4,264 research outputs found
Quadratic BSDEs with convex generators and unbounded terminal conditions
In a previous work, we proved an existence result for BSDEs with quadratic
generators with respect to the variable z and with unbounded terminal
conditions. However, no uniqueness result was stated in that work. The main
goal of this paper is to fill this gap. In order to obtain a comparison theorem
for this kind of BSDEs, we assume that the generator is convex with respect to
the variable z. Under this assumption of convexity, we are also able to prove a
stability result in the spirit of the a priori estimates stated in the article
of N. El Karoui, S. Peng and M.-C. Quenez. With these tools in hands, we can
derive the nonlinear Feynman--Kac formula in this context
Normally ordered forms of powers of differential operators and their combinatorics
We investigate the combinatorics of the general formulas for the
powers of the operator h∂k, where h is a central element of a ring
and ∂ is a differential operator. This generalizes previous work on
the powers of operators h∂. New formulas for the generalized Stirling
numbers are obtained.Ministerio de EconomÃa y competitividad MTM2016-75024-PJunta de AndalucÃa P12-FQM-2696Junta de AndalucÃa FQM–33
Entanglement monotones and maximally entangled states in multipartite qubit systems
We present a method to construct entanglement measures for pure states of
multipartite qubit systems. The key element of our approach is an antilinear
operator that we call {\em comb} in reference to the {\em hairy-ball theorem}.
For qubits (or spin 1/2) the combs are automatically invariant under
SL(2,\CC). This implies that the {\em filters} obtained from the combs are
entanglement monotones by construction. We give alternative formulae for the
concurrence and the 3-tangle as expectation values of certain antilinear
operators. As an application we discuss inequivalent types of genuine four-,
five- and six-qubit entanglement.Comment: 7 pages, revtex4. Talk presented at the Workshop on "Quantum
entanglement in physical and information sciences", SNS Pisa, December 14-18,
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Choix d’approvisionnement en eau des ménages de Dakar : une étude économétrique à partir de données d’enquête
LTM: Scalable and Black-box Similarity-based Test Suite Minimization based on Language Models
Test suites tend to grow when software evolves, making it often infeasible to
execute all test cases with the allocated testing budgets, especially for large
software systems. Therefore, test suite minimization (TSM) is employed to
improve the efficiency of software testing by removing redundant test cases,
thus reducing testing time and resources, while maintaining the fault detection
capability of the test suite. Most of the TSM approaches rely on code coverage
(white-box) or model-based features, which are not always available for test
engineers. Recent TSM approaches that rely only on test code (black-box) have
been proposed, such as ATM and FAST-R. To address scalability, we propose LTM
(Language model-based Test suite Minimization), a novel, scalable, and
black-box similarity-based TSM approach based on large language models (LLMs).
To support similarity measurement, we investigated three different pre-trained
language models: CodeBERT, GraphCodeBERT, and UniXcoder, to extract embeddings
of test code, on which we computed two similarity measures: Cosine Similarity
and Euclidean Distance. Our goal is to find similarity measures that are not
only computationally more efficient but can also better guide a Genetic
Algorithm (GA), thus reducing the overall search time. Experimental results,
under a 50% minimization budget, showed that the best configuration of LTM
(using UniXcoder with Cosine similarity) outperformed the best two
configurations of ATM in three key facets: (a) achieving a greater saving rate
of testing time (40.38% versus 38.06%, on average); (b) attaining a
significantly higher fault detection rate (0.84 versus 0.81, on average); and,
more importantly, (c) minimizing test suites much faster (26.73 minutes versus
72.75 minutes, on average) in terms of both preparation time (up to two orders
of magnitude faster) and search time (one order of magnitude faster)
A study of the effectiveness of a phonetic and activity approach to the teaching of spelling in grade four,
Includes appendices.
Thesis (M.A.)--Boston Universit
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