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fractional differential equations ( fdes ) have become more and more popular in applied science and engineering field recently .the history and mathematical background of fractional differential operators are given in with definitions and applications of fractional calculus .this kind of equations has been used increas... | a hybridized discontinuous galerkin method is proposed for solving 2d fractional convection - diffusion equations containing derivatives of fractional order in space on a finite domain . the riemann - liouville derivative is used for the spatial derivative . combining the characteristic method and the hybridized discon... |
answer set programming ( asp ) , namely logic programming under the answer set semantics , is a constraint programming paradigm , which has been successfully deployed in many applications .recently , asp was extended to include constraints to facilitate reasoning with sets of atoms .these constraints include weight con... | weight constraint and aggregate programs are among the most widely used logic programs with constraints . in this paper , we relate the semantics of these two classes of programs , namely the stable model semantics for weight constraint programs and the answer set semantics based on conditional satisfaction for aggrega... |
in this work we study rotating waves in rings of neurons described by the theta model . the theta model , which is derived as a canonical model for neurons near a ` saddle - node on a limit cycle ' bifurcation , assumes the state of the neuron is given by an angle , with , corresponding to the ` firing ' state , and th... | we study rotating waves in the theta model for a ring of synaptically - interacting neurons . we prove that when the neurons are oscillatory , at least one rotating wave always exists . in the case of excitable neurons , we prove that no travelling waves exist when the synaptic coupling is weak , and at least two rotat... |
the permeability of porous media is an important parameter to predict the unconventional gas production . for laminar flows in highly permeable porous media ,the darcy s law states that the volume flow rate is proportional to the pressure gradient : where is the cross - section area of the flow , is the shear viscosity... | in a recent paper by lasseux , valds - parada and porter ( j. fluid mech . * 805 * ( 2016 ) 118 - 146 ) , it is found that the apparent gas permeability of the porous media is a nonlinear function of the knudsen number . however , this result is highly questionable , because the adopted navier - stokes equations and th... |
continuous - variable quantum key distribution ( cvqkd ) encodes information into the quadratures of optical fields and extracts it with homodyne detection , which has higher efficiency and repetition rate than that of the single photon detector .cvqkd , especially the gg02 protocol , is hopeful to realize high speed k... | the noise in optical source needs to be characterized for the security of continuous - variable quantum key distribution ( cvqkd ) . two feasible schemes , based on either active optical switch or passive beamsplitter are proposed to monitor the variance of source noise , through which , eve s knowledge can be properly... |
along with turbo codes , low - density parity - check ( ldpc ) block codes form a class of codes which approach the ( theoretical ) shannon limit .ldpc codes were first introduced in the by gallager .however , they were considered impractical at that time and very little related work was done until tanner provided a gr... | ldpc convolutional codes have been shown to be capable of achieving the same capacity - approaching performance as ldpc block codes with iterative message - passing decoding . in this paper , asymptotic methods are used to calculate a lower bound on the free distance for several ensembles of asymptotically good protogr... |
entanglement is a key property that makes quantum information theory different from its classical counterpart .maximally entangled states , for example , are the basis of quantum state teleportation which has recently been demonstrated . under realistic conditions ,however , one will only be able to generate partially ... | we compare the entanglement of formation with a measure defined as the modulus of the negative eigenvalue of the partial transpose . in particular we investigate whether both measures give the same ordering of density operators with respect to the amount of entanglement . 2 |
a number of papers have recently considered the problem of constructing a coherent quantum observer for a quantum system ; e.g. , see . in the coherent quantum observer problem , a quantum plantis coupled to a quantum observer which is also a quantum system .the quantum observer is constructed to be a physically realiz... | this paper considers the problem of constructing a direct coupling quantum observer for a quantum harmonic oscillator system . the proposed observer is shown to be able to estimate one but not both of the plant variables and produces a measureable output using homodyne detection . |
large complex systems are composed of various interconnected components .the measure of the behavior of a single component thus results from the superimposition of different factors acting at different levels .common factors such as global trends or external socio - economical conditions obviously play a role but usual... | a single social phenomenon ( such as crime , unemployment or birth rate ) can be observed through temporal series corresponding to units at different levels ( cities , regions , countries ... ) . units at a given local level may follow a collective trend imposed by external conditions , but also may display fluctuation... |
one of the oldest problem in galactic dynamics is the determination of the mass distribution in the stellar and gaseous disk from observed velocities .observationally , noisy measurements along with a certain velocity dispersion makes this inverse problem difficult to solve ( beauvais & bothum , 2001 ) . from a theoret... | there is apparently a widespread belief that the gravitational field ( and subsequently the rotation curve ) `` inside '' razor - thin , axially symmetric disks can not be determined accurately from elliptic integrals because of the singular kernel in the poisson integral . here , we report a simple and powerful method... |
the range is commonly regarded as a bound in spectral reconstructions . rather than being a fundamental limit , however , this bound only holds for certain classes of control sequences . here, we show that the ultimate bound is set by the _time resolution _ of the control sequence , .specifically , , with sequence havi... | we introduce open - loop quantum control protocols for characterizing the spectral properties of non - gaussian noise , applicable to both classical and quantum dephasing environments . the basic idea is to engineer a multi - dimensional frequency comb via repetition of suitably designed pulse sequences , through which... |
the second law of newtonian mechanics states that if is the force acting on a point particle of mass and is its acceleration , then . in a sense ,the physical meaning of this expression lies in its tacit assumptions , namely that forces are vectors , that is , elements of a vector space , and as such they sum .this exp... | this work introduces screw theory , a venerable but yet little known theory aimed at describing rigid body dynamics . this formulation of mechanics unifies in the concept of screw the translational and rotational degrees of freedom of the body . it captures a remarkable mathematical analogy between mechanical momenta a... |
while conventional causal inference methods use conditional independences to infer a directed acyclic graph of causal relations among at least three random variables , there is a whole family of recent methods that employ more information from the joint distribution than just conditional independences .therefore , thes... | information geometric causal inference ( igci ) is a new approach to distinguish between cause and effect for two variables . it is based on an independence assumption between input distribution and causal mechanism that can be phrased in terms of orthogonality in information space . we describe two intuitive reinterpr... |
intro a remarkable phenomenon quite ubiquitous in nature is that of collective synchronization , in which a large population of coupled oscillators spontaneously synchronizes to oscillate at a common frequency , despite each constituent having a different natural frequency of oscillation .one witnesses such a spectacul... | the phenomenon of spontaneous synchronization , particularly within the framework of the kuramoto model , has been a subject of intense research over the years . the model comprises oscillators with distributed natural frequencies interacting through a mean - field coupling , and serves as a paradigm to study synchroni... |
the development of strategies to control the dynamic of a viral spread in a population is a central problem in public health and network security . in particular , how to control the traffic between subpopulations in the case of an epidemic outbreak is of critical importance . in this paper, we analyze the problem of c... | we propose a novel framework to study viral spreading processes in metapopulation models . large subpopulations ( i.e. , cities ) are connected via metalinks ( i.e. , roads ) according to a metagraph structure ( i.e. , the traffic infrastructure ) . the problem of containing the propagation of an epidemic outbreak in a... |
the essence of radiotherapy with protons and heavier ions lies in precise control of incident particles that are designed to stop in tumor volume .the targeting precision will be inevitably deteriorated by multiple scattering in beam modifiers and patient body and such effects must be accurately handled for dose calcul... | dose calculation for radiotherapy with protons and heavier ions deals with a large volume of path integrals involving a scattering power of body tissue . this work provides a simple model for such demanding applications . there is an approximate linearity between rms end - point displacement and range of incident parti... |
an important topic of interest , in modeling of saturated flow through porous media , is the analysis of the phenomenon when there is a microstructure present in the rock matrix .some of the achievements in the preexisting literature address the case when the microstructure is periodic ; see for the analytical approach... | we seek suitable exchange conditions for saturated fluid flow in a porous medium , where the interface of interest is a fractal microstructure embedded in the porous matrix . two different deterministic models are introduced and rigorously analyzed . also , numerical experiments for each of them are presented to verify... |
there have been many studies of dynamical predator - prey systems that simulate biological processes .particularly interesting early work was done by bell , who showed that the immune response can be modeled quite effectively by such systems . in bells work the time evolution of competing concentrations of one antigen ... | the study of -symmetric physical systems began in 1998 as a complex generalization of conventional quantum mechanics , but beginning in 2007 experiments began to be published in which the predicted phase transition was clearly observed in classical rather than in quantum - mechanical systems . this paper examines the p... |
a number of studies over the past ten years have estimated the inter - galactic void probability function and investigated its departure from randomness .the basic random model is that arising from a poisson process of mean density galaxies per unit volume in a large box . then , in a _ given region of volume _ the pro... | a number of recent studies have estimated the inter - galactic void probability function and investigated its departure from various random models . we study a family of parametric statistical models based on gamma distributions , which do give realistic descriptions for other stochastic porous media . gamma distributi... |
ocean - tide information has considerably many applications .the data obtained is used to solve vital problems in oceanography and geophysics , and to study earth tides , elastic properties of the earth s crust and tidal gravity variations .it is also used in space studies to calculate the trajectories of man - made sa... | in this work we first present the existence , uniqueness and regularity of the strong solution of the tidal dynamics model perturbed by lvy noise . monotonicity arguments have been exploited in the proofs . we then formulate a martingale problem of stroock and varadhan associated to an initial value control problem and... |
this is to certify that : 1 .the thesis comprises only my original work towards the mphil ; 2 .due acknowledgement has been made to all other material used ; and 3 .the thesis is less than 50,000 words in length . [cols="^",options="header " , ] in this section , we will prove that under certain conditions , the ... | we consider a hidden markov model with multiple observation processes , one of which is chosen at each point in time by a policy a deterministic function of the information state and attempt to determine which policy minimises the limiting expected entropy of the information state . focusing on a special case , we prov... |
binary exponential backoff ( beb ) is widely adopted as a key collision resolution mechanism in popular random - access networks , such as ieee ethernet and ieee wireless local area network ( wlan ) . with exponential backoff ( eb ) ,a packet is transmitted after waiting a number of time slots randomly selected from a ... | exponential backoff ( eb ) is a widely adopted collision resolution mechanism in many popular random - access networks including ethernet and wireless lan ( wlan ) . the prominence of eb is primarily attributed to its asymptotic throughput stability , which ensures a non - zero throughput even when the number of users ... |
the design and management of green wireless networks has become increasingly important for modern wireless networks , in particular , to manage operating costs .futuristic ( beyond 5 g ) cellular networks face the dual challenges of being able to respond to the explosion of data rates and also to manage network energy ... | the main objective of this work is to improve the energy - efficiency ( ee ) of a multiple access channel ( mac ) system , through power control , in a distributed manner . in contrast with many existing works on energy - efficient power control , which ignore the possible presence of a queue at the transmitter , we co... |
in classical logic , _ material implication _ or _ material conditional _ is defined by negation and disjunction . specifically , `` if _ p _ then _ q _ '' [ ole_link3][ole_link4]or `` _ _ p _ _ implies _ q _ '' is defined as `` not _ p _ or _, i.e. , _ p _ _ q _ _ _ _ q_. it is well known that this definition is prob... | simple and useful classical logic is unfortunately defective with its problematic definition of material implication . this paper presents an implication relation defined by a simple equation to replace the traditional material implication in classical logic . common `` paradoxes '' of material implication are avoided ... |
epidemic , one of the most important issues related to our real lives , such as computer virus on internet and venereal disease on sexual contact networks , attracts a lot of attention . among all the models on the process of the epidemic , susceptible - infected ( si ) model , susceptible - infected - susceptible ( si... | in this paper , a susceptible - infected - susceptible ( sis ) model with identical infectivity , where each node is assigned with the same capability of active contacts , , at each time step , is presented . we found that on scale - free networks , the density of the infected nodes shows the existence of threshold , w... |
this article is concerned with the approximation of the distribution of markov processes conditioned to not hit a given absorbing state .let be a discrete time markov process evolving in a state space , where is an absorbing state , which means that where .our first aim is to provide an approximation method based on an... | we consider a general method for the approximation of the distribution of a process conditioned to not hit a given set . existing methods are based on particle system that are failable , in the sense that , in many situations , they are not well defined after a given random time . we present a method based on a new par... |
in recent years , a large number of investigations has been made into the control of chaotic dynamics , and many techniques have been applied in simulations and experiments ( see , for instance , for an overview ) .two techniques have been proposed for an _ open - loop _ control of chaos .the first approach is related ... | it is demonstrated that improved entrainment control of chaotic systems can maintain periodic goal dynamics near unstable periodic orbits without feedback . the method is based on the optimization of goal trajectories and leads to small open - loop control forces . |
consider communication over a discrete - time memoryless channel modeled by a conditional point mass function ( pmf ) or probability density function ( pdf ) , where and are the input and output symbols , and are the input and output alphabets , respectively .let be the shannon capacity .fano showed in that the minimum... | guruswami and indyk showed in that forney s error exponent can be achieved with linear coding complexity over binary symmetric channels . this paper extends this conclusion to general discrete - time memoryless channels and shows that forney s and blokh - zyablov error exponents can be arbitrarily approached by one - l... |
stochastic approximation algorithms and their variants are commonly found in control , communication and related fields .popularity has grown due to increased computing power , and the interest in various ` machine learning ' algorithms . when the algorithm is linear , then the error equations take the following linear... | we give a development of the ode method for the analysis of recursive algorithms described by a stochastic recursion . with variability modelled via an underlying markov process , and under general assumptions , the following results are obtained : ( i ) : : stability of an associated ode implies that the stochastic ... |
an amazing characteristic of some old fashion problems is their endurement .the projectile motion is one of them .being one of the main problems used to teach elementary physics , variations and not well known facts about it appear in the physics literature of the xxi century .a search in the web or in the _ science ci... | we present an analysis on the geometrical place formed by the set of maxima of the trajectories of a projectile launched in a media with linear drag . such a place , the locus of apexes , is written in term of the lambert function in polar coordinates , confirming the special role played by this function in the problem... |
the density matrix is a useful operator for quantum mechanical calculations . for a given system ,one may be unsure about what is the state vector .if the possible state vectors and their associated probabilities are , one creates the _ _ proper__ density matrix it is hermitian : .it is trace 1 : , where are an arbi... | the lindblad equation is an evolution equation for the density matrix in quantum theory . it is the general linear , markovian , form which ensures that the density matrix is hermitian , trace 1 , positive and completely positive . some elementary examples of the lindblad equation are given . the derivation of the lind... |
we analyse the problem of controllability for linear finite - dimensional systems submitted to parametrised perturbations , depending on unknown parameters in a deterministic manner .in previous works we have analysed the property of averaged control looking for a control , independent of the values of these parameters... | we analyse the problem of controllability for parameter - dependent linear finite - dimensional systems . the goal is to identify the most distinguished realisations of those parameters so to better describe or approximate the whole range of controls . we adapt recent results on greedy and weak greedy algorithms for pa... |
stochastic modelling is often the most effective tool available in order to describe complex systems in physical , biological and social networks . in particular , since natural noise sources are mostly gaussian , stationary and non - stationary gaussian processes are often used to model the response of a system expose... | we address the characterization of classical fractional random noise via quantum probes . in particular , we focus on estimation and discrimination problems involving the fractal dimension of the trajectories of a system subject to fractional brownian noise . we assume that the classical degree of freedom exposed to th... |
the time - varying nature of the underlying channel is one of the most significant design challenges in wireless communication systems . in particular, real - time media traffic typically has a stringent delay constraint , so the exploitation of long blocklength frames is infeasible and the entire frame may fall into d... | we consider transmission of stationary and ergodic sources over non - ergodic composite channels with channel state information at the receiver ( csir ) . previously we introduced alternate capacity definitions to shannon capacity , including the capacity versus outage and the expected capacity . these generalized defi... |
in einstein s theory of general relativity , linearization of the field equations shows that small perturbations of the metric obey a wave equation ( misner , thorne & wheeler 1973 ) .these small disturbances , referred to as gravitational waves , travel at the speed of light .however , some other gravity theories pred... | we describe a method by which gravitational wave observations of eccentric binary systems could be used to test general relativity s prediction that gravitational waves are dispersionless . we present our results in terms of the graviton having a non - zero rest mass , or equivalently a non - infinite compton wavelengt... |
quantum discord ( qd ) is a measure of quantum correlation defined by ollivier and zurek almost ten years ago and , yet , a subject of increasing interest today .it is well known that , for a bipartite pure state , the definition of qd coincides with that of the entanglement of formation ( eof ) .but it has remained an... | we present a direct relation , based upon a monogamic principle , between entanglement of formation ( eof ) and quantum discord ( qd ) , showing how they are distributed in an arbitrary tripartite pure system . by extending it to a paradigmatic situation of a bipartite system coupled to an environment , we demonstrate ... |
a challenging problem in quantitative biology is to successfully model the evolutionary response of organisms to various environmental pressures . aside from its intrinsic interest , the development of models which can predict the time evolution of a population s genotype could prove useful in understanding a number of... | in this paper , we study the equilibrium behavior of eigen s quasispecies equations for an arbitrary gene network . we consider a genome consisting of genes , so that each gene sequence may be written as . we assume a single fitness peak ( sfp ) model for each gene , so that gene has some `` master '' sequence for whic... |
in the context of the predictive maintenance of the french railway switches ( or points ) which enable trains to be guided from one track to another at a railway junction , we have been brought to parameterize switch operations signals representing the electrical power consumed during a point operation ( see figure [ s... | a new approach for signal parametrization , which consists of a specific regression model incorporating a discrete hidden logistic process , is proposed . the model parameters are estimated by the maximum likelihood method performed by a dedicated expectation maximization ( em ) algorithm . the parameters of the hidden... |
nowadays , the diffused innovation policies require frequent survival estimates based on necessarily small samples .that may happen when the reliability of technological products continuously improved must be monitored ; or when the efficacy of always - new chemotherapy must be promptly checked .in helping statistician... | the peculiar properties of the inverse weibull ( iw ) distribution are shown . it is proven that the iw distribution is one of the few models having upside - down bathtub ( ubt ) shaped hazard function . three real and typical degenerative mechanisms , which lead exactly to the iw random variable , are formulated . so ... |
networks are useful constructs to schematize the organization of interactions in social and biological systems. networks are particularly valuable for characterizing _interdependent _ interactions , where the interaction between components a and b influences the interaction between components b and c , and so on . for ... | many real - world networks are so large that we must simplify their structure before we can extract useful information about the systems they represent . as the tools for doing these simplifications proliferate within the network literature , researchers would benefit from some guidelines about which of the so - called... |
the ligo and virgo gravitational wave interferometric detectors are approaching their design sensitivity , and in the near future , coincidences between the three detectors ( ligo - hanford , ligo - livingston and virgo ) will be possible . in order to reconstruct the direction of the astrophysical sources in the sky ,... | this paper deals with the reconstruction of the direction of a gravitational wave source using the detection made by a network of interferometric detectors , mainly the ligo and virgo detectors . we suppose that an event has been seen in coincidence using a filter applied on the three detector data streams . using the ... |
it is well known that adequate relativistic modelling is indispensable for the success of microarcsecond space astrometry .one of the most important relativistic effects for astrometric observations in the solar system is the gravitational light deflection .the largest contribution in the light deflection comes from th... | * gaia - ca - tn - lo - sz-002 - 2 * issue 2 , numerical integration of the differential equations of light propagation in the schwarzschild metric shows that in some extreme situations relevant for practical observations ( e.g. for gaia ) the well - known standard post - newtonian formula for the boundary problem ha... |
an extensive class of financial time series models is based on two interrelated processes . in particular , many models include an unobservable part that reflects a certain regime or the volatility of the process .a well - known example is given by the garch family .it is typically applied in order to model financial l... | we study the behavior of a real - valued and unobservable process under an extreme event of a related process that is observable . our analysis is motivated by the well - known garch model which represents two such sequences , i.e. the observable log returns of an asset as well as the hidden volatility process . our ... |
in massive mimo systems a base station ( bs ) with a large number of antennas ( , a few hundreds ) communicates with several user terminals ( , a few tens ) on the same time - frequency resource . there has been recent interest in massive mimo systems due to their ability to increase spectral and energy efficiency even... | we consider downlink precoding in a frequency - selective multi - user massive mimo system with highly efficient but non - linear power amplifiers at the base station ( bs ) . a low - complexity precoding algorithm is proposed , which generates constant - envelope ( ce ) transmit signals for each bs antenna . to avoid ... |
calibration is ubiquitous in all fields of science and engineering . it is an essential step to guarantee that the devices measure accurately what scientists and engineers want . if sensor devices are not properly calibrated , their measurements are likely of little use to the application .while calibration is mostly d... | whenever we use devices to take measurements , calibration is indispensable . while the purpose of calibration is to reduce bias and uncertainty in the measurements , it can be quite difficult , expensive and sometimes even impossible to implement . we study a challenging problem called _ self - calibration _ , i.e. , ... |
the cosmological principle is one of the cornerstones of modern cosmology . roughly speaking , the principle states that the universe is homogeneous and isotropic on large scales .although large - scale homogeneity and isotropy were initially postulated , in recent decades the principle has received mounting experiment... | a central assumption in our analysis of cosmic structure is that cosmological perturbations have zero ensemble mean . this property is one of the consequences of statistically homogeneity , the invariance of correlation functions under spatial translations . in this article we explore whether cosmological perturbations... |
makespan minimization is a fundamental and extensively studied problem in scheduling theory .consider a sequence of jobs that has to be scheduled on identical parallel machines .each job is specified by a processing time , .preemption of jobs is not allowed .the goal is to minimize the makespan , i.e. the maximum compl... | online makespan minimization is a classical problem in which a sequence of jobs has to be scheduled on identical parallel machines so as to minimize the maximum completion time of any job . in this paper we investigate the problem with an essentially new model of resource augmentation . more specifically , an online al... |
pareto optimality is a natural extension of the concept of maximum to multi - objective optimization problems .a solution is part of the pareto optimal set , or pareto front , if it is impossible to improve one objective without worsening another . instead of imposing an arbitrary aggregation of the different objective... | we developed a graph - based method to solve the multi - objective optimization problem of minimizing or maximizing subsets of bounded variables under partial order constraints . this problem , motivated by the optimization of the response of multi - input monotone systems applied to biological gene networks , can find... |
throughout the world , devastating earthquakes constantly occur with little or no advance warning . brune ( 1979 ) proposed that earthquakes may be inherently unpredictable since large earthquakes start as smaller earthquakes , which in turn start as smaller earthquakes , and so on . in his model ,most of the fault is ... | over the last decades strong efforts have been made to apply new spaceborne technologies to the study and possible forecast of strong earthquakes . in this study we use aster / terra multispectral satellite images for detection and analysis of changes in the system of lineaments previous to a strong earthquake . a line... |
, where is the underlying genotype . with ; or indicates the state of the mutable site ( e.g. , amino acid position ) .the effect of a single , double , triple mutation is given by the red arrows .pairwise ( or second - order ) epistasis is defined as the differential effect of a mutation depending on the background in... | defining the extent of epistasis the non - independence of the effects of mutations is essential for understanding the relationship of genotype , phenotype , and fitness in biological systems . the applications cover many areas of biological research , including biochemistry , genomics , protein and systems engineering... |
collisionless magnetized plasmas are described by the kinetic ( vlasov - maxwell ) equations and are characterized by high dimensionality , anisotropy and a wide variety of spatial and temporal scales , thus requiring the use of sophisticated numerical techniques to capture accurately their rich non - linear behavior .... | we present the design and implementation of an -stable spectral method for the discretization of the vlasov - poisson model of a collisionless plasma in one space and velocity dimension . the velocity and space dependence of the vlasov equation are resolved through a truncated spectral expansion based on legendre and f... |
turbulent flows in many different physical and engineering applications have a reynolds number so high that a direct numerical simulation of the navier - stokes equations ( dns ) is not feasible .the large - eddy simulation ( les ) is a method in which the large scales of turbulence only are directly solved while the e... | a new method for the localization of the regions where small scale turbulent fluctuations are present in hypersonic flows is applied to the large - eddy simulation ( les ) of a compressible turbulent jet with an initial mach number equal to 5 . the localization method used is called selective les and is based on the ex... |
for the description of pll - based circuits a physical model in the signals space and a mathematical model in the signal s phase space are used .the equations describing the model of pll - based circuits in the signals space are difficult for the study , since that equations are nonautonomous ( see , e.g. , ) .by contr... | in the present work pll - based circuits with sinusoidal phase detector characteristic and active proportionally - integrating ( pi ) filter are considered . the notion of lock - in range an important characteristic of pll - based circuits , which corresponds to the synchronization without cycle slipping , is studied ... |
derived the equivalence of mass and energy ( ) by considering an object of mass that simultaneously emits two electromagnetic packets , each with energy in opposite ( and ) directions . by momentum conservation in the rest frame of the object, it does not change its velocity after emission .seen from a frame moving at... | the equivalence of mass and energy is indelibly linked with relativity , both by scientists and in the popular mind . here i prove that by demanding momentum conservation of an object that emits two equal electromagnetic wave packets in opposite directions in its own frame . in contrast to einstein s derivation of this... |
the precision of measurements may in principle be improved using quantum mechanical effects , viz . , the quantum aided metrology . a convenient way of quantifying the precision in parameter estimation , for instance , is via the quantum fisher information ( qfi ) .also , non - classical states of light have become a p... | in this paper we analyze the quantum phase estimation problem using continuous - variable , entangled squeezed coherent states ( quasi - bell states ) . we calculate the quantum fisher information having the quasi - bell states as probe states and find that both squeezing and entanglement might bring advantages , incre... |
you are asked to complete a task drawn according to a pmf from a finite set of tasks .you do not get to see but only its description , where in other words , is described to you using bits .you know the mapping and you promise to complete based on , which leaves you no choice but to complete every task in the set in th... | a task is randomly drawn from a finite set of tasks and is described using a fixed number of bits . all the tasks that share its description must be performed . upper and lower bounds on the minimum -th moment of the number of performed tasks are derived . the key is an analog of the kraft inequality for partitions of ... |
transient lunar phenomena are defined for the purposes of this investigation as localized ( smaller than a few hundred km across ) , transient ( up to a few hours duration , and probably longer than typical impact events - less than 1s to a few seconds ) , and presumably confined to processes near the lunar surface .ho... | in paper i of this series , we show that transient lunar phenomena ( tlps ) correlate with lunar outgassing , geographically , based on surface radon release episodes versus the visual record of telescopic observers ( the later prone to major systematic biases of unspecified nature , which we were able to constrain in ... |
the deviation of an active region ( ar ) magnetic field from its potential configuration can arise due to photospheric footpoint motions and/or during flux emergence .however , studies with the high - quality data from space and ground based observatories over the last decade suggest that the latter is more dominant me... | the non - potentiality ( np ) of the solar magnetic fields is measured traditionally in terms of magnetic shear angle i.e. , the angle between observed and potential field azimuth . here , we introduce another measure of shear that has not been studied earlier in solar active regions , i.e. the one that is associated w... |
we have recorded the flight of a fly during take off and landing using digital high speed photography .it is shown that the dynamics of flexible wings are different for these procedures . during this observation flyflew freely in a big box and it was not tethered . | in this fluid dynamics video , we demonstrated take off and landing of a fly . the deformation of wings is in focus in this video . |
the feedback structure considered in this note is depicted in fig . 1 and the related transfer functions of the process and the controller are given by where is the plant steady - state gain , and the plant time constants , is the positive plant time delay and , and are the parameters of the pid controller .complete e... | the stability of feedback systems consisting of linear time - delay plants and pid controllers has been investigated for many years by means of several methods , of which the nyquist criterion , a generalization of the hermite - biehler theorem , and the root location method are well known . the main purpose of these r... |
we acknowledge useful and stimulating discussions with m. g. cosenza and v. m. kenkre .this work was supported by the nsf under grant no .j. c. is also supported by the james s. mcdonnell foundation and the national science foundation itr dmr-0426737 and cns-0540348 within the dddas program .99 w. weidlich , phys . rep... | in the context of an extension of axelrod s model for social influence , we study the interplay and competition between the cultural drift , represented as random perturbations , and mass media , introduced by means of an external homogeneous field . unlike previous studies [ j. c. gonzlez - avella _ et al _ , phys . r... |
the _ partially asymmetric simple exclusion process _( pasep ) is a physical model in which sites on a one - dimensional lattice are either empty or occupied by a single particle .these particles may hop to the left or to the right with fixed probabilities , which defines a markov chain on the states of the model .the ... | staircase tableaux are combinatorial objects which appear as key tools in the study of the pasep physical model . the aim of this work is to show how the discovery of a tree structure in staircase tableaux is a significant feature to derive properties on these objects . |
in this paper , we will use probabilistic methods to solve the dirichlet boundary value problem for the semilinear second order elliptic pde of the following form : where is a bounded domain in .the operator is given by where ( ) is a measurable , symmetric matrix - valued function satisfying a uniform elliptic conditi... | in this paper , we prove that there exists a unique solution to the dirichlet boundary value problem for a general class of semilinear second order elliptic partial differential equations . our approach is probabilistic . the theory of dirichlet processes and backward stochastic differential equations play a crucial ro... |
recent years witness an avalanche investigation of complex networks .complex systems in diverse fields can be described with networks , the elements as nodes and the relations between these elements as edges .the structure - induced features of dynamical systems on networks attract special attentions , to cite examples... | the random matrix theory is used to bridge the network structures and the dynamical processes defined on them . we propose a possible dynamical mechanism for the enhancement effect of network structures on synchronization processes , based upon which a dynamic - based index of the synchronizability is introduced in the... |
recent observations of type ia supernovae supported by wmap measurements of anisotropy of the angular temperature fluctuations indicate that our universe is spatially flat and accelerating . on the other hand, the power spectrum of galaxy clustering indicates that about of critical density of the universe should be in ... | we demonstrate a model - independent method of estimating qualitative dynamics of an accelerating universe from observations of distant type ia supernovae . our method is based on the luminosity - distance function , optimized to fit observed distances of supernovae , and the hamiltonian representation of dynamics for ... |
consider any system of chemical reactions , in which certain molecule types catalyse reactions and where there is a pool of simple molecule types available from the environment ( a ` food source ' ) .one can then ask whether , within this system , there is a subset of reactions that is both self - sustaining ( each mol... | given any finite and closed chemical reaction system , it is possible to efficiently determine whether or not it contains a ` self - sustaining and collectively autocatalytic ' subset of reactions , and to find such subsets when they exist . however , for systems that are potentially open - ended ( for example , when n... |
over the past decade or so two separate developments have occurred in computer science whose intersection promises to open a vast new area of research , an area extending far beyond the current boundaries of computer science .the first of these developments is the growing realization of how useful it would be to be abl... | this paper surveys the emerging science of how to design a `` collective intelligence '' ( coin ) . a coin is a large multi - agent system where : \i ) there is little to no centralized communication or control . \ii ) there is a provided world utility function that rates the possible histories of the full system . ... |
the exact string matching is one of the oldest tasks in computer science .the need for it started when computers began processing text . at that timethe documents were short and there were not so many of them .now , we are overwhelmed by amount of data of various kind .the string matching is a crucial task in finding i... | more than 120 algorithms have been developed for exact string matching within the last 40 years . we show by experiments that the nave algorithm exploiting simd instructions of modern cpus ( with symbols compared in a special order ) is the fastest one for patterns of length up to about 50 symbols and extremely good fo... |
probabilistic models of application domains are central to pattern recognition , machine learning , and scientific modeling in various fields .consequently , unifying frameworks are likely to be fruitful for one or more of these fields .there are also more technical motivations for pursuing the unification of diverse m... | we define a class of probabilistic models in terms of an operator algebra of stochastic processes , and a representation for this class in terms of stochastic parameterized grammars . a syntactic specification of a grammar is mapped to semantics given in terms of a ring of operators , so that grammatical composition c... |
complex systems with interacting constituents are ubiquitous in nature and society . to understand the microscopic mechanisms of emerging statistical laws of complex systems , one records and analyzes time series of observable quantities .these time series are usually nonstationary and possess long - range power - law ... | when common factors strongly influence two power - law cross - correlated time series recorded in complex natural or social systems , using classic detrended cross - correlation analysis ( dcca ) without considering these common factors will bias the results . we use detrended partial cross - correlation analysis ( dpx... |
there have been many models for the evolution of the bias derived from empirical knowledge , theory , simulations and from observations which account for the growth and merging of collapsed structure .however , all of these bias fitting forms include the unknown free parameters which need to be fitted with the set of g... | since kaiser introduced galaxies as a biased tracer of the underlying total mass field , the linear galaxies bias , appears ubiquitously both in theoretical calculations and in observational measurements related to galaxy surveys . however , the generic approaches to the galaxy density is a non - local and stochastic f... |
in physics , formal simplicity is often a reliable guide to the significance of a result .the concept of weak measurement , due to aharonov and his coworkers , derives some of its appeal from the formal simplicity of its basic formulae .one can extend the basic concept to a sequence of weak measurements carried out at ... | a weak measurement on a system is made by coupling a pointer weakly to the system and then measuring the position of the pointer . if the initial wavefunction for the pointer is real , the mean displacement of the pointer is proportional to the so - called weak value of the observable being measured . this gives an int... |
when optical , electromagnetic or acoustic signals are measured , often the measurement apparatus records an intensity , the magnitude of the signal amplitude , while discarding phase information .this is the case for x - ray crystallography , many optical and acoustic systems , and also an intrinsic feature of quantum... | the main objective of this paper is to find algorithms accompanied by explicit error bounds for phase retrieval from noisy magnitudes of frame coefficients when the underlying frame has a low redundancy . we achieve these goals with frames consisting of vectors spanning a -dimensional complex hilbert space . the two al... |
complex networks have become a natural abstraction of the interactions between elements in complex systems .when the type of interaction is essentially identical between any two elements , the theory of complex networks provides with a wide set of tools and diagnostics that turn out to be very useful to gain insight in... | multiplex networks are representations of multilayer interconnected complex networks where the nodes are the same at every layer . they turn out to be good abstractions of the intricate connectivity of multimodal transportation networks , among other types of complex systems . one of the most important critical phenome... |
questions such as whether the universe will expand forever or eventually re - collapse and end with a big crunch , and what its shape and size may be , are among the most fundamental challenges in cosmology . regarding the former question ,it is well known that the ultimate fate of the universe is intrinsically associa... | given the wealth of increasingly accurate cosmological observations , especially the recent results from the wmap , and the development of methods and strategies in the search for cosmic topology , it is reasonable to expect that we should be able to detect the spatial topology of the universe in the near future . moti... |
in recent years , there have been a considerable number of important developments in the extension of ( classical ) information - theoretic concepts to a quantum - mechanical setting .bennett and shor have surveyed this progress in the outstanding commemorative issue 19481998 of the _ ieee transactions on information t... | clarke and barron have recently shown that the jeffreys invariant prior of bayesian theory yields the common asymptotic ( minimax and maximin ) redundancy of universal data compression in a parametric setting . we seek a possible analogue of this result for the two - level _ quantum _ systems . we restrict our consider... |
transient lunar phenomena ( tlps or ltps ) are defined for the purposes of this investigation as localized ( smaller than a few hundred km across ) , transient ( up to a few hours duration , and probably longer than typical impact events - less than 1s to a few seconds ) , and presumably confined to processes near the ... | we follow paper i with predictions of how gas leaking through the lunar surface could influence the regolith , as might be observed via optical transient lunar phenomena ( tlps ) and related effects . we touch on several processes , but concentrate on low and high flow rate extremes , perhaps the most likely . we model... |
preprocessing and the analysis of preprocessed data are ubiquitous components of statistical inference , but their treatment has often been informal .we aim to develop a theory that provides a set of formal statistical principles for such problems under the banner of multiphase inference .the term `` multiphase '' refe... | preprocessing forms an oft - neglected foundation for a wide range of statistical and scientific analyses . however , it is rife with subtleties and pitfalls . decisions made in preprocessing constrain all later analyses and are typically irreversible . hence , data analysis becomes a collaborative endeavor by all part... |
due to the high frequency of the fastest internal motions in molecular systems , the discrete time step for molecular dynamics simulations must be very small ( of the order of femtoseconds ) , while the actual span of biochemical proceses typically require the choice of relatively long total times for simulations ( e.g... | in order to accelerate molecular dynamics simulations , it is very common to impose holonomic constraints on their hardest degrees of freedom . in this way , the time step used to integrate the equations of motion can be increased , thus allowing , in principle , to reach longer total simulation times . the imposition ... |
e. rasmusen , _ games and information : an introduction to game theory _( blackwell pub , oxford , 2001 ) , r. b. myerson , _ game theory : analysis of conflict _ ( harvard univ . press , cambridge ma , 1997 ) . in bos ,if the source is ideal , that is , there are multiple ne s with the same payoff .( th... | effects of a corrupt source on the dynamics of simultaneous move strategic games are analyzed both for classical and quantum settings . the corruption rate dependent changes in the payoffs and strategies of the players are observed . it is shown that there is a critical corruption rate at which the players lose their q... |
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