We follow the history and development of Brouwer's use of individual choice sequences up to the discovery of a method to apply them successfully in 1927. With the principles we derive from this first use we analyze in detail Brouwer's work from that time onward. Our reconstruction uses only very basic principles. It aligns exactly with Brouwer's work after 1927 and, moreover, it gives a clear explanation of the proofs of his results and the terms he uses.
Long user history is highly valuable signal for recommendation systems, but effectively incorporating it often comes with high cost in terms of data center power consumption and GPU. In this work, we chose offline embedding over end-to-end sequence length optimization methods to enable extremely long user sequence modeling as a cost-effective solution, and propose a new user embedding learning strategy, multi-slicing and summarization, that generates highly generalizable user representation of user's long-term stable interest. History length we encoded in this embedding is up to 70,000 and on average 40,000. This embedding, named as DV365, is proven highly incremental on top of advanced attentive user sequence models deployed in Instagram. Produced by a single upstream foundational model, it is launched in 15 different models across Instagram and Threads with significant impact, and has been production battle-proven for >1 year since our first launch.
Christoph Draxler, Henk van den Heuvel, Arjan van Hessen
et al.
Oral history is about oral sources of witnesses and commentors on historical events. Speech technology is an important instrument to process such recordings in order to obtain transcription and further enhancements to structure the oral account In this contribution we address the transcription portal and the webservices associated with speech processing at BAS, speech solutions developed at LINDAT, how to do it yourself with Whisper, remaining challenges, and future developments.
In 2006 and 2016, the University of Pennsylvania denied any ties to slavery. In 2017, a group of undergraduate researchers, led by Professor Kathleen Brown, investigated this claim. Initial research, focused on 18th century faculty and trustees who owned slaves, revealed deep connections between the university's history and the institution of slavery. These findings, and discussions amongst the researchers shaped the Penn and Slavery Project's goal of redefining complicity beyond ownership. Breanna Moore's contributions in PSP's second semester expanded the project's focus to include generational wealth gaps. In 2018, VanJessica Gladney served as the PSP's Public History Fellow and spread the project outreach in the greater Philadelphia area. That year, the PSP team began to design an augmented reality app as a Digital Interruption and an attempt to display the truth about Penn's history on its campus. Unfortunately, PSP faced delays due to COVID 19. Despite setbacks, the project persisted, engaging with activists and the wider community to confront historical injustices and modern inequalities.
We propose a novel method to quantify the assembly histories of dark matter halos with the redshift evolution of the mass-weighted spatial variance of their progenitor halos, i.e. the protohalo size history. We find that the protohalo size history for each individual halo at z~0 can be described by a double power-law function. The amplitude of the fitting function strongly correlates to the central-to-total stellar mass ratios of descendant halos. The variation of the amplitude of the protohalo size history can induce a strong halo assembly bias effect for massive halos. This effect is detectable in observation using the central-to-total stellar mass ratio as a proxy of the protohalo size. The correlation to the descendant central-to-total stellar mass ratio and the halo assembly bias effect seen in the protohalo size are much stronger than that seen in the commonly adopted half-mass formation time derived from the mass accretion history. This indicates that the information loss caused by the compression of halo merger trees to mass accretion histories can be captured by the protohalo size history. Protohalo size thus provides a useful quantity to connect protoclusters across cosmic time and to link protoclusters with their descendant clusters in observations.
To understand the evolution of the Moon, we numerically modeled mantle convection and magmatism in a two-dimensional polar rectangular mantle. Magmatism occurs as an upward permeable flow of magma generated by decompression melting through the convecting matrix. The mantle is assumed to be initially enriched in heat-producing elements (HPEs) and compositionally dense ilmenite-bearing cumulates (IBC) at its base. Here, we newly show that magma generation and migration play a crucial role in the calculated volcanic and radial expansion/contraction history. Magma is generated in the deep mantle by internal heating for the first several hundred million years. A large volume of the generated magma ascends to the surface as partially molten fingers and plumes driven by melt-buoyancy to cause a volcanic activity and radial expansion of the planet with the peak at 3.5-4 Gyr ago. Eventually, however, the planet begins to radially contract when the mantle solidifies by cooling from the surface boundary. As the mantle is cooled, the activity of partially molten plumes declines but continues for billions of years after the peak because some basal materials enriched in the dense IBC components hold HPEs. The calculated volcanic and radial expansion/contraction history is consistent with the observed history of the Moon. Our simulations suggest a substantial fraction of the mantle was solid, and there was a basal layer enriched in HPEs and the IBC components at the beginning of the history of the Moon.
Andrew Iskauskas, Ian Vernon, Michael Goldstein
et al.
Modelling complex real-world situations such as infectious diseases, geological phenomena, and biological processes can present a dilemma: the computer model (referred to as a simulator) needs to be complex enough to capture the dynamics of the system, but each increase in complexity increases the evaluation time of such a simulation, making it difficult to obtain an informative description of parameter choices that would be consistent with observed reality. While methods for identifying acceptable matches to real-world observations exist, for example optimisation or Markov chain Monte Carlo methods, they may result in non-robust inferences or may be infeasible for computationally intensive simulators. The techniques of emulation and history matching can make such determinations feasible, efficiently identifying regions of parameter space that produce acceptable matches to data while also providing valuable information about the simulator's structure, but the mathematical considerations required to perform emulation can present a barrier for makers and users of such simulators compared to other methods. The hmer package provides an accessible framework for using history matching and emulation on simulator data, leveraging the computational efficiency of the approach while enabling users to easily match to, visualise, and robustly predict from their complex simulators.
Sachini Herath, Saghar Irandoust, Bowen Chen
et al.
The paper proposes a multi-modal sensor fusion algorithm that fuses WiFi, IMU, and floorplan information to infer an accurate and dense location history in indoor environments. The algorithm uses 1) an inertial navigation algorithm to estimate a relative motion trajectory from IMU sensor data; 2) a WiFi-based localization API in industry to obtain positional constraints and geo-localize the trajectory; and 3) a convolutional neural network to refine the location history to be consistent with the floorplan. We have developed a data acquisition app to build a new dataset with WiFi, IMU, and floorplan data with ground-truth positions at 4 university buildings and 3 shopping malls. Our qualitative and quantitative evaluations demonstrate that the proposed system is able to produce twice as accurate and a few orders of magnitude denser location history than the current standard, while requiring minimal additional energy consumption. We will publicly share our code, data and models.
The problem of how to interpret quantum mechanics has persisted for a century. The disconnect between the wavefunction state vector and what is observed in experimental apparati has had no shortage of explanations. But all explanations so far fall short of a compelling and complete interpretation. In this letter, I present a novel interpretation called dynamic histories. I show mathematically how quantum mechanics can be reinterpreted as deterministically evolving dynamical world lines in a 5D universe. Quantum probabilities can be then be reinterpreted as stemming from ignorance of the state of our own world line. Meanwhile, the lack of observed superposition in experimental apparati is explained in that we only live on a single history with a definite set of properties. Hence, superposition is not an actual state of a particle but a model of ignorance as in classical probability theory. This explains nonlocal effects without superluminal communication. I also discuss how this relates to 5D Kaluza-Klein theory.
The United Nations' Sustainable Development Goal 3.2 aims to reduce under-5 child mortality to 25 deaths per 1,000 live births by 2030. Child mortality tends to be concentrated in developing regions where much of the information needed to assess achievement of this goal comes from surveys and censuses. In both, women are asked about their birth histories, but with varying degrees of detail. Full birth history (FBH) data contain the reported dates of births and deaths of every surveyed mother's children. In contrast, summary birth history (SBH) data contain only the total number of children born and total number of children who died for each mother. Specialized methods are needed to accommodate this type of data into analyses of child mortality trends. We develop a data augmentation scheme within a Bayesian framework where for SBH data, birth and death dates are introduced as auxiliary variables. Since we specify a full probability model for the data, many of the well-known biases that exist in this data can be accommodated, along with space-time smoothing on the underlying mortality rates. We illustrate our approach in a simulation, showing that uncertainty is reduced when incorporating SBH data over simply analyzing all available FBH data. We also apply our approach to data in the Central region of Malawi. We compare with the well-known Brass method.
Xiaodong Luo, Tuhin Bhakta, Morten Jakobsen
et al.
In this work we propose an ensemble 4D seismic history matching framework for reservoir characterization. Compared to similar existing frameworks in reservoir engineering community, the proposed one consists of some relatively new ingredients, in terms of the type of seismic data in choice, wavelet multiresolution analysis for the chosen seismic data and related data noise estimation, and the use of recently developed iterative ensemble history matching algorithms. Typical seismic data used for history matching, such as acoustic impedance, are inverted quantities, whereas extra uncertainties may arise during the inversion processes. In the proposed framework we avoid such intermediate inversion processes. In addition, we also adopt wavelet-based sparse representation to reduce data size. Concretely, we use intercept and gradient attributes derived from amplitude versus angle (AVA) data, apply multilevel discrete wavelet transforms (DWT) to attribute data, and estimate noise level of resulting wavelet coefficients. We then select the wavelet coefficients above a certain threshold value, and history-match these leading wavelet coefficients using an iterative ensemble smoother. (The rest of the abstract is omitted for exceeding the limit of length)
Emilio Delgado Lopez-Cozar, Manuel Ramirez Sanchez
Google Scholar Metrics (GSM), which was recently launched in April 2012, features new bibliometric systems for gauging scientific journals by counting the number of citations obtained in Google Scholar. This way, it opens new possibilities for measuring journal impacts in the field of Humanities. The present article intends to evaluate the scope of this tool through analysing GSM searches, from the 5th through 6th of December 2012, of History journals published in Spain. In sum, 69 journals were identified, accounting for only 24% of the History journals published in Spain. The ranges of H index values for this field are so small that the ranking can no longer be said to show a discriminating potential. In the light of this, we would like to propose a change in the way Google Scholar Metrics is designed so that it could also accommodate production and citation patterns in the particular field of History, and, in a broader scope, in the area of Humanities as well.
We present the first results from a study designed to test whether, given high-quality spectrophotometry spanning the mid-UV--optical wavelength regime, it is possible to distinguish the metal content (Z) and star-formation history (sfh) of individual elliptical galaxies with sufficient accuracy to establish whether their formation history is linked to their detailed morphology and position on the Fundamental Plane. From a detailed analysis of UV-optical spectrophotometry of the `cuspy' elliptical galaxy NGC 3605 and the giant elliptical NGC 5018 we find that: 1) optical spectra with l > 3500 A may not contain sufficient data to robustly uncover all the stellar populations present in individual galaxies, even in such relatively passive objects as ellipticals, 2) the addition of the UV data approaching l = 2500 A holds the key to establishing well-constrained sfhs, from which we can infer a formation and evolution history which is consistent with their photometric properties, 3) despite the superficial similarity of their spectra, the two galaxies have very different `recent' sfhs -- the smaller, cuspy elliptical NGC 3605 contains a high-Z population of age ~= 1 Gyr, and has a position on the fundamental plane typical of the product of a low-z gas-rich merger (most likely at z ~ 0.08), while the giant elliptical NGC 5018, with a sub-solar secondary population, appears to have gained its more recent stars via mass transfer / accretion of gas from its spiral companion, 4) despite these differences in detailed history, more than 85% of the stellar mass of both galaxies is associated with an old (9-12 Gyr) stellar population of near-solar Z. This pilot study provides strong motivation for the construction and analysis of high-quality UV-optical spectra for a substantial sample of ellipticals spanning the Fundamental Plane.
Mary M. Crone, Regina E. Schulte-Ladbeck, Laura Greggio
et al.
We present the star formation history of UGCA 290, a galaxy with properties intermediate between Blue Compact Dwarfs and Dwarf Irregulars. This galaxy is particularly interesting because its young stellar population is extremely similar to that of the well-studied type iE Blue Compact Dwarf VII Zw 403, despite its different spatial morphology and old stellar content. Our Hubble Space Telescope/Wide Field Planetary Camera 2 single-star photometry for UGCA 290 extends over nine magnitudes in I, and allows a detailed study of its star formation history. Using synthetic color-magnitude diagrams, we show that the recent "burst" which gives this galaxy its BCD status is a moderate enhancement in star formation which lasted for approximately 20 Myr, at a rate about ten times above its previous rate. The star formation history for most of the previous billion years is consistent with a constant rate, although enhancements as large as the current one are possible at times ealier than 400 Myr ago. We estimate that the total mass converted into stars in UGCA 290 more than one billion years ago is about three times the astrated mass since that time. The initial mass function is consistent with a Salpeter slope, and the stellar metallicity is bracketed by Z_sun/50 and Z_sun/5, with evidence for metallicity evolution. Similar results for the star formation history over the past 600 Myr apply to VII Zw 403. Our main result is that despite the traditional picture of BCDs, the current bursts in these two galaxies are neither remarkably intense nor short-lived, and that most of their star formation occured more than a billion years ago.
We extend the Poisson bracket from a Lie bracket of phase space functions to a Lie bracket of functions on the space of canonical histories and investigate the resulting algebras. Typically, such extensions define corresponding Lie algebras on the space of Lagrangian histories via pull back to a space of partial solutions. These are the same spaces of histories studied with regard to path integration and decoherence. Such spaces of histories are familiar from path integration and some studies of decoherence. For gauge systems, we extend both the canonical and reduced Poisson brackets to the full space of histories. We then comment on the use of such algebras in time reparameterization invariant systems and systems with a Gribov ambiguity, though our main goal is to introduce concepts and techniques for use in a companion paper.
We study the evolution of baryonic gas before the reionization in the lognormal (LN) model of cosmic clustering. We show that the thermal history of the universe around the reionization can roughly be divided into three epochs: 1) cold dark age $z>z_r$, in which baryon gas is neutral, and opaque to Ly$α$ photons; 2) hot dark age $z_r > z> z_{gp}$, in which a predominant part of baryon gas is ionized and hot, but it is still opaque to Ly$α$ photons; 3) bright age $z<z_{gp}$, in which the universe is ionized highly enough to be transparent to Ly$α$ photons. In the flat cold dark matter cosmological models given by WMAP and COBE, the difference of the two redshifts $z_r - z_{gp}$ is found to be as large as $\sim 10$ with $z_r\sim 17$ and $z_{gp}\sim 7$. This reionization history naturally yields a high optical depth to the CMB $τ_e \simeq 0.12 - 0.19$ observed by the TE polarization of the WMAP, and a low redshift $z_{gp}$ of the appearance of the Ly$α$ Gunn-Peterson trough $z_{gp} \simeq 6 - 8$ in QSO's absorption spectra. The reason why the universe stays long in an ionized, yet Ly$α$ opaque, stage is because the first photo-ionization heats the intergalactic gas effectively and has balanced the gravitational clustering a long period of time. Therefore, the result of a high $τ_e$ and low $z_{gp}$ is a common feature of all the models considered. Besides the cosmological parameters, the only free parameter we used in the calculation is $N_{ion}$, the mean ionization photons produced by each baryon in collapsed objects. We take it to be 40 - 80 in the calculation.
James L. Anderson analyzed the novelty of Einstein's theory of gravity as its lack of "absolute objects." Michael Friedman's related work has been criticized by Roger Jones and Robert Geroch for implausibly admitting as absolute the timelike 4-velocity field of dust in cosmological models in Einstein's theory. Using the Rosen-Sorkin Lagrange multiplier trick, I complete Anna Maidens's argument that the problem is not solved by prohibiting variation of absolute objects in an action principle. Recalling Anderson's proscription of "irrelevant" variables, I generalize that proscription to locally irrelevant variables that do no work in some places in some models. This move vindicates Friedman's intuitions and removes the Jones-Geroch counterexample: some regions of some models of gravity with dust are dust-free and so naturally lack a timelike 4-velocity, so diffeomorphic equivalence to (1,0,0,0) is spoiled. Torretti's example involving constant curvature spaces is shown to have an absolute object on Anderson's analysis, viz., the conformal spatial metric density. The previously neglected threat of an absolute object from an orthonormal tetrad used for coupling spinors to gravity appears resolvable by eliminating irrelevant fields. However, given Anderson's definition, GTR itself has an absolute object (as Robert Geroch has observed recently): a change of variables to a conformal metric density and a scalar density shows that the latter is absolute.
We reconsider the Decoherent Histories approach to Quantum Mechanics and we analyze some problems related to its interpretation which, according to us, have not been adequately clarified by its proponents. We put forward some assumptions which, in our opinion, are necessary for a realistic interpretation of the probabilities that the formalism attaches to decoherent histories. We prove that such assumptions, unless one limits the set of the decoherent families which can be taken into account, lead to a logical contradiction. The line of reasoning we will follow is conceptually different from other arguments which have been presented and which have been rejected by the supporters of the Decoherent Histories approach. The conclusion is that the Decoherent Histories approach, to be considered as an interesting realistic alternative to the orthodox interpretation of Quantum Mechanics, requires the identification of a mathematically precise criterion to characterize an appropriate set of decoherent families which does not give rise to any problem.
Adopting a single degenerate scenario for Type Ia supernova progenitors with the metallicity effect, we make a prediction of the cosmic supernova rate history as a composite of the supernova rates in spiral and elliptical galaxies, and compare with the recent observational data up to z ~ 0.55.