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the aim of this work is to study how the thermodynamic temperature is related to the known thermometers for nuclei especially in view of studying the microcanonical phase transition. we find within the mmmc - model that the " s - shape " of the caloric equation of state e ^ * ( t ) which is the signal of a phase transition in a system with conserved energy, can be seen in the experimentally accessible slope temperatures t _ slope for different particle types and also in the isotopic temperatures t _ he - li. the isotopic temperatures t _ h - he are weaker correlated to the shape of the thermodynamic temperature and therefore are less favorable to study the signal of a microcanonical phase transition. we also show that the signal is very sensitive to variations in mass of the source. | arxiv:nucl-th/9901017 |
dual descent methods are commonly used to solve network flow optimization problems, since their implementation can be distributed over the network. these algorithms, however, often exhibit slow convergence rates. approximate newton methods which compute descent directions locally have been proposed as alternatives to accelerate the convergence rates of conventional dual descent. the effectiveness of these methods, is limited by the accuracy of such approximations. in this paper, we propose an efficient and accurate distributed second order method for network flow problems. the proposed approach utilizes the sparsity pattern of the dual hessian to approximate the the newton direction using a novel distributed solver for symmetric diagonally dominant linear equations. our solver is based on a distributed implementation of a recent parallel solver of spielman and peng ( 2014 ). we analyze the properties of the proposed algorithm and show that, similar to conventional newton methods, superlinear convergence within a neighbor - hood of the optimal value is attained. we finally demonstrate the effectiveness of the approach in a set of experiments on randomly generated networks. | arxiv:1503.06883 |
we suggest new closely related methods for numerical inversion of $ z $ - transform and wiener - hopf factorization of functions on the unit circle, based on sinh - deformations of the contours of integration, corresponding changes of variables and the simplified trapezoid rule. as applications, we consider evaluation of high moments of probability distributions and construction of causal filters. programs in matlab running on a mac with moderate characteristics achieves the precision e - 14 in several dozen of microseconds and e - 11 in several milliseconds, respectively. | arxiv:2404.19290 |
near out - of - distribution detection ( oodd ) aims at discriminating semantically similar data points without the supervision required for classification. this paper puts forward an oodd use case for radar targets detection extensible to other kinds of sensors and detection scenarios. we emphasize the relevance of oodd and its specific supervision requirements for the detection of a multimodal, diverse targets class among other similar radar targets and clutter in real - life critical systems. we propose a comparison of deep and non - deep oodd methods on simulated low - resolution pulse radar micro - doppler signatures, considering both a spectral and a covariance matrix input representation. the covariance representation aims at estimating whether dedicated second - order processing is appropriate to discriminate signatures. the potential contributions of labeled anomalies in training, self - supervised learning, contrastive learning insights and innovative training losses are discussed, and the impact of training set contamination caused by mislabelling is investigated. | arxiv:2205.07869 |
we found an infinite number of potentials surrounding 2d black hole. according to the transmission $ { \ cal t } $ and reflection $ { \ cal r } $ coefficients for scattering of string fields off 2d black hole, we can classify an infinite number of potentials into three : graviton - dilaton, tachyon and the other types. we suggest that the discrete states from all the virasoro levels be candidates for new potentials ( modes ). | arxiv:hep-th/9510123 |
in this paper, we present a tube - based framework for robust adaptive model predictive control ( rampc ) for nonlinear systems subject to parametric uncertainty and additive disturbances. set - membership estimation is used to provide accurate bounds on the parametric uncertainty, which are employed for the construction of the tube in a robust mpc scheme. the resulting rampc framework ensures robust recursive feasibility and robust constraint satisfaction, while allowing for less conservative operation compared to robust mpc schemes without model / parameter adaptation. furthermore, by using an additional mean - squared point estimate in the objective function the framework ensures finite - gain $ \ mathcal { l } _ 2 $ stability w. r. t. additive disturbances. as a first contribution we derive suitable monotonicity and non - increasing properties on general parameter estimation algorithms and tube / set based rampc schemes that ensure robust recursive feasibility and robust constraint satisfaction under recursive model updates. then, as the main contribution of this paper, we provide similar conditions for a tube based formulation that is parametrized using an incremental lyapunov function, a scalar contraction rate and a function bounding the uncertainty. with this result, we can provide simple constructive designs for different rampc schemes with varying computational complexity and conservatism. as a corollary, we can demonstrate that state of the art formulations for nonlinear rampc are a special case of the proposed framework. we provide a numerical example that demonstrates the flexibility of the proposed framework and showcase improvements compared to state of the art approaches. | arxiv:1911.02899 |
ovarian cancer ( oc ) is one of the most prevalent types of cancer in women. early and accurate diagnosis is crucial for the survival of the patients. however, the majority of women are diagnosed in advanced stages due to the lack of effective biomarkers and accurate screening tools. while previous studies sought a common biomarker, our study suggests different biomarkers for the premenopausal and postmenopausal populations. this can provide a new perspective in the search for novel predictors for the effective diagnosis of oc. lack of explainability is one major limitation of current ai systems. the stochastic nature of the ml algorithms raises concerns about the reliability of the system as it is difficult to interpret the reasons behind the decisions. to increase the trustworthiness and accountability of the diagnostic system as well as to provide transparency and explanations behind the predictions, explainable ai has been incorporated into the ml framework. shap is employed to quantify the contributions of the selected biomarkers and determine the most discriminative features. a hybrid decision support system has been established that can eliminate the bottlenecks caused by the black - box nature of the ml algorithms providing a safe and trustworthy ai tool. the diagnostic accuracy obtained from the proposed system outperforms the existing methods as well as the state - of - the - art roma algorithm by a substantial margin which signifies its potential to be an effective tool in the differential diagnosis of oc. | arxiv:2312.08381 |
we show that qcd minkowski observables such as the $ e ^ { + } e ^ { - } $ r - ratio and the hadronic tau decay $ r _ { \ tau } $ are completely determined by the effective charge ( ec ) beta - function, $ \ rho ( x ) $, corresponding to the euclidean qcd vacuum polarization adler d - function, together with the next - to - leading order ( nlo ) perturbative coefficient of d. an efficient numerical algorithm is given for evaluating r, $ r _ { \ tau } $ from a weighted contour integration of $ d ( se ^ { i \ theta } ) $ around a circle in the complex squared energy s - plane, with $ \ rho ( x ) $ used to evolve in s around the contour. the ec beta - function can be truncated at next - to - nlo ( nnlo ) using the known exact perturbative calculation or the uncalculated n ^ 3 lo and higher terms can be approximated by the portion containing the highest power of b, the first qcd beta - function coefficient. the difference between the r, $ r _ { \ tau } $ constructed using the nnlo and " leading - b " resummed versions of $ \ rho ( x ) $ provides an estimate of the uncertainty due to the uncalculated higher order corrections. simple numerical parametrizations are given to facilitate these fits. for $ r _ { \ tau } $ we estimate an uncertainty $ \ delta \ alpha _ { s } ( m _ { \ tau } ^ { 2 } ) \ simeq0. 01 $, corresponding to $ \ delta \ alpha _ { s } ( m _ { z } ^ { 2 } ) \ simeq0. 002 $. this encouragingly small uncertainty is much less than rather pessimistic estimates by other authors based on analogous all - orders resummations, which we demonstrate to be extremely dependent on the chosen renormalization scheme, and hence misleading. | arxiv:hep-ph/9705314 |
how do we know if two systems - biological or artificial - process information in a similar way? similarity measures such as linear regression, centered kernel alignment ( cka ), normalized bures similarity ( nbs ), and angular procrustes distance, are often used to quantify this similarity. however, it is currently unclear what drives high similarity scores and even what constitutes a " good " score. here, we introduce a novel tool to investigate these questions by differentiating through similarity measures to directly maximize the score. surprisingly, we find that high similarity scores do not guarantee encoding task - relevant information in a manner consistent with neural data ; and this is particularly acute for cka and even some variations of cross - validated and regularized linear regression. we find no consistent threshold for a good similarity score - it depends on both the measure and the dataset. in addition, synthetic datasets optimized to maximize similarity scores initially learn the highest variance principal component of the target dataset, but some methods like angular procrustes capture lower variance dimensions much earlier than methods like cka. to shed light on this, we mathematically derive the sensitivity of cka, angular procrustes, and nbs to the variance of principal component dimensions, and explain the emphasis cka places on high variance components. finally, by jointly optimizing multiple similarity measures, we characterize their allowable ranges and reveal that some similarity measures are more constraining than others. while current measures offer a seemingly straightforward way to quantify the similarity between neural systems, our work underscores the need for careful interpretation. we hope the tools we developed will be used by practitioners to better understand current and future similarity measures. | arxiv:2407.07059 |
we analyze a higgs transition from a u ( 1 ) dirac spin liquid to a gapless $ \ mathbb { z } _ 2 $ spin liquid. this $ \ mathbb { z } _ 2 $ spin liquid is of relevance to the spin $ s = 1 / 2 $ square lattice antiferromagnet, where recent numerical studies have given evidence for such a phase existing in the regime of high frustration between nearest neighbor and next - nearest neighbor antiferromagnetic interactions ( the $ j _ 1 $ - $ j _ 2 $ model ), appearing in a parameter regime between the vanishing of n \ ' eel order and the onset of valence bond solid ordering. the proximate dirac spin liquid is unstable to monopole proliferation on the square lattice, ultimately leading to n \ ' eel or valence bond solid ordering. as such, we conjecture that this higgs transition describes the critical theory separating the gapless $ \ mathbb { z } _ 2 $ spin liquid of the $ j _ 1 $ - $ j _ 2 $ model from one of the two proximate ordered phases. the transition into the other ordered phase can be described in a unified manner via a transition into an unstable su ( 2 ) spin liquid, which we have analyzed in prior work. by studying the deconfined critical theory separating the u ( 1 ) dirac spin liquid from the gapless $ \ mathbb { z } _ 2 $ spin liquid in a $ 1 / n _ f $ expansion, with $ n _ f $ proportional to the number of fermions, we find a stable fixed point with an anisotropic spinon dispersion and a dynamical critical exponent $ z \ neq 1 $. we analyze the consequences of this anisotropic dispersion by calculating the angular profiles of the equal - time n \ ' eel and valence bond solid correlation functions, and we find them to be distinct. we also note the influence of the anisotropy on the scaling dimension of monopoles. | arxiv:2203.01962 |
we study the number of individuals per level defined by excursions of random walks with state dependent jump law. these level numbersdetermine the probability of the excursion, and the set of transformations preserving the level numbers is, generically, the set of transformation that preserve the probability law of excursions. we compute the number of excursions having a fixed level numbers and we show that the class of shifts of excursions generate all the excursions having a fixed level numbers. we study the behaviorof the level numbers under the vervaat transform and the doob transform. | arxiv:2307.14002 |
consider the macdonald group $ g ( \ alpha, \ beta ) = \ langle a, b \, | \, a ^ { [ a, b ] } = a ^ \ alpha, \, b ^ { [ b, a ] } = b ^ \ beta \ rangle $, where $ \ alpha $ and $ \ beta $ are integers different from one. we fill a gap in macdonald ' s original proof that $ g ( \ alpha, \ beta ) $ is nilpotent, and find the order and nilpotency class of each sylow subgroup of $ g ( \ alpha, \ beta ) $. | arxiv:2405.10356 |
the vera c. rubin observatory ' s legacy survey of space and time ( lsst ) will catalogue the light - curves of up to 100 million quasars. among these there can be up to approximately 100 ultra - compact massive black hole ( mbh ) binaries, which 5 - 15 years later can be detected in gravitational waves ( gws ) by the laser interferometer space antenna ( lisa ). here we assume that gws from a mbh binary have been detected by lisa, and we assess whether or not its electromagnetic ( em ) counterpart can be uniquely identified in archival lsst data as a periodic quasar. we use the binary ' s properties derived from the lisa waveform, such as the past evolution of its orbital frequency, its total mass, distance and sky localization, to predict the redshift, magnitude and historical periodicity of the quasar expected in the archival lsst data. we then use monte carlo simulations to compute the false alarm probability, i. e. the number of quasars in the lsst catalogue matching these properties by chance, based on the ( extrapolated ) quasar luminosity function, the sampling cadence of lsst, and intrinsic ` ` damped random walk ( drw ) " quasar variability. we perform our analysis on four fiducial lisa binaries, with total masses and redshifts of $ ( m _ { \ rm bin } / { \ rm m _ { \ odot } }, z ) = ( 3 \ times10 ^ 5, 0. 3 ) $, $ ( 3 \ times10 ^ 6, 0. 3 ) $, $ ( 10 ^ 7, 0. 3 ) $ and $ ( 10 ^ 7, 1 ) $. while drw noise and aliasing due to lsst ' s cadence can produce false periodicities by chance, we find that the frequency chirp of the lisa source during the lsst observations washes out these noise peaks and allows the genuine source to stand out in lomb - scargle periodograms. we find that all four fiducial binaries yield excellent chances to be uniquely identified, with false alarm probabilities below $ 10 ^ { - 5 } $, a week or more before their merger. this then enables deep follow - up em observations targeting the individual em counterparts during their inspiral stage. | arxiv:2403.18751 |
with the insulating phase of \ kappa - ( bedt - ttf ) _ 2x in mind, we study a t - j model on an anisotropic triangular lattice, where the hopping integral is t ' in one of the three directions, using a variational monte carlo method. by changing the value of t ' / t, we study the stability of superconducting ( sc ) states with d - and d + id - wave symmetries and of an antiferromagnetic ( af ) state. as t ' / t decreases from 1, the stable state immediately switches from the d + id wave to the d wave. the af state is stabilized from the normal spin liquid state for t ' / t \ lsim 0. 7 at half filling. we also take account of nagaoka ferromagnetism and a phase separation. | arxiv:cond-mat/0411711 |
we show that it is consistent relative to a weakly compact cardinal that strong homology is additive and compactly supported within the class of locally compact separable metric spaces. this complements work of marde \ v { s } i \ ' { c } and prasolov showing that the continuum hypothesis implies that a countable sum of hawaiian earrings witnesses the failure of strong homology to possess either of these properties. our results build directly on work of lambie - hanson and the second author which establishes the consistency, relative to a weakly compact cardinal, of $ \ mathrm { lim } ^ s \ mathbf { a } = 0 $ for all $ s \ geq 1 $ for a certain pro - abelian group $ \ mathbf { a } $ ; we show that that work ' s arguments carry implications for the vanishing and additivity of the $ \ mathrm { lim } ^ s $ functors over a substantially more general class of pro - abelian groups indexed by $ \ mathbb { n } ^ { \ mathbb { n } } $. | arxiv:2008.13089 |
cascading failure causes a major risk to society currently. to effectively mitigate the risk, dynamic thermal rating ( dtr ) technique can be applied as a cost - effective strategy to exploit potential transmission capability. from the perspectives of service life and braess paradox, it is important and challenging to jointly optimize the dtr placement and operation schedule for changing system state, which is a two - stage combinatorial problem with only discrete variables, suffering from no approximation guarantee and dimension curse only based on traditional models. thus, the present work proposes a novel two - stage submodular optimization ( tsso ) of dtr for risk mitigation considering placement and operation schedule. specifically, it optimizes dtr placement with proper redundancy in first stage, and then determines the corresponding dtr operation for each system state in second stage. under the condition of the markov and submodular features in sub - function of risk mitigation, the submodularity of total objective function of tsso can be proven for the first time. based on this, a state - of - the - art efficient solving algorithm is developed that can provide a better approximation guarantee than previous studies by coordinating the separate curvature and error form. the performance of the proposed algorithms is verified by case results. | arxiv:2209.09708 |
unobserved confounding is one of the main challenges when estimating causal effects. we propose a causal reduction method that, given a causal model, replaces an arbitrary number of possibly high - dimensional latent confounders with a single latent confounder that takes values in the same space as the treatment variable, without changing the observational and interventional distributions the causal model entails. this allows us to estimate the causal effect in a principled way from combined data without relying on the common but often unrealistic assumption that all confounders have been observed. we apply our causal reduction in three different settings. in the first setting, we assume the treatment and outcome to be discrete. the causal reduction then implies bounds between the observational and interventional distributions that can be exploited for estimation purposes. in certain cases with highly unbalanced observational samples, the accuracy of the causal effect estimate can be improved by incorporating observational data. second, for continuous variables and assuming a linear - gaussian model, we derive equality constraints for the parameters of the observational and interventional distributions. third, for the general continuous setting ( possibly nonlinear and non - gaussian ), we parameterize the reduced causal model using normalizing flows, a flexible class of easily invertible nonlinear transformations. we perform a series of experiments on synthetic data and find that in several cases the number of interventional samples can be reduced when adding observational training samples without sacrificing accuracy. | arxiv:2103.04786 |
vision research showed remarkable success in understanding our world, propelled by datasets of images and videos. sensor data from radar, lidar and cameras supports research in robotics and autonomous driving for at least a decade. however, while visual sensors may fail in some conditions, sound has recently shown potential to complement sensor data. simulated room impulse responses ( rir ) in 3d apartment - models became a benchmark dataset for the community, fostering a range of audiovisual research. in simulation, depth is predictable from sound, by learning bat - like perception with a neural network. concurrently, the same was achieved in reality by using rgb - d images and echoes of chirping sounds. biomimicking bat perception is an exciting new direction but needs dedicated datasets to explore the potential. therefore, we collected the batvision dataset to provide large - scale echoes in complex real - world scenes to the community. we equipped a robot with a speaker to emit chirps and a binaural microphone to record their echoes. synchronized rgb - d images from the same perspective provide visual labels of traversed spaces. we sampled modern us office spaces to historic french university grounds, indoor and outdoor with large architectural variety. this dataset will allow research on robot echolocation, general audio - visual tasks and sound ph { \ ae } nomena unavailable in simulated data. we show promising results for audio - only depth prediction and show how state - of - the - art work developed for simulated data can also succeed on our dataset. project page : https : / / amandinebtto. github. io / batvision - dataset / | arxiv:2303.07257 |
in section 1, we revisit the partial differential equation ( pde ) for the probability generating function ( pgf ) of the time - nonhomogeneous bdi ( birth - and - death - with - immigration ) process and derive a closed form solution. to the best of our knowledge, this is a new mathematical result. we state this result as proposition 1. we state as corollary 1 that the negative binomial distribution of the time - homogeneous bdi process discussed in part i extends to the general time - nonhomogeneous case, provided that the ratio of the immigration rate to the birth rate is a constant. in section 1. 2, we take up the heuristic approach discussed by bartlett and bailey ( 1964 ), and carry it out to completion by arriving at the solution obtained above,. in section 2, we present the results of our extensive simulation experiments of the time - nonhomogeneous bd process that was analyzed in part iii - a and confirm our analytic results. in section 3, we undertake similar simulation experiments for the bdi process that is analyzed in section 1. as we discuss in section 4, our stochastic model now seems more promising and powerful than has been heretofore expected. in appendix b, a closed form solution for the m ( t ) / m ( t ) / infinity queue is obtained, as a special case of this bdi process model. | arxiv:2104.00529 |
fiducial and total $ w ^ \ pm $ and $ z $ boson cross sections, their ratios and the ratio of top - antitop - quark pair and $ w $ - boson fiducial cross sections are measured in proton - proton collisions at a centre - of - mass energy of $ \ sqrt { s } = 13. 6 $ tev, corresponding to an integrated luminosity of 29 fb $ ^ { - 1 } $ of data collected in 2022 by the atlas experiment at the large hadron collider. the measured fiducial cross - section values for $ w ^ + \ to \ ell ^ + \ nu $, $ w ^ - \ to \ ell ^ - \ bar { \ nu } $, and $ z \ to \ ell ^ + \ ell ^ - $ ( $ \ ell = e $ or $ \ mu $ ) boson productions are $ 4250 \ pm 150 $ pb, $ 3310 \ pm 120 $ pb, and $ 744 \ pm 20 $ pb, respectively, where the uncertainty is the total uncertainty, including that arising from the luminosity of about 2. 2 %. the measurements are in agreement with standard - model predictions calculated at next - to - next - to - leading - order in $ \ alpha _ s $, next - to - next - to - leading logarithmic accuracy and next - to - leading - order electroweak accuracy. | arxiv:2403.12902 |
in this note we present numerical study of spin dynamics of $ \ vartheta $ - soliton in homogeneously precessing domain ( hpd ) in superfluid $ ^ 3 $ he - b. the soliton consists of a small heavy core and long tails, in 1d simulation we observe their mutual motion. we also discuss mass density and tension of the soliton membrane and its 3d oscillations in a cylindrical cell. | arxiv:2212.12232 |
in the context of filtering chaotic dynamical systems it is well - known that partial observations, if sufficiently informative, can be used to control the inherent uncertainty due to chaos. the purpose of this paper is to investigate, both theoretically and numerically, conditions on the observations of chaotic systems under which they can be accurately filtered. in particular, we highlight the advantage of adaptive observation operators over fixed ones. the lorenz ' 96 model is used to exemplify our findings. we consider discrete - time and continuous - time observations in our theoretical developments. we prove that, for fixed observation operator, the 3dvar filter can recover the system state within a neighbourhood determined by the size of the observational noise. it is required that a sufficiently large proportion of the state vector is observed, and an explicit form for such sufficient fixed observation operator is given. numerical experiments, where the data is incorporated by use of the 3dvar and extended kalman filters, suggest that less informative fixed operators than given by our theory can still lead to accurate signal reconstruction. adaptive observation operators are then studied numerically ; we show that, for carefully chosen adaptive observation operators, the proportion of the state vector that needs to be observed is drastically smaller than with a fixed observation operator. indeed, we show that the number of state coordinates that need to be observed may even be significantly smaller than the total number of positive lyapunov exponents of the underlying system. | arxiv:1411.3113 |
we propose a practical approach to spin - polarized systems within the van der waals density functional ( vdw - df ). the method was applied to a gas phase oxygen molecule and a parallel ( h - type ) pair of oxygen molecules. it was found that vdw - df improves the equilibrium distance and binding energy. in particular, one type of vdw - df can describe such systems reasonably well. the van der waals interaction has been confirmed to have an energy comparable to the magnetic one, while emerging at a distance rather longer than the latter. | arxiv:1310.4104 |
a perturbative hybrid ideal - mhd / drift - kinetic approach to assess the stability of alpha - particle - driven alfven eigenmodes in burning plasmas is used to show that certain foreseen iter scenarios, namely the ip = 15 ma baseline scenario with very low and broad core magnetic shear, are sensitive to small changes in the background magnetic equilibrium. slight variations ( of the order of 1 % ) of the safety - factor value on axis are seen to cause large changes in the growth rate, toroidal mode number, and radial location of the most unstable eigenmodes found. the observed sensitivity is shown to proceed from the very low magnetic shear values attained throughout the plasma core, raising issues about reliable predictions of alpha - particle transport in burning plasmas. | arxiv:1601.01485 |
in the machine learning and optimization community, there are two main approaches for the convex risk minimization problem, namely, the stochastic approximation ( sa ) and the sample average approximation ( saa ). in terms of oracle complexity ( required number of stochastic gradient evaluations ), both approaches are considered equivalent on average ( up to a logarithmic factor ). the total complexity depends on the specific problem, however, starting from work \ cite { nemirovski2009robust } it was generally accepted that the sa is better than the saa. % nevertheless, in case of large - scale problems sa may run out of memory as storing all data on one machine and organizing online access to it can be impossible without communications with other machines. saa in contradistinction to sa allows parallel / distributed calculations. we show that for the wasserstein barycenter problem this superiority can be inverted. we provide a detailed comparison by stating the complexity bounds for the sa and the saa implementations calculating barycenters defined with respect to optimal transport distances and entropy - regularized optimal transport distances. as a byproduct, we also construct confidence intervals for the barycenter defined with respect to entropy - regularized optimal transport distances in the $ \ ell _ 2 $ - norm. the preliminary results are derived for a general convex optimization problem given by the expectation in order to have other applications besides the wasserstein barycenter problem. | arxiv:2001.07697 |
free ribbon lemma that every free sphere - link in the 4 - sphere is a ribbon sphere - link is shown in an earlier paper by the author. in this paper, another proof of this lemma is given. | arxiv:2408.04793 |
in the present report the author presents a simple and systematically defined formula for the fine structure constant based only on the number $ \ pi $. the difference between the suggested value and the currently known experimental one is about 60 times smaller than the uncertainty interval. | arxiv:physics/9712044 |
we report the detection of a massive neutral gas outflow in the z = 2. 09 gravitationally lensed dusty star - forming galaxy hatlasj085358. 9 + 015537 ( g09v1. 40 ), seen in absorption with the oh + ( 1 _ 1 - 1 _ 0 ) transition using spatially resolved ( 0. 5 " x0. 4 " ) atacama large millimeter / submillimeter array ( alma ) observations. the blueshifted oh + line is observed simultaneously with the co ( 9 - 8 ) emission line and underlying dust continuum. these data are complemented by high angular resolution ( 0. 17 " x0. 13 " ) alma observations of ch + ( 1 - 0 ) and underlying dust continuum, and keck 2. 2 micron imaging tracing the stellar emission. the neutral outflow, dust, dense molecular gas and stars all show spatial offsets from each other. the total atomic gas mass of the observed outflow is 6. 7x10 ^ 9 m _ sun, > 25 % as massive as the gas mass of the galaxy. we find that a conical outflow geometry best describes the oh + kinematics and morphology and derive deprojected outflow properties as functions of possible inclination ( 0. 38 deg - 64 deg ). the neutral gas mass outflow rate is between 83 - 25400 m _ sun / yr, exceeding the star formation rate ( 788 + / - 300 m _ sun / yr ) if the inclination is > 3. 6 deg ( mass - loading factor = 0. 3 - 4. 7 ). kinetic energy and momentum fluxes span 4. 4 - 290x10 ^ 9 l _ sun and 0. 1 - 3. 7x10 ^ 37 dyne, respectively ( energy - loading factor = 0. 013 - 16 ), indicating that the feedback mechanisms required to drive the outflow depend on the inclination assumed. we derive a gas depletion time between 29 and 1 myr, but find that the neutral outflow is likely to remain bound to the galaxy, unless the inclination is small, and may be re - accreted if additional feedback processes do not occur. | arxiv:2104.10077 |
in this paper i propose a novel approach to volume weighted average price ( vwap ) execution that addresses two key practical challenges : the need for asset - specific model training and the capture of complex temporal dependencies. building upon my recent work in dynamic vwap execution arxiv : 2502. 18177, i demonstrate that a single neural network trained across multiple assets can achieve performance comparable to or better than traditional asset - specific models. the proposed architecture combines a transformer - based design inspired by arxiv : 2406. 02486 with path signatures for capturing geometric features of price - volume trajectories, as in arxiv : 2406. 17890. the empirical analysis, conducted on hourly cryptocurrency trading data from 80 trading pairs, shows that the globally - fitted model with signature features ( gft - sig ) achieves superior performance in both absolute and quadratic vwap loss metrics compared to asset - specific approaches. notably, these improvements persist for out - of - sample assets, demonstrating the model ' s ability to generalize across different market conditions. the results suggest that combining global parameter sharing with signature - based feature extraction provides a scalable and robust approach to vwap execution, offering significant practical advantages over traditional asset - specific implementations. | arxiv:2503.02680 |
we develop a new approach toward a high resolution non - parametric reconstruction of the primordial power spectrum using wmap cosmic microwave background temperature anisotropies that we confront with sdss large - scale structure data in the range k ~ 0. 01 - 0. 1 h / mpc. we utilise the standard lambdacdm cosmological model but we allow the baryon fraction to vary. in particular, for the concordance baryon fraction, we compare indications of a possible feature at k ~ 0. 05 h / mpc in wmap data with suggestions of similar features in large scale structure surveys. | arxiv:astro-ph/0402583 |
we propose a procedure for defining all single - photon observables in terms of positive - operator valued measures ( povms ), in particular spin and position. we identify the suppression of $ 0 $ - helicity photon states as a projection from an extended hilbert space onto the photon hilbert space. we show that all single - photon observables are in general described by povms, obtained by applying this projection to opportune projection - valued measures ( pvms ), defined on the extended hilbert space. the povms associated to momentum and helicity reduce to pvms, unlike those associated to position and spin, this fact reflecting the intrinsic unsharpness of these observables. we finally extensively study the preparation uncertainty relations for position and momentum and the probability distribution of spin, exploring single photon gaussian states for several choices of spin and polarization. | arxiv:1403.6405 |
existing 3d mesh shape evaluation metrics mainly focus on the overall shape but are usually less sensitive to local details. this makes them inconsistent with human evaluation, as human perception cares about both overall and detailed shape. in this paper, we propose an analytic metric named spectrum area under the curve difference ( saucd ) that demonstrates better consistency with human evaluation. to compare the difference between two shapes, we first transform the 3d mesh to the spectrum domain using the discrete laplace - beltrami operator and fourier transform. then, we calculate the area under the curve ( auc ) difference between the two spectrums, so that each frequency band that captures either the overall or detailed shape is equitably considered. taking human sensitivity across frequency bands into account, we further extend our metric by learning suitable weights for each frequency band which better aligns with human perception. to measure the performance of saucd, we build a 3d mesh evaluation dataset called shape grading, along with manual annotations from more than 800 subjects. by measuring the correlation between our metric and human evaluation, we demonstrate that saucd is well aligned with human evaluation, and outperforms previous 3d mesh metrics. | arxiv:2403.01619 |
toxic behavior is one of the problems most associated with the gaming community. reports of hate speech and anti - gaming behavior are common in many online multiplayer games. many studies address this area, focusing on players and, principally, on the content and its negative impact on the community. however, it is possible that other factors influence the toxicity. in this article, we investigate how game design elements influence toxic behavior, using toxic disinhibition factors as a basis for the analysis. for this, four of the main games of the moba genre were analyzed with the support of the mda framework and a questionnaire with players. the results show that most players suffered offenses and offended other people in the game, in addition to recognizing moba as the genre that generates the most impatience among them. furthermore, we raise and discuss different elements and mechanics in games that impact the well - being of the community through the individualization of the player, elimination of solidarities, and affirmation of indifference towards toxic behavior. with this, we hope to help game developers and communities to promote integration dynamics. | arxiv:2109.14730 |
a search for the higgsstrahlung process $ { \ rm e } ^ + { \ rm e } ^ - \ to { \ rm hz } $ is carried out, covering decays of the higgs boson into any quark pair, a gluon pair or a tau pair. the analysis is based on the $ 630 { \ rm pb } ^ { - 1 } $ of data collected by the aleph detector at lep at centre - of - mass energies from 189 to 209 gev. a 95 % c. l. lower mass limit of 109. 1 \ mc2 is obtained for a higgs boson cross section equal to that expected from the standard model if the higgs boson decays exclusively into hadrons and / or taus, irrespective of the relative branching fractions. | arxiv:hep-ex/0205055 |
multi - frequency vlbi observations allow studies of the continuum spectrum in the different parts of the parsec scale jets of agn, providing information on the physical properties of the plasma and magnetic fields in them. since vlbi networks cannot be scaled, the range of spatial frequencies observed differs significantly between the different observing frequencies, which makes it difficult to obtain a broadband spectrum of the individual emission features in the jet. in this paper we discuss a model - fitting based spectral extraction method, which can significantly relieve this problem. the method uses a priori knowledge of the source structure, measured at high frequencies, to allow at lower frequencies the derivation of the sizes and flux densities of even those emission features that have mutual separations significantly less than the rayleigh limit at the given frequency. we have successfully used this method in the analysis of 5 - 86 ghz vlba data of 3c273. the spectra and sizes of several individual jet features were measured, thus allowing derivation of the magnetic flux density and the energy density of the relativistic electrons in the different parts of the jet. we discuss the results, which include e. g. a detection of a strong gradient in the magnetic field across the jet of 3c273. | arxiv:0812.1486 |
in optical wireless communications, a broadcast channel ( bc ) employing intensity modulation and direct detection ( im / dd ) is often modelled as a peak - constrained bc. a closed - form expression for its capacity region of the peak - constrained bc is not known. this paper presents an analytical capacity inner bound for the peak - constrained gaussian bc achieved by a class of discrete input distribution, specifically, the evenly - spaced discrete uniform distribution ( esdu ). in contrast to the continuous input distribution that provides the benchmark, esdu is more promising in the application of peak - constrained gaussian channels. the newly obtained capacity inner bound is easily - computable and is numerically shown to be tighter than the benchmark. besides, we remark the newly developed analytical upper bound for the esdu rate, which is tight in all tested settings. | arxiv:2208.05654 |
despite being known for his pioneering work on chaotic unpredictability, the key discovery at the core of meteorologist ed lorenz ' s work is the link between space - time calculus and state - space fractal geometry. indeed, properties of lorenz ' s fractal invariant set relate space - time calculus to deep areas of mathematics such as g \ " { o } del ' s incompleteness theorem. these properties, combined with some recent developments in theoretical and observational cosmology, motivate what is referred to as the ` cosmological invariant set postulate ' : that the universe $ u $ can be considered a deterministic dynamical system evolving on a causal measure - zero fractal invariant set $ i _ u $ in its state space. symbolic representations of $ i _ u $ are constructed explicitly based on permutation representations of quaternions. the resulting ` invariant set theory ' provides some new perspectives on determinism and causality in fundamental physics. for example, whilst the cosmological invariant set appears to have a rich enough structure to allow a description of quantum probability, its measure - zero character ensures it is sparse enough to prevent invariant set theory being constrained by the bell inequality ( consistent with a partial violation of the so - called measurement independence postulate ). the primacy of geometry as embodied in the proposed theory extends the principles underpinning general relativity. as a result, the physical basis for contemporary programmes which apply standard field quantisation to some putative gravitational lagrangian is questioned. consistent with penrose ' s suggestion of a deterministic but non - computable theory of fundamental physics, a ` gravitational theory of the quantum ' is proposed based on the geometry of $ i _ u $, with potential observational consequences for the dark universe. | arxiv:1309.2396 |
the new development in sublattice - phase - resolved imaging of electronic structure now allow for the visualisation of the nematic - order state characteristic energy of cuprate superconductors in a wide doping regime. however, it is still unclear how this characteristic energy of the nematic - order state is correlated with the enhancement of superconductivity. here the doping dependence of the nematic - order state characteristic energy in cuprate superconductors and of its possible connection to the enhancement of superconductivity is investigated within the framework of the kinetic - energy - driven superconductivity. it is shown that the characteristic energy of the nematic - order state is found to be particularly large in the underdoped regime, then it smoothly decreases upon the increase of doping, in full agreement with the corresponding experimental observations. moreover, the characteristic energy of the nematic - order state as a function of the nematic - order state strength in the underdoped regime presents a similar behavior of the superconducting transition temperature. this suggests a possible connection between the nematic - order state characteristic energy and the enhancement of the superconductivity. | arxiv:2109.10079 |
we study the properties of the odd catalan numbers, c _ n, modulo 2 ^ k for k > = 2. we show that there exist only k - 1 different congruences of the odd catalan numbers modulo 2 ^ k. moreover, these congruences can be obtained by c _ { 2 ^ m - 1 } ( mod 2 ^ k ) for m = 1, 2,..., k - 1. | arxiv:1012.1756 |
a model is proposed for gamma - ray bursts based upon a neutrino burst of about 10 ^ 52 ergs lasting a few seconds above a heated collapsing neutron star. this type of thermal neutrino burst is suggested by relativistic hydrodynamic studies of the compression, heating, and collapse of close binary neutron stars as they approach their last stable orbit, but may arise from other sources as well. we present a hydrodynamic simulation of the formation and evolution of the pair plasma associated with such a neutrino burst. this pair plasma leads to the production of ~ 10 ^ 51 - 10 ^ 52 ergs in gamma - rays with spectral and temporal properties consistent with observed gamma - ray bursts. | arxiv:astro-ph/0002312 |
we study the set $ { \ cal c } $ consisting of pairs of orthogonal projections $ p, q $ acting in a hilbert space $ { \ cal h } $ such that $ pq $ is a compact operator. these pairs have a rich geometric structure which we describe here. they are parted in three subclasses : $ { \ cal c } _ 0 $ which consists of pairs where $ p $ or $ q $ have finite rank, $ { \ cal c } _ 1 $ of pairs such that $ q $ lies in the restricted grassmannian ( also called sato grassmannian ) of the polarization $ { \ cal h } = n ( p ) \ oplus r ( p ) $, and $ { \ cal c } _ \ infty $. belonging to this last subclass one has the pairs $ $ p _ if = \ chi _ if, \ \ q _ jf = \ left ( \ chi _ j \ hat { f } \ right ) \ check { \ }, \ \ f \ in l ^ 2 ( \ mathbb { r } ^ n ), $ $ where $ i, j \ subset \ mathbb { r } ^ n $ are sets of finite lebesgue measure, $ \ chi _ i, \ chi _ j $ denote the corresponding characteristic functions and $ \ hat { \ }, \ check { \ } $ denote the fourier - plancherel transform $ l ^ 2 ( \ mathbb { r } ^ 2 ) \ to l ^ 2 ( \ mathbb { r } ^ 2 ) $ and its inverse. we characterize the connected components of these classes : the components of $ { \ cal c } _ 0 $ are parametrized by the rank, the components of $ { \ cal c } _ 1 $ are parametrized by the fredholm index of the pairs, and $ { \ cal c } _ \ infty $ is connected. we show that these subsets are ( non complemented ) differentiable submanifolds of $ { \ cal b } ( { \ cal h } ) \ times { \ cal b } ( { \ cal h } ) $. | arxiv:1701.03737 |
lidar sensors are used widely in autonomous vehicles for better perceiving the environment which enables safer driving decisions. recent work has demonstrated serious lidar spoofing attacks with alarming consequences. in particular, model - level lidar spoofing attacks aim to inject fake depth measurements to elicit ghost objects that are erroneously detected by 3d object detectors, resulting in hazardous driving decisions. in this work, we explore the use of motion as a physical invariant of genuine objects for detecting such attacks. based on this, we propose a general methodology, 3d temporal consistency check ( 3d - tc2 ), which leverages spatio - temporal information from motion prediction to verify objects detected by 3d object detectors. our preliminary design and implementation of a 3d - tc2 prototype demonstrates very promising performance, providing more than 98 % attack detection rate with a recall of 91 % for detecting spoofed vehicle ( car ) objects, and is able to achieve real - time detection at 41hz | arxiv:2106.07833 |
systems that can be described with the same mathematical models that account for the properties of electrons in graphene are known as graphene - like systems. these include magnons, photons, polaritons, acoustic waves, and electrons in honeycomb lattices, either natural or artificial. all of them feature an outstanding property, the existence of states localized at the edges. we distinguish two classes of edge states depending on whether or not a topological band gap is present in the two - dimensional energy bands. we introduce the theory of edge states in terms of tight - binding models and discuss their properties, with an emphasis on the interplay between their one - way character and the topological nature of the bulk phase. | arxiv:2210.07568 |
in an introductory paper on dollar game played on a graph, matt baker wrote the following : ` ` the total number of borrowing moves required to win the game when playing the ' borrowing binge strategy ' is independent of which borrowing moves you do in which order! note, however, that it is usually possible to win in fewer moves by employing lending moves in combination with borrowing moves. the optimal strategy when one uses both kinds of moves is not yet understood. ' ' in this article, we give a lower bound on the minimum number $ m _ { \ text { min } } $ of such moves of an optimal algorithm in terms of the number of moves $ m _ 0 $ of the borrowing binge strategy. concretely, we have : $ m _ { \ text { min } } \ geq \ frac { m _ 0 } { n - 1 } $ where $ n $ is the number of vertices of the graph. this bound is tight. | arxiv:2308.12787 |
this chapter deals with error and uncertainty in data. treats their measuring methods and meaning. it shows that uncertainty is a natural property of many data sets. uncertainty is fundamental for the survival os living species, uncertainty of the " chaos " type occurs in many systems, is fundamental to understand these systems. | arxiv:2406.19885 |
quantum key distribution ( qkd ) is a prominent application in the field of quantum cryptography providing information - theoretic security for secret key exchange. the implementation of qkd systems on photonic integrated circuits ( pics ) can reduce the size and cost of such systems and facilitate their deployment in practical infrastructures. to this end, continuous - variable ( cv ) qkd systems are particularly well - suited as they do not require single - photon detectors, whose integration is presently challenging. here we present a cv - qkd receiver based on a silicon pic capable of performing balanced detection. we characterize its performance in a laboratory qkd setup using a frequency multiplexed pilot scheme with specifically designed data processing allowing for high modulation and secret key rates. the obtained excess noise values are compatible with asymptotic secret key rates of 2. 4 mbit / s and 220 kbit / s at an emulated distance of 10 km and 23 km, respectively. these results demonstrate the potential of this technology towards fully integrated devices suitable for high - speed, metropolitan - distance secure communication. | arxiv:2311.03978 |
undirected graphical models are compact representations of joint probability distributions over random variables. to solve inference tasks of interest, graphical models of arbitrary topology can be trained using empirical risk minimization. however, to solve inference tasks that were not seen during training, these models ( egms ) often need to be re - trained. instead, we propose an inference - agnostic adversarial training framework which produces an infinitely - large ensemble of graphical models ( agms ). the ensemble is optimized to generate data within the gan framework, and inference is performed using a finite subset of these models. agms perform comparably with egms on inference tasks that the latter were specifically optimized for. most importantly, agms show significantly better generalization to unseen inference tasks compared to egms, as well as deep neural architectures like gibbsnet and vaeac which allow arbitrary conditioning. finally, agms allow fast data sampling, competitive with gibbs sampling from egms. | arxiv:2007.05033 |
we consider a phase - coherent system of two parallel quantum wires that are coupled via a tunneling barrier of finite length. the usual perturbative treatment of tunneling fails in this case, even in the diffusive limit, once the length l of the coupling region exceeds a characteristic length scale l _ t set by tunneling. exact solution of the scattering problem posed by the extended tunneling barrier allows us to compute tunneling conductances as a function of applied voltage and magnetic field. we take into account charging effects in the quantum wires due to applied voltages and find that these are important for 1d - to - 1d tunneling transport. | arxiv:cond-mat/0103372 |
in this paper, we study the inverse scattering problem for energy - dependent schr \ " { o } dinger equations on the half - line with energy - dependent boundary conditions at the origin. under certain positivity and very mild regularity assumptions, we transform this scattering problem to the one for non - canonical dirac systems and show that, in turn, the latter can be placed within the known scattering theory for zs - akns systems. this allows us to give a complete description of the corresponding scattering functions s for the class of problems under consideration and justify an algorithm of reconstructing the problem from s | arxiv:2006.12284 |
the increasing gap between the growth of datacenter traffic volume and the capacity of electrical switches led to the emergence of reconfigurable datacenter network designs based on optical circuit switching. a multitude of research works, ranging from demand - oblivious ( e. g., rotornet, sirius ) to demand - aware ( e. g., helios, projector ) reconfigurable networks, demonstrate significant performance benefits. unfortunately, little is formally known about the achievable throughput of such networks. only recently have the throughput bounds of demand - oblivious networks been studied. in this paper, we tackle a fundamental question : whether and to what extent can demand - aware reconfigurable networks improve the throughput of datacenters? this paper attempts to understand the landscape of the throughput bounds of reconfigurable datacenter networks. given the rise of machine learning workloads and collective communication in modern datacenters, we specifically focus on their typical communication patterns, namely uniform - residual demand matrices. we formally establish a separation bound of demand - aware networks over demand - oblivious networks, proving analytically that the former can provide at least $ 16 \ % $ higher throughput. our analysis further uncovers new design opportunities based on periodic, fixed - duration reconfigurations that can harness the throughput benefits of demand - aware networks while inheriting the simplicity and low reconfiguration overheads of demand - oblivious networks. finally, our evaluations corroborate the theoretical results of this paper, demonstrating that demand - aware networks significantly outperform oblivious networks in terms of throughput. this work barely scratches the surface and unveils several intriguing open questions, which we discuss at the end of this paper. | arxiv:2405.20869 |
state - of - the - art image captioning methods mostly focus on improving visual features, less attention has been paid to utilizing the inherent properties of language to boost captioning performance. in this paper, we show that vocabulary coherence between words and syntactic paradigm of sentences are also important to generate high - quality image caption. following the conventional encoder - decoder framework, we propose the reflective decoding network ( rdn ) for image captioning, which enhances both the long - sequence dependency and position perception of words in a caption decoder. our model learns to collaboratively attend on both visual and textual features and meanwhile perceive each word ' s relative position in the sentence to maximize the information delivered in the generated caption. we evaluate the effectiveness of our rdn on the coco image captioning datasets and achieve superior performance over the previous methods. further experiments reveal that our approach is particularly advantageous for hard cases with complex scenes to describe by captions. | arxiv:1908.11824 |
in this paper, we propose and study a semi - random model for the correlation clustering problem on arbitrary graphs g. we give two approximation algorithms for correlation clustering instances from this model. the first algorithm finds a solution of value $ ( 1 + \ delta ) optcost + o _ { \ delta } ( n \ log ^ 3 n ) $ with high probability, where $ optcost $ is the value of the optimal solution ( for every $ \ delta > 0 $ ). the second algorithm finds the ground truth clustering with an arbitrarily small classification error $ \ eta $ ( under some additional assumptions on the instance ). | arxiv:1406.5667 |
we present the results of a combined metadynamics - - umbrella sampling investigation of the puckered conformers of pyranoses described using the gromos 45a4 force field. the free energy landscape of cremer - - pople puckering coordinates has been calculated for the whole series of alpha and beta aldohexoses, showing that the current force field parameters fail in reproducing proper puckering free energy differences between chair conformers. we suggest a modification to the gromos 45a4 parameter set which improves considerably the agreement of simulation results with theoretical and experimental estimates of puckering free energies. we also report on the experimental measurement of altrose conformers populations by means of nmr spectroscopy, which show good agreement with the predictions of current theoretical models. | arxiv:1006.2515 |
we deduce an overcomplete free energy functional for d = 1 particle systems with next neighbor interactions, where the set of redundant variables are the local block densities $ \ varrho _ i $ of $ i $ interacting particles. the idea is to analyze the decomposition of a given pure system into blocks of $ i $ interacting particles by means of a mapping onto a hard rod mixture. this mapping uses the local activity of component $ i $ of the mixture to control the local association of $ i $ particles of the pure system. thus it identifies the local particle density of component $ i $ of the mixture with the local block density $ \ varrho _ i $ of the given system. consequently, our overcomplete free energy functional takes on the hard rod mixture form with the set of block densities $ \ varrho _ i $ representing the sequence of partition functions of the local aggregates of particle numbers $ i $. the system of equations for the local particle density $ \ varrho $ of the original system is closed via a subsidiary condition for the block densities in terms of $ \ varrho $. analoguous to the uniform isothermal - isobaric technique, all our results are expressible in terms of effective pressures. we illustrate the theory with two standard examples, the adhesive interaction and the square - well potential. for the uniform case, our proof of such an overcomplete format is based on the exponential boundedness of the number of partitions of a positive integer ( hardy - ramanujan formula ) and on varadhan ' s theorem on the asymptotics of a class of integrals. we also discuss the applicability of our strategy in higher dimensional space, as well as models suggested thereof. | arxiv:cond-mat/0205661 |
a $ ( c _ 1, c _ 2,..., c _ k ) $ - coloring of $ g $ is a mapping $ \ varphi : v ( g ) \ mapsto \ { 1, 2,..., k \ } $ such that for every $ i, 1 \ leq i \ leq k $, $ g [ v _ i ] $ has maximum degree at most $ c _ i $, where $ g [ v _ i ] $ denotes the subgraph induced by the vertices colored $ i $. borodin and raspaud conjecture that every planar graph without intersecting triangles and $ 5 $ - cycles is $ 3 $ - colorable. we prove in this paper that every planar graph without intersecting triangles and $ 5 $ - cycles is ( 2, 0, 0 ) - colorable. | arxiv:1407.5138 |
takamura established a theory on splitting families of degenerations of complex curves. he introduced a powerful method for constructing a splitting family, called a barking family, in which there appear not only a singular fiber over the origin but also singular fibers over other points, called subordinate fibers. in this paper, for the case of degenerations of elliptic curves, we determine the types of these subordinate fibers. | arxiv:1205.1592 |
this paper obtains criteria for a fano variety x with normal crossing singularities defined over an algebraically closed field of characteristic zero, to be smoothable. the difference with the original version is that the theory of logarithmic structures and deformations is used in order to prove that x is smoothable by a smooth variety, if and only if t ^ 1 ( x ) = o _ d, where d is the singular locus of x. | arxiv:1005.0531 |
we present a reduced order method ( rom ) based on proper orthogonal decomposition ( pod ) for the viscous burgers ' equation and the incompressible navier - stokes equations discretized using an implicit - explicit hybrid discontinuous galerkin / discoutinuous galerkin ( imex hdg / dg ) scheme. a novel closure model, which can be easily computed offline, is introduced. numerical results are presented to test the proposed pod model and the closure model. | arxiv:2004.08411 |
we consider finite quantum systems defined by a mixed set of commutation and anti - commutation relations between components of the hamiltonian operator. these relations are represented by an anti - commutativity graph which contains a necessary and sufficient information for computing the full quantum partition function. we derive a second - order differential equation for an extended partition function $ z [ \ beta, \ beta ', j ] $ which describes a transformation from a ` ` parent ' ' partition function $ z [ 0, \ beta ', j ] $ ( or anti - commutativity graph ) to a ` ` child ' ' partition function $ z [ \ beta, 0, j ] $ ( or anti - commutativity graph ). the procedure can be iterated and then one forms a pseudo - forest of duality transformations between quantum systems, i. e. a directed graph in which every vertex ( or quantum system ) has at most one incoming edge ( from its parent system ). the pseudo - forest has a single tree connected to a constant partition function, many pseudo - trees connected to self - dual systems and all other pseudo - trees connected to closed cycles of transformations between mutually dual systems. we also show how the differential equation for the extended partition function can be used to study disordered systems. | arxiv:1910.11268 |
neurological and physiological disorders that impact emotional regulation each have their own unique characteristics which are important to understand in order to create a generalized solution to all of them. the purpose of this experiment is to explore the potential applications of eeg - based brain - computer interfaces ( bcis ) in enhancing emotional regulation for individuals with neurological and physiological disorders. the research focuses on the development of a novel neural network algorithm for understanding eeg data, with a particular emphasis on recognizing and regulating emotional states. the procedure involves the collection of eeg - based emotion data from open - neuro. using novel data modification techniques, information from the dataset can be altered to create a dataset that has neural patterns of patients with disorders whilst showing emotional change. the data analysis reveals promising results, as the algorithm is able to successfully classify emotional states with a high degree of accuracy. this suggests that eeg - based bcis have the potential to be a valuable tool in aiding individuals with a range of neurological and physiological disorders in recognizing and regulating their emotions. to improve upon this work, data collection on patients with neurological disorders should be done to improve overall sample diversity. | arxiv:2411.14666 |
we reexamine the role of electron binding effects in the inelastic neutrino - atom scattering induced by the neutrino magnetic moment. the differential cross section of the process is presented as a sum of the longitudinal and transverse components, according to whether the force that the neutrino magnetic moment exerts on electrons is parallel or perpendicular to momentum transfer. the atomic electrons are treated nonrelativistically. on this basis, the recent theoretical predictions concerning the magnetic neutrino - impact ionization of atoms are critically discussed. numerical calculations are performed for ionization of a hydrogenlike ge $ ^ { + 31 } $ ion by neutrino impact. | arxiv:1011.5847 |
we investigate the transmission of electrons between conducting nanoribbon leads oriented at multiples of 60 degrees with respect to one another, connected either directly or through graphene polygons. a mode - matching analysis suggests that the transmission at low - energies is sensitive to the precise way in which the ribbons are joined. most strikingly, we find that armchair leads forming 120 - degree angles can support either a large transmission or a highly suppressed transmission, depending on the specific geometry. tight - binding calculations demonstrate the effects in detail, and are also used to study transmission at higher energies as well as for zigzag ribbon leads. | arxiv:0804.0246 |
capsule networks have shown encouraging results on \ textit { defacto } benchmark computer vision datasets such as mnist, cifar and smallnorb. although, they are yet to be tested on tasks where ( 1 ) the entities detected inherently have more complex internal representations and ( 2 ) there are very few instances per class to learn from and ( 3 ) where point - wise classification is not suitable. hence, this paper carries out experiments on face verification in both controlled and uncontrolled settings that together address these points. in doing so we introduce \ textit { siamese capsule networks }, a new variant that can be used for pairwise learning tasks. the model is trained using contrastive loss with $ \ ell _ 2 $ - normalized capsule encoded pose features. we find that \ textit { siamese capsule networks } perform well against strong baselines on both pairwise learning datasets, yielding best results in the few - shot learning setting where image pairs in the test set contain unseen subjects. | arxiv:1805.07242 |
in the context of quantum metrology, optical cavity - qed platforms have primarily been focused on the generation of entangled atomic spin states useful for next - generation frequency and time standards. here, we report a complementary application : the use of optical cavities to generate non - classical states of light for electric field sensing below the standard quantum limit. we show that cooperative atom - light interactions in the strong collective coupling regime can be used to engineer generalized atom - light cat states which enable quantum enhanced sensing of small displacements of the cavity field even in the presence of photon loss. we demonstrate that metrological gains of 10 - 20 db below the standard quantum limit are within reach for current cavity - qed systems operating with long - lived alkaline - earth atoms. | arxiv:1909.07524 |
graph structural information such as topologies or connectivities provides valuable guidance for graph convolutional networks ( gcns ) to learn nodes ' representations. existing gcn models that capture nodes ' structural information weight in - and out - neighbors equally or differentiate in - and out - neighbors globally without considering nodes ' local topologies. we observe that in - and out - neighbors contribute differently for nodes with different local topologies. to explore the directional structural information for different nodes, we propose a gcn model with weighted structural features, named wgcn. wgcn first captures nodes ' structural fingerprints via a direction and degree aware random walk with restart algorithm, where the walk is guided by both edge direction and nodes ' in - and out - degrees. then, the interactions between nodes ' structural fingerprints are used as the weighted node structural features. to further capture nodes ' high - order dependencies and graph geometry, wgcn embeds graphs into a latent space to obtain nodes ' latent neighbors and geometrical relationships. based on nodes ' geometrical relationships in the latent space, wgcn differentiates latent, in -, and out - neighbors with an attention - based geometrical aggregation. experiments on transductive node classification tasks show that wgcn outperforms the baseline models consistently by up to 17. 07 % in terms of accuracy on five benchmark datasets. | arxiv:2104.14060 |
in 2007, a. i. aptekarev and his collaborators discovered a sequence of rational approximations to euler ' s constant $ \ gamma $ defined by a linear recurrence. in this paper, we generalize this result and present an explicit construction of rational approximations for the numbers $ \ ln ( b ) - \ psi ( a + 1 ), $ $ a, b \ in { \ mathbb q }, $ $ b > 0, a > - 1, $ where $ \ psi $ defines the logarithmic derivative of the euler gamma function. we prove exact formulas for denominators and numerators of the approximations in terms of hypergeometric sums. as a consequence, we get rational approximations for the numbers $ \ pi / 2 \ pm \ gamma. $ we compare the results obtained with those of t. rivoal for the numbers $ \ gamma + \ ln ( b ) $ and prove denominators conjectures proposed by rivoal for denominators of rational approximations for $ \ gamma + \ ln ( b ) $ and common denominators of simultaneous approximations for the numbers $ \ gamma $ and $ \ zeta ( 2 ) - \ gamma ^ 2. $ | arxiv:1004.0578 |
we count subrings of small index of $ \ mathbb { z } ^ n $, where the addition and multiplication are defined componentwise. let $ f _ n ( k ) $ denote the number of subrings of index $ k $. for any $ n $, we give a formula for this quantity for all integers $ k $ that are not divisible by a 9th power of a prime, extending a result of liu. | arxiv:1609.06433 |
we describe a project - based physics lab, which we proposed to third - year university students. theses labs are based on new open - source low - cost equipment ( arduino microcontrollers and compatible sensors ). students are given complete autonomy : they develop their own experimental setup and study the physics topic of their choice. the goal of these projects is to let students discover the reality of experimental physics. technical specifications of the acquisition material and case studies are presented for practical implementation in other universities. | arxiv:1601.06659 |
the problem of constructing optimal discriminating designs for a class of regression models is considered. we investigate a version of the $ t _ p $ - optimality criterion as introduced by atkinson and fedorov [ biometrika 62 ( 1975a ) 289 - 303 ]. the numerical construction of optimal designs is very hard and challenging, if the number of pairwise comparisons is larger than 2. it is demonstrated that optimal designs with respect to this type of criteria can be obtained by solving ( nonlinear ) vector - valued approximation problems. we use a characterization of the best approximations to develop an efficient algorithm for the determination of the optimal discriminating designs. the new procedure is compared with the currently available methods in several numerical examples, and we demonstrate that the new method can find optimal discriminating designs in situations where the currently available procedures fail. | arxiv:1306.1320 |
we have performed 1 - dimensional calculations for explosive nucleosynthesis in collapse - driven supernova and investigated its sensitivity to the initial form of the shock wave. we have found the tendency that the peak temperature becomes higher around the mass cut if the input energy is injected more in the form of kinetic energy rather than internal energy. then, the mass cut becomes larger, and, as a result, neutron - rich matter is less included in the ejecta ; this is favorable for producing the observational data compared with a previous model. our results imply that the standard method to treat various processes for stellar evolution, such as convection and electron capture during the silicon burning stage, are still compatible with the calculation of explosive nucleosynthesis. | arxiv:astro-ph/9807014 |
we consider infinitely - wide multi - layer perceptrons ( mlps ) which are limits of standard deep feed - forward neural networks. we assume that, for each layer, the weights of an mlp are initialized with i. i. d. samples from either a light - tailed ( finite variance ) or heavy - tailed distribution in the domain of attraction of a symmetric $ \ alpha $ - stable distribution, where $ \ alpha \ in ( 0, 2 ] $ may depend on the layer. for the bias terms of the layer, we assume i. i. d. initializations with a symmetric $ \ alpha $ - stable distribution having the same $ \ alpha $ parameter of that layer. we then extend a recent result of favaro, fortini, and peluchetti ( 2020 ), to show that the vector of pre - activation values at all nodes of a given hidden layer converges in the limit, under a suitable scaling, to a vector of i. i. d. random variables with symmetric $ \ alpha $ - stable distributions. | arxiv:2106.11064 |
we study the maximum geometric independent set and clique problems in the streaming model. given a collection of geometric objects arriving in an insertion only stream, the aim is to find a subset such that all objects in the subset are pairwise disjoint or intersect respectively. we show that no constant factor approximation algorithm exists to find a maximum set of independent segments or $ 2 $ - intervals without using a linear number of bits. interestingly, our proof only requires a set of segments whose intersection graph is also an interval graph. this reveals an interesting discrepancy between segments and intervals as there does exist a $ 2 $ - approximation for finding an independent set of intervals that uses only $ o ( \ alpha ( \ mathcal { i } ) \ log | \ mathcal { i } | ) $ bits of memory for a set of intervals $ \ mathcal { i } $ with $ \ alpha ( \ mathcal { i } ) $ being the size of the largest independent set of $ \ mathcal { i } $. on the flipside we show that for the geometric clique problem there is no constant - factor approximation algorithm using less than a linear number of bits even for unit intervals. on the positive side we show that the maximum geometric independent set in a set of axis - aligned unit - height rectangles can be $ 4 $ - approximated using only $ o ( \ alpha ( \ mathcal { r } ) \ log | \ mathcal { r } | ) $ bits. | arxiv:2207.01108 |
testing facility in 1920. between world wars i and ii, great leaps were made in the field, accelerated by the advent of mainstream civil aviation. notable airplanes of this era include the curtiss jn 4, farman f. 60 goliath, and fokker trimotor. notable military airplanes of this period include the mitsubishi a6m zero, supermarine spitfire and messerschmitt bf 109 from japan, united kingdom, and germany respectively. a significant development came with the first operational jet engine - powered airplane, the messerschmitt me 262 which entered service in 1944 towards the end of the second world war. the first definition of aerospace engineering appeared in february 1958, considering the earth ' s atmosphere and outer space as a single realm, thereby encompassing both aircraft ( aero ) and spacecraft ( space ) under the newly coined term aerospace. = = = cold war = = = in response to the ussr launching the first satellite, sputnik, into space on october 4, 1957, u. s. aerospace engineers launched the first american satellite on january 31, 1958. the national aeronautics and space administration was founded in 1958 after the sputnik crisis. in 1969, apollo 11, the first human space mission to the moon, took place. it saw three astronauts enter orbit around the moon, with two, neil armstrong and buzz aldrin, visiting the lunar surface. the third astronaut, michael collins, stayed in orbit to rendezvous with armstrong and aldrin after their visit. an important innovation came on january 30, 1970, when the boeing 747 made its first commercial flight from new york to london. this aircraft made history and became known as the " jumbo jet " or " queen of the skies " due to its ability to hold up to 480 passengers. = = = 1976 : first passenger supersonic aircraft = = = another significant development came in 1976, with the development of the first passenger supersonic aircraft, the concorde. the development of this aircraft was agreed upon by the french and british on november 29, 1962. on december 21, 1988, the antonov an - 225 mriya cargo aircraft commenced its first flight. it holds the records for the world ' s heaviest aircraft, heaviest airlifted cargo, and longest airlifted cargo of any aircraft in operational service. on october 25, 2007, the airbus a380 made its maiden commercial flight from singapore to sydney, australia. this aircraft was the first passenger plane to surpass the boeing 747 in terms of passenger capacity, with a maximum of 853 | https://en.wikipedia.org/wiki/Aerospace_engineering |
we examine the possibility of using near - infrared scattering to constrain the local radiation field and the dust properties, for example, the size distribution of the grains, and maximum grain size. we use radiative transfer modelling to examine the constraints provided by j, h, and k bands in combination with mid - infrared surface brightness at 3. 6 $ \ mu $ m. we use a spherical one - dimensional and elliptical three - dimensional cloud models to study the observable effects of different grain size distributions with varying absorption and scattering properties. as an example, we analyse observations of a molecular cloud in taurus, tmc - 1n. the observed surface brightness ratios between the bands change when the dust properties are changed. however, even a small change of 10 % in the surface brightness of one channel changes the estimated powerlaw exponent of the size distribution $ \ gamma $ by up to ~ 30 % and the estimated strength of the radiation field k _ isrf by up to ~ 60 %. the maximum grain size a _ max and $ \ gamma $ are always strongly anti - correlated. for example, overestimating the surface brightness by 10 % changes the estimated radiation field strength by ~ 20 % and the exponent of the size distribution by ~ 15 %. the analysis of our synthetic observations indicates that the relative uncertainty of the parameter distributions are on average a _ max, $ \ gamma $ ~ 25 %, and the deviation between the estimated and correct values $ \ delta $ q < 15 %. we show that scattered infrared light can be used to derive meaningful limits for the dust parameters. however, errors in the surface brightness data can result in considerable uncertainties in the derived parameters. | arxiv:1802.07517 |
the two still unidentified mev sources egr j1122 - 5946 and agl j2022 + 3622 are here tentatively associated with soft gamma - ray candidate counterparts detected through integral / ibis observations. on the basis of spatial proximity and / or similar transient behaviour, we propose the supergiant fast x - ray transient ( sfxt ) igr j11215 - 5952 and the candidate sfxt igr j20188 + 3647 as possible candidate counterparts of egr j1122 - 5946 and agl j2022 + 3622, respectively. our findings possibly suggest that hard fast x - ray transients could represent a new class of galactic transient mev / tev emitters. additional evidence for the existence of such new class is also provided by very recent agile and glast discoveries on the galactic plane of several unidentified transient mev sources lasting only a few days. | arxiv:0902.0245 |
in this article we generalize the notion of constant angle surfaces in s ^ 2 x r and h ^ 2 x r to general bianchi - cartan - vranceanu spaces, i. e. essentially to three - dimensional homogeneous spaces with a four - dimensional isometry group. we show that these surfaces have constant gaussian curvature and we give a complete local classification in the heisenberg group. | arxiv:0907.5528 |
let $ n $ be a positive integer, and let $ k $ be a field ( of arbitrary characteristic ) accessible to symbolic computation. we describe an algorithmic test for determining whether or not a finitely presented $ k $ - algebra $ r $ has infinitely many equivalence classes of semisimple representations $ r \ to m _ n ( k ' ) $, where $ k ' $ is the algebraic closure of $ k $. the test reduces the problem to computational commutative algebra over $ k $, via famous results of artin, procesi, and shirshov. the test is illustrated by explicit examples, with $ n = 3 $. | arxiv:0708.3190 |
for an increasing number of data intensive scientific applications, parallel i / o concepts are a major performance issue. tackling this issue, we develop an input / output system designed for highly efficient, scalable and conveniently usable parallel i / o on distributed memory systems. the main focus of this research is the parallel i / o runtime system support provided for software - generated programs produced by parallelizing compilers in the context of high performance fortran efforts. specifically, our design aims for the vienna fortran compilation system. in our research project we investigate the i / o problem from a runtime system support perspective. we focus on the design of an advanced parallel i / o support, called vipios ( vienna parallel i / o system ), to be targeted by language compilers supporting the same programming model like high performance fortran ( hpf ). the vipios design is partly influenced by the concepts of parallel database technology. at the beginning of the project we developed a formal model, which forms a theoretical framework on which the vipios design is based. this model describes the mapping of the problem specific data space starting from the application program data structures down to the physical layout on disk across several intermediate representation levels. based on this formal model we designed and developed an i / o runtime system, vipios, which provides support for several issues, as - parallel access to files for read / write operations, - optimization of data - layout on disks, - redistribution of data stored on disks, - communication of out - of - core ( ooc ) data, and - many optimizations including data prefetching from disks based on the access pattern knowledge extracted from the program by the compiler or provided by a user specification. | arxiv:1808.01166 |
gifts are important instruments for forming bonds in interpersonal relationships. our study analyzes the phenomenon of gift contagion in online groups. gift contagion encourages social bonds by prompting further gifts ; it may also promote group interaction and solidarity. using data on 36 million online red packet gifts on a large social site in east asia, we leverage a natural experimental design to identify the social contagion of gift giving in online groups. our natural experiment is enabled by the randomization of the gift amount allocation algorithm on the platform, which addresses the common challenge of causal identifications in observational data. our study provides evidence of gift contagion : on average, receiving one additional dollar causes a recipient to send 18 cents back to the group within the subsequent 24 hours. decomposing this effect, we find that it is mainly driven by the extensive margin - - more recipients are triggered to send red packets. moreover, we find that this effect is stronger for " luckiest draw " recipients, suggesting the presence of a group norm regarding the next red packet sender. finally, we investigate the moderating effects of group - and individual - level social network characteristics on gift contagion as well as the causal impact of receiving gifts on group network structure. our study has implications for promoting group dynamics and designing marketing strategies for product adoption. | arxiv:1906.09698 |
fringe projection profilometry ( fpp ) has become increasingly important in dynamic 3 - d shape measurement. in fpp, it is necessary to retrieve the phase of the measured object before shape profiling. however, traditional phase retrieval techniques often require a large number of fringes, which may generate motion - induced error for dynamic objects. in this paper, a novel phase retrieval technique based on deep learning is proposed, which uses an end - to - end deep convolution neural network to transform a single or two fringes into the phase retrieval required fringes. when the object ' s surface is located in a restricted depth, the presented network only requires a single fringe as the input, which otherwise requires two fringes in an unrestricted depth. the proposed phase retrieval technique is first theoretically analyzed, and then numerically and experimentally verified on its applicability for dynamic 3 - d measurement. | arxiv:1906.05652 |
the 2024 edition of the cg : shop challenge focused on the knapsack polygonal packing problem. each instance consists of a convex polygon known as the container and a multiset of items, where each item is a simple polygon with an associated integer value. a feasible packing solution places a selection of the items inside the container without overlapping and using only translations. the goal is to achieve a packing that maximizes the total value of the items in the solution. our approach to win first place is divided into two main steps. first, we generate promising initial solutions using two strategies : one based on integer linear programming and the other on employing a combination of geometric greedy heuristics. in the second step, we enhance these solutions through local search techniques, which involve repositioning items and exploring potential replacements to improve the total value of the packing. | arxiv:2403.20123 |
in this note we revisit the analysis performed in arxiv : 2305. 07217 of odd - parity perturbations around static and spherically symmetric black holes in einsteinian cubic gravity ( ecg ). we show that the additional propagating modes always have masses much above the cutoff of the theory. therefore, contrary to what is claimed in that paper, the ecg black holes remain stable within the effective field theory regime. we consider the same analysis for a general cubic theory, showing that the ecg results are not special in this regard. we use the occasion to make some clarifications on the role, uses and limitations of ecg and its generalizations. | arxiv:2306.02924 |
the dispersive sweep of fast radio bursts ( frbs ) has been used to probe the ionized baryon content of the intergalactic medium, which is assumed to dominate the total extragalactic dispersion. while the host galaxy contributions to dispersion measure ( dm ) appear to be small for most frbs, in at least one case there is evidence for an extreme magneto - ionic local environment and a compact persistent radio source. here we report the detection and localization of the repeating frb 20190520b, which is co - located with a compact, persistent radio source and associated with a dwarf host galaxy of high specific star formation rate at a redshift $ z = 0. 241 \ pm0. 001 $. the estimated host galaxy dm $ \ approx 903 ^ { + 72 } _ { - 111 } $ pc cm $ ^ { - 3 } $, nearly an order of magnitude higher than the average of frb host galaxies, far exceeds the dm contribution of the intergalactic medium. caution is thus warranted in inferring redshifts for frbs without accurate host galaxy identifications. | arxiv:2110.07418 |
after galileo ' s publication of the sidereus nuncius in 1610, giovanni battista agucchi obtained in 1611 an estimate of the orbital periods of the galilean satellites of jupiter using the figures published in the book. the article shows how to repeat these measurements in a teaching context for high school students. | arxiv:2404.01410 |
several states were proposed as candidates for the $ \ nu = 5 / 2 $ quantum hall plateau. we suggest an experiment which can determine the physical state. the proposal involves transport measurements in the geometry with three quantum hall edges connected by two quantum point contacts. in contrast to interference experiments, this approach can distinguish the pfaffian and anti - pfaffian states as well as different states with identical pfaffian or anti - pfaffian statistics. the transport is not sensitive to the fluctuations of the number of the quasiparticles trapped in the system. | arxiv:0807.2908 |
a shapeable planar hall sensor has been fabricated by lift - off a bilayer structure of nife ( 10 nm ) / irmn ( 8 nm ) grown on a kapton / pdms substrate without using a buffer layer. the sensor exhibits a magnetic field sensitivity of 0. 74 $ \ mu $ v / oe. ma and provides a stable response under repetitive on / off experiments. the concave and convex bending measurements indicate that the amr voltage of the sensor is very sensitive to the stress and strain. however, the planar hall sensitivity is independent from them with a stable linear region and unchanged peak positions in the magnetic field axis. this type of behaviour has been observed for the first time in the planar hall sensors. therefore, this novel device can fulfill simultaneous multifunctional sensing of small magnetic fields, stress and strain. this makes it promising for tactile sensing applications in humanoid robotics. | arxiv:1901.08867 |
cost estimation is a very crucial field for software developing companies. in the context of learning organizations, estimation applicability and accuracy are not the only acceptance criteria. the contribution of an estimation technique to the understanding and maturing of related organizational processes ( such as identification of cost and productivity factors, measurement, data validation, model validation, model maintenance ) has recently been gaining increasing importance. yet, most of the proposed cost modeling approaches provide software engineers with hardly any assistance in supporting related processes. insufficient support is provided for validating created cost models ( including underlying data collection processes ) or, if valid models are obtained, for applying them to achieve an organization ' s objectives such as improved productivity or reduced schedule. this paper presents an enhancement of the cobra ( r ) cost modeling method by systematically including additional quantitative methods into iterative analysis - feedback cycles. applied at oki electric industry co., ltd., japan, the cobra ( r ) method contributed to the achievement of the following objectives, including : ( 1 ) maturation of existing measurement processes, ( 2 ) increased expertise of oki software project decision makers regarding cost - related software processes, and, finally, ( 3 ) reduction of initial estimation error from an initial 120 % down to 14 %. | arxiv:1402.2389 |
nucleation is a common phenomenon in all types of galaxies and at least 70 % of them host nuclear star clusters ( nscs ) in their centres. many of the nscs co - habit with super - massive black holes and follow similar scaling relations with host galaxy properties. nscs, unlike black holes, preserve the signature of their evolutionary path imprinted onto their kinematics and stellar populations. thus their study provides us with important information about the formation of galactic nuclei. in this paper we explored the angular momentum of the nuclei of six intermediate mass ( 9. 7 > log ( mdyn / m _ sun ) > 10. 6 ) early - type galaxies in the fornax cluster that host nscs. our goal was to derive a link between the nuclear angular momentum and the proposed formation scenarios of nscs. we used adaptive optics assisted ifu observations with vlt / sinfoni to derive the spatially resolved stellar kinematics of the galaxy nuclei. we measured their specific stellar angular momenta ( $ \ lambda _ \ mathrm { re } $ ), and compared these with milky way globular clusters and n - body simulations of nsc formation. we found that all studied nuclei exhibit varied stellar kinematics. their specific stellar angular momenta and ellipticities are similar to milky way globular clusters ( gcs ). five out of six galaxy nuclei are consistent with the $ \ lambda _ \ mathrm { re } - \ epsilon _ \ mathrm { e } $ of simulated nscs embedded in a contaminating nuclear bulge that have formed via the in - spiralling and merging of gcs. it has previously been suggested that the nscs in higher mass galaxies, like the ones studied in this paper, form via dissipational sinking of gas onto the galactic nuclei with hints that some might also involve the merger of gcs. here we showed that we cannot exclude the pure gc merging scenario as a viable path for the formation of nscs. | arxiv:1903.10918 |
we extend our previous calculation of the breakup of 11be using halo effective field theory and the dynamical eikonal approximation to include an effective 10be - n - target force. the force is constructed to account for the virtual excitation of 10be to its low - lying 2 + excited state. in the case of breakup on a 12c target this improves the description of the neutron - energy and angular spectra, especially in the vicinity of the 11be 5 / 2 + state. by fine - tuning the range parameters of the three - body force, a reasonable description of data in the region of the 3 / 2 + 11be state can also be obtained. this sensitivity to the three - body force ' s range results from the structure of the overlap integral that governs the 11be s - to - d - state transitions induced by the three - body force. | arxiv:2008.05898 |
we establish a theory of $ q $ - valued functions minimizing a suitable generalization of the dirichlet integral. in a second paper the theory will be used to approximate efficiently area minimizing currents $ \ mathrm { mod } ( p ) $ when $ p = 2q $, and to establish a first general partial regularity theorem for every $ p $ in any dimension and codimension. | arxiv:1909.03305 |
nigeria is a multilingual country with 500 + languages. naija is a nigerian pidgin spoken by approximately 120m speakers and it is a mixed language ( e. g., english, portuguese, yoruba, hausa and igbo ). although it has mainly been a spoken language until recently, there are some online platforms ( e. g., wikipedia ), publishing in written naija as well. west african pidgin english ( wape ) is also spoken in nigeria and it is used by bbc to broadcast news on the internet to a wider audience not only in nigeria but also in other west african countries ( e. g., cameroon and ghana ). through statistical analyses and machine translation experiments, our paper shows that these two pidgin varieties do not represent each other ( i. e., there are linguistic differences in word order and vocabulary ) and generative ai operates only based on wape. in other words, naija is underrepresented in generative ai, and it is hard to teach llms with few examples. in addition to the statistical analyses, we also provide historical information on both pidgins as well as insights from the interviews conducted with volunteer wikipedia contributors in naija. | arxiv:2404.19442 |
in this paper, we study semi - supervised graph classification, which aims at accurately predicting the categories of graphs in scenarios with limited labeled graphs and abundant unlabeled graphs. despite the promising capability of graph neural networks ( gnns ), they typically require a large number of costly labeled graphs, while a wealth of unlabeled graphs fail to be effectively utilized. moreover, gnns are inherently limited to encoding local neighborhood information using message - passing mechanisms, thus lacking the ability to model higher - order dependencies among nodes. to tackle these challenges, we propose a hypergraph - enhanced dual framework named heal for semi - supervised graph classification, which captures graph semantics from the perspective of the hypergraph and the line graph, respectively. specifically, to better explore the higher - order relationships among nodes, we design a hypergraph structure learning to adaptively learn complex node dependencies beyond pairwise relations. meanwhile, based on the learned hypergraph, we introduce a line graph to capture the interaction between hyperedges, thereby better mining the underlying semantic structures. finally, we develop a relational consistency learning to facilitate knowledge transfer between the two branches and provide better mutual guidance. extensive experiments on real - world graph datasets verify the effectiveness of the proposed method against existing state - of - the - art methods. | arxiv:2405.04773 |
assuming that the world - sheet sigma - model in the ads / cft correspondence is an integrable { \ em quantum } field theory, we deduce that there might be new corrections to the spin - chain / string bethe ansatz paradigm. these come from virtual particles propagating around the circumference of the cylinder and render bethe ansatz quantization conditions only approximate. we determine the nature of these corrections both at weak and at strong coupling in the near bmn limit, and find that the first corrections behave qualitatively as wrapping interactions at weak coupling. | arxiv:hep-th/0510171 |
a central paradigm of polymer physics states that chains in melts behave like random walks as intra - and interchain interactions effectively cancel each other out. likewise, $ \ theta $ - chains, i. e., chains at the transition from a swollen coil to a globular phase, are also thought to behave like ideal chains, as attractive forces are counterbalanced by repulsive entropic contributions. while the simple mapping to an equivalent kuhn chain works rather well in most scenarios with corrections to scaling, random walks do not accurately capture the topology and knots particularly for flexible chains. in this paper, we demonstrate with monte carlo and molecular dynamics simulations that chains in polymer melts and $ \ theta $ - chains not only agree on a structural level for a range of stiffnesses, but also topologically. they exhibit similar knotting probabilities and knot sizes, both of which are not captured by ideal chain representations. this discrepancy comes from the suppression of small knots in real chains, which is strongest for very flexible chains because excluded volume effects are still active locally and become weaker with increasing semiflexibility. our findings suggest that corrections to ideal behavior are indeed similar for the two scenarios of real chains and that structure and topology of a chain in a melt can be approximately reproduced by a corresponding $ \ theta $ - chain. | arxiv:2411.13357 |
we study the approximation rates of a class of deep neural network approximations of operators, which arise as data - to - solution maps $ \ mathcal { g } ^ \ dagger $ of linear elliptic partial differential equations ( pdes ), and act between pairs $ x, y $ of suitable infinite - dimensional spaces. we prove expression rate bounds for approximate neural operators $ \ mathcal { g } $ with the structure $ \ mathcal { g } = \ mathcal { r } \ circ \ mathcal { a } \ circ \ mathcal { e } $, with linear encoders $ \ mathcal { e } $ and decoders $ \ mathcal { r } $. the constructive proofs are via a recurrent nn structure obtained by unrolling exponentially convergent, self - consistent ( ` ` richardson ' ' ) iterations. we bound the operator approximation error with respect to the linear kolmogorov $ n $ - widths of the data and solution sets and in terms of the size of the approximation network. we prove expression rate bounds for approximate, neural solution operators emulating the coefficient - to - solution maps for elliptic pdes set in $ d $ - dimensional polytopes, with $ d \ in \ { 2, 3 \ } $, and subject to dirichlet -, neumann - or mixed boundary conditions. exploiting weighted norm characterizations of the solution sets of elliptic pdes in polytopes, we show algebraic rates of expression for problems with data with finite regularity, and exponential operator expression rates for analytic data. | arxiv:2409.17552 |
##l - thomson would be marketed under the tcl brand in asia, and the thomson and rca brands in europe and north america. in april 2004, tcl and alcatel announced the creation of a mobile phone manufacturing joint venture : alcatel mobile. tcl injected 55 million euros in the venture in return for a 55 per cent shareholding. in april 2005, tcl closed its manufacturing plant in turkheim, bavaria, laying off 120 former schneider employees. in may 2005, tcl announced that its hong kong - listed unit would acquire alcatel ' s 45 per cent stake in their mobile - phone joint venture for consideration of hk $ 63. 34 million ( $ 8. 1 million ) worth of tcl communication shares. in june 2007, tcl announced that its mobile phone division planned to cease using the alcatel brand and switch entirely to the tcl brand within five years. in april 2008, samsung electronics announced that it would be outsourcing the production of some lcd tv modules to tcl. in july 2008, tcl announced that it planned to raise 1. 7 billion yuan ( $ 249 million ) via a share placement on the shenzhen stock exchange to fund the construction of two production lines for lcd televisions ; one for screens of up to 42 inches, and the other for screens of up to 56 inches. tcl sold a total of 4. 18 million lcd tv sets in 2008, more than triple the number during 2007. in january 2009, tcl announced plans to double its lcd tv production capacity to 10 million units by the end of 2009. in november 2009, tcl announced that it had formed a joint - venture with the shenzhen government to construct an 8. 5 - generation thin film transistor - liquid crystal display production facility in the city at a cost of $ 3. 9 billion. in march 2010, tcl electronics raised hk $ 525 million through the sale of shares on the hong kong stock exchange, in order to fund the development of its lcd and led businesses and to generate working capital. in may 2011, tcl launched the china smart multimedia terminal technology association in partnership with hisense electric co. and sichuan changhong electric co., with the aim of helping to establish industry standards for smart televisions. in january 2013, tcl bought the naming rights for grauman ' s chinese theatre for $ 5 million. in 2014, tcl changed the meaning of its identifying initials from " telephone communication limited " to a branding slogan, " the creative life ", for commercial purposes | https://en.wikipedia.org/wiki/TCL_Technology |
three different characterizations of one - component bounded analytic functions are provided. the first one is related to the the inner - outer factorization, the second one is in terms of the size of the reproducing kernels in the corresponding de branges - rovnyak spaces and the last one concerns the associated clark measure. | arxiv:2206.01985 |
we show that there is a consistent polynomial quantization of the coordinate ring of a basic nilpotent coadjoint orbit of a semisimple lie group. we also show, at least in the case of a nilpotent orbit in sl ( 2, r ) *, that any such quantization is essentially trivial. furthermore, we prove that the coordinate ring of a basic semisimple orbit in sl ( 2, r ) * cannot be consistently polynomially quantized. | arxiv:math-ph/0012034 |
in this paper, a novel protocol for bidirectional controlled quantum teleportation ( bcqt ) is proposed. based on entanglement swapping of initiate bell state, two users can teleport an unknown single - qubit state to each other under the permission of the supervisor. this proposed protocol would be utilized to a system in which a controller controls the communication in one direction only. indeed, just one of the users needs the permission of the controller to reconstruct the unknown quantum state. in comparison to the existing bcqt protocols which their quantum channels are cluster and brown state, the proposed protocol is more practical within todays technology, since it merely uses bell states as the quantum resource. | arxiv:1502.03551 |
this paper reports on an automated control strategy to set and stabilize a 2x2 integrated optical gate implemented with a balanced mach - zehnder interferometer ( mzi ). the control strategy reliably configures the gate in any desired working point without any prior calibration or complex algorithm for the correction of hardware non - idealities. it has been tested on a multistage silicon photonic chip comprising a coherent input vector generator, the 2x2 gate used as matrix - vector multiplier and a coherent receiver for phase measurement. by leveraging the presence of transparent photodiodes in key positions, precise control of light beams in any point of the circuit is obtained, which translates into a resolution in the computation of the matrix - vector product of 7. 2 and 8. 5 bits for the output power and phase, respectively. high accuracy, robustness against non - idealities and stability over long - term operation, ensured by the feedback - controlled architecture, provide scalability towards optical processors of any size. additionally, the possibility of using the mzi both as computing gate and phase validation unit avoids propagation of programming errors, solving a significant issue of coherent optical computing architectures. | arxiv:2502.12869 |
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