pinecone/core-2020-05-10-deduplication huggingface dataset:
Evaluating Sparse Codes on Handwritten Digits

Sparse coding of visual information has been of interest to  the neuroscientific community for many decades and it is widely recognised  that sparse codes should exhibit a high degree of statistical independence,  typically measured by the kurtosis of the response distributions.  In this paper we extend work on the hierarchical temporal memory  model by studying the suitability of the augmented spatial pooling  (ASP) sparse coding algorithm in comparison with independent component  analysis (ICA) when applied to the recognition of handwritten  digits. We present an extension to the ASP algorithm that forms synaptic  receptive fields located closer to their respective columns and show  that this produces lower Naive Bayes classification errors than both ICA  and the original ASP algorithm. In evaluating kurtosis as a predictor  of classification performance, we also show that additional measures of  dispersion and mutual information are needed to reliably distinguish between  competing approaches.Griffith Sciences, School of Information and Communication TechnologyFull Tex
Ultimate Order Statistics-Based Prototype Reduction Schemes

Published version of a chapter in the book: AI 2013: Advances in Artificial Intelligence. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-319-03680-9_42The objective of Prototype Reduction Schemes (PRSs) and Border Identification (BI) algorithms is to reduce the number of training vectors, while simultaneously attempting to guarantee that the classifier built on the reduced design set performs as well, or nearly as well, as the classifier built on the original design set. In this paper, we shall push the limit on the field of PRSs to see if we can obtain a classification accuracy comparable to the optimal, by condensing the information in the data set into a single training point. We, indeed, demonstrate that such PRSs exist and are attainable, and show that the design and implementation of such schemes work with the recently-introduced paradigm of Order Statistics (OS)-based classifiers. These classifiers, referred to as Classification by Moments of Order Statistics (CMOS) is essentially anti-Bayesian in its modus operandus. In this paper, we demonstrate the power and potential of CMOS to yield single-element PRSs which are either “selective” or “creative”, where in each case we resort to a non-parametric or a parametric paradigm respectively. We also report a single-feature single-element creative PRS. All of these solutions have been used to achieve classification for real-life data sets from the UCI Machine Learning Repository, where we have followed an approach that is similar to the Naïve-Bayes’ (NB) strategy although it is essentially of an anti-Naïve-Bayes’ paradigm. The amazing facet of this approach is that the training set can be reduced to a single pattern from each of the classes which is, in turn, determined by the CMOS features. It is even more fascinating to see that the scheme can be rendered operational by using the information in a single feature of such a single data point. In each of these cases, the accuracy of the proposed PRS-based approach is very close to the optimal Bayes’ bound and is almost comparable to that of the SVM
A new paradigm for pattern classification: Nearest Border Techniques

Published version of a chapter in the book: AI 2013: Advances in Artificial Intelligence. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-319-03680-9_44There are many paradigms for pattern classification. As opposed to these, this paper introduces a paradigm that has not been reported in the literature earlier, which we shall refer to as the Nearest Border (NB) paradigm. The philosophy for developing such a NB strategy is as follows: Given the training data set for each class, we shall first attempt to create borders for each individual class. After that, we advocate that testing is accomplished by assigning the test sample to the class whose border it lies closest to. This claim is actually counter-intuitive, because unlike the centroid or the median, these border samples are often “outliers” and are, really, the points that represent the class the least. However, we have formally proven this claim, and the theoretical results have been verified by rigorous experimental testing
Neighborhood Selection in Constraint-Based Local Search for Protein Structure Prediction

Protein structure prediction (PSP) is a very challenging constraint optimization problem. Constraint-based local search approaches have obtained promising results in solving constraint models for PSP. However, the neighborhood exploration policies adopted in these approaches either remain exhaustive or are based on random decisions. In this paper, we propose heuristics to intelligently explore only the promising areas of the search neighborhood. On face centered cubic lattice using a realistic 20ײ0 energy model and standard benchmark proteins, we obtain structures with significantly lower energy and RMSD values than those obtained by the state-of-the-art algorithms.Griffith Sciences, School of Information and Communication TechnologyFull Tex
Efficient Retransmission QoS-Aware MAC Scheme in Wireless Sensor Networks

In this paper, an Efficient Retransmission Random Access Protocol (ERRAP) is designed that combines scheme of collision avoidance and energy management for low-cost, short-range wireless radios and low-energy sensor nodes applications. This protocol focuses on efficient Media Access Control (MAC) schemes to provide autonomous Quality of Service (QoS) to the sensor nodes in one-hop QoS retransmission group in WSNs where the source nodes do not have receiver circuits. These sensor nodes can only transmit data to a destination node, but cannot receive acknowledgement or control signals from the destination node. The proposed scheme ERRAP provides QoS to the nodes which work independently on predefined time by allowing them to transmit each packet an optimal number of times within a given period. Our simulation results demonstrate the superiority of ERRAP scheme which increases the delivery probability and reduces the energy consumption
Improving Histogram-Based Image Registration in Video Sequences through Warping

This paper presents two computationally efficient dynamic-time warping algorithms for image registration in video sequence through histogram based image segmentation. The key idea is to warp the histogram in an input frame to create an approximation of a reference frame. Any histogram based thresholding method can then be applied to create consistent regions in both the input and the approximated reference frames. Experiments of the proposed algorithm are used to demonstrate that more consistent matches can found after thresholding.Griffith Sciences, School of Information and Communication TechnologyFull Tex
Superconformal symmetry and higher-derivative Lagrangians

Superconformal methods are useful to build invariant actions in supergravity.
We have a good insight in the possibilities of actions that are at most
quadratic in spacetime derivatives, but insight in general higher-derivative
actions is missing. Recently higher-derivative actions got more attention for
several applications. One of these is the understanding of finiteness of loop
computations in supergravities. Divergences can only occur if invariant
counterterms or anomalies exist. One can wonder whether conformal symmetry
might also play a role in this context. In order to construct higher-derivative
supergravities with the conformal methods, one should first get more insight in
such rigid supersymmetric actions with extra fermionic symmetries. We show how
Dirac--Born--Infeld actions with Volkov--Akulov supersymmetries can be
constructed in all orders.Comment: 22 pages; Contribution to the proceedings of 'Breaking of
  supersymmetry and Ultraviolet Divergences in extended Supergravity',
  Frascati, March 2013, to be published as Springer Lecture Note
Thermodynamic curvature and black holes

I give a relatively broad survey of thermodynamic curvature $R$, one spanning
results in fluids and solids, spin systems, and black hole thermodynamics. $R$
results from the thermodynamic information metric giving thermodynamic
fluctuations. $R$ has a unique status in thermodynamics as being a geometric
invariant, the same for any given thermodynamic state. In fluid and solid
systems, the sign of $R$ indicates the character of microscopic interactions,
repulsive or attractive. $|R|$ gives the average size of organized mesoscopic
fluctuating structures. The broad generality of thermodynamic principles might
lead one to believe the same for black hole thermodynamics. This paper explores
this issue with a systematic tabulation of results in a number of cases.Comment: 27 pages, 10 figures, 7 tables, 78 references. Talk presented at the
  conference Breaking of Supersymmetry and Ultraviolet Divergences in extended
  Supergravity, in Frascati, Italy, March 27, 2013. v2 corrects some small
  problem
Coset approach to the partial breaking of global supersymmetry

We propose a method to construct on-shell component actions for theories with
1/2 partial breaking of global supersymmetry within the nonlinear realization
(coset) approach. In contrast with the standard superfield approach in which
unbroken supersymmetry plays the leading role, we have shifted the attention to
the spontaneously broken supersymmetry. It turns out that in theories in which
half of supersymmetries is spontaneously broken, all physical fermions are just
the fermions of the nonlinear realization. Moreover, transformation properties
of these fermions with respect to broken supersymmetry are the same as in the
Volkov-Akulov model. Just this completely fixed all possible appearances of
fermions in the component action: they can enter the action through the
determinant of the vielbein and covariant derivatives, only. In our
parametrization of the coset the rest of physical components, i.e. all bosonic
components, transform as "matter fields" with respect to broken supersymmetry.
Clearly, the component action acquires the form of the Volkov-Akulov action for
these "matter fields". The complete form of the action can be further fixed by
two additional requirements: a) to reproduce the bosonic limit, which is
explicitly known in many interesting cases, and b) to have a proper linearized
form, which has to be invariant with respect to linearized unbroken
supersymmetry. In some cases additional Wess-Zumino terms (which disappear in
the bosonic limit) have to be added to the action. We supply the general
consideration by detailed examples of actions for the superparticle in D=3,5,
the on-shell component action for N=1, D=5 supermembrane and its dual cousins
and the component action of N=1 supermembrane in D=4, providing the exact proof
of the invariance of the constructed component actions with respect to both
broken and unbroken supersymmetries.Comment: 31 pages, to appear in Breaking of supersymmetry and Ultraviolet
  Divergences in extended Supergravity Workshop, Proceedings of the
  INFN-Laboratori Nazionali di Frascati School 2013, Springer Heidelberg New
  York Dordrecht London, Springer Proceedings in Physics (2014), PACS:
  11.30.Pb, 12.60.J
Constitutive relations, off shell duality rotations and the
  hypergeometric form of Born-Infeld theory

We review equivalent formulations of nonlinear and higher derivatives
theories of electromagnetism exhibiting electric-magnetic duality rotations
symmetry. We study in particular on shell and off shell formulations of this
symmetry, at the level of action functionals as well as of equations of motion.
We prove the conjecture that the action functional leading to Born-Infeld
nonlinear electromagnetism, that is duality rotation invariant off shell and
that is known to be a root of an algebraic equation of fourth order, is a
hypergeometric function.Comment: 20 pages. Contribution to the proceedings of the conference BUDS2013,
  Frascat
Pure spinor superfields -- an overview

Maximally supersymmetric theories do not allow off-shell superspace
formulations with traditional superfields containing a finite set of auxiliary
fields. It has become clear that off-shell supersymmetric action formulations
of such models can be achieved by the introduction of pure spinors. In this
talk, an overview of this formalism is given, with emphasis on D=10
super-Yang-Mills theory and D=11 supergravity. This a somewhat expanded version
of a talk presented at the workshop "Breaking of supersymmetry and ultraviolet
divergences in extended supergravity" (BUDS), Laboratori Nazionali di Frascati,
March 25-28, 2013.Comment: 34 pp., 2 figs., contributions to the proceedings of the workshop
  "Breaking of supersymmetry and ultraviolet divergences in extended
  supergravity" (BUDS), Laboratori Nazionali di Frascati, March 25-28, 201
Colored spanning graphs for set visualization

We study an algorithmic problem that is motivated by ink minimization for sparse set visualizations. Our input is a set of points in the plane which are either blue, red, or purple. Blue points belong exclusively to the blue set, red\ud
points belong exclusively to the red set, and purple points belong to both sets.\ud
A red-blue-purple spanning graph (RBP spanning graph) is a set of edges connecting the points such that the subgraph induced by the red and purple points is connected, and the subgraph induced by the blue and purple points is connected.\ud
We study the geometric properties of minimum RBP spanning graphs and the algorithmic problems associated with computing them. Specifically, we show that the general problem is NP-hard. Hence we give an (1/2¿+1)-approximation, where ¿ is the Steiner ratio. We also present efficient exact solutions if the points are located on a line or a circle. Finally we consider extensions to more than two sets.Peer ReviewedPostprint (published version
An Optimal Broadcast Algorithm for Content-Addressable Networks

International audienceStructured peer-to-peer networks are powerful underlying structures for communication and storage systems in large-scale setting. In the context of the Content-Addressable Network (CAN), this paper addresses the following challenge: how to perform an efficient broadcast while the local view of the network is restricted to a set of neighbours? In existing approaches, either the broadcast is inefficient (there are dupli- cated messages) or it requires to maintain a particular structure among neighbours, e.g. a spanning tree. We define a new broadcast primitive for CAN that sends a minimum number of messages while covering the whole network, without any global knowledge. Currently, no other al- gorithm achieves those two goals in the context of CAN. In this sense, the contribution we propose in this paper is threefold. First, we pro- vide an algorithm that sends exactly one message per recipient without building a global view of the network. Second, we prove the absence of duplicated messages and the coverage of the whole network when using this algorithm. Finally, we show the practical benefits of the algorithm throughout experiments
Parameterized complexity of two edge contraction problems with degree constraints.

Motivated by recent results of Mathieson and Szeider (J. Comput. Syst. Sci. 78(1): 179–191, 2012), we study two graph modification problems where the goal is to obtain a graph whose vertices satisfy certain degree constraints. The Regular Contraction problem takes as input a graph G and two integers d and k, and the task is to decide whether G can be modified into a d-regular graph using at most k edge contractions. The Bounded Degree Contraction problem is defined similarly, but here the objective is to modify G into a graph with maximum degree at most d. We observe that both problems are fixed-parameter tractable when parameterized jointly by k and d. We show that when only k is chosen as the parameter, Regular Contraction becomes W[1]-hard, while Bounded Degree Contraction becomes W[2]-hard even when restricted to split graphs. We also prove both problems to be NP-complete for any fixed d ≥ 2. On the positive side, we show that the problem of deciding whether a graph can be modified into a cycle using at most k edge contractions, which is equivalent to Regular Contraction when d = 2, admits an O(k) vertex kernel. This complements recent results stating that the same holds when the target is a path, but that the problem admits no polynomial kernel when the target is a tree, unless NP ⊆ coNP/poly (Heggernes et al., IPEC 2011)
The information literacy self-efficacy of disadvantaged teachers in South Africa

The aim of this study was to gauge teachers’ information literacy
self-efficacy thereby eliciting clues to possible gaps in teachers’ knowledge and
skills which could be addressed during an information literacy education course.
Twenty nine teachers completed a pre-and post-course information literacy
questionnaire. The teachers were part of a school librarianship programme
offered at the University of the Western Cape. The results of the study indicate
that the intervention of the course had a positive effect on teachers’
information literacy.Web of Scienc
Conference Keynote: Information literacy research and practice: An experiential perspective

In this paper I will explore some experience-based perspectives on information literacy research and practice. The research based understanding of what information literacy looks like to those experiencing it, is very different from the standard interpretations of information literacy as involving largely text based information searching, interpretation, evaluation and use. It also involves particular understandings of the interrelation between information and learning experiences.\ud
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In following this thread of the history of information literacy I will reflect on aspects of the past, present and future of information literacy research. In each of these areas I explore experiential, especially phenomenographic approaches to information literacy and information literacy education, to reveal the unfolding understanding of people’s experience of information literacy stemming from this orientation.\ud
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In addressing the past I will look in particular at the contribution of the seven faces of information literacy and some lessons learned from attending to variation in experience. I will explore important directions and insights that this history may help us to retain; including the value of understanding peoples’ information literacy experience.\ud
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In addressing the present, I will introduce more recent work that adopts the key ideas of informed learning by attending to both information and learning experiences in specific contexts. I will look at some contemporary directions and key issues, including the reinvention of the phenomenographic, or relational approach to information literacy as informed learning or using information to learn.\ud
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I will also provide some examples of the contribution of experiential approaches to information literacy research and practice. The evolution and development of the phenomenographic approach to information literacy, and the growing attention to a dual focus on information and learning experiences in this approach will be highlighted. Finally, in addressing the future I will return to advocacy, the recognition and pursuit of the transforming and empowering heart of information literacy; and suggest that for information literacy research, including the experiential, a turn towards the emancipatory has much to offer
Empowering information literacy and continuing professional development of librarians: new paradigms for learning.

Information professionals play a key role in facilitating and advocating the development of information literacy in educational, organizational and everyday life contexts. However, their information literacy continuing professional needs have not attracted sufficient attention in research. This qualitative study explores information professionals? perspectives of information literacy within their working practices. The paper reports on the preliminary findings of interviews conducted with a total of seventeen professional and non-professional librarians with experience of working in academic, public or special libraries. Librarians? definitions of information literacy highlighted a weak connection between information literacy development needs and everyday working context, when not directly involving information services to library users. However, information literacy and digital literacy were perceived as interconnected competencies, with the latter requiring ongoing development. Participants highlighted examples of blockage to their overall continuing professional development (e.g. management style, lack of resources) which emphasize the need for expanding online professional educational opportunities and promoting a culture of sharing and openness in the library profession
Selecting Mathematical Software for Dependability Assessment of Computer Systems Described by Stiff Markov Chains

Markov and semi-Markov models are widely used in dependability assessment of complex computer-based systems. Model stiffness poses a serious problem both in terms of computational difficulties and in terms of accuracy of the assessment. Selecting an appropriate method and software package for solving stiff Markov models proved to be a non-trivial task. In this paper we provide an empirical comparison of two approaches to dealing with stiffness – stiffness avoidance and stiffness-tolerance. The study includes several well known techniques and software tools used for solving Kolmogorov’s differential equations derived from complex stiff Markov models. In the comparison we used realistic cases studies developed by others in the past: i) a computer system with hardware redundancy and diverse software, and ii) a queuing system with a server break-down and repair. The results indicate that the accuracy of the known methods is significantly affected by the stiffness of the Markov models, which led us to developing a procedure (an algorithm) for selecting the optimal method and tool for solving a given stiff Markov model. The algorithm is, also included in the paper
Carbon storage and DNA absorption in allophanic soils and paleosols

Andisols and andic paleosols dominated by the nanocrystalline mineral allophane sequester large amounts of carbon (C), attributable mainly to its chemical bonding with charged hydroxyl groups on the surface of allophane together with its physical protection in nanopores within and between allophane nanoaggregates. C near-edge X-ray absorption fine structure (NEXAFS) spectra for a New Zealand Andisol (Tirau series) showed that the organic matter (OM) mainly comprises quinonic, aromatic, aliphatic, and carboxylic C. In different buried horizons from several other Andisols, C contents varied but the C species were similar, attributable to pedogenic processes operating during developmental upbuilding, downward leaching, or both. The presence of OM in natural allophanic soils weakened the adsorption of DNA on clay; an adsorption isotherm experiment involving humic acid (HA) showed that HA-free synthetic allophane adsorbed seven times more DNA than HA-rich synthetic allophane. Phosphorus X-ray absorption near-edge structure (XANES) spectra for salmonsperm DNA and DNA-clay complexes indicated that DNA was bound to the allophane clay through the phosphate group, but it is not clear if DNA was chemically bound to the surface of the allophane or to OM, or both. We plan more experiments to investigate interactions among DNA, allophane (natural and synthetic), and OM. Because DNA shows a high affinity to allophane, we are studying the potential to reconstruct late Quaternary palaeoenvironments by attempting to extract and characterise ancient DNA from allophanic paleosol