3,847 research outputs found
Optimal Hashing-based Time-Space Trade-offs for Approximate Near Neighbors
[See the paper for the full abstract.]
We show tight upper and lower bounds for time-space trade-offs for the
-Approximate Near Neighbor Search problem. For the -dimensional Euclidean
space and -point datasets, we develop a data structure with space and query time for
every such that: \begin{equation} c^2 \sqrt{\rho_q} +
(c^2 - 1) \sqrt{\rho_u} = \sqrt{2c^2 - 1}. \end{equation}
This is the first data structure that achieves sublinear query time and
near-linear space for every approximation factor , improving upon
[Kapralov, PODS 2015]. The data structure is a culmination of a long line of
work on the problem for all space regimes; it builds on Spherical
Locality-Sensitive Filtering [Becker, Ducas, Gama, Laarhoven, SODA 2016] and
data-dependent hashing [Andoni, Indyk, Nguyen, Razenshteyn, SODA 2014] [Andoni,
Razenshteyn, STOC 2015].
Our matching lower bounds are of two types: conditional and unconditional.
First, we prove tightness of the whole above trade-off in a restricted model of
computation, which captures all known hashing-based approaches. We then show
unconditional cell-probe lower bounds for one and two probes that match the
above trade-off for , improving upon the best known lower bounds
from [Panigrahy, Talwar, Wieder, FOCS 2010]. In particular, this is the first
space lower bound (for any static data structure) for two probes which is not
polynomially smaller than the one-probe bound. To show the result for two
probes, we establish and exploit a connection to locally-decodable codes.Comment: 62 pages, 5 figures; a merger of arXiv:1511.07527 [cs.DS] and
arXiv:1605.02701 [cs.DS], which subsumes both of the preprints. New version
contains more elaborated proofs and fixed some typo
An O(n^3)-Time Algorithm for Tree Edit Distance
The {\em edit distance} between two ordered trees with vertex labels is the
minimum cost of transforming one tree into the other by a sequence of
elementary operations consisting of deleting and relabeling existing nodes, as
well as inserting new nodes. In this paper, we present a worst-case
-time algorithm for this problem, improving the previous best
-time algorithm~\cite{Klein}. Our result requires a novel
adaptive strategy for deciding how a dynamic program divides into subproblems
(which is interesting in its own right), together with a deeper understanding
of the previous algorithms for the problem. We also prove the optimality of our
algorithm among the family of \emph{decomposition strategy} algorithms--which
also includes the previous fastest algorithms--by tightening the known lower
bound of ~\cite{Touzet} to , matching our
algorithm's running time. Furthermore, we obtain matching upper and lower
bounds of when the two trees have
different sizes and~, where .Comment: 10 pages, 5 figures, 5 .tex files where TED.tex is the main on
«ДОФЕНОМЕНОЛОГІЧНА» КОНЦЕПЦІЯ БРЕНТАНО ЯК ТЛО ДЛЯ РОЗВИТКУФЕНОМЕНОЛОГІЇ ТА АКСІОЛОГІЇ ХІХ- ХХСТОЛІТТЯ
В представленном исследовании автор анализирует эмпирическую психологію Ф.
Брентано, в частности, процесс конституированиянепосредственных данностей– внутреннее
существование предмета. Такой подход стал новым акцентированием «эмпиричности» и
попыткой возобновления связи между философией и психологией посредством понятия
«интенциональность», которое является теоретико-познавательным принципом.In this investigation author analyses empirical psychology of F.Brentano –the procces of constitute
spontaneous facts as inside existence the object.
This idea have an influence development of the transcendental phenomenology, hermeneutical
phenomenology and have be essential for development of the contemporary philosophy of the value
Adaptive and Application-agnostic Caching in Service Meshes for Resilient Cloud Applications
Service meshes factor out code dealing with inter-micro-service communication. The overall resilience of a cloud application is improved if constituent micro-services return stale data, instead of no data at all. This paper proposes and implements application agnostic caching for micro services. While caching is widely employed for serving web service traffic, its usage in inter-micro-service communication is lacking. Micro-services responses are highly dynamic, which requires carefully choosing adaptive time-to-life caching algorithms. Our approach is application agnostic, is cloud native, and supports gRPC. We evaluate our approach and implementation using the micro-service benchmark by Google Cloud called Hipster Shop. Our approach results in caching of about 80% of requests. Results show the feasibility and efficiency of our approach, which encourages implementing caching in service meshes. Additionally, we make the code, experiments, and data publicly available
Power scaling of an extreme ultraviolet light source for future lithography
For future lithography applications, high-power extreme ultraviolet (EUV) light sources are needed at a central wavelength of 13.5 nm within 2% bandwidth. We have demonstrated that from a physics point of view the Philips alpha-prototype source concept is scalable up to the power levels required for high-volume manufacturing (HVM) purposes. Scalability is shown both in frequency, up to 100 kHz, and pulse energy, up to 55 mJ collectable EUV per pulse, which allows us to find an optimal working point for future HVM sources within a wide parameter space. (C) 2008 American Institute of Physics
Towards Soft Circuit Breaking in Service Meshes via Application-agnostic Caching
Service meshes factor out code dealing with inter-micro-service
communication, such as circuit breaking. Circuit breaking actuation is
currently limited to an "on/off" switch, i.e., a tripped circuit breaker will
return an application-level error indicating service unavailability to the
calling micro-service. This paper proposes a soft circuit breaker actuator,
which returns cached data instead of an error. The overall resilience of a
cloud application is improved if constituent micro-services return stale data,
instead of no data at all. While caching is widely employed for serving web
service traffic, its usage in inter-micro-service communication is lacking.
Micro-services responses are highly dynamic, which requires carefully choosing
adaptive time-to-life caching algorithms. We evaluate our approach through two
experiments. First, we quantify the trade-off between traffic reduction and
data staleness using a purpose-build service, thereby identifying algorithm
configurations that keep data staleness at about 3% or less while reducing
network load by up to 30%. Second, we quantify the network load reduction with
the micro-service benchmark by Google Cloud called Hipster Shop. Our approach
results in caching of about 80% of requests. Results show the feasibility and
efficiency of our approach, which encourages implementing caching as a circuit
breaking actuator in service meshes
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