9,615 research outputs found
Adaptive versus Static Security in the UC Model
We show that for certain class of unconditionally secure protocols and
target functionalities, static security implies adaptive security in the UC
model. Similar results were previously only known for models with
weaker security and/or composition guarantees. The result is, for
instance, applicable to a wide range of protocols based on secret
sharing. It ``explains\u27\u27 why an often used proof technique for such
protocols works, namely where the simulator runs in its head a copy of
the honest players using dummy inputs and generates a protocol
execution by letting the dummy players interact with the
adversary. When a new player is corrupted, the simulator
adjusts the state of its dummy copy of to be consistent with
the real inputs and outputs of and gives the state to the
adversary. Our result gives a characterisation of the cases where this
idea will work to prove adaptive security. As a special case,
we use our framework to give the first proof of adaptive security
of the seminal BGW protocol in the UC framework
Adaptive Robust Optimization with Dynamic Uncertainty Sets for Multi-Period Economic Dispatch under Significant Wind
The exceptional benefits of wind power as an environmentally responsible
renewable energy resource have led to an increasing penetration of wind energy
in today's power systems. This trend has started to reshape the paradigms of
power system operations, as dealing with uncertainty caused by the highly
intermittent and uncertain wind power becomes a significant issue. Motivated by
this, we present a new framework using adaptive robust optimization for the
economic dispatch of power systems with high level of wind penetration. In
particular, we propose an adaptive robust optimization model for multi-period
economic dispatch, and introduce the concept of dynamic uncertainty sets and
methods to construct such sets to model temporal and spatial correlations of
uncertainty. We also develop a simulation platform which combines the proposed
robust economic dispatch model with statistical prediction tools in a rolling
horizon framework. We have conducted extensive computational experiments on
this platform using real wind data. The results are promising and demonstrate
the benefits of our approach in terms of cost and reliability over existing
robust optimization models as well as recent look-ahead dispatch models.Comment: Accepted for publication at IEEE Transactions on Power System
Simulatable security for quantum protocols
The notion of simulatable security (reactive simulatability, universal
composability) is a powerful tool for allowing the modular design of
cryptographic protocols (composition of protocols) and showing the security of
a given protocol embedded in a larger one. Recently, these methods have
received much attention in the quantum cryptographic community.
We give a short introduction to simulatable security in general and proceed
by sketching the many different definitional choices together with their
advantages and disadvantages.
Based on the reactive simulatability modelling of Backes, Pfitzmann and
Waidner we then develop a quantum security model. By following the BPW
modelling as closely as possible, we show that composable quantum security
definitions for quantum protocols can strongly profit from their classical
counterparts, since most of the definitional choices in the modelling are
independent of the underlying machine model.
In particular, we give a proof for the simple composition theorem in our
framework.Comment: Added proof of combination lemma; added comparison to the model of
Ben-Or, Mayers; minor correction
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An Assessment of PIER Electric Grid Research 2003-2014 White Paper
This white paper describes the circumstances in California around the turn of the 21st century that led the California Energy Commission (CEC) to direct additional Public Interest Energy Research funds to address critical electric grid issues, especially those arising from integrating high penetrations of variable renewable generation with the electric grid. It contains an assessment of the beneficial science and technology advances of the resultant portfolio of electric grid research projects administered under the direction of the CEC by a competitively selected contractor, the University of Californiaās California Institute for Energy and the Environment, from 2003-2014
AMaĻoSāAbstract Machine for Xcerpt
Web query languages promise convenient and efficient access
to Web data such as XML, RDF, or Topic Maps. Xcerpt is one such Web
query language with strong emphasis on novel high-level constructs for
effective and convenient query authoring, particularly tailored to versatile
access to data in different Web formats such as XML or RDF.
However, so far it lacks an efficient implementation to supplement the
convenient language features. AMaĻoS is an abstract machine implementation
for Xcerpt that aims at efficiency and ease of deployment. It
strictly separates compilation and execution of queries: Queries are compiled
once to abstract machine code that consists in (1) a code segment
with instructions for evaluating each rule and (2) a hint segment that
provides the abstract machine with optimization hints derived by the
query compilation. This article summarizes the motivation and principles
behind AMaĻoS and discusses how its current architecture realizes
these principles
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