect ofthe operation.

  3. Multilayer coatings and their use in spectroscopic applications

    Energy Technology Data Exchange (ETDEWEB)

    Pelizzo, M.G., E-mail: pelizzo@dei.unipd.it [CNR—IFN UOS Padova, Via Trasea 7, 35131 Padova (Italy); DEI, Padua University, Via Gradenigo, 35131 Padova (Italy); Corso, A.J. [CNR—IFN UOS Padova, Via Trasea 7, 35131 Padova (Italy); DEI, Padua University, Via Gradenigo, 35131 Padova (Italy); Zuppella, P. [CNR—IFN UOS Padova, Via Trasea 7, 35131 Padova (Italy); Nicolosi, P. [DEI, Padua University, Via Gradenigo, 35131 Padova (Italy)

    2013-08-21

    Multilayers coatings are widely used in different fields ranging from new generation sources applications to astrophysical observations. Novel materials couples have been recently considered to improve the efficiency performances in different spectral regions. The deposition of capping layer structures onto standard periodic Mo/Si multilayers is used to add specific properties, such as high resistance to aging and different damage processes, or to regulate the reflectance in other spectral regions. This solution is adopted in the development of multilayer to be used in FERMI@ELETTRA FEL beam transport systems for third harmonics selection.

  4. Enhanced electrical properties from barium strontium titanate multilayer films

    Science.gov (United States)

    Wang, Xiaofei; Sun, Mengle; Zhang, Chao; Li, Liben; Chen, Qingdong

    2013-09-01

    Both multilayered and homogeneous BST films with the same ratio of Ba to Sr are prepared by metal-organic deposition on (111) Pt/Ti/SiO2/Si substrates. X-ray diffraction reveals the microstructure of the samples. Compared with the homogeneous BST film, the multilayered BST film shows improved electrical properties with smaller leakage current, larger dielectric constant, higher tunability and better ferroelectrity. These results are associated with the multilayered structure and strain-related interactions between layers, and the possible causes of which are discussed.

  5. Degradation of Ag/Si multilayers during heat treatments

    OpenAIRE

    Kapta, K.; Daroczi, L.; Papp, Z; Beke, D. L.; Langer, G A; Csik, A.; Kis-Varga, M.; A.L. Greer; Barber, Z. H.

    2009-01-01

    Microstructure changes during annealing of nano-crystalline silver and amorphous silicon multilayers (Ag/a-Si) have been studied by X-ray diffraction and transmission electron microscopy. The dc-magnetron sputtered Ag/a-Si multilayers remained stable even after annealing at 523K for 10h, and microstructural changes occurred only above 600K. The degradation of Ag/a-Si multilayers can be described by the increase of size of Ag grains, formation of grooves and pinholes at Ag gr...

  6. Magnetoresistance of electrodeposited iron-cobalt-nickel-copper multilayers

    International Nuclear Information System (INIS)

    Giant magnetoresistance (GMR) is observed in electrodeposited FeCoNiCu/Cu multilayers with Cu layer thickness varying from 1.0 to 2.5 nm at a fixed alloy layer thickness of 2.0 nm. A maximum GMR occurred at a copper layer thickness of 1.8 nm, which corresponds to the second maximum peak reported for similar multilayers fabricated by vapor deposition. The saturation magnetic field was considerably larger than that for the vapor deposited counterparts. The GMR of multilayers with a thicker alloy layer was sensitive to the magnetic field history, indicating the onset of anisotropic magnetoresistance

  7. Multilayer coatings and their use in spectroscopic applications

    International Nuclear Information System (INIS)

    Multilayers coatings are widely used in different fields ranging from new generation sources applications to astrophysical observations. Novel materials couples have been recently considered to improve the efficiency performances in different spectral regions. The deposition of capping layer structures onto standard periodic Mo/Si multilayers is used to add specific properties, such as high resistance to aging and different damage processes, or to regulate the reflectance in other spectral regions. This solution is adopted in the development of multilayer to be used in FERMI@ELETTRA FEL beam transport systems for third harmonics selection

  8. SOLID STATE AMORPHIZATION OF MgNi MULTILAYERS

    OpenAIRE

    Ben Ameur, T.; Yavari, A

    1990-01-01

    We report for the first time, the formation of amorphous MgNi alloys during cold-rolling of crystalline Mg-Ni multilayers. Amorphization of AB multilayers by solid state reaction usually occurs in systems with largely negative heats of mixing ?Hmix and with diffusivities DB ? DA in the amorphising A matrices. While the heat of formation of MgNi of the order of 10 % of that of ZrNi, Ni diffuses interstitially in Mg. We prepared MgNi multilayer composites with nominal atomic compositions MgxNi1...

  9. On degree-degree correlations in multilayer networks

    CERN Document Server

    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.

  10. Recovery and subsequent recurrence in patients with recurrent major depressive disorder

    OpenAIRE

    Dunlop, Boadie W.; Holland, Peter; Bao, Weihang; Ninan, Philip T.; Keller, Martin B.

    2012-01-01

    In contrast to “remission” from an episode of major depressive disorder (MDD), for which there is general agreement in the literature, the optimal definition of “recovery” from MDD is uncertain. Previous definitions of recovery have used inconsistent thresholds for symptom severity and duration of wellness. To address the effects of duration and degree of recovery from an episode of MDD on recurrence risk, and the impact of maintenance antidepressant treatment on recurrence, we analyzed 258 p...

  11. Anal incontinence in women with recurrent obstetric anal sphincter rupture

    DEFF Research Database (Denmark)

    Bøgeskov, Reneé; Nickelsen, Carsten Nahne Amtoft; Secher, Niels J

    2015-01-01

    UNLABELLED: Abstract Objectives: To determine the risk of recurrent anal sphincter rupture (ASR), and compare the risk of anal incontinence (AI) after recurrent ASR, with that seen in women with previous ASR who deliver by caesarean section or vaginally without sustaining a recurrent ASR. METHODS: Women with recurrent ASR between January 2000 and June 2011 were identified at two delivery wards in Copenhagen. The women answered a questionnaire with a validated scoring system for AI (St. Mark`s sc...

  12. The countable versus uncountable branching recurrences in computability logic

    CERN Document Server

    Xu, Wenyan

    2011-01-01

    This paper introduces a new simplified version of the countable branching recurrence of Computability Logic, proves its equivalence to the old one, and shows that the basic logic induced by it is a proper superset of the basic logic induced by the uncountable branching recurrence. A further result of this paper is showing that the countable branching recurrence is strictly weaker than the uncountable branching recurrence in the sense that the latter logically implies the former but not vice versa.

  13. Recurrent Dreams and Psychosocial Adjustment in Preteenaged Children

    OpenAIRE

    Gauchat, Aline; Zadra, Antonio; Tremblay, Richard E.; Zelazo, Philip David; Séguin, Jean R

    2009-01-01

    Research indicates that recurrent dreams in adults are associated with impoverished psychological well-being. Whether similar associations exist in children remains unknown. The authors hypothesized that children reporting recurrent dreams would show poorer psychosocial adjustment than children without recurrent dreams. One hundred sixty-eight 11-year-old children self-reported on their recurrent dreams and on measures of psychosocial adjustment. Although 35% of children reported having exper...

  14. Future directions of failed implantation and recurrent miscarriage research

    DEFF Research Database (Denmark)

    Christiansen, Ole B; Nielsen, Henriette Svarre; Kolte, Astrid M

    2006-01-01

    Recurrent implantation failure is today the major reason for women completing several IVF/intracytoplasmic sperm injection attempts without having achieved a child, and is probably also the explanation for many cases of unexplained infertility. Most causes of recurrent miscarriage are still poorly elucidated, but from a theoretical point of view recurrent implantation failure and recurrent miscarriage are suggested to have partly overlapping causes. Recent research has indeed documented that bot...

  15. Operative findings in recurrent hernia after a Lichtenstein procedure

    DEFF Research Database (Denmark)

    Bay-Nielsen, M; Nordin, P; Nilsson, E; Kehlet, H; NN, NN

    2001-01-01

    BACKGROUND: Recurrence after inguinal herniorraphy continues to be a problem, although the Lichtenstein technique (anterior, open fixated sheet mesh) is associated with reduced recurrence rates. Recurrence after Lichtenstein repair is suspected to be caused by insufficient fixation and overlap at the pubic tubercle. METHODS: A review was made of 87 records from operations for recurrence after a previous Lichtenstein procedure, based upon national and large area data bases, recording 95% (Denmark...

  16. Challenges of recurrent hepatitis C in the liver transplant patient

    OpenAIRE

    Dhanasekaran, Renumathy; Firpi, Roberto J.

    2014-01-01

    Cirrhosis secondary to hepatitis C virus (HCV) is a very common indication for liver transplant. Unfortunately recurrence of HCV is almost universal in patients who are viremic at the time of transplant. The progression of fibrosis has been shown to be more rapid in the post-transplant patients than in the transplant naïve, hence treatment of recurrent HCV needs to be considered for all patients with documented recurrent HCV. Management of recurrent HCV is a challenging situation both for pat...

  17. A New Family of Somos-like Recurrences

    OpenAIRE

    Heideman, Paul; Hogan, Emilie

    2007-01-01

    We exhibit a three parameter infinite family of quadratic recurrence relations inspired by the well known Somos sequences. For one infinite subfamily we prove that the recurrence generates an infinite sequence of integers by showing that the same sequence is generated by a linear recurrence (with suitable initial conditions). We also give conjectured relations among the three parameters so that the quadratic recurrences generate sequences of integers.

  18. Highly Swollen Porous Microstructures in Polyelectrolyte Multilayers

    Science.gov (United States)

    Cho, Chungyeon; Kaiser, Jeremy; Zacharia, Nicole

    2011-03-01

    We investigated the creation of porous morphologies from polyelectrolyte multilayers (PEMs) consisting of linear poly(ethylenimine) and poly(acrylic acid), and poly (allylamine hydrochloride) and poly (acrylic acid) as a function of pH and immersion time under post-base assembly treatment. The porous transition is linked to the neutralization of the polycations electrolytes as well as ionization of PAA by the exposing LbL films to high pH. This causes PEMs to undergo spinodal decomposition, creating pores and an increase in film thickness. By using reactive wet stamping technique, we were able to locally cause porosity changes under high pH conditions in the LbL films. Further investigation of the mechanical properties of patterned LbL films was done by performing nano-indentation analysis. The results showed clear difference of physical properties such as hardness and modulus between stamped and unstamped regions based on porous transition.

  19. Brownian Thermal Noise in Multilayer Coated Mirrors

    CERN Document Server

    Hong, Ting; Gustafson, Eric K; Adhikari, Rana X; Chen, Yanbei

    2012-01-01

    We analyze the Brownian thermal noise of a multi-layer dielectric coating, used in high-precision optical measurements including interferometric gravitational-wave detectors. We assume the coating material to be isotropic, and therefore study thermal noises arising from shear and bulk losses of the coating materials. We show that coating noise arises not only from layer thickness fluctuations, but also from fluctuations of the interface between the coating and substrate, driven by internal fluctuating stresses of the coating. In addition, the non-zero photoeleastic coefficients of the thin films modifies the influence of the thermal noise on the laser field. The thickness fluctuations of different layers are statistically independent, however, there exists a finite coherence between layers and the substrate-coating interface. Taking into account uncertainties in material parameters, we show that significant uncertainties still exist in estimating coating Brownian noise.

  20. Multilayer Bicontinuous DMRT Model for Terrestrial Snowpack

    Science.gov (United States)

    Xu, X.; Tan, S.; Tsang, L.; Yueh, S. H.; Lemmetyinen, J.

    2013-12-01

    Recently the bicontinuous model has drawn a lot of attention due to its ability of representing the complex structure of the snow samples. In the previous paper, we discussed the generation of the bicontinuous microstructure for snow sample, the statistical characterization of the bicontinuous media and the electromagnetic scattering properties. This flexibility of the snow sample generation and corresponding distinct scattering properties made the bicontinuous model easier to handle a variety of snow types, from fresh snow to depth hoar. The backscattering of one layer of snow was calculated by combining the bicontinuous model into the dense media radiative transfer (DMRT) theory. The purpose of this paper is to illustrate the connection between the input parameters for bicontinuous configuration and snow pit measurements in detail and incorporate layering effect by extending the signal layer Bicontinuous/DMRT into multi-layer model. The digitized random morphology is generated by superimposing a large number of stochastic waves. The corresponding random function is determined by the cutting level, the shape and scale parameters of the distribution function. By using those three parameters, the equations have been derived to calculate the snow density, auto correlation function, specific surface area of the snow and effective snow grain sizes. That means we can set up the bicontinuous model according to the snow pit measurements. Then, we check the scattering coefficients of the bicontinuous sample verses different snow densities and grain sizes, which is in agree with the experiments. Moderate forward scattering has been found in the new model by calculating the mean cosine. Next, we couple the bicontinuous model with the multi-layer DMRT. In general, snow from different storms will go through different metamorphism and form layered structure. Therefore, we take into account the layering effect by formulating the multi-layer DMRT. The bistatic scattering properties of the differential snow volume are calculated from bicontinuous model for each layer. To solve the dense media radiative transfer equation for layered snow, the specific intensity in the equation is decomposed into a sum of the reduced intensity and diffuse intensity. The reduced intensities in every layer can be solved analytically. We decompose the diffuse intensities into Fourier series in the azimuthal direction, and then using the Eigen-quadrature approach to solve the coefficient of every harmonic. We consider full multiple scattering effects with 16 Gaussian quadrature angles. As for the ground surface under the snow, the rough surface effect is considered through a look up table. The look up table is generated by solving full wave simulations of Numerical Maxwell Model in 3 Dimensional (NMM3D) rough surfaces. The Bicontinuous/DMRT multi-layer model has been validated by the data acquired at Colorado with 13.4GHz POLSCAT data and at Finland with the dual frequency (9.6GHz &17.2 GHz) SNOWSAR data.

  1. A multilayer surface detector for ultracold neutrons

    CERN Document Server

    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.

  2. Multilayer X-ray imaging systems

    Science.gov (United States)

    Shealy, David L.; Gabardi, David R.; Hoover, Richard B.

    1986-01-01

    An assessment of the imaging properties of multilayer X-ray imaging systems with spherical surfaces has been made. A ray trace analysis was performed to investigate the effects of using spherical substrates (rather than the conventional paraboloidal/hyperboloidal contours) for doubly reflecting Cassegrain telescopes. These investigations were carried out for mirrors designed to operate at selected soft X-ray/XUV wavelengths that are of significance for studies of the solar corona/transition region from the Stanford/MSFC Rocket X-Ray Telescope. The effects of changes in separation of the primary and secondary elements were also investigated. These theoretical results are presented as well as the results of ray trace studies to establish the resolution and vignetting effects as a function of field angle and system parameters.

  3. PROACTIVE NETWORK SECURITYAPPROACH FOR MULTILAYERED ARCHITECURE

    Directory of Open Access Journals (Sweden)

    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.

  4. Fast multilayer fission chamber with 239Pu

    Science.gov (United States)

    Bogdzel, A. A.; Gundorin, N. A.; Duka-Zolyòmi, À.; Kliman, J.; Grigoriev, Yu. V.

    1994-04-01

    For the investigation of neutron induced fission of heavy nuclei in the resonance energy range the fast multilayer ionization fission chamber with a 239Pu content of 1.6 g was constructed. The chamber is compact and a minimum of material has been used for its construction. The chamber is divided into 19 sections containing no more than 100 mg of 239Pu in a section whose intrinsic capacity is less than 100 pF. By using fast preamplifiers and constant fraction discriminators together with the combined method of amplitude and pulse length discrimination the background due to ?-particles is suppressed and a less perturbed pulse height distribution is obtained. The absolute fission fragments detection efficiency of the chamber is (60±8)%. Its time resolution does not exceed 2.6 ns.

  5. Fast multilayer fission chamber with 239Pu

    International Nuclear Information System (INIS)

    For the investigation of neutron induced fission of heavy nuclei in the resonance energy range, a fast multilayer ionization fission chamber with a 239Pu content of 1.6 g was constructed. The chamber is compact and a minimum of material has been used for its construction. There is not more than 100 mg of plutonium in every section whose intrinsic capacity is less than 100 pF. By using fast preamplifiers and constant fraction discriminators, together with the combined method of amplitude and pulse length discrimination the background due to ?-particles is suppressed and a less perturbed pulse height distribution is obtained. The absolute fission fragment detection efficiency of the chamber is (60±8)%. Its time resolution does not exceed 2.6 ns

  6. An ultra-broadband multilayered graphene absorber

    KAUST Repository

    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.

  7. Plasmon Resonance in Multilayer Graphene Nanoribbons

    CERN Document Server

    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...

  8. Optimisation of Multilayer Insulation an Engineering Approach

    CERN Document Server

    Chorowski, M; Parente, C; Riddone, G

    2001-01-01

    A mathematical model has been developed to describe the heat flux through multilayer insulation (MLI). The total heat flux between the layers is the result of three distinct heat transfer modes: radiation, residual gas conduction and solid spacer conduction. The model describes the MLI behaviour considering a layer-to-layer approach and is based on an electrical analogy, in which the three heat transfer modes are treated as parallel thermal impedances. The values of each of the transfer mode vary from layer to layer, although the total heat flux remains constant across the whole MLI blanket. The model enables the optimisation of the insulation with regard to different MLI parameters, such as residual gas pressure, number of layers and boundary temperatures. The model has been tested with experimental measurements carried out at CERN and the results revealed to be in a good agreement, especially for insulation vacuum between 10-5 Pa and 10-3 Pa.

  9. Recurrent Klebsiella pneumoniae Liver Abscess: Clinical and Microbiological Characteristics?

    OpenAIRE

    Yang, Ya-Sung; Siu, L K; Yeh, Kuo-Ming; Fung, Chang-Phong; Huang, Shenq-Jie; Hung, Han-Chang; Lin, Jung-Chung; Chang, Feng-Yee

    2009-01-01

    Recurrent Klebsiella pneumoniae liver abscesses (KLAs) are rarely reported. Six cases of recurrent KLAs are characterized. Most of the patients had diabetes and K1 serotype KLAs. All of the isolates were uniformly susceptible to cefazolin. Distinct molecular fingerprints were found for the strains isolated from both primary and recurrent KLAs.

  10. Recurrent rates and risk factors associated with recurrent painful bullous keratopathy after primary phototherapeutic keratectomy

    Directory of Open Access Journals (Sweden)

    Kasetsuwan N

    2015-09-01

    Full Text Available Ngamjit Kasetsuwan, Kanokorn Sakpisuttivanit, Usanee Reinprayoon, Vilavun Puangsricharern Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok, Thailand Objective: To assess the recurrent rate, mean survival time, and risk factors associated with recurrent painful bullous keratopathy (BK after primary treatment with phototherapeutic keratectomy.Methods: Medical records from 72 patients (72 eyes who had phototherapeutic keratectomy for painful BK were evaluated. Data for sex, age, duration of BK, associated ocular and systemic diseases (hypertension, diabetes mellitus, ischemic heart disease, asthma, dyslipidemia, and rheumatoid arthritis, frequency and degree of pain (grade 1–3, visual acuity, corneal thickness, intraocular pressure, and laser setting were extracted and analyzed.Results: The mean age of the patients was 64.2±11.4 years. The mean preoperative duration of BK was 15.0±11.0 months. Most patients had pseudophakic BK (69.40%. Majority of the cases had grade 3 degree of pain (48.60%. Glaucoma and hypertension were markedly found among these patients (51.40% and 19.40%, respectively. Preoperative mean intraocular pressure and corneal thickness were 13.70±4.95 mmHg and 734.1±83.80 µm, respectively. The mean laser diameter and depth were 8.36±1.22 mm and 38.89±8.81 µm, respectively. Systemic disease was significantly associated with the risk for developing recurrent painful BK (P=0.022, hazard ratio [HR] 1.673, 95% confidence interval [CI] 1.08–2.58. The overall recurrent rate was 51%. The average duration time of recurrent painful BK was 17.3±12.9 months (range 1–50 months. The median survival time before recurrence was 29.0±6.6 months.Conclusion: Systemic disease was found to be the only risk factor significantly associated with the development of recurrent painful BK. Low recurrent rate and long mean survival time showed that phototherapeutic keratectomy was effective in relieving recurrent painful BK and can be used as an alternative procedure for patients waiting for corneal transplantation. Keywords: bullous keratopathy, recurrent painful, phototherapeutic keratectomy, PTK, risk factor, mean survival time

  11. Sunitinib Malate in Treating Younger Patients With Recurrent, Refractory, or Progressive Malignant Glioma or Ependymoma

    Science.gov (United States)

    2015-08-18

    Childhood Cerebellar Anaplastic Astrocytoma; Childhood Cerebral Anaplastic Astrocytoma; Childhood Cerebral Astrocytoma; Childhood Infratentorial Ependymoma; Childhood Mixed Glioma; Childhood Oligodendroglioma; Childhood Supratentorial Ependymoma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Subependymal Giant Cell Astrocytoma

  12. Dual-Band EUV Multilayer Coatings for Solar Physics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and commercialize a new class of multilayer interference coating that is designed to provide high reflection efficiency in two disparate...

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

    Data.gov (United States)

    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...

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

    Data.gov (United States)

    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...

  15. Multi-layer Far-Infrared Component Technology Project

    Data.gov (United States)

    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...

  16. Magnetic properties of epitaxial and polycrystalline Fe/Si multilayers

    CERN Document Server

    Chaiken, A; Wang, C T

    1995-01-01

    Fe/Si multilayers with antiferromagnetic interlayer coupling have been grown via ion-beam sputtering on both glass and single-crystal substrates. High-angle x-ray diffraction measurements show that both sets of films have narrow Fe peaks, implying a large crystallite size and crystalline iron silicide spacer layers. Low-angle x-ray diffraction measurements show that films grown on glass have rougher interfaces than those grown on single-crystal substrates. The multilayers grown on glass have a larger remanent magnetization than the multilayers grown on single-crystal substrates. The observation of magnetocrystalline anisotropy in hysteresis loops and (hkl) peaks in x-ray diffraction demonstrates that the films grown on MgO and Ge are epitaxial. The smaller remanent magnetization in Fe/Si multilayers with better layering suggests that the remanence is not an intrinsic property.

  17. Developing Multilayer Thin Film Strain Sensors With High Thermal Stability

    Science.gov (United States)

    Wrbanek, John D.; Fralick, Gustave C.; Gonzalez, Jose M., III

    2006-01-01

    A multilayer thin film strain sensor for large temperature range use is under development using a reactively-sputtered process. The sensor is capable of being fabricated in fine line widths utilizing the sacrificial-layer lift-off process that is used for micro-fabricated noble-metal sensors. Tantalum nitride films were optimized using reactive sputtering with an unbalanced magnetron source. A first approximation model of multilayer resistance and temperature coefficient of resistance was used to set the film thicknesses in the multilayer film sensor. Two multifunctional sensors were fabricated using multilayered films of tantalum nitride and palladium chromium, and tested for low temperature resistivity, TCR and strain response. The low temperature coefficient of resistance of the films will result in improved stability in thin film sensors for low to high temperature use.

  18. Kinetics of multilayer deposition of colloidal particles in magnetic fields

    International Nuclear Information System (INIS)

    The kinetics of multilayer deposition of colloidal particles (hematite (?-Fe2O3), chromium (hydrous) oxide (Cr(OH)3, rod-like akageneite (?-FeOOH) and magnetite (Fe3O4) in distilled water) on C1018 steel beads is studied under the influence of magnetic fields. The study is conducted using a packed column technique under the conditions of constant flow rate (3 cm min-1) and pH value (11). The rate of deposition increases rapidly in a magnetic field which remains constant and at a late-stage deposition multilayers are formed. A model of multilayer deposition is proposed. The model involves new parameters which characterize the multilayer deposition probability

  19. Lamellar multilayer gratings with very high diffraction efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Martynov, V.V. [Russian Academy of Sciences, Moscow (Russian Federation). Institute of Microelectronics Technology]|[Lawrence Berkeley National Lab., CA (US); Yakshin, A.; Agafonov, Yu.A. [Russian Academy of Sciences, Moscow (Russian Federation). Institute of Microelectronics Technology; Padmore, H.A. [Lawrence Berkeley National Lab., CA (US)

    1997-07-01

    The authors report here the development of a hard x-ray multilayer grating that has achieved an absolute efficiency of 34% at a wavelength of 1.54{angstrom}. The W-C multilayer itself has a reflectivity of 57% and the grating has a 0th order absolute efficiency of 36%. The origin of this extraordinarily high efficiency is that the short period and highly asymmetric structure of the gratings combined with its deep grooves allows light to interact with a large number of layer pairs. This increases angular separation of the diffraction orders and reduces the multilayer bandwidth to the point where there is little or no order to order overlap in the grating structure, and hence maximum intensity can be diffracted into a selected order. This paper reports on the development of an optimized multilayer grating and some of its unique characteristics.

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

    Directory of Open Access Journals (Sweden)

    Jian Luo

    2008-03-01

    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.

  1. Shear banding deformation in Cu/Ta nano-multilayers

    International Nuclear Information System (INIS)

    Highlights: ? Formation of shear bands in Cu/Ta multilayers is layer thickness dependent. ? Unique layer-morphology with prevalent mismatched laminate structure was observed. ? A new physical mechanism that dominates shear band formation is suggested. - Abstract: Nanoscale Cu/Ta multilayers with individual layer thickness ranging from 3 to 70 nm were deformed under nanoindentation at room temperature. Shear bands can be observed only when individual layer thickness is reduced to 9 nm or below, indicating formation of shear bands in the Cu/Ta multilayers is layer thickness dependent. By observing the cross sectional transmission electron microscope images of the indentation fabricated through focused ion beam technique, shear banding deformation causing a unique layer-morphology with prevalent mismatched laminate structure has been reported for the first time. By capturing and analyzing a series of typical indentation-induced deformed microstructures, a new physical mechanism of shear banding behavior in metallic nano-multilayers is suggested.

  2. Direct and indirect electrocaloric measurements using multilayer capacitors

    International Nuclear Information System (INIS)

    We report the discovery of serendipitous electrocaloric (EC) effects in commercial multilayer capacitors based on ferroelectric BaTiO3. Direct thermometry records ?0.5 K changes due to 300 kV cm-1, over a wide range of temperatures near and above room temperature. Similar results are obtained indirectly, via thermodynamic analysis of ferroelectric hysteresis loops. We compare and contrast these two results. Optimized EC multilayer capacitors could find applications in future cooling technologies. (fast track communication)

  3. Characterization of Acoustic Waves in Multi-Layered Structures

    OpenAIRE

    Pykhteev, Oleg

    2011-01-01

    The work is devoted to the modeling of acoustic waves in multi-layered structures surrounded by a fluid and consisting of different kinds of materials including piezoelectric materials and composite multilayers. It consists of three parts. The first part describes the modeling of an acoustic sensor by the finite element method. The existence and uniqueness of a time-harmonic solution are rigorously established under physically appropriate assumptions. The convergence of Ritz-Galerkin solution...

  4. Multilayer DNA Origami Packed on Hexagonal and Hybrid Lattices

    OpenAIRE

    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 r...

  5. Young's modulus of polyelectrolyte multilayers from microcapsule swelling

    OpenAIRE

    Vinogradova, O. I.; D. Andrienko; Lulevich, V. V.; Nordschild, S.; Sukhorukov, G. B.

    2003-01-01

    We measure Young's modulus of a free polyelectrolyte multilayer film by studying osmotically induced swelling of polyelectrolyte multilayer microcapsules filled with the polyelectrolyte solution. Different filling techniques and core templates were used for the capsule preparation. Varying the concentration of the polyelectrolyte inside the capsule, its radius and the shell thickness yielded an estimate of an upper limit for Young's modulus of the order of 100 MPa. This corr...

  6. Three-dimensional ultrasonic imaging in multilayered media

    OpenAIRE

    Skjelvareid, Martin Hansen; Olofsson, Tomas; Birkelund, Yngve

    2011-01-01

    The synthetic aperture focusing technique is a method for focusing ultrasonic scans used in nondestructive testing. Traditionally, the technique has mainly been used for contact testing, where the speed of sound is constant throughout the whole medium, but a number of recently proposed algorithms have extended the technique to multilayered media. One important application for such multilayer methods is immersion testing, where an object is immersed in water and the transducer is scanned withi...

  7. Three-dimensional ultrasonic imaging in multilayered media

    OpenAIRE

    Skjelvareid, Martin Hansen; Olofsson, Tomas; Birkelund, Yngve

    2011-01-01

    The synthetic aperture focusing technique is a method for focusing ultrasonic scans used in nondestructive testing. Traditionally, the technique has mainly been used for contact testing, where the speed of sound is constant throughout the whole medium, but a number of recently proposed algorithms have extended the technique to multilayered media. One important application for such multilayer methods is immersion testing, where an object is immersed in water and the transducer is scanned wi...

  8. Fluorescence imaging assisted by surface modes on dielectric multilayers

    OpenAIRE

    Descrovi, E.; Morrone, D.; Angelini, A.; Frascella, F.; Ricciardi, S.; Rivolo, P.; De Leo, N.; Boarino, L.; Munzert, P.; Michelotti, F.; Giorgis, F.

    2014-01-01

    We propose a novel approach for wide-field fluorescence imaging based on dielectric multilayers on glass coverslides. It is demonstrated that the fluorescence radiated by emitters in proximity to the multilayer surface can couple to Bloch Surface Waves and subsequently leaks into the glass. The coupled fluorescence is beamed with low divergence according to the Bloch Surface Waves spectral/angular dispersion and then collected with a low-magnification imaging system. Since the coupling betwee...

  9. ATOM PROBE CHARACTERISATION OF Co/TRANSITION-METAL MULTILAYER STRUCTURES

    OpenAIRE

    CEREZO, A; Hetherington, M.; Petford-Long, A.

    1989-01-01

    Cobalt/transition-metal multilayer structures grown on Co field-ion specimens have been analysed by both conventional atom probe (AP) and the position-sensitive atom probe (POSAP). The combination of the two techniques allows the chemical abruptness and the roughness of the interfaces to be studied independently, and can be supported by high resolution transmission electron microscope (HREM) studies of multilayers deposited simultaneously on flat substrates. Layered structures can be formed w...

  10. Broad band invisibility cloak made of normal dielectric multilayer

    OpenAIRE

    Xu, Xiaofei; Feng, Yijun; 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 multilay...

  11. Quantum Mechanics of Spin Transfer in Ferromagnetic Multilayers

    OpenAIRE

    Kim, Wonkee; F. Marsiglio

    2004-01-01

    We use a quantum mechanical treatment of a ballistic spin current to describe novel aspects of spin transfer to a ferromagnetic multilayer. We demonstrate quantum phenomena from spin transmission resonance (STR) to magnetoelectric spin echo (MESE), depending on the coupling between the magnetic moments in the ferromagnetic thin films. Our calculation reveals new channels through which the zero spin transfer occurs in multilayers: the STR and MESE. We also illustrate that cou...

  12. MONOCHROMATIC X-RAY AND XUV IMAGING WITH MULTILAYER OPTICS

    OpenAIRE

    Walker, A.; Lindblom, J.; Hoover, R; Barbee, T.

    1988-01-01

    The development of techniques for the fabrication of multilayer coated mirrors which can function as energy selective X-ray and XUV mirrors at normal incidence has greatly expanded the options available to the astronomical spectroscopist. We have developed a rocket spectroheliograph which utilizes multilayer optics in three configurations : i) As Cassegrain telescopes for imaging at 256 Å (He II) and 173 Å (Fe IX, X ) ; ii) As tertiary mirrors used with a conventional Wolter I telescope for i...

  13. Thermodynamics of Polydomain Ferroelectric Bilayers and Graded Multilayers

    OpenAIRE

    Roytburd, A. L.; Slutsker, J.

    2006-01-01

    The equilibrium domain structure and its evolution under an electric field in ferroelectric bilayers and graded multilayers are considered. The equilibrium bilayer is self-poled and contains a single-domain and a polydomain (with 180 domains) layers. The polarization of a graded multilayer proceeds by movement of wedge-like domains as a result of progressive transformation of polydomain layers to a single-domain state. The theory provides the principal explanation of peculia...

  14. Tardive and chronically recurrent oculogyric crises.

    Science.gov (United States)

    Sachdev, P

    1993-01-01

    Six patients with chronically recurrent oculogyric crises (OGC) are reported. Four of these were derived from a study of 100 schizophrenic patients on maintenance neuroleptic medication, thereby giving a prevalence of 4% in such patients. Three of the six had the OGC develop as a tardive side-effect, and in one patient the episodes persisted for some months after the cessation of the offending neuroleptic drug. The episodes of ocular dystonia were associated with other dystonic movements and a number of psychiatric symptoms, with obsessional thoughts and hallucinations being the outstanding features in one patient each. This paper argues for an increased recognition of chronically recurrent and tardive OGC. It also draws attention to the fact that drug-induced OGC may be a multifaceted disorder with disturbances of movement, thought, behavior, and emotion, reminiscent of the OGC described in association with epidemic encephalitis lethargica. PMID:8093550

  15. Human papillomavirus types and recurrent cervical warts

    Energy Technology Data Exchange (ETDEWEB)

    Nuovo, G.J. (Columbia Presbyterian Medical Center, New York, NY (USA)); Pedemonte, B.M. (Harlem Hospital Medical Center, New York, NY (USA))

    1990-03-02

    The authors analyzed cervical intraepithelial neoplasias (CINs) detected after cryotherapy to determine if recurrence is associated with the same human papillomavirus (HPV) type found in the original lesion. Eight women had detectable HPV DNA in CINs that occurred after ablation of another CIN, and for each patient the HPV type in the pretreatment lesion was different from that in the CIN that appeared after cryotherapy. This compares with 12 women who had HPV detected in two or more CINs present at the same time, 11 of whom had the same HPv type noted. they concluded that although multiple, simultaneous CINs in a woman often contain the same HPV type, recurrent CINs that occur after cryotherapy contain an HPV type different from that present in the pretreatment lesion.

  16. An unusual cause for recurrent chest infections.

    LENUS (Irish Health Repository)

    Lobo, Ronstan

    2012-10-01

    We present a case of an elderly non-smoking gentleman who, since 2005, had been admitted multiple times for recurrent episodes of shortness of breath, wheeze, cough and sputum. The patient was treated as exacerbations of chronic obstructive pulmonary disease (COPD) and\\/or lower respiratory tract infections. Bronchoscopy was done which revealed multiple hard nodules in the trachea and bronchi with posterior tracheal wall sparing. Biopsies confirmed this as tracheopathia osteochondroplastica (TO). He had increasing frequency of admission due to methicillin-resistant Staphylococcus aureus and pseudomonas infections, which failed to clear despite intravenous, prolonged oral and nebulised antibiotics. The patient developed increasing respiratory distress and respiratory failure. The patient died peacefully in 2012. This case report highlights the typical pathological and radiological findings of TO and the pitfalls of misdiagnosing patients with recurrent chest infections as COPD.

  17. Radiotherapeutic alternatives for previously irradiated recurrent gliomas

    International Nuclear Information System (INIS)

    Re-irradiation for recurrent gliomas has been discussed controversially in the past. This was mainly due to only marginal palliation while being associated with a high risk for side effects using conventional radiotherapy. With modern high-precision radiotherapy re-irradiation has become a more wide-spread, effective and well-tolerated treatment option. Besides external beam radiotherapy, a number of invasive and/or intraoperative radiation techniques have been evaluated in patients with recurrent gliomas. The present article is a review on the available methods in radiation oncology and summarizes results with respect to outcome and side effects in comparison to clinical results after neurosurgical resection or different chemotherapeutic approaches

  18. Equine recurrent uveitis: Human and equine perspectives.

    Science.gov (United States)

    Malalana, Fernando; Stylianides, Amira; McGowan, Catherine

    2015-10-01

    Equine recurrent uveitis (ERU) is a spontaneous disease characterised by repeated episodes of intraocular inflammation. The epidemiology of ERU has not been fully elucidated, but the condition appears to be much more common in horses than is recurrent uveitis in humans, especially in certain breeds and geographical regions. Both humans and horses show a similarly altered immune response and a marked autoimmune response as the primary disease pathophysiology. However, an inciting cause is not always clear. Potential inciting factors in horses include microbial agents such as Leptospira spp. Microbial factors and genetic predisposition to the disease may provide clues as to why the horse appears so susceptible to this disease. The aim of this review is to discuss the immunology and genetics of ERU, compare the disease in horses with autoimmune anterior uveitis in humans, and discuss potential reasons for the increased prevalence in the horse. PMID:26188862

  19. Recurrent Oligodendroglioma Treated with Acupuncture and Pharmacopuncture.

    Science.gov (United States)

    Kim, Jae Soo; Lee, Hyun Jong; Lee, Sang Hoon; Lee, Bong Hyo

    2015-06-01

    Acupuncture and pharmacopuncture have been shown to be effective in tumor treatment. However, their effectiveness for treating oligodendroglioma has not been reported yet. The purpose of this study was to provide an initial report on the effectiveness of acupuncture and pharmacopuncture for the treatment of an oligodendroglioma by presenting a case that was treated successfully. A 54-year-old man, who had experienced intracranial hemorrhage, was diagnosed with recurrent oligodendroglioma. His expected survival period was 3-6 months. The patient received daily acupuncture and weekly pharmacopuncture of mountain ginseng and bee venom. After treatment for 18 months, the tumor size was decreased markedly on brain magnetic resonance imaging, and severe seizures had disappeared. In this case, a combination of acupuncture and pharmacopuncture was shown to be effective for the treatment of recurrent oligodendroglioma. PMID:26100069

  20. Human papillomavirus types and recurrent cervical warts

    International Nuclear Information System (INIS)

    The authors analyzed cervical intraepithelial neoplasias (CINs) detected after cryotherapy to determine if recurrence is associated with the same human papillomavirus (HPV) type found in the original lesion. Eight women had detectable HPV DNA in CINs that occurred after ablation of another CIN, and for each patient the HPV type in the pretreatment lesion was different from that in the CIN that appeared after cryotherapy. This compares with 12 women who had HPV detected in two or more CINs present at the same time, 11 of whom had the same HPv type noted. they concluded that although multiple, simultaneous CINs in a woman often contain the same HPV type, recurrent CINs that occur after cryotherapy contain an HPV type different from that present in the pretreatment lesion

  1. Stochastic Variational Learning in Recurrent Spiking Networks

    Directory of Open Access Journals (Sweden)

    Danilo Jimenez Rezende

    2014-04-01

    Full Text Available The ability to learn and perform statistical inference with biologically plausible recurrent network of spiking neurons is an important step towards understanding perception and reasoning. Here we derive and investigate a new learning rule for recurrent spiking networks with hidden neurons, combining principles from variational learning and reinforcement learning. Our network defines a generative model over spike train histories and the derived learning rule has the form of a local Spike Timing Dependent Plasticity rule modulated by global factors (neuromodulators conveying information about ``novelty" on a statistically rigorous ground.Simulations show that our model is able to learn bothstationary and non-stationary patterns of spike trains.We also propose one experiment that could potentially be performed with animals in order to test the dynamics of the predicted novelty signal.

  2. Supervised Sequence Labelling with Recurrent Neural Networks

    CERN Document Server

    Graves, Alex

    2012-01-01

    Supervised sequence labelling is a vital area of machine learning, encompassing tasks such as speech, handwriting and gesture recognition, protein secondary structure prediction and part-of-speech tagging. Recurrent neural networks are powerful sequence learning tools—robust to input noise and distortion, able to exploit long-range contextual information—that would seem ideally suited to such problems. However their role in large-scale sequence labelling systems has so far been auxiliary.    The goal of this book is a complete framework for classifying and transcribing sequential data with recurrent neural networks only. Three main innovations are introduced in order to realise this goal. Firstly, the connectionist temporal classification output layer allows the framework to be trained with unsegmented target sequences, such as phoneme-level speech transcriptions; this is in contrast to previous connectionist approaches, which were dependent on error-prone prior segmentation. Secondly, multidimensional...

  3. Desktop aligner for fabrication of multilayer microfluidic devices

    Science.gov (United States)

    Li, Xiang; Yu, Zeta Tak For; Geraldo, Dalton; Weng, Shinuo; Alve, Nitesh; Dun, Wu; Kini, Akshay; Patel, Karan; Shu, Roberto; Zhang, Feng; Li, Gang; Jin, Qinghui; Fu, Jianping

    2015-07-01

    Multilayer assembly is a commonly used technique to construct multilayer polydimethylsiloxane (PDMS)-based microfluidic devices with complex 3D architecture and connectivity for large-scale microfluidic integration. Accurate alignment of structure features on different PDMS layers before their permanent bonding is critical in determining the yield and quality of assembled multilayer microfluidic devices. Herein, we report a custom-built desktop aligner capable of both local and global alignments of PDMS layers covering a broad size range. Two digital microscopes were incorporated into the aligner design to allow accurate global alignment of PDMS structures up to 4 in. in diameter. Both local and global alignment accuracies of the desktop aligner were determined to be about 20 ?m cm-1. To demonstrate its utility for fabrication of integrated multilayer PDMS microfluidic devices, we applied the desktop aligner to achieve accurate alignment of different functional PDMS layers in multilayer microfluidics including an organs-on-chips device as well as a microfluidic device integrated with vertical passages connecting channels located in different PDMS layers. Owing to its convenient operation, high accuracy, low cost, light weight, and portability, the desktop aligner is useful for microfluidic researchers to achieve rapid and accurate alignment for generating multilayer PDMS microfluidic devices.

  4. Recurrent Vertigo: Is it Takayasu's Arteritis?

    OpenAIRE

    Tiwari Ashutosh; Kumar Nilesh; Varshney Ankur Nandan; Behera Dibyaranjan; Anand Arvind; Anand Ravi; Singh, N.K. (Nitin)

    2013-01-01

    Takayasu's arteritis (TA) is a chronic, idiopathic, inflammatory disease, that is more common in females and Asian countries. A 38-year-old female presented with recurrent vertigo. Detailed examination revealed discrepancies in peripheral pulses and raised blood pressure in bilateral lower limbs. Possibility of vasculitis involving arch of aorta or its branches was kept. Investigations were suggestive of Takayasu's arteritis, and noncontrast tomographic scanning (NCCT) of head showed B/L pari...

  5. Sibling recurrence risk in Dupuytren's disease.

    OpenAIRE

    Capstick, R; Bragg, T; Giele, H; Furniss, D

    2013-01-01

    Dupuytren's disease is a complex condition, with both genetic and environmental factors contributing to its aetiology. We aimed to quantify the extent to which genetic factors predispose to the disease, through the calculation of sibling recurrence risk (ls), and to calculate the proportion of heritability accounted for by currently known genetic loci. From 174 siblings of patients with surgically confirmed disease, 100 were randomly selected. Controls were recruited from patients attending a...

  6. Research Methodology in Recurrent Pregnancy Loss

    DEFF Research Database (Denmark)

    Christiansen, Ole B

    2014-01-01

    The aim of this article is to highlight pitfalls in research methodology that may explain why studies in recurrent pregnancy loss (RPL) often provide very divergent results. It is hoped that insight into this issue may help clinicians decide which published studies are the most valid. It may help researchers to eliminate methodological flaws in future studies, which may hopefully come to some kind of agreement about the usefulness of diagnostic tests and treatments in RPL.

  7. Current management of locally recurrent rectal cancer

    DEFF Research Database (Denmark)

    Nielsen, Mette Bak; Laurberg, Søren; Holm, Thorbjörn

    2011-01-01

    ABSTRACT Objective: A review of the literature was undertaken to provide an overview of the surgical management of locally recurrent rectal cancer (LRRC) after the introduction of total mesorectal excision (TME). Method: A systematic literature search was undertaken using PubMed, Embase, Web of Science and Cochrane databases. Only studies on patients having surgery for their primary tumour after 1995, or if more than half of the patients were operated on after 1995, were considered for analysis....

  8. Current management of locally recurrent rectal cancer

    DEFF Research Database (Denmark)

    Nielsen, M B; Laurberg, S; Holm, T

    2009-01-01

    Abstract Objective: A review of the literature was undertaken to provide an overview of the surgical management of locally recurrent rectal cancer (LRRC) after the introduction of total mesorectal excision (TME). Method: A systematic literature search was undertaken using PubMed, Embase, Web of Science and Cochrane databases. Only studies on patients having surgery for their primary tumour after 1995, or if more than half of the patients were operated on after 1995, were considered for analysis....

  9. Current management of locally recurrent rectal cancer

    DEFF Research Database (Denmark)

    Nielsen, M B; Laurberg, S; Holm, T

    2009-01-01

    ABSTRACT Objective: A review of the literature was undertaken to provide an overview of the surgical management of locally recurrent rectal cancer (LRRC) after the introduction of total mesorectal excision (TME). Method: A systematic literature search was undertaken using PubMed, Embase, Web of Science and Cochrane databases. Only studies on patients having surgery for their primary tumour after 1995, or if more than half of the patients were operated on after 1995, were considered for analysis....

  10. Manganese superoxide dismutase and breast cancer recurrence

    DEFF Research Database (Denmark)

    Cronin-Fenton, Deirdre P; Christensen, Mariann; Lash, Timothy L; Ahern, Thomas P; Pedersen, Lars; Garne, Jens Peter; Ewertz, Marianne; Autrup, Herman; Sørensen, Henrik T; Hamilton-Dutoit, Stephen

    2014-01-01

    Manganese superoxide dismutase (MnSOD) inhibits oxidative damage and cancer therapy effectiveness. A polymorphism in its encoding gene (SOD2: Val16Ala rs4880) may confer poorer breast cancer survival, but data are inconsistent. We examined the association of SOD2 genotype and breast cancer recurrence (BCR) among patients treated with cyclophosphamide-based chemotherapy (Cyclo). We compared our findings with published studies using meta-analyses.

  11. Recurrent flares in active region NOAA 11283

    Science.gov (United States)

    Romano, P.; Zuccarello, F.; Guglielmino, S. L.; Berrilli, F.; Bruno, R.; Carbone, V.; Consolini, G.; de Lauretis, M.; Del Moro, D.; Elmhamdi, A.; Ermolli, I.; Fineschi, S.; Francia, P.; Kordi, A. S.; Landi Degl'Innocenti, E.; Laurenza, M.; Lepreti, F.; Marcucci, M. F.; Pallocchia, G.; Pietropaolo, E.; Romoli, M.; Vecchio, A.; Vellante, M.; Villante, U.

    2015-10-01

    Context. Flares and coronal mass ejections (CMEs) are solar phenomena that are not yet fully understood. Several investigations have been performed to single out their related physical parameters that can be used as indices of the magnetic complexity leading to their occurrence. Aims: In order to shed light on the occurrence of recurrent flares and subsequent associated CMEs, we studied the active region NOAA 11283 where recurrent M and X GOES-class flares and CMEs occurred. Methods: We use vector magnetograms taken by HMI/SDO to calculate the horizontal velocity fields of the photospheric magnetic structures, the shear and the dip angles of the magnetic field, the magnetic helicity flux distribution, and the Poynting fluxes across the photosphere due to the emergence and the shearing of the magnetic field. Results: Although we do not observe consistent emerging magnetic flux through the photosphere during the observation time interval, we detected a monotonic increase of the magnetic helicity accumulated in the corona. We found that both the shear and the dip angles have high values along the main polarity inversion line (PIL) before and after all the events. We also note that before the main flare of X2.1 GOES class, the shearing motions seem to inject a more significant energy than the energy injected by the emergence of the magnetic field. Conclusions: We conclude that the very long duration (about 4 days) of the horizontal displacement of the main photospheric magnetic structures along the PIL has a primary role in the energy release during the recurrent flares. This peculiar horizontal velocity field also contributes to the monotonic injection of magnetic helicity into the corona. This process, coupled with the high shear and dip angles along the main PIL, appears to be responsible for the consecutive events of loss of equilibrium leading to the recurrent flares and CMEs. A movie associated to Fig. 4 is available in electronic form at http://www.aanda.org

  12. Research methodology in recurrent pregnancy loss

    DEFF Research Database (Denmark)

    Christiansen, Ole B

    2014-01-01

    The aim of this article is to highlight pitfalls in research methodology that may explain why studies in recurrent pregnancy loss (RPL) often provide very divergent results. It is hoped that insight into this issue may help clinicians decide which published studies are the most valid. It may help researchers to eliminate methodological flaws in future studies, which may hopefully come to some kind of agreement about the usefulness of diagnostic tests and treatments in RPL.

  13. Deep Recurrent Neural Networks for Acoustic Modelling

    OpenAIRE

    Chan, William; Lane, Ian

    2015-01-01

    We present a novel deep Recurrent Neural Network (RNN) model for acoustic modelling in Automatic Speech Recognition (ASR). We term our contribution as a TC-DNN-BLSTM-DNN model, the model combines a Deep Neural Network (DNN) with Time Convolution (TC), followed by a Bidirectional Long Short-Term Memory (BLSTM), and a final DNN. The first DNN acts as a feature processor to our model, the BLSTM then generates a context from the sequence acoustic signal, and the final DNN takes ...

  14. Recurrent binge eating in black American women.

    OpenAIRE

    Striegel-Moore, RH; Wilfley, DE; Pike, KM; Dohm, FA; Fairburn, CG

    2000-01-01

    CONTEXT: Recurrent binge eating is a core diagnostic feature of bulimia nervosa and binge eating disorder, and in samples of white women has been associated with obesity and psychiatric symptoms. Eating disorders have been believed to occur primarily among white women; in fact, the limited preliminary data available suggest that black women may be as likely as white women to report binge eating. OBJECTIVE: To examine race differences in prevalence of behavioral symptoms of eating disorders an...

  15. Recurrent opisthotonus in catatonia: An atypical presentation

    Directory of Open Access Journals (Sweden)

    Manjunatha Narayana

    2009-11-01

    Full Text Available Opisthotonus is known to occur in tetanus, rabies, cerebral malaria, neurosyphilis, acute cerebral injury and other medical conditions. Opisthotonus, so far, has not been reported in any major psychiatric disorder. Authors report a case of recurrent opisthotonus presenting concurrently with other catatonic signs which showed dramatic response to combination of lorazepam and electroconvulsive therapy (ECT. Clinicians should consider the possibility of catatonia in the differential diagnosis of opisthotonus since catatonia can be treated easily with benzodiazepines and ECT.

  16. A Case of Recurrent Superficial Acral Fibromyxoma

    OpenAIRE

    Goo, Jawoong; Jung, Ye-Jin; Kim, Jae-Hong; Lee, Sung-Yul; Ahn, Sung Ku

    2010-01-01

    Superficial acral fibromyxoma (SAFM) is a rare myxoid tumor that was first described in 2001. The presence of a very slow growing solitary tender mass in the subungual area is the typical clinical feature at presentation. Histopathologically, SAFM is composed of stellate cells in a myxocollagenous matrix with a poorly circumscribed margin. This tumor is thought to be benign, but its natural course is not fully understood. We describe a 15-year-old patient with recurrent SAFM and discuss the p...

  17. Disease recurrence in paediatric renal transplantation

    OpenAIRE

    Cochat, Pierre; Fargue, Sonia; Mestrallet, Guillaume; Jungraithmayr, Therese; Koch-Nogueira, Paulo; Ranchin, Bruno; Zimmerhackl, Lothar Bernd

    2009-01-01

    Renal transplantation (Tx) is the treatment of choice for end-stage renal disease. The incidence of acute rejection after renal Tx has decreased because of improving early immunosuppression, but the risk of disease recurrence (DR) is becoming relatively high, with a greater prevalence in children than in adults, thereby increasing patient morbidity, graft loss (GL) and, sometimes, mortality rate. The current overall graft loss to DR is 7–8%, mainly due to primary glomerulonephritis (70–80%) a...

  18. Recurrent granulomatous mastitis mimicking inflammatory breast cancer

    OpenAIRE

    Ergin, Ahmet Bahadir; Cristofanilli, Massimo; Daw, Hamed; Tahan, Gulgun; GONG, Yun

    2011-01-01

    Granulomatous mastitis (GM) is an uncommon benign breast lesion. Diagnosis is a matter of exclusion from other inflammatory, infectious and granulomatous aetiologies. Here, we presented an atypical GM case, which had clinical and radiologic features overlapping with inflammatory breast cancer (IBC). The disease had multiple recurrences. The patient is a 40-year-old Caucasian woman with a sudden onset of left breast swelling accompanied by diffuse skin redness, especially of the subareolar reg...

  19. Recurrence of Primary Hyperoxaluria After Kidney Transplantation

    OpenAIRE

    Tahereh Malakoutian; Mojgan Asgari; Massoud Houshmand; Ronak Mohammadi; Omid Aryani; Esmaeel Mohammadi Pargoo; Ahad J. Ghods

    2011-01-01

    Primary hyperoxaluria is a genetic disorder in glyoxylate metabolism that leads to systemic overproduction of oxalate. Functional deficiency of alanine-glyoxylate aminotransferase in this disease leads to recurrent nephrolithiasis, nephrocalcinosis, systemic oxalosis, and kidney failure. We present a young woman with end-stage renal disease who received a kidney allograft and experienced early graft failure presumed to be an acute rejection. There was no improvement in kidney function, and s...

  20. Recurrence of Lupus Nephritis after Kidney Transplantation

    OpenAIRE

    Contreras, Gabriel; Mattiazzi, Adela; Guerra, Giselle; Ortega, Luis M; Tozman, Elaine C.; Li, Hua; Tamariz, Leonardo; Carvalho, Cristiane; Kupin, Warren; Ladino, Marco; Leclercq, Baudouin; Jaraba, Isabel; Carvalho, Decio; Carles, Efrain; Roth, David

    2010-01-01

    The frequency and outcome of recurrent lupus nephritis (RLN) among recipients of a kidney allograft vary among single-center reports. From the United Network for Organ Sharing files, we estimated the period prevalence and predictors of RLN in recipients who received a transplant between 1987 and 2006 and assessed the effects of RLN on allograft failure and recipients' survival. Among 6850 recipients of a kidney allograft with systemic lupus erythematosus, 167 recipients had RLN, 1770 experien...

  1. Recurrence and Relapse in Bipolar Mood Disorder

    OpenAIRE

    S Gh Mousavi; S Moalemi; Sadeghi, S.

    2004-01-01

    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, Isf...

  2. Recurrent cutaneous leishmaniasis Leishmaniose recidiva cútis

    OpenAIRE

    Ciro Martins Gomes; Fabiana dos Santos Damasco; Orlando Oliveira de Morais; Carmen Déa Ribeiro de Paula; Raimunda Nonata Ribeiro Sampaio

    2013-01-01

    We present a case of an 18-year-old male patient who, after two years of inappropriate treatment for cutaneous leishmaniasis, began to show nodules arising at the edges of the former healing scar. He was immune competent and denied any trauma. The diagnosis of recurrent cutaneous leishmaniasis was made following positive culture of aspirate samples. The patient was treated with N-methylglucamine associated with pentoxifylline for 30 days. Similar cases require special attention mainly because...

  3. Recurrent Supracondylar Humerus Fracture Following Prior Malunion

    OpenAIRE

    Noonan, Kenneth J.; Jones, Jedediah W

    2001-01-01

    In this report, two patients sustained a recurrent supracondylar humerus fracture following malunion of a previous supracondylar humerus fracture. The patients were treated for their first fracture at 5 and 6 years of age, respectively. One underwent open reduction with percutaneous pinning, and the other was treated with closed reduction with casting. Both patients healed in a moderate degree of extension after the first fracture.Two years later, both sustained a second fracture of the supra...

  4. Recurrent severe vomiting due to hyperthyroidism

    OpenAIRE

    Chen, Li-Ying; Zhou, Bo; Chen, Zhou-wen; Fang, Li-Zheng

    2010-01-01

    Thyrotoxicosis may present in many ways; severe vomiting as a prominent symptom of thyrotoxicosis is uncommon. In this paper, we report a 24-year-old Chinese male with hyperthyroidism who presented with recurrent severe vomiting. The patient had had intermittent vomiting for seven years and had lost approximately 15 kg of weight. Gastroscopic examinations revealed chronic gastritis and one occasion peptic ulcer. He was treated with antacid and proton pump inhibitors, but his symptoms had no r...

  5. COMPLICATIONS OF RECURRENT CHOLESTEATOMA: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Srinivas

    2015-08-01

    Full Text Available Chronic suppurative otitis media , infection of the middle ear cleft , is a common disease in the developing countries and the complications associated with it still pose a major problem. The proximity of the middle ear cleft and mastoid air cells to the extracranial and intracranial compartments places structures located in these areas at increased risk of complications. We report a case of recurrent cholesteatoma in a patient presenting with intracranial complications and facial nerve palsy .

  6. High-dimensional conformally recurrent manifolds

    OpenAIRE

    Mantica, Carlo A.; Molinari, Luca G.

    2014-01-01

    Conformally recurrent pseudo-Riemannian manifolds of dimension n>4 are investigated. The Weyl tensor is represented as a Kulkarni-Nomizu product. If the square of the Weyl tensor is nonzero, a covariantly constant symmetric tensor is constructed, that is quadratic in the Weyl tensor. Then, by Grycak's theorem, the explicit expression of the traceless part of the Ricci tensor is obtained, up to a scalar function. The Ricci tensor has at most two distinct eigenvalues, and the ...

  7. Recurrent scoliosis one year after surgical correction.

    Science.gov (United States)

    van Luijk, P J; de Nies, F

    2011-07-01

    A year after anterolateral spondylodesis for progressive scoliosis, the patient showed a flexion gait pattern with recurrent deformity, due to late infection. Surgical debridement resolved all symptoms. Whereas most postoperative infections occur after posterior spondylodesis and present with back pain and mild increase of infection parameters, late infection after anterolateral approach is rare. In this case the patient did not present with the classic symptoms. PMID:20680371

  8. Recurrent transient thyrotoxicosis in multinodular goitre.

    OpenAIRE

    Arem, R.

    1990-01-01

    A patient initially presented with an autonomously functioning right thyroid nodule and transient hyperthyroidism which lasted for a few months. Several months after resolution of thyrotoxicosis, the patient had a recurrent episode of hyperthyroidism and was found to have a left hot nodule. The right hyperfunctioning nodule had become cold on scintigraphy, and its aspiration revealed haemorrhagic fluid suggesting haemorrhagic infarction as the mechanism of resolution of the first episode of h...

  9. Oral saccharomyces experience in recurrent necrotizing enterocolitis

    Directory of Open Access Journals (Sweden)

    Y?ld?z Dallar

    2010-01-01

    Full Text Available Necrotizing enterocolitis (NEC is a gastrointestinal disease characterized by intestinal ischemia which is one of the major causes of mortality and morbidity in preterm neonates. Recently, probiotics have been used for management of NEC. Lactobacillus species, Bifidobacterium and Saccharomyces boulardii are the most commonly used preparations. We presented a premature infant with recurrent NEC who was treated with Saccharomyces boulardii successfully. A premature infant with a gestational age of 27 weeks and body weight of 900 gr was diagnosed as sepsis and NEC on postnatal fifth day. Physical examination was normal except abdominal distention and there was no peristaltic activity heard by auscultation. In laboratory evaluation, white blood cell count was 30500/mm3, Hb: 16.3 g/dL, platelets: 144000/mm3. Hepatic and renal function tests were within normal limits. Appropriate intravenous (?V antibiotics and IV hydration were given. On postnatal 10th day, the infant was allowed to be fed by nasogastric tube but this was followed by NEC. After every feeding attempt on postnatal 18, 29, 45 and 64th days, the patient developed NEC; in each episode, he was treated with antibiotics. Oral Saccharomyces boulardii was given to treat recurrent NEC. The premature infant with recurrent NEC was managed successfully by Saccharomyces boulardii as probiotic, a preparation available in Turkey. We did not observe any complications therefore this probiotic might be considered as a safe alternative. However, further studies are needed to confirm the effectiveness of probiotics to treat NEC during neonatal period.

  10. Management of Recurrent Rhinosinusitis in Children

    Directory of Open Access Journals (Sweden)

    P?nar Uysal

    2012-04-01

    Full Text Available 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 viral upper respiratory tract infections, allergic rhinitis, septal deviation, adenoidal hypertrophy, ciliary dysfunction syndromes, foreign body in nazal cavity, gastroesophageal reflux disease and cystic fibrosis in children. The rhinosinusitis should be diagnosed clinically. Generally plain X-ray films are not helpful in demonstration of the infection. Computed tomography (CT scan and magnetic resonans imaging have advantages in a suspicion of a complication of rhinosinusitis. The management of acute/chronic rhinosinusitis with antibiotics is still in debate. High dose amoksisilin is the first choise of drug for both of the severe acute and chronic bacterial rhinosinusitis. Parenteral antibiotic regiments are taken in account in the case of severe chronic cases. Additive therapies with mucolitics, decongestans and antihistamines give no additional benefit, therefore are not recommended routinely. Nazal steroids might have a role in treatment of children with chronic or recurrent rhinosinusitis. (Jo­ur­nal of Cur­rent Pe­di­at­rics 2012; 10: 24-30

  11. Posterior fossa involvement in a recurrent gliosarcoma

    Directory of Open Access Journals (Sweden)

    Srikant Balasubramaniam

    2012-01-01

    Full Text Available Gliosarcoma (GSM is a WHO grade 4 tumor and a variant of glioblastoma multiforme with predilection for the temporal lobe. We record, perhaps the first case in literature, of a temporal lobe GSM with recurrence involving the posterior fossa. A 50-year-old man presented to us with headache, vomiting, and lethargy of relatively recent onset. Magnetic resonance imaging revealed a well-circumscribed lesion in the left temporal lobe for which left temporal craniotomy with radical excision of the tumor was performed. Histopathology was suggestive of GSM. He presented to us within a month of the first surgery with a large recurrence involving the temporal lobe. He underwent a second surgery with radical excision of the tumor. Histopathology was confirmatory of GSM. He was administered concomitant chemotherapy and radiotherapy. Within a fortnight of starting adjuvant therapy, the bone flap started bulging and a repeat computed tomography scan revealed a large recurrence extending into the posterior fossa. The patient?s relatives refused consent for third surgery and he finally succumbed on postoperative day 21. GSMs are aggressive tumors that have a temporal lobe predilection, but they may present anywhere in the brain. Detailed studies on larger cohort of cases are needed to understand the true nature of these biphasic tumors.

  12. Morphological features and recurrence of incisional hernia

    International Nuclear Information System (INIS)

    To emphasize the importance of the size, shape and multiplicity of incisional hernia defect and its recurrence after repair. From June 1990 to August 1993, fifty-two patients presented to Queen Alia Military Hospital (QAMH), with incisional hernias and were included in this study. Mean age was 52.35 years. Fourteen (26.9 %) were males and 38 (73.1%) were females. Thirty-five (92.2%) were multiparous and 3 (7.8%) were nuliparous. Cholecystectomy was the commonest primary surgery with 11 patients (21.1%), followed by Cesarien Section in 10 patients (19.2%). All the smaller sized (less than 1 cm diameter) and middle sized (1-5 cm diameter) defects were circular in shape whereas the large sized (more than 5 cm) were ovoid. In 20 patients (38.4%) there was one defect only and in 32 patients (61.6%) there were more than one defect. We used mesh graft (prolene mesh) or classical repair using non-absorbable suture material. All patients were followed up for 84 months and one recurrence (1.92%) was noted. Cholecystectomy was the commonest cause of incisional hernia and multiple defects were found in many cases. With our approach in repairing incisional hernia, recurrence rate was low. (author)

  13. Recurrent urinary tract infections in females

    International Nuclear Information System (INIS)

    Uncomplicated Urinary tract infections are common in adult women across the entire age spectrum, with mean annual incidence of 15% and 10% in those aged 15-39 and 40-79 years, respectively. Urinary tract infection (UTI), with its diverse clinical syndromes and affected host groups, remains one of the most common but widely misunderstood and challenging infectious diseases encountered in clinical practice. Recurrent urinary tract infections (UTIs) present a significant problem for women and a challenge for the doctors who care for them. The diagnosis of uncomplicated UTI can be achieved best by a thorough assessment of patient symptoms with or without the addition of a urine dipstick test. Treatment should be based on the most recent guidelines, taking into account resistance patterns in the local community. The patient who suffers from recurrent UTIs can be treated safely and effectively with continuous antibiotic prophylaxis, post-coital therapy, or self-initiated treatment. This review article covers the latest trends in the management of recurrent UTI among women. Further research is needed regarding rapid diagnosis of UTI, accurate presumptive identification of patients with resistant pathogens, and development of new antimicrobials for drug-resistant UTI. (author)

  14. Prognostic Factors for Tumor Recurrence after Gamma Knife Radiosurgery of Partially Resected and Recurrent Craniopharyngiomas

    Directory of Open Access Journals (Sweden)

    TATSUYA KOBAYASHI

    2012-02-01

    Full Text Available A study was conducted to clarify the prognostic factors related to recurrence of craniopharyngioma and to improve the quality of life of patients by the treatment with intentional partial removal and gamma knife radiosurgery. One hundred cases of craniopharyngioma have been treated at Komaki City Hospital since 1991. In a mean follow-up period of 65.5 months, the tumor control rate was 79.5%. The 5- and 10-year actuarial survival rates were 94.1% and 91%, respectively. However, the recurrence-free survival rates were 73.6% at 5 years and 60.2% at 10 years. Nine factors thought to be related to the recurrence were selected from past references and previous studies, including gender, age, pediatric (?17 years or adult patient, partial removal or recurrence, mean tumor diameter, tumor type (solid or cyst, pathological types (squamous cell or adamantinoma, number of previous treatments, and radiation dose. Statistical analysis was performed to determine which factors had a significant prognostic impact. Multivariate analysis showed that mean tumor diameter and radiation dose were independent predictors of outcome. To maximize the prognostic power of these factors, cut-off levels were determined using ROC analysis. These levels were 19 mm for tumor diameter and 13.2 Gy for marginal dose. Significant prognostic factors related to recurrence of craniopharyngioma are tumor diameter and radiation dose. A tumor diameter of <19 mm and a marginal dose of ?13.2 Gy are favorable prognostic factors for gamma knife radiosurgery.

  15. Disease recurrence in paediatric renal transplantation.

    Science.gov (United States)

    Cochat, Pierre; Fargue, Sonia; Mestrallet, Guillaume; Jungraithmayr, Therese; Koch-Nogueira, Paulo; Ranchin, Bruno; Zimmerhackl, Lothar Bernd

    2009-11-01

    Renal transplantation (Tx) is the treatment of choice for end-stage renal disease. The incidence of acute rejection after renal Tx has decreased because of improving early immunosuppression, but the risk of disease recurrence (DR) is becoming relatively high, with a greater prevalence in children than in adults, thereby increasing patient morbidity, graft loss (GL) and, sometimes, mortality rate. The current overall graft loss to DR is 7-8%, mainly due to primary glomerulonephritis (70-80%) and inherited metabolic diseases. The more typical presentation is a recurrence of the full disease, either with a high risk of GL (focal and segmental glomerulosclerosis 14-50% DR, 40-60% GL; atypical haemolytic uraemic syndrome 20-80% DR, 10-83% GL; membranoproliferative glomerulonephritis 30-100% DR, 17-61% GL; membranous nephropathy approximately 30% DR, approximately 50% GL; lipoprotein glomerulopathy approximately 100% DR and GL; primary hyperoxaluria type 1 80-100% DR and GL) or with a low risk of GL [immunoglobulin (Ig)A nephropathy 36-60% DR, 7-10% GL; systemic lupus erythematosus 0-30% DR, 0-5% GL; anti-neutrophilic cytoplasmic antibody (ANCA)-associated glomerulonephritis]. Recurrence may also occur with a delayed risk of GL, such as insulin-dependent diabetes mellitus, sickle cell disease, endemic nephropathy, and sarcoidosis. In other primary diseases, the post-Tx course may be complicated by specific events that are different from overt recurrence: proteinuria or cancer in some genetic forms of nephrotic syndrome, anti-glomerular basement membrane antibodies-associated glomerulonephritis (Alport syndrome, Goodpasture syndrome), and graft involvement as a consequence of lower urinary tract abnormality or human immunodeficiency virus (HIV) nephropathy. Some other post-Tx conditions may mimic recurrence, such as de novo membranous glomerulonephritis, IgA nephropathy, microangiopathy, or isolated specific deposits (cystinosis, Fabry disease). Adequate strategies should therefore be added to kidney Tx, such as donor selection, associated liver Tx, plasmatherapy, specific immunosuppression protocols. In such conditions, very few patients may be excluded from kidney Tx only because of a major risk of DR and repeated GL. In the near future the issue of DR after kidney Tx may benefit from alternatives to organ Tx, such as recombinant proteins, specific monoclonal antibodies, cell/gene therapy, and chaperone molecules. PMID:19247694

  16. 76 FR 64318 - Multilayered Wood Flooring From the People's Republic of China: Final Determination of Sales at...

    Science.gov (United States)

    2011-10-18

    ...Administration [A-570-970] Multilayered Wood Flooring From the People's Republic of...antidumping investigation of multilayered wood flooring from the People's Republic of...antidumping investigation of multilayered wood flooring from the PRC.\\2\\ The...

  17. 78 FR 52502 - Multilayered Wood Flooring From the People's Republic of China: Final Results of Antidumping Duty...

    Science.gov (United States)

    2013-08-23

    ...Administration [A-570-970] Multilayered Wood Flooring From the People's Republic of...duty new shipper review of multilayered wood flooring (``MLWF'') from the People's...1\\ See Multilayered Wood Flooring From the People's Republic...

  18. 76 FR 33782 - Multilayered Wood Flooring From China; Scheduling of the Final Phase of Countervailing Duty and...

    Science.gov (United States)

    2011-06-09

    ...and 731-TA-1179 Final] Multilayered Wood Flooring From China; Scheduling of the...less-than-fair-value imports from China of multilayered wood flooring (``MLWF''), provided for...subject merchandise as `` * * * multilayered wood flooring, composed of an assembly of...

  19. MORAb-004 in Treating Young Patients With Recurrent or Refractory Solid Tumors or Lymphoma

    Science.gov (United States)

    2015-09-17

    Adult Nasal Type Extranodal NK/T-cell Lymphoma; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Childhood Burkitt Lymphoma; Childhood Diffuse Large Cell Lymphoma; Childhood Immunoblastic Large Cell Lymphoma; Childhood Nasal Type Extranodal NK/T-cell Lymphoma; Cutaneous B-cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Hepatosplenic T-cell Lymphoma; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Noncutaneous Extranodal Lymphoma; Peripheral T-cell Lymphoma; Post-transplant Lymphoproliferative Disorder; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Childhood Anaplastic Large Cell Lymphoma; Recurrent Childhood Grade III Lymphomatoid Granulomatosis; Recurrent Childhood Large Cell Lymphoma; Recurrent Childhood Lymphoblastic Lymphoma; Recurrent Childhood Small Noncleaved Cell Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Recurrent/Refractory Childhood Hodgkin Lymphoma; Refractory Hairy Cell Leukemia; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; T-cell Large Granular Lymphocyte Leukemia; Testicular Lymphoma; Unspecified Adult Solid Tumor, Protocol Specific; Unspecified Childhood Solid Tumor, Protocol Specific; Waldenström Macroglobulinemia

  20. Nonlinear acoustic effects in multilayer ceramic capacitors

    Science.gov (United States)

    Johnson, W. L.; Kim, S. A.; Quinn, T. P.; White, G. S.

    2013-01-01

    Nonlinear resonant acoustics was explored as an approach for nondestructively evaluating the susceptibility of BaTiO3-based multilayer ceramic capacitors to electrical failure during service. The acoustic nonlinearity was characterized through measurements of the dependence of the frequency of a selected dominant mode near 1.16 MHz on driving amplitude, employing direct ferroelectric tone-burst transduction, time-domain signal acquisition, and frequency-domain spectral analysis. Finite-element modeling and consideration of the symmetry of the excitation led to identification of the selected mode as the lowest-order extensional mode. Measurements as a function of the number of thermal treatments (of two types) provided evidence for increases in acoustic nonlinearity arising from thermal-stress-induced material damage. No evidence for further systematic changes in nonlinearity was found after nine heat treatments. Signals and analysis for some samples were complicated by the emergence of a second resonance in the waveforms and an apparent reduction in acoustic nonlinearity as a function of time under DC bias. The second of these effects is suggested as being associated with changes in nonlinear elements of the material (presumably, microcracks) that arise from interactions of internal stresses during domain reorientation.