213 research outputs found
Fast But Not Furious. When Sped Up Bit Rate of Information Drives Rule Induction
The language abilities of young and adult learners range from memorizing specific items to finding statistical regularities between them (item-bound generalization) and generalizing rules to novel instances (category-based generalization). Both external factors, such as input variability, and internal factors, such as cognitive limitations, have been shown to drive these abilities. However, the exact dynamics between these factors and circumstances under which rule induction emerges remain largely underspecified. Here, we extend our information-theoretic model (Radulescu et al., 2019), based on Shannonâs noisy-channel coding theory, which adds into the âformulaâ for rule induction the crucial dimension of time: the rate of encoding information by a time-sensitive mechanism. The goal of this study is to test the channel capacity-based hypothesis of our model: if the input entropy per second is higher than the maximum rate of information transmission (bits/second), which is determined by the channel capacity, the encoding method moves gradually from item-bound generalization to a more efficient category-based generalization, so as to avoid exceeding the channel capacity. We ran two artificial grammar experiments with adults, in which we sped up the bit rate of information transmission, crucially not by an arbitrary amount but by a factor calculated using the channel capacity formula on previous data. We found that increased bit rate of information transmission in a repetition-based XXY grammar drove the tendency of learners toward category-based generalization, as predicted by our model. Conversely, we found that increased bit rate of information transmission in complex non-adjacent dependency aXb grammar impeded the item-bound generalization of the specific a_b frames, and led to poorer learning, at least judging by our accuracy assessment method. This finding could show that, since increasing the bit rate of information precipitates a change from item-bound to category-based generalization, it impedes the item-bound generalization of the specific a_b frames, and that it facilitates category-based generalization both for the intervening Xs and possibly for a/b categories. Thus, sped up bit rate does not mean that an unrestrainedly increasing bit rate drives rule induction in any context, or grammar. Rather, it is the specific dynamics between the input entropy and the maximum rate of information transmission
Dynamic Strength of Titin's Z-Disk End
Titin is a giant filamentous protein traversing the half sarcomere of striated muscle with putative functions as diverse as providing structural template, generating elastic response, and sensing and relaying mechanical information. The Z-disk region of titin, which corresponds to the N-terminal end of the molecule, has been thought to be a hot spot for mechanosensing while also serving as anchorage for its sarcomeric attachment. Understanding the mechanics of titin's Z-disk region, particularly under the effect of binding proteins, is of great interest. Here we briefly review recent findings on the structure, molecular associations, and mechanics of titin's Z-disk region. In addition, we report experimental results on the dynamic strength of titin's Z1Z2 domains measured by nanomechanical manipulation of the chemical dimer of a recombinant protein fragment
Lokalna promjenljivost (nestalnost) mehaniÄkih svojstava tandemskih Ig/segmenata titina
The functionally elastic, I-band part of the myofibrillar protein titin (connectin) contains differentially expressed arrays of serially linked immunoglobulin (Ig)-like domains, the length and composition of which vary among the titin isoforms. The biological rationale of the differential expression as well as the contribution of the Ig domain mechanical characteristics to the overall mechanical behavior of titin are not exactly known. The paper briefly reviews the relevant works that have addressed the Ig-domain mechanics problems and presents the authorsâ experimental approach to studying the mechanical behavior of Ig domains. The mechanics of an eight domain segment from the differentially expressed tandem Ig region of titin (I55-62) was studied with an atomic force microscope specially used for stretching single molecules, and the results were compared to known mechanical properties of other domains and segments.Funkcionalno elastiÄna I-vrpca miofibrilarnoga proteina titina (konektina) sadrĆŸi razlicito izraĆŸene vrste serijski povezanih domena sliÄnih imunoglobulinu (Ig) Äija se duljina i sastav razlikuju u pojedinim titinskim izoformama. BioloĆĄki razlozi diferencijalne ekspresije kao i doprinos mehaniÄkih svojstava domena koje su sliÄne Ig ponaĆĄanju titina nisu u cjelosti poznati. U ovom su Älanku pregledno prikazani dosadaĆĄnji relevantni radovi koji se bave problemima mehaniÄkih svojstava Ig-domena te autorski eksperimentalni pristupi u istraĆŸivanju toga problema. U radu su takoÄer prikazani rezultati istraĆŸivanja mehaniÄkih svojstava diferencijalno eksprimiranoga tandemskoga Ig-podruÄja titina (155-62), koji se sastoji od osam domena, pomoÄu mikroskopa atomske snage razluÄivanja specijaliziranoga za rastezanje pojedinaÄne molekule. Ovim postupkom utvrÄena mehaniÄka svojstva ispitivanoga dijela titinske molekule usporeÄena su s poznatim mehaniÄkim svojstvima drugih domena i segmenata
LINVIEW: Incremental View Maintenance for Complex Analytical Queries
Many analytics tasks and machine learning problems can be naturally expressed
by iterative linear algebra programs. In this paper, we study the incremental
view maintenance problem for such complex analytical queries. We develop a
framework, called LINVIEW, for capturing deltas of linear algebra programs and
understanding their computational cost. Linear algebra operations tend to cause
an avalanche effect where even very local changes to the input matrices spread
out and infect all of the intermediate results and the final view, causing
incremental view maintenance to lose its performance benefit over
re-evaluation. We develop techniques based on matrix factorizations to contain
such epidemics of change. As a consequence, our techniques make incremental
view maintenance of linear algebra practical and usually substantially cheaper
than re-evaluation. We show, both analytically and experimentally, the
usefulness of these techniques when applied to standard analytics tasks. Our
evaluation demonstrates the efficiency of LINVIEW in generating parallel
incremental programs that outperform re-evaluation techniques by more than an
order of magnitude.Comment: 14 pages, SIGMO
Developed Adomian method for quadratic Kaluza-Klein relativity
We develop and modify the Adomian decomposition method (ADecM) to work for a
new type of nonlinear matrix differential equations (MDE's) which arise in
general relativity (GR) and possibly in other applications. The approach
consists in modifying both the ADecM linear operator with highest order
derivative and ADecM polynomials. We specialize in the case of a 44
nonlinear MDE along with a scalar one describing stationary cylindrically
symmetric metrics in quadratic 5-dimensional GR, derive some of their
properties using ADecM and construct the \textit{most general unique power
series solutions}. However, because of the constraint imposed on the MDE by the
scalar one, the series solutions terminate in closed forms exhausting all
possible solutions.Comment: 17 pages (minor changes in reference [30]
Using Performance Forecasting to Accelerate Elasticity
Cloud computing facilitates dynamic resource provisioning. The automation of resource management, known as elasticity, has been subject to much research. In this context, monitoring of a running service plays a crucial role, and adjustments are made when certain thresholds are crossed. On such occasions, it is common practice to simply add or remove resources. In this paper we investigate how we can predict the performance of a service to dynamically adjust allocated resources based on predictions. In other words, instead of ârepairingâ because a threshold has been crossed, we attempt to stay ahead and allocate an optimized amount of resources in advance. To do so, we need to have accurate predictive models that are based on workloads. We present our approach, based on the Universal Scalability Law, and discuss initial experiments
Asymptotic equivalence of discretely observed diffusion processes and their Euler scheme: small variance case
This paper establishes the global asymptotic equivalence, in the sense of the
Le Cam -distance, between scalar diffusion models with unknown drift
function and small variance on the one side, and nonparametric autoregressive
models on the other side. The time horizon is kept fixed and both the cases
of discrete and continuous observation of the path are treated. We allow non
constant diffusion coefficient, bounded but possibly tending to zero. The
asymptotic equivalences are established by constructing explicit equivalence
mappings.Comment: 21 page
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