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Sample records for optimizing cortical hierarchies

  1. Criteria for optimizing cortical hierarchies with continuous ranges

    Directory of Open Access Journals (Sweden)

    Antje Krumnack

    2010-03-01

    Full Text Available In a recent paper (Reid et al.; 2009, NeuroImage we introduced a method to calculate optimal hierarchies in the visual network that utilizes continuous, rather than discrete, hierarchical levels, and permits a range of acceptable values rather than attempting to fit fixed hierarchical distances. There, to obtain a hierarchy, the sum of deviations from the constraints that define the hierarchy was minimized using linear optimization. In the short time since publication of that paper we noticed that many colleagues misinterpreted the meaning of the term optimal hierarchy. In particular, a majority of them were under the impression that there was perhaps only one optimal hierarchy, but a substantial difficulty in finding that one. However, there is not only more than one optimal hierarchy but also more than one option for defining optimality. Continuing the line of this work we look at additional options for optimizing the visual hierarchy: minimizing the number of violated constraints and minimizing the maximal size of a constraint violation using linear optimization and mixed integer programming. The implementation of both optimization criteria is explained in detail. In addition, using constraint sets based on the data from Felleman and Van Essen, optimal hierarchies for the visual network are calculated for both optimization methods.

  2. Optimization of cortical hierarchies with continuous scales and ranges.

    NARCIS (Netherlands)

    Reid, A.T.; Krumnack, A.; Wanke, E.; Kotter, R.

    2009-01-01

    Although information flow in the neocortex has an apparent hierarchical organization, there is much ambiguity with respect to the definition of such a hierarchy, particularly in higher cortical regions. This ambiguity has been addressed by utilizing observable anatomical criteria, based upon tract

  3. Optimization of cortical hierarchies with continuous scales and ranges.

    NARCIS (Netherlands)

    Reid, A.T.; Krumnack, A.; Wanke, E.; Kotter, R.

    2009-01-01

    Although information flow in the neocortex has an apparent hierarchical organization, there is much ambiguity with respect to the definition of such a hierarchy, particularly in higher cortical regions. This ambiguity has been addressed by utilizing observable anatomical criteria, based upon tract t

  4. Cortical hierarchy governs rat claustrocortical circuit organization.

    Science.gov (United States)

    White, Michael G; Cody, Patrick A; Bubser, Michael; Wang, Hui-Dong; Deutch, Ariel Y; Mathur, Brian N

    2017-04-15

    The claustrum is a telencephalic gray matter structure with various proposed functions, including sensory integration and attentional allocation. Underlying these concepts is the reciprocal connectivity of the claustrum with most, if not all, areas of the cortex. What remains to be elucidated to inform functional hypotheses further is whether a pattern exists in the strength of connectivity between a given cortical area and the claustrum. To this end, we performed a series of retrograde neuronal tract tracer injections into rat cortical areas along the cortical processing hierarchy, from primary sensory and motor to frontal cortices. We observed that the number of claustrocortical projections increased as a function of processing hierarchy; claustrum neurons projecting to primary sensory cortices were scant and restricted in distribution across the claustrum, whereas neurons projecting to the cingulate cortex were densely packed and more evenly distributed throughout the claustrum. This connectivity pattern suggests that the claustrum may preferentially subserve executive functions orchestrated by the cingulate cortex. J. Comp. Neurol. 525:1347-1362, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Optimal Organizational Hierarchies: Source Coding: Disaster Relief

    CERN Document Server

    Murthy, G Rama

    2011-01-01

    ulticasting is an important communication paradigm for enabling the dissemination of information selectively. This paper considers the problem of optimal secure multicasting in a communication network captured through a graph (optimal is in an interesting sense) and provides a doubly optimal solution using results from source coding. It is realized that the solution leads to optimal design (in a well defined optimality sense) of organizational hierarchies captured through a graph. In this effort two novel concepts : prefix free path, graph entropy are introduced. Some results of graph entropy are provided. Also some results on Kraft inequality are discussed. As an application Hierarchical Hybrid Communication Network is utilized as a model of structured Mobile Adhoc network for utility in Disaster Management. Several new research problems that naturally emanate from this research are summarized.

  6. OPTIMAL HIERARCHY STRUCTURES FOR MULTI-ATTRIBUTE-CRITERIA DECISIONS

    Institute of Scientific and Technical Information of China (English)

    Stan LIPOVETSKY

    2009-01-01

    A problem of a hierarchy structure optimization is considered. Hierarchical structures are widely used in the Analytic Hierarchy Process, conjoint analysis, and various other methods of multiple criteria decision making. The problem consists in finding a structure that needs a minimum number of pair comparisons for a given total number of the alternatives. For an optimal hierarchy, the minimum efforts are needed for eliciting data and synthesizing the local References across the hierarchy to get the global priorities or utilities. Special estimation techniques are developed and numerical simulations performed. Analytical and numerical results suggest optimal ways of priority evaluations for practical managerial decisions in a complex environment.

  7. Optimal mesh hierarchies in Multilevel Monte Carlo methods

    KAUST Repository

    Von Schwerin, Erik

    2016-01-08

    I will discuss how to choose optimal mesh hierarchies in Multilevel Monte Carlo (MLMC) simulations when computing the expected value of a quantity of interest depending on the solution of, for example, an Ito stochastic differential equation or a partial differential equation with stochastic data. I will consider numerical schemes based on uniform discretization methods with general approximation orders and computational costs. I will compare optimized geometric and non-geometric hierarchies and discuss how enforcing some domain constraints on parameters of MLMC hierarchies affects the optimality of these hierarchies. I will also discuss the optimal tolerance splitting between the bias and the statistical error contributions and its asymptotic behavior. This talk presents joint work with N.Collier, A.-L.Haji-Ali, F. Nobile, and R. Tempone.

  8. Optimality Conditions and Finite Convergence of Lasserre's Hierarchy

    CERN Document Server

    Nie, Jiawang

    2012-01-01

    Lasserre's hierarchy is a sequence of semidefinite relaxations for solving polynomial optimization problems globally. This paper studies the relationship between optimality conditions in nonlinear programming theory and finite convergence of Lasserre's hierarchy. Our main results are: i) Lasserre's hierarchy has finite convergence when the constraint qualification, strict complementarity and second order sufficiency conditions hold at every global minimizer, under the standard archimedean assumption; ii) these optimality conditions are all satisfied at every local minimizer if a finite set of polynomials, which are in the coefficients of input polynomials, do not vanish at the input data (i.e., they hold in a Zariski open set). This implies that Lasserre's hierarchy has finite convergence generically.

  9. A Bayesian Sampler for Optimization of Protein Domain Hierarchies

    Science.gov (United States)

    2014-01-01

    Abstract The process of identifying and modeling functionally divergent subgroups for a specific protein domain class and arranging these subgroups hierarchically has, thus far, largely been done via manual curation. How to accomplish this automatically and optimally is an unsolved statistical and algorithmic problem that is addressed here via Markov chain Monte Carlo sampling. Taking as input a (typically very large) multiple-sequence alignment, the sampler creates and optimizes a hierarchy by adding and deleting leaf nodes, by moving nodes and subtrees up and down the hierarchy, by inserting or deleting internal nodes, and by redefining the sequences and conserved patterns associated with each node. All such operations are based on a probability distribution that models the conserved and divergent patterns defining each subgroup. When we view these patterns as sequence determinants of protein function, each node or subtree in such a hierarchy corresponds to a subgroup of sequences with similar biological properties. The sampler can be applied either de novo or to an existing hierarchy. When applied to 60 protein domains from multiple starting points in this way, it converged on similar solutions with nearly identical log-likelihood ratio scores, suggesting that it typically finds the optimal peak in the posterior probability distribution. Similarities and differences between independently generated, nearly optimal hierarchies for a given domain help distinguish robust from statistically uncertain features. Thus, a future application of the sampler is to provide confidence measures for various features of a domain hierarchy. PMID:24494927

  10. Oscillatory Hierarchy Controlling Cortical Excitability and Stimulus Integration

    Science.gov (United States)

    Shah, A. S.; Lakatos, P.; McGinnis, T.; O'Connell, N.; Mills, A.; Knuth, K. H.; Chen, C.; Karmos, G.; Schroeder, C. E.

    2004-01-01

    Cortical gamma band oscillations have been recorded in sensory cortices of cats and monkeys, and are thought to aid in perceptual binding. Gamma activity has also been recorded in the rat hippocampus and entorhinal cortex, where it has been shown, that field gamma power is modulated at theta frequency. Since the power of gamma activity in the sensory cortices is not constant (gamma-bursts). we decided to examine the relationship between gamma power and the phase of low frequency oscillation in the auditory cortex of the awake macaque. Macaque monkeys were surgically prepared for chronic awake electrophysiological recording. During the time of the experiments. linear array multielectrodes were inserted in area AI to obtain laminar current source density (CSD) and multiunit activity profiles. Instantaneous theta and gamma power and phase was extracted by applying the Morlet wavelet transformation to the CSD. Gamma power was averaged for every 1 degree of low frequency oscillations to calculate power-phase relation. Both gamma and theta-delta power are largest in the supragranular layers. Power modulation of gamma activity is phase locked to spontaneous, as well as stimulus-related local theta and delta field oscillations. Our analysis also revealed that the power of theta oscillations is always largest at a certain phase of delta oscillation. Auditory stimuli produce evoked responses in the theta band (Le., there is pre- to post-stimulus addition of theta power), but there is also indication that stimuli may cause partial phase re-setting of spontaneous delta (and thus also theta and gamma) oscillations. We also show that spontaneous oscillations might play a role in the processing of incoming sensory signals by 'preparing' the cortex.

  11. Optimizing an immersion ESL curriculum using analytic hierarchy process.

    Science.gov (United States)

    Tang, Hui-Wen Vivian

    2011-11-01

    The main purpose of this study is to fill a substantial knowledge gap regarding reaching a uniform group decision in English curriculum design and planning. A comprehensive content-based course criterion model extracted from existing literature and expert opinions was developed. Analytical hierarchy process (AHP) was used to identify the relative importance of course criteria for the purpose of tailoring an optimal one-week immersion English as a second language (ESL) curriculum for elementary school students in a suburban county of Taiwan. The hierarchy model and AHP analysis utilized in the present study will be useful for resolving several important multi-criteria decision-making issues in planning and evaluating ESL programs. This study also offers valuable insights and provides a basis for further research in customizing ESL curriculum models for different student populations with distinct learning needs, goals, and socioeconomic backgrounds. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Improving resource utilization in hierarchy network by optimizing topological structure

    Science.gov (United States)

    Liu, G. L.; Peng, H. P.; Li, L. X.; Sun, F.; Yang, Y. X.

    2012-02-01

    We study the performance of peer-to-peer (P2P) network built on the top of hierarchy topological structure of local area networks (LAN). We find that the topological structure of the underlying physical network has significant impacts on the resource utilization of the P2P overlay network. The larger size of the physical network is, the lower resource utilization of the overlay network is. Through optimizing the topological structure of physical network, we propose two novel schemes to improve the resource utilization. The experimental results show that in any case the resource utilization of P2P network can always achieve 100% by these two schemes.

  13. Towards an optimal paradigm for simultaneously recording cortical and brainstem auditory evoked potentials.

    Science.gov (United States)

    Bidelman, Gavin M

    2015-02-15

    Simultaneous recording of brainstem and cortical event-related brain potentials (ERPs) may offer a valuable tool for understanding the early neural transcription of behaviorally relevant sounds and the hierarchy of signal processing operating at multiple levels of the auditory system. To date, dual recordings have been challenged by technological and physiological limitations including different optimal parameters necessary to elicit each class of ERP (e.g., differential adaptation/habitation effects and number of trials to obtain adequate response signal-to-noise ratio). We investigated a new stimulus paradigm for concurrent recording of the auditory brainstem frequency-following response (FFR) and cortical ERPs. The paradigm is "optimal" in that it uses a clustered stimulus presentation and variable interstimulus interval (ISI) to (i) achieve the most ideal acquisition parameters for eliciting subcortical and cortical responses, (ii) obtain an adequate number of trials to detect each class of response, and (iii) minimize neural adaptation/habituation effects. Comparison between clustered and traditional (fixed, slow ISI) stimulus paradigms revealed minimal change in amplitude or latencies of either the brainstem FFR or cortical ERP. The clustered paradigm offered over a 3× increase in recording efficiency compared to conventional (fixed ISI presentation) and thus, a more rapid protocol for obtaining dual brainstem-cortical recordings in individual listeners. We infer that faster recording of subcortical and cortical potentials might allow more complete and sensitive testing of neurophysiological function and aid in the differential assessment of auditory function. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Social hierarchies and emotions: cortical prefrontal activity, facial feedback (EMG), and cognitive performance in a dynamic interaction.

    Science.gov (United States)

    Balconi, Michela; Pagani, Silvia

    2015-04-01

    In the present research, we manipulated the perceived superior/inferior status during a competitive cognitive task. In two experiments, we created an explicit and strongly reinforced social hierarchy based on incidental rating on an attentional task. Based on our hypotheses, social rank may influence nonverbal cues (such as facial mimic related to emotional response), cortical lateralized activity in frontal areas (brain oscillations), and cognitive outcomes in response to rank modulation. Thus, the facial mimic (corrugators vs. zygomatic muscle activity), frequency bands (delta, theta, alpha, beta), and real cognitive performance [(error rate (ER); response times (RTs)] were considered. Specifically, a peer-group comparison was enrolled and an improved (experiment 1, N = 29) or decreased (experiment 2, N = 31) performance was artificially manipulated by the experimenter. Results showed a significant improved cognitive performance (decreased ER and RTs), an increased zygomatic activity (positive emotions), and a more prefrontal left-lateralized cortical response in the case of a perceived increased social ranking. On the contrary, a significant decreased cognitive performance (increased ER and RTs), an increased corrugators activity (negative emotions), and a less left-lateralized cortical response were observed as a consequence of a perceived decreased social ranking. Moreover, the correlational values revealed a consistent trend between behavioral (RTs) and EMG and EEG measures for both experiments. The present results suggest that social status not only guides social behavior, but it also influences cognitive processes and subjects' performance.

  15. Multiobjective Optimization in Combinatorial Wind Farms System Integration and Resistive SFCL Using Analytical Hierarchy Process

    DEFF Research Database (Denmark)

    Moghadasi, Amirhasan; Sarwat, Arif; Guerrero, Josep M.

    2016-01-01

    on the extreme load reduction is effectively demonstrated. A large WPP has a complicated structure using several components, and the inclusion of RSFCL composes this layout more problematic for optimal performance of the system. Hence, the most-widely decision-making technique based on the analytic hierarchy...... process (AHP) is proposed for the optimal design of the combinatorial RSFCL and 50MW WPP to compute the three-dimensional alignment in Pareto front at the end of the optimization run. The numerical simulations verify effectiveness of the proposed approach, using the Pareto optimality concept....

  16. Causal hierarchy within the thalamo-cortical network in spike and wave discharges.

    Directory of Open Access Journals (Sweden)

    Anna E Vaudano

    Full Text Available BACKGROUND: Generalised spike wave (GSW discharges are the electroencephalographic (EEG hallmark of absence seizures, clinically characterised by a transitory interruption of ongoing activities and impaired consciousness, occurring during states of reduced awareness. Several theories have been proposed to explain the pathophysiology of GSW discharges and the role of thalamus and cortex as generators. In this work we extend the existing theories by hypothesizing a role for the precuneus, a brain region neglected in previous works on GSW generation but already known to be linked to consciousness and awareness. We analysed fMRI data using dynamic causal modelling (DCM to investigate the effective connectivity between precuneus, thalamus and prefrontal cortex in patients with GSW discharges. METHODOLOGY AND PRINCIPAL FINDINGS: We analysed fMRI data from seven patients affected by Idiopathic Generalized Epilepsy (IGE with frequent GSW discharges and significant GSW-correlated haemodynamic signal changes in the thalamus, the prefrontal cortex and the precuneus. Using DCM we assessed their effective connectivity, i.e. which region drives another region. Three dynamic causal models were constructed: GSW was modelled as autonomous input to the thalamus (model A, ventromedial prefrontal cortex (model B, and precuneus (model C. Bayesian model comparison revealed Model C (GSW as autonomous input to precuneus, to be the best in 5 patients while model A prevailed in two cases. At the group level model C dominated and at the population-level the p value of model C was approximately 1. CONCLUSION: Our results provide strong evidence that activity in the precuneus gates GSW discharges in the thalamo-(fronto cortical network. This study is the first demonstration of a causal link between haemodynamic changes in the precuneus -- an index of awareness -- and the occurrence of pathological discharges in epilepsy.

  17. Determination of Optimal Opening Scheme for Electromagnetic Loop Networks Based on Fuzzy Analytic Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Yang Li

    2016-01-01

    Full Text Available Studying optimization and decision for opening electromagnetic loop networks plays an important role in planning and operation of power grids. First, the basic principle of fuzzy analytic hierarchy process (FAHP is introduced, and then an improved FAHP-based scheme evaluation method is proposed for decoupling electromagnetic loop networks based on a set of indicators reflecting the performance of the candidate schemes. The proposed method combines the advantages of analytic hierarchy process (AHP and fuzzy comprehensive evaluation. On the one hand, AHP effectively combines qualitative and quantitative analysis to ensure the rationality of the evaluation model; on the other hand, the judgment matrix and qualitative indicators are expressed with trapezoidal fuzzy numbers to make decision-making more realistic. The effectiveness of the proposed method is validated by the application results on the real power system of Liaoning province of China.

  18. Optimal Intra-Urban Hierarchy of Activity Centers—A Minimized Household Travel Energy Consumption Approach

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    2015-08-01

    Full Text Available An intra-urban hierarchy of activity centers interconnected by non-motorized and public transportation is broadly believed to be the ideal urban spatial structure for sustainable cities. However, the proper hinterland area for centers at each level lacks empirical study. Based on the concentric structure of everyday travel distances, working centers, shopping centers, and neighborhood centers are extracted from corresponding types of POIs in 286 Chinese cities at the prefectural level and above. A U-shaped curve between Household Transportation Energy Consumption (HTEC per capita and center density at each of the three levels has been found through regression analysis. An optimal intra-urban hierarchy of activity centers is suggested to construct energy-efficient cities.

  19. Optimizing working memory with heterogeneity of recurrent cortical excitation.

    Science.gov (United States)

    Kilpatrick, Zachary P; Ermentrout, Bard; Doiron, Brent

    2013-11-27

    A neural correlate of parametric working memory is a stimulus-specific rise in neuron firing rate that persists long after the stimulus is removed. Network models with local excitation and broad inhibition support persistent neural activity, linking network architecture and parametric working memory. Cortical neurons receive noisy input fluctuations that cause persistent activity to diffusively wander about the network, degrading memory over time. We explore how cortical architecture that supports parametric working memory affects the diffusion of persistent neural activity. Studying both a spiking network and a simplified potential well model, we show that spatially heterogeneous excitatory coupling stabilizes a discrete number of persistent states, reducing the diffusion of persistent activity over the network. However, heterogeneous coupling also coarse-grains the stimulus representation space, limiting the storage capacity of parametric working memory. The storage errors due to coarse-graining and diffusion trade off so that information transfer between the initial and recalled stimulus is optimized at a fixed network heterogeneity. For sufficiently long delay times, the optimal number of attractors is less than the number of possible stimuli, suggesting that memory networks can under-represent stimulus space to optimize performance. Our results clearly demonstrate the combined effects of network architecture and stochastic fluctuations on parametric memory storage.

  20. Solving Sparse Polynomial Optimization Problems with Chordal Structure Using the Sparse, Bounded-Degree Sum-of-Squares Hierarchy

    NARCIS (Netherlands)

    Marandi, Ahmadreza; de Klerk, Etienne; Dahl, Joachim

    The sparse bounded degree sum-of-squares (sparse-BSOS) hierarchy of Weisser, Lasserre and Toh [arXiv:1607.01151,2016] constructs a sequence of lower bounds for a sparse polynomial optimization problem. Under some assumptions, it is proven by the authors that the sequence converges to the optimal

  1. Effective factors on optimizing banks’ balance sheet using fuzzy analytical hierarchy process

    Directory of Open Access Journals (Sweden)

    Shoja Rezaei

    2013-11-01

    Full Text Available Every bank seeks methods to optimize its assets and liabilities, thus the main subject is managing assets-liabilities in the balance sheet and the main question is by which factor banks will be enabled to have an optimized combination of assets and liabilities in a common level of risk to get the most return. This case study is dedicated to Refah bank and is an applicable study. The data has collected from the headquarter by a questionnaire and finally effective factors weight on optimizing bank balance sheet determined by using Fuzzy analytical hierarchy process. Results showed that revenue has more effect on optimizing for %39.5 and also loan to deposit ratio for %.74, regarding revenue as a symbol of efficiency in banks, it seems to be the most important factor and goal in banking industry. Furthermore banks need to have some liquidity to respond customers demand to cover one of the most important risks of banking. This factor importance determined to be %18 in Refah Bank by using model and experts view.

  2. Brackish groundwater membrane system design for sustainable irrigation: Optimal configuration selection using analytic hierarchy process and multi-dimension scaling

    OpenAIRE

    Beni eLew; Lolita eTrachtengertz; Shany eRatsin; Gideon eOron; Amos eBick

    2014-01-01

    The recent high demands for reuse of salty water for irrigation affected membrane producers to assess new potential technologies for undesirable physical, chemical, and biological contaminants removal. This paper studies the assembly options by the analytic hierarchy process (AHP) model and the multi-dimension scaling (MDS) techniques. A specialized form of MDS (CoPlot software) enables presentation of the AHP outcomes in a two dimensional space and the optimal model can be visualized clearly...

  3. Research on load optimization of DHT-based hierarchy peer-to-peer system

    Science.gov (United States)

    Zhong, Haifeng; Luo, Dongjian; Wu, Wei; Xiao, Liang

    2009-08-01

    The main reason of causing the cost in p2p system is the maintenance cost that nodes build their routing information. In a large-scale system or a dynamic environment, p2p system generates considerable maintenance workload, which not only increase the bandwidth consumption but also affect the routing efficiency. So we present here a new Hierarchy_based maintenance method to minimize the maintenance cost which combines the hierarchical DHT algorithm with a peer proximity mechanism. The analysis results show our design can significantly decrease maintenance cost and improve scalability of the P2P system.

  4. A decision support system using analytical hierarchy process (AHP) for the optimal environmental reclamation of an open-pit mine

    Science.gov (United States)

    Bascetin, A.

    2007-04-01

    The selection of an optimal reclamation method is one of the most important factors in open-pit design and production planning. It also affects economic considerations in open-pit design as a function of plan location and depth. Furthermore, the selection is a complex multi-person, multi-criteria decision problem. The group decision-making process can be improved by applying a systematic and logical approach to assess the priorities based on the inputs of several specialists from different functional areas within the mine company. The analytical hierarchy process (AHP) can be very useful in involving several decision makers with different conflicting objectives to arrive at a consensus decision. In this paper, the selection of an optimal reclamation method using an AHP-based model was evaluated for coal production in an open-pit coal mine located at Seyitomer region in Turkey. The use of the proposed model indicates that it can be applied to improve the group decision making in selecting a reclamation method that satisfies optimal specifications. Also, it is found that the decision process is systematic and using the proposed model can reduce the time taken to select a optimal method.

  5. Brackish groundwater membrane system design for sustainable irrigation: Optimal configuration selection using analytic hierarchy process and multi-dimension scaling

    Directory of Open Access Journals (Sweden)

    Beni eLew

    2014-12-01

    Full Text Available The recent high demands for reuse of salty water for irrigation affected membrane producers to assess new potential technologies for undesirable physical, chemical and biological contaminants removal. This paper studies the assembly options by the analytic hierarchy process (AHP model and the multi-dimension scaling (MDS techniques. A specialized form of MDS (CoPlot software enables presentation of the AHP outcomes in a two dimensional space and the optimal model can be visualized clearly. Four types of 8 membranes were selected: (i Nanofiltration low rejection and high flux (ESNA1-LF-LD, 86% rejection, 10,500gpd; (ii Nanofiltration medium rejection and medium flux (ESNA1-LF2-LD, 91% rejection, 8,200gpd; (iii Reverse Osmosis high rejection and high flux (CPA5-MAX, 99.7 rejection, 12,000gpd ; and (iv Reverse Osmosis medium rejection and extreme high flux (ESPA4-MAX, 99.2 rejection, 13,200gpd. The results indicate that: (i Nanofiltration membrane (High flux and Low rejection can produce water for irrigation with valuable levels of nutrient ions and a reduction in the sodium absorption ratio (SAR, minimizing soil salinity; this is an attractive option for agricultural irrigation and is the optimal solution; and (ii implementing the MDS approach with reference to the variables is consequently useful to characterize membrane system design.

  6. Conformal mapping via metric optimization with application for cortical label fusion.

    Science.gov (United States)

    Shi, Yonggang; Lai, Rongjie; Toga, Arthur W

    2013-01-01

    In this paper we develop a novel approach for computing conformal maps between anatomical surfaces with the ability of aligning anatomical features and achieving greatly reduced metric distortion. In contrast to conventional approaches that focused on conformal maps to the sphere or plane, our method computes the conformal map between surfaces in the embedding space formed the intrinsically defined Laplace-Beltrami (LB) eigenfunctions. Utilizing the power of LB eigenfunctions as informative descriptors of global geometry, the conformal maps computed by our method can effectively align anatomical features on cortical surfaces. By computing such feature-aware conformal maps to a group-wisely optimal atlas surface, which is also computed with metric optimization in the LB embedding space, we develop a fully automated system for cortical labeling with the fusion of labels on a large number of atlas surfaces. In our experiments, we build our system with 40 labeled surfaces and demonstrate its excellent performance with leave-one-out cross validation. We also applied the automated labeling system to cortical surfaces reconstructed from MR scans of 50 patients with Alzheimer's disease (AD) and 50 normal controls (NC) to illustrate its robustness and effectiveness in clinical data analysis.

  7. Delegated Contracting and Corporate Hierarchies

    OpenAIRE

    Choe, Chongwoo; Park, In-Uck

    2004-01-01

    In a typical corporate hierarchy, the manager is delegated the authority to make decisions that set directions for the organization, employ subordinates and contract with external suppliers. This paper explains when such delegation of authority can be optimal, using a model of a firm with three parties: the principal, the manager and the worker. In centralization with two two-tier hierarchies, the principal designs contracts for both agents. In delegation with a three-tier hierarchy, the prin...

  8. Geometric-attributes-based segmentation of cortical bone slides using optimized neural networks.

    Science.gov (United States)

    Hage, Ilige S; Hamade, Ramsey F

    2016-05-01

    In cortical bone, solid (lamellar and interstitial) matrix occupies space left over by porous microfeatures such as Haversian canals, lacunae, and canaliculi-containing clusters. In this work, pulse-coupled neural networks (PCNN) were used to automatically distinguish the microfeatures present in histology slides of cortical bone. The networks' parameters were optimized using particle swarm optimization (PSO). When forming the fitness functions for the PSO, we considered the microfeatures' geometric attributes-namely, their size (based on measures of elliptical perimeter or area), shape (based on measures of compactness or the ratio of minor axis length to major axis length), and a two-way combination of these two geometric attributes. This hybrid PCNN-PSO method was further enhanced for pulse evaluation by combination with yet another method, adaptive threshold (AT), where the PCNN algorithm is repeated until the best threshold is found corresponding to the maximum variance between two segmented regions. Together, this framework of using PCNN-PSO-AT constitutes, we believe, a novel framework in biomedical imaging. Using this framework and extracting microfeatures from only one training image, we successfully extracted microfeatures from other test images. The high fidelity of all resultant segments was established using quantitative metrics such as precision, specificity, and Dice indices.

  9. Hypothesis-driven methods to augment human cognition by optimizing cortical oscillations

    Directory of Open Access Journals (Sweden)

    Jörn M. Horschig

    2014-06-01

    Full Text Available Cortical oscillations have been shown to represent fundamental functions of a working brain, e.g. communication, stimulus binding, error monitoring, and inhibition, and are directly linked to behavior. Recent studies intervening with these oscillations have demonstrated effective modulation of both the oscillations and behavior. In this review, we collect evidence in favor of how hypothesis-driven methods can be used to augment cognition by optimizing cortical oscillations. We elaborate their potential usefulness for three target groups: healthy elderly, patients with attention deficit/hyperactivity disorder, and healthy young adults. We discuss the relevance of neuronal oscillations in each group and show how each of them can benefit from the manipulation of functionally-related oscillations. Further, we describe methods for manipulation of neuronal oscillations including direct brain stimulation as well as indirect task alterations. We also discuss practical considerations about the proposed techniques. In conclusion, we propose that insights from neuroscience should guide techniques to augment human cognition, which in turn can provide a better understanding of how the human brain works.

  10. Participatory hierarchies

    DEFF Research Database (Denmark)

    Kristiansen, Marianne; Bloch-Poulsen, Jørgen

    2016-01-01

    is to show that a participatory approach can unintentionally create new hierarchies or reinforce existing ones, thus leading to the exclusion of certain employees (or action researchers) in terms of voice and/or choice. Second, the theoretical purpose is to show how participation in OAR projects can......This article focuses on employee participation in organisational action research (OAR), presenting three examples of OAR in one private and two public organisations in Denmark, respectively. Each of these examples shows how participatory hierarchies between employees and between them and action...... researchers are constructed in OAR projects, leading in these cases to the exclusion of silent pedagogues, elderly foremen, and a critical employee. Based on these examples, the article has three mutually connected purposes, an empirical, theoretical, and methodological purpose. First, the empirical purpose...

  11. Parabolic movement primitives and cortical states: merging optimality with geometric invariance.

    Science.gov (United States)

    Polyakov, Felix; Stark, Eran; Drori, Rotem; Abeles, Moshe; Flash, Tamar

    2009-02-01

    Previous studies have suggested that several types of rules govern the generation of complex arm movements. One class of rules consists of optimizing an objective function (e.g., maximizing motion smoothness). Another class consists of geometric and kinematic constraints, for instance the coupling between speed and curvature during drawing movements as expressed by the two-thirds power law. It has also been suggested that complex movements are composed of simpler elements or primitives. However, the ability to unify the different rules has remained an open problem. We address this issue by identifying movement paths whose generation according to the two-thirds power law yields maximally smooth trajectories. Using equi-affine differential geometry we derive a mathematical condition which these paths must obey. Among all possible solutions only parabolic paths minimize hand jerk, obey the two-thirds power law and are invariant under equi-affine transformations (which preserve the fit to the two-thirds power law). Affine transformations can be used to generate any parabolic stroke from an arbitrary parabolic template, and a few parabolic strokes may be concatenated to compactly form a complex path. To test the possibility that parabolic elements are used to generate planar movements, we analyze monkeys' scribbling trajectories. Practiced scribbles are well approximated by long parabolic strokes. Of the motor cortical neurons recorded during scribbling more were related to equi-affine than to Euclidean speed. Unsupervised segmentation of simulta- neously recorded multiple neuron activity yields states related to distinct parabolic elements. We thus suggest that the cortical representation of movements is state-dependent and that parabolic elements are building blocks used by the motor system to generate complex movements.

  12. ELEMENTS OF CONTROL OVER HIERARCHIE SYSTEMS WITH ASSUMED HIERARCHY

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    Kushnir N. V.

    2015-05-01

    Full Text Available The article presents a mathematical model of control over dynamic hierarchy system. The model was proposed for dealing with systems with assumed order in the technical problem of predicting destructions depending onto the amount of defects on different scale levels. The problem of the closest to a certain point of shelf life of hierarchy system is solved. The example of approach control during the given time is given. The problem concerns mathematic programming. Formulation of multi-parameter vector optimization criteria (improvement with its own hierarchy and the formal exercise of multi-criteria optimization of the model parameters. The research can achieve clarity about the conditions under which the structure is preserved. Managing sustainable development system with a given level of the hierarchy for the technical systems can only be achieved in keeping

  13. Optimal Medical Equipment Maintenance Service Proposal Decision Support System combining Activity Based Costing (ABC) and the Analytic Hierarchy Process (AHP).

    Science.gov (United States)

    da Rocha, Leticia; Sloane, Elliot; M Bassani, Jose

    2005-01-01

    This study describes a framework to support the choice of the maintenance service (in-house or third party contract) for each category of medical equipment based on: a) the real medical equipment maintenance management system currently used by the biomedical engineering group of the public health system of the Universidade Estadual de Campinas located in Brazil to control the medical equipment maintenance service, b) the Activity Based Costing (ABC) method, and c) the Analytic Hierarchy Process (AHP) method. Results show the cost and performance related to each type of maintenance service. Decision-makers can use these results to evaluate possible strategies for the categories of equipment.

  14. Automated Sperm Head Detection Using Intersecting Cortical Model Optimised by Particle Swarm Optimization

    Science.gov (United States)

    Tan, Weng Chun; Mat Isa, Nor Ashidi

    2016-01-01

    In human sperm motility analysis, sperm segmentation plays an important role to determine the location of multiple sperms. To ensure an improved segmentation result, the Laplacian of Gaussian filter is implemented as a kernel in a pre-processing step before applying the image segmentation process to automatically segment and detect human spermatozoa. This study proposes an intersecting cortical model (ICM), which was derived from several visual cortex models, to segment the sperm head region. However, the proposed method suffered from parameter selection; thus, the ICM network is optimised using particle swarm optimization where feature mutual information is introduced as the new fitness function. The final results showed that the proposed method is more accurate and robust than four state-of-the-art segmentation methods. The proposed method resulted in rates of 98.14%, 98.82%, 86.46% and 99.81% in accuracy, sensitivity, specificity and precision, respectively, after testing with 1200 sperms. The proposed algorithm is expected to be implemented in analysing sperm motility because of the robustness and capability of this algorithm. PMID:27632581

  15. Optimal sensorimotor integration in recurrent cortical networks: a neural implementation of Kalman filters.

    Science.gov (United States)

    Denève, Sophie; Duhamel, Jean-René; Pouget, Alexandre

    2007-05-23

    Several behavioral experiments suggest that the nervous system uses an internal model of the dynamics of the body to implement a close approximation to a Kalman filter. This filter can be used to perform a variety of tasks nearly optimally, such as predicting the sensory consequence of motor action, integrating sensory and body posture signals, and computing motor commands. We propose that the neural implementation of this Kalman filter involves recurrent basis function networks with attractor dynamics, a kind of architecture that can be readily mapped onto cortical circuits. In such networks, the tuning curves to variables such as arm velocity are remarkably noninvariant in the sense that the amplitude and width of the tuning curves of a given neuron can vary greatly depending on other variables such as the position of the arm or the reliability of the sensory feedback. This property could explain some puzzling properties of tuning curves in the motor and premotor cortex, and it leads to several new predictions.

  16. New integrable lattice hierarchies

    Energy Technology Data Exchange (ETDEWEB)

    Pickering, Andrew [Area de Matematica Aplicada, ESCET, Universidad Rey Juan Carlos, c/ Tulipan s/n, 28933 Mostoles, Madrid (Spain); Zhu Zuonong [Departamento de Matematicas, Universidad de Salamanca, Plaza de la Merced 1, 37008 Salamanca (Spain) and Department of Mathematics, Shanghai Jiao Tong University, Shanghai 200030 (China)]. E-mail: znzhu2@yahoo.com.cn

    2006-01-23

    In this Letter we give a new integrable four-field lattice hierarchy, associated to a new discrete spectral problem. We obtain our hierarchy as the compatibility condition of this spectral problem and an associated equation, constructed herein, for the time-evolution of eigenfunctions. We consider reductions of our hierarchy, which also of course admit discrete zero curvature representations, in detail. We find that our hierarchy includes many well-known integrable hierarchies as special cases, including the Toda lattice hierarchy, the modified Toda lattice hierarchy, the relativistic Toda lattice hierarchy, and the Volterra lattice hierarchy. We also obtain here a new integrable two-field lattice hierarchy, to which we give the name of Suris lattice hierarchy, since the first equation of this hierarchy has previously been given by Suris. The Hamiltonian structure of the Suris lattice hierarchy is obtained by means of a trace identity formula.

  17. Hierarchy of model Kohn–Sham potentials for orbital-dependent functionals: A practical alternative to the optimized effective potential method

    Energy Technology Data Exchange (ETDEWEB)

    Kohut, Sviataslau V.; Staroverov, Viktor N., E-mail: vstarove@uwo.ca [Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7 (Canada); Ryabinkin, Ilya G. [Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4 (Canada)

    2014-05-14

    We describe a method for constructing a hierarchy of model potentials approximating the functional derivative of a given orbital-dependent exchange-correlation functional with respect to electron density. Each model is derived by assuming a particular relationship between the self-consistent solutions of Kohn–Sham (KS) and generalized Kohn–Sham (GKS) equations for the same functional. In the KS scheme, the functional is differentiated with respect to density, in the GKS scheme—with respect to orbitals. The lowest-level approximation is the orbital-averaged effective potential (OAEP) built with the GKS orbitals. The second-level approximation, termed the orbital-consistent effective potential (OCEP), is based on the assumption that the KS and GKS orbitals are the same. It has the form of the OAEP plus a correction term. The highest-level approximation is the density-consistent effective potential (DCEP), derived under the assumption that the KS and GKS electron densities are equal. The analytic expression for a DCEP is the OCEP formula augmented with kinetic-energy-density-dependent terms. In the case of exact-exchange functional, the OAEP is the Slater potential, the OCEP is roughly equivalent to the localized Hartree–Fock approximation and related models, and the DCEP is practically indistinguishable from the true optimized effective potential for exact exchange. All three levels of the proposed hierarchy require solutions of the GKS equations as input and have the same affordable computational cost.

  18. Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields.

    Science.gov (United States)

    Ruffini, Giulio; Fox, Michael D; Ripolles, Oscar; Miranda, Pedro Cavaleiro; Pascual-Leone, Alvaro

    2014-04-01

    Recently, multifocal transcranial current stimulation (tCS) devices using several relatively small electrodes have been used to achieve more focal stimulation of specific cortical targets. However, it is becoming increasingly recognized that many behavioral manifestations of neurological and psychiatric disease are not solely the result of abnormality in one isolated brain region but represent alterations in brain networks. In this paper we describe a method for optimizing the configuration of multifocal tCS for stimulation of brain networks, represented by spatially extended cortical targets. We show how, based on fMRI, PET, EEG or other data specifying a target map on the cortical surface for excitatory, inhibitory or neutral stimulation and a constraint on the maximal number of electrodes, a solution can be produced with the optimal currents and locations of the electrodes. The method described here relies on a fast calculation of multifocal tCS electric fields (including components normal and tangential to the cortical boundaries) using a five layer finite element model of a realistic head. Based on the hypothesis that the effects of current stimulation are to first order due to the interaction of electric fields with populations of elongated cortical neurons, it is argued that the optimization problem for tCS stimulation can be defined in terms of the component of the electric field normal to the cortical surface. Solutions are found using constrained least squares to optimize current intensities, while electrode number and their locations are selected using a genetic algorithm. For direct current tCS (tDCS) applications, we provide some examples of this technique using an available tCS system providing 8 small Ag/AgCl stimulation electrodes. We demonstrate the approach both for localized and spatially extended targets defined using rs-fcMRI and PET data, with clinical applications in stroke and depression. Finally, we extend these ideas to more general

  19. An Optimization Algorithm for the Design of an Irregularly-Shaped Bridge Based on the Orthogonal Test and Analytic Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Hanbing Liu

    2016-11-01

    Full Text Available Irregularly-shaped bridges are usually adopted to connect the main bridge and ramps in urban overpasses, which are under significant flexion-torsion coupling effects and in complicated stress states. In irregular-shaped bridge design, the parameters such as ramp radius, bifurcation diaphragm stiffness, box girder height, and supporting condition could affect structural performance in different manners. In this paper, the influence of various parameters on three indices, including maximum stress, the stress variation coefficient, and the fundamental frequency of torsional vibration, is investigated and analyzed based on orthogonal test method. Through orthogonal analysis, the major influence parameters and corresponding optimal values for these indices are achieved. Combining with the analytic hierarchy process (AHP, the hierarchical structure model of the multi-indices orthogonal test is established and a comprehensive weight analysis method is proposed to reflect the parameter influence on overall mechanical properties of an irregularly-shaped bridge. Influence order and optimal values of parameters for overall mechanical properties are determined based on the weight of factors and levels calculated by the comprehensive weight analysis method. The results indicate that the comprehensive weight analysis method is superior to the overall balance method, which verifies the effectiveness and accuracy of the comprehensive weight analysis in the parameter optimization of the multi-indices orthogonal test for an irregularly-shaped bridge. Optimal parameters obtained in this paper can provide reference and guidance for parameter control in irregularly-shaped bridge design.

  20. 基于优属度和层次分析法的冷热源方案优选%Scheme optimization for heat and cold sources based on optimal membership and analytic hierarchy process

    Institute of Scientific and Technical Information of China (English)

    闫加贺; 黄建恩; 冯伟; 张丙利

    2011-01-01

    建立了基于优属度和层次分析法的优选模型,并以海门某办公大楼为实例,对不同的冷热源方案进行优选.结果显示,该模型计算简便,能够达到客观的、科学的优选空调系统冷热源的目的.%The model based on optimal membership and analytic hierarchy process was established. Different heat and cold sources were select for the optimization of central air-conditioning system of a office building in Haimen city. It is proved that the model could optimize the heat and cold sources easy、objectively and scientifically.

  1. Higher-Order Hierarchies

    DEFF Research Database (Denmark)

    Ernst, Erik

    2003-01-01

    . Finally, it must be possible to write generic code that works on every hierarchy derived from the hierarchy for which it was written. This paper presents a language design that supports such a notion of higher-order hierarchies. It has been implemented in context of a full-fledged, statically typed...... be possible to create hierarchies incrementally based on existing hierarchies, such that commonalities are expressed via reuse, not duplication. Second, the hierarchies must themselves be organized into hierarchies, such that their relationships are made explicit and can be exploited in a type safe manner...... language....

  2. Baseline Optimization for the Measurement of CP Violation, Mass Hierarchy, and $\\theta_{23}$ Octant in a Long-Baseline Neutrino Oscillation Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bass, M. [Colorado State U.; Bishai, M. [Brookhaven; Cherdack, D. [Colorado State U.; Diwan, M. [Brookhaven; Djurcic, Z. [Argonne; Hernandez, J. [Houston U.; Lundberg, B. [Fermilab; Paolone, V. [Pittsburgh U.; Qian, X. [Brookhaven; Rameika, R. [Fermilab; Whitehead, L. [Houston U.; Wilson, R. J. [Colorado State U.; Worcester, E. [Brookhaven; Zeller, G. [Fermilab

    2015-03-19

    Next-generation long-baseline electron neutrino appearance experiments will seek to discover CP violation, determine the mass hierarchy and resolve the θ23 octant. In light of the recent precision measurements of θ13, we consider the sensitivity of these measurements in a study to determine the optimal baseline, including practical considerations regarding beam and detector performance. We conclude that a detector at a baseline of at least 1000 km in a wide-band muon neutrino beam is the optimal configuration.

  3. Establishing the ferret as a gyrencephalic animal model of traumatic brain injury: Optimization of controlled cortical impact procedures.

    Science.gov (United States)

    Schwerin, Susan C; Hutchinson, Elizabeth B; Radomski, Kryslaine L; Ngalula, Kapinga P; Pierpaoli, Carlo M; Juliano, Sharon L

    2017-06-15

    Although rodent TBI studies provide valuable information regarding the effects of injury and recovery, an animal model with neuroanatomical characteristics closer to humans may provide a more meaningful basis for clinical translation. The ferret has a high white/gray matter ratio, gyrencephalic neocortex, and ventral hippocampal location. Furthermore, ferrets are amenable to behavioral training, have a body size compatible with pre-clinical MRI, and are cost-effective. We optimized the surgical procedure for controlled cortical impact (CCI) using 9 adult male ferrets. We used subject-specific brain/skull morphometric data from anatomical MRIs to overcome across-subject variability for lesion placement. We also reflected the temporalis muscle, closed the craniotomy, and used antibiotics. We then gathered MRI, behavioral, and immunohistochemical data from 6 additional animals using the optimized surgical protocol: 1 control, 3 mild, and 1 severely injured animals (surviving one week) and 1 moderately injured animal surviving sixteen weeks. The optimized surgical protocol resulted in consistent injury placement. Astrocytic reactivity increased with injury severity showing progressively greater numbers of astrocytes within the white matter. The density and morphological changes of microglia amplified with injury severity or time after injury. Motor and cognitive impairments scaled with injury severity. The optimized surgical methods differ from those used in the rodent, and are integral to success using a ferret model. We optimized ferret CCI surgery for consistent injury placement. The ferret is an excellent animal model to investigate pathophysiological and behavioral changes associated with TBI. Published by Elsevier B.V.

  4. Differentiation of motor cortical representation of hand muscles by navigated mapping of optimal TMS current directions in healthy subjects.

    Science.gov (United States)

    Bashir, Shahid; Perez, Jennifer M; Horvath, Jared C; Pascual-Leone, Alvaro

    2013-08-01

    The precision of navigated transcranial magnetic stimulation (TMS) to map the human primary motor cortex may be effected by the direction of TMS-induced current in the brain as determined by the orientation of the stimulation coil. In this study, the authors investigated the effect of current directionality on motor output mapping using navigated brain stimulation. The goal of this study was to determine the optimal coil orientation (and, thus, induced brain current) to activate hand musculature representations relative to each subject's unique neuroanatomical landmarks. The authors studied motor output maps for the first dorsal interosseous, abductor pollicis brevis, and abductor digiti minimi muscles in 10 normal volunteers. Monopolar current pulses were delivered through a figure-of-eight-shaped TMS coil, and motor evoked potentials were recorded using electromyography. At each targeted brain region, the authors systematically rotated the TMS coil to determine the direction of induced current in the brain for induction of the largest motor evoked potentials. These optimal current directions were expressed as an angle relative to each subject's central sulcus. Consistency of the optimal current direction was assessed by repeating the entire mapping procedure on two different occasions across subjects. The authors demonstrate that systematic optimization of current direction as guided by MRI-based neuronavigation improves the resolution of cortical output motor mapping with TMS.

  5. Optimized gamma synchronization enhances functional binding of fronto-parietal cortices in mathematically gifted adolescents during deductive reasoning

    Directory of Open Access Journals (Sweden)

    Li eZhang

    2014-06-01

    Full Text Available As enhanced fronto-parietal network has been suggested to support reasoning ability of math-gifted adolescents, the main goal of this EEG source analysis is to investigate the temporal binding of the gamma-band (30-60Hz synchronization between frontal and parietal cortices in adolescents with exceptional mathematical ability, including the functional connectivity of gamma neurocognitive network, the temporal dynamics of fronto-parietal network (phase-locking durations and network lability in time domain, and the self-organized criticality of synchronizing oscillation. Compared with the average-ability subjects, the math-gifted adolescents show a highly integrated fronto-parietal network due to distant gamma phase-locking oscillations, which is indicated by lower modularity of the global network topology, more connector bridges between the frontal and parietal cortices and less connector hubs in the sensorimotor cortex. The time-domain analysis finds that, while maintaining more stable phase dynamics of the fronto-parietal coupling, the math-gifted adolescents are characterized by more extensive fronto-parietal connection reconfiguration. The results from sample fitting in the power-law model further find that the phase-locking durations in the math-gifted brain abides by a wider interval of the power-law distribution. This phase-lock distribution mechanism could represent a relatively optimized pattern for the functional binding of frontal-parietal network, which underlies stable fronto-parietal connectivity and increases flexibility of timely network reconfiguration.

  6. Optimization of pile foundation program based on Analytic Hierarchy Process%基于AHP的基坑支护方案的优选研究

    Institute of Scientific and Technical Information of China (English)

    贺晨; 陈建宏

    2011-01-01

    基坑工程是一个复杂的系统工程,支护方案的优劣受很多因素影响,应用层次分析法原理,将复杂的深基坑支护方案决策问题层次化,并且,根据深基坑支护系统的特点建立层次结构模型,通过层次分析法比较,选出最优支护方案.实例研究表明,层次分析法简便、高效、科学合理,是一种处理复杂的多目标决策问题的实用方法.通过层次总排序得到各个备选方案的优劣排序,使选择过程更加全面、科学、公正、准确.%Deep foundation pit was a complex systematic project, supporting the merits of the program affected by many factors. This paper, through using analytic hierarchy principle, discusses the complex program of deep foundation pit hierarchical decision - making problems, and, under the Sbenzhen - based pit support system, it is characterized by the establishment of a hierarchical model and through the comparison of AHP to select the optimal supporting program. Case studies show: AHP is simple, efficient, scientific and rational, and it is a complex multi -objective decision - making problem in practical ways. Total sorting through the layers to be pros and cons of various options will make the selection process become more comprehensive, scientific, fair and accurate.

  7. Mathematical hierarchies and biology

    CERN Document Server

    Mirkin, Boris; Roberts, Fred S; Roberts, Fred S; Rzhetsky, Andrey

    1997-01-01

    The mathematical approach to the study of hierarchies presents the theoretical basis for many important areas of current scientific investigation. Biology has benefited from this research and has also stimulated the mathematical study of hierarchies. This collection presents papers devoted to theoretical, algorithmical, and application issues related to (1) reconstructing hierarchies (trees or ranking) from (dis)similarity or entity-to-character data, (2) using hierarchies for modeling evolution and other processes, and (3) combining (gene) trees. The papers in this volume provide a contemporary sample of many new results in hierarchy theory with applications in biology, psychology, data analysis, and systems engineering. Features: Mathematical treatment of hierarchies in several interconnected frameworks: set systems, linear subspaces, graph objects, and tree metrics. The relationship of hierarchies to many issues of current application-from learning robots to wavelets to intron evolution to the evolution ...

  8. Comparison and optimization of hiPSC forebrain cortical differentiation protocols.

    Science.gov (United States)

    Muratore, Christina R; Srikanth, Priya; Callahan, Dana G; Young-Pearse, Tracy L

    2014-01-01

    Several protocols have been developed for human induced pluripotent stem cell neuronal differentiation. We compare several methods for forebrain cortical neuronal differentiation by assessing cell morphology, immunostaining and gene expression. We evaluate embryoid aggregate vs. monolayer with dual SMAD inhibition differentiation protocols, manual vs. AggreWell aggregate formation, plating substrates, neural progenitor cell (NPC) isolation methods, NPC maintenance and expansion, and astrocyte co-culture. The embryoid aggregate protocol, using a Matrigel substrate, consistently generates a high yield and purity of neurons. NPC isolation by manual selection, enzymatic rosette selection, or FACS all are efficient, but exhibit some differences in resulting cell populations. Expansion of NPCs as neural aggregates yields higher cell purity than expansion in a monolayer. Finally, co-culture of iPSC-derived neurons with astrocytes increases neuronal maturity by day 40. This study directly compares commonly employed methods for neuronal differentiation of iPSCs, and can be used as a resource for choosing between various differentiation protocols.

  9. Comparison and optimization of hiPSC forebrain cortical differentiation protocols.

    Directory of Open Access Journals (Sweden)

    Christina R Muratore

    Full Text Available Several protocols have been developed for human induced pluripotent stem cell neuronal differentiation. We compare several methods for forebrain cortical neuronal differentiation by assessing cell morphology, immunostaining and gene expression. We evaluate embryoid aggregate vs. monolayer with dual SMAD inhibition differentiation protocols, manual vs. AggreWell aggregate formation, plating substrates, neural progenitor cell (NPC isolation methods, NPC maintenance and expansion, and astrocyte co-culture. The embryoid aggregate protocol, using a Matrigel substrate, consistently generates a high yield and purity of neurons. NPC isolation by manual selection, enzymatic rosette selection, or FACS all are efficient, but exhibit some differences in resulting cell populations. Expansion of NPCs as neural aggregates yields higher cell purity than expansion in a monolayer. Finally, co-culture of iPSC-derived neurons with astrocytes increases neuronal maturity by day 40. This study directly compares commonly employed methods for neuronal differentiation of iPSCs, and can be used as a resource for choosing between various differentiation protocols.

  10. Eliciting Naturalistic Cortical Responses with a Sensory Prosthesis via Optimized Microstimulation

    Science.gov (United States)

    2016-08-12

    by electrical stimulation along the sensory neural pathways. Such stimulation, when informed by electronic sensors , could provide naturalistic... naturally occurring stimuli into biomimetic percepts via multi-channel microstimulation are lacking. More specifically, generating spatiotemporal patterns... naturally occurring touch responses as closely as possible. Main results. Here we show that such optimization produces responses in the S1 cortex of the

  11. A two-stage planning and control model toward Economically Adapted Power Distribution Systems using analytical hierarchy processes and fuzzy optimization

    Energy Technology Data Exchange (ETDEWEB)

    Schweickardt, Gustavo [Instituto de Economia Energetica, Fundacion Bariloche, Centro Atomico Bariloche - Pabellon 7, Av. Bustillo km 9500, 8400 Bariloche (Argentina); Miranda, Vladimiro [INESC Porto, Instituto de Engenharia de Sistemas e Computadores do Porto and FEUP, Faculdade de Engenharia da Universidade do Porto, R. Dr. Roberto Frias, 378, 4200-465 Porto (Portugal)

    2009-07-15

    This work presents a model to evaluate the Distribution System Dynamic De-adaptation respecting its planning for a given period of Tariff Control. The starting point for modeling is brought about by the results from a multi-criteria method based on Fuzzy Dynamic Programming and on Analytic Hierarchy Processes applied in a mid/short-term horizon (stage 1). Then, the decision-making activities using the Hierarchy Analytical Processes will allow defining, for a Control of System De-adaptation (stage 2), a Vector to evaluate the System Dynamic Adaptation. It is directly associated to an eventual series of inbalances that take place during its evolution. (author)

  12. Eliciting naturalistic cortical responses with a sensory prosthesis via optimized microstimulation

    Science.gov (United States)

    Choi, John S.; Brockmeier, Austin J.; McNiel, David B.; von Kraus, Lee M.; Príncipe, José C.; Francis, Joseph T.

    2016-10-01

    Objective. Lost sensations, such as touch, could one day be restored by electrical stimulation along the sensory neural pathways. Such stimulation, when informed by electronic sensors, could provide naturalistic cutaneous and proprioceptive feedback to the user. Perceptually, microstimulation of somatosensory brain regions produces localized, modality-specific sensations, and several spatiotemporal parameters have been studied for their discernibility. However, systematic methods for encoding a wide array of naturally occurring stimuli into biomimetic percepts via multi-channel microstimulation are lacking. More specifically, generating spatiotemporal patterns for explicitly evoking naturalistic neural activation has not yet been explored. Approach. We address this problem by first modeling the dynamical input-output relationship between multichannel microstimulation and downstream neural responses, and then optimizing the input pattern to reproduce naturally occurring touch responses as closely as possible. Main results. Here we show that such optimization produces responses in the S1 cortex of the anesthetized rat that are highly similar to natural, tactile-stimulus-evoked counterparts. Furthermore, information on both pressure and location of the touch stimulus was found to be highly preserved. Significance. Our results suggest that the currently presented stimulus optimization approach holds great promise for restoring naturalistic levels of sensation.

  13. Optimization of process parameters for drilled hole quality characteristics during cortical bone drilling using Taguchi method.

    Science.gov (United States)

    Singh, Gurmeet; Jain, Vivek; Gupta, Dheeraj; Ghai, Aman

    2016-09-01

    Orthopaedic surgery involves drilling of bones to get them fixed at their original position. The drilling process used in orthopaedic surgery is most likely to the mechanical drilling process and there is all likelihood that it may harm the already damaged bone, the surrounding bone tissue and nerves, and the peril is not limited at that. It is very much feared that the recovery of that part may be impeded so that it may not be able to sustain life long. To achieve sustainable orthopaedic surgery, a surgeon must try to control the drilling damage at the time of bone drilling. The area around the holes decides the life of bone joint and so, the contiguous area of drilled hole must be intact and retain its properties even after drilling. This study mainly focuses on optimization of drilling parameters like rotational speed, feed rate and the type of tool at three levels each used by Taguchi optimization for surface roughness and material removal rate. The confirmation experiments were also carried out and results found with the confidence interval. Scanning electrode microscopy (SEM) images assisted in getting the micro level information of bone damage.

  14. The Analytical Hierarchy Process

    DEFF Research Database (Denmark)

    Barfod, Michael Bruhn

    2007-01-01

    The technical note gathers the theory behind the Analytical Hierarchy Process (AHP) and present its advantages and disadvantages in practical use.......The technical note gathers the theory behind the Analytical Hierarchy Process (AHP) and present its advantages and disadvantages in practical use....

  15. The Analytical Hierarchy Process

    DEFF Research Database (Denmark)

    Barfod, Michael Bruhn

    2007-01-01

    The technical note gathers the theory behind the Analytical Hierarchy Process (AHP) and present its advantages and disadvantages in practical use.......The technical note gathers the theory behind the Analytical Hierarchy Process (AHP) and present its advantages and disadvantages in practical use....

  16. The Star Height Hierarchy Vs. The Variable Hierarchy

    OpenAIRE

    Belkhir, Walid

    2009-01-01

    The star height hierarchy (resp. the variable hierarchy) results in classifying $\\mu$-terms into classes according to the nested depth of fixed point operators (resp. to the number of bound variables). We prove, under some assumptions, that the variable hierarchy is a proper refinement of the star height hierarchy. We mean that the non collapse of the variable hierarchy implies the non collapse of the star height hierarchy. The proof relies on the combinatorial characterization of the two hie...

  17. Why hierarchies thrive.

    Science.gov (United States)

    Leavitt, Harold J

    2003-03-01

    Hardly anyone has a good word to say about hierarchies. Academics, consultants, and management gurus regularly forecast their imminent replacement because hierarchies--even when populated by considerate and intelligent people--can be cruel and stupid. They routinely transform motivated and loyal employees into disaffected Dilberts. It's no wonder that we continue to search for more humane and productive alternatives to them. Yet the intensity with which we struggle against hierarchies only serves to highlight their durability. Hierarchy, it seems, may be intrinsic not only to the natural world but also to our own natures. In this article, organizational behavior expert Harold J. Leavitt presents neither a defense of human hierarchies nor another attack on them. Instead, he offers a reality check, a reminder that hierarchy remains the basic structure of most, if not all, large, ongoing human organizations. That's because although they are often depicted as being out of date, hierarchies have proved to be extraordinarily adaptive. Over the past 50 years, for example, they have co-opted the three major managerial movements--human relations, analytic management, and communities of practice. Hierarchies also persist because they deliver real practical and psychological value, and they fulfill our deep need for order and security. Despite the good they may do, hierarchies are inevitably authoritarian. That authoritarianism shows up in all kinds of ways and influences everything in organizations, particularly communication. In multilevel organizations, for instance, messages get distorted as they travel up and down the ladder of command. Self-protection and self-interest weigh in, and relevant information is lost as messages make stops along the route. Sensitive leaders take steps to make speaking the truth as painless as possible. But it never is in organizations, because authoritarianism is an immutable element of hierarchy.

  18. Extracting tag hierarchies.

    Directory of Open Access Journals (Sweden)

    Gergely Tibély

    Full Text Available Tagging items with descriptive annotations or keywords is a very natural way to compress and highlight information about the properties of the given entity. Over the years several methods have been proposed for extracting a hierarchy between the tags for systems with a "flat", egalitarian organization of the tags, which is very common when the tags correspond to free words given by numerous independent people. Here we present a complete framework for automated tag hierarchy extraction based on tag occurrence statistics. Along with proposing new algorithms, we are also introducing different quality measures enabling the detailed comparison of competing approaches from different aspects. Furthermore, we set up a synthetic, computer generated benchmark providing a versatile tool for testing, with a couple of tunable parameters capable of generating a wide range of test beds. Beside the computer generated input we also use real data in our studies, including a biological example with a pre-defined hierarchy between the tags. The encouraging similarity between the pre-defined and reconstructed hierarchy, as well as the seemingly meaningful hierarchies obtained for other real systems indicate that tag hierarchy extraction is a very promising direction for further research with a great potential for practical applications. Tags have become very prevalent nowadays in various online platforms ranging from blogs through scientific publications to protein databases. Furthermore, tagging systems dedicated for voluntary tagging of photos, films, books, etc. with free words are also becoming popular. The emerging large collections of tags associated with different objects are often referred to as folksonomies, highlighting their collaborative origin and the "flat" organization of the tags opposed to traditional hierarchical categorization. Adding a tag hierarchy corresponding to a given folksonomy can very effectively help narrowing or broadening the scope of

  19. Extracting tag hierarchies.

    Science.gov (United States)

    Tibély, Gergely; Pollner, Péter; Vicsek, Tamás; Palla, Gergely

    2013-01-01

    Tagging items with descriptive annotations or keywords is a very natural way to compress and highlight information about the properties of the given entity. Over the years several methods have been proposed for extracting a hierarchy between the tags for systems with a "flat", egalitarian organization of the tags, which is very common when the tags correspond to free words given by numerous independent people. Here we present a complete framework for automated tag hierarchy extraction based on tag occurrence statistics. Along with proposing new algorithms, we are also introducing different quality measures enabling the detailed comparison of competing approaches from different aspects. Furthermore, we set up a synthetic, computer generated benchmark providing a versatile tool for testing, with a couple of tunable parameters capable of generating a wide range of test beds. Beside the computer generated input we also use real data in our studies, including a biological example with a pre-defined hierarchy between the tags. The encouraging similarity between the pre-defined and reconstructed hierarchy, as well as the seemingly meaningful hierarchies obtained for other real systems indicate that tag hierarchy extraction is a very promising direction for further research with a great potential for practical applications. Tags have become very prevalent nowadays in various online platforms ranging from blogs through scientific publications to protein databases. Furthermore, tagging systems dedicated for voluntary tagging of photos, films, books, etc. with free words are also becoming popular. The emerging large collections of tags associated with different objects are often referred to as folksonomies, highlighting their collaborative origin and the "flat" organization of the tags opposed to traditional hierarchical categorization. Adding a tag hierarchy corresponding to a given folksonomy can very effectively help narrowing or broadening the scope of search. Moreover

  20. Extracting Tag Hierarchies

    Science.gov (United States)

    Tibély, Gergely; Pollner, Péter; Vicsek, Tamás; Palla, Gergely

    2013-01-01

    Tagging items with descriptive annotations or keywords is a very natural way to compress and highlight information about the properties of the given entity. Over the years several methods have been proposed for extracting a hierarchy between the tags for systems with a "flat", egalitarian organization of the tags, which is very common when the tags correspond to free words given by numerous independent people. Here we present a complete framework for automated tag hierarchy extraction based on tag occurrence statistics. Along with proposing new algorithms, we are also introducing different quality measures enabling the detailed comparison of competing approaches from different aspects. Furthermore, we set up a synthetic, computer generated benchmark providing a versatile tool for testing, with a couple of tunable parameters capable of generating a wide range of test beds. Beside the computer generated input we also use real data in our studies, including a biological example with a pre-defined hierarchy between the tags. The encouraging similarity between the pre-defined and reconstructed hierarchy, as well as the seemingly meaningful hierarchies obtained for other real systems indicate that tag hierarchy extraction is a very promising direction for further research with a great potential for practical applications. Tags have become very prevalent nowadays in various online platforms ranging from blogs through scientific publications to protein databases. Furthermore, tagging systems dedicated for voluntary tagging of photos, films, books, etc. with free words are also becoming popular. The emerging large collections of tags associated with different objects are often referred to as folksonomies, highlighting their collaborative origin and the “flat” organization of the tags opposed to traditional hierarchical categorization. Adding a tag hierarchy corresponding to a given folksonomy can very effectively help narrowing or broadening the scope of search

  1. Evaluating, Comparing, and Interpreting Protein Domain Hierarchies

    Science.gov (United States)

    2014-01-01

    Abstract Arranging protein domain sequences hierarchically into evolutionarily divergent subgroups is important for investigating evolutionary history, for speeding up web-based similarity searches, for identifying sequence determinants of protein function, and for genome annotation. However, whether or not a particular hierarchy is optimal is often unclear, and independently constructed hierarchies for the same domain can often differ significantly. This article describes methods for statistically evaluating specific aspects of a hierarchy, for probing the criteria underlying its construction and for direct comparisons between hierarchies. Information theoretical notions are used to quantify the contributions of specific hierarchical features to the underlying statistical model. Such features include subhierarchies, sequence subgroups, individual sequences, and subgroup-associated signature patterns. Underlying properties are graphically displayed in plots of each specific feature's contributions, in heat maps of pattern residue conservation, in “contrast alignments,” and through cross-mapping of subgroups between hierarchies. Together, these approaches provide a deeper understanding of protein domain functional divergence, reveal uncertainties caused by inconsistent patterns of sequence conservation, and help resolve conflicts between competing hierarchies. PMID:24559108

  2. On the Optimization of the Geodesic Active Fields (GAF) for Image Registration: Application to multi-scale registration of cortical maps on the sphere

    OpenAIRE

    Ciller Ruiz, Carlos

    2012-01-01

    [ANGLÈS] This work presents an analysis and optimization, both in terms of optimal parameters and speed, of the novel geodesic active fields framework for surface image registration on the sphere, presented by Zosso, Dominique in his PhD thesis at the École Polytechnique Fédérale de Lausanne. The relevance of surface registration to medical imaging is that there is a lot of anatomical information in the form of collected surface points, giving information about the cortical folding pattern. H...

  3. 基于粒子群算法的模糊层次分析法改进及其应用研究%Improvement of Fuzzy Analytic Hierarchy Process Based on Particle Swarm Optimization and Its Application Research

    Institute of Scientific and Technical Information of China (English)

    李壮阔; 薛有添

    2013-01-01

    提出了基于粒子群算法( Particle Swarm Optimization )的模糊层次分析法( Fuzzy Analytic Hierarchy Process)模型,简称PSO-FAHP,将模糊判断矩阵一致性的检验、修正及各元素权重值的计算过程转化成非线性带约束系统优化问题,并利用粒子群算法实现了该问题的求解。构建了制造企业供应商选择评价指标体系,最后将该模型应用于制造企业供应商选择评价,结果表明,此模型能有效帮助企业选择较佳的供应商,对供应链构建有一定的指导意义。%This paper proposed a model of fuzzy analytic hierarchy process ( FAHP) based on particle swarm opti-mization( PSO) called PSO-FAHP.It transformed the consistency modified and elements ranking alternative of fuzzy judgement matrix into an optimization problem for nonlinear constrained system , and made use of particle swarm optimization to solve it .Finally, it built a evaluation index system for manufacturing enterprises ’ vendors selection and applied the PSO-FAHP model to manufacturing enterprises ’ venders selection and evaluation .The results show that this model can effectively help companies choose better venders and have certain guiding signifi -cance for building the supply chain .

  4. Convergence and divergence are mostly reciprocated properties of the connections in the network of cortical areas.

    Science.gov (United States)

    Négyessy, László; Nepusz, Tamás; Zalányi, László; Bazsó, Fülöp

    2008-10-22

    Cognition is based on the integrated functioning of hierarchically organized cortical processing streams in a manner yet to be clarified. Because integration fundamentally depends on convergence and the complementary notion of divergence of the neuronal connections, we analysed integration by measuring the degree of convergence/divergence through the connections in the network of cortical areas. By introducing a new index, we explored the complementary convergent and divergent nature of connectional reciprocity and delineated the backward and forward cortical sub-networks for the first time. Integrative properties of the areas defined by the degree of convergence/divergence through their afferents and efferents exhibited distinctive characteristics at different levels of the cortical hierarchy. Areas previously identified as hubs exhibit information bottleneck properties. Cortical networks largely deviate from random graphs where convergence and divergence are balanced at low reciprocity level. In the cortex, which is dominated by reciprocal connections, balance appears only by further increasing the number of reciprocal connections. The results point to the decisive role of the optimal number and placement of reciprocal connections in large-scale cortical integration. Our findings also facilitate understanding of the functional interactions between the cortical areas and the information flow or its equivalents in highly recurrent natural and artificial networks.

  5. Quantifying the Effects of Formalin Fixation on the Mechanical Properties of Cortical Bone Using Beam Theory and Optimization Methodology With Specimen-Specific Finite Element Models.

    Science.gov (United States)

    Zhang, Guan-Jun; Yang, Jie; Guan, Feng-Jiao; Chen, Dan; Li, Na; Cao, Libo; Mao, Haojie

    2016-09-01

    The effects of formalin fixation on bone material properties remain debatable. In this study, we collected 36 fresh-frozen cuboid-shaped cortical specimens from five male bovine femurs and immersed half of the specimens into 4% formalin fixation liquid for 30 days. We then conducted three-point bending tests and used both beam theory method and an optimization method combined with specimen-specific finite element (FE) models to identify material parameters. Through the optimization FE method, the formalin-fixed bones showed a significantly lower Young's modulus (-12%) compared to the fresh-frozen specimens, while no difference was observed using the beam theory method. Meanwhile, both the optimization FE and beam theory methods revealed higher effective failure strains for formalin-fixed bones compared to fresh-frozen ones (52% higher through the optimization FE method and 84% higher through the beam theory method). Hence, we conclude that the formalin fixation has a significant effect on bovine cortical bones at small, elastic, as well as large, plastic deformations.

  6. Identification and prioritization of the effective factors on the choice of optimal marketing strategy in recession situations using fuzzy and Group Analytic Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Amir Kariznoee

    2014-05-01

    Full Text Available It is obvious that recession situation leads to demands reduction. Therefore, companies encounter challenges and weak businesses are disappeared and resistant and strength companies remain. In this situation considering the marketing department especially marketing strategy play a significant role. There are many marketing strategies. Companies use these strategies based on their needs or formulate new strategy with regard to their internal and external circumstances. This paper identify and prioritize the important factors in determination and selection appropriate marketing strategy through reviewing previous studies related to strategies used in recession condition and interviewing with experts. Thus, fuzzy and group analytic hierarchy process, which is a common and widely used decision making method, have been used in this study also the excel software was used in this study. The results of this study indicate that the major factors influencing the selection of appropriate marketing strategies, in order of preference, are price, product, distribution networks, and staff.

  7. Delegation Within Hierarchies

    DEFF Research Database (Denmark)

    Dobrajska, Magdalena; Billinger, Stephan; Karim, Samina

    2015-01-01

    We investigate trade-offs associated with delegating authority over multiple interrelated decisions in a complex task structure. The empirical setting is a business process of a global Fortune 50 firm. The firm decentralized its organization and redefined decision authority across organizational......-relevant knowledge, the matching of required knowledge and managers’ expertise, and information processing intensity affect (a) the occurrence of delegation and, (b) if delegation occurs, how far down the organizational hierarchy authority is delegated. We discuss how these findings complement existing theories...... hierarchies between 2008 and 2011. We employ regression analysis of microlevel data on the allocation of decision authority between formal and real authority, and further on the organization design of 761 decision tasks within a hierarchy. Our findings show how the specialization of decision...

  8. Rethinking the waste hierarchy

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, C.; Vigsoe, D. (eds.)

    2005-03-01

    There is an increasing need to couple environmental and economic considerations within waste management. Consumers and companies alike generate ever more waste. The waste-policy challenges of the future lie in decoupling growth in waste generation from growth in consumption, and in setting priorities for the waste management. This report discusses the criteria for deciding priorities for waste management methods, and questions the current principles of EU waste policies. The basis for the discussion is the so-called waste hierarchy which has dominated the waste policy in the EU since the mid-1970s. The waste hierarchy ranks possible methods of waste management. According to the waste hierarchy, the very best solution is to reduce the amount of waste. After that, reuse is preferred to recycling which, in turn, is preferred to incineration. Disposal at a landfill is the least favourable solution. (BA)

  9. Extracting tag hierarchies

    CERN Document Server

    Tibély, Gergely; Vicsek, Tamás; Palla, Gergely

    2014-01-01

    Tagging items with descriptive annotations or keywords is a very natural way to compress and highlight information about the properties of the given entity. Over the years several methods have been proposed for extracting a hierarchy between the tags for systems with a "flat", egalitarian organization of the tags, which is very common when the tags correspond to free words given by numerous independent people. Here we present a complete framework for automated tag hierarchy extraction based on tag occurrence statistics. Along with proposing new algorithms, we are also introducing different quality measures enabling the detailed comparison of competing approaches from different aspects. Furthermore, we set up a synthetic, computer generated benchmark providing a versatile tool for testing, with a couple of tunable parameters capable of generating a wide range of test beds. Beside the computer generated input we also use real data in our studies, including a biological example with a pre-defined hierarchy betwe...

  10. Hierarchies in student groups

    OpenAIRE

    Güntert, Manuel

    2008-01-01

    This is a research about hierarchies in student groups. It shows how they are built und what sense they have. The position of a student in his student peer group is evaluated. The influence of the look, the style, the behaviour of the other sex, the gender, the origin, the prehistory, the appearance, achievement and their effect on hierarchies is analysed and the impact of charisma and organisation are compared. The meaning of this research is to indicate how a student must be to get the lead...

  11. The Reinforcement Hierarchy

    Science.gov (United States)

    Forness, Steven R.

    1973-01-01

    Reinforcement hierarchy implies movement along a continuum from top to bottom, from primitive levels of reinforcement to more sophisticated levels. Unless it is immediately obvious that a child cannot function without the use of lower-order reinforcers, we should approach him as though he responds to topmost reinforcers until he demonstrates…

  12. What is the optimal duration of middle-cerebral artery occlusion consistently resulting in isolated cortical selective neuronal loss in the spontaneously hypertensive rat?

    Directory of Open Access Journals (Sweden)

    Sohail eEjaz

    2015-03-01

    Full Text Available Introduction and Objectives: Selective neuronal loss (SNL in the reperfused penumbra may impact clinical recovery and is thus important to investigate. Brief proximal middle cerebral artery occlusion (MCAo results in predominantly striatal SNL, yet cortical damage is more relevant given its behavioral implications and that thrombolytic therapy mainly rescues the cortex. Distal temporary MCAo (tMCAo does target the cortex, but the optimal occlusion duration that results in isolated SNL has not been determined. In the present study we assessed different distal tMCAo durations looking for consistently pure SNL.Methods: Microclip distal tMCAo (md-tMCAo was performed in ~6-month old male spontaneously hypertensive rats (SHRs. We previously reported that 45min md-tMCAo in SHRs results in pan-necrosis in the majority of subjects. Accordingly, three shorter MCAo durations were investigated here in decremental succession, namely 30, 22 and 15mins (n=3, 3 and 7 subjects, respectively. Recanalization was confirmed by MR angiography just prior to brain collection at 28 days and T2-weighted MRI was obtained for characterization of ischemic lesions. NeuN, OX42 and GFAP immunohistochemistry appraised changes in neurons, microglia and astrocytes, respectively. Ischemic lesions were categorized into three main types: 1 pan-necrosis; 2 partial infarction; and 3 SNL. Results: Pan-necrosis or partial infarction was present in all 30min and 22min subjects, but not in the 15min group (p < 0.001, in which isolated cortical SNL was consistently present. MRI revealed characteristic hyperintense abnormalities in all rats with pan-necrosis or partial infarction, but no change in any 15min subject. Conclusions: We found that 15min distal MCAo consistently resulted in pure cortical SNL, whereas durations equal or longer than 22min consistently resulted in infarcts. This model may be of use to study the pathophysiology of cortical SNL and its prevention by appropriate

  13. Optimizing finite element predictions of local subchondral bone structural stiffness using neural network-derived density-modulus relationships for proximal tibial subchondral cortical and trabecular bone.

    Science.gov (United States)

    Nazemi, S Majid; Amini, Morteza; Kontulainen, Saija A; Milner, Jaques S; Holdsworth, David W; Masri, Bassam A; Wilson, David R; Johnston, James D

    2017-01-01

    Quantitative computed tomography based subject-specific finite element modeling has potential to clarify the role of subchondral bone alterations in knee osteoarthritis initiation, progression, and pain. However, it is unclear what density-modulus equation(s) should be applied with subchondral cortical and subchondral trabecular bone when constructing finite element models of the tibia. Using a novel approach applying neural networks, optimization, and back-calculation against in situ experimental testing results, the objective of this study was to identify subchondral-specific equations that optimized finite element predictions of local structural stiffness at the proximal tibial subchondral surface. Thirteen proximal tibial compartments were imaged via quantitative computed tomography. Imaged bone mineral density was converted to elastic moduli using multiple density-modulus equations (93 total variations) then mapped to corresponding finite element models. For each variation, root mean squared error was calculated between finite element prediction and in situ measured stiffness at 47 indentation sites. Resulting errors were used to train an artificial neural network, which provided an unlimited number of model variations, with corresponding error, for predicting stiffness at the subchondral bone surface. Nelder-Mead optimization was used to identify optimum density-modulus equations for predicting stiffness. Finite element modeling predicted 81% of experimental stiffness variance (with 10.5% error) using optimized equations for subchondral cortical and trabecular bone differentiated with a 0.5g/cm(3) density. In comparison with published density-modulus relationships, optimized equations offered improved predictions of local subchondral structural stiffness. Further research is needed with anisotropy inclusion, a smaller voxel size and de-blurring algorithms to improve predictions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. An extension of heat hierarchy

    OpenAIRE

    Wang, Joe S.

    2014-01-01

    We propose a formally completely integrable extension of heat hierarchy based on the space of symmetries isomorphic to the Weyl algebra $\\mathcal{A}_1$. The extended heat hierarchy will be the basic model for the analysis of the extension of KP hierarchy, and other integrable equations.

  15. Ansatz for dynamical hierarchies

    DEFF Research Database (Denmark)

    Rasmussen, S.; Baas, N.A.; Mayer, B.

    2001-01-01

    Complex, robust functionalities can be generated naturally in at least two ways: by the assembly of structures and by the evolution of structures. This work is concerned with spontaneous formation of structures. We define the notion of dynamical hierarchies in natural systems and show...... the importance of this particular kind of organization for living systems. We then define a framework that enables us to formulate, investigate, and manipulate such dynamical hierarchies. This framework allows us to simultaneously investigate different levels of description together with them interrelationship...... three. Formulating this system as a simple two-dimensional molecular dynamics (MD) lattice gas allows us within one dynamical system to demonstrate the successive emergence of two higher levels (three levels all together) of robust structures with associated properties. Second, we demonstrate how...

  16. Hierarchies in Dependence Logic

    CERN Document Server

    Durand, Arnaud

    2011-01-01

    We study fragments of dependence logic defined either by restricting the number k of universal quantifiers or the width of dependence atoms in formulas. We find the sublogics of existential second-order logic corresponding to these fragments of dependence logic. We also show that these both ways of defining fragments of dependence logic give rise to a hierarchy in expressive power with respect to k.

  17. Development and Optimization of Hybrid Friction Materials Consisting of Nanoclay and Carbon Nanotubes by using Analytical Hierarchy Process (AHP and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS under Fuzzy Atmosphere

    Directory of Open Access Journals (Sweden)

    Tej SINGH

    2013-07-01

    Full Text Available The tribo-performance of nanoclay and multi-walled carbon nanotube (MWNT filled and graphite lubricated phenolic composites, reinforced with a combination of lapinus and kevlar fibers, have been evaluated on a Kraus friction testing machine. The combined fuzzy analytical hierarchy process (FAHP and fuzzy technique for order preference by similarity to ideal solution (FTOPSIS approach, taking into account performance defining attributes (PDAs such as friction performance, wear, friction-fade, friction-recovery, stability coefficient, variability coefficient, friction fluctuations and temperature rise of the disc, was used for the performance assessment of fabricated friction composite materials. The weight of different PDAs were evaluated by FAHP; μ-performance (0.144, 0.255, 0.435, wear (0.144, 0.255, 0.435, fade-% (0.073, 0.15, 0.307, recovery-% (0.063, 0.126, 0.268, stability coefficient (0.037, 0.075, 0.156, variability coefficient (0.032, 0.063, 0.136, frictional fluctuations (0.023, 0.037, 0.069, and DTR (0.023, 0.037, 0.069 respectively.  FTOPSIS was employed to determine the optimal ranking of the friction composite materials as NC-7>NC-8>NC-6>NC-5>NC-3>NC-4>NC-2>NC-1. The alternative with kevlar: lapinus, 2.5:27.5 wt-% and graphite: nanoclay: carbon nanotube, 2.25:2.75 wt-% exhibits the optimal properties.

  18. [Cortical blindness].

    Science.gov (United States)

    Chokron, S

    2014-02-01

    Cortical blindness refers to a visual loss induced by a bilateral occipital lesion. The very strong cooperation between psychophysics, cognitive psychology, neurophysiology and neuropsychology these latter twenty years as well as recent progress in cerebral imagery have led to a better understanding of neurovisual deficits, such as cortical blindness. It thus becomes possible now to propose an earlier diagnosis of cortical blindness as well as new perspectives for rehabilitation in children as well as in adults. On the other hand, studying complex neurovisual deficits, such as cortical blindness is a way to infer normal functioning of the visual system.

  19. INFORMATION GATHERING, DELEGATED CONTRACTING AND CORPORATE HIERARCHIES

    OpenAIRE

    Chongwoo Choe; In-Uck Park

    2008-01-01

    In a typical corporate hierarchy, the manager is delegated the authority to make strategic decisions, and to contract with other employees. We study when such delegation can be optimal. In centralization, the owner retains the authority, which fails to motivate the manager to acquire valuable information, leading to suboptimal decisions and inefficient incentive provision to the worker. Beneficial delegation should necessarily motivate the manager to acquire information, which is possible onl...

  20. Nonlinear Integrable Couplings of Levi Hierarchy and WKI Hierarchy

    Directory of Open Access Journals (Sweden)

    Zhengduo Shan

    2014-01-01

    Full Text Available With the help of the known Lie algebra, a type of new 8-dimensional matrix Lie algebra is constructed in the paper. By using the 8-dimensional matrix Lie algebra, the nonlinear integrable couplings of the Levi hierarchy and the Wadati-Konno-Ichikawa (WKI hierarchy are worked out, which are different from the linear integrable couplings. Based on the variational identity, the Hamiltonian structures of the above hierarchies are derived.

  1. Nonlinear Integrable Couplings of Levi Hierarchy and WKI Hierarchy

    OpenAIRE

    Zhengduo Shan; Hongwei Yang; Baoshu Yin

    2014-01-01

    With the help of the known Lie algebra, a type of new 8-dimensional matrix Lie algebra is constructed in the paper. By using the 8-dimensional matrix Lie algebra, the nonlinear integrable couplings of the Levi hierarchy and the Wadati-Konno-Ichikawa (WKI) hierarchy are worked out, which are different from the linear integrable couplings. Based on the variational identity, the Hamiltonian structures of the above hierarchies are derived.

  2. Optimal Planning of the Capacity and Site of EV Charging Facilities by the Analytical Hierarchy Process%电动汽车充电设施分层递进式定址定容最优规划

    Institute of Scientific and Technical Information of China (English)

    孙元; 丁茂生; 柳劲松; 杨永标; 许晓慧; 徐青山; 时姗姗

    2014-01-01

    电动汽车充电设施作为发展电动汽车产业的重要配套基础设施,是电动汽车产业推广与普及的前提。文章采用分层递进式方法对充电设施进行定址定容规划建模求解。首先,根据交通、地理、需求等因素,采用层次分析法来确定充电设施的候选站址;然后,建立以总体建设成本最小为目标,以充电需求和线路传输容量为约束的优化模型,采用遗传算法,对候选站址进行优化,得到充电设施的建设地址和容量。最后通过一个充电设施规划算例,建立最优化模型并予以求解,验证本文所给的充电设施规划方法的合理性和可行性。%As an important supporting infrastructure for the development of the electric vehicle industry,the electric vehicle charging facilities are the prerequisite of the promotion and popularization of the electric vehicle industry. This paper made a model for the EV charging facilities planning and sought the solution by the Analytical Hierarchy Process. Firstly,the Analytical Hierarchy Process was adopted to find the candidate sites of the charging facilities, according to the factorssuch as transportation,geography,demand and others. Secondly,an optimal model was made, with the smallest overall construction cost as the objective,and the charging demand and the transmission capacity of the power lines as the restraint. Then by using the genetic algorithm,the candidate sites of the charging facilities were optimized to obtain the construction sites and capacity of the charging facilities. Finally,a hypothetical example of the charging facilities planning was given to further elaborate the model and to verify the rationality and feasibility of the model and the method.

  3. A hierarchy of intrinsic timescales across primate cortex

    Science.gov (United States)

    Murray, John D.; Bernacchia, Alberto; Freedman, David J.; Romo, Ranulfo; Wallis, Jonathan D.; Cai, Xinying; Padoa-Schioppa, Camillo; Pasternak, Tatiana; Seo, Hyojung; Lee, Daeyeol; Wang, Xiao-Jing

    2014-01-01

    Specialization and hierarchy are organizing principles for primate cortex, yet there is little direct evidence for how cortical areas are specialized in the temporal domain. We measured timescales of intrinsic fluctuations in spiking activity across areas, and found a hierarchical ordering, with sensory and prefrontal areas exhibiting shorter and longer timescales, respectively. Based on our findings, we suggest that intrinsic timescales reflect areal specialization for task-relevant computations over multiple temporal ranges. PMID:25383900

  4. A hierarchy of intrinsic timescales across primate cortex

    OpenAIRE

    Murray, John D.; Bernacchia, Alberto; Freedman, David J.; Romo, Ranulfo,; Wallis, Jonathan D.; Cai, Xinying; Padoa-Schioppa, Camillo; Pasternak, Tatiana; Seo, Hyojung; Lee, Daeyeol; WANG Xiao-jing

    2014-01-01

    Specialization and hierarchy are organizing principles for primate cortex, yet there is little direct evidence for how cortical areas are specialized in the temporal domain. We measured timescales of intrinsic fluctuations in spiking activity across areas, and found a hierarchical ordering, with sensory and prefrontal areas exhibiting shorter and longer timescales, respectively. Based on our findings, we suggest that intrinsic timescales reflect areal specialization for task-relevant computat...

  5. Hierarchies of Inefficient Kernelizability

    CERN Document Server

    Hermelin, Danny; Sołtys, Karolina; Wahlström, Magnus; Wu, Xi

    2011-01-01

    The framework of Bodlaender et al. (ICALP 2008) and Fortnow and Santhanam (STOC 2008) allows us to exclude the existence of polynomial kernels for a range of problems under reasonable complexity-theoretical assumptions. However, there are also some issues that are not addressed by this framework, including the existence of Turing kernels such as the "kernelization" of Leaf Out Branching(k) into a disjunction over n instances of size poly(k). Observing that Turing kernels are preserved by polynomial parametric transformations, we define a kernelization hardness hierarchy, akin to the M- and W-hierarchy of ordinary parameterized complexity, by the PPT-closure of problems that seem likely to be fundamentally hard for efficient Turing kernelization. We find that several previously considered problems are complete for our fundamental hardness class, including Min Ones d-SAT(k), Binary NDTM Halting(k), Connected Vertex Cover(k), and Clique(k log n), the clique problem parameterized by k log n.

  6. The tensor hierarchy algebra

    Energy Technology Data Exchange (ETDEWEB)

    Palmkvist, Jakob, E-mail: palmkvist@ihes.fr [Institut des Hautes Etudes Scientifiques, 35 Route de Chartres, FR-91440 Bures-sur-Yvette (France)

    2014-01-15

    We introduce an infinite-dimensional Lie superalgebra which is an extension of the U-duality Lie algebra of maximal supergravity in D dimensions, for 3 ⩽ D ⩽ 7. The level decomposition with respect to the U-duality Lie algebra gives exactly the tensor hierarchy of representations that arises in gauge deformations of the theory described by an embedding tensor, for all positive levels p. We prove that these representations are always contained in those coming from the associated Borcherds-Kac-Moody superalgebra, and we explain why some of the latter representations are not included in the tensor hierarchy. The most remarkable feature of our Lie superalgebra is that it does not admit a triangular decomposition like a (Borcherds-)Kac-Moody (super)algebra. Instead the Hodge duality relations between level p and D − 2 − p extend to negative p, relating the representations at the first two negative levels to the supersymmetry and closure constraints of the embedding tensor.

  7. Maslow's Hierarchy of Needs Revisited.

    Science.gov (United States)

    Frame, Douglas

    1996-01-01

    Reviews Maslow's hierarchy of needs and characterization of the self-actualizing personality, suggesting that since few people meet his self-actualization criteria, an educational system designed to produce such personalities may fail, with teachers attending only to the hierarchy's lower stages (self-esteem and self-actualization) which dilutes…

  8. Loewner equations and dispersionless hierarchies

    Energy Technology Data Exchange (ETDEWEB)

    Takebe, Takashi [Department of Mathematics, Ochanomizu University, Otsuka 2-1-1, Bunkyo-ku, Tokyo, 112-8610 (Japan); Teo, Lee-Peng [Faculty of Information Technology, Multimedia University, Jalan Multimedia, Cyberjaya, 63100, Selangor Darul Ehsan (Malaysia); Zabrodin, Anton [Institute of Biochemical Physics, Kosygina str. 4, 119991 Moscow, Russia and ITEP, Bol. Cheremushkinskaya str. 25, 117259 Moscow (Russian Federation)

    2006-09-15

    Using the Hirota representation of dispersionless dKP and dToda hierarchies, we show that the chordal Loewner equations and radial Loewner equations respectively serve as consistency conditions for one-variable reductions of these integrable hierarchies. We also clarify the geometric meaning of this result by relating it to the eigenvalue distribution of normal random matrices in the large N limit.

  9. Maslow's Hierarchy of Needs Revisited.

    Science.gov (United States)

    Frame, Douglas

    1996-01-01

    Reviews Maslow's hierarchy of needs and characterization of the self-actualizing personality, suggesting that since few people meet his self-actualization criteria, an educational system designed to produce such personalities may fail, with teachers attending only to the hierarchy's lower stages (self-esteem and self-actualization) which dilutes…

  10. Neutrino mass hierarchy determination at reactor antineutrino experiments

    CERN Document Server

    Yang, Guang

    2015-01-01

    After the neutrino mixing angle $\\theta_{13}$ has been precisely measured by the reactor antineutrino experiments, one of the most important open questions left in neutrino physics is the neutrino mass hierarchy. Jiangmen Underground Neutrino Observatory (JUNO) is designed to determine the neutrino mass hierarchy (MH) without exploring the matter effect. The JUNO site location is optimized to have the best sensitivity for the mass hierarchy determination. JUNO will employ a 20 kton liquid scintillator detector located in a laboratory 700 meters underground. The excellent energy resolution and PMT coverage will give us an unprecedented opportunity to reach a 3-4 $\\sigma$ precision. In this paper, the JUNO detector design and simulation work will be presented. Also, RENO-50, another medium distance reactor antineutrino experiment, will do a similar measurement. With the efforts of these experiments, it is very likely that the neutrino mass hierarchy will be determined in the next 10 years.

  11. Uncertainty relation for resolution in space, spatial frequency, and orientation optimized by two-dimensional visual cortical filters.

    Science.gov (United States)

    Daugman, J G

    1985-07-01

    Two-dimensional spatial linear filters are constrained by general uncertainty relations that limit their attainable information resolution for orientation, spatial frequency, and two-dimensional (2D) spatial position. The theoretical lower limit for the joint entropy, or uncertainty, of these variables is achieved by an optimal 2D filter family whose spatial weighting functions are generated by exponentiated bivariate second-order polynomials with complex coefficients, the elliptic generalization of the one-dimensional elementary functions proposed in Gabor's famous theory of communication [J. Inst. Electr. Eng. 93, 429 (1946)]. The set includes filters with various orientation bandwidths, spatial-frequency bandwidths, and spatial dimensions, favoring the extraction of various kinds of information from an image. Each such filter occupies an irreducible quantal volume (corresponding to an independent datum) in a four-dimensional information hyperspace whose axes are interpretable as 2D visual space, orientation, and spatial frequency, and thus such a filter set could subserve an optimally efficient sampling of these variables. Evidence is presented that the 2D receptive-field profiles of simple cells in mammalian visual cortex are well described by members of this optimal 2D filter family, and thus such visual neurons could be said to optimize the general uncertainty relations for joint 2D-spatial-2D-spectral information resolution. The variety of their receptive-field dimensions and orientation and spatial-frequency bandwidths, and the correlations among these, reveal several underlying constraints, particularly in width/length aspect ratio and principal axis organization, suggesting a polar division of labor in occupying the quantal volumes of information hyperspace.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Anarchy and hierarchy

    Energy Technology Data Exchange (ETDEWEB)

    Haba, Naoyuki; Murayama, Hitoshi

    2000-09-14

    We advocate a new approach to study models of fermion massesand mixings, namely anarchy proposed in hep-ph/9911341. In this approach,we scan the O(1) coefficients randomly. We argue that this is the correctapproach when the fundamental theory is sufficiently complicated.Assuming there is no physical distinction among three generations ofneutrinos, the probability distributions in MNS mixing angles can bepredicted independent of the choice of the measure. This is because themixing angles are distributed according to the Haar measure of the Liegroups whose elements diagonalize the mass matrices. The near-maximalmixings, as observed in the atmospheric neutrino data and as required inthe LMA solution to the solar neutrino problem, are highly probable. Asmall hierarchy between the Delta m2 for the atmospheric and the solarneutrinos is obtained very easily; the complex seesaw case gives ahierarchy of a factor of 20 as the most probable one, even though thisconclusion is more measure-dependent. U_e3 has to be just below thecurrent limit from the CHOOZ experiment. The CP-violating parameter sindelta is preferred to be maximal. We present a simple SU(5)-likeextension of anarchy to the charged-lepton and quark sectors which workswell phenomenologically.

  13. Amplification of local changes along the timescale processing hierarchy.

    Science.gov (United States)

    Yeshurun, Yaara; Nguyen, Mai; Hasson, Uri

    2017-08-29

    Small changes in word choice can lead to dramatically different interpretations of narratives. How does the brain accumulate and integrate such local changes to construct unique neural representations for different stories? In this study, we created two distinct narratives by changing only a few words in each sentence (e.g., "he" to "she" or "sobbing" to "laughing") while preserving the grammatical structure across stories. We then measured changes in neural responses between the two stories. We found that differences in neural responses between the two stories gradually increased along the hierarchy of processing timescales. For areas with short integration windows, such as early auditory cortex, the differences in neural responses between the two stories were relatively small. In contrast, in areas with the longest integration windows at the top of the hierarchy, such as the precuneus, temporal parietal junction, and medial frontal cortices, there were large differences in neural responses between stories. Furthermore, this gradual increase in neural differences between the stories was highly correlated with an area's ability to integrate information over time. Amplification of neural differences did not occur when changes in words did not alter the interpretation of the story (e.g., sobbing to "crying"). Our results demonstrate how subtle differences in words are gradually accumulated and amplified along the cortical hierarchy as the brain constructs a narrative over time.

  14. Hamiltonian Structure of PI Hierarchy

    Directory of Open Access Journals (Sweden)

    Kanehisa Takasaki

    2007-03-01

    Full Text Available The string equation of type (2,2g+1 may be thought of as a higher order analogue of the first Painlevé equation that corresponds to the case of g = 1. For g > 1, this equation is accompanied with a finite set of commuting isomonodromic deformations, and they altogether form a hierarchy called the PI hierarchy. This hierarchy gives an isomonodromic analogue of the well known Mumford system. The Hamiltonian structure of the Lax equations can be formulated by the same Poisson structure as the Mumford system. A set of Darboux coordinates, which have been used for the Mumford system, can be introduced in this hierarchy as well. The equations of motion in these Darboux coordinates turn out to take a Hamiltonian form, but the Hamiltonians are different from the Hamiltonians of the Lax equations (except for the lowest one that corresponds to the string equation itself.

  15. Hierarchies of Predominantly Connected Communities

    CERN Document Server

    Hamann, Michael; Wagner, Dorothea

    2013-01-01

    We consider communities whose vertices are predominantly connected, i.e., the vertices in each community are stronger connected to other community members of the same community than to vertices outside the community. Flake et al. introduced a hierarchical clustering algorithm that finds such predominantly connected communities of different coarseness depending on an input parameter. We present a simple and efficient method for constructing a clustering hierarchy according to Flake et al. that supersedes the necessity of choosing feasible parameter values and guarantees the completeness of the resulting hierarchy, i.e., the hierarchy contains all clusterings that can be constructed by the original algorithm for any parameter value. However, predominantly connected communities are not organized in a single hierarchy. Thus, we develop a framework that, after precomputing at most $2(n-1)$ maximum flows, admits a linear time construction of a clustering $\\C(S)$ of predominantly connected communities that contains ...

  16. Principles of synchronous digital hierarchy

    CERN Document Server

    Jain, Rajesh Kumar

    2012-01-01

    The book presents the current standards of digital multiplexing, called synchronous digital hierarchy, including analog multiplexing technologies. It is aimed at telecommunication professionals who want to develop an understanding of digital multiplexing and synchronous digital hierarchy in particular and the functioning of practical telecommunication systems in general. The text includes all relevant fundamentals and provides a handy reference for problem solving or defining operations and maintenance strategies. The author covers digital conversion and TDM principles, line coding and digital

  17. The Return of the Hierarchy

    DEFF Research Database (Denmark)

    Tolstrup Christensen, Lene

    2015-01-01

    corporatisation. This layered set-up provided the state with a double governance grip that drove marketisation until 2011. However, the SOE as a hybrid created ripple effects between the market and the hierarchy that hampered the marketisation. The hierarchical governance turned towards centralisation and market....... It presents a case on how hybridity is altered and evolves in SOEs as a hybrid mode of governance between hierarchy and market in marketisation and how this can lead to re-centralisation....

  18. Information slows down hierarchy growth.

    Science.gov (United States)

    Czaplicka, Agnieszka; Suchecki, Krzysztof; Miñano, Borja; Trias, Miquel; Hołyst, Janusz A

    2014-06-01

    We consider models of growing multilevel systems wherein the growth process is driven by rules of tournament selection. A system can be conceived as an evolving tree with a new node being attached to a contestant node at the best hierarchy level (a level nearest to the tree root). The proposed evolution reflects limited information on system properties available to new nodes. It can also be expressed in terms of population dynamics. Two models are considered: a constant tournament (CT) model wherein the number of tournament participants is constant throughout system evolution, and a proportional tournament (PT) model where this number increases proportionally to the growing size of the system itself. The results of analytical calculations based on a rate equation fit well to numerical simulations for both models. In the CT model all hierarchy levels emerge, but the birth time of a consecutive hierarchy level increases exponentially or faster for each new level. The number of nodes at the first hierarchy level grows logarithmically in time, while the size of the last, "worst" hierarchy level oscillates quasi-log-periodically. In the PT model, the occupations of the first two hierarchy levels increase linearly, but worse hierarchy levels either do not emerge at all or appear only by chance in the early stage of system evolution to further stop growing at all. The results allow us to conclude that information available to each new node in tournament dynamics restrains the emergence of new hierarchy levels and that it is the absolute amount of information, not relative, which governs such behavior.

  19. Model-Based Analysis and Optimization of the Mapping of Cortical Sources in the Spontaneous Scalp EEG

    Directory of Open Access Journals (Sweden)

    Andrei V. Sazonov

    2007-01-01

    Full Text Available The mapping of brain sources into the scalp electroencephalogram (EEG depends on volume conduction properties of the head and on an electrode montage involving a reference. Mathematically, this source mapping (SM is fully determined by an observation function (OF matrix. This paper analyses the OF-matrix for a generation model for the desynchronized spontaneous EEG. The model involves a four-shell spherical volume conductor containing dipolar sources that are mutually uncorrelated so as to reflect the desynchronized EEG. The reference is optimized in order to minimize the impact in the SM of the sources located distant from the electrodes. The resulting reference is called the localized reference (LR. The OF-matrix is analyzed in terms of the relative power contribution of the sources and the cross-channel correlation coefficient for five existing references as well as for the LR. It is found that the Hjorth Laplacian reference is a fair approximation of the LR, and thus is close to optimum for practical intents and purposes. The other references have a significantly poorer performance. Furthermore, the OF-matrix is analyzed for limits to the spatial resolution for the EEG. These are estimated to be around 2 cm.

  20. Hippocampal-neocortical interaction: a hierarchy of associativity.

    Science.gov (United States)

    Lavenex, P; Amaral, D G

    2000-01-01

    The structures forming the medial temporal lobe appear to be necessary for the establishment of long-term declarative memory. In particular, they may be involved in the "consolidation" of information in higher-order associational cortices, perhaps through feedback projections. This review highlights the fact that the medial temporal lobe is organized as a hierarchy of associational networks. Indeed, associational connections within the perirhinal, parahippocampal, and entorhinal cortices enables a significant amount of integration of unimodal and polymodal inputs, so that only highly integrated information reaches the remainder of the hippocampal formation. The feedback efferent projections from the perirhinal and parahippocampal cortices to the neocortex largely reciprocate the afferent projections from the neocortex to these areas. There are, however, noticeable differences in the degree of reciprocity of connections between the perirhinal and parahippocampal cortices and certain areas of the neocortex, in particular in the frontal and temporal lobes. These observations are particularly important for models of hippocampal-neocortical interaction and long-term storage of information in the neocortex. Furthermore, recent functional studies suggest that the perirhinal and parahippocampal cortices are more than interfaces for communication between the neocortex and the hippocampal formation. These structures participate actively in memory processes, but the precise role they play in the service of memory or other cognitive functions is currently unclear.

  1. Information slows down hierarchy growth

    CERN Document Server

    Czaplicka, Agnieszka; Minano, Borja; Trias, Miquel; Holyst, Janusz A

    2013-01-01

    We consider models of a growing tree with the growth process driven by the rules of tournament selection, where a new node is attached to a contestant node at the best hierarchy level (closest to the tree root). The proposed evolution reflects limited information about the network topology that is available for new nodes. Two cases are considered: the constant tournament (CT) model where the number of tournament participants is constant throughout the tree evolution, and the proportional tournament (PT) model where it is grows proportionally to the actual tree size. The results of analytical calculations based on a rate equation fit well to numerical simulations for both models. In the CT model all hierarchy levels emerge in the tree but the birth time of the hierarchy level increases exponentially or faster with level number. The number of nodes at the first hierarchy level (just below the root) grows logarithmically in time, while the size of the last, "worst" hierarchy level oscillates quasi log-periodical...

  2. Poisson hierarchy of discrete strings

    Energy Technology Data Exchange (ETDEWEB)

    Ioannidou, Theodora, E-mail: ti3@auth.gr [Faculty of Civil Engineering, School of Engineering, Aristotle University of Thessaloniki, 54249, Thessaloniki (Greece); Niemi, Antti J., E-mail: Antti.Niemi@physics.uu.se [Department of Physics and Astronomy, Uppsala University, P.O. Box 803, S-75108, Uppsala (Sweden); Laboratoire de Mathematiques et Physique Theorique CNRS UMR 6083, Fédération Denis Poisson, Université de Tours, Parc de Grandmont, F37200, Tours (France); Department of Physics, Beijing Institute of Technology, Haidian District, Beijing 100081 (China)

    2016-01-28

    The Poisson geometry of a discrete string in three dimensional Euclidean space is investigated. For this the Frenet frames are converted into a spinorial representation, the discrete spinor Frenet equation is interpreted in terms of a transfer matrix formalism, and Poisson brackets are introduced in terms of the spinor components. The construction is then generalised, in a self-similar manner, into an infinite hierarchy of Poisson algebras. As an example, the classical Virasoro (Witt) algebra that determines reparametrisation diffeomorphism along a continuous string, is identified as a particular sub-algebra, in the hierarchy of the discrete string Poisson algebra. - Highlights: • Witt (classical Virasoro) algebra is derived in the case of discrete string. • Infinite dimensional hierarchy of Poisson bracket algebras is constructed for discrete strings. • Spinor representation of discrete Frenet equations is developed.

  3. Psychophysical "blinding" methods reveal a functional hierarchy of unconscious visual processing.

    Science.gov (United States)

    Breitmeyer, Bruno G

    2015-09-01

    Numerous non-invasive experimental "blinding" methods exist for suppressing the phenomenal awareness of visual stimuli. Not all of these suppressive methods occur at, and thus index, the same level of unconscious visual processing. This suggests that a functional hierarchy of unconscious visual processing can in principle be established. The empirical results of extant studies that have used a number of different methods and additional reasonable theoretical considerations suggest the following tentative hierarchy. At the highest levels in this hierarchy is unconscious processing indexed by object-substitution masking. The functional levels indexed by crowding, the attentional blink (and other attentional blinding methods), backward pattern masking, metacontrast masking, continuous flash suppression, sandwich masking, and single-flash interocular suppression, fall at progressively lower levels, while unconscious processing at the lowest levels is indexed by eye-based binocular-rivalry suppression. Although unconscious processing levels indexed by additional blinding methods is yet to be determined, a tentative placement at lower levels in the hierarchy is also given for unconscious processing indexed by Troxler fading and adaptation-induced blindness, and at higher levels in the hierarchy indexed by attentional blinding effects in addition to the level indexed by the attentional blink. The full mapping of levels in the functional hierarchy onto cortical activation sites and levels is yet to be determined. The existence of such a hierarchy bears importantly on the search for, and the distinctions between, neural correlates of conscious and unconscious vision. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Hierarchy-Direction Selective Approach for Locally Adaptive Sparse Grids

    Energy Technology Data Exchange (ETDEWEB)

    Stoyanov, Miroslav K [ORNL

    2013-09-01

    We consider the problem of multidimensional adaptive hierarchical interpolation. We use sparse grids points and functions that are induced from a one dimensional hierarchical rule via tensor products. The classical locally adaptive sparse grid algorithm uses an isotropic refinement from the coarser to the denser levels of the hierarchy. However, the multidimensional hierarchy provides a more complex structure that allows for various anisotropic and hierarchy selective refinement techniques. We consider the more advanced refinement techniques and apply them to a number of simple test functions chosen to demonstrate the various advantages and disadvantages of each method. While there is no refinement scheme that is optimal for all functions, the fully adaptive family-direction-selective technique is usually more stable and requires fewer samples.

  5. Hierarchy in directed random networks: analytical and numerical results

    CERN Document Server

    Mones, Enys

    2012-01-01

    In recent years, the theory and application of complex networks has been quickly developing in a markable way due to the increasing amount of data from real systems and to the fruitful application of powerful methods used in statistical physics. Many important characteristics of social or biological systems can be described by the study of their underlying structure of interactions. Hierarchy is one of these features that can be formulated in the language of networks. In this paper we present the analytic results on the hierarchical properties of random network models with zero correlations and also investigate the effects of different type of correlations. The behavior of hierarchy is different in the absence and the presence of the giant components. We show that the hierarchical structure can be drastically different if there are one-point correlations in the network. We also show numerical results suggesting that hierarchy does not change monotonously with the correlations and there is an optimal level of ...

  6. Assessment of Personal Goal Hierarchies.

    Science.gov (United States)

    Wadsworth, Marlene; Ford, Donald H.

    1983-01-01

    Developed a new method for measuring goal hierarchies, called the Adult Intentional and Motivational Systems Chart, by interviewing 53 men and constructing a system summarizing their goals. Results suggested the continued use of the chart for research on self-direction and adult development as well as intervention. (LLL)

  7. Maslow's Hierarchy and Student Retention.

    Science.gov (United States)

    Brookman, David M.

    1989-01-01

    Abraham Maslow's hierarchy of needs offers perspective on student motivation and a rationale for college retention programing. Student affairs and faculty interventions addressing student safety needs and engaging students' sense of purpose reinforce persistence. A mentor program is a possible cooperative effort between student personnel and…

  8. The Evolutionary Origins of Hierarchy.

    Science.gov (United States)

    Mengistu, Henok; Huizinga, Joost; Mouret, Jean-Baptiste; Clune, Jeff

    2016-06-01

    Hierarchical organization-the recursive composition of sub-modules-is ubiquitous in biological networks, including neural, metabolic, ecological, and genetic regulatory networks, and in human-made systems, such as large organizations and the Internet. To date, most research on hierarchy in networks has been limited to quantifying this property. However, an open, important question in evolutionary biology is why hierarchical organization evolves in the first place. It has recently been shown that modularity evolves because of the presence of a cost for network connections. Here we investigate whether such connection costs also tend to cause a hierarchical organization of such modules. In computational simulations, we find that networks without a connection cost do not evolve to be hierarchical, even when the task has a hierarchical structure. However, with a connection cost, networks evolve to be both modular and hierarchical, and these networks exhibit higher overall performance and evolvability (i.e. faster adaptation to new environments). Additional analyses confirm that hierarchy independently improves adaptability after controlling for modularity. Overall, our results suggest that the same force-the cost of connections-promotes the evolution of both hierarchy and modularity, and that these properties are important drivers of network performance and adaptability. In addition to shedding light on the emergence of hierarchy across the many domains in which it appears, these findings will also accelerate future research into evolving more complex, intelligent computational brains in the fields of artificial intelligence and robotics.

  9. Combinatorial solutions to integrable hierarchies

    OpenAIRE

    Kazarian, M.; Lando, S.

    2015-01-01

    We give a review of modern approaches to constructing formal solutions to integrable hierarchies of mathematical physics, whose coefficients are answers to various enumerative problems. The relationship between these approaches and combinatorics of symmetric groups and their representations is explained. Applications of the results to constructing efficient computations in problems related to models of quantum field theories are given.

  10. Dressing Technique for Intermediate Hierarchies

    OpenAIRE

    Holod, P.; Pakuliak, S.

    1994-01-01

    A generalized AKNS systems introduced and discussed recently in \\cite{dGHM} are considered. It was shown that the dressing technique both in matrix pseudo-differential operators and formal series with respect to the spectral parameter can be developed for these hierarchies.

  11. Maslow's Hierarchy and Student Retention.

    Science.gov (United States)

    Brookman, David M.

    1989-01-01

    Abraham Maslow's hierarchy of needs offers perspective on student motivation and a rationale for college retention programing. Student affairs and faculty interventions addressing student safety needs and engaging students' sense of purpose reinforce persistence. A mentor program is a possible cooperative effort between student personnel and…

  12. The Evolutionary Origins of Hierarchy.

    Directory of Open Access Journals (Sweden)

    Henok Mengistu

    2016-06-01

    Full Text Available Hierarchical organization-the recursive composition of sub-modules-is ubiquitous in biological networks, including neural, metabolic, ecological, and genetic regulatory networks, and in human-made systems, such as large organizations and the Internet. To date, most research on hierarchy in networks has been limited to quantifying this property. However, an open, important question in evolutionary biology is why hierarchical organization evolves in the first place. It has recently been shown that modularity evolves because of the presence of a cost for network connections. Here we investigate whether such connection costs also tend to cause a hierarchical organization of such modules. In computational simulations, we find that networks without a connection cost do not evolve to be hierarchical, even when the task has a hierarchical structure. However, with a connection cost, networks evolve to be both modular and hierarchical, and these networks exhibit higher overall performance and evolvability (i.e. faster adaptation to new environments. Additional analyses confirm that hierarchy independently improves adaptability after controlling for modularity. Overall, our results suggest that the same force-the cost of connections-promotes the evolution of both hierarchy and modularity, and that these properties are important drivers of network performance and adaptability. In addition to shedding light on the emergence of hierarchy across the many domains in which it appears, these findings will also accelerate future research into evolving more complex, intelligent computational brains in the fields of artificial intelligence and robotics.

  13. Quark masses without Yukawa hierarchies

    Energy Technology Data Exchange (ETDEWEB)

    Fanchiotti, H.; Garcia-Canal, C. [Plata Univ. Nacional, Laboratorio de Fisica Teorica, Dept. de Fisica, Facultad de Ciencias Exactas, La Plata (Argentina); Ponce, W.A. [Antioquia Univ., Instituto de Fisica, Colombia La (Argentina)

    2005-12-15

    A model based on the local gauge group SU(3){sub c}*SU(3){sub L}*U(1){sub X} without particles with exotic electric charges is shown to be able to provide the quark mass spectrum and their mixing, by means of universal see-saw mechanisms, avoiding a hierarchy in the Yukawa coupling constants. (authors)

  14. The Evolutionary Origins of Hierarchy.

    Directory of Open Access Journals (Sweden)

    Henok Mengistu

    2016-06-01

    Full Text Available Hierarchical organization-the recursive composition of sub-modules-is ubiquitous in biological networks, including neural, metabolic, ecological, and genetic regulatory networks, and in human-made systems, such as large organizations and the Internet. To date, most research on hierarchy in networks has been limited to quantifying this property. However, an open, important question in evolutionary biology is why hierarchical organization evolves in the first place. It has recently been shown that modularity evolves because of the presence of a cost for network connections. Here we investigate whether such connection costs also tend to cause a hierarchical organization of such modules. In computational simulations, we find that networks without a connection cost do not evolve to be hierarchical, even when the task has a hierarchical structure. However, with a connection cost, networks evolve to be both modular and hierarchical, and these networks exhibit higher overall performance and evolvability (i.e. faster adaptation to new environments. Additional analyses confirm that hierarchy independently improves adaptability after controlling for modularity. Overall, our results suggest that the same force-the cost of connections-promotes the evolution of both hierarchy and modularity, and that these properties are important drivers of network performance and adaptability. In addition to shedding light on the emergence of hierarchy across the many domains in which it appears, these findings will also accelerate future research into evolving more complex, intelligent computational brains in the fields of artificial intelligence and robotics.

  15. Adapting Memory Hierarchies for Emerging Datacenter Interconnects

    Institute of Scientific and Technical Information of China (English)

    江涛; 董建波; 侯锐; 柴琳; 张立新; 孙凝晖; 田斌

    2015-01-01

    Efficient resource utilization requires that emerging datacenter interconnects support both high performance communication and efficient remote resource sharing. These goals require that the network be more tightly coupled with the CPU chips. Designing a new interconnection technology thus requires considering not only the interconnection itself, but also the design of the processors that will rely on it. In this paper, we study memory hierarchy implications for the design of high-speed datacenter interconnects—particularly as they affect remote memory access—and we use PCIe as the vehicle for our investigations. To that end, we build three complementary platforms: a PCIe-interconnected prototype server with which we measure and analyze current bottlenecks; a software simulator that lets us model microarchitectural and cache hierarchy changes;and an FPGA prototype system with a streamlined switchless customized protocol Thunder with which we study hardware optimizations outside the processor. We highlight several architectural modifications to better support remote memory access and communication, and quantify their impact and limitations.

  16. Preferred hierarchy scales from the product landscape

    OpenAIRE

    Songlin Lv; Zheng Sun; Lina Wu

    2014-01-01

    The product landscape method has been recently proposed to solve hierarchy problems such as the cosmological constant problem. We suggest that the parameter distribution on logarithmic scales should be used as a benchmark for hierarchy, and the preferred hierarchy scales can be obtained from the distribution peak. It is shown that generating hierarchy from purely product distribution is very inefficient. To achieve a reasonably acceptable efficiency, other effects such as accumulation of weak...

  17. Generalized W-algebras and integrable hierarchies

    CERN Document Server

    Burroughs, N J; Hollowood, Timothy J; Miramontes, J L

    1992-01-01

    We report on generalizations of the KdV-type integrable hierarchies of Drinfel'd and Sokolov. These hierarchies lead to the existence of new classical $W$-algebras, which arise as the second Hamiltonian structure of the hierarchies. In particular, we present a construction of the $W_n^{(l)}$ algebras.

  18. Reductions of Lower Triangular Toda Hierarchies

    NARCIS (Netherlands)

    Helminck, G.F.; Mishina, Marina G.; Polenkova, Svetlana V.

    2007-01-01

    Deforming commutative algebras in the lower triangular (ℤ×ℤ)-matrices yields lower triangular Toda hierarchies and their associated nonlinear equations. Like for their counterpart in the ring of pseudodifferential operators, the KP-hierarchy, one also has for these hierarchies a geometric picture:

  19. Cortical Visual Impairment

    Science.gov (United States)

    ... Frequently Asked Questions Español Condiciones Chinese Conditions Cortical Visual Impairment En Español Read in Chinese What is cortical visual impairment? Cortical visual impairment (CVI) is a decreased visual ...

  20. Approximation Limits of Linear Programs (Beyond Hierarchies)

    CERN Document Server

    Braun, Gábor; Pokutta, Sebastian; Steurer, David

    2012-01-01

    We develop a framework for approximation limits of polynomial-size linear programs from lower bounds on the nonnegative ranks of suitably defined matrices. This framework yields unconditional impossibility results that are applicable to any linear program as opposed to only programs generated by hierarchies. Using our framework, we prove that O(n^{1/2-eps})-approximations for CLIQUE require linear programs of size 2^{n^\\Omega(eps)}. (This lower bound applies to linear programs using a certain encoding of CLIQUE as a linear optimization problem.) Moreover, we establish a similar result for approximations of semidefinite programs by linear programs. Our main ingredient is a quantitative improvement of Razborov's rectangle corruption lemma for the high error regime, which gives strong lower bounds on the nonnegative rank of certain perturbations of the unique disjointness matrix.

  1. Predictability and hierarchy in Drosophila behavior

    CERN Document Server

    Berman, Gordon J; Shaevitz, Joshua W

    2016-01-01

    Even the simplest of animals exhibit behavioral sequences with complex temporal dynamics. Prominent amongst the proposed organizing principles for these dynamics has been the idea of a hierarchy, wherein the movements an animal makes can be understood as a set of nested sub-clusters. Although this type of organization holds potential advantages in terms of motion control and neural circuitry, measurements demonstrating this for an animal's entire behavioral repertoire have been limited in scope and temporal complexity. Here, we use a recently developed unsupervised technique to discover and track the occurrence of all stereotyped behaviors performed by fruit flies moving in a shallow arena. Calculating the optimally predictive representation of the fly's future behaviors, we show that fly behavior exhibits multiple time scales and is organized into a hierarchical structure that is indicative of its underlying behavioral programs and its changing internal states.

  2. Measuring Maslow's hierarchy of needs.

    Science.gov (United States)

    Lester, David

    2013-08-01

    Two scales have been proposed to measure Maslow's hierarchy of needs in college students, one by Lester (1990) and one by Strong and Fiebert (1987). In a sample of 51 college students, scores on the corresponding scales for the five needs did not correlate significantly and positively, except for the measures of physiological needs. Furthermore, there was limited support for Maslow's hypothesis that need deprivation would predict psychopathology (specifically, mania and depression).

  3. The stochastic integrable AKNS hierarchy

    OpenAIRE

    Arnaudon, Alexis

    2015-01-01

    We derive a stochastic AKNS hierarchy using geometrical methods. The integrability is shown via a stochastic zero curvature relation associated with a stochastic isospectral problem. We expose some of the stochastic integrable partial differential equations which extend the stochastic KdV equation discovered by M. Wadati in 1983 for all the AKNS flows. We also show how to find stochastic solitons from the stochastic evolution of the scattering data of the stochastic IST. We finally expose som...

  4. KP hierarchy for Hodge integrals

    OpenAIRE

    Kazarian, M.

    2008-01-01

    Starting from the ELSV formula, we derive a number of new equations on the generating functions for Hodge integrals over the moduli space of complex curves. This gives a new simple and uniform treatment of certain known results on Hodge integrals like Witten's conjecture, Virasoro constrains, Faber's lambda_g conjecture etc. Among other results we show that a properly arranged generating function for Hodge integrals satisfies the equations of the KP hierarchy.

  5. Combinatorial solutions to integrable hierarchies

    Science.gov (United States)

    Kazarian, M. E.; Lando, S. K.

    2015-06-01

    This paper reviews modern approaches to the construction of formal solutions to integrable hierarchies of mathematical physics whose coefficients are answers to various enumerative problems. The relationship between these approaches and the combinatorics of symmetric groups and their representations is explained. Applications of the results to the construction of efficient computations in problems related to models of quantum field theories are described. Bibliography: 34 titles.

  6. Hierarchy Measure for Complex Networks

    Science.gov (United States)

    Mones, Enys; Vicsek, Lilla; Vicsek, Tamás

    2012-01-01

    Nature, technology and society are full of complexity arising from the intricate web of the interactions among the units of the related systems (e.g., proteins, computers, people). Consequently, one of the most successful recent approaches to capturing the fundamental features of the structure and dynamics of complex systems has been the investigation of the networks associated with the above units (nodes) together with their relations (edges). Most complex systems have an inherently hierarchical organization and, correspondingly, the networks behind them also exhibit hierarchical features. Indeed, several papers have been devoted to describing this essential aspect of networks, however, without resulting in a widely accepted, converging concept concerning the quantitative characterization of the level of their hierarchy. Here we develop an approach and propose a quantity (measure) which is simple enough to be widely applicable, reveals a number of universal features of the organization of real-world networks and, as we demonstrate, is capable of capturing the essential features of the structure and the degree of hierarchy in a complex network. The measure we introduce is based on a generalization of the m-reach centrality, which we first extend to directed/partially directed graphs. Then, we define the global reaching centrality (GRC), which is the difference between the maximum and the average value of the generalized reach centralities over the network. We investigate the behavior of the GRC considering both a synthetic model with an adjustable level of hierarchy and real networks. Results for real networks show that our hierarchy measure is related to the controllability of the given system. We also propose a visualization procedure for large complex networks that can be used to obtain an overall qualitative picture about the nature of their hierarchical structure. PMID:22470477

  7. Hamilton-Jacobi skeleton on cortical surfaces.

    Science.gov (United States)

    Shi, Y; Thompson, P M; Dinov, I; Toga, A W

    2008-05-01

    In this paper, we propose a new method to construct graphical representations of cortical folding patterns by computing skeletons on triangulated cortical surfaces. In our approach, a cortical surface is first partitioned into sulcal and gyral regions via the solution of a variational problem using graph cuts, which can guarantee global optimality. After that, we extend the method of Hamilton-Jacobi skeleton [1] to subsets of triangulated surfaces, together with a geometrically intuitive pruning process that can trade off between skeleton complexity and the completeness of representing folding patterns. Compared with previous work that uses skeletons of 3-D volumes to represent sulcal patterns, the skeletons on cortical surfaces can be easily decomposed into branches and provide a simpler way to construct graphical representations of cortical morphometry. In our experiments, we demonstrate our method on two different cortical surface models, its ability of capturing major sulcal patterns and its application to compute skeletons of gyral regions.

  8. Memory Hierarchy Sensitive Graph Layout

    CERN Document Server

    Roy, Amitabha

    2012-01-01

    Mining large graphs for information is becoming an increasingly important workload due to the plethora of graph structured data becoming available. An aspect of graph algorithms that has hitherto not received much interest is the effect of memory hierarchy on accesses. A typical system today has multiple levels in the memory hierarchy with differing units of locality; ranging across cache lines, TLB entries and DRAM pages. We postulate that it is possible to allocate graph structured data in main memory in a way as to improve the spatial locality of the data. Previous approaches to improving cache locality have focused only on a single unit of locality, either the cache line or virtual memory page. On the other hand cache oblivious algorithms can optimise layout for all levels of the memory hierarchy but unfortunately need to be specially designed for individual data structures. In this paper we explore hierarchical blocking as a technique for closing this gap. We require as input a specification of the units...

  9. Hierarchy of knowledge in GIS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    An intelligent geographic information system (GIS) has to handle various types and huge volumes of geoscience-related knowledge as well as enormous amounts of data and information. More recent attention concentrates on collection,represen-tation,management,and usage of knowledge. This article presents a three-tier hi-erarchy for geoscience knowledge in a GIS. The first tier is for knowledge of data. It includes knowledge of feature objects definition,data structure,data model,and relations among data as well as rules,restrictions,and regulations about data. The second tier is for knowledge of processing. It describes analysis models,data processing procedures,workflows,and conditions. The third tier contains knowl-edge of a GIS for the public sector. This tier provides knowledge to people on how to access this GIS and what the GIS can do. The three-tier hierarchy of knowledge in a GIS provides an understandable and practical category frame to handle geo-science knowledge. One of the advantages of this hierarchy is that it separates system resource consumption into different stages so it can avoid exhausting the system at peak times when the GIS handles a complex,large task.

  10. Solving the Wrong Hierarchy Problem

    CERN Document Server

    Blinov, Nikita

    2016-01-01

    Many theories require augmenting the Standard Model with additional scalar fields with large order one couplings. We present a new solution to the hierarchy problem for these scalar fields. We explore parity- and $\\mathbb{Z}_2$-symmetric theories where the Standard Model Higgs potential has two vacua. The parity or $\\mathbb{Z}_2$ copy of the Higgs lives in the minimum far from the origin while our Higgs occupies the minimum near the origin of the potential. This approach results in a theory with multiple light scalar fields but with only a single hierarchy problem, since the bare mass is tied to the Higgs mass by a discrete symmetry. The new scalar does not have a new hierarchy problem associated with it because its expectation value and mass are generated by dimensional transmutation of the scalar quartic coupling. The location of the second Higgs minimum is not a free parameter, but is rather a function of the matter content of the theory. As a result, these theories are extremely predictive. We develop thi...

  11. Solving the wrong hierarchy problem

    Science.gov (United States)

    Blinov, Nikita; Hook, Anson

    2016-06-01

    Many theories require augmenting the Standard Model with additional scalar fields with large order one couplings. We present a new solution to the hierarchy problem for these scalar fields. We explore parity- and Z_2 -symmetric theories where the Standard Model Higgs potential has two vacua. The parity or Z_2 copy of the Higgs lives in the minimum far from the origin while our Higgs occupies the minimum near the origin of the potential. This approach results in a theory with multiple light scalar fields but with only a single hierarchy problem, since the bare mass is tied to the Higgs mass by a discrete symmetry. The new scalar does not have a new hierarchy problem associated with it because its expectation value and mass are generated by dimensional transmutation of the scalar quartic coupling. The location of the second Higgs minimum is not a free parameter, but is rather a function of the matter content of the theory. As a result, these theories are extremely predictive. We develop this idea in the context of a solution to the strong CP problem. We show this mechanism postdicts the top Yukawa to be within 1 σ of the currently measured value and predicts scalar color octets with masses in the range 9-200 TeV.

  12. Optimalisasi Alokasi Penggunaan Lahan di Sub DAS Ambang: Pendekatan Analitikal Hirarki Proses dan Goal Programming (Optimalization of Land Use Planning in Ambang Sub-Watershed: Analytical Hierarchy Process and Goal Programming Approach

    Directory of Open Access Journals (Sweden)

    Kresno Agus Hendarto

    2011-01-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 The purpose of land use planning on a river basin or a watershed is "to promote the accomplishment of service wide objectives and targets" subject to the lands potential and the public's desires. This paper aimed to describe a representative formulation of the analitical hierarchi process and linear programming application and show how it may be modified for goal programming. The purposive sampling was used to collect primary data. From five persons were represented each stakeholders on a watershed. The secondary data was collected from the report of each stakeholders and internet. The results show that goal programing had generated considerable interest as a tool for land use planning in multiple goal situations. It does present problems in terms of somewhat difficult data requirements-linearity in its usual form, possible inferior solutions, and lack of explicit recognition of tradeoffs. Keywords:  ambang watershed, linear program, analytical hierarchy process, goal programming, land use planning

  13. 小鼠大脑皮质神经元电穿孔转染条件的优化%Optimization of electroporation parameters for cerebral cortical neurons of mouse

    Institute of Scientific and Technical Information of China (English)

    詹从清; 黄静; 魏燕燕; 陈晶; 李云庆; 武胜昔

    2011-01-01

    Objective: To optimize the electroporation parameters in primary cultured cerebral cortical neurons of mouse. Methods: Green fluorescent protein (GFP) expression plasmid shNC was transferred into cortical neurons using different electroporation voltages and impulse times. Expression of GFP was observed after twenty-four hours of transfection and the electroporation efficiencies were analyzed to determine the optimal electroporation conditions. Results: The highest electroporation transfection rate was achieved under the conditions of voltage 200 v, pulse time 25 ms or voltage 250 v, pulse time 15 ms for the mouse cortical neurons. The transfection rate was (31. 15 ± 1.89)% and(29. 10 ±1.93 ) % respectively. Conclusion: Electroporation is a highly efficient gene transfection method. Optimized electroporation parameters can improve the electroporation efficiency of the mouse cortical neurons.%目的:以原代培养的小鼠大脑皮质神经元为研究工具,优化电穿孔转染条件.方法:通过设置不同的电压和脉冲时间组合等电转染条件,将表达绿色荧光蛋白(GFP)的shNC质粒导入小鼠大脑皮质神经元,24 h后观察并比较神经元的转染效率,确定最佳电转染条件.结果:200 v电压,25 ms,脉冲时间或250 v电压,15 ms脉冲时间的转染条件下,小鼠大脑皮质神经元可获得较好的转染效率,分别为(31.15±1.89)%和(29.10±1.93)%.结论:电穿孔转染是一种高效的基因转染方法,通过条件的优化,可以提高小鼠大脑皮质神经元的电转染效率.

  14. A Bayesian Generative Model for Learning Semantic Hierarchies

    Directory of Open Access Journals (Sweden)

    Roni eMittelman

    2014-05-01

    Full Text Available Building fine-grained visual recognition systems that are capable of recognizing tens of thousands of categories, has received much attention in recent years. The well known semantic hierarchical structure of categories and concepts, has been shown to provide a key prior which allows for optimal predictions. The hierarchical organization of various domains and concepts has been subject to extensive research, and led to the development of the WordNet domains hierarchy [18], which was also used to organize the images in the ImageNet [11] dataset, in which the category count approaches the human capacity. Still, for the human visual system, the form of the hierarchy must be discovered with minimal use of supervision or innate knowledge. In this work, we propose a new Bayesian generative model for learning such domain hierarchies, based on semantic input. Our model is motivated by the super-subordinate organization of domain labels and concepts that characterizes WordNet, and accounts for several important challenges: maintaining context information when progressing deeper into the hierarchy, learning a coherent semantic concept for each node, and modeling uncertainty in the perception process.

  15. A Bayesian generative model for learning semantic hierarchies.

    Science.gov (United States)

    Mittelman, Roni; Sun, Min; Kuipers, Benjamin; Savarese, Silvio

    2014-01-01

    Building fine-grained visual recognition systems that are capable of recognizing tens of thousands of categories, has received much attention in recent years. The well known semantic hierarchical structure of categories and concepts, has been shown to provide a key prior which allows for optimal predictions. The hierarchical organization of various domains and concepts has been subject to extensive research, and led to the development of the WordNet domains hierarchy (Fellbaum, 1998), which was also used to organize the images in the ImageNet (Deng et al., 2009) dataset, in which the category count approaches the human capacity. Still, for the human visual system, the form of the hierarchy must be discovered with minimal use of supervision or innate knowledge. In this work, we propose a new Bayesian generative model for learning such domain hierarchies, based on semantic input. Our model is motivated by the super-subordinate organization of domain labels and concepts that characterizes WordNet, and accounts for several important challenges: maintaining context information when progressing deeper into the hierarchy, learning a coherent semantic concept for each node, and modeling uncertainty in the perception process.

  16. A hierarchy of timescales explains distinct effects of local inhibition of primary visual cortex and frontal eye fields.

    Science.gov (United States)

    Cocchi, Luca; Sale, Martin V; L Gollo, Leonardo; Bell, Peter T; Nguyen, Vinh T; Zalesky, Andrew; Breakspear, Michael; Mattingley, Jason B

    2016-09-06

    Within the primate visual system, areas at lower levels of the cortical hierarchy process basic visual features, whereas those at higher levels, such as the frontal eye fields (FEF), are thought to modulate sensory processes via feedback connections. Despite these functional exchanges during perception, there is little shared activity between early and late visual regions at rest. How interactions emerge between regions encompassing distinct levels of the visual hierarchy remains unknown. Here we combined neuroimaging, non-invasive cortical stimulation and computational modelling to characterize changes in functional interactions across widespread neural networks before and after local inhibition of primary visual cortex or FEF. We found that stimulation of early visual cortex selectively increased feedforward interactions with FEF and extrastriate visual areas, whereas identical stimulation of the FEF decreased feedback interactions with early visual areas. Computational modelling suggests that these opposing effects reflect a fast-slow timescale hierarchy from sensory to association areas.

  17. Study of Injection Molding Warpage Using Analytic Hierarchy Process and Taguchi Method

    Directory of Open Access Journals (Sweden)

    Dyi-Cheng Chen

    2016-10-01

    Full Text Available This study integrated Analytic Hierarchy Process and Taguchi method to investigate into injection molding warpage. The warpage important factor will be elected by Analytic Hierarchy Process (AHP, the AHP hierarchy analysis factor from documents collected and aggregate out data, then through the expert questionnaire delete low weight factor. Finally, we used Taguchi quality engineering method to decide injection molding optimized combination factors. Furthermore, the paper used injection pressure, holding pressure, holding time, mold temperature to analyze four factors, three levels Taguchi design data. Moreover, the paper discussed the reaction of each factor on the S / N ratio and analysis of variance to obtain the best combination of minimal warpage.

  18. Multi-Core Cache Hierarchies

    CERN Document Server

    Balasubramonian, Rajeev

    2011-01-01

    A key determinant of overall system performance and power dissipation is the cache hierarchy since access to off-chip memory consumes many more cycles and energy than on-chip accesses. In addition, multi-core processors are expected to place ever higher bandwidth demands on the memory system. All these issues make it important to avoid off-chip memory access by improving the efficiency of the on-chip cache. Future multi-core processors will have many large cache banks connected by a network and shared by many cores. Hence, many important problems must be solved: cache resources must be allocat

  19. Emergent Power Hierarchies and Group Performance.

    Science.gov (United States)

    Frauendorfer, Denise; Schmid Mast, Marianne; Sanchez-Cortes, Dairazalia; Gatica-Perez, Daniel

    2015-10-01

    In newly formed groups, informal hierarchies emerge automatically and readily. In this study, we argue that emergent group hierarchies enhance group performance (Hypothesis 1) and we assume that the more the power hierarchy within a group corresponds to the task-competence differences of the individual group members, the better the group performs (Hypothesis 2). Twelve three-person groups and 28 four-person groups were investigated while solving the Winter Survival Task. Results show that emerging power hierarchies positively impact group performance but the alignment between task-competence and power hierarchy did not affect group performance. Thus, emergent power hierarchies are beneficial for group performance and although they were on average created around individual group members' competence, this correspondence was not a prerequisite for better group performance.

  20. Generalized NLS Hierarchies from Rational $W$ Algebras

    CERN Document Server

    Toppan, F

    1994-01-01

    Finite rational $\\cw$ algebras are very natural structures appearing in coset constructions when a Kac-Moody subalgebra is factored out. In this letter we address the problem of relating these algebras to integrable hierarchies of equations, by showing how to associate to a rational $\\cw$ algebra its corresponding hierarchy. We work out two examples: the $sl(2)/U(1)$ coset, leading to the Non-Linear Schr\\"{o}dinger hierarchy, and the $U(1)$ coset of the Polyakov-Bershadsky $\\cw$ algebra, leading to a $3$-field representation of the KP hierarchy already encountered in the literature. In such examples a rational algebra appears as algebra of constraints when reducing a KP hierarchy to a finite field representation. This fact arises the natural question whether rational algebras are always associated to such reductions and whether a classification of rational algebras can lead to a classification of the integrable hierarchies.

  1. The role of pulvinar in the transmission of information in the visual hierarchy.

    Science.gov (United States)

    Cortes, Nelson; van Vreeswijk, Carl

    2012-01-01

    VISUAL RECEPTIVE FIELD (RF) ATTRIBUTES IN VISUAL CORTEX OF PRIMATES HAVE BEEN EXPLAINED MAINLY FROM CORTICAL CONNECTIONS: visual RFs progress from simple to complex through cortico-cortical pathways from lower to higher levels in the visual hierarchy. This feedforward flow of information is paired with top-down processes through the feedback pathway. Although the hierarchical organization explains the spatial properties of RFs, is unclear how a non-linear transmission of activity through the visual hierarchy can yield smooth contrast response functions in all level of the hierarchy. Depending on the gain, non-linear transfer functions create either a bimodal response to contrast, or no contrast dependence of the response in the highest level of the hierarchy. One possible mechanism to regulate this transmission of visual contrast information from low to high level involves an external component that shortcuts the flow of information through the hierarchy. A candidate for this shortcut is the Pulvinar nucleus of the thalamus. To investigate representation of stimulus contrast a hierarchical model network of ten cortical areas is examined. In each level of the network, the activity from the previous layer is integrated and then non-linearly transmitted to the next level. The arrangement of interactions creates a gradient from simple to complex RFs of increasing size as one moves from lower to higher cortical levels. The visual input is modeled as a Gaussian random input, whose width codes for the contrast. This input is applied to the first area. The output activity ratio among different contrast values is analyzed for the last level to observe sensitivity to a contrast and contrast invariant tuning. For a purely cortical system, the output of the last area can be approximately contrast invariant, but the sensitivity to contrast is poor. To account for an alternative visual processing pathway, non-reciprocal connections from and to a parallel pulvinar like structure

  2. An Operational Investigation of the CPS Hierarchy

    DEFF Research Database (Denmark)

    Danvy, Olivier; Yang, Zhe

    1999-01-01

    We explore the hierarchy of control induced by successive transformations into continuation-passing style (CPS) in the presence of “control delimiters ” and “composable continuations ”. Specifically, we investigate the structural operational semantics associated with the CPS hierarchy. To this en...... a native and modular implementation of the entire hierarchy. We illustrate it with several examples, the most significant of which is layered monads....

  3. An Operational Investigation of the CPS Hierarchy

    DEFF Research Database (Denmark)

    Danvy, Olivier; Yang, Zhe

    1998-01-01

    We explore the hierarchy of control induced by successive transformations into continuation-passing style (CPS) in the presence of “control delimiters ” and “composable continuations ”. Specifically, we investigate the structural operational semantics associated with the CPS hierarchy. To this end...... a native and modular implementation of the entire hierarchy. We illustrate it with several examples, the most significant of which is layered monads....

  4. The Appropriateness of Hierarchies (Editorial

    Directory of Open Access Journals (Sweden)

    Denise Koufogiannakis

    2010-09-01

    Full Text Available In the early days of EBLIP, then referred to as evidence based librarianship (EBL, there were calls to strengthen our research base with "better" forms of evidence. These proposed better quality research methods were all quantitative and I admit myself to saying that ‚librarianship tends to reflect more qualitative, social sciences/humanities in its research methods and study types which tend to be less rigorous and more prone to bias‛ (Crumley and Koufogiannakis 2002, p.61. Although this was not meant to be a slight to qualitative research, I can see how it came across as one. Now, I would not put ‚less rigorous and more prone to bias‛ in that sentence, although the first half of the statement certainly still holds true. In our 2002 article, the general point that Ellen Crumley and I were trying to make is that a medical style research hierarchy is not a good fit for librarianship, where qualitative methods are generally more appropriate. At that time, we proposed a ‚core-centred approach to librarianship research‛ (p.68 rather than a hierarchical one, although this did not gain much traction within the EBLIP literature. We noted: ‚rather than relying on an evidence hierarchy, which is an artificial concept for librarians, Fig.3 suggests a core-centred approach. The types of studies that are likely to be conducted by librarians are placed near the centre, moving from a hierarchical to an encompassing model. … *This+ presents a more equitable view of a model for research in the profession‛ (p.67.Today I am even more resolved that it is time to remove the concept of a hierarchy of evidence from EBLIP. This concept is tied very closely to the medical model of evidence based medicine (EBM and is solely focused on quantitative research. Library and information studies (LIS is a social sciences discipline and as such is concerned mostly with questions of why we do things and how people function in the world. The actions of people

  5. Hierarchy of non-glucose sugars in Escherichia coli.

    Science.gov (United States)

    Aidelberg, Guy; Towbin, Benjamin D; Rothschild, Daphna; Dekel, Erez; Bren, Anat; Alon, Uri

    2014-12-24

    Understanding how cells make decisions, and why they make the decisions they make, is of fundamental interest in systems biology. To address this, we study the decisions made by E. coli on which genes to express when presented with two different sugars. It is well-known that glucose, E. coli's preferred carbon source, represses the uptake of other sugars by means of global and gene-specific mechanisms. However, less is known about the utilization of glucose-free sugar mixtures which are found in the natural environment of E. coli and in biotechnology. Here, we combine experiment and theory to map the choices of E. coli among 6 different non-glucose carbon sources. We used robotic assays and fluorescence reporter strains to make precise measurements of promoter activity and growth rate in all pairs of these sugars. We find that the sugars can be ranked in a hierarchy: in a mixture of a higher and a lower sugar, the lower sugar system shows reduced promoter activity. The hierarchy corresponds to the growth rate supported by each sugar- the faster the growth rate, the higher the sugar on the hierarchy. The hierarchy is 'soft' in the sense that the lower sugar promoters are not completely repressed. Measurement of the activity of the master regulator CRP-cAMP shows that the hierarchy can be quantitatively explained based on differential activation of the promoters by CRP-cAMP. Comparing sugar system activation as a function of time in sugar pair mixtures at sub-saturating concentrations, we find cases of sequential activation, and also cases of simultaneous expression of both systems. Such simultaneous expression is not predicted by simple models of growth rate optimization, which predict only sequential activation. We extend these models by suggesting multi-objective optimization for both growing rapidly now and preparing the cell for future growth on the poorer sugar. We find a defined hierarchy of sugar utilization, which can be quantitatively explained by

  6. A descending hierarchy of reflection principles

    NARCIS (Netherlands)

    Visser, A.

    2008-01-01

    This paper can best be viewed as a portrait in miniature of a fascinating structure: a. descending hierarchy of reflection principles. Ascending hierarchies of reflection principles are amply studied, e.g. in Feferman's great paper Transfinite Recursive Progressions of Axiomatic Theories (Feferman[l

  7. Ordinal ultrafilters versus P-hierarchy

    CERN Document Server

    Starosolski, Andrzej

    2012-01-01

    An earlier paper, entitled "P-hierarchy on $\\beta\\omega$", investigated the relations between ordinal ultrafilters and the so-called P-hierarchy. This study is continued in the present paper and focuses on the aspects of characterization of classes of finite index, existence, generic existence and the Rudin-Keisler-order.

  8. A Suggested Modification to Maslow's Need Hierarchy

    Science.gov (United States)

    Groves, David L.; And Others

    1975-01-01

    Since its development, Maslow's need hierarchy has been criticized and applauded. This investigation was undertaken to explore a modification of the upper levels of the need hierarchy based upon the application of power, competition, and achievement to self, as well as the concept of "other directed." (Author)

  9. A Suggested Modification to Maslow's Need Hierarchy

    Science.gov (United States)

    Groves, David L.; And Others

    1975-01-01

    Since its development, Maslow's need hierarchy has been criticized and applauded. This investigation was undertaken to explore a modification of the upper levels of the need hierarchy based upon the application of power, competition, and achievement to self, as well as the concept of "other directed." (Author)

  10. Hierarchy of Modular Graph Identities

    CERN Document Server

    D'Hoker, Eric

    2016-01-01

    The low energy expansion of Type II superstring amplitudes at genus one is organized in terms of modular graph functions associated with Feynman graphs of a conformal scalar field on the torus. In earlier work, surprising identities between two-loop graphs at all weights, and between higher-loop graphs of weights four and five were constructed. In the present paper, these results are generalized in two complementary directions. First, all identities at weight six and all dihedral identities at weight seven are obtained and proven. Whenever the Laurent polynomial at the cusp is available, the form of these identities confirms the pattern by which the vanishing of the Laurent polynomial governs the full modular identity. Second, the family of modular graph functions is extended to include all graphs with derivative couplings and worldsheet fermions. These extended families of modular graph functions are shown to obey a hierarchy of inhomogeneous Laplace eigenvalue equations. The eigenvalues are calculated analy...

  11. A hierarchy of Poisson brackets

    CERN Document Server

    Pavelka, Michal; Esen, Ogul; Grmela, Miroslav

    2015-01-01

    The vector field generating reversible time evolution of macroscopic systems involves two ingredients: gradient of a potential (a covector) and a degenerate Poisson structure transforming the covector into a vector. The Poisson structure is conveniently expressed in Poisson brackets, its degeneracy in their Casimirs (i.e. potentials whose gradients produce no vector field). In this paper we investigate in detail hierarchies of Poisson brackets, together with their Casimirs, that arise in passages from more to less detailed (i.e. more macroscopic) descriptions. In particular, we investigate the passage from mechanics of particles (in its Liouville representation) to the reversible kinetic theory and the passage from the reversible kinetic theory to the reversible fluid mechanics. From the physical point of view, the investigation includes binary mixtures and two-point formulations suitable for describing turbulent flows. From the mathematical point of view, we reveal the Lie algebra structure involved in the p...

  12. Hierarchy measure for complex networks

    CERN Document Server

    Mones, Enys; Vicsek, Tamás

    2012-01-01

    Nature, technology and society are full of complexity arising from the intricate web of the interactions among the units of the related systems (e.g., proteins, computers, people). Consequently, one of the most successful recent approaches to capturing the fundamental features of the structure and dynamics of complex systems has been the investigation of the networks associated with the above units (nodes) together with their relations (edges). Most complex systems have an inherently hierarchical organization and, correspondingly, the networks behind them also exhibit hierarchical features. Indeed, several papers have been devoted to describing this essential aspect of networks, however, without resulting in a widely accepted, converging concept concerning the quantitative characterization of the level of their hierarchy. Here we develop an approach and propose a quantity (measure) which is simple enough to be widely applicable, reveals a number of universal features of the organization of real-world networks...

  13. Flavor hierarchies from dynamical scales

    CERN Document Server

    Panico, Giuliano

    2016-07-20

    One main obstacle for any beyond the SM (BSM) scenario solving the hierarchy problem is its potentially large contributions to electric dipole moments. An elegant way to avoid this problem is to have the light SM fermions couple to the BSM sector only through bilinears, $\\bar ff$. This possibility can be neatly implemented in composite Higgs models. We study the implications of dynamically generating the fermion Yukawa couplings at different scales, relating larger scales to lighter SM fermions. We show that all flavor and CP-violating constraints can be easily accommodated for a BSM scale of few TeV, without requiring any extra symmetry. Contributions to B physics are mainly mediated by the top, giving a predictive pattern of deviations in $\\Delta F=2$ and $\\Delta F=1$ flavor observables that could be seen in future experiments.

  14. Normalization of Class Hierarchy in Databases

    Institute of Scientific and Technical Information of China (English)

    李天柱; 肖计田; 等

    1996-01-01

    In complex object oriented databases,the purpose of introducing class hierarchy is to express ISA semantics,to realize inheriting and to reuse schema definition codes.The schema defintition and schema evolution,based on the partial order of lattice,often cause the loss o information inheriting and the redundance of schema definition.Based on the fullness of the inheritance shown by class hierarchy,three normal forms of class hierarchy are given in this paper,and a general algorithm of normalization of class hierarchy is presented,following the Boolean algebra model of class hierarchy.The loss of information inheritance can be avoided when they are applied to schema design and schema evolution.

  15. Is there a hierarchy of survival reflexes?

    Science.gov (United States)

    Macphail, Kieran

    2013-10-01

    A hierarchy of survival reflexes for prioritising assessment and treatment in patients with pain of insidious onset is hypothesised. The hierarchy asserts that some systems are more vital than others and that the central nervous system (CNS) prioritises systems based on their significance to survival. The hypothesis suggests that dysfunction in more important systems will cause compensation in less important systems. This paper presents studies examining these effects for each system, arguing that each section of the hierarchy may have effects on other systems within the hierarchy. This concept is untested empirically, highly speculative and substantial research is required to validate the suggested hierarchical prioritisation by the CNS. Nonetheless, the hierarchy does provide a theoretical framework to use to exclude contributing systems in patients with pain of insidious onset. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Detectability of ranking hierarchies in directed networks

    CERN Document Server

    Letizia, Elisa; Lillo, Fabrizio

    2016-01-01

    Identifying hierarchies and rankings of nodes in directed graphs is fundamental in many applications such as social network analysis, biology, economics, and finance. A recently proposed method identifies the hierarchy by finding the ordered partition of nodes which minimizes a score function, termed agony. This function penalizes the links violating the hierarchy in a way depending on the strength of the violation. To investigate the detectability of ranking hierarchies we introduce an ensemble of random graphs, the Hierarchical Stochastic Block Model. We find that agony may fail to identify hierarchies when the structure is not strong enough and the size of the classes is small with respect to the whole network. We analytically characterize the detectability threshold and we show that an iterated version of agony can partly overcome this resolution limit.

  17. The recursion operator for a constrained CKP hierarchy

    CERN Document Server

    Li, Chuanzhong; He, Jingsong; Cheng, Yi

    2010-01-01

    This paper gives a recursion operator for a 1-constrained CKP hierarchy, and by the recursion operator it proves that the 1-constrained CKP hierarchy can be reduced to the mKdV hierarchy under condition $q=r$.

  18. The recursion operator for a constrained CKP hierarchy

    OpenAIRE

    Li, Chuanzhong; Tian, Kelei; He, Jingsong; Cheng, Yi

    2010-01-01

    This paper gives a recursion operator for a 1-constrained CKP hierarchy, and by the recursion operator it proves that the 1-constrained CKP hierarchy can be reduced to the mKdV hierarchy under condition $q=r$.

  19. Modeling Leadership Hierarchy in Multilevel Animal Societies

    CERN Document Server

    Ozogány, Katalin

    2014-01-01

    A typical feature of many natural and social networks is the presence of communities giving rise to multiple levels of organization. We investigate the decision-making process of a group combining self organization and social dynamics, and reproduce the simultaneous emergence of a hierarchical and modular leadership network. All individuals in the model try, with varying degrees of ability, to find a direction of movement, with the result that leader-follower relationships evolve between them, since they tend to follow the more successful ones. The harem-forming ambitions of male individuals inspired by an observed Przewalski horse herd (Hortob\\'agy, Hungary) leads to modular structure. In this approach we find that the harem-leader to harem-member ratio observed in horses corresponds to an optimal network regarding common success, and that modularly structured hierarchy is more benefical than a non-modular one, in the sense that common success is higher, and the underlying network is more hierarchical. We al...

  20. Hierarchy is Detrimental for Human Cooperation.

    Science.gov (United States)

    Cronin, Katherine A; Acheson, Daniel J; Hernández, Penélope; Sánchez, Angel

    2015-12-22

    Studies of animal behavior consistently demonstrate that the social environment impacts cooperation, yet the effect of social dynamics has been largely excluded from studies of human cooperation. Here, we introduce a novel approach inspired by nonhuman primate research to address how social hierarchies impact human cooperation. Participants competed to earn hierarchy positions and then could cooperate with another individual in the hierarchy by investing in a common effort. Cooperation was achieved if the combined investments exceeded a threshold, and the higher ranked individual distributed the spoils unless control was contested by the partner. Compared to a condition lacking hierarchy, cooperation declined in the presence of a hierarchy due to a decrease in investment by lower ranked individuals. Furthermore, hierarchy was detrimental to cooperation regardless of whether it was earned or arbitrary. These findings mirror results from nonhuman primates and demonstrate that hierarchies are detrimental to cooperation. However, these results deviate from nonhuman primate findings by demonstrating that human behavior is responsive to changing hierarchical structures and suggests partnership dynamics that may improve cooperation. This work introduces a controlled way to investigate the social influences on human behavior, and demonstrates the evolutionary continuity of human behavior with other primate species.

  1. Exploring memory hierarchy design with emerging memory technologies

    CERN Document Server

    Sun, Guangyu

    2014-01-01

    This book equips readers with tools for computer architecture of high performance, low power, and high reliability memory hierarchy in computer systems based on emerging memory technologies, such as STTRAM, PCM, FBDRAM, etc.  The techniques described offer advantages of high density, near-zero static power, and immunity to soft errors, which have the potential of overcoming the “memory wall.”  The authors discuss memory design from various perspectives: emerging memory technologies are employed in the memory hierarchy with novel architecture modification;  hybrid memory structure is introduced to leverage advantages from multiple memory technologies; an analytical model named “Moguls” is introduced to explore quantitatively the optimization design of a memory hierarchy; finally, the vulnerability of the CMPs to radiation-based soft errors is improved by replacing different levels of on-chip memory with STT-RAMs.   ·         Provides a holistic study of using emerging memory technologies i...

  2. Diagonal gates in the Clifford hierarchy

    Science.gov (United States)

    Cui, Shawn X.; Gottesman, Daniel; Krishna, Anirudh

    2017-01-01

    The Clifford hierarchy is a set of gates that appears in the theory of fault-tolerant quantum computation, but its precise structure remains elusive. We give a complete characterization of the diagonal gates in the Clifford hierarchy for prime-dimensional qudits. They turn out to be pmth roots of unity raised to polynomial functions of the basis state to which they are applied, and we determine which level of the Clifford hierarchy a given gate sits in based on m and the degree of the polynomial.

  3. Formal language theory: refining the Chomsky hierarchy.

    Science.gov (United States)

    Jäger, Gerhard; Rogers, James

    2012-07-19

    The first part of this article gives a brief overview of the four levels of the Chomsky hierarchy, with a special emphasis on context-free and regular languages. It then recapitulates the arguments why neither regular nor context-free grammar is sufficiently expressive to capture all phenomena in the natural language syntax. In the second part, two refinements of the Chomsky hierarchy are reviewed, which are both relevant to the extant research in cognitive science: the mildly context-sensitive languages (which are located between context-free and context-sensitive languages), and the sub-regular hierarchy (which distinguishes several levels of complexity within the class of regular languages).

  4. UC hierarchy and monodromy preserving deformation

    CERN Document Server

    Tsuda, Teruhisa

    2010-01-01

    The UC hierarchy is an extension of the KP hierarchy, which possesses not only an infinite set of positive time evolutions but also that of negative ones. Through a similarity reduction we derive from the UC hierarchy a class of the Schlesinger systems including the Garnier system and the sixth Painleve equation, which describes the monodromy preserving deformations of Fuchsian linear differential equations with certain spectral types. We also present a unified formulation of the above Schlesinger systems as a canonical Hamiltonian system whose Hamiltonian functions are polynomials in the canonical variables.

  5. Hierarchy and information in feedforward networks

    CERN Document Server

    Corominas-Murtra, Bernat; Rodríguez-Caso, Carlos; Solé, Ricard

    2010-01-01

    In this paper we define a hierarchical index for feedforward structures taking, as the starting point, three fundamental concepts underlying hierarchy: order, predictability and pyramidal structure. Our definition applies to the so called causal graphs, i.e., connected, directed acyclic graphs in which the arrows depict a direct causal relation between two elements defining the nodes. The estimator of hierarchy is obtained by evaluating the complexity of causal paths against the uncertainty in recovering them from a given end point. This naturally leads us to a definition of mutual information which, properly normalized and weighted through the layered structure of the graph, results in suitable index of hierarchy with strong theoretical grounds.

  6. Topological Strings and Integrable Hierarchies

    CERN Document Server

    Aganagic, M; Klemm, A D; Marino, M; Vafa, C; Aganagic, Mina; Dijkgraaf, Robbert; Klemm, Albrecht; Marino, Marcos; Vafa, Cumrun

    2006-01-01

    We consider the topological B-model on local Calabi-Yau geometries. We show how one can solve for the amplitudes by using W-algebra symmetries which encodes the symmetries of holomorphic diffeomorphisms of the Calabi-Yau. In the highly effective fermionic/brane formulation this leads to a free fermion description of the amplitudes. Furthermore we argue that topological strings on Calabi-Yau geometries provide a unifying picture connecting non-critical (super)strings, integrable hierarchies, and various matrix models. In particular we show how the ordinary matrix model, the double scaling limit of matrix models, and Kontsevich-like matrix model are all related and arise from studying branes in specific local Calabi-Yau three-folds. We also show how A-model topological string on P^1 and local toric threefolds (and in particular the topological vertex) can be realized and solved as B-model topological string amplitudes on a Calabi-Yau manifold.

  7. Topological Strings and Integrable Hierarchies

    Science.gov (United States)

    Aganagic, Mina; Dijkgraaf, Robbert; Klemm, Albrecht; Mariño, Marcos; Vafa, Cumrun

    2006-01-01

    We consider the topological B-model on local Calabi-Yau geometries. We show how one can solve for the amplitudes by using -algebra symmetries which encode the symmetries of holomorphic diffeomorphisms of the Calabi-Yau. In the highly effective fermionic/brane formulation this leads to a free fermion description of the amplitudes. Furthermore we argue that topological strings on Calabi-Yau geometries provide a unifying picture connecting non-critical (super)strings, integrable hierarchies, and various matrix models. In particular we show how the ordinary matrix model, the double scaling limit of matrix models, and Kontsevich-like matrix model are all related and arise from studying branes in specific local Calabi-Yau three-folds. We also show how an A-model topological string on P1 and local toric threefolds (and in particular the topological vertex) can be realized and solved as B-model topological string amplitudes on a Calabi-Yau manifold.

  8. Quark masses and their hierarchies

    Science.gov (United States)

    Ida, M.

    1987-12-01

    Electroweak symmetry breaking is attributed to dynamical generation of quark masses. Quarks q (and leptons l) are assumed to be produced by hypercolor confinement of preons at an intermediate scale Λ hc. Hierarchies observed in the q mass spectra can be explained by a BCS mechanism if the color interaction is enough asymptotically free and if residual ones emerging by the confinement are medium strong. The former assumption claims that N≦4, where N is the family number of q and l. Dynamical equations to determine q masses and mixings are given, but they require knowledge on the physics at Λ hc. A phenomenological approach is also made on the basis of an SU(7)× SU(7) chiral preon model with N=4. The mass ratio m t/ mb is related to ( m c/ m s)ηB with η B≃1.1 and m t'/ mb' to ( m u/ m d)ηA with η A≃1.4. In this scheme the fourth down quark is the heaviest (˜ 110 GeV) and contributes dominantly to F 2, where F is the Fermi scale.

  9. Hierarchies in Dictionary Definition Space

    CERN Document Server

    Picard, Olivier; Harnad, Stevan; Marcotte, Odile; Chicoisne, Guillaume; Gargouri, Yassine

    2009-01-01

    A dictionary defines words in terms of other words. Definitions can tell you the meanings of words you don't know, but only if you know the meanings of the defining words. How many words do you need to know (and which ones) in order to be able to learn all the rest from definitions? We reduced dictionaries to their "grounding kernels" (GKs), about 10% of the dictionary, from which all the other words could be defined. The GK words turned out to have psycholinguistic correlates: they were learned at an earlier age and more concrete than the rest of the dictionary. But one can compress still more: the GK turns out to have internal structure, with a strongly connected "kernel core" (KC) and a surrounding layer, from which a hierarchy of definitional distances can be derived, all the way out to the periphery of the full dictionary. These definitional distances, too, are correlated with psycholinguistic variables (age of acquisition, concreteness, imageability, oral and written frequency) and hence perhaps with th...

  10. Hierarchy of modular graph identities

    Energy Technology Data Exchange (ETDEWEB)

    D’Hoker, Eric; Kaidi, Justin [Mani L. Bhaumik Institute for Theoretical Physics, Department of Physics and Astronomy,University of California,Los Angeles, CA 90095 (United States)

    2016-11-09

    The low energy expansion of Type II superstring amplitudes at genus one is organized in terms of modular graph functions associated with Feynman graphs of a conformal scalar field on the torus. In earlier work, surprising identities between two-loop graphs at all weights, and between higher-loop graphs of weights four and five were constructed. In the present paper, these results are generalized in two complementary directions. First, all identities at weight six and all dihedral identities at weight seven are obtained and proven. Whenever the Laurent polynomial at the cusp is available, the form of these identities confirms the pattern by which the vanishing of the Laurent polynomial governs the full modular identity. Second, the family of modular graph functions is extended to include all graphs with derivative couplings and worldsheet fermions. These extended families of modular graph functions are shown to obey a hierarchy of inhomogeneous Laplace eigenvalue equations. The eigenvalues are calculated analytically for the simplest infinite sub-families and obtained by Maple for successively more complicated sub-families. The spectrum is shown to consist solely of eigenvalues s(s−1) for positive integers s bounded by the weight, with multiplicities which exhibit rich representation-theoretic patterns.

  11. Multiple markers of cortical morphology reveal evidence of supragranular thinning in schizophrenia

    Science.gov (United States)

    Wagstyl, K; Ronan, L; Whitaker, K J; Goodyer, I M; Roberts, N; Crow, T J; Fletcher, P C

    2016-01-01

    In vivo structural neuroimaging can reliably identify changes to cortical morphology and its regional variation but cannot yet relate these changes to specific cortical layers. We propose, however, that by synthesizing principles of cortical organization, including relative contributions of different layers to sulcal and gyral thickness, regional patterns of variation in thickness of different layers across the cortical sheet and profiles of layer variation across functional hierarchies, it is possible to develop indirect morphological measures as markers of more specific cytoarchitectural changes. We developed four indirect measures sensitive to changes specifically occurring in supragranular cortical layers, and applied these to test the hypothesis that supragranular layers are disproportionately affected in schizophrenia. Our findings from the four different measures converge to indicate a predominance of supragranular thinning in schizophrenia, independent of medication and illness duration. We propose that these indirect measures offer novel ways of identifying layer-specific cortical changes, offering complementary in vivo observations to existing post-mortem studies. PMID:27070408

  12. Structural hierarchy of autism spectrum disorder symptoms: an integrative framework.

    Science.gov (United States)

    Kim, Hyunsik; Keifer, Cara M; Rodriguez-Seijas, Craig; Eaton, Nicholas R; Lerner, Matthew D; Gadow, Kenneth D

    2017-02-14

    In an attempt to resolve questions regarding the symptom classification of autism spectrum disorder (ASD), previous research generally aimed to demonstrate superiority of one model over another. Rather than adjudicating which model may be optimal, we propose an alternative approach that integrates competing models using Goldberg's bass-ackwards method, providing a comprehensive understanding of the underlying symptom structure of ASD. The study sample comprised 3,825 individuals, consecutive referrals to a university hospital developmental disabilities specialty clinic or a child psychiatry outpatient clinic. This study analyzed DSM-IV-referenced ASD symptom statements from parent and teacher versions of the Child and Adolescent Symptom Inventory-4R. A series of exploratory structural equation models was conducted in order to produce interpretable latent factors that account for multivariate covariance. Results indicated that ASD symptoms were structured into an interpretable hierarchy across multiple informants. This hierarchy includes five levels; key features of ASD bifurcate into different constructs with increasing specificity. This is the first study to examine an underlying structural hierarchy of ASD symptomatology using the bass-ackwards method. This hierarchy demonstrates how core features of ASD relate at differing levels of resolution, providing a model for conceptualizing ASD heterogeneity and a structure for integrating divergent theories of cognitive processes and behavioral features that define the disorder. These findings suggest that a more coherent and complete understanding of the structure of ASD symptoms may be reflected in a metastructure rather than at one level of resolution. © 2017 Association for Child and Adolescent Mental Health.

  13. Integrable Couplings of the Coupled Burgers Hierarchy

    Institute of Scientific and Technical Information of China (English)

    XIATie-Cheng; CHENXiao-Hong; CHENDeng-Yuan; ZHANGYu-Feng

    2004-01-01

    In this letter, a new loop algebra G is constructed, from which a new isospectral problem is established. It follows that integrable couplings of the well-known coupled Burgers hierarchy are obtained.

  14. Cache and memory hierarchy design a performance directed approach

    CERN Document Server

    Przybylski, Steven A

    1991-01-01

    An authoritative book for hardware and software designers. Caches are by far the simplest and most effective mechanism for improving computer performance. This innovative book exposes the characteristics of performance-optimal single and multi-level cache hierarchies by approaching the cache design process through the novel perspective of minimizing execution times. It presents useful data on the relative performance of a wide spectrum of machines and offers empirical and analytical evaluations of the underlying phenomena. This book will help computer professionals appreciate the impact of ca

  15. Cities, Wages, and the Urban Hierarchy

    OpenAIRE

    Juan D. Soto; Dusan Paredes

    2014-01-01

    We present evidence regarding the unequal spatial distribution of population in the north and south of Chile which implies that even when geographical distances to the main urban center are similar, the distances in a context of urban hierarchy are completely di?erent. Given this economic geography, we postulate that Central Place Theory provides a better understanding for the study of city size wage gap in Chile. In order to test our hypothesis, we construct ?ve tiers of urban hierarchy usin...

  16. Existence of Hierarchies and Human's Pursuit of Top Hierarchy Lead to Power Law

    CERN Document Server

    Yu, Shuiyuan; Liu, Haitao

    2016-01-01

    The power law is ubiquitous in natural and social phenomena, and is considered as a universal relationship between the frequency and its rank for diverse social systems. However, a general model is still lacking to interpret why these seemingly unrelated systems share great similarity. Through a detailed analysis of natural language texts and simulation experiments based on the proposed 'Hierarchical Selection Model', we found that the existence of hierarchies and human's pursuit of top hierarchy lead to the power law. Further, the power law is a statistical and emergent performance of hierarchies, and it is the universality of hierarchies that contributes to the ubiquity of the power law.

  17. Optimism

    Science.gov (United States)

    Carver, Charles S.; Scheier, Michael F.; Segerstrom, Suzanne C.

    2010-01-01

    Optimism is an individual difference variable that reflects the extent to which people hold generalized favorable expectancies for their future. Higher levels of optimism have been related prospectively to better subjective well-being in times of adversity or difficulty (i.e., controlling for previous well-being). Consistent with such findings, optimism has been linked to higher levels of engagement coping and lower levels of avoidance, or disengagement, coping. There is evidence that optimism is associated with taking proactive steps to protect one's health, whereas pessimism is associated with health-damaging behaviors. Consistent with such findings, optimism is also related to indicators of better physical health. The energetic, task-focused approach that optimists take to goals also relates to benefits in the socioeconomic world. Some evidence suggests that optimism relates to more persistence in educational efforts and to higher later income. Optimists also appear to fare better than pessimists in relationships. Although there are instances in which optimism fails to convey an advantage, and instances in which it may convey a disadvantage, those instances are relatively rare. In sum, the behavioral patterns of optimists appear to provide models of living for others to learn from. PMID:20170998

  18. Optimization

    CERN Document Server

    Pearce, Charles

    2009-01-01

    Focuses on mathematical structure, and on real-world applications. This book includes developments in several optimization-related topics such as decision theory, linear programming, turnpike theory, duality theory, convex analysis, and queuing theory.

  19. The enemy within: propagation of aberrant corticostriatal learning to cortical function in Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Jeff A Beeler

    2013-09-01

    Full Text Available Motor dysfunction in Parkinson’s disease is believed to arise primarily from pathophysiology in the dorsal striatum and its related corticostriatal and thalamostriatal circuits during progressive dopamine denervation. One function of these circuits is to provide a filter that selectively facilitates or inhibits cortical activity to optimize cortical processing, making motor responses rapid and efficient. Corticostriatal synaptic plasticity mediates the learning that underlies this performance-optimizing filter. Under dopamine denervation, corticostriatal plasticity is altered, resulting in aberrant learning that induces inappropriate basal ganglia filtering that impedes rather than optimizes cortical processing. Human imaging suggests that increased cortical activity may compensate for striatal dysfunction in PD patients. In this Perspective article, we consider how aberrant learning at corticostriatal synapses may impair cortical processing and learning and undermine potential cortical compensatory mechanisms. Blocking or remediating aberrant corticostriatal plasticity may protect cortical function and support cortical compensatory mechanisms mitigating the functional decline associated with progressive dopamine denervation.

  20. The Ups and Downs of Hierarchy: the causes and consequences of hierarchy struggles and positional loss

    NARCIS (Netherlands)

    M.E. Schouten (Maartje)

    2016-01-01

    markdownabstractScholars have assumed that social hierarchies, the rank ordering of individuals with respect to a valued social dimension within a team, are stable over time. However, hierarchies change and the more changeable they are, the more likely they are to lead to conflicts and have other ne

  1. The Ups and Downs of Hierarchy: the causes and consequences of hierarchy struggles and positional loss

    NARCIS (Netherlands)

    M.E. Schouten (Maartje)

    2016-01-01

    markdownabstractScholars have assumed that social hierarchies, the rank ordering of individuals with respect to a valued social dimension within a team, are stable over time. However, hierarchies change and the more changeable they are, the more likely they are to lead to conflicts and have other

  2. The network motif architecture of dominance hierarchies.

    Science.gov (United States)

    Shizuka, Daizaburo; McDonald, David B

    2015-04-01

    The widespread existence of dominance hierarchies has been a central puzzle in social evolution, yet we lack a framework for synthesizing the vast empirical data on hierarchy structure in animal groups. We applied network motif analysis to compare the structures of dominance networks from data published over the past 80 years. Overall patterns of dominance relations, including some aspects of non-interactions, were strikingly similar across disparate group types. For example, nearly all groups exhibited high frequencies of transitive triads, whereas cycles were very rare. Moreover, pass-along triads were rare, and double-dominant triads were common in most groups. These patterns did not vary in any systematic way across taxa, study settings (captive or wild) or group size. Two factors significantly affected network motif structure: the proportion of dyads that were observed to interact and the interaction rates of the top-ranked individuals. Thus, study design (i.e. how many interactions were observed) and the behaviour of key individuals in the group could explain much of the variations we see in social hierarchies across animals. Our findings confirm the ubiquity of dominance hierarchies across all animal systems, and demonstrate that network analysis provides new avenues for comparative analyses of social hierarchies.

  3. Cohesion and Hierarchy in Physically Abusive Families

    Directory of Open Access Journals (Sweden)

    Clarissa De Antoni

    2009-06-01

    Full Text Available This paper investigates cohesion (emotional bonding and hierarchy (powerstructure in families with abuse against their children. Twenty low-incomefamilies participated. Father, mother and child’s perspective of family relations(cohesion and hierarchy were evaluated by the Family System Test(FAST. The relationship between father-child, mother-child, couple, andamong siblings were evaluated at typical and conflictive situations. Resultsshow a significance regarding to cohesion in typical and conflictive situationfor father-child and mother-child dyads in all perspectives (by father, mother,and child. There is no significant differences regarding to hierarchy. Theseresults suggest that the families see the intrafamilial violence as a constant,since they cannot differentiate between both situations.

  4. The mammary cellular hierarchy and breast cancer.

    Science.gov (United States)

    Oakes, Samantha R; Gallego-Ortega, David; Ormandy, Christopher J

    2014-11-01

    Advances in the study of hematopoietic cell maturation have paved the way to a deeper understanding the stem and progenitor cellular hierarchy in the mammary gland. The mammary epithelium, unlike the hematopoietic cellular hierarchy, sits in a complex niche where communication between epithelial cells and signals from the systemic hormonal milieu, as well as from extra-cellular matrix, influence cell fate decisions and contribute to tissue homeostasis. We review the discovery, definition and regulation of the mammary cellular hierarchy and we describe the development of the concepts that have guided our investigations. We outline recent advances in in vivo lineage tracing that is now challenging many of our assumptions regarding the behavior of mammary stem cells, and we show how understanding these cellular lineages has altered our view of breast cancer.

  5. Formal language theory: refining the Chomsky hierarchy

    Science.gov (United States)

    Jäger, Gerhard; Rogers, James

    2012-01-01

    The first part of this article gives a brief overview of the four levels of the Chomsky hierarchy, with a special emphasis on context-free and regular languages. It then recapitulates the arguments why neither regular nor context-free grammar is sufficiently expressive to capture all phenomena in the natural language syntax. In the second part, two refinements of the Chomsky hierarchy are reviewed, which are both relevant to the extant research in cognitive science: the mildly context-sensitive languages (which are located between context-free and context-sensitive languages), and the sub-regular hierarchy (which distinguishes several levels of complexity within the class of regular languages). PMID:22688632

  6. Research on Marketing Channel of Mobile Manufacturer Based on Analytic Hierarchy Process

    Institute of Scientific and Technical Information of China (English)

    XIONG Hui; LI Shi-ming; LAN Yong

    2006-01-01

    Research on "marketing channel" of mobile attracts much attention in these years,but there're only few articles referring to how to optimize the disposition of channel resources for mobile manufacturers. Based on a typically multiplex marketing channel system of mobile manufacturer, the analytic hierarchy process (AHP) structure model is established. Through the judgment matrix, simple and total hierarchy arrangement, consistent test, this paper gets the weight of each kind of marketing channel of mobile manufacturer. It provides the practical reference value for mobile manufacturers to distribute resources of marketing channels.

  7. Integrable couplings of a generalized AKNS hierarchy

    Institute of Scientific and Technical Information of China (English)

    张玉峰; 张鸿庆; 闫庆友

    2002-01-01

    A generalized AKNS isospectral problem where the trace of corresponding spectral matrix is not zero, is transformed to a new isospectral problem where the trace of the resulting matrix is zero, by using transformation of Lax pairs, and these two spectral problems lead to the same hierarchy of equations. The authors started from the transformed spectral problem and constructed a new loop algebra which has not appeared before, and obtained the integrable coupling of the generalized AKNS hierarchy. Specially, the integrable couplings of the KdV equation and MKdV equation are obtained.

  8. An Operational Investigation of the CPS Hierarchy

    DEFF Research Database (Denmark)

    Danvy, Olivier; Yang, Zhe

    1998-01-01

    We explore the hierarchy of control induced by successive transformations into continuation-passing style (CPS) in the presence of “control delimiters ” and “composable continuations ”. Specifically, we investigate the structural operational semantics associated with the CPS hierarchy. To this end......, we characterize an operational notion of continuation semantics. We relate it to the traditional CPS transformation and we use it to account for the control operator shift and the control delimiter reset operationally. We then transcribe the resulting continuation semantics in ML, thus obtaining...

  9. Neuroanatomical Markers of Social Hierarchy Recognition in Humans: A Combined ERP/MRI Study.

    Science.gov (United States)

    Santamaría-García, Hernando; Burgaleta, Miguel; Sebastián-Gallés, Nuria

    2015-07-29

    Social hierarchy is an ubiquitous principle of social organization across animal species. Although some progress has been made in our understanding of how humans infer hierarchical identity, the neuroanatomical basis for perceiving key social dimensions of others remains unexplored. Here, we combined event-related potentials and structural MRI to reveal the neuroanatomical substrates of early status recognition. We designed a covertly simulated hierarchical setting in which participants performed a task either with a superior or with an inferior player. Participants showed higher amplitude in the N170 component when presented with a picture of a superior player compared with an inferior player. Crucially, the magnitude of this effect correlated with brain morphology of the posterior cingulate cortex, superior temporal gyrus, insula, fusiform gyrus, and caudate nucleus. We conclude that early recognition of social hierarchies relies on the structural properties of a network involved in the automatic recognition of social identity. Humans can perceive social hierarchies very rapidly, an ability that is key for social interactions. However, some individuals are more sensitive to hierarchical information than others. Currently, it is unknown how brain structure supports such fast-paced processes of social hierarchy perception and their individual differences. Here, we addressed this issue for the first time by combining the high temporal resolution of event-related potentials (ERPs) and the high spatial resolution of structural MRI. This methodological approach allowed us to unveil a novel association between ERP neuromarkers of social hierarchy perception and the morphology of several cortical and subcortical brain regions typically assumed to play a role in automatic processes of social cognition. Our results are a step forward in our understanding of the human social brain. Copyright © 2015 the authors 0270-6474/15/3510843-08$15.00/0.

  10. Evolution of cortical neurogenesis.

    Science.gov (United States)

    Abdel-Mannan, Omar; Cheung, Amanda F P; Molnár, Zoltán

    2008-03-18

    The neurons of the mammalian neocortex are organised into six layers. By contrast, the reptilian and avian dorsal cortices only have three layers which are thought to be equivalent to layers I, V and VI of mammals. Increased repertoire of mammalian higher cognitive functions is likely a result of an expanded cortical surface area. The majority of cortical cell proliferation in mammals occurs in the ventricular zone (VZ) and subventricular zone (SVZ), with a small number of scattered divisions outside the germinal zone. Comparative developmental studies suggest that the appearance of SVZ coincides with the laminar expansion of the cortex to six layers, as well as the tangential expansion of the cortical sheet seen within mammals. In spite of great variation and further compartmentalisation in the mitotic compartments, the number of neurons in an arbitrary cortical column appears to be remarkably constant within mammals. The current challenge is to understand how the emergence and elaboration of the SVZ has contributed to increased cortical cell diversity, tangential expansion and gyrus formation of the mammalian neocortex. This review discusses neurogenic processes that are believed to underlie these major changes in cortical dimensions in vertebrates.

  11. Cortical Lewy Body Dementia

    Directory of Open Access Journals (Sweden)

    W. R. G. Gibb

    1990-01-01

    Full Text Available In cortical Lewy body dementia the distribution of Lewy bodies in the nervous system follows that of Parkinson's disease, except for their greater profusion in the cerebral cortex. The cortical tangles and plaques of Alzheimer pathology are often present, the likely explanation being that Alzheimer pathology provokes dementia in many patients. Pure cortical Lewy body dementia without Alzheimer pathology is uncommon. The age of onset reflects that of Parkinson's disease, and clinical features, though not diagnostic, include aphasias, apraxias, agnosias, paranoid delusions and visual hallucinations. Parkinsonism may present before or after the dementia, and survival duration is approximately half that seen in Parkinson's disease without dementia.

  12. Assessment of cortical maturation with prenatal MRI. Part I: normal cortical maturation

    Energy Technology Data Exchange (ETDEWEB)

    Fogliarini, Celine [Faculte Timone, Centre de Resonance Magnetique Biologique et Medicale, Marseille (France); Chaumoitre, Katia [Hopital Nord, Department of Radiology, Marseille (France); Chapon, Frederique; Levrier, Olivier; Girard, Nadine [Hopital Timone, Department of Neuroradiology, Marseille Cedex 5 (France); Fernandez, Carla; Figarella-Branger, Dominique [Hopital Timone, Department of Pathology, Marseille (France)

    2005-08-01

    Cortical maturation, especially gyral formation, follows a temporospatial schedule and is a good marker of fetal maturation. Although ultrasonography is still the imaging method of choice to evaluate fetal anatomy, MRI has an increasingly important role in the detection of brain abnormalities, especially of cortical development. Knowledge of MRI techniques in utero with the advantages and disadvantages of some sequences is necessary, in order to try to optimize the different magnetic resonance sequences to be able to make an early diagnosis. The different steps of cortical maturation known from histology represent the background necessary for the understanding of maturation in order to be then able to evaluate brain maturation through neuroimaging. Illustrations of the normal cortical maturation are given for each step accessible to MRI for both the cerebral hemispheres and the posterior fossa. (orig.)

  13. A Game-Theoretical Winner and Loser Model of Dominance Hierarchy Formation.

    Science.gov (United States)

    Kura, Klodeta; Broom, Mark; Kandler, Anne

    2016-06-01

    Many animals spend large parts of their lives in groups. Within such groups, they need to find efficient ways of dividing available resources between them. This is often achieved by means of a dominance hierarchy, which in its most extreme linear form allocates a strict priority order to the individuals. Once a hierarchy is formed, it is often stable over long periods, but the formation of hierarchies among individuals with little or no knowledge of each other can involve aggressive contests. The outcome of such contests can have significant effects on later contests, with previous winners more likely to win (winner effects) and previous losers more likely to lose (loser effects). This scenario has been modelled by a number of authors, in particular by Dugatkin. In his model, individuals engage in aggressive contests if the assessment of their fighting ability relative to their opponent is above a threshold [Formula: see text]. Here we present a model where each individual can choose its own value [Formula: see text]. This enables us to address questions such as how aggressive should individuals be in order to take up one of the first places in the hierarchy? We find that a unique strategy evolves, as opposed to a mixture of strategies. Thus, in any scenario there exists a unique best level of aggression, and individuals should not switch between strategies. We find that for optimal strategy choice, the hierarchy forms quickly, after which there are no mutually aggressive contests.

  14. Large hierarchies from approximate R symmetries

    Energy Technology Data Exchange (ETDEWEB)

    Kappl, Rolf; Ratz, Michael [Technische Univ. Muenchen, Garching (Germany). Physik Dept. T30; Nilles, Hans Peter [Bonn Univ. (Germany). Bethe Zentrum fuer Theoretische Physik und Physikalisches Inst.; Ramos-Sanchez, Saul; Schmidt-Hoberg, Kai [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Vaudrevange, Patrick K.S. [Ludwig-Maximilians-Univ. Muenchen (Germany). Arnold Sommerfeld Zentrum fuer Theoretische Physik

    2008-12-15

    We show that hierarchically small vacuum expectation values of the superpotential in supersymmetric theories can be a consequence of an approximate R symmetry. We briefly discuss the role of such small constants in moduli stabilization and understanding the huge hierarchy between the Planck and electroweak scales. (orig.)

  15. Integrable hierarchies of Heisenberg ferromagnet equation

    Science.gov (United States)

    Nugmanova, G.; Azimkhanova, A.

    2016-08-01

    In this paper we consider the coupled Kadomtsev-Petviashvili system. From compatibility conditions we obtain the form of matrix operators. After using a gauge transformation, obtained a new type of Lax representation for the hierarchy of Heisenberg ferromagnet equation, which is equivalent to the gauge coupled Kadomtsev-Petviashvili system.

  16. Geometrical hierarchy and spontaneous symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Farakos, K.; Koutsoumbas, G.; Surridge, M.; Zoupanos, G.

    1987-06-04

    A four-dimensional gauge theory, where Higgs fields and the corresponding potential appear naturally, is obtained by dimensionally reducing a pure gauge theory over a compact coset space S/R. We show, using an explicit example, that a hierarchy of the scales in the coset space can change the spontaneous symmetry breaking of the four-dimensional gauge theory.

  17. Beyond Hierarchy: The Search for High Performance.

    Science.gov (United States)

    Galagan, Patricia A.; And Others

    1992-01-01

    This special report of the reorganization of work looks at approaches to organizational renewal that are challenging the notion of the hierarchy as the only form that works. Looks at models for organizing work presented by Gary Rummler, D. Quinn Mills, and Marvin Weisbord and a blueprint for creating common futures with large groups of people.…

  18. Dark energy and the hierarchy problem

    CERN Document Server

    Chen, P

    2007-01-01

    The well-known hierarchy between the Planck scale (~10^{19}GeV) and the TeV scale, namely a ratio of ~10^{16} between the two, is coincidentally repeated in a inverted order between the TeV scale and the dark energy scale at \\~10^{-3}eV implied by the observations. We argue that this is not a numerical coincidence. The same brane-world setups to address the first hierarchy problem may also in principle address this second hierarchy issue. Specifically, we consider supersymmetry in the bulk and its breaking on the brane and resort to the Casimir energy induced by the bulk graviton-gravitino mass-shift on the brane as the dark energy. For the ADD model we found that our notion is sensible only if the number of extra dimension n=2. We extend our study to the Randall-Sundrum model. Invoking the chirality-flip on the boundaries for SUSY-breaking, the zero-mode gravitino contribution to the Casimir energy does give rise to the double hierarchy. Unfortunately since the higher Kaluza-Klein modes acquire relative mass...

  19. Beyond Hierarchy: The Search for High Performance.

    Science.gov (United States)

    Galagan, Patricia A.; And Others

    1992-01-01

    This special report of the reorganization of work looks at approaches to organizational renewal that are challenging the notion of the hierarchy as the only form that works. Looks at models for organizing work presented by Gary Rummler, D. Quinn Mills, and Marvin Weisbord and a blueprint for creating common futures with large groups of people.…

  20. Self-organization of divided hierarchy

    Science.gov (United States)

    Odagaki, Takashi; Kitada, Keigo; Omizo, Kenta; Fujie, Ryo

    2015-03-01

    There are two types of extreme form of hierarchy, one is the plutonomy where small fraction of winners and losers and many people in the middle class appear and the other a divided hierarchy where half of population become winners and the remaining half become losers. We study the emergence of the divided hierarchy in a model society which consists of bellicose individuals who always try to fight and fight with the strongest neighbor and pacific individuals who always try not to fight and when necessary fight with the weakest neighbor. In our model society, (1) individuals make random walk on a square lattice, (2) when two individuals encounter they fight each other and (3) the winner deprives wealth from the loser. By a Monte Carlo simulation, we show that there are two transitions when the population density is increased; one is a transition from the egalitarian society to a hierarchical society I where winners, losers and middle classes coexist and the other is a transition from the hierarchical society I to a hierarchical society II where winners and losers exist but no middle classes exist, that is the divided hierarchy. We also show that clusters consisting mostly of bellicose individuals appear in the hierarchical society I.

  1. The FO^2 alternation hierarchy is decidable

    CERN Document Server

    Kufleitner, Manfred

    2012-01-01

    We consider the two-variable fragment FO^2[<] of first-order logic over finite words. Numerous characterizations of this class are known. Th\\'erien and Wilke have shown that it is decidable whether a given regular language is definable in FO^2[<]. From a practical point of view, as shown by Weis, FO^2[<] is interesting since its satisfiability problem is in NP. Restricting the number of quantifier alternations yields an infinite hierarchy inside the class of FO^2[<]-definable languages. We show that each level of this hierarchy is decidable. For this purpose, we relate each level of the hierarchy with a decidable variety of finite monoids. Our result implies that there are many different ways of climbing up the FO^2[<]-quantifier alternation hierarchy: deterministic and co-deterministic products, Mal'cev products with definite and reverse definite semigroups, iterated block products with J-trivial monoids, and some inductively defined omega-term identities. A combinatorial tool in the process o...

  2. Using Analytic Hierarchy Process in Textbook Evaluation

    Science.gov (United States)

    Kato, Shigeo

    2014-01-01

    This study demonstrates the application of the analytic hierarchy process (AHP) in English language teaching materials evaluation, focusing in particular on its potential for systematically integrating different components of evaluation criteria in a variety of teaching contexts. AHP is a measurement procedure wherein pairwise comparisons are made…

  3. Integrating partonomic hierarchies in anatomy ontologies

    Directory of Open Access Journals (Sweden)

    Yang Yiya

    2004-11-01

    Full Text Available Abstract Background Anatomy ontologies play an increasingly important role in developing integrated bioinformatics applications. One of the primary relationships between anatomical tissues represented in such ontologies is part-of. As there are a number of ways to divide up the anatomical structure of an organism, each may be represented by more than one valid partonomic (part-of hierarchy. This raises the issue of how to represent and integrate multiple such hierarchies. Results In this paper we describe a solution that is based on our work on an anatomy ontology for mouse embryo development, which is part of the Edinburgh Mouse Atlas Project (EMAP. The paper describes the basic conceptual aspects of our approach and discusses strengths and limitations of the proposed solution. A prototype was implemented in Prolog for evaluation purposes. Conclusion With the proposed name set approach, rather than having to standardise hierarchies, it is sufficient to agree on a suitable set of basic tissue terms and their meaning in order to facilitate the integration of multiple partonomic hierarchies.

  4. The Analytic Hierarchy Process and Participatory Decisionmaking

    Science.gov (United States)

    Daniel L. Schmoldt; Daniel L. Peterson; Robert L. Smith

    1995-01-01

    Managing natural resource lands requires social, as well as biophysical, considerations. Unfortunately, it is extremely difficult to accurately assess and quantify changing social preferences, and to aggregate conflicting opinions held by diverse social groups. The Analytic Hierarchy Process (AHP) provides a systematic, explicit, rigorous, and robust mechanism for...

  5. Focal cortical dysplasia - review.

    Science.gov (United States)

    Kabat, Joanna; Król, Przemysław

    2012-04-01

    Focal cortical dysplasia is a malformation of cortical development, which is the most common cause of medically refractory epilepsy in the pediatric population and the second/third most common etiology of medically intractable seizures in adults.Both genetic and acquired factors are involved in the pathogenesis of cortical dysplasia. Numerous classifications of the complex structural abnormalities of focal cortical dysplasia have been proposed - from Taylor et al. in 1971 to the last modification of Palmini classification made by Blumcke in 2011. In general, three types of cortical dysplasia are recognized.Type I focal cortical dysplasia with mild symptomatic expression and late onset, is more often seen in adults, with changes present in the temporal lobe.Clinical symptoms are more severe in type II of cortical dysplasia usually seen in children. In this type, more extensive changes occur outside the temporal lobe with predilection for the frontal lobes.New type III is one of the above dysplasias with associated another principal lesion as hippocampal sclerosis, tumor, vascular malformation or acquired pathology during early life.Brain MRI imaging shows abnormalities in the majority of type II dysplasias and in only some of type I cortical dysplasias.THE MOST COMMON FINDINGS ON MRI IMAGING INCLUDE: focal cortical thickening or thinning, areas of focal brain atrophy, blurring of the gray-white junction, increased signal on T2- and FLAIR-weighted images in the gray and subcortical white matter often tapering toward the ventricle. On the basis of the MRI findings, it is possible to differentiate between type I and type II cortical dysplasia. A complete resection of the epileptogenic zone is required for seizure-free life. MRI imaging is very helpful to identify those patients who are likely to benefit from surgical treatment in a group of patients with drug-resistant epilepsy.However, in type I cortical dysplasia, MR imaging is often normal, and also in both types

  6. Postpartum cortical blindness.

    Science.gov (United States)

    Faiz, Shakeel Ahmed

    2008-09-01

    A 30-years-old third gravida with previous normal pregnancies and an unremarkable prenatal course had an emergency lower segment caesarean section at a periphery hospital for failure of labour to progress. She developed bilateral cortical blindness immediately after recovery from anesthesia due to cerebral angiopathy shown by CT and MR scan as cortical infarct cerebral angiopathy, which is a rare complication of a normal pregnancy.

  7. Cortical tracking of hierarchical linguistic structures in connected speech.

    Science.gov (United States)

    Ding, Nai; Melloni, Lucia; Zhang, Hang; Tian, Xing; Poeppel, David

    2016-01-01

    The most critical attribute of human language is its unbounded combinatorial nature: smaller elements can be combined into larger structures on the basis of a grammatical system, resulting in a hierarchy of linguistic units, such as words, phrases and sentences. Mentally parsing and representing such structures, however, poses challenges for speech comprehension. In speech, hierarchical linguistic structures do not have boundaries that are clearly defined by acoustic cues and must therefore be internally and incrementally constructed during comprehension. We found that, during listening to connected speech, cortical activity of different timescales concurrently tracked the time course of abstract linguistic structures at different hierarchical levels, such as words, phrases and sentences. Notably, the neural tracking of hierarchical linguistic structures was dissociated from the encoding of acoustic cues and from the predictability of incoming words. Our results indicate that a hierarchy of neural processing timescales underlies grammar-based internal construction of hierarchical linguistic structure.

  8. Mass Hierarchy Determination Using Neutrinos from Multiple Reactors

    CERN Document Server

    Ciuffoli, Emilio; Zhang, Xinmin

    2012-01-01

    We report the results of Monte Carlo simulations of a medium baseline reactor neutrino experiment. The difference in baselines resulting from the 1 km separations of Daya Bay and Ling Ao reactors reduces the amplitudes of 1-3 oscillations at low energies, decreasing the sensitivity to the neutrino mass hierarchy. A perpendicular detector location eliminates this effect. We simulate experiments under several mountains perpendicular to the Daya Bay/Ling Ao reactors, considering in particular the background from the TaiShan and YangJiang reactor complexes. In general the hierarchy can be determined most reliably underneath the 1000 meter mountain BaiYunZhang, which is 44.5 km from Daya Bay. If some planned reactors are not built then nearby 700 meter mountains at 47-51 km baselines gain a small advantage. Neglecting their low overhead burdens, hills near DongKeng would be the optimal locations. We use a weighted Fourier transform to avoid a spurious dependence on the high energy neutrino spectrum and find that a...

  9. A mechanism for the cortical computation of hierarchical linguistic structure.

    Science.gov (United States)

    Martin, Andrea E; Doumas, Leonidas A A

    2017-03-01

    Biological systems often detect species-specific signals in the environment. In humans, speech and language are species-specific signals of fundamental biological importance. To detect the linguistic signal, human brains must form hierarchical representations from a sequence of perceptual inputs distributed in time. What mechanism underlies this ability? One hypothesis is that the brain repurposed an available neurobiological mechanism when hierarchical linguistic representation became an efficient solution to a computational problem posed to the organism. Under such an account, a single mechanism must have the capacity to perform multiple, functionally related computations, e.g., detect the linguistic signal and perform other cognitive functions, while, ideally, oscillating like the human brain. We show that a computational model of analogy, built for an entirely different purpose-learning relational reasoning-processes sentences, represents their meaning, and, crucially, exhibits oscillatory activation patterns resembling cortical signals elicited by the same stimuli. Such redundancy in the cortical and machine signals is indicative of formal and mechanistic alignment between representational structure building and "cortical" oscillations. By inductive inference, this synergy suggests that the cortical signal reflects structure generation, just as the machine signal does. A single mechanism-using time to encode information across a layered network-generates the kind of (de)compositional representational hierarchy that is crucial for human language and offers a mechanistic linking hypothesis between linguistic representation and cortical computation.

  10. Sociality, hierarchy, health comparative biodemography: a collection of papers

    National Research Council Canada - National Science Library

    Weinstein, Maxine; Lane, Meredith A

    2014-01-01

    "Sociality, Hierarchy, Health: Comparative Biodemography is a collection of papers that examine cross-species comparisons of social environments with a focus on social behaviors along with social hierarchies and connections...

  11. Stress amplifies memory for social hierarchy

    Directory of Open Access Journals (Sweden)

    María I Cordero

    2007-10-01

    Full Text Available Individuals differ in their social status and societies in the extent of social status differences among their members. There is great interest in understanding the key factors that contribute to the establishment of social dominance structures. Given that stress can affect behavior and cognition, we hypothesized that, given equal opportunities to become either dominant or submissive, stress experienced by one of the individuals during their first encounter would determine the long-term establishment of a social hierarchy by acting as a two-stage rocket: (1 by influencing the rank achieved after a social encounter and (2 by facilitating and/or promoting a long-term memory for the specific hierarchy. Using a novel model for the assessment of long-term dominance hierarchies in rats, we present here the first evidence supporting such hypothesis. In control conditions, the social rank established through a first interaction and food competition test between two male rats is not maintained when animals are confronted 1 week later. However, if one of the rats is stressed just before their first encounter, the dominance hierarchy developed on day 1 is still clearly observed 1 week later, with the stressed animal becoming submissive (i.e., looser in competition tests in both social interactions. Our findings also allow us to propose that stress potentiates a hierarchy-linked recognition memory between “specific” individuals through mechanisms that involve de novo protein synthesis. These results implicate stress among the key mechanisms contributing to create social imbalance and highlight memory mechanisms as key mediators of stress-induced long-term establishment of social rank.

  12. Improving Maslow’s Hierarchy of Needs: New Approach to needs hierarchy

    OpenAIRE

    Babak Nemati

    2013-01-01

    In this article Maslow's hierarchy of needs is reviewed with two viewpoints: critical and supportive. We try to extract and classify the relevant subject related to the research content after studying and analysis of documents. Thus, because of their common characters, the needs that have been cited from some scientists could be gathered and make some new levels.The new Maslow's hierarchy of needs has been presented in this research and we added three levels EPISTEMOLOGY, LOG and EROS (Freedo...

  13. The concept of hierarchy in general systems theory.

    Science.gov (United States)

    Gasparski, W

    1994-01-01

    The paper reviews main ideas related to the concept of hierarchy as they are discussed in contemporary general systems theory. After presenting a dictionary definition of the concept, the author examines the intuitive idea of hierarchy quoting Mario Bunge's notion of level structure. Then relationship between two other concepts: a system and a hierarchy is characterised on the bases of Bowler's, Bunge's again, Klir's, and the author's studies. Finally, the paper is concluded that hierarchy is not an otological concept but epistemological one.

  14. Dispersionless and multicomponent BKP hierarchies with quantum torus symmetries

    Science.gov (United States)

    Li, Chuanzhong

    2017-09-01

    In this article, we will construct the additional perturbative quantum torus symmetry of the dispersionless BKP hierarchy based on the W∞ infinite dimensional Lie symmetry. These results show that the complete quantum torus symmetry is broken from the BKP hierarchy to its dispersionless hierarchies. Further a series of additional flows of the multicomponent BKP hierarchy will be defined and these flows constitute an N-folds direct product of the positive half of the quantum torus symmetries.

  15. Vector Loop Algebra and Its Applications to Tu Hierarchy

    Institute of Scientific and Technical Information of China (English)

    WANG Yan

    2007-01-01

    A vector loop algebra and its extended loop algebra are proposed, which are devoted to obtaining the Tu hierarchy. By making use of the extended trace identity, the Hamiltonian structure of the Tu hierarchy is constructed.Furthermore, we apply the quadratic-form identity to the integrable coupling system of the Tu hierarchy.

  16. Basic Studies of Learning Hierarchies in School Subjects. Final Report.

    Science.gov (United States)

    Gagne, Robert M.

    This study explores three areas of learning hierarchies: (1) the condition for learning in accordance with learning hierarchies; (2) the use of hierarchies in the diagnosis and learning of prerequisite intellectual skills; and (3) the conditions of learning and retention of principles. There were seven studies undertaken using elementary and…

  17. Anatomy of hierarchy: Feedforward and feedback pathways in macaque visual cortex

    Science.gov (United States)

    Markov, Nikola T; Vezoli, Julien; Chameau, Pascal; Falchier, Arnaud; Quilodran, René; Huissoud, Cyril; Lamy, Camille; Misery, Pierre; Giroud, Pascale; Ullman, Shimon; Barone, Pascal; Dehay, Colette; Knoblauch, Kenneth; Kennedy, Henry

    2013-01-01

    The laminar location of the cell bodies and terminals of interareal connections determines the hierarchical structural organization of the cortex and has been intensively studied. However, we still have only a rudimentary understanding of the connectional principles of feedforward (FF) and feedback (FB) pathways. Quantitative analysis of retrograde tracers was used to extend the notion that the laminar distribution of neurons interconnecting visual areas provides an index of hierarchical distance (percentage of supragranular labeled neurons [SLN]). We show that: 1) SLN values constrain models of cortical hierarchy, revealing previously unsuspected areal relations; 2) SLN reflects the operation of a combinatorial distance rule acting differentially on sets of connections between areas; 3) Supragranular layers contain highly segregated bottom-up and top-down streams, both of which exhibit point-to-point connectivity. This contrasts with the infragranular layers, which contain diffuse bottom-up and top-down streams; 4) Cell filling of the parent neurons of FF and FB pathways provides further evidence of compartmentalization; 5) FF pathways have higher weights, cross fewer hierarchical levels, and are less numerous than FB pathways. Taken together, the present results suggest that cortical hierarchies are built from supra- and infragranular counterstreams. This compartmentalized dual counterstream organization allows point-to-point connectivity in both bottom-up and top-down directions. PMID:23983048

  18. [Research advances on cortical functional and structural deficits of amblyopia].

    Science.gov (United States)

    Wu, Y; Liu, L Q

    2017-05-11

    Previous studies have observed functional deficits in primary visual cortex. With the development of functional magnetic resonance imaging and electrophysiological technique, the research of the striate, extra-striate cortex and higher-order cortical deficit underlying amblyopia reaches a new stage. The neural mechanisms of amblyopia show that anomalous responses exist throughout the visual processing hierarchy, including the functional and structural abnormalities. This review aims to summarize the current knowledge about structural and functional deficits of brain regions associated with amblyopia. (Chin J Ophthalmol, 2017, 53: 392-395).

  19. A 2 + 1 non-isospectral integrable lattice hierarchy related to a generalized discrete second Painleve hierarchy

    Energy Technology Data Exchange (ETDEWEB)

    Gordoa, Pilar R. [Area de Matematica Aplicada, ESCET, Universidad Rey Juan Carlos, C/Tulipan s/n, 28933 Mostoles, Madrid (Spain); Pickering, Andrew [Area de Matematica Aplicada, ESCET, Universidad Rey Juan Carlos, C/Tulipan s/n, 28933 Mostoles, Madrid (Spain)]. E-mail: andrew.pickering@urjc.es; Zhu Zuonong [Department of Mathematics, Shanghai Jiao Tong University, Shanghai, 200030 (China); Departamento de Matematicas, Universidad de Salamanca, Plaza de la Merced 1, 37008 Salamanca (Spain)

    2006-08-15

    In this article, by considering a 2 + 1 dimensional discrete non-isospectral linear problem, a new 2 + 1 dimensional integrable lattice hierarchy is constructed. It is shown that a generalization of the discrete second Painleve hierarchy can be obtained as a reduction. Other reductions include new 1 + 1 dimensional integrable lattice hierarchies.

  20. Neural basis of social status hierarchy across species.

    Science.gov (United States)

    Chiao, Joan Y

    2010-12-01

    Social status hierarchy is a ubiquitous principle of social organization across the animal kingdom. Recent findings in social neuroscience reveal distinct neural networks associated with the recognition and experience of social hierarchy in humans, as well as modulation of these networks by personality and culture. Additionally, allelic variation in the serotonin transporter gene is associated with prevalence of social hierarchy across species and cultures, suggesting the importance of the study of genetic factors underlying social hierarchy. Future studies are needed to determine how genetic and environmental factors shape neural systems involved in the production and maintenance of social hierarchy across ontogeny and phylogeny. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. An Imperative Type Hierarchy with Partial Products

    DEFF Research Database (Denmark)

    Schwartzbach, Michael Ignatieff; Schmidt, Erik Meineche

    1989-01-01

    notation for defining recursive types, that is superior to traditional type sums and products. We show how the ordering on types extends to an ordering on types with invariants. We allow the use of least upper bounds in type definitions and show how to compute upper bounds of invariants.......A type hierarchy for a programming language defines an ordering on the types such that any application for small types may be reused for all larger types. The imperative facet makes this non-trivial; the straight-forward definitions will yield an inconsistent system. We introduce a new type...... constructor, the partial product, and show how to define a consistent hierarchy in the context of fully recursive types. A simple polymorphism is derived by introducing a notion of placeholder types. By extending the partial product types to include structural invariants we obtain a particularly appropriate...

  2. Mass Hierarchy of Collisional Energy Loss

    CERN Document Server

    Kolevatov, Rodion

    2008-01-01

    Collisional parton energy loss is revisited within a simple model assuming incoherent elastic scattering of on-shell projectile partons on partonic constituents of the QGP with HTL screening. The thermal motion of plasma particles is carefully taken into account. Results on $dE/dx$ are found to be consistent with other authors. There is a significant discrepancy in the energy loss pattern for the cases with thermal motion on and off, which illustrates the importance of taking the kinematics into account exactly. The dependence on the mass of the partons forming the plasma is included in the calculations and its influence on the collisional energy loss is studied. The mass hierarchy of collisional energy loss is found to have a strong dependence on the mass introduced for plasma particles. Due to difference in the mass hierarchy with radiative energy loss, the collisional one when included increases the relative suppression of heavy quarks compared to light quarks.

  3. Size structures sensory hierarchy in ocean life

    DEFF Research Database (Denmark)

    Martens, Erik Andreas; Wadhwa, Navish; Jacobsen, Nis Sand

    2015-01-01

    the use of remote sensing. In this study, we explore how sensing mode and range depend on body size. We reveal a hierarchy of sensing modes (chemosensing, mechanosensing, vision, hearing, and echolocation) where body size determines the available battery of sensing modes and where larger body size means...... a longer sensing range. The size-dependent hierarchy and the transitions between primary sensory modes are explained on the grounds of limiting factors set by physiology and the physical laws governing signal generation, transmission and reception. We characterize the governing mechanisms and theoretically...... predict the body size limits for various sensory modes, which align very well with size ranges found in literature. The treatise of all ocean life, from unicellular organisms to whales, demonstrates how body size determines available sensing modes, and thereby acts as a major structuring factor of aquatic...

  4. Deep Hierarchies in the Primate Visual Cortex

    DEFF Research Database (Denmark)

    Krüger, Norbert; Jannsen, Per; Kalkan, S.

    2013-01-01

    Computational modeling of the primate visual system yields insights of potential relevance to some of the challenges that computer vision is facing, such as object recognition and categorization, motion detection and activity recognition or vision-based navigation and manipulation. This article...... reviews some functional principles and structures that are generally thought to underlie the primate visual cortex, and attempts to extract biological principles that could further advance computer vision research. Organized for a computer vision audience, we present functional principles...... of the processing hierarchies present in the primate visual system considering recent discoveries in neurophysiology. The hierarchal processing in the primate visual system is characterized by a sequence of different levels of processing (in the order of ten) that constitute a deep hierarchy in contrast to the flat...

  5. Hierarchy of Scales in Language Dynamics

    CERN Document Server

    Blythe, Richard A

    2015-01-01

    Methods and insights from statistical physics are finding an increasing variety of applications where one seeks to understand the emergent properties of a complex interacting system. One such area concerns the dynamics of language at a variety of levels of description, from the behaviour of individual agents learning simple artificial languages from each other, up to changes in the structure of languages shared by large groups of speakers over historical timescales. In this Colloquium, we survey a hierarchy of scales at which language and linguistic behaviour can be described, along with the main progress in understanding that has been made at each of them---much of which has come from the statistical physics community. We argue that future developments may arise by linking the different levels of the hierarchy together in a more coherent fashion, in particular where this allows more effective use of rich empirical data sets.

  6. Size structures sensory hierarchy in ocean life.

    Science.gov (United States)

    Martens, Erik A; Wadhwa, Navish; Jacobsen, Nis S; Lindemann, Christian; Andersen, Ken H; Visser, André

    2015-09-22

    Survival in aquatic environments requires organisms to have effective means of collecting information from their surroundings through various sensing strategies. In this study, we explore how sensing mode and range depend on body size. We find a hierarchy of sensing modes determined by body size. With increasing body size, a larger battery of modes becomes available (chemosensing, mechanosensing, vision, hearing and echolocation, in that order) while the sensing range also increases. This size-dependent hierarchy and the transitions between primary sensory modes are explained on the grounds of limiting factors set by physiology and the physical laws governing signal generation, transmission and reception. We theoretically predict the body size limits for various sensory modes, which align well with size ranges found in literature. The treatise of all ocean life, from unicellular organisms to whales, demonstrates how body size determines available sensing modes, and thereby acts as a major structuring factor of aquatic life. © 2015 The Author(s).

  7. Solving moment hierarchies for chemical reaction networks

    Science.gov (United States)

    Krishnamurthy, Supriya; Smith, Eric

    2017-10-01

    The study of chemical reaction networks (CRN’s) is a very active field. Earlier well-known results (Feinberg 1987 Chem. Enc. Sci. 42 2229, Anderson et al 2010 Bull. Math. Biol. 72 1947) identify a topological quantity called deficiency, for any CRN, which, when exactly equal to zero, leads to a unique factorized steady-state for these networks. No results exist however for the steady states of non-zero-deficiency networks. In this paper, we show how to write the full moment-hierarchy for any non-zero-deficiency CRN obeying mass-action kinetics, in terms of equations for the factorial moments. Using these, we can recursively predict values for lower moments from higher moments, reversing the procedure usually used to solve moment hierarchies. We show, for non-trivial examples, that in this manner we can predict any moment of interest, for CRN’s with non-zero deficiency and non-factorizable steady states.

  8. Feminist Praxis, Critical Theory and Informal Hierarchies

    Directory of Open Access Journals (Sweden)

    Eva Giraud

    2015-05-01

    Full Text Available This article draws on my experiences teaching across two undergraduate media modules in a UK research-intensive institution to explore tactics for combatting both institutional and informal hierarchies within university teaching contexts. Building on Sara Motta’s (2012 exploration of implementing critical pedagogic principles at postgraduate level in an elite university context, I discuss additional tactics for combatting these hierarchies in undergraduate settings, which were developed by transferring insights derived from informal workshops led by the University of Nottingham’s Feminism and Teaching network into the classroom. This discussion is framed in relation to the concepts of “cyborg pedagogies” and “political semiotics of articulation,” derived from the work of Donna Haraway, in order to theorize how these tactics can engender productive relationships between radical pedagogies and critical theory.

  9. Homology and the hierarchy of biological systems.

    Science.gov (United States)

    Sommer, Ralf J

    2008-07-01

    Homology is the similarity between organisms due to common ancestry. Introduced by Richard Owen in 1843 in a paper entitled "Lectures on comparative anatomy and physiology of the invertebrate animals", the concept of homology predates Darwin's "Origin of Species" and has been very influential throughout the history of evolutionary biology. Although homology is the central concept of all comparative biology and provides a logical basis for it, the definition of the term and the criteria of its application remain controversial. Here, I will discuss homology in the context of the hierarchy of biological organization. I will provide insights gained from an exemplary case study in evolutionary developmental biology that indicates the uncoupling of homology at different levels of biological organization. I argue that continuity and hierarchy are separate but equally important issues of homology. (c) 2008 Wiley Periodicals, Inc.

  10. Hamiltonian hierarchy and the Hulthen potential

    CERN Document Server

    Gönül, B

    2000-01-01

    We deal with the Hamiltonian hierarchy problem of the Hulth\\'{e}n potential within the frame of the supersymmetric quantum mechanics and find that the associated superymmetric partner potentials simulate the effect of the centrifugal barrier. Incorporating the supersymmetric solutions and using the first-order perturbation theory we obtain an expression for the energy levels of theHulth\\'{e}n potential which gives satisfactory values for the non-zero angular momentum states.

  11. Context-dependent hierarchies in pigeons.

    Science.gov (United States)

    Nagy, Máté; Vásárhelyi, Gábor; Pettit, Benjamin; Roberts-Mariani, Isabella; Vicsek, Tamás; Biro, Dora

    2013-08-06

    Hierarchical organization is widespread in the societies of humans and other animals, both in social structure and in decision-making contexts. In the case of collective motion, the majority of case studies report that dominant individuals lead group movements, in agreement with the common conflation of the terms "dominance" and "leadership." From a theoretical perspective, if social relationships influence interactions during collective motion, then social structure could also affect leadership in large, swarm-like groups, such as fish shoals and bird flocks. Here we use computer-vision-based methods and miniature GPS tracking to study, respectively, social dominance and in-flight leader-follower relations in pigeons. In both types of behavior we find hierarchically structured networks of directed interactions. However, instead of being conflated, dominance and leadership hierarchies are completely independent of each other. Although dominance is an important aspect of variation among pigeons, correlated with aggression and access to food, our results imply that the stable leadership hierarchies in the air must be based on a different set of individual competences. In addition to confirming the existence of independent and context-specific hierarchies in pigeons, we succeed in setting out a robust, scalable method for the automated analysis of dominance relationships, and thus of social structure, applicable to many species. Our results, as well as our methods, will help to incorporate the broader context of animal social organization into the study of collective behavior.

  12. Do Convolutional Neural Networks Learn Class Hierarchy?

    Science.gov (United States)

    Alsallakh, Bilal; Jourabloo, Amin; Ye, Mao; Liu, Xiaoming; Ren, Liu

    2017-08-29

    Convolutional Neural Networks (CNNs) currently achieve state-of-the-art accuracy in image classification. With a growing number of classes, the accuracy usually drops as the possibilities of confusion increase. Interestingly, the class confusion patterns follow a hierarchical structure over the classes. We present visual-analytics methods to reveal and analyze this hierarchy of similar classes in relation with CNN-internal data. We found that this hierarchy not only dictates the confusion patterns between the classes, it furthermore dictates the learning behavior of CNNs. In particular, the early layers in these networks develop feature detectors that can separate high-level groups of classes quite well, even after a few training epochs. In contrast, the latter layers require substantially more epochs to develop specialized feature detectors that can separate individual classes. We demonstrate how these insights are key to significant improvement in accuracy by designing hierarchy-aware CNNs that accelerate model convergence and alleviate overfitting. We further demonstrate how our methods help in identifying various quality issues in the training data.

  13. Cortical myoclonus and cerebellar pathology

    NARCIS (Netherlands)

    Tijssen, MAJ; Thom, M; Ellison, DW; Wilkins, P; Barnes, D; Thompson, PD; Brown, P

    2000-01-01

    Objective To study the electrophysiologic and pathologic findings in three patients with cortical myoclonus. In two patients the myoclonic ataxic syndrome was associated with proven celiac disease. Background: The pathologic findings in conditions associated with cortical myoclonus commonly involve

  14. Cortical Abnormalities in ADHD

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2003-12-01

    Full Text Available Grey-matter abnormalities at the cortical surface and regional brain size were mapped by high-resolution MRI and surface-based, computational image analytical techniques in a group of 27 children and adolescents with attention deficit hyperactivity disorder (ADHD and 46 controls, matched by age and sex, at the University of California at Los Angeles.

  15. Changing meaning causes coupling changes within higher levels of the cortical hierarchy.

    Science.gov (United States)

    Schofield, T M; Iverson, P; Kiebel, S J; Stephan, K E; Kilner, J M; Friston, K J; Crinion, J T; Price, C J; Leff, A P

    2009-07-14

    Processing of speech and nonspeech sounds occurs bilaterally within primary auditory cortex and surrounding regions of the superior temporal gyrus; however, the manner in which these regions interact during speech and nonspeech processing is not well understood. Here, we investigate the underlying neuronal architecture of the auditory system with magnetoencephalography and a mismatch paradigm. We used a spoken word as a repeating "standard" and periodically introduced 3 "oddball" stimuli that differed in the frequency spectrum of the word's vowel. The closest deviant was perceived as the same vowel as the standard, whereas the other 2 deviants were perceived as belonging to different vowel categories. The neuronal responses to these vowel stimuli were compared with responses elicited by perceptually matched tone stimuli under the same paradigm. For both speech and tones, deviant stimuli induced coupling changes within the same bilateral temporal lobe system. However, vowel oddball effects increased coupling within the left posterior superior temporal gyrus, whereas perceptually equivalent nonspeech oddball effects increased coupling within the right primary auditory cortex. Thus, we show a dissociation in neuronal interactions, occurring at both different hierarchal levels of the auditory system (superior temporal versus primary auditory cortex) and in different hemispheres (left versus right). This hierarchical specificity depends on whether auditory stimuli are embedded in a perceptual context (i.e., a word). Furthermore, our lateralization results suggest left hemisphere specificity for the processing of phonological stimuli, regardless of their elemental (i.e., spectrotemporal) characteristics.

  16. A mechanism for the cortical computation of hierarchical linguistic structure

    Science.gov (United States)

    Doumas, Leonidas A. A.

    2017-01-01

    Biological systems often detect species-specific signals in the environment. In humans, speech and language are species-specific signals of fundamental biological importance. To detect the linguistic signal, human brains must form hierarchical representations from a sequence of perceptual inputs distributed in time. What mechanism underlies this ability? One hypothesis is that the brain repurposed an available neurobiological mechanism when hierarchical linguistic representation became an efficient solution to a computational problem posed to the organism. Under such an account, a single mechanism must have the capacity to perform multiple, functionally related computations, e.g., detect the linguistic signal and perform other cognitive functions, while, ideally, oscillating like the human brain. We show that a computational model of analogy, built for an entirely different purpose—learning relational reasoning—processes sentences, represents their meaning, and, crucially, exhibits oscillatory activation patterns resembling cortical signals elicited by the same stimuli. Such redundancy in the cortical and machine signals is indicative of formal and mechanistic alignment between representational structure building and “cortical” oscillations. By inductive inference, this synergy suggests that the cortical signal reflects structure generation, just as the machine signal does. A single mechanism—using time to encode information across a layered network—generates the kind of (de)compositional representational hierarchy that is crucial for human language and offers a mechanistic linking hypothesis between linguistic representation and cortical computation. PMID:28253256

  17. Static multiresolution grids with inline hierarchy information for cosmic ray propagation

    Science.gov (United States)

    Müller, Gero

    2016-08-01

    For numerical simulations of cosmic-ray propagation fast access to static magnetic field data is required. We present a data structure for multiresolution vector grids which is optimized for fast access, low overhead and shared memory use. The hierarchy information is encoded into the grid itself, reducing the memory overhead. Benchmarks show that in certain scenarios the differences in deflections introduced by sampling the magnetic field model can be significantly reduced when using the multiresolution approach.

  18. Hierarchy, Dominance, and Deliberation: Egalitarian Values Require Mental Effort.

    Science.gov (United States)

    Van Berkel, Laura; Crandall, Christian S; Eidelman, Scott; Blanchar, John C

    2015-09-01

    Hierarchy and dominance are ubiquitous. Because social hierarchy is early learned and highly rehearsed, the value of hierarchy enjoys relative ease over competing egalitarian values. In six studies, we interfere with deliberate thinking and measure endorsement of hierarchy and egalitarianism. In Study 1, bar patrons' blood alcohol content was correlated with hierarchy preference. In Study 2, cognitive load increased the authority/hierarchy moral foundation. In Study 3, low-effort thought instructions increased hierarchy endorsement and reduced equality endorsement. In Study 4, ego depletion increased hierarchy endorsement and caused a trend toward reduced equality endorsement. In Study 5, low-effort thought instructions increased endorsement of hierarchical attitudes among those with a sense of low personal power. In Study 6, participants' thinking quickly allocated more resources to high-status groups. Across five operationalizations of impaired deliberative thought, hierarchy endorsement increased and egalitarianism receded. These data suggest hierarchy may persist in part because it has a psychological advantage. © 2015 by the Society for Personality and Social Psychology, Inc.

  19. BACH:A Bandwidth-Aware Hybrid Cache Hierarchy Design with Nonvolatile Memories

    Institute of Scientific and Technical Information of China (English)

    Jishen Zhao; Cong Xu; Tao Zhang; Yuan Xie

    2016-01-01

    Limited main memory bandwidth is becoming a fundamental performance bottleneck in chip-multiprocessor (CMP) design. Yet directly increasing the peak memory bandwidth can incur high cost and power consump-tion. In this paper, we address this problem by proposing a memory, a bandwidth-aware reconfigurable cache hierarchy, BACH, with hybrid memory technologies. Components of our BACH design include a hybrid cache hierarchy, a reconfigura-tion mechanism, and a statistical prediction engine. Our hybrid cache hierarchy chooses different memory technologies with various bandwidth characteristics, such as spin-transfer torque memory (STT-MRAM), resistive memory (ReRAM), and embedded DRAM (eDRAM), to configure each level so that the peak bandwidth of the overall cache hierarchy is optimized. Our reconfiguration mechanism can dynamically adjust the cache capacity of each level based on the predicted bandwidth demands of running workloads. The bandwidth prediction is performed by our prediction engine. We evaluate the system performance gain obtained by BACH design with a set of multithreaded and multiprogrammed workloads with and without the limitation of system power budget. Compared with traditional SRAM-based cache design, BACH improves the system throughput by 58%and 14%with multithreaded and multiprogrammed workloads respectively.

  20. Experimental conditions for determination of the neutrino mass hierarchy with reactor antineutrinos

    Science.gov (United States)

    Pac, Myoung Youl

    2016-01-01

    This article reports the optimized experimental requirements to determine neutrino mass hierarchy using electron antineutrinos (νbare) generated in a nuclear reactor. The features of the neutrino mass hierarchy can be extracted from the | Δ m312 | and | Δ m322 | oscillations by applying the Fourier sine and cosine transforms to the L / E spectrum. To determine the neutrino mass hierarchy above 90% probability, the requirements on the energy resolution as a function of the baseline are studied at sin2 ⁡ 2θ13 = 0.1. If the energy resolution of the neutrino detector is less than 0.04 /√{Eν} and the determination probability obtained from Bayes' theorem is above 90%, the detector needs to be located around 48-53 km from the reactor(s) to measure the energy spectrum of νbare. These results will be helpful for setting up an experiment to determine the neutrino mass hierarchy, which is an important problem in neutrino physics.

  1. Memory-Scalable GPU Spatial Hierarchy Construction.

    Science.gov (United States)

    Qiming Hou; Xin Sun; Kun Zhou; Lauterbach, C; Manocha, D

    2011-04-01

    Recent GPU algorithms for constructing spatial hierarchies have achieved promising performance for moderately complex models by using the breadth-first search (BFS) construction order. While being able to exploit the massive parallelism on the GPU, the BFS order also consumes excessive GPU memory, which becomes a serious issue for interactive applications involving very complex models with more than a few million triangles. In this paper, we propose to use the partial breadth-first search (PBFS) construction order to control memory consumption while maximizing performance. We apply the PBFS order to two hierarchy construction algorithms. The first algorithm is for kd-trees that automatically balances between the level of parallelism and intermediate memory usage. With PBFS, peak memory consumption during construction can be efficiently controlled without costly CPU-GPU data transfer. We also develop memory allocation strategies to effectively limit memory fragmentation. The resulting algorithm scales well with GPU memory and constructs kd-trees of models with millions of triangles at interactive rates on GPUs with 1 GB memory. Compared with existing algorithms, our algorithm is an order of magnitude more scalable for a given GPU memory bound. The second algorithm is for out-of-core bounding volume hierarchy (BVH) construction for very large scenes based on the PBFS construction order. At each iteration, all constructed nodes are dumped to the CPU memory, and the GPU memory is freed for the next iteration's use. In this way, the algorithm is able to build trees that are too large to be stored in the GPU memory. Experiments show that our algorithm can construct BVHs for scenes with up to 20 M triangles, several times larger than previous GPU algorithms.

  2. Vanishing point: Scale independence in geomorphological hierarchies

    Science.gov (United States)

    Phillips, Jonathan D.

    2016-08-01

    Scale linkage problems in geosciences are often associated with a hierarchy of components. Both dynamical systems perspectives and intuition suggest that processes or relationships operating at fundamentally different scales are independent with respect to influences on system dynamics. But how far apart is "fundamentally different"-that is, what is the "vanishing point" at which scales are no longer interdependent? And how do we reconcile that with the idea (again, supported by both theory and intuition) that we can work our way along scale hierarchies from microscale to planetary (and vice-versa)? Graph and network theory are employed here to address these questions. Analysis of two archetypal hierarchical networks shows low algebraic connectivity, indicating low levels of inferential synchronization. This explains the apparent paradox between scale independence and hierarchical linkages. Incorporating more hierarchical levels results in an increase in complexity or entropy of the network as a whole, but at a nonlinear rate. Complexity increases as a power α of the number of levels in the hierarchy, with α < 1 and usually ≤ 0.6. However, algebraic connectivity decreases at a more rapid rate. Thus, the ability to infer one part of the hierarchical network from other level decays rapidly as more levels are added. Relatedness among system components decreases with differences in scale or resolution, analogous to distance decay in the spatial domain. These findings suggest a strategy of identifying and focusing on the most important or interesting scale levels, rather than attempting to identify the smallest or largest scale levels and work top-down or bottom-up from there. Examples are given from soil geomorphology and karst flow networks.

  3. K-shell decomposition reveals hierarchical cortical organization of the human brain

    Science.gov (United States)

    Lahav, Nir; Ksherim, Baruch; Ben-Simon, Eti; Maron-Katz, Adi; Cohen, Reuven; Havlin, Shlomo

    2016-08-01

    In recent years numerous attempts to understand the human brain were undertaken from a network point of view. A network framework takes into account the relationships between the different parts of the system and enables to examine how global and complex functions might emerge from network topology. Previous work revealed that the human brain features ‘small world’ characteristics and that cortical hubs tend to interconnect among themselves. However, in order to fully understand the topological structure of hubs, and how their profile reflect the brain’s global functional organization, one needs to go beyond the properties of a specific hub and examine the various structural layers that make up the network. To address this topic further, we applied an analysis known in statistical physics and network theory as k-shell decomposition analysis. The analysis was applied on a human cortical network, derived from MRI\\DSI data of six participants. Such analysis enables us to portray a detailed account of cortical connectivity focusing on different neighborhoods of inter-connected layers across the cortex. Our findings reveal that the human cortex is highly connected and efficient, and unlike the internet network contains no isolated nodes. The cortical network is comprised of a nucleus alongside shells of increasing connectivity that formed one connected giant component, revealing the human brain’s global functional organization. All these components were further categorized into three hierarchies in accordance with their connectivity profile, with each hierarchy reflecting different functional roles. Such a model may explain an efficient flow of information from the lowest hierarchy to the highest one, with each step enabling increased data integration. At the top, the highest hierarchy (the nucleus) serves as a global interconnected collective and demonstrates high correlation with consciousness related regions, suggesting that the nucleus might serve as a

  4. White Paper: Measuring the Neutrino Mass Hierarchy

    CERN Document Server

    Cahn, R N; Freedman, S J; Haxton, W C; Kadel, R W; Kolomensky, Yu G; Luk, K B; McDonald, P; Gann, G D Orebi; Poon, A W P

    2013-01-01

    This white paper is a condensation of a report by a committee appointed jointly by the Nuclear Science and Physics Divisions at Lawrence Berkeley National Laboratory (LBNL). The goal of this study was to identify the most promising technique(s) for resolving the neutrino mass hierarchy. For the most part, we have relied on calculations and simulations presented by the proponents of the various experiments. We have included evaluations of the opportunities and challenges for these experiments based on what is available already in the literature.

  5. Mixed superposition rules and the Riccati hierarchy

    Science.gov (United States)

    Grabowski, Janusz; de Lucas, Javier

    Mixed superposition rules, i.e., functions describing the general solution of a system of first-order differential equations in terms of a generic family of particular solutions of first-order systems and some constants, are studied. The main achievement is a generalization of the celebrated Lie-Scheffers Theorem, characterizing systems admitting a mixed superposition rule. This somehow unexpected result says that such systems are exactly Lie systems, i.e., they admit a standard superposition rule. This provides a new and powerful tool for finding Lie systems, which is applied here to studying the Riccati hierarchy and to retrieving some known results in a more efficient and simpler way.

  6. Mixed superposition rules and the Riccati hierarchy

    CERN Document Server

    Grabowski, Janusz

    2012-01-01

    Mixed superposition rules, i.e., functions describing the general solution of a system of first-order differential equations in terms of a generic family of particular solutions of first-order systems and some constants, are studied. The main achievement is a generalization of the celebrated Lie-Scheffers Theorem, characterizing systems admitting a mixed superposition rule. This somehow unexpected result says that such systems are exactly Lie systems, i.e., they admit a standard superposition rule. This provides a new and powerful tool for finding Lie systems, which is applied here to studying the Riccati hierarchy and to retrieving some known results in a more efficient and simpler way.

  7. Cascade Hierarchy in SUSY SU(5) GUT

    CERN Document Server

    Kojima, Kentaro; Takahashi, Ryo

    2010-01-01

    We study cascade hierarchy in supersymmetric SU(5) grand unified theory. The neutrino Dirac mass matrix of the cascade form can lead to the tri-bimaximal generation mixing at the leading order in the seesaw mechanism while the down quark mass matrix of a hybrid cascade form naturally gives the CKM structure. We embed such experimentally favored mass textures into supersymmetric SU(5) GUT, which gives a relation between the down quark and charged lepton mass matrices. Related phenomenologies, such as lepton flavor violating processes and leptogenesis, are also investigated in addition to lepton mixing angles.

  8. Three New Integrable Hierarchies of Equations

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A general Lie algebra Vs and the corresponding loop algebra ~Vs are constructed, from which the linear isospectral Lax pairs are established, whose compatibility presents the zero curvature equation. As its application, a new Lax integrable hierarchy containing two parameters is worked out. It is not Liouville-integrable, however, its two reduced systems are Liouville-integrable, whose Hamiltonian structures are derived by making use of the quadratic-form identity and the γ formula (i.e. the computational formula on the constant γ appeared in the trace identity and the quadratic-form identity).

  9. Attention to color sharpens neural population tuning via feedback processing in the human visual cortex hierarchy.

    Science.gov (United States)

    Bartsch, Mandy V; Loewe, Kristian; Merkel, Christian; Heinze, Hans-Jochen; Schoenfeld, Mircea A; Tsotsos, John K; Hopf, Jens-Max

    2017-09-25

    Attention can facilitate the selection of elementary object features like color, orientation, or motion. This is referred to as feature-based attention and commonly attributed to a modulation of the gain and tuning of feature-selective units in visual cortex. While gain mechanisms are well characterized, little is known about the cortical processes underlying the sharpening of feature selectivity. Here, we show with high-resolution magnetoencephalography in human observers (men and women) that sharpened selectivity for a particular color arises from feedback processing in the human visual cortex hierarchy. To assess color selectivity, we analyze the response to a color probe that varies in color-distance from an attended color target. We find that attention causes an initial gain enhancement in anterior ventral extrastriate cortex that is coarsely selective for the target color and transitions within ∼100 ms into a sharper tuned profile in more posterior ventral occipital cortex (VO-1/hV4). We conclude that attention sharpens selectivity over time by attenuating the response at lower levels of the cortical hierarchy to color values neighboring the target in color space. These observations support computational models proposing that attention tunes feature selectivity in visual cortex through backward-propagating attenuation of units less tuned to the target.SIGNIFICANCE STATEMENTWhether searching for your car, a particular item of clothing, or just obeying traffic lights, in everyday life we must select items based on color. But how does attention allow us to select a specific color? Here, we use high spatiotemporal resolution neuromagnetic recordings to examine how color selectivity emerges in the human brain. We find that color selectivity evolves as a coarse-to-fine process from higher to lower levels within the visual cortex hierarchy. Our observations support computational models proposing that feature selectivity increases over time, by attenuating the

  10. The Hierarchy Solution to the LHC Inverse Problem

    CERN Document Server

    Gainer, James S; Park, Myeonghun

    2015-01-01

    Supersymmetric (SUSY) models, even those described by relatively few parameters, generically allow many possible SUSY particle (sparticle) mass hierarchies. As the sparticle mass hierarchy determines, to a great extent, the collider phenomenology of a model, the enumeration of these hierarchies is of the utmost importance. We therefore provide a readily generalizable procedure for determining the number of sparticle mass hierarchies in a given SUSY model. As an application, we analyze the gravity-mediated SUSY breaking scenario with various combinations of GUT-scale boundary conditions involving different levels of universality among the gaugino and scalar masses. For each of the eight considered models, we provide the complete list of forbidden hierarchies in a compact form. Our main result is that the complete (typically rather large) set of forbidden hierarchies among the eight sparticles considered in this analysis can be fully specified by just a few forbidden relations involving much smaller subsets of ...

  11. The hierarchy solution to the LHC inverse problem

    Science.gov (United States)

    Gainer, James S.; Matchev, Konstantin T.; Park, Myeonghun

    2015-06-01

    Supersymmetric (SUSY) models, even those described by relatively few parameters, generically allow many possible SUSY particle (sparticle) mass hierarchies. As the sparticle mass hierarchy determines, to a great extent, the collider phenomenology of a model, the enumeration of these hierarchies is of the utmost importance. We therefore provide a readily generalizable procedure for determining the number of sparticle mass hierarchies in a given SUSY model. As an application, we analyze the gravity-mediated SUSY breaking scenario with various combinations of GUT-scale boundary conditions involving different levels of universality among the gaugino and scalar masses. For each of the eight considered models, we provide the complete list of forbidden hierarchies in a compact form. Our main result is that the complete (typically rather large) set of forbidden hierarchies among the eight sparticles considered in this analysis can be fully specified by just a few forbidden relations involving much smaller subsets of sparticles.

  12. Public Management and the Metagovernance of Hierarchies, Networks and Markets: The feasibility of designing and managing governance style combinations

    NARCIS (Netherlands)

    A.A.M. Meuleman (Louis)

    2008-01-01

    textabstractWhat is modern governance? Is it the battle against "oldfashioned" hierarchy, or is it the restoration of key hierarchical values? Is it optimizing network management, or maximizing the benefits of market thinking in the publicsector? This book argues that it is the combination of all

  13. The Impact of Formal Hierarchies on Enterprise Social Networking Behavior

    DEFF Research Database (Denmark)

    Behrendt, Sebastian; Klier, Julia; Klier, Mathias

    2015-01-01

    With more and more companies using enterprise social networks (ESN) for employee communication and collaboration, the influence of ESN on organizational hierarchies has been subject of countless discussions in practice-oriented media and first academic studies. Conversely, the question whether...... impact on social networking behavior. By applying means of social network analysis and supported by statements from interviews, we illustrate how deeply formal hierarchy impacts the three examined types of relationships. Our results motivate academics to further study the interrelation between hierarchy...

  14. Hamiltonian and Godunov Structures of the Grad Hierarchy

    CERN Document Server

    Grmela, Miroslav; Jou, David; Lebon, Georgy; Pavelka, Michal

    2016-01-01

    The time evolution governed by the Boltzmann kinetic equation is compatible with mechanics and thermodynamics. The former compatibility is mathematically expressed in the Hamiltonian and Godunov structures, the latter in the structure of gradient dynamics guaranteeing the growth of entropy and consequently the approach to equilibrium. We carry all three structures to the Grad reformulation of the Boltzmann equation (to the Grad hierarchy). First, we recognize the structures in the infinite Grad hierarchy and then in several examples of finite hierarchies representing extended hydrodynamic equations. In the context of Grad's hierarchies we also investigate relations between Hamiltonian and Godunov structures.

  15. The Impact of Formal Hierarchies on Enterprise Social Networking Behavior

    DEFF Research Database (Denmark)

    Behrendt, Sebastian; Klier, Julia; Klier, Mathias;

    2015-01-01

    and how formal organizational hierarchies influence ESN usage behavior has not yet been addressed. Drawing on a rich data set comprising 2.5 years of relationship building via direct messages, confirmed contact requests, and group messages, we are able to show that formal hierarchies have an important...... impact on social networking behavior. By applying means of social network analysis and supported by statements from interviews, we illustrate how deeply formal hierarchy impacts the three examined types of relationships. Our results motivate academics to further study the interrelation between hierarchy...

  16. Correlating Dimensions of Inheritance Hierarchy with Complexity & Reuse

    Directory of Open Access Journals (Sweden)

    Nasib S. Gill

    2011-09-01

    Full Text Available Inheritance is the vital feature of any object oriented software which provides reuse of exiting classes for designing new classes. Higher reuse provides higher productivity and greater quality.Inheritance hierarchy is one of the very important artifacts targeted for measurement of reuse and reusability. Reuse through inheritance hierarchy can be measured from two dimensions- Depth and Breadth. Higher depth and breadth may increase complexity of software which makes the software difficult to understand and maintain. This paper aimed to correlate the depth and breadth of inheritance hierarchy with reuse and complexity of inheritance hierarchy using design oriented metrics.

  17. When Do Types Induce the Same Belief Hierarchy?

    Directory of Open Access Journals (Sweden)

    Andrés Perea

    2016-10-01

    Full Text Available Type structures are a simple device to describe higher-order beliefs. However, how can we check whether two types generate the same belief hierarchy? This paper generalizes the concept of a type morphism and shows that one type structure is contained in another if and only if the former can be mapped into the other using a generalized type morphism. Hence, every generalized type morphism is a hierarchy morphism and vice versa. Importantly, generalized type morphisms do not make reference to belief hierarchies. We use our results to characterize the conditions under which types generate the same belief hierarchy.

  18. An extended integrable fractional-order KP soliton hierarchy

    Energy Technology Data Exchange (ETDEWEB)

    Li Li, E-mail: li07099@163.co [College of Maths and Systematic Science, Shenyang Normal University, Shenyang 110034 (China)

    2011-01-17

    In this Letter, we consider the modified derivatives and integrals of fractional-order pseudo-differential operators. A sequence of Lax KP equations hierarchy and extended fractional KP (fKP) hierarchy are introduced, and the fKP hierarchy has Lax presentations with the extended Lax operators. In the case of the extension with the half-order pseudo-differential operators, a new integrable fKP hierarchy is obtained. A few particular examples of fractional order will be listed, together with their Lax pairs.

  19. The analytic hierarchy process as a support for decision making

    Directory of Open Access Journals (Sweden)

    Filipović Milanka

    2007-01-01

    Full Text Available The first part of this text deals with a convention site selection as one of the most lucrative areas in the tourism industry. The second part gives a further description of a method for decision making - the analytic hierarchy process. The basic characteristics: hierarchy constructions and pair wise comparison on the given level of the hierarchy are allured. The third part offers an example of application. This example is solved using the Super - Decision software, which is developed as a computer support for the analytic hierarchy process. This indicates that the AHP approach is a useful tool to help support a decision of convention site selection. .

  20. Purely Cortical Anaplastic Ependymoma

    Directory of Open Access Journals (Sweden)

    Flávio Ramalho Romero

    2012-01-01

    Full Text Available Ependymomas are glial tumors derived from ependymal cells lining the ventricles and the central canal of the spinal cord. It may occur outside the ventricular structures, representing the extraventicular form, or without any relationship of ventricular system, called ectopic ependymona. Less than fifteen cases of ectopic ependymomas were reported and less than five were anaplastic. We report a rare case of pure cortical ectopic anaplastic ependymoma.

  1. Gravitational inflaton decay and the hierarchy problem

    CERN Document Server

    Watanabe, Yuki

    2007-01-01

    We study implications of the large-N species solution to the hierarchy problem, proposed by G. Dvali, for reheating of the universe after inflation. Dvali's proposal contains additional N~10^{32} Z_2-conserved quantum fields beyond the Standard Model particles with mass ~1 TeV, which weaken gravity by a factor of 1/N, and thus explain the hierarchy between the Plank scale and the electroweak scale. We show that, in this scenario, the decay rates of inflaton fields through gravitational decay channels are enhanced by a factor of N, and thus they decay into N species of the quantum fields very efficiently, in the limit that quantum gravity effects are unimportant for the gravitational decay rate. In order not to over-reheat the universe, inflaton mass, vacuum expectation value of inflaton, or non-minimal gravitational coupling should be tightly fine-tuned. Our conclusion holds even when the gravitational decay is prohibited by some symmetry of the theory; the universe may still be over-reheated via annihilation...

  2. Instability-induced hierarchy in bipedal locomotion

    Science.gov (United States)

    Ohgane, Kunishige; Ueda, Kei-Ichi

    2008-05-01

    One of the important features of human locomotion is its instant adaptability to various unpredictable changes of physical and environmental conditions. This property is known as flexibility. Modeling the bipedal locomotion system, we show that initial-state coordination by a global variable which encodes the attractor basins of the system can yield flexibility. This model is based on the following hypotheses: (i) the walking velocity is a global variable, and (ii) the leg posture at the beginning of the stance phase is the initial state of the gait. Moreover, we confirm these hypotheses. We investigate the regions near the neutral states between walking and falling phases using numerical experiments and demonstrate that global variables can be defined as the dominant unstable directions of the system dynamics near the neutral states. We propose the concept of an “instability-induced hierarchy.” In this hierarchy, global variables govern other variables near neutral states; i.e., they become elements of a higher level.

  3. [Posterior cortical atrophy].

    Science.gov (United States)

    Solyga, Volker Moræus; Western, Elin; Solheim, Hanne; Hassel, Bjørnar; Kerty, Emilia

    2015-06-02

    Posterior cortical atrophy is a neurodegenerative condition with atrophy of posterior parts of the cerebral cortex, including the visual cortex and parts of the parietal and temporal cortices. It presents early, in the 50s or 60s, with nonspecific visual disturbances that are often misinterpreted as ophthalmological, which can delay the diagnosis. The purpose of this article is to present current knowledge about symptoms, diagnostics and treatment of this condition. The review is based on a selection of relevant articles in PubMed and on the authors' own experience with the patient group. Posterior cortical atrophy causes gradually increasing impairment in reading, distance judgement, and the ability to perceive complex images. Examination of higher visual functions, neuropsychological testing, and neuroimaging contribute to diagnosis. In the early stages, patients do not have problems with memory or insight, but cognitive impairment and dementia can develop. It is unclear whether the condition is a variant of Alzheimer's disease, or whether it is a separate disease entity. There is no established treatment, but practical measures such as the aid of social care workers, telephones with large keypads, computers with voice recognition software and audiobooks can be useful. Currently available treatment has very limited effect on the disease itself. Nevertheless it is important to identify and diagnose the condition in its early stages in order to be able to offer patients practical assistance in their daily lives.

  4. Retribution as hierarchy regulation: Hierarchy preferences moderate the effect of offender socioeconomic status on support for retribution.

    Science.gov (United States)

    Redford, Liz; Ratliff, Kate A

    2017-09-17

    People punish others for various reasons, including deterring future crime, incapacitating the offender, and retribution, or payback. The current research focuses on retribution, testing whether support for retribution is motivated by the desire to maintain social hierarchies. If so, then the retributive tendencies of hierarchy enhancers or hierarchy attenuators should depend on whether offenders are relatively lower or higher in status, respectively. Three studies showed that hierarchy attenuators were more retributive against high-status offenders than for low-status offenders, that hierarchy enhancers showed a stronger orientation towards retributive justice, and that relationship was stronger for low-status, rather than high-status, criminal offenders. These findings clarify the purpose and function of retributive punishment. They also reveal how hierarchy-regulating motives underlie retribution, motives which, if allowed to influence judgements, may contribute to biased or ineffective justice systems. © 2017 The British Psychological Society.

  5. ON GAUGE EQUIVALENT INTEGRABLE SYSTEMS AND r-MATRICES FOR AKNS HIERARCHY AND A COUPLED MKdV HIERARCHY

    Institute of Scientific and Technical Information of China (English)

    刘响林; 陈庆辉; 张保才

    2003-01-01

    The new coupled MKdV hierarchy is obtained. By using gauge transformation,the corns trained flow, the integrable system and Lax representation for the coupled MKdVhierarchy were first corstructed from the AKNS hierarchy and then using the Laxrepresentation, the r-matrix for the constrained flow of the coupled MKdV hierarchy wasconstructed. The second set of conserved integrals of this constrained flow and theirinvolutivity were also given.

  6. Hazardous Waste Landfill Siting using GIS Technique and Analytical Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Ozeair Abessi

    2010-07-01

    Full Text Available Disposal of large amount of generated hazardous waste in power plants, has always received communities' and authori¬ties attentions. In this paper using site screening method and Analytical Hierarchy Process (AHP a sophisticated approach for siting hazardous waste landfill in large areas is presented. This approach demonstrates how the evaluation criteria such as physical, socio-economical, technical, environmental and their regulatory sub criteria can be introduced into an over layer technique to screen some limited appropriate zones in the area. Then, in order to find the optimal site amongst the primary screened site utilizing a Multiple Criteria Decision Making (MCDM method for hierarchy computations of the process is recommended. Using the introduced method an accurate siting procedure for environmental planning of the landfills in an area would be enabled. In the study this approach was utilized for disposal of hazardous wastes of Shahid Rajaee thermal power plant located in Qazvin province west central part of Iran. As a result of this study 10 suitable zones were screened in the area at first, then using analytical hierarchy process a site near the power plant were chosen as the optimal site for landfilling of the hazardous wastes in Qazvin province.

  7. Control and amplification of cortical neurodynamics

    Science.gov (United States)

    Liljenstroem, Hans; Aronsson, P.

    1999-03-01

    We investigate different mechanisms for the control and amplification of cortical neurodynamics, using a neural network model of a three layered cortical structure. We show that different dynamical states can be obtained by changing a control parameter of the input-output relation, or by changing the noise level. Point attractor, limit cycle, and strange attractor dynamics occur at different values of the control parameter. For certain, optimal noise levels, system performance is maximized, analogous to stochastic resonance phenomena. Noise can also be used to induce different dynamical states. A few noisy network units distributed in a network layer can result in global synchronous oscillations, or waves of activity moving across the network. We further demonstrate that fast synchronization of network activity can be obtained by implementing electromagnetic interactions between network units.

  8. A numerical evaluation of the bounded degree sum-of-squares hierarchy of Lasserre, Toh, and Yang on the pooling problem

    NARCIS (Netherlands)

    Marandi, Ahmadreza; Dahl, Joachim; de Klerk, Etienne

    2016-01-01

    The bounded degree sum-of-squares (BSOS) hierarchy of Lasserre, Toh, and Yang [EURO J. Comput. Optim., 2015] constructs lower bounds for a general polynomial optimization problem with compact feasible set, by solving a sequence of semi-definite programming (SDP) problems. Lasserre, Toh, and Yang pro

  9. A numerical evaluation of the bounded degree sum-of-squares hierarchy of Lasserre, Toh, and Yang on the pooling problem

    NARCIS (Netherlands)

    Marandi, Ahmadreza; Dahl, Joachim; de Klerk, Etienne

    2017-01-01

    The bounded degree sum-of-squares (BSOS) hierarchy of Lasserre, Toh, and Yang [EURO J. Comput. Optim., 2015] constructs lower bounds for a general polynomial optimization problem with compact feasible set, by solving a sequence of semi-definite programming (SDP) problems. Lasserre, Toh, and Yang pro

  10. Optimizing Real-Time Performance of 3D Virtual Mining Environment with MultiGen Creator

    Institute of Scientific and Technical Information of China (English)

    WANGWei-chen; JIANGXiao-hong; HANKe-qi; HANWen-ji

    2004-01-01

    System optimization plays a crucial role in developing VR system after 3D modeling, affecting the system's Immersion and Interaction performance enormously. In this article, several key techniques of optimizing a virtual mining system were discussed: optimizing 3D models to keep the polygon number in VR system within target hardware's processing ability;optimizing texture database to save texture memory with perfect visual effect; optimizing database hierarchy structure to accelerate model retrieval; and optimizing LOD hierarchy structure to speed up rendering~

  11. Inequality Matters : Classroom Status Hierarchy and Adolescents' Bullying

    NARCIS (Netherlands)

    Garandeau, Claire F.; Lee, Ihno A.; Salmivalli, Christina

    2014-01-01

    The natural emergence of status hierarchies in adolescent peer groups has long been assumed to help prevent future intragroup aggression. However, clear evidence of this beneficial influence is lacking. In fact, few studies have examined between-group differences in the degree of status hierarchy (d

  12. The Diversity Education Dilemma: Exposing Status Hierarchies without Reinforcing Them

    Science.gov (United States)

    Amoroso, Lisa M.; Loyd, Denise Lewin; Hoobler, Jenny M.

    2010-01-01

    A "diversity education dilemma" occurs when exposure to information concerning status hierarchies, related to demographic and other socially salient identity groups, reinforces those hierarchies in the classroom. Discussions of diversity-related issues in a variety of management courses (e.g., immigrant issues in labor relations, the composition…

  13. THE HAMILTONIAN SYSTEMS OF THE LCZ HIERARCHY BY NONLINEARIZATION

    Institute of Scientific and Technical Information of China (English)

    Li Lu

    2000-01-01

    In this paper, we first search for the Hamiltonian structure of LCZ hierarchy by use of a trace identity. Then we determine a higher-order constraint condition between the potentials and the eigenfunctions of the LCZ spectral problem, and under this constraint condition, the Lax pairs of LCZ hierarchy are all nonlinearized into the finite-dimensional integrable Hamiltonian systems in Liouville sense.

  14. Inferring heuristic classification hierarchies from natural language input

    Science.gov (United States)

    Hull, Richard; Gomez, Fernando

    1993-01-01

    A methodology for inferring hierarchies representing heuristic knowledge about the check out, control, and monitoring sub-system (CCMS) of the space shuttle launch processing system from natural language input is explained. Our method identifies failures explicitly and implicitly described in natural language by domain experts and uses those descriptions to recommend classifications for inclusion in the experts' heuristic hierarchies.

  15. Reactions to Crime as a Hierarchy Regulating Strategy:

    DEFF Research Database (Denmark)

    Green, Eva G. T.; Thomsen, Lotte; Sidanius, Jim;

    2009-01-01

    Across two studies, we demonstrated that support for group-based hierarchies differentially affects evaluation of ingroup and outgroup criminal offenders and that this effect generalizes to overall evaluations of their respective groups. Drawing on social dominance theory, our results show...... of ethnicity or nationality, not education level and employment status, were the important cues for hierarchy-regulating judgments of criminal offenders...

  16. A Second Look at Maslow's Hierarchy of Basic Needs.

    Science.gov (United States)

    White, Charles M.

    Implications of Maslow's Need Hierarchy are considered in this paper, along with possible qualifications to the suggested structure and potential effects of superimposing relative deprivation theory onto the hierarchy as an approach to adult education. The interfacing of needs and alternative structurings is discussed in terms of two theories: (1)…

  17. The Academic Structure in Japan: Institutional Hierarchy and Academic Mobility.

    Science.gov (United States)

    Arimoto, Akira

    The characteristics of the Japanese academic structure are examined with attention to the evolution of institutional hierarchy, the closed academic structure, and the effects of the academic structure upon academic research. The evolution of Japan's institutional hierarchy in academics has been tightly related to factors of nationalism,…

  18. A Validation Study of Maslow's Hierarchy of Needs Theory.

    Science.gov (United States)

    Clay, Rex J.

    A study was conducted to expand the body of research that tests the validity of Abraham Maslow's hierarchy of needs theory in a work context where it often serves as a guide for the supervisor's relationships with his subordinates. Data was gathered by questionnaire which tested for a hierarchy of needs among instructors at four community colleges…

  19. A Second Look at Maslow's Hierarchy of Basic Needs.

    Science.gov (United States)

    White, Charles M.

    Implications of Maslow's Need Hierarchy are considered in this paper, along with possible qualifications to the suggested structure and potential effects of superimposing relative deprivation theory onto the hierarchy as an approach to adult education. The interfacing of needs and alternative structurings is discussed in terms of two theories: (1)…

  20. Genus-zero Whitham hierarchies in conformal-map dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Alonso, Luis [Departamento de Fisica Teorica II, Universidad Complutense, E-28040 Madrid (Spain)]. E-mail: luism@fis.ucm.es; Medina, Elena [Departamento de Matematicas, Universidad de Cadiz, E-11510 Puerto Real, Cadiz (Spain)

    2006-10-26

    A scheme for solving quasiclassical string equations is developed to prove that genus-zero Whitham hierarchies describe the deformations of planar domains determined by rational conformal maps. This property is applied in normal matrix models to show that deformations of simply-connected supports of eigenvalues under changes of coupling constants are governed by genus-zero Whitham hierarchies.

  1. A Validation Study of Maslow's Hierarchy of Needs Theory.

    Science.gov (United States)

    Clay, Rex J.

    A study was conducted to expand the body of research that tests the validity of Abraham Maslow's hierarchy of needs theory in a work context where it often serves as a guide for the supervisor's relationships with his subordinates. Data was gathered by questionnaire which tested for a hierarchy of needs among instructors at four community colleges…

  2. Integrable dispersionless KdV hierarchy with sources

    OpenAIRE

    2006-01-01

    An integrable dispersionless KdV hierarchy with sources (dKdVHWS) is derived. Lax pair equations and bi-Hamiltonian formulation for dKdVHWS are formulated. Hodograph solution for the dispersionless KdV equation with sources (dKdVWS) is obtained via hodograph transformation. Furthermore, the dispersionless Gelfand-Dickey hierarchy with sources (dGDHWS) is presented.

  3. Nonlinear Super Integrable Couplings of Super Classical-Boussinesq Hierarchy

    Directory of Open Access Journals (Sweden)

    Xiuzhi Xing

    2014-01-01

    Full Text Available Nonlinear integrable couplings of super classical-Boussinesq hierarchy based upon an enlarged matrix Lie super algebra were constructed. Then, its super Hamiltonian structures were established by using super trace identity. As its reduction, nonlinear integrable couplings of the classical integrable hierarchy were obtained.

  4. Detecting Hidden Hierarchy of Non Hierarchical Terrorist Networks

    DEFF Research Database (Denmark)

    Memon, Nasrullah

    to analyze terrorist networks and prioritize their targets. Applying recently introduced mathematical methods for constructing the hidden hierarchy of "nonhierarchical" terrorist networks; we present case studies of the terrorist attacks occurred / planned in the past, in order to identify hidden hierarchy...

  5. Scale-independent inflation and hierarchy generation

    Directory of Open Access Journals (Sweden)

    Pedro G. Ferreira

    2016-12-01

    Full Text Available We discuss models involving two scalar fields coupled to classical gravity that satisfy the general criteria: (i the theory has no mass input parameters, (ii classical scale symmetry is broken only through −112ςϕ2R couplings where ς departs from the special conformal value of 1; (iii the Planck mass is dynamically generated by the vacuum expectations values (VEVs of the scalars (iv there is a stage of viable inflation associated with slow roll in the two-scalar potential; (v the final vacuum has a small to vanishing cosmological constant and an hierarchically small ratio of the VEVs and the ratio of the scalar masses to the Planck scale. This assumes the paradigm of classical scale symmetry as a custodial symmetry of large hierarchies.

  6. Scale-Independent Inflation and Hierarchy Generation

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Pedro G. [Oxford U.; Hill, Christopher T. [Fermilab; Ross, Graham G. [Oxford U., Theor. Phys.

    2016-03-18

    We discuss models involving two scalar fields coupled to classical gravity that satisfy the general criteria: (i) the theory has no mass input parameters, (ii) classical scale symmetry is broken only through $-\\frac{1}{12}\\varsigma \\phi^2 R$ couplings where $\\varsigma$ departs from the special conformal value of $1$; (iii) the Planck mass is dynamically generated by the vacuum expectations values (VEVs) of the scalars (iv) there is a stage of viable inflation associated with slow roll in the two--scalar potential; (v) the final vacuum has a small to vanishing cosmological constant and an hierarchically small ratio of the VEVs and the ratio of the scalar masses to the Planck scale. This assumes the paradigm of classical scale symmetry as a custodial symmetry of large hierarchies.

  7. Structural hierarchy governs fibrin gel mechanics.

    Science.gov (United States)

    Piechocka, Izabela K; Bacabac, Rommel G; Potters, Max; Mackintosh, Fred C; Koenderink, Gijsje H

    2010-05-19

    Fibrin gels are responsible for the mechanical strength of blood clots, which are among the most resilient protein materials in nature. Here we investigate the physical origin of this mechanical behavior by performing rheology measurements on reconstituted fibrin gels. We find that increasing levels of shear strain induce a succession of distinct elastic responses that reflect stretching processes on different length scales. We present a theoretical model that explains these observations in terms of the unique hierarchical architecture of the fibers. The fibers are bundles of semiflexible protofibrils that are loosely connected by flexible linker chains. This architecture makes the fibers 100-fold more flexible to bending than anticipated based on their large diameter. Moreover, in contrast with other biopolymers, fibrin fibers intrinsically stiffen when stretched. The resulting hierarchy of elastic regimes explains the incredible resilience of fibrin clots against large deformations.

  8. Lax operator algebras and Hamiltonian integrable hierarchies

    CERN Document Server

    Sheinman, Oleg K

    2009-01-01

    We consider the theory of Lax equations in complex simple and reductive classical Lie algebras with the spectral parameter on a Riemann surface of finite genus. Our approach is based on the new objects -- the Lax operator algebras, and develops the approach of I.Krichever treating the $\\gl(n)$ case. For every Lax operator considered as the mapping sending a point of the cotangent bundle on the space of extended Tyrin data to an element of the corresponding Lax operator algebra we construct the hierarchy of mutually commuting flows given by Lax equations and prove that those are Hamiltonian with respect to the Krichever-Phong symplectic structure. The corresponding Hamiltonians give integrable finite-dimensional Hitchin-type systems. For example we derive elliptic $A_n$, $C_n$, $D_n$ Calogero-Moser systems in frame of our approach.

  9. Lax operator algebras and Hamiltonian integrable hierarchies

    Energy Technology Data Exchange (ETDEWEB)

    Sheinman, Oleg K [Steklov Mathematical Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2011-02-28

    This paper considers the theory of Lax equations with a spectral parameter on a Riemann surface, proposed by Krichever in 2001. The approach here is based on new objects, the Lax operator algebras, taking into consideration an arbitrary complex simple or reductive classical Lie algebra. For every Lax operator, regarded as a map sending a point of the cotangent bundle on the space of extended Tyurin data to an element of the corresponding Lax operator algebra, a hierarchy of mutually commuting flows given by the Lax equations is constructed, and it is proved that they are Hamiltonian with respect to the Krichever-Phong symplectic structure. The corresponding Hamiltonians give integrable finite-dimensional Hitchin-type systems. For example, elliptic A{sub n}, C{sub n}, and D{sub n} Calogero-Moser systems are derived in the framework of our approach. Bibliography: 13 titles.

  10. A new wavefunction hierarchy for interacting geminals

    Science.gov (United States)

    Limacher, Peter A.

    2016-11-01

    A new truncation scheme for non-orthogonal antisymmetrized products of interacting geminals (APIG) is introduced based on antisymmetrized products of strongly orthogonal geminals (APSG). This wavefunction hierarchy of interacting geminals (IG) allows us to gradually increase the accuracy at which the ground state of a seniority-zero Hamiltonian can be estimated, ranging from APSG up to approximation-free APIG. Mathematical expressions for the lowest four orders (IG0, IG1, IG2, and IG3) are given explicitly and the computational cost to evaluate their transition density matrix is verified to scale only cubically with system size. Exemplary numerical calculations indicate that already a very early truncation level leads to results virtually identical to APIG.

  11. Scale-Independent Inflation and Hierarchy Generation

    CERN Document Server

    Ferreira, Pedro G; Ross, Graham G

    2016-01-01

    We discuss models involving two scalar fields coupled to classical gravity that satisfy the general criteria: (i) the theory has no mass input parameters, (ii) classical scale symmetry is broken only through $-\\frac{1}{12}\\varsigma \\phi^2 R$ couplings where $\\varsigma$ departs from the special conformal value of $1$; (iii) the Planck mass is dynamically generated by the vacuum expectations values (VEVs) of the scalars (iv) there is a stage of viable inflation associated with slow roll in the two--scalar potential; (v) the final vacuum has a small to vanishing cosmological constant and an hierarchically small ratio of the VEVs and the ratio of the scalar masses to the Planck scale. This assumes the paradigm of classical scale symmetry as a custodial symmetry of large hierarchies.

  12. Simple Resonance Hierarchy for Surmounting Quantum Uncertainty

    Science.gov (United States)

    Amoroso, Richard L.

    2010-12-01

    For a hundred years violation or surmounting the Quantum Uncertainty Principle has remained a Holy Grail of both theoretical and empirical physics. Utilizing an operationally completed form of Quantum Theory cast in a string theoretic Higher Dimensional (HD) form of Dirac covariant polarized vacuum with a complex Einstein energy dependent spacetime metric, M̂4±C4 with sufficient degrees of freedom to be causally free of the local quantum state, we present a simple empirical model for ontologically surmounting the phenomenology of uncertainty through a Sagnac Effect RF pulsed Laser Oscillated Vacuum Energy Resonance hierarchy cast within an extended form of a Wheeler-Feynman-Cramer Transactional Calabi-Yau mirror symmetric spacetime bachcloth.

  13. Scale-independent inflation and hierarchy generation

    Science.gov (United States)

    Ferreira, Pedro G.; Hill, Christopher T.; Ross, Graham G.

    2016-12-01

    We discuss models involving two scalar fields coupled to classical gravity that satisfy the general criteria: (i) the theory has no mass input parameters, (ii) classical scale symmetry is broken only through -1/12 ςϕ2 R couplings where ς departs from the special conformal value of 1; (iii) the Planck mass is dynamically generated by the vacuum expectations values (VEVs) of the scalars (iv) there is a stage of viable inflation associated with slow roll in the two-scalar potential; (v) the final vacuum has a small to vanishing cosmological constant and an hierarchically small ratio of the VEVs and the ratio of the scalar masses to the Planck scale. This assumes the paradigm of classical scale symmetry as a custodial symmetry of large hierarchies.

  14. Influence of motivation on control hierarchy in the human frontal cortex.

    Science.gov (United States)

    Bahlmann, Jörg; Aarts, Esther; D'Esposito, Mark

    2015-02-18

    The frontal cortex mediates cognitive control and motivation to shape human behavior. It is generally observed that medial frontal areas are involved in motivational aspects of behavior, whereas lateral frontal regions are involved in cognitive control. Recent models of cognitive control suggest a rostro-caudal gradient in lateral frontal regions, such that progressively more rostral (anterior) regions process more complex aspects of cognitive control. How motivation influences such a control hierarchy is still under debate. Although some researchers argue that both systems work in parallel, others argue in favor of an interaction between motivation and cognitive control. In the latter case it is yet unclear how motivation would affect the different levels of the control hierarchy. This was investigated in the present functional MRI study applying different levels of cognitive control under different motivational states (low vs high reward anticipation). Three levels of cognitive control were tested by varying rule complexity: stimulus-response mapping (low-level), flexible task updating (mid-level), and sustained cue-task associations (high-level). We found an interaction between levels of cognitive control and motivation in medial and lateral frontal subregions. Specifically, flexible updating (mid-level of control) showed the strongest beneficial effect of reward and only this level exhibited functional coupling between dopamine-rich midbrain regions and the lateral frontal cortex. These findings suggest that motivation differentially affects the levels of a control hierarchy, influencing recruitment of frontal cortical control regions depending on specific task demands. Copyright © 2015 the authors 0270-6474/15/353207-11$15.00/0.

  15. Lepton mass hierarchy from the quark mass hierarchy in the light of the quark Technicolor Dynamics

    CERN Document Server

    Sauli, Vladimir

    2013-01-01

    We explore the possibility that all electroweak symmetry breaking (EWSB) comes from the strong dynamics of Technicolor while these are the only quarks which receive masses through Technicolor dynamics. We assume the leptons are not embedded in a representation of Extended Technigroup. In this paper we suggest a model where the leptons receive their masses through the loop corrections which includes at least one closed quark loop. For this purpose we introduce model based on private family SU(2) scalar two doublets which interact very weakly with the Standard Model(SM) fermions and which do not condense at tree level. Assuming quark/lepton universality of suggested Yukawa interactions the model becomes strongly predictive and we calculate mass contributions to the all known SM lepton gauge eigenstates. Up to not yet explored mixing, the model suggests that the lepton mass hierarchy comes from the quark mass hierarchy. Within a single universal Yukawa coupling the absolute values of masses for neutrino family e...

  16. Detecting the Neutrinos Mass Hierarchy from Cosmological Data

    CERN Document Server

    Xu, Lixin

    2016-01-01

    We propose a new parameterization to measure the neutrino mass hierarchy, namely $\\Delta=(m_3-m_1)/(m_1+m_3)$ which is dimensionless and varies in the range $[-1,1]$. Taking into account the results of neutrino oscillation experiments, $\\Delta$ is the unique parameter for determining all the masses of neutrinos, and a positive (negative) sign of $\\Delta$ denotes the normal (inverted) mass hierarchy. Adopting the currently available cosmic observations, we find that the normal mass hierarchy is slightly favored, and the mass of lightest neutrino is less than $0.030$ eV for the normal mass hierarchy and $0.024$ eV for the inverted mass hierarchy at $95\\%$ confidence level.

  17. The Impact of Formal Hierarchies on Enterprise Social Networking Behavior

    DEFF Research Database (Denmark)

    Behrendt, Sebastian; Klier, Julia; Klier, Mathias

    2015-01-01

    With more and more companies using enterprise social networks (ESN) for employee communication and collaboration, the influence of ESN on organizational hierarchies has been subject of countless discussions in practice-oriented media and first academic studies. Conversely, the question whether...... and how formal organizational hierarchies influence ESN usage behavior has not yet been addressed. Drawing on a rich data set comprising 2.5 years of relationship building via direct messages, confirmed contact requests, and group messages, we are able to show that formal hierarchies have an important...... impact on social networking behavior. By applying means of social network analysis and supported by statements from interviews, we illustrate how deeply formal hierarchy impacts the three examined types of relationships. Our results motivate academics to further study the interrelation between hierarchy...

  18. Status hierarchy, attractiveness hierarchy and sex ratio : Three contextual factors explaining the status-aggression link among adolescents

    NARCIS (Netherlands)

    Zwaan, Michiel; Dijkstra, Jan; Veenstra, René

    2013-01-01

    The moderating effects of three specific conditions (status hierarchy, attractiveness hierarchy and sex ratio) on the link between status (popularity) and physical and relational aggression were examined in a large sample of adolescent boys (N = 1,665) and girls (N = 1,637) (M age = 13.60). In line

  19. Status hierarchy, attractiveness hierarchy and sex ratio : Three contextual factors explaining the status-aggression link among adolescents

    NARCIS (Netherlands)

    Zwaan, Michiel; Dijkstra, Jan; Veenstra, René

    The moderating effects of three specific conditions (status hierarchy, attractiveness hierarchy and sex ratio) on the link between status (popularity) and physical and relational aggression were examined in a large sample of adolescent boys (N = 1,665) and girls (N = 1,637) (M age = 13.60). In line

  20. Status Hierarchy, Attractiveness Hierarchy and Sex Ratio: Three Contextual Factors Explaining the Status-Aggression Link among Adolescents

    Science.gov (United States)

    Zwaan, Michiel; Dijkstra, Jan Kornelis; Veenstra, Rene

    2013-01-01

    The moderating effects of three specific conditions (status hierarchy, attractiveness hierarchy and sex ratio) on the link between status (popularity) and physical and relational aggression were examined in a large sample of adolescent boys ("N" = 1,665) and girls ("N" = 1,637) ("M" age = 13.60). In line with the…

  1. Embedded Memory Hierarchy Exploration Based on Magnetic Random Access Memory

    Directory of Open Access Journals (Sweden)

    Luís Vitório Cargnini

    2014-08-01

    Full Text Available Static random access memory (SRAM is the most commonly employed semiconductor in the design of on-chip processor memory. However, it is unlikely that the SRAM technology will have a cell size that will continue to scale below 45 nm, due to the leakage current that is caused by the quantum tunneling effect. Magnetic random access memory (MRAM is a candidate technology to replace SRAM, assuming appropriate dimensioning given an operating threshold voltage. The write current of spin transfer torque (STT-MRAM is a known limitation; however, this has been recently mitigated by leveraging perpendicular magnetic tunneling junctions. In this article, we present a comprehensive comparison of spin transfer torque-MRAM (STT-MRAM and SRAM cache set banks. The non-volatility of STT-MRAM allows the definition of new instant on/off policies and leakage current optimizations. Through our experiments, we demonstrate that STT-MRAM is a candidate for the memory hierarchy of embedded systems, due to the higher densities and reduced leakage of MRAM.We demonstrate that adopting STT-MRAM in L1 and L2 caches mitigates the impact of higher write latencies and increased current draw due to the use of MRAM. With the correct system-on-chip (SoC design, we believe that STT-MRAM is a viable alternative to SRAM, which minimizes leakage current and the total power consumed by the SoC.

  2. Emergent Intentionality in Perception-Action Subsumption Hierarchies

    Directory of Open Access Journals (Sweden)

    David Windridge

    2017-08-01

    Full Text Available A cognitively autonomous artificial agent may be defined as one able to modify both its external world-model and the framework by which it represents the world, requiring two simultaneous optimization objectives. This presents deep epistemological issues centered on the question of how a framework for representation (as opposed to the entities it represents may be objectively validated. In this article, formalizing previous work in this field, it is argued that subsumptive perception-action learning has the capacity to resolve these issues by (a building the perceptual hierarchy from the bottom up so as to ground all proposed representations and (b maintaining a bijective coupling between proposed percepts and projected action possibilities to ensure empirical falsifiability of these grounded representations. In doing so, we will show that such subsumptive perception-action learners intrinsically incorporate a model for how intentionality emerges from randomized exploratory activity in the form of “motor babbling.” Moreover, such a model of intentionality also naturally translates into a model for human–computer interfacing that makes minimal assumptions as to cognitive states.

  3. Evaluating mandibular cortical index quantitatively.

    Science.gov (United States)

    Yasar, Fusun; Akgunlu, Faruk

    2008-10-01

    The aim was to assess whether Fractal Dimension and Lacunarity analysis can discriminate patients having different mandibular cortical shape. Panoramic radiographs of 52 patients were evaluated for mandibular cortical index. Weighted Kappa between the observations were varying between 0.718-0.805. These radiographs were scanned and converted to binary images. Fractal Dimension and Lacunarity were calculated from the regions where best represents the cortical morphology. It was found that there were statistically significant difference between the Fractal Dimension and Lacunarity of radiographs which were classified as having Cl 1 and Cl 2 (Fractal Dimension P:0.000; Lacunarity P:0.003); and Cl 1 and Cl 3 cortical morphology (Fractal Dimension P:0.008; Lacunarity P:0.001); but there was no statistically significant difference between Fractal Dimension and Lacunarity of radiographs which were classified as having Cl 2 and Cl 3 cortical morphology (Fractal Dimension P:1.000; Lacunarity P:0.758). FD and L can differentiate Cl 1 mandibular cortical shape from both Cl 2 and Cl 3 mandibular cortical shape but cannot differentiate Cl 2 from Cl 3 mandibular cortical shape on panoramic radiographs.

  4. Cortico-cortical communication dynamics

    Directory of Open Access Journals (Sweden)

    Per E Roland

    2014-05-01

    Full Text Available IIn principle, cortico-cortical communication dynamics is simple: neurons in one cortical area communicate by sending action potentials that release glutamate and excite their target neurons in other cortical areas. In practice, knowledge about cortico-cortical communication dynamics is minute. One reason is that no current technique can capture the fast spatio-temporal cortico-cortical evolution of action potential transmission and membrane conductances with sufficient spatial resolution. A combination of optogenetics and monosynaptic tracing with virus can reveal the spatio-temporal cortico-cortical dynamics of specific neurons and their targets, but does not reveal how the dynamics evolves under natural conditions. Spontaneous ongoing action potentials also spread across cortical areas and are difficult to separate from structured evoked and intrinsic brain activity such as thinking. At a certain state of evolution, the dynamics may engage larger populations of neurons to drive the brain to decisions, percepts and behaviors. For example, successfully evolving dynamics to sensory transients can appear at the mesoscopic scale revealing how the transient is perceived. As a consequence of these methodological and conceptual difficulties, studies in this field comprise a wide range of computational models, large-scale measurements (e.g., by MEG, EEG, and a combination of invasive measurements in animal experiments. Further obstacles and challenges of studying cortico-cortical communication dynamics are outlined in this critical review.

  5. Topographic mapping of a hierarchy of temporal receptive windows using a narrated story.

    Science.gov (United States)

    Lerner, Yulia; Honey, Christopher J; Silbert, Lauren J; Hasson, Uri

    2011-02-23

    Real-life activities, such as watching a movie or engaging in conversation, unfold over many minutes. In the course of such activities, the brain has to integrate information over multiple time scales. We recently proposed that the brain uses similar strategies for integrating information across space and over time. Drawing a parallel with spatial receptive fields, we defined the temporal receptive window (TRW) of a cortical microcircuit as the length of time before a response during which sensory information may affect that response. Our previous findings in the visual system are consistent with the hypothesis that TRWs become larger when moving from low-level sensory to high-level perceptual and cognitive areas. In this study, we mapped TRWs in auditory and language areas by measuring fMRI activity in subjects listening to a real-life story scrambled at the time scales of words, sentences, and paragraphs. Our results revealed a hierarchical topography of TRWs. In early auditory cortices (A1+), brain responses were driven mainly by the momentary incoming input and were similarly reliable across all scrambling conditions. In areas with an intermediate TRW, coherent information at the sentence time scale or longer was necessary to evoke reliable responses. At the apex of the TRW hierarchy, we found parietal and frontal areas that responded reliably only when intact paragraphs were heard in a meaningful sequence. These results suggest that the time scale of processing is a functional property that may provide a general organizing principle for the human cerebral cortex.

  6. Modeling cortical circuits.

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, Brandon Robinson; Rothganger, Fredrick H.; Verzi, Stephen J.; Xavier, Patrick Gordon

    2010-09-01

    The neocortex is perhaps the highest region of the human brain, where audio and visual perception takes place along with many important cognitive functions. An important research goal is to describe the mechanisms implemented by the neocortex. There is an apparent regularity in the structure of the neocortex [Brodmann 1909, Mountcastle 1957] which may help simplify this task. The work reported here addresses the problem of how to describe the putative repeated units ('cortical circuits') in a manner that is easily understood and manipulated, with the long-term goal of developing a mathematical and algorithmic description of their function. The approach is to reduce each algorithm to an enhanced perceptron-like structure and describe its computation using difference equations. We organize this algorithmic processing into larger structures based on physiological observations, and implement key modeling concepts in software which runs on parallel computing hardware.

  7. Cortical and spinal assessment

    DEFF Research Database (Denmark)

    Fischer, I W; Gram, Mikkel; Hansen, T M

    2017-01-01

    BACKGROUND: Standardized objective methods to assess the analgesic effects of opioids, enable identification of underlying mechanisms of drug actions in the central nervous system. Opioids may exert their effect on both cortical and spinal levels. In this study actions of morphine at both levels...... subjects was included in the data analysis. There was no change in the activity in resting EEG (P>0.05) after morphine administration as compared to placebo. During cold pressor stimulation, morphine significantly lowered the relative activity in the delta (1-4Hz) band (P=0.03) and increased the activity...... morphine administration (P>0.05). CONCLUSIONS: Cold pressor EEG and the nociceptive reflex were more sensitive to morphine analgesia than resting EEG and can be used as standardized objective methods to assess opioid effects. However, no correlation between the analgesic effect of morphine on the spinal...

  8. Hiperostosis cortical infantil

    OpenAIRE

    Salvador Javier Santos Medina; Orelvis Pérez Duerto

    2015-01-01

    La enfermedad de Caffey, o hiperostosis cortical infantil, es una rara enfermedad ósea autolimitada, que aparece de preferencia en lactantes con signos inespecíficos sistémicos; el más relevante es la reacción subperióstica e hiperostosis en varios huesos del cuerpo, con predilección en el 75-80 % de los casos por la mandíbula. Su pronóstico es bueno, la mayoría no deja secuelas. El propósito del presente trabajo es describir las características clínicas, presentes en un lactante de cinco mes...

  9. Progressive posterior cortical dysfunction

    Directory of Open Access Journals (Sweden)

    Fábio Henrique de Gobbi Porto

    Full Text Available Abstract Progressive posterior cortical dysfunction (PPCD is an insidious syndrome characterized by prominent disorders of higher visual processing. It affects both dorsal (occipito-parietal and ventral (occipito-temporal pathways, disturbing visuospatial processing and visual recognition, respectively. We report a case of a 67-year-old woman presenting with progressive impairment of visual functions. Neurologic examination showed agraphia, alexia, hemispatial neglect (left side visual extinction, complete Balint's syndrome and visual agnosia. Magnetic resonance imaging showed circumscribed atrophy involving the bilateral parieto-occipital regions, slightly more predominant to the right . Our aim was to describe a case of this syndrome, to present a video showing the main abnormalities, and to discuss this unusual presentation of dementia. We believe this article can contribute by improving the recognition of PPCD.

  10. Cortical plasticity and rehabilitation.

    Science.gov (United States)

    Moucha, Raluca; Kilgard, Michael P

    2006-01-01

    The brain is constantly adapting to environmental and endogenous changes (including injury) that occur at every stage of life. The mechanisms that regulate neural plasticity have been refined over millions of years. Motivation and sensory experience directly shape the rewiring that makes learning and neurological recovery possible. Guiding neural reorganization in a manner that facilitates recovery of function is a primary goal of neurological rehabilitation. As the rules that govern neural plasticity become better understood, it will be possible to manipulate the sensory and motor experience of patients to induce specific forms of plasticity. This review summarizes our current knowledge regarding factors that regulate cortical plasticity, illustrates specific forms of reorganization induced by control of each factor, and suggests how to exploit these factors for clinical benefit.

  11. Quasi-periodic Solutions to the K(-2, -2) Hierarchy

    Science.gov (United States)

    Wu, Lihua; Geng, Xianguo

    2016-07-01

    With the help of the characteristic polynomial of Lax matrix for the K(-2, -2) hierarchy, we define a hyperelliptic curve 𝒦n+1 of arithmetic genus n+1. By introducing the Baker-Akhiezer function and meromorphic function, the K(-2, -2) hierarchy is decomposed into Dubrovin-type differential equations. Based on the theory of hyperelliptic curve, the explicit Riemann theta function representation of meromorphic function is given, and from which the quasi-periodic solutions to the K(-2, -2) hierarchy are obtained.

  12. The $n$-component KP hierarchy and representation theory

    CERN Document Server

    Kac, V G

    1993-01-01

    Starting from free charged fermions we give equivalent definitions of the $n\\/$-component KP hierarchy, in terms of $\\tau\\/$-functions $\\tau_\\alpha\\/$ (where $\\alpha \\in M =\\/$ root lattice of $sl_n\\/$), in terms of $n \\times n\\/$ matrix valued wave functions $W_\\alpha(\\alpha\\in M)\\/$, and in terms of pseudodifferential wave operators $P_\\alpha(\\alpha\\in M)\\/$. These imply the deformation and the zero curvature equations. We show that the 2-component KP hierarchy contains the Davey-Stewartson system and the $n\\geq3\\/$ component KP hierarchy continues the $n\\/$-wave interaction equations. This allows us to construct theis solutions.

  13. Cortical Auditory Evoked Potentials in Unsuccessful Cochlear Implant Users

    Science.gov (United States)

    Munivrana, Boska; Mildner, Vesna

    2013-01-01

    In some cochlear implant users, success is not achieved in spite of optimal clinical factors (including age at implantation, duration of rehabilitation and post-implant hearing level), which may be attributed to disorders at higher levels of the auditory pathway. We used cortical auditory evoked potentials to investigate the ability to perceive…

  14. Cortical Auditory Evoked Potentials in Unsuccessful Cochlear Implant Users

    Science.gov (United States)

    Munivrana, Boska; Mildner, Vesna

    2013-01-01

    In some cochlear implant users, success is not achieved in spite of optimal clinical factors (including age at implantation, duration of rehabilitation and post-implant hearing level), which may be attributed to disorders at higher levels of the auditory pathway. We used cortical auditory evoked potentials to investigate the ability to perceive…

  15. How transportation hierarchy shapes human mobility

    CERN Document Server

    Gallotti, Riccardo; Rambaldi, Sandro; Barthelemy, Marc

    2015-01-01

    The recent availability of data allowing to monitor the position of individuals triggered a wealth of quantitative studies on human mobility. In particular, it is now believed that displacements can be described by a L\\'evy type of walk, characterized by many small movements and some rare long jumps. We show here that this view is not correct and that effective movements in urban and inter-urban areas are much simpler. We use a database containing the trajectories of $780,000$ private vehicles in Italy and an open dataset describing the temporal characteristics of the entire public transportation system in Great Britain. We observe that trips for both private and public transportation are on average accelerated as a consequence of the multilayer hierarchy of transportation infrastructures. In other terms, the speed depends on the duration of the trip, with larger speed for longer trips. This sole ingredient leads, starting from the observed exponential distribution of travel-times and velocities, to a distrib...

  16. 6D RG Flows and Nilpotent Hierarchies

    CERN Document Server

    Heckman, Jonathan J; Tomasiello, Alessandro

    2016-01-01

    With the eventual aim of classifying renormalization group flows between 6D superconformal field theories (SCFTs), we study flows generated by the vevs of "conformal matter," a generalization of conventional hypermultiplets which naturally appear in the F-theory classification of 6D SCFTs. We consider flows in which the parent UV theory is (on its partial tensor branch) a linear chain of gauge groups connected by conformal matter, with one flavor group G at each end of the chain, and in which the symmetry breaking of the conformal matter at each end is parameterized by the orbit of a nilpotent element, i.e. T-brane data, of one of these flavor symmetries. Such nilpotent orbits admit a partial ordering, which is reflected in a hierarchy of IR fixed points. For each such nilpotent orbit, we determine the corresponding tensor branch for the resulting SCFT. An important feature of this algebraic approach is that it also allows us to systematically compute the unbroken flavor symmetries inherited from the parent U...

  17. Hierarchy Formation and Self-Determination

    Directory of Open Access Journals (Sweden)

    Stefano I. Di Domenico

    2014-12-01

    Full Text Available We examined how self-determination, the subjective experience of one’s behavior as internally initiated and personally endorsed, depends on one’s standing in real-world social hierarchies. We predicted that those with the traits most relevant to status attainment would be those afforded the most opportunities to be self-determining. We examined the trait of physical attractiveness, given its documented association with social status and no known association with self-determination. First-year undergraduates living in same-sex residences rated their housemates’ social status, while an independent set of observers rated the participants’ physical attractiveness. Consistent with prediction, physically attractive individuals attained the highest levels of social status; in turn, those who attained the highest levels of social status experienced the highest levels of self-determination. These findings provide new insights into self-determination as an inherently relational phenomenon and specifically highlight the formative influence of social status on people’s capacities for self-determination.

  18. Mirror quintic vacua: hierarchies and inflation

    CERN Document Server

    Bizet, Nana Cabo; Zavala, Ivonne

    2016-01-01

    We study the moduli space of type IIB string theory flux compactifications on the mirror of the CY quintic 3-fold in P4. We focus on the dynamics of the four dimensional moduli space, defined by the axio-dilaton {\\tau} and the complex structure modulus z. The z-plane has critical points, the conifold, the orbifold and the large complex structure with non trivial monodromies. We find the solutions to the Picard-Fuchs equations obeyed by the periods of the CY in the full z-plane as a series expansion in z around the critical points to arbitrary order. This allows us to discard fake vacua, which appear as a result of keeping only the leading order term in the series expansions. Due to monodromies vacua are located at a given sheet in the z-plane. A dS vacuum appears for a set of fluxes. We revisit vacua with hierarchies among the 4D and 6D physical scales close to the conifold point and compare them with those found at leading order in [1, 2]. We explore slow-roll inflationary directions of the scalar potential ...

  19. 6D RG flows and nilpotent hierarchies

    Energy Technology Data Exchange (ETDEWEB)

    Heckman, Jonathan J. [Department of Physics, University of North Carolina,Chapel Hill, NC 27599 (United States); Department of Physics, Columbia University,New York, NY 10027 (United States); CUNY Graduate Center, Initiative for the Theoretical Sciences,New York, NY 10016 (United States); Rudelius, Tom [Jefferson Physical Laboratory, Harvard University,Cambridge, MA 02138 (United States); Tomasiello, Alessandro [Dipartimento di Fisica, Università di Milano-Bicocca,Milan (Italy); INFN, sezione di Milano-Bicocca,Milan (Italy)

    2016-07-15

    With the eventual aim of classifying renormalization group flows between 6D superconformal field theories (SCFTs), we study flows generated by the vevs of “conformal matter,” a generalization of conventional hypermultiplets which naturally appear in the F-theory classification of 6D SCFTs. We consider flows in which the parent UV theory is (on its partial tensor branch) a linear chain of gauge groups connected by conformal matter, with one flavor group G at each end of the chain, and in which the symmetry breaking of the conformal matter at each end is parameterized by the orbit of a nilpotent element, i.e. T-brane data, of one of these flavor symmetries. Such nilpotent orbits admit a partial ordering, which is reflected in a hierarchy of IR fixed points. For each such nilpotent orbit, we determine the corresponding tensor branch for the resulting SCFT. An important feature of this algebraic approach is that it also allows us to systematically compute the unbroken flavor symmetries inherited from the parent UV theory.

  20. A Complex Integrable Hierarchy and Its Hamiltonian Structure for Integrable Couplings of WKI Soliton Hierarchy

    Directory of Open Access Journals (Sweden)

    Fajun Yu

    2014-01-01

    Full Text Available We generate complex integrable couplings from zero curvature equations associated with matrix spectral problems in this paper. A direct application to the WKI spectral problem leads to a novel soliton equation hierarchy of integrable coupling system; then we consider the Hamiltonian structure of the integrable coupling system. We select the U¯, V¯ and generate the nonlinear composite parts, which generate new extended WKI integrable couplings. It is also indicated that the method of block matrix is an efficient and straightforward way to construct the integrable coupling system.

  1. Spatial hierarchy and emerging typologies inside world city network

    National Research Council Canada - National Science Library

    Ilya Chubarov

    2015-01-01

    ...). Based upon the results of media- popular ‘global city rankings’ produced by several international think tanks, our calculation allowed to reveal global urban hierarchy and identify several subnetworks inside of world cities...

  2. INTEGRABLE COUPLINGS OF THE TB HIERARCHY AND ITS HAMILTONIAN STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper,we obtain integrable couplings of the TB hierarchy using the new subalgebra of the loop algebra A_3.Then the Hamiltonian structure of the above system is given by the quadratic-form identity.

  3. Bidifferential Calculus Approach to AKNS Hierarchies and Their Solutions

    Directory of Open Access Journals (Sweden)

    Aristophanes Dimakis

    2010-07-01

    Full Text Available We express AKNS hierarchies, admitting reductions to matrix NLS and matrix mKdV hierarchies, in terms of a bidifferential graded algebra. Application of a universal result in this framework quickly generates an infinite family of exact solutions, including e.g. the matrix solitons in the focusing NLS case. Exploiting a general Miura transformation, we recover the generalized Heisenberg magnet hierarchy and establish a corresponding solution formula for it. Simply by exchanging the roles of the two derivations of the bidifferential graded algebra, we recover ''negative flows'', leading to an extension of the respective hierarchy. In this way we also meet a matrix and vector version of the short pulse equation and also the sine-Gordon equation. For these equations corresponding solution formulas are also derived. In all these cases the solutions are parametrized in terms of matrix data that have to satisfy a certain Sylvester equation.

  4. Know Your Place: Neural Processing of Social Hierarchy in Humans

    Science.gov (United States)

    Zink, Caroline F.; Tong, Yunxia; Chen, Qiang; Bassett, Danielle S.; Stein, Jason L.; Meyer-Lindenberg, Andreas

    2008-01-01

    Summary Social hierarchies guide behavior in many species, including humans, where status also has an enormous impact on motivation and health. However, little is known about the underlying neural representation of social hierarchies in humans. In the present study, we identify dissociable neural responses to perceived social rank using functional magnetic resonance imaging (fMRI) in an interactive simulated social context. In both stable and unstable social hierarchies, viewing a superior individual differentially engaged perceptual-attentional, saliency, and cognitive systems, notably dorsolateral prefrontal cortex. In the unstable hierarchy setting, additional regions were recruited related to emotional processing (amygdala), social cognition (medial prefrontal cortex), and behavioral readiness. Furthermore, social hierarchical consequences of performance were neurally dissociable and of comparable salience to monetary reward, providing a neural basis for the high motivational value of status. Our results identify neural mechanisms that may mediate the enormous influence of social status on human behavior and health. PMID:18439411

  5. Self-organizing social hierarchies in a timid society

    Science.gov (United States)

    Odagaki, Takashi; Tsujiguchi, Masaru

    2006-07-01

    Emergence of hierarchies is investigated by Monte Carlo simulation in a timid society where all individuals are pacifist. The self-organization of hierarchies is shown to occur in two steps as the population is increased, i.e. there are three states, one egalitarian and two hierarchical states; the transition from the egalitarian to the first hierarchical state is continuous and the transition from the first hierarchical state to the second one is discontinuous. In the first hierarchical society, all individuals belong to either middle class or losers and no winners appear. In the second hierarchical society, many winners emerge and the population of the middle class is reduced. The hierarchy in the second hierarchical society is stronger than the hierarchy in a no-preference society studied by Bonabeau et al. [Physica A 217 (1995) 373].

  6. The multicomponent KP hierarchy: differential Fay identities and Lax equations

    Science.gov (United States)

    Teo, Lee Peng

    2011-06-01

    In this paper, we show that four sets of differential Fay identities of an N-component KP hierarchy derived from the bilinear relation satisfied by the tau function of the hierarchy are sufficient to derive the auxiliary linear equations for the wavefunctions. From this, we derive the Lax representation for the N-component KP hierarchy, which are equations satisfied by some pseudo-differential operators with matrix coefficients. Besides the Lax equations with respect to the time variables proposed in Date et al (1981 J. Phys. Soc. Japan 50 3806-12), we also obtain a set of equations relating different charge sectors, which can be considered as a generalization of the modified KP hierarchy proposed in Takebe (2002 Lett. Math. Phys. 59 157-72).

  7. Improving the hierarchy sensitivity of ICAL using neural network

    Science.gov (United States)

    Ajmi, Ali; Dev, Abhish; Nizam, Mohammad; Nayak, Nitish; Sankar, S. Uma

    2017-09-01

    Atmospheric neutrino experiments can determine the neutrino mass hierarchy for any value of δCP . The Iron Calorimeter (ICAL) detector at the India-based Neutrino Observatory can distinguish between the charged current interactions of νμ and {\\overline ν _π } by determining the charge of the produced muon. Hence it is particularly well suited to determine the hierarchy. The hierarchy signature is more prominent in neutrinos with energy of a few GeV and with pathlength of a few thousand kilometers, i.e. neutrinos whose direction is not close to horizontal. We use adaptive neural networks to identify such events with good efficiency and good purity. The hierarchy sensitivity, calculated from these selected events, is above 3σ level.

  8. Super-Affine Hierarchies and their Poisson Embeddings

    CERN Document Server

    Toppan, F

    1998-01-01

    The link between (super)-affine Lie algebras as Poisson brackets structures and integrable hierarchies provides both a classification and a tool for obtaining superintegrable hierarchies. The lack of a fully systematic procedure for constructing matrix-type Lax operators, which makes the supersymmetric case essentially different from the bosonic counterpart, is overcome via the notion of Poisson embeddings (P.E.), i.e. Poisson mappings relating affine structures to conformal structures (in their simplest version P.E. coincide with the Sugawara construction). A full class of hierarchies can be recovered by using uniquely Lie-algebraic notions. The group-algebraic properties implicit in the super-affine picture allow a systematic derivation of reduced hierarchies by imposing either coset conditions or hamiltonian constraints (or possibly both).

  9. Maslow's Implied Matrix: A Clarification of the Need Hierarchy Theory.

    Science.gov (United States)

    Marsh, Edward

    1978-01-01

    Maslow's need hierarchy theory is restated by means of a matrix arrangement of the constructs within the theory. After consideration of the consequences of this restatement, some significant research is discussed and directions for future research suggested. (Author)

  10. Maslow's Implied Matrix: A Clarification of the Need Hierarchy Theory.

    Science.gov (United States)

    Marsh, Edward

    1978-01-01

    Maslow's need hierarchy theory is restated by means of a matrix arrangement of the constructs within the theory. After consideration of the consequences of this restatement, some significant research is discussed and directions for future research suggested. (Author)

  11. Integrable Coupling of KN Hierarchy and Its Hamiltonian Structure

    Institute of Scientific and Technical Information of China (English)

    GUO Fu-Kui; ZHANG Yu-Feng

    2006-01-01

    The Hamiltonian structure of the integrable couplings obtained by our method has not been solved. In this paper, the Hamiltonian structure of the KN hierarchy is obtained by making use of the quadratic-form identity.

  12. Quantifier hierarchies over the first-Order definable tree languages

    Institute of Scientific and Technical Information of China (English)

    沈云付

    1996-01-01

    Using Boolean operations and concatenation product w.r.t special trees,quantifier hierarchies are given by way of alternate existential and universal quantifiers for the first-order definable tree languages.

  13. A Lecture on the Hierarchy Problem and Gravity

    CERN Document Server

    Dvali, G

    2013-01-01

    In this lecture we shall briefly review some motivations for physics beyond the Standard Model. We focus our attention on the hierarchy problem and discuss the role of gravity in defining and solving this problem.

  14. Fuzzy analytical hierarchy process and GIS for predictive cu -au ...

    African Journals Online (AJOL)

    Fuzzy analytical hierarchy process and GIS for predictive cu -au porphyry in ... process (Fuzzy AHP) that is the most popular multi-criteria decision-making techniques. ... for predictive Mineral prospectively mapping (MPM) for Cu -Au porphyry.

  15. An Improved Functional Hierarchy Frame Model for System Maintainability

    Institute of Scientific and Technical Information of China (English)

    CHEN Dai-Lin; CHEN Dong-lin; WANG Ru-gen; ZHU Xue-ping

    2003-01-01

    By means of analogy, this paper analyses the present functional hierarchy frame model for system maintainability, and presents an improved model. Practical application indicates that the improved model is visualized, more convenient and perfected over the pervious models.

  16. On the origins of hierarchy in complex networks

    Science.gov (United States)

    Corominas-Murtra, Bernat; Goñi, Joaquín; Solé, Ricard V.; Rodríguez-Caso, Carlos

    2013-01-01

    Hierarchy seems to pervade complexity in both living and artificial systems. Despite its relevance, no general theory that captures all features of hierarchy and its origins has been proposed yet. Here we present a formal approach resulting from the convergence of theoretical morphology and network theory that allows constructing a 3D morphospace of hierarchies and hence comparing the hierarchical organization of ecological, cellular, technological, and social networks. Embedded within large voids in the morphospace of all possible hierarchies, four major groups are identified. Two of them match the expected from random networks with similar connectivity, thus suggesting that nonadaptive factors are at work. Ecological and gene networks define the other two, indicating that their topological order is the result of functional constraints. These results are consistent with an exploration of the morphospace, using in silico evolved networks. PMID:23898177

  17. Hierarchy in complex systems: the possible and the actual

    CERN Document Server

    Corominas-Murtra, Bernat; Solé, Ricard V; Rodríguez-Caso, Carlos

    2013-01-01

    Hierarchy seems to pervade complexity in both living and artificial systems. Despite its relevance, no general theory that captures all features of hierarchy and its origins has been proposed yet. Here we present a formal approach resulting from the convergence of theoretical morphology and network theory that allows constructing a 3D morphospace of hierarchies and hence comparing the hierarchical organization of ecological, cellular, technological and social networks. Embedded within large voids in the morphospace of all possible hierarchies, four major groups are identified. Two of them match the expected from random networks with similar connectivity, thus suggesting that non-adaptive factors are at work. Ecological and gene networks define the other two, indicating that their topological order is the result of functional constraints. These results are consistent with an exploration of the morphospace using {\\em in silico} evolved networks.

  18. Pattern tree-based XOLAP rollup operator for XML complex hierarchies

    CERN Document Server

    Hachicha, Marouane

    2011-01-01

    With the rise of XML as a standard for representing business data, XML data warehousing appears as a suitable solution for decision-support applications. In this context, it is necessary to allow OLAP analyses on XML data cubes. Thus, XQuery extensions are needed. To define a formal framework and allow much-needed performance optimizations on analytical queries expressed in XQuery, defining an algebra is desirable. However, XML-OLAP (XOLAP) algebras from the literature still largely rely on the relational model. Hence, we propose in this paper a rollup operator based on a pattern tree in order to handle multidimensional XML data expressed within complex hierarchies.

  19. Trust hierarchy trees applied in team management and data access

    Directory of Open Access Journals (Sweden)

    Laura Danilescu

    2011-12-01

    Full Text Available Controlling access to data and information within organizations is an important concerntoday and also our aim. This paper is based on the concept of trust, which allows access control andcontrol of actions that can be applied to data and information indocuments held in computer systems.Methods we have used are: defining trust hierarchies applied to team members, data and actions.Results we have obtained are trust policies based on trust hierarchies.

  20. An Improved Semidefinite Programming Hierarchy for Testing Entanglement

    Science.gov (United States)

    Harrow, Aram W.; Natarajan, Anand; Wu, Xiaodi

    2017-06-01

    We present a stronger version of the Doherty-Parrilo-Spedalieri (DPS) hierarchy of approximations for the set of separable states. Unlike DPS, our hierarchy converges exactly at a finite number of rounds for any fixed input dimension. This yields an algorithm for separability testing that is singly exponential in dimension and polylogarithmic in accuracy. Our analysis makes use of tools from algebraic geometry, but our algorithm is elementary and differs from DPS only by one simple additional collection of constraints.

  1. Low-energy supersymmetry breaking and fermion mass hierarchies

    CERN Document Server

    Gherghetta, Tony; Poppitz, E R; Gherghetta, Tony; Jungman, Gerard; Poppitz, Erich

    1995-01-01

    In models with low-energy supersymmetry breaking, an anomalous Abelian horizontal gauge symmetry can simultaneously explain the fermion mass hierarchy and the values of the \\mu and B terms. We construct an explicit model where the anomaly is cancelled by the Green-Schwarz mechanism at the string scale. We show that with our charge assignments, the breaking of the horizontal symmetry generates the correct order of magnitude and correct hierarchy for all Yukawa couplings.

  2. Centrally extended W$_{1+\\infty}$ and the KP hierarchy

    CERN Document Server

    Martínez-Moras, F; Martinez-Moras, Fernando; Mas, Javier

    1994-01-01

    It is well known that the centerless \\W_{1+\\infty} algebra provides a hamiltonian structure for the KP hierarchy. In this letter we address the question whether the centerfull version plays a similar r\\^ole in any related integrable system. We find that, surprisingly enough the centrally extended W_{1+\\infty} algebra yields another Poisson structure for the same standard KP hierarchy. This is proven by explicit construction of the infinitely many new hamiltonians in closed form.

  3. Hamiltonian Structures for the Generalized Dispersionless KdV Hierarchy

    OpenAIRE

    Brunelli, J. C.

    1996-01-01

    We study from a Hamiltonian point of view the generalized dispersionless KdV hierarchy of equations. From the so called dispersionless Lax representation of these equations we obtain three compatible Hamiltonian structures. The second and third Hamiltonian structures are calculated directly from the r-matrix approach. Since the third structure is not related recursively with the first two ones the generalized dispersionless KdV hierarchy can be characterized as a truly tri-Hamiltonian system.

  4. Scalable distributed computing hierarchy: cloud, fog and dew computing

    OpenAIRE

    Skala, Karolj; Davidović, Davor; Afgan, Enis; Sović, Ivan; Šojat, Zorislav

    2015-01-01

    The paper considers the conceptual approach for organization of the vertical hierarchical links between the scalable distributed computing paradigms: Cloud Computing, Fog Computing and Dew Computing. In this paper, the Dew Computing is described and recognized as a new structural layer in the existing distributed computing hierarchy. In the existing computing hierarchy, the Dew computing is positioned as the ground level for the Cloud and Fog computing paradigms. Vertical, complementary, hier...

  5. Mirror quintic vacua: hierarchies and inflation

    Science.gov (United States)

    Bizet, Nana Cabo; Loaiza-Brito, Oscar; Zavala, Ivonne

    2016-10-01

    We study the moduli space of type IIB string theory flux compactifications on the mirror of the CY quintic 3-fold in P^4 . We focus on the dynamics of the four dimensional moduli space, defined by the axio-dilaton τ and the complex structure modulus z. The z-plane has critical points, the conifold, the orbifold and the large complex structure with non trivial monodromies. We find the solutions to the Picard-Fuchs equations obeyed by the periods of the CY in the full z-plane as a series expansion in z around the critical points to arbitrary order. This allows us to discard fake vacua, which appear as a result of keeping only the leading order term in the series expansions. Due to monodromies vacua are located at a given sheet in the z-plane. A dS vacuum appears for a set of fluxes. We revisit vacua with hierarchies among the 4D and 6D physical scales close to the conifold point and compare them with those found at leading order in [1, 2]. We explore slow-roll inflationary directions of the scalar potential by looking at regions where the multi-field slow-roll parameters ɛ and η are smaller than one. The value of ɛ depends strongly on the approximation of the periods and to achieve a stable value, several orders in the expansion are needed. We do not find realizations of single field axion monodromy inflation. Instead, we find that inflationary regions appear along linear combinations of the four real field directions and for certain configurations of fluxes.

  6. Mirror quintic vacua: hierarchies and inflation

    Energy Technology Data Exchange (ETDEWEB)

    Bizet, Nana Cabo [Mandelstam Institute for Theoretical Physics, School of Physics,and NITheP, University of the Witwatersrand, WITS 2050, Johannesburg (South Africa); Departamento de Física, Universidad de Guanajuato,Loma del Bosque 103, CP 37150, León, Guanajuato (Mexico); Loaiza-Brito, Oscar [Departamento de Física, Universidad de Guanajuato,Loma del Bosque 103, CP 37150, León, Guanajuato (Mexico); Zavala, Ivonne [Department of Physics, Swansea University, Singleton Park,Swansea, SA2 8PP (United Kingdom)

    2016-10-17

    We study the moduli space of type IIB string theory flux compactifications on the mirror of the CY quintic 3-fold in ℙ{sup 4}. We focus on the dynamics of the four dimensional moduli space, defined by the axio-dilaton τ and the complex structure modulus z. The z-plane has critical points, the conifold, the orbifold and the large complex structure with non trivial monodromies. We find the solutions to the Picard-Fuchs equations obeyed by the periods of the CY in the full z-plane as a series expansion in z around the critical points to arbitrary order. This allows us to discard fake vacua, which appear as a result of keeping only the leading order term in the series expansions. Due to monodromies vacua are located at a given sheet in the z-plane. A dS vacuum appears for a set of fluxes. We revisit vacua with hierarchies among the 4D and 6D physical scales close to the conifold point and compare them with those found at leading order in http://dx.doi.org/10.1103/PhysRevD.66.106006, http://dx.doi.org/10.1007/JHEP03(2011)119. We explore slow-roll inflationary directions of the scalar potential by looking at regions where the multi-field slow-roll parameters ϵ and η are smaller than one. The value of ϵ depends strongly on the approximation of the periods and to achieve a stable value, several orders in the expansion are needed. We do not find realizations of single field axion monodromy inflation. Instead, we find that inflationary regions appear along linear combinations of the four real field directions and for certain configurations of fluxes.

  7. Inequality matters: classroom status hierarchy and adolescents' bullying.

    Science.gov (United States)

    Garandeau, Claire F; Lee, Ihno A; Salmivalli, Christina

    2014-07-01

    The natural emergence of status hierarchies in adolescent peer groups has long been assumed to help prevent future intragroup aggression. However, clear evidence of this beneficial influence is lacking. In fact, few studies have examined between-group differences in the degree of status hierarchy (defined as within-group variation in individual status) and how they are related to bullying, a widespread form of aggression in schools. Data from 11,296 eighth- and ninth-graders (mean age = 14.57, 50.6 % female) from 583 classes in 71 schools were used to determine the direction of the association between classroom degree of status hierarchy and bullying behaviors, and to investigate prospective relationships between these two variables over a 6-month period. Multilevel structural equation modeling analyses showed that higher levels of classroom status hierarchy were concurrently associated with higher levels of bullying at the end of the school year. Higher hierarchy in the middle of the school year predicted higher bullying later in the year. No evidence was found to indicate that initial bullying predicted future hierarchy. These findings highlight the importance of a shared balance of power in the classroom for the prevention of bullying among adolescents.

  8. Decoding Brain States Based on Magnetoencephalography From Prespecified Cortical Regions.

    Science.gov (United States)

    Zhang, Jinyin; Li, Xin; Foldes, Stephen T; Wang, Wei; Collinger, Jennifer L; Weber, Douglas J; Bagić, Anto

    2016-01-01

    Brain state decoding based on whole-head MEG has been extensively studied over the past decade. Recent MEG applications pose an emerging need of decoding brain states based on MEG signals originating from prespecified cortical regions. Toward this goal, we propose a novel region-of-interest-constrained discriminant analysis algorithm (RDA) in this paper. RDA integrates linear classification and beamspace transformation into a unified framework by formulating a constrained optimization problem. Our experimental results based on human subjects demonstrate that RDA can efficiently extract the discriminant pattern from prespecified cortical regions to accurately distinguish different brain states.

  9. The quadratic-form identity for constructing Hamiltonian structures of the Guo hierarchy

    Institute of Scientific and Technical Information of China (English)

    Dong Huan-He; Zhang Ning

    2006-01-01

    The trace identity is extended to the quadratic-form identity. The Hamiltonian structures of the multi-component Guo hierarchy, integrable coupling of Guo hierarchy and (2+1)-dimensional Guo hierarchy are obtained by the quadraticform identity. The method can be used to produce the Hamiltonian structures of the other integrable couplings or multi-component hierarchies.

  10. Are we 'Nazi Germans' or 'Lazy Greeks'? Negotiating International Hierarchies in the Euro Crisis

    DEFF Research Database (Denmark)

    Adler-Nissen, Rebecca

    2016-01-01

    This chapter argues that to understand international hierarchies, we need to examine not only the type of hierarchy, but also processes of internalization of – and resistance to – hierarchies. We will then discover that many hierarchies are not simply imposed from above, but that subordinate acto...

  11. Age-Dependent Cortical Thinning of Peripheral Visual Field Representations in Primary Visual Cortex.

    Science.gov (United States)

    Griffis, Joseph C; Burge, Wesley K; Visscher, Kristina M

    2016-01-01

    The cerebral cortex changes throughout the lifespan, and the cortical gray matter in many brain regions becomes thinner with advancing age. Effects of aging on cortical thickness (CT) have been observed in many brain regions, including areas involved in basic perceptual functions such as processing visual inputs. An important property of early visual cortices is their topographic organization-the cortical structure of early visual areas forms a topographic map of retinal inputs. Primary visual cortex (V1) is considered to be the most basic cortical area in the visual processing hierarchy, and is topographically organized from posterior (central visual representation) to anterior (peripheral visual representation) along the calcarine sulcus. Some studies have reported strong age-dependent cortical thinning in portions of V1 that likely correspond to peripheral visual representations, while there is less evidence of substantial cortical thinning in central V1. However, the effect of aging on CT in V1 as a function of its topography has not been directly investigated. To address this gap in the literature, we estimated the CT of different eccentricity sectors in V1 using T1-weighted MRI scans acquired from groups of healthy younger and older adults, and then assessed whether between-group differences in V1 CT depended on cortical eccentricity. These analyses revealed age-dependent cortical thinning specific to peripheral visual field representations in anterior portions of V1, but did not provide evidence for age-dependent cortical thinning in other portions of V1. Additional analyses found similar effects when analyses were restricted to the gyral crown, sulcul depth and sulcul wall, indicating that these effects are not likely due to differences in gyral/sulcul contributions to our regions of interest (ROI). Importantly, this finding indicates that age-dependent changes in cortical structure may differ among functionally distinct zones within larger canonical

  12. Focal cortical dysplasia – review

    Science.gov (United States)

    Kabat, Joanna; Król, Przemysław

    2012-01-01

    Summary Focal cortical dysplasia is a malformation of cortical development, which is the most common cause of medically refractory epilepsy in the pediatric population and the second/third most common etiology of medically intractable seizures in adults. Both genetic and acquired factors are involved in the pathogenesis of cortical dysplasia. Numerous classifications of the complex structural abnormalities of focal cortical dysplasia have been proposed – from Taylor et al. in 1971 to the last modification of Palmini classification made by Blumcke in 2011. In general, three types of cortical dysplasia are recognized. Type I focal cortical dysplasia with mild symptomatic expression and late onset, is more often seen in adults, with changes present in the temporal lobe. Clinical symptoms are more severe in type II of cortical dysplasia usually seen in children. In this type, more extensive changes occur outside the temporal lobe with predilection for the frontal lobes. New type III is one of the above dysplasias with associated another principal lesion as hippocampal sclerosis, tumor, vascular malformation or acquired pathology during early life. Brain MRI imaging shows abnormalities in the majority of type II dysplasias and in only some of type I cortical dysplasias. The most common findings on MRI imaging include: focal cortical thickening or thinning, areas of focal brain atrophy, blurring of the gray-white junction, increased signal on T2- and FLAIR-weighted images in the gray and subcortical white matter often tapering toward the ventricle. On the basis of the MRI findings, it is possible to differentiate between type I and type II cortical dysplasia. A complete resection of the epileptogenic zone is required for seizure-free life. MRI imaging is very helpful to identify those patients who are likely to benefit from surgical treatment in a group of patients with drug-resistant epilepsy. However, in type I cortical dysplasia, MR imaging is often normal, and also

  13. Analysis of Cortical Flow Models In Vivo

    Science.gov (United States)

    Benink, Hélène A.; Mandato, Craig A.; Bement, William M.

    2000-01-01

    Cortical flow, the directed movement of cortical F-actin and cortical organelles, is a basic cellular motility process. Microtubules are thought to somehow direct cortical flow, but whether they do so by stimulating or inhibiting contraction of the cortical actin cytoskeleton is the subject of debate. Treatment of Xenopus oocytes with phorbol 12-myristate 13-acetate (PMA) triggers cortical flow toward the animal pole of the oocyte; this flow is suppressed by microtubules. To determine how this suppression occurs and whether it can control the direction of cortical flow, oocytes were subjected to localized manipulation of either the contractile stimulus (PMA) or microtubules. Localized PMA application resulted in redirection of cortical flow toward the site of application, as judged by movement of cortical pigment granules, cortical F-actin, and cortical myosin-2A. Such redirected flow was accelerated by microtubule depolymerization, showing that the suppression of cortical flow by microtubules is independent of the direction of flow. Direct observation of cortical F-actin by time-lapse confocal analysis in combination with photobleaching showed that cortical flow is driven by contraction of the cortical F-actin network and that microtubules suppress this contraction. The oocyte germinal vesicle serves as a microtubule organizing center in Xenopus oocytes; experimental displacement of the germinal vesicle toward the animal pole resulted in localized flow away from the animal pole. The results show that 1) cortical flow is directed toward areas of localized contraction of the cortical F-actin cytoskeleton; 2) microtubules suppress cortical flow by inhibiting contraction of the cortical F-actin cytoskeleton; and 3) localized, microtubule-dependent suppression of actomyosin-based contraction can control the direction of cortical flow. We discuss these findings in light of current models of cortical flow. PMID:10930453

  14. Hiperostosis cortical infantil

    Directory of Open Access Journals (Sweden)

    Salvador Javier Santos Medina

    2015-04-01

    Full Text Available La enfermedad de Caffey, o hiperostosis cortical infantil, es una rara enfermedad ósea autolimitada, que aparece de preferencia en lactantes con signos inespecíficos sistémicos; el más relevante es la reacción subperióstica e hiperostosis en varios huesos del cuerpo, con predilección en el 75-80 % de los casos por la mandíbula. Su pronóstico es bueno, la mayoría no deja secuelas. El propósito del presente trabajo es describir las características clínicas, presentes en un lactante de cinco meses de edad, atendido en el Hospital Pediátrico Provincial “Mártires de Las Tunas” con este diagnóstico, quien ingresó en el servicio de miscelánea B por una celulitis facial. Presentaba aumento de volumen en la región geniana izquierda, febrícola e inapetencia. Se impuso tratamiento con cefazolina y se egresó a los siete días. Acudió nuevamente con tumefacción blanda y difusa de ambas hemicaras, irritabilidad y fiebre. Se interconsultó con cirugía maxilofacial, se indicaron estudios sanguíneos y radiológicos. Se diagnosticó como enfermedad de Caffey, basado en la edad del niño, tumefacción facial sin signos inflamatorios agudos e hiperostosis en ambas corticales mandibulares a la radiografía AP mandíbula; unido a anemia ligera, leucocitosis y eritrosedimentación acelerada. El paciente se trató sintomáticamente y con antinflamatorios no esteroideos. Esta rara entidad se debe tener presente en casos de niños y lactantes con irritabilidad y fiebre inespecífica

  15. Cortical Button Fixation: A Better Patellar Tendon Repair?

    Science.gov (United States)

    Ode, Gabriella E; Piasecki, Dana P; Habet, Nahir A; Peindl, Richard D

    2016-10-01

    Patellar tendon ruptures require surgical repair to optimize outcomes, but no consensus exists regarding the ideal repair technique. Cortical button fixation is a secure method for tendon repair that has not been studied in patellar tendons. Cortical button repair is biomechanically superior to the standard transpatellar repair and biomechanically equivalent to suture anchor repair. Controlled laboratory study. Twenty-three fresh-frozen cadaveric knees were used to compare 3 techniques of patellar tendon repair after a simulated rupture at the inferior pole of the patella. Repairs were performed at 45° of flexion using a standard transpatellar suture repair (n = 7), polyetheretherketone (PEEK) suture anchor repair (n = 8), or cortical button repair (n = 8). All specimens were tested on a custom apparatus to simulate cyclic open kinetic chain quadriceps contraction from extension to 90(o) of flexion. Outcomes of gap formation up to 250 cycles, maximum load to failure, and mode of failure were evaluated. Cortical button repair had significantly less gap formation than anchor repair after 1 cycle (P button repair sustained significantly higher loads to failure than anchor repair and suture repair (P button repairs either failed through the suture (n = 5), secondary failure of the patellar tendon (n = 2), or subsidence of the button through the anterior cortex of the patella (n = 1). Patellar tendon repair using cortical button fixation demonstrated mechanical advantages over suture repair and anchor repair in cadaveric specimens. Cortical button fixation showed less cyclic gap formation and withstood at least twice the load to failure of the construct. The biomechanical superiority of cortical button fixation may impart clinical advantages in accelerating postoperative rehabilitation. © 2016 The Author(s).

  16. Optimization Design for Digital Binoculars

    Institute of Scientific and Technical Information of China (English)

    CEN Jun-bo; CHEN Wei-min; LI Hui; HUANG Shang-lian

    2005-01-01

    In order to develop competitive and high performance/cost ratio of digital binoculars, design scheme should be optimized in term of technical capacity, economic benefit, product performance, risk management, etc. The common optimization method is limited in qualitative analysis, and the parameter optimization method is limited in obtaining optimal parameter only from technical side. Each method has its limitation. Based on the analysis of digital binoculars parameters, optional design schemes are laid down.Analytic hierarchy process combined the qualitative analysis with the quantitative analysis together. The design schemes are optimized, and result is worked out.

  17. Decision making software for effective selection of treatment train alternative for wastewater using analytical hierarchy process.

    Science.gov (United States)

    Prasad, A D; Tembhurkar, A R

    2013-10-01

    Proper selection of treatment process and synthesis of treatment train is complex engineering activity requires crucial decision making during planning and designing of any Wastewater Treatment Plant (WWTP). Earlier studies on process selection mainly considered cost as the most important selection criteria and number of studies focused on cost optimization models using dynamic programming, geometric programming and nonlinear programming. However, it has been noticed that traditional cost analysis alone cannot be applied to evaluate Treatment Train (TT) alternatives, as number of important non-tangible factors cannot be easily expressed in monetary units. Recently researches focus on use of multi-criteria technique for selection of treatment process. AHP provides a powerful tool for multi-hierarchy and multi-variable system overcoming limitation of traditional techniques. The AHP model designed to facilitate proper decision making and reduce the margin of errors during optimization due to number of parameters in the hierarchy levels has been used in this study. About 14 important factors and 13 sub factors were identified for the selection of treatment alternatives for wastewater and sludge stream although cost is one of the most important selection criteria. The present paper provides details of developing a soft-tool called "ProSelArt" using an AHP model aiding for proper decision making.

  18. Collateral blood flow in different cerebrovascular hierarchy provides endogenous protection in cerebral ischemia.

    Science.gov (United States)

    Luo, Chuanming; Liang, Fengyin; Ren, Huixia; Yao, Xiaoli; Liu, Qiang; Li, Mingyue; Qin, Dajiang; Yuan, Ti-Fei; Pei, Zhong; Su, Huanxing

    2016-11-15

    Collateral blood flow as vascular adaptions to focal cerebral ischemia is well recognized. However, few studies directly investigate the dynamics of collateral vessel recruitment in vivo and little is known about the effect of collateral blood flow in different cerebrovascular hierarchy on the neuropathology after focal ischemic stroke. Here, we report that collateral blood flow is critically involved in blood vessel compensations following regional ischemia. We occluded a pial arteriole using femtosecond laser ablating under the intact thinned skull and documented the changes of collateral flow around the surface communication network and between the surface communication network and subsurface microcirculation network using in vivo two photon microscopy imaging. Occlusion of the pial arteriole apparently increased the diameter and collateral blood flow of its leptomeningeal anastomoses, which significantly reduced the cortical infarction size. This result suggests that the collateral flow via surface communicating network connected with leptomeningeal anastomoses could greatly impact on the extent of infarction. We then further occluded the target pial arteriole and all of its leptomeningeal anastomoses. Notably, this type of occlusion led to reversals of blood flow in the penetrating arterioles mainly proximal to the occluded pial arteriole in a direction from the subsurface microcirculation network to surface arterioles. Interesting, the cell death in the area of ischemic penumbra was accelerated when we performed occlusion to cease the reversed blood flow in those penetrating arterioles, suggesting that the collateral blood flow from subsurface microcirculation network exerts protective roles in delaying cell death in the ischemic penumbra. In conclusion, we provide the first experimental evidence that collateral blood vessels at different cerebrovascular hierarchy are endogenously compensatory mechanisms in brain ischemia. This article is protected by

  19. Stroke rehabilitation using noninvasive cortical stimulation: hemispatial neglect.

    Science.gov (United States)

    Mylius, Veit; Ayache, Samar S; Zouari, Hela G; Aoun-Sebaïti, Mehdi; Farhat, Wassim H; Lefaucheur, Jean-Pascal

    2012-08-01

    The rehabilitation of neuropsychological sequels of cerebral stroke such as hemispatial neglect by noninvasive cortical stimulation (NICS) attracts increasing attention from the scientific community. The NICS techniques include primarily repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS). They are based on the concept of either reactivating a hypoactive cortical region affected by the stroke (the right hemisphere in case of neglect) or reducing cortical hyperactivity of the corresponding cortical region in the contralateral hemisphere (the left hemisphere). In the studies published to date on the topic of neglect rehabilitation, rTMS was used to inhibit the left parietal cortex and tDCS to either activate the right or inhibit the left parietal cortex. Sham-controlled NICS studies assessed short-term effects, whereas long-term effects were only assessed in noncontrolled rTMS studies. Further controlled studies of large series of patients are necessary to determine the best parameters of stimulation (including the optimal cortical target location) according to each subtype of neglect presentation and to the time course of stroke recovery. To date, even if there are serious therapeutic perspectives based on imaging data and experimental studies, the evidence is not compelling enough to recommend any particular NICS protocol to treat this disabling condition in clinical practice.

  20. The Development of Hierarchy of Effects Model in Advertising

    Directory of Open Access Journals (Sweden)

    Bambang Sukma Wijaya

    2012-04-01

    Full Text Available This paper aims to review the hierarchy of effects models in adverti-sing, especially the well-known model, AIDA (Attention, Interest, De-sire, and Action. Since its introduction by Lewis (1900 and generally attributed in the marketing and advertising literature by Strong (1925, the concept of AIDA’s hierarchy of effects model has been used by many researchers, both academicians and practitioners. The model is used to measure the effect of an advertisement. However, the deve-lopment of information technology has radically changed the way of how people communicate and socialize; as well as a paradigm shift from product-oriented marketing to consumer-oriented marketing or people-oriented marketing. Therefore, the variables in the hierarchy of effects model needs to be updated in respond to the latest develop-ments in the notice of public power as consumer audience. Based on deep literature review and reflective method, this paper introduces a new developed concept of hierarchy of effects model that was adop-ted from AIDA’s hierarchy of effects model, namely: AISDALSLove (At-tention, Interest, Search, Desire, Action, Like/dislike, Share, and Love/hate.

  1. Visual Hierarchy and Mind Motion in Advertising Design

    Directory of Open Access Journals (Sweden)

    Doaa Farouk Badawy Eldesouky

    2013-06-01

    Full Text Available Visual hierarchy is a significant concept in the field of advertising, a field that is dominated by effective communication, visual recognition and motion. Designers of advertisements have always been trying to organize the visual hierarchy throughout their advertising designs to aid the eye to recognize information in the desired order, to achieve the ultimate goals of clear perception and effectively delivering the advertising messages. However many assumptions and questions usually rise on how to create effective hierarchy throughout advertising designs and lead the eye and mind of the viewer in the most favorable way. This paper attempts to study visual hierarchy and mind motion in advertising designs and why it is important to develop visual paths when designing an advertisement. It explores the theory behind it, and how the very principles can be used to put these concepts into practice. The paper demonstrates some advertising samples applying visual hierarchy and mind motion in a representation of applying the basics and discussing the results.

  2. Global network structure of dominance hierarchy of ant workers.

    Science.gov (United States)

    Shimoji, Hiroyuki; Abe, Masato S; Tsuji, Kazuki; Masuda, Naoki

    2014-10-06

    Dominance hierarchy among animals is widespread in various species and believed to serve to regulate resource allocation within an animal group. Unlike small groups, however, detection and quantification of linear hierarchy in large groups of animals are a difficult task. Here, we analyse aggression-based dominance hierarchies formed by worker ants in Diacamma sp. as large directed networks. We show that the observed dominance networks are perfect or approximate directed acyclic graphs, which are consistent with perfect linear hierarchy. The observed networks are also sparse and random but significantly different from networks generated through thinning of the perfect linear tournament (i.e. all individuals are linearly ranked and dominance relationship exists between every pair of individuals). These results pertain to global structure of the networks, which contrasts with the previous studies inspecting frequencies of different types of triads. In addition, the distribution of the out-degree (i.e. number of workers that the focal worker attacks), not in-degree (i.e. number of workers that attack the focal worker), of each observed network is right-skewed. Those having excessively large out-degrees are located near the top, but not the top, of the hierarchy. We also discuss evolutionary implications of the discovered properties of dominance networks. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  3. Hierarchy through composition with multitask LMDPs

    CSIR Research Space (South Africa)

    Saxe, AM

    2017-08-01

    Full Text Available (akin to value iteration),98 zi QiPizi +QiPbzb. (5) F nally, the optimal policy may be computed in closed form as99 a⇤(s0|s) = P (s 0|s)Z(s0) G[Z]( ) , (6) where the normalizing constant G[Z](s) =Ps0 P (s0|s)Z(s0). Detailed derivations of these results... flow fr m the linearity of the Bellman equation, whic we exploit in the following.96 So ving for zi may be done explicitly a zi = (I � QiPi)�1QiPbzb or via the z-iteration method7 (ak n to value iteration),98 zi QiPizi +QiPbzb. (5) Finally, the optimal...

  4. Cortical Correlates of Fitts’ Law

    Directory of Open Access Journals (Sweden)

    Peter eIfft

    2011-12-01

    Full Text Available Fitts' law describes the fundamental trade-off between movement accuracy and speed: It states that the duration of reaching movements is a function of target size and distance. While Fitts' law has been extensively studied in ergonomics and has guided the design of human-computer interfaces, there have been few studies on its neuronal correlates. To elucidate sensorimotor cortical activity underlying Fitts’ law, we implanted two monkeys with multielectrode arrays in the primary motor (M1 and primary somatosensory (S1 cortices. The monkeys performed reaches with a joystick-controlled cursor towards targets of different size. The reaction time, movement time and movement velocity changed with target size, and M1 and S1 activity reflected these changes. Moreover, modifications of cortical activity could not be explained by changes of movement parameters alone, but required target size as an additional parameter. Neuronal representation of target size was especially prominent during the early reaction time period where it influenced the slope of the firing rate rise preceding movement initiation. During the movement period, cortical activity was mostly correlated with movement velocity. Neural decoders were applied to simultaneously decode target size and motor parameters from cortical modulations. We suggest using such classifiers to improve neuroprosthetic control.

  5. Inverse neutrino mass hierarchy in a flavour GUT model

    Energy Technology Data Exchange (ETDEWEB)

    Antusch, Stefan, E-mail: stefan.antusch@unibas.ch [Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel (Switzerland); Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 München (Germany); Gross, Christian, E-mail: christian.gross@unibas.ch [Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel (Switzerland); Maurer, Vinzenz, E-mail: vinzenz.maurer@unibas.ch [Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel (Switzerland); Sluka, Constantin, E-mail: constantin.sluka@unibas.ch [Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel (Switzerland)

    2014-02-15

    We construct a supersymmetric SU(5)×A{sub 4} flavour GUT model in which an inverse neutrino mass hierarchy is realised without fine-tuning of parameters. The model shares some properties with the normal hierarchy model which we presented in (arXiv:1305.6612) – in particular the relation θ{sub 13}{sup PMNS}≃θ{sub C}/√(2). Besides these shared features, there are also important differences, mainly due to the different neutrino sector. These differences not only change the predictions in the lepton sector, but also in the quark sector, and will allow to discriminate between the two models using the results of present and future experiments. From a Markov Chain Monte Carlo fit we find that the inverse hierarchy model is in excellent agreement with the present experimental data.

  6. Inverse neutrino mass hierarchy in a flavour GUT model

    CERN Document Server

    Antusch, Stefan; Maurer, Vinzenz; Sluka, Constantin

    2014-01-01

    We construct a supersymmetric SU(5) x A_4 flavour GUT model in which an inverse neutrino mass hierarchy is realised without fine-tuning of parameters. The model shares some properties with the normal hierarchy model which we presented in arXiv:1305.6612 - in particular the relation theta_13^PMNS = theta_C / sqrt(2). Besides these shared features, there are also important differences, mainly due to the different neutrino sector. These differences not only change the predictions in the lepton sector, but also in the quark sector, and will allow to discriminate between the two models using the results of present and future experiments. From a Markov Chain Monte Carlo fit we find that the inverse hierarchy model is in excellent agreement with the present experimental data.

  7. Biochemical energetics of hierarchy formation in Betta splendens.

    Science.gov (United States)

    Haller, J; Wittenberger, C

    1988-01-01

    Two different stages of hierarchy formation in Betta splendens were considered. Winners and losers in a short social contact, and dominant and submissive individuals after the establishment of a hierarchy, respectively, were identified. Metabolical determinations (free glucose, glycogen and protein content, glycogen and protein synthesis, glucose and amino acid oxidation, carbohydrate degradation) were performed. Winners and dominant individuals were shown to be able to produce more energy per unit time than losers and submissives, respectively. Differences in energy metabolism between individuals found in different stages of hierarchy formation also occurred: the carbohydrate degradation reached very high values after a short social contact. This is related to the noticed substitution of aggressive encounters with threat displays in the course of cohabitation.

  8. Hierarchy, Violence and Bullying Among Students of Public Middle Schools

    Directory of Open Access Journals (Sweden)

    José Leon Crochík

    Full Text Available Abstract Hierarchies established in schools can lead to violence among students, particularly bullying, and this relationship is investigated in this study. A School Hierarchies Scale and a Peer Perception of Aggression Scale were applied to 274 9th grade students, both sexes, aged 14.08 years (SD = 0.81 old on average, attending four public schools in the state of São Paulo, Brazil. The students more frequently perceived to be popular, were among the best in physical education and/or among the worst in academic subjects were also more frequently perceived to be bullies, while those more frequently perceived to be unpopular and having the worst performance in physical education were also more frequently perceived to be victims. Therefore, teachers should reflect upon the issue and fight school violence that may arise from these hierarchies.

  9. Learning Concept Hierarchies from Text Corpora using Formal Concept Analysis

    CERN Document Server

    Cimiano, P; Staab, S; 10.1613/jair.1648

    2011-01-01

    We present a novel approach to the automatic acquisition of taxonomies or concept hierarchies from a text corpus. The approach is based on Formal Concept Analysis (FCA), a method mainly used for the analysis of data, i.e. for investigating and processing explicitly given information. We follow Harris distributional hypothesis and model the context of a certain term as a vector representing syntactic dependencies which are automatically acquired from the text corpus with a linguistic parser. On the basis of this context information, FCA produces a lattice that we convert into a special kind of partial order constituting a concept hierarchy. The approach is evaluated by comparing the resulting concept hierarchies with hand-crafted taxonomies for two domains: tourism and finance. We also directly compare our approach with hierarchical agglomerative clustering as well as with Bi-Section-KMeans as an instance of a divisive clustering algorithm. Furthermore, we investigate the impact of using different measures wei...

  10. Vagus nerve stimulation inhibits cortical spreading depression.

    Science.gov (United States)

    Chen, Shih-Pin; Ay, Ilknur; de Morais, Andreia Lopes; Qin, Tao; Zheng, Yi; Sadeghian, Homa; Oka, Fumiaki; Simon, Bruce; Eikermann-Haerter, Katharina; Ayata, Cenk

    2016-04-01

    Vagus nerve stimulation has recently been reported to improve symptoms of migraine. Cortical spreading depression is the electrophysiological event underlying migraine aura and is a trigger for headache. We tested whether vagus nerve stimulation inhibits cortical spreading depression to explain its antimigraine effect. Unilateral vagus nerve stimulation was delivered either noninvasively through the skin or directly by electrodes placed around the nerve. Systemic physiology was monitored throughout the study. Both noninvasive transcutaneous and invasive direct vagus nerve stimulations significantly suppressed spreading depression susceptibility in the occipital cortex in rats. The electrical stimulation threshold to evoke a spreading depression was elevated by more than 2-fold, the frequency of spreading depressions during continuous topical 1 M KCl was reduced by ∼40%, and propagation speed of spreading depression was reduced by ∼15%. This effect developed within 30 minutes after vagus nerve stimulation and persisted for more than 3 hours. Noninvasive transcutaneous vagus nerve stimulation was as efficacious as direct invasive vagus nerve stimulation, and the efficacy did not differ between the ipsilateral and contralateral hemispheres. Our findings provide a potential mechanism by which vagus nerve stimulation may be efficacious in migraine and suggest that susceptibility to spreading depression is a suitable platform to optimize its efficacy.

  11. Cortical myoclonus in Huntington's disease.

    Science.gov (United States)

    Thompson, P D; Bhatia, K P; Brown, P; Davis, M B; Pires, M; Quinn, N P; Luthert, P; Honovar, M; O'Brien, M D; Marsden, C D

    1994-11-01

    We describe three patients with Huntington's disease, from two families, in whom myoclonus was the predominant clinical feature. The diagnosis was confirmed at autopsy in two cases and by DNA analysis in all three. These patients all presented before the age of 30 years and were the offspring of affected fathers. Neurophysiological studies documented generalised and multifocal action myoclonus of cortical origin that was strikingly stimulus sensitive, without enlargement of the cortical somatosensory evoked potential. The myoclonus improved with piracetam therapy in one patient and a combination of sodium valproate and clonazepam in the other two. Cortical reflex myoclonus is a rare but disabling component of the complex movement disorder of Huntington's disease, which may lead to substantial diagnostic difficulties.

  12. Equal-Time Hierarchies for Quantum Transport Theory

    CERN Document Server

    Zhuang, P; Zhuang, Pengfei; Heinz, Ulrich

    1998-01-01

    We investigate in the equal-time formalism the derivation and truncation of infinite hierarchies of equations of motion for the energy moments of the covariant Wigner function. From these hierarchies we then extract kinetic equations for the physical distribution functions which are related to low-order energy moments, and show how to determine the higher order moments in terms of these lowest order ones. We apply the general formalism to scalar and spinor QED with classical background fields and compare with the results derived from the three-dimensional Wigner transformation method.

  13. The Alternation Hierarchy for the Theory of µ-lattices

    DEFF Research Database (Denmark)

    Santocanale, Luigi

    2002-01-01

    independent of φ. In this paper we give a proof that the alternation hierarchy for the theory of µ-lattices is strict, meaning that such a constant does not exist if µ-term are built up from the basic lattice operations and are interpreted as expected. The proof relies on the explicit characterization of free......The alternation hierarchy problem asks whether every µ-term φ, that is, a term built up also using a least fixed point constructor as well as a greatest fixed point constructor, is equivalent to a µ-term where the number of nested fixed points of a different type is bounded by a constant...

  14. Critical Analysis of Maslow’s Hierarchy of Need

    OpenAIRE

    King-Hill, Sophie

    2015-01-01

    This paper intends to provide a critique of Maslow’s Hierarchy of Need, a psychological model that often goes unquestioned within the education sector. Examples will be given of the authors own professional practice and experience in relation to the Hierarchy of Need (HON) and discussed in terms of the critique. The paper concludes that whilst some elements of the HON may be useful in education it does have some serious flaws that also need to be considered when applying this to practice. Thi...

  15. An Operational Foundation for Delimited Continuations in the CPS Hierarchy

    DEFF Research Database (Denmark)

    Biernacka, Malgorzata; Biernacki, Dariusz; Danvy, Olivier

    2004-01-01

    We present an abstract machine and a reduction semantics for the lambda-calculus extended with control operators that give access to delimited continuations in the CPS hierarchy. The abstract machine is derived from an evaluator in continuation-passing style (CPS); the reduction semantics (i.......e., a small-step operational semantics with an explicit representation of evaluation contexts) is constructed from the abstract machine; and the control operators are the shift and reset family. We also present new applications of delimited continuations in the CPS hierarchy: finding list prefixes...

  16. Probing the Neutrino Mass Hierarchy with Super-Kamiokande

    CERN Document Server

    Agarwalla, Sanjib Kumar

    2012-01-01

    We show that a superbeam with an average neutrino energy of ~ 5 GeV, such as those being proposed at CERN, if pointing to Super-Kamiokande (L \\simeq 8770 km), could reveal the neutrino mass hierarchy at 5 sigma in less than two years irrespective of the true hierarchy and CP phase. The measurement relies on the near resonant matter effect in the numu \\rightarrow nue oscillation channel, and can be done counting the total number of appearance events with just a neutrino beam.

  17. Extended (Super-) KP-hierarchies and generalised String equations

    CERN Document Server

    Maroufi, B; Sedra, M B

    2000-01-01

    We propose a consistently algebraic formulation of the extended KP (supersymmetric) integrable -hierarchy systems. We exploit the results already established in [14] and which consist in a framework suspected to unify in a fascinating way all the possible supersymmetric KP-hierarchies and then their underlying supergravity theories . This construction leads among other to built explicit non standard integrable Lax evolution equations suspected to reduce to the well known KP integrable equation. We present also a contribution of our construction to the subject of string equation and solitons. Other algebraic properties are also presented

  18. PHC: A Fast Partition and Hierarchy-Based Clustering Algorithm

    Institute of Scientific and Technical Information of China (English)

    ZHOU HaoFeng(周皓峰); YUAN QingQing(袁晴晴); CHENG ZunPing(程尊平); SHI BaiLe(施伯乐)

    2003-01-01

    Cluster analysis is a process to classify data in a specified data set. In this field,much attention is paid to high-efficiency clustering algorithms. In this paper, the features in thecurrent partition-based and hierarchy-based algorithms are reviewed, and a new hierarchy-basedalgorithm PHC is proposed by combining advantages of both algorithms, which uses the cohesionand the closeness to amalgamate the clusters. Compared with similar algorithms, the performanceof PHC is improved, and the quality of clustering is guaranteed. And both the features were provedby the theoretic and experimental analyses in the paper.

  19. Open intersection numbers, matrix models and MKP hierarchy

    CERN Document Server

    Alexandrov, A

    2014-01-01

    In this paper we claim that the generating function of the intersection numbers on the moduli spaces of Riemann surfaces with boundary, constructed recently by R. Pandharipande, J. Solomon and R. Tessler and extended by A. Buryak, is a tau-function of the KP integrable hierarchy. Moreover, it is given by a simple modification of the Kontsevich matrix integral so that the generating functions of open and closed intersection numbers are described by the MKP integrable hierarchy. Virasoro constraints for the open intersection numbers naturally follow from the matrix integral representation.

  20. Open intersection numbers, matrix models and MKP hierarchy

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrov, A. [Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg,Albertstrasse 19, 79104 Freiburg (Germany); Mathematics Institute, University of Freiburg,Eckerstrasse 1, 79104 Freiburg (Germany); ITEP,Bolshaya Cheremushkinskaya 25, 117218 Moscow (Russian Federation)

    2015-03-09

    In this paper we conjecture that the generating function of the intersection numbers on the moduli spaces of Riemann surfaces with boundary, constructed recently by R. Pandharipande, J. Solomon and R. Tessler and extended by A. Buryak, is a tau-function of the KP integrable hierarchy. Moreover, it is given by a simple modification of the Kontsevich matrix integral so that the generating functions of open and closed intersection numbers are described by the MKP integrable hierarchy. Virasoro constraints for the open intersection numbers naturally follow from the matrix integral representation.

  1. Headwater biodiversity among different levels of stream habitat hierarchy

    DEFF Research Database (Denmark)

    Göthe, Emma; Friberg, Nikolai; Kahlert, Maria

    2014-01-01

    of a- and b-diversity to y-diversity between two levels of stream habitat hierarchy (catchment and region level). The relationship between species community structure and local environmental factors was also assessed. Our results show that both a- and b-diversity made a significant contribution to y......-diversity. b-diversity remained relatively constant between the two levels of habitat hierarchy even though local environmental control of the biota decreased from the catchment to the region level. To capture most of headwater y-diversity, management should therefore target sites that are locally diverse...

  2. Singular sector of the Burgers-Hopf hierarchy and deformations of hyperelliptic curves

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, Yuji [Department of Mathematics, Ohio State University, Columbus, OH (United States)]. E-mail: kodama@math.ohio-state.edu; Konopelchenko, Boris G. [Dipartimento di Fisica, Universita di Lecce and Sezione INFN, Lecce (Italy)]. E-mail: konopel@le.infn.it

    2002-08-09

    We discuss the structure of shock singularities of the Burgers-Hopf hierarchy. It is shown that the set of singular solutions defines a stratification of the affine space of the flow parameters in the hierarchy. The stratification is associated with the Birkhoff decomposition of the Grassmannian given by the set of linear spaces spanned by the hierarchy. We then construct integrable hierarchy on each stratum and demonstrate that it describes a deformation of a hyperelliptic curve parametrizing the stratum. The hierarchy is called the hidden Burgers-Hopf hierarchy, and we found the Riemann invariant form and the hodograph solution. (author)

  3. Block algebra in two-component BKP and D type Drinfeld-Sokolov hierarchies

    Science.gov (United States)

    Li, Chuanzhong; He, Jingsong

    2013-11-01

    We construct generalized additional symmetries of a two-component BKP hierarchy defined by two pseudo-differential Lax operators. These additional symmetry flows form a Block type algebra with some modified (or additional) terms because of a B type reduction condition of this integrable hierarchy. Further we show that the D type Drinfeld-Sokolov hierarchy, which is a reduction of the two-component BKP hierarchy, possess a complete Block type additional symmetry algebra. That D type Drinfeld-Sokolov hierarchy has a similar algebraic structure as the bigraded Toda hierarchy which is a differential-discrete integrable system.

  4. New Positive and Negative Hierarchies of Integrable Differential-Difference Equations and Conservation Laws

    Institute of Scientific and Technical Information of China (English)

    LI Xin-Yue; ZHAO Qiu-Lan

    2009-01-01

    Two hierarchies of nonlinear integrable positive and negative lattice equations are derived from a discrete spectral problem. The two lattice hierarchies are proved to have discrete zero curvature representations associated with a discrete spectral problem, which also shows that the positive and negative hierarchies correspond to positive and negative power expansions of Lax operators with respect to the spectral parameter, respectively. Moreover, the integrable lattice models in the positive hierarchy are of polynomial type, and the integrable lattice models in the negative hierarchy are of rationed type. Further, we construct infinite conservation laws about the positive hierarchy.

  5. Integrable lattice hierarchies associated with two new (2+1)-dimensional discrete spectral problems

    Energy Technology Data Exchange (ETDEWEB)

    Pickering, Andrew [Dpto. de Matematica Aplicada, ESCET, Universidad Rey Juan Carlos C/ Tulipan s/n, 28933 Mostoles, Madrid (Spain); Zhu Zuonong, E-mail: znzhu2@yahoo.com.c [Department of Mathematics, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

    2009-10-19

    In this Letter, by considering two new (2+1)-dimensional discrete linear spectral problems, new (2+1)-dimensional integrable lattice hierarchies are constructed. It is shown that the two new (2+1)-dimensional integrable lattice hierarchies are extensions (to nonisospectral and (2+1)-dimensional cases) of a (1+1)-dimensional 3-field lattice hierarchy of Zhang et al. and a (1+1)-dimensional 2-field lattice hierarchy due to Merola, Ragnisco and Tu. We also obtain new (1+1)-dimensional nonisospectral lattice hierarchies which include a nonisospectral relativistic Toda lattice hierarchy.

  6. Block algebra in two-component BKP and D type Drinfeld-Sokolov hierarchies

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chuanzhong, E-mail: lichuanzhong@nbu.edu.cn; He, Jingsong, E-mail: hejingsong@nbu.edu.cn [Department of Mathematics, Ningbo University, Ningbo 315211 (China)

    2013-11-15

    We construct generalized additional symmetries of a two-component BKP hierarchy defined by two pseudo-differential Lax operators. These additional symmetry flows form a Block type algebra with some modified (or additional) terms because of a B type reduction condition of this integrable hierarchy. Further we show that the D type Drinfeld-Sokolov hierarchy, which is a reduction of the two-component BKP hierarchy, possess a complete Block type additional symmetry algebra. That D type Drinfeld-Sokolov hierarchy has a similar algebraic structure as the bigraded Toda hierarchy which is a differential-discrete integrable system.

  7. Grid cells and cortical representation.

    Science.gov (United States)

    Moser, Edvard I; Roudi, Yasser; Witter, Menno P; Kentros, Clifford; Bonhoeffer, Tobias; Moser, May-Britt

    2014-07-01

    One of the grand challenges in neuroscience is to comprehend neural computation in the association cortices, the parts of the cortex that have shown the largest expansion and differentiation during mammalian evolution and that are thought to contribute profoundly to the emergence of advanced cognition in humans. In this Review, we use grid cells in the medial entorhinal cortex as a gateway to understand network computation at a stage of cortical processing in which firing patterns are shaped not primarily by incoming sensory signals but to a large extent by the intrinsic properties of the local circuit.

  8. Paroxysmal kinesigenic dyskinesia : Cortical or non-cortical origin

    NARCIS (Netherlands)

    van Strien, Teun W.; van Rootselaar, Anne-Fleur; Hilgevoord, Anthony A. J.; Linssen, Wim H. J. P.; Groffen, Alexander J. A.; Tijssen, Marina A. J.

    2012-01-01

    Paroxysmal kinesigenic dyskinesia (PKD) is characterized by involuntary dystonia and/or chorea triggered by a sudden movement. Cases are usually familial with an autosomal dominant inheritance. Hypotheses regarding the pathogenesis of PKD focus on the controversy whether PKD has a cortical or non-co

  9. Face activated neurodynamic cortical networks.

    Science.gov (United States)

    Susac, Ana; Ilmoniemi, Risto J; Ranken, Doug; Supek, Selma

    2011-05-01

    Previous neuroimaging studies have shown that complex visual stimuli, such as faces, activate multiple brain regions, yet little is known on the dynamics and complexity of the activated cortical networks during the entire measurable evoked response. In this study, we used simulated and face-evoked empirical MEG data from an oddball study to investigate the feasibility of accurate, efficient, and reliable spatio-temporal tracking of cortical pathways over prolonged time intervals. We applied a data-driven, semiautomated approach to spatio-temporal source localization with no prior assumptions on active cortical regions to explore non-invasively face-processing dynamics and their modulation by task. Simulations demonstrated that the use of multi-start downhill simplex and data-driven selections of time intervals submitted to the Calibrated Start Spatio-Temporal (CSST) algorithm resulted in improved accuracy of the source localization and the estimation of the onset of their activity. Locations and dynamics of the identified sources indicated a distributed cortical network involved in face processing whose complexity was task dependent. This MEG study provided the first non-invasive demonstration, agreeing with intracranial recordings, of an early onset of the activity in the fusiform face gyrus (FFG), and that frontal activation preceded parietal for responses elicited by target faces.

  10. Using the analytical hierarchy process to evaluate target signatures

    CSIR Research Space (South Africa)

    Baumbach, J

    2008-10-01

    Full Text Available The Analytical Hierarchy Process (AHP) and the Law of Comparative Judgement (LCJ) are pairwise comparison methods. A large number of observers need to perform an LCJ evaluation in order to get accurate results. LCJ also does not provide an absolute...

  11. Effects of Hierarchy Vocabulary Exercises on English Vocabulary Acquisition

    Science.gov (United States)

    Lin, Ching-Ying; Hsu, Wei Shu

    2013-01-01

    The purpose of the study was to compare the effectiveness of hierarchy vocabulary exercises and copying vocabulary exercises on EFL students' vocabulary acquisition and reading comprehension. Two specific factors were probed: (a) vocabulary gains and retention from different exercises; (b) reading comprehension performance through different…

  12. Student Affairs as Perceived Through Abraham Maslow's Hierarchy of Needs.

    Science.gov (United States)

    Nowacki, Steven

    The needs of human behavior are explored and correlated to the various departments within Student Affairs in an effort to show how Student Affairs can satisfy those needs. Maslow's Hierarchy of needs is briefly explained and related to the following Student Affairs departments: Financial Aid, Student Management, Career Development and Placement,…

  13. Supersymmetry : the ultimate hierarchy of matter ? Conference MT17

    CERN Multimedia

    2001-01-01

    The concept of "Supersymmetry", SUSY for short, promises a solution to the hierarchy problem. SUSY enlarges the space-time symmetry of physical laws, by connecting the realms of particles and fields. It predicts a variety of new species of particles at the energy scale around 1 TeV - waiting to be discovered at the LHC.

  14. Periodic Hamiltonian hierarchies and non-uniqueness of superpotentials

    Indian Academy of Sciences (India)

    PARTHA MANDAL; ABHIJIT BANERJEE

    2017-01-01

    In this article, a family of periodic quantum Hamiltonians, that is subject to a closure condition is considered. In the context of the factorization method, we address the question of non-uniqueness of the governing superpotentials and study an alternative factorization to generate new hierarchies of potentials.

  15. An Operational Foundation for Delimited Continuations in the CPS Hierarchy

    DEFF Research Database (Denmark)

    Biernacka, Malgorzata; Biernacki, Dariusz; Danvy, Olivier

    2005-01-01

    .e., a small-step operational semantics with an explicit representation of evaluation contexts) is constructed from the abstract machine; and the control operators are the shift and reset family. We also present new applications of delimited continuations in the CPS hierarchy: finding list prefixes...

  16. An Operational Foundation for Delimited Continuations in the CPS Hierarchy

    DEFF Research Database (Denmark)

    Biernacka, Malgorzata; Biernacki, Dariusz; Danvy, Olivier

    2004-01-01

    .e., a small-step operational semantics with an explicit representation of evaluation contexts) is constructed from the abstract machine; and the control operators are the shift and reset family. We also present new applications of delimited continuations in the CPS hierarchy: finding list prefixes...

  17. Social Hierarchy and Depression: The Role of Emotion Suppression

    Science.gov (United States)

    Langner, Carrie A.; Epel, Elissa; Matthews, Karen; Moskowitz, Judith T.; Adler, Nancy

    2017-01-01

    Position in the social hierarchy is a major determinant of health outcomes. We examined the associations between aspects of social hierarchy and depressive symptoms with a specific focus on one potential psychological mechanism: emotion suppression. Suppressing negative emotion has mental health costs, but individuals with low social power and low social status may use these strategies to avoid conflict. Study 1 assessed perceived social power, tendency to suppress negative emotion, and depressive symptoms in a community sample of women. Low social power was related to greater depressive symptoms, and this relationship was partially mediated by emotion suppression. Study 2 examined education as a proxy for social hierarchy position, anger suppression, and depressive symptoms in a national, longitudinal cohort study (The Coronary Artery Risk Development in Young Adults (CARDIA) study). Similar to Study 1, low education levels were correlated with greater depressive symptoms, and this relationship was partially mediated by anger suppression. Further, suppression mediated the relationship between low education and subsequent depression up to 15 years later. These findings support the theory that social hierarchy affects mental health in part through a process of emotion suppression. PMID:22808688

  18. Working with ESL Writers: Turning Up and Down the Hierarchy.

    Science.gov (United States)

    Slocum, Sheryl

    2003-01-01

    Discusses a hierarchy of concerns tutors can use in working with ESL writers. Suggests that the student's understanding of the assignment, development of a thesis, logical organization, and fully developed ideas all supplant minor issues, such as improper use of the definite article or subject/verb agreement. (NB)

  19. Using the Analytical Hierarchy Process (AHP) to evaluate target signatures

    CSIR Research Space (South Africa)

    Baumbach, J

    2009-10-01

    Full Text Available www.csir.co.za two……..“ • Scientific method Field Evaluation of Camouflage Uniforms Current techniques: • Cumulative Probability of Detection (Sweden, WTD52) • Sliding Scales (USA) • Law of Comparative Judgment (Thurstone) • Analytic Hierarchy...

  20. Tissue-specific designs of stem cell hierarchies

    NARCIS (Netherlands)

    Visvader, Jane E; Clevers, Hans

    Recent work in the field of stem cell biology suggests that there is no single design for an adult tissue stem cell hierarchy, and that different tissues employ distinct strategies to meet their self-renewal and repair requirements. Stem cells may be multipotent or unipotent, and can exist in

  1. Factorization and resummation for generic hierarchies between jets

    Energy Technology Data Exchange (ETDEWEB)

    Pietrulewicz, Piotr; Tackmann, Frank J. [DESY, Hamburg (Germany). Theory Group; Waalewijn, Wouter J. [Amsterdam Univ. (Netherlands). ITFA; Nikhef, Amsterdam (Netherlands). Theory Group

    2016-01-15

    Jets are an important probe to identify the hard interaction of interest at the LHC. They are routinely used in Standard Model precision measurements as well as in searches for new heavy particles, including jet substructure methods. In processes with several jets, one typically encounters hierarchies in the jet transverse momenta and/or dijet invariant masses. Large logarithms of the ratios of these kinematic jet scales in the cross section are at present primarily described by parton showers. We present a general factorization framework called SCET{sub +}, which is an extension of Soft-Collinear Effective Theory (SCET) and allows for a systematic higher-order resummation of such kinematic logarithms for generic jet hierarchies. In SCET{sub +} additional intermediate soft/collinear modes are used to resolve jets arising from additional soft and/or collinear QCD emissions. The resulting factorized cross sections utilize collinear splitting amplitudes and soft gluon currents and fully capture spin and color correlations. We discuss how to systematically combine the different kinematic regimes to obtain a complete description of the jet phase space. To present its application in a simple context, we use the case of e{sup +}e{sup -} → 3 jets. We then discuss in detail the application to N-jet processes at hadron colliders, considering representative classes of hierarchies from which the most general case can be built. This includes in particular multiple hierarchies that are either strongly ordered in angle or energy or not.

  2. Dynamic fuzzy hierarchy analysis for evaluation of professionalization degree

    Science.gov (United States)

    Jin, Lin; Min, Luo; Ma, Jingxi

    2016-06-01

    This paper presents the model of dynamic fuzzy hierarchy analysis for evaluation of professionalization degree, as a combination of the dynamic fuzzy theory and the AHP, which can show the changes and trends of the value of each index of professionalization.

  3. Extending the applicability of the analytic hierarchy process

    NARCIS (Netherlands)

    Huizingh, K.R.E.; Vrolijk, H.C.J.

    1997-01-01

    The Analytic Hierarchy Process (AHP) has often been used to support decisions that only have to be made once. in this study, we explore whether the AHP can be applied to repetitive decision-making. We suggest a variant of the process to elicit implicit decision models that evaluate alternatives not

  4. CKP Hierarchy, Bosonic Tau Function and Bosonization Formulae

    NARCIS (Netherlands)

    van de Leur, J.W.; Orlov, A. Yu.; Shiota, T.

    2012-01-01

    We develop the theory of CKP hierarchy introduced in the papers of Kyoto school [Date E., Jimbo M., Kashiwara M., Miwa T., J. Phys. Soc. Japan 50 (1981), 3806-3812] (see also [Kac V.G., van de Leur J.W., Adv. Ser. Math. Phys., Vol. 7, World Sci. Publ., Teaneck, NJ, 1989, 369-406]). We present approp

  5. Evaluating Modeling Sessions Using the Analytic Hierarchy Process

    NARCIS (Netherlands)

    Ssebuggwawo, D.; Hoppenbrouwers, S.J.B.A.; Proper, H.A.

    2008-01-01

    In this paper, which is methodological in nature, we propose to use an established method from the field of Operations Research, the Analytic Hierarchy Process (AHP), in the integrated, stakeholder- oriented evaluation of enterprise modeling sessions: their language, pro- cess, tool (medium), and pr

  6. Supersymmetry : the ultimate hierarchy of matter? Exhibition LEPFest 2000

    CERN Multimedia

    2000-01-01

    The concept of "Supersymmetry", SUSY for short, promises a solution to the 'hierarchy' problem: the mystery of the enormous ratio between the electroweak scale (at 100-300 GeV), defined by the masses of the W and Z particles, and possibly the Higgs particle, and the Planck scale (10 19 GeV), when gravitational effects become comparable to the other forces.

  7. Factorization and resummation for generic hierarchies between Jets

    Science.gov (United States)

    Pietrulewicz, Piotr; Tackmann, Frank J.; Waalewijn, Wouter J.

    2016-08-01

    Jets are an important probe to identify the hard interaction of interest at the LHC. They are routinely used in Standard Model precision measurements as well as in searches for new heavy particles, including jet substructure methods. In processes with several jets, one typically encounters hierarchies in the jet transverse momenta and/or dijet invariant masses. Large logarithms of the ratios of these kinematic jet scales in the cross section are at present primarily described by parton showers. We present a general factorization framework called SCET+, which is an extension of Soft-Collinear Effective Theory (SCET) and allows for a systematic higher-order resummation of such kinematic logarithms for generic jet hierarchies. In SCET+ additional intermediate soft/collinear modes are used to resolve jets arising from additional soft and/or collinear QCD emissions. The resulting factorized cross sections utilize collinear splitting amplitudes and soft gluon currents and fully capture spin and color correlations. We discuss how to systematically combine the different kinematic regimes to obtain a complete description of the jet phase space. To present its application in a simple context, we use the case of e + e - → 3 jets. We then discuss in detail the application to N -jet processes at hadron colliders, considering representative classes of hierarchies from which the general case can be built. This includes in particular multiple hierarchies that are either strongly ordered in angle or energy or not.

  8. Theories of Gender Hierarchy for an Introductory Women's Studies Class

    Science.gov (United States)

    Jabbra, Nancy W.

    2008-01-01

    Issues of gender hierarchy are central in an introductory women's studies class. The author wishes to give students an overview of some of the classical feminist theories and also some of the newest thinking. Also, through showing them multiple feminist perspectives, she would like them to learn that there is no single hegemonic feminist view. Her…

  9. Restructuring Large Data Hierarchies for Scientific Query Tools

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, M

    2005-02-08

    Today's large-scale scientific simulations produce data sets tens to hundreds of terabytes in size. The DataFoundry project is developing querying and analysis tools for these data sets. The Approximate Ad-Hoc Query Engine for Simulation Data (AQSIM) uses a multi-resolution, tree-shaped data structure that allows users to place runtime limits on queries over scientific simulation data. In this AQSIM data hierarchy, each node in the tree contains an abstract model describing all of the information contained in the subtree below that node. AQSIM is able to create the data hierarchy in a single pass. However, the nodes in the hierarchy frequently have low node fanout, which leads to inefficient I/O behavior during query processing. Low node fanout is a common problem in tree-shaped indices. This paper presents a set of one-pass tree ''pruning'' algorithms that efficiently restructure the data hierarchy by removing inner nodes, thereby increasing node fanout. As our experimental results show, the best approach is a combination of two algorithms, one that focuses on increasing node fanout and one that attempts to reduce the maximum tree height.

  10. The Hierarchy of Minority Languages in New Zealand

    Science.gov (United States)

    de Bres, Julia

    2015-01-01

    This article makes a case for the existence of a minority language hierarchy in New Zealand. Based on an analysis of language ideologies expressed in recent policy documents and interviews with policymakers and representatives of minority language communities, it presents the arguments forwarded in support of the promotion of different types of…

  11. Shifting and Narrowing Masculinity Hierarchies in Physical Education: Status Matters

    Science.gov (United States)

    Tischler, Amy; McCaughtry, Nate

    2014-01-01

    The purpose of this study was to examine boys' perceptions of masculinity hierarchies in adventure physical education in relation to past experiences in sport-based physical education and their evolving views about physical activity in their lives. Theoretical principles of masculinity guided this study. Data were collected with 55 male high…

  12. Plasticity within stem cell hierarchies in mammalian epithelia

    NARCIS (Netherlands)

    Tetteh, Paul W; Farin, Henner F; Clevers, Hans

    Tissue homeostasis and regeneration are fueled by resident stem cells that have the capacity to self-renew, and to generate all the differentiated cell types that characterize a particular tissue. Classical models of such cellular hierarchies propose that commitment and differentiation occur

  13. Integrable coupling system of fractional soliton equation hierarchy

    Energy Technology Data Exchange (ETDEWEB)

    Yu Fajun, E-mail: yfajun@163.co [College of Maths and Systematic Science, Shenyang Normal University, Shenyang 110034 (China)

    2009-10-05

    In this Letter, we consider the derivatives and integrals of fractional order and present a class of the integrable coupling system of the fractional order soliton equations. The fractional order coupled Boussinesq and KdV equations are the special cases of this class. Furthermore, the fractional AKNS soliton equation hierarchy is obtained.

  14. Decision support for information systems management : applying analytic hierarchy process

    NARCIS (Netherlands)

    Huizingh, Eelko K.R.E.; Vrolijk, Hans C.J.

    1995-01-01

    Decision-making in the field of information systems has become more complex due to a larger number of alternatives, multiple and sometimes conflicting goals, and an increasingly turbulent environment. In this paper we explore the appropriateness of Analytic Hierarchy Process to support I/S decision

  15. Maslow's Need Hierarchy and the Adjustment of Immigrants

    Science.gov (United States)

    Adler, Seymour

    1977-01-01

    In this paper the need hierarchy theory of Abraham Maslow is used to describe stages in the adjustment process of new immigrants. This notion is developed and applied to interpreting some longitudinal data on the changing needs of immigrants to Israel during the first two years after their arrival. (Author/GC)

  16. A Program Based on Maslow's Hierarchy Helps Students in Trouble

    Science.gov (United States)

    Yates, Mary Ruth; Saunders, Ron; Watkins, J. Foster

    1980-01-01

    The article discusses the development of an "alternative school" in an urban school system for students having trouble in the regular secondary setting. The program was based upon "Maslow's Hierarchy of Needs" and is described in detail. The initial assessment of the program produced very positive results.

  17. Student Affairs as Perceived Through Abraham Maslow's Hierarchy of Needs.

    Science.gov (United States)

    Nowacki, Steven

    The needs of human behavior are explored and correlated to the various departments within Student Affairs in an effort to show how Student Affairs can satisfy those needs. Maslow's Hierarchy of needs is briefly explained and related to the following Student Affairs departments: Financial Aid, Student Management, Career Development and Placement,…

  18. Plasticity within stem cell hierarchies in mammalian epithelia

    NARCIS (Netherlands)

    Tetteh, Paul W; Farin, Henner F; Clevers, Hans

    2015-01-01

    Tissue homeostasis and regeneration are fueled by resident stem cells that have the capacity to self-renew, and to generate all the differentiated cell types that characterize a particular tissue. Classical models of such cellular hierarchies propose that commitment and differentiation occur unidire

  19. Tissue-specific designs of stem cell hierarchies

    NARCIS (Netherlands)

    Visvader, Jane E; Clevers, Hans

    2016-01-01

    Recent work in the field of stem cell biology suggests that there is no single design for an adult tissue stem cell hierarchy, and that different tissues employ distinct strategies to meet their self-renewal and repair requirements. Stem cells may be multipotent or unipotent, and can exist in quiesc

  20. Shifting and Narrowing Masculinity Hierarchies in Physical Education: Status Matters

    Science.gov (United States)

    Tischler, Amy; McCaughtry, Nate

    2014-01-01

    The purpose of this study was to examine boys' perceptions of masculinity hierarchies in adventure physical education in relation to past experiences in sport-based physical education and their evolving views about physical activity in their lives. Theoretical principles of masculinity guided this study. Data were collected with 55 male high…

  1. The $N=2$ supersymmetric unconstrained matrix GNLS hierarchies

    NARCIS (Netherlands)

    Sorin, A.S.; Kersten, P.H.M.

    2002-01-01

    The generalization of the $N=2$ supersymmetric chiral matrix $(k|n,m)$--GNLS hierarchy to the case when matrix entries are bosonic and fermionic unconstrained $N=2$ superfields is proposed. This is done by exhibiting the corresponding matrix Lax--pair representation in terms of $N=2$ unconstrained s

  2. Object class hierarchy for an incremental hypertext editor

    Directory of Open Access Journals (Sweden)

    A. Colesnicov

    1995-02-01

    Full Text Available The object class hierarchy design is considered due to a hypertext editor implementation. The following basic classes were selected: the editor's coordinate system, the memory manager, the text buffer executing basic editing operations, the inherited hypertext buffer, the edit window, the multi-window shell. Special hypertext editing features, the incremental hypertext creation support and further generalizations are discussed.

  3. The Hierarchy of Minority Languages in New Zealand

    Science.gov (United States)

    de Bres, Julia

    2015-01-01

    This article makes a case for the existence of a minority language hierarchy in New Zealand. Based on an analysis of language ideologies expressed in recent policy documents and interviews with policymakers and representatives of minority language communities, it presents the arguments forwarded in support of the promotion of different types of…

  4. Knowledge-Based Hierarchies: Using Organizations to Understand the Economy

    Science.gov (United States)

    Garicano, Luis; Rossi-Hansberg, Esteban

    2015-01-01

    Incorporating the decision of how to organize the acquisition, use, and communication of knowledge into economic models is essential to understand a wide variety of economic phenomena. We survey the literature that has used knowledge-based hierarchies to study issues such as the evolution of wage inequality, the growth and productivity of firms,…

  5. A type of multi-component integrable hierarchy

    Institute of Scientific and Technical Information of China (English)

    Zhang Yu-Feng; Zhang Yu-Sen

    2004-01-01

    A new isospectral problem is established by constructing a simple interesting loop algebra. A commutation operation of the loop algebra is as straightforward as the loop algebra (A)1. It follows that a type of multi-component integrable hierarchy is obtained. This can be used as a general method.

  6. Decision support for information systems management : applying analytic hierarchy process

    NARCIS (Netherlands)

    Huizingh, Eelko K.R.E.; Vrolijk, Hans C.J.

    1995-01-01

    Decision-making in the field of information systems has become more complex due to a larger number of alternatives, multiple and sometimes conflicting goals, and an increasingly turbulent environment. In this paper we explore the appropriateness of Analytic Hierarchy Process to support I/S decision

  7. Modeling rises and falls in money addicted social hierarchies

    DEFF Research Database (Denmark)

    Dybiec, Bartłomiej; Mitarai, Namiko; Sneppen, Kim

    2014-01-01

    ambition by modeling the interplay of social networking and an uneven distribution of external resources. The model naturally generates social hierarchies. Remarkably, this social structure exhibits a rise-and-fall behavior. A well pronounced quasi-periodic dynamics, which is closely associated...

  8. Knowledge-Based Hierarchies: Using Organizations to Understand the Economy

    Science.gov (United States)

    Garicano, Luis; Rossi-Hansberg, Esteban

    2015-01-01

    Incorporating the decision of how to organize the acquisition, use, and communication of knowledge into economic models is essential to understand a wide variety of economic phenomena. We survey the literature that has used knowledge-based hierarchies to study issues such as the evolution of wage inequality, the growth and productivity of firms,…

  9. Maximizing Sensory Dynamic Range by Tuning the Cortical State to Criticality.

    Directory of Open Access Journals (Sweden)

    Shree Hari Gautam

    2015-12-01

    Full Text Available Modulation of interactions among neurons can manifest as dramatic changes in the state of population dynamics in cerebral cortex. How such transitions in cortical state impact the information processing performed by cortical circuits is not clear. Here we performed experiments and computational modeling to determine how somatosensory dynamic range depends on cortical state. We used microelectrode arrays to record ongoing and whisker stimulus-evoked population spiking activity in somatosensory cortex of urethane anesthetized rats. We observed a continuum of different cortical states; at one extreme population activity exhibited small scale variability and was weakly correlated, the other extreme had large scale fluctuations and strong correlations. In experiments, shifts along the continuum often occurred naturally, without direct manipulation. In addition, in both the experiment and the model we directly tuned the cortical state by manipulating inhibitory synaptic interactions. Our principal finding was that somatosensory dynamic range was maximized in a specific cortical state, called criticality, near the tipping point midway between the ends of the continuum. The optimal cortical state was uniquely characterized by scale-free ongoing population dynamics and moderate correlations, in line with theoretical predictions about criticality. However, to reproduce our experimental findings, we found that existing theory required modifications which account for activity-dependent depression. In conclusion, our experiments indicate that in vivo sensory dynamic range is maximized near criticality and our model revealed an unanticipated role for activity-dependent depression in this basic principle of cortical function.

  10. Maximizing Sensory Dynamic Range by Tuning the Cortical State to Criticality

    Science.gov (United States)

    Gautam, Shree Hari; Hoang, Thanh T.; McClanahan, Kylie; Grady, Stephen K.; Shew, Woodrow L.

    2015-01-01

    Modulation of interactions among neurons can manifest as dramatic changes in the state of population dynamics in cerebral cortex. How such transitions in cortical state impact the information processing performed by cortical circuits is not clear. Here we performed experiments and computational modeling to determine how somatosensory dynamic range depends on cortical state. We used microelectrode arrays to record ongoing and whisker stimulus-evoked population spiking activity in somatosensory cortex of urethane anesthetized rats. We observed a continuum of different cortical states; at one extreme population activity exhibited small scale variability and was weakly correlated, the other extreme had large scale fluctuations and strong correlations. In experiments, shifts along the continuum often occurred naturally, without direct manipulation. In addition, in both the experiment and the model we directly tuned the cortical state by manipulating inhibitory synaptic interactions. Our principal finding was that somatosensory dynamic range was maximized in a specific cortical state, called criticality, near the tipping point midway between the ends of the continuum. The optimal cortical state was uniquely characterized by scale-free ongoing population dynamics and moderate correlations, in line with theoretical predictions about criticality. However, to reproduce our experimental findings, we found that existing theory required modifications which account for activity-dependent depression. In conclusion, our experiments indicate that in vivo sensory dynamic range is maximized near criticality and our model revealed an unanticipated role for activity-dependent depression in this basic principle of cortical function. PMID:26623645

  11. Cancellous Screws Are Biomechanically Superior to Cortical Screws in Metaphyseal Bone.

    Science.gov (United States)

    Wang, Tim; Boone, Christopher; Behn, Anthony W; Ledesma, Justin B; Bishop, Julius A

    2016-09-01

    Cancellous screws are designed to optimize fixation in metaphyseal bone environments; however, certain clinical situations may require the substitution of cortical screws for use in cancellous bone, such as anatomic constraints, fragment size, or available instrumentation. This study compares the biomechanical properties of commercially available cortical and cancellous screw designs in a synthetic model representing various bone densities. Commercially available, fully threaded, 4.0-mm outer-diameter cortical and cancellous screws were tested in terms of pullout strength and maximum insertion torque in standard-density and osteoporotic cancellous bone models. Pullout strength and maximum insertion torque were both found to be greater for cancellous screws than cortical screws in all synthetic densities tested. The magnitude of difference in pullout strength between cortical and cancellous screws increased with decreasing synthetic bone density. Screw displacement prior to failure and total energy absorbed during pullout strength testing were also significantly greater for cancellous screws in osteoporotic models. Stiffness was greater for cancellous screws in standard and osteoporotic models. Cancellous screws have biomechanical advantages over cortical screws when used in metaphyseal bone, implying the ability to both achieve greater compression and resist displacement at the screw-plate interface. Surgeons should preferentially use cancellous over cortical screws in metaphyseal environments where cortical bone is insufficient for fixation. [Orthopedics.2016; 39(5):e828-e832.].

  12. A hierarchy of event-related potential markers of auditory processing in disorders of consciousness

    Directory of Open Access Journals (Sweden)

    Steve Beukema

    2016-01-01

    Full Text Available Functional neuroimaging of covert perceptual and cognitive processes can inform the diagnoses and prognoses of patients with disorders of consciousness, such as the vegetative and minimally conscious states (VS;MCS. Here we report an event-related potential (ERP paradigm for detecting a hierarchy of auditory processes in a group of healthy individuals and patients with disorders of consciousness. Simple cortical responses to sounds were observed in all 16 patients; 7/16 (44% patients exhibited markers of the differential processing of speech and noise; and 1 patient produced evidence of the semantic processing of speech (i.e. the N400 effect. In several patients, the level of auditory processing that was evident from ERPs was higher than the abilities that were evident from behavioural assessment, indicating a greater sensitivity of ERPs in some cases. However, there were no differences in auditory processing between VS and MCS patient groups, indicating a lack of diagnostic specificity for this paradigm. Reliably detecting semantic processing by means of the N400 effect in passively listening single-subjects is a challenge. Multiple assessment methods are needed in order to fully characterise the abilities of patients with disorders of consciousness.

  13. Adapting wave-front algorithms to efficiently utilize systems with deep communication hierarchies

    Energy Technology Data Exchange (ETDEWEB)

    Kerbyson, Darren J [Los Alamos National Laboratory; Lang, Michael [Los Alamos National Laboratory; Pakin, Scott [Los Alamos National Laboratory

    2009-01-01

    Large-scale systems increasingly exhibit a differential between intra-chip and inter-chip communication performance. Processor-cores on the same socket are able to communicate at lower latencies, and with higher bandwidths, than cores on different sockets either within the same node or between nodes. A key challenge is to efficiently use this communication hierarchy and hence optimize performance. We consider here the class of applications that contain wave-front processing. In these applications data can only be processed after their upstream neighbors have been processed. Similar dependencies result between processors in which communication is required to pass boundary data downstream and whose cost is typically impacted by the slowest communication channel in use. In this work we develop a novel hierarchical wave-front approach that reduces the use of slower communications in the hierarchy but at the cost of additional computation and higher use of on-chip communications. This tradeoff is explored using a performance model and an implementation on the Petascale Roadrunner system demonstrates a 27% performance improvement at full system-scale on a kernel application. The approach is generally applicable to large-scale multi-core and accelerated systems where a differential in system communication performance exists.

  14. Selection of the Bank Investment Strategy on the Basis of the Hierarchy Analysis Method

    Directory of Open Access Journals (Sweden)

    Zhytar Maksym O.

    2014-02-01

    Full Text Available The goal of the article lies in identification of a methodical approach to selection of the investment strategy of banks on the basis of factors of its formation with the use of the hierarchy analysis method. Factors of formation of the bank’s investment strategy were identified in the result of the study. The article demonstrates that selection of the investment strategy of the bank could be efficiently realised on the basis of the hierarchy analysis method, which is the most popular under conditions of a multi-criteria assessment of the search for optimal solution of the set task. The article offers a hierarchical structure of decision making, which could be a basis of selection of the bank’s investment strategy with consideration of the institutional flexibility. The prospect of further study in this direction is development of an optimisation model of the bank’s investment portfolio with consideration of not only institutional, but also market flexibility of decision making.

  15. Organ hierarchy during low blood flow on-pump: a randomized experimental positron emission tomography study

    DEFF Research Database (Denmark)

    Thomassen, Sisse Anette; Kjærgaard, Benedict; Frøkiær, Jørgen;

    ; normothermic CPB with a blood flow of 2.5 L/min/m2 for one hour followed by a randomisation to a blood flow of either 2.0 L/min/m2 (Group I) or 1.5 L/min/m2 (Group II) for another hour and finally one hour with blood flow of 2.5 L/min/m2. Regional tissue perfusion of brain, liver, kidney, and muscle...... indicates existence of an organ hierarchy with persevered perfusion of the brain but affected muscle tissue perfusion in in both Groups of suboptimal blood flow. The finally results will be ready for presentation at DASAIM 2014 in November. Non-parametric statistical method will be used. Discussion To our...... knowledge this is the first study investigating organ hierarchy with dynamic PET-CT during profound systemic ischemia due to suboptimal blood flows during normothermic CPB. References 1. Murphy JM, Hessel II EA, Groom RC. Optimal perfusion during cardiopulmonary bypass: an Evidence-based approach. Anesth...

  16. A Hierarchy of New Nonlinear Evolution Equations Associated with a 3 × 3 Matrix Spectral Problem

    Institute of Scientific and Technical Information of China (English)

    GENG Xian-Guo; LI Fang

    2009-01-01

    A 3 × 3 matrix spectral problem with three potentials and the corresponding hierarchy of new nonlinear evolution equations are proposed. Generalized Hamiltonian structures for the hierarchy of nonlinear evolution equations are derived with the aid of trace identity.

  17. Language variety, language hierarchy, and language choice in the international university

    DEFF Research Database (Denmark)

    Haberland, Hartmut; Mortensen, Janus

    2012-01-01

    Introduction to thematic issue on Language variety, language hierarchy, and language choice in the international university......Introduction to thematic issue on Language variety, language hierarchy, and language choice in the international university...

  18. Parvalbumin-producing cortical interneurons receive inhibitory inputs on proximal portions and cortical excitatory inputs on distal dendrites.

    Science.gov (United States)

    Kameda, Hiroshi; Hioki, Hiroyuki; Tanaka, Yasuyo H; Tanaka, Takuma; Sohn, Jaerin; Sonomura, Takahiro; Furuta, Takahiro; Fujiyama, Fumino; Kaneko, Takeshi

    2012-03-01

    To examine inputs to parvalbumin (PV)-producing interneurons, we generated transgenic mice expressing somatodendritic membrane-targeted green fluorescent protein specifically in the interneurons, and completely visualized their dendrites and somata. Using immunolabeling for vesicular glutamate transporter (VGluT)1, VGluT2, and vesicular GABA transporter, we found that VGluT1-positive terminals made contacts 4- and 3.1-fold more frequently with PV-producing interneurons than VGluT2-positive and GABAergic terminals, respectively, in the primary somatosensory cortex. Even in layer 4, where VGluT2-positive terminals were most densely distributed, VGluT1-positive inputs to PV-producing interneurons were 2.4-fold more frequent than VGluT2-positive inputs. Furthermore, although GABAergic inputs to PV-producing interneurons were as numerous as VGluT2-positive inputs in most cortical layers, GABAergic inputs clearly preferred the proximal dendrites and somata of the interneurons, indicating that the sites of GABAergic inputs were more optimized than those of VGluT2-positive inputs. Simulation analysis with a PV-producing interneuron model compatible with the present morphological data revealed a plausible reason for this observation, by showing that GABAergic and glutamatergic postsynaptic potentials evoked by inputs to distal dendrites were attenuated to 60 and 87%, respectively, of those evoked by somatic inputs. As VGluT1-positive and VGluT2-positive axon terminals were presumed to be cortical and thalamic glutamatergic inputs, respectively, cortical excitatory inputs to PV-producing interneurons outnumbered the thalamic excitatory and intrinsic inhibitory inputs more than two-fold in any cortical layer. Although thalamic inputs are known to evoke about two-fold larger unitary excitatory postsynaptic potentials than cortical ones, the present results suggest that cortical inputs control PV-producing interneurons at least as strongly as thalamic inputs.

  19. Classical Affine W-Algebras for gl_N and Associated Integrable Hamiltonian Hierarchies

    Science.gov (United States)

    De Sole, Alberto; Kac, Victor G.; Valeri, Daniele

    2016-11-01

    We apply the new method for constructing integrable Hamiltonian hierarchies of Lax type equations developed in our previous paper to show that all W-algebras W({gl}N, f)} carry such a hierarchy. As an application, we show that all vector constrained KP hierarchies and their matrix generalizations are obtained from these hierarchies by Dirac reduction, which provides the former with a bi-Poisson structure.

  20. An integrable coupling system of lattice hierarchy and its continuous limits

    Energy Technology Data Exchange (ETDEWEB)

    Yu Fajun [College of Maths and Systematic Science, Shenyang Normal University, Shenyang 110034 (China)], E-mail: yfajun@163.com; Li Li [College of Maths and Systematic Science, Shenyang Normal University, Shenyang 110034 (China)

    2009-04-13

    In [E.G. Fan, Phys. Lett. A 372 (2008) 6368], Fan present a lattice hierarchy and its continuous limits. In this Letter, we extend this method, by introducing a complex discrete spectral problem, a coupling lattice hierarchy is derived. It is shown that a new sequence of combinations of complex lattice spectral problem converges to the integrable coupling couplings of soliton equation hierarchy, which has the integrable coupling system of AKNS hierarchy as a continuous limit.

  1. Continuous limits for an integrable coupling system of Toda equation hierarchy

    Energy Technology Data Exchange (ETDEWEB)

    Li Li [College of Maths and Systematic Science, Shenyang Normal University, Shenyang 110034 (China); Yu Fajun, E-mail: yfajun@163.co [College of Maths and Systematic Science, Shenyang Normal University, Shenyang 110034 (China)

    2009-09-21

    In this Letter, we present an integrable coupling system of lattice hierarchy and its continuous limits by using of Lie algebra sl(4). By introducing a complex discrete spectral problem, the integrable coupling system of Toda lattice hierarchy is derived. It is shown that a new complex lattice spectral problem converges to the integrable couplings of discrete soliton equation hierarchy, which has the integrable coupling system of C-KdV hierarchy as a new kind of continuous limit.

  2. Two New Reformulation Convexification Based Hierarchies for 0-1 MIPs

    Directory of Open Access Journals (Sweden)

    Hacene Ouzia

    2015-01-01

    Full Text Available First, we introduce two new reformulation convexification based hierarchies called RTC and RSC for which the rank d continuous relaxations are denoted by P^RTCd and P^RSCd, respectively. These two hierarchies are obtained using two different convexification schemes: term convexification in the case of the RTC hierarchy and standard convexification in the case of the RSC hierarchy. Secondly, we compare the strength of these two hierarchies. We will prove that (i the hierarchy RTC is equivalent to the RLT hierarchy of Sherali-Adams, (ii the hierarchy RTC dominates the hierarchy RSC, and (iii the hierarchy RSC is dominated by the Lift-and-Project hierarchy. Thirdly, for every rank d, we will prove that convTd∩Etd⊆P^RTCd⊆Td and convSd∩Esd⊆P^RSCd⊆Sd where the sets Td and Sd are convex, while Etd and Esd are two nonconvex sets with empty interior (all these sets depend on the convexification step. The first inclusions allow, in some cases, an explicit characterization (in the space of the original variables of the RLT relaxations. Finally, we will discuss weak version of both RTC and RSC hierarchies and we will emphasize some connections between them.

  3. A Hidden Connection between Lax Descriptions and Superextensions of KdV Hierarchy

    OpenAIRE

    Huang, Wen-Jui

    1996-01-01

    A previously unnoticed connection between the Lax descriptions and the superextensions of the KdV hierarchy is presented. It is shown that the two different Lax descriptions of the KdV hierarchy come out naturally from two different bihamiltonian superextensions of the KdV hierarchy. Some implications of this observation are briefly mentioned.

  4. A Hierarchy of Lax Integrable Lattice Equations,Liouville Integrability and a New Integrable Symplectic Map

    Institute of Scientific and Technical Information of China (English)

    XU Xi-Xiang; ZHANG Yu-Feng

    2004-01-01

    A discrete matrix spectral problem and the associated hierarchy of Lax integrable lattice equations are presented, and it is shown that the resulting Lax integrable lattice equations are all Liouville integrable discrete Hamiltonian systems. A new integrable symplectic map is given by binary Bargmann .constraint of the resulting hierarchy.Finally, an infinite set of conservation laws is given for the resulting hierarchy.

  5. Block (or Hamiltonian) Lie Symmetry of Dispersionless D-Type Drinfeld-Sokolov Hierarchy

    Science.gov (United States)

    Li, Chuan-Zhong; He, Jing-Song; Su, Yu-Cai

    2014-04-01

    In this paper, the dispersionless D-type Drinfeld-Sokolov hierarchy, i.e. a reduction of the dispersionless two-component BKP hierarchy, is studied. The additional symmetry flows of this hierarchy are presented. These flows form an infinite-dimensional Lie algebra of Block type as well as a Lie algebra of Hamiltonian type.

  6. Conservation laws and self-consistent sources for a super-CKdV equation hierarchy

    Energy Technology Data Exchange (ETDEWEB)

    Li Li, E-mail: li07099@163.co [College of Maths and Systematic Science, Shenyang Normal University, Shenyang 110034 (China)

    2011-03-14

    From the super-matrix Lie algebras, we consider a super-extension of the CKdV equation hierarchy in the present Letter, and propose the super-CKdV hierarchy with self-consistent sources. Furthermore, we establish the infinitely many conservation laws for the integrable super-CKdV hierarchy.

  7. Analyzing Learning Hierarchies Relative to Transfer Relationships Within Arithmetic. Final Report.

    Science.gov (United States)

    Kane, Robert B.; And Others

    The purpose of this study was to develop and evaluate procedures for validating a learning hierarchy from test data. An initial hierarchy for the computational skills of adding rational numbers with like denominators was constructed using Gagne's task analysis. A test designed to assess mastery at each of the 11 levels in this hierarchy was…

  8. GPU accelerated tandem traversal of blocked bounding volume hierarchy collision detection for multibody dynamics

    DEFF Research Database (Denmark)

    Damkjær, Jesper; Erleben, Kenny

    2009-01-01

    hierarchies. Our approach makes it possible to perform non-convex object versus non-convex object collision on the GPU, using tandem traversals of bounding volume hierarchies. Prior work only supports single traversals on GPUs. We introduce a blocked hierarchy data structure, using imaginary nodes...

  9. Motor cortical thresholds and cortical silent periods in epilepsy.

    Science.gov (United States)

    Tataroglu, Cengiz; Ozkiziltan, Safa; Baklan, Baris

    2004-10-01

    We studied motor cortical thresholds (TIs) and cortical silent periods (SPs) evoked by transcranial magnetic stimulation (TMS) in 110 epileptic patients. Sixty-two had primary generalised, 48 had partial type seizures. Fifteen out 110 patients were analysed both before and after anticonvulsant medication. Our aims were to evaluate the TI levels and the duration of SPs in patients with epilepsy and to determine the reliability of TMS in patients with epilepsy. There was no negative effect of TMS on the clinical status and EEG findings in patients with epilepsy. TIs obtained from patients with partial epilepsy were higher than those obtained from both controls and primary epileptics. The duration of SP in patients with primary epileptics was more prolonged than those obtained from controls. There was no correlation between EEG lateralisation and both SP duration and TI values. In de novo patient group, SP duration was significantly prolonged after anticonvulsant medication. We concluded that TMS is a reliable electrophysiological investigation in patients with epilepsy. The analysis of SP duration may be an appropriate investigation in monitoring the effect of anticonvulsant medication on the cortical inhibitory activity.

  10. Imprinting and recalling cortical ensembles.

    Science.gov (United States)

    Carrillo-Reid, Luis; Yang, Weijian; Bando, Yuki; Peterka, Darcy S; Yuste, Rafael

    2016-08-12

    Neuronal ensembles are coactive groups of neurons that may represent building blocks of cortical circuits. These ensembles could be formed by Hebbian plasticity, whereby synapses between coactive neurons are strengthened. Here we report that repetitive activation with two-photon optogenetics of neuronal populations from ensembles in the visual cortex of awake mice builds neuronal ensembles that recur spontaneously after being imprinted and do not disrupt preexisting ones. Moreover, imprinted ensembles can be recalled by single- cell stimulation and remain coactive on consecutive days. Our results demonstrate the persistent reconfiguration of cortical circuits by two-photon optogenetics into neuronal ensembles that can perform pattern completion. Copyright © 2016, American Association for the Advancement of Science.

  11. LSP Squark Decays at the LHC and the Neutrino Mass Hierarchy

    CERN Document Server

    Marshall, Zachary; Purves, Austin; Spinner, Sogee

    2014-01-01

    The existence of R-parity in supersymmetric models can be naturally explained as being a discrete subgroup of gauged baryon minus lepton number (B-L). The most minimal supersymmetric B-L model triggers spontaneous R-parity violation, while remaining consistent with proton stability. This model is well-motivated by string theory and makes several interesting, testable predictions. Furthermore, R-parity violation contributes to neutrino masses, thereby connecting the neutrino sector to the decay of the lightest supersymmetric particle (LSP). This paper analyzes the decays of third generation squark LSPs into a quark and a lepton. In certain cases, the branching ratios into charged leptons reveal information about the neutrino mass hierarchy, a current goal of experimental neutrino physics, as well as the $\\theta_{23}$ neutrino mixing angle. Furthermore, optimization of leptoquark searches for this scenario is discussed. Using currently available data, the lower bounds on the third generation squarks are compute...

  12. Hybrid Quantum-Classical Hierarchy for Mitigation of Decoherence and Determination of Excited States

    CERN Document Server

    McClean, Jarrod R; Carter, Jonathan; de Jong, Wibe A

    2016-01-01

    Using quantum devices supported by classical computational resources is a promising approach to quantum-enabled computation. One example of such a hybrid quantum-classical approach is the variational quantum eigensolver (VQE) built to utilize quantum resources for the solution of eigenvalue problems and optimizations with minimal coherence time requirements by leveraging classical computational resources. These algorithms have been placed among the candidates for first to achieve supremacy over classical computation. Here, we provide evidence for the conjecture that variational approaches can automatically suppress even non-systematic decoherence errors by introducing an exactly solvable channel model of variational state preparation. Moreover, we show how variational quantum-classical approaches fit in a more general hierarchy of measurement and classical computation that allows one to obtain increasingly accurate solutions with additional classical resources. We demonstrate numerically on a sample electroni...

  13. Using Fuzzy Analytic Hierarchy Process multicriteria and Geographical information system for coastal vulnerability analysis in Morocco: The case of Mohammedia

    Science.gov (United States)

    Tahri, Meryem; Maanan, Mohamed; Hakdaoui, Mustapha

    2016-04-01

    This paper shows a method to assess the vulnerability of coastal risks such as coastal erosion or submarine applying Fuzzy Analytic Hierarchy Process (FAHP) and spatial analysis techniques with Geographic Information System (GIS). The coast of the Mohammedia located in Morocco was chosen as the study site to implement and validate the proposed framework by applying a GIS-FAHP based methodology. The coastal risk vulnerability mapping follows multi-parametric causative factors as sea level rise, significant wave height, tidal range, coastal erosion, elevation, geomorphology and distance to an urban area. The Fuzzy Analytic Hierarchy Process methodology enables the calculation of corresponding criteria weights. The result shows that the coastline of the Mohammedia is characterized by a moderate, high and very high level of vulnerability to coastal risk. The high vulnerability areas are situated in the east at Monika and Sablette beaches. This technical approach is based on the efficiency of the Geographic Information System tool based on Fuzzy Analytical Hierarchy Process to help decision maker to find optimal strategies to minimize coastal risks.

  14. Cortical sensorimotor integration: a hypothesis.

    Science.gov (United States)

    Batuev, A S

    1989-01-01

    A hypothesis is proposed that neocortex is constructed from structural neuronal modules (columns and rings). Each module is considered as unit for cortical sensorimotor integration. Complex functional relationships between modules can be arranged by intracortical inhibition participation. High pronounced neocortical plasticity ensures the process of continuous formation of various dominating operative constellations comprising stable neuronal modules whose component structure and distributive characteristic are determined by the dominant motivation and the central motor program.

  15. [Parietal Cortices and Body Information].

    Science.gov (United States)

    Naito, Eiichi; Amemiya, Kaoru; Morita, Tomoyo

    2016-11-01

    Proprioceptive signals originating from skeletal muscles and joints contribute to the formation of both the human body schema and the body image. In this chapter, we introduce various types of bodily illusions that are elicited by proprioceptive inputs, and we discuss distinct functions implemented by different parietal cortices. First, we illustrate the primary importance of the motor network in the processing of proprioceptive (kinesthetic) signals originating from muscle spindles. Next, we argue that the right inferior parietal cortex, in concert with the inferior frontal cortex (both regions connected by the inferior branch of the superior longitudinal fasciculus-SLF III), may be involved in the conscious experience of body image. Further, we hypothesize other functions of distinct parietal regions: the association between internal hand motor representation with external object representation in the left inferior parietal cortex, visuo-kinesthetic processing in the bilateral posterior parietal cortices, and the integration of somatic signals from different body parts in the higher-order somatosensory parietal cortices. Our results indicate that a distinct parietal region, in concert with its anatomically and functionally connected frontal regions, probably plays specialized roles in the processing of body-related information.

  16. Growth of fat slits and dispersionless KP hierarchy

    CERN Document Server

    Zabrodin, A

    2008-01-01

    A "fat slit" is a compact domain in the upper half plane bounded by a curve with endpoints on the real axis and a segment of the real axis between them. We consider conformal maps of the upper half plane to the exterior of a fat slit parameterized by harmonic moments of the latter and show that they obey an infinite set of Lax equations for the dispersionless KP hierarchy. Deformation of a fat slit under changing a particular harmonic moment can be treated as a growth process similar to the Laplacian growth of domains in the whole plane. This construction extends the well known link between solutions to the dispersionless KP hierarchy and conformal maps of slit domains in the upper half plane and provides a new, large family of solutions.

  17. Maximum-entropy closure of hydrodynamic moment hierarchies including correlations.

    Science.gov (United States)

    Hughes, Keith H; Burghardt, Irene

    2012-06-07

    Generalized hydrodynamic moment hierarchies are derived which explicitly include nonequilibrium two-particle and higher-order correlations. The approach is adapted to strongly correlated media and nonequilibrium processes on short time scales which necessitate an explicit treatment of time-evolving correlations. Closure conditions for the extended moment hierarchies are formulated by a maximum-entropy approach, generalizing related closure procedures for kinetic equations. A self-consistent set of nonperturbative dynamical equations are thus obtained for a chosen set of single-particle and two-particle (and possibly higher-order) moments. Analytical results are derived for generalized Gaussian closures including the dynamic pair distribution function and a two-particle correction to the current density. The maximum-entropy closure conditions are found to involve the Kirkwood superposition approximation.

  18. The tensor hierarchy of 8-dimensional field theories

    Science.gov (United States)

    Andino, Óscar Lasso; Ortín, Tomás

    2016-10-01

    We construct the tensor hierarchy of generic, bosonic, 8-dimensional field theories. We first study the form of the most general 8-dimensional bosonic theory with Abelian gauge symmetries only and no massive deformations. This study determines the tensors that occur in the Chern-Simons terms of the (electric and magnetic) field strengths and the action for the electric fields, which we determine. Having constructed the most general Abelian theory we study the most general gaugings of its global symmetries and the possible massive deformations using the embedding tensor formalism, constructing the complete tensor hierarchy using the Bianchi identities. We find the explicit form of all the field strengths of the gauged theory up to the 6-forms. Finally, we find the equations of motion comparing the Noether identities with the identities satisfied by the Bianchi identities themselves. We find that some equations of motion are not simply the Bianchi identities of the dual fields, but combinations of them.

  19. The tensor hierarchy of 8-dimensional field theories

    CERN Document Server

    Andino, Oscar Lasso

    2016-01-01

    We construct the tensor hierarchy of generic, bosonic, 8-dimensional field theories. We first study the form of the most general 8-dimensional bosonic theory with Abelian gauge symmetries only and no massive deformations. This study determines the tensors that occur in the Chern-Simons terms of the (electric and magnetic) field strengths and the action for the electric fields, which we determine. Having constructed the most general Abelian theory we study the most general gaugings of its global symmetries and the possible massive deformations using the embedding tensor formalism, constructing the complete tensor hierarchy using the Bianchi identities. We find the explicit form of all the field strengths of the gauged theory up to the 6-forms. Finally, we find the equations of motion comparing the Noether identities with the identities satisfied by the Bianchi identities themselves. We find that some equations of motion are not simply the Bianchi identities of the dual fields, but combinations of them.

  20. Truncation identities for the small polaron fusion hierarchy

    CERN Document Server

    Grabinski, André M

    2012-01-01

    We study a one-dimensional lattice model of interacting spinless fermions. This model is integrable for both periodic and open boundary conditions, the latter case includes the presence of Grassmann valued non-diagonal boundary fields breaking the bulk U(1) symmetry of the model. Starting from the embedding of this model into a graded Yang-Baxter algebra an infinite hierarchy of comuting transfer matrices is constructed by means of a fusion procedure. For certain values of the coupling constant related to anisotropies of the underlying vertex model taken at roots of unity this hierarchy is shown to truncate giving a finite set of functional equations for the spectrum of the transfer matrices. For generic coupling constants the spectral problem is formulated in terms of a TQ-equation which can be solved by Bethe ansatz methods for periodic and diagonal open boundary conditions. Possible approaches for the solution of the model with generic non-diagonal boundary fields are discussed.

  1. Investigating a Hierarchy of Students’ Interpretations of Graphs

    Directory of Open Access Journals (Sweden)

    Kazuhiro Aoyama

    2007-10-01

    Full Text Available The ability to analyse qualitative information from quantitative information, and/or to create new information from qualitative and quantitative information is the key task of statistical literacy in the 21st century. Although several studies have focussed on critical evaluation of statistical information, this aspect of research has not been clearly conceptualised as yet. This paper presents a hierarchy of the graphical interpretation component of statistical literacy. 175 participants from different educational levels (junior high school to graduate students responded to a questionnaire and some of them were also interviewed. The SOLO Taxonomy was used for coding the students’ responses and the Rasch model was used to clarify the construction of the hierarchy. Five different levels of interpretations of graphs were identified: Idiosyncratic, Basic graph reading, Rational/Literal, Critical, and Hypothesising and Modelling. These results will provide guidelines for teaching statistical literacy.

  2. Weight hierarchies of linear codes satisfying the almost chain condition

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The weight hierarchy of a linear [n, k; q] code C over GF(q) is the sequence (d1, d2,…,dk) where dr is the size of the smallest support of an r-dimensional subcode of C. An [n, k; q] codehas dimension r and support of size dr for all r. Further, C satisfies the almost chain condition ifit does not satisfy the chain condition, but there exist subcodes Dr of dimension r and support offor a sequence to be the weight hierarchy of a code satisfying the almost chain condition is given.Further, explicit constructions of such codes are given, showing that in almost all cases, the necessaryconditions are also sufficient.

  3. Factorization and Resummation for Generic Hierarchies between Jets

    CERN Document Server

    Pietrulewicz, Piotr; Waalewijn, Wouter J

    2016-01-01

    Jets are an important probe to identify the hard interaction of interest at the LHC. They are routinely used in Standard Model precision measurements as well as in searches for new heavy particles, including jet substructure methods. In processes with several jets, one typically encounters hierarchies in the jet transverse momenta and/or dijet invariant masses. Large logarithms of the ratios of these kinematic jet scales in the cross section are at present primarily described by parton showers. We present a general factorization framework called SCET$_+$, which is an extension of Soft-Collinear Effective Theory (SCET) and allows for a systematic higher-order resummation of such kinematic logarithms for generic jet hierarchies. In SCET$_+$ additional intermediate soft/collinear modes are used to resolve jets arising from additional soft and/or collinear QCD emissions. The resulting factorized cross sections utilize collinear splitting amplitudes and soft gluon currents and fully capture spin and color correlat...

  4. Signatures of the neutrino mass hierarchy in supernova neutrinos

    CERN Document Server

    Chiu, S H; Lai, Kwang-Chang

    2013-01-01

    The undetermined neutrino mass hierarchy may leave observable imprint on the neutrino fluxes from the core-collpse supernova (SN). The interpretation of the observables, however, is subject to the uncertain SN models and the flavor conversion mechanism of neutrinos in a SN. We attempt to propose a qualitative and model-independent interpretation of the expected neutrino events at terrestrial detectors, focusing on the accretion phase of the neutrino burst. The flavor conversions due to the neutrino self-interaction, the MSW effect, and the Earth regeneration effect are incorporated in the calculation. It leads to several distinct scenarios that are identified by the neutrino mass hierarchies and the collective flavor transitions. Consequences resulting from the variation of incident angles and SN models are also discussed.

  5. Entangled parametric hierarchies: problems for an overspecified universal grammar.

    Directory of Open Access Journals (Sweden)

    Cedric Boeckx

    Full Text Available This study addresses the feasibility of the classical notion of parameter in linguistic theory from the perspective of parametric hierarchies. A novel program-based analysis is implemented in order to show certain empirical problems related to these hierarchies. The program was developed on the basis of an enriched data base spanning 23 contemporary and 5 ancient languages. The empirical issues uncovered cast doubt on classical parametric models of language acquisition as well as on the conceptualization of an overspecified Universal Grammar that has parameters among its primitives. Pinpointing these issues leads to the proposal that (i the (biological problem of language acquisition does not amount to a process of triggering innately pre-wired values of parameters and (ii it paves the way for viewing language, epigenetic ('parametric' variation as an externalization-related epiphenomenon, whose learning component may be more important than what sometimes is assumed.

  6. Entangled parametric hierarchies: problems for an overspecified universal grammar.

    Science.gov (United States)

    Boeckx, Cedric; Leivada, Evelina

    2013-01-01

    This study addresses the feasibility of the classical notion of parameter in linguistic theory from the perspective of parametric hierarchies. A novel program-based analysis is implemented in order to show certain empirical problems related to these hierarchies. The program was developed on the basis of an enriched data base spanning 23 contemporary and 5 ancient languages. The empirical issues uncovered cast doubt on classical parametric models of language acquisition as well as on the conceptualization of an overspecified Universal Grammar that has parameters among its primitives. Pinpointing these issues leads to the proposal that (i) the (bio)logical problem of language acquisition does not amount to a process of triggering innately pre-wired values of parameters and (ii) it paves the way for viewing language, epigenetic ('parametric') variation as an externalization-related epiphenomenon, whose learning component may be more important than what sometimes is assumed.

  7. Yukawa Hierarchies From Extra Dimensions With Small FCNC

    CERN Document Server

    Lillie, Benjamin Huntington

    2003-01-01

    We investigate a class of extra dimensional models where all of the Standard Model fermions are localized to a single fixed point in an $S_1/Z_2$ orbifold, and each species is localized with an exponential wavefunction with a different width. We show that this naturally generates Yukawa hierarchies of the size present in the Standard Model, and we find a set of model parameters that reproduces the observed masses and mixings to experimental accuracy. In addition, the dominant constraints, arising from flavor changing neutral currents, are shown to restrict the compactification scale to be $1/R \\ge 2-5 \\tev$, which is a much less stringent constraint than in similar extra dimensional models of the Yukawa hierarchy.

  8. A hierarchy of cosmic compact objects - without black holes

    CERN Document Server

    Hansson, J

    2006-01-01

    We make the case for the existence of a, hitherto unknown and unobserved, hierarchy of ever more compact cosmic objects in the universe. This hypothesis is based on i) the assumption of "elementary" particle sub-constituents on several levels below the presently known, inspired by Glashow's "blooming desert", ii) the existence of nearly scale-invariant density fluctuations in the early universe, e.g. as predicted by inflationary models, iii) our own previous theoretical work showing that a class of objects considerably more compact than previously thought possible in astrophysics can exist. We also give several independent arguments strongly pointing towards the non-existence of black holes. Some brief suggestions on observational signals due to the hierarchy, both in collected astronomical data and in possible future observations, concludes the paper.

  9. Fuzzy Analytical Hierarchy Process for Ecological Risk Assessment

    Directory of Open Access Journals (Sweden)

    Radionovs Andrejs

    2016-12-01

    Full Text Available Being able to evaluate risks is an important task in many areas of human activity: economics, ecology, etc. Usually, environmental risk assessment is carried out on the basis of multiple and sometimes conflicting factors. Using multiple criteria decision-making (MCDM methodology is one of the possible ways to solve the problem. Analytic hierarchy process (AHP is one of the most commonly used MCDM methods, which combines subjective and personal preferences in the risk assessment process. However, the AHP involves human subjectivity, which introduces vagueness type of uncertainty and requires the use of decision making under those uncertainties. In this paper, work with uncertainty is considered using fuzzy-based techniques. The paper also analyses the ecological risk assessment towards human health in case of gaseous substance escape at a chemical factory using the fuzzy analytical hierarchy process.

  10. Scales and hierarchies in warped compactifications and brane worlds

    CERN Document Server

    De Wolfe, O; Wolfe, Oliver De; Giddings, Steven B.

    2003-01-01

    Warped compactifications with branes provide a new approach to the hierarchy problem and generate a diversity of four-dimensional thresholds. We investigate the relationships between these scales, which fall into two classes. Geometrical scales, such as thresholds for Kaluza-Klein, excited string, and black hole production, are generically determined soley by the spacetime geometry. Dynamical scales, notably the scale of supersymmetry breaking and moduli masses, depend on other details of the model. We illustrate these relationships in a class of solutions of type IIB string theory with imaginary self-dual fluxes. After identifying the geometrical scales and the resulting hierarchy, we determine the gravitino and moduli masses through explicit dimensional reduction, and estimate their value to be near the four-dimensional Planck scale. In the process we obtain expressions for the superpotential and Kahler potential, including the effects of warping. We identify matter living on certain branes to be effectivel...

  11. The analytic hierarchy process in decisionmaking for caprine health programmes.

    Science.gov (United States)

    Maino, M; Pérez, P; Oviedo, P; Sotomayor, G; Abalos, P

    2012-12-01

    The purpose of this study was to apply the analytic hierarchy process (AHP) to assist decision-making when planning animal health programmes, by assigning priorities to issues of concern to producers in Chile's main goat production region. This process allows a multi-criteria approach to problems, by analysing and ranking them in a hierarchical structure. Industry experts have highlighted the following animal health and disease control criteria: acceptance by breeders of disease control measures; impact of specific diseases on regional animal trade; the cost and efficacy of control measures; a decrease in flock production; and the impact of caprine diseases on human public health. Using these criteria in the AHP, the study found that the most important impacts were on human public health and on the animal trade. The disease priorities were tuberculosis, brucellosis and echinococcosis/hydatidosis, due mainlyto their zoonotic impact. The analytic hierarchy process proved useful when several criteria were involved in public health issues.

  12. Computational Study of Subdural Cortical Stimulation: Effects of Simulating Anisotropic Conductivity on Activation of Cortical Neurons.

    Directory of Open Access Journals (Sweden)

    Hyeon Seo

    Full Text Available Subdural cortical stimulation (SuCS is an appealing method in the treatment of neurological disorders, and computational modeling studies of SuCS have been applied to determine the optimal design for electrotherapy. To achieve a better understanding of computational modeling on the stimulation effects of SuCS, the influence of anisotropic white matter conductivity on the activation of cortical neurons was investigated in a realistic head model. In this paper, we constructed pyramidal neuronal models (layers 3 and 5 that showed primary excitation of the corticospinal tract, and an anatomically realistic head model reflecting complex brain geometry. The anisotropic information was acquired from diffusion tensor magnetic resonance imaging (DT-MRI and then applied to the white matter at various ratios of anisotropic conductivity. First, we compared the isotropic and anisotropic models; compared to the isotropic model, the anisotropic model showed that neurons were activated in the deeper bank during cathodal stimulation and in the wider crown during anodal stimulation. Second, several popular anisotropic principles were adapted to investigate the effects of variations in anisotropic information. We observed that excitation thresholds varied with anisotropic principles, especially with anodal stimulation. Overall, incorporating anisotropic conductivity into the anatomically realistic head model is critical for accurate estimation of neuronal responses; however, caution should be used in the selection of anisotropic information.

  13. Intersection Theory, Integrable Hierarchies and Topological Field Theory

    OpenAIRE

    Dijkgraaf, Robbert

    1992-01-01

    In these lecture notes we review the various relations between intersection theory on the moduli space of Riemann surfaces, integrable hierarchies of KdV type, matrix models, and topological quantum field theories. We explain in particular why matrix integrals of the type considered by Kontsevich naturally appear as tau-functions associated to minimal models. Our starting point is the extremely simple form of the string equation for the topological (p,1) models, where the so-called Baker-Akhi...

  14. The Hierarchy of Transcriptional Activation: From Enhancer to Promoter.

    Science.gov (United States)

    Vernimmen, Douglas; Bickmore, Wendy A

    2015-12-01

    Regulatory elements (enhancers) that are remote from promoters play a critical role in the spatial, temporal, and physiological control of gene expression. Studies on specific loci, together with genome-wide approaches, suggest that there may be many common mechanisms involved in enhancer-promoter communication. Here, we discuss the multiprotein complexes that are recruited to enhancers and the hierarchy of events taking place between regulatory elements and promoters.

  15. Hamiltonian hierarchy and the Hulthén potential

    Science.gov (United States)

    Gönül, B.; Özer, O.; Cançelik, Y.; Koçak, M.

    2000-10-01

    We deal with the Hamiltonian hierarchy problem of the Hulthén potential within the frame of the supersymmetric quantum mechanics and find that the associated supersymmetric partner potentials simulate the effect of the centrifugal barrier. Incorporating the supersymmetric solutions and using the first-order perturbation theory we obtain an expression for the energy levels of the Hulthén potential which gives satisfactory values for the non-zero angular momentum states.

  16. Modeling the shape hierarchy for visually guided grasping

    CSIR Research Space (South Africa)

    Rezai, O

    2014-10-01

    Full Text Available of object features Frontiers in Computational Neuroscience www.frontiersin.org October 2014 | Volume 8 | Article 132 | 1 COMPUTATIONAL NEUROSCIENCE Rezai et al. Shape hierarchy for visually guided grasping (Borra et al., 2008). AIP also contains other... of depth and its first and second spatial derivatives. CIP has been proposed to encode these variables (Orban et al., 2006), and they have been the basis for several experimental studies of CIP responses (Sakata et al., Frontiers in Computational...

  17. Encoding Lexicalized Tree Adjoining Grammars with a Nonmonotonic Inheritance Hierarchy

    CERN Document Server

    Evans, R; Weir, D; Evans, Roger; Gazdar, Gerald; Weir, David

    1995-01-01

    This paper shows how DATR, a widely used formal language for lexical knowledge representation, can be used to define an LTAG lexicon as an inheritance hierarchy with internal lexical rules. A bottom-up featural encoding is used for LTAG trees and this allows lexical rules to be implemented as covariation constraints within feature structures. Such an approach eliminates the considerable redundancy otherwise associated with an LTAG lexicon.

  18. An Integrable Symplectic Map of a Differential-Difference Hierarchy

    Institute of Scientific and Technical Information of China (English)

    DONG Huan-He; YI Fang-Jiao; SU Jie; LU Guo-Zhi

    2012-01-01

    By choosing a discrete matrix spectral problem, a hierarchy of integrable differential-difference equations is derived from the discrete zero curvature equation, and the Hamiltonian structures are built. Through a higher-order Bargmann symmetry constraint, the spatial part and the temporal part of the Lax pairs and adjoint Lax pairs, which we obtained are respectively nonlinearized into a new integrable symplectic map and a finite-dimensional integrable Hamiltonian system in Liouville sense.

  19. Hamiltonian Forms for a Hierarchy of Discrete Integrable Coupling Systems

    Institute of Scientific and Technical Information of China (English)

    XU Xi-Xiang; YANG Hong-Xiang; LU Rong-Wu

    2008-01-01

    A semi-direct sum of two Lie algebras of four-by-four matrices is presented, and a discrete four-by-fore matrix spectral problem is introduced. A hierarchy of discrete integrable coupling systems is derived. The obtained integrable coupling systems are all written in their Hamiltonian forms by the discrete variational identity. Finally, we prove that the lattice equations in the obtained integrable coupling systems are all Liouville integrable discrete Hamiltonian systems.

  20. The double scaling limit method in the Toda hierarchy

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Alonso, L [Departamento de Fisica Teorica II, Universidad Complutense, E28040 Madrid (Spain); Medina, E [Departamento de Matematicas, Universidad de Cadiz, E11510 Puerto Real, Cadiz (Spain)

    2008-08-22

    Critical points of semiclassical expansions of solutions to the dispersionful Toda hierarchy are considered and a double scaling limit method of regularization is formulated. The analogues of the critical points characterized by the strong conditions in the Hermitian matrix model are analysed and the property of doubling of equations is proved. A wide family of sets of critical points is introduced and the corresponding double scaling limit expansions are discussed.

  1. Application of Fuzzy QFD to Aircraft Top Hierarchy Design

    Institute of Scientific and Technical Information of China (English)

    XIE Jian-xi; SONG Bi-feng; LIU Dong-xia

    2004-01-01

    In this paper, based on the Quality Function Deployment (QFD) method, the Fuzzy Quality Function Deployment (FQFD) theory and the step-by-step hierarchy structure in aircraft top decision design are studied. The fuzzy model for computing competitive factor in evaluation is presented.The decision of key technologies for improving the performance and affordability of a fixed-wing aircraft is studied using the model, and the result proves the feasibility of this model.

  2. Decision support for information systems management: applying analytic hierarchy process

    OpenAIRE

    Huizingh, Eelko K.R.E.; Vrolijk, Hans C.J.

    1995-01-01

    Decision-making in the field of information systems has become more complex due to a larger number of alternatives, multiple and sometimes conflicting goals, and an increasingly turbulent environment. In this paper we explore the appropriateness of Analytic Hierarchy Process to support I/S decision making. AHP can be applied if the decision problem includes multiple objectives, conflicting criteria, incommensurable units, and aims at selecting an alternative from a known set of alternatives. ...

  3. MPQC: Performance Analysis and Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Sarje, Abhinav [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Williams, Samuel [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bailey, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-01-24

    MPQC (Massively Parallel Quantum Chemistry) is a widely used computational quantum chemistry code. It is capable of performing a number of computations commonly occurring in quantum chemistry. In order to achieve better performance of MPQC, in this report we present a detailed performance analysis of this code. We then perform loop and memory access optimizations, and measure performance improvements by comparing the performance of the optimized code with that of the original MPQC code. We observe that the optimized MPQC code achieves a significant improvement in the performance through a better utilization of vector processing and memory hierarchies.

  4. Varying and inverting the mass hierarchy in collisional energy loss

    CERN Document Server

    Kolevatov, Rodion

    2008-01-01

    Heavy ion collisions at RHIC and at the LHC give access to the medium-induced suppression patterns of heavy-flavored single inclusive hadron spectra at high transverse momentum. This opens novel opportunities for a detailed characterization of the medium produced in the collision. In this note, we point out that the capacity of a QCD medium to absorb the recoil of a partonic projectile is an independent signature, which may differ for different media at the same density. In particular, while the mass hierarchy (i.e., the projectile mass dependence) of radiative energy loss depends solely on a property of the projectile, the mass hierarchy of collisional energy loss depends significantly on properties of the medium. By varying these properties in a class of models, we find that the mass hierarchy of collisional parton energy loss can be modified considerably and can even be inverted, compared to that of radiative parton energy loss. This may help to disentangle the relative strengths of radiative and collision...

  5. Climbing social media in medicine's hierarchy of needs.

    Science.gov (United States)

    Chretien, Katherine C; Kind, Terry

    2014-10-01

    The social media and medicine landscape is evolving rapidly. Early research, social media policies, and educational efforts focused on risk avoidance, while more current efforts have encouraged reflection and explored opportunities. This trajectory has affirmed physicians' professional commitment to maintaining public trust in the face of new challenges in the digital age. In this Commentary, the authors propose viewing physicians' social media use as a hierarchy of needs, similar to Maslow's psychological theory which posits that more basic levels of needs must be met before higher, aspirational levels can be fully attained. The three levels in the social media in medicine's hierarchy of needs are Security, Reflection, and Discovery. Critical to this model is respecting the essential need for Security in order to move towards Reflection and into Discovery. The social media in medicine hierarchy of needs pyramid rests on a foundation of Public Trust. How physicians as a profession have responded to past--and continue to respond to present and future--social media challenges to professionalism reveals what matters most: maintaining public trust and honoring the physicians' contract with society. A victory for online professionalism would be providing trainees with the tools and guidance needed to ascend to Discovery, while ensuring that their basic social media needs are first met. To do this, physician educators need to continue increasing trainees' awareness through designing relevant curricula, encouraging reflection, and providing positive role modeling and effective mentorship.

  6. Developing a hierarchy of needs for Type 1 diabetes.

    Science.gov (United States)

    Beran, D

    2014-01-01

    The aim of this study was to use the concept of Maslow's hierarchy of needs and apply this to Type 1 diabetes. Qualitative methods were employed using semi-structured interviews with 101 people from 13 countries. Grounded theory was used for data collection and analysis, with thematic analysis employed to identify the interviewees' needs. Sixteen needs were identified and links between these were mapped. Aligning these with Maslow's hierarchy allowed for a hierarchy to be developed for Type 1 diabetes with 'Policies', 'Organization of health system', 'Insulin', 'Delivery of insulin', 'Control', 'Healthcare workers' and 'Information and education' at the base, as they were needed for survival. Next came 'Community, family and peers' and changing roles for 'Healthcare workers' in their approach to care and delivering 'Information and education'. This enabled people to learn how to use 'Insulin', 'Delivery of insulin' and 'Control' flexibly. People's 'Experience' and 'Personality' then helped them 'Adapt' and 'Be open' about their diabetes, allowing for 'Acceptance' and viewing 'Diabetes as something positive'. Despite limitations, this work highlights that some needs are required for survival and others for well-being. Some are tangible as they can be directly provided, whereas others are intangible and cannot be provided directly by the health system. These results might be used for policy and practice in identifying needs that are met within a health system or what needs are lacking for the individual to then implement targeted interventions. © 2013 The Author. Diabetic Medicine © 2013 Diabetes UK.

  7. Introducing a Concept Hierarchy for the Journal of Research Practice

    Directory of Open Access Journals (Sweden)

    Werner Ulrich

    2011-01-01

    Full Text Available With this issue of the Journal of Research Practice, we initiate a conceptual framework for thinking and writing about research, defining areas of editorial focus, and indexing work published in the journal. The framework takes the form of a concept hierarchy that offers index terms at three interrelated levels: (1 focus areas for reflection on research practice within which the journal aims to achieve excellence and strengthen its profile and visibility, (2 subject areas relevant to research practice that the journal aims to cover and in terms of which it defines its focus areas, and (3 keywords for capturing the content of research work done in these subject areas or for reflecting and writing about it. Focus areas are characterized by assigned subject areas; subject areas are characterized by assigned keywords. The concept hierarchy is part of a more comprehensive initiative to strengthen the journal's profile and visibility, an initiative that will also include a restructuring of the editorial team and new roles for the journal's dedicated reviewers and active readers. The article introduces an initial version of the concept hierarchy, explains its intended use and further development, and situates it in the larger effort of which it is a part.

  8. Non-degenerate solutions of universal Whitham hierarchy

    CERN Document Server

    Takasaki, Kanehisa; Teo, Lee Peng

    2010-01-01

    The notion of non-degenerate solutions for the dispersionless Toda hierarchy is generalized to the universal Whitham hierarchy of genus zero with $M+1$ marked points. These solutions are characterized by a Riemann-Hilbert problem (generalized string equations) with respect to two-dimensional canonical transformations, and may be thought of as a kind of general solutions of the hierarchy. The Riemann-Hilbert problem contains $M$ arbitrary functions $H_a(z_0,z_a)$, $a = 1,...,M$, which play the role of generating functions of two-dimensional canonical transformations. The solution of the Riemann-Hilbert problem is described by period maps on the space of $(M+1)$-tuples $(z_\\alpha(p) : \\alpha = 0,1,...,M)$ of conformal maps from $M$ disks of the Riemann sphere and their complements to the Riemann sphere. The period maps are defined by an infinite number of contour integrals that generalize the notion of harmonic moments. The $F$-function (free energy) of these solutions is also shown to have a contour integral r...

  9. Internal and International Migration Across the Urban Hierarchy in Albania.

    Science.gov (United States)

    Lerch, Mathias

    2016-01-01

    The interactions between the processes of urbanization and international migration in less developed and transition countries have important repercussions for socioeconomic development, but are not well understood. Based on the retrospective data from the Albanian Living Standards Measurement Survey 2008, we first assess the geography of migration in terms of the rural-urban continuum, the urban hierarchy and the outside world since 1990. We then investigate the spatio-temporal diffusion of rural-to-urban and international movements using survival models. Results reveal an immediate onset of large-scale rural exodus, despite the post-communist crisis. Internal migrants mainly moved to the capital, bypassing secondary cities, and were predominantly female. Initially, international migrants were primarily men who tended to originate from the main urban agglomerations. The diffusion of opportunities to emigrate down the urban hierarchy and across the sexes then redirected the rural exodus abroad, despite domestic economic development. This evolution in population mobility is related to the gendered patterns and interlinkages of the two flows, as well as to rising inequalities within the urban hierarchy.

  10. Topological hierarchy matters — topological matters with superlattices of defects

    Science.gov (United States)

    He, Jing; Kou, Su-Peng

    2016-11-01

    Topological insulators/superconductors are new states of quantum matter with metallic edge/surface states. In this paper, we review the defects effect in these topological states and study new types of topological matters — topological hierarchy matters. We find that both topological defects (quantized vortices) and non topological defects (vacancies) can induce topological mid-gap states in the topological hierarchy matters after considering the superlattice of defects. These topological mid-gap states have nontrivial topological properties, including the nonzero Chern number and the gapless edge states. Effective tight-binding models are obtained to describe the topological mid-gap states in the topological hierarchy matters. Project supported by the National Basic Research Program of China (Grant Nos. 2011CB921803 and 2012CB921704), the National Natural Science Foundation of China (Grant Nos. 11174035, 11474025, 11404090, and 11674026), the Natural Science Foundation of Hebei Province, China (Grant No. A2015205189), the Hebei Education Department Natural Science Foundation, China (Grant No. QN2014022), and the Specialized Research Fund for the Doctoral Program of Higher Education, China.

  11. Inheritance Hierarchy Based Reuse & Reusability Metrics in OOSD

    Directory of Open Access Journals (Sweden)

    Nasib S. Gill,

    2011-06-01

    Full Text Available Reuse and reusability are two major aspects in object oriented software which can be measured from inheritance hierarchy. Reusability is the prerequisite of reuse but both may or may not bemeasured using same metric. This paper characterizes metrics of reuse and reusability in Object Oriented Software Development (OOSD. Reuse metrics compute the extent to which classes have been reused and reusability metrics computes the extent to which classes can be reused. In this paper five new metrics namely- Breadth of Inheritance Tree (BIT, Method Reuse Per Inheritance Relation (MRPIR,Attribute Reuse Per Inheritance Relation (ARPIR, Generality of Class (GC and Reuse Probability (RP have been proposed. These metrics help to evaluate reuse and reusability of object oriented software.Four extensively validated existing object oriented metrics, namely- Depth of Inheritance Tree (DIT, Number of Children (NOC, Method Inheritance Factor (MIF and Attribute Inheritance Factor (AIFhave been selected and investigated for comparison with proposed metrics. All metrics can be computed from inheritance hierarchies and classified according to their characteristics. Further, metrics areevaluated against a case study. These metrics are helpful in comparing alternative inheritance hierarchies at design time to select best alternative, so that the development time and cost can be reduced.

  12. Cognitive Hierarchy Theory and Two-Person Games

    Directory of Open Access Journals (Sweden)

    Carlos Gracia-Lázaro

    2017-01-01

    Full Text Available The outcome of many social and economic interactions, such as stock-market transactions, is strongly determined by the predictions that agents make about the behavior of other individuals. Cognitive hierarchy theory provides a framework to model the consequences of forecasting accuracy that has proven to fit data from certain types of game theory experiments, such as Keynesian beauty contests and entry games. Here, we focus on symmetric two-player-two-action games and establish an algorithm to find the players’ strategies according to the cognitive hierarchy approach. We show that the snowdrift game exhibits a pattern of behavior whose complexity grows as the cognitive levels of players increases. In addition to finding the solutions up to the third cognitive level, we demonstrate, in this theoretical frame, two new properties of snowdrift games: (i any snowdrift game can be characterized by only a parameter, its class; (ii they are anti-symmetric with respect to the diagonal of the pay-off’s space. Finally, we propose a model based on an evolutionary dynamics that captures the main features of the cognitive hierarchy theory.

  13. Structural Measures to Track the Evolution of SNOMED CT Hierarchies

    Science.gov (United States)

    Wei, Duo; Gu, Huanying (Helen); Perl, Yehoshua; Halper, Michael; Ochs, Christopher; Elhanan, Gai; Chen, Yan

    2015-01-01

    The Systematized Nomenclature of Medicine Clinical Terms (SNOMED CT) is an extensive reference terminology with an attendant amount of complexity. It has been updated continuously and revisions have been released semi-annually to meet users’ needs and to reflect the results of quality assurance (QA) activities. Two measures based on structural features are proposed to track the effects of both natural terminology growth and QA activities based on aspects of the complexity of SNOMED CT. These two measures, called the structural density measure and accumulated structural measure, are derived based on two abstraction networks, the area taxonomy and the partial-area taxonomy. The measures derive from attribute relationship distributions and various concept groupings that are associated with the abstraction networks. They are used to track the trends in the complexity of structures as SNOMED CT changes over time. The measures were calculated for consecutive releases of five SNOMED CT hierarchies, including the Specimen hierarchy. The structural density measure shows that natural growth tends to move a hierarchy’s structure toward a more complex state, whereas the accumulated structural measure shows that QA processes tend to move a hierarchy’s structure toward a less complex state. It is also observed that both the structural density and accumulated structural measures are useful tools to track the evolution of an entire SNOMED CT hierarchy and reveal internal concept migration within it. PMID:26260003

  14. The Alternation Hierarchy for the Theory of µ-lattices

    DEFF Research Database (Denmark)

    Santocanale, Luigi

    2002-01-01

    The alternation hierarchy problem asks whether every µ-term φ, that is, a term built up also using a least fixed point constructor as well as a greatest fixed point constructor, is equivalent to a µ-term where the number of nested fixed points of a different type is bounded by a constant independ......The alternation hierarchy problem asks whether every µ-term φ, that is, a term built up also using a least fixed point constructor as well as a greatest fixed point constructor, is equivalent to a µ-term where the number of nested fixed points of a different type is bounded by a constant...... independent of φ. In this paper we give a proof that the alternation hierarchy for the theory of µ-lattices is strict, meaning that such a constant does not exist if µ-term are built up from the basic lattice operations and are interpreted as expected. The proof relies on the explicit characterization of free...

  15. Social hierarchy modulates neural responses of empathy for pain.

    Science.gov (United States)

    Feng, Chunliang; Li, Zhihao; Feng, Xue; Wang, Lili; Tian, Tengxiang; Luo, Yue-Jia

    2016-03-01

    Recent evidence indicates that empathic responses to others' pain are modulated by various situational and individual factors. However, few studies have examined how empathy and underlying brain functions are modulated by social hierarchies, which permeate human society with an enormous impact on social behavior and cognition. In this study, social hierarchies were established based on incidental skill in a perceptual task in which all participants were mediumly ranked. Afterwards, participants were scanned with functional magnetic resonance imaging while watching inferior-status or superior-status targets receiving painful or non-painful stimulation. The results revealed that painful stimulation applied to inferior-status targets induced higher activations in the anterior insula (AI) and anterior medial cingulate cortex (aMCC), whereas these empathic brain activations were significantly attenuated in response to superior-status targets' pain. Further, this neural empathic bias to inferior-status targets was accompanied by stronger functional couplings of AI with brain regions important in emotional processing (i.e. thalamus) and cognitive control (i.e. middle frontal gyrus). Our findings indicate that emotional sharing with others' pain is shaped by relative positions in a social hierarchy such that underlying empathic neural responses are biased toward inferior-status compared with superior-status individuals. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  16. Role of the cerebellum in high stages of motor planning hierarchy.

    Science.gov (United States)

    Casartelli, Luca; Federici, Alessandra; Cesareo, Ambra; Biffi, Emilia; Valtorta, Giulia; Molteni, Massimo; Ronconi, Luca; Borgatti, Renato

    2017-04-01

    Motor planning is not a monolithic process, and distinct stages of motor planning are responsible for encoding different levels of abstractness. However, how these distinct components are mapped into different neural substrates remains an open question. We studied one of these high-level motor planning components, defined as second-order motor planning, in a patient (R.G.) with an extremely rare case of cerebellar agenesis but without any other cortical malformations. Second-order motor planning dictates that when two acts must be performed sequentially, planning of the second act can influence execution of the first. We used an optoelectronic system for kinematic analysis to compare R.G.'s performance with age-matched controls in a second-order motor planning task. The first act was to reach for an object, and the second was to place it into a small or large container. Our results showed that despite the expected difficulties in fine-motor skills, second-order motor planning (i.e., the ability to modulate the first act as a function of the nature of the second act) was preserved even in the patient with congenital absence of the cerebellum. These results open new intriguing speculations about the role of the cerebellum in motor planning abilities. Although prudence is imperative when suggesting conclusions made on the basis of single-case findings, this evidence suggests fascinating hypotheses about the neural circuits that support distinct stages of the motor planning hierarchy, and regarding the functional role of second-order motor planning in motor cognition and its potential dysfunction in autism.NEW & NOTEWORTHY Traditionally, the cerebellum was considered essential for motor planning. By studying an extremely rare patient with cerebellar agenesis and a group of neurotypical controls, we found that high stages of the motor planning hierarchy can be preserved even in this patient with congenital absence of the cerebellum. Our results provide interesting

  17. Self-organizing model of motor cortical activities during drawing

    Science.gov (United States)

    Lin, Siming H.; Si, Jennie; Schwartz, Andrew B.

    1996-05-01

    The population vector algorithm has been developed to combine the simultaneous direction- related activities of a population of motor cortical neurons to predict the trajectory of the arm movement. In our study, we consider a self-organizing model of a neural representation of the arm trajectory based on neuronal discharge rates. Self-organizing feature mapping (SOFM) is used to select the optimal set of weights in the model to determine the contribution of individual neuron to the overall movement. The correspondence between the movement directions and the discharge patterns of the motor cortical neurons is established in the output map. The topology preserving property of the SOFM is used to analyze real recorded data of a behavior monkey. The data used in this analysis were taken while the monkey was drawing spirals and doing the center out movement. Using such a statistical model, the monkey's arm moving directions could be well predicted based on the motor cortex neuronal firing information.

  18. Attention modulations on the perception of social hierarchy at distinct temporal stages: an electrophysiological investigation.

    Science.gov (United States)

    Feng, Chunliang; Tian, Tengxiang; Feng, Xue; Luo, Yue-Jia

    2015-04-01

    Recent behavioral and neuroscientific studies have revealed the preferential processing of superior-hierarchy cues. However, it remains poorly understood whether top-down controlled mechanisms modulate temporal dynamics of neurocognitive substrates underlying the preferential processing of these biologically and socially relevant cues. This was investigated in the current study by recording event-related potentials from participants who were presented with superior or inferior social hierarchy. Participants performed a hierarchy-judgment task that required attention to hierarchy cues or a gender-judgment task that withdrew their attention from these cues. Superior-hierarchy cues evoked stronger neural responses than inferior-hierarchy cues at both early (N170/N200) and late (late positive potential, LPP) temporal stages. Notably, the modulations of top-down attention were identified on the LPP component, such that superior-hierarchy cues evoked larger LPP amplitudes than inferior-hierarchy cues only in the attended condition; whereas the modulations of the N170/N200 component by hierarchy cues were evident in both attended and unattended conditions. These findings suggest that the preferential perception of superior-hierarchy cues involves both relatively automatic attentional bias at the early temporal stage as well as flexible and voluntary cognitive evaluation at the late temporal stage. Finally, these hierarchy-related effects were absent when participants were shown the same stimuli which, however, were not associated with social-hierarchy information in a non-hierarchy task (Experiment 2), suggesting that effects of social hierarchy at early and late temporal stages could not be accounted for by differences in physical attributes between these social cues. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. METODE ANALYTICAL HIERARCHY PROCESS: SISTEM REKOMENDER DATABASE SOFTWARE

    Directory of Open Access Journals (Sweden)

    Doni Purnama Alam Syah

    2014-09-01

    Full Text Available Abstract - Rekomender electoral system is a database software application that can be used to look for alternative software database selection strategy, the method of analytical hierarchy process (AHP. Rekomender systems needed by companies that have a large enough data processing such as the Bureau of Bina Sarana IT Information, expensive investments in the provision of Information Technology (IT makes IT Bina Sarana Information Bureau to be more careful in determining the selection of database software. This study focuses on research of database software selection system with the method of analytical hierarchy process (AHP, a case study of IT Bureau Bina Sarana Infromatika with the observation unit administrator. The results of the study found that there are two (2 main criteria, namely the selection of technology and a user with an alternative strategy My SQL, Oracle and SQL Server. Having tested the system rekomender My SQL result that the top priority in the selection of database software with a 41% weighting, followed by SQL Server and Oracle 39% 21%. The end result of a system that has been created rekomender concluded that the Bureau of Bina Sarana Informatics IT can define strategy alternatives before determining database software to be used more effectively and efficiently. Abstrak¬¬ - Sistem rekomender pemilihan database software merupakan aplikasi yang dapat digunakan untuk mencari alternatif strategi pemilihan database software, dengan metode analytical hierarchy process (AHP. Sistem rekomender dibutuhkan oleh perusahaan yang memiliki pengolahan data yang cukup besar seperti Biro TI Bina Sarana Informatika, mahalnya investasi pada penyediaan Teknologi Informasi (TI membuat Biro TI Bina Sarana Informatika lebih berhati-hati dalam menentukan pemilihan database software. Penelitian ini berfokus kepada penetilian tentang sistem pemilihan database sofware dengan metode analytical hierarchy process (AHP, studi kasus Biro TI Bina Sarana

  20. PENGGUNAAN METODE ANALYTICAL HIERARCHY PROCESS DALAM PEMILIHAN LOKASI MANGROVE PARK

    Directory of Open Access Journals (Sweden)

    Mustika Mustika

    2017-02-01

    Full Text Available Demak district is a district that has quite a lot of mangrove forests, beautiful expanse of mangrove is a natural potential that can be developed as a regional tourism assets. Mangrove Park is one of the utilization of conservation area into tourism areas of education and recreation The Selection of Planning site locations required an appropriate location in the terms of land use, The appropriate land is a land that has a Mangrove area which still leafy, natural (unprocessed and intended as a tourism area, an easy accessibility, the network infrastructure is also needed in the election of location in order to support the available facilities in the building. In addition, the view of the inside and outside of the site that will be a tourism place attraction. Decision Support System can be used as a tool to help the site selection process that involves many criteria. Analytical Hierarchy Process (AHP can be used to analyze which support the decision to choose a location. Phases of AHP used in this research is the identification of causes, preparation of hierarchy, prioritization, consistency, and the priority weight. From the Implementation of the method on the study case successfully find the best location for mangrove park, it is in the village Bedono it has the highest total global priorities 1.2349. Keywords: Site Location, Analytical Hierarchy Process, Mangrove Park Kabupaten Demak adalah kabupaten yang memiliki hutan mangrove yang cukup banyak, hamparan mangrove yang indah merupakan potensi alam yang dapat dikembangkan sebagai aset pariwisata daerah. Mangrove Park adalah salah satu bentuk pemanfaatan kawasan konservasi menjadi kawasan wisata edukasi dan rekreasi. Pemilihan lokasi tapak perencanaan diperlukan sebuah lokasi yang tepat dari segi peruntukan lahan, lahan yang tepat adalah lahan yang memiliki area Mangrove yang masih rimbun, alami (belum diolah dan diperuntukkan sebagai kawasan wisata, aksebilitas yang mudah dijangkau, jaringan