Papers by Daniel Ionel Preda
Proceedings, 2020
Honey is a natural product that has the characteristics of a deep eutectic natural solvent (NADES... more Honey is a natural product that has the characteristics of a deep eutectic natural solvent (NADES) due to the intermolecular interactions between monosaccharides and disaccharides, especially the hydrogen bonds formed between them. [...]
Proceedings, 2020
CO2 emissions are well-known for creating a lot of environmental issues, at a global scale. [...]
Proceedings, 2020
Diatomite, also known as diatomaceous earth (DE), is a sedimentary rock formed by the deposition ... more Diatomite, also known as diatomaceous earth (DE), is a sedimentary rock formed by the deposition of shells of unicellular microscopic algae of the class Bacillariophyceae (diatoms). [...]
Proceedings, 2020
Spent mushroom substrate (SMS) is a significant source of enzymes and bioactive compounds [...]
The analysis of some practical methods for limit state verification in coupled instability—comparison with the experimental evidence
Thin-Walled Structures, 1994
Abstract The paper analyzes the concept of evaluation by calculus of the stability limit state fo... more Abstract The paper analyzes the concept of evaluation by calculus of the stability limit state for members subjected to combined bending and axial compression. The calculus procedure stipulated in Eurocode 3, Design of Steel Structures, 1990 1 is presented for the case in which flexural-torsional buckling is a potential failure mode (compression and bending about the major axis of the section). The verification function, stipulated in the Eurocode is analyzed by comparison with some experimental results. The analysis is one of the Steel Structures Department's (Civil Engineering Institute, Bucharest) concerns regarding the improvement of Romanian Code STAS 10108/0–78 ‘Metal Structures’.
Science, 2001
A quantum system will stay near its instantaneous ground state if the Hamiltonian that governs it... more A quantum system will stay near its instantaneous ground state if the Hamiltonian that governs its evolution varies slowly enough. This quantum adiabatic behavior is the basis of a new class of algorithms for quantum computing. We tested one such algorithm by applying it to randomly generated hard instances of an NP-complete problem. For the small examples that we could simulate, the quantum adiabatic algorithm worked well, providing evidence that quantum computers (if large ones can be built) may be able to outperform ordinary computers on hard sets of instances of NP-complete problems.
2008 23rd Annual IEEE Conference on Computational Complexity, 2008
A central question in quantum information theory and computational complexity is how powerful non... more A central question in quantum information theory and computational complexity is how powerful nonlocal strategies are in cooperative games with imperfect information, such as multi-prover interactive proof systems. This paper develops a new method for proving limits of nonlocal strategies that make use of prior entanglement among players (or, provers, in the terminology of multi-prover interactive proofs). Instead of proving the limits for usual isolated provers who initially share entanglement, this paper proves the limits for "commuting-operator provers", who share private space, but can apply only such operators that are commutative with any operator applied by other provers. Obviously, these commuting-operator provers are at least as powerful as usual isolated but prior-entangled provers, and thus, limits in the model with commuting-operator provers immediately give limits in the usual model with prior-entangled provers. Using this method, we obtain an n-party generalization of the Tsirelson bound for the Clauser-Horne-Shimony-Holt inequality, for every n. Our bounds are tight in the sense that, in every n-party case, the equality is achievable by a usual nonlocal strategy with prior entanglement. We also apply our method to a three-prover one-round binary interactive proof system for NEXP. Combined with the technique developed by Kempe, Kobayashi, Matsumoto, Toner and Vidick to analyze the soundness of the proof system, it is proved to be NP-hard to distinguish whether the entangled value of a three-prover one-round binary-answer game is equal to one or at most 1 − 1/p(n) for some polynomial p, where n is the number of questions. This is in contrast to the two-prover one-round binary-answer case, where the corresponding problem is efficiently decidable. Alternatively, NEXP has a three-prover one-round binary interactive proof system with perfect completeness and soundness 1 − 2 −poly .
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Papers by Daniel Ionel Preda