339 research outputs found
On IVF Approximating Spaces
We introduce the concept of IVF approximating spaces and obtain decision conditions that every IVF topological space is an IVF approximating space
HDIdx: High-Dimensional Indexing for Efficient Approximate Nearest Neighbor Search
Fast Nearest Neighbor (NN) search is a fundamental challenge in large-scale
data processing and analytics, particularly for analyzing multimedia contents
which are often of high dimensionality. Instead of using exact NN search,
extensive research efforts have been focusing on approximate NN search
algorithms. In this work, we present "HDIdx", an efficient high-dimensional
indexing library for fast approximate NN search, which is open-source and
written in Python. It offers a family of state-of-the-art algorithms that
convert input high-dimensional vectors into compact binary codes, making them
very efficient and scalable for NN search with very low space complexity
Learning a Complete Image Indexing Pipeline
To work at scale, a complete image indexing system comprises two components:
An inverted file index to restrict the actual search to only a subset that
should contain most of the items relevant to the query; An approximate distance
computation mechanism to rapidly scan these lists. While supervised deep
learning has recently enabled improvements to the latter, the former continues
to be based on unsupervised clustering in the literature. In this work, we
propose a first system that learns both components within a unifying neural
framework of structured binary encoding
Learning a Complete Image Indexing Pipeline
To work at scale, a complete image indexing system comprises two components:
An inverted file index to restrict the actual search to only a subset that
should contain most of the items relevant to the query; An approximate distance
computation mechanism to rapidly scan these lists. While supervised deep
learning has recently enabled improvements to the latter, the former continues
to be based on unsupervised clustering in the literature. In this work, we
propose a first system that learns both components within a unifying neural
framework of structured binary encoding
Martingale-coboundary decomposition for stationary random fields
We prove a martingale-coboundary representation for random fields with a
completely commuting filtration. For random variables in L2 we present a
necessary and sufficient condition which is a generalization of Heyde's
condition for one dimensional processes from 1975. For Lp spaces with 2 \leq p
< \infty we give a necessary and sufficient condition which extends Volny's
result from 1993 to random fields and improves condition of El Machkouri and
Giraudo from 2016 (arXiv:1410.3062). In application, new weak invariance
principle and estimates of large deviations are found.Comment: Stochastics and Dynamics 201
Landau levels in wrinkled and rippled graphene sheets
We study the discrete energy spectrum of curved graphene sheets in the
presence of a magnetic field. The shifting of the Landau levels is determined
for complex and realistic geometries of curved graphene sheets. The energy
levels follow a similar square root dependence on the energy quantum number as
for rippled and flat graphene sheets. The Landau levels are shifted towards
lower energies proportionally to the average deformation and the effect is
larger compared to a simple uni-axially rippled geometry. Furthermore, the
resistivity of wrinkled graphene sheets is calculated for different average
space curvatures and shown to obey a linear relation. The study is carried out
with a quantum lattice Boltzmann method, solving the Dirac equation on curved
manifolds.Comment: 6 pages, 4 figures, 27th International Conference on Discrete
Simulation of Fluid Dynamic
Co-design Hardware and Algorithm for Vector Search
Vector search has emerged as the foundation for large-scale information
retrieval and machine learning systems, with search engines like Google and
Bing processing tens of thousands of queries per second on petabyte-scale
document datasets by evaluating vector similarities between encoded query texts
and web documents. As performance demands for vector search systems surge,
accelerated hardware offers a promising solution in the post-Moore's Law era.
We introduce \textit{FANNS}, an end-to-end and scalable vector search framework
on FPGAs. Given a user-provided recall requirement on a dataset and a hardware
resource budget, \textit{FANNS} automatically co-designs hardware and
algorithm, subsequently generating the corresponding accelerator. The framework
also supports scale-out by incorporating a hardware TCP/IP stack in the
accelerator. \textit{FANNS} attains up to 23.0 and 37.2 speedup
compared to FPGA and CPU baselines, respectively, and demonstrates superior
scalability to GPUs, achieving 5.5 and 7.6 speedup in median
and 95\textsuperscript{th} percentile (P95) latency within an eight-accelerator
configuration. The remarkable performance of \textit{FANNS} lays a robust
groundwork for future FPGA integration in data centers and AI supercomputers.Comment: 11 page
Boundary values of holomorphic semigroups of unbounded operators and similarity of certain perturbations
AbstractWe obtain sufficient conditions for a âholomorphicâ semigroup of unbounded operators to possess a boundary group of bounded operators. The theorem is applied to generalize to unbounded operators results of Kantorovitz about the similarity of certain perturbations. Our theory includes a result of Fisher on the Riemann-Liouville semigroup in Lp(0, â) 1 < p < â. In this particular case we give also an alternative approach, where the boundary group is obtained as the limit of groups in the weak operator topology
Boundary values of holomorphic semigroups of unbounded operators and similarity of certain perturbations
AbstractWe obtain sufficient conditions for a âholomorphicâ semigroup of unbounded operators to possess a boundary group of bounded operators. The theorem is applied to generalize to unbounded operators results of Kantorovitz about the similarity of certain perturbations. Our theory includes a result of Fisher on the Riemann-Liouville semigroup in Lp(0, â) 1 < p < â. In this particular case we give also an alternative approach, where the boundary group is obtained as the limit of groups in the weak operator topology
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