An Algebraic Approach to the Complexity of Generalized Conjunctive Queries

Author(s):  
Michael Bauland ◽  
Philippe Chapdelaine ◽  
Nadia Creignou ◽  
Miki Hermann ◽  
Heribert Vollmer
2019 ◽  
Vol 38 (4) ◽  
pp. 817-850 ◽  
Author(s):  
Luisa D'Amore ◽  
Valeria Mele ◽  
Diego Romano ◽  
Giuliano Laccetti

Author(s):  
Carina Curto ◽  
Alan Veliz-Cuba ◽  
Nora Youngs

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
C. F. Lo

The Lie-algebraic approach has been applied to solve the bond pricing problem in single-factor interest rate models. Four of the popular single-factor models, namely, the Vasicek model, Cox-Ingersoll-Ross model, double square-root model, and Ahn-Gao model, are investigated. By exploiting the dynamical symmetry of their bond pricing equations, analytical closed-form pricing formulae can be derived in a straightfoward manner. Time-varying model parameters could also be incorporated into the derivation of the bond price formulae, and this has the added advantage of allowing yield curves to be fitted. Furthermore, the Lie-algebraic approach can be easily extended to formulate new analytically tractable single-factor interest rate models.


2014 ◽  
Vol 26 (6) ◽  
pp. 1532-1543 ◽  
Author(s):  
Biao Qin ◽  
Shan Wang ◽  
Xiaofang Zhou ◽  
Xiaoyong Du
Keyword(s):  

2017 ◽  
Vol 46 (2) ◽  
pp. 5-17 ◽  
Author(s):  
Pablo Barceló ◽  
Andreas Pieris ◽  
Miguel Romero
Keyword(s):  

Cryptography ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 2
Author(s):  
Tushar Kanti Saha ◽  
Takeshi Koshiba

Conjunctive queries play a key role in retrieving data from a database. In a database, a query containing many conditions in its predicate, connected by an “and/&/∧” operator, is called a conjunctive query. Retrieving the outcome of a conjunctive query from thousands of records is a heavy computational task. Private data access to an outsourced database is required to keep the database secure from adversaries; thus, private conjunctive queries (PCQs) are indispensable. Cheon, Kim, and Kim (CKK) proposed a PCQ protocol using search-and-compute circuits in which they used somewhat homomorphic encryption (SwHE) for their protocol security. As their protocol is far from being able to be used practically, we propose a practical batch private conjunctive query (BPCQ) protocol by applying a batch technique for processing conjunctive queries over an outsourced database, in which both database and queries are encoded in binary format. As a main technique in our protocol, we develop a new data-packing method to pack many data into a single polynomial with the batch technique. We further enhance the performances of the binary-encoded BPCQ protocol by replacing the binary encoding with N-ary encoding. Finally, we compare the performance to assess the results obtained by the binary-encoded BPCQ protocol and the N-ary-encoded BPCQ protocol.


2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Sotaro Sugishita

Abstract We consider entanglement of first-quantized identical particles by adopting an algebraic approach. In particular, we investigate fermions whose wave functions are given by the Slater determinants, as for singlet sectors of one-matrix models. We show that the upper bounds of the general Rényi entropies are N log 2 for N particles or an N × N matrix. We compute the target space entanglement entropy and the mutual information in a free one-matrix model. We confirm the area law: the single-interval entropy for the ground state scales as $$ \frac{1}{3} $$ 1 3 log N in the large N model. We obtain an analytical $$ \mathcal{O}\left({N}^0\right) $$ O N 0 expression of the mutual information for two intervals in the large N expansion.


Sign in / Sign up

Export Citation Format

Share Document