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additive models provide an important family of models for semiparametric regression or classification . some reasons for the success of additive models are their increased flexibility when compared to linear or generalized linear models and their increased interpretability when compared to fully nonparametric models .i... | additive models play an important role in semiparametric statistics . this paper gives learning rates for regularized kernel based methods for additive models . these learning rates compare favourably in particular in high dimensions to recent results on optimal learning rates for purely nonparametric regularized kerne... |
the transport properties of nonlinear non - equilibrium dynamical systems are far from well - understood .consider in particular so - called ratchet systems which are asymmetric periodic potentials where an ensemble of particles experience directed transport .the origins of the interest in this lie in considerations ab... | in 84 , 258 ( 2000 ) , mateos conjectured that current reversal in a classical deterministic ratchet is associated with bifurcations from chaotic to periodic regimes . this is based on the comparison of the current and the bifurcation diagram as a function of a given parameter for a periodic asymmetric potential . barb... |
with significant research efforts being directed to the development of neurocomputers based on the functionalities of the brain , a seismic shift is expected in the domain of computing based on the traditional von - neumann model .the , and the ibm are instances of recent flagship neuromorphic projects that aim to d... | synaptic memory is considered to be the main element responsible for learning and cognition in humans . although traditionally non - volatile long - term plasticity changes have been implemented in nanoelectronic synapses for neuromorphic applications , recent studies in neuroscience have revealed that biological synap... |
the segmentation process as a whole can be thought of as consisting of two tasks : recognition and delineation .recognition is to determine roughly `` where '' the object is and to distinguish it from other object - like entities .although delineation is the final step for defining the spatial extent of the object regi... | this paper investigates , using prior shape models and the concept of ball scale ( b - scale ) , ways of automatically recognizing objects in 3d images without performing elaborate searches or optimization . that is , the goal is to place the model in a single shot close to the right pose ( position , orientation , and... |
biological aggregations such as fish schools , bird flocks , bacterial colonies , and insect swarms have characteristic morphologies governed by the group members interactions with each other and with their environment .the _ endogenous _ interactions , _i.e. _ , those between individuals , often involve organisms reac... | we study equilibrium configurations of swarming biological organisms subject to exogenous and pairwise endogenous forces . beginning with a discrete dynamical model , we derive a variational description of the corresponding continuum population density . equilibrium solutions are extrema of an energy functional , and s... |
inflation generically predicts a primordial spectrum of density perturbations which is almost precisely gaussian . in recent yearsthe small non - gaussian component has emerged as an important observable , and will be measured with good precision by the _planck surveyor _ satellite . in the near future ,as observationa... | we present a novel method for calculating the primordial non - gaussianity produced by super - horizon evolution during inflation . our method evolves the distribution of coarse - grained inflationary field values using a transport equation . we present simple evolution equations for the moments of this distribution , ... |
invariants are a popular concept in object recognition and image retrieval .they aim to provide descriptions that remain constant under certain geometric or radiometric transformations of the scene , thereby reducing the search space .they can be classified into global invariants , typically based either on a set of k... | _ this paper presents invariants under gamma correction and similarity transformations . the invariants are local features based on differentials which are implemented using derivatives of the gaussian . the use of the proposed invariant representation is shown to yield improved correlation results in a template matchi... |
developments are currently underway to promote the sensitivity of ligo and to improve its prospect for detecting gravitational waves emitted by compact object binaries . of particular interestare the detection of gravitational waves released during the inspiral and merger of binary black hole ( bbh ) systems .detection... | matched - filtering for the identification of compact object mergers in gravitational - wave antenna data involves the comparison of the data stream to a bank of template gravitational waveforms . typically the template bank is constructed from phenomenological waveform models since these can be evaluated for an arbitr... |
the origin - destination ( od ) matrix is important in transportation analysis .the matrix contains information on the number of travellers that commute or the amount of freight shipped between different zones of a region .the od matrix is difficult and often costly to obtain by direct measurements / interviews or surv... | the estimation of the number of passengers with the identical journey is a common problem for public transport authorities . this problem is also known as the origin - destination estimation ( od ) problem and it has been widely studied for the past thirty years . however , the theory is missing when the observations a... |
a fair number of astronomers and astronomy students have a physical challenge .it is our responsibility to learn the basics of accessibility to be able to help our library patrons to gain access to things that they need for their studies and work .astronomy is often seen as a very visual science .after all , its origin... | making online resources more accessible to physically challenged library users is a topic deserving informed attention from astronomy librarians . recommendations like wcag 2.0 standards and section 508 , in the united states , have proven valuable , and some vendors are already making their products compliant with the... |
in adaptive control and recursive parameter estimation one often needs to adjust recursively an estimate of a vector , which comprises constant but unknown parameters , using measurements of a quantity here is a vector of known data , often called the regressor , and is a measurement error signal .the goal of tuning is... | we propose a tuner , suitable for adaptive control and ( in its discrete - time version ) adaptive filtering applications , that sets the second derivative of the parameter estimates rather than the first derivative as is done in the overwhelming majority of the literature . comparative stability and performance analys... |
the experimental data used in this paper were collected by the forward looking radar of the us army research laboratory . that radar was built for detection and possible identification of shallow explosive - like targets .since targets are three dimensional objects , one needs to measure a three dimensional information... | a new numerical method is proposed for a 1-d inverse medium scattering problem with multi - frequency data . this method is based on the construction of a weighted cost functional . the weight is a carleman weight function ( cwf ) . in other words , this is the function , which is present in the carleman estimate for t... |
in a database containing a solution of the 3d incompressible navier - stokes ( ns ) equations is presented .the equations were solved numerically with a standard pseudo - spectral simulation in a periodic domain , using a real space grid of grid points .a large - scale body force drives a turbulent flow with a taylor m... | the jhu turbulence database can be used with a state of the art visualisation tool to generate high quality link : anc / dfdsubmissionquarterres.mpg[fluid dynamics videos ] . in this work we investigate the classical idea that smaller structures in turbulent flows , while engaged in their own internal dynamics , are ad... |
the open connectome project ( located at http://openconnecto.me ) aims to annotate all the features in a 3d volume of neural em data , connect these features , and compute a high resolution wiring diagram of the brain , known as a connectome .it is hoped that such work will help elucidate the structure and function of ... | * _ abstract _ : * in this paper , we present a new pipeline which automatically identifies and annotates axoplasmic reticula , which are small subcellular structures present only in axons . we run our algorithm on the kasthuri11 dataset , which was color corrected using gradient - domain techniques to adjust contrast ... |
over the past 70 years , there have been multiple attempts to dynamically model the movement of polymer chains with brownian dynamics , which have more recently been used as a model for dna filament dynamics .one of the first and simplest descriptions was given as the rouse model , which is a bead - spring model , ... | a multi - resolution bead - spring model for polymer dynamics is developed as a generalization of the rouse model . a polymer chain is described using beads of variable sizes connected by springs with variable spring constants . a numerical scheme which can use different timesteps to advance the positions of different ... |
in the last years wireless communication systems coped with the problem of delivering reliable information while granting high throughput . this problem has often been faced resorting to channel codes able to correct errors even at low signal to noise ratios .as pointed out in table i in , several standards for wireles... | this work proposes a general framework for the design and simulation of network on chip based turbo decoder architectures . several parameters in the design space are investigated , namely the network topology , the parallelism degree , the rate at which messages are sent by processing nodes over the network and the ro... |
monte carlo methods appeared about sixty years ago with the need to evaluate numerical values for various complex problems .these methods evolved and were applied early to quantum problems , thus putting within reach exact numerical solutions to non - trivial quantum problems .many improvements of these methods followe... | in a recent publication we have presented the stochastic green function ( sgf ) algorithm , which has the properties of being general and easy to apply to any lattice hamiltonian of the form , where is diagonal in the chosen occupation number basis and has only positive matrix elements . we propose here a modified vers... |
model selection is an important problem in many areas including machine learning .if a proper model is not selected , any effort for parameter estimation or prediction of the algorithm s outcome is hopeless .given a set of candidate models , the goal of model selection is to select the model that best approximates the ... | this paper introduces kernel - based information criterion ( kic ) for model selection in regression analysis . the novel kernel - based complexity measure in kic efficiently computes the interdependency between parameters of the model using a variable - wise variance and yields selection of better , more robust regres... |
this work on pricing american options under proportional transaction costs goes back to the seminal discovery by that to hedge against a buyer who can exercise the option at any ( ordinary ) stopping time , the seller must in effect be protected against all mixed ( randomised ) stopping times .this was followed by , wh... | american options in a multi - asset market model with proportional transaction costs are studied in the case when the holder of an option is able to exercise it gradually at a so - called mixed ( randomised ) stopping time . the introduction of gradual exercise leads to tighter bounds on the option price when compared ... |
consider a network which evolves under the removal and addition of vertices . in each unit of timewe add vertex and remove vertices .removal of a vertex also implies that all the edges incident on that vertex vanish and consequently the degree of vertices at the end of those edges decrease . here can be interpreted as ... | there has been a considerable amount of interest in recent years on the robustness of networks to failures . many previous studies have concentrated on the effects of node and edge removals on the connectivity structure of a _ static _ network ; the networks are considered to be static in the sense that no compensatory... |
information - theoretic research on capacity and coding for write - limited memory originates in , , and . in ,the authors consider a model of write - once memory ( wom ) .in particular , each memory cell can be in state either 0 or 1 .the state of a cell can go from 0 to 1 , but not from 1 back to 0 later .these write... | in this paper , we consider modulation codes for practical multilevel flash memory storage systems with cell levels . instead of maximizing the lifetime of the device , we maximize the average amount of information stored per cell - level , which is defined as storage efficiency . using this framework , we show that th... |
we present a detailed study on the nature of biases in network sampling strategies to shed light on how best to sample from networks .a _ network _ is a system of interconnected entities typically represented mathematically as a graph : a set of vertices and a set of edges among the vertices .networks are ubiquitous an... | from social networks to p2p systems , network sampling arises in many settings . we present a detailed study on the nature of biases in network sampling strategies to shed light on how best to sample from networks . we investigate connections between specific biases and various measures of structural representativeness... |
set theory was proposed with the intended use to the fields of pattern classification and information processing [ 1 ] .indeed , it has attracted many researchers , and their applications to real - life problems are of a great significance .simpson [ 2 ] presented the fuzzy min max neural network ( fmm ) , which makes ... | recently , a multi - level fuzzy min max neural network ( mlf ) was proposed , which improves the classification accuracy by handling an overlapped region ( area of confusion ) with the help of a tree structure . in this brief , an extension of mlf is proposed which defines a new boundary region , where the previously ... |
collisionless shocks are widely thought to be effective accelerators of energetic , nonthermal particles ( hereafter cosmic - rays or crs ) .those particles play central roles in many astrophysical problems .the physical basis of the responsible diffusive shock acceleration ( dsa ) process is now well established throu... | we have developed a new , very efficient numerical scheme to solve the cr diffusion convection equation that can be applied to the study of the nonlinear time evolution of cr modified shocks for arbitrary spatial diffusion properties . the efficiency of the scheme derives from its use of coarse - grained finite momentu... |
real time operation of the power grid and computation of electricity prices require accurate estimation of its structure and critical state variables .remote terminal units ( rtus ) transmit measurements collected from different grid components to the central control center for state estimation and subsequent use in an... | a coordinated cyber - attack on grid meter readings and breaker statuses can lead to incorrect state estimation that can subsequently destabilize the grid . this paper studies cyber - attacks by an adversary that changes breaker statuses on transmission lines to affect the estimation of the grid topology . the adversar... |
recently a new method for analyzing multifractal functions was introduced .it exploits the fact that the fractional derivative of order ( denoted here by ) of has , for a suitable range of , a power - law tail in its cumulative probability the exponent is the unique solution of the equation where is the scaling exponen... | it is shown that fractional derivatives of the ( integrated ) invariant measure of the feigenbaum map at the onset of chaos have power - law tails in their cumulative distributions , whose exponents can be related to the spectrum of singularities . this is a new way of characterizing multifractality in dynamical system... |
the primary goal of tomography is to determine the internal structure of an object without cutting it , namely using data obtained by methods that leave the object under investigation undamaged .these data can be obtained by exploiting the interaction between the object and various kinds of probes including x - rays , ... | in this article we present a review of the radon transform and the instability of the tomographic reconstruction process . we show some new mathematical results in tomography obtained by a variational formulation of the reconstruction problem based on the minimization of a mumford - shah type functional . finally , we ... |
reciprocity , which was first found by lorentz at the end of 19th century , has a long history and has been derived in several formalisms .there are two typical reciprocal configurations in optical responses as shown in fig .the configurations in figs .[ fig1](a ) and [ fig1](b ) are transmission reciprocal and those i... | we present an elementary proof concerning reciprocal transmittances and reflectances . the proof is direct , simple , and valid for the diverse objects that can be absorptive and induce diffraction and scattering , as long as the objects respond linearly and locally to electromagnetic waves . the proof enables students... |
turbulence is a key element of the dynamics of astrophysical fluids , including those of interstellar medium ( ism ) , clusters of galaxies and circumstellar regions .the realization of the importance of turbulence induces sweeping changes , for instance , in the paradigm of ism .it became clear , for instance , that t... | we continue our work on developing techniques for studying turbulence with spectroscopic data . we show that doppler - broadened absorption spectral lines , in particularly , saturated absorption lines , can be used within the framework of the earlier - introduced technique termed the velocity coordinate spectrum ( vcs... |
threshold nets are obtained by assigning a weight , from a distribution , to each of nodes and connecting any two nodes and whose combined weights exceed a certain threshold , : .threshold nets can be produced of ( almost ) arbitrary degree distributions , including scale - free , by judiciously choosing the weight di... | we study a new class of networks , generated by sequences of letters taken from a finite alphabet consisting of letters ( corresponding to types of nodes ) and a fixed set of connectivity rules . recently , it was shown how a binary alphabet might generate threshold nets in a similar fashion [ hagberg et al . , phys . ... |
variable selection methods based on penalty theory have received great attention in high - dimensional data analysis .a principled approach is due to the lasso of , which uses the -norm penalty . also pointed out that the lasso estimate can be viewed as the mode of the posterior distribution .indeed , the penalty can b... | in this paper we discuss bayesian nonconvex penalization for sparse learning problems . we explore a nonparametric formulation for latent shrinkage parameters using subordinators which are one - dimensional lvy processes . we particularly study a family of continuous compound poisson subordinators and a family of discr... |
synchronization in chaotic systems is a surprising phenomenon , which recently received a lot of attention , see e.g. .even though the heuristic theory and the classification of the synchronization phenomena are well studied and reasonably well understood , a mathematically rigorous theory is still lacking . generally ... | we consider a three - dimensional chaotic system consisting of the suspension of arnold s cat map coupled with a clock via a weak dissipative interaction . we show that the coupled system displays a synchronization phenomenon , in the sense that the relative phase between the suspension flow and the clock locks to a sp... |
in high energy physics ( hep ) , unfolding ( also called unsmearing ) is a general term describing methods that attempt to take out the effect of smearing resolution in order to obtain a measurement of the true underlying distribution of a quantity .typically the acquired data ( distorted by detector response , ineffic... | in many analyses in high energy physics , attempts are made to remove the effects of detector smearing in data by techniques referred to as `` unfolding '' histograms , thus obtaining estimates of the true values of histogram bin contents . such unfolded histograms are then compared to theoretical predictions , either ... |
understanding and characterizing general features of the dynamics of open quantum systems is of great importance to physics , chemistry , and biology .the non - markovian character is one of the most central aspects of an open quantum process , and attracts increasing attentions .markovian dynamics of quantum systems... | trace distance is available to capture the dynamical information of the unital aspect of a quantum process . however , it can not reflect the non - unital part . so , the non - divisibility originated from the non - unital aspect can not be revealed by the corresponding measure based on the trace distance . we provide ... |
classification problem is one of the most important tasks in time series data mining . a well - known 1-nearest neighbor ( 1-nn ) with dynamic time warping ( dtw )distance is one of the best classifier to classify time series data , among other approaches , such as support vector machine ( svm ) , artificial neural net... | 1-nearest neighbor with the dynamic time warping ( dtw ) distance is one of the most effective classifiers on time series domain . since the global constraint has been introduced in speech community , many global constraint models have been proposed including sakoe - chiba ( s - c ) band , itakura parallelogram , and r... |
given competing mathematical models to describe a process , we wish to know whether our data is compatible with the candidate models . often comparing models requires optimization and fitting time course data to estimate parameter values and then applying an information criterion to select a ` best ' model .however som... | we present a method for rejecting competing models from noisy time - course data that does not rely on parameter inference . first we characterize ordinary differential equation models in only measurable variables using differential algebra elimination . next we extract additional information from the given data using ... |
in 2011 , i described a timing sequencer and related laser lab instrumentation based on 16-bit microcontrollers and a homemade custom keypad / display unit. since then , two new developments have enabled a far more powerful approach : the availability of high - performance 32-bit microcontrollers in low - pin - count p... | several high - performance lab instruments suitable for manual assembly have been developed using low - pin - count 32-bit microcontrollers that communicate with an android tablet via a usb interface . a single android tablet app accommodates multiple interface needs by uploading parameter lists and graphical data from... |
where river water meets the sea , an enormous amount of energy is dissipated as a result of the irreversible mixing of fresh and salt water .the dissipated energy is about 2 kj per liter of river water , _i.e. _ equivalent to a waterfall of 200 m .it is estimated that the combined power from all large estuaries in the... | a huge amount of entropy is produced at places where fresh water and seawater mix , for example at river mouths . this mixing process is a potentially enormous source of sustainable energy , provided it is harnessed properly , for instance by a cyclic charging and discharging process of porous electrodes immersed in sa... |
we consider the following sequence space model where are the coefficients of a signal and the noise has a diagonal covariance matrix .this heterogeneous model may appear in several frameworks where the variance is fluctuating , for example in heterogeneous regression , coloured noise , fractional brownian motion models... | we consider a gaussian sequence space model where has a diagonal covariance matrix . we consider the situation where the parameter vector is sparse . our goal is to estimate the unknown parameter by a model selection approach . the heterogenous case is much more involved than the direct model . indeed , there is no mor... |
in order to formally handle ( specify and prove ) some properties of prolog execution , we needed above all a definition of a port .a port is perhaps the single most popular notion in prolog debugging , but theoretically it appears still rather elusive .the notion stems from the seminal article of l.byrd which identifi... | a simple mathematical definition of the 4-port model for pure prolog is given . the model combines the intuition of ports with a compact representation of execution state . forward and backward derivation steps are possible . the model satisfies a modularity claim , making it suitable for formal reasoning . |
today , with a vast amount of publications being produced in every discipline of scientific research , it can be rather overwhelming to select a good quality work ; that is enriched with original ideas and relevant to scientific community .more often this type of publications are discovered through the citation mechani... | we introduce and solve a model which considers two coupled networks growing simultaneously . the dynamics of the networks is governed by the new arrival of network elements ( nodes ) making preferential attachments to pre - existing nodes in both networks . the model segregates the links in the networks as intra - link... |
the impossibility of superluminal communication through the use of quantum entanglement has already been vividly discussed in the past , see for example .recently this topic has re - entered the stage of present research in the context of quantum cloning : the no - signalling constraint has been used to derive upper bo... | we show that non - locality of quantum mechanics can not lead to superluminal transmission of information , even if most general local operations are allowed , as long as they are linear and trace preserving . in particular , any quantum mechanical approximate cloning transformation does not allow signalling . on the o... |
one of the most important motivations of these series of conferences is to promote vigorous interaction between statisticians and astronomers .the organizers merit our admiration for bringing together such a stellar cast of colleagues from both fields . in this third edition ,one of the central subjects is cosmology , ... | in this introductory talk we will establish connections between the statistical analysis of galaxy clustering in cosmology and recent work in mainstream spatial statistics . the lecture will review the methods of spatial statistics used by both sets of scholars , having in mind the cross - fertilizing purpose of the me... |
we are interested in the following nonconvex semidefinite programming problem : where is convex , is a nonempty , closed convex set in and ( ) are nonconvex matrix - valued mappings and smooth .the notation means that is a symmetric negative semidefinite matrix .optimization problems involving matrix - valued mapping i... | in this work , we propose a new local optimization method to solve a class of nonconvex semidefinite programming ( sdp ) problems . the basic idea is to approximate the feasible set of the nonconvex sdp problem by inner positive semidefinite convex approximations via a parameterization technique . this leads to an iter... |
the collective dynamics of complex distributed systems often can be usefully described in terms of a superposition of rate processes or frequencies which determine the changes in macroscopically measurable variables as energy flows through the system ; that is , a dynamical model expressed as a system of coupled ordina... | a case study in bifurcation and stability analysis is presented , in which reduced dynamical system modelling yields substantial new global and predictive information about the behaviour of a complex system . the first smooth pathway , free of pathological and persistent degenerate singularities , is surveyed through t... |
the long - time dynamics of biological evolution have recently attracted considerable interest among statistical physicists , who find in this field new and challenging interacting nonequilibrium systems .an example is the bak - sneppen model , in which interacting species are the basic units , and less fit " species c... | we present long monte carlo simulations of a simple model of biological macroevolution in which births , deaths , and mutational changes in the genome take place at the level of individual organisms . the model displays punctuated equilibria and flicker noise with a -like power spectrum , consistent with some current t... |
the need for the efficient use of the scarce spectrum in wireless applications has led to significant interest in the analysis of cognitive radio systems .one possible scheme for the operation of the cognitive radio network is to allow the secondary users to transmit concurrently on the same frequency band with the pri... | in this paper , a cognitive relay channel is considered , and amplify - and - forward ( af ) relay beamforming designs in the presence of an eavesdropper and a primary user are studied . our objective is to optimize the performance of the cognitive relay beamforming system while limiting the interference in the directi... |
sigmoidal input - output response modules are very well - conserved in cell signaling networks that might be used to implement binary responses , a key element in cellular decision processes .additionally , sigmoidal modules might be part of more complex structures , where they can provide the nonlinearities which are ... | ultrasensitive response motifs , which are capable of converting graded stimulus in binary responses , are very well - conserved in signal transduction networks . although it has been shown that a cascade arrangement of multiple ultrasensitive modules can produce an enhancement of the system s ultrasensitivity , how th... |
the self - avoiding walk ( saw ) model is an important model in statistical physics .it models the excluded - volume effect observed in real polymers , and exactly captures universal features such as critical exponents and amplitude ratios .it is also an important model in the study of critical phenomena , as it is th... | the pivot algorithm for self - avoiding walks has been implemented in a manner which is dramatically faster than previous implementations , enabling extremely long walks to be efficiently simulated . we explicitly describe the data structures and algorithms used , and provide a heuristic argument that the mean time per... |
being able to read news from other countries and written in other languages allows readers to be better informed .it allows them to detect national news bias and thus improves transparency and democracy .existing online translation systems such as _ google translate _ and _ _ bing translator _ _ are thus a great servic... | we propose a real - time machine translation system that allows users to select a news category and to translate the related live news articles from arabic , czech , danish , farsi , french , german , italian , polish , portuguese , spanish and turkish into english . the moses - based system was optimised for the news ... |
biometric authentication systems are becoming prevalent in access control and in consumer technology .in such systems , the user submits their user name and his / her biometric sample , which is compared to the stored biometric template associated with this user name ( one - to - one matching ) .the popularity of biome... | one of the main challenges faced by biometric - based authentication systems is the need to offer secure authentication while maintaining the privacy of the biometric data . previous solutions , such as secure sketch and fuzzy extractors , rely on assumptions that can not be guaranteed in practice , and often affect th... |
in 1988 , a. barkai and c.d mcquaid reported a novel observation in population ecology while studying benthic fauna in south african shores : a predator - prey role reversal between a decapod crustacean and a marine snail .specifically , in malgas island , the rock lobster _ jasus lalandii _ preys on a type of whelk , ... | predator - prey relationships are one of the most studied interactions in population ecology . however , little attention has been paid to the possibility of role exchange between species once determined as predators and preys , despite firm field evidence of such phenomena in the nature . in this paper , we build a mo... |
starting from the first telescopic sunspot observations by david and johannes fabricius , galileo galilei , thomas harriot and christoph scheiner , the 400-year sunspot record is one of the longest directly recorded scientific data series , and forms the basis for numerous studies in a wide range of research such as , ... | because of the lack of reliable sunspot observation , the quality of sunspot number series is poor in the late 18th century , leading to the abnormally long solar cycle ( 17841799 ) before the dalton minimum . using the newly recovered solar drawings by the 1819th century observers staudacher and hamilton , we construc... |
coordinated networks of mobile robots are already in use for environmental monitoring and warehouse logistics . in the near future, autonomous robotic teams will revolutionize transportation of passengers and goods , search and rescue operations , and other applications .these tasks share a common feature : the robots ... | we propose distributed algorithms to automatically deploy a team of mobile robots to partition and provide coverage of a non - convex environment . to handle arbitrary non - convex environments , we represent them as graphs . our partitioning and coverage algorithm requires only short - range , unreliable pairwise `` g... |
reachability for continuous and hybrid systems has been an important topic of research in the dynamics and control literature .numerous problems regarding safety of air traffic management systems , , flight control , , ground transportation systems , , etc . have been formulated in the framework of reachability theory ... | a new framework for formulating reachability problems with competing inputs , nonlinear dynamics and state constraints as optimal control problems is developed . such reach - avoid problems arise in , among others , the study of safety problems in hybrid systems . earlier approaches to reach - avoid computations are ei... |
twitter and other social media have become important communication channels for the general public .it is thus not surprising that various stakeholder groups in science also participate on these platforms .scientists , for instance , use twitter for generating research ideas and disseminating and discussing scientific ... | metrics derived from twitter and other social media often referred to as altmetrics are increasingly used to estimate the broader social impacts of scholarship . such efforts , however , may produce highly misleading results , as the entities that participate in conversations about science on these platforms are largel... |
* power - law fit for overall flight . *first , we fit the flight length distribution of the geolife and nokia mdc datasets regardless of transportation modes ( see methods section ) .we fit truncated power - law , lognormal , power - law and exponential distribution ( see supplementary table s1 ) .we find that the ove... | human mobility has been empirically observed to exhibit lvy flight characteristics and behaviour with power - law distributed jump size . the fundamental mechanisms behind this behaviour has not yet been fully explained . in this paper , we propose to explain the lvy walk behaviour observed in human mobility patterns b... |
quantum bits , or qubits , have been realized using , for example , superconducting circuits , quantum dots , trapped ions , single dopants in silicon , and nitrogen vacancy centres .the state of a qubit is affected by various sources of error such as finite qubit lifetime , measurement imperfections , non - idea... | in the near future , a major challenge in quantum computing is to scale up robust qubit prototypes to practical problem sizes and to implement comprehensive error correction for computational precision . due to inevitable quantum uncertainties in resonant control pulses , increasing the precision of quantum gates comes... |
the lisa observatory has incredible science potential , but that potential can only be fully realized by employing advanced data analysis techniques .lisa will explore the low frequency portion of the gravitational wave spectrum , which is thought to be home to a vast number of sources .since gravitational wave source... | the laser interferometer space antenna ( lisa ) is expected to simultaneously detect many thousands of low frequency gravitational wave signals . this presents a data analysis challenge that is very different to the one encountered in ground based gravitational wave astronomy . lisa data analysis requires the identific... |
non - gaussian quantum states , endowed with properly enhanced nonclassical properties , may constitute powerful resources for the efficient implementation of quantum information , communication , computation and metrology tasks .indeed , it has been shown that , at fixed first and second moments , gaussian states _min... | we study the continuous - variable quantum teleportation of states , statistical moments of observables , and scale parameters such as squeezing . we investigate the problem both in ideal and imperfect vaidman - braunstein - kimble protocol setups . we show how the teleportation fidelity is maximized and the difference... |
in terms of the role in increasing the efficiency and aggregate network throughput , cognitive radio concept plays differently than the conventional spectrum allocation methods . in cognitive networks ,unlicensed secondary users opportunistically access radio bandwidth owned by licensed primary users in order to maxim... | traditional concept of cognitive radio is the coexistence of primary and secondary user in multiplexed manner . we consider the opportunistic channel access scheme in ieee 802.11 based networks subject to the interference mitigation scenario . according to the protocol rule and due to the constraint of message passing ... |
the problem of simultaneous localization and mapping ( slam ) has a rich history over the past two decades , which is too broad to cover here , see e.g. .the extended kalman filter ( ekf ) based slam ( the ekf - slam ) has played an important historical role , and is still used , notably for its ability to close loops ... | in this paper we address the inconsistency of the ekf - based slam algorithm that stems from non - observability of the origin and orientation of the global reference frame . we prove on the non - linear two - dimensional problem with point landmarks observed that this type of inconsistency is remedied using the invari... |
* this article reviews the recently developed g - ratio imaging framework .* confounds in the methodology are detailed .* recent progress and applications are reviewed .the g - ratio is an explicit quantitative measure of the relative myelin thickness of a myelinated axon , given by the ratio of the inner to the outer ... | the fiber g - ratio is the ratio of the inner to the outer diameter of the myelin sheath of a myelinated axon . it has a limited dynamic range in healthy white matter , as it is optimized for speed of signal conduction , cellular energetics , and spatial constraints . _ in vivo _ imaging of the g - ratio in health and ... |
spatial indexes has always been an important issue for multi dimensional data sets in relational databases ( dbs ) , in particular for those dealing with spherical coordinates , e.g. latitude / longitude for earth locations or ra / dec for celestial objects .some db servers offer built - in capabilities to create index... | in various astronomical projects it is crucial to have coordinates indexed tables . all sky optical and ir catalogues have up to 1 billion objects that will increase with forthcoming projects . also partial sky surveys at various wavelengths can collect information ( not just source lists ) which can be saved in coordi... |
any cooperation among agents ( players ) being able to make strategic decisions becomes a _ coalition formation game _ when the players may for various personal reasons wish to belong to a relative _ small coalition _ rather than the `` grand coalition '' . partitioning players represents the crucial question in the ga... | this paper studies _ the nash stability _ in hedonic coalition formation games . we address the following issue : for a general problem formulation , is there any utility allocation method ensuring a nash - stable partition ? we propose the definition of _ the nash - stable core _ and we analyze the conditions for havi... |
as is well known , the atom or atoms in the atomic clock are passive they do not `` tick''so the clock needs an active oscillator in addition to the atom(s ) . in designing an atomic clock to realize the second as a measurement unit in the international system of units ( si ) , one encounters two problems : ( a ) the r... | a clock steps a computer through a cycle of phases . for the propagation of logical symbols from one computer to another , each computer must mesh its phases with arrivals of symbols from other computers . even the best atomic clocks drift unforeseeably in frequency and phase ; feedback steers them toward aiming points... |
within the framework of continuum mechanics there are surface and bulk material failure models .surface failure models are known by name of cohesive zone models ( czms ) . in the latter case ,continuum is enriched with discontinuities along surfaces - cohesive zones - with additional traction - displacement - separatio... | cracks are created by massive breakage of molecular or atomic bonds . the latter , in its turn , leads to the highly localized loss of material , which is the reason why even closed cracks are visible by a naked eye . thus , fracture can be interpreted as the local material sink . mass conservation is violated locally ... |
in this paper we consider the numerical integration of autonomous stochastic differential delay equations ( sddes ) in the it s sense with initial data ] .and the functions and are both locally lipschitz continuous in and , i.e. , there exists a constant such that for all with .moreover , we assume that [ init ] is ... | a new , improved split - step backward euler ( ssbe ) method is introduced and analyzed for stochastic differential delay equations(sddes ) with generic variable delay . the method is proved to be convergent in mean - square sense under conditions ( assumption [ olc ] ) that the diffusion coefficient is globally lipsch... |
during past few years research in areas of wireless ad - hoc networks and wireless sensor networks ( wsns ) are escalated .ieee 802.15.4 is targeted for wireless body area networks ( wbans ) , which requires low power and low data rate applications .invasive computing is term used to describe future of computing and co... | ieee 802.15.4 standard is designed for low power and low data rate applications with high reliability . it operates in beacon enable and non - beacon enable modes . in this work , we analyze delay , throughput , load , and end - to - end delay of non - beacon enable mode . analysis of these parameters are performed at ... |
the hypothesis testing theory is a well developed branch of mathematical statistics .the asymptotic approach allows to find satisfactory solutions in many different situations .the simplest problems , like the testing of two simple hypotheses , have well known solutions . recall that if we fix the first type error and... | we consider the problem of hypothesis testing in the situation when the first hypothesis is simple and the second one is local one - sided composite . we describe the choice of the thresholds and the power functions of the score function test , of the general likelihood ratio test , of the wald test and of two bayes te... |
the solution of the absolute value equation ( ave ) of the following form is considered : here , , and denotes the component - wise absolute value of vector , i.e. , .the ave ( [ eq:1 ] ) is a special case of the generalized absolute value equation ( gave ) of the type where and .the gave ( [ eq:1a ] ) was introduced i... | salkuyeh proposed the picard - hss iteration method to solve the absolute value equation ( ave ) , which is a class of non - differentiable np - hard problem . to further improve its performance , a nonlinear hss - like iteration method is proposed . compared to that the picard - hss method is an inner - outer double -... |
humans have evolved large brains , in part to handle the cognitive demands of social relationships .the social structures resulting from these relationships confer numerous fitness advantages .scholars distinguish between two types of social relationships : those representing strong and weak ties .strong ties are char... | the social connections people form online affect the quality of information they receive and their online experience . although a host of socioeconomic and cognitive factors were implicated in the formation of offline social ties , few of them have been empirically validated , particularly in an online setting . in thi... |
recent evolution of mobile devices such as smart - phones and tablets has facilitated access to multi - media contents anytime and anywhere but such devices result in an explosive data traffic increase .the cisco expects by 2019 that these traffic demands will be grown up to 24.3 exabytes per month and the mobile video... | content delivery success in wireless caching helper networks depends mainly on cache - based channel selection diversity and network interference . for given channel fading and network geometry , both channel selection diversity and network interference dynamically vary according to what and how the caching helpers cac... |
multiple optimised parameter estimation and data compression ( moped ; ) is a patented algorithm for the compression of data and the speeding up of the evaluation of likelihood functions in astronomical data analysis and beyond .it becomes particularly useful when the noise covariance matrix is dependent upon the para... | we investigate the use of the multiple optimised parameter estimation and data compression algorithm ( moped ) for data compression and faster evaluation of likelihood functions . since moped only guarantees maintaining the fisher matrix of the likelihood at a chosen point , multimodal and some degenerate distributions... |
the mathematical theory of compressive sensing ( cs ) asserts that one can acquire signals from measurements whose rate is much lower than the total bandwidth . whereas the cs theory is now well developed , challenges concerning hardware implementations of cs - based acquisition devices , especially in optics , have on... | a bayesian compressive sensing framework is developed for video reconstruction based on the color coded aperture compressive temporal imaging ( cacti ) system . by exploiting the three dimension ( 3d ) tree structure of the wavelet and discrete cosine transformation ( dct ) coefficients , a bayesian compressive sensing... |
kullback - leibler ( kl ) divergence ( relative entropy ) can be considered as a measure of the difference / dissimilarity between sources .estimating kl divergence from finite realizations of a stochastic process with unknown memory is a long - standing problem , with interesting mathematical aspects and useful applic... | the entropy of an ergodic source is the limit of properly rescaled 1-block entropies of sources obtained applying successive non - sequential recursive pairs substitutions , . in this paper we prove that the cross entropy and the kullback - leibler divergence can be obtained in a similar way . _ keywords _ : informat... |
smoothed particle hydrodynamics ( sph ) is a particle - based numerical method , pioneered by and , for solving the equations of hydrodynamics ( recent reviews include ; ; ; ) . in sph ,the particles trace the flow and serve as interpolation points for their neighbours .this lagrangian nature of sph makes the method pa... | the numerical convergence of smoothed particle hydrodynamics ( sph ) can be severely restricted by random force errors induced by particle disorder , especially in shear flows , which are ubiquitous in astrophysics . the increase in the number of neighbours when switching to more extended smoothing kernels _ at fixed r... |
humankind has accrued _ a priori _ knowledge since the onset of _ homo sapiens_. from ancient cave paintings to modern research papers , the species desire toward sedimentation has been displayed as a documentary .an encyclopedia , a set of documents that contains a vast collection of information from the entire field ... | wikipedia is a free internet encyclopedia with an enormous amount of content . this encyclopedia is written by volunteers with various backgrounds in a collective fashion ; anyone can access and edit most of the articles . this open - editing nature may give us prejudice that wikipedia is an unstable and unreliable sou... |
graphical models are a class of statistical models which combine the rigour of a probabilistic approach with the intuitive representation of relationships given by graphs .they are composed by a set of _ random variables _ describing the data and a _ graph _ in which each _ vertex _ or _ node _ is associated with one o... | graphical model learning and inference are often performed using bayesian techniques . in particular , learning is usually performed in two separate steps . first , the graph structure is learned from the data ; then the parameters of the model are estimated conditional on that graph structure . while the probability d... |
the application of cross - correlation techniques to measure velocity shifts has a long history ( simkin 1972 , 1974 ; lacy 1977 ; tonry & davis 1979 ) , and with the advent of massive digital spectroscopic surveys of galaxies and stars , the subject has renewed interest .the recently completed sloan digital sky survey... | the measurement of doppler velocity shifts in spectra is a ubiquitous theme in astronomy , usually handled by computing the cross - correlation of the signals , and finding the location of its maximum . this paper addresses the problem of the determination of wavelength or velocity shifts among multiple spectra of the ... |
studying the dynamics of nearly one - dimensional structures has various scientific and industrial applications , for example in biophysics ( cf . and the references therein ) and visual computing ( cf . ) as well as in civil and mechanical engineering ( cf . ) , microelectronics and robotics ( cf . ) . in this regard... | based on a lie symmetry analysis , we construct a closed form solution to the kinematic part of the ( partial differential ) cosserat equations describing the mechanical behavior of elastic rods . the solution depends on two arbitrary analytical vector functions and is analytical everywhere except a certain domain of t... |
embedded control systems are ubiquitous and can be found in several applications including aircraft , automobiles , process control , and buildings .an embedded control system is one in which the computer system is designed to perform dedicated functions with real - time computational constraints .typical features of s... | the focus of this paper is on the co - design of control and communication protocol for the control of multiple applications with unknown parameters using a distributed embedded system . the co - design consists of an adaptive switching controller and a hybrid communication architecture that switches between a time - t... |
going hand - in - glove with analytic models of accretion disks , discussed in chapter 2.1 , are direct numerical simulations .although analytic theories have been extremely successful at explaining many general observational properties of black hole accretion disks , numerical simulations have become an indispensable ... | as the title suggests , the purpose of this chapter is to review the current status of numerical simulations of black hole accretion disks . this chapter focuses exclusively on _ global _ simulations of the accretion process within a few tens of gravitational radii of the black hole . most of the simulations discussed ... |
integration of the form , where is either or , is widely encountered in many engineering and scientific applications , such as those involving fourier or laplace transforms. often such integrals are approximated by numerical integrations over a finite domain , resulting in a truncation error , in addition to the discre... | integration of the form , where is either or , is widely encountered in many engineering and scientific applications , such as those involving fourier or laplace transforms . often such integrals are approximated by a numerical integration over a finite domain , leaving a truncation error equal to the tail integration ... |
in constructing a model for the self - assembly of addressable structures , we note that the designed interactions should be much stronger than any attractive interactions between subunits that are not adjacent in a correctly assembled structure .the designed interactions that stabilize the target structure can be desc... | the field of complex self - assembly is moving toward the design of multi - particle structures consisting of thousands of distinct building blocks . to exploit the potential benefits of structures with such ` addressable complexity , ' we need to understand the factors that optimize the yield and the kinetics of self ... |
despite a few important successes ( e.g. , bean et al . 2007 , and references therein ) , astrometric measurements with mas precision have so far proved of limited utility when employed as either a follow - up tool or to independently search for planetary mass companions orbiting nearby stars ( see for example sozzetti... | in this paper , we first summarize the results of a large - scale double - blind tests campaign carried out for the realistic estimation of the gaia potential in detecting and measuring planetary systems . then , we put the identified capabilities in context by highlighting the unique contribution that the gaia exoplan... |
models of cyclic dominance are traditionally employed to study biodiversity in biologically inspired settings .the simplest such model is the rock - paper - scissors game , where rock crashes scissors , scissors cut paper , and paper wraps rock to close the loop of dominance .the game has no obvious winner and is very ... | global , population - wide oscillations in models of cyclic dominance may result in the collapse of biodiversity due to the accidental extinction of one species in the loop . previous research has shown that such oscillations can emerge if the interaction network has small - world properties , and more generally , beca... |
due to the exploding popularity of all things wireless , the demand for wireless data traffic increases dramatically . according to a cisco report, global mobile data traffic will increase 13-fold between 2012 and 2017 .this dramatic demand puts on pressure on mobile network operators ( mnos ) to purchase more spectrum... | we study bidding and pricing competition between two spiteful mobile network operators ( mnos ) with considering their existing spectrum holdings . given asymmetric - valued spectrum blocks are auctioned off to them via a first - price sealed - bid auction , we investigate the interactions between two spiteful mnos and... |
unlike water , a layer of sand will not flow unless its surface is inclined beyond a characteristic angle , known as the maximum angle of stability .this simple fact translates into a host of threshold phenomena wherever granular material is found .many such phenomena play a crucial role in the erosion of earth s surfa... | we study channelization and slope destabilization driven by subsurface ( groundwater ) flow in a laboratory experiment . the pressure of the water entering the sandpile from below as well as the slope of the sandpile are varied . we present quantitative understanding of the three modes of sediment mobilization in this ... |
since the pioneering papers by watts and strogatz on small - world networks and barabsi and albert on scale - free networks , complex networks , which describe many systems in nature and society , have become an area of tremendous recent interest . in the last few years , modeling real - life systems has attracted an e... | we propose a general geometric growth model for pseudofractal scale - free web , which is controlled by two tunable parameters . we derive exactly the main characteristics of the networks : degree distribution , second moment of degree distribution , degree correlations , distribution of clustering coefficient , as wel... |
it is well established that the magnetic field that permeates the solar corona has a highly complex structure .although it is very difficult to measure directly the magnetic field vector in the corona , this complexity can be inferred from observations of the line - of - sight magnetic field at the photosphere . with e... | global magnetic field extrapolations are now revealing the huge complexity of the sun s corona , and in particular the structure of the boundary between open and closed magnetic flux . moreover , recent developments indicate that magnetic reconnection in the corona likely occurs in highly fragmented current layers , an... |
we are assisting at a booming expansion of nanoparticle research and technology .synthesis method especially make fast progresses .analysis methods , however , are not up to speed . a fundamental simple task as determining and controllingthe size distribution of nanoparticles ( nps hereafter ) is currently a complex ex... | the increasing scientific and technological interest in nanoparticles has raised the need for fast , efficient and precise characterization techniques . powder diffraction is a very efficient experimental method , as it is straightforward and non - destructive . however , its use for extracting information regarding ve... |
since many decades , design codes ensure a very low probability that a building collapses under ordinary loads , like self weight , dead and live service load , or snow .nevertheless buildings still do collapse , from time to time .an extremely small fraction of collapses originates from unlikely combinations of intens... | in this paper , we study the response of 2d framed structures made of rectangular cells , to the sudden removal of columns . we employ a simulation algorithm based on the discrete element method , where the structural elements are represented by elasto - plastic euler bernoulli beams with elongation - rotation failure ... |
in healthy cells , a loopback mechanism involving the protein p53 is believed to cause growth arrest and apoptosis as a response to dna damage .mutations in the sequence of p53 that potentially interfere with this mechanism have been observed to lead to the upraise of cancer . under normal conditionsthe amount of p53 ... | a feedback mechanism that involves the proteins p53 and mdm2 , induces cell death as a controled response to severe dna damage . a minimal model for this mechanism demonstrates that the respone may be dynamic and connected with the time needed to translate the mdm2 protein . the response takes place if the dissociation... |
complex system modeling and simulation often mandate global sensitivity analysis , which constitutes the study of how the global variation of input , due to its uncertainty , influences the overall uncertain behavior of a response of interest .most common approaches to sensitivity analysis are firmly anchored in the se... | this article presents a general multivariate -sensitivity index , rooted in the -divergence between the unconditional and conditional probability measures of a stochastic response , for global sensitivity analysis . unlike the variance - based sobol index , the -sensitivity index is applicable to random input following... |
the introduction of new quantum mechanical technologies promises to fundamentally alter the way we communicate .quantum key distribution ( qkd ) , for instance , will allow us to communicate in an intrinsically secure way .but new quantum communication technologies will require a new telecommunications infrastructure ,... | quantum communication relies on optical implementations of channels , memories and repeaters . in the absence of perfect devices , a minimum requirement on real - world devices is that they preserve quantum correlations , meaning that they have some thoughput of a quantum mechanical nature . previous work has verified ... |
in both classical and quantum physics isolated systems can display unpredictable behavior , but the reasons for the unpredictability are quite different . in classical ( hamiltonian )mechanics unpredictability is a consequence of chaotic dynamics , or exponential sensitivity to initial conditions , which makes it impos... | hypersensitivity to perturbation is a criterion for chaos based on the question of how much information about a perturbing environment is needed to keep the entropy of a hamiltonian system from increasing . in this paper we give a brief overview of our work on hypersensitivity to perturbation in classical and quantum s... |
video compression is a major requirement in many of the recent applications like medical imaging , studio applications and broadcasting applications .compression ratio of the encoder completely depends on the underlying compression algorithms .the goal of compression techniques is to reduce the immense amount of visual... | this paper presents a memory efficient , high throughput parallel lifting based running three dimensional discrete wavelet transform ( 3-d dwt ) architecture . 3-d dwt is constructed by combining the two spatial and four temporal processors . spatial processor ( sp ) apply the two dimensional dwt on a frame , using lif... |
opportunistic beamforming ( obf ) is a well known adaptive signaling scheme that has received a great deal of attention in the literature as it attains the sum - rate capacity with full channel state information ( csi ) to a first order for large numbers of mobile users in the network , while operating on partial csi f... | in this paper , we consider a multi - cell multi - user miso broadcast channel . the system operates according to the opportunistic beamforming framework in a multi - cell environment with variable number of transmit beams ( may alternatively be referred as the transmission rank ) at each base station . the maximum num... |
registration , the task of establishing correspondences between multiple instances of objects such as images , landmarks , curves , and surfaces , plays a fundamental role in a range of computer vision applications including shape modeling , motion compensation and optical flow , remote sension , and medical imaging . ... | we survey the role of symmetry in diffeomorphic registration of landmarks , curves , surfaces , images and higher - order data . the infinite dimensional problem of finding correspondences between objects can for a range of concrete data types be reduced resulting in compact representations of shape and spatial structu... |
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