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following recent experimental developments, in this study we re - evaluate if the interplay of high - and low - energy lepton flavour violating observables remains a viable probe to test the high - scale type - i supersymmetric seesaw. our analysis shows that fully constrained supersymmetric scenarios no longer allow to explore this interplay, since recent lhc data precludes the possibility of having sizeable slepton mass differences for a slepton spectrum sufficiently light to be produced, and in association to br ( mu - > e gamma ) within experimental reach. however, relaxing the strict universality of supersymmetric soft - breaking terms, and fully exploring heavy neutrino dynamics, still allows to have slepton mass splittings o ( few % ), for slepton masses accessible at the lhc, with associated mu - > e gamma rates within future sensitivity. for these scenarios, we illustrate how the correlation between high - and low - energy lepton flavour violating observables allows to probe the high - scale supersymmetric seesaw. | arxiv:1309.7951 |
we explore the origin and yukawa interactions of the scalars with peculiar cp - properties which were recently found in a multi - higgs model based on an order - 4 cp symmetry. we relate the existence of such scalars to the enhanced freedom of defining cp, even beyond the well - known generalized cp symmetries, which arises in models with several zero - charge scalar fields. we also show that despite possessing exotic cp quantum numbers, these scalars do not have to be inert : they can have cp - conserving yukawa interactions provided the cp acts on fermions by also mixing generations. this paper focuses on formal aspects - - - exposed in a pedagogical manner - - - and includes a brief discussion of possible phenomenological consequences. | arxiv:1608.08922 |
the field of video compression has developed some of the most sophisticated and efficient compression algorithms known in the literature, enabling very high compressibility for little loss of information. whilst some of these techniques are domain specific, many of their underlying principles are universal in that they can be adapted and applied for compressing different types of data. in this work we present deepcabac, a compression algorithm for deep neural networks that is based on one of the state - of - the - art video coding techniques. concretely, it applies a context - based adaptive binary arithmetic coder ( cabac ) to the network ' s parameters, which was originally designed for the h. 264 / avc video coding standard and became the state - of - the - art for lossless compression. moreover, deepcabac employs a novel quantization scheme that minimizes the rate - distortion function while simultaneously taking the impact of quantization onto the accuracy of the network into account. experimental results show that deepcabac consistently attains higher compression rates than previously proposed coding techniques for neural network compression. for instance, it is able to compress the vgg16 imagenet model by x63. 6 with no loss of accuracy, thus being able to represent the entire network with merely 8. 7mb. the source code for encoding and decoding can be found at https : / / github. com / fraunhoferhhi / deepcabac. | arxiv:1907.11900 |
we describe a general approach of determining the distribution of spanning subgraphs in the random graph $ \ g ( n, p ) $. in particular, we determine the distribution of spanning subgraphs of certain given degree sequences, which is a generalisation of the $ d $ - factors, of spanning triangle - free subgraphs, of ( directed ) hamilton cycles and of spanning subgraphs that are isomorphic to a collection of vertex disjoint ( directed ) triangles. | arxiv:1105.5913 |
graph embedding based retrieval has become one of the most popular techniques in the information retrieval community and search engine industry. the classical paradigm mainly relies on the flat euclidean geometry. in recent years, hyperbolic ( negative curvature ) and spherical ( positive curvature ) representation methods have shown their superiority to capture hierarchical and cyclic data structures respectively. however, in industrial scenarios such as e - commerce sponsored search platforms, the large - scale heterogeneous query - item - advertisement interaction graphs often have multiple structures coexisting. existing methods either only consider a single geometry space, or combine several spaces manually, which are incapable and inflexible to model the complexity and heterogeneity in the real scenario. to tackle this challenge, we present a web - scale adaptive mixed - curvature advertisement retrieval system ( amcad ) to automatically capture the complex and heterogeneous graph structures in non - euclidean spaces. specifically, entities are represented in adaptive mixed - curvature spaces, where the types and curvatures of the subspaces are trained to be optimal combinations. besides, an attentive edge - wise space projector is designed to model the similarities between heterogeneous nodes according to local graph structures and the relation types. moreover, to deploy amcad in taobao, one of the largest ecommerce platforms with hundreds of million users, we design an efficient two - layer online retrieval framework for the task of graph based advertisement retrieval. extensive evaluations on real - world datasets and a / b tests on online traffic are conducted to illustrate the effectiveness of the proposed system. | arxiv:2203.14683 |
the article is devoted to the investigation of transformation groups of polynomials over cayley - dickson algebras and their manifolds of zeros. the problems about expressibility of zeros with the help of roots and decomposibility of polynomials as products of linear terms are studied. | arxiv:math/0406048 |
we report the search for low - mass x - ray binaries in quiescence ( qlmxbs ) in the globular cluster ngc 6304 using xmm observations. we present the spectral analysis leading to the identification of three candidate qlmxbs within the field of this globular cluster ( gc ), each consistent with the x - ray spectral properties of previously identified qlmxbs in the field and in other globular clusters - - specifically, with a hydrogen atmosphere neutron star with radius between 5 - - 20 \ km. one ( source 4, with r = 11. 7 ^ { + 8. 3 } _ { - 0. 4 } ( d / 5. 97 kpc ) km and kt _ eff = 117 ^ { + 59 } _ { - 44 } ev ) is located within one core radius ( r _ c ) of the centre of ngc 6304. this candidate also presents a spectral power - law component contributing 49 per cent of the 0. 5 - 10 kev flux. a second one ( source 9 with r = 15. 3 ^ { + 11. 2 } _ { - 6. 5 } ( d / 5. 97 kpc ) km and kt _ eff = 100 ^ { + 24 } _ { - 19 } ev ) is found well outside the optical core ( at 32 r _ c ) but still within the tidal radius. from spatial coincidence, we identify a bright 2mass infrared counterpart which, at the distance of ngc 6304, seems to be a post - asymptotic giant branch star. the third qlmxb ( source 5 with r = 23 ^ { + 38 } _ { - 14 } ( d / 5. 97 kpc ) km and kt _ eff = 70 ^ { + 28 } _ { - 20 } ev ) is a low signal - to - noise candidate for which we also identify from spatial coincidence a bright 2mass infrared counterpart, with 99. 916 per cent confidence. three qlmxbs from this gc is marginally consistent with that expected from the encounter rate of ngc 6304. we also report a low signal - to - noise source with an unusually hard photon index ( \ alpha = - 2. 0 ^ { + 1. 2 } _ { - 2. 2 } ). finally, we present an updated catalogue of the x - ray sources lying in the field of ngc 6304, and compare this with the previous catalogue compiled from rosat observations | arxiv:0808.1305 |
we consider cellular base stations ( bss ) equipped with a large number of antennas and operating in the unlicensed band. we denote such system as massive mimo unlicensed ( mmimo - u ). we design the key procedures required to guarantee coexistence between a cellular bs and nearby wi - fi devices. these include : neighboring wi - fi channel covariance estimation, allocation of spatial degrees of freedom for interference suppression, and enhanced channel sensing and data transmission phases. we evaluate the performance of the so - designed mmimo - u, showing that it allows simultaneous cellular and wi - fi transmissions by keeping their mutual interference below the regulatory threshold. the same is not true for conventional listen - before - talk ( lbt ) operations. as a result, mmimo - u boosts the aggregate cellular - plus - wi - fi data rate in the unlicensed band with respect to conventional lbt, exhibiting increasing gains as the number of bs antennas grows. | arxiv:1703.05690 |
an interpretation of the ridge phenomenon found in pp collisions at 7 tev is given in terms of enhancement of soft partons due to energy loss of semihard jets. a description of ridge formation in nuclear collisions can directly be extended to pp collisions, since hydrodynamics is not used, and azimuthal anisotropy is generated by semihard scattering. both the p _ t and multiplicity dependencies are well reproduced. some suggestions are made about other observables. | arxiv:1011.0965 |
we consider a massive fermionic quantum field localized on a plane in external constant and homogeneous electric and magnetic fields. the magnetic field is perpendicular to the plane and the electric field is parallel. the complete set of solutions to the dirac equation is presented. as important physical characteristics of the vacuum state, the fermion condensate and the expectation value of the energy - momentum tensor are investigated. the renormalization is performed using the hurwitz function. the results are compared with those previously studied in the case of zero electric field. we discuss the behavior of the vacuum expectation values in different regions for the values of the problem parameters. applications of the results include the electronic subsystem of graphene sheet described by the dirac model in the long - wavelength approximation. | arxiv:2306.11402 |
background : tumour budding is an independent predictor of metastasis and prognosis in colorectal cancer and is a vital part of the pathology specification report. in a conventional pathological section observation process, pathologists have to repeatedly switch from 10x objective to 20x objective several times to localize and image the target region. besides the switching operations, repeated manual or electro - mechanical focusing is also very time - consuming, affecting the total time for pathological diagnosis. in addition, it is usually necessary to remove the manually marked symbols on the stained pathology slides used for classification and management before observation. methods : in this paper, we utilize fourier ptychographic microscopy ( fpm ) in the pathological diagnosis process to realize large space - bandwidth product imaging, quantitative phase imaging, and digital refocusing in the observation process without any mechanical operations, which can therefore simplify the above - mentioned cumbersome diagnostic processes. we first verify the effectiveness and efficiency of the proposed method with several typical pathological sections. then, instead of manually erasing, we also prove that fp framework can digitally remove the artificial markers with its digital refocusing ability. results : at last, we demonstrated pathologists can achieve 100 % diagnostic accuracy with fpm imaging results. conclusions : the proposed method can greatly simplify the process of pathological diagnosis, and the related addon hardware system does not require expensive components, which makes it have great potential for promotion in the field of pathological diagnosis. | arxiv:2503.16170 |
important cellular processes such as migration, differentiation, and development often rely on precise timing. yet, the molecular machinery that regulates timing is inherently noisy. how do cells achieve precise timing with noisy components? we investigate this question using a first - passage - time approach, for an event triggered by a molecule that crosses an abundance threshold and that is regulated by either an accumulating activator or a diminishing repressor. we find that the optimal strategy corresponds to a nonlinear increase in the amount of the target molecule over time. optimality arises from a tradeoff between minimizing the extrinsic timing noise of the regulator, and minimizing the intrinsic timing noise of the target molecule itself. although either activation or repression outperforms an unregulated strategy, when we consider the effects of cell division, we find that repression outperforms activation if division occurs late in the process. our results explain the nonlinear increase and low noise of mig - 1 gene expression in migrating neuroblast cells during caenorhabditis elegans development, and suggest that mig - 1 regulation is dominated by repression for maximal temporal precision. these findings suggest that dynamic regulation may be a simple and powerful strategy for precise cellular timing. | arxiv:1711.07918 |
we establish an optimal regularity result for parametrized two - dimensional stationary varifolds. namely, we show that the parametrization map is a smooth minimal branched immersion and that the multiplicity function is constant. we provide some applications of this regularity result, especially in the calculus of variations for the area functional. | arxiv:1708.02211 |
the elasto - inertial effects on particle focusing in a square - tube flow were investigated experimentally and numerically. microscale experiments using spherical particles in dilute polymer solutions demonstrated that the particles are focused on the midline and / or the diagonal in a downstream cross - section, depending on the polymer concentration. numerical computations based on the fene - p model for the viscoelastic flow reproduced these focusing patterns. it was revealed that the transitions among the patterns are accounted for by the elastic forces due to the first normal stress difference and the polymer elongation, which are the essentials of the viscoelastic fluid. | arxiv:2106.07259 |
the circular polarization of direct gap emission of ge is studied in optically - excited tensile - strained ge - on - si heterostructures as a function of doping and temperature. owing to the spin - dependent optical selection rules, the radiative recombinations involving strain - split light ( cg - lh ) and heavy hole ( cg - hh ) bands are unambiguously resolved. the fundamental cg - lh transition is found to have a low temperature circular polarization degree of about 85 % despite an off - resonance excitation of more than 300 mev. by photoluminescence ( pl ) measurements and tight binding calculations we show that this exceptionally high value is due to the peculiar energy dependence of the optically - induced electron spin population. finally, our observation of the direct gap doublet clarifies that the light hole contribution, previously considered to be negligible, can dominate the room temperature pl even at low tensile strain values of about 0. 2 %. | arxiv:1510.08614 |
the optimization of expensive black - box simulators arises in a myriad of modern scientific and engineering applications. bayesian optimization provides an appealing solution, by leveraging a fitted surrogate model to guide the selection of subsequent simulator evaluations. in practice, however, the objective is often not to obtain a single good solution, but rather a ` ` basket ' ' of good solutions from which users can choose for downstream decision - making. this need arises in our motivating application for real - time control of internal combustion engines for flight propulsion, where a diverse set of control strategies is essential for stable flight control. there has been little work on this front for bayesian optimization. we thus propose a new expected diverse utility ( edu ) method that searches for diverse ` ` $ \ epsilon $ - optimal ' ' solutions : locally - optimal solutions within a tolerance level $ \ epsilon > 0 $ from a global optimum. we show that edu yields a closed - form acquisition function under a gaussian process surrogate model, which facilitates efficient sequential queries via automatic differentiation. this closed form further reveals a novel exploration - exploitation - diversity trade - off, which incorporates the desired diversity property within the well - known exploration - exploitation trade - off. we demonstrate the improvement of edu over existing methods in a suite of numerical experiments, then explore the edu in two applications on rover trajectory optimization and engine control for flight propulsion. | arxiv:2410.01196 |
the t2k collaboration has recently reported a remarkable indication of the \ nu _ \ mu - > \ nu _ e oscillation which is consistent with a relatively large value of \ theta _ { 13 } in the three - flavor neutrino mixing scheme. we show that it is possible to account for such a result of \ theta _ { 13 } by introducing a natural perturbation to the democratic neutrino mixing pattern, without or with cp violation. a testable correlation between \ theta _ { 13 } and \ theta _ { 23 } is predicted in this ansatz. we also discuss the wolfenstein - like parametrization of neutrino mixing, and comment on other possibilities of generating sufficiently large \ theta _ { 13 } at the electroweak scale. | arxiv:1106.3244 |
we present a preliminary measurement of the branching fraction of the exclusive penguin decay b ^ 0 - > k ^ * 0 gamma using ( 8. 6 + / - 0. 3 ) x 10 ^ 6 b - anti - b decays bf ( b ^ 0 - > k ^ * 0 gamma ) = ( 5. 2 + / - 0. 82 ( stat. ) + / - 0. 47 ( sys. ) ) x 10 ^ - 5. in addition we search for the related penguin decays with a lepton pair in the final state, b ^ + - > k ^ + l ^ + l ^ -, b ^ 0 - > k ^ * 0 l ^ + l ^ -. we find no evidence for these decays in 3. 7 + / - 0. 1 x 10 ^ 6 b - anti - b decays and set preliminary 90 % c. l upper limits of bf ( b ^ + - > k ^ + e ^ + e ^ - ) < 12. 5 x 10 ^ { - 6 }, bf ( b ^ + - > k ^ + mu ^ + mu ^ - ) < 8. 3 x 10 ^ { - 6 }, bf ( b ^ 0 - > k ^ * 0 e ^ + e ^ - ) < 24. 1 x 10 ^ { - 6 }, bf ( b ^ 0 - > k ^ * 0 mu ^ + mu ^ - ) < 24. 5 x 10 ^ { - 6 }. | arxiv:hep-ex/0011054 |
in this paper we give the description of generic representations of metaplectic groups over p - adic fields in terms of their langlands parameters and calculate their theta lifts on all levels for any tower of odd orthogonal groups. we also describe precisely all the occurrences of the failure of the standard module conjecture for metaplectic groups. | arxiv:1902.07357 |
we study the bell nonlocality of high dimensional quantum systems based on quantum entanglement. a quantitative relationship between the maximal expectation value b of bell operators and the quantum entanglement concurrence c is obtained for even dimension pure states, with the upper and lower bounds of b governed by c. | arxiv:2108.06634 |
scaling properties of the quantum hall metal - insulator transition are severely affected by finite size effects in small systems. surprisingly, despite the narrow spatial range where probability structure functions exhibit multifractal scaling, we clearly verify the existence of extended self - similarity - - a hidden infrared scaling phenomenon related to the peculiar form of the crossover at the onset of nonmultifractal behavior. as finite size effects get stronger for structure functions with negative orders, the parabolic approximation for the multifractal spectrum loses accuracy. however, by means of an extended self - similarity analysis, an improved evaluation of the multifractal exponents is attained for negative orders too, rendering them consistent with previous results, which rely on computations performed for considerably larger systems. | arxiv:cond-mat/0307736 |
this paper studies content caching in cloud - aided wireless networks where small cell base stations with limited storage are connected to the cloud via limited capacity fronthaul links. by formulating a utility ( inverse of service delay ) maximization problem, we propose a cache update algorithm based on spatio - temporal traffic demands. to account for the large number of contents, we propose a content clustering algorithm to group similar contents. subsequently, with the aid of regret learning at small cell base stations and the cloud, each base station caches contents based on the learned content popularity subject to its storage constraints. the performance of the proposed caching algorithm is evaluated for sparse and dense environments while investigating the tradeoff between global and local class popularity. simulation results show 15 % and 40 % gains in the proposed method compared to various baselines. | arxiv:1710.00506 |
the firas instrument on the cobe satellite has conducted an unbiased survey of the far - infrared emission from our galaxy. the first results of this survey were reported by wright et al. ( 1991 ). we report the results of new analyses of this spectral survey, which includes emission lines from 158 um c +, 122 um and 205 um n +, 370 um and 609 um c, and co j = 2 - 1 through 5 - 4. we report the morphological distribution along the galactic plane ( b = 0 ) of the spectral line emission, and the high galactic latitude intensities of the c + and 205 um n + emission. the high galactic latitude intensity cosecant of the 158 um fine structure transition from c + is presented, and c + is seen to decrease more rapidly than the far infrared intensity with increasing galactic latitude. c + and h i emission are closely correlated with a c + cooling rate of ( 2. 65 + / - 0. 15 ) x10 ^ { - 26 } erg / s / h - atom. we conclude that this emission arises almost entirely from the cold neutral medium. the high galactic latitude intensity of the 205 um fine structure transition from n + arises entirely from the warm ionized medium, and its cosecant is presented. we estimate the total ionizing photon rate in the galaxy to be 3. 5x10 ^ { 53 } ionizing photons per second, based on the 205 um n + transition. | arxiv:astro-ph/9311032 |
the underlying mechanism of unconventional high - temperature superconductivity is a great challenge to condensed matter physics. however, zero dissipation of electric current is the commonness of superconductors whether they are conventional or unconventional ones. in this presentation, the ohm law in a nonmagnetic conductor is derived from a set of modified electromagnetic equations that involve maxwell ones. it is found that, the steady current dissipation in a conductor can be expressed as $ { j } \ cdot { e } = { c ^ 2 } \ rho / ( u { \ epsilon _ r } { \ mu _ r } ) $, where j, e, $ \ rho $, c, u, $ { \ epsilon _ r } $ and $ { \ mu _ r } $ are the electric current density, electric field strength, free electric charge density, light speed in vacuum, effective mobility of carriers, relative dielectric constant and permeability, respectively. this relation indicates that, in a steady state of $ j \ ne 0 $, if $ \ rho = 0 $, then $ { j } \ cdot { e } = 0 $ and the conductor comes into a superconducting state. it is also found that the condition $ \ rho = 0 $ is valid for superconductivity of magnetic materials and is a sufficient than necessary one. when $ \ rho = 0 $ the ( involving the hall electric field strength ) becomes zero, which solves the pending problem why vanishing of hall - effect in some superconducting states, besides, suggests a superconductive pairing mechanism of holes and electrons. two examples of superconducting state under the condition $ \ rho = 0 $ are discussed. | arxiv:1105.5705 |
inorganic metal - halide cubic perovskite semiconductors have become more popular in industrial applications of photovoltaic and optoelectronic devices. among various perovskites, lead - free materials are currently most explored due to their non - toxic effect on the environment. in this study, the structural, electronic, optical, and mechanical properties of lead - free cubic perovskite materials frbx3 ( b = ge, sn ; x = cl, br, i ) are investigated through first - principles density - functional theory ( dft ) calculations. these materials are found to exhibit semiconducting behavior with direct bandgap energy and mechanical phase stability. the observed variation in the bandgap is explained based on the substitutions of cations and anions sitting over b and x - sites of the frbx3 compounds. the high absorption coefficient, low reflectivity, and high optical conductivity make these materials suitable for photovoltaic and other optoelectronic device applications. it is observed that the material containing ge ( germanium ) in the b - site has higher optical absorption and conductivity than sn containing materials. a systematic analysis of the electronic, optical, and mechanical properties suggests that among all the perovskite materials, frgei3 would be a potential candidate for optoelectronic applications. the radioactive element fr - containing perovskite frgei3 may have applications in nuclear medicine and diagnosis such as x - ray imaging technology. | arxiv:2203.08754 |
fast and accurate prediction of hurricane evolution from genesis onwards is needed to reduce loss of life and enhance community resilience. in this work, a novel model development methodology for predicting storm trajectory is proposed based on two classes of recurrent neural networks ( rnns ). the rnn models are trained on input features available in or derived from the hurdat2 north atlantic hurricane database maintained by the national hurricane center ( nhc ). the models use probabilities of storms passing through any location, computed from historical data. a detailed analysis of model forecasting error shows that many - to - one prediction models are less accurate than many - to - many models owing to compounded error accumulation, with the exception of $ 6 - hr $ predictions, for which the two types of model perform comparably. application to 75 or more test storms in the north atlantic basin showed that, for short - term forecasting up to 12 hours, the many - to - many rnn storm trajectory prediction models presented herein are significantly faster than ensemble models used by the nhc, while leading to errors of comparable magnitude. | arxiv:2111.12683 |
touchscreens equipped with friction modulation can provide rich tactile feedback to their users. to date, there are no standard metrics to properly quantify the benefit brought by haptic feedback. the definition of such metrics is not straightforward since friction modulation technologies can be achieved by either ultrasonic waves or with electroadhesion. in addition, the output depends strongly on the user, both because of the mechanical behavior of the fingertip and personal tactile somatosensory capabilities. this paper proposes a method to evaluate and compare the performance of haptic tablets on an objective scale. the method first defines multiple metrics using physical measurements of friction and latency. the comparison is completed with metrics derived from information theory and based on pointing tasks performed by users. we evaluated the comparison method with two haptic devices, one based on ultrasonic friction modulation and the other based on electroadhesion. this work paves the way toward the definitions of standard specifications for haptic tablets, to establish benchmarks and guidelines for improving surface haptic devices. | arxiv:2308.15190 |
we have performed a systematic angle - resolved photoemission spectroscopy ( arpes ) study of the high - tc cuprates la2 - xsrxcuo4, ranging from the underdoped insulator to the superconductor to the overdoped metal. we have revealed a systematic doping evolution of the band dispersions and ( underlying ) fermi surfaces, pseudogap and quasi - particle features under the influence of strong electron - electron interaction and electron - phonon interaction. the unusual transport and thermodynamic properties are explained by taking into account the pseudogap opening and the fermi arc formation, due to which the carrier number decreases as the doped hole concentration decreases. | arxiv:cond-mat/0610759 |
we systematically study the chiral symmetry breaking and restoration in the presence of a pure electric field in the nambu - - jona - lasinio ( njl ) model at finite temperature and baryon chemical potential. in addition, we also study the effect of the chiral phase transition on the charged pair production due to the schwinger mechanism. for these purposes, a general formalism for parallel electric and magnetic fields is developed at finite temperature and chemical potential for the first time. in the pure electric field limit $ b \ rightarrow0 $, we compute the order parameter, the transverse - to - longitudinal ratio of the goldstone mode velocities, and the schwinger pair production rate as functions of the electric field. the inverse catalysis effect of the electric field to chiral symmetry breaking is recovered. and the goldstone mode is find to disperse anisotropically such that the transverse velocity is always smaller than the longitudinal one, especially at nonzero temperature and baryon chemical potential. as expected, the quark - pair production rate is greatly enhanced by the chiral symmetry restoration. | arxiv:1510.05125 |
periodically driven systems offer a perfect breeding ground for out - of - equilibrium engineering of topological boundary states at zero energy ( $ 0 $ - mode ), as well as finite energy ( $ \ pi $ - mode ), with the latter having no static analog. the floquet operator and the effective floquet hamiltonian, which encapsulate the stroboscopic features of the driven system, capture both spectral and localization properties of the $ 0 $ - and $ \ pi $ - modes but sometimes fail to provide complete topological characterization, especially when $ 0 $ - and $ \ pi $ - modes coexist. in this work, we utilize the spectral localizer, a powerful local probe that can provide numerically efficient, spatially local, and energy - resolved topological characterization. in particular, we apply the spectral localizer to the effective floquet hamiltonian for driven one - and two - dimensional topological systems with no or limited symmetries and are able to assign topological invariants, or local markers, that characterize the $ 0 $ - and the $ \ pi $ - boundary modes individually and unambiguously. due to the spatial resolution, we also demonstrate that the extracted topological invariants are suitable for studying driven disordered systems and can even capture disorder - induced phase transitions. | arxiv:2408.08548 |
we consider the problem of modeling heterogeneous materials where micro - scale dynamics and interactions affect global behavior. in the presence of heterogeneities in material microstructure it is often impractical, if not impossible, to provide quantitative characterization of material response. the goal of this work is to develop a bayesian framework for uncertainty quantification ( uq ) in material response prediction when using nonlocal models. our approach combines the nonlocal operator regression ( nor ) technique and bayesian inference. specifically, we use a markov chain monte carlo ( mcmc ) method to sample the posterior probability distribution on parameters involved in the nonlocal constitutive law, and associated modeling discrepancies relative to higher fidelity computations. as an application, we consider the propagation of stress waves through a one - dimensional heterogeneous bar with randomly generated microstructure. several numerical tests illustrate the construction, enabling uq in nonlocal model predictions. although nonlocal models have become popular means for homogenization, their statistical calibration with respect to high - fidelity models has not been presented before. this work is a first step towards statistical characterization of nonlocal model discrepancy in the context of homogenization. | arxiv:2211.01330 |
the paper defines a generic birman - wenzl algebra of coxeter type d and investigates its structure as a semi - simple algebra. | arxiv:1610.03992 |
the performance of the atlas muon trigger system is evaluated with proton - proton collision data collected in 2012 at the large hadron collider at a centre - of - mass energy of 8 tev. it is primarily evaluated using events containing a pair of muons from the decay of $ z $ bosons. the efficiency of the single - muon trigger is measured for muons with transverse momentum 25 < $ p _ t $ < 100 gev, with a statistical uncertainty of less than 0. 01 % and a systematic uncertainty of 0. 6 %. the $ p _ t $ range for efficiency determination is extended by using muons from decays of $ j / \ psi $ mesons, $ w $ bosons, and top quarks. the muon trigger shows highly uniform and stable performance. the performance is compared to the prediction of a detailed simulation. | arxiv:1408.3179 |
we use the shadow wave function formalism as a convenient model to study the fermion sign problem affecting all projector quantum monte carlo methods in continuum space. we demonstrate that the efficiency of imaginary time projection algorithms decays exponentially with increasing number of particles and / or imaginary - time propagation. moreover, we derive an analytical expression that connects the localization of the system with the magnitude of the sign problem, illustrating this prediction through some numerical results. finally, we discuss the fermion sign problem computational complexity and methods for alleviating its severity. | arxiv:1601.01558 |
we investigate how the dynamical production of quantum entanglement for weakly coupled mapping systems is influenced by the chaotic dynamics of the corresponding classical system. we derive a general perturbative formula for the entanglement production rate which is defined by using the linear entropy of the subsystem. this formula predicts that { \ it the increment of the strength of chaos does not enhance the production rate of entanglement } when the coupling is weak enough and the subsystems are strongly chaotic. the prediction is confirmed by numerical experiments for coupled kicked tops and rotors. we also discuss the entanglement production using the husimi representation of the reduced density matrix. | arxiv:quant-ph/0302015 |
we propose to couple the flux degree of freedom of one mode with the charge degree of freedom of a second mode in a hybrid superconducting - semiconducting architecture. nonreciprocity can arise in this architecture in the presence of external static magnetic fields alone. we leverage this property to engineer a passive on - chip gyrator, the fundamental two - port nonreciprocal device which can be used to build other nonreciprocal devices such as circulators. we analytically and numerically investigate how the nonlinearity of the interaction, circuit disorder and parasitic couplings affect the scattering response of the gyrator. | arxiv:2209.06194 |
we report symmetry - breaking and restoring bifurcations of solitons in a fractional schr \ " { o } dinger equation with the cubic or cubic - quintic ( cq ) nonlinearity and a parity - time ( pt ) - symmetric potential, which may be realized in optical cavities. solitons are destabilized at the bifurcation point, and, in the case of the cq nonlinearity, the stability is restored by an inverse bifurcation. two mutually - conjugate branches of ghost states ( gss ), with complex propagation constants, are created by the bifurcation, solely in the case of the fractional diffraction. while gss are not true solutions, direct simulations confirm that their shapes and results of their stability analysis provide a blueprint for the evolution of genuine localized modes in the system. | arxiv:2106.05446 |
we introduce a weighted sobolev space theory for the non - local elliptic equation $ $ \ delta ^ { \ alpha / 2 } u = f, \ quad x \ in d \, ; \ quad u | _ { \ overline { d } ^ c } = g $ $ as well as for the non - local parabolic equation $ $ u _ t = \ delta ^ { \ alpha / 2 } u + f, \ quad t > 0, \, x \ in d \, ; \ quad u ( 0, \ cdot ) | _ d = u _ 0, \, u | _ { ( 0, t ) \ times \ overline { d } ^ c } = g. $ $ here, $ \ alpha \ in ( 0, 2 ) $ and $ d $ is a $ c ^ { 1, 1 } $ open set. we prove uniqueness and existence results in weighted sobolev spaces. we measure the sobolev and h \ " older regularities of arbitrary order derivatives of solutions using a system of weights consisting of appropriate powers of the distance to the boundary. one of the most interesting features of our results is that, unlike the classical result in sobolev spaces without weights, the weighted regularities of solutions in $ d $ are barely affected by those of $ g $ in $ \ overline { d } ^ c $. for instance, even if $ g = \ delta _ { x _ 0 } $, the dirac delta distribution concentrated at $ x _ 0 \ in \ overline { d } ^ c $, the solution to the elliptic equation given with $ f = 0 $ is infinitely differentiable in $ d $, and for any $ k = 0, 1, 2, 3, \ cdots $, $ \ varepsilon > 0 $, and $ \ delta \ in ( 0, 1 ) $, it holds that $ $ | d _ x ^ { - \ frac { \ alpha } { 2 } + \ varepsilon + k } d ^ k _ xu | _ { c ( d ) } + | d _ x ^ { - \ frac { \ alpha } { 2 } + \ varepsilon + k + \ delta } d ^ k _ xu | _ { c ^ { \ delta } ( d ) } < \ infty, $ $ where $ d _ x = dist ( x, \ partial d ) $. | arxiv:2305.08934 |
radioastron space - ground vlbi observations of the pulsar b0950 + 08, conducted with the 10 - m space radio telescope in conjunction with the arecibo 300 - m telescope and westerbork synthesis radio telescope at a frequency of 324 mhz, were analyzed in order to investigate plasma inhomogeneities in the direction of this nearby pulsar. the observations were conducted at a spacecraft distance of 330, 000 km, resulting in a projected baseline of 220, 000 km, providing the greatest angular resolution ever achieved at meter wavelengths. our analysis is based on fundamental behavior of structure and coherence functions. we find that the pulsar shows scintillation on two frequency scales, both much less than the observing frequency ; but modulation is less than 100 %. we infer that the scattering is weak, but a refracting wedge disperses the scintillation pattern. the refraction angle of this " cosmic prism " is measured as theta _ 0 = 1. 1 - 4. 4 mas, with the refraction direction being approximately perpendicular to the observer velocity. we show that the observed parameters of scintillation effects indicate that two plasma layers lie along the line of sight to the pulsar, at distances of 4. 4 - 16. 4 pc and 26 - 170 pc, and traveling in different directions relative to the line of sight. spectra of turbulence for the two layers are found to follow a power law with the indices gamma _ 1 = gamma _ 2 = 3. 00 + / - 0. 08, significantly different from the index expected for a kolmogorov spectrum of turbulence, gamma = 11 / 3. | arxiv:1402.6346 |
in this work, we investigate the problem of finite time blow up as well as the upper bound estimates of lifespan for solutions to small - amplitude semilinear wave equations with time dependent damping and potential, and mixed nonlinearities $ c _ 1 | u _ t | ^ p + c _ 2 | u | ^ q $, posed on asymptotically euclidean manifolds, which is related to both the strauss conjecture and the glassey conjecture. | arxiv:2104.08497 |
to foster the verifiability and testability of deep neural networks ( dnn ), an increasing number of methods for test case generation techniques are being developed. when confronted with testing dnn models, the user can apply any existing test generation technique. however, it needs to do so for each technique and each dnn model under test, which can be expensive. therefore, a paradigm shift could benefit this testing process : rather than regenerating the test set independently for each dnn model under test, we could transfer from existing dnn models. this paper introduces gist ( generated inputs sets transferability ), a novel approach for the efficient transfer of test sets. given a property selected by a user ( e. g., neurons covered, faults ), gist enables the selection of good test sets from the point of view of this property among available test sets. this allows the user to recover similar properties on the transferred test sets as he would have obtained by generating the test set from scratch with a test cases generation technique. experimental results show that gist can select effective test sets for the given property to transfer. moreover, gist scales better than reapplying test case generation techniques from scratch on dnn models under test. | arxiv:2311.00801 |
image classification has significantly improved using deep learning. this is mainly due to convolutional neural networks ( cnns ) that are capable of learning rich feature extractors from large datasets. however, most deep learning classification methods are trained on clean images and are not robust when handling noisy ones, even if a restoration preprocessing step is applied. while novel methods address this problem, they rely on modified feature extractors and thus necessitate retraining. we instead propose a method that can be applied on a $ pretrained $ classifier. our method exploits a fidelity map estimate that is fused into the internal representations of the feature extractor, thereby guiding the attention of the network and making it more robust to noisy data. we improve the noisy - image classification ( nic ) results by significantly large margins, especially at high noise levels, and come close to the fully retrained approaches. furthermore, as proof of concept, we show that when using our oracle fidelity map we even outperform the fully retrained methods, whether trained on noisy or restored images. | arxiv:2106.00673 |
low - rank tensor completion problem aims to recover a tensor from limited observations, which has many real - world applications. due to the easy optimization, the convex overlapping nuclear norm has been popularly used for tensor completion. however, it over - penalizes top singular values and lead to biased estimations. in this paper, we propose to use the nonconvex regularizer, which can less penalize large singular values, instead of the convex one for tensor completion. however, as the new regularizer is nonconvex and overlapped with each other, existing algorithms are either too slow or suffer from the huge memory cost. to address these issues, we develop an efficient and scalable algorithm, which is based on the proximal average ( pa ) algorithm, for real - world problems. compared with the direct usage of pa algorithm, the proposed algorithm runs orders faster and needs orders less space. we further speed up the proposed algorithm with the acceleration technique, and show the convergence to critical points is still guaranteed. experimental comparisons of the proposed approach are made with various other tensor completion approaches. empirical results show that the proposed algorithm is very fast and can produce much better recovery performance. | arxiv:1807.08725 |
sequences of the form $ ( \ gcd ( u _ n, v _ n ) ) _ { n \ in \ mathbb n } $, with $ ( u _ n ) _ n $, $ ( v _ n ) _ n $ sums of $ s $ - units, have been considered by several authors. the study of $ \ gcd ( n, u _ n ) $ corresponds, following silverman, to divisibility sequences arising from the split algebraic group $ \ mathbb g _ { \ mathrm { a } } \ times \ mathbb g _ { \ mathrm { m } } $ ; in this case, sanna determined all asymptotic moments of the arithmetic function $ \ log \, \ gcd ( n, u _ n ) $ when $ ( u _ n ) _ n $ is a lucas sequence. here, we characterize the asymptotic behavior of the moments themselves $ \ sum _ { n \ leq x } \, \ gcd ( n, u _ n ) ^ \ lambda $, thus solving the moment problem for $ \ mathbb g _ { \ mathrm { a } } \ times \ mathbb g _ { \ mathrm { m } } $. we give both unconditional and conditional results, the latter only relying on standard conjectures in analytic number theory. | arxiv:2408.05820 |
we consider a $ 2d $ magnetic schr \ " odinger operator perturbed by a weak magnetic field which slowly varies around a positive mean. in a previous paper we proved the appearance of a ` landau type ' structure of spectral islands at the bottom of the spectrum, under the hypothesis that the lowest bloch eigenvalue of the unperturbed operator remained simple on the whole brillouin zone, even though its range may overlap with the range of the second eigenvalue. we also assumed that the first bloch spectral projection was smooth and had a zero chern number. in this paper we extend our previous results to the only two remaining possibilities : either the first bloch eigenvalue remains isolated while its corresponding spectral projection has a non - zero chern number, or the first two bloch eigenvalues cross each other. | arxiv:1711.00329 |
in industrial settings, surface defects on steel can significantly compromise its service life and elevate potential safety risks. traditional defect detection methods predominantly rely on manual inspection, which suffers from low efficiency and high costs. although automated defect detection approaches based on convolutional neural networks ( e. g., mask r - cnn ) have advanced rapidly, their reliability remains challenged due to data annotation uncertainties during deep model training and overfitting issues. these limitations may lead to detection deviations when processing the given new test samples, rendering automated detection processes unreliable. to address this challenge, we first evaluate the detection model ' s practical performance through calibration data that satisfies the independent and identically distributed ( i. i. d ) condition with test data. specifically, we define a loss function for each calibration sample to quantify detection error rates, such as the complement of recall rate and false discovery rate. subsequently, we derive a statistically rigorous threshold based on a user - defined risk level to identify high - probability defective pixels in test images, thereby constructing prediction sets ( e. g., defect regions ). this methodology ensures that the expected error rate ( mean error rate ) on the test set remains strictly bounced by the predefined risk level. additionally, we observe a negative correlation between the average prediction set size and the risk level on the test set, establishing a statistically rigorous metric for assessing detection model uncertainty. furthermore, our study demonstrates robust and efficient control over the expected test set error rate across varying calibration - to - test partitioning ratios, validating the method ' s adaptability and operational effectiveness. | arxiv:2504.17721 |
we present a new matlab toolbox for generating phase and amplitude patterns for digital micro - mirror device ( dmd ) and liquid crystal ( lc ) based spatial light modulators ( slms ). this toolbox consists of a collection of algorithms commonly used for generating patterns for these devices with a focus on optical tweezers beam shaping applications. in addition to the algorithms provided, we have put together a range of user interfaces for simplifying the use of these patterns. the toolbox currently has functionality to generate patterns which can be saved as a image or displayed on a device / screen using the supplied interface. we have only implemented interfaces for the devices our group currently uses but we believe that extending the code we provide to other devices should be fairly straightforward. the range of algorithms included in the toolbox is not exhaustive. however, by making the toolbox open sources and available on github we hope that other researchers working with these devices will contribute their patterns / algorithms to the toolbox. | arxiv:2002.10564 |
we argue that the mass of the inflaton can be much smaller than the hubble constant in supergravity models in which inflation is driven by d - - terms and not f - - terms. we investigate a supergravity toy model which leads to hybrid inflation due to an anomalous d - - term. we show that the slow - - roll condition can be satisfied and the correct magnitude for density perturbations can be obtained for some choice of model parameters. the kind of model considered can naturally arise in some string derived supergravity models. | arxiv:hep-ph/9606423 |
in this paper, we exploit the maximum correntropy criterion ( mcc ) to robustify the traditional time - difference - of - arrival ( tdoa ) location estimator in the presence of non - line - of - sight ( nlos ) propagation conditions. for the sake of statistical efficiency, the correntropy - based robust loss is imposed on the underlying time - of - arrival composition via joint estimation of the source position and onset time, instead of the tdoa counterpart generated in the postprocessing of sensor - collected timestamps. we then employ a neurodynamic optimization approach to tackle the highly nonconvex mcc formulation. furthermore, we examine the local stability of equilibrium for the corresponding projection - type neural network model. simulation investigations in representative nlos propagation scenarios demonstrate that our neurodynamic robust tdoa localization solution is capable of outperforming several existing schemes in terms of positioning accuracy. | arxiv:2009.06281 |
inventory models with lost sales and large lead times have traditionally been considered intractable due to the curse of dimensionality. recently, goldberg and co - authors laid the foundations for a new approach to solving these models, by proving that as the lead time grows large, a simple constant - order policy is asymptotically optimal. however, the bounds proven there require the lead time to be very large before the constant - order policy becomes effective, in contrast to the good numerical performance demonstrated by zipkin even for small lead time values. in this work, we prove that for the infinite - horizon variant of the same lost sales problem, the optimality gap of the same constant - order policy actually converges \ emph { exponentially fast } to zero, with the optimality gap decaying to zero at least as fast as the exponential rate of convergence of the expected waiting time in a related single - server queue to its steady - state value. we also derive simple and explicit bounds for the optimality gap, and demonstrate good numerical performance across a wide range of parameter values for the special case of exponentially distributed demand. our main proof technique combines convexity arguments with ideas from queueing theory. | arxiv:1409.1499 |
a fundamental mystery in earthquake physics is ` ` how can an earthquake be triggered by distant seismic sources? ' ' here, we use discrete element method simulations of a granular layer, during stick - slip, that is subject to transient vibrational excitation to gain further insight into the physics of dynamic earthquake triggering. using coulomb friction law for grains interaction, we observe delayed triggering of slip in the granular gouge. we find that at a critical vibrational amplitude ( strain ) there is an abrupt transition from negligible time - advanced slip ( clock advance ) to full clock advance, { \ it i. e. }, transient vibration and triggered slip are simultaneous. the critical strain is order of $ 10 ^ { - 6 } $, similar to observations in the laboratory and in earth. the transition is related to frictional weakening of the granular layer due to a dramatic decrease in coordination number and the weakening of the contact force network. associated with this frictional weakening is a pronounced decrease in the elastic modulus of the layer. the study has important implications for mechanisms of triggered earthquakes and induced seismic events and points out the underlying processes in response of the fault gouge to dynamic transient stresses. | arxiv:1507.04710 |
simple stochastic games can be solved by value iteration ( vi ), which yields a sequence of under - approximations of the value of the game. this sequence is guaranteed to converge to the value only in the limit. since no stopping criterion is known, this technique does not provide any guarantees on its results. we provide the first stopping criterion for vi on simple stochastic games. it is achieved by additionally computing a convergent sequence of over - approximations of the value, relying on an analysis of the game graph. consequently, vi becomes an anytime algorithm returning the approximation of the value and the current error bound. as another consequence, we can provide a simulation - based asynchronous vi algorithm, which yields the same guarantees, but without necessarily exploring the whole game graph. | arxiv:1804.04901 |
we consider ( a variant of ) the external multi - particle diffusion - limited aggregation ( mdla ) process of rosenstock and marquardt on the plane. based on the recent findings of [ 11 ], [ 10 ] in one space dimension it is natural to conjecture that the scaling limit of the growing aggregate in such a model is given by the growing solid phase in a suitable " probabilistic " formulation of the single - phase supercooled stefan problem for the heat equation. to address this conjecture, we extend the probabilistic formulation from [ 10 ] to multiple space dimensions. we then show that the equation that characterizes the growth rate of the solid phase in the supercooled stefan problem is satisfied by the scaling limit of the external mdla process with an inequality, which can be strict in general. in the course of the proof, we establish two additional results interesting in their own right : ( i ) the stability of a " crossing property " of planar brownian motion and ( ii ) a rigorous connection between the probabilistic solutions to the supercooled stefan problem and its classical and weak solutions. | arxiv:2102.09040 |
brain activity is characterized by brain - wide spatiotemporal patterns which emerge from synapse - mediated interactions between individual neurons. calcium imaging provides access to in vivo recordings of whole - brain activity at single - neuron resolution and, therefore, allows the study of how large - scale brain dynamics emerge from local activity. in this study, we used a statistical mechanics approach - the pairwise maximum entropy model ( mem ) - to infer microscopic network features from collective patterns of activity in the larval zebrafish brain, and relate these features to the emergence of observed whole - brain dynamics. our findings indicate that the pairwise interactions between neural populations and their intrinsic activity states are sufficient to explain observed whole - brain dynamics. in fact, the pairwise relationships between neuronal populations estimated with the mem strongly correspond to observed structural connectivity patterns. model simulations also demonstrated how tuning pairwise neuronal interactions drives transitions between critical and pathologically hyper - excitable whole - brain regimes. finally, we use virtual resection to identify the brain structures that are important for maintaining the brain in a critical regime. together, our results indicate that whole - brain activity emerges out of a complex dynamical system that transitions between basins of attraction whose strength and topology depend on the connectivity between brain areas. | arxiv:2309.05939 |
we calculate the decay amplitude of a harmonically trapped bose - einstein condensate with attractive interaction via the feynman path integral. we find that when the number of particles is less than a critical number, the condensate decays relatively slowly through quantum tunneling. when the number exceeds the critical one, a " black hole " opens up at the center of the trap, in which density fluctuations become large due to a negative pressure, and collisional loss will drain the particles from the trap. as the black hole is fed by tunneling particles, we have a novel system in which quantum tunneling serves as a hydrodynamic source. | arxiv:cond-mat/9807359 |
the n - dimensional quantum torus is defined as the $ f $ - algebra generated by variables $ x _ 1, \ cdots, x _ n $ together with their inverses satisfying the relations $ x _ ix _ j = q _ { ij } x _ jx _ i $, where $ q _ { ij } \ in f $. the krull and global dimensions of this algebra are known to coincide and the common value is equal to the supremum of the rank of certain subgroups of $ \ langle x _ 1, \ cdots, x _ n \ rangle $ that can be associated with this algebra. in this paper we study how these dimensions behave with respect to taking tensor products of quantum tori % over the base field. we derive a best possible upper bound for the dimension of such a tensor product and % deduce from this special cases in which the dimension is additive with respect to tensoring. | arxiv:1409.6434 |
context. new estimates of the masses and radii of the seven planets orbiting the ultracool m - dwarf trappist - 1 star permit improved modelling of their compositions, heating by tidal dissipation, and removal of tidal heat by solid - state convection. aims. here, we compute the heat flux due to insolation and tidal heating for the inner four planets. methods. we apply a maxwell viscoelastic rheology to compute the tidal response of the planets using the volume - weighted average of the viscosities and rigidities of the metal, rock, high - pressure ice and liquid water / ice i layers. results. we show that trappist - 1d and e can avoid entering a runaway greenhouse state. planet e is the most likely to support a habitable environment, with earth - like surface temperatures and possibly liquid water oceans. planet d also avoids a runaway greenhouse, if its surface reflectance is at least as high as that of the earth. planets b and c, closer to the star, have heat fluxes high enough to trigger a runaway greenhouse and support volcanism on the surfaces of their rock layers, rendering them too warm for life. planets f, g, and h are too far from the star to experience significant tidal heating, and likely have solid ice surfaces with possible subsurface liquid water oceans. | arxiv:1902.03867 |
this study aims to explore the automatic classification method of pneumonia x - ray images based on vgg19 deep convolutional neural network, and evaluate its application effect in pneumonia diagnosis by comparing with classic models such as svm, xgboost, mlp, and resnet50. the experimental results show that vgg19 performs well in multiple indicators such as accuracy ( 92 % ), auc ( 0. 95 ), f1 score ( 0. 90 ) and recall rate ( 0. 87 ), which is better than other comparison models, especially in image feature extraction and classification accuracy. although resnet50 performs well in some indicators, it is slightly inferior to vgg19 in recall rate and f1 score. traditional machine learning models svm and xgboost are obviously limited in image classification tasks, especially in complex medical image analysis tasks, and their performance is relatively mediocre. the research results show that deep learning, especially convolutional neural networks, have significant advantages in medical image classification tasks, especially in pneumonia x - ray image analysis, and can provide efficient and accurate automatic diagnosis support. this research provides strong technical support for the early detection of pneumonia and the development of automated diagnosis systems and also lays the foundation for further promoting the application and development of automated medical image processing technology. | arxiv:2412.20345 |
we consider the task of grasping a target object based on a natural language command query. previous work primarily focused on localizing the object given the query, which requires a separate grasp detection module to grasp it. the cascaded application of two pipelines incurs errors in overlapping multi - object cases due to ambiguity in the individual outputs. this work proposes a model named command grasping network ( cgnet ) to directly output command satisficing grasps from rgb image and textual command inputs. a dataset with ground truth ( image, command, grasps ) tuple is generated based on the vmrd dataset to train the proposed network. experimental results on the generated test set show that cgnet outperforms a cascaded object - retrieval and grasp detection baseline by a large margin. three physical experiments demonstrate the functionality and performance of cgnet. | arxiv:2104.00492 |
this paper describes a learning environment for image - guided prostate biopsies in cancer diagnosis ; it is based on an ultrasound probe simulator virtually exploring real datasets obtained from patients. the aim is to make the training of young physicians easier and faster with a tool that combines lectures, biopsy simulations and recommended exercises to master this medical gesture. it will particularly help acquiring the three - dimensional representation of the prostate needed for practicing biopsy sequences. the simulator uses a haptic feedback to compute the position of the virtual probe from three - dimensional ( 3d ) ultrasound recorded data. this paper presents the current version of this learning environment. | arxiv:1011.2107 |
we present and prove properties of a new offline policy evaluator for an exploration learning setting which is superior to previous evaluators. in particular, it simultaneously and correctly incorporates techniques from importance weighting, doubly robust evaluation, and nonstationary policy evaluation approaches. in addition, our approach allows generating longer histories by careful control of a bias - variance tradeoff, and further decreases variance by incorporating information about randomness of the target policy. empirical evidence from synthetic and realworld exploration learning problems shows the new evaluator successfully unifies previous approaches and uses information an order of magnitude more efficiently. | arxiv:1210.4862 |
motivation : the study of diverse enzyme superfamilies can provide important insight into the relationships between protein sequence, structure and function. it is often challenging, however, to discover these relationships across a large and diverse superfamily. contemporary similarity network visualization techniques allow researchers to aggregate sequence similarity information into a single global view. network visualization provides a qualitative estimate of functional diversity within a superfamily, but is unable to quantitate explicit boundaries, when present, between neighboring families in sequence space. this limits the potential of existing sequence - based algorithms to generate functional predictions from superfamily datasets. results : by building on current network analysis tools, we have developed a new algorithm for elucidating pairs of homologous families within a sequence dataset. our algorithm is able to filter through a dense similarity network in order to estimate both the boundaries of individual families and also how the families neighbor one another. globally, these neighboring families define a topology across the entire superfamily. the topology is simple to interpret by visualizing the network output generated by our filtration protocol. we have compared the network topology within the kinase superfamily against available phylogenetic data. our results suggest that neighbors within the filtered kinase network are more likely to share structural and functional properties than more distant network clusters. | arxiv:1408.2575 |
we investigate the separability properties of quantum two - party gaussian states in the framework of the operator formalism for the density operator. such states arise as natural generalizations of the entangled state originally introduced by einstein, podolsky, and rosen. we present explicit forms of separable and nonseparable gaussian states. | arxiv:quant-ph/0107131 |
we prove that the short - pulse equation, which is derived from maxwell equations with formal asymptotic methods, can be rigorously justified. the justification procedure applies to small - norm solutions of the short - pulse equation. although the small - norm solutions exist for infinite times and include modulated pulses and their elastic interactions, the error bound for arbitrary initial data can only be controlled over finite time intervals. | arxiv:1108.5970 |
stimulated raman adiabatic passage ( stirap ) is a standard technique to combat experimental imperfections and can be used to realize robust quantum state control, which has many applications in physics, chemistry, and beyond. however, stirap is susceptible to decoherence since it requires long evolution time. to overcome this problem, stimulated raman user - defined passage ( stirup ) is proposed, which allows users to design the passages unlike the stirap but fast and robust against both decoherence and experimental imperfections. here, we further develop a more general stirup method. comparing with shortcut to adiabaticity and its ' variants, the generalized stirup is more simpler and compatible with more complex energy - level structure and manybody systems. furthermore, the generalized stirup has many important applications such as geometric phase measurement, coherent population transfer, and quantum state preparation. specifically, as examples, we show how to realize the high - fidelity quantum state transfer and entangled state generation in a robust way via stirup with the state - of - the - art experimental superconducting circuits. | arxiv:2008.06868 |
the problem of grasping objects using a multi - finger hand has received significant attention in recent years. however, it remains challenging to handle a large number of unfamiliar objects in real and cluttered environments. in this work, we propose a representation that can be effectively mapped to the multi - finger grasp space. based on this representation, we develop a simple decision model that generates accurate grasp quality scores for different multi - finger grasp poses using only hundreds to thousands of training samples. we demonstrate that our representation performs well on a real robot and achieves a success rate of 78. 64 % after training with only 500 real - world grasp attempts and 87 % with 4500 grasp attempts. additionally, we achieve a success rate of 84. 51 % in a dynamic human - robot handover scenario using a multi - finger hand. | arxiv:2408.02455 |
a recently fertile strand of research in group theory is developing non - abelian analogues of classical combinatorial results for arithmetic cayley graphs, describing properties such as growth, expansion, mixing, diameter, etc. we consider these problems for the symmetric and alternating groups. the case of normal cayley graphs ( those generated by unions of conjugacy classes ) has seen significant progress via character theory ( whereby larsen and shalev resolved several open problems ), but the general case still remains poorly understood. in this paper we generalise the background assumption from being normal to being global ( a pseudorandomness condition ), replacing character bounds by spectral estimates for convolution operators of global functions, thus obtaining qualitative generalisations of several results on normal cayley graphs. furthermore, our theory in the pseudorandom setting can be applied ( via density increment arguments ) to several results for general sets that are not too sparse, including analogues of polynomial freiman - ruzsa, bogolyubov ' s lemma, roth ' s theorem, the waring problem and essentially sharp estimates for the diameter problem of cayley graphs whose density is at least exponential in - n. our main tool is a sharp new hypercontractive inequality for global functions on the symmetric group. | arxiv:2307.15030 |
social media are extensively used in today ' s world, and facilitate quick and easy sharing of information, which makes them a good way to advertise products. influencers of a social media network, owing to their massive popularity, provide a huge potential customer base. however, it is not straightforward to decide which influencers should be selected for an advertizing campaign that can generate high returns with low investment. in this work, we present an agent - based model ( abm ) that can simulate the dynamics of influencer advertizing campaigns in a variety of scenarios and can help to discover the best influencer marketing strategy. our system is a probabilistic graph - based model that provides the additional advantage to incorporate real - world factors such as customers ' interest in a product, customer behavior, the willingness to pay, a brand ' s investment cap, influencers ' engagement with influence diffusion, and the nature of the product being advertized viz. luxury and non - luxury. using customer acquisition cost and conversion ratio as a unit economic, we evaluate the performance of different kinds of influencers under a variety of circumstances that are simulated by varying the nature of the product and the customers ' interest. our results exemplify the circumstance - dependent nature of influencer marketing and provide insight into which kinds of influencers would be a better strategy under respective circumstances. for instance, we show that as the nature of the product varies from luxury to non - luxury, the performance of celebrities declines whereas the performance of nano - influencers improves. in terms of the customers ' interest, we find that the performance of nano - influencers declines with the decrease in customers ' interest whereas the performance of celebrities improves. | arxiv:2106.01750 |
recently, many approaches tackle the unsupervised domain adaptive person re - identification ( uda re - id ) problem through pseudo - label - based contrastive learning. during training, a uni - centroid representation is obtained by simply averaging all the instance features from a cluster with the same pseudo label. however, a cluster may contain images with different identities ( label noises ) due to the imperfect clustering results, which makes the uni - centroid representation inappropriate. in this paper, we present a novel multi - centroid memory ( mcm ) to adaptively capture different identity information within the cluster. mcm can effectively alleviate the issue of label noises by selecting proper positive / negative centroids for the query image. moreover, we further propose two strategies to improve the contrastive learning process. first, we present a domain - specific contrastive learning ( dscl ) mechanism to fully explore intradomain information by comparing samples only from the same domain. second, we propose second - order nearest interpolation ( soni ) to obtain abundant and informative negative samples. we integrate mcm, dscl, and soni into a unified framework named multi - centroid representation network ( mcrn ). extensive experiments demonstrate the superiority of mcrn over state - of - the - art approaches on multiple uda re - id tasks and fully unsupervised re - id tasks. | arxiv:2112.11689 |
we study the stability of anyonic models on lattices to perturbations. we establish a cluster expansion for the energy of the perturbed models and use it to study the stability of the models to local perturbations. we show that the spectral gap is stable when the model is defined on a sphere, so that there is no ground state degeneracy. we then consider the toric code hamiltonian on a torus with a class of abelian perturbations and show that it is stable when the torus directions are taken to infinity simultaneously, and is unstable when the thin torus limit is taken. | arxiv:0912.0945 |
in order to adapt to the differentiable setting a formula for linear response proved by pollicott and vytnova in the analytic setting, we show a result of regularity of dynamical determinants of expanding maps of the circle. the main tool is the decomposition of a transfer operator as a sum of a nuclear part and a " small " bounded part. | arxiv:1708.01055 |
layer ( ssl ). ssl requires a server with a certificate. when a client requests access to an ssl - secured server, the server sends a copy of the certificate to the client. the ssl client checks this certificate ( all web browsers come with an exhaustive list of root certificates preloaded ), and if the certificate checks out, the server is authenticated and the client negotiates a symmetric - key cipher for use in the session. the session is now in a very secure encrypted tunnel between the ssl server and the ssl client. = = views of networks = = users and network administrators typically have different views of their networks. users can share printers and some servers from a workgroup, which usually means they are in the same geographic location and are on the same lan, whereas a network administrator is responsible for keeping that network up and running. a community of interest has less of a connection of being in a local area and should be thought of as a set of arbitrarily located users who share a set of servers, and possibly also communicate via peer - to - peer technologies. network administrators can see networks from both physical and logical perspectives. the physical perspective involves geographic locations, physical cabling, and the network elements ( e. g., routers, bridges and application - layer gateways ) that interconnect via the transmission media. logical networks, called, in the tcp / ip architecture, subnets, map onto one or more transmission media. for example, a common practice in a campus of buildings is to make a set of lan cables in each building appear to be a common subnet, using vlans. users and administrators are aware, to varying extents, of a network ' s trust and scope characteristics. again using tcp / ip architectural terminology, an intranet is a community of interest under private administration usually by an enterprise, and is only accessible by authorized users ( e. g. employees ). intranets do not have to be connected to the internet, but generally have a limited connection. an extranet is an extension of an intranet that allows secure communications to users outside of the intranet ( e. g. business partners, customers ). unofficially, the internet is the set of users, enterprises, and content providers that are interconnected by internet service providers ( isp ). from an engineering viewpoint, the internet is the set of subnets, and aggregates of subnets, that share the registered ip address space and exchange information | https://en.wikipedia.org/wiki/Computer_network |
this article is an overview of the results obtained in recent years on symplectic connections. we present what is known about preferred connections ( critical points of a variational principle ). the class of ricci - type connections ( for which the curvature is entirely determined by the ricci tensor ) is described in detail, as well as its far reaching generalization to special connections. a twistorial construction shows a relation between ricci - type connections and complex geometry. we give a construction of ricci - flat symplectic connections. we end up by presenting, through an explicit example, an approach to noncommutative symplectic symmetric spaces. | arxiv:math/0511194 |
we study the possibility that minor mergers resolve the loss cone depletion problem, which is the difficulty occured in the coalescence process of the supermassive black hole ( smbh ) binary, by performing numerical simulations with a highly accurate $ n $ - body code. we show that the minor merger of a dwarf galaxy disturbs stellar orbits in the galactic central region of the host galaxy where the loss cone depletion is already caused by the smbh binary. the disturbed stars are supplied into the loss cone. stars of the dwarf galaxy are also supplied into the loss cone. the gravitational interactions between the smbh binary and these stars become very effective. the gravitational interaction decreases the binding energy of the smbh binary effectively. as a result, the shrink of the separation of the smbh binary is accelerated. our numerical results strongly suggest that the minor mergers are one of the important processes to reduce the coalescence time of the smbh binary much less than the hubble time. | arxiv:0812.4473 |
the use of high order fully implicit runge - kutta methods is of significant importance in the context of the numerical solution of transient partial differential equations, in particular when solving large scale problems due to fine space resolution with many millions of spatial degrees of freedom and long time intervals. in this study we consider strongly a - stable implicit runge - kutta methods of arbitrary order of accuracy, based on radau quadratures, for which efficient preconditioners have been introduced. a refined spectral analysis of the corresponding matrices and matrix - sequences is presented, both in terms of localization and asymptotic global distribution of the eigenvalues. specific expressions of the eigenvectors are also obtained. the given study fully agrees with the numerically observed spectral behavior and substantially improves the theoretical studies done in this direction so far. concluding remarks and open problems end the current work, with specific attention to the potential generalizations of the hereby suggested general approach. | arxiv:2302.04657 |
we give a crystal structure on the set of gelfand - tsetlin patterns which parametrize bases for finite - dimensional irreducible representations of the general linear lie algebra. the crystal data are given in closed form, expressed using tropical polynomial functions of the entries of the patterns. we prove that with this crystal structure, the natural bijection between gelfand - tsetlin patterns and semistandard young tableaux is a crystal isomorphism. | arxiv:2005.06639 |
motivated by a recent experiment by yacoby et al. \ [ preprint, 1994 ], we calculate magnitude and phase $ \ alpha $ of the transmission amplitude through a quantum dot. we work in the coulomb blockade regime, assume the electrons not to interact, and consider tunneling through isolated resonances. assuming a non - - resonant background, we find that $ \ alpha $ increases by $ 2 \ pi $ over each resonance, with a sharp rise by $ \ pi $ over an energy interval much smaller than the thermal width. this is consistent with the experimental data. our assumptions can be tested by further experiments. | arxiv:cond-mat/9502033 |
use of representations ( aka ' codes ' ) common in second - order arithmetic, is greatly reduced. for example, a continuous function on the cantor space is just a function that maps binary sequences to binary sequences, and that also satisfies the usual ' epsilon - delta ' - definition of continuity. higher - order reverse mathematics includes higher - order versions of ( second - order ) comprehension schemes. such a higher - order axiom states the existence of a functional that decides the truth or falsity of formulas of a given complexity. in this context, the complexity of formulas is also measured using the arithmetical hierarchy and analytical hierarchy. the higher - order counterparts of the major subsystems of second - order arithmetic generally prove the same second - order sentences ( or a large subset ) as the original second - order systems. for instance, the base theory of higher - order reverse mathematics, called rcaΟ0, proves the same sentences as rca0, up to language. as noted in the previous paragraph, second - order comprehension axioms easily generalize to the higher - order framework. however, theorems expressing the compactness of basic spaces behave quite differently in second - and higher - order arithmetic : on one hand, when restricted to countable covers / the language of second - order arithmetic, the compactness of the unit interval is provable in wkl0 from the next section. on the other hand, given uncountable covers / the language of higher - order arithmetic, the compactness of the unit interval is only provable from ( full ) second - order arithmetic. other covering lemmas ( e. g. due to lindelof, vitali, besicovitch, etc. ) exhibit the same behavior, and many basic properties of the gauge integral are equivalent to the compactness of the underlying space. = = the big five subsystems of second - order arithmetic = = second - order arithmetic is a formal theory of the natural numbers and sets of natural numbers. many mathematical objects, such as countable rings, groups, and fields, as well as points in effective polish spaces, can be represented as sets of natural numbers, and modulo this representation can be studied in second - order arithmetic. reverse mathematics makes use of several subsystems of second - order arithmetic. a typical reverse mathematics theorem shows that a particular mathematical theorem t is equivalent to a particular subsystem s of second - order arithmetic over a weaker subsystem b. this weaker system b is known as the base system for the result | https://en.wikipedia.org/wiki/Reverse_mathematics |
the success of any business depends on how well it is able to satisfy customer demand, while remaining financially viable. globalisation and the growth of e - commerce have resulted in retail businesses having to manage increasing numbers of products. as the number of products sold increases, so does the complexity of the corresponding inventory management problem. high - quality decision making, in this regard, necessitates the utilisation of computerised decision support systems capable of accommodating the complexity presented by a large number of products. existing frameworks for decision support in inventory management are mainly focused on a single facet of the inventory management problem - generic, integrated frameworks seem to be absent from the literature. in this paper, a holistic framework design is proposed which integrates all of the major components expected to form part of a generic framework for inventory management. the objective of the framework is to provide decision support in respect of various inventory management operations, such as product segmentation, demand forecasting and determining the sizes and timings of replenishment orders, in pursuit of a desirable balance between the conflicting objectives in inventory management. | arxiv:2207.13923 |
innovative contributions to statistics and biometry education in india. haldane was also the first to construct human gene maps for haemophilia and colour blindness on the x chromosome and he was one of the first people to conceive abiogenesis. alan hale ( 1958 β ) : american professional astronomer, who co - discovered comet hale β bopp, and specializes in the study of sun - like stars and the search for extra - solar planetary systems, and has side interests in the fields of comets and near - earth asteroids. sir james hall ( 1761 β 1832 ) : scottish geologist and chemist, president of the royal society of edinburgh and leading figure in the scottish enlightenment. g. stanley hall ( 1846 β 1924 ) : pioneering american psychologist and educator. his interests focused on childhood development and evolutionary theory. hall was the first president of the american psychological association and the first president of clark university. beverly halstead ( 1933 β 1991 ) : british paleontologist and populariser of science. gerhard armauer hansen ( 1841 β 1912 ) : norwegian physician, remembered for his identification of the bacterium mycobacterium leprae in 1873 as the causative agent of leprosy. g. h. hardy ( 1877 β 1947 ) : prominent english mathematician, known for his achievements in number theory and mathematical analysis. herbert a. hauptman ( 1917 β 2011 ) : american mathematician. along with jerome karle, won the nobel prize in chemistry in 1985. stephen hawking ( 1942 β 2018 ) : british theoretical physicist, cosmologist, author, and director of research at the centre for theoretical cosmology within the university of cambridge. ewald hering ( 1834 β 1918 ) : german physiologist who did much research into color vision, binocular perception and eye movements. he proposed opponent color theory in 1892. peter higgs ( 1929 β 2024 ) : british theoretical physicist, recipient of the dirac medal and prize, known for his prediction of the existence of a new particle, the higgs boson, nicknamed the " god particle ". he won the nobel prize in physics in 2013. roald hoffmann ( 1937 β ) : american theoretical chemist who won the 1981 nobel prize in chemistry. lancelot hogben ( 1895 β 1975 ) : english experimental zoologist and medical statistician, now best known for his popularising books on science, mathematics and language. brigid hogan frs ( 1943 β ) : british developmental biologist noted for her contributions to stem cell research and transgenic technology and techniques | https://en.wikipedia.org/wiki/List_of_atheists_in_science_and_technology |
we report measurements of the cmb polarization power spectra from the january 2003 antarctic flight of boomerang. the primary results come from six days of observation of a patch covering 0. 22 % of the sky centered near r. a. = 82. 5 deg., dec = - 45 deg. the observations were made using four pairs of polarization sensitive bolometers operating in bands centered at 145 ghz. using two independent analysis pipelines, we measure a non - zero < ee > signal in the range 100 < l < 1000 with a significance 4. 8 - sigma, a 2 - sigma upper limit of 8. 6 uk ^ 2 for any < bb > contribution, and a 2 - sigma upper limit of 7. 0 uk ^ 2 for the < eb > spectrum. estimates of foreground intensity fluctuations and the non - detection of < bb > and < eb > signals rule out any significant contribution from galactic foregrounds. the results are consistent with a lambda - cdm cosmology seeded by adiabatic perturbations. we note that this is the first detection of cmb polarization with bolometric detectors. | arxiv:astro-ph/0507514 |
we review some aspects of quantum gravity in the context of cosmology. in particular, we focus on models with a phenomenology accessible to current and near - future observations, as the early universe might be our only chance to peep through the quantum gravity realm. | arxiv:1201.4543 |
in this short note we introduce higher graph manifolds and use a version of the barycenter technique to characterize when they undergo volume collapse. in the case when the pure pieces are hyperbolic, we compute the exact value of the minimal volume. we verify the coarse baum - - connes conjecture for these manifolds and show that they do not admit positive scalar curvature metrics. in the case without any pure pieces, we show the yamabe invariant vanishes. | arxiv:1208.4876 |
an integer $ n \ ge 1 $ is said to be practical if every natural number $ m \ le n $ can be expressed as a sum of distinct positive divisors of $ n $. the number of practical numbers up to $ x $ is asymptotic to $ c x / \ log x $, where $ c $ is a constant. in this note we show that $ c = 1. 33607... $. | arxiv:1906.07819 |
we examine the simple model put forth in a recent note by loeb regarding the brightness of space debris in the size range of 1 - 10 cm and their impact on the rubin observatory legacy survey of space and time ( lsst ) transient object searches. their main conclusion was that " image contamination by untracked space debris might pose a bigger challenge [ than large commercial satellite constellations in leo ] ". following corrections and improvements to this model, we calculate the apparent brightness of tumbling low - earth orbit ( leo ) debris of various sizes, and we briefly discuss the likely impact and potential mitigations of glints from space debris in lsst. we find the majority of the difference in predicted signal - to - noise ratio ( s / n ), about a factor of 6, arises from the defocus of leo objects due to the large simonyi survey telescope primary mirror and finite range of the debris. the largest change from the loeb estimates is that 1 - 10 cm debris in leo pose no threat to lsst transient object alert generation because their s / n for detection will be much lower than estimated by loeb due to defocus. we find that only tumbling leo debris larger than 10 cm or with significantly greater reflectivity, which give 1 ms glints, might be detected with high confidence ( s / n > 5 ). we estimate that only one in five lsst exposures low on the sky during twilight might be affected. more slowly tumbling objects of larger size can give flares in brightness that are easily detected ; however, these will not be cataloged by the lsst science pipelines because of the resulting long streak. | arxiv:2403.04942 |
increasing the speed of battery formation can significantly lower lithium - ion battery manufacturing costs. however, adopting faster formation protocols in practical manufacturing settings is challenging due to a lack of inexpensive, rapid diagnostic signals that can inform possible impacts to long - term battery lifetime. this work identifies the cell resistance measured at low states of charge as an early - life diagnostic feature for screening new formation protocols. we show that this signal correlates to cycle life and improves the accuracy of data - driven battery lifetime prediction models. the signal is obtainable at the end of the manufacturing line, takes seconds to acquire, and does not require specialized test equipment. we explore a physical connection between this resistance signal and the quantity of lithium consumed during formation, suggesting that the signal may be broadly applicable for evaluating any manufacturing process change that could impact the total lithium consumed during formation. | arxiv:2203.14158 |
based on a simple site - independent approach, we attempt to reproduce the solar $ r $ - process abundance with four nuclear mass models, and investigate the impact of the nuclear mass uncertainties on the $ r $ process. in this paper, we first analyze the reliability of an adopted empirical formula for $ \ beta $ - decay half - lives which is a key ingredient for the $ r $ process. then we apply four different mass tables to study the $ r $ - process nucleosynthesis together with the calculated $ \ beta $ - decay half - lives, and the existing $ \ beta $ - decay data from frdm + qrpa is also considered for comparison. the numerical results show that the main features of the solar $ r $ - process pattern and the locations of the abundance peaks can be reproduced well via the $ r $ - process simulations. moreover, we also find that the mass uncertainties can significantly affect the derived astrophysical conditions for the $ r $ - process site, and resulting in a remarkable impact on the $ r $ process. | arxiv:1902.00642 |
ubiquitous sensing devices frequently disseminate their data between them. the use of a distributed event - based system that decouples publishers of subscribers arises as an ideal candidate to implement the dissemination process. in this paper, we present a network architecture which merges the network and overlay layers of typical structured event - based systems. directional random walks ( drws ) are used for the construction of this merged layer. our first results show that drws are suitable to balance the load using a few nodes in the network to construct the dissemination path. as future work, we propose to study the properties of this new layer and to work on the design of bloom filters to manage broker nodes. | arxiv:1408.3033 |
we present a numerical method for the reconstruction and optimization of complex field synthesis using coherent pulse combination systems. a genetic algorithm utilizing a fourier optics based propagation method is developed for accurate convergence and modeling of near and far field distributions, achieving better than $ \ pi / 10 $ phase accuracy in reconstructed input parameters. | arxiv:2005.13671 |
this paper proposes an online tree - based bayesian approach for reinforcement learning. for inference, we employ a generalised context tree model. this defines a distribution on multivariate gaussian piecewise - linear models, which can be updated in closed form. the tree structure itself is constructed using the cover tree method, which remains efficient in high dimensional spaces. we combine the model with thompson sampling and approximate dynamic programming to obtain effective exploration policies in unknown environments. the flexibility and computational simplicity of the model render it suitable for many reinforcement learning problems in continuous state spaces. we demonstrate this in an experimental comparison with least squares policy iteration. | arxiv:1305.1809 |
we study the center symmetry of su ( n ) gauge theories with fermions in the two - index representations, by computing the effective potential of the polyakov loop in the large - mass expansion on the lattice. in the large - n limit and at non - zero temperature, we find that the center symmetry is z _ n for fermions in the adjoint representation and just z _ 2 for fermions in the ( anti ) symmetric representation. we discuss the fact that our results do not contradict the orientifold planar equivalence, which relates a common sector defined by the bosonic gauge - invariant c - even states of theories with fermions in different two - index representations. our results complement the work of armoni et al. ( 2007 ), who showed how at zero temperature a z _ n center symmetry is dynamically recovered also for fermions in the ( anti ) symmetric representation, by considering the theories at finite temperature. | arxiv:0812.3617 |
in this work a large language model ( llm ) based workflow is presented that utilizes openai chatgpt model gpt - 3. 5 - turbo - 1106 and google gemini pro model to create summary of text, data and images from research articles. it is demonstrated that by using a series of processing, the key information can be arranged in tabular form and knowledge graphs to capture underlying concepts. our method offers efficiency and comprehension, enabling researchers to extract insights more effectively. evaluation based on a diverse scientific paper collection demonstrates our approach in facilitating discovery of knowledge. this work contributes to accelerated material design by smart literature review. the method has been tested based on various qualitative and quantitative measures of gathered information. the chatgpt model achieved an f1 score of 0. 40 for an exact match ( rouge - 1, rouge - 2 ) but an impressive 0. 479 for a relaxed match ( rouge - l, rouge - lsum ) structural data format in performance evaluation. the google gemini pro outperforms chatgpt with an f1 score of 0. 50 for an exact match and 0. 63 for a relaxed match. this method facilitates high - throughput development of a database relevant to materials informatics. for demonstration, an example of data extraction and knowledge graph formation based on a manuscript about a titanium alloy is discussed. | arxiv:2402.11323 |
the need for the extra dimension in kustaanheimo - stiefel ( ks ) regularization is explained by the topology of the hopf fibration, which defines the geometry and structure of ks space. a trajectory in cartesian space is represented by a four - dimensional manifold, called the fundamental manifold. based on geometric and topological aspects classical concepts of stability are translated to ks language. the separation between manifolds of solutions generalizes the concept of lyapunov stability. the dimension - raising nature of the fibration transforms fixed points, limit cycles, attractive sets, and poincar \ ' e sections to higher - dimensional subspaces. from these concepts chaotic systems are studied. in strongly perturbed problems the numerical error can break the topological structure of ks space : points in a fiber are no longer transformed to the same point in cartesian space. an observer in three dimensions will see orbits departing from the same initial conditions but diverging in time. this apparent randomness of the integration can only be understood in four dimensions. the concept of topological stability results in a simple method for estimating the time scale in which numerical simulations can be trusted. ideally all trajectories departing from the same fiber should be ks transformed to a unique trajectory in three - dimensional space, because the fundamental manifold that they constitute is unique. by monitoring how trajectories departing from one fiber separate from the fundamental manifold a critical time, equivalent to the lyapunov time, is estimated. these concepts are tested on n - body examples : the pythagorean problem, and an example of field stars interacting with a binary. | arxiv:1604.06673 |
new vectorlike fermions that mix with the third generation can significantly affect the tau and b yukawa couplings. consistent with precision electroweak measurements, the width of the higgs boson to tau tau, b b can be reduced by o ( 1 ) with respect to the standard model values. in the case of the b quark, a reduced width would result in an enhanced branching ratio for other final states, such as gamma gamma. new leptons can also substantially modify the higgs boson branching ratio to photons through radiative effects, while new quarks can contribute to g g fusion. the combined effect can be as much as a factor of two on the branching ratio to gamma gamma. the new quarks and leptons could be light, which would allow discovery at the lhc. in the case of significant suppression of h - > tau tau, searches for new leptons decaying to tau - rich final states, perhaps in association with higgs bosons, are motivated. | arxiv:1207.7062 |
motivated by our observation of fast echo decay and a surprising coherence freeze, we have developed a pump - probe spectroscopy technique for vibrational states of ultracold $ ^ { 85 } $ rb atoms in an optical lattice to gain information about the memory dynamics of the system. we use pump - probe spectroscopy to monitor the time - dependent changes of frequencies experienced by atoms and to characterize the probability distribution of these frequency trajectories. we show that the inferred distribution, unlike a naive microscopic model of the lattice, correctly predicts the main features of the observed echo decay. | arxiv:1005.2635 |
we discuss some recent advances concerning the symmetry of stochastic differential equations, and in particular the interrelations between these and the integrability - - complete or partial - - of the equations. | arxiv:1901.05533 |
this is an expanded version of lectures given at a summer school " geometric methods in representation theory " ( grenoble, 2008 ). | arxiv:0905.0686 |
this paper tackles the problem of generalizable 3d - aware generation from monocular datasets, e. g., imagenet. the key challenge of this task is learning a robust 3d - aware representation without multi - view or dynamic data, while ensuring consistent texture and geometry across different viewpoints. although some baseline methods are capable of 3d - aware generation, the quality of the generated images still lags behind state - of - the - art 2d generation approaches, which excel in producing high - quality, detailed images. to address this severe limitation, we propose a novel feed - forward pipeline based on pixel - aligned gaussian splatting, coined as f3d - gaus, which can produce more realistic and reliable 3d renderings from monocular inputs. in addition, we introduce a self - supervised cycle - aggregative constraint to enforce cross - view consistency in the learned 3d representation. this training strategy naturally allows aggregation of multiple aligned gaussian primitives and significantly alleviates the interpolation limitations inherent in single - view pixel - aligned gaussian splatting. furthermore, we incorporate video model priors to perform geometry - aware refinement, enhancing the generation of fine details in wide - viewpoint scenarios and improving the model ' s capability to capture intricate 3d textures. extensive experiments demonstrate that our approach not only achieves high - quality, multi - view consistent 3d - aware generation from monocular datasets, but also significantly improves training and inference efficiency. | arxiv:2501.06714 |
one of the most effective orthogonal moments, discrete racah polynomials ( drps ) and their moments are used in many disciplines of sciences, including image processing, and computer vision. moments are the projections of a signal on the polynomial basis functions. racah polynomials were introduced by wilson and modified by zhu for image processing and they are orthogonal on a discrete set of samples. however, when the moment order is high, they experience the issue of numerical instability. in this paper, we propose a new algorithm for the computation of drps coefficients called improved stabilization ( imst ). in the proposed algorithm, { the drp plane is partitioned into four parts, which are asymmetric because they rely on the values of the polynomial size and the drp parameters. } the logarithmic gamma function is utilized to compute the initial values, which empower the computation of the initial value for a wide range of drp parameter values as well as large size of the polynomials. in addition, a new formula is used to compute the values of the initial sets based on the initial value. moreover, we optimized the use of the stabilizing condition in specific parts of the algorithm. imst works for wider range of parameters until higher degree than the current algorithms. we compare it with the other methods in a number of experiments. | arxiv:2302.00596 |
electric - field control of spin - dependent properties has become one of the most attractive phenomena in modern materials research due the promise of new device functionalities. one of the paradigms in this approach is to electrically toggle the spin polarization of carriers injected into a semiconductor using ferroelectric polarization as a control parameter. using first - principles density functional calculations, we explore the effect of ferroelectric polarization of electron - doped batio3 ( n - batio3 ) on the spin - polarized transmission across the srruo3 / n - batio3 ( 001 ) interface. our study reveals that the interface transmission is negatively spin - polarized and that ferroelectric polarization reversal leads to a change in the transport spin polarization from - 65 % to - 98 %. we show that this effect stems from the large difference in fermi wave vectors between up - and down - spins in ferromagnetic srruo3 and a change in the transport regime driven by ferroelectric polarization switching. the predicted sizeable change in the spin polarization provides a non - volatile mechanism to electrically control spin injection in semiconductor - based spintronics devices. | arxiv:1406.1434 |
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