WorldWideScience

Sample records for normalized mutual information

  1. Cross Correlation versus Normalized Mutual Information on Image Registration

    Science.gov (United States)

    Tan, Bin; Tilton, James C.; Lin, Guoqing

    2016-01-01

    This is the first study to quantitatively assess and compare cross correlation and normalized mutual information methods used to register images in subpixel scale. The study shows that the normalized mutual information method is less sensitive to unaligned edges due to the spectral response differences than is cross correlation. This characteristic makes the normalized image resolution a better candidate for band to band registration. Improved band-to-band registration in the data from satellite-borne instruments will result in improved retrievals of key science measurements such as cloud properties, vegetation, snow and fire.

  2. Normalized mutual information based PET-MR registration using K-Means clustering and shading correction

    NARCIS (Netherlands)

    Knops, Z.F.; Maintz, J.B.A.; Viergever, M.A.; Pluim, J.P.W.; Gee, J.C.; Maintz, J.B.A.; Vannier, M.W.

    2003-01-01

    A method for the efficient re-binning and shading based correction of intensity distributions of the images prior to normalized mutual information based registration is presented. Our intensity distribution re-binning method is based on the K-means clustering algorithm as opposed to the generally

  3. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-09-07

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  4. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yi; Zhao, Shiguang; Gao, Xin

    2014-01-01

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  5. Two Phase Non-Rigid Multi-Modal Image Registration Using Weber Local Descriptor-Based Similarity Metrics and Normalized Mutual Information

    Directory of Open Access Journals (Sweden)

    Feng Yang

    2013-06-01

    Full Text Available Non-rigid multi-modal image registration plays an important role in medical image processing and analysis. Existing image registration methods based on similarity metrics such as mutual information (MI and sum of squared differences (SSD cannot achieve either high registration accuracy or high registration efficiency. To address this problem, we propose a novel two phase non-rigid multi-modal image registration method by combining Weber local descriptor (WLD based similarity metrics with the normalized mutual information (NMI using the diffeomorphic free-form deformation (FFD model. The first phase aims at recovering the large deformation component using the WLD based non-local SSD (wldNSSD or weighted structural similarity (wldWSSIM. Based on the output of the former phase, the second phase is focused on getting accurate transformation parameters related to the small deformation using the NMI. Extensive experiments on T1, T2 and PD weighted MR images demonstrate that the proposed wldNSSD-NMI or wldWSSIM-NMI method outperforms the registration methods based on the NMI, the conditional mutual information (CMI, the SSD on entropy images (ESSD and the ESSD-NMI in terms of registration accuracy and computation efficiency.

  6. A multiscale approach to mutual information matching

    NARCIS (Netherlands)

    Pluim, J.P.W.; Maintz, J.B.A.; Viergever, M.A.; Hanson, K.M.

    1998-01-01

    Methods based on mutual information have shown promising results for matching of multimodal brain images. This paper discusses a multiscale approach to mutual information matching, aiming for an acceleration of the matching process while considering the accuracy and robustness of the method. Scaling

  7. Speech Intelligibility Prediction Based on Mutual Information

    DEFF Research Database (Denmark)

    Jensen, Jesper; Taal, Cees H.

    2014-01-01

    This paper deals with the problem of predicting the average intelligibility of noisy and potentially processed speech signals, as observed by a group of normal hearing listeners. We propose a model which performs this prediction based on the hypothesis that intelligibility is monotonically related...... to the mutual information between critical-band amplitude envelopes of the clean signal and the corresponding noisy/processed signal. The resulting intelligibility predictor turns out to be a simple function of the mean-square error (mse) that arises when estimating a clean critical-band amplitude using...... a minimum mean-square error (mmse) estimator based on the noisy/processed amplitude. The proposed model predicts that speech intelligibility cannot be improved by any processing of noisy critical-band amplitudes. Furthermore, the proposed intelligibility predictor performs well ( ρ > 0.95) in predicting...

  8. Canonical analysis based on mutual information

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Vestergaard, Jacob Schack

    2015-01-01

    combinations with the information theoretical measure mutual information (MI). We term this type of analysis canonical information analysis (CIA). MI allows for the actual joint distribution of the variables involved and not just second order statistics. While CCA is ideal for Gaussian data, CIA facilitates...

  9. MISTIC: mutual information server to infer coevolution

    DEFF Research Database (Denmark)

    Simonetti, Franco L.; Teppa, Elin; Chernomoretz, Ariel

    2013-01-01

    of several information-related quantities using a circos representation. This provides an integrated view of the MSA in terms of (i) the mutual information (MI) between residue pairs, (ii) sequence conservation and (iii) the residue cumulative and proximity MI scores. Further, an interactive interface...... of circos representation of MI networks and the visualization of the cumulative MI and proximity MI concepts is novel....

  10. Holographic mutual information of two disjoint spheres

    Science.gov (United States)

    Chen, Bin; Fan, Zhong-Ying; Li, Wen-Ming; Zhang, Cheng-Yong

    2018-04-01

    We study quantum corrections to holographic mutual information for two disjoint spheres at a large separation by using the operator product expansion of the twist field. In the large separation limit, the holographic mutual information is vanishing at the semiclassical order, but receive quantum corrections from the fluctuations. We show that the leading contributions from the quantum fluctuations take universal forms as suggested from the boundary CFT. We find the universal behavior for the scalar, the vector, the tensor and the fermionic fields by treating these fields as free fields propagating in the fixed background and by using the 1 /n prescription. In particular, for the fields with gauge symmetries, including the massless vector boson and massless graviton, we find that the gauge parts in the propagators play an indispensable role in reading the leading order corrections to the bulk mutual information.

  11. Learning curves for mutual information maximization

    International Nuclear Information System (INIS)

    Urbanczik, R.

    2003-01-01

    An unsupervised learning procedure based on maximizing the mutual information between the outputs of two networks receiving different but statistically dependent inputs is analyzed [S. Becker and G. Hinton, Nature (London) 355, 161 (1992)]. For a generic data model, I show that in the large sample limit the structure in the data is recognized by mutual information maximization. For a more restricted model, where the networks are similar to perceptrons, I calculate the learning curves for zero-temperature Gibbs learning. These show that convergence can be rather slow, and a way of regularizing the procedure is considered

  12. Information Content of Mutual Fund Portfolio Disclosure

    NARCIS (Netherlands)

    Y. Wang (Yu)

    2011-01-01

    textabstractAcademic financial economists have been keenly interested in the value of active portfolio management since the seminal paper of Jensen (1968). This book examines the information advantages that active mutual fund managers attain in financial markets through an analysis of disclosed fund

  13. Fast mutual-information-based contrast enhancement

    Science.gov (United States)

    Cao, Gang; Yu, Lifang; Tian, Huawei; Huang, Xianglin; Wang, Yongbin

    2017-07-01

    Recently, T. Celik proposed an effective image contrast enhancement (CE) method based on spatial mutual information and PageRank (SMIRANK). According to the state-of-the-art evaluation criteria, it achieves the best visual enhancement quality among existing global CE methods. However, SMIRANK runs much slower than the other counterparts, such as histogram equalization (HE) and adaptive gamma correction. Low computational complexity is also required for good CE algorithms. In this paper, we novelly propose a fast SMIRANK algorithm, called FastSMIRANK. It integrates both spatial and gray-level downsampling into the generation of pixel value mapping function. Moreover, the computation of rank vectors is speeded up by replacing PageRank with a simple yet efficient row-based operation of mutual information matrix. Extensive experimental results show that the proposed FastSMIRANK could accelerate the processing speed of SMIRANK by about 20 times, and is even faster than HE. Comparable enhancement quality is preserved simultaneously.

  14. Quantum corrections to holographic mutual information

    International Nuclear Information System (INIS)

    Agón, Cesar A.; Faulkner, Thomas

    2016-01-01

    We compute the leading contribution to the mutual information (MI) of two disjoint spheres in the large distance regime for arbitrary conformal field theories (CFT) in any dimension. This is achieved by refining the operator product expansion method introduced by Cardy http://dx.doi.org/10.1088/1751-8113/46/28/285402. For CFTs with holographic duals the leading contribution to the MI at long distances comes from bulk quantum corrections to the Ryu-Takayanagi area formula. According to the FLM proposal http://dx.doi.org/10.1007/JHEP11(2013)074 this equals the bulk MI between the two disjoint regions spanned by the boundary spheres and their corresponding minimal area surfaces. We compute this quantum correction and provide in this way a non-trivial check of the FLM proposal.

  15. Quantum corrections to holographic mutual information

    Energy Technology Data Exchange (ETDEWEB)

    Agón, Cesar A. [Martin Fisher School of Physics, Brandeis University,Waltham, MA 02453 (United States); Faulkner, Thomas [University of Illinois, Urbana-Champaign,Urbana, IL 61801-3080 (United States)

    2016-08-22

    We compute the leading contribution to the mutual information (MI) of two disjoint spheres in the large distance regime for arbitrary conformal field theories (CFT) in any dimension. This is achieved by refining the operator product expansion method introduced by Cardy http://dx.doi.org/10.1088/1751-8113/46/28/285402. For CFTs with holographic duals the leading contribution to the MI at long distances comes from bulk quantum corrections to the Ryu-Takayanagi area formula. According to the FLM proposal http://dx.doi.org/10.1007/JHEP11(2013)074 this equals the bulk MI between the two disjoint regions spanned by the boundary spheres and their corresponding minimal area surfaces. We compute this quantum correction and provide in this way a non-trivial check of the FLM proposal.

  16. Generalized mutual information and Tsirelson's bound

    Energy Technology Data Exchange (ETDEWEB)

    Wakakuwa, Eyuri [Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan); Murao, Mio [Institute for Nano Quantum Information Electronics, The University of Tokyo, Tokyo 113-0033, Japan and Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan)

    2014-12-04

    We introduce a generalization of the quantum mutual information between a classical system and a quantum system into the mutual information between a classical system and a system described by general probabilistic theories. We apply this generalized mutual information (GMI) to a derivation of Tsirelson's bound from information causality, and prove that Tsirelson's bound can be derived from the chain rule of the GMI. By using the GMI, we formulate the 'no-supersignalling condition' (NSS), that the assistance of correlations does not enhance the capability of classical communication. We prove that NSS is never violated in any no-signalling theory.

  17. Landauer current and mutual information in a bosonic quantum dot

    Science.gov (United States)

    Shashikant Sable, Hrushikesh; Singh Bhakuni, Devendra; Sharma, Auditya

    2018-02-01

    We study the quantum transport of bosons through a quantum dot coupled to two macroscopic heat baths L and R, held at fixed temperatures TL and TR respectively. We manage to cast the particle as well as the heat current into the Landauer form. Following the correlation matrix approach, we compute the time-dependent mutual information of the dot with the baths. We find that mutual information goes logarithmically as the number of bosons, and at low temperatures, it is possible to set up the parameters in such a way that in steady-state, the mutual information goes quadratically as a function of current.

  18. Information asymmetry, mutual funds and earnings management: Evidence from China

    Directory of Open Access Journals (Sweden)

    Yunhao Dai

    2013-09-01

    Full Text Available This paper investigates how information asymmetry and mutual fund ownership affect listed companies’ earnings management. We show that (1 reducing information asymmetry improves firms’ earnings management behavior; (2 relative to short-term mutual funds, long-term mutual funds promote earnings quality by adopting a monitoring role; and (3 by dividing firms into high/low information asymmetry groups, we find that the information environment significantly increases the effect of long-term mutual funds on firms’ earnings management. In this paper, we provide new evidence for the role that institutional investors play in a typical emerging capital market. Our results have clear policy implications: to increase earnings quality, it is essential to improve information transparency and develop long-term institutional investors.

  19. Ambiguity towards Multiple Historical Performance Information Signals: Evidence from Indonesian Open-Ended Mutual Fund Investors

    Directory of Open Access Journals (Sweden)

    Haris Pratama Loeis

    2015-10-01

    Full Text Available This study focuses on the behavior of open-ended mutual fund investors when encountered with multiple information signals of mutual fund’s historical performance. The behavior of investors can be reflected on their decision to subscribe or redeem their funds from mutual funds. Moreover, we observe the presence of ambiguity within investors due to multiple information signals, and also their reaction towards it. Our finding shows that open-ended mutual fund investors do not only have sensitivity towards past performance information signals, but also have additional sensitivity towards the ambiguity of multiple information signals. Because of the presence of ambiguity, investors give more consideration to negative information signals and the worst information signal in their investment decisions. Normal 0 false false false EN-US X-NONE X-NONE

  20. Mutual information against correlations in binary communication channels.

    Science.gov (United States)

    Pregowska, Agnieszka; Szczepanski, Janusz; Wajnryb, Eligiusz

    2015-05-19

    Explaining how the brain processing is so fast remains an open problem (van Hemmen JL, Sejnowski T., 2004). Thus, the analysis of neural transmission (Shannon CE, Weaver W., 1963) processes basically focuses on searching for effective encoding and decoding schemes. According to the Shannon fundamental theorem, mutual information plays a crucial role in characterizing the efficiency of communication channels. It is well known that this efficiency is determined by the channel capacity that is already the maximal mutual information between input and output signals. On the other hand, intuitively speaking, when input and output signals are more correlated, the transmission should be more efficient. A natural question arises about the relation between mutual information and correlation. We analyze the relation between these quantities using the binary representation of signals, which is the most common approach taken in studying neuronal processes of the brain. We present binary communication channels for which mutual information and correlation coefficients behave differently both quantitatively and qualitatively. Despite this difference in behavior, we show that the noncorrelation of binary signals implies their independence, in contrast to the case for general types of signals. Our research shows that the mutual information cannot be replaced by sheer correlations. Our results indicate that neuronal encoding has more complicated nature which cannot be captured by straightforward correlations between input and output signals once the mutual information takes into account the structure and patterns of the signals.

  1. A multivariate extension of mutual information for growing neural networks.

    Science.gov (United States)

    Ball, Kenneth R; Grant, Christopher; Mundy, William R; Shafer, Timothy J

    2017-11-01

    Recordings of neural network activity in vitro are increasingly being used to assess the development of neural network activity and the effects of drugs, chemicals and disease states on neural network function. The high-content nature of the data derived from such recordings can be used to infer effects of compounds or disease states on a variety of important neural functions, including network synchrony. Historically, synchrony of networks in vitro has been assessed either by determination of correlation coefficients (e.g. Pearson's correlation), by statistics estimated from cross-correlation histograms between pairs of active electrodes, and/or by pairwise mutual information and related measures. The present study examines the application of Normalized Multiinformation (NMI) as a scalar measure of shared information content in a multivariate network that is robust with respect to changes in network size. Theoretical simulations are designed to investigate NMI as a measure of complexity and synchrony in a developing network relative to several alternative approaches. The NMI approach is applied to these simulations and also to data collected during exposure of in vitro neural networks to neuroactive compounds during the first 12 days in vitro, and compared to other common measures, including correlation coefficients and mean firing rates of neurons. NMI is shown to be more sensitive to developmental effects than first order synchronous and nonsynchronous measures of network complexity. Finally, NMI is a scalar measure of global (rather than pairwise) mutual information in a multivariate network, and hence relies on less assumptions for cross-network comparisons than historical approaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Mutuality

    DEFF Research Database (Denmark)

    Arnould, E. J.; Rose, A. S.

    2016-01-01

    and epistemological grounds and reproduces an array of problematic modernist dichotomies (e.g., agency/structure, nurturing family/instrumental public, gift/market, and altruism/self-interest) that significantly constrain the analytical enterprise. This work redresses some of the conceptual problems in the current...... formulation. The critique highlights a focus on resource distribution based on a more holistic, socially grounded perspective on circulation. We offer the alternative concept of mutuality or generalized exchange and the metaphor of inclusion rather than exchange as central to this perspective. We argue...

  3. Conditional mutual information of bipartite unitaries and scrambling

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Dawei; Hayden, Patrick; Walter, Michael [Stanford Institute for Theoretical Physics, Department of Physics, Stanford University,382 Via Pueblo, Stanford, CA 94305 (United States)

    2016-12-28

    One way to diagnose chaos in bipartite unitary channels is via the tripartite information of the corresponding Choi state, which for certain choices of the subsystems reduces to the negative conditional mutual information (CMI). We study this quantity from a quantum information-theoretic perspective to clarify its role in diagnosing scrambling. When the CMI is zero, we find that the channel has a special normal form consisting of local channels between individual inputs and outputs. However, we find that arbitrarily low CMI does not imply arbitrary proximity to a channel of this form, although it does imply a type of approximate recoverability of one of the inputs. When the CMI is maximal, we find that the residual channel from an individual input to an individual output is completely depolarizing when the other input is maximally mixed. However, we again find that this result is not robust. We also extend some of these results to the multipartite case and to the case of Haar-random pure input states. Finally, we look at the relationship between tripartite information and its Rényi-2 version which is directly related to out-of-time-order correlation functions. In particular, we demonstrate an arbitrarily large gap between the two quantities.

  4. Rényi generalizations of the conditional quantum mutual information

    International Nuclear Information System (INIS)

    Berta, Mario; Seshadreesan, Kaushik P.; Wilde, Mark M.

    2015-01-01

    The conditional quantum mutual information I(A; B|C) of a tripartite state ρ ABC is an information quantity which lies at the center of many problems in quantum information theory. Three of its main properties are that it is non-negative for any tripartite state, that it decreases under local operations applied to systems A and B, and that it obeys the duality relation I(A; B|C) = I(A; B|D) for a four-party pure state on systems ABCD. The conditional mutual information also underlies the squashed entanglement, an entanglement measure that satisfies all of the axioms desired for an entanglement measure. As such, it has been an open question to find Rényi generalizations of the conditional mutual information, that would allow for a deeper understanding of the original quantity and find applications beyond the traditional memoryless setting of quantum information theory. The present paper addresses this question, by defining different α-Rényi generalizations I α (A; B|C) of the conditional mutual information, some of which we can prove converge to the conditional mutual information in the limit α → 1. Furthermore, we prove that many of these generalizations satisfy non-negativity, duality, and monotonicity with respect to local operations on one of the systems A or B (with it being left as an open question to prove that monotonicity holds with respect to local operations on both systems). The quantities defined here should find applications in quantum information theory and perhaps even in other areas of physics, but we leave this for future work. We also state a conjecture regarding the monotonicity of the Rényi conditional mutual informations defined here with respect to the Rényi parameter α. We prove that this conjecture is true in some special cases and when α is in a neighborhood of one

  5. Quantum mutual information and the one-time pad

    International Nuclear Information System (INIS)

    Schumacher, Benjamin; Westmoreland, Michael D.

    2006-01-01

    Alice and Bob share a correlated composite quantum system AB. If AB is used as the key for a one-time pad cryptographic system, we show that the maximum amount of information that Alice can send securely to Bob is the quantum mutual information of AB

  6. Thermalization of mutual information in hyperscaling violating backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Tanhayi, M. Reza [Department of Physics, Faculty of Basic Science,Islamic Azad University Central Tehran Branch (IAUCTB),P.O. Box 14676-86831, Tehran (Iran, Islamic Republic of); School of Physics, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2016-03-31

    We study certain features of scaling behaviors of the mutual information during a process of thermalization, more precisely we extend the time scaling behavior of mutual information which has been discussed in http://dx.doi.org/10.1007/JHEP09(2015)165 to time-dependent hyperscaling violating geometries. We use the holographic description of entanglement entropy for two disjoint system consisting of two parallel strips whose widths are much larger than the separation between them. We show that during the thermalization process, the dynamical exponent plays a crucial rule in reading the general time scaling behavior of mutual information (e.g., at the pre-local-equilibration regime). It is shown that the scaling violating parameter can be employed to define an effective dimension.

  7. Anomalous behaviour of mutual information in finite flocks

    Science.gov (United States)

    Barnett, L.; Brown, J.; Bossomaier, T.

    2017-11-01

    The existing consensus is that flocks are poised at criticality, entailing long correlation lengths and a maximal value of Shannon mutual information in the large-system limit. We show, by contrast, that for finite flocks which do not truly break ergodicity in the long-observation-time limit, mutual information may not only fail to peak at criticality —as observed for other critical systems— but also diverge as noise tends to zero. This result carries implications for other finite-size, out-of-equilibrium systems, where observation times may vary widely compared to time scales of internal system dynamics; thus it may not be assumed that mutual information locates the phase transition.

  8. Reducing Interpolation Artifacts for Mutual Information Based Image Registration

    Science.gov (United States)

    Soleimani, H.; Khosravifard, M.A.

    2011-01-01

    Medical image registration methods which use mutual information as similarity measure have been improved in recent decades. Mutual Information is a basic concept of Information theory which indicates the dependency of two random variables (or two images). In order to evaluate the mutual information of two images their joint probability distribution is required. Several interpolation methods, such as Partial Volume (PV) and bilinear, are used to estimate joint probability distribution. Both of these two methods yield some artifacts on mutual information function. Partial Volume-Hanning window (PVH) and Generalized Partial Volume (GPV) methods are introduced to remove such artifacts. In this paper we show that the acceptable performance of these methods is not due to their kernel function. It's because of the number of pixels which incorporate in interpolation. Since using more pixels requires more complex and time consuming interpolation process, we propose a new interpolation method which uses only four pixels (the same as PV and bilinear interpolations) and removes most of the artifacts. Experimental results of the registration of Computed Tomography (CT) images show superiority of the proposed scheme. PMID:22606673

  9. Inference of financial networks using the normalised mutual information rate

    Science.gov (United States)

    2018-01-01

    In this paper, we study data from financial markets, using the normalised Mutual Information Rate. We show how to use it to infer the underlying network structure of interrelations in the foreign currency exchange rates and stock indices of 15 currency areas. We first present the mathematical method and discuss its computational aspects, and apply it to artificial data from chaotic dynamics and to correlated normal-variates data. We then apply the method to infer the structure of the financial system from the time-series of currency exchange rates and stock indices. In particular, we study and reveal the interrelations among the various foreign currency exchange rates and stock indices in two separate networks, of which we also study their structural properties. Our results show that both inferred networks are small-world networks, sharing similar properties and having differences in terms of assortativity. Importantly, our work shows that global economies tend to connect with other economies world-wide, rather than creating small groups of local economies. Finally, the consistent interrelations depicted among the 15 currency areas are further supported by a discussion from the viewpoint of economics. PMID:29420644

  10. Inference of financial networks using the normalised mutual information rate.

    Science.gov (United States)

    Goh, Yong Kheng; Hasim, Haslifah M; Antonopoulos, Chris G

    2018-01-01

    In this paper, we study data from financial markets, using the normalised Mutual Information Rate. We show how to use it to infer the underlying network structure of interrelations in the foreign currency exchange rates and stock indices of 15 currency areas. We first present the mathematical method and discuss its computational aspects, and apply it to artificial data from chaotic dynamics and to correlated normal-variates data. We then apply the method to infer the structure of the financial system from the time-series of currency exchange rates and stock indices. In particular, we study and reveal the interrelations among the various foreign currency exchange rates and stock indices in two separate networks, of which we also study their structural properties. Our results show that both inferred networks are small-world networks, sharing similar properties and having differences in terms of assortativity. Importantly, our work shows that global economies tend to connect with other economies world-wide, rather than creating small groups of local economies. Finally, the consistent interrelations depicted among the 15 currency areas are further supported by a discussion from the viewpoint of economics.

  11. Information content when mutual funds deviate from benchmarks

    NARCIS (Netherlands)

    H. Jiang (Hao); M.J.C.M. Verbeek (Marno); Y. Wang (Yu)

    2014-01-01

    markdownabstract__Abstract__ The consensus wisdom of active mutual fund managers, as reflected in their average over-and underweighting decisions, contains valuable information about future stock returns. Analyzing a comprehensive sample of active U.S. equity funds from 1984 to 2008, we find that

  12. Sensitivity Analysis for Urban Drainage Modeling Using Mutual Information

    Directory of Open Access Journals (Sweden)

    Chuanqi Li

    2014-11-01

    Full Text Available The intention of this paper is to evaluate the sensitivity of the Storm Water Management Model (SWMM output to its input parameters. A global parameter sensitivity analysis is conducted in order to determine which parameters mostly affect the model simulation results. Two different methods of sensitivity analysis are applied in this study. The first one is the partial rank correlation coefficient (PRCC which measures nonlinear but monotonic relationships between model inputs and outputs. The second one is based on the mutual information which provides a general measure of the strength of the non-monotonic association between two variables. Both methods are based on the Latin Hypercube Sampling (LHS of the parameter space, and thus the same datasets can be used to obtain both measures of sensitivity. The utility of the PRCC and the mutual information analysis methods are illustrated by analyzing a complex SWMM model. The sensitivity analysis revealed that only a few key input variables are contributing significantly to the model outputs; PRCCs and mutual information are calculated and used to determine and rank the importance of these key parameters. This study shows that the partial rank correlation coefficient and mutual information analysis can be considered effective methods for assessing the sensitivity of the SWMM model to the uncertainty in its input parameters.

  13. Mutual information as an order parameter for quantum synchronization

    Science.gov (United States)

    Ameri, V.; Eghbali-Arani, M.; Mari, A.; Farace, A.; Kheirandish, F.; Giovannetti, V.; Fazio, R.

    2015-01-01

    Spontaneous synchronization is a fundamental phenomenon, important in many theoretical studies and applications. Recently, this effect has been analyzed and observed in a number of physical systems close to the quantum-mechanical regime. In this work we propose mutual information as a useful order parameter which can capture the emergence of synchronization in very different contexts, ranging from semiclassical to intrinsically quantum-mechanical systems. Specifically, we first study the synchronization of two coupled Van der Pol oscillators in both classical and quantum regimes and later we consider the synchronization of two qubits inside two coupled optical cavities. In all these contexts, we find that mutual information can be used as an appropriate figure of merit for determining the synchronization phases independently of the specific details of the system.

  14. Information properties of a hologram of mutually conjugate waves

    International Nuclear Information System (INIS)

    Rubanov, A.S.; Serebryakova, L.M.

    1995-01-01

    A theoretical study of information properties of a correlation response to a fragment of an image of a thin referenceless hologram of mutually conjugate waves that is recorded with a phase-conjugating (PC) mirror is reported. It is shown that this hologram reconstructs a full image in reflected light and can be used as an associative storage device and as a selective PC mirror. 7 refs., 1 fig

  15. Feature Selection for Chemical Sensor Arrays Using Mutual Information

    Science.gov (United States)

    Wang, X. Rosalind; Lizier, Joseph T.; Nowotny, Thomas; Berna, Amalia Z.; Prokopenko, Mikhail; Trowell, Stephen C.

    2014-01-01

    We address the problem of feature selection for classifying a diverse set of chemicals using an array of metal oxide sensors. Our aim is to evaluate a filter approach to feature selection with reference to previous work, which used a wrapper approach on the same data set, and established best features and upper bounds on classification performance. We selected feature sets that exhibit the maximal mutual information with the identity of the chemicals. The selected features closely match those found to perform well in the previous study using a wrapper approach to conduct an exhaustive search of all permitted feature combinations. By comparing the classification performance of support vector machines (using features selected by mutual information) with the performance observed in the previous study, we found that while our approach does not always give the maximum possible classification performance, it always selects features that achieve classification performance approaching the optimum obtained by exhaustive search. We performed further classification using the selected feature set with some common classifiers and found that, for the selected features, Bayesian Networks gave the best performance. Finally, we compared the observed classification performances with the performance of classifiers using randomly selected features. We found that the selected features consistently outperformed randomly selected features for all tested classifiers. The mutual information filter approach is therefore a computationally efficient method for selecting near optimal features for chemical sensor arrays. PMID:24595058

  16. Mutual-friction induced instability of normal-fluid vortex tubes in superfluid helium-4

    Science.gov (United States)

    Kivotides, Demosthenes

    2018-06-01

    It is shown that, as a result of its interactions with superfluid vorticity, a normal-fluid vortex tube in helium-4 becomes unstable and disintegrates. The superfluid vorticity acquires only a small (few percents of normal-fluid tube strength) polarization, whilst expanding in a front-like manner in the intervortex space of the normal-fluid, forming a dense, unstructured tangle in the process. The accompanied energy spectra scalings offer a structural explanation of analogous scalings in fully developed finite-temperature superfluid turbulence. A macroscopic mutual-friction model incorporating these findings is proposed.

  17. Shannon Entropy and Mutual Information for Multivariate Skew-Elliptical Distributions

    KAUST Repository

    Arellano-Valle, Reinaldo B.

    2012-02-27

    The entropy and mutual information index are important concepts developed by Shannon in the context of information theory. They have been widely studied in the case of the multivariate normal distribution. We first extend these tools to the full symmetric class of multivariate elliptical distributions and then to the more flexible families of multivariate skew-elliptical distributions. We study in detail the cases of the multivariate skew-normal and skew-t distributions. We implement our findings to the application of the optimal design of an ozone monitoring station network in Santiago de Chile. © 2012 Board of the Foundation of the Scandinavian Journal of Statistics.

  18. Shannon Entropy and Mutual Information for Multivariate Skew-Elliptical Distributions

    KAUST Repository

    Arellano-Valle, Reinaldo B.; Contreras-Reyes, Javier E.; Genton, Marc G.

    2012-01-01

    The entropy and mutual information index are important concepts developed by Shannon in the context of information theory. They have been widely studied in the case of the multivariate normal distribution. We first extend these tools to the full symmetric class of multivariate elliptical distributions and then to the more flexible families of multivariate skew-elliptical distributions. We study in detail the cases of the multivariate skew-normal and skew-t distributions. We implement our findings to the application of the optimal design of an ozone monitoring station network in Santiago de Chile. © 2012 Board of the Foundation of the Scandinavian Journal of Statistics.

  19. Mutual information based feature selection for medical image retrieval

    Science.gov (United States)

    Zhi, Lijia; Zhang, Shaomin; Li, Yan

    2018-04-01

    In this paper, authors propose a mutual information based method for lung CT image retrieval. This method is designed to adapt to different datasets and different retrieval task. For practical applying consideration, this method avoids using a large amount of training data. Instead, with a well-designed training process and robust fundamental features and measurements, the method in this paper can get promising performance and maintain economic training computation. Experimental results show that the method has potential practical values for clinical routine application.

  20. Conditional Mutual Information Based Feature Selection for Classification Task

    Czech Academy of Sciences Publication Activity Database

    Novovičová, Jana; Somol, Petr; Haindl, Michal; Pudil, Pavel

    2007-01-01

    Roč. 45, č. 4756 (2007), s. 417-426 ISSN 0302-9743 R&D Projects: GA MŠk 1M0572; GA AV ČR IAA2075302 EU Projects: European Commission(XE) 507752 - MUSCLE Grant - others:GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : Pattern classification * feature selection * conditional mutual information * text categorization Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.402, year: 2005

  1. Mutual information measures applied to EEG signals for sleepiness characterization.

    Science.gov (United States)

    Melia, Umberto; Guaita, Marc; Vallverdú, Montserrat; Embid, Cristina; Vilaseca, Isabel; Salamero, Manel; Santamaria, Joan

    2015-03-01

    Excessive daytime sleepiness (EDS) is one of the main symptoms of several sleep related disorders with a great impact on the patient lives. While many studies have been carried out in order to assess daytime sleepiness, the automatic EDS detection still remains an open problem. In this work, a novel approach to this issue based on non-linear dynamical analysis of EEG signal was proposed. Multichannel EEG signals were recorded during five maintenance of wakefulness (MWT) and multiple sleep latency (MSLT) tests alternated throughout the day from patients suffering from sleep disordered breathing. A group of 20 patients with excessive daytime sleepiness (EDS) was compared with a group of 20 patients without daytime sleepiness (WDS), by analyzing 60-s EEG windows in waking state. Measures obtained from cross-mutual information function (CMIF) and auto-mutual-information function (AMIF) were calculated in the EEG. These functions permitted a quantification of the complexity properties of the EEG signal and the non-linear couplings between different zones of the scalp. Statistical differences between EDS and WDS groups were found in β band during MSLT events (p-value CMIF measures yielded sensitivity and specificity above 80% and AUC of ROC above 0.85 in classifying EDS and WDS patients. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  2. Mutual information and redundancy in spontaneous communication between cortical neurons.

    Science.gov (United States)

    Szczepanski, J; Arnold, M; Wajnryb, E; Amigó, J M; Sanchez-Vives, M V

    2011-03-01

    An important question in neural information processing is how neurons cooperate to transmit information. To study this question, we resort to the concept of redundancy in the information transmitted by a group of neurons and, at the same time, we introduce a novel concept for measuring cooperation between pairs of neurons called relative mutual information (RMI). Specifically, we studied these two parameters for spike trains generated by neighboring neurons from the primary visual cortex in the awake, freely moving rat. The spike trains studied here were spontaneously generated in the cortical network, in the absence of visual stimulation. Under these conditions, our analysis revealed that while the value of RMI oscillated slightly around an average value, the redundancy exhibited a behavior characterized by a higher variability. We conjecture that this combination of approximately constant RMI and greater variable redundancy makes information transmission more resistant to noise disturbances. Furthermore, the redundancy values suggest that neurons can cooperate in a flexible way during information transmission. This mostly occurs via a leading neuron with higher transmission rate or, less frequently, through the information rate of the whole group being higher than the sum of the individual information rates-in other words in a synergetic manner. The proposed method applies not only to the stationary, but also to locally stationary neural signals.

  3. Ambiguity Towards Multiple Historical Performance Information Signals: Evidence From Indonesian Open-Ended Mutual Fund Investors

    OpenAIRE

    Haris Pratama Loeis; Ruslan Prijadi

    2015-01-01

    This study focuses on the behavior of open-ended mutual fund investors when encountered with multiple information signals of mutual fund’s historical performance. The behavior of investors can be reflected on their decision to subscribe or redeem their funds from mutual funds. Moreover, we observe the presence of ambiguity within investors due to multiple information signals, and also their reaction towards it. Our finding shows that open-ended mutual fund investors do not only have sen...

  4. Information trimming: Sufficient statistics, mutual information, and predictability from effective channel states

    Science.gov (United States)

    James, Ryan G.; Mahoney, John R.; Crutchfield, James P.

    2017-06-01

    One of the most basic characterizations of the relationship between two random variables, X and Y , is the value of their mutual information. Unfortunately, calculating it analytically and estimating it empirically are often stymied by the extremely large dimension of the variables. One might hope to replace such a high-dimensional variable by a smaller one that preserves its relationship with the other. It is well known that either X (or Y ) can be replaced by its minimal sufficient statistic about Y (or X ) while preserving the mutual information. While intuitively reasonable, it is not obvious or straightforward that both variables can be replaced simultaneously. We demonstrate that this is in fact possible: the information X 's minimal sufficient statistic preserves about Y is exactly the information that Y 's minimal sufficient statistic preserves about X . We call this procedure information trimming. As an important corollary, we consider the case where one variable is a stochastic process' past and the other its future. In this case, the mutual information is the channel transmission rate between the channel's effective states. That is, the past-future mutual information (the excess entropy) is the amount of information about the future that can be predicted using the past. Translating our result about minimal sufficient statistics, this is equivalent to the mutual information between the forward- and reverse-time causal states of computational mechanics. We close by discussing multivariate extensions to this use of minimal sufficient statistics.

  5. Machine Learning with Squared-Loss Mutual Information

    Directory of Open Access Journals (Sweden)

    Masashi Sugiyama

    2012-12-01

    Full Text Available Mutual information (MI is useful for detecting statistical independence between random variables, and it has been successfully applied to solving various machine learning problems. Recently, an alternative to MI called squared-loss MI (SMI was introduced. While ordinary MI is the Kullback–Leibler divergence from the joint distribution to the product of the marginal distributions, SMI is its Pearson divergence variant. Because both the divergences belong to the ƒ-divergence family, they share similar theoretical properties. However, a notable advantage of SMI is that it can be approximated from data in a computationally more efficient and numerically more stable way than ordinary MI. In this article, we review recent development in SMI approximation based on direct density-ratio estimation and SMI-based machine learning techniques such as independence testing, dimensionality reduction, canonical dependency analysis, independent component analysis, object matching, clustering, and causal inference.

  6. Identifying Statistical Dependence in Genomic Sequences via Mutual Information Estimates

    Directory of Open Access Journals (Sweden)

    Wojciech Szpankowski

    2007-12-01

    Full Text Available Questions of understanding and quantifying the representation and amount of information in organisms have become a central part of biological research, as they potentially hold the key to fundamental advances. In this paper, we demonstrate the use of information-theoretic tools for the task of identifying segments of biomolecules (DNA or RNA that are statistically correlated. We develop a precise and reliable methodology, based on the notion of mutual information, for finding and extracting statistical as well as structural dependencies. A simple threshold function is defined, and its use in quantifying the level of significance of dependencies between biological segments is explored. These tools are used in two specific applications. First, they are used for the identification of correlations between different parts of the maize zmSRp32 gene. There, we find significant dependencies between the 5′ untranslated region in zmSRp32 and its alternatively spliced exons. This observation may indicate the presence of as-yet unknown alternative splicing mechanisms or structural scaffolds. Second, using data from the FBI's combined DNA index system (CODIS, we demonstrate that our approach is particularly well suited for the problem of discovering short tandem repeats—an application of importance in genetic profiling.

  7. Mutual information-based LPI optimisation for radar network

    Science.gov (United States)

    Shi, Chenguang; Zhou, Jianjiang; Wang, Fei; Chen, Jun

    2015-07-01

    Radar network can offer significant performance improvement for target detection and information extraction employing spatial diversity. For a fixed number of radars, the achievable mutual information (MI) for estimating the target parameters may extend beyond a predefined threshold with full power transmission. In this paper, an effective low probability of intercept (LPI) optimisation algorithm is presented to improve LPI performance for radar network. Based on radar network system model, we first provide Schleher intercept factor for radar network as an optimisation metric for LPI performance. Then, a novel LPI optimisation algorithm is presented, where for a predefined MI threshold, Schleher intercept factor for radar network is minimised by optimising the transmission power allocation among radars in the network such that the enhanced LPI performance for radar network can be achieved. The genetic algorithm based on nonlinear programming (GA-NP) is employed to solve the resulting nonconvex and nonlinear optimisation problem. Some simulations demonstrate that the proposed algorithm is valuable and effective to improve the LPI performance for radar network.

  8. AUTOMATIC REGISTRATION OF MULTI-SOURCE DATA USING MUTUAL INFORMATION

    Directory of Open Access Journals (Sweden)

    E. G. Parmehr

    2012-07-01

    Full Text Available Automatic image registration is a basic step in multi-sensor data integration in remote sensing and photogrammetric applications such as data fusion. The effectiveness of Mutual Information (MI as a technique for automated multi-sensor image registration has previously been demonstrated for medical and remote sensing applications. In this paper, a new General Weighted MI (GWMI approach that improves the robustness of MI to local maxima, particularly in the case of registering optical imagery and 3D point clouds, is presented. Two different methods including a Gaussian Mixture Model (GMM and Kernel Density Estimation have been used to define the weight function of joint probability, regardless of the modality of the data being registered. The Expectation Maximizing method is then used to estimate parameters of GMM, and in order to reduce the cost of computation, a multi-resolution strategy has been used. The performance of the proposed GWMI method for the registration of aerial orthotoimagery and LiDAR range and intensity information has been experimentally evaluated and the results obtained are presented.

  9. Anisotropic magnetotelluric inversion using a mutual information constraint

    Science.gov (United States)

    Mandolesi, E.; Jones, A. G.

    2012-12-01

    In recent years, several authors pointed that the electrical conductivity of many subsurface structures cannot be described properly by a scalar field. With the development of field devices and techniques, data quality improved to the point that the anisotropy in conductivity of rocks (microscopic anisotropy) and tectonic structures (macroscopic anisotropy) cannot be neglected. Therefore a correct use of high quality data has to include electrical anisotropy and a correct interpretation of anisotropic data characterizes directly a non-negligible part of the subsurface. In this work we test an inversion routine that takes advantage of the classic Levenberg-Marquardt (LM) algorithm to invert magnetotelluric (MT) data generated from a bi-dimensional (2D) anisotropic domain. The LM method is routinely used in inverse problems due its performance and robustness. In non-linear inverse problems -such the MT problem- the LM method provides a spectacular compromise betwee quick and secure convergence at the price of the explicit computation and storage of the sensitivity matrix. Regularization in inverse MT problems has been used extensively, due to the necessity to constrain model space and to reduce the ill-posedness of the anisotropic MT problem, which makes MT inversions extremely challenging. In order to reduce non-uniqueness of the MT problem and to reach a model compatible with other different tomographic results from the same target region, we used a mutual information (MI) based constraint. MI is a basic quantity in information theory that can be used to define a metric between images, and it is routinely used in fields as computer vision, image registration and medical tomography, to cite some applications. We -thus- inverted for the model that best fits the anisotropic data and that is the closest -in a MI sense- to a tomographic model of the target area. The advantage of this technique is that the tomographic model of the studied region may be produced by any

  10. Fuzzy Mutual Information Based min-Redundancy and Max-Relevance Heterogeneous Feature Selection

    Directory of Open Access Journals (Sweden)

    Daren Yu

    2011-08-01

    Full Text Available Feature selection is an important preprocessing step in pattern classification and machine learning, and mutual information is widely used to measure relevance between features and decision. However, it is difficult to directly calculate relevance between continuous or fuzzy features using mutual information. In this paper we introduce the fuzzy information entropy and fuzzy mutual information for computing relevance between numerical or fuzzy features and decision. The relationship between fuzzy information entropy and differential entropy is also discussed. Moreover, we combine fuzzy mutual information with qmin-Redundancy-Max-Relevanceq, qMax-Dependencyq and min-Redundancy-Max-Dependencyq algorithms. The performance and stability of the proposed algorithms are tested on benchmark data sets. Experimental results show the proposed algorithms are effective and stable.

  11. Research on electricity consumption forecast based on mutual information and random forests algorithm

    Science.gov (United States)

    Shi, Jing; Shi, Yunli; Tan, Jian; Zhu, Lei; Li, Hu

    2018-02-01

    Traditional power forecasting models cannot efficiently take various factors into account, neither to identify the relation factors. In this paper, the mutual information in information theory and the artificial intelligence random forests algorithm are introduced into the medium and long-term electricity demand prediction. Mutual information can identify the high relation factors based on the value of average mutual information between a variety of variables and electricity demand, different industries may be highly associated with different variables. The random forests algorithm was used for building the different industries forecasting models according to the different correlation factors. The data of electricity consumption in Jiangsu Province is taken as a practical example, and the above methods are compared with the methods without regard to mutual information and the industries. The simulation results show that the above method is scientific, effective, and can provide higher prediction accuracy.

  12. Mutual information and the fidelity of response of gene regulatory models

    International Nuclear Information System (INIS)

    Tabbaa, Omar P; Jayaprakash, C

    2014-01-01

    We investigate cellular response to extracellular signals by using information theory techniques motivated by recent experiments. We present results for the steady state of the following gene regulatory models found in both prokaryotic and eukaryotic cells: a linear transcription-translation model and a positive or negative auto-regulatory model. We calculate both the information capacity and the mutual information exactly for simple models and approximately for the full model. We find that (1) small changes in mutual information can lead to potentially important changes in cellular response and (2) there are diminishing returns in the fidelity of response as the mutual information increases. We calculate the information capacity using Gillespie simulations of a model for the TNF-α-NF-κ B network and find good agreement with the measured value for an experimental realization of this network. Our results provide a quantitative understanding of the differences in cellular response when comparing experimentally measured mutual information values of different gene regulatory models. Our calculations demonstrate that Gillespie simulations can be used to compute the mutual information of more complex gene regulatory models, providing a potentially useful tool in synthetic biology. (paper)

  13. Inferring the Directionality of Coupling with Conditional Mutual Information

    Czech Academy of Sciences Publication Activity Database

    Vejmelka, Martin; Paluš, Milan

    2008-01-01

    Roč. 77, - (2008), Art.no.-026214 ISSN 1539-3755 EU Projects: European Commission(XE) 517133 - BRACCIA Institutional research plan: CEZ:AV0Z10300504 Keywords : directionality * chaotic oscillators * time series analysis * information theory * phase dynamics Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.508, year: 2008

  14. Estimating Mutual Information for High-to-Low Calibration

    Energy Technology Data Exchange (ETDEWEB)

    Michaud, Isaac James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Williams, Brian J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Weaver, Brian Phillip [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-05

    Presentation shows that KSG2 is superior to KSG1 because it scales locally automatically; KSG estimators are limited to a maximum MI due to sample size; LNC extends the capability of KSG without onerous assumptions; iLNC allows LNC to estimate information gain.

  15. Mutual Funds and Information Diffusion: The Role of Country-Level Governance

    NARCIS (Netherlands)

    C. Lin (Chunmei); M. Massa (Massimo); H. Zhang (Hong)

    2014-01-01

    markdownabstract__Abstract__ We hypothesize that poor country-level governance, which makes public information less reliable, induces fund managers to increase their use of semi-public information. Utilizing data from international mutual funds and stocks over the 2000-2009 period, we find that

  16. [Non-rigid medical image registration based on mutual information and thin-plate spline].

    Science.gov (United States)

    Cao, Guo-gang; Luo, Li-min

    2009-01-01

    To get precise and complete details, the contrast in different images is needed in medical diagnosis and computer assisted treatment. The image registration is the basis of contrast, but the regular rigid registration does not satisfy the clinic requirements. A non-rigid medical image registration method based on mutual information and thin-plate spline was present. Firstly, registering two images globally based on mutual information; secondly, dividing reference image and global-registered image into blocks and registering them; then getting the thin-plate spline transformation according to the shift of blocks' center; finally, applying the transformation to the global-registered image. The results show that the method is more precise than the global rigid registration based on mutual information and it reduces the complexity of getting control points and satisfy the clinic requirements better by getting control points of the thin-plate transformation automatically.

  17. Deciphering robust reactor kinetic data using mutual information

    International Nuclear Information System (INIS)

    Kumar, P.T. Krishna

    2007-01-01

    Experimentalists use Chauvenets's criterion to check the quality of any measured data. Based on this criterion they rejected data having high degree of correlation. Multivariate techniques like principal component analysis used for analysis of these correlated data, does not provide any scope to minimize the effect of correlation. We propose a novel method using information theory and the technique of determinant inequalities developed by us to reduce the effect of correlation among these data without summarily rejecting them. We demonstrate the utility of our technique in transient measurements of kinetic parameters performed on the commercially advanced gas cooled reactor (CAGCR)

  18. Mutual information, neural networks and the renormalization group

    Science.gov (United States)

    Koch-Janusz, Maciej; Ringel, Zohar

    2018-06-01

    Physical systems differing in their microscopic details often display strikingly similar behaviour when probed at macroscopic scales. Those universal properties, largely determining their physical characteristics, are revealed by the powerful renormalization group (RG) procedure, which systematically retains `slow' degrees of freedom and integrates out the rest. However, the important degrees of freedom may be difficult to identify. Here we demonstrate a machine-learning algorithm capable of identifying the relevant degrees of freedom and executing RG steps iteratively without any prior knowledge about the system. We introduce an artificial neural network based on a model-independent, information-theoretic characterization of a real-space RG procedure, which performs this task. We apply the algorithm to classical statistical physics problems in one and two dimensions. We demonstrate RG flow and extract the Ising critical exponent. Our results demonstrate that machine-learning techniques can extract abstract physical concepts and consequently become an integral part of theory- and model-building.

  19. Localized nonlinear waves on quantized superfluid vortex filaments in the presence of mutual friction and a driving normal fluid flow.

    Science.gov (United States)

    Shah, Rehan; Van Gorder, Robert A

    2016-03-01

    We demonstrate the existence of localized structures along quantized vortex filaments in superfluid helium under the quantum form of the local induction approximation (LIA), which includes mutual friction and normal fluid effects. For small magnitude normal fluid velocities, the dynamics are dissipative under mutual friction. On the other hand, when normal fluid velocities are sufficiently large, we observe parametric amplification of the localized disturbances along quantized vortex filaments, akin to the Donnelly-Glaberson instability for regular Kelvin waves. As the waves amplify they will eventually cause breakdown of the LIA assumption (and perhaps the vortex filament itself), and we derive a characteristic time for which this breakdown occurs under our model. More complicated localized waves are shown to occur, and we study these asymptotically and through numerical simulations. Such solutions still exhibit parametric amplification for large enough normal fluid velocities, although this amplification may be less uniform than would be seen for more regular filaments such as those corresponding to helical curves. We find that large rotational velocities or large wave speeds of nonlinear waves along the filaments will result in more regular and stable structures, while small rotational velocities and wave speeds will permit far less regular dynamics.

  20. Mutual information optimization for mass spectra data alignment.

    Science.gov (United States)

    Zoppis, Italo; Gianazza, Erica; Borsani, Massimiliano; Chinello, Clizia; Mainini, Veronica; Galbusera, Carmen; Ferrarese, Carlo; Galimberti, Gloria; Sorbi, Sandro; Borroni, Barbara; Magni, Fulvio; Antoniotti, Marco; Mauri, Giancarlo

    2012-01-01

    "Signal" alignments play critical roles in many clinical setting. This is the case of mass spectrometry data, an important component of many types of proteomic analysis. A central problem occurs when one needs to integrate (mass spectrometry) data produced by different sources, e.g., different equipment and/or laboratories. In these cases some form of "data integration'" or "data fusion'" may be necessary in order to discard some source specific aspects and improve the ability to perform a classification task such as inferring the "disease classes'" of patients. The need for new high performance data alignments methods is therefore particularly important in these contexts. In this paper we propose an approach based both on an information theory perspective, generally used in a feature construction problem, and on the application of a mathematical programming task (i.e. the weighted bipartite matching problem). We present the results of a competitive analysis of our method against other approaches. The analysis was conducted on data from plasma/ethylenediaminetetraacetic acid (EDTA) of "control" and Alzheimer patients collected from three different hospitals. The results point to a significant performance advantage of our method with respect to the competing ones tested.

  1. Admixture mapping of end stage kidney disease genetic susceptibility using estimated mutual information ancestry informative markers

    Directory of Open Access Journals (Sweden)

    Geiger Dan

    2010-10-01

    Full Text Available Abstract Background The question of a genetic contribution to the higher prevalence and incidence of end stage kidney disease (ESKD among African Americans (AA remained unresolved, until recent findings using admixture mapping pointed to the association of a genomic locus on chromosome 22 with this disease phenotype. In the current study we utilize this example to demonstrate the utility of applying a multi-step admixture mapping approach. Methods A multi-step case only admixture mapping study, consisted of the following steps was designed: 1 Assembly of the sample dataset (ESKD AA; 2 Design of the estimated mutual information ancestry informative markers (n = 2016 screening panel 3; Genotyping the sample set whose size was determined by a power analysis (n = 576 appropriate for the initial screening panel; 4 Inference of local ancestry for each individual and identification of regions with increased AA ancestry using two different ancestry inference statistical approaches; 5 Enrichment of the initial screening panel; 6 Power analysis of the enriched panel 7 Genotyping of additional samples. 8 Re-analysis of the genotyping results to identify a genetic risk locus. Results The initial screening phase yielded a significant peak using the ADMIXMAP ancestry inference program applying case only statistics. Subgroup analysis of 299 ESKD patients with no history of diabetes yielded peaks using both the ANCESTRYMAP and ADMIXMAP ancestry inference programs. The significant peak was found on chromosome 22. Genotyping of additional ancestry informative markers on chromosome 22 that took into account linkage disequilibrium in the ancestral populations, and the addition of samples increased the statistical significance of the finding. Conclusions A multi-step admixture mapping analysis of AA ESKD patients replicated the finding of a candidate risk locus on chromosome 22, contributing to the heightened susceptibility of African Americans to develop non

  2. Mutual trust method for forwarding information in wireless sensor networks using random secret pre-distribution

    Directory of Open Access Journals (Sweden)

    Chih-Hsueh Lin

    2016-04-01

    Full Text Available In wireless sensor networks, sensing information must be transmitted from sensor nodes to the base station by multiple hopping. Every sensor node is a sender and a relay node that forwards the sensing information that is sent by other nodes. Under an attack, the sensing information may be intercepted, modified, interrupted, or fabricated during transmission. Accordingly, the development of mutual trust to enable a secure path to be established for forwarding information is an important issue. Random key pre-distribution has been proposed to establish mutual trust among sensor nodes. This article modifies the random key pre-distribution to a random secret pre-distribution and incorporates identity-based cryptography to establish an effective method of establishing mutual trust for a wireless sensor network. In the proposed method, base station assigns an identity and embeds n secrets into the private secret keys for every sensor node. Based on the identity and private secret keys, the mutual trust method is utilized to explore the types of trust among neighboring sensor nodes. The novel method can resist malicious attacks and satisfy the requirements of wireless sensor network, which are resistance to compromising attacks, masquerading attacks, forger attacks, replying attacks, authentication of forwarding messages, and security of sensing information.

  3. Identifying relevant group of miRNAs in cancer using fuzzy mutual information.

    Science.gov (United States)

    Pal, Jayanta Kumar; Ray, Shubhra Sankar; Pal, Sankar K

    2016-04-01

    MicroRNAs (miRNAs) act as a major biomarker of cancer. All miRNAs in human body are not equally important for cancer identification. We propose a methodology, called FMIMS, which automatically selects the most relevant miRNAs for a particular type of cancer. In FMIMS, miRNAs are initially grouped by using a SVM-based algorithm; then the group with highest relevance is determined and the miRNAs in that group are finally ranked for selection according to their redundancy. Fuzzy mutual information is used in computing the relevance of a group and the redundancy of miRNAs within it. Superiority of the most relevant group to all others, in deciding normal or cancer, is demonstrated on breast, renal, colorectal, lung, melanoma and prostate data. The merit of FMIMS as compared to several existing methods is established. While 12 out of 15 selected miRNAs by FMIMS corroborate with those of biological investigations, three of them viz., "hsa-miR-519," "hsa-miR-431" and "hsa-miR-320c" are possible novel predictions for renal cancer, lung cancer and melanoma, respectively. The selected miRNAs are found to be involved in disease-specific pathways by targeting various genes. The method is also able to detect the responsible miRNAs even at the primary stage of cancer. The related code is available at http://www.jayanta.droppages.com/FMIMS.html .

  4. Development of stock correlation networks using mutual information and financial big data.

    Science.gov (United States)

    Guo, Xue; Zhang, Hu; Tian, Tianhai

    2018-01-01

    Stock correlation networks use stock price data to explore the relationship between different stocks listed in the stock market. Currently this relationship is dominantly measured by the Pearson correlation coefficient. However, financial data suggest that nonlinear relationships may exist in the stock prices of different shares. To address this issue, this work uses mutual information to characterize the nonlinear relationship between stocks. Using 280 stocks traded at the Shanghai Stocks Exchange in China during the period of 2014-2016, we first compare the effectiveness of the correlation coefficient and mutual information for measuring stock relationships. Based on these two measures, we then develop two stock networks using the Minimum Spanning Tree method and study the topological properties of these networks, including degree, path length and the power-law distribution. The relationship network based on mutual information has a better distribution of the degree and larger value of the power-law distribution than those using the correlation coefficient. Numerical results show that mutual information is a more effective approach than the correlation coefficient to measure the stock relationship in a stock market that may undergo large fluctuations of stock prices.

  5. Mutual information and phase dependencies: measures of reduced nonlinear cardiorespiratory interactions after myocardial infarction.

    Science.gov (United States)

    Hoyer, Dirk; Leder, Uwe; Hoyer, Heike; Pompe, Bernd; Sommer, Michael; Zwiener, Ulrich

    2002-01-01

    The heart rate variability (HRV) is related to several mechanisms of the complex autonomic functioning such as respiratory heart rate modulation and phase dependencies between heart beat cycles and breathing cycles. The underlying processes are basically nonlinear. In order to understand and quantitatively assess those physiological interactions an adequate coupling analysis is necessary. We hypothesized that nonlinear measures of HRV and cardiorespiratory interdependencies are superior to the standard HRV measures in classifying patients after acute myocardial infarction. We introduced mutual information measures which provide access to nonlinear interdependencies as counterpart to the classically linear correlation analysis. The nonlinear statistical autodependencies of HRV were quantified by auto mutual information, the respiratory heart rate modulation by cardiorespiratory cross mutual information, respectively. The phase interdependencies between heart beat cycles and breathing cycles were assessed basing on the histograms of the frequency ratios of the instantaneous heart beat and respiratory cycles. Furthermore, the relative duration of phase synchronized intervals was acquired. We investigated 39 patients after acute myocardial infarction versus 24 controls. The discrimination of these groups was improved by cardiorespiratory cross mutual information measures and phase interdependencies measures in comparison to the linear standard HRV measures. This result was statistically confirmed by means of logistic regression models of particular variable subsets and their receiver operating characteristics.

  6. A Feature Subset Selection Method Based On High-Dimensional Mutual Information

    Directory of Open Access Journals (Sweden)

    Chee Keong Kwoh

    2011-04-01

    Full Text Available Feature selection is an important step in building accurate classifiers and provides better understanding of the data sets. In this paper, we propose a feature subset selection method based on high-dimensional mutual information. We also propose to use the entropy of the class attribute as a criterion to determine the appropriate subset of features when building classifiers. We prove that if the mutual information between a feature set X and the class attribute Y equals to the entropy of Y , then X is a Markov Blanket of Y . We show that in some cases, it is infeasible to approximate the high-dimensional mutual information with algebraic combinations of pairwise mutual information in any forms. In addition, the exhaustive searches of all combinations of features are prerequisite for finding the optimal feature subsets for classifying these kinds of data sets. We show that our approach outperforms existing filter feature subset selection methods for most of the 24 selected benchmark data sets.

  7. Butterfly effect and holographic mutual information under external field and spatial noncommutativity

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Wung-Hong; Du, Yi-Hsien [Department of Physics, National Cheng Kung University,No. 1, University Road, Tainan City 701, Taiwan (China)

    2017-02-07

    We apply the transformation of mixing azimuthal and internal coordinate or mixing time and internal coordinate to a stack of N black M-branes to find the Melvin spacetime of a stack of N black D-branes with magnetic or electric flux in string theory, after the Kaluza-Klein reduction. We slightly extend previous formulas to investigate the external magnetic and electric effects on the butterfly effect and holographic mutual information. It shows that the Melvin fields do not modify the scrambling time and will enhance the mutual information. In addition, we also T-dualize and twist a stack of N black D-branes to find a Melvin Universe supported by the flux of the NSNS b-field, which describes a non-comutative spacetime. It also shows that the spatial noncommutativity does not modify the scrambling time and will enhance the mutual information. We also study the corrected mutual information in the backreaction geometry due to the shock wave in our three model spacetimes.

  8. Evaluation of optimization methods for nonrigid medical image registration using mutual information and B-splines

    NARCIS (Netherlands)

    Klein, S.; Staring, M.; Pluim, J.P.W.

    2007-01-01

    A popular technique for nonrigid registration of medical images is based on the maximization of their mutual information, in combination with a deformation field parameterized by cubic B-splines. The coordinate mapping that relates the two images is found using an iterative optimization procedure.

  9. The chain rule implies Tsirelson's bound: an approach from generalized mutual information

    International Nuclear Information System (INIS)

    Wakakuwa, Eyuri; Murao, Mio

    2012-01-01

    In order to analyze an information theoretical derivation of Tsirelson's bound based on information causality, we introduce a generalized mutual information (GMI), defined as the optimal coding rate of a channel with classical inputs and general probabilistic outputs. In the case where the outputs are quantum, the GMI coincides with the quantum mutual information. In general, the GMI does not necessarily satisfy the chain rule. We prove that Tsirelson's bound can be derived by imposing the chain rule on the GMI. We formulate a principle, which we call the no-supersignaling condition, which states that the assistance of nonlocal correlations does not increase the capability of classical communication. We prove that this condition is equivalent to the no-signaling condition. As a result, we show that Tsirelson's bound is implied by the nonpositivity of the quantitative difference between information causality and no-supersignaling. (paper)

  10. Mutual information as a two-point correlation function in stochastic lattice models

    International Nuclear Information System (INIS)

    Müller, Ulrich; Hinrichsen, Haye

    2013-01-01

    In statistical physics entropy is usually introduced as a global quantity which expresses the amount of information that would be needed to specify the microscopic configuration of a system. However, for lattice models with infinitely many possible configurations per lattice site it is also meaningful to introduce entropy as a local observable that describes the information content of a single lattice site. Likewise, the mutual information between two sites can be interpreted as a two-point correlation function which quantifies how much information a lattice site has about the state of another one and vice versa. Studying a particular growth model we demonstrate that the mutual information exhibits scaling properties that are consistent with the established phenomenological scaling picture. (paper)

  11. Information fusion performance evaluation for motion imagery data using mutual information: initial study

    Science.gov (United States)

    Grieggs, Samuel M.; McLaughlin, Michael J.; Ezekiel, Soundararajan; Blasch, Erik

    2015-06-01

    As technology and internet use grows at an exponential rate, video and imagery data is becoming increasingly important. Various techniques such as Wide Area Motion imagery (WAMI), Full Motion Video (FMV), and Hyperspectral Imaging (HSI) are used to collect motion data and extract relevant information. Detecting and identifying a particular object in imagery data is an important step in understanding visual imagery, such as content-based image retrieval (CBIR). Imagery data is segmented and automatically analyzed and stored in dynamic and robust database. In our system, we seek utilize image fusion methods which require quality metrics. Many Image Fusion (IF) algorithms have been proposed based on different, but only a few metrics, used to evaluate the performance of these algorithms. In this paper, we seek a robust, objective metric to evaluate the performance of IF algorithms which compares the outcome of a given algorithm to ground truth and reports several types of errors. Given the ground truth of a motion imagery data, it will compute detection failure, false alarm, precision and recall metrics, background and foreground regions statistics, as well as split and merge of foreground regions. Using the Structural Similarity Index (SSIM), Mutual Information (MI), and entropy metrics; experimental results demonstrate the effectiveness of the proposed methodology for object detection, activity exploitation, and CBIR.

  12. MIToS.jl: mutual information tools for protein sequence analysis in the Julia language

    DEFF Research Database (Denmark)

    Zea, Diego J.; Anfossi, Diego; Nielsen, Morten

    2017-01-01

    Motivation: MIToS is an environment for mutual information analysis and a framework for protein multiple sequence alignments (MSAs) and protein structures (PDB) management in Julia language. It integrates sequence and structural information through SIFTS, making Pfam MSAs analysis straightforward....... MIToS streamlines the implementation of any measure calculated from residue contingency tables and its optimization and testing in terms of protein contact prediction. As an example, we implemented and tested a BLOSUM62-based pseudo-count strategy in mutual information analysis. Availability...... and Implementation: The software is totally implemented in Julia and supported for Linux, OS X and Windows. It’s freely available on GitHub under MIT license: http://mitos.leloir.org.ar. Contacts:diegozea@gmail.com or cmb@leloir.org.ar Supplementary information: Supplementary data are available at Bioinformatics...

  13. Feature extraction and learning using context cue and Rényi entropy based mutual information

    DEFF Research Database (Denmark)

    Pan, Hong; Olsen, Søren Ingvor; Zhu, Yaping

    2015-01-01

    information. In particular, for feature extraction, we develop a new set of kernel descriptors−Context Kernel Descriptors (CKD), which enhance the original KDES by embedding the spatial context into the descriptors. Context cues contained in the context kernel enforce some degree of spatial consistency, thus...... improving the robustness of CKD. For feature learning and reduction, we propose a novel codebook learning method, based on a Rényi quadratic entropy based mutual information measure called Cauchy-Schwarz Quadratic Mutual Information (CSQMI), to learn a compact and discriminative CKD codebook. Projecting...... as the information about the underlying labels of the CKD using CSQMI. Thus the resulting codebook and reduced CKD are discriminative. We verify the effectiveness of our method on several public image benchmark datasets such as YaleB, Caltech-101 and CIFAR-10, as well as a challenging chicken feet dataset of our own...

  14. An HVS-based location-sensitive definition of mutual information between two images

    Science.gov (United States)

    Zhu, Haijun; Wu, Huayi

    2006-10-01

    Quantitative measure of image information amount is of great importance in many image processing applications, e.g. image compression and image registration. Many commonly used metrics are defined mathematically. However, the ultimate consumers of images are human observers in most situations, thus such measures without consideration of internal mechanism of human visual system (HVS) may not be appropriate. This paper proposes an improved definition of mutual information between two images based on the visual information which is actually perceived by human beings in different subbands of image. This definition is both sensitive to the pixels' spatial location and correlates well with human perceptual feeling than mutual information purely calculated by pixels' grayscale value. Experimental results on images with different noises and JPEG&JPEG2000 compressed images are also given.

  15. Study of three-dimensional PET and MR image registration based on higher-order mutual information

    International Nuclear Information System (INIS)

    Ren Haiping; Chen Shengzu; Wu Wenkai; Yang Hu

    2002-01-01

    Mutual information has currently been one of the most intensively researched measures. It has been proven to be accurate and effective registration measure. Despite the general promising results, mutual information sometimes might lead to misregistration because of neglecting spatial information and treating intensity variations with undue sensitivity. An extension of mutual information framework was proposed in which higher-order spatial information regarding image structures was incorporated into the registration processing of PET and MR. The second-order estimate of mutual information algorithm was applied to the registration of seven patients. Evaluation from Vanderbilt University and authors' visual inspection showed that sub-voxel accuracy and robust results were achieved in all cases with second-order mutual information as the similarity measure and with Powell's multidimensional direction set method as optimization strategy

  16. Reference evapotranspiration forecasting based on local meteorological and global climate information screened by partial mutual information

    Science.gov (United States)

    Fang, Wei; Huang, Shengzhi; Huang, Qiang; Huang, Guohe; Meng, Erhao; Luan, Jinkai

    2018-06-01

    In this study, reference evapotranspiration (ET0) forecasting models are developed for the least economically developed regions subject to meteorological data scarcity. Firstly, the partial mutual information (PMI) capable of capturing the linear and nonlinear dependence is investigated regarding its utility to identify relevant predictors and exclude those that are redundant through the comparison with partial linear correlation. An efficient input selection technique is crucial for decreasing model data requirements. Then, the interconnection between global climate indices and regional ET0 is identified. Relevant climatic indices are introduced as additional predictors to comprise information regarding ET0, which ought to be provided by meteorological data unavailable. The case study in the Jing River and Beiluo River basins, China, reveals that PMI outperforms the partial linear correlation in excluding the redundant information, favouring the yield of smaller predictor sets. The teleconnection analysis identifies the correlation between Nino 1 + 2 and regional ET0, indicating influences of ENSO events on the evapotranspiration process in the study area. Furthermore, introducing Nino 1 + 2 as predictors helps to yield more accurate ET0 forecasts. A model performance comparison also shows that non-linear stochastic models (SVR or RF with input selection through PMI) do not always outperform linear models (MLR with inputs screen by linear correlation). However, the former can offer quite comparable performance depending on smaller predictor sets. Therefore, efforts such as screening model inputs through PMI and incorporating global climatic indices interconnected with ET0 can benefit the development of ET0 forecasting models suitable for data-scarce regions.

  17. Mutual information identifies spurious Hurst phenomena in resting state EEG and fMRI data

    Science.gov (United States)

    von Wegner, Frederic; Laufs, Helmut; Tagliazucchi, Enzo

    2018-02-01

    Long-range memory in time series is often quantified by the Hurst exponent H , a measure of the signal's variance across several time scales. We analyze neurophysiological time series from electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) resting state experiments with two standard Hurst exponent estimators and with the time-lagged mutual information function applied to discretized versions of the signals. A confidence interval for the mutual information function is obtained from surrogate Markov processes with equilibrium distribution and transition matrix identical to the underlying signal. For EEG signals, we construct an additional mutual information confidence interval from a short-range correlated, tenth-order autoregressive model. We reproduce the previously described Hurst phenomenon (H >0.5 ) in the analytical amplitude of alpha frequency band oscillations, in EEG microstate sequences, and in fMRI signals, but we show that the Hurst phenomenon occurs without long-range memory in the information-theoretical sense. We find that the mutual information function of neurophysiological data behaves differently from fractional Gaussian noise (fGn), for which the Hurst phenomenon is a sufficient condition to prove long-range memory. Two other well-characterized, short-range correlated stochastic processes (Ornstein-Uhlenbeck, Cox-Ingersoll-Ross) also yield H >0.5 , whereas their mutual information functions lie within the Markovian confidence intervals, similar to neural signals. In these processes, which do not have long-range memory by construction, a spurious Hurst phenomenon occurs due to slow relaxation times and heteroscedasticity (time-varying conditional variance). In summary, we find that mutual information correctly distinguishes long-range from short-range dependence in the theoretical and experimental cases discussed. Our results also suggest that the stationary fGn process is not sufficient to describe neural data, which

  18. Adaptive DSPI phase denoising using mutual information and 2D variational mode decomposition

    Science.gov (United States)

    Xiao, Qiyang; Li, Jian; Wu, Sijin; Li, Weixian; Yang, Lianxiang; Dong, Mingli; Zeng, Zhoumo

    2018-04-01

    In digital speckle pattern interferometry (DSPI), noise interference leads to a low peak signal-to-noise ratio (PSNR) and measurement errors in the phase map. This paper proposes an adaptive DSPI phase denoising method based on two-dimensional variational mode decomposition (2D-VMD) and mutual information. Firstly, the DSPI phase map is subjected to 2D-VMD in order to obtain a series of band-limited intrinsic mode functions (BLIMFs). Then, on the basis of characteristics of the BLIMFs and in combination with mutual information, a self-adaptive denoising method is proposed to obtain noise-free components containing the primary phase information. The noise-free components are reconstructed to obtain the denoising DSPI phase map. Simulation and experimental results show that the proposed method can effectively reduce noise interference, giving a PSNR that is higher than that of two-dimensional empirical mode decomposition methods.

  19. Mutual information as a measure of reconstruction quality in 3D dynamic lung EIT

    International Nuclear Information System (INIS)

    Crabb, M G; Lionheart, W R B; Davidson, J L; Wright, P; McCann, H; Little, R; Naish, J H; Parker, G J M; Kikinis, R

    2013-01-01

    We report on a pilot study with healthy subjects who had an MR scan in addition to EIT data acquired with the Manchester fEITER system. The MR images are used to inform the external shape of a 3D EIT reconstruction model of the thorax, and small changes in the boundary that occur during respiration are addressed by incorporating the sensitivity with respect to boundary shape into a robust reconstruction algorithm. A quantitative comparison of the image quality for different EIT reconstructions is achieved through calculation of their mutual information with a segmented MR image. A shape corrected reconstruction algorithm reduces boundary artefacts relative to a standard reconstruction, and has a greater mutual information of approximately 4% with the segmented MR image.

  20. Estimation of time-delayed mutual information and bias for irregularly and sparsely sampled time-series

    International Nuclear Information System (INIS)

    Albers, D.J.; Hripcsak, George

    2012-01-01

    Highlights: ► Time-delayed mutual information for irregularly sampled time-series. ► Estimation bias for the time-delayed mutual information calculation. ► Fast, simple, PDF estimator independent, time-delayed mutual information bias estimate. ► Quantification of data-set-size limits of the time-delayed mutual calculation. - Abstract: A method to estimate the time-dependent correlation via an empirical bias estimate of the time-delayed mutual information for a time-series is proposed. In particular, the bias of the time-delayed mutual information is shown to often be equivalent to the mutual information between two distributions of points from the same system separated by infinite time. Thus intuitively, estimation of the bias is reduced to estimation of the mutual information between distributions of data points separated by large time intervals. The proposed bias estimation techniques are shown to work for Lorenz equations data and glucose time series data of three patients from the Columbia University Medical Center database.

  1. Comparison of co-expression measures: mutual information, correlation, and model based indices.

    Science.gov (United States)

    Song, Lin; Langfelder, Peter; Horvath, Steve

    2012-12-09

    Co-expression measures are often used to define networks among genes. Mutual information (MI) is often used as a generalized correlation measure. It is not clear how much MI adds beyond standard (robust) correlation measures or regression model based association measures. Further, it is important to assess what transformations of these and other co-expression measures lead to biologically meaningful modules (clusters of genes). We provide a comprehensive comparison between mutual information and several correlation measures in 8 empirical data sets and in simulations. We also study different approaches for transforming an adjacency matrix, e.g. using the topological overlap measure. Overall, we confirm close relationships between MI and correlation in all data sets which reflects the fact that most gene pairs satisfy linear or monotonic relationships. We discuss rare situations when the two measures disagree. We also compare correlation and MI based approaches when it comes to defining co-expression network modules. We show that a robust measure of correlation (the biweight midcorrelation transformed via the topological overlap transformation) leads to modules that are superior to MI based modules and maximal information coefficient (MIC) based modules in terms of gene ontology enrichment. We present a function that relates correlation to mutual information which can be used to approximate the mutual information from the corresponding correlation coefficient. We propose the use of polynomial or spline regression models as an alternative to MI for capturing non-linear relationships between quantitative variables. The biweight midcorrelation outperforms MI in terms of elucidating gene pairwise relationships. Coupled with the topological overlap matrix transformation, it often leads to more significantly enriched co-expression modules. Spline and polynomial networks form attractive alternatives to MI in case of non-linear relationships. Our results indicate that MI

  2. An improved discriminative filter bank selection approach for motor imagery EEG signal classification using mutual information.

    Science.gov (United States)

    Kumar, Shiu; Sharma, Alok; Tsunoda, Tatsuhiko

    2017-12-28

    Common spatial pattern (CSP) has been an effective technique for feature extraction in electroencephalography (EEG) based brain computer interfaces (BCIs). However, motor imagery EEG signal feature extraction using CSP generally depends on the selection of the frequency bands to a great extent. In this study, we propose a mutual information based frequency band selection approach. The idea of the proposed method is to utilize the information from all the available channels for effectively selecting the most discriminative filter banks. CSP features are extracted from multiple overlapping sub-bands. An additional sub-band has been introduced that cover the wide frequency band (7-30 Hz) and two different types of features are extracted using CSP and common spatio-spectral pattern techniques, respectively. Mutual information is then computed from the extracted features of each of these bands and the top filter banks are selected for further processing. Linear discriminant analysis is applied to the features extracted from each of the filter banks. The scores are fused together, and classification is done using support vector machine. The proposed method is evaluated using BCI Competition III dataset IVa, BCI Competition IV dataset I and BCI Competition IV dataset IIb, and it outperformed all other competing methods achieving the lowest misclassification rate and the highest kappa coefficient on all three datasets. Introducing a wide sub-band and using mutual information for selecting the most discriminative sub-bands, the proposed method shows improvement in motor imagery EEG signal classification.

  3. The Quantitative Evaluation of Functional Neuroimaging Experiments: Mutual Information Learning Curves

    DEFF Research Database (Denmark)

    Kjems, Ulrik; Hansen, Lars Kai; Anderson, Jon

    2002-01-01

    Learning curves are presented as an unbiased means for evaluating the performance of models for neuroimaging data analysis. The learning curve measures the predictive performance in terms of the generalization or prediction error as a function of the number of independent examples (e.g., subjects......) used to determine the parameters in the model. Cross-validation resampling is used to obtain unbiased estimates of a generic multivariate Gaussian classifier, for training set sizes from 2 to 16 subjects. We apply the framework to four different activation experiments, in this case \\$\\backslash......\\$[/sup 15/ O]water data sets, although the framework is equally valid for multisubject fMRI studies. We demonstrate how the prediction error can be expressed as the mutual information between the scan and the scan label, measured in units of bits. The mutual information learning curve can be used...

  4. Conditional entropy and mutual information in Pb+Pb interactions at 158 A GeV

    International Nuclear Information System (INIS)

    Shah, T.H.

    2017-01-01

    Many models have been proposed to explain the phenomenon, usually called intermittency. Most of them contain essentially a kind of self-similar cascading process. In this context, self-similar random cascading is the most natural and hopeful mechanism that can reproduce the intermittency phenomena in multiparticle production. Wu Yuanfang and Liu Lianshou developed a method for observing and examining this mechanism of self- similar random cascading, making use of the concepts of conditional entropy and mutual information. In the study we examine the data on photon multiplicity produced in Lead - Lead central collisions at 158 A GeV for the existence of self-similar random cascading using conditional entropy and mutual information variables. The results are compared with Monte Carlo simulation studies using VENUS event generator and GEANT detector simulation software. The experiment is also compared with predictions from Alpha-Model

  5. Elman RNN based classification of proteins sequences on account of their mutual information.

    Science.gov (United States)

    Mishra, Pooja; Nath Pandey, Paras

    2012-10-21

    In the present work we have employed the method of estimating residue correlation within the protein sequences, by using the mutual information (MI) of adjacent residues, based on structural and solvent accessibility properties of amino acids. The long range correlation between nonadjacent residues is improved by constructing a mutual information vector (MIV) for a single protein sequence, like this each protein sequence is associated with its corresponding MIVs. These MIVs are given to Elman RNN to obtain the classification of protein sequences. The modeling power of MIV was shown to be significantly better, giving a new approach towards alignment free classification of protein sequences. We also conclude that sequence structural and solvent accessible property based MIVs are better predictor. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Large distance expansion of mutual information for disjoint disks in a free scalar theory

    Energy Technology Data Exchange (ETDEWEB)

    Agón, Cesar A.; Cohen-Abbo, Isaac; Schnitzer, Howard J. [Martin Fisher School of Physics, Brandeis University,Waltham, MA 02454 (United States)

    2016-11-11

    We compute the next-to-leading order term in the long-distance expansion of the mutual information for free scalars in three space-time dimensions. The geometry considered is two disjoint disks separated by a distance r between their centers. No evidence for non-analyticity in the Rényi parameter n for the continuation n→1 in the next-to-leading order term is found.

  7. Mutual Information in Frequency and Its Application to Measure Cross-Frequency Coupling in Epilepsy

    Science.gov (United States)

    Malladi, Rakesh; Johnson, Don H.; Kalamangalam, Giridhar P.; Tandon, Nitin; Aazhang, Behnaam

    2018-06-01

    We define a metric, mutual information in frequency (MI-in-frequency), to detect and quantify the statistical dependence between different frequency components in the data, referred to as cross-frequency coupling and apply it to electrophysiological recordings from the brain to infer cross-frequency coupling. The current metrics used to quantify the cross-frequency coupling in neuroscience cannot detect if two frequency components in non-Gaussian brain recordings are statistically independent or not. Our MI-in-frequency metric, based on Shannon's mutual information between the Cramer's representation of stochastic processes, overcomes this shortcoming and can detect statistical dependence in frequency between non-Gaussian signals. We then describe two data-driven estimators of MI-in-frequency: one based on kernel density estimation and the other based on the nearest neighbor algorithm and validate their performance on simulated data. We then use MI-in-frequency to estimate mutual information between two data streams that are dependent across time, without making any parametric model assumptions. Finally, we use the MI-in- frequency metric to investigate the cross-frequency coupling in seizure onset zone from electrocorticographic recordings during seizures. The inferred cross-frequency coupling characteristics are essential to optimize the spatial and spectral parameters of electrical stimulation based treatments of epilepsy.

  8. Higher-Order Statistical Correlations and Mutual Information Among Particles in a Quantum Well

    International Nuclear Information System (INIS)

    Yépez, V. S.; Sagar, R. P.; Laguna, H. G.

    2017-01-01

    The influence of wave function symmetry on statistical correlation is studied for the case of three non-interacting spin-free quantum particles in a unidimensional box, in position and in momentum space. Higher-order statistical correlations occurring among the three particles in this quantum system is quantified via higher-order mutual information and compared to the correlation between pairs of variables in this model, and to the correlation in the two-particle system. The results for the higher-order mutual information show that there are states where the symmetric wave functions are more correlated than the antisymmetric ones with same quantum numbers. This holds in position as well as in momentum space. This behavior is opposite to that observed for the correlation between pairs of variables in this model, and the two-particle system, where the antisymmetric wave functions are in general more correlated. These results are also consistent with those observed in a system of three uncoupled oscillators. The use of higher-order mutual information as a correlation measure, is monitored and examined by considering a superposition of states or systems with two Slater determinants. (author)

  9. Higher-Order Statistical Correlations and Mutual Information Among Particles in a Quantum Well

    Science.gov (United States)

    Yépez, V. S.; Sagar, R. P.; Laguna, H. G.

    2017-12-01

    The influence of wave function symmetry on statistical correlation is studied for the case of three non-interacting spin-free quantum particles in a unidimensional box, in position and in momentum space. Higher-order statistical correlations occurring among the three particles in this quantum system is quantified via higher-order mutual information and compared to the correlation between pairs of variables in this model, and to the correlation in the two-particle system. The results for the higher-order mutual information show that there are states where the symmetric wave functions are more correlated than the antisymmetric ones with same quantum numbers. This holds in position as well as in momentum space. This behavior is opposite to that observed for the correlation between pairs of variables in this model, and the two-particle system, where the antisymmetric wave functions are in general more correlated. These results are also consistent with those observed in a system of three uncoupled oscillators. The use of higher-order mutual information as a correlation measure, is monitored and examined by considering a superposition of states or systems with two Slater determinants.

  10. Robust Feature Selection from Microarray Data Based on Cooperative Game Theory and Qualitative Mutual Information

    Directory of Open Access Journals (Sweden)

    Atiyeh Mortazavi

    2016-01-01

    Full Text Available High dimensionality of microarray data sets may lead to low efficiency and overfitting. In this paper, a multiphase cooperative game theoretic feature selection approach is proposed for microarray data classification. In the first phase, due to high dimension of microarray data sets, the features are reduced using one of the two filter-based feature selection methods, namely, mutual information and Fisher ratio. In the second phase, Shapley index is used to evaluate the power of each feature. The main innovation of the proposed approach is to employ Qualitative Mutual Information (QMI for this purpose. The idea of Qualitative Mutual Information causes the selected features to have more stability and this stability helps to deal with the problem of data imbalance and scarcity. In the third phase, a forward selection scheme is applied which uses a scoring function to weight each feature. The performance of the proposed method is compared with other popular feature selection algorithms such as Fisher ratio, minimum redundancy maximum relevance, and previous works on cooperative game based feature selection. The average classification accuracy on eleven microarray data sets shows that the proposed method improves both average accuracy and average stability compared to other approaches.

  11. [Prediction of regional soil quality based on mutual information theory integrated with decision tree algorithm].

    Science.gov (United States)

    Lin, Fen-Fang; Wang, Ke; Yang, Ning; Yan, Shi-Guang; Zheng, Xin-Yu

    2012-02-01

    In this paper, some main factors such as soil type, land use pattern, lithology type, topography, road, and industry type that affect soil quality were used to precisely obtain the spatial distribution characteristics of regional soil quality, mutual information theory was adopted to select the main environmental factors, and decision tree algorithm See 5.0 was applied to predict the grade of regional soil quality. The main factors affecting regional soil quality were soil type, land use, lithology type, distance to town, distance to water area, altitude, distance to road, and distance to industrial land. The prediction accuracy of the decision tree model with the variables selected by mutual information was obviously higher than that of the model with all variables, and, for the former model, whether of decision tree or of decision rule, its prediction accuracy was all higher than 80%. Based on the continuous and categorical data, the method of mutual information theory integrated with decision tree could not only reduce the number of input parameters for decision tree algorithm, but also predict and assess regional soil quality effectively.

  12. Spatially weighted mutual information image registration for image guided radiation therapy

    International Nuclear Information System (INIS)

    Park, Samuel B.; Rhee, Frank C.; Monroe, James I.; Sohn, Jason W.

    2010-01-01

    Purpose: To develop a new metric for image registration that incorporates the (sub)pixelwise differential importance along spatial location and to demonstrate its application for image guided radiation therapy (IGRT). Methods: It is well known that rigid-body image registration with mutual information is dependent on the size and location of the image subset on which the alignment analysis is based [the designated region of interest (ROI)]. Therefore, careful review and manual adjustments of the resulting registration are frequently necessary. Although there were some investigations of weighted mutual information (WMI), these efforts could not apply the differential importance to a particular spatial location since WMI only applies the weight to the joint histogram space. The authors developed the spatially weighted mutual information (SWMI) metric by incorporating an adaptable weight function with spatial localization into mutual information. SWMI enables the user to apply the selected transform to medically ''important'' areas such as tumors and critical structures, so SWMI is neither dominated by, nor neglects the neighboring structures. Since SWMI can be utilized with any weight function form, the authors presented two examples of weight functions for IGRT application: A Gaussian-shaped weight function (GW) applied to a user-defined location and a structures-of-interest (SOI) based weight function. An image registration example using a synthesized 2D image is presented to illustrate the efficacy of SWMI. The convergence and feasibility of the registration method as applied to clinical imaging is illustrated by fusing a prostate treatment planning CT with a clinical cone beam CT (CBCT) image set acquired for patient alignment. Forty-one trials are run to test the speed of convergence. The authors also applied SWMI registration using two types of weight functions to two head and neck cases and a prostate case with clinically acquired CBCT/MVCT image sets. The

  13. Spatially weighted mutual information image registration for image guided radiation therapy.

    Science.gov (United States)

    Park, Samuel B; Rhee, Frank C; Monroe, James I; Sohn, Jason W

    2010-09-01

    To develop a new metric for image registration that incorporates the (sub)pixelwise differential importance along spatial location and to demonstrate its application for image guided radiation therapy (IGRT). It is well known that rigid-body image registration with mutual information is dependent on the size and location of the image subset on which the alignment analysis is based [the designated region of interest (ROI)]. Therefore, careful review and manual adjustments of the resulting registration are frequently necessary. Although there were some investigations of weighted mutual information (WMI), these efforts could not apply the differential importance to a particular spatial location since WMI only applies the weight to the joint histogram space. The authors developed the spatially weighted mutual information (SWMI) metric by incorporating an adaptable weight function with spatial localization into mutual information. SWMI enables the user to apply the selected transform to medically "important" areas such as tumors and critical structures, so SWMI is neither dominated by, nor neglects the neighboring structures. Since SWMI can be utilized with any weight function form, the authors presented two examples of weight functions for IGRT application: A Gaussian-shaped weight function (GW) applied to a user-defined location and a structures-of-interest (SOI) based weight function. An image registration example using a synthesized 2D image is presented to illustrate the efficacy of SWMI. The convergence and feasibility of the registration method as applied to clinical imaging is illustrated by fusing a prostate treatment planning CT with a clinical cone beam CT (CBCT) image set acquired for patient alignment. Forty-one trials are run to test the speed of convergence. The authors also applied SWMI registration using two types of weight functions to two head and neck cases and a prostate case with clinically acquired CBCT/ MVCT image sets. The SWMI registration with

  14. Analytical Calculation of Mutual Information between Weakly Coupled Poisson-Spiking Neurons in Models of Dynamically Gated Communication.

    Science.gov (United States)

    Cannon, Jonathan

    2017-01-01

    Mutual information is a commonly used measure of communication between neurons, but little theory exists describing the relationship between mutual information and the parameters of the underlying neuronal interaction. Such a theory could help us understand how specific physiological changes affect the capacity of neurons to synaptically communicate, and, in particular, they could help us characterize the mechanisms by which neuronal dynamics gate the flow of information in the brain. Here we study a pair of linear-nonlinear-Poisson neurons coupled by a weak synapse. We derive an analytical expression describing the mutual information between their spike trains in terms of synapse strength, neuronal activation function, the time course of postsynaptic currents, and the time course of the background input received by the two neurons. This expression allows mutual information calculations that would otherwise be computationally intractable. We use this expression to analytically explore the interaction of excitation, information transmission, and the convexity of the activation function. Then, using this expression to quantify mutual information in simulations, we illustrate the information-gating effects of neural oscillations and oscillatory coherence, which may either increase or decrease the mutual information across the synapse depending on parameters. Finally, we show analytically that our results can quantitatively describe the selection of one information pathway over another when multiple sending neurons project weakly to a single receiving neuron.

  15. Correct mutual information, quantum bit error rate and secure transmission efficiency in Wojcik's eavesdropping scheme on ping-pong protocol

    OpenAIRE

    Zhang, Zhanjun

    2004-01-01

    Comment: The wrong mutual information, quantum bit error rate and secure transmission efficiency in Wojcik's eavesdropping scheme [PRL90(03)157901]on ping-pong protocol have been pointed out and corrected

  16. Quantifying Complexity in Quantum Phase Transitions via Mutual Information Complex Networks.

    Science.gov (United States)

    Valdez, Marc Andrew; Jaschke, Daniel; Vargas, David L; Carr, Lincoln D

    2017-12-01

    We quantify the emergent complexity of quantum states near quantum critical points on regular 1D lattices, via complex network measures based on quantum mutual information as the adjacency matrix, in direct analogy to quantifying the complexity of electroencephalogram or functional magnetic resonance imaging measurements of the brain. Using matrix product state methods, we show that network density, clustering, disparity, and Pearson's correlation obtain the critical point for both quantum Ising and Bose-Hubbard models to a high degree of accuracy in finite-size scaling for three classes of quantum phase transitions, Z_{2}, mean field superfluid to Mott insulator, and a Berzinskii-Kosterlitz-Thouless crossover.

  17. Quantifying Complexity in Quantum Phase Transitions via Mutual Information Complex Networks

    Science.gov (United States)

    Valdez, Marc Andrew; Jaschke, Daniel; Vargas, David L.; Carr, Lincoln D.

    2017-12-01

    We quantify the emergent complexity of quantum states near quantum critical points on regular 1D lattices, via complex network measures based on quantum mutual information as the adjacency matrix, in direct analogy to quantifying the complexity of electroencephalogram or functional magnetic resonance imaging measurements of the brain. Using matrix product state methods, we show that network density, clustering, disparity, and Pearson's correlation obtain the critical point for both quantum Ising and Bose-Hubbard models to a high degree of accuracy in finite-size scaling for three classes of quantum phase transitions, Z2, mean field superfluid to Mott insulator, and a Berzinskii-Kosterlitz-Thouless crossover.

  18. Maximum mutual information vector quantization of log-likelihood ratios for memory efficient HARQ implementations

    DEFF Research Database (Denmark)

    Danieli, Matteo; Forchhammer, Søren; Andersen, Jakob Dahl

    2010-01-01

    analysis leads to using maximum mutual information (MMI) as optimality criterion and in turn Kullback-Leibler (KL) divergence as distortion measure. Simulations run based on an LTE-like system have proven that VQ can be implemented in a computationally simple way at low rates of 2-3 bits per LLR value......Modern mobile telecommunication systems, such as 3GPP LTE, make use of Hybrid Automatic Repeat reQuest (HARQ) for efficient and reliable communication between base stations and mobile terminals. To this purpose, marginal posterior probabilities of the received bits are stored in the form of log...

  19. FEATURE SELECTION METHODS BASED ON MUTUAL INFORMATION FOR CLASSIFYING HETEROGENEOUS FEATURES

    Directory of Open Access Journals (Sweden)

    Ratri Enggar Pawening

    2016-06-01

    Full Text Available Datasets with heterogeneous features can affect feature selection results that are not appropriate because it is difficult to evaluate heterogeneous features concurrently. Feature transformation (FT is another way to handle heterogeneous features subset selection. The results of transformation from non-numerical into numerical features may produce redundancy to the original numerical features. In this paper, we propose a method to select feature subset based on mutual information (MI for classifying heterogeneous features. We use unsupervised feature transformation (UFT methods and joint mutual information maximation (JMIM methods. UFT methods is used to transform non-numerical features into numerical features. JMIM methods is used to select feature subset with a consideration of the class label. The transformed and the original features are combined entirely, then determine features subset by using JMIM methods, and classify them using support vector machine (SVM algorithm. The classification accuracy are measured for any number of selected feature subset and compared between UFT-JMIM methods and Dummy-JMIM methods. The average classification accuracy for all experiments in this study that can be achieved by UFT-JMIM methods is about 84.47% and Dummy-JMIM methods is about 84.24%. This result shows that UFT-JMIM methods can minimize information loss between transformed and original features, and select feature subset to avoid redundant and irrelevant features.

  20. Prediction of microsleeps using pairwise joint entropy and mutual information between EEG channels.

    Science.gov (United States)

    Baseer, Abdul; Weddell, Stephen J; Jones, Richard D

    2017-07-01

    Microsleeps are involuntary and brief instances of complete loss of responsiveness, typically of 0.5-15 s duration. They adversely affect performance in extended attention-driven jobs and can be fatal. Our aim was to predict microsleeps from 16 channel EEG signals. Two information theoretic concepts - pairwise joint entropy and mutual information - were independently used to continuously extract features from EEG signals. k-nearest neighbor (kNN) with k = 3 was used to calculate both joint entropy and mutual information. Highly correlated features were discarded and the rest were ranked using Fisher score followed by an average of 3-fold cross-validation area under the curve of the receiver operating characteristic (AUC ROC ). Leave-one-out method (LOOM) was performed to test the performance of microsleep prediction system on independent data. The best prediction for 0.25 s ahead was AUCROC, sensitivity, precision, geometric mean (GM), and φ of 0.93, 0.68, 0.33, 0.75, and 0.38 respectively with joint entropy using single linear discriminant analysis (LDA) classifier.

  1. Mutual information as a measure of image quality for 3D dynamic lung imaging with EIT.

    Science.gov (United States)

    Crabb, M G; Davidson, J L; Little, R; Wright, P; Morgan, A R; Miller, C A; Naish, J H; Parker, G J M; Kikinis, R; McCann, H; Lionheart, W R B

    2014-05-01

    We report on a pilot study of dynamic lung electrical impedance tomography (EIT) at the University of Manchester. Low-noise EIT data at 100 frames per second were obtained from healthy male subjects during controlled breathing, followed by magnetic resonance imaging (MRI) subsequently used for spatial validation of the EIT reconstruction. The torso surface in the MR image and electrode positions obtained using MRI fiducial markers informed the construction of a 3D finite element model extruded along the caudal-distal axis of the subject. Small changes in the boundary that occur during respiration were accounted for by incorporating the sensitivity with respect to boundary shape into a robust temporal difference reconstruction algorithm. EIT and MRI images were co-registered using the open source medical imaging software, 3D Slicer. A quantitative comparison of quality of different EIT reconstructions was achieved through calculation of the mutual information with a lung-segmented MR image. EIT reconstructions using a linear shape correction algorithm reduced boundary image artefacts, yielding better contrast of the lungs, and had 10% greater mutual information compared with a standard linear EIT reconstruction.

  2. On the mutual information of 3D massive MIMO systems: An asymptotic approach

    KAUST Repository

    Nadeem, Qurrat-Ul-Ain

    2015-10-01

    Motivated by the recent interest in 3D beamforming to enhance system performance, we present an information-theoretic channel model for multiple-input multiple-output (MIMO) systems, that can support the elevation dimension. The principle of maximum entropy is used to determine the distribution of the channel matrix consistent with the prior angular information. We provide an explicit expression for the cumulative density function (CDF) of the mutual information in the large number of transmit antennas and paths regime. The derived Gaussian approximation is quite accurate even for realistic system dimensions. The simulation results study the achievable performance through the meticulous selection of the transmit antenna downtilt angles. The results are directly applicable to the analysis of 5G 3D massive MIMO systems. © 2015 IEEE.

  3. Mutual Information Based Analysis for the Distribution of Financial Contagion in Stock Markets

    Directory of Open Access Journals (Sweden)

    Xudong Wang

    2017-01-01

    Full Text Available This paper applies mutual information to research the distribution of financial contagion in global stock markets during the US subprime crisis. First, we symbolize the daily logarithmic stock returns based on their quantiles. Then, the mutual information of the stock indices is calculated and the block bootstrap approach is adopted to test the financial contagion. We analyze not only the contagion distribution during the entire crisis period but also its evolution over different stages by using the sliding window method. The empirical results prove the widespread existence of financial contagion and show that markets impacted by contagion tend to cluster geographically. The distribution of the contagion strength is positively skewed and leptokurtic. The average contagion strength is low at the beginning and then witnesses an uptrend. It has larger values in the middle stage and declines in the late phase of the crisis. Meanwhile, the cross-regional contagion between Europe and America is stronger than that between either America and Asia or Europe and Asia. Europe is found to be the region most deeply impacted by the contagion, whereas Asia is the least affected.

  4. A Semidefinite Programming Based Search Strategy for Feature Selection with Mutual Information Measure.

    Science.gov (United States)

    Naghibi, Tofigh; Hoffmann, Sarah; Pfister, Beat

    2015-08-01

    Feature subset selection, as a special case of the general subset selection problem, has been the topic of a considerable number of studies due to the growing importance of data-mining applications. In the feature subset selection problem there are two main issues that need to be addressed: (i) Finding an appropriate measure function than can be fairly fast and robustly computed for high-dimensional data. (ii) A search strategy to optimize the measure over the subset space in a reasonable amount of time. In this article mutual information between features and class labels is considered to be the measure function. Two series expansions for mutual information are proposed, and it is shown that most heuristic criteria suggested in the literature are truncated approximations of these expansions. It is well-known that searching the whole subset space is an NP-hard problem. Here, instead of the conventional sequential search algorithms, we suggest a parallel search strategy based on semidefinite programming (SDP) that can search through the subset space in polynomial time. By exploiting the similarities between the proposed algorithm and an instance of the maximum-cut problem in graph theory, the approximation ratio of this algorithm is derived and is compared with the approximation ratio of the backward elimination method. The experiments show that it can be misleading to judge the quality of a measure solely based on the classification accuracy, without taking the effect of the non-optimum search strategy into account.

  5. ARACNe-AP: gene network reverse engineering through adaptive partitioning inference of mutual information.

    Science.gov (United States)

    Lachmann, Alexander; Giorgi, Federico M; Lopez, Gonzalo; Califano, Andrea

    2016-07-15

    The accurate reconstruction of gene regulatory networks from large scale molecular profile datasets represents one of the grand challenges of Systems Biology. The Algorithm for the Reconstruction of Accurate Cellular Networks (ARACNe) represents one of the most effective tools to accomplish this goal. However, the initial Fixed Bandwidth (FB) implementation is both inefficient and unable to deal with sample sets providing largely uneven coverage of the probability density space. Here, we present a completely new implementation of the algorithm, based on an Adaptive Partitioning strategy (AP) for estimating the Mutual Information. The new AP implementation (ARACNe-AP) achieves a dramatic improvement in computational performance (200× on average) over the previous methodology, while preserving the Mutual Information estimator and the Network inference accuracy of the original algorithm. Given that the previous version of ARACNe is extremely demanding, the new version of the algorithm will allow even researchers with modest computational resources to build complex regulatory networks from hundreds of gene expression profiles. A JAVA cross-platform command line executable of ARACNe, together with all source code and a detailed usage guide are freely available on Sourceforge (http://sourceforge.net/projects/aracne-ap). JAVA version 8 or higher is required. califano@c2b2.columbia.edu Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press.

  6. Geometric k-nearest neighbor estimation of entropy and mutual information

    Science.gov (United States)

    Lord, Warren M.; Sun, Jie; Bollt, Erik M.

    2018-03-01

    Nonparametric estimation of mutual information is used in a wide range of scientific problems to quantify dependence between variables. The k-nearest neighbor (knn) methods are consistent, and therefore expected to work well for a large sample size. These methods use geometrically regular local volume elements. This practice allows maximum localization of the volume elements, but can also induce a bias due to a poor description of the local geometry of the underlying probability measure. We introduce a new class of knn estimators that we call geometric knn estimators (g-knn), which use more complex local volume elements to better model the local geometry of the probability measures. As an example of this class of estimators, we develop a g-knn estimator of entropy and mutual information based on elliptical volume elements, capturing the local stretching and compression common to a wide range of dynamical system attractors. A series of numerical examples in which the thickness of the underlying distribution and the sample sizes are varied suggest that local geometry is a source of problems for knn methods such as the Kraskov-Stögbauer-Grassberger estimator when local geometric effects cannot be removed by global preprocessing of the data. The g-knn method performs well despite the manipulation of the local geometry. In addition, the examples suggest that the g-knn estimators can be of particular relevance to applications in which the system is large, but the data size is limited.

  7. An Estimator of Mutual Information and its Application to Independence Testing

    Directory of Open Access Journals (Sweden)

    Joe Suzuki

    2016-03-01

    Full Text Available This paper proposes a novel estimator of mutual information for discrete and continuous variables. The main feature of this estimator is that it is zero for a large sample size n if and only if the two variables are independent. The estimator can be used to construct several histograms, compute estimations of mutual information, and choose the maximum value. We prove that the number of histograms constructed has an upper bound of O(log n and apply this fact to the search. We compare the performance of the proposed estimator with an estimator of the Hilbert-Schmidt independence criterion (HSIC, though the proposed method is based on the minimum description length (MDL principle and the HSIC provides a statistical test. The proposed method completes the estimation in O(n log n time, whereas the HSIC kernel computation requires O(n3 time. We also present examples in which the HSIC fails to detect independence but the proposed method successfully detects it.

  8. The Generalization of Mutual Information as the Information between a Set of Variables: The Information Correlation Function Hierarchy and the Information Structure of Multi-Agent Systems

    Science.gov (United States)

    Wolf, David R.

    2004-01-01

    The topic of this paper is a hierarchy of information-like functions, here named the information correlation functions, where each function of the hierarchy may be thought of as the information between the variables it depends upon. The information correlation functions are particularly suited to the description of the emergence of complex behaviors due to many- body or many-agent processes. They are particularly well suited to the quantification of the decomposition of the information carried among a set of variables or agents, and its subsets. In more graphical language, they provide the information theoretic basis for understanding the synergistic and non-synergistic components of a system, and as such should serve as a forceful toolkit for the analysis of the complexity structure of complex many agent systems. The information correlation functions are the natural generalization to an arbitrary number of sets of variables of the sequence starting with the entropy function (one set of variables) and the mutual information function (two sets). We start by describing the traditional measures of information (entropy) and mutual information.

  9. Measuring the usefulness of hidden units in Boltzmann machines with mutual information.

    Science.gov (United States)

    Berglund, Mathias; Raiko, Tapani; Cho, Kyunghyun

    2015-04-01

    Restricted Boltzmann machines (RBMs) and deep Boltzmann machines (DBMs) are important models in deep learning, but it is often difficult to measure their performance in general, or measure the importance of individual hidden units in specific. We propose to use mutual information to measure the usefulness of individual hidden units in Boltzmann machines. The measure is fast to compute, and serves as an upper bound for the information the neuron can pass on, enabling detection of a particular kind of poor training results. We confirm experimentally that the proposed measure indicates how much the performance of the model drops when some of the units of an RBM are pruned away. We demonstrate the usefulness of the measure for early detection of poor training in DBMs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Ethics of care in medical tourism: Informal caregivers' narratives of responsibility, vulnerability and mutuality.

    Science.gov (United States)

    Whitmore, Rebecca; Crooks, Valorie A; Snyder, Jeremy

    2015-09-01

    This study examines the experiences of informal caregivers in medical tourism through an ethics of care lens. We conducted semi-structured interviews with 20 Canadians who had accompanied their friends or family members abroad for surgery, asking questions that dealt with their experiences prior to, during and after travel. Thematic analysis revealed three themes central to an ethics of care: responsibility, vulnerability and mutuality. Ethics of care theorists have highlighted how care has been historically devalued. We posit that medical tourism reproduces dominant narratives about care in a novel care landscape. Informal care goes unaccounted for by the industry, as it occurs in largely private spaces at a geographic distance from the home countries of medical tourists. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Information-Theoretic Limits on Broadband Multi-Antenna Systems in the Presence of Mutual Coupling

    Science.gov (United States)

    Taluja, Pawandeep Singh

    2011-12-01

    Multiple-input, multiple-output (MIMO) systems have received considerable attention over the last decade due to their ability to provide high throughputs and mitigate multipath fading effects. While most of these benefits are obtained for ideal arrays with large separation between the antennas, practical devices are often constrained in physical dimensions. With smaller inter-element spacings, signal correlation and mutual coupling between the antennas start to degrade the system performance, thereby limiting the deployment of a large number of antennas. Various studies have proposed transceiver designs based on optimal matching networks to compensate for this loss. However, such networks are considered impractical due to their multiport structure and sensitivity to the RF bandwidth of the system. In this dissertation, we investigate two aspects of compact transceiver design. First, we consider simpler architectures that exploit coupling between the antennas, and second, we establish information-theoretic limits of broadband communication systems with closely-spaced antennas. We begin with a receiver model of a diversity antenna selection system and propose novel strategies that make use of inactive elements by virtue of mutual coupling. We then examine the limits on the matching efficiency of a single antenna system using broadband matching theory. Next, we present an extension to this theory for coupled MIMO systems to elucidate the impact of coupling on the RF bandwidth of the system, and derive optimal transceiver designs. Lastly, we summarize the main findings of this dissertation and suggest open problems for future work.

  12. Unsupervised segmentation of medical image based on difference of mutual information

    Institute of Scientific and Technical Information of China (English)

    L(U) Qingwen; CHEN Wufan

    2006-01-01

    In the scope of medical image processing, segmentation is important and difficult. There are still two problems which trouble us in this field. One is how to determine the number of clusters in an image and the other is how to segment medical images containing lesions. A new segmentation method called DDC, based on difference of mutual information (dMI) and pixon, is proposed in this paper. Experiments demonstrate that dMI shows one kind of intrinsic relationship between the segmented image and the original one and so it can be used to well determine the number of clusters. Furthermore, multi-modality medical images with lesions can be automatically and successfully segmented by DDC method.

  13. Mutual Information Based Dynamic Integration of Multiple Feature Streams for Robust Real-Time LVCSR

    Science.gov (United States)

    Sato, Shoei; Kobayashi, Akio; Onoe, Kazuo; Homma, Shinichi; Imai, Toru; Takagi, Tohru; Kobayashi, Tetsunori

    We present a novel method of integrating the likelihoods of multiple feature streams, representing different acoustic aspects, for robust speech recognition. The integration algorithm dynamically calculates a frame-wise stream weight so that a higher weight is given to a stream that is robust to a variety of noisy environments or speaking styles. Such a robust stream is expected to show discriminative ability. A conventional method proposed for the recognition of spoken digits calculates the weights front the entropy of the whole set of HMM states. This paper extends the dynamic weighting to a real-time large-vocabulary continuous speech recognition (LVCSR) system. The proposed weight is calculated in real-time from mutual information between an input stream and active HMM states in a searchs pace without an additional likelihood calculation. Furthermore, the mutual information takes the width of the search space into account by calculating the marginal entropy from the number of active states. In this paper, we integrate three features that are extracted through auditory filters by taking into account the human auditory system's ability to extract amplitude and frequency modulations. Due to this, features representing energy, amplitude drift, and resonant frequency drifts, are integrated. These features are expected to provide complementary clues for speech recognition. Speech recognition experiments on field reports and spontaneous commentary from Japanese broadcast news showed that the proposed method reduced error words by 9.2% in field reports and 4.7% in spontaneous commentaries relative to the best result obtained from a single stream.

  14. Measuring global oil trade dependencies: An application of the point-wise mutual information method

    International Nuclear Information System (INIS)

    Kharrazi, Ali; Fath, Brian D.

    2016-01-01

    Oil trade is one of the most vital networks in the global economy. In this paper, we analyze the 1998–2012 oil trade networks using the point-wise mutual information (PMI) method and determine the pairwise trade preferences and dependencies. Using examples of the USA's trade partners, this research demonstrates the usefulness of the PMI method as an additional methodological tool to evaluate the outcomes from countries' decisions to engage in preferred trading partners. A positive PMI value indicates trade preference where trade is larger than would be expected. For example, in 2012 the USA imported 2,548.7 kbpd despite an expected 358.5 kbpd of oil from Canada. Conversely, a negative PMI value indicates trade dis-preference where the amount of trade is smaller than what would be expected. For example, the 15-year average of annual PMI between Saudi Arabia and the U.S.A. is −0.130 and between Russia and the USA −1.596. We reflect the three primary reasons of discrepancies between actual and neutral model trade can be related to position, price, and politics. The PMI can quantify the political success or failure of trade preferences and can more accurately account temporal variation of interdependencies. - Highlights: • We analyzed global oil trade networks using the point-wise mutual information method. • We identified position, price, & politics as drivers of oil trade preference. • The PMI method is useful in research on complex trade networks and dependency theory. • A time-series analysis of PMI can track dependencies & evaluate policy decisions.

  15. Evaluation of respiratory muscles activity by means of cross mutual information function at different levels of ventilatory effort.

    Science.gov (United States)

    Alonso, Joan Francesc; Mañanas, Miguel A; Hoyer, Dirk; Topor, Zbigniew L; Bruce, Eugene N

    2007-09-01

    Analysis of respiratory muscles activity is an effective technique for the study of pulmonary diseases such as obstructive sleep apnea syndrome (OSAS). Respiratory diseases, especially those associated with changes in the mechanical properties of the respiratory apparatus, are often associated with disruptions of the normally highly coordinated contractions of respiratory muscles. Due to the complexity of the respiratory control, the assessment of OSAS related dysfunctions by linear methods are not sufficient. Therefore, the objective of this study was the detection of diagnostically relevant nonlinear complex respiratory mechanisms. Two aims of this work were: (1) to assess coordination of respiratory muscles contractions through evaluation of interactions between respiratory signals and myographic signals through nonlinear analysis by means of cross mutual information function (CMIF); (2) to differentiate between functioning of respiratory muscles in patients with OSAS and in normal subjects. Electromyographic (EMG) and mechanomyographic (MMG) signals were recorded from three respiratory muscles: genioglossus, sternomastoid and diaphragm. Inspiratory pressure and flow were also acquired. All signals were measured in eight patients with OSAS and eight healthy subjects during an increased respiratory effort while awake. Several variables were defined and calculated from CMIF in order to describe correlation between signals. The results indicate different nonlinear couplings of respiratory muscles in both populations. This effect is progressively more evident at higher levels of respiratory effort.

  16. Characteristics analysis of acupuncture electroencephalograph based on mutual information Lempel—Ziv complexity

    International Nuclear Information System (INIS)

    Luo Xi-Liu; Wang Jiang; Deng Bin; Wei Xi-Le; Bian Hong-Rui; Han Chun-Xiao

    2012-01-01

    As a convenient approach to the characterization of cerebral cortex electrical information, electroencephalograph (EEG) has potential clinical application in monitoring the acupuncture effects. In this paper, a method composed of the mutual information method and Lempel—Ziv complexity method (MILZC) is proposed to investigate the effects of acupuncture on the complexity of information exchanges between different brain regions based on EEGs. In the experiments, eight subjects are manually acupunctured at ‘Zusanli’ acupuncture point (ST-36) with different frequencies (i.e., 50, 100, 150, and 200 times/min) and the EEGs are recorded simultaneously. First, MILZC values are compared in general. Then average brain connections are used to quantify the effectiveness of acupuncture under the above four frequencies. Finally, significance index P values are used to study the spatiality of the acupuncture effect on the brain. Three main findings are obtained: (i) MILZC values increase during the acupuncture; (ii) manual acupunctures (MAs) with 100 times/min and 150 times/min are more effective than with 50 times/min and 200 times/min; (iii) contralateral hemisphere activation is more prominent than ipsilateral hemisphere's. All these findings suggest that acupuncture contributes to the increase of brain information exchange complexity and the MILZC method can successfully describe these changes. (interdisciplinary physics and related areas of science and technology)

  17. Mutual information spectrum for selection of event-related spatial components. Application to eloquent motor cortex mapping.

    Directory of Open Access Journals (Sweden)

    Alexei eOssadtchi

    2014-01-01

    Full Text Available Spatial component analysis is often used to explore multidimensional time series data whose sources cannot be measured directly. Several methods may be used to decompose the data into a set of spatial components with temporal loadings. Component selection is of crucial importance, and should be supported by objective criteria. In some applications, the use of a well defined component selection criterion may provide for automation of the analysis.In this paper we describe a novel approach for ranking of spatial components calculated from the EEG or MEG data recorded within evoked response paradigm. Our method is called Mutual Information Spectrum and is based on gauging the amount of mutual information of spatial component temporal loadings with a synthetically created reference signal. We also describe the appropriate randomization based statistical assessment scheme that can be used for selection of components with statistically significant amount of mutual information. Using simulated data with realistic trial to trial variations and SNR corresponding to the real recordings we demonstrate the superior performance characteristics of the described mutual information based measure as compared to a more conventionally used power driven gauge. We also demonstrate the application of the Mutual Information Spectrum for the selection of task-related independent components from real MEG data. We show that the Mutual Information spectrum allows to identify task-related components reliably in a consistent fashion, yielding stable results even from a small number of trials. We conclude that the proposed method fits naturally the information driven nature of ICA and can be used for routine and automatic ranking of independent components calculated from the functional neuroimaging data collected within event-related paradigms.

  18. Cloud-assisted mutual authentication and privacy preservation protocol for telecare medical information systems.

    Science.gov (United States)

    Li, Chun-Ta; Shih, Dong-Her; Wang, Chun-Cheng

    2018-04-01

     With the rapid development of wireless communication technologies and the growing prevalence of smart devices, telecare medical information system (TMIS) allows patients to receive medical treatments from the doctors via Internet technology without visiting hospitals in person. By adopting mobile device, cloud-assisted platform and wireless body area network, the patients can collect their physiological conditions and upload them to medical cloud via their mobile devices, enabling caregivers or doctors to provide patients with appropriate treatments at anytime and anywhere. In order to protect the medical privacy of the patient and guarantee reliability of the system, before accessing the TMIS, all system participants must be authenticated.  Mohit et al. recently suggested a lightweight authentication protocol for cloud-based health care system. They claimed their protocol ensures resilience of all well-known security attacks and has several important features such as mutual authentication and patient anonymity. In this paper, we demonstrate that Mohit et al.'s authentication protocol has various security flaws and we further introduce an enhanced version of their protocol for cloud-assisted TMIS, which can ensure patient anonymity and patient unlinkability and prevent the security threats of report revelation and report forgery attacks.  The security analysis proves that our enhanced protocol is secure against various known attacks as well as found in Mohit et al.'s protocol. Compared with existing related protocols, our enhanced protocol keeps the merits of all desirable security requirements and also maintains the efficiency in terms of computation costs for cloud-assisted TMIS.  We propose a more secure mutual authentication and privacy preservation protocol for cloud-assisted TMIS, which fixes the mentioned security weaknesses found in Mohit et al.'s protocol. According to our analysis, our authentication protocol satisfies most functionality features

  19. Mutually exclusive aspects of information carried by physical systems: Complementarity between local and nonlocal information

    International Nuclear Information System (INIS)

    Oppenheim, Jonathan; Horodecki, Karol; Horodecki, Michal; Horodecki, Ryszard; Horodecki, Pawel

    2003-01-01

    Complex physical systems contain information which, under some well-defined processes can differentiate between local and nonlocal information. Both these fundamental aspects of information are defined operationally. Local information is locally accessible and allows one to perform processes, such as physical work, while nonlocal information allows one to perform processes such as teleportation. It is shown that these two kinds of information are complementary in the sense that two parties can either gain access to the nonlocal information or to the local information but not both. This complementarity has a form similar to that expressed by entropic uncertainty relations. For pure states, the entanglement plays the role of Planck's constant. We also find another class of complementarity relations which applies to operators and is induced when two parties can only perform local operations and communicate classical (LOCC). In particular, observables such as the parity and phase of two qubits commute but under LOCC, they are complementary observables. It is also found this complementarity is pure in the sense that it can be ''decoupled'' from the uncertainty principle. It is suggested that these complementarities represent an essential extension of Bohr's complementarity to complex (distributed) systems which are entangled

  20. Automatic registration of optical imagery with 3d lidar data using local combined mutual information

    Directory of Open Access Journals (Sweden)

    E. G. Parmehr

    2013-10-01

    Full Text Available Automatic registration of multi-sensor data is a basic step in data fusion for photogrammetric and remote sensing applications. The effectiveness of intensity-based methods such as Mutual Information (MI for automated registration of multi-sensor image has been previously reported for medical and remote sensing applications. In this paper, a new multivariable MI approach that exploits complementary information of inherently registered LiDAR DSM and intensity data to improve the robustness of registering optical imagery and LiDAR point cloud, is presented. LiDAR DSM and intensity information has been utilised in measuring the similarity of LiDAR and optical imagery via the Combined MI. An effective histogramming technique is adopted to facilitate estimation of a 3D probability density function (pdf. In addition, a local similarity measure is introduced to decrease the complexity of optimisation at higher dimensions and computation cost. Therefore, the reliability of registration is improved due to the use of redundant observations of similarity. The performance of the proposed method for registration of satellite and aerial images with LiDAR data in urban and rural areas is experimentally evaluated and the results obtained are discussed.

  1. Implementation of mutual information and bayes theorem for classification microarray data

    Science.gov (United States)

    Dwifebri Purbolaksono, Mahendra; Widiastuti, Kurnia C.; Syahrul Mubarok, Mohamad; Adiwijaya; Aminy Ma’ruf, Firda

    2018-03-01

    Microarray Technology is one of technology which able to read the structure of gen. The analysis is important for this technology. It is for deciding which attribute is more important than the others. Microarray technology is able to get cancer information to diagnose a person’s gen. Preparation of microarray data is a huge problem and takes a long time. That is because microarray data contains high number of insignificant and irrelevant attributes. So, it needs a method to reduce the dimension of microarray data without eliminating important information in every attribute. This research uses Mutual Information to reduce dimension. System is built with Machine Learning approach specifically Bayes Theorem. This theorem uses a statistical and probability approach. By combining both methods, it will be powerful for Microarray Data Classification. The experiment results show that system is good to classify Microarray data with highest F1-score using Bayesian Network by 91.06%, and Naïve Bayes by 88.85%.

  2. Input Selection for Return Temperature Estimation in Mixing Loops using Partial Mutual Information with Flow Variable Delay

    DEFF Research Database (Denmark)

    Overgaard, Anders; Kallesøe, Carsten Skovmose; Bendtsen, Jan Dimon

    2017-01-01

    adgang til data, er ønsker at skabe en datadreven model til kontrol. Grundet den store mængde tilgængelig data anvendes der en metode til valg af inputs kaldet "Partial Mutual Information" (PMI). Denne artikel introducerer en metode til at inkluderer flow variable forsinkelser i PMI. Data fra en...... kontorbygning i Bjerringbro anvendes til analyse. Det vises at "Mutual Information" og et "Generalized Regression Neural Network" begge forbedres ved at anvende flow variabelt forsinkelse i forhold til at anvende konstante delay....

  3. On the Keyhole Hypothesis: High Mutual Information between Ear and Scalp EEG

    Directory of Open Access Journals (Sweden)

    Kaare B. Mikkelsen

    2017-06-01

    Full Text Available We propose and test the keyhole hypothesis—that measurements from low dimensional EEG, such as ear-EEG reflect a broadly distributed set of neural processes. We formulate the keyhole hypothesis in information theoretical terms. The experimental investigation is based on legacy data consisting of 10 subjects exposed to a battery of stimuli, including alpha-attenuation, auditory onset, and mismatch-negativity responses and a new medium-long EEG experiment involving data acquisition during 13 h. Linear models were estimated to lower bound the scalp-to-ear capacity, i.e., predicting ear-EEG data from simultaneously recorded scalp EEG. A cross-validation procedure was employed to ensure unbiased estimates. We present several pieces of evidence in support of the keyhole hypothesis: There is a high mutual information between data acquired at scalp electrodes and through the ear-EEG “keyhole,” furthermore we show that the view—represented as a linear mapping—is stable across both time and mental states. Specifically, we find that ear-EEG data can be predicted reliably from scalp EEG. We also address the reverse view, and demonstrate that large portions of the scalp EEG can be predicted from ear-EEG, with the highest predictability achieved in the temporal regions and when using ear-EEG electrodes with a common reference electrode.

  4. VERIFICATION OF 3D BUILDING MODELS USING MUTUAL INFORMATION IN AIRBORNE OBLIQUE IMAGES

    Directory of Open Access Journals (Sweden)

    A. P. Nyaruhuma

    2012-07-01

    Full Text Available This paper describes a method for automatic verification of 3D building models using airborne oblique images. The problem being tackled is identifying buildings that are demolished or changed since the models were constructed or identifying wrong models using the images. The models verified are of CityGML LOD2 or higher since their edges are expected to coincide with actual building edges. The verification approach is based on information theory. Corresponding variables between building models and oblique images are used for deriving mutual information for individual edges, faces or whole buildings, and combined for all perspective images available for the building. The wireframe model edges are projected to images and verified using low level image features – the image pixel gradient directions. A building part is only checked against images in which it may be visible. The method has been tested with models constructed using laser points against Pictometry images that are available for most cities of Europe and may be publically viewed in the so called Birds Eye view of the Microsoft Bing Maps. Results are that nearly all buildings are correctly categorised as existing or demolished. Because we now concentrate only on roofs we also used the method to test and compare results from nadir images. This comparison made clear that especially height errors in models can be more reliably detected in oblique images because of the tilted view. Besides overall building verification, results per individual edges can be used for improving the 3D building models.

  5. Adaptive design optimization: a mutual information-based approach to model discrimination in cognitive science.

    Science.gov (United States)

    Cavagnaro, Daniel R; Myung, Jay I; Pitt, Mark A; Kujala, Janne V

    2010-04-01

    Discriminating among competing statistical models is a pressing issue for many experimentalists in the field of cognitive science. Resolving this issue begins with designing maximally informative experiments. To this end, the problem to be solved in adaptive design optimization is identifying experimental designs under which one can infer the underlying model in the fewest possible steps. When the models under consideration are nonlinear, as is often the case in cognitive science, this problem can be impossible to solve analytically without simplifying assumptions. However, as we show in this letter, a full solution can be found numerically with the help of a Bayesian computational trick derived from the statistics literature, which recasts the problem as a probability density simulation in which the optimal design is the mode of the density. We use a utility function based on mutual information and give three intuitive interpretations of the utility function in terms of Bayesian posterior estimates. As a proof of concept, we offer a simple example application to an experiment on memory retention.

  6. Spectral-spatial classification of hyperspectral data with mutual information based segmented stacked autoencoder approach

    Science.gov (United States)

    Paul, Subir; Nagesh Kumar, D.

    2018-04-01

    Hyperspectral (HS) data comprises of continuous spectral responses of hundreds of narrow spectral bands with very fine spectral resolution or bandwidth, which offer feature identification and classification with high accuracy. In the present study, Mutual Information (MI) based Segmented Stacked Autoencoder (S-SAE) approach for spectral-spatial classification of the HS data is proposed to reduce the complexity and computational time compared to Stacked Autoencoder (SAE) based feature extraction. A non-parametric dependency measure (MI) based spectral segmentation is proposed instead of linear and parametric dependency measure to take care of both linear and nonlinear inter-band dependency for spectral segmentation of the HS bands. Then morphological profiles are created corresponding to segmented spectral features to assimilate the spatial information in the spectral-spatial classification approach. Two non-parametric classifiers, Support Vector Machine (SVM) with Gaussian kernel and Random Forest (RF) are used for classification of the three most popularly used HS datasets. Results of the numerical experiments carried out in this study have shown that SVM with a Gaussian kernel is providing better results for the Pavia University and Botswana datasets whereas RF is performing better for Indian Pines dataset. The experiments performed with the proposed methodology provide encouraging results compared to numerous existing approaches.

  7. Compression of a Deep Competitive Network Based on Mutual Information for Underwater Acoustic Targets Recognition

    Directory of Open Access Journals (Sweden)

    Sheng Shen

    2018-04-01

    Full Text Available The accuracy of underwater acoustic targets recognition via limited ship radiated noise can be improved by a deep neural network trained with a large number of unlabeled samples. However, redundant features learned by deep neural network have negative effects on recognition accuracy and efficiency. A compressed deep competitive network is proposed to learn and extract features from ship radiated noise. The core idea of the algorithm includes: (1 Competitive learning: By integrating competitive learning into the restricted Boltzmann machine learning algorithm, the hidden units could share the weights in each predefined group; (2 Network pruning: The pruning based on mutual information is deployed to remove the redundant parameters and further compress the network. Experiments based on real ship radiated noise show that the network can increase recognition accuracy with fewer informative features. The compressed deep competitive network can achieve a classification accuracy of 89.1 % , which is 5.3 % higher than deep competitive network and 13.1 % higher than the state-of-the-art signal processing feature extraction methods.

  8. A statistic to estimate the variance of the histogram-based mutual information estimator based on dependent pairs of observations

    NARCIS (Netherlands)

    Moddemeijer, R

    In the case of two signals with independent pairs of observations (x(n),y(n)) a statistic to estimate the variance of the histogram based mutual information estimator has been derived earlier. We present such a statistic for dependent pairs. To derive this statistic it is necessary to avail of a

  9. Estimation of Delta Wave by Mutual Information of Heartbeat During Sleep

    Science.gov (United States)

    Kurihara, Yosuke; Watanabe, Kajiro; Kobayashi, Kazuyuki; Tanaka, Hiroshi

    The quality of sleep is evaluated based on the sleep stages judged by R-K method or the manual of American Academy of Sleep Medicine. The brainwaves, eye movements, and chin EMG of sleeping subjects are used for the judgment. These methods above, however, require some electrodes to be attached to the head and the face to obtain the brainwaves, eye movements, and chin EMG, thus making the measurements troublesome to be held on a daily basis. If non-invasive measurements of brainwaves, eye movements, and chin EMG are feasible, or their equivalent data can be estimated through other bio-signals, the monitoring of the quality of daily sleeps, which influences the health condition, will be easy. In this paper, we discuss the appearance rate of delta wave occurrences, which is deeply related with the depth of sleep, can be estimated based on the average amount of mutual information calculated by pulse wave signals and body movements measured non-invasively by the pneumatic method. As a result, the root mean square error between the appearance rate of delta wave occurrences measured with a polysomnography and the estimated delta pulse was 14.93%.

  10. Causal inference in nonlinear systems: Granger causality versus time-delayed mutual information

    Science.gov (United States)

    Li, Songting; Xiao, Yanyang; Zhou, Douglas; Cai, David

    2018-05-01

    The Granger causality (GC) analysis has been extensively applied to infer causal interactions in dynamical systems arising from economy and finance, physics, bioinformatics, neuroscience, social science, and many other fields. In the presence of potential nonlinearity in these systems, the validity of the GC analysis in general is questionable. To illustrate this, here we first construct minimal nonlinear systems and show that the GC analysis fails to infer causal relations in these systems—it gives rise to all types of incorrect causal directions. In contrast, we show that the time-delayed mutual information (TDMI) analysis is able to successfully identify the direction of interactions underlying these nonlinear systems. We then apply both methods to neuroscience data collected from experiments and demonstrate that the TDMI analysis but not the GC analysis can identify the direction of interactions among neuronal signals. Our work exemplifies inference hazards in the GC analysis in nonlinear systems and suggests that the TDMI analysis can be an appropriate tool in such a case.

  11. Deblurring sequential ocular images from multi-spectral imaging (MSI) via mutual information.

    Science.gov (United States)

    Lian, Jian; Zheng, Yuanjie; Jiao, Wanzhen; Yan, Fang; Zhao, Bojun

    2018-06-01

    Multi-spectral imaging (MSI) produces a sequence of spectral images to capture the inner structure of different species, which was recently introduced into ocular disease diagnosis. However, the quality of MSI images can be significantly degraded by motion blur caused by the inevitable saccades and exposure time required for maintaining a sufficiently high signal-to-noise ratio. This degradation may confuse an ophthalmologist, reduce the examination quality, or defeat various image analysis algorithms. We propose an early work specially on deblurring sequential MSI images, which is distinguished from many of the current image deblurring techniques by resolving the blur kernel simultaneously for all the images in an MSI sequence. It is accomplished by incorporating several a priori constraints including the sharpness of the latent clear image, the spatial and temporal smoothness of the blur kernel and the similarity between temporally-neighboring images in MSI sequence. Specifically, we model the similarity between MSI images with mutual information considering the different wavelengths used for capturing different images in MSI sequence. The optimization of the proposed approach is based on a multi-scale framework and stepwise optimization strategy. Experimental results from 22 MSI sequences validate that our approach outperforms several state-of-the-art techniques in natural image deblurring.

  12. A feasibility study of mutual information based setup error estimation for radiotherapy

    International Nuclear Information System (INIS)

    Kim, Jeongtae; Fessler, Jeffrey A.; Lam, Kwok L.; Balter, James M.; Haken, Randall K. ten

    2001-01-01

    We have investigated a fully automatic setup error estimation method that aligns DRRs (digitally reconstructed radiographs) from a three-dimensional planning computed tomography image onto two-dimensional radiographs that are acquired in a treatment room. We have chosen a MI (mutual information)-based image registration method, hoping for robustness to intensity differences between the DRRs and the radiographs. The MI-based estimator is fully automatic since it is based on the image intensity values without segmentation. Using 10 repeated scans of an anthropomorphic chest phantom in one position and two single scans in two different positions, we evaluated the performance of the proposed method and a correlation-based method against the setup error determined by fiducial marker-based method. The mean differences between the proposed method and the fiducial marker-based method were smaller than 1 mm for translational parameters and 0.8 degree for rotational parameters. The standard deviations of estimates from the proposed method due to detector noise were smaller than 0.3 mm and 0.07 degree for the translational parameters and rotational parameters, respectively

  13. Mutual-Information-Based Incremental Relaying Communications for Wireless Biomedical Implant Systems

    Directory of Open Access Journals (Sweden)

    Yangzhe Liao

    2018-02-01

    Full Text Available Network lifetime maximization of wireless biomedical implant systems is one of the major research challenges of wireless body area networks (WBANs. In this paper, a mutual information (MI-based incremental relaying communication protocol is presented where several on-body relay nodes and one coordinator are attached to the clothes of a patient. Firstly, a comprehensive analysis of a system model is investigated in terms of channel path loss, energy consumption, and the outage probability from the network perspective. Secondly, only when the MI value becomes smaller than the predetermined threshold is data transmission allowed. The communication path selection can be either from the implanted sensor to the on-body relay then forwards to the coordinator or from the implanted sensor to the coordinator directly, depending on the communication distance. Moreover, mathematical models of quality of service (QoS metrics are derived along with the related subjective functions. The results show that the MI-based incremental relaying technique achieves better performance in comparison to our previous proposed protocol techniques regarding several selected performance metrics. The outcome of this paper can be applied to intra-body continuous physiological signal monitoring, artificial biofeedback-oriented WBANs, and telemedicine system design.

  14. Mutual Information-Based Inputs Selection for Electric Load Time Series Forecasting

    Directory of Open Access Journals (Sweden)

    Nenad Floranović

    2013-02-01

    Full Text Available Providing accurate load forecast to electric utility corporations is essential in order to reduce their operational costs and increase profits. Hence, training set selection is an important preprocessing step which has to be considered in practice in order to increase the accuracy of load forecasts. The usage of mutual information (MI has been recently proposed in regression tasks, mostly for feature selection and for identifying the real instances from training sets that contains noise and outliers. This paper proposes a methodology for the training set selection in a least squares support vector machines (LS-SVMs load forecasting model. A new application of the concept of MI is presented for the selection of a training set based on MI computation between initial training set instances and testing set instances. Accordingly, several LS-SVMs models have been trained, based on the proposed methodology, for hourly prediction of electric load for one day ahead. The results obtained from a real-world data set indicate that the proposed method increases the accuracy of load forecasting as well as reduces the size of the initial training set needed for model training.

  15. Evaluation of gene-expression clustering via mutual information distance measure

    Directory of Open Access Journals (Sweden)

    Maimon Oded

    2007-03-01

    Full Text Available Abstract Background The definition of a distance measure plays a key role in the evaluation of different clustering solutions of gene expression profiles. In this empirical study we compare different clustering solutions when using the Mutual Information (MI measure versus the use of the well known Euclidean distance and Pearson correlation coefficient. Results Relying on several public gene expression datasets, we evaluate the homogeneity and separation scores of different clustering solutions. It was found that the use of the MI measure yields a more significant differentiation among erroneous clustering solutions. The proposed measure was also used to analyze the performance of several known clustering algorithms. A comparative study of these algorithms reveals that their "best solutions" are ranked almost oppositely when using different distance measures, despite the found correspondence between these measures when analysing the averaged scores of groups of solutions. Conclusion In view of the results, further attention should be paid to the selection of a proper distance measure for analyzing the clustering of gene expression data.

  16. MEG connectivity analysis in patients with Alzheimer's disease using cross mutual information and spectral coherence.

    Science.gov (United States)

    Alonso, Joan Francesc; Poza, Jesús; Mañanas, Miguel Angel; Romero, Sergio; Fernández, Alberto; Hornero, Roberto

    2011-01-01

    Alzheimer's disease (AD) is an irreversible brain disorder which represents the most common form of dementia in western countries. An early and accurate diagnosis of AD would enable to develop new strategies for managing the disease; however, nowadays there is no single test that can accurately predict the development of AD. In this sense, only a few studies have focused on the magnetoencephalographic (MEG) AD connectivity patterns. This study compares brain connectivity in terms of linear and nonlinear couplings by means of spectral coherence and cross mutual information function (CMIF), respectively. The variables defined from these functions provide statistically significant differences (p CMIF. The results suggest that AD is characterized by both decreases and increases of functional couplings in different frequency bands as well as by an increase in regularity, that is, more evident statistical deterministic relationships in AD patients' MEG connectivity. The significant differences obtained indicate that AD could disturb brain interactions causing abnormal brain connectivity and operation. Furthermore, the combination of coherence and CMIF features to perform a diagnostic test based on logistic regression improved the tests based on individual variables for its robustness.

  17. Normalised Mutual Information of High-Density Surface Electromyography during Muscle Fatigue

    Directory of Open Access Journals (Sweden)

    Adrian Bingham

    2017-12-01

    Full Text Available This study has developed a technique for identifying the presence of muscle fatigue based on the spatial changes of the normalised mutual information (NMI between multiple high density surface electromyography (HD-sEMG channels. Muscle fatigue in the tibialis anterior (TA during isometric contractions at 40% and 80% maximum voluntary contraction levels was investigated in ten healthy participants (Age range: 21 to 35 years; Mean age = 26 years; Male = 4, Female = 6. HD-sEMG was used to record 64 channels of sEMG using a 16 by 4 electrode array placed over the TA. The NMI of each electrode with every other electrode was calculated to form an NMI distribution for each electrode. The total NMI for each electrode (the summation of the electrode’s NMI distribution highlighted regions of high dependence in the electrode array and was observed to increase as the muscle fatigued. To summarise this increase, a function, M(k, was defined and was found to be significantly affected by fatigue and not by contraction force. The technique discussed in this study has overcome issues regarding electrode placement and was used to investigate how the dependences between sEMG signals within the same muscle change spatially during fatigue.

  18. Testing the mutual information expansion of entropy with multivariate Gaussian distributions.

    Science.gov (United States)

    Goethe, Martin; Fita, Ignacio; Rubi, J Miguel

    2017-12-14

    The mutual information expansion (MIE) represents an approximation of the configurational entropy in terms of low-dimensional integrals. It is frequently employed to compute entropies from simulation data of large systems, such as macromolecules, for which brute-force evaluation of the full configurational integral is intractable. Here, we test the validity of MIE for systems consisting of more than m = 100 degrees of freedom (dofs). The dofs are distributed according to multivariate Gaussian distributions which were generated from protein structures using a variant of the anisotropic network model. For the Gaussian distributions, we have semi-analytical access to the configurational entropy as well as to all contributions of MIE. This allows us to accurately assess the validity of MIE for different situations. We find that MIE diverges for systems containing long-range correlations which means that the error of consecutive MIE approximations grows with the truncation order n for all tractable n ≪ m. This fact implies severe limitations on the applicability of MIE, which are discussed in the article. For systems with correlations that decay exponentially with distance, MIE represents an asymptotic expansion of entropy, where the first successive MIE approximations approach the exact entropy, while MIE also diverges for larger orders. In this case, MIE serves as a useful entropy expansion when truncated up to a specific truncation order which depends on the correlation length of the system.

  19. Task-Driven Dictionary Learning Based on Mutual Information for Medical Image Classification.

    Science.gov (United States)

    Diamant, Idit; Klang, Eyal; Amitai, Michal; Konen, Eli; Goldberger, Jacob; Greenspan, Hayit

    2017-06-01

    We present a novel variant of the bag-of-visual-words (BoVW) method for automated medical image classification. Our approach improves the BoVW model by learning a task-driven dictionary of the most relevant visual words per task using a mutual information-based criterion. Additionally, we generate relevance maps to visualize and localize the decision of the automatic classification algorithm. These maps demonstrate how the algorithm works and show the spatial layout of the most relevant words. We applied our algorithm to three different tasks: chest x-ray pathology identification (of four pathologies: cardiomegaly, enlarged mediastinum, right consolidation, and left consolidation), liver lesion classification into four categories in computed tomography (CT) images and benign/malignant clusters of microcalcifications (MCs) classification in breast mammograms. Validation was conducted on three datasets: 443 chest x-rays, 118 portal phase CT images of liver lesions, and 260 mammography MCs. The proposed method improves the classical BoVW method for all tested applications. For chest x-ray, area under curve of 0.876 was obtained for enlarged mediastinum identification compared to 0.855 using classical BoVW (with p-value 0.01). For MC classification, a significant improvement of 4% was achieved using our new approach (with p-value = 0.03). For liver lesion classification, an improvement of 6% in sensitivity and 2% in specificity were obtained (with p-value 0.001). We demonstrated that classification based on informative selected set of words results in significant improvement. Our new BoVW approach shows promising results in clinically important domains. Additionally, it can discover relevant parts of images for the task at hand without explicit annotations for training data. This can provide computer-aided support for medical experts in challenging image analysis tasks.

  20. Pointwise mutual information quantifies intratumor heterogeneity in tissue sections labeled with multiple fluorescent biomarkers

    Directory of Open Access Journals (Sweden)

    Daniel M Spagnolo

    2016-01-01

    Full Text Available Background: Measures of spatial intratumor heterogeneity are potentially important diagnostic biomarkers for cancer progression, proliferation, and response to therapy. Spatial relationships among cells including cancer and stromal cells in the tumor microenvironment (TME are key contributors to heterogeneity. Methods: We demonstrate how to quantify spatial heterogeneity from immunofluorescence pathology samples, using a set of 3 basic breast cancer biomarkers as a test case. We learn a set of dominant biomarker intensity patterns and map the spatial distribution of the biomarker patterns with a network. We then describe the pairwise association statistics for each pattern within the network using pointwise mutual information (PMI and visually represent heterogeneity with a two-dimensional map. Results: We found a salient set of 8 biomarker patterns to describe cellular phenotypes from a tissue microarray cohort containing 4 different breast cancer subtypes. After computing PMI for each pair of biomarker patterns in each patient and tumor replicate, we visualize the interactions that contribute to the resulting association statistics. Then, we demonstrate the potential for using PMI as a diagnostic biomarker, by comparing PMI maps and heterogeneity scores from patients across the 4 different cancer subtypes. Estrogen receptor positive invasive lobular carcinoma patient, AL13-6, exhibited the highest heterogeneity score among those tested, while estrogen receptor negative invasive ductal carcinoma patient, AL13-14, exhibited the lowest heterogeneity score. Conclusions: This paper presents an approach for describing intratumor heterogeneity, in a quantitative fashion (via PMI, which departs from the purely qualitative approaches currently used in the clinic. PMI is generalizable to highly multiplexed/hyperplexed immunofluorescence images, as well as spatial data from complementary in situ methods including FISSEQ and CyTOF, sampling many different

  1. Improving efficiency of multi-modality registration of brain scans based on mutual information

    International Nuclear Information System (INIS)

    Thurfjell, L.; Lau, Y.; Hutton, B.; Westmead Hospital, Sydney, NSW; University of Technology, Sydney, NSW

    1999-01-01

    Full text: One approach for multi-modality registration uses a similarity measure based on mutual information (MI) of voxel intensities. MI measures the statistical dependence between two images by comparing the joint probability distribution (approximated by the 2D joint histogram), with the distribution in the case of complete independence (approximated from the I D histograms). The MI measure reaches a maximum when the images are aligned. The purpose of the current work was to investigate if the registration process could be accelerated through subsampling, i.e. by using only a subset of all voxels for the calculations. The behaviour of the MI measure at different subsampling factors was studied. It was observed that subsampling caused MI to exhibit multiple local maxima unless it was accompanied by a reduction in the number of bins used for the histograms. However, too few bins in the histograms made the peak of the MI measure broader. It was therefore concluded that a coarse-to-fine subsampling procedure, followed by a corresponding increase in the number of bins in the histogram, would be the best choice. The method was validated on SPET-MRI data from seven healthy volunteers. Using a 64:1, 32:1 and 16:1 subsampling scheme with a corresponding bin size of 24, 32 and 48, the new method converged in an average time of 2.5 min as compared to 46 min for the original method (PC Pentium 200). The average absolute differences were 0.24, 0.34, 0.30 mm translation and 0.58, 0.41, 0.66 degrees rotation. We conclude that the suggested scheme renders the registration method sufficiently rapid for routine use in the clinical setting

  2. A Mutual Self- and Informant-Report of Cognitive Complaint Correlates with Neuropathological Outcomes in Mild Cognitive Impairment.

    Directory of Open Access Journals (Sweden)

    Katherine A Gifford

    Full Text Available This study examines whether different sources of cognitive complaint (i.e., self and informant predict Alzheimer's disease (AD neuropathology in elders with mild cognitive impairment (MCI.Data were drawn from the National Alzheimer's Coordinating Center Uniform and Neuropathology Datasets (observational studies for participants with a clinical diagnosis of MCI and postmortem examination (n = 1843, 74±8 years, 52% female. Cognitive complaint (0.9±0.5 years prior to autopsy was classified into four mutually exclusive groups: no complaint, self-only, informant-only, or mutual (both self and informant complaint. Postmortem neuropathological outcomes included amyloid plaques and neurofibrillary tangles. Proportional odds regression related complaint to neuropathology, adjusting for age, sex, race, education, depressed mood, cognition, APOE4 status, and last clinical visit to death interval.Mutual complaint related to increased likelihood of meeting NIA/Reagan Institute (OR = 6.58, p = 0.004 and Consortium to Establish a Registry for Alzheimer's Disease criteria (OR = 5.82, p = 0.03, and increased neurofibrillary tangles (OR = 3.70, p = 0.03, neuritic plaques (OR = 3.52, p = 0.03, and diffuse plaques (OR = 4.35, p = 0.02. Informant-only and self-only complaint was not associated with any neuropathological outcome (all p-values>0.12.In MCI, mutual cognitive complaint relates to AD pathology whereas self-only or informant-only complaint shows no relation to pathology. Findings support cognitive complaint as a marker of unhealthy brain aging and highlight the importance of obtaining informant corroboration to increase confidence of underlying pathological processes.

  3. LCD denoise and the vector mutual information method in the application of the gear fault diagnosis under different working conditions

    Science.gov (United States)

    Xiangfeng, Zhang; Hong, Jiang

    2018-03-01

    In this paper, the full vector LCD method is proposed to solve the misjudgment problem caused by the change of the working condition. First, the signal from different working condition is decomposed by LCD, to obtain the Intrinsic Scale Component (ISC)whose instantaneous frequency with physical significance. Then, calculate of the cross correlation coefficient between ISC and the original signal, signal denoising based on the principle of mutual information minimum. At last, calculate the sum of absolute Vector mutual information of the sample under different working condition and the denoised ISC as the characteristics to classify by use of Support vector machine (SVM). The wind turbines vibration platform gear box experiment proves that this method can identify fault characteristics under different working conditions. The advantage of this method is that it reduce dependence of man’s subjective experience, identify fault directly from the original data of vibration signal. It will has high engineering value.

  4. Mutual information based CT registration of the lung at exhale and inhale breathing states using thin-plate splines

    International Nuclear Information System (INIS)

    Coselmon, Martha M.; Balter, James M.; McShan, Daniel L.; Kessler, Marc L.

    2004-01-01

    The advent of dynamic radiotherapy modeling and treatment techniques requires an infrastructure to weigh the merits of various interventions (breath holding, gating, tracking). The creation of treatment planning models that account for motion and deformation can allow the relative worth of such techniques to be evaluated. In order to develop a treatment planning model of a moving and deforming organ such as the lung, registration tools that account for deformation are required. We tested the accuracy of a mutual information based image registration tool using thin-plate splines driven by the selection of control points and iterative alignment according to a simplex algorithm. Eleven patients each had sequential CT scans at breath-held normal inhale and exhale states. The exhale right lung was segmented from CT and served as the reference model. For each patient, thirty control points were used to align the inhale CT right lung to the exhale CT right lung. Alignment accuracy (the standard deviation of the difference in the actual and predicted inhale position) was determined from locations of vascular and bronchial bifurcations, and found to be 1.7, 3.1, and 3.6 mm about the RL, AP, and IS directions. The alignment accuracy was significantly different from the amount of measured movement during breathing only in the AP and IS directions. The accuracy of alignment including thin-plate splines was more accurate than using affine transformations and the same iteration and scoring methodology. This technique shows promise for the future development of dynamic models of the lung for use in four-dimensional (4-D) treatment planning

  5. Optimization of PET-MR Registrations for Nonhuman Primates Using Mutual Information Measures: A Multi-Transform Method (MTM)

    Science.gov (United States)

    Sandiego, Christine M.; Weinzimmer, David; Carson, Richard E.

    2012-01-01

    An important step in PET brain kinetic analysis is the registration of functional data to an anatomical MR image. Typically, PET-MR registrations in nonhuman primate neuroreceptor studies used PET images acquired early post-injection, (e.g., 0–10 min) to closely resemble the subject’s MR image. However, a substantial fraction of these registrations (~25%) fail due to the differences in kinetics and distribution for various radiotracer studies and conditions (e.g., blocking studies). The Multi-Transform Method (MTM) was developed to improve the success of registrations between PET and MR images. Two algorithms were evaluated, MTM-I and MTM-II. The approach involves creating multiple transformations by registering PET images of different time intervals, from a dynamic study, to a single reference (i.e., MR image) (MTM-I) or to multiple reference images (i.e., MR and PET images pre-registered to the MR) (MTM-II). Normalized mutual information was used to compute similarity between the transformed PET images and the reference image(s) to choose the optimal transformation. This final transformation is used to map the dynamic dataset into the animal’s anatomical MR space, required for kinetic analysis. The chosen transformed from MTM-I and MTM-II were evaluated using visual rating scores to assess the quality of spatial alignment between the resliced PET and reference. One hundred twenty PET datasets involving eleven different tracers from 3 different scanners were used to evaluate the MTM algorithms. Studies were performed with baboons and rhesus monkeys on the HR+, HRRT, and Focus-220. Successful transformations increased from 77.5%, 85.8%, to 96.7% using the 0–10 min method, MTM-I, and MTM-II, respectively, based on visual rating scores. The Multi-Transform Methods proved to be a robust technique for PET-MR registrations for a wide range of PET studies. PMID:22926293

  6. Determination of relevant neuron-neuron connections for neural prosthetics using time-delayed mutual information: tutorial and preliminary results.

    Science.gov (United States)

    Taghva, Alexander; Song, Dong; Hampson, Robert E; Deadwyler, Sam A; Berger, Theodore W

    2012-12-01

    Identification of functional dependence among neurons is a necessary component in both the rational design of neural prostheses as well as in the characterization of network physiology. The objective of this article is to provide a tutorial for neurosurgeons regarding information theory, specifically time-delayed mutual information, and to compare time-delayed mutual information, an information theoretic quantity based on statistical dependence, with cross-correlation, a commonly used metric for this task in a preliminary analysis of rat hippocampal neurons. Spike trains were recorded from rats performing delayed nonmatch-to-sample task using an array of electrodes surgically implanted into the hippocampus of each hemisphere of the brain. In addition, spike train simulations of positively correlated neurons, negatively correlated neurons, and neurons correlated by nonlinear functions were generated. These were evaluated by time-delayed mutual information (MI) and cross-correlation. Application of time-delayed MI to experimental data indicated the optimal bin size for information capture in the CA3-CA1 system was 40 ms, which may provide some insight into the spatiotemporal nature of encoding in the rat hippocampus. On simulated data, time-delayed MI showed peak values at appropriate time lags in positively correlated, negatively correlated, and complexly correlated data. Cross-correlation showed peak and troughs with positively correlated and negatively correlated data, but failed to capture some higher order correlations. Comparison of time-delayed MI to cross-correlation in identification of functionally dependent neurons indicates that the methods are not equivalent. Time-delayed MI appeared to capture some interactions between CA3-CA1 neurons at physiologically plausible time delays missed by cross-correlation. It should be considered as a method for identification of functional dependence between neurons and may be useful in the development of neural

  7. Finding coevolving amino acid residues using row and column weighting of mutual information and multi-dimensional amino acid representation

    DEFF Research Database (Denmark)

    Oliveira, Rodrigo Gouveia; Pedersen, Anders Gorm

    2007-01-01

    ABSTRACT: BACKGROUND: Some amino acid residues functionally interact with each other. This interaction will result in an evolutionary co-variation between these residues - coevolution. Our goal is to find these coevolving residues. RESULTS: We present six new methods for detecting coevolving...... residues. Among other things, we suggest measures that are variants of Mutual Information, and measures that use a multidimensional representation of each residue in order to capture the physico-chemical similarities between amino acids. We created a benchmarking system, in silico, able to evaluate...

  8. Automatic Time Sequence Alignment in Contrast Enhanced MRI by Maximization of Mutual Information

    National Research Council Canada - National Science Library

    Positano, Vicenzo

    2001-01-01

    The use of contrast medium allows joining the high-resolution anatomical information provided by standard magnetic resonance with functional information obtained by means of the diffusion of contrast...

  9. Probabilistic models for 2D active shape recognition using Fourier descriptors and mutual information

    CSIR Research Space (South Africa)

    Govender, N

    2014-08-01

    Full Text Available information to improve the initial shape recognition results. We propose an initial system which performs shape recognition using the euclidean distances of Fourier descriptors. To improve upon these results we build multinomial and Gaussian probabilistic...

  10. Classifying Pediatric Central Nervous System Tumors through near Optimal Feature Selection and Mutual Information: A Single Center Cohort

    Directory of Open Access Journals (Sweden)

    Mohammad Faranoush

    2013-10-01

    Full Text Available Background: Labeling, gathering mutual information, clustering and classificationof central nervous system tumors may assist in predicting not only distinct diagnosesbased on tumor-specific features but also prognosis. This study evaluates the epidemi-ological features of central nervous system tumors in children who referred to Mahak’sPediatric Cancer Treatment and Research Center in Tehran, Iran.Methods: This cohort (convenience sample study comprised 198 children (≤15years old with central nervous system tumors who referred to Mahak's PediatricCancer Treatment and Research Center from 2007 to 2010. In addition to the descriptiveanalyses on epidemiological features and mutual information, we used the LeastSquares Support Vector Machines method in MATLAB software to propose apreliminary predictive model of pediatric central nervous system tumor feature-labelanalysis. Results:Of patients, there were 63.1% males and 36.9% females. Patients' mean±SDage was 6.11±3.65 years. Tumor location was as follows: supra-tentorial (30.3%, infra-tentorial (67.7% and 2% (spinal. The most frequent tumors registered were: high-gradeglioma (supra-tentorial in 36 (59.99% patients and medulloblastoma (infra-tentorialin 65 (48.51% patients. The most prevalent clinical findings included vomiting,headache and impaired vision. Gender, age, ethnicity, tumor stage and the presence ofmetastasis were the features predictive of supra-tentorial tumor histology.Conclusion: Our data agreed with previous reports on the epidemiology of centralnervous system tumors. Our feature-label analysis has shown how presenting features maypartially predict diagnosis. Timely diagnosis and management of central nervous systemtumors can lead to decreased disease burden and improved survival. This may be furtherfacilitated through development of partitioning, risk prediction and prognostic models.

  11. A novel mutual information-based Boolean network inference method from time-series gene expression data.

    Directory of Open Access Journals (Sweden)

    Shohag Barman

    Full Text Available Inferring a gene regulatory network from time-series gene expression data in systems biology is a challenging problem. Many methods have been suggested, most of which have a scalability limitation due to the combinatorial cost of searching a regulatory set of genes. In addition, they have focused on the accurate inference of a network structure only. Therefore, there is a pressing need to develop a network inference method to search regulatory genes efficiently and to predict the network dynamics accurately.In this study, we employed a Boolean network model with a restricted update rule scheme to capture coarse-grained dynamics, and propose a novel mutual information-based Boolean network inference (MIBNI method. Given time-series gene expression data as an input, the method first identifies a set of initial regulatory genes using mutual information-based feature selection, and then improves the dynamics prediction accuracy by iteratively swapping a pair of genes between sets of the selected regulatory genes and the other genes. Through extensive simulations with artificial datasets, MIBNI showed consistently better performance than six well-known existing methods, REVEAL, Best-Fit, RelNet, CST, CLR, and BIBN in terms of both structural and dynamics prediction accuracy. We further tested the proposed method with two real gene expression datasets for an Escherichia coli gene regulatory network and a fission yeast cell cycle network, and also observed better results using MIBNI compared to the six other methods.Taken together, MIBNI is a promising tool for predicting both the structure and the dynamics of a gene regulatory network.

  12. A New Variable Selection Method Based on Mutual Information Maximization by Replacing Collinear Variables for Nonlinear Quantitative Structure-Property Relationship Models

    Energy Technology Data Exchange (ETDEWEB)

    Ghasemi, Jahan B.; Zolfonoun, Ehsan [Toosi University of Technology, Tehran (Korea, Republic of)

    2012-05-15

    Selection of the most informative molecular descriptors from the original data set is a key step for development of quantitative structure activity/property relationship models. Recently, mutual information (MI) has gained increasing attention in feature selection problems. This paper presents an effective mutual information-based feature selection approach, named mutual information maximization by replacing collinear variables (MIMRCV), for nonlinear quantitative structure-property relationship models. The proposed variable selection method was applied to three different QSPR datasets, soil degradation half-life of 47 organophosphorus pesticides, GC-MS retention times of 85 volatile organic compounds, and water-to-micellar cetyltrimethylammonium bromide partition coefficients of 62 organic compounds.The obtained results revealed that using MIMRCV as feature selection method improves the predictive quality of the developed models compared to conventional MI based variable selection algorithms.

  13. A New Variable Selection Method Based on Mutual Information Maximization by Replacing Collinear Variables for Nonlinear Quantitative Structure-Property Relationship Models

    International Nuclear Information System (INIS)

    Ghasemi, Jahan B.; Zolfonoun, Ehsan

    2012-01-01

    Selection of the most informative molecular descriptors from the original data set is a key step for development of quantitative structure activity/property relationship models. Recently, mutual information (MI) has gained increasing attention in feature selection problems. This paper presents an effective mutual information-based feature selection approach, named mutual information maximization by replacing collinear variables (MIMRCV), for nonlinear quantitative structure-property relationship models. The proposed variable selection method was applied to three different QSPR datasets, soil degradation half-life of 47 organophosphorus pesticides, GC-MS retention times of 85 volatile organic compounds, and water-to-micellar cetyltrimethylammonium bromide partition coefficients of 62 organic compounds.The obtained results revealed that using MIMRCV as feature selection method improves the predictive quality of the developed models compared to conventional MI based variable selection algorithms

  14. SU-F-J-96: Comparison of Frame-Based and Mutual Information Registration Techniques for CT and MR Image Sets

    Energy Technology Data Exchange (ETDEWEB)

    Popple, R; Bredel, M; Brezovich, I; Dobelbower, M; Fisher, W; Fiveash, J; Guthrie, B; Riley, K; Wu, X [The University of Alabama at Birmingham, Birmingham, AL (United States)

    2016-06-15

    Purpose: To compare the accuracy of CT-MR registration using a mutual information method with registration using a frame-based localizer box. Methods: Ten patients having the Leksell head frame and scanned with a modality specific localizer box were imported into the treatment planning system. The fiducial rods of the localizer box were contoured on both the MR and CT scans. The skull was contoured on the CT images. The MR and CT images were registered by two methods. The frame-based method used the transformation that minimized the mean square distance of the centroids of the contours of the fiducial rods from a mathematical model of the localizer. The mutual information method used automated image registration tools in the TPS and was restricted to a volume-of-interest defined by the skull contours with a 5 mm margin. For each case, the two registrations were adjusted by two evaluation teams, each comprised of an experienced radiation oncologist and neurosurgeon, to optimize alignment in the region of the brainstem. The teams were blinded to the registration method. Results: The mean adjustment was 0.4 mm (range 0 to 2 mm) and 0.2 mm (range 0 to 1 mm) for the frame and mutual information methods, respectively. The median difference between the frame and mutual information registrations was 0.3 mm, but was not statistically significant using the Wilcoxon signed rank test (p=0.37). Conclusion: The difference between frame and mutual information registration techniques was neither statistically significant nor, for most applications, clinically important. These results suggest that mutual information is equivalent to frame-based image registration for radiosurgery. Work is ongoing to add additional evaluators and to assess the differences between evaluators.

  15. Use of mutual information to decrease entropy: Implications for the second law of thermodynamics

    International Nuclear Information System (INIS)

    Lloyd, S.

    1989-01-01

    Several theorems on the mechanics of gathering information are proved, and the possibility of violating the second law of thermodynamics by obtaining information is discussed in light of these theorems. Maxwell's demon can lower the entropy of his surroundings by an amount equal to the difference between the maximum entropy of his recording device and its initial entropy, without generating a compensating entropy increase. A demon with human-scale recording devices can reduce the entropy of a gas by a negligible amount only, but the proof of the demon's impracticability leaves open the possibility that systems highly correlated with their environment can reduce the environment's entropy by a substantial amount without increasing entropy elsewhere. In the event that a boundary condition for the universe requires it to be in a state of low entropy when small, the correlations induced between different particle modes during the expansion phase allow the modes to behave like Maxwell's demons during the contracting phase, reducing the entropy of the universe to a low value

  16. A new approach to elastography using mutual information and finite elements

    International Nuclear Information System (INIS)

    Miga, Michael I

    2003-01-01

    Historically, increased mechanical stiffness during tissue palpation exams has been associated with assessing organ health as well as with detecting the growth of a potentially life-threatening cell mass. As such, techniques to image elasticity parameters (i.e., elastography) have recently become of great interest to scientists. In this work, a new method of elastography will be introduced within the context of mammographic imaging. The elastography method proposed represents a non-rigid iterative image registration algorithm that varies material properties within a finite element model to improve registration. More specifically, regional measures of image similarity are used within an objective function minimization framework to reconstruct elasticity images of tissue stiffness. Numerical simulations illustrate: (1) the encoding of stiffness information within the context of a regional image similarity criterion, (2) the methodology for an iterative elastographic imaging framework and (3) elasticity reconstruction simulations. The real strength in this approach is that images from any modality (e.g., magnetic resonance, computed tomography, ultrasound, etc) that have sufficient anatomically-based intensity heterogeneity and remain consistent from a pre- to a post-deformed state could be used in this paradigm

  17. Design and Analysis of an Enhanced Patient-Server Mutual Authentication Protocol for Telecare Medical Information System.

    Science.gov (United States)

    Amin, Ruhul; Islam, S K Hafizul; Biswas, G P; Khan, Muhammad Khurram; Obaidat, Mohammad S

    2015-11-01

    In order to access remote medical server, generally the patients utilize smart card to login to the server. It has been observed that most of the user (patient) authentication protocols suffer from smart card stolen attack that means the attacker can mount several common attacks after extracting smart card information. Recently, Lu et al.'s proposes a session key agreement protocol between the patient and remote medical server and claims that the same protocol is secure against relevant security attacks. However, this paper presents several security attacks on Lu et al.'s protocol such as identity trace attack, new smart card issue attack, patient impersonation attack and medical server impersonation attack. In order to fix the mentioned security pitfalls including smart card stolen attack, this paper proposes an efficient remote mutual authentication protocol using smart card. We have then simulated the proposed protocol using widely-accepted AVISPA simulation tool whose results make certain that the same protocol is secure against active and passive attacks including replay and man-in-the-middle attacks. Moreover, the rigorous security analysis proves that the proposed protocol provides strong security protection on the relevant security attacks including smart card stolen attack. We compare the proposed scheme with several related schemes in terms of computation cost and communication cost as well as security functionalities. It has been observed that the proposed scheme is comparatively better than related existing schemes.

  18. Transfer Learning for SSVEP Electroencephalography Based Brain–Computer Interfaces Using Learn++.NSE and Mutual Information

    Directory of Open Access Journals (Sweden)

    Matthew Sybeldon

    2017-01-01

    Full Text Available Brain–Computer Interfaces (BCI using Steady-State Visual Evoked Potentials (SSVEP are sometimes used by injured patients seeking to use a computer. Canonical Correlation Analysis (CCA is seen as state-of-the-art for SSVEP BCI systems. However, this assumes that the user has full control over their covert attention, which may not be the case. This introduces high calibration requirements when using other machine learning techniques. These may be circumvented by using transfer learning to utilize data from other participants. This paper proposes a combination of ensemble learning via Learn++ for Nonstationary Environments (Learn++.NSEand similarity measures such as mutual information to identify ensembles of pre-existing data that result in higher classification. Results show that this approach performed worse than CCA in participants with typical SSVEP responses, but outperformed CCA in participants whose SSVEP responses violated CCA assumptions. This indicates that similarity measures and Learn++.NSE can introduce a transfer learning mechanism to bring SSVEP system accessibility to users unable to control their covert attention.

  19. Rating mutual funds

    DEFF Research Database (Denmark)

    Bechmann, Ken L.; Rangvid, Jesper

    2007-01-01

    We develop a new rating of mutual funds: the atpRating. The atpRating assigns crowns to each individual mutual fund based upon the costs an investor pays when investing in the fund in relation to what it would cost to invest in the fund's peers. Within each investment category, the rating assigns...... the return of a fund in a certain year generally contains only little information about the future return that the fund will generate. Finally, we have information on the investments in different mutual funds made by a small subgroup of investors known to have been exposed to both the atp...... five crowns to funds with the lowest costs and one crown to funds with the highest costs. We investigate the ability of the atpRating to predict the future performance of a fund. We find that an investor who has invested in the funds with the lowest costs within an investment category would have...

  20. Rating Mutual Funds

    DEFF Research Database (Denmark)

    Bechmann, Ken L.; Rangvid, Jesper

    We develop a new rating of mutual funds: the atpRating. The atpRating assigns crowns to each individual mutual fund based upon the costs an investor pays when investing in the fund in relation to what it would cost to invest in the fund’s peers. Within each investment category, the rating assigns......, whereas the return of a fund in a certain year generally contains only little information about the future return that the fund will generate. Finally, we have information on the investments in different mutual funds made by a small subgroup of investors known to have been exposed to both the atp...... five crowns to funds with the lowest costs and one crown to funds with the highest costs. We investigate the ability of the atpRating to predict the future performance of a fund. We find that an investor who has invested in the funds with the lowest costs within an investment category would have...

  1. Networks of high mutual information define the structural proximity of catalytic sites: implications for catalytic residue identification.

    Directory of Open Access Journals (Sweden)

    Cristina Marino Buslje

    Full Text Available Identification of catalytic residues (CR is essential for the characterization of enzyme function. CR are, in general, conserved and located in the functional site of a protein in order to attain their function. However, many non-catalytic residues are highly conserved and not all CR are conserved throughout a given protein family making identification of CR a challenging task. Here, we put forward the hypothesis that CR carry a particular signature defined by networks of close proximity residues with high mutual information (MI, and that this signature can be applied to distinguish functional from other non-functional conserved residues. Using a data set of 434 Pfam families included in the catalytic site atlas (CSA database, we tested this hypothesis and demonstrated that MI can complement amino acid conservation scores to detect CR. The Kullback-Leibler (KL conservation measurement was shown to significantly outperform both the Shannon entropy and maximal frequency measurements. Residues in the proximity of catalytic sites were shown to be rich in shared MI. A structural proximity MI average score (termed pMI was demonstrated to be a strong predictor for CR, thus confirming the proposed hypothesis. A structural proximity conservation average score (termed pC was also calculated and demonstrated to carry distinct information from pMI. A catalytic likeliness score (Cls, combining the KL, pC and pMI measures, was shown to lead to significantly improved prediction accuracy. At a specificity of 0.90, the Cls method was found to have a sensitivity of 0.816. In summary, we demonstrate that networks of residues with high MI provide a distinct signature on CR and propose that such a signature should be present in other classes of functional residues where the requirement to maintain a particular function places limitations on the diversification of the structural environment along the course of evolution.

  2. Networks of high mutual information define the structural proximity of catalytic sites: implications for catalytic residue identification.

    Science.gov (United States)

    Marino Buslje, Cristina; Teppa, Elin; Di Doménico, Tomas; Delfino, José María; Nielsen, Morten

    2010-11-04

    Identification of catalytic residues (CR) is essential for the characterization of enzyme function. CR are, in general, conserved and located in the functional site of a protein in order to attain their function. However, many non-catalytic residues are highly conserved and not all CR are conserved throughout a given protein family making identification of CR a challenging task. Here, we put forward the hypothesis that CR carry a particular signature defined by networks of close proximity residues with high mutual information (MI), and that this signature can be applied to distinguish functional from other non-functional conserved residues. Using a data set of 434 Pfam families included in the catalytic site atlas (CSA) database, we tested this hypothesis and demonstrated that MI can complement amino acid conservation scores to detect CR. The Kullback-Leibler (KL) conservation measurement was shown to significantly outperform both the Shannon entropy and maximal frequency measurements. Residues in the proximity of catalytic sites were shown to be rich in shared MI. A structural proximity MI average score (termed pMI) was demonstrated to be a strong predictor for CR, thus confirming the proposed hypothesis. A structural proximity conservation average score (termed pC) was also calculated and demonstrated to carry distinct information from pMI. A catalytic likeliness score (Cls), combining the KL, pC and pMI measures, was shown to lead to significantly improved prediction accuracy. At a specificity of 0.90, the Cls method was found to have a sensitivity of 0.816. In summary, we demonstrate that networks of residues with high MI provide a distinct signature on CR and propose that such a signature should be present in other classes of functional residues where the requirement to maintain a particular function places limitations on the diversification of the structural environment along the course of evolution.

  3. Transliteration normalization for Information Extraction and Machine Translation

    Directory of Open Access Journals (Sweden)

    Yuval Marton

    2014-12-01

    Full Text Available Foreign name transliterations typically include multiple spelling variants. These variants cause data sparseness and inconsistency problems, increase the Out-of-Vocabulary (OOV rate, and present challenges for Machine Translation, Information Extraction and other natural language processing (NLP tasks. This work aims to identify and cluster name spelling variants using a Statistical Machine Translation method: word alignment. The variants are identified by being aligned to the same “pivot” name in another language (the source-language in Machine Translation settings. Based on word-to-word translation and transliteration probabilities, as well as the string edit distance metric, names with similar spellings in the target language are clustered and then normalized to a canonical form. With this approach, tens of thousands of high-precision name transliteration spelling variants are extracted from sentence-aligned bilingual corpora in Arabic and English (in both languages. When these normalized name spelling variants are applied to Information Extraction tasks, improvements over strong baseline systems are observed. When applied to Machine Translation tasks, a large improvement potential is shown.

  4. SU-E-J-132: Automated Segmentation with Post-Registration Atlas Selection Based On Mutual Information

    Energy Technology Data Exchange (ETDEWEB)

    Ren, X; Gao, H [Shanghai Jiao Tong University, Shanghai, Shanghai (China); Sharp, G [Massachusetts General Hospital, Boston, MA (United States)

    2015-06-15

    Purpose: The delineation of targets and organs-at-risk is a critical step during image-guided radiation therapy, for which manual contouring is the gold standard. However, it is often time-consuming and may suffer from intra- and inter-rater variability. The purpose of this work is to investigate the automated segmentation. Methods: The automatic segmentation here is based on mutual information (MI), with the atlas from Public Domain Database for Computational Anatomy (PDDCA) with manually drawn contours.Using dice coefficient (DC) as the quantitative measure of segmentation accuracy, we perform leave-one-out cross-validations for all PDDCA images sequentially, during which other images are registered to each chosen image and DC is computed between registered contour and ground truth. Meanwhile, six strategies, including MI, are selected to measure the image similarity, with MI to be the best. Then given a target image to be segmented and an atlas, automatic segmentation consists of: (a) the affine registration step for image positioning; (b) the active demons registration method to register the atlas to the target image; (c) the computation of MI values between the deformed atlas and the target image; (d) the weighted image fusion of three deformed atlas images with highest MI values to form the segmented contour. Results: MI was found to be the best among six studied strategies in the sense that it had the highest positive correlation between similarity measure (e.g., MI values) and DC. For automated segmentation, the weighted image fusion of three deformed atlas images with highest MI values provided the highest DC among four proposed strategies. Conclusion: MI has the highest correlation with DC, and therefore is an appropriate choice for post-registration atlas selection in atlas-based segmentation. Xuhua Ren and Hao Gao were partially supported by the NSFC (#11405105), the 973 Program (#2015CB856000) and the Shanghai Pujiang Talent Program (#14PJ1404500)

  5. Evaluation of the mutual information cost function for registration of SPET and MRI images of the brain

    International Nuclear Information System (INIS)

    Taleb, M.; McKay, E.

    1999-01-01

    Full text: Any strategy for image registration requires some method (a cost function) by which two images may be compared The mutual information (MI) between images is one such cost function. MI measures the structural similarity between pairs of gray-scale images and performs cross-modality image registration with minimal image pre-processing. This project compares the performance of MI vs the sum of absolute differences (SAD) 'gold standard' in monomodality image registration problems. It also examines the precision of cross-modality registration based on MI, using a human observer to decide whether registration is accurate. Thirteen paired brain SPET scans were registered using SAD as a cost function. Registration was repeated using MI and differences from the SAD results were recorded. Ten paired MRI and SPET brain scans registered using the MI cost function. Registration was repeated three times for each pair, varying the SPET position or orientation each time. Comparing MI to SAD, the median values of translation error were 2.85, 4.63 and 2.56 mm in the x, y and z axis and 0.5 j , 1.1 j and 1.0 j around the x, y and z axis respectively. For the cross-modality problems, the mean standard deviation (MSD) observed in x, y and z positioning was 0.18, 0.28 and 0.16 mm respectively. The MSD of orientation was 5.35 j , 1.95 j and 2.48 j around the x, y and z axis respectively. MI performed as well as SAD for monomodality registration. Unlike SAD, MI is also useful for cross-modality image registration tasks, producing visually acceptable results with minimal preprocessing

  6. SU-E-J-132: Automated Segmentation with Post-Registration Atlas Selection Based On Mutual Information

    International Nuclear Information System (INIS)

    Ren, X; Gao, H; Sharp, G

    2015-01-01

    Purpose: The delineation of targets and organs-at-risk is a critical step during image-guided radiation therapy, for which manual contouring is the gold standard. However, it is often time-consuming and may suffer from intra- and inter-rater variability. The purpose of this work is to investigate the automated segmentation. Methods: The automatic segmentation here is based on mutual information (MI), with the atlas from Public Domain Database for Computational Anatomy (PDDCA) with manually drawn contours.Using dice coefficient (DC) as the quantitative measure of segmentation accuracy, we perform leave-one-out cross-validations for all PDDCA images sequentially, during which other images are registered to each chosen image and DC is computed between registered contour and ground truth. Meanwhile, six strategies, including MI, are selected to measure the image similarity, with MI to be the best. Then given a target image to be segmented and an atlas, automatic segmentation consists of: (a) the affine registration step for image positioning; (b) the active demons registration method to register the atlas to the target image; (c) the computation of MI values between the deformed atlas and the target image; (d) the weighted image fusion of three deformed atlas images with highest MI values to form the segmented contour. Results: MI was found to be the best among six studied strategies in the sense that it had the highest positive correlation between similarity measure (e.g., MI values) and DC. For automated segmentation, the weighted image fusion of three deformed atlas images with highest MI values provided the highest DC among four proposed strategies. Conclusion: MI has the highest correlation with DC, and therefore is an appropriate choice for post-registration atlas selection in atlas-based segmentation. Xuhua Ren and Hao Gao were partially supported by the NSFC (#11405105), the 973 Program (#2015CB856000) and the Shanghai Pujiang Talent Program (#14PJ1404500)

  7. Beyond the 2×2 -contingency table: a primer on entropies and mutual information in various scenarios involving m diagnostic categories and n categories of diagnostic tests.

    Science.gov (United States)

    Reibnegger, Gilbert

    2013-10-21

    Usual evaluation tools for diagnostic tests such as, sensitivity/specificity and ROC analyses, are designed for the discrimination between two diagnostic categories, using dichotomous test results. Information theoretical quantities such as mutual information allow in depth-analysis of more complex discrimination problems, including continuous test results, but are rarely used in clinical chemistry. This paper provides a primer on useful information theoretical concepts with a strong focus on typical diagnostic scenarios. Information theoretical concepts are shortly explained. Mathematica CDF documents are provided which compute entropies and mutual information as function of pretest probabilities and the distribution of test results among the categories, and allow interactive exploration of the behavior of these quantities in comparison with more conventional diagnostic measures. Using data from a previously published study, the application of information theory to practical diagnostic problems involving up to 4×4 -contingency tables is demonstrated. Information theoretical concepts are particularly useful for diagnostic problems requiring more than the usual binary classification. Quantitative test results can be properly analyzed, and in contrast to popular concepts such as ROC analysis, the effects of variations of pre-test probabilities of the diagnostic categories can be explicitly taken into account. © 2013 Elsevier B.V. All rights reserved.

  8. Correction for phylogeny, small number of observations and data redundancy improves the identification of coevolving amino acid pairs using mutual information

    DEFF Research Database (Denmark)

    Buslje, C.M.; Santos, J.; Delfino, J.M.

    2009-01-01

    Motivation: Mutual information (MI) theory is often applied to predict positional correlations in a multiple sequence alignment (MSA) to make possible the analysis of those positions structurally or functionally important in a given fold or protein family. Accurate identification of coevolving......-weighting techniques to reduce sequence redundancy and low-count corrections to account for small number of observations in limited size sequence families, can significantly improve the predictability of MI. The evaluation is made on large sets of both in silico-generated alignments as well as on biological sequence...

  9. Normal mode analysis as a method to derive protein dynamics information from the Protein Data Bank.

    Science.gov (United States)

    Wako, Hiroshi; Endo, Shigeru

    2017-12-01

    Normal mode analysis (NMA) can facilitate quick and systematic investigation of protein dynamics using data from the Protein Data Bank (PDB). We developed an elastic network model-based NMA program using dihedral angles as independent variables. Compared to the NMA programs that use Cartesian coordinates as independent variables, key attributes of the proposed program are as follows: (1) chain connectivity related to the folding pattern of a polypeptide chain is naturally embedded in the model; (2) the full-atom system is acceptable, and owing to a considerably smaller number of independent variables, the PDB data can be used without further manipulation; (3) the number of variables can be easily reduced by some of the rotatable dihedral angles; (4) the PDB data for any molecule besides proteins can be considered without coarse-graining; and (5) individual motions of constituent subunits and ligand molecules can be easily decomposed into external and internal motions to examine their mutual and intrinsic motions. Its performance is illustrated with an example of a DNA-binding allosteric protein, a catabolite activator protein. In particular, the focus is on the conformational change upon cAMP and DNA binding, and on the communication between their binding sites remotely located from each other. In this illustration, NMA creates a vivid picture of the protein dynamics at various levels of the structures, i.e., atoms, residues, secondary structures, domains, subunits, and the complete system, including DNA and cAMP. Comparative studies of the specific protein in different states, e.g., apo- and holo-conformations, and free and complexed configurations, provide useful information for studying structurally and functionally important aspects of the protein.

  10. Interpretation of the auto-mutual information rate of decrease in the context of biomedical signal analysis. Application to electroencephalogram recordings

    International Nuclear Information System (INIS)

    Escudero, Javier; Hornero, Roberto; Abásolo, Daniel

    2009-01-01

    The mutual information (MI) is a measure of both linear and nonlinear dependences. It can be applied to a time series and a time-delayed version of the same sequence to compute the auto-mutual information function (AMIF). Moreover, the AMIF rate of decrease (AMIFRD) with increasing time delay in a signal is correlated with its entropy and has been used to characterize biomedical data. In this paper, we aimed at gaining insight into the dependence of the AMIFRD on several signal processing concepts and at illustrating its application to biomedical time series analysis. Thus, we have analysed a set of synthetic sequences with the AMIFRD. The results show that the AMIF decreases more quickly as bandwidth increases and that the AMIFRD becomes more negative as there is more white noise contaminating the time series. Additionally, this metric detected changes in the nonlinear dynamics of a signal. Finally, in order to illustrate the analysis of real biomedical signals with the AMIFRD, this metric was applied to electroencephalogram (EEG) signals acquired with eyes open and closed and to ictal and non-ictal intracranial EEG recordings

  11. Interpretation of the auto-mutual information rate of decrease in the context of biomedical signal analysis. Application to electroencephalogram recordings.

    Science.gov (United States)

    Escudero, Javier; Hornero, Roberto; Abásolo, Daniel

    2009-02-01

    The mutual information (MI) is a measure of both linear and nonlinear dependences. It can be applied to a time series and a time-delayed version of the same sequence to compute the auto-mutual information function (AMIF). Moreover, the AMIF rate of decrease (AMIFRD) with increasing time delay in a signal is correlated with its entropy and has been used to characterize biomedical data. In this paper, we aimed at gaining insight into the dependence of the AMIFRD on several signal processing concepts and at illustrating its application to biomedical time series analysis. Thus, we have analysed a set of synthetic sequences with the AMIFRD. The results show that the AMIF decreases more quickly as bandwidth increases and that the AMIFRD becomes more negative as there is more white noise contaminating the time series. Additionally, this metric detected changes in the nonlinear dynamics of a signal. Finally, in order to illustrate the analysis of real biomedical signals with the AMIFRD, this metric was applied to electroencephalogram (EEG) signals acquired with eyes open and closed and to ictal and non-ictal intracranial EEG recordings.

  12. Image fusion between whole body FDG PET images and whole body MRI images using a full-automatic mutual information-based multimodality image registration software

    International Nuclear Information System (INIS)

    Uchida, Yoshitaka; Nakano, Yoshitada; Fujibuchi, Toshiou; Isobe, Tomoko; Kazama, Toshiki; Ito, Hisao

    2006-01-01

    We attempted image fusion between whole body PET and whole body MRI of thirty patients using a full-automatic mutual information (MI) -based multimodality image registration software and evaluated accuracy of this method and impact of the coregistrated imaging on diagnostic accuracy. For 25 of 30 fused images in body area, translating gaps were within 6 mm in all axes and rotating gaps were within 2 degrees around all axes. In head and neck area, considerably much gaps caused by difference of head inclination at imaging occurred in 16 patients, however these gaps were able to decrease by fused separately. In 6 patients, diagnostic accuracy using PET/MRI fused images was superior compared by PET image alone. This work shows that whole body FDG PET images and whole body MRI images can be automatically fused using MI-based multimodality image registration software accurately and this technique can add useful information when evaluating FDG PET images. (author)

  13. Evaluation of Respiratory Muscles Activity by means of Cross Mutual Information Function at Different Levels of Ventilatory Effort

    OpenAIRE

    Alonso López, Joan Francesc; Mañanas Villanueva, Miguel Ángel; Hoyer, Dirk; Bruce, Eugene N.; Zbigniew L., Topor

    2007-01-01

    Analysis of respiratory muscles activity is an effective technique for the study of pulmonary diseases such as obstructive sleep apnea syndrome (OSAS). Respiratory diseases, especially those associated with changes in the mechanical properties of the respiratory apparatus, are often associated with disruptions of the normally highly coordinated contractions of respiratory muscles. Due to the complexity of the respiratory control, the assessment of OSAS related dysfunctions by linear ...

  14. Demonstration of accuracy and clinical versatility of mutual information for automatic multimodality image fusion using affine and thin-plate spline warped geometric deformations.

    Science.gov (United States)

    Meyer, C R; Boes, J L; Kim, B; Bland, P H; Zasadny, K R; Kison, P V; Koral, K; Frey, K A; Wahl, R L

    1997-04-01

    This paper applies and evaluates an automatic mutual information-based registration algorithm across a broad spectrum of multimodal volume data sets. The algorithm requires little or no pre-processing, minimal user input and easily implements either affine, i.e. linear or thin-plate spline (TPS) warped registrations. We have evaluated the algorithm in phantom studies as well as in selected cases where few other algorithms could perform as well, if at all, to demonstrate the value of this new method. Pairs of multimodal gray-scale volume data sets were registered by iteratively changing registration parameters to maximize mutual information. Quantitative registration errors were assessed in registrations of a thorax phantom using PET/CT and in the National Library of Medicine's Visible Male using MRI T2-/T1-weighted acquisitions. Registrations of diverse clinical data sets were demonstrated including rotate-translate mapping of PET/MRI brain scans with significant missing data, full affine mapping of thoracic PET/CT and rotate-translate mapping of abdominal SPECT/CT. A five-point thin-plate spline (TPS) warped registration of thoracic PET/CT is also demonstrated. The registration algorithm converged in times ranging between 3.5 and 31 min for affine clinical registrations and 57 min for TPS warping. Mean error vector lengths for rotate-translate registrations were measured to be subvoxel in phantoms. More importantly the rotate-translate algorithm performs well even with missing data. The demonstrated clinical fusions are qualitatively excellent at all levels. We conclude that such automatic, rapid, robust algorithms significantly increase the likelihood that multimodality registrations will be routinely used to aid clinical diagnoses and post-therapeutic assessment in the near future.

  15. Prediction of Intelligibility of Noisy and Time-Frequency Weighted Speech based on Mutual Information Between Amplitude Envelopes

    DEFF Research Database (Denmark)

    Jensen, Jesper; Taal, C.H.

    2013-01-01

    of Shannon information the critical-band amplitude envelopes of the noisy/processed signal convey about the corresponding clean signal envelopes. The resulting intelligibility predictor turns out to be a simple function of the correlation between noisy/processed and clean amplitude envelopes. The proposed...

  16. IMPROVEMENT IN HANDWRITTEN NUMERAL STRING RECOGNITION BY SLANT NORMALIZATION AND CONTEXTUAL INFORMATION

    NARCIS (Netherlands)

    Britto jr., A. de S.; Sabourin, R.; Lethelier, E.; Bortolozzi, F.; Suen, C.Y.

    2004-01-01

    This work describes a way of enhancing handwritten numeral string recognition by considering slant normalization and contextual information to train an implicit segmentation­based system. A word slant normalization method is modified in order to improve the results for handwritten numeral strings.

  17. A Semi-Supervised Learning Algorithm for Predicting Four Types MiRNA-Disease Associations by Mutual Information in a Heterogeneous Network.

    Science.gov (United States)

    Zhang, Xiaotian; Yin, Jian; Zhang, Xu

    2018-03-02

    Increasing evidence suggests that dysregulation of microRNAs (miRNAs) may lead to a variety of diseases. Therefore, identifying disease-related miRNAs is a crucial problem. Currently, many computational approaches have been proposed to predict binary miRNA-disease associations. In this study, in order to predict underlying miRNA-disease association types, a semi-supervised model called the network-based label propagation algorithm is proposed to infer multiple types of miRNA-disease associations (NLPMMDA) by mutual information derived from the heterogeneous network. The NLPMMDA method integrates disease semantic similarity, miRNA functional similarity, and Gaussian interaction profile kernel similarity information of miRNAs and diseases to construct a heterogeneous network. NLPMMDA is a semi-supervised model which does not require verified negative samples. Leave-one-out cross validation (LOOCV) was implemented for four known types of miRNA-disease associations and demonstrated the reliable performance of our method. Moreover, case studies of lung cancer and breast cancer confirmed effective performance of NLPMMDA to predict novel miRNA-disease associations and their association types.

  18. PET-MR image fusion in soft tissue sarcoma: accuracy, reliability and practicality of interactive point-based and automated mutual information techniques

    International Nuclear Information System (INIS)

    Somer, Edward J.R.; Marsden, Paul K.; Benatar, Nigel A.; O'Doherty, Michael J.; Goodey, Joanne; Smith, Michael A.

    2003-01-01

    The fusion of functional positron emission tomography (PET) data with anatomical magnetic resonance (MR) or computed tomography images, using a variety of interactive and automated techniques, is becoming commonplace, with the technique of choice dependent on the specific application. The case of PET-MR image fusion in soft tissue is complicated by a lack of conspicuous anatomical features and deviation from the rigid-body model. Here we compare a point-based external marker technique with an automated mutual information algorithm and discuss the practicality, reliability and accuracy of each when applied to the study of soft tissue sarcoma. Ten subjects with suspected sarcoma in the knee, thigh, groin, flank or back underwent MR and PET scanning after the attachment of nine external fiducial markers. In the assessment of the point-based technique, three error measures were considered: fiducial localisation error (FLE), fiducial registration error (FRE) and target registration error (TRE). FLE, which represents the accuracy with which the fiducial points can be located, is related to the FRE minimised by the registration algorithm. The registration accuracy is best characterised by the TRE, which is the distance between corresponding points in each image space after registration. In the absence of salient features within the target volume, the TRE can be measured at fiducials excluded from the registration process. To assess the mutual information technique, PET data, acquired after physically removing the markers, were reconstructed in a variety of ways and registered with MR. Having applied the transform suggested by the algorithm to the PET scan acquired before the markers were removed, the residual distance between PET and MR marker-pairs could be measured. The manual point-based technique yielded the best results (RMS TRE =8.3 mm, max =22.4 mm, min =1.7 mm), performing better than the automated algorithm (RMS TRE =20.0 mm, max =30.5 mm, min =7.7 mm) when

  19. Minimizing Mutual Couping

    DEFF Research Database (Denmark)

    2010-01-01

    Disclosed herein are techniques, systems, and methods relating to minimizing mutual coupling between a first antenna and a second antenna.......Disclosed herein are techniques, systems, and methods relating to minimizing mutual coupling between a first antenna and a second antenna....

  20. A configuration space of homologous proteins conserving mutual information and allowing a phylogeny inference based on pair-wise Z-score probabilities.

    Science.gov (United States)

    Bastien, Olivier; Ortet, Philippe; Roy, Sylvaine; Maréchal, Eric

    2005-03-10

    Popular methods to reconstruct molecular phylogenies are based on multiple sequence alignments, in which addition or removal of data may change the resulting tree topology. We have sought a representation of homologous proteins that would conserve the information of pair-wise sequence alignments, respect probabilistic properties of Z-scores (Monte Carlo methods applied to pair-wise comparisons) and be the basis for a novel method of consistent and stable phylogenetic reconstruction. We have built up a spatial representation of protein sequences using concepts from particle physics (configuration space) and respecting a frame of constraints deduced from pair-wise alignment score properties in information theory. The obtained configuration space of homologous proteins (CSHP) allows the representation of real and shuffled sequences, and thereupon an expression of the TULIP theorem for Z-score probabilities. Based on the CSHP, we propose a phylogeny reconstruction using Z-scores. Deduced trees, called TULIP trees, are consistent with multiple-alignment based trees. Furthermore, the TULIP tree reconstruction method provides a solution for some previously reported incongruent results, such as the apicomplexan enolase phylogeny. The CSHP is a unified model that conserves mutual information between proteins in the way physical models conserve energy. Applications include the reconstruction of evolutionary consistent and robust trees, the topology of which is based on a spatial representation that is not reordered after addition or removal of sequences. The CSHP and its assigned phylogenetic topology, provide a powerful and easily updated representation for massive pair-wise genome comparisons based on Z-score computations.

  1. A configuration space of homologous proteins conserving mutual information and allowing a phylogeny inference based on pair-wise Z-score probabilities

    Directory of Open Access Journals (Sweden)

    Maréchal Eric

    2005-03-01

    Full Text Available Abstract Background Popular methods to reconstruct molecular phylogenies are based on multiple sequence alignments, in which addition or removal of data may change the resulting tree topology. We have sought a representation of homologous proteins that would conserve the information of pair-wise sequence alignments, respect probabilistic properties of Z-scores (Monte Carlo methods applied to pair-wise comparisons and be the basis for a novel method of consistent and stable phylogenetic reconstruction. Results We have built up a spatial representation of protein sequences using concepts from particle physics (configuration space and respecting a frame of constraints deduced from pair-wise alignment score properties in information theory. The obtained configuration space of homologous proteins (CSHP allows the representation of real and shuffled sequences, and thereupon an expression of the TULIP theorem for Z-score probabilities. Based on the CSHP, we propose a phylogeny reconstruction using Z-scores. Deduced trees, called TULIP trees, are consistent with multiple-alignment based trees. Furthermore, the TULIP tree reconstruction method provides a solution for some previously reported incongruent results, such as the apicomplexan enolase phylogeny. Conclusion The CSHP is a unified model that conserves mutual information between proteins in the way physical models conserve energy. Applications include the reconstruction of evolutionary consistent and robust trees, the topology of which is based on a spatial representation that is not reordered after addition or removal of sequences. The CSHP and its assigned phylogenetic topology, provide a powerful and easily updated representation for massive pair-wise genome comparisons based on Z-score computations.

  2. Conjunction of wavelet transform and SOM-mutual information data pre-processing approach for AI-based Multi-Station nitrate modeling of watersheds

    Science.gov (United States)

    Nourani, Vahid; Andalib, Gholamreza; Dąbrowska, Dominika

    2017-05-01

    Accurate nitrate load predictions can elevate decision management of water quality of watersheds which affects to environment and drinking water. In this paper, two scenarios were considered for Multi-Station (MS) nitrate load modeling of the Little River watershed. In the first scenario, Markovian characteristics of streamflow-nitrate time series were proposed for the MS modeling. For this purpose, feature extraction criterion of Mutual Information (MI) was employed for input selection of artificial intelligence models (Feed Forward Neural Network, FFNN and least square support vector machine). In the second scenario for considering seasonality-based characteristics of the time series, wavelet transform was used to extract multi-scale features of streamflow-nitrate time series of the watershed's sub-basins to model MS nitrate loads. Self-Organizing Map (SOM) clustering technique which finds homogeneous sub-series clusters was also linked to MI for proper cluster agent choice to be imposed into the models for predicting the nitrate loads of the watershed's sub-basins. The proposed MS method not only considers the prediction of the outlet nitrate but also covers predictions of interior sub-basins nitrate load values. The results indicated that the proposed FFNN model coupled with the SOM-MI improved the performance of MS nitrate predictions compared to the Markovian-based models up to 39%. Overall, accurate selection of dominant inputs which consider seasonality-based characteristics of streamflow-nitrate process could enhance the efficiency of nitrate load predictions.

  3. A novel model-free data analysis technique based on clustering in a mutual information space: application to resting-state fMRI

    Directory of Open Access Journals (Sweden)

    Simon Benjaminsson

    2010-08-01

    Full Text Available Non-parametric data-driven analysis techniques can be used to study datasets with few assumptions about the data and underlying experiment. Variations of Independent Component Analysis (ICA have been the methods mostly used on fMRI data, e.g. in finding resting-state networks thought to reflect the connectivity of the brain. Here we present a novel data analysis technique and demonstrate it on resting-state fMRI data. It is a generic method with few underlying assumptions about the data. The results are built from the statistical relations between all input voxels, resulting in a whole-brain analysis on a voxel level. It has good scalability properties and the parallel implementation is capable of handling large datasets and databases. From the mutual information between the activities of the voxels over time, a distance matrix is created for all voxels in the input space. Multidimensional scaling is used to put the voxels in a lower-dimensional space reflecting the dependency relations based on the distance matrix. By performing clustering in this space we can find the strong statistical regularities in the data, which for the resting-state data turns out to be the resting-state networks. The decomposition is performed in the last step of the algorithm and is computationally simple. This opens up for rapid analysis and visualization of the data on different spatial levels, as well as automatically finding a suitable number of decomposition components.

  4. Correlation Feature Selection and Mutual Information Theory Based Quantitative Research on Meteorological Impact Factors of Module Temperature for Solar Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Yujing Sun

    2016-12-01

    Full Text Available The module temperature is the most important parameter influencing the output power of solar photovoltaic (PV systems, aside from solar irradiance. In this paper, we focus on the interdisciplinary research that combines the correlation analysis, mutual information (MI and heat transfer theory, which aims to figure out the correlative relations between different meteorological impact factors (MIFs and PV module temperature from both quality and quantitative aspects. The identification and confirmation of primary MIFs of PV module temperature are investigated as the first step of this research from the perspective of physical meaning and mathematical analysis about electrical performance and thermal characteristic of PV modules based on PV effect and heat transfer theory. Furthermore, the quantitative description of the MIFs influence on PV module temperature is mathematically formulated as several indexes using correlation-based feature selection (CFS and MI theory to explore the specific impact degrees under four different typical weather statuses named general weather classes (GWCs. Case studies for the proposed methods were conducted using actual measurement data of a 500 kW grid-connected solar PV plant in China. The results not only verified the knowledge about the main MIFs of PV module temperatures, more importantly, but also provide the specific ratio of quantitative impact degrees of these three MIFs respectively through CFS and MI based measures under four different GWCs.

  5. Classification of brain signals associated with imagination of hand grasping, opening and reaching by means of wavelet-based common spatial pattern and mutual information.

    Science.gov (United States)

    Amanpour, Behzad; Erfanian, Abbas

    2013-01-01

    An important issue in designing a practical brain-computer interface (BCI) is the selection of mental tasks to be imagined. Different types of mental tasks have been used in BCI including left, right, foot, and tongue motor imageries. However, the mental tasks are different from the actions to be controlled by the BCI. It is desirable to select a mental task to be consistent with the desired action to be performed by BCI. In this paper, we investigated the detecting the imagination of the hand grasping, hand opening, and hand reaching in one hand using electroencephalographic (EEG) signals. The results show that the ERD/ERS patterns, associated with the imagination of hand grasping, opening, and reaching are different. For classification of brain signals associated with these mental tasks and feature extraction, a method based on wavelet packet, regularized common spatial pattern (CSP), and mutual information is proposed. The results of an offline analysis on five subjects show that the two-class mental tasks can be classified with an average accuracy of 77.6% using proposed method. In addition, we examine the proposed method on datasets IVa from BCI Competition III and IIa from BCI Competition IV.

  6. An Analysis of the Mutual Fund Industry: Mutual Fund Investors, Mutual Fund Managers and Mutual Fund Companies

    OpenAIRE

    Fang, Jieyan

    2012-01-01

    In this dissertation I investigate the mutual fund industry, especially the three most important participants within this industry: mutual fund investors, mutual fund companies and mutual fund managers. The main research questions of this dissertation are: 1. Does rapid trading exist among German equity mutual fund investors? What are the determinants of rapid trading? Does rapid trading have a negative impact on mutual fund performance? 2. Do mutual fund investors, as a whole, have...

  7. Mutual Fund Competition and Stock Market Liquidity

    OpenAIRE

    Massa, Massimo

    2004-01-01

    We study how competition in the mutual fund industry affects stock market liquidity. We argue that mutual fund families operate as multi-product firms, jointly choosing fees, performance and number of funds and sharing common research facilities. The family-based organization generates economies of scale in information that induce a trade off between performance and number of funds. The presence of more and relatively less-informed funds impacts the market, increasing stock liquidity. This in...

  8. Impaired precision, but normal retention, of auditory sensory ("echoic") memory information in schizophrenia.

    Science.gov (United States)

    Javitt, D C; Strous, R D; Grochowski, S; Ritter, W; Cowan, N

    1997-05-01

    Working memory is the type of memory that allows one to hold information in mind while working on a task or problem. The present study investigated attention-independent auditory sensory ("echoic") memory in 18 schizophrenic participants and 17 controls. Schizophrenic participants showed impaired delayed tone matching performance in comparison with controls. However, when groups were matched for performance at 1 s by varying the difficulty of the task across groups, schizophrenic participants showed normal retention of information as reflected in normal tone matching performance. These findings demonstrate that schizophrenic may be in the sensitivity of the system rather than the duration for which memory traces were retained.

  9. Harmonization versus Mutual Recognition

    DEFF Research Database (Denmark)

    Jørgensen, Jan Guldager; Schröder, Philipp

    The present paper examines trade liberalization driven by the coordination of product standards. For oligopolistic firms situated in separate markets that are initially sheltered by national standards, mutual recognition of standards implies entry and reduced profits at home paired with the oppor......The present paper examines trade liberalization driven by the coordination of product standards. For oligopolistic firms situated in separate markets that are initially sheltered by national standards, mutual recognition of standards implies entry and reduced profits at home paired...... countries and three firms, where firms first lobby for the policy coordination regime (harmonization versus mutual recognition), and subsequently, in case of harmonization, the global standard is auctioned among the firms. We discuss welfare effects and conclude with policy implications. In particular......, harmonized standards may fail to harvest the full pro-competitive effects from trade liberalization compared to mutual recognition; moreover, the issue is most pronounced in markets featuring price competition....

  10. Mutual information registration of multi-spectral and multi-resolution images of DigitalGlobe's WorldView-3 imaging satellite

    Science.gov (United States)

    Miecznik, Grzegorz; Shafer, Jeff; Baugh, William M.; Bader, Brett; Karspeck, Milan; Pacifici, Fabio

    2017-05-01

    WorldView-3 (WV-3) is a DigitalGlobe commercial, high resolution, push-broom imaging satellite with three instruments: visible and near-infrared VNIR consisting of panchromatic (0.3m nadir GSD) plus multi-spectral (1.2m), short-wave infrared SWIR (3.7m), and multi-spectral CAVIS (30m). Nine VNIR bands, which are on one instrument, are nearly perfectly registered to each other, whereas eight SWIR bands, belonging to the second instrument, are misaligned with respect to VNIR and to each other. Geometric calibration and ortho-rectification results in a VNIR/SWIR alignment which is accurate to approximately 0.75 SWIR pixel at 3.7m GSD, whereas inter-SWIR, band to band registration is 0.3 SWIR pixel. Numerous high resolution, spectral applications, such as object classification and material identification, require more accurate registration, which can be achieved by utilizing image processing algorithms, for example Mutual Information (MI). Although MI-based co-registration algorithms are highly accurate, implementation details for automated processing can be challenging. One particular challenge is how to compute bin widths of intensity histograms, which are fundamental building blocks of MI. We solve this problem by making the bin widths proportional to instrument shot noise. Next, we show how to take advantage of multiple VNIR bands, and improve registration sensitivity to image alignment. To meet this goal, we employ Canonical Correlation Analysis, which maximizes VNIR/SWIR correlation through an optimal linear combination of VNIR bands. Finally we explore how to register images corresponding to different spatial resolutions. We show that MI computed at a low-resolution grid is more sensitive to alignment parameters than MI computed at a high-resolution grid. The proposed modifications allow us to improve VNIR/SWIR registration to better than ¼ of a SWIR pixel, as long as terrain elevation is properly accounted for, and clouds and water are masked out.

  11. Evolution of mutualism between species

    Energy Technology Data Exchange (ETDEWEB)

    Post, W.M.; Travis, C.C.; DeAngelis, D.L.

    1980-01-01

    Recent theoretical work on mutualism, the interaction between species populations that is mutually beneficial, is reviewed. Several ecological facts that should be addressed in the construction of dynamic models for mutualism are examined. Basic terminology is clarified. (PSB)

  12. RMT Assessments of the Market Latent Information Embedded in the Stocks' Raw, Normalized, and Partial Correlations

    OpenAIRE

    Kenett, Dror Y.; Shapira, Yoash; Ben-Jacob, Eshel

    2009-01-01

    We present here assessment of the latent market information embedded in the raw, affinity (normalized), and partial correlations. We compared the Zipf plot, spectrum, and distribution of the eigenvalues for each matrix with the results of the corresponding random matrix. The analysis was performed on stocks belonging to the New York ...

  13. Evaluating accounting information systems that support multiple GAAP reporting using Normalized Systems Theory

    NARCIS (Netherlands)

    Vanhoof, E.; Huysmans, P.; Aerts, Walter; Verelst, J.; Aveiro, D.; Tribolet, J.; Gouveia, D.

    2014-01-01

    This paper uses a mixed methods approach of design science and case study research to evaluate structures of Accounting Information Systems (AIS) that report in multiple Generally Accepted Accounting Principles (GAAP), using Normalized Systems Theory (NST). To comply with regulation, many companies

  14. The Impact of Simultaneously Applying Normal Stress and Vibrotactile Stimulation for Feedback of Exteroceptive Information.

    Science.gov (United States)

    Reza Motamedi, M; Otis, Martin; Duchaine, Vincent

    2017-06-01

    Commercially available prosthetic hands do not convey any tactile information, forcing amputees to rely solely on visual attention. A promising solution to this problem is haptics, which could lead to new prostheses in which tactile information is conveyed between the amputee and the artificial limb. However, the haptic feedback must be optimized so that amputees can use it effectively; and although several studies have examined how specific haptic feedback systems can transmit certain types of tactile information, there has not yet been much research on the effects of superposing two or more types of feedback at the same location, which might prove to be more effective than using a single type of feedback alone. This paper investigates how the simultaneous application of two different types of haptic feedback-vibration and normal stress-impacts the human sensory perception of each separate feedback type. These stimuli were applied to glabrous skin on the forearms of 14 participants. Our experiments tested whether participants experienced more accurate sensory perception, compared to vibration or normal stress alone, when vibration was applied at the same time as the normal stress, at either the same location, or at a different location 6 cm away. Results indicate that although participants' perception of the normal stress diminished when vibration was applied at the same location, the same combination improved their perception of the vibration. Apparently, vibration has a negative impact upon the ability to perceive normal stress, whether applied at the same or a different location; whereas the opposite is true for the effect of normal stress upon the perception of vibration.

  15. Relationship between pre-reconstruction filter and accuracy of registration software based on mutual-information maximization. A study of SPECT-MR brain phantom images

    International Nuclear Information System (INIS)

    Mito, Suzuko; Magota, Keiichi; Arai, Hiroshi; Omote, Hidehiko; Katsuura, Hidenori; Suzuki, Kotaro; Kubo Naoki

    2005-01-01

    Image registration technique is becoming an increasingly important tool in SPECT. Recently, software based on mutual-information maximization has been developed for automatic multimodality image registration. The accuracy of the software is important for its application to image registration. During SPECT reconstruction, the projection data are pre-filtered in order to reduce Poisson noise, commonly using a Butterworth filter. We have investigated the dependence of the absolute accuracy of MRI-SPECT registration on the cut-off frequencies of a range of Butterworth filters. This study used a 3D Hoffman phantom (Model No. 9000, Data-spectrum Co.). For the reference volume, an magnetization prepared rapid gradient echo (MPRage) sequence was performed on a Vision MRI (Siemence, 1.5 T). For the floating volumes, SPECT data of a phantom including 99m Tc 85 kBq/mL were acquired by a GCA-9300 (Toshiba Medical Systems Co.). During SPECT, the orbito-meatal (OM) line of the phantom was tilted by 5 deg and 15 deg to mimic the incline of a patient's head. The projection data were pre-filtered with Butterworth filters (cut-off frequency varying between 0.24 to 0.94 cycles/cm in 0.02 steps, order 8). The automated registrations were performed using iNRT β version software (Nihon Medi. Co.) and the rotation angles of SPECT for registration were noted. In this study, the registrations of all SPECT data were successful. Graphs of registration rotation angles against cut-off frequencies were scattered and showed no correlation between the two. The registration rotation angles ranged with changing cut-off frequency from -0.4 deg to +3.8 deg at a 5 deg tilt and from +12.7 deg to +19.6 deg at a 15 deg tilt. The registration rotation angles showed variation even for slight differences in cut-off frequencies. The absolute errors were a few degrees for any cut-off frequency. Regardless of the cut-off frequency, automatic registration using this software provides similar results. (author)

  16. Downside Risk Timing by Mutual Funds

    OpenAIRE

    Bodnaruk, Andriy; Chokaev, Bekhan; Simonov, Andrei

    2015-01-01

    We study whether mutual funds systematically manage downside risk of their portfolios in ways that improve their performance. We find that actively managed mutual funds on average possess positive downside risk timing ability. Funds investing in large-cap and value stocks have stronger downside risk timing skills. Managers adjust funds’ downside risk exposure in response to macroeconomic information. The economic value of downside risk timing is comparable to that of market timing.

  17. Fisher information and asymptotic normality in system identification for quantum Markov chains

    International Nuclear Information System (INIS)

    Guta, Madalin

    2011-01-01

    This paper deals with the problem of estimating the coupling constant θ of a mixing quantum Markov chain. For a repeated measurement on the chain's output we show that the outcomes' time average has an asymptotically normal (Gaussian) distribution, and we give the explicit expressions of its mean and variance. In particular, we obtain a simple estimator of θ whose classical Fisher information can be optimized over different choices of measured observables. We then show that the quantum state of the output together with the system is itself asymptotically Gaussian and compute its quantum Fisher information, which sets an absolute bound to the estimation error. The classical and quantum Fisher information are compared in a simple example. In the vicinity of θ=0 we find that the quantum Fisher information has a quadratic rather than linear scaling in output size, and asymptotically the Fisher information is localized in the system, while the output is independent of the parameter.

  18. Danish mutual fund performance

    DEFF Research Database (Denmark)

    Christensen, Michael

    2013-01-01

    This article provides the first independent performance analysis of Danish mutual funds. We analyse selectivity and market timing abilities for 71 mutual funds that have been in operation from 2001 to 2010. The results show great fund performance diversity. Half the funds have performed neutrally......, whereas 42% of the funds have shown significantly negative performance and only 7% of the funds have over-performed their benchmark. Furthermore, 14% of the funds analysed possess market timing abilities, but for 8 out of 10 funds, their market timing ability has been unsuccessful....

  19. Mutually unbiased bases

    Indian Academy of Sciences (India)

    Mutually unbiased bases play an important role in quantum cryptography [2] and in the optimal determination of the density operator of an ensemble [3,4]. A density operator ρ in N-dimensions depends on N2 1 real quantities. With the help of MUB's, any such density operator can be encoded, in an optimal way, in terms of ...

  20. Comparing Sensory Information Processing and Alexithymia between People with Substance Dependency and Normal.

    Science.gov (United States)

    Bashapoor, Sajjad; Hosseini-Kiasari, Seyyedeh Tayebeh; Daneshvar, Somayeh; Kazemi-Taskooh, Zeinab

    2015-01-01

    Sensory information processing and alexithymia are two important factors in determining behavioral reactions. Some studies explain the effect of the sensitivity of sensory processing and alexithymia in the tendency to substance abuse. Giving that, the aim of the current study was to compare the styles of sensory information processing and alexithymia between substance-dependent people and normal ones. The research method was cross-sectional and the statistical population of the current study comprised of all substance-dependent men who are present in substance quitting camps of Masal, Iran, in October 2013 (n = 78). 36 persons were selected randomly by simple randomly sampling method from this population as the study group, and 36 persons were also selected among the normal population in the same way as the comparison group. Both groups was evaluated by using Toronto alexithymia scale (TAS) and adult sensory profile, and the multivariate analysis of variance (MANOVA) test was applied to analyze data. The results showed that there are significance differences between two groups in low registration (P processing and difficulty in describing emotions (P process sensory information in a different way than normal people and show more alexithymia features than them.

  1. RMT Assessments of the Market Latent Information Embedded in the Stocks' Raw, Normalized, and Partial Correlations

    Directory of Open Access Journals (Sweden)

    Dror Y. Kenett

    2009-01-01

    Full Text Available We present here assessment of the latent market information embedded in the raw, affinity (normalized, and partial correlations. We compared the Zipf plot, spectrum, and distribution of the eigenvalues for each matrix with the results of the corresponding random matrix. The analysis was performed on stocks belonging to the New York and Tel Aviv Stock Exchange, for the time period of January 2000 to March 2009. Our results show that in comparison to the raw correlations, the affinity matrices highlight the dominant factors of the system, and the partial correlation matrices contain more information. We propose that significant stock market information, which cannot be captured by the raw correlations, is embedded in the affinity and partial correlations. Our results further demonstrate the differences between NY and TA markets.

  2. Reconstruction of normal forms by learning informed observation geometries from data.

    Science.gov (United States)

    Yair, Or; Talmon, Ronen; Coifman, Ronald R; Kevrekidis, Ioannis G

    2017-09-19

    The discovery of physical laws consistent with empirical observations is at the heart of (applied) science and engineering. These laws typically take the form of nonlinear differential equations depending on parameters; dynamical systems theory provides, through the appropriate normal forms, an "intrinsic" prototypical characterization of the types of dynamical regimes accessible to a given model. Using an implementation of data-informed geometry learning, we directly reconstruct the relevant "normal forms": a quantitative mapping from empirical observations to prototypical realizations of the underlying dynamics. Interestingly, the state variables and the parameters of these realizations are inferred from the empirical observations; without prior knowledge or understanding, they parametrize the dynamics intrinsically without explicit reference to fundamental physical quantities.

  3. How to derive biological information from the value of the normalization constant in allometric equations.

    Science.gov (United States)

    Kaitaniemi, Pekka

    2008-04-09

    Allometric equations are widely used in many branches of biological science. The potential information content of the normalization constant b in allometric equations of the form Y = bX(a) has, however, remained largely neglected. To demonstrate the potential for utilizing this information, I generated a large number of artificial datasets that resembled those that are frequently encountered in biological studies, i.e., relatively small samples including measurement error or uncontrolled variation. The value of X was allowed to vary randomly within the limits describing different data ranges, and a was set to a fixed theoretical value. The constant b was set to a range of values describing the effect of a continuous environmental variable. In addition, a normally distributed random error was added to the values of both X and Y. Two different approaches were then used to model the data. The traditional approach estimated both a and b using a regression model, whereas an alternative approach set the exponent a at its theoretical value and only estimated the value of b. Both approaches produced virtually the same model fit with less than 0.3% difference in the coefficient of determination. Only the alternative approach was able to precisely reproduce the effect of the environmental variable, which was largely lost among noise variation when using the traditional approach. The results show how the value of b can be used as a source of valuable biological information if an appropriate regression model is selected.

  4. Kenya Economic Update, March 2016 : Kazi ni kazi - Informal Should Not Be Normal

    OpenAIRE

    World Bank Group

    2016-01-01

    This update comes in the wake of three game changing and mutually reinforcing trends. First, monetary policy in the United States (U.S.) will determine the direction of capital flows and currency stability. Second, the persistent decline in commodity prices will determine winners and losers and third, the cooling and rebalancing of the Chinese economy is likely to see a recalibration and c...

  5. [Implications of mental image processing in the deficits of verbal information coding during normal aging].

    Science.gov (United States)

    Plaie, Thierry; Thomas, Delphine

    2008-06-01

    Our study specifies the contributions of image generation and image maintenance processes occurring at the time of imaginal coding of verbal information in memory during normal aging. The memory capacities of 19 young adults (average age of 24 years) and 19 older adults (average age of 75 years) were assessed using recall tasks according to the imagery value of the stimuli to learn. The mental visual imagery capacities are assessed using tasks of image generation and temporary storage of mental imagery. The variance analysis indicates a more important decrease with age of the concretness effect. The major contribution of our study rests on the fact that the decline with age of dual coding of verbal information in memory would result primarily from the decline of image maintenance capacities and from a slowdown in image generation. (PsycINFO Database Record (c) 2008 APA, all rights reserved).

  6. Defense mutualisms enhance plant diversification.

    Science.gov (United States)

    Weber, Marjorie G; Agrawal, Anurag A

    2014-11-18

    The ability of plants to form mutualistic relationships with animal defenders has long been suspected to influence their evolutionary success, both by decreasing extinction risk and by increasing opportunity for speciation through an expanded realized niche. Nonetheless, the hypothesis that defense mutualisms consistently enhance plant diversification across lineages has not been well tested due to a lack of phenotypic and phylogenetic information. Using a global analysis, we show that the >100 vascular plant families in which species have evolved extrafloral nectaries (EFNs), sugar-secreting organs that recruit arthropod mutualists, have twofold higher diversification rates than families that lack species with EFNs. Zooming in on six distantly related plant clades, trait-dependent diversification models confirmed the tendency for lineages with EFNs to display increased rates of diversification. These results were consistent across methodological approaches. Inference using reversible-jump Markov chain Monte Carlo (MCMC) to model the placement and number of rate shifts revealed that high net diversification rates in EFN clades were driven by an increased number of positive rate shifts following EFN evolution compared with sister clades, suggesting that EFNs may be indirect facilitators of diversification. Our replicated analysis indicates that defense mutualisms put lineages on a path toward increased diversification rates within and between clades, and is concordant with the hypothesis that mutualistic interactions with animals can have an impact on deep macroevolutionary patterns and enhance plant diversity.

  7. 100% classification accuracy considered harmful: the normalized information transfer factor explains the accuracy paradox.

    Directory of Open Access Journals (Sweden)

    Francisco J Valverde-Albacete

    Full Text Available The most widely spread measure of performance, accuracy, suffers from a paradox: predictive models with a given level of accuracy may have greater predictive power than models with higher accuracy. Despite optimizing classification error rate, high accuracy models may fail to capture crucial information transfer in the classification task. We present evidence of this behavior by means of a combinatorial analysis where every possible contingency matrix of 2, 3 and 4 classes classifiers are depicted on the entropy triangle, a more reliable information-theoretic tool for classification assessment. Motivated by this, we develop from first principles a measure of classification performance that takes into consideration the information learned by classifiers. We are then able to obtain the entropy-modulated accuracy (EMA, a pessimistic estimate of the expected accuracy with the influence of the input distribution factored out, and the normalized information transfer factor (NIT, a measure of how efficient is the transmission of information from the input to the output set of classes. The EMA is a more natural measure of classification performance than accuracy when the heuristic to maximize is the transfer of information through the classifier instead of classification error count. The NIT factor measures the effectiveness of the learning process in classifiers and also makes it harder for them to "cheat" using techniques like specialization, while also promoting the interpretability of results. Their use is demonstrated in a mind reading task competition that aims at decoding the identity of a video stimulus based on magnetoencephalography recordings. We show how the EMA and the NIT factor reject rankings based in accuracy, choosing more meaningful and interpretable classifiers.

  8. Learning weighted sparse representation of encoded facial normal information for expression-robust 3D face recognition

    KAUST Repository

    Li, Huibin

    2011-10-01

    This paper proposes a novel approach for 3D face recognition by learning weighted sparse representation of encoded facial normal information. To comprehensively describe 3D facial surface, three components, in X, Y, and Z-plane respectively, of normal vector are encoded locally to their corresponding normal pattern histograms. They are finally fed to a sparse representation classifier enhanced by learning based spatial weights. Experimental results achieved on the FRGC v2.0 database prove that the proposed encoded normal information is much more discriminative than original normal information. Moreover, the patch based weights learned using the FRGC v1.0 and Bosphorus datasets also demonstrate the importance of each facial physical component for 3D face recognition. © 2011 IEEE.

  9. Mutual aid fund commission

    CERN Multimedia

    Staff Association

    2011-01-01

    The composition of the Board of the Mutual Aid Fund for 2011 is as follows: President: Pascal Droux Vice-president: Connie Potter Treasurer: Louis Pereira Deputy treasurer: Barbara Brugger Secretary: Sonia Casenove Deputy secretary: Isabelle Mardirossian Members: Christopher David Thomas   Jean-Claude Vialis (GAC member)   Marie-Luce Falipou   Gunilla Santiard (Jean-Claude Vialis’s alternate) The role of the Fund is to provide financial help to members of personnel and beneficiaries of the Pension Fund who are in need of exceptional financial assistance. All requests are treated in the strictest confidence. Should you wish to apply for aid from the Fund, kindly contact any member of the Board as given above or Social Services, tel.74479 – 73867.

  10. Learning weighted sparse representation of encoded facial normal information for expression-robust 3D face recognition

    KAUST Repository

    Li, Huibin; Di, Huang; Morvan, Jean-Marie; Chen, Liming

    2011-01-01

    This paper proposes a novel approach for 3D face recognition by learning weighted sparse representation of encoded facial normal information. To comprehensively describe 3D facial surface, three components, in X, Y, and Z-plane respectively

  11. Mutual capacitor and its applications

    Directory of Open Access Journals (Sweden)

    Chun Li

    2014-06-01

    Full Text Available This study presents a new ac circuit element – the mutual capacitor, being a dual of the mutual inductor, which is also a new ac transformer. This element is characteristic of the mutual-capacitance coupling of a multi-capacitance system. A unity-coupled mutual capacitor works as an ideal current or voltage transformer, and incidentally acts as waveform separating when inductor employed or waveform converting from square-wave to quasi-sine or waveform filtering, between ports. As a transformer, the mutual capacitor is easy to design, easy for heat cooling, more accurate for current or voltage transformation, dissipating less energy as well as saving materials, suitable for high-power and high-voltage applications. Experiments to demonstrate performances of unity-coupled mutual capacitors are also given.

  12. Subcategory learning in normal and language learning-disabled adults: how much information do they need?

    Science.gov (United States)

    Richardson, Jessica; Harris, Laurel; Plante, Elena; Gerken, Louann

    2006-12-01

    The purpose of this experiment was to determine if nonreferential morphophonological information was sufficient to facilitate the learning of gender subcategories (i.e., masculine vs. feminine) in individuals with normal language (NL) and those with a history of language-based learning disabilities (HLD). Thirty-two adults listened for 18 min to a familiarization set of Russian words that included either 1 (single-marked) or 2 (double-marked) morphophonological markers indicating gender. Participants were then tested on their knowledge of both trained and untrained members of each gender subcategory. Testing indicated that morphophonological information is sufficient for lexical subcategory learning in both NL and HLD groups, although the HLD group had lower overall accuracy. The HLD group benefited from double-marking relative to single-marking for subcategory learning. The results demonstrated that learning through implicit mechanisms occurred after a relatively brief exposure to the language stimuli. In addition, the weaker overall learning by the HLD group was facilitated when multiple cues to linguistic subcategory were available in the input group members received.

  13. Information processing in micro and meso-scale neural circuits during normal and disease states

    Science.gov (United States)

    Luongo, Francisco

    Neural computation can occur at multiple spatial and temporal timescales. The sum total of all of these processes is to guide optimal behaviors within the context of the constraints imposed by the physical world. How the circuits of the brain achieves this goal represents a central question in systems neuroscience. Here I explore the many ways in which the circuits of the brain can process information at both the micro and meso scale. Understanding the way information is represented and processed in the brain could shed light on the neuropathology underlying complex neuropsychiatric diseases such as autism and schizophrenia. Chapter 2 establishes an experimental paradigm for assaying patterns of microcircuit activity and examines the role of dopaminergic modulation on prefrontal microcircuits. We find that dopamine type 2 (D2) receptor activation results in an increase in spontaneous activity while dopamine type 1 (D1) activation does not. Chapter 3 of this dissertation presents a study that illustrates how cholingergic activation normally produces what has been suggested as a neural substrate of attention; pairwise decorrelation in microcircuit activity. This study also shows that in two etiologicall distinct mouse models of autism, FMR1 knockout mice and Valproic Acid exposed mice, this ability to decorrelate in the presence of cholinergic activation is lost. This represents a putative microcircuit level biomarker of autism. Chapter 4 examines the structure/function relationship within the prefrontal microcircuit. Spontaneous activity in prefrontal microcircuits is shown to be organized according to a small world architecture. Interestingly, this architecture is important for one concrete function of neuronal microcircuits; the ability to produce temporally stereotyped patterns of activation. In the final chapter, we identify subnetworks in chronic intracranial electrocorticographic (ECoG) recordings using pairwise electrode coherence and dimensionality reduction

  14. 26 CFR 1.831-1 - Tax on insurance companies (other than life or mutual), mutual marine insurance companies, and...

    Science.gov (United States)

    2010-04-01

    ... mutual), mutual marine insurance companies, and mutual fire insurance companies issuing perpetual... companies (other than life or mutual), mutual marine insurance companies, and mutual fire insurance... insurance companies and mutual fire insurance companies exclusively issuing either perpetual policies, or...

  15. MR guided spatial normalization of SPECT scans

    International Nuclear Information System (INIS)

    Crouch, B.; Barnden, L.R.; Kwiatek, R.

    2010-01-01

    Full text: In SPECT population studies where magnetic resonance (MR) scans are also available, the higher resolution of the MR scans allows for an improved spatial normalization of the SPECT scans. In this approach, the SPECT images are first coregistered to their corresponding MR images by a linear (affine) transformation which is calculated using SPM's mutual information maximization algorithm. Non-linear spatial normalization maps are then computed either directly from the MR scans using SPM's built in spatial normalization algorithm, or, from segmented TI MR images using DARTEL, an advanced diffeomorphism based spatial normalization algorithm. We compare these MR based methods to standard SPECT based spatial normalization for a population of 27 fibromyalgia patients and 25 healthy controls with spin echo T 1 scans. We identify significant perfusion deficits in prefrontal white matter in FM patients, with the DARTEL based spatial normalization procedure yielding stronger statistics than the standard SPECT based spatial normalization. (author)

  16. 26 CFR 1.831-3 - Tax on insurance companies (other than life or mutual), mutual marine insurance companies, mutual...

    Science.gov (United States)

    2010-04-01

    ... mutual), mutual marine insurance companies, mutual fire insurance companies issuing perpetual policies, and mutual fire or flood insurance companies operating on the basis of premium deposits; taxable years... fire insurance companies issuing perpetual policies, and mutual fire or flood insurance companies...

  17. Strategy as Mutually Contingent Choice

    Directory of Open Access Journals (Sweden)

    Neil Martin

    2016-05-01

    Full Text Available Thomas Schelling’s The Strategy of Conflict carries significant behavioral implications which have been overlooked by economic readers. I argue that these implications are central to Schelling’s vision of game theory, that they fit well with recent advances in experimental psychology and behavioral economics, and provide a comprehensive framework that can inform research on strategy. In my view, Schelling develops a non-mathematical approach to strategy which anticipates on Gigerenzer and Selten’s “ecological rationality” program. This approach maps the processes involved in strategic reasoning and highlights their reliance on the particular information structure of interactive social environments. Building on this approach, I model strategy as a heuristic form of reasoning that governs the way in which individuals search for and provide cues in situations of mutually contingent choice. I conclude by examining how the reference to ecological rationality can help clarify Schelling’s contribution to game theory and outline potential avenues of research into strategic reasoning and interaction.

  18. Non-local correlations via Wigner-Yanase skew information in two SC-qubit having mutual interaction under phase decoherence

    Science.gov (United States)

    Mohamed, Abdel-Baset A.

    2017-10-01

    An analytical solution of the master equation that describes a superconducting cavity containing two coupled superconducting charge qubits is obtained. Quantum-mechanical correlations based on Wigner-Yanase skew information, as local quantum uncertainty and uncertainty-induced quantum non-locality, are compared to the concurrence under the effects of the phase decoherence. Local quantum uncertainty exhibits sudden changes during its time evolution and revival process. Sudden death and sudden birth occur only for entanglement, depending on the initial state of the two coupled charge qubits, while the correlations of skew information does not vanish. The quantum correlations of skew information are found to be sensitive to the dephasing rate, the photons number in the cavity, the interaction strength between the two qubits, and the qubit distribution angle of the initial state. With a proper initial state, the stationary correlation of the skew information has a non-zero stationary value for a long time interval under the phase decoherence, that it may be useful in quantum information and computation processes.

  19. Normalization to specific gravity prior to analysis improves information recovery from high resolution mass spectrometry metabolomic profiles of human urine.

    Science.gov (United States)

    Edmands, William M B; Ferrari, Pietro; Scalbert, Augustin

    2014-11-04

    Extraction of meaningful biological information from urinary metabolomic profiles obtained by liquid-chromatography coupled to mass spectrometry (MS) necessitates the control of unwanted sources of variability associated with large differences in urine sample concentrations. Different methods of normalization either before analysis (preacquisition normalization) through dilution of urine samples to the lowest specific gravity measured by refractometry, or after analysis (postacquisition normalization) to urine volume, specific gravity and median fold change are compared for their capacity to recover lead metabolites for a potential future use as dietary biomarkers. Twenty-four urine samples of 19 subjects from the European Prospective Investigation into Cancer and nutrition (EPIC) cohort were selected based on their high and low/nonconsumption of six polyphenol-rich foods as assessed with a 24 h dietary recall. MS features selected on the basis of minimum discriminant selection criteria were related to each dietary item by means of orthogonal partial least-squares discriminant analysis models. Normalization methods ranked in the following decreasing order when comparing the number of total discriminant MS features recovered to that obtained in the absence of normalization: preacquisition normalization to specific gravity (4.2-fold), postacquisition normalization to specific gravity (2.3-fold), postacquisition median fold change normalization (1.8-fold increase), postacquisition normalization to urinary volume (0.79-fold). A preventative preacquisition normalization based on urine specific gravity was found to be superior to all curative postacquisition normalization methods tested for discovery of MS features discriminant of dietary intake in these urinary metabolomic datasets.

  20. A configuration space of homologous proteins conserving mutual information and allowing a phylogeny inference based on pair-wise Z-score probabilities

    OpenAIRE

    Maréchal Eric; Ortet Philippe; Roy Sylvaine; Bastien Olivier

    2005-01-01

    Abstract Background Popular methods to reconstruct molecular phylogenies are based on multiple sequence alignments, in which addition or removal of data may change the resulting tree topology. We have sought a representation of homologous proteins that would conserve the information of pair-wise sequence alignments, respect probabilistic properties of Z-scores (Monte Carlo methods applied to pair-wise comparisons) and be the basis for a novel method of consistent and stable phylogenetic recon...

  1. Revisiting Mutual Fund Performance Evaluation

    OpenAIRE

    Angelidis, Timotheos; Giamouridis, Daniel; Tessaromatis, Nikolaos

    2012-01-01

    Mutual fund manager excess performance should be measured relative to their self-reported benchmark rather than the return of a passive portfolio with the same risk characteristics. Ignoring the self-reported benchmark introduces biases in the measurement of stock selection and timing components of excess performance. We revisit baseline empirical evidence in mutual fund performance evaluation utilizing stock selection and timing measures that address these biases. We introduce a new factor e...

  2. Rate of Visual Information Pick-Up in Learning Disabled and Normal Boys.

    Science.gov (United States)

    Bryant, Susan K.; And Others

    1983-01-01

    A span-of-apprehension task and a backward masking technique were combined to allow measurement of the apprehension span of a sample of 34 learning disabled and normal boys about 8 to 13 years old at various time intervals following stimulus presentation. (Author/SW)

  3. Entanglement in mutually unbiased bases

    Energy Technology Data Exchange (ETDEWEB)

    Wiesniak, M; Zeilinger, A [Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna (Austria); Paterek, T, E-mail: tomasz.paterek@nus.edu.sg [Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore (Singapore)

    2011-05-15

    One of the essential features of quantum mechanics is that most pairs of observables cannot be measured simultaneously. This phenomenon manifests itself most strongly when observables are related to mutually unbiased bases. In this paper, we shed some light on the connection between mutually unbiased bases and another essential feature of quantum mechanics, quantum entanglement. It is shown that a complete set of mutually unbiased bases of a bipartite system contains a fixed amount of entanglement, independent of the choice of the set. This has implications for entanglement distribution among the states of a complete set. In prime-squared dimensions we present an explicit experiment-friendly construction of a complete set with a particularly simple entanglement distribution. Finally, we describe the basic properties of mutually unbiased bases composed of product states only. The constructions are illustrated with explicit examples in low dimensions. We believe that the properties of entanglement in mutually unbiased bases may be one of the ingredients to be taken into account to settle the question of the existence of complete sets. We also expect that they will be relevant to applications of bases in the experimental realization of quantum protocols in higher-dimensional Hilbert spaces.

  4. Mutual emergency assistance for radiation accidents

    International Nuclear Information System (INIS)

    1983-03-01

    A revised document on ''Mutual Emergency Assistance for Radiation Accidents'' jointly prepared by the Agency with the participation of the World Health Organization (WHO), the Food and Agricultural Organization of the United Nations (FAO), the International Labour Organisation (ILO) and the Office of the United Nations Disaster Relief Co-ordinator (UNDRO) was issued in 1980 as TECDOC-237. The present document lists the additional information received after publication of the 1980 edition and is issued as a Supplement to TECDOC-237 (1980 Edition). Some useful information contained in TECDOC-237 such as the IAEA arrangement and the WHO Collaborating Centres for Radiation Emergency Assistance are reprinted for ready reference

  5. Predicting RNA Structure Using Mutual Information

    DEFF Research Database (Denmark)

    Freyhult, E.; Moulton, V.; Gardner, P. P.

    2005-01-01

    , to display and predict conserved RNA secondary structure (including pseudoknots) from an alignment. Results: We show that MIfold can be used to predict simple pseudoknots, and that the performance can be adjusted to make it either more sensitive or more selective. We also demonstrate that the overall...... package. Conclusion: MIfold provides a useful supplementary tool to programs such as RNA Structure Logo, RNAalifold and COVE, and should be useful for automatically generating structural predictions for databases such as Rfam. Availability: MIfold is freely available from http......Background: With the ever-increasing number of sequenced RNAs and the establishment of new RNA databases, such as the Comparative RNA Web Site and Rfam, there is a growing need for accurately and automatically predicting RNA structures from multiple alignments. Since RNA secondary structure...

  6. Alignment by Maximization of Mutual Information

    Science.gov (United States)

    1995-06-01

    me how truly valuable unconditional support can be. Students are the AI lab’s most precious resource and I benefited from discussions with Phil Agre...to analyze these problems is purely convenience. There is nothing random about these problems once the samples are drawn. One of the benefits of...To provide further intuition regarding the behavior of ECA we have run ECA, PCA, and two related procedures BCM and BINGO on the same density. BCM

  7. Estimating Mutual Information by Local Gaussian Approximation

    Science.gov (United States)

    2015-07-13

    proposed a variety of methods to overcome the bias, such as the reflection method (Schuster, 1985), ( Silverman , 1986); the boundary kernel method...Stephen Marron and David Ruppert. Transformations to reduce boundary bias in kernel density estimation. Journal of the Royal Statistical Society. Series B...estimation with applications to machine learning on distributions. In Proceedings of Uncertainty in Artificial In- telligence (UAI), 2011. David N Reshef

  8. Compton scattering spectrum as a source of information of normal and neoplastic breast tissues' composition

    Energy Technology Data Exchange (ETDEWEB)

    Antoniassi, M.; Conceicao, A.L.C. [Departamento de Fisica-Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, 14040-901 Sao Paulo (Brazil); Poletti, M.E., E-mail: poletti@ffclrp.usp.br [Departamento de Fisica-Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, 14040-901 Sao Paulo (Brazil)

    2012-07-15

    In this work we measured X-ray scatter spectra from normal and neoplastic breast tissues using photon energy of 17.44 keV and a scattering angle of 90 Degree-Sign , in order to study the shape (FWHM) of the Compton peaks. The obtained results for FWHM were discussed in terms of composition and histological characteristics of each tissue type. The statistical analysis shows that the distribution of FWHM of normal adipose breast tissue clearly differs from all other investigated tissues. Comparison between experimental values of FWHM and effective atomic number revealed a strong correlation between them, showing that the FWHM values can be used to provide information about elemental composition of the tissues. - Highlights: Black-Right-Pointing-Pointer X-ray scatter spectra from normal and neoplastic breast tissues were measured. Black-Right-Pointing-Pointer Shape (FWHM) of Compton peak was related with elemental composition and characteristics of each tissue type. Black-Right-Pointing-Pointer A statistical hypothesis test showed clear differences between normal and neoplastic breast tissues. Black-Right-Pointing-Pointer There is a strong correlation between experimental values of FWHM and effective atomic number. Black-Right-Pointing-Pointer Shape (FWHM) of Compton peak can be used to provide information about elemental composition of the tissues.

  9. Improved inference in the evaluation of mutual fund performance using panel bootstrap methods

    OpenAIRE

    Blake, David; Caulfield, Tristan; Ioannidis, Christos; Tonks, I P

    2014-01-01

    Two new methodologies are introduced to improve inference in the evaluation of mutual fund performance against benchmarks. First, the benchmark models are estimated using panel methods with both fund and time effects. Second, the non-normality of individual mutual fund returns is accounted for by using panel bootstrap methods. We also augment the standard benchmark factors with fund-specific characteristics, such as fund size. Using a dataset of UK equity mutual fund returns, we find that fun...

  10. Mutual Recogniton of Professional Qualifications

    DEFF Research Database (Denmark)

    Enemark, Stig; Plimmer, Francis

    The publication aims to review the concept of mutual recognition of qualifications within the world wide surveying community, and to develop a framework for the introduction of standards of global professional competence in this area. The publication also includes a number of case studies from...

  11. The evolution of mutual ornamentation

    NARCIS (Netherlands)

    Kraaijeveld, Ken; Kraaijeveld-Smit, Femmie J. L.; Komdeur, Jan

    2007-01-01

    Many conspicuous ornamental traits in animals are expressed in both males and females. Despite this, most research has focused on sexually dimorphic ornamentation. Mutual ornamentation has often been viewed as a result of either a nonadaptive genetic correlation between the sexes or similar

  12. The Mutual Storytelling Writing Game.

    Science.gov (United States)

    Scorzelli, James F.; Gold, Julie

    1999-01-01

    Because of differences in cultural backgrounds and learning styles, some children have a difficult time verbalizing their emotions or appear resistant to talking about themselves. Describes a technique, referred to as the mutual storytelling writing game, that has been found to be useful for children who have difficulty in engaging in traditional…

  13. An implementation of mutual inclusion

    NARCIS (Netherlands)

    Hoogerwoord, R.R.

    1986-01-01

    We consider the parallel composition of two cyclic programs. The interaction of these programs consists of a form of synchronisation sometimes referred to as ‘mutual inclusion’. For a given implementation of this synchronisation by means of semaphore operations, we prove the correctness of the

  14. Feature Selection Based on Mutual Correlation

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Somol, Petr; Ververidis, D.; Kotropoulos, C.

    2006-01-01

    Roč. 19, č. 4225 (2006), s. 569-577 ISSN 0302-9743. [Iberoamerican Congress on Pattern Recognition. CIARP 2006 /11./. Cancun, 14.11.2006-17.11.2006] R&D Projects: GA AV ČR 1ET400750407; GA MŠk 1M0572; GA AV ČR IAA2075302 EU Projects: European Commission(XE) 507752 - MUSCLE Institutional research plan: CEZ:AV0Z10750506 Keywords : feature selection Subject RIV: BD - Theory of Information Impact factor: 0.402, year: 2005 http://library.utia.cas.cz/separaty/historie/haindl-feature selection based on mutual correlation.pdf

  15. Motor thalamus integration of cortical, cerebellar and basal ganglia information: implications for normal and parkinsonian conditions

    Directory of Open Access Journals (Sweden)

    Clémentine eBosch-Bouju

    2013-11-01

    Full Text Available Motor thalamus (Mthal is implicated in the control of movement because it is strategically located between motor areas of the cerebral cortex and motor-related subcortical structures, such as the cerebellum and basal ganglia (BG. The role of BG and cerebellum in motor control has been extensively studied but how Mthal processes inputs from these two networks is unclear. Specifically, there is considerable debate about the role of BG inputs on Mthal activity. This review summarises anatomical and physiological knowledge of the Mthal and its afferents and reviews current theories of Mthal function by discussing the impact of cortical, BG and cerebellar inputs on Mthal activity. One view is that Mthal activity in BG and cerebellar-receiving territories is primarily driven by glutamatergic inputs from the cortex or cerebellum, respectively, whereas BG inputs are modulatory and do not strongly determine Mthal activity. This theory is steeped in the assumption that the Mthal processes information in the same way as sensory thalamus, through interactions of modulatory inputs with a single driver input. Another view, from BG models, is that BG exert primary control on the BG-receiving Mthal so it effectively relays information from BG to cortex. We propose a new super-integrator theory where each Mthal territory processes multiple driver or driver-like inputs (cortex and BG, cortex and cerebellum, which are the result of considerable integrative processing. Thus, BG and cerebellar Mthal territories assimilate motivational and proprioceptive motor information previously integrated in cortico-BG and cortico-cerebellar networks, respectively, to develop sophisticated motor signals that are transmitted in parallel pathways to cortical areas for optimal generation of motor programmes. Finally, we briefly review the pathophysiological changes that occur in the BG in parkinsonism and generate testable hypotheses about how these may affect processing of inputs

  16. Evidence-informed obstetric practice during normal birth in China: trends and influences in four hospitals

    Directory of Open Access Journals (Sweden)

    Liang Ji

    2006-03-01

    Full Text Available Abstract Background A variety of international organizations, professional groups and individuals are promoting evidence-informed obstetric care in China. We measured change in obstetric practice during vaginal delivery that could be attributed to the diffusion of evidence-based messages, and explored influences on practice change. Methods Sample surveys of women at postnatal discharge in three government hospitals in Shanghai and one in neighbouring Jiangsu province carried out in 1999, repeated in 2003, and compared. Main outcome measures were changes in obstetric practice and influences on provider behaviour. "Routine practice" was defined as more than 65% of vaginal births. Semi-structured interviews with doctors explored influences on practice. Results In 1999, episiotomy was routine at all four hospitals; pubic shaving, rectal examination (to monitor labour and electronic fetal heart monitoring were routine at three hospitals; and enema on admission was common at one hospital. In 2003, episiotomy rates remained high at all hospitals, and actually significantly increased at one; pubic shaving was less common at one hospital; one hospital stopped rectal examination for monitoring labour, and the one hospital where enemas were common stopped this practice. Mobility during labour increased in three hospitals. Continuous support was variable between hospitals at baseline and showed no change with the 2003 survey. Provider behaviour was mainly influenced by international best practice standards promoted by hospital directors, and national legislation about clinical practice. Conclusion Obstetric practice became more evidence-informed in this selected group of hospitals in China. Change was not directly related to the promotion of evidence-based practice in the region. Hospital directors and national legislation seem to be particularly important influences on provider behaviour at the hospital level.

  17. A neural network model of normal and abnormal auditory information processing.

    Science.gov (United States)

    Du, X; Jansen, B H

    2011-08-01

    The ability of the brain to attenuate the response to irrelevant sensory stimulation is referred to as sensory gating. A gating deficiency has been reported in schizophrenia. To study the neural mechanisms underlying sensory gating, a neuroanatomically inspired model of auditory information processing has been developed. The mathematical model consists of lumped parameter modules representing the thalamus (TH), the thalamic reticular nucleus (TRN), auditory cortex (AC), and prefrontal cortex (PC). It was found that the membrane potential of the pyramidal cells in the PC module replicated auditory evoked potentials, recorded from the scalp of healthy individuals, in response to pure tones. Also, the model produced substantial attenuation of the response to the second of a pair of identical stimuli, just as seen in actual human experiments. We also tested the viewpoint that schizophrenia is associated with a deficit in prefrontal dopamine (DA) activity, which would lower the excitatory and inhibitory feedback gains in the AC and PC modules. Lowering these gains by less than 10% resulted in model behavior resembling the brain activity seen in schizophrenia patients, and replicated the reported gating deficits. The model suggests that the TRN plays a critical role in sensory gating, with the smaller response to a second tone arising from a reduction in inhibition of TH by the TRN. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Modelling nutritional mutualisms: challenges and opportunities for data integration.

    Science.gov (United States)

    Clark, Teresa J; Friel, Colleen A; Grman, Emily; Shachar-Hill, Yair; Friesen, Maren L

    2017-09-01

    Nutritional mutualisms are ancient, widespread, and profoundly influential in biological communities and ecosystems. Although much is known about these interactions, comprehensive answers to fundamental questions, such as how resource availability and structured interactions influence mutualism persistence, are still lacking. Mathematical modelling of nutritional mutualisms has great potential to facilitate the search for comprehensive answers to these and other fundamental questions by connecting the physiological and genomic underpinnings of mutualisms with ecological and evolutionary processes. In particular, when integrated with empirical data, models enable understanding of underlying mechanisms and generalisation of principles beyond the particulars of a given system. Here, we demonstrate how mathematical models can be integrated with data to address questions of mutualism persistence at four biological scales: cell, individual, population, and community. We highlight select studies where data has been or could be integrated with models to either inform model structure or test model predictions. We also point out opportunities to increase model rigour through tighter integration with data, and describe areas in which data is urgently needed. We focus on plant-microbe systems, for which a wealth of empirical data is available, but the principles and approaches can be generally applied to any nutritional mutualism. © 2017 John Wiley & Sons Ltd/CNRS.

  19. Benefit and cost curves for typical pollination mutualisms.

    Science.gov (United States)

    Morris, William F; Vázquez, Diego P; Chacoff, Natacha P

    2010-05-01

    Mutualisms provide benefits to interacting species, but they also involve costs. If costs come to exceed benefits as population density or the frequency of encounters between species increases, the interaction will no longer be mutualistic. Thus curves that represent benefits and costs as functions of interaction frequency are important tools for predicting when a mutualism will tip over into antagonism. Currently, most of what we know about benefit and cost curves in pollination mutualisms comes from highly specialized pollinating seed-consumer mutualisms, such as the yucca moth-yucca interaction. There, benefits to female reproduction saturate as the number of visits to a flower increases (because the amount of pollen needed to fertilize all the flower's ovules is finite), but costs continue to increase (because pollinator offspring consume developing seeds), leading to a peak in seed production at an intermediate number of visits. But for most plant-pollinator mutualisms, costs to the plant are more subtle than consumption of seeds, and how such costs scale with interaction frequency remains largely unknown. Here, we present reasonable benefit and cost curves that are appropriate for typical pollinator-plant interactions, and we show how they can result in a wide diversity of relationships between net benefit (benefit minus cost) and interaction frequency. We then use maximum-likelihood methods to fit net-benefit curves to measures of female reproductive success for three typical pollination mutualisms from two continents, and for each system we chose the most parsimonious model using information-criterion statistics. We discuss the implications of the shape of the net-benefit curve for the ecology and evolution of plant-pollinator mutualisms, as well as the challenges that lie ahead for disentangling the underlying benefit and cost curves for typical pollination mutualisms.

  20. Mutuality in the provision of Scottish healthcare.

    Science.gov (United States)

    Howieson, Brian

    2015-11-01

    The backdrop to this article is provided by the Better Health, Better Care Action Plan (Scottish Government, 2007), Section 1 of which is entitled 'Towards a Mutual NHS'. According to Better Health, Better Care (Scottish Government, 2007: 5): 'Mutual organisations are designed to serve their members. They are designed to gather people around a common sense of purpose. They are designed to bring the organisation together in what people often call "co-production."' The aim of this article is to précis the current knowledge of mutuality in the provision of Scottish healthcare. In detail, it will: introduce the 'mutual' organisation; offer a historical perspective of mutuality; suggest why healthcare mutuality is important; and briefly, detail the differences in mutual health-care policy in England and Scotland. It is hoped that this analysis will help researchers and practitioners alike appreciate further the philosophy of mutuality in the provision of Scottish healthcare. © The Author(s) 2015.

  1. Mutual funds: temporary problem or permanent morass?

    OpenAIRE

    Paula A. Tkac

    2004-01-01

    The improprieties in the mutual fund industry that surfaced in the fall of 2003 prompted the passage and drafting of legislation and regulations that cover nearly every facet of mutual fund pricing and operations. While this regulatory flurry is clearly intended to protect shareholders’ interests, the question remains: How will these scandals and regulatory changes ultimately affect mutual fund investors? ; When considering the problems inherent in mutual fund management and the best ways to ...

  2. Comparison of investment opportunities in mutual funds

    OpenAIRE

    NOVÁKOVÁ, Petra

    2012-01-01

    This thesis deals with the comparison of selected mutual funds in the Czech Republic. The main aim of this thesis is to evaluate the situation on the securities market of mutual funds and help to the investor with right choice of mutual fund. Work is initially devoted to the characteristics and history of collective investment. The following section describes mutual funds their characteristics, classification, creation and termination. Conclusion of the theoretical part is devoted to investme...

  3. External Monitoring and Dynamic Behavior in Mutual Funds

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2016-01-01

    Full Text Available This paper studies the impact of external monitoring on the behavior in mutual funds. Specifically, we investigate how and why external monitoring can alleviate contracting inefficiency caused by information asymmetry between investors and the manager. It is shown that efficiency loss emerges when investors contract with the manager just relying on her investment return history. The establishment of external monitoring that provides investors more information about the manager’s ability can improve contracting efficiency, which converges to first-best as external monitoring strengthens. These results provide strong support for tightening supervision in mutual fund industry.

  4. Implementation of mutual exclusion in VHDL

    NARCIS (Netherlands)

    Boersma, M.V.; Benders, L.P.M.; Stevens, M.P.J.; Wilsey, P.A.; Rhodes, D.

    1994-01-01

    In VHDL it is difficult to implement mutual exclusion at an abstract level since atomic actions are required. A local status model and an arbiter model are presented to achieve mutual exclusion in VHDL. Shared data, protected by a mutual exclusion mechanism, cannot be modelled as a simple, resolved

  5. Mandatory portfolio disclosure, stock liquidity, and mutual fund performance

    OpenAIRE

    Agarwal, Vikas; Mullally, Kevin Andrew; Tang, Yuehua; Yang, Baozhong

    2014-01-01

    We examine the impact of mandatory portfolio disclosure by mutual funds on stock liquidity and fund performance. We develop a model of informed trading with disclosure and test its predictions using the SEC regulation in May 2004 requiring more frequent disclosure. Stocks with higher fund ownership, especially those held by more informed funds or subject to greater information asymmetry, experience larger increases in liquidity after the regulation change. More informed funds, especially thos...

  6. Comparison of the performance of Islamic, Sri and green mutual funds

    OpenAIRE

    Paradinovic, Ivana

    2017-01-01

    This paper measures and compares performance of Islamic, SRI and Green mutual equity funds worldwide in the period from 1 January 2001 to 31 December 2015. The sample consists of 611 mutual equity funds and their performance was assessed by using traditional risk-adjusted measures, namely Sharpe ratio, Modified Sharpe Ratio, Adjusted Sharpe Ratio, Treynor measure, Information ratio and Jensen’s alpha. The main findings show that Green mutual equity funds, on average, outperform both SRI and I...

  7. Mutual attraction of magnetic knots

    International Nuclear Information System (INIS)

    Parker, E.N.

    1978-01-01

    It is observed that the magnetic knots associated with active regions on the Sun have an attraction for each other during the formative period of the active regions, when new magnetic flux is coming to the surface. The attraction disappears when new flux ceases to rise through the surface. Then the magnetic spots and knots tend to come apart, leading to disintegration of the sunspots previously formed. The dissolution of the fields is to be expected, as a consequence of the magnetic repulsion of knots of like polarity and as a consequence of the hydromagnetic exchange instability.The purpose of this paper is to show that the mutual attraction of knots during the formative stages of a sunspot region may be understood as the mutual hydrodynamic attraction of the rising flux tubes. Two rising tubes attract each other, as a consequence of the wake of the leading tube when one is moving behind the other, and as a consequence of the Bernoulli effect when rising side by side

  8. Mutual Contextualization in Tripartite Graphs of Folksonomies

    Science.gov (United States)

    Yeung, Ching-Man Au; Gibbins, Nicholas; Shadbolt, Nigel

    The use of tags to describe Web resources in a collaborative manner has experienced rising popularity among Web users in recent years. The product of such activity is given the name folksonomy, which can be considered as a scheme of organizing information in the users' own way. This research work attempts to analyze tripartite graphs - graphs involving users, tags and resources - of folksonomies and discuss how these elements acquire their semantics through their associations with other elements, a process we call mutual contextualization. By studying such process, we try to identify solutions to problems such as tag disambiguation, retrieving documents of similar topics and discovering communities of users. This paper describes the basis of the research work, mentions work done so far and outlines future plans.

  9. Energy information needs for U. S. state-level policy making: Minimal data requirements during normal and emergency periods

    Energy Technology Data Exchange (ETDEWEB)

    Barkenbus, J.N.; Leff, H.S.

    1983-01-01

    Since the oil embargo of 1973, state governments have increased their efforts to track and understand energy flows within their boundaries. There is a commonly perceived need to comprehend the status of present and expected future energy availability, demand, and price and to be prepared to exercise responsible and effective management during energy emergencies. This responsibility has brought with it new needs for accurate and timely state-level information on energy transactions and the external parameters that effect energy availability and disposition. What energy data are needed by a state, regardless of its idiosyncracies, during both normal and energy emergency periods, and to what extent are these data available now. The authors find that needed ongoing (core) data are only partially available at present, and that emergency data can be obtained only with a carefully planned monitoring program that can be fitted to specific emergency conditions. Overall, this paper provides a realistic assessment of the state-level energy data needed to provide state policy makers with sufficient information to make considered judgments.

  10. Energy-information needs for US state-level policy making: minimal data requirements during normal and emergency periods

    Energy Technology Data Exchange (ETDEWEB)

    Barkenbus, J.N.; Leff, H.S.

    1983-01-01

    Since the oil embargo of 1973, state governments have increased their efforts to track and understand energy flows within their boundaries. There is a commonly perceived need to comprehend the status of present and expected future energy availability, demand, and price and to be prepared to exercise responsible and effective management during energy emergencies. This responsibility has brought with it new needs for accurate and timely state-level information on energy transactions and the external parameters that effect energy availability and disposition. Hence, we ask: what energy data are needed by a state, regardless of its idiosyncracies, during both normal and energy emergency periods, and to what extent are these data available now. We find that needed ongoing (core) data are only partially available at present, and that emergency data can be obtained only with a carefully planned monitoring program that can be fitted to specific emergency conditions. Overall, this paper provides a realistic assessment of the state-level energy data needed to provide state policy makers with sufficient information to make considered judgments. 7 references, 6 tables.

  11. Mutually unbiased coarse-grained measurements of two or more phase-space variables

    Science.gov (United States)

    Paul, E. C.; Walborn, S. P.; Tasca, D. S.; Rudnicki, Łukasz

    2018-05-01

    Mutual unbiasedness of the eigenstates of phase-space operators—such as position and momentum, or their standard coarse-grained versions—exists only in the limiting case of infinite squeezing. In Phys. Rev. Lett. 120, 040403 (2018), 10.1103/PhysRevLett.120.040403, it was shown that mutual unbiasedness can be recovered for periodic coarse graining of these two operators. Here we investigate mutual unbiasedness of coarse-grained measurements for more than two phase-space variables. We show that mutual unbiasedness can be recovered between periodic coarse graining of any two nonparallel phase-space operators. We illustrate these results through optics experiments, using the fractional Fourier transform to prepare and measure mutually unbiased phase-space variables. The differences between two and three mutually unbiased measurements is discussed. Our results contribute to bridging the gap between continuous and discrete quantum mechanics, and they could be useful in quantum-information protocols.

  12. Empirical study on mutual fund objective classification.

    Science.gov (United States)

    Jin, Xue-jun; Yang, Xiao-lan

    2004-05-01

    Mutual funds are usually classified on the basis of their objectives. If the activities of mutual funds are consistent with their stated objectives, investors may look at the latter as signals of their risks and incomes. This work analyzes mutual fund objective classification in China by statistical methods of distance analysis and discriminant analysis; and examines whether the stated investment objectives of mutual funds adequately represent their attributes to investors. That is, if mutual funds adhere to their stated objectives, attributes must be heterogeneous between investment objective groups and homogeneous within them. Our conclusion is to some degree, the group of optimized exponential funds is heterogeneous to other groups. As a whole, there exist no significant differences between different objective groups; and 50% of mutual funds are not consistent with their objective groups.

  13. Explaining mutualism variation: a new evolutionary paradox?

    Science.gov (United States)

    Heath, Katy D; Stinchcombe, John R

    2014-02-01

    The paradox of mutualism is typically framed as the persistence of interspecific cooperation, despite the potential advantages of cheating. Thus, mutualism research has tended to focus on stabilizing mechanisms that prevent the invasion of low-quality partners. These mechanisms alone cannot explain the persistence of variation for partner quality observed in nature, leaving a large gap in our understanding of how mutualisms evolve. Studying partner quality variation is necessary for applying genetically explicit models to predict evolution in natural populations, a necessary step for understanding the origins of mutualisms as well as their ongoing dynamics. An evolutionary genetic approach, which is focused on naturally occurring mutualist variation, can potentially synthesize the currently disconnected fields of mutualism evolution and coevolutionary genetics. We outline explanations for the maintenance of genetic variation for mutualism and suggest approaches necessary to address them. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  14. Asset Allocation of Mutual Fund Investors

    OpenAIRE

    Dengpan Luo

    2003-01-01

    This paper studies mutual fund investors' asset allocation decisions using monthly flow data of U.S mutual fund industry from 1984 to 1998. We find that mutual fund investors change their asset allocations between stocks and bonds in reaction to business conditions tracked by changes in expected stock market returns. They tend to allocate less into stock funds during the trough of a business cycle when expected stock market returns are higher and to allocate more into stock funds during the p...

  15. The Effect of Mutual Coupling on a High Altitude Platform Diversity System Using Compact Antenna Arrays

    Directory of Open Access Journals (Sweden)

    Tommy Hult

    2010-01-01

    Full Text Available We analyze the destructive effects of mutual coupling and spatial correlation between the separate antenna elements on a combined diversity system consisting of multiple HAPs (High-Altitude Platforms employing various compact MIMO (Multiple-Input Multiple-Output antenna array configurations, in order to enhance the mutual information in HAP communication links. In addition, we assess the influence of the separation angle between HAPs on system performance, and determine the optimal separation angles that maximize the total mutual information of the system for various compact MIMO antennas. Simulation results show that although the mutual information is degraded by mutual coupling and spatial correlation, the proposed HAP diversity system still provides better performance compared to a nondiversity system for all tested scenarios.

  16. Measuring the influence of a mutual support educational intervention within a nursing team

    Directory of Open Access Journals (Sweden)

    Renée Bridges

    2014-03-01

    Conclusion: The study demonstrates that education can have an impact on perceptions and awareness of mutual support among nursing team members. The survey instrument can be used effectively to inform leadership areas for improvement and staff development in the effort to improve team coordination and mutual support.

  17. Forming mutually beneficial Aboriginal partnerships

    Energy Technology Data Exchange (ETDEWEB)

    Brewster, L.; Shaw, M. [ATCO Frontec, Edmonton, AB (Canada)

    2002-07-01

    The Alberta-based ATCO Group is engaged in power generation, utilities logistics and energy services and technologies in Alaska, Canada's north, and around the world. In 2001, 56 per cent of ATCO's revenue came from Aboriginal joint ventures. ATCO's foundation for successful partnerships is a mutual trust, an understanding of the environment, and constant communication. The partnerships begin with a long term vision, resulting in community-based northern businesses that benefit Aboriginal partners, shareholders, customers and local staff. This paper described 2 unique joint venture case studies: (1) the north warning system in Cambridge Bay, a radar and communication service for government, and (2) Yellowknife's Tli Cho logistics site for support and municipal services to the mining industry. The north warning system joint venture includes Pan Arctic Inuit Logistics (PAIL), representing Inuvialuit, Labrador, Nunavik and Nunavut, while the Tli Cho joint venture includes participation of the Dog Rib Rae band. Management practices in all joint ventures reflect cultural differences, and Aboriginal people are involved in long term jobs relating to northern pipeline development. 21 figs.

  18. Modulation of the inter-hemispheric processing of semantic information during normal aging. A divided visual field experiment.

    Science.gov (United States)

    Hoyau, E; Cousin, E; Jaillard, A; Baciu, M

    2016-12-01

    We evaluated the effect of normal aging on the inter-hemispheric processing of semantic information by using the divided visual field (DVF) method, with words and pictures. Two main theoretical models have been considered, (a) the HAROLD model which posits that aging is associated with supplementary recruitment of the right hemisphere (RH) and decreased hemispheric specialization, and (b) the RH decline theory, which assumes that the RH becomes less efficient with aging, associated with increased LH specialization. Two groups of subjects were examined, a Young Group (YG) and an Old Group (OG), while participants performed a semantic categorization task (living vs. non-living) in words and pictures. The DVF was realized in two steps: (a) unilateral DVF presentation with stimuli presented separately in each visual field, left or right, allowing for their initial processing by only one hemisphere, right or left, respectively; (b) bilateral DVF presentation (BVF) with stimuli presented simultaneously in both visual fields, followed by their processing by both hemispheres. These two types of presentation permitted the evaluation of two main characteristics of the inter-hemispheric processing of information, the hemispheric specialization (HS) and the inter-hemispheric cooperation (IHC). Moreover, the BVF allowed determining the driver-hemisphere for processing information presented in BVF. Results obtained in OG indicated that: (a) semantic categorization was performed as accurately as YG, even if more slowly, (b) a non-semantic RH decline was observed, and (c) the LH controls the semantic processing during the BVF, suggesting an increased role of the LH in aging. However, despite the stronger involvement of the LH in OG, the RH is not completely devoid of semantic abilities. As discussed in the paper, neither the HAROLD nor the RH decline does fully explain this pattern of results. We rather suggest that the effect of aging on the hemispheric specialization and inter

  19. Bright Lights and Questions: Using Mutual Interrogation

    Science.gov (United States)

    Adam, Aishikin; Alangui, Willy; Barton, Bill

    2010-01-01

    Mutual Interrogation is a research methodology for ethnomathematics proposed by Alangui in 2006 in an attempt to avoid the potential inequality set up when a restricted cultural practice is viewed through the lens of the near-universal and highly developed research domain of mathematics. Using three significant examples of mutual interrogation in…

  20. Trading Cost Management of Mutual Funds

    NARCIS (Netherlands)

    R. Xing (Rang)

    2016-01-01

    textabstractThis paper documents the trading behaviour of actively managed equity mutual funds from the perspective of their trading cost management. Consistent with the predictions in the literature of portfolio choice with trading costs, I present three main findings. Firstly, mutual funds trade

  1. Longitudinal analysis of mutual fund performance

    NARCIS (Netherlands)

    Ter Horst, J.R.

    1998-01-01

    Many different motivations for investing in mutual funds have been provided in the literature, including the claim that managers of mutual funds have special abilities that can be used to outperform the market. Testing of the validity of these claims is complicated by two facts. First, the expected

  2. Economic contract theory tests models of mutualism.

    Science.gov (United States)

    Weyl, E Glen; Frederickson, Megan E; Yu, Douglas W; Pierce, Naomi E

    2010-09-07

    Although mutualisms are common in all ecological communities and have played key roles in the diversification of life, our current understanding of the evolution of cooperation applies mostly to social behavior within a species. A central question is whether mutualisms persist because hosts have evolved costly punishment of cheaters. Here, we use the economic theory of employment contracts to formulate and distinguish between two mechanisms that have been proposed to prevent cheating in host-symbiont mutualisms, partner fidelity feedback (PFF) and host sanctions (HS). Under PFF, positive feedback between host fitness and symbiont fitness is sufficient to prevent cheating; in contrast, HS posits the necessity of costly punishment to maintain mutualism. A coevolutionary model of mutualism finds that HS are unlikely to evolve de novo, and published data on legume-rhizobia and yucca-moth mutualisms are consistent with PFF and not with HS. Thus, in systems considered to be textbook cases of HS, we find poor support for the theory that hosts have evolved to punish cheating symbionts; instead, we show that even horizontally transmitted mutualisms can be stabilized via PFF. PFF theory may place previously underappreciated constraints on the evolution of mutualism and explain why punishment is far from ubiquitous in nature.

  3. Designing experiments for maximum information from cyclic oxidation tests and their statistical analysis using half Normal plots

    International Nuclear Information System (INIS)

    Coleman, S.Y.; Nicholls, J.R.

    2006-01-01

    Cyclic oxidation testing at elevated temperatures requires careful experimental design and the adoption of standard procedures to ensure reliable data. This is a major aim of the 'COTEST' research programme. Further, as such tests are both time consuming and costly, in terms of human effort, to take measurements over a large number of cycles, it is important to gain maximum information from a minimum number of tests (trials). This search for standardisation of cyclic oxidation conditions leads to a series of tests to determine the relative effects of cyclic parameters on the oxidation process. Following a review of the available literature, databases and the experience of partners to the COTEST project, the most influential parameters, upper dwell temperature (oxidation temperature) and time (hot time), lower dwell time (cold time) and environment, were investigated in partners' laboratories. It was decided to test upper dwell temperature at 3 levels, at and equidistant from a reference temperature; to test upper dwell time at a reference, a higher and a lower time; to test lower dwell time at a reference and a higher time and wet and dry environments. Thus an experiment, consisting of nine trials, was designed according to statistical criteria. The results of the trial were analysed statistically, to test the main linear and quadratic effects of upper dwell temperature and hot time and the main effects of lower dwell time (cold time) and environment. The nine trials are a quarter fraction of the 36 possible combinations of parameter levels that could have been studied. The results have been analysed by half Normal plots as there are only 2 degrees of freedom for the experimental error variance, which is rather low for a standard analysis of variance. Half Normal plots give a visual indication of which factors are statistically significant. In this experiment each trial has 3 replications, and the data are analysed in terms of mean mass change, oxidation kinetics

  4. [Maintaining solidarity: is mutuality the solution?].

    Science.gov (United States)

    Gevers, J K M; Ploem, M C

    2013-01-01

    Solidarity is essentially the willingness to contribute to the community and its demands, which may even involve contributing more than one is expecting to receive. Another principle is mutuality: this refers to a balance between rights and obligations or between mutual obligations. In its advisory document 'The importance of mutuality......solidarity takes work!', The Dutch Council for Public Health and Health Care underlines the importance of ensuring solidarity within the Dutch health care system, e.g. by encouraging patients to take responsibility for their own health, possibly by introducing elements of mutuality. In our contribution, we comment on the Council's advice. Although we fully agree with the overall conclusion that solidarity should be maintained within the system, we do not see how the introduction of increased mutuality will contribute to this goal.

  5. Mutually orthogonal Latin squares from the inner products of vectors in mutually unbiased bases

    International Nuclear Information System (INIS)

    Hall, Joanne L; Rao, Asha

    2010-01-01

    Mutually unbiased bases (MUBs) are important in quantum information theory. While constructions of complete sets of d + 1 MUBs in C d are known when d is a prime power, it is unknown if such complete sets exist in non-prime power dimensions. It has been conjectured that complete sets of MUBs only exist in C d if a maximal set of mutually orthogonal Latin squares (MOLS) of side length d also exists. There are several constructions (Roy and Scott 2007 J. Math. Phys. 48 072110; Paterek, Dakic and Brukner 2009 Phys. Rev. A 79 012109) of complete sets of MUBs from specific types of MOLS, which use Galois fields to construct the vectors of the MUBs. In this paper, two known constructions of MUBs (Alltop 1980 IEEE Trans. Inf. Theory 26 350-354; Wootters and Fields 1989 Ann. Phys. 191 363-381), both of which use polynomials over a Galois field, are used to construct complete sets of MOLS in the odd prime case. The MOLS come from the inner products of pairs of vectors in the MUBs.

  6. Semantic Representation of Mutual-Consent Divorce

    Directory of Open Access Journals (Sweden)

    مهری سادات موسوی

    2016-09-01

    Full Text Available This article discussed mutual-consent divorce in the context of thoughts and attitude of female applicants of this type of divorce with an inductive qualitative and ethnographic method. Based on the qualitative purposive sampling, 30 women of those who had referred for divorce to family court of Karaj, were selected and deeply interviewed. The results obtained in six major categories as follows: Rethinking the role of men as families’ breadwinners, inappropriate sexual relationships, emotional conflicts, cultural- social dissensions, normative pressures of family and relatives, and personality and behavioral disorders. The core-oriented category of this study is "Women's attitude towards mutual-consent divorce" that includes other major categories and can semantically alter and redirect women’s opinion about mutual-consent divorce. According to the results, the term of mutual-consent is thought-provoking in this type of divorce; because considering the situations which were leaded to mutual-consent divorce and quantifying them revealed that nearly 32% of mutual-consent divorces were not mutual in fact; since, these women accepted divorce with desperation, coercion and threat.

  7. The evolution of plant-insect mutualisms.

    Science.gov (United States)

    Bronstein, Judith L; Alarcón, Ruben; Geber, Monica

    2006-01-01

    Mutualisms (cooperative interactions between species) have had a central role in the generation and maintenance of life on earth. Insects and plants are involved in diverse forms of mutualism. Here we review evolutionary features of three prominent insect-plant mutualisms: pollination, protection and seed dispersal. We focus on addressing five central phenomena: evolutionary origins and maintenance of mutualism; the evolution of mutualistic traits; the evolution of specialization and generalization; coevolutionary processes; and the existence of cheating. Several features uniting very diverse insect-plant mutualisms are identified and their evolutionary implications are discussed: the involvement of one mobile and one sedentary partner; natural selection on plant rewards; the existence of a continuum from specialization to generalization; and the ubiquity of cheating, particularly on the part of insects. Plant-insect mutualisms have apparently both arisen and been lost repeatedly. Many adaptive hypotheses have been proposed to explain these transitions, and it is unlikely that any one of them dominates across interactions differing so widely in natural history. Evolutionary theory has a potentially important, but as yet largely unfilled, role to play in explaining the origins, maintenance, breakdown and evolution of insect-plant mutualisms.

  8. Mutual emergency assistance for radiation accidents

    International Nuclear Information System (INIS)

    1980-11-01

    In 1963 the International Atomic Energy Agency (IAEA) issued a document, WP.35, dated 23 November 1963, based on information provided by a number of its Member States on the type of radiological assistance that they might be able to make available in the event of a radiation emergency in another country at the request of that country. The document was subsequently revised in 1968 and 1971 with the participation of the World Health Organization (WHO), the Food and Agriculture Organization of the United Nations (FAO) and the International Labour Organisation (ILO). In 1979, an expanded questionnaire to ascertain what could be required by the State in the event of a major radiation accident, was sent jointly by these organizations with the participation of the Office of the United Nations Disaster Relief Co-ordinator (UNDRO), to all their Member States. The text of the expanded questionnaire is reproduced. The present document lists all the information, received up to mid 1980, that contains offers of assistance made by a State. It also lists information on the assistance that might be required by the State. In general, the replies have been reproduced in the form in which they were received, although a few changes in presentation have been introduced in the interest of brevity and clarity. Some countries have pointed out that their replies are necessarily of a general character and that the full extent of the assistance they would be capable of providing could be determined only after a specific request had been received. The information given in this document should therefore be regarded only as a guide to the type of radiological assistance that might be available and/or needed. Other available international assistance includes that provided by the Agency through the IAEA Radiation (Emergency) Assistance Procedures, by WHO through its system of Collaborating Centres on human radiation pathology, and by various States via regional or inter-countries' agreements on

  9. PERFORMANCE OF SELECT MUTUAL FUNDS IN INDIA

    OpenAIRE

    Manoj Kumar Dash*

    2018-01-01

    Mutual funds is one of the major instruments for wealth creation and wealth saving in the current years. It is a financial instrument which gives positive result and satisfactory return to its investors. The mutual industries in have undergone a most successful phase in the last 15 years. The AUM has shown tremendous growth since inception from Rs. 25 crore in 1965 to Rs. 22,36,717 crore in December 2017. But this tremendous growth in the mutual fund industries in India is still lacking for b...

  10. Basic legal instruments of mutual assistance in tax matters in European Union

    Directory of Open Access Journals (Sweden)

    Cvjetković Cvjetana

    2011-01-01

    Full Text Available This paper presents the basic legal instruments of mutual assistance in tax matters in the field of direct and indirect taxation in European union, forms of mutual assistance and its importance in fight against international tax evasion and international double taxation. Namely, processes of globalization and liberalization, in terms of taxation in accordance with the principle of worldwide income, have meant that information that is available to a tax administration is not enough to correctly determine tax liability. In such situations states can rely on mutual assistance which may be manifested as exchange of tax information, collaboration by officials and simultaneous controls.

  11. A measure of mutual divergence among a number of probability distributions

    Directory of Open Access Journals (Sweden)

    J. N. Kapur

    1987-01-01

    major inequalities due to Shannon, Renyi and Holder. The inequalities are then used to obtain some useful results in information theory. In particular measures are obtained to measure the mutual divergence among two or more probability distributions.

  12. Nordic Mutual Emergency Assistance Agreement in Connection with Radiation Accidents

    International Nuclear Information System (INIS)

    1963-01-01

    The text of the Nordic Mutual Emergency Assistance Agreement in Connection with Radiation Accidents, which was signed on 17 October 1963 by the Director General and by representatives of the Governments of Denmark, Finland, Norway and Sweden, is reproduced in this document for the information of all Members. The entry into force of the Agreement in accordance with Article IX will be notified to Members in an Addendum to this document [es

  13. Nordic Mutual Emergency Assistance Agreement in Connection with Radiation Accidents

    International Nuclear Information System (INIS)

    1963-01-01

    The text of the Nordic Mutual Emergency Assistance Agreement in Connection with Radiation Accidents, which was signed on 17 October 1963 by the Director General and by representatives of the Governments of Denmark, Finland, Norway and Sweden, is reproduced in this document for the information of all Members. The entry into force of the Agreement in accordance with Article IX will be notified to Members in an Addendum to this document

  14. Economic game theory for mutualism and cooperation.

    Science.gov (United States)

    Archetti, Marco; Scheuring, István; Hoffman, Moshe; Frederickson, Megan E; Pierce, Naomi E; Yu, Douglas W

    2011-12-01

    We review recent work at the interface of economic game theory and evolutionary biology that provides new insights into the evolution of partner choice, host sanctions, partner fidelity feedback and public goods. (1) The theory of games with asymmetrical information shows that the right incentives allow hosts to screen-out parasites and screen-in mutualists, explaining successful partner choice in the absence of signalling. Applications range from ant-plants to microbiomes. (2) Contract theory distinguishes two longstanding but weakly differentiated explanations of host response to defectors: host sanctions and partner fidelity feedback. Host traits that selectively punish misbehaving symbionts are parsimoniously interpreted as pre-adaptations. Yucca-moth and legume-rhizobia mutualisms are argued to be examples of partner fidelity feedback. (3) The theory of public goods shows that cooperation in multi-player interactions can evolve in the absence of assortment, in one-shot social dilemmas among non-kin. Applications include alarm calls in vertebrates and exoenzymes in microbes. 2011 Blackwell Publishing Ltd/CNRS.

  15. THE PERFORMANCE OF MUTUAL FUNDS IN SLOVAKIA

    Directory of Open Access Journals (Sweden)

    F. Tudorache

    2016-11-01

    Full Text Available A good indicator for the financial markets performance in different countries is the evolution of mutual funds in terms of their inflows and outflows. The goal of the present paper is to analyse the performance of the mutual funds in Slovakia. The research objectives are twofold: to study the flows of funds into and out of mutual funds from Slovakia during the period 2007-2014 and to analyse how investors in Slovakian mutual funds behave in terms of their investment choice. The analysis focuses on identifying patterns in investors' decision making process and on examining the similarity of their behavioural patterns with the ones identi¬fied at international level.

  16. Sino-U.S. Strategic Mutual Trust

    Institute of Scientific and Technical Information of China (English)

    Yuan Peng; Zhang Yimeng

    2008-01-01

    Relations between China and the U.S. have been relatively stable for nearly seven years, for the first time since the end of the Cold War. Strategic mutual trust, however, is not enough and there is a long way to go before both countries can achieve a permanent strategic stability. Four problems have prevented stability in bilateral relations, namely structural, internal, accidental, and cognitive issues. The goal of building strategic mutual trust still remains distant, and developing a good understanding between each other is the thorniest problem for both countries. Better mutual understanding can lead to an expansion of bilateral relations. China and the U.S. need to increase mutual trust and work towards achieving strategic stability.

  17. Indian mutual fund industry: Opportunities and challenges

    OpenAIRE

    Jayant R. Kale; Venkatesh Panchapagesan

    2012-01-01

    This article presents an overview of the mutual fund industry in India and the reasons for its poor penetration, which includes lack of objective research. It benchmarks the industry globally, and raises key issues regarding the ownership and performance of mutual funds, the sensitivity of fund flows to performance, and the importance of regulation to its growth, all of which have been largely under researched in India. It then captures the views of leading practitioners on these and other is...

  18. Can Chinese Mutual Fund Time Market Liquidity?

    OpenAIRE

    LI, Xiaoqing

    2012-01-01

    Extant researches have focused on mutual fund managers’ ability to time market returns or volatility. In this paper, the author offers a new perspective on the traditional timing issue by examining Chinese fund managers’ liquidity timing ability. Using the Chinese mutual fund database, the author finds little evidence that over the period from 2004 to 2012, fund managers cannot demonstrate the ability to time market liquidity in China, i.e., increase (reduce) market exposure in anticipation o...

  19. Mutual Visibility by Robots with Persistent Memory

    OpenAIRE

    Bhagat, Subhash; Mukhopadhyaya, Krishnendu

    2017-01-01

    This paper addresses the mutual visibility problem for a set of semi-synchronous, opaque robots occupying distinct positions in the Euclidean plane. Since robots are opaque, if three robots lie on a line, the middle robot obstructs the visions of the two other robots. The mutual visibility problem asks the robots to coordinate their movements to form a configuration, within finite time and without collision, in which no three robots are collinear. Robots are endowed with a constant bits of pe...

  20. A recursive field-normalized bibliometric performance indicator: an application to the field of library and information science.

    Science.gov (United States)

    Waltman, Ludo; Yan, Erjia; van Eck, Nees Jan

    2011-10-01

    Two commonly used ideas in the development of citation-based research performance indicators are the idea of normalizing citation counts based on a field classification scheme and the idea of recursive citation weighing (like in PageRank-inspired indicators). We combine these two ideas in a single indicator, referred to as the recursive mean normalized citation score indicator, and we study the validity of this indicator. Our empirical analysis shows that the proposed indicator is highly sensitive to the field classification scheme that is used. The indicator also has a strong tendency to reinforce biases caused by the classification scheme. Based on these observations, we advise against the use of indicators in which the idea of normalization based on a field classification scheme and the idea of recursive citation weighing are combined.

  1. The Mutual Impact of Global Strategy and Organizational Learning

    DEFF Research Database (Denmark)

    Hotho, Jasper J.; Lyles, Marjorie A.; Easterby-Smith, Mark

    2015-01-01

    Despite the interest in issues of knowing and learning in the global strategy field, there has been limited mutual engagement and interaction between the fields of global strategy and organizational learning. The purpose of our article is to reflect on and articulate how the mutual exchange...... of ideas between these fields can be encouraged. To this end, we first conduct a review of the intersection of the fields of global strategy and organizational learning. We then present two recommendations regarding how the interaction between the two fields can be enhanced. Our first recommendation...... is for global strategy research to adopt a broader notion of organizational learning. Our second recommendation is for global strategy research to capitalize on its attention to context in order to inform and enhance organizational learning theory. We discuss the use of context in a number of common research...

  2. The Analysis of Mutual Fund Performance: Evidence from U.S. Equity Mutual Funds

    NARCIS (Netherlands)

    D.P. Budiono (Diana)

    2010-01-01

    textabstractWe study the mutual fund performance for about 45 years. There are several key points that we can withdraw from this dissertation. First, to study the persistence of mutual fund performance, it is important to consider time-varying exposures because when they are ignored, the persistence

  3. Mutual Fund Flight-to-Liquidity

    DEFF Research Database (Denmark)

    Rzeznik, Aleksandra

    This paper examines the liquidity choices of mutual funds during times of market uncertainty. I find that when markets are uncertain, mutual funds actively increase the liquidity of their portfolio – often referred to as a ‘flight-to-liquidity.’ In aggregate, mutual fund behaviour has implications...... for the market; the market driven flight-toliquidity places upward pressure on the liquidity premium. I examine the underlying mechanisms driving fund behaviour. I show that market volatility is associated with lower fund performance and withdrawals, which causes funds to adjust the composition...... of their portfolio towards more liquid assets in order to meet potential redemptions. This causal chain is consistent with Vayanos (2004), who argues that fund managers are investors with time-varying liquidity preferences due to threat of withdrawal. Aggregated over funds, the effect is substantial: a one standard...

  4. Mutual Fund Flight-to-Liquidity

    DEFF Research Database (Denmark)

    Rzeznik, Aleksandra

    This paper examines the liquidity choices of mutual funds during times of market uncertainty. I find that when markets are uncertain, mutual funds actively increase the liquidity of their portfolio { often referred to as a `flight-to-liquidity.' In aggregate, mutual fund behaviour has implications...... for the market; the market driven flight-toliquidity places upward pressure on the liquidity premium. I examine the underlying mechanisms driving fund behaviour. I show that market volatility is associated with lower fund performance and withdrawals, which causes funds to adjust the composition...... of their portfolio towards more liquid assets in order to meet potential redemptions. This causal chain is consistent with Vayanos (2004), who argues that fund managers are investors with time-varying liquidity preferences due to threat of withdrawal. Aggregated over funds, the effect is substantial: a one standard...

  5. Elections to the Mutual Aid Fund

    CERN Document Server

    2016-01-01

    Every two years, according to Article 6 of the Regulations of the Mutual Aid Fund, the Committee of the Mutual Aid Fund must renew one third of its membership. This year three members are outgoing. Of these three, two will stand again and one will not.   Candidates should be ready to give approximately two hours a month during working time to the Fund whose aim is to assist colleagues in financial difficulties. We invite applications from CERN Staff who wish to stand for election as a member of the CERN Mutual Aid Fund to send in their application before 17 June 2016, by email to the Fund’s President, Connie Potter (connie.potter@cern.ch).

  6. Mutual Workshops enhancing Curriculum Integration

    DEFF Research Database (Denmark)

    Bjerregaard Jensen, Lotte; Markvorsen, Steen; Almegaard, Henrik

    2011-01-01

    . A course in material science was moved from the fourth to the first semester so that the project could be informed by material science. A new course in geometry was prepared and software that could facilitate an integrated design project was introduced (STAAD Pro). The ‘full package’ of the new third....... Every semester has a teaching team consisting of all the teachers for courses in that semester. Each semester also has its own theme and a multidisciplinary, joint project. So the most active members of the teaching team, of course, are those responsible for courses that address the theme and contribute...... to the joint project. The theme of the third semester is ‘structural design’. Structural design is defined as an integration of material science, statics and geometry in relation to an architectural project. Anticipating the implementation of CDIO and this theme, major changes were made to the curriculum...

  7. EGYPTIAN MUTUAL FUNDS ANALYSIS: HISTORY, PERFORMANCE, OBJECTIVES, RISK AND RETURN

    Directory of Open Access Journals (Sweden)

    Petru STEFEA

    2013-10-01

    Full Text Available The present research aims to overview the mutual fund in Egypt. The establishment of the first mutual funds was achieved in 1994. Nowadays, the total mutual funds reached 90 funds , approximately. The income funds represent the largest share of the Egyptian mutual funds (40%, growth funds (25% and the private equity funds is at least (1%. The total population of the Egyptian mutual funds reached 22. Finally, the study proved that the Egyptian mutual funds have an impact on fund return , total risk and systemic; when analysis relationship between risk and return. The study found influencing for mutual fund's objectives on Sharpe and Terynor ratios.

  8. Performance of mutual funds in european countries

    OpenAIRE

    Γκογκάκη, Ελεωνόρα

    2012-01-01

    In this thesis, the performance of 220 open-end domestic equity mutual funds of european countries (from 'weak' and 'strong' economies) is analyzed for an eight- year period from 1st January 2004 until 31st December 2011, which is then split in two four-year sub periods in order to examine their performance prior to the global financial crisis and after its burst in 2008. In order to compare the mutual funds' performance to that of each country's market, it used as benchmarks the countries' m...

  9. Indian mutual fund industry: Opportunities and challenges

    Directory of Open Access Journals (Sweden)

    Jayant R. Kale

    2012-12-01

    Full Text Available This article presents an overview of the mutual fund industry in India and the reasons for its poor penetration, which includes lack of objective research. It benchmarks the industry globally, and raises key issues regarding the ownership and performance of mutual funds, the sensitivity of fund flows to performance, and the importance of regulation to its growth, all of which have been largely under researched in India. It then captures the views of leading practitioners on these and other issues, including the challenges posed by poor financial literacy, the equity culture in the country, and the weakly supportive regulatory environment.

  10. Ranking mutual funds using Sortino method

    Directory of Open Access Journals (Sweden)

    Khosro Faghani Makrani

    2014-04-01

    Full Text Available One of the primary concerns on most business activities is to determine an efficient method for ranking mutual funds. This paper performs an empirical investigation to rank 42 mutual funds listed on Tehran Stock Exchange using Sortino method over the period 2011-2012. The results of survey have been compared with market return and the results have confirmed that there were some positive and meaningful relationships between Sortino return and market return. In addition, there were some positive and meaningful relationship between two Sortino methods.

  11. Exploring Proxy Measures of Mutuality for Strategic Partnership Development: A Case Study.

    Science.gov (United States)

    Mayo-Gamble, Tilicia L; Barnes, Priscilla A; Sherwood-Laughlin, Catherine M; Reece, Michael; DeWeese, Sandy; Kennedy, Carol Weiss; Valenta, Mary Ann

    2017-07-01

    Partnerships between academic and clinical-based health organizations are becoming increasingly important in improving health outcomes. Mutuality is recognized as a vital component of these partnerships. If partnerships are to achieve mutuality, there is a need to define what it means to partnering organizations. Few studies have described the elements contributing to mutuality, particularly in new relationships between academic and clinical partners. This study seeks to identify how mutuality is expressed and to explore potential proxy measures of mutuality for an alliance consisting of a hospital system and a School of Public Health. Key informant interviews were conducted with faculty and hospital representatives serving on the partnership steering committee. Key informants were asked about perceived events that led to the development of the Alliance; perceived goals, expectations, and outcomes; and current/future roles with the Alliance. Four proxy measures of mutuality for an academic-clinical partnership were identified: policy directives, community beneficence, procurement of human capital, and partnership longevity. Findings can inform the development of tools for assisting in strengthening relationships and ensuring stakeholders' interests align with the mission and goal of the partnership by operationalizing elements necessary to evaluate the progress of the partnership.

  12. Empirical Studies on Actively Managed Mutual Funds: New Insights into the Costs and Benefits of Portfolio Disclosure

    NARCIS (Netherlands)

    T.C. Dyakov (Teodor)

    2014-01-01

    markdownabstract__Abstract__ Dyakov’s dissertation bundles three empirical studies on actively managed mutual funds. His studies provide new knowledge of the costs and benefits of portfolio disclosure and shed more light into the question whether mutual fund investors have an information

  13. Mutual Group Hypnosis: A Social Interaction Analysis.

    Science.gov (United States)

    Sanders, Shirley

    Mutual Group Hypnosis is discussed in terms of its similarity to group dynamics in general and in terms of its similarity to a social interaction program (Role Modeling) designed to foster the expression of warmth and acceptance among group members. Hypnosis also fosters a regression to prelogical thought processes in the service of the ego. Group…

  14. Mutual fund performance: dividends do matter

    OpenAIRE

    De Mingo López, Diego Víctor; Matallín Sáez, Juan Carlos

    2015-01-01

    This article studies the bias in mutual fund performance when a nondividend-reinvesting benchmark is used. Our empirical findings show how performance worsens when using a benchmark that includes reinvestment dividends. We also find that inferences about managers’ ability related to economic states are biased by the effect of omitting dividends when selecting a benchmark.

  15. The Persistence of Mutual Fund Performance.

    OpenAIRE

    Grinblatt, Mark; Titman, Sheridan

    1992-01-01

    This paper analyzes how mutual fund performance relates to past performance. These tests are based on a multiple portfolio benchmark that was formed on the basis of securities characteristics. The authors find evidence that differences in performance between funds persist over time and that this persistence is consistent with the ability of fund managers to earn abnormal returns. Copyright 1992 by American Finance Association.

  16. Starvation-free mutual exclusion with semaphores

    NARCIS (Netherlands)

    Hesselink, Wim H.; IJbema, Mark

    The standard implementation of mutual exclusion by means of a semaphore allows starvation of processes. Between 1979 and 1986, three algorithms were proposed that preclude starvation. These algorithms use a special kind of semaphore. We model this so-called buffered semaphore rigorously and provide

  17. Deadlocks and dihomotopy in mutual exclusion models

    DEFF Research Database (Denmark)

    Raussen, Martin

    2005-01-01

    spaces, the directed ($d$-spaces) of M.Grandis and the flows of P. Gaucher. All models invite to use or modify ideas from algebraic topology, notably homotopy. In specific semaphore models for mutual exclusion, we have developed methods and algorithms that can detect deadlocks and unsafe regions and give...

  18. Competition as a mechanism structuring mutualisms

    Science.gov (United States)

    Robert J. Warren; Itamar Giladi; Mark A. Bradford

    2014-01-01

    Summary 1. Hutchinsonian niche theory posits that organisms have fundamental abiotic resource requirements from which they are limited by competition. Organisms also have fundamental biotic requirements, such as mutualists, for which they also might compete. 2. We test this idea with a widespread ant–plant mutualism. Ant-mediated seed dispersal (myrmecochory) in...

  19. Management of mutual health organizations in Ghana.

    NARCIS (Netherlands)

    Baltussen, R.M.P.M.; Bruce, E.; Rhodes, G.; Narh-Bana, S.A.; Agyepong, I.

    2006-01-01

    OBJECTIVE: Mutual Health Organizations (MHO) emerged in Ghana in the mid-1990s. The organizational structure and financial management of private and public MHO hold important lessons for the development of national health insurance in Ghana, but there is little evidence to date on their features.

  20. Partner selection in the mycorrhizal mutualism

    NARCIS (Netherlands)

    Werner, G.D.A.; Kiers, E.T.

    2015-01-01

    Partner selection in the mycorrhizal symbiosis is thought to be a key factor stabilising the mutualism. Both plant hosts and mycorrhizal fungi have been shown to preferentially allocate resources to higher quality partners. This can help maintain underground cooperation, although it is likely that

  1. Reconstructing Normality

    DEFF Research Database (Denmark)

    Gildberg, Frederik Alkier; Bradley, Stephen K.; Fristed, Peter Billeskov

    2012-01-01

    Forensic psychiatry is an area of priority for the Danish Government. As the field expands, this calls for increased knowledge about mental health nursing practice, as this is part of the forensic psychiatry treatment offered. However, only sparse research exists in this area. The aim of this study...... was to investigate the characteristics of forensic mental health nursing staff interaction with forensic mental health inpatients and to explore how staff give meaning to these interactions. The project included 32 forensic mental health staff members, with over 307 hours of participant observations, 48 informal....... The intention is to establish a trusting relationship to form behaviour and perceptual-corrective care, which is characterized by staff's endeavours to change, halt, or support the patient's behaviour or perception in relation to staff's perception of normality. The intention is to support and teach the patient...

  2. [Struggling for normal in an instable situation - informal caregivers self-management in palliative home care. A meta-synthesis].

    Science.gov (United States)

    Kreyer, Christiane; Pleschberger, Sabine

    2014-10-01

    Family caregivers play a key role in palliative home care for persons with advanced cancer. Although research has shown numerous burdens and strains of family caregiving, there is a lack of family-oriented support strategies in palliative home care. Little is known about family caregivers' self-management in this context so far. Qualitative research provides insight into families' perspectives of the transition to and management of palliative care at home and can be used as a starting point. The aim of the study was to increase knowledge of family caregivers' self-management in palliative home care by synthesizing evidence from qualitative research. Based on a systematic review of literature a meta-synthesis was conducted following the approach of Noblit and Hare (1988). A total of 13 qualitative studies from six countries, published from 2002 onward, formed the basis for an interpretative synthesis. Caring for a person with advanced cancer at the end of life at home is characterized by an instable transition process in which families are 'struggling for normal'. Six different family self-management strategies to deal with this were identified: acknowledging the transition, restructuring everyday life, maintaining balance in family relationships, taking responsibility for care, using social support, and acquiring caring-skills. Self-management strategies may provide a key for supporting family caregivers in palliative home care by focusing on resources and problem solving skills of families.

  3. A robust cloud access scheme with mutual authentication

    Directory of Open Access Journals (Sweden)

    Chen Chin-Ling

    2016-01-01

    Full Text Available Due to the progress of network technology, we can access some information through remote servers, and we also can save and access lots of personal data in remote servers. Therefore, to protect these data and resist unauthorized access is an important issue. Some researchers proposed authentication scheme, but there still exist some security weaknesses. This article is based on the concept of HDFS (Hadoop Distributed File System, and offers a robust authentication scheme. The proposed scheme achieves mutual authentication, prevents re-play attack, solves asynchronous issue, and prevents offline password guessing attack.

  4. Characteristic properties of Fibonacci-based mutually unbiased bases

    Energy Technology Data Exchange (ETDEWEB)

    Seyfarth, Ulrich; Alber, Gernot [Institut fuer Angewandte Physik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Ranade, Kedar [Institut fuer Quantenphysik, Universitaet Ulm, Albert-Einstein-Allee 11, 89069 Ulm (Germany)

    2012-07-01

    Complete sets of mutually unbiased bases (MUBs) offer interesting applications in quantum information processing ranging from quantum cryptography to quantum state tomography. Different construction schemes provide different perspectives on these bases which are typically also deeply connected to various mathematical research areas. In this talk we discuss characteristic properties resulting from a recently established connection between construction methods for cyclic MUBs and Fibonacci polynomials. As a remarkable fact this connection leads to construction methods which do not involve any relations to mathematical properties of finite fields.

  5. A Comparative Study of information searching behavior of elite saffron farmers with that of normal saffron farmers in South Khorasan province

    Directory of Open Access Journals (Sweden)

    somaye zadehrahim

    2017-01-01

    Full Text Available Saffron is one of export products which has a competitive advantage in Iran and saffron farmers need proper information in order to improve the quality of their agricultural performance. Thus, addressing and identification of their information behavior components, sources, and strategies as well as the challenges and problems would help the authorities to make proper policies and decisions. The present research has been conducted in order to compare elite saffron farmers’ information-searching behavior with that of normal saffron farmers in the South Khorasan province. The study population comprised of all the saffron farmers of South Khorasan province (N =17387. Using Morgan formula and cluster sampling, 375 people were selected for the purpose of this study. The results showed that saffron onion (M=3.58 of 5, pesticides and fertilizers (M=3.56 and farmland worker (3.54 were the main components of saffron farmers’ information-searching of the two groups, respectively. The sources of information for both groups included reference to past experience (M=2.68 of 5, neighboring saffron farmers (M=2.67, contact with informants (2.64 and other family members (M=2.64. The information available in local language (M=4 of 5, by native people (M=3.98, clear and intelligible information (M=3.98 and low cost (M=3.82 were among the main criteria that affect the behavior of the two groups in the use of information sources.  Also they are confronted with common problems such as lack of attention to the needs of farmers (M=3.57 of 5, and insufficient number of technical experts (M=3.42. It was also found that there was no significant relationship between information searching behavior of elite and normal saffron farmers and their performance (r= -0.08, p= 0.133. Regarding the “lack of attention to the needs of farmers by technical experts” as the most major problem, South Khorasan Organization of Agricultural Extension is advised to design and implement

  6. (Mutual Security Mutual Affluence) Negative Factors = Sustained Stability: A Framework for Establishing Stability Between Like States

    Science.gov (United States)

    2017-03-31

    160-163. 2 The Concept of Mutually Assured Destruction (MAD) dates back to the post-WWFI em and the Cold War where the United States and Soviet Unions...United States. Following its defeat in W\\VH, Japan was in shambles. The bombing campaigns left nine million Japanese homeless and three million more...the United States, the Charlie Hebdo attacks in Paris in 2015, and the bombings in Istanbul in 2016. Michael Bamier, “From Mutual Assistance to

  7. Mutual altruism: evidence from Alzheimer patients and their spouse caregivers.

    Science.gov (United States)

    König, Markus; Pfarr, Christian; Zweifel, Peter

    2014-01-01

    Preferences of both Alzheimer patients and their spouse caregivers are related to a willingness-to-pay (WTP) measure which is used to test for the presence of mutual (rather than conventional unilateral) altruism. Contingent valuation experiments were conducted in 2000-2002, involving 126 Alzheimer patients and their caregiving spouses living in the Zurich metropolitan area (Switzerland). WTP values for three hypothetical treatments of the demented patient were elicited. The treatment Stabilization prevents the worsening of the disease, bringing dementia to a standstill. Cure restores patient health to its original level. In No burden, dementia takes its normal course while caregiver's burden is reduced to its level before the disease. The three different types of therapies are reflected in different WTP values of both caregivers and patients, suggesting that moderate levels of Alzheimer's disease still permit clear expression of preference. According to the WTP values found, patients do not rank Cure higher than No burden, implying that their preferences are entirely altruistic. Caregiving spouses rank Cure before Burden, reflecting less than perfect altruism which accounts for some 40 percent of their total WTP. Still, this constitutes evidence of mutual altruism. VALUE: The evidence suggests that WTP values reflect individuals' preferences even in Alzheimer patients. The estimates suggest that an economically successful treatment should provide relief to caregivers, with its curative benefits being of secondary importance.

  8. On Information Metrics for Spatial Coding.

    Science.gov (United States)

    Souza, Bryan C; Pavão, Rodrigo; Belchior, Hindiael; Tort, Adriano B L

    2018-04-01

    The hippocampal formation is involved in navigation, and its neuronal activity exhibits a variety of spatial correlates (e.g., place cells, grid cells). The quantification of the information encoded by spikes has been standard procedure to identify which cells have spatial correlates. For place cells, most of the established metrics derive from Shannon's mutual information (Shannon, 1948), and convey information rate in bits/s or bits/spike (Skaggs et al., 1993, 1996). Despite their widespread use, the performance of these metrics in relation to the original mutual information metric has never been investigated. In this work, using simulated and real data, we find that the current information metrics correlate less with the accuracy of spatial decoding than the original mutual information metric. We also find that the top informative cells may differ among metrics, and show a surrogate-based normalization that yields comparable spatial information estimates. Since different information metrics may identify different neuronal populations, we discuss current and alternative definitions of spatially informative cells, which affect the metric choice. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

  9. Hardware device binding and mutual authentication

    Science.gov (United States)

    Hamlet, Jason R; Pierson, Lyndon G

    2014-03-04

    Detection and deterrence of device tampering and subversion by substitution may be achieved by including a cryptographic unit within a computing device for binding multiple hardware devices and mutually authenticating the devices. The cryptographic unit includes a physically unclonable function ("PUF") circuit disposed in or on the hardware device, which generates a binding PUF value. The cryptographic unit uses the binding PUF value during an enrollment phase and subsequent authentication phases. During a subsequent authentication phase, the cryptographic unit uses the binding PUF values of the multiple hardware devices to generate a challenge to send to the other device, and to verify a challenge received from the other device to mutually authenticate the hardware devices.

  10. Mutual Learning in the European Employment Strategy

    DEFF Research Database (Denmark)

    Nedergaard, Peter

    in the European employment strategy have been either determined by the sender's interests or have underestimated how mutual learning between countries takes place. In stead the article develops a constructivist approach to learning and uses it to generate some concrete hypothesis about when learning in committees...... is most likely to take place. Afterwards, this constructivist approach is used to analyse the institutional framework surrounding the European employment strategy in order to evaluate whether the potential for learning is optimal. Finally, the article concludes that even though some basic premises......Mutual learning among the Member States is the primary purpose of the employment policy of the European Union. The two most important questions in this regard are how learning occurs and how much learning takes place. In this article I argue that the existing analyses of the effects of learning...

  11. Behavioral aspects of negotiations on mutual security

    International Nuclear Information System (INIS)

    Druckman, D.; Hopmann, P.T.

    1989-01-01

    This article surveys theory and research about the process of international negotiation. The goal, of this paper is to apply behavioral science research to find ways to negotiate an improved mutual security regime between the nuclear superpowers that would make nuclear war less likely in the years ahead. When President John F. Kennedy presented the first nuclear arms control agreement, the Partial Nuclear Test Ban Treaty, to the U.S. public in 1963 he noted the ancient Chinese proverb: A journey of a thousand miles must begin with a single step. Just as the Partial Nuclear Test Ban Treaty represented for Kennedy the first step on the road to nuclear arms control, so the research reviewed here represents at best the first few steps in a long journey to a better understanding of how to negotiate a regime of mutual security between the nuclear superpowers

  12. Clarifying Normalization

    Science.gov (United States)

    Carpenter, Donald A.

    2008-01-01

    Confusion exists among database textbooks as to the goal of normalization as well as to which normal form a designer should aspire. This article discusses such discrepancies with the intention of simplifying normalization for both teacher and student. This author's industry and classroom experiences indicate such simplification yields quicker…

  13. Returns on Sustainable Mutual Funds in India

    OpenAIRE

    Jain, Anant

    2011-01-01

    The world has seen a huge growth in investment through the sustainable sector. But the study on the cost in construction and measuring the performance of such investments is confined to the limited countries. Thus to compare the performance of the sustainable investment with that of traditional investments it is necessary to increase the sample size of the study. Considering this in mind the paper aims to study the performance and risk of the sustainable mutual fund investments with that of t...

  14. Managerial multitasking in the mutual fund industry

    OpenAIRE

    Agarwal, Vikas; Ma, Linlin; Mullally, Kevin

    2015-01-01

    We examine the determinants and consequences of mutual fund managers simultaneously managing multiple funds. Well-performing managers multitask by taking over poorly performing funds or launching new funds. Subsequent to multitasking, funds run by managers prior to multitasking (i.e., incumbent funds) experience performance deterioration while the performance of the acquired funds improves. Multitasking increases the assets of fund companies but results in a wealth transfer from shareholders ...

  15. Mutuality and solidarity: assessing risks and sharing losses.

    Science.gov (United States)

    Wilkie, D

    1997-01-01

    Mutuality is the principle of private, commercial insurance; individuals enter the pool for sharing losses, and pay according to the best estimate of the risk they bring with them. Solidarity is the sharing of losses with payment according to some other scheme; this is the principle of state social insurance; essential features of solidarity are comprehensiveness and compulsion. Private insurance is subject to the uberrima fides principle, or utmost good faith; each side declares all it knows about the risk. The Disability Discrimination Act requires insurers to justify disability discrimination on the basis of relevant information, acturial, statistical or medical, on which it is reasonable to rely. It could be very damaging to private insurance to abandon uberrima fides. However, although some genetic information is clearly useful to underwriters, other information may be so general as to be of little use. The way in which mortality rates are assessed is also explained. PMID:9304668

  16. The Mutual Benchmarking Method for Smes’ Competitive Strategy Development

    Directory of Open Access Journals (Sweden)

    Rostek Katarzyna

    2013-12-01

    Full Text Available Competitive advantage is a relative feature, evaluated in respect of other competing enterprises. The gaining of sustainable competitive advantage is conditioned by knowledge of own performance and the results of the competitive environment. SMEs have limited opportunities to obtain such information on their own. The method of mutual benchmarking changes this situation by introducing the collaborative network. The aim of the cooperation is to support each of the group members to achieve sustainable competitive advantage, which is the result of a conscious strategy, and not only a matter of chance. This cooperation is based on the collecting and processing of data and sharing information through a common IT platform: for example, a group of Polish SMEs was shown how to implement such a common IT solution and how to provide the information preparing within the proposed service. The whole is a complete proposal for effective support of creating a competitive strategy in SMEs.

  17. Performance Evaluation of Investment (Mutual Funds

    Directory of Open Access Journals (Sweden)

    Povilas Vyšniauskas

    2014-12-01

    Full Text Available The efficiency of an investment fund is one of the main components in evaluating the performance of the fund. This study seeks for introducing and comparing risk and performance evaluation ratios. The paper is aimed at testing the worked out ratios and at distinguishing between the best ones for the purpose of evaluating the performance of Lithuanian mutual funds. Scientific studies show that a standard deviation, alpha, beta, Sharpe and Treynor ratios are mostly employed for identifying the performance of mutual funds that are also compared with their benchmark index to establish if these funds are outperformed and if is it worth paying management fees to investment banks for managing mutual funds. Historical data were selected for the period from 2012-01-02 to 2013-10-15 analysing the prices of monthly funds. The paper points out the areas of a practical application of the proposed model for investment fund valuation, which may not only provide valuable outcomes for practitioners but also may inspire further research on this article.

  18. Herbivory eliminates fitness costs of mutualism exploiters.

    Science.gov (United States)

    Simonsen, Anna K; Stinchcombe, John R

    2014-04-01

    A common empirical observation in mutualistic interactions is the persistence of variation in partner quality and, in particular, the persistence of exploitative phenotypes. For mutualisms between hosts and symbionts, most mutualism theory assumes that exploiters always impose fitness costs on their host. We exposed legume hosts to mutualistic (nitrogen-fixing) and exploitative (non-nitrogen-fixing) symbiotic rhizobia in field conditions, and manipulated the presence or absence of insect herbivory to determine if the costly fitness effects of exploitative rhizobia are context-dependent. Exploitative rhizobia predictably reduced host fitness when herbivores were excluded. However, insects caused greater damage on hosts associating with mutualistic rhizobia, as a consequence of feeding preferences related to leaf nitrogen content, resulting in the elimination of fitness costs imposed on hosts by exploitative rhizobia. Our experiment shows that herbivory is potentially an important factor in influencing the evolutionary dynamic between legumes and rhizobia. Partner choice and host sanctioning are theoretically predicted to stabilize mutualisms by reducing the frequency of exploitative symbionts. We argue that herbivore pressure may actually weaken selection on choice and sanction mechanisms, thus providing one explanation of why host-based discrimination mechanisms may not be completely effective in eliminating nonbeneficial partners. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  19. Effect of acculturation and mutuality on family loyalty among Mexican American caregivers of elders.

    Science.gov (United States)

    Kao, Hsueh-Fen S; An, Kyungeh

    2012-06-01

    Informal family care for elders is conventional in Mexican American communities despite increasing intergenerational gaps in filial values. In our study, we explored whether acculturation and dyadic mutuality, as perceived by Mexican American family caregivers, explain the caregivers' expectations of family loyalty toward elderly relatives. A nonexperimental, correlational design with convenience sampling was used in El Paso, Texas, from October 2007 to January 2008. Three bilingual promotoras collected data from 193 Mexican American adult caregivers of community-dwelling elders using three scales designed for Mexican Americans: the Acculturation Rating Scale for Mexican Americans II-Short Form, the Mutuality Scale, and the Expectations of Family Loyalty of Children Toward Elderly Relatives Scale. Confirmatory factor analysis was used to analyze the data. Acculturation had a marginal effect (r = .21, p loyalty toward elderly relatives. There was no significant correlation between acculturation and mutuality (r = .05). Although Mexican American caregivers with strong Mexican orientation may have high expectations of family loyalty toward elderly relatives, mutuality exhibits more significant effects on expectations. Among Mexican Americans, mutuality between the caregiving dyad, as perceived by caregivers, may be a better predictor of filial values than caregivers' acculturation alone. It may be useful to incorporate the dual paradigm of acculturation and mutuality into immigrant family care for elderly relatives. © 2012 Sigma Theta Tau International.

  20. Mutual repression enhances the steepness and precision of gene expression boundaries.

    Directory of Open Access Journals (Sweden)

    Thomas R Sokolowski

    Full Text Available Embryonic development is driven by spatial patterns of gene expression that determine the fate of each cell in the embryo. While gene expression is often highly erratic, embryonic development is usually exceedingly precise. In particular, gene expression boundaries are robust not only against intra-embryonic fluctuations such as noise in gene expression and protein diffusion, but also against embryo-to-embryo variations in the morphogen gradients, which provide positional information to the differentiating cells. How development is robust against intra- and inter-embryonic variations is not understood. A common motif in the gene regulation networks that control embryonic development is mutual repression between pairs of genes. To assess the role of mutual repression in the robust formation of gene expression patterns, we have performed large-scale stochastic simulations of a minimal model of two mutually repressing gap genes in Drosophila, hunchback (hb and knirps (kni. Our model includes not only mutual repression between hb and kni, but also the stochastic and cooperative activation of hb by the anterior morphogen Bicoid (Bcd and of kni by the posterior morphogen Caudal (Cad, as well as the diffusion of Hb and Kni between neighboring nuclei. Our analysis reveals that mutual repression can markedly increase the steepness and precision of the gap gene expression boundaries. In contrast to other mechanisms such as spatial averaging and cooperative gene activation, mutual repression thus allows for gene-expression boundaries that are both steep and precise. Moreover, mutual repression dramatically enhances their robustness against embryo-to-embryo variations in the morphogen levels. Finally, our simulations reveal that diffusion of the gap proteins plays a critical role not only in reducing the width of the gap gene expression boundaries via the mechanism of spatial averaging, but also in repairing patterning errors that could arise because of the

  1. mutual participation in the health worker-patient relationship

    African Journals Online (AJOL)

    Medunsa) ... Keywords: mutual participation, health worker-patient relationship, decision ... The importance of a mutual participatory model in medical care and decision ... workers become aware of differences in opinion or in the balance of power, ...

  2. Zen and the Brain: Mutually Illuminating Topics

    Directory of Open Access Journals (Sweden)

    James H Austin

    2013-10-01

    Full Text Available Zen Buddhist meditative practices emphasize the long-term, mindful training of attention and awareness during one’s ordinary daily-life activities, the shedding of egocentric behaviors, and the skillful application of one’s innate compassionate resources of insight-wisdom toward others and oneself.This review focuses on how such a comprehensive approach to training the brain could relate to a distinctive flavor of Zen: its emphasis on direct experience, with special reference to those major acute states of awakening that create deep transformations of consciousness and behavior. In Japanese, these advanced states are called kensho and satori.Ten key concepts are reviewed. They begin by distinguishing between the concentrative and receptive forms of meditation, noticing the complementary ways that they each train our normal ‘top-down’ and ‘bottom-up’ modes of attentive processing. Additional concepts distinguish between our two major processing pathways. The self-centered, egocentric frame of reference processes information in relation to our body (our soma or to our mental functions (our psyche. The other-centered frame of reference processes information anonymously. Its prefix, allo- simply means ‘other’ in Greek. Subsequent concepts consider how these useful Greek words --- ego/allo, soma/psyche --- correlate with the normal functional anatomy of important thalamo↔cortical connections. A plausible model then envisions how a triggering stimulus that captures attention could prompt the reticular nucleus to release GABA; how its selective inhibition of the dorsal thalamus could then block both our higher somatic and psychic cortical functions; so as to: a delete the maladaptive aspects of selfhood, while also b releasing the direct, all-inclusive, globally-unified experience of other.Two final concepts consider how the long-term meditative training of intuitive functions relates to certain kinds of word-free spatial tasks that

  3. Conditional selectivity performance of Indian mutual fund schemes: An empirical study

    Directory of Open Access Journals (Sweden)

    Subrata Roy

    2015-06-01

    Full Text Available The present study seeks to examine the stock-selection performance of the sample open-ended equity mutual fund schemes of Birla Sun Life Mutual Fund Company based on traditional and conditional performance measures. It is generally expected that inclusion of some relevant predetermined public information variables in the conditional CAPM provides better performance estimates as compared to the traditional measures. The study reports that after inclusion of conditioning public information variables, the selectivity performances of the schemes have dramatically improved relative to the traditional measure and also found that conditional measure is superior to traditional measure in statistical test.

  4. Danish Mutual Fund Performance - Selectivity, Market Timing and Persistence

    DEFF Research Database (Denmark)

    Christensen, Michael

    Funds under management by Danish mutual funds have increased by 25% annually during the last 10 years and measured per capita Denmark has the third largest mutual fund industry in Europe. This paper provides the first independent performance analysis of Danish mutual funds. We analyse selectivity...

  5. 12 CFR 563.74 - Mutual capital certificates.

    Science.gov (United States)

    2010-01-01

    ... the funds for redemption are raised by the issuance of mutual capital certificates approved pursuant... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Mutual capital certificates. 563.74 Section 563...-OPERATIONS Securities and Borrowings § 563.74 Mutual capital certificates. (a) General. No savings...

  6. Mutual funds : Management styles, social responsibility, performance and efficiency

    NARCIS (Netherlands)

    Barkó, Tamás; Renneboog, Luc; Baker, H.; Filbeck, G.; Kiymaz, H.

    2015-01-01

    The mutual fund industry represents a substantial part of global financial markets with approximately 20 percent invested in mutual funds. Mutual funds offer a simple and easy-to-understand way to invest either into stocks or fixed income products, both for retail and institutional investors. This

  7. Defined Contribution Pension Plans: Mutual Fund Asset Allocation Changes

    OpenAIRE

    Clemens Sialm; Laura Starks; Hanjiang Zhang

    2015-01-01

    In this paper we compare changes in asset allocations between mutual funds held in defined contribution pension plans and funds held by other investors. We investigate how flows into equity and fixed income mutual funds depend on macroeconomic conditions. We find that defined contribution plans react more sensitively to these conditions, suggesting effects on mutual fund managers and other investors.

  8. MUTUAL CONCESSIONS - SPECIFIC ELEMENT OF THE COMPROMISE/TRANSACTION CONTRACT

    Directory of Open Access Journals (Sweden)

    Georgeta-Bianca Spîrchez

    2012-11-01

    Full Text Available Given the usefulness and practical importance of the compromise contract conclusion and of the amicably dispute resolution, within the business world, we aim to analyze, in what follows, the concrete means by which these kind of settlement are achieved. Two questions become legitimate in the context of concerns about mutual concessions which the parties make in a compromise contract. These questions are the following: “What are the mutual concessions? Do mutual concessions mean equivalent concessions?” and “How mutual concessions are required to complete a valid settlement? Is the requirement of mutual concessions grounded?”

  9. Creating a culture of mutual respect.

    Science.gov (United States)

    Kaplan, Kathryn; Mestel, Pamela; Feldman, David L

    2010-04-01

    The Joint Commission mandates that hospitals seeking accreditation have a process to define and address disruptive behavior. Leaders at Maimonides Medical Center, Brooklyn, New York, took the initiative to create a code of mutual respect that not only requires respectful behavior, but also encourages sensitivity and awareness to the causes of frustration that often lead to inappropriate behavior. Steps to implementing the code included selecting code advocates, setting up a system for mediating disputes, tracking and addressing operational system issues, providing training for personnel, developing a formal accountability process, and measuring the results. Copyright 2010 AORN, Inc. Published by Elsevier Inc. All rights reserved.

  10. Group-ID based RFID Mutual Authentication

    Directory of Open Access Journals (Sweden)

    LEE, Y.

    2013-11-01

    Full Text Available For passive type RFID tags, EPCglobal Class 1 Generation-2 Revision is used widely as a de facto standard. As it was designed for low cost, it is quite vulnerable to security issues, such as privacy concerns. This paper presents a new RFID mutual authentication protocol, which is designed to be configured on EPC Gen2 platform and to meet various security requirements while providing efficiency using PRNG (Pseudo Random Number Generator. Group-ID is used to minimize the authentication time. Security analysis of the proposed protocol is discussed.

  11. Cash Holdings and Mutual Fund Performance

    OpenAIRE

    Mikhail Simutin

    2014-01-01

    Cash holdings of equity mutual funds impose a drag on fund performance but also allow managers to make quick investments in attractive stocks and satisfy outflows without costly fire sales. This article shows that actively managed equity funds with high abnormal cash—that is, with cash holdings in excess of the level predicted by fund attributes—outperform their low abnormal cash peers by over 2% per year. Managers carrying high abnormal cash compensate for the low return on cash by making su...

  12. THE COOPERATIVE CREDIT MUTUAL IN BRAZIL.

    Directory of Open Access Journals (Sweden)

    Laércio Baptista da Silva

    2013-06-01

    Full Text Available This study presents an analysis of the reality of credit unions in Brazil, in view of the singular importance of credit unions for the whole society as an alternative to private resources in favor of members of the community where they are located. It confirms that, in Brazil, the mutual credit unions, besides being presented as one of the viable options within the financial system, are also seen as an alternative by which some sectors of society promote the humanization of the financial system by offering credit and return on capital with fairer interest rates.

  13. Identity theory and personality theory: mutual relevance.

    Science.gov (United States)

    Stryker, Sheldon

    2007-12-01

    Some personality psychologists have found a structural symbolic interactionist frame and identity theory relevant to their work. This frame and theory, developed in sociology, are first reviewed. Emphasized in the review are a multiple identity conception of self, identities as internalized expectations derived from roles embedded in organized networks of social interaction, and a view of social structures as facilitators in bringing people into networks or constraints in keeping them out, subsequently, attention turns to a discussion of the mutual relevance of structural symbolic interactionism/identity theory and personality theory, looking to extensions of the current literature on these topics.

  14. Birkhoff normalization

    NARCIS (Netherlands)

    Broer, H.; Hoveijn, I.; Lunter, G.; Vegter, G.

    2003-01-01

    The Birkhoff normal form procedure is a widely used tool for approximating a Hamiltonian systems by a simpler one. This chapter starts out with an introduction to Hamiltonian mechanics, followed by an explanation of the Birkhoff normal form procedure. Finally we discuss several algorithms for

  15. FY 1999 project on the development of new industry support type international standards. Standardization for securing mutual connection among informative household electric appliances; 1999 nendo shinki sangyo shiengata kokusai hyojun kaihatsu jigyo seika hokokusho. Joho kaden kikikan no sogo setsuzokusei kakuho no tame no hyojunka

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    The R and D were conducted with the aim of the international standardization for securing mutual connection among informative household electric appliances, and the FY 1999 results were summarized. In FY 1999, the following were conducted: trial manufacture (for mass production) and evaluation of wide band POF (plastic optical fiber), trial manufacture and evaluation of home use small connector, and trial manufacture and evaluation of optical transceiver module. Various data required for the targeted standardization (transmission band: S400 or more, transmission distance: 100m) were obtained. In the next fiscal year, tests to demonstrate validity/reliability of the data are conducted so that the standards to be accepted as an international standard can be established. In the study of strategies of international standardization, the contents of the standards proposed were discussed, and activities of IEC/TC100 (multi-media) and the related TC were investigated. Early in the next fiscal year, the TC to be proposed is fixed, and international proposing activities are started such as the introduction of the standardization for this R and D to the organizations and persons concerned overseas. (NEDO)

  16. Mutual information, perceptual independence, and holistic face perception.

    Science.gov (United States)

    Fitousi, Daniel

    2013-07-01

    The concept of perceptual independence is ubiquitous in psychology. It addresses the question of whether two (or more) dimensions are perceived independently. Several authors have proposed perceptual independence (or its lack thereof) as a viable measure of holistic face perception (Loftus, Oberg, & Dillon, Psychological Review 111:835-863, 2004; Wenger & Ingvalson, Learning, Memory, and Cognition 28:872-892, 2002). According to this notion, the processing of facial features occurs in an interactive manner. Here, I examine this idea from the perspective of two theories of perceptual independence: the multivariate uncertainty analysis (MUA; Garner & Morton, Definitions, models, and experimental paradigms. Psychological Bulletin 72:233-259, 1969), and the general recognition theory (GRT; Ashby & Townsend, Psychological Review 93:154-179, 1986). The goals of the study were to (1) introduce the MUA, (2) examine various possible relations between MUA and GRT using numerical simulations, and (3) apply the MUA to two consensual markers of holistic face perception(-)recognition of facial features (Farah, Wilson, Drain, & Tanaka, Psychological Review 105:482-498, 1998) and the composite face effect (Young, Hellawell, & Hay, Perception 16:747-759, 1987). The results suggest that facial holism is generated by violations of several types of perceptual independence. They highlight the important theoretical role played by converging operations in the study of holistic face perception.

  17. Renyi generalizations of the conditional quantum mutual information

    Science.gov (United States)

    2015-02-23

    Physical Review Letters, 100(23):230501, June 2008. [20] Frederic Dupuis , Lea Kramer, Philippe Faist, Joseph M. Renes, and Renato Renner. Pro- ceedings...relative Rényi entropy. Journal of Mathematical Physics, 54(12):122201, December 2013. arXiv:1306.5358. 49 [25] Christopher A. Fuchs and Jeroen van de...Lennert, Frédéric Dupuis , Oleg Szehr, Serge Fehr, and Marco Tomamichel. On quantum Rényi entropies: a new definition and some properties. Journal

  18. Mutual information measures applied to EEG signals for sleepiness characterization

    OpenAIRE

    Melia, Umberto Sergio Pio; Guaita, Marc; Vallverdú Ferrer, Montserrat; Embid, Cristina; Vilaseca, I; Salamero, Manuel; Santamaria, Joan

    2015-01-01

    Excessive daytime sleepiness (EDS) is one of the main symptoms of several sleep related disorders with a great impact on the patient lives. While many studies have been carried out in order to assess daytime sleepiness, the automatic EDS detection still remains an open problem. In this work, a novel approach to this issue based on non-linear dynamical analysis of EEG signal was proposed. Multichannel EEG signals were recorded during five maintenance of wakefulness (MWT) and multiple sleep lat...

  19. Do firm characteristics influence mutual fund performance? An empirical study for European mutual funds

    NARCIS (Netherlands)

    de Jong, F.C.J.M.; Wingens, L.

    2013-01-01

    This study investigates the influence of fund management firm characteristics on mutual fund performance. Using a sample of European domiciled open-end equity funds for the period 1998-2008, this study finds that the funds of private companies have performed better than the funds of public

  20. A new mutually reinforcing network node and link ranking algorithm.

    Science.gov (United States)

    Wang, Zhenghua; Dueñas-Osorio, Leonardo; Padgett, Jamie E

    2015-10-23

    This study proposes a novel Normalized Wide network Ranking algorithm (NWRank) that has the advantage of ranking nodes and links of a network simultaneously. This algorithm combines the mutual reinforcement feature of Hypertext Induced Topic Selection (HITS) and the weight normalization feature of PageRank. Relative weights are assigned to links based on the degree of the adjacent neighbors and the Betweenness Centrality instead of assigning the same weight to every link as assumed in PageRank. Numerical experiment results show that NWRank performs consistently better than HITS, PageRank, eigenvector centrality, and edge betweenness from the perspective of network connectivity and approximate network flow, which is also supported by comparisons with the expensive N-1 benchmark removal criteria based on network efficiency. Furthermore, it can avoid some problems, such as the Tightly Knit Community effect, which exists in HITS. NWRank provides a new inexpensive way to rank nodes and links of a network, which has practical applications, particularly to prioritize resource allocation for upgrade of hierarchical and distributed networks, as well as to support decision making in the design of networks, where node and link importance depend on a balance of local and global integrity.

  1. A new mutually reinforcing network node and link ranking algorithm

    Science.gov (United States)

    Wang, Zhenghua; Dueñas-Osorio, Leonardo; Padgett, Jamie E.

    2015-10-01

    This study proposes a novel Normalized Wide network Ranking algorithm (NWRank) that has the advantage of ranking nodes and links of a network simultaneously. This algorithm combines the mutual reinforcement feature of Hypertext Induced Topic Selection (HITS) and the weight normalization feature of PageRank. Relative weights are assigned to links based on the degree of the adjacent neighbors and the Betweenness Centrality instead of assigning the same weight to every link as assumed in PageRank. Numerical experiment results show that NWRank performs consistently better than HITS, PageRank, eigenvector centrality, and edge betweenness from the perspective of network connectivity and approximate network flow, which is also supported by comparisons with the expensive N-1 benchmark removal criteria based on network efficiency. Furthermore, it can avoid some problems, such as the Tightly Knit Community effect, which exists in HITS. NWRank provides a new inexpensive way to rank nodes and links of a network, which has practical applications, particularly to prioritize resource allocation for upgrade of hierarchical and distributed networks, as well as to support decision making in the design of networks, where node and link importance depend on a balance of local and global integrity.

  2. A new mutually reinforcing network node and link ranking algorithm

    Science.gov (United States)

    Wang, Zhenghua; Dueñas-Osorio, Leonardo; Padgett, Jamie E.

    2015-01-01

    This study proposes a novel Normalized Wide network Ranking algorithm (NWRank) that has the advantage of ranking nodes and links of a network simultaneously. This algorithm combines the mutual reinforcement feature of Hypertext Induced Topic Selection (HITS) and the weight normalization feature of PageRank. Relative weights are assigned to links based on the degree of the adjacent neighbors and the Betweenness Centrality instead of assigning the same weight to every link as assumed in PageRank. Numerical experiment results show that NWRank performs consistently better than HITS, PageRank, eigenvector centrality, and edge betweenness from the perspective of network connectivity and approximate network flow, which is also supported by comparisons with the expensive N-1 benchmark removal criteria based on network efficiency. Furthermore, it can avoid some problems, such as the Tightly Knit Community effect, which exists in HITS. NWRank provides a new inexpensive way to rank nodes and links of a network, which has practical applications, particularly to prioritize resource allocation for upgrade of hierarchical and distributed networks, as well as to support decision making in the design of networks, where node and link importance depend on a balance of local and global integrity. PMID:26492958

  3. Improving index mutual fund risk perception : Increase financial literacy or communicate better?

    NARCIS (Netherlands)

    de Goeij, Peter; Van Campenhout, Geert; Subotic, Marjana

    2017-01-01

    We investigate the effect of financial literacy and index mutual fund risk disclosure format on investors’ risk perception by examining the risk disclosure part in the Key Investor Information Document (KIID) for UCITS funds in Europe. Using an experimental survey administered to 244 university

  4. School/Business Partnerships: We Expanded the Idea into a Mutual-Benefit Plan.

    Science.gov (United States)

    Cameron, S. L.

    1987-01-01

    Describes a "mutual benefit" arrangement that expanded the school-business partnership model. Westfall Secondary School and an industrial operation in Owen Sound Ontario, Canada, linked their strengths and needs to offer students actual work and project experiences and to give the company useful information, services, and adult basic…

  5. Performance Evaluation of Equity Mutual Funds in Indonesia

    Directory of Open Access Journals (Sweden)

    Irene Rini Demi Pangestuti

    2017-11-01

    Full Text Available Mutual funds considered as an investment alternative for investors. One type of mutual fund that attracts many investors was the equity mutual funds. Equity mutual fund is a type of mutual funds that most part of the investment consists of stocks in the capital market so the risk rate was higher than the other types of mutual funds. For its different characteristic, the measurement for equity funds performance did not be same with other types of mutual funds. As a stock portfolio, equity mutual funds can be measured by portfolio measurement methods such as Sharpe Index, Treynor Ratio, Jensen Index, Adjusted Sharpe Index, Adjusted Jensen Index, and Sortino Ratio. This study was conducted by using all of those performance measurements as most research in Indonesia was conducted by using limited performance measurements (focusing on Sharpe Index, Treynor Ratio, and Jensen Index. This study aims to evaluated the performance of 42 equity mutual funds available in Indonesia by employing Sharpe Index, Treynor Ratio, Jensen Index, Adjusted Sharpe Index (ASI, Adjusted Jensen Index (AJI, and Sortino Ratio because most previous researches in Indonesian setting disregards ASI and AJI. In general, it was concluded that the SAM Indonesian Equity was the best performing equity fund during the study period. It was further found that most equity mutual fund studied have been well diversified.

  6. Investors Perception And Attitude Towards Mutual Fund As An Investment Option

    OpenAIRE

    Sharma, Priyanka; Agrawal, Payal

    2015-01-01

    Mutual funds have opened new vistas to millions of investors by virtually taking investment to their doorstep. In India, a investor generally goes for such kind of information, which do not provide hedge against inflation and often have negative real returns. He finds himself to be an odd man out in the investment game. Mutual funds have come, as a much needed help to these investors. Thus the success of MFs is essentially the result of the combined efforts of competent fund managers and aler...

  7. Mutual benefits in academic-service partnership: An integrative review.

    Science.gov (United States)

    Sadeghnezhad, Maliheh; Heshmati Nabavi, Fatemeh; Najafi, Fereshteh; Kareshki, Hossein; Esmaily, Habibollah

    2018-05-30

    Academic and service institutions involve with many challenges. Partnership programs are a golden opportunity to achieve mutual benefits to overcome these challenges. Identifying mutual benefits is the cornerstone of forming a successful partnership and guarantee to its continuity. There are definitions and instances of mutual benefits in the literature related to partnership programs, but there is no coherent evidence and clear picture of these benefits. This study is conducted to identify mutual benefits in academic-service partnership by analyzing the definitions and instances of it in the literature. An integrative review of key papers regarding mutual benefits in academic-service partnership was undertaken. This review was guided by the framework described by Whittemore and Knafl. Search of the following databases was conducted: MEDLINE, ERIC, Google Scholar, Emerald Insight and Science Direct. The search terms were mutual benefits, mutual gains, mutual interest, mutual expectations, mutual goals, mutual demand, partnership, collaboration, academic-service partnership and academic service collaboration. Cooper's five-stage integrative review method was used. Quality evaluation of articles was conducted. Data were abstracted from included articles. The analysis was conducted based on the qualitative content analysis of the literature suggested by Zhang and Wildemuth. 28 articles were included in this review. Mutual benefits are described in four categories include: synergy in training and empowerment of human resources, education improvement, access to shared resources, facilitate production and application of beneficial knowledge into practice. Mutual benefits in the academic-service partnership include a range of goals, interests, expectations, and needs of partner organizations that is achievable and measurable through joint planning and collaboration. We suggest academic and service policymakers to consider these benefits in the planning and evaluating

  8. Election to the Board of the Mutual Aid Fund

    CERN Multimedia

    Mutual Aid Fund

    2013-01-01

    Every two years, the Board of the Mutual Aid Fund has to replace a proportion of its members. In accordance with article 6 of the Fund’s General Regulations, three members must leave and have to be replaced. These three members may subscribe again. All members of the CERN staff are eligible. If you are prepared to devote about two hours a month during working hours to assist your colleagues with financial problems, do not hesitate to join this self-governing Board. Candidates must announce their intention to stand for election by 31st January 2014. Fill in the present form and return it to P. Droux/FP (72265) who will also be pleased to provide further information. Name, First Name ................................................................. Department .................................... Tel .............................

  9. Election to the Board of the Mutual Aid Fund

    CERN Multimedia

    Mutual Aid Fund

    2013-01-01

    Every two years, the Board of the Mutual Aid Fund has to replace a proportion of its members. In accordance with article 6 of the Fund’s General Regulations, three members must leave and have to be replaced. These three members may apply again. All members of the CERN staff are eligible. If you are prepared to devote about two hours a month during working hours to assist your colleagues with financial problems, do not hesitate to join this self-governing board. Candidates must announce their intention to stand for election by 31 January 2014. Fill in the present form and return it to P. Droux/FP (72265)  who will also be pleased to provide further information. Name, First Name: ................................................................. Department: .................................... Tel.: ..............................

  10. Election to the Board of the Mutual Aid Fund

    CERN Multimedia

    Mutual Aid Fund

    2011-01-01

    Every year, the Board of the Mutual Aid Fund has to replace a proportion of its members. In accordance with article 6 of the Fund’s General Regulations, three members must leave and have to be replaced. These three members may subscribe again. All members of the CERN staff are eligible. If you are prepared to devote about two hours a month during working hours to assist your colleagues with financial problems, do not hesitate to join this self-governing Board. Candidates must announce their intention to stand for election by 1st Mars 2011. Fill in the present form and return it to P. Droux/FP (72265) or C. Potter/PH (74279) who will also be pleased to provide further information. Name, First Name ................................................................. Department .................................... Tel .............................

  11. Election to the Board of the Mutual Aid Fund

    CERN Multimedia

    Fonds d'Entraide

    2011-01-01

    Every year, the Board of the Mutual Aid Fund has to replace a proportion of its members. In accordance with article 6 of the Fund’s General Regulations, three members must leave and have to be replaced. These three members may subscribe again. All members of the CERN staff are eligible. If you are prepared to devote about two hours a month during working hours to assist your colleagues with financial problems, do not hesitate to join this self-governing Board. Candidates must announce their intention to stand for election by 1st Mars 2011. Fill in the present form and return it to P. Droux/FP (72265) or C. Potter/PH (74279) who will also be pleased to provide further information. Name, First Name Department Tel  

  12. How Can Polarization States of Reflected Light from Snow Surfaces Inform Us on Surface Normals and Ultimately Snow Grain Size Measurements?

    Science.gov (United States)

    Schneider, A. M.; Flanner, M.; Yang, P.; Yi, B.; Huang, X.; Feldman, D.

    2016-12-01

    The Snow Grain Size and Pollution (SGSP) algorithm is a method applied to Moderate Resolution Imaging Spectroradiometer data to estimate snow grain size from space-borne measurements. Previous studies validate and quantify potential sources of error in this method, but because it assumes flat snow surfaces, however, large scale variations in surface normals can cause biases in its estimates due to its dependence on solar and observation zenith angles. To address these variations, we apply the Monte Carlo method for photon transport using data containing the single scattering properties of different ice crystals to calculate polarization states of reflected monochromatic light at 1500nm from modeled snow surfaces. We evaluate the dependence of these polarization states on solar and observation geometry at 1500nm because multiple scattering is generally a mechanism for depolarization and the ice crystals are relatively absorptive at this wavelength. Using 1500nm thus results in a higher number of reflected photons undergoing fewer scattering events, increasing the likelihood of reflected light having higher degrees of polarization. In evaluating the validity of the model, we find agreement with previous studies pertaining to near-infrared spectral directional hemispherical reflectance (i.e. black-sky albedo) and similarities in measured bidirectional reflectance factors, but few studies exist modeling polarization states of reflected light from snow surfaces. Here, we present novel results pertaining to calculated polarization states and compare dependences on solar and observation geometry for different idealized snow surfaces. If these dependencies are consistent across different ice particle shapes and sizes, then these findings could inform the SGSP algorithm by providing useful relationships between measurable physical quantities and solar and observation geometry to better understand variations in snow surface normals from remote sensing observations.

  13. Market timing and selectivity performance of mutual funds in Ghana

    Directory of Open Access Journals (Sweden)

    Abubakar Musah

    2014-07-01

    Full Text Available The growing interest in mutual funds in Ghana has been tremendous over the last decade as evidenced by the continuous increases in number and total funds under management. However, no empirical work has been done on the selectivity and timing ability of the mutual fund managers. Using monthly returns data hand-collected from the reports of the mutual fund managers for the period January 2007-December 2012, this paper examines the market timing and selectivity ability of mutual fund managers in Ghana using the classic Treynor-Mazuy (1966 model and Henriksson- Merton (1981 model. The results suggest that, in general mutual fund managers in Ghana are not able to effectively select stocks and also are not able to predict both the magnitude and direction of future market returns. More specifically, all of the sample mutual fund managers attain significant negative selectivity coefficients and also most of them attain insignificant negative timing coefficients.

  14. Performance Measurement without Benchmarks: An Examination of Mutual Fund Returns.

    OpenAIRE

    Grinblatt, Mark; Titman, Sheridan

    1993-01-01

    This article introduces a new measure of portfolio performance and applies it to study the performance of a large sample of mutual funds. In contrast to previous studies of mutual fund performance, the measure used in this study employs portfolio holdings and does not require the use of a benchmark portfolio. It finds that the portfolio choices of mutual fund managers, particularly those that managed aggressive growth funds, earned significantly positive risk-adjusted returns in the 1976-85 p...

  15. Risk and Return Analysis of Mutual Fund Industry in India

    OpenAIRE

    Bilal Ahmad Pandow; Khurshid Ahmad Butt

    2017-01-01

    The mutual funds is one of the important classes of financial intermediaries which enables millions of small and large savers spread across India as well as internationally to participate in and derive the benefits of the capital market growth. Thus the involvement of mutual funds in the transformation of Indian economy has made it urgent to view their services as they are playing role in mobilizing and allocation of investable funds through markets. The fact is that mutual funds have a lot o...

  16. Investors’ perception on mutual funds with reference to Chidambaram town

    OpenAIRE

    N. Geetha; M. Ramesh

    2011-01-01

    Mutual funds in India play a vital role in mobilizing funds for capital and financial markets. The role of mutual funds in India felt significant as it generates funds from small investors at large across the country. The main objective of the study is to elucidate the perceptions and behaviours of the small investors located in the town of Chidambaram, Tamil Nadu, South India towards the mutual funds and also suggest some measures to increase the quantum of investors and investments as well.

  17. Performance of Mutual Funds In INDIA: 2000 - 2006.

    OpenAIRE

    Kabra, Krishna

    2006-01-01

    Numerous scholarly researches have been carried out to evaluate the performance of mutual funds. These researches may differ in time period but most studies conclude that mutual funds on average have failed to outperform the market and therefore the efficient market hypothesis holds good. This research is carried out to evaluate the performance of 20 surviving diversified equity growth mutual funds for the period of 6 years from July 2000 to June 2006. The data of the fund is collected on Mon...

  18. Modeling the Substrate Skin Effects in Mutual RL Characteristics.,

    Directory of Open Access Journals (Sweden)

    D. de Roest

    2003-12-01

    Full Text Available The goal of this work was to model the influence of the substrateskin effects on the distributed mutual impedance per unit lengthparameters of multiple coupled on-chip interconnects. The proposedanalytic model is based on the frequency-dependent distribution of thecurrent in the silicon substrate and the closed form integrationapproach. It is shown that the calculated frequency-dependentdistributed mutual inductance and the associated mutual resistance arein good agreement with the results obtained from CAD-oriented circuitmodeling technique.

  19. Financial Crisis and Corporate Social Responsible Mutual Fund Flows

    OpenAIRE

    Sitikantha Parida; Zhihong Wang

    2018-01-01

    In this paper, we investigate investment flows into mutual funds that hold more high corporate social responsible stocks (top CSR funds) vs. mutual funds that hold more low corporate social responsible stocks (bottom CSR funds). Using a large sample of equity mutual funds spanning 2003–2012, we find that top CSR funds on average receive about 5% less investment per annum compared to the other funds; whereas bottom CSR funds receive about 5.6% more investments. These relative negative and posi...

  20. Tax-Efficient Asset Management: Evidence from Equity Mutual Funds

    OpenAIRE

    Clemens Sialm; Hanjiang Zhang

    2015-01-01

    Investment taxes have a substantial impact on the performance of taxable mutual fund investors. Mutual funds can reduce the tax burdens of their shareholders by avoiding securities that are heavily taxed and by avoiding realizing capital gains that trigger higher tax burdens to the funds’ investors. Such tax avoidance strategies constrain the investment opportunities of the mutual funds and might reduce their before-tax performance. Our paper empirically investigates the costs and benefits of...

  1. Mutual couling reduction using a lumped LC circuit

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2004-01-01

    A technique to reduce the mutual coupling between two Planar Inverted F Antennas (PIFA) is presented in this paper. By the use of a parallel LC circuit it is possible to reduce the mutual coupling between two antennas. This results in a 16 % improvement in the radiation efficiency.......A technique to reduce the mutual coupling between two Planar Inverted F Antennas (PIFA) is presented in this paper. By the use of a parallel LC circuit it is possible to reduce the mutual coupling between two antennas. This results in a 16 % improvement in the radiation efficiency....

  2. Mutual inactivation of Notch receptors and ligands facilitates developmental patterning.

    Directory of Open Access Journals (Sweden)

    David Sprinzak

    2011-06-01

    Full Text Available Developmental patterning requires juxtacrine signaling in order to tightly coordinate the fates of neighboring cells. Recent work has shown that Notch and Delta, the canonical metazoan juxtacrine signaling receptor and ligand, mutually inactivate each other in the same cell. This cis-interaction generates mutually exclusive sending and receiving states in individual cells. It generally remains unclear, however, how this mutual inactivation and the resulting switching behavior can impact developmental patterning circuits. Here we address this question using mathematical modeling in the context of two canonical pattern formation processes: boundary formation and lateral inhibition. For boundary formation, in a model motivated by Drosophila wing vein patterning, we find that mutual inactivation allows sharp boundary formation across a broader range of parameters than models lacking mutual inactivation. This model with mutual inactivation also exhibits robustness to correlated gene expression perturbations. For lateral inhibition, we find that mutual inactivation speeds up patterning dynamics, relieves the need for cooperative regulatory interactions, and expands the range of parameter values that permit pattern formation, compared to canonical models. Furthermore, mutual inactivation enables a simple lateral inhibition circuit architecture which requires only a single downstream regulatory step. Both model systems show how mutual inactivation can facilitate robust fine-grained patterning processes that would be difficult to implement without it, by encoding a difference-promoting feedback within the signaling system itself. Together, these results provide a framework for analysis of more complex Notch-dependent developmental systems.

  3. Impaired smooth-pursuit in Parkinson's disease: normal cue-information memory, but dysfunction of extra-retinal mechanisms for pursuit preparation and execution.

    Science.gov (United States)

    Fukushima, Kikuro; Ito, Norie; Barnes, Graham R; Onishi, Sachiyo; Kobayashi, Nobuyoshi; Takei, Hidetoshi; Olley, Peter M; Chiba, Susumu; Inoue, Kiyoharu; Warabi, Tateo

    2015-03-01

    While retinal image motion is the primary input for smooth-pursuit, its efficiency depends on cognitive processes including prediction. Reports are conflicting on impaired prediction during pursuit in Parkinson's disease. By separating two major components of prediction (image motion direction memory and movement preparation) using a memory-based pursuit task, and by comparing tracking eye movements with those during a simple ramp-pursuit task that did not require visual memory, we examined smooth-pursuit in 25 patients with Parkinson's disease and compared the results with 14 age-matched controls. In the memory-based pursuit task, cue 1 indicated visual motion direction, whereas cue 2 instructed the subjects to prepare to pursue or not to pursue. Based on the cue-information memory, subjects were asked to pursue the correct spot from two oppositely moving spots or not to pursue. In 24/25 patients, the cue-information memory was normal, but movement preparation and execution were impaired. Specifically, unlike controls, most of the patients (18/24 = 75%) lacked initial pursuit during the memory task and started tracking the correct spot by saccades. Conversely, during simple ramp-pursuit, most patients (83%) exhibited initial pursuit. Popping-out of the correct spot motion during memory-based pursuit was ineffective for enhancing initial pursuit. The results were similar irrespective of levodopa/dopamine agonist medication. Our results indicate that the extra-retinal mechanisms of most patients are dysfunctional in initiating memory-based (not simple ramp) pursuit. A dysfunctional pursuit loop between frontal eye fields (FEF) and basal ganglia may contribute to the impairment of extra-retinal mechanisms, resulting in deficient pursuit commands from the FEF to brainstem. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  4. Mutual Events in the Uranian satellite system in 2007

    Science.gov (United States)

    Arlot, J. E.

    2008-09-01

    The equinox time on the giant planets When the Sun crosses the equatorial plane of a giant planet, it is the equinox time occurring every half orbit of the planet, i.e. every 6 years for Jupiter, 14 years for Saturn, 42 years for Uranus and 82 years for Neptune. Except Neptune, each planet have several major satellites orbiting in the equatorial plane, then, during the equinox time, the satellites will eclipse each other mutually. Since the Earth follows the Sun, during the equinox time, a terrestrial observer will see each satellite occulting each other during the same period. These events may be observed with photometric receivers since the light from the satellites will decrease during the events. The light curve will provide information on the geometric configuration of the the satellites at the time of the event with an accuracy of a few kilometers, not depending on the distance of the satellite system. Then, we are able to get an astrometric observation with an accuracy several times better than using direct imaging for positions. Equinox on Uranus in 2007 In 2007, it was equinox time on Uranus. The Sun crossed the equatorial plane of Uranus on December 6, 2007. Since the opposition Uranus-Sun was at the end of August 2007, observations were performed from May to December 2007. Since the declination of Uranus was between -5 and -6 degrees, observations were better to make in the southern hemisphere. However, some difficulties had to be solved: the faintness of the satellites (magnitude between 14 and 16), the brightness of the planet (magnitude 5) making difficult the photometric observation of the satellites. The used of K' filter associated to a large telescope allows to increase the number of observable events. Dynamics of the Uranian satellites One of the goals of the observations was to evaluate the accuracy of the current dynamical models of the motion of the satellites. This knowledge is important for several reasons: most of time the Uranian system is

  5. Quantum turbulence in superfluids with wall-clamped normal component.

    Science.gov (United States)

    Eltsov, Vladimir; Hänninen, Risto; Krusius, Matti

    2014-03-25

    In Fermi superfluids, such as superfluid (3)He, the viscous normal component can be considered to be stationary with respect to the container. The normal component interacts with the superfluid component via mutual friction, which damps the motion of quantized vortex lines and eventually couples the superfluid component to the container. With decreasing temperature and mutual friction, the internal dynamics of the superfluid component becomes more important compared with the damping and coupling effects from the normal component. As a result profound changes in superfluid dynamics are observed: the temperature-dependent transition from laminar to turbulent vortex motion and the decoupling from the reference frame of the container at even lower temperatures.

  6. Malware Normalization

    OpenAIRE

    Christodorescu, Mihai; Kinder, Johannes; Jha, Somesh; Katzenbeisser, Stefan; Veith, Helmut

    2005-01-01

    Malware is code designed for a malicious purpose, such as obtaining root privilege on a host. A malware detector identifies malware and thus prevents it from adversely affecting a host. In order to evade detection by malware detectors, malware writers use various obfuscation techniques to transform their malware. There is strong evidence that commercial malware detectors are susceptible to these evasion tactics. In this paper, we describe the design and implementation of a malware normalizer ...

  7. Clinical supervision, is it mutually beneficial

    International Nuclear Information System (INIS)

    Adams, E.J.

    2000-01-01

    Full text: Clinical education in Nuclear Medicine is essential for student learning as it enables them to develop knowledge and competence and put theory into practice. While the benefit to the student is clear, the clinical education experience should be mutually beneficial. The role of the clinical supervisor involves teaching, role modelling, management and assessment. It could be assumed that the Supervisor would find the teaching role leading to increased knowledge; role modelling leading to increased reflection which improves practice; management skills being enhanced and assessment improving critical evaluation skills. The aim of this study was to assess the perceived benefits of taking on the role of a clinical supervisor. Clinical Supervisors participating in the Nuclear Medicine program were surveyed. Questions were grouped into three main categories - professional, interpersonal and communication. A Likert scale was used to assess perceived level of benefit and open-ended questions were included to obtain additional understanding of Supervisors' perceptions. Results from the survey indicate that 64% of supervisors felt an increase in work satisfaction by taking students, 68% agreed their level of performance was improved and 61% agreed that it deepened their understanding of Nuclear Medicine. It is concluded that respondents perceived a positive benefit to areas within the role of Clinical Supervisor. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  8. Grounding Animal Rights in Mutual Advantage Contractarianism

    Directory of Open Access Journals (Sweden)

    Matthew Taylor

    2014-09-01

    Full Text Available Contrary to critics and advocates of contractarianism alike, I argue that mutual advantage contractarianism entails rights and protections for animals. In section one I outline the criteria that must be met in order for an individual to qualify for moral rights on the contractarian view. I then introduce an alternative form of ‘rights,’ which I call ‘protectorate status,’ from which an individual can receive protections indirectly. In section two I suggest guidelines for assigning animal rights based on two ways of categorizing animals. On the basis of the categorization according to benefit derived, I argue that animals used for companionship, security, hunting assistance, transportation, entertainment, medical service, nourishment, or clothing will tend to qualify for basic rights against starvation, predation, and disease. On the basis of the categorization according to species, I argue that, on top of the basic rights above, dogs tend to qualify for rights against abuse, and against frivolous medical experimentation, as well as further negotiated rights. Cows have the basic rights against starvation, predation, and disease, but squirrels and bears have no rights. In section three I argue that some animals qualify for protectorate status, which would establish various protections for different animals, but would also generally prohibit cruelty towards animals.

  9. Calcium and ROS: A mutual interplay

    Science.gov (United States)

    Görlach, Agnes; Bertram, Katharina; Hudecova, Sona; Krizanova, Olga

    2015-01-01

    Calcium is an important second messenger involved in intra- and extracellular signaling cascades and plays an essential role in cell life and death decisions. The Ca2+ signaling network works in many different ways to regulate cellular processes that function over a wide dynamic range due to the action of buffers, pumps and exchangers on the plasma membrane as well as in internal stores. Calcium signaling pathways interact with other cellular signaling systems such as reactive oxygen species (ROS). Although initially considered to be potentially detrimental byproducts of aerobic metabolism, it is now clear that ROS generated in sub-toxic levels by different intracellular systems act as signaling molecules involved in various cellular processes including growth and cell death. Increasing evidence suggests a mutual interplay between calcium and ROS signaling systems which seems to have important implications for fine tuning cellular signaling networks. However, dysfunction in either of the systems might affect the other system thus potentiating harmful effects which might contribute to the pathogenesis of various disorders. PMID:26296072

  10. Friendly Home and Inhabitants' Morality: Mutual Relationships

    Science.gov (United States)

    Nartova-Bochaver, Sofya K.; Kuznetsova, Valeriya B.

    2018-01-01

    The study is aimed at investigating the connection between the friendliness of the home environment and the moral motives' level. The friendliness of the home environment includes two aspects: the number of functions provided by home (functionality) and the congruence of these functions with inhabitants' needs (relevance). The theoretical framework of the study was formed by research and ideas emphasizing the interplay between people and their environments. We hypothesized that the friendliness of the home environment and inhabitants' moral motives would have a reciprocal relationship: the friendlier the home the higher the inhabitants' moral motives' level, and, vice versa, the higher the person's moral motives' level the more positive home image. The respondents were 550 students (25% male). The Home Environment Functionality Questionnaire, the Home Environment Relevance Questionnaire, and the Moral Motivation Model Scale were used. As expected, it was found that the friendliness of the home environment and the inhabitants' moral motives are in reciprocal synergetic relationships. Relevance formed more nuanced correlation patterns with moral motives than functionality did. Functionality predicted moral motives poorly whereas moral motives predicted functionality strongly. Finally, relevance and moral motives were found to be in mutual relationships whereas the perceived functionality was predicted by moral motives only. PMID:29375450

  11. Indirect control and power in mutual control structures

    NARCIS (Netherlands)

    Karos, D.; Peters, H.J.M.

    2013-01-01

    In a mutual control structure agents exercise control over each other. Typical examples occur in the area of corporate governance: firms and investment companies exercise mutual control, in particular by owning each others’ stocks. In this paper we formulate a general model for such situations.

  12. Estimation of skill of Russian mutual fund managers

    OpenAIRE

    Parshakov, Petr

    2015-01-01

    Our work is focused on Russian mutual funds managers’ skills versus luck estimating. Using bootstrap procedure we build Jensen’s alpha density for each fund. We find that only 5% of Russian equity mutual funds do have skills (in contrast to luck) to outperform the benchmark.

  13. Mutuality, Self-Silencing, and Disordered Eating in College Women

    Science.gov (United States)

    Wechsler, Lisa S.; Riggs, Shelley A.; Stabb, Sally D.; Marshall, David M.

    2006-01-01

    The current study examined patterns of association among mutuality, self-silencing, and disordered eating in an ethnically diverse sample of college women (N = 149). Partner mutuality and overall self-silencing were negatively correlated and together were associated with six disordered eating indices. All four self-silencing subscales were…

  14. Two high-frequency mutual inductance bridges with high resolution

    NARCIS (Netherlands)

    Flokstra, Jakob; Gerritsma, G.J.; Kreuwel, H.J.M.; van der Marel, L.C.

    1980-01-01

    Two mutual inductance bridges are described for operation up to about 100 kHz. Special attention is paid to the sensitivity and resolution of the bridges. Both bridges can be used to measure variations of about 10 pH in the mutual inductance. The first bridge consists of passive elements only

  15. Performance Evaluation of Open-Ended ELSS Mutual Fund ...

    African Journals Online (AJOL)

    This study examined the performance of the open-ended equity linked saving mutual fund schemes (ELSS) in India during the financial distress in 2008-2009. In this study, the month end net asset values of selected equity linked saving mutual fund schemes were considered and the data was obtained from the website of ...

  16. Mutual intelligibility between closely related language in Europe.

    NARCIS (Netherlands)

    Gooskens, Charlotte; van Heuven, Vincent; Golubovic, Jelena; Schüppert, Anja; Swarte, Femke; Voigt, Stefanie

    2018-01-01

    By means of a large-scale web-based investigation, we established the degree of mutual intelligibility of 16 closely related spoken languages within the Germanic, Slavic and Romance language families in Europe. We first present the results of a selection of 1833 listeners representing the mutual

  17. Mutual intelligibility between closely related languages in Europe

    NARCIS (Netherlands)

    Gooskens, C.; Heuven, van V.J.J.P.; Golubović, J.; Schüppert, A.; Swarte, F.; Voigt, S.

    2017-01-01

    By means of a large-scale web-based investigation, we established the degree of mutual intelligibility of 16 closely related spoken languages within the Germanic, Slavic and Romance language families in Europe. We first present the results of a selection of 1833 listeners representing the mutual

  18. Reducing Deviance Through Youths' Mutual Aid Group Dynamics.

    Science.gov (United States)

    Cheung, Chau-kiu; Ngai, Steven Sek-yum

    2016-01-01

    The mutual aid group, as supported by the social worker, emerges to play a vital role in helping group members reduce their deviance or behavioral problem. However, how the collaboration of the group and social worker accomplishes the reduction has remained uncharted. Based on social capital theory, mutual aid and cohesion within the group and social workers' specific aid for the group are likely responsible for the reduction. The test of such hypotheses relies on a two-wave panel survey of the members of 60 mutual aid groups who had deviant behavioral problems, located in Hong Kong, China. These groups had 241 youths completing both initial and 1-year follow-up surveys. Results manifested the direct or unconditional contributions of mutual aid, group cohesion, and social workers' specific aid to reducing deviance. Hence, social workers can enhance the effectiveness of the mutual aid group in reducing youths' deviance. © The Author(s) 2014.

  19. Mutual proximity graphs for improved reachability in music recommendation.

    Science.gov (United States)

    Flexer, Arthur; Stevens, Jeff

    2018-01-01

    This paper is concerned with the impact of hubness, a general problem of machine learning in high-dimensional spaces, on a real-world music recommendation system based on visualisation of a k-nearest neighbour (knn) graph. Due to a problem of measuring distances in high dimensions, hub objects are recommended over and over again while anti-hubs are nonexistent in recommendation lists, resulting in poor reachability of the music catalogue. We present mutual proximity graphs, which are an alternative to knn and mutual knn graphs, and are able to avoid hub vertices having abnormally high connectivity. We show that mutual proximity graphs yield much better graph connectivity resulting in improved reachability compared to knn graphs, mutual knn graphs and mutual knn graphs enhanced with minimum spanning trees, while simultaneously reducing the negative effects of hubness.

  20. Secure anonymous mutual authentication for star two-tier wireless body area networks.

    Science.gov (United States)

    Ibrahim, Maged Hamada; Kumari, Saru; Das, Ashok Kumar; Wazid, Mohammad; Odelu, Vanga

    2016-10-01

    Mutual authentication is a very important service that must be established between sensor nodes in wireless body area network (WBAN) to ensure the originality and integrity of the patient's data sent by sensors distributed on different parts of the body. However, mutual authentication service is not enough. An adversary can benefit from monitoring the traffic and knowing which sensor is in transmission of patient's data. Observing the traffic (even without disclosing the context) and knowing its origin, it can reveal to the adversary information about the patient's medical conditions. Therefore, anonymity of the communicating sensors is an important service as well. Few works have been conducted in the area of mutual authentication among sensor nodes in WBAN. However, none of them has considered anonymity among body sensor nodes. Up to our knowledge, our protocol is the first attempt to consider this service in a two-tier WBAN. We propose a new secure protocol to realize anonymous mutual authentication and confidential transmission for star two-tier WBAN topology. The proposed protocol uses simple cryptographic primitives. We prove the security of the proposed protocol using the widely-accepted Burrows-Abadi-Needham (BAN) logic, and also through rigorous informal security analysis. In addition, to demonstrate the practicality of our protocol, we evaluate it using NS-2 simulator. BAN logic and informal security analysis prove that our proposed protocol achieves the necessary security requirements and goals of an authentication service. The simulation results show the impact on the various network parameters, such as end-to-end delay and throughput. The nodes in the network require to store few hundred bits. Nodes require to perform very few hash invocations, which are computationally very efficient. The communication cost of the proposed protocol is few hundred bits in one round of communication. Due to the low computation cost, the energy consumed by the nodes is

  1. Normal accidents

    International Nuclear Information System (INIS)

    Perrow, C.

    1989-01-01

    The author has chosen numerous concrete examples to illustrate the hazardousness inherent in high-risk technologies. Starting with the TMI reactor accident in 1979, he shows that it is not only the nuclear energy sector that bears the risk of 'normal accidents', but also quite a number of other technologies and industrial sectors, or research fields. The author refers to the petrochemical industry, shipping, air traffic, large dams, mining activities, and genetic engineering, showing that due to the complexity of the systems and their manifold, rapidly interacting processes, accidents happen that cannot be thoroughly calculated, and hence are unavoidable. (orig./HP) [de

  2. Prior Knowledge Facilitates Mutual Gaze Convergence and Head Nodding Synchrony in Face-to-face Communication.

    Science.gov (United States)

    Thepsoonthorn, C; Yokozuka, T; Miura, S; Ogawa, K; Miyake, Y

    2016-12-02

    As prior knowledge is claimed to be an essential key to achieve effective education, we are interested in exploring whether prior knowledge enhances communication effectiveness. To demonstrate the effects of prior knowledge, mutual gaze convergence and head nodding synchrony are observed as indicators of communication effectiveness. We conducted an experiment on lecture task between lecturer and student under 2 conditions: prior knowledge and non-prior knowledge. The students in prior knowledge condition were provided the basic information about the lecture content and were assessed their understanding by the experimenter before starting the lecture while the students in non-prior knowledge had none. The result shows that the interaction in prior knowledge condition establishes significantly higher mutual gaze convergence (t(15.03) = 6.72, p < 0.0001; α = 0.05, n = 20) and head nodding synchrony (t(16.67) = 1.83, p = 0.04; α = 0.05, n = 19) compared to non-prior knowledge condition. This study reveals that prior knowledge facilitates mutual gaze convergence and head nodding synchrony. Furthermore, the interaction with and without prior knowledge can be evaluated by measuring or observing mutual gaze convergence and head nodding synchrony.

  3. A Lightweight RFID Mutual Authentication Protocol Based on Physical Unclonable Function.

    Science.gov (United States)

    Xu, He; Ding, Jie; Li, Peng; Zhu, Feng; Wang, Ruchuan

    2018-03-02

    With the fast development of the Internet of Things, Radio Frequency Identification (RFID) has been widely applied into many areas. Nevertheless, security problems of the RFID technology are also gradually exposed, when it provides life convenience. In particular, the appearance of a large number of fake and counterfeit goods has caused massive loss for both producers and customers, for which the clone tag is a serious security threat. If attackers acquire the complete information of a tag, they can then obtain the unique identifier of the tag by some technological means. In general, because there is no extra identifier of a tag, it is difficult to distinguish an original tag and its clone one. Once the legal tag data is obtained, attackers can be able to clone this tag. Therefore, this paper shows an efficient RFID mutual verification protocol. This protocol is based on the Physical Unclonable Function (PUF) and the lightweight cryptography to achieve efficient verification of a single tag. The protocol includes three process: tag recognition, mutual verification and update. The tag recognition is that the reader recognizes the tag; mutual verification is that the reader and tag mutually verify the authenticity of each other; update is supposed to maintain the latest secret key for the following verification. Analysis results show that this protocol has a good balance between performance and security.

  4. Multi-objective portfolio optimization of mutual funds under downside risk measure using fuzzy theory

    Directory of Open Access Journals (Sweden)

    M. Amiri

    2012-10-01

    Full Text Available Mutual fund is one of the most popular techniques for many people to invest their funds where a professional fund manager invests people's funds based on some special predefined objectives; therefore, performance evaluation of mutual funds is an important problem. This paper proposes a multi-objective portfolio optimization to offer asset allocation. The proposed model clusters mutual funds with two methods based on six characteristics including rate of return, variance, semivariance, turnover rate, Treynor index and Sharpe index. Semivariance is used as a downside risk measure. The proposed model of this paper uses fuzzy variables for return rate and semivariance. A multi-objective fuzzy mean-semivariance portfolio optimization model is implemented and fuzzy programming technique is adopted to solve the resulted problem. The proposed model of this paper has gathered the information of mutual fund traded on Nasdaq from 2007 to 2009 and Pareto optimal solutions are obtained considering different weights for objective functions. The results of asset allocation, rate of return and risk of each cluster are also determined and they are compared with the results of two clustering methods.

  5. Potentials for mutually beneficial collaboration between FIA specialists and IEG-40 pathologists and geneticists working on fusiform rust

    Science.gov (United States)

    Ellis Cowling; KaDonna Randolph

    2013-01-01

    The purpose of this article is to encourage development of an enduring mutually beneficial collaboration between data and information analysts in the US Forest Service’s "Enhanced Forest Inventory and Analysis (FIA) Program" and forest pathologists and geneticists in the information exchange group (IEG) titled "Genetics and Breeding of Southern Forest...

  6. Pursuing Normality

    DEFF Research Database (Denmark)

    Madsen, Louise Sofia; Handberg, Charlotte

    2018-01-01

    implying an influence on whether to participate in cancer survivorship care programs. Because of "pursuing normality," 8 of 9 participants opted out of cancer survivorship care programming due to prospects of "being cured" and perceptions of cancer survivorship care as "a continuation of the disease......BACKGROUND: The present study explored the reflections on cancer survivorship care of lymphoma survivors in active treatment. Lymphoma survivors have survivorship care needs, yet their participation in cancer survivorship care programs is still reported as low. OBJECTIVE: The aim of this study...... was to understand the reflections on cancer survivorship care of lymphoma survivors to aid the future planning of cancer survivorship care and overcome barriers to participation. METHODS: Data were generated in a hematological ward during 4 months of ethnographic fieldwork, including participant observation and 46...

  7. The mutual recognition arrangement and primary standard dosimetry laboratory comparisons

    International Nuclear Information System (INIS)

    Allisy-Roberts, P.J.; Burns, D.T.

    2002-01-01

    Full text: The majority of the Member States of the Metre Convention have signed an arrangement for the mutual recognition (MRA) of national measurement standards and calibration and measurement capabilities (CMCs). Part of the MRA involves an open access database of CMCs that in turn need to be supported by key and supplementary comparisons of national standards. This paper outlines the MRA, describing the comparisons of national primary standards in the field of dosimetry that support the claims of the CMCs in the key comparison database (KCDB). The MRA was drawn up by the International Committee for Weights and Measures (Comite International des Poids et Mesures CIPM) and was signed at a meeting held in Paris on 14 October 1999 by the directors of the national metrology institutes (NMIs) of thirty-eight Member States of the Metre Convention and representatives of two international organizations. Since that date, the directors of the NMIs of several other Member States and nine Associates of the General Conference (Conference Generale des Poids et Mesures CGPM) have also signed the MRA. The metrological objectives of the MRA are to establish the degree of equivalence of national measurement standards maintained by NMIs and thus provide the basis for the mutual recognition of calibration and measurement certificates issued by NMIs. The NMIs provide the traceability to the international system of units (SI) required for these services and thus mutual recognition of the capabilities of the NMIs is a prerequisite for the mutual recognition of the metrology services of countries in general. The objectives of the MRA are achieved through a process of: (a) international comparisons of measurements, known as key comparisons (b) supplementary international comparisons of measurements, and (c) quality systems and demonstrations of competence by the NMIs. The outcome of the MRA is a determination of the degrees of equivalence of national standards and a set of statements of

  8. The mutual extraction industry: drug use and the normative structure of social capital in the Russian far north.

    Science.gov (United States)

    Pilkington, Hilary; Sharifullina, El'vira

    2009-05-01

    The article contributes to the literature on the role of social networks and social capital in young people's drug use. It considers the structural and cultural dimensions of the 'risk environment' of post-Soviet Russia, the micro risk-environment of a de-industrializing city in the far north of the country and the kind of social capital that circulates in young people's social networks there. Its focus is thus on social capital at the micro-level, the 'bridging' networks of peer friendship groups and the norms that govern them. The research is based on a small ethnographic study of the friendship groups and social networks of young people in the city of Vorkuta in 2006-2007. It draws on data from 32 respondents aged 17-27 in the form of 17 semi-structured audio and video interviews and field diaries. Respondents were selected from friendship groups in which drug use was a regular and symbolically significant practice. The risk environment of the Russian far north is characterised by major de-industrialization, poor health indicators, low life expectancy and limited educational and employment opportunities. It is also marked by a 'work hard, play hard' cultural ethos inherited from the Soviet period when risk-laden manual labour was well-rewarded materially and symbolically. However, young people today often rely on informal economic practices to generate the resource needed to fulfil their expectations. This is evident from the social networks among respondents which were found to be focused around a daily routine of generating and spending income, central to which is the purchase, sale and use of drugs. These practices are governed by norms that often invert those normally ascribed to social networks: reciprocity is replaced by mutual exploitation and trust by cheating. Social networks are central to young people's management of the risk environment associated with post-Soviet economic transformation. However, such networks are culturally as well as structurally

  9. Seasonal asset allocation: Evidence from mutual fund flows

    OpenAIRE

    Kamstra, Mark J.; Kramer, Lisa A.; Levi, Maurice D.; Wermers, Russ

    2013-01-01

    Over the past 30 years, mutual funds have become the dominant vehicle through which individual investors prepare for retirement via defined contribution plans. Further, money market mutual funds, which hold $2.7 trillion as of September 2013, are now a major part of the cash economy in the U.S. Accordingly, the flow of money to and from different mutual fund categories (e.g., equities vs. money funds) increasingly reflects the sentiment or risk aversion of the general population. In this stud...

  10. Controlled mutual quantum entity authentication using entanglement swapping

    International Nuclear Information System (INIS)

    Kang, Min-Sung; Hong, Chang-Ho; Heo, Jino; Lim, Jong-In; Yang, Hyung-Jin

    2015-01-01

    In this paper, we suggest a controlled mutual quantum entity authentication protocol by which two users mutually certify each other on a quantum network using a sequence of Greenberger–Horne–Zeilinger (GHZ)-like states. Unlike existing unidirectional quantum entity authentication, our protocol enables mutual quantum entity authentication utilizing entanglement swapping; moreover, it allows the managing trusted center (TC) or trusted third party (TTP) to effectively control the certification of two users using the nature of the GHZ-like state. We will also analyze the security of the protocol and quantum channel. (paper)

  11. Performance of Mutual Funds in India: (2002-2006)

    OpenAIRE

    Saboo, Manish

    2006-01-01

    There has been many studies in the past on performance of Mutual Funds in comparison to the market. These studies might differ in time and the market under study but most of them concluded that on an average, Mutual Funds have failed to outperform the market and thus the Efficient Market Hypothesis holds good. This research was based on performance of 25 mutual funds for a period of almost 5 years on monthly basis. Funds were evaluated using measures like Sharpe ratio, Treynor ratio, Jense...

  12. Performance of Mutual Funds in India 2003-2008

    OpenAIRE

    Raizada, Shantanu

    2008-01-01

    Many studies have been conducted in the past on the performance of Mutual Funds in comparison to the market index. These studies may differ in their time period, but most of them concluded that on an average the Mutual Funds failed to outperform the market thus the Efficient Market Hypothesis holds good. This research was based on the performance of 20 open ended equity diversified growth Mutual Funds for a period of 5 years from April 2003 to March 2008 and was compared to the BSE 500. Funds...

  13. The Mutual Investments in Romania - Current Developments and Trends

    Directory of Open Access Journals (Sweden)

    Florina Oana VIRLANUTA

    2013-03-01

    Full Text Available Mutual fund industry in Romania has undergone significant growth in recent years in the number of investors and the net assets managed, but still very small compared to other European countries. Capital market development in Romania, the emergence of new investment instruments provides a greater variety of mutual funds investments. Managers decide on the structure of the portfolio by selecting categories of assets in accordance with the rules set out in the Prospectus and according to the degree of risk. In this paper we propose to realize an analysis of mutual investments system in Romania, the progress and their efficiency.

  14. Mutually unbiased bases and semi-definite programming

    Energy Technology Data Exchange (ETDEWEB)

    Brierley, Stephen; Weigert, Stefan, E-mail: steve.brierley@ulb.ac.be, E-mail: stefan.weigert@york.ac.uk

    2010-11-01

    A complex Hilbert space of dimension six supports at least three but not more than seven mutually unbiased bases. Two computer-aided analytical methods to tighten these bounds are reviewed, based on a discretization of parameter space and on Groebner bases. A third algorithmic approach is presented: the non-existence of more than three mutually unbiased bases in composite dimensions can be decided by a global optimization method known as semidefinite programming. The method is used to confirm that the spectral matrix cannot be part of a complete set of seven mutually unbiased bases in dimension six.

  15. Mutually unbiased bases and semi-definite programming

    International Nuclear Information System (INIS)

    Brierley, Stephen; Weigert, Stefan

    2010-01-01

    A complex Hilbert space of dimension six supports at least three but not more than seven mutually unbiased bases. Two computer-aided analytical methods to tighten these bounds are reviewed, based on a discretization of parameter space and on Groebner bases. A third algorithmic approach is presented: the non-existence of more than three mutually unbiased bases in composite dimensions can be decided by a global optimization method known as semidefinite programming. The method is used to confirm that the spectral matrix cannot be part of a complete set of seven mutually unbiased bases in dimension six.

  16. Mutual Coupling Effects on Pattern Diversity Antennas for MIMO Femtocells

    Directory of Open Access Journals (Sweden)

    Yue Gao

    2010-01-01

    Full Text Available Diversity antennas play an important role in wireless communications. However, mutual coupling between multiple ports of a diversity antenna has significant effects on wireless radio links and channel capacity. In this paper, dual-port pattern diversity antennas for femtocell applications are proposed to cover GSM1800, UMTS, and WLAN frequency bands. The channel capacities of the proposed antennas and two ideal dipoles with different mutual coupling levels are investigated in an indoor environment. The relation between mutual coupling and channel capacity is observed through investigations of these antennas.

  17. Human Security and Mutual Vulnerability: The Global Political ...

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

    -Cold War era: the search for an analytical framework that will help us understand this turbulent and chaotic period in human history. His lucid and visionary analysis rests on the concept of mutual vulnerability: that in an increasingly ...

  18. The decision making on mutual investment of thai investors ...

    African Journals Online (AJOL)

    The decision making on mutual investment of thai investors. ... Journal of Fundamental and Applied Sciences. Journal Home ... The study was a research survey that used questionnaires to collect data from 400 samples of Thai investors.

  19. Mutual incomprehension: U.S.- German value gaps beyond Iraq

    OpenAIRE

    Larres, Klaus

    2003-01-01

    Differences over Iraq policy have revealed deep U.S.- German value gaps over multilateralism, nationalism, and the role of force in international relations. Cooperation in four areas of mutual importance can help compensate for them.

  20. 75 FR 47063 - Mutual Fund Distribution Fees; Confirmations

    Science.gov (United States)

    2010-08-04

    ... section 12(b) is to prevent mutual funds from incurring ``excessive sales, promotion expenses, and so... plans and used the revenue to pay for advertising and sales materials.\\55\\ In time, however, funds began... to revenue sharing. [[Page 47069

  1. Generalized Mutual Synchronization between Two Controlled Interdependent Networks

    Directory of Open Access Journals (Sweden)

    Quan Xu

    2014-01-01

    Full Text Available This paper mainly focuses on the generalized mutual synchronization between two controlled interdependent networks. First, we propose the general model of controlled interdependent networks A and B with time-varying internetwork delays coupling. Then, by constructing Lyapunov functions and utilizing adaptive control technique, some sufficient conditions are established to ensure that the mutual synchronization errors between the state variables of networks A and B can asymptotically converge to zero. Finally, two numerical examples are given to illustrate the effectiveness of the theoretical results and to explore potential application in future smart grid. The simulation results also show how interdependent topologies and internetwork coupling delays influence the mutual synchronizability, which help to design interdependent networks with optimal mutual synchronizability.

  2. Public-channel cryptography based on mutual chaos pass filters.

    Science.gov (United States)

    Klein, Einat; Gross, Noam; Kopelowitz, Evi; Rosenbluh, Michael; Khaykovich, Lev; Kinzel, Wolfgang; Kanter, Ido

    2006-10-01

    We study the mutual coupling of chaotic lasers and observe both experimentally and in numeric simulations that there exists a regime of parameters for which two mutually coupled chaotic lasers establish isochronal synchronization, while a third laser coupled unidirectionally to one of the pair does not synchronize. We then propose a cryptographic scheme, based on the advantage of mutual coupling over unidirectional coupling, where all the parameters of the system are public knowledge. We numerically demonstrate that in such a scheme the two communicating lasers can add a message signal (compressed binary message) to the transmitted coupling signal and recover the message in both directions with high fidelity by using a mutual chaos pass filter procedure. An attacker, however, fails to recover an errorless message even if he amplifies the coupling signal.

  3. Measuring the performance of mutual funds: A case study

    Directory of Open Access Journals (Sweden)

    Jakšić Milena

    2015-01-01

    Full Text Available In this paper we evaluate the performance of eight open-end mutual funds in the Republic of Serbia for the period 2009-2012, with the aim of testing the justification of active portfolio management of mutual funds, and determining the selection capability of Serbian portfolio managers. Risk-weighted returns of mutual funds are compared with the risk-weighted return of the leading Belgrade Stock Exchange index, Belex15, whereas the following are used as performance measures: Sharpe ratio (Si, Treynor ratio (Ti, and Jensen's or Alpha index (αi. The results suggest that the portfolio of Serbian mutual funds has inferior performance compared to the market portfolio, which indicates the lack of selection capabilities of domestic portfolio managers.

  4. Mutual emergency assistance arrangements at the international level

    International Nuclear Information System (INIS)

    Swindell, G.E.; Ha Vinh Phuong

    1979-01-01

    All countries do not necessarily have resources in skilled manpower and equipment enabling them to deal satisfactorily with the consequences of a nuclear incident. Therefore, a mechanism whereby such countries could obtain or provide mutual emergency assistance at international level is extremely useful. This article analyses the provisions of the Nordic Mutual Emergency Assistance Agreement and the measures taken in respect of emergency assistance by international organisations such as IAEA. (NEA) [fr

  5. Importance of mutual benefits in online knowledge sharing communities

    OpenAIRE

    Tian, Y.; Lau, L.M.S.; Dew, P.M.

    2004-01-01

    The sustainability of knowledge sharing e-communities is a major issue at present. A hypothesis was\\ud proposed at the outset in the paper that the provision of mutual benefits among participants will lead to positive\\ud participation. Drawing from the economic and social theories, a framework for analysis was developed and tested in\\ud an empirical study. The preliminary results demonstrated a direct relationship between mutual benefits and the level\\ud of participation, and hence supported ...

  6. Generalized Mutual Synchronization between Two Controlled Interdependent Networks

    OpenAIRE

    Xu, Quan; Zhuang, Shengxian; Hu, Dan; Zeng, Yingfeng; Xiao, Jian

    2014-01-01

    This paper mainly focuses on the generalized mutual synchronization between two controlled interdependent networks. First, we propose the general model of controlled interdependent networks $A$ and $B$ with time-varying internetwork delays coupling. Then, by constructing Lyapunov functions and utilizing adaptive control technique, some sufficient conditions are established to ensure that the mutual synchronization errors between the state variables of networks $A$ and $B$ can asymptotically c...

  7. On the behavior of mutual fund investors and managers

    OpenAIRE

    Goriaev, A.P.

    2002-01-01

    This thesis investigates empirically and theoretically the behavior of mutual fund investors and managers. These two aspects are closely related to each other. Investors try to select funds that follow an optimal investment policy from their point of view, while fund managers are typically interested in maximizing net fund inflows. In the first part of the thesis, we analyze the determinants of mutual fund flows, concentrating on the impact of past performance on fund flows. In particular, we...

  8. Mutually shared team competence of professionals in early childhood intervention

    OpenAIRE

    Ališauskienė, Stefanija; Kairienė, Daiva

    2011-01-01

    The article is based on theoretical study as well as on written survey. The aim of theoretical analysis to present a theoretical model of the concept of the mutually shared team competence in an interprofessional team meeting early special needs of child and family and to find out presumptions of its development. The aim of survey is to reveal ECI professionals' reflections about competences necessary for teamwork. The mutually shared team competence is analysed on the basis of the teamwork p...

  9. Liquidity risk and the performance of UK mutual funds

    OpenAIRE

    Foran, Jason; O'Sullivan, Niall

    2014-01-01

    We examine the role of liquidity risk, both as a stock characteristic as well as systematic liquidity risk, in UK mutual fund performance for the first time. Using four alternative measures of stock liquidity we extract principal components across stocks in order to construct systematic or market liquidity factors. We find that on average UK mutual funds are tilted towards liquid stocks (except for small stock funds as might be expected) but that, counter-intuitively, liquidity as a stock cha...

  10. Enhanced mutual capture of colored solitons by matched modulator

    Science.gov (United States)

    Feigenbaum, Eyal; Orenstein, Meir

    2004-08-01

    The mutual capture of two colored solitons is enhanced by a modulator, to a level which enables its practical exploitation, e.g., for a read- write mechanism in a soliton buffer. The enhanced capture was analyzed using closed form particle-like soliton perturbation, and verified by numerical simulations. Optimal modulator frequency and modulation depth are obtained. This mutual capture can be utilized for all-optical soliton logic and memory.

  11. Quantum process reconstruction based on mutually unbiased basis

    International Nuclear Information System (INIS)

    Fernandez-Perez, A.; Saavedra, C.; Klimov, A. B.

    2011-01-01

    We study a quantum process reconstruction based on the use of mutually unbiased projectors (MUB projectors) as input states for a D-dimensional quantum system, with D being a power of a prime number. This approach connects the results of quantum-state tomography using mutually unbiased bases with the coefficients of a quantum process, expanded in terms of MUB projectors. We also study the performance of the reconstruction scheme against random errors when measuring probabilities at the MUB projectors.

  12. Team Reasoning and Intentional Cooperation for Mutual Benefit

    OpenAIRE

    Sugden Robert

    2015-01-01

    This paper proposes a concept of intentional cooperation for mutual benefit. This concept uses a form of team reasoning in which team members aim to achieve common interests, rather than maximising a common utility function, and in which team reasoners can coordinate their behaviour by following pre-existing practices. I argue that a market transaction can express intentions for mutually beneficial cooperation even if, extensionally, participation in the transaction promotes each party’s self...

  13. On the Importance of Mutual Fund Families in Emerging Markets

    OpenAIRE

    Ekholm, Anders; Pasternack, Daniel; Sandvall, Thomas

    2000-01-01

    This study contributes to the mutual fund literature by looking at performance persistence on a fund family level, allowing for individual equity, bond and balanced funds to be included under single family umbrellas. The study is conducted on the emerging Finnish mutual fund market, an environment in which the importance of superior fund family teams is likely to be accentuated. Using both non–parametric and parametric tests we find robust evidence of performance persistence for the fund fami...

  14. Mutual friction in superfluid 3He: Effects of bound states in the vortex core

    International Nuclear Information System (INIS)

    Kopnin, N.B.; Salomaa, M.M.

    1991-01-01

    The motion of singular quantized vortex lines in superfluid 3 He is considered for the A and B phases. Mutual friction is calculated within a microscopic quantum-mechanical Green's-function formalism, valid for dynamical processes. This enables us to include all the different physical phenomena in a unified approach. We consider axisymmetric vortices for temperatures considerably lower than T c . In this regime, the main contribution to the force exerted on a moving vortex originates from the localized Fermi excitations occupying quantized energy eigenstates in the vortex core. These 3 He quasiparticle states are similar to the quantized motion of charge in a magnetic field; thus vortex motion in 3 He resembles the Hall phenomenon in metals. The outcome is that the viscous drag cannot simply be expressed through the cross sections for 3 He quasiparticles scattering off the vortex, but is rather due to the mutual interactions between the localized quasiparticles and the normal excitations. Our calculations conform with the experimental values for the mutual-friction parameters. We also discuss vortex oscillations, and predict that strong dissipation should be observed at a resonant frequency of about 10 kHz, owing to transitions between the bound-state energy levels. This effect could be used for detecting and measuring the quantization of the bound-state spectrum for superfluid 3 He in the vortex-core matter

  15. Maximally Informative Stimuli and Tuning Curves for Sigmoidal Rate-Coding Neurons and Populations

    Science.gov (United States)

    McDonnell, Mark D.; Stocks, Nigel G.

    2008-08-01

    A general method for deriving maximally informative sigmoidal tuning curves for neural systems with small normalized variability is presented. The optimal tuning curve is a nonlinear function of the cumulative distribution function of the stimulus and depends on the mean-variance relationship of the neural system. The derivation is based on a known relationship between Shannon’s mutual information and Fisher information, and the optimality of Jeffrey’s prior. It relies on the existence of closed-form solutions to the converse problem of optimizing the stimulus distribution for a given tuning curve. It is shown that maximum mutual information corresponds to constant Fisher information only if the stimulus is uniformly distributed. As an example, the case of sub-Poisson binomial firing statistics is analyzed in detail.

  16. Normalization of satellite imagery

    Science.gov (United States)

    Kim, Hongsuk H.; Elman, Gregory C.

    1990-01-01

    Sets of Thematic Mapper (TM) imagery taken over the Washington, DC metropolitan area during the months of November, March and May were converted into a form of ground reflectance imagery. This conversion was accomplished by adjusting the incident sunlight and view angles and by applying a pixel-by-pixel correction for atmospheric effects. Seasonal color changes of the area can be better observed when such normalization is applied to space imagery taken in time series. In normalized imagery, the grey scale depicts variations in surface reflectance and tonal signature of multi-band color imagery can be directly interpreted for quantitative information of the target.

  17. Mutual Guarantee Institutions and Small Business Finance

    NARCIS (Netherlands)

    Columba, F.; Gambacorta, L.; Mistrulli, P.E.

    2009-01-01

    A large literature showed that small firms experience difficulties in accessing the credit market due to informational asymmetries; these may be mitigated by collateral or relationship lending, possibilities often precluded to small business. We investigate the effect on small business finance of an

  18. 12-Step Interventions and Mutual Support Programs for Substance Use Disorders: An Overview

    Science.gov (United States)

    Donovan, Dennis M.; Ingalsbe, Michelle H.; Benbow, James; Daley, Dennis C.

    2013-01-01

    Social workers and other behavioral health professionals are likely to encounter individuals with substance use disorders in a variety of practice settings outside of specialty treatment. 12-Step mutual support programs represent readily available, no cost community-based resources for such individuals; however, practitioners are often unfamiliar with such programs. The present article provides a brief overview of 12-Step programs, the positive substance use and psychosocial outcomes associated with active 12-Step involvement, and approaches ranging from ones that can be utilized by social workers in any practice setting to those developed for specialty treatment programs to facilitate engagement in 12-Step meetings and recovery activities. The goal is to familiarize social workers with 12-Step approaches so that they are better able to make informed referrals that match clients to mutual support groups that best meet the individual’s needs and maximize the likelihood of engagement and positive outcomes. PMID:23731422

  19. Mutual Payments in Increase of the Level of Economic Security of Energy Generating Enterprises

    Directory of Open Access Journals (Sweden)

    Ruzhytskyi Andrіy V

    2013-12-01

    Full Text Available The article presents main approaches to the essence of the economic security of an enterprise notion, namely, approach of counter-action to threats, approach of successful market activity and approach of achievement of certain development goals; it identifies the role of economic security of energy generating enterprises in economic security of other subjects and the country in general; it offers definition of the economic security of an enterprise notion as a complex characteristic of the state of the enterprise that reflects the level of the enterprise possibility to ensure functioning and development; it marks out functional components of economic security, which are connected with mutual payments, namely, financial, personnel, technical and technological, political and legal, informational and interface ones; it presents connection of mutual payments with the level of financial component of economic security of enterprises, which envisages financial flow from or to the enterprise for changing the obligation status or its quantitative characteristics.

  20. Study on a program for support of women nuclear experts exchange and mutual utilization between WANO Korea and WANO Global

    International Nuclear Information System (INIS)

    Lee, Haecho; No, Inyoung; Min, Byungju

    2010-12-01

    - Nuclear energy, unlike other international human and material essential to mutual understanding, exchange of information and technology-intensive industries as required by an active technical cooperation and information exchange between countries is very important - WiN-Global Women's Domestic Nuclear specialists and professionals between countries belonging to the network for women through nuclear technology and nuclear power expansion opportunities to exchange information to secure a variety of communication

  1. Smooth quantile normalization.

    Science.gov (United States)

    Hicks, Stephanie C; Okrah, Kwame; Paulson, Joseph N; Quackenbush, John; Irizarry, Rafael A; Bravo, Héctor Corrada

    2018-04-01

    Between-sample normalization is a critical step in genomic data analysis to remove systematic bias and unwanted technical variation in high-throughput data. Global normalization methods are based on the assumption that observed variability in global properties is due to technical reasons and are unrelated to the biology of interest. For example, some methods correct for differences in sequencing read counts by scaling features to have similar median values across samples, but these fail to reduce other forms of unwanted technical variation. Methods such as quantile normalization transform the statistical distributions across samples to be the same and assume global differences in the distribution are induced by only technical variation. However, it remains unclear how to proceed with normalization if these assumptions are violated, for example, if there are global differences in the statistical distributions between biological conditions or groups, and external information, such as negative or control features, is not available. Here, we introduce a generalization of quantile normalization, referred to as smooth quantile normalization (qsmooth), which is based on the assumption that the statistical distribution of each sample should be the same (or have the same distributional shape) within biological groups or conditions, but allowing that they may differ between groups. We illustrate the advantages of our method on several high-throughput datasets with global differences in distributions corresponding to different biological conditions. We also perform a Monte Carlo simulation study to illustrate the bias-variance tradeoff and root mean squared error of qsmooth compared to other global normalization methods. A software implementation is available from https://github.com/stephaniehicks/qsmooth.

  2. It Takes Two to Tango: How Parents' and Adolescents' Personalities Link to the Quality of Their Mutual Relationship

    Science.gov (United States)

    Denissen, Jaap J. A.; van Aken, Marcel A. G.; Dubas, Judith S.

    2009-01-01

    According to J. Belsky's (1984) process model of parenting, both adolescents' and parents' personality should exert a significant impact on the quality of their mutual relationship. Using multi-informant, symmetric data on the Big Five personality traits and the relationship quality of mothers, fathers, and two adolescent children, the current…

  3. It takes two to tango: How parents' and adolescents' personalities link to the quality of their mutual relationship

    NARCIS (Netherlands)

    Denissen, J.J.A.; Aken, M.A.G. van; Dubas, J.S.

    2009-01-01

    According to Belsky’s (1984) process model of parenting, both adolescents’ and parents’ personality should exert a significant impact on the quality of their mutual relationship. Using multi-informant, symmetric data on the Big Five personality traits and relationship quality of mothers, fathers,

  4. Persistence of pollination mutualisms in the presence of ants.

    Science.gov (United States)

    Wang, Yuanshi; Wang, Shikun

    2015-01-01

    This paper considers plant-pollinator-ant systems in which the plant-pollinator interaction is mutualistic but ants have both positive and negative effects on plants. The ants also interfere with pollinators by preventing them from accessing plants. While a Beddington-DeAngelis (BD) formula can describe the plant-pollinator interaction, the formula is extended in this paper to characterize the pollination mutualism under the ant interference. Then, a plant-pollinator-ant system with the extended BD functional response is discussed, and global dynamics of the model demonstrate the mechanisms by which pollination mutualism can persist in the presence of ants. When the ant interference is strong, it can result in extinction of pollinators. Moreover, if the ants depend on pollination mutualism for survival, the strong interference could drive pollinators into extinction, which consequently lead to extinction of the ants themselves. When the ant interference is weak, a cooperation between plant-ant and plant-pollinator mutualisms could occur, which promotes survival of both ants and pollinators, especially in the case that ants (respectively, pollinators) cannot survive in the absence of pollinators (respectively, ants). Even when the level of ant interference remains invariant, varying ants' negative effect on plants can result in survival/extinction of both ants and pollinators. Therefore, our results provide an explanation for the persistence of pollination mutualism when there exist ants.

  5. Mutualism Disruption Threatens Global Plant Biodiversity: A Systematic Review.

    Directory of Open Access Journals (Sweden)

    Clare E Aslan

    Full Text Available As global environmental change accelerates, biodiversity losses can disrupt interspecific interactions. Extinctions of mutualist partners can create "widow" species, which may face reduced ecological fitness. Hypothetically, such mutualism disruptions could have cascading effects on biodiversity by causing additional species coextinctions. However, the scope of this problem - the magnitude of biodiversity that may lose mutualist partners and the consequences of these losses - remains unknown.We conducted a systematic review and synthesis of data from a broad range of sources to estimate the threat posed by vertebrate extinctions to the global biodiversity of vertebrate-dispersed and -pollinated plants. Though enormous research gaps persist, our analysis identified Africa, Asia, the Caribbean, and global oceanic islands as geographic regions at particular risk of disruption of these mutualisms; within these regions, percentages of plant species likely affected range from 2.1-4.5%. Widowed plants are likely to experience reproductive declines of 40-58%, potentially threatening their persistence in the context of other global change stresses.Our systematic approach demonstrates that thousands of species may be impacted by disruption in one class of mutualisms, but extinctions will likely disrupt other mutualisms, as well. Although uncertainty is high, there is evidence that mutualism disruption directly threatens significant biodiversity in some geographic regions. Conservation measures with explicit focus on mutualistic functions could be necessary to bolster populations of widowed species and maintain ecosystem functions.

  6. The Profile of a Polish Mutual Fund Manager

    Directory of Open Access Journals (Sweden)

    Dariusz Filip

    2018-05-01

    Full Text Available Aim/purpose - The purpose of this paper is to identify the characteristics that are typical of mutual fund managers. Design/methodology/approach - The study concentrates on a set of socio-demographic data, such as: age, gender, education, experience, and professional qualifications of 336 portfolio managers. The applied research strategy relies on an analysis concerning a set of statistical metrics describing the population under examination. Findings - The average Polish fund manager is a 37-year-old man, a holder of a stock-broker or investment adviser license. He obtained the authorization from the Polish Financial Supervision Authority (KNF a few years after graduating from the Warsaw School of Economics (SGH. He has 11 years' experience in financial markets and 7 years' experience in the mutual fund industry. Research implications/limitations - The identification of managerial characteristics for the purpose of creating a profile of a Polish mutual fund manager will provide an important basis for further surveys and analyses aimed to evaluate the effectiveness of mutual funds. Originality/value/contribution - There are no investigations within the discussed area in Polish studies. Therefore, the identification of the characteristics that are typical of mutual fund managers will make a contribution to the finance literature.(original abstract

  7. A fast and automatically paired 2-D direction-of-arrival estimation with and without estimating the mutual coupling coefficients

    Science.gov (United States)

    Filik, Tansu; Tuncer, T. Engin

    2010-06-01

    A new technique is proposed for the solution of pairing problem which is observed when fast algorithms are used for two-dimensional (2-D) direction-of-arrival (DOA) estimation. Proposed method is integrated with array interpolation for efficient use of antenna elements. Two virtual arrays are generated which are positioned accordingly with respect to the real array. ESPRIT algorithm is used by employing both the real and virtual arrays. The eigenvalues of the rotational transformation matrix have the angle information at both magnitude and phase which allows the estimation of azimuth and elevation angles by using closed-form expressions. This idea is used to obtain the paired interpolated ESPRIT algorithm which can be applied for arbitrary arrays when there is no mutual coupling. When there is mutual coupling, two approaches are proposed in order to obtain 2-D paired DOA estimates. These blind methods can be applied for the array geometries which have mutual coupling matrices with a Toeplitz structure. The first approach finds the 2-D paired DOA angles without estimating the mutual coupling coefficients. The second approach estimates the coupling coefficients and iteratively improves both the coupling coefficients and the DOA estimates. It is shown that the proposed techniques solve the pairing problem for uniform circular arrays and effectively estimate the DOA angles in case of unknown mutual coupling.

  8. Mutual control of X-rays and nuclear transitions

    Energy Technology Data Exchange (ETDEWEB)

    Gunst, Jonas Friedrich

    2015-12-14

    In the course of this Thesis the mutual control between X-rays and nuclear transitions is investigated theoretically. In the first Part, we study the nuclear photoexcitation with the highly brilliant and coherent X-ray free-electron lasers (XFELs). Apart from amplifying the direct resonant interaction with nuclear transitions, the super-intense XFEL can produce new states of matter like cold, high-density plasmas where secondary nuclear excitation channels may come into play, e.g., nuclear excitation by electron capture (NEEC). Our results predict that in the case of {sup 57}Fe targets secondary NEEC can be safely neglected, whereas it is surprisingly the dominating contribution (in comparison to the direct photoexcitation) for the XFEL-induced {sup 93m}Mo isomer triggering. Based on these case studies, we elaborate a general set of criteria to identify the prevailing excitation channel for a certain nuclear isotope. These criteria may be most relevant for future nuclear resonance experiments at XFEL facilities. On the opposite frontier, the interplay between single X-ray photons and nuclear transitions offer potential storage and processing applications for information science in their most compact form. In the second Part of this Thesis, we show that nuclear forward scattering off {sup 57}Fe targets can be employed to process polarization-encoded single X-rays via timed magnetic field rotations. Apart from the realization of logical gates with X-rays, the polarization encoding is used to design an X-ray quantum eraser scheme where the interference between scattering paths can be switched off and on in a controlled manner. Such setups may advance time-energy complementarity tests to so far unexplored parameter regimes, e.g., to the domain of X-ray quanta.

  9. The Mutual Relationship Between Men's Drinking and Depression: A 4-Year Longitudinal Analysis.

    Science.gov (United States)

    Lee, Soo Bi; Chung, Sulki; Lee, HaeKook; Seo, Jeong Seok

    2018-03-17

    The purpose of the current study was to examine the longitudinal reciprocal relationship between depression and drinking among male adults from the general population. This study used a panel dataset from the Korean Welfare Panel (from 2011 to 2014). The subjects were 2511 male adults aged between 20 and 65 years. Based on the Korean Version of the Alcohol Use Disorders Identification Test (AUDIT-K) scores, 2191 subjects were categorized as the control group (AUDIT-K AUDIT-K ≥ 12). An autoregressive cross-lagged modelling analysis was performed to investigate the mutual relationship between problem drinking and depression measured consecutively over time. The results indicated that alcohol drinking and depression were stable over time. In the control group, there was no significant causal relationship between problem drinking and depression while in the problem drinking group, drinking in the previous year significantly influenced depression in the following second, third and fourth years. This study compared normal versus problem drinkers and showed a 4-year mutual causal relationship between depression and drinking. No longitudinal interaction between drinking and depression occurred in normal drinkers, while drinking intensified depression over time in problem drinkers. This study found that problem drinking was a risk factor for development of depression. Therefore, more attention should be given to problem alcohol use in the general population and evaluation of past alcohol use history in patients with depressive disorders.

  10. Sparse Bayesian Learning for DOA Estimation with Mutual Coupling

    Directory of Open Access Journals (Sweden)

    Jisheng Dai

    2015-10-01

    Full Text Available Sparse Bayesian learning (SBL has given renewed interest to the problem of direction-of-arrival (DOA estimation. It is generally assumed that the measurement matrix in SBL is precisely known. Unfortunately, this assumption may be invalid in practice due to the imperfect manifold caused by unknown or misspecified mutual coupling. This paper describes a modified SBL method for joint estimation of DOAs and mutual coupling coefficients with uniform linear arrays (ULAs. Unlike the existing method that only uses stationary priors, our new approach utilizes a hierarchical form of the Student t prior to enforce the sparsity of the unknown signal more heavily. We also provide a distinct Bayesian inference for the expectation-maximization (EM algorithm, which can update the mutual coupling coefficients more efficiently. Another difference is that our method uses an additional singular value decomposition (SVD to reduce the computational complexity of the signal reconstruction process and the sensitivity to the measurement noise.

  11. Occurrence and characteristics of mutual interference between LIDAR scanners

    Science.gov (United States)

    Kim, Gunzung; Eom, Jeongsook; Park, Seonghyeon; Park, Yongwan

    2015-05-01

    The LIDAR scanner is at the heart of object detection of the self-driving car. Mutual interference between LIDAR scanners has not been regarded as a problem because the percentage of vehicles equipped with LIDAR scanners was very rare. With the growing number of autonomous vehicle equipped with LIDAR scanner operated close to each other at the same time, the LIDAR scanner may receive laser pulses from other LIDAR scanners. In this paper, three types of experiments and their results are shown, according to the arrangement of two LIDAR scanners. We will show the probability that any LIDAR scanner will interfere mutually by considering spatial and temporal overlaps. It will present some typical mutual interference scenario and report an analysis of the interference mechanism.

  12. Impact of Competition on Mutual Fund Marketing Expenses

    Directory of Open Access Journals (Sweden)

    Sitikantha Parida

    2018-03-01

    Full Text Available In this paper, I study the impact of market competition on mutual fund marketing expenses. In a sample of US domestic equity mutual funds, I find that marketing expenses decrease with the competition. This effect is stronger for top-performing funds. These results are counterintuitive, as one would ordinarily expect funds to incur more marketing expenses in response to pressure from competing funds. However, these results support the narrative that mutual funds employ marketing to draw attention to their performance in a tournament-like market, where the top-performing funds (the winners are rewarded with disproportionately high new investments. Higher competition decreases the chances of each fund to outperform the others and adversely affect their ability to attract new investments, and the funds respond by decreasing marketing expenses. Thus, competition appears to have implications for investor search cost.

  13. Information

    International Nuclear Information System (INIS)

    Boyard, Pierre.

    1981-01-01

    The fear for nuclear energy and more particularly for radioactive wastes is analyzed in the sociological context. Everybody agree on the information need, information is available but there is a problem for their diffusion. Reactions of the public are analyzed and journalists, scientists and teachers have a role to play [fr

  14. The mutuality metaphor: understanding healthcare provision in NHS Scotland.

    Science.gov (United States)

    Howieson, Brian

    2016-06-20

    Purpose - Better Health, Better Care Action Plan (Scottish Government, 2007) sets out how the Scottish Government intends to strengthen public ownership of the National Health Service in Scotland. The purpose of this paper is to advance extant knowledge by understanding how a state-led mutual health policy may be interpreted, and importantly, communicated. Design/methodology/approach - The definitional problem of mutuality will be discussed and analysed in terms of how it is (or perhaps should be) communicated? will be offered. Findings - It actually may be more instructive to think of, and communicate, mutuality as a metaphor to aid understanding of the openness and fluidity found in NHS Scotland. Research limitations/implications - The existence of paradox and ambiguity does not, however, negate the usefulness of the term "mutuality". Quite the opposite in fact: it is precisely by examining healthcare and its delivery through the lens of mutuality (rather than rejecting its complexity as a failure) that this amorphousness can be better appreciated. Practical implications - There is a need for more public, professional, and academic debate to explore and clarify its implementation, and how it is to be led. This must be provided whilst recognising the daily imperatives that NHS leaders must face. This would suggest, therefore, that a dual development path may help. Originality/value - Although Better Health, Better Care Action Plan was published in 2007, some eight years on there is still confusion and misunderstanding as to what mutuality in healthcare is, not only in policy and theory, but also in practice. It is hoped that this analysis will help address, in part, some of this confusion and misunderstanding.

  15. An efficient and adaptive mutual authentication framework for heterogeneous wireless sensor network-based applications.

    Science.gov (United States)

    Kumar, Pardeep; Ylianttila, Mika; Gurtov, Andrei; Lee, Sang-Gon; Lee, Hoon-Jae

    2014-02-11

    Robust security is highly coveted in real wireless sensor network (WSN) applications since wireless sensors' sense critical data from the application environment. This article presents an efficient and adaptive mutual authentication framework that suits real heterogeneous WSN-based applications (such as smart homes, industrial environments, smart grids, and healthcare monitoring). The proposed framework offers: (i) key initialization; (ii) secure network (cluster) formation (i.e., mutual authentication and dynamic key establishment); (iii) key revocation; and (iv) new node addition into the network. The correctness of the proposed scheme is formally verified. An extensive analysis shows the proposed scheme coupled with message confidentiality, mutual authentication and dynamic session key establishment, node privacy, and message freshness. Moreover, the preliminary study also reveals the proposed framework is secure against popular types of attacks, such as impersonation attacks, man-in-the-middle attacks, replay attacks, and information-leakage attacks. As a result, we believe the proposed framework achieves efficiency at reasonable computation and communication costs and it can be a safeguard to real heterogeneous WSN applications.

  16. An Efficient and Adaptive Mutual Authentication Framework for Heterogeneous Wireless Sensor Network-Based Applications

    Directory of Open Access Journals (Sweden)

    Pardeep Kumar

    2014-02-01

    Full Text Available Robust security is highly coveted in real wireless sensor network (WSN applications since wireless sensors’ sense critical data from the application environment. This article presents an efficient and adaptive mutual authentication framework that suits real heterogeneous WSN-based applications (such as smart homes, industrial environments, smart grids, and healthcare monitoring. The proposed framework offers: (i key initialization; (ii secure network (cluster formation (i.e., mutual authentication and dynamic key establishment; (iii key revocation; and (iv new node addition into the network. The correctness of the proposed scheme is formally verified. An extensive analysis shows the proposed scheme coupled with message confidentiality, mutual authentication and dynamic session key establishment, node privacy, and message freshness. Moreover, the preliminary study also reveals the proposed framework is secure against popular types of attacks, such as impersonation attacks, man-in-the-middle attacks, replay attacks, and information-leakage attacks. As a result, we believe the proposed framework achieves efficiency at reasonable computation and communication costs and it can be a safeguard to real heterogeneous WSN applications.

  17. An Efficient and Adaptive Mutual Authentication Framework for Heterogeneous Wireless Sensor Network-Based Applications

    Science.gov (United States)

    Kumar, Pardeep; Ylianttila, Mika; Gurtov, Andrei; Lee, Sang-Gon; Lee, Hoon-Jae

    2014-01-01

    Robust security is highly coveted in real wireless sensor network (WSN) applications since wireless sensors' sense critical data from the application environment. This article presents an efficient and adaptive mutual authentication framework that suits real heterogeneous WSN-based applications (such as smart homes, industrial environments, smart grids, and healthcare monitoring). The proposed framework offers: (i) key initialization; (ii) secure network (cluster) formation (i.e., mutual authentication and dynamic key establishment); (iii) key revocation; and (iv) new node addition into the network. The correctness of the proposed scheme is formally verified. An extensive analysis shows the proposed scheme coupled with message confidentiality, mutual authentication and dynamic session key establishment, node privacy, and message freshness. Moreover, the preliminary study also reveals the proposed framework is secure against popular types of attacks, such as impersonation attacks, man-in-the-middle attacks, replay attacks, and information-leakage attacks. As a result, we believe the proposed framework achieves efficiency at reasonable computation and communication costs and it can be a safeguard to real heterogeneous WSN applications. PMID:24521942

  18. About mutually unbiased bases in even and odd prime power dimensions

    Science.gov (United States)

    Durt, Thomas

    2005-06-01

    Mutually unbiased bases generalize the X, Y and Z qubit bases. They possess numerous applications in quantum information science. It is well known that in prime power dimensions N = pm (with p prime and m a positive integer), there exists a maximal set of N + 1 mutually unbiased bases. In the present paper, we derive an explicit expression for those bases, in terms of the (operations of the) associated finite field (Galois division ring) of N elements. This expression is shown to be equivalent to the expressions previously obtained by Ivanovic (1981 J. Phys. A: Math. Gen. 14 3241) in odd prime dimensions, and Wootters and Fields (1989 Ann. Phys. 191 363) in odd prime power dimensions. In even prime power dimensions, we derive a new explicit expression for the mutually unbiased bases. The new ingredients of our approach are, basically, the following: we provide a simple expression of the generalized Pauli group in terms of the additive characters of the field, and we derive an exact groupal composition law between the elements of the commuting subsets of the generalized Pauli group, renormalized by a well-chosen phase-factor.

  19. About mutually unbiased bases in even and odd prime power dimensions

    International Nuclear Information System (INIS)

    Durt, Thomas

    2005-01-01

    Mutually unbiased bases generalize the X, Y and Z qubit bases. They possess numerous applications in quantum information science. It is well known that in prime power dimensions N = p m (with p prime and m a positive integer), there exists a maximal set of N + 1 mutually unbiased bases. In the present paper, we derive an explicit expression for those bases, in terms of the (operations of the) associated finite field (Galois division ring) of N elements. This expression is shown to be equivalent to the expressions previously obtained by Ivanovic (1981 J. Phys. A: Math. Gen. 14 3241) in odd prime dimensions, and Wootters and Fields (1989 Ann. Phys. 191 363) in odd prime power dimensions. In even prime power dimensions, we derive a new explicit expression for the mutually unbiased bases. The new ingredients of our approach are, basically, the following: we provide a simple expression of the generalized Pauli group in terms of the additive characters of the field, and we derive an exact groupal composition law between the elements of the commuting subsets of the generalized Pauli group, renormalized by a well-chosen phase-factor

  20. UK equity mutual fund alphas make a comeback

    OpenAIRE

    Mateus, Irina B.; Mateus, Cesario; Todorovic, Natasa

    2016-01-01

    In this study, we re-visit the performance of 887 active UK equity mutual funds using a new approach proposed by Angelidis, Giamouridis, and Tessaromatis. The authors argue that mutual funds stock selection is driven by the benchmark index, so if the benchmark generates alpha, there will be a bias in interpretation of manager's stock-picking ability. In their model, the alpha of a fund is adjusted by the benchmark's alpha. By applying this method, we eliminate bias inflicted by the persistent...

  1. Mutual Impact of Diabetes Mellitus and Tuberculosis in China.

    Science.gov (United States)

    Cheng, Jun; Zhang, Hui; Zhao, Yan Lin; Wang, Li Xia; Chen, Ming Ting

    2017-05-01

    China has a double burden of diabetes mellitus and tuberculosis, and many studies have been carried out on the mutual impact of these two diseases. This paper systematically reviewed studies conducted in China covering the mutual impact of epidemics of diabetes and tuberculosis, the impact of diabetes on multi-drug resistant tuberculosis and on the tuberculosis clinical manifestation and treatment outcome, the yields of bi-directional screening, and economic evaluation for tuberculosis screening among diabetes patients. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  2. Use of the mutual exclusivity assumption by young word learners

    DEFF Research Database (Denmark)

    Markman, Ellen M.; Wasow, Judith L.; Hansen, Mikkel

    2003-01-01

    A critical question about early word learning is whether word learning constraints such as mutual exclusivity exist and foster early language acquisition. It is well established that children will map a novel label to a novel rather than a familiar object. Evidence for the role of mutual...... these concerns by having only a familiar object visible. Fifteen to seventeen and 18-20-month-olds were selected to straddle the vocabulary spurt. In Study 1, babies saw a familiar object and an opaque bucket as a location to search. Study 2 handed babies the familiar object to play with. Study 3 eliminated...

  3. Evaluating Selection and Timing Ability of a Mutual Fund

    Directory of Open Access Journals (Sweden)

    Duguleană L.

    2009-12-01

    Full Text Available The paper presents the methodology and a case study to evaluate the performance of a mutual fund by taking a look at the timing and selection abilities of a portfolio manager. Separating the timing and selection abilities of the fund manager is taken into consideration by two major models. The data about the mutual fund chosen for study is the German blue chip fund “DWS Deutsche Aktien Typ O”, which includes most of the DAX 30 companies. The data consists of 117 monthly observations of the fund returns from January 1999 to September 2008. We used EViews to analyse the data.

  4. The Tradeoff Between Mutual Fund and Direct Stock Investments

    DEFF Research Database (Denmark)

    Marekwica, Marcel; Steininger, Bertram I.

    2014-01-01

    We study the tradeoff between direct and indirect stock investments through equity mutual funds for a utility-maximizing investor. Whereas direct investments impose higher transaction costs on the formation of a well-diversified portfolio, mutual funds charge fees for their services. Our results...... show that the fee levels that make private investors indifferent between direct and indirect stock investments vary heavily according to risk aversion, the amounts invested, correlations between assets, transaction costs, and the length of investment horizon. In particular, our results suggest...

  5. Exploratory study of the impacts of Mutual Health Organizations on social dynamics in Benin.

    Science.gov (United States)

    Ridde, Valery; Haddad, Slim; Yacoubou, Moussa; Yacoubou, Ismaelou

    2010-08-01

    The primary aim of Mutual Health Organizations (MHOs) is the financial protection of their members. However, given their community-based, participative and voluntary nature, it is conceivable that MHOs, as social organizations, would affect social dynamics. In an exploratory study in Benin, we studied social dynamics related to mutual aid, relationships of trust, and empowerment. Four MHOs, as contrasted cases, were selected from among the 11 in the region. Focus groups (n = 20) and individual interviews (n = 29) were conducted with members, non-members, and elected leaders of the four MHOs, and with professionals from the health facilities concerned. We carried out a qualitative thematic analysis of the content. Mutual aid practices, which pre-date MHOs, can be mobilized to promote MHO membership. Mutual aid practices are based on relationships of trust. The primary reason for joining an MHO is to improve financial accessibility to health services. Non-members see that members have a strong sense of empowerment in this regard, based on a high level of trust in MHOs and their elected leaders, even if their trust in health professionals is not as strong. Non-members share these feelings of confidence in MHOs and their leadership, although they trust health professionals somewhat less than do the members. The MHOs' low penetration rate therefore cannot be explained by lack of trust, as this study shows that, even with some distrust of the professionals, the overall level of trust in MHOs is high and MHOs and their leaders function as intermediaries with health professionals. Other explanatory factors are the lack of information available to villagers and, most especially, the problems they face in being able to pay the MHO premiums. Copyright 2010 Elsevier Ltd. All rights reserved.

  6. A Comparison of the Effects of Interference and Distortion in Visual Information Processing by Normal and Retarded Children and by Adults. Final Report.

    Science.gov (United States)

    Meyer, Philip A.

    Reported were four experiments which investigated the developmental and mental retardation aspects of an initial stage of visual information processing termed iconic memory. The stage was explained to involve processing visual stimuli prior to sensation and through to recognition. In three of the four experiments, the paradigm of visual masking…

  7. Mudaraba-Venture Capital Closed-end Mutual Funds and Mudaraba-Venture Capital Open-end Mutual Funds

    OpenAIRE

    Halil Ibrahim Bulut

    2008-01-01

    The important part of this study attempts to explain that both venture capital and interest-free financing are based on similar ground, if not the same. Two new models called Mudaraba-Venture Capital Closed-End Mutual Funds and Mudaraba-Venture Capital Open-End Mutual Funds, based on both the similarities and the needs of financial innovation in the interest-free financing system, are detailed. It is believed that the development of these two models could make some improvements not only in th...

  8. Mutual Funds as a Form of Collective Investment in Russia

    Science.gov (United States)

    Tershukova, Marina B.; Savinov, Oleg G.; Zhegalova, Elena V.; Zhuruhinc, Georgy I.; Zhegalova, Alexandra S.

    2016-01-01

    The relevance of the research problem inspired with the fact nowadays there is a need for theoretical generalization based on international experience the essence of the collective investment system and the rationale for prioritizing the mutual funds development as the most attractive form of collective investment. The goal of the article lies in…

  9. Spillover Effects of Marketing in Mutual Fund Families

    NARCIS (Netherlands)

    M.J.C.M. Verbeek (Marno); J.J. Huij (Joop)

    2007-01-01

    textabstractThis paper investigates the presence of spillover effects of marketing in mutual fund families. We find that funds with high marketing expenses generate spillovers, and enhance cash inflows to family members with low marketing expenses. In particular, low-marketing funds that are

  10. By-product mutualism with evolving common enemies

    NARCIS (Netherlands)

    De Jaegher, K.J.M.

    2017-01-01

    The common-enemy hypothesis of by-product mutualism states that organisms cooperate when it is in their individual interests to do so, with benefits for other organisms arising as a by-product; in particular, such cooperation is hypothesized to arise when organisms face the common enemy of a

  11. High-Contention Mutual Exclusion by Elevator Algorithms

    NARCIS (Netherlands)

    Buhr, Peter A.; Dice, Dave; Hesselink, Wim H.

    2018-01-01

    This paper presents new starvation-free hardware-assisted and software-only algorithms for the N-thread mutual-exclusion problem. The hardware-assisted versions use a single atomic-CAS instruction and no fences. The software-only algorithms simulate the CAS instruction using a variation of

  12. Front-running of Mutual Fund Fire-sales

    NARCIS (Netherlands)

    Dyakov, T.C.; Verbeek, M.

    2013-01-01

    We show that a real-time trading strategy which front-runs the anticipated forced sales by mutual funds experiencing extreme capital outflows generates an alpha of 0.5% per month during the 1990-2010 period. The abnormal return stems from selling pressure among stocks that are below the NYSE mean

  13. Application of Joint Error Maximal Mutual Compensation to hexapod robots

    DEFF Research Database (Denmark)

    Veryha, Yauheni; Petersen, Henrik Gordon

    2008-01-01

    A good practice to ensure high-positioning accuracy in industrial robots is to use joint error maximum mutual compensation (JEMMC). This paper presents an application of JEMMC for positioning of hexapod robots to improve end-effector positioning accuracy. We developed an algorithm and simulation ...

  14. On the determination of the mutual exclusion statistics parameter

    Indian Academy of Sciences (India)

    On the determination of the mutual exclusion statistics parameter. SAPTARSHI MANDAL. Department of Theoretical Physics, Indian Association for the Cultivation of Science,. 2A&2B Raja S.C. Mullick Road, Jadavpur, Kolkata 700 032, India. E-mail: mandal.saptarshi1@gmail.com. MS received 7 September 2012; revised ...

  15. Evolutionary dynamics of fluctuating populations with strong mutualism

    Science.gov (United States)

    Chotibut, Thiparat; Nelson, David

    2013-03-01

    Evolutionary game theory with finite interacting populations is receiving increased attention, including subtle phenomena associated with number fluctuations, i.e., ``genetic drift.'' Models of cooperation and competition often utilize a simplified Moran model, with a strictly fixed total population size. We explore a more general evolutionary model with independent fluctuations in the numbers of two distinct species, in a regime characterized by ``strong mutualism.'' The model has two absorbing states, each corresponding to fixation of one of the two species, and allows exploration of the interplay between growth, competition, and mutualism. When mutualism is favored, number fluctuations eventually drive the system away from a stable fixed point, characterized by cooperation, to one of the absorbing states. Well-mixed populations will thus be taken over by a single species in a finite time, despite the bias towards cooperation. We calculate both the fixation probability and the mean fixation time as a function of the initial conditions and carrying capacities in the strong mutualism regime, using the method of matched asymptotic expansions. Our results are compared to computer simulations.

  16. Dynamics of chaotic oscillations in mutually coupled microchip lasers

    CERN Document Server

    Uchida, A; Kinugawa, S; Yoshimori, S

    2003-01-01

    We have numerically and experimentally investigated the dynamics of mutually coupled microchip lasers. Chaotic oscillations are observed in the vicinity of the boundary of the injection-locking range when the coupling strength and the difference of the optical frequencies are varied. Synchronization of chaos is always achieved under the condition to generate chaos.

  17. Synchronization scenario of two distant mutually coupled semiconductor lasers

    DEFF Research Database (Denmark)

    Mulet, Josep; Mirasso, Claudio; Heil, Tilmann

    2004-01-01

    We present numerical and experimental investigations of the synchronization of the coupling-induced instabilities in two distant mutually coupled semiconductor lasers. In our experiments, two similar Fabry-Perot lasers are coupled via their coherent optical fields. Our theoretical framework is ba...

  18. Institutionalized Mutuality in Canada-China Management Education Collaboration

    Science.gov (United States)

    Wei, Shuguang; Liu, Xianjun

    2015-01-01

    This paper examines the Canada-China Management Education Program (CCMEP, 1983-1996) between the University of Toronto (UT) and Huazhong University of Science and Technology (HUST). In this paper, we create a "Three Levels/Four Parameters" analytical framework, based on the concept of mutuality from Johan Galtung (1980) and the concept…

  19. Market Timing : A Decomposition of Mutual Fund Returns

    NARCIS (Netherlands)

    Swinkels, L.A.P.; van der Sluis, P.J.; Verbeek, M.J.C.M.

    2003-01-01

    We decompose the conditional expected mutual fund return in ve parts.Two parts, selectivity and expert market timing, can be attributed to manager skill, and three to variation in market exposure that can be achieved by private investors as well.The dynamic model that we use to estimate the relative

  20. Measurement reduction for mutual coupling calibration in DOA estimation

    Science.gov (United States)

    Aksoy, Taylan; Tuncer, T. Engin

    2012-01-01

    Mutual coupling is an important source of error in antenna arrays that should be compensated for super resolution direction-of-arrival (DOA) algorithms, such as Multiple Signal Classification (MUSIC) algorithm. A crucial step in array calibration is the determination of the mutual coupling coefficients for the antenna array. In this paper, a system theoretic approach is presented for the mutual coupling characterization of antenna arrays. The comprehension and implementation of this approach is simple leading to further advantages in calibration measurement reduction. In this context, a measurement reduction method for antenna arrays with omni-directional and identical elements is proposed which is based on the symmetry planes in the array geometry. The proposed method significantly decreases the number of measurements during the calibration process. This method is evaluated using different array types whose responses and the mutual coupling characteristics are obtained through numerical electromagnetic simulations. It is shown that a single calibration measurement is sufficient for uniform circular arrays. Certain important and interesting characteristics observed during the experiments are outlined.

  1. Investor Attrition and Fund Flows in Mutual Funds

    DEFF Research Database (Denmark)

    Christoffersen, Susan E. K.; Xu, Haoyu

    2017-01-01

    We explore the properties of equity mutual funds that experience a loss of assets after poor performance. We document that both inflows and outflows are less sensitive to performance, because performance-sensitive investors leave or decide not to invest after bad performance. Consistent with the ...

  2. When are enhanced relationship tax compliance programs mutually beneficial?

    NARCIS (Netherlands)

    De Simone, L.; Sansing, R.; Seidman, J.K.

    2013-01-01

    This study investigates the circumstances under which “enhanced relationship” tax-compliance programs are mutually beneficial to taxpayers and tax authorities, as well as how these benefits are shared. We develop a model of taxpayer and tax authority behavior inside and outside of an enhanced

  3. 77 FR 48566 - The Hartford Mutual Funds, Inc., et al.;

    Science.gov (United States)

    2012-08-14

    ... SECURITIES AND EXCHANGE COMMISSION [Investment Company Act Release No. 30164; File No. 812-14024] The Hartford Mutual Funds, Inc., et al.; Notice of Application August 8, 2012. AGENCY: Securities and Exchange Commission (``Commission''). ACTION: Notice of an application under section 6(c) of the Investment...

  4. Human Security and Mutual Vulnerability: The Global Political ...

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

    Human Security and Mutual Vulnerability: The Global Political Economy of Development and ... that will help us understand this turbulent and chaotic period in human history. ... The Rapid Research Fund (RRF) for Ebola Virus Disease Outbreaks will fund ... Copyright · Open access policy · Privacy policy · Research ethics ...

  5. Collision detection and prediction using a mutual configuration state approach

    NARCIS (Netherlands)

    Schoute, Albert L.; Weiss, N.; Jesse, N.; Reusch, B.

    A configuration state approach is presented that simplifies the mutual collision analysis of objects with known shapes that move along known paths. Accurate and fast prediction of contact situations in games such as robot soccer enables improved anticipatory and corrective actions of the state

  6. A Swedish Mutual Support Society of Problem Gamblers

    Science.gov (United States)

    Binde, Per

    2012-01-01

    Mutual support societies for problem gamblers have existed in Sweden for 20 years. They have helped more people with gambling problems than any other institution inside or outside the Swedish health care system. This paper outlines the background of these societies and describes the meetings of one of them. Data come from interviews with members…

  7. On the behavior of mutual fund investors and managers

    NARCIS (Netherlands)

    Goriaev, A.P.

    2002-01-01

    This thesis investigates empirically and theoretically the behavior of mutual fund investors and managers. These two aspects are closely related to each other. Investors try to select funds that follow an optimal investment policy from their point of view, while fund managers are typically

  8. On the Empirical Evidence of Mutual Fund Strategic Risk Taking

    NARCIS (Netherlands)

    Goriaev, A.P.; Nijman, T.E.; Werker, B.J.M.

    2001-01-01

    We reexamine empirical evidence on strategic risk-taking behavior by mutual fund managers.Several studies suggest that fund performance in the first semester of a year influences risk-taking in the second semester.However, we show that previous empirical studies implicitly assume that idiosyncratic

  9. 12 CFR 544.5 - Federal mutual savings association bylaws.

    Science.gov (United States)

    2010-01-01

    ... by the association. (3) Corporate governance procedures. A Federal mutual association may elect to follow the corporate governance procedures of the laws of the state where the main office of the... corporate governance procedures, and shall file a copy of such bylaws, which are effective upon adoption...

  10. Mutual recognition and the right to damages for criminal investigations

    DEFF Research Database (Denmark)

    Bang Fuglsang Madsen Sørensen, Henning

    2015-01-01

    This article considers how the citizen who has been surrendered on an EAW in a case ending with acquittal or non-prosecution may achieve compensation for the loss of freedom and the surrender to another Member State. The analysis shows how the EAW and the principle of mutual recognition have been...

  11. Normal Pressure Hydrocephalus (NPH)

    Science.gov (United States)

    ... local chapter Join our online community Normal Pressure Hydrocephalus (NPH) Normal pressure hydrocephalus is a brain disorder ... Symptoms Diagnosis Causes & risks Treatments About Normal Pressure Hydrocephalus Normal pressure hydrocephalus occurs when excess cerebrospinal fluid ...

  12. Differences of biased recall memory for emotional information among children and adolescents of mothers with MDD, children and adolescents with MDD, and normal controls.

    Science.gov (United States)

    Fattahi Asl, Abouzar; Ghanizadeh, Ahmad; Mollazade, Javad; Aflakseir, Abdolaziz

    2015-08-15

    This study examines explicit memory bias for emotional information in children and adolescents with major depressive disorder (MDD). Participants were a convenient sample of 28 children and adolescents of mothers with MDD, 28 children and adolescents with MDD, and 29 healthy controls. Their age range was 11-17 years old. The groups were matched for gender ratio, mean age, and the years of educational level. They were assessed by the Recall Task. Emotional stimuli consisted of three sets of words namely sad, happy, and neutral words. Children and adolescents of mothers with MDD similar to children and adolescents with MDD recalled more sadness stimuli in comparison with the controls. In other words, they showed an explicit memory bias towards sad stimuli. Also, healthy children significantly recalled more happy words than the other two groups. There was no significant difference among the three groups for the recall of neutral stimuli. Current findings support that there is a recall memory bias for emotional information in children with MDD. These children more than healthy children recall sad words. Moreover, healthy children recall happy words more than children with MDD. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Informe

    Directory of Open Access Journals (Sweden)

    Egon Lichetenberger

    1950-10-01

    Full Text Available Informe del doctor Egon Lichetenberger ante el Consejo Directivo de la Facultad, sobre el  curso de especialización en Anatomía Patológica patrocinado por la Kellogg Foundation (Departamento de Patología

  14. Multi-user quantum key distribution based on Bell states with mutual authentication

    International Nuclear Information System (INIS)

    Lin Song; Huang Chuan; Liu Xiaofen

    2013-01-01

    A new multi-user quantum key distribution protocol with mutual authentication is proposed on a star network. Here, two arbitrary users are able to perform key distribution with the assistance of a semi-trusted center. Bell states are used as information carriers and transmitted in a quantum channel between the center and one user. A keyed hash function is utilized to ensure the identities of three parties. Finally, the security of this protocol with respect to various kinds of attacks is discussed. (paper)

  15. The Relation between Past Flows and Future Performance: Simple Investment Strategies in the Mutual Fund Sector

    Directory of Open Access Journals (Sweden)

    Martin Rohleder

    2015-02-01

    Full Text Available In the mutual fund literature, it is an established fact that investors “chase past performance”. However, the opposite impact of flows on performance is widely discussed. Mainly, liquidity costs are held responsible for short-term erosion of performance, while high inflows enhance performance over longer horizons. I investigate this relation for various groups of equity, bond, and money market funds and find significant outperformance in high inflow funds over several months, especially for specific bond fund groups. In addition, I test whether this information can be exploited using simple investment strategies but find that the abnormal returns are too low to offset associated costs.

  16. Normalization: A Preprocessing Stage

    OpenAIRE

    Patro, S. Gopal Krishna; Sahu, Kishore Kumar

    2015-01-01

    As we know that the normalization is a pre-processing stage of any type problem statement. Especially normalization takes important role in the field of soft computing, cloud computing etc. for manipulation of data like scale down or scale up the range of data before it becomes used for further stage. There are so many normalization techniques are there namely Min-Max normalization, Z-score normalization and Decimal scaling normalization. So by referring these normalization techniques we are ...

  17. Mutual punishment promotes cooperation in the spatial public goods game

    International Nuclear Information System (INIS)

    Yang, Han-Xin; Rong, Zhihai

    2015-01-01

    Punishment has been proved to be an effective mechanism to sustain cooperation among selfish individuals. In previous studies, punishment is unidirectional: an individual i can punish j but j cannot punish i. In this paper, we propose a mechanism of mutual punishment, in which the two individuals will punish each other if their strategies are different. Because of the symmetry in imposing the punishment, one might expect intuitively the strategy to have little effect on cooperation. Surprisingly, we find that the mutual punishment can promote cooperation in the spatial public goods game. Other pertinent quantities such as the time evolution of cooperator density and the spatial distribution of cooperators and defectors are also investigated

  18. Integrated semiconductor twin-microdisk laser under mutually optical injection

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Ling-Xiu; Liu, Bo-Wen; Lv, Xiao-Meng; Yang, Yue-De; Xiao, Jin-Long; Huang, Yong-Zhen, E-mail: yzhuang@semi.ac.cn [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2015-05-11

    We experimentally study the characteristics of an integrated semiconductor twin-microdisk laser under mutually optical injection through a connected optical waveguide. Based on the lasing spectra, four-wave mixing, injection locking, and period-two oscillation states are observed due to the mutually optical injection by adjusting the injected currents applied to the two microdisks. The enhanced 3 dB bandwidth is realized for the microdisk laser at the injection locking state, and photonic microwave is obtained from the electrode of the microdisk laser under the period-two oscillation state. The plentifully dynamical states similar as semiconductor lasers subject to external optical injection are realized due to strong optical interaction between the two microdisks.

  19. Role of mutual punishment in the snowdrift game

    Science.gov (United States)

    Yang, Han-Xin; Wang, Zhen

    2015-09-01

    The effects of punishment on cooperation have drawn increasing attention. In this paper, we propose a new mechanism of punishment, in which an individual will punish each neighbor if their strategies are different, and vice versa. We incorporate the mutual punishment into the snowdrift game. Results for well-mixed and structured populations have shown that, for no punishment or small values of punishment fine, the fraction of cooperators continuously decreases with the temptation to defect. However, for large values of punishment fine, there exists an abrupt transition point, at which the fraction of cooperators suddenly drops from 1 to 0. Compared to no punishment, mutual punishment promotes cooperation when the temptation to defect is small but inhibits cooperation when the temptation to defect is large. For weak (strong) temptation to defect, the cooperation level increases (decreases) with the punishment fine. For moderate temptation to defect, there exists an optimal value of the punishment fine that leads to the highest cooperation level.

  20. Spatially resolved detection of mutually locked Josephson junctions in arrays

    International Nuclear Information System (INIS)

    Keck, M.; Doderer, T.; Huebener, R.P.; Traeuble, T.; Dolata, R.; Weimann, T.; Niemeyer, J.

    1997-01-01

    Mutual locking due to the internal coupling in two-dimensional arrays of Josephson junctions was investigated. The appearance of Shapiro steps in the current versus voltage curve of a coupled on-chip detector junction is used to indicate coherent oscillations in the array. A highly coherent state is observed for some range of the array bias current. By scanning the array with a low-power electron beam, mutually locked junctions remain locked while the unlocked junctions generate a beam-induced additional voltage drop at the array. This imaging technique allows the detection of the nonlocked or weakly locked Josephson junctions in a (partially) locked array state. copyright 1997 American Institute of Physics

  1. Mutual diffusion of sodium hyaluranate in aqueous solutions

    International Nuclear Information System (INIS)

    Veríssimo, Luís M.P.; Valada, Teresa I.C.; Sobral, Abilio J.F.N.; Azevedo, Eduarda E.F.G.; Azevedo, Maria L.G.; Ribeiro, Ana C.F.

    2014-01-01

    Highlights: • Binary diffusion coefficients for the systems containing sodium hyaluronate. • Influence of the aggregation on diffusion of the sodium hyaluronate in the aqueous media. • Estimation of the thermodynamic and mobility factors from mutual diffusion. -- Abstract: The Taylor dispersion technique has been used for measuring mutual diffusion coefficients of sodium hyaluronate in aqueous solutions at T = 298.15 K, and concentrations ranging from (0.00 to 0.50) g · dm −3 . The results are interpreted on the basis of Nernst, and Onsager and Fuoss theoretical equations. From the diffusion coefficient at infinitesimal concentration, the limiting ionic conductivity and the tracer diffusion coefficient of hyaluronate ion were estimated. These studies have been complemented by molecular mechanics calculations

  2. The use of information theory for the evaluation of biomarkers of aging and physiological age.

    Science.gov (United States)

    Blokh, David; Stambler, Ilia

    2017-04-01

    The present work explores the application of information theoretical measures, such as entropy and normalized mutual information, for research of biomarkers of aging. The use of information theory affords unique methodological advantages for the study of aging processes, as it allows evaluating non-linear relations between biological parameters, providing the precise quantitative strength of those relations, both for individual and multiple parameters, showing cumulative or synergistic effect. Here we illustrate those capabilities utilizing a dataset on heart disease, including diagnostic parameters routinely available to physicians. The use of information-theoretical methods, utilizing normalized mutual information, revealed the exact amount of information that various diagnostic parameters or their combinations contained about the persons' age. Based on those exact informative values for the correlation of measured parameters with age, we constructed a diagnostic rule (a decision tree) to evaluate physiological age, as compared to chronological age. The present data illustrated that younger subjects suffering from heart disease showed characteristics of people of higher age (higher physiological age). Utilizing information-theoretical measures, with additional data, it may be possible to create further clinically applicable information-theory-based markers and models for the evaluation of physiological age, its relation to age-related diseases and its potential modifications by therapeutic interventions. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Does the third mutual friction coefficient B'' exist

    International Nuclear Information System (INIS)

    Mathieu, P.; Placais, B.; Simon, Y.

    1985-01-01

    Precise measurements of the attenuation of a second-sound wave propagation axially in rotating He II at first sight suggest that the third mutual-friction coefficient B'' has a non-zero value (B'' = 0.021 at 1.9 K). But the observation of metastable states associated with various levels of attenuation is not reconcilable with the semi-classical model of the vortex line [fr

  4. The Persistence of Risk-Adjusted Mutual Fund Performance.

    OpenAIRE

    Elton, Edwin J; Gruber, Martin J; Blake, Christopher R

    1996-01-01

    The authors examine predictability for stock mutual funds using risk-adjusted returns. They find that past performance is predictive of future risk-adjusted performance. Applying modern portfolio theory techniques to past data improves selection and allows the authors to construct a portfolio of funds that significantly outperforms a rule based on past rank alone. In addition, they can form a combination of actively managed portfolios with the same risk as a portfolio of index funds but with ...

  5. Geometric Performance Analysis of Mutual Exclusion: The Model

    OpenAIRE

    Abrams, Marc

    1990-01-01

    This paper is motivated by the need to better understand parallel program run-time behavior. The paper first formally describes a general model of program execution based on Djkstra's progress graphs. The paper then defines a special case of the model representing two cyclic processes sharing mutually exclusive, reusable resources. Processes synchronize through semaphore operations that are not embedded in conditionally executed code segments. Model parameters are the times at which each ...

  6. Resonator coupled Josephson junctions; parametric excitations and mutual locking

    DEFF Research Database (Denmark)

    Jensen, H. Dalsgaard; Larsen, A.; Mygind, Jesper

    1991-01-01

    Self-pumped parametric excitations and mutual locking in systems of Josephson tunnel junctions coupled to multimode resonators are reported. For the very large values of the coupling parameter, obtained with small Nb-Al2O3-Nb junctions integrated in superconducting microstrip resonators, the DC I......-V characteristic shows an equidistant series of current steps generated by subharmonic pumping of the fundamental resonator mode. This is confirmed by measurement of frequency and linewidth of the emitted Josephson radiation...

  7. La Crema: A case study of mutual fire insurance

    OpenAIRE

    Antonio Cabrales; Antoni Calvó; Matthew O. Jackson

    2000-01-01

    We analyze a mutual fire insurance mechanism used in Andorra, which is called La Crema in the local language. This mechanism relies on households' announced property values to determine how much a household is reimbursed in the case of a fire and how payments are apportioned among other households. The only Pareto-efficient al- location reachable through the mechanism requires that all house- holds honestly report the true value of their property. However, such honest reporting is not an equi...

  8. The performance of mutual funds : evidence from Turkey

    OpenAIRE

    Parlak, Deniz

    2014-01-01

    In academic world much controversy exists regarding the performance of pension and mutual funds. Some studies have concluded that actively managed funds on average, underperform their passively managed counterparts whereas other studies have shown just the reverse. Another important debate centers on the persistence of under- and over-performance of portfolios. Still evidence from emerging markets which are characterized by high volatility in terms of terms of stock returns is scarce. Hence t...

  9. Mutually Exclusive CBC-Containing Complexes Contribute to RNA Fate

    DEFF Research Database (Denmark)

    Giacometti, Simone; Benbahouche, Nour El Houda; Domanski, Michal

    2017-01-01

    The nuclear cap-binding complex (CBC) stimulates processing reactions of capped RNAs, including their splicing, 3′-end formation, degradation, and transport. CBC effects are particular for individual RNA families, but how such selectivity is achieved remains elusive. Here, we analyze three main CBC......-containing complexes are short lived in vivo, and we therefore suggest that RNA fate involves the transient formation of mutually exclusive CBC complexes, which may only be consequential at particular checkpoints during RNA biogenesis....

  10. Exometabolomics Assisted Design and Validation of Synthetic Obligate Mutualism.

    Science.gov (United States)

    Kosina, Suzanne M; Danielewicz, Megan A; Mohammed, Mujahid; Ray, Jayashree; Suh, Yumi; Yilmaz, Suzan; Singh, Anup K; Arkin, Adam P; Deutschbauer, Adam M; Northen, Trent R

    2016-07-15

    Synthetic microbial ecology has the potential to enhance the productivity and resiliency of biotechnology processes compared to approaches using single isolates. Engineering microbial consortia is challenging; however, one approach that has attracted significant attention is the creation of synthetic obligate mutualism using auxotrophic mutants that depend on each other for exchange or cross-feeding of metabolites. Here, we describe the integration of mutant library fitness profiling with mass spectrometry based exometabolomics as a method for constructing synthetic mutualism based on cross-feeding. Two industrially important species lacking known ecological interactions, Zymomonas mobilis and Escherichia coli, were selected as the test species. Amino acid exometabolites identified in the spent medium of Z. mobilis were used to select three corresponding E. coli auxotrophs (proA, pheA and IlvA), as potential E. coli counterparts for the coculture. A pooled mutant fitness assay with a Z. mobilis transposon mutant library was used to identify mutants with improved growth in the presence of E. coli. An auxotroph mutant in a gene (ZMO0748) with sequence similarity to cysteine synthase A (cysK), was selected as the Z. mobilis counterpart for the coculture. Exometabolomic analysis of spent E. coli medium identified glutathione related metabolites as potentially available for rescue of the Z. mobilis cysteine synthase mutant. Three sets of cocultures between the Z. mobilis auxotroph and each of the three E. coli auxotrophs were monitored by optical density for growth and analyzed by flow cytometry to confirm high cell counts for each species. Taken together, our methods provide a technological framework for creating synthetic mutualisms combining existing screening based methods and exometabolomics for both the selection of obligate mutualism partners and elucidation of metabolites involved in auxotroph rescue.

  11. A SOUTH AFRICAN PERSPECTIVE ON MUTUAL LEGAL ASSISTANCE AND EXTRADITION IN A GLOBALIZED WORLD

    Directory of Open Access Journals (Sweden)

    Murdoch Watney

    2012-08-01

    demands of sophisticated international criminal conduct. Mutual legal assistance and extradition provisions may show that the world is becoming smaller for fugitives and criminals, but the processes are far from expeditious and seamless. An overview of the South African law pertaining to mutual legal assistance and extradition indicates that the South African legislative framework and policies as well as international treaties make sufficient provision to render international assistance in respect of mutual legal assistance and extradition. The role of the courts in upholding the rule of law and protecting the constitutionally enshrined bill of rights, is indicative of the important function that the judiciary fulfills in this regard. It is important that extradition is not only seen as the function of the executive as it also involves the judiciary. It appears that South Africa has displayed the necessary commitment to normalize its international position since 1994 and to fulfill its obligations in a globalized world by reaching across borders in an attempt to address international criminal conduct.

  12. Mutual understanding: a communication model for general practice.

    Science.gov (United States)

    Hantho, Arne; Jensen, Lena; Malterud, Kirsti

    2002-12-01

    To present our pursuits towards development of a simple model for clinical communication intended for application by the practitioner as a tool for enhancing mutual understanding. Inspired by theories about patient-centredness and interactive modes of understanding, and supported by the perspectives of the Danish philosopher Niels Thomassen, we reviewed audiotapes from our own consultations. Recognising four dimensions assumed to be essential for mutual understanding in the transcripts, we explored these dimensions further. We present a communication model consisting of the following dimensions: The Framework, within which the communication takes place; The Subject, about which the communication takes place; The Persons, between whom the communication takes place; and The Action, verbally and non-verbally, through which communication takes place. We describe these dimensions in detail. The nature of the dimensions indicates that there is an interrelationship between them, implying that the character of the communication may change if one of the factors is changed. Analysis of an ongoing or recent consultation completed in accordance with these four dimensions allows the doctor to refocus the communication, thus leading to a more extensive mutual understanding and perhaps enhanced freedom of action.

  13. Mutual fund performance: A synthesis of taxonomic and methodological issues

    Directory of Open Access Journals (Sweden)

    S.G. Badrinath

    2010-12-01

    Full Text Available This paper provides a comprehensive taxonomy of mutual funds and discusses the relative importance of these fund types. While most academic research focuses on US equity funds, we provide results for many more asset classes with this taxonomy—fixed income, balanced, global, International, sector, market-neutral and long-short funds. For each, we start by reporting statistics on the number of funds and their total net asset values at different intervals over the last four decades. We then identify short and long-term patterns in annual returns to mutual funds. We study the cross-sectional and time-series properties of the distribution of investor flows into different types of mutual funds, describe the relationship between flows and performance and discuss its implications for the strategic behaviour of managers and investors. We estimate and interpret fund performance alphas using both the single-factor and four-factor Fama-French models for each taxonomy type. Finally we describe the state of academic research on portfolio performance evaluation tilted towards an applied audience.

  14. Link overlap, viability, and mutual percolation in multiplex networks

    International Nuclear Information System (INIS)

    Min, Byungjoon; Lee, Sangchul; Lee, Kyu-Min; Goh, K.-I.

    2015-01-01

    Many real-world complex systems are best modeled by multiplex networks. The multiplexity has proved to have broad impact on the system’s structure and function. Most theoretical studies on multiplex networks to date, however, have largely ignored the effect of the link overlap across layers despite strong empirical evidences for its significance. In this article, we investigate the effect of the link overlap in the viability of multiplex networks, both analytically and numerically. After a short recap of the original multiplex viability study, the distinctive role of overlapping links in viability and mutual connectivity is emphasized and exploited for setting up a proper analytic framework. A rich phase diagram for viability is obtained and greatly diversified patterns of hysteretic behavior in viability are observed in the presence of link overlap. Mutual percolation with link overlap is revisited as a limit of multiplex viability problem, and the controversy between existing results is clarified. The distinctive role of overlapping links is further demonstrated by the different responses of networks under random removals of overlapping and non-overlapping links, respectively, as well as under several link-removal strategies. Our results show that the link overlap facilitates the viability and mutual percolation; at the same time, the presence of link overlap poses a challenge in analytical approaches to the problem

  15. Yucca aloifolia (Asparagaceae) opts out of an obligate pollination mutualism.

    Science.gov (United States)

    Rentsch, Jeremy D; Leebens-Mack, Jim

    2014-12-01

    • According to Cope's 'law of the unspecialized' highly dependent species interactions are 'evolutionary dead ends,' prone to extinction because reversion to more generalist interactions is thought to be unlikely. Cases of extreme specialization, such as those seen between obligate mutualists, are cast as evolutionarily inescapable, inevitably leading to extinction rather than diversification of participating species. The pollination mutualism between Yucca plants and yucca moths (Tegeticula and Parategeticula) would seem to be locked into such an obligate mutualism. Yucca aloifolia populations, however, can produce large numbers of fruit lacking moth oviposition scars. Here, we investigate the pollination ecology of Y. aloifolia, in search of the non-moth pollination of a Yucca species.• We perform pollinator exclusion studies on Yucca aloifolia and a sympatric yucca species, Y. filamentosa. We then perform postvisit exclusion treatments, an analysis of dissected fruits, and a fluorescent dye transfer experiment.• As expected, Yucca filamentosa plants set fruit only when inflorescences were exposed to crepuscular and nocturnal pollinating yucca moths. In contrast, good fruit set was observed when pollinators were excluded from Y. aloifolia inflorescences from dusk to dawn, and no fruit set was observed when pollinators were excluded during the day. Follow up experiments indicated that European honeybees (Apis mellifera) were passively yet effectively pollinating Y. aloifolia flowers.• These results indicate that even highly specialized mutualisms may not be entirely obligate interactions or evolutionary dead ends. © 2014 Botanical Society of America, Inc.

  16. Basolateral amygdala lesions abolish mutual reward preferences in rats.

    Science.gov (United States)

    Hernandez-Lallement, Julen; van Wingerden, Marijn; Schäble, Sandra; Kalenscher, Tobias

    2016-01-01

    In a recent study, we demonstrated that rats prefer mutual rewards in a Prosocial Choice Task. Here, employing the same task, we show that the integrity of basolateral amygdala was necessary for the expression of mutual reward preferences. Actor rats received bilateral excitotoxic (n=12) or sham lesions (n=10) targeting the basolateral amygdala and were subsequently tested in a Prosocial Choice Task where they could decide between rewarding ("Both Reward") or not rewarding a partner rat ("Own Reward"), either choice yielding identical reward to the actors themselves. To manipulate the social context and control for secondary reinforcement sources, actor rats were paired with either a partner rat (partner condition) or with an inanimate rat toy (toy condition). Sham-operated animals revealed a significant preference for the Both-Reward-option in the partner condition, but not in the toy condition. Amygdala-lesioned animals exhibited significantly lower Both-Reward preferences than the sham group in the partner but not in the toy condition, suggesting that basolateral amygdala was required for the expression of mutual reward preferences. Critically, in a reward magnitude discrimination task in the same experimental setup, both sham-operated and amygdala-lesioned animals preferred large over small rewards, suggesting that amygdala lesion effects were restricted to decision making in social contexts, leaving self-oriented behavior unaffected. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Synchronization in human musical rhythms and mutually interacting complex systems.

    Science.gov (United States)

    Hennig, Holger

    2014-09-09

    Though the music produced by an ensemble is influenced by multiple factors, including musical genre, musician skill, and individual interpretation, rhythmic synchronization is at the foundation of musical interaction. Here, we study the statistical nature of the mutual interaction between two humans synchronizing rhythms. We find that the interbeat intervals of both laypeople and professional musicians exhibit scale-free (power law) cross-correlations. Surprisingly, the next beat to be played by one person is dependent on the entire history of the other person's interbeat intervals on timescales up to several minutes. To understand this finding, we propose a general stochastic model for mutually interacting complex systems, which suggests a physiologically motivated explanation for the occurrence of scale-free cross-correlations. We show that the observed long-term memory phenomenon in rhythmic synchronization can be imitated by fractal coupling of separately recorded or synthesized audio tracks and thus applied in electronic music. Though this study provides an understanding of fundamental characteristics of timing and synchronization at the interbrain level, the mutually interacting complex systems model may also be applied to study the dynamics of other complex systems where scale-free cross-correlations have been observed, including econophysics, physiological time series, and collective behavior of animal flocks.

  18. Financial Crisis and Corporate Social Responsible Mutual Fund Flows

    Directory of Open Access Journals (Sweden)

    Sitikantha Parida

    2018-01-01

    Full Text Available In this paper, we investigate investment flows into mutual funds that hold more high corporate social responsible stocks (top CSR funds vs. mutual funds that hold more low corporate social responsible stocks (bottom CSR funds. Using a large sample of equity mutual funds spanning 2003–2012, we find that top CSR funds on average receive about 5% less investment per annum compared to the other funds; whereas bottom CSR funds receive about 5.6% more investments. These relative negative and positive flows into the top and bottom CSR funds respectively were larger during the pre-financial crisis period (2003–2007. This trend, however, reversed during the financial crisis (2008–2009. Top CSR funds attracted about 8.7% more investments during the financial crisis compared to the pre-crisis period; whereas bottom CSR funds received about 9.8% less investment. This higher investment into the top CSR funds during the crisis seems to have disappeared during the post-crisis period (2009–2012. Additional analysis shows that the corporate social ratings of top CSR funds improved through the crisis, whereas it deteriorated for the bottom CSR funds. Our findings are consistent with the “flight to quality” phenomenon observed in financial markets during market crises, indicating that investors perceive top CSR fund investments as relatively safe or of higher quality and hence, invest more in them during financial crises.

  19. Comparative Analysis of Risk, Return and Diversification of Mutual Fund

    Directory of Open Access Journals (Sweden)

    Rais Ahmad

    2015-01-01

    Full Text Available Mutual Funds have become a widely popular and effective way for investors to participate in financial markets in an easy, low-cost fashion, while muting risk characteristics by spreading the investment across different types of securities, also known as diversification. It can play a central role in an individual's investment strategy. With the plethora of schemes available in the Indian markets, an investors needs to evaluate and consider various factors before making an investment decision. The present investigation is aimed to examine the performance of safest investment instrument in the security market in the eyes of investors. Five mutual fund large cap scheme have been selected for this purpose. The examination is achieved by assessing various financial tests like Sharpe Ratio, Standard Deviation, Alpha, and Beta. Furthermore, in-depth analysis also has been done by considering return over the period of last five years on various basis, expenses ratio, corpus-size etc. The data has been taken from various websites of mutual fund schemes and from www.valueresearch.com. The study will be helpful for the researchers and financial analysts to analyze various securities or funds while selecting the best investment alternative out of the galaxy of investment alternatives.

  20. Alternative power supply and dump resistor connections for similar, mutually coupled, superconducting coils

    International Nuclear Information System (INIS)

    Owen, E.W.; Shimer, W.; Wang, S.T.

    1983-01-01

    Alternative methods of connecting similar mutually coupled coils to their power supplies and dump resistors are investigated. The circuits are evaluated for both operating and fault conditions. The factors considered are the voltage to ground during a dump, short circuits, open circuits, quenches, and failure of the protection system to detect a quench. Of particular interest are the currents induced in coils that remain superconducting when one or more coils quench. The alternative connections include combined power supplies, individual dump resistors, combined resistors and series and parallel dump resistors. A new circuit that contains ''coupling'' resistors is proposed. The coupling resistors do not affect normal fast dumps but reduce the peak induced currents while also reducing the energy rating of the dump resistors. Another novel circuit, the series circuit with diodes, is discussed. The MFTF-B central-cell solenoids are used as an example