Combo separability criteria and lower bound on concurrence

2021 ◽  
Author(s):  
Zangi Sultan ◽  
Jiansheng Wu ◽  
Cong-Feng Qiao
Keyword(s):  
Lower Bound ◽  
Correlation Matrix ◽  
Density Operator ◽  
Singular Values ◽  
Quantum Information Theory ◽  
Separability Criteria ◽  
The Given ◽  
Ky Fan ◽  
Natural Way ◽  
Extract Information

Abstract Detection and quantification of entanglement are extremely important in quantum information theory. We can extract information by using the spectrum or singular values of the density operator. The correlation matrix norm deals with the concept of quantum entanglement in a mathematically natural way. In this work, we use Ky Fan norm of the Bloch matrix to investigate the disentanglement of quantum states. Our separability criterion not only unifies some well-known criteria but also leads to a better lower bound on concurrence. We explain with an example how the entanglement of the given state is missed by existing criteria but can be detected by our criterion. The proposed lower bound on concurrence also has advantages over some investigated bounds.

A Model of Secure Functioning of Computer Systems

2021 ◽  
Vol 12 (3) ◽  
pp. 150-156
Author(s):  
A. V. Galatenko ◽  
◽  
V. A. Kuzovikhina ◽  
Keyword(s):  
Lower Bound ◽  
Computer System ◽  
Finite Automaton ◽  
Nonnegative Integer ◽  
The Other ◽  
Shannon Function ◽  
Security Breaches ◽  
System Functioning ◽  
The Cost ◽  
The Given

We propose an automata model of computer system security. A system is represented by a finite automaton with states partitioned into two subsets: "secure" and "insecure". System functioning is secure if the number of consecutive insecure states is not greater than some nonnegative integer k. This definition allows one to formally reflect responsiveness to security breaches. The number of all input sequences that preserve security for the given value of k is referred to as a k-secure language. We prove that if a language is k-secure for some natural and automaton V, then it is also k-secure for any 0 < k < k and some automaton V = V (k). Reduction of the value of k is performed at the cost of amplification of the number of states. On the other hand, for any non-negative integer k there exists a k-secure language that is not k"-secure for any natural k" > k. The problem of reconstruction of a k-secure language using a conditional experiment is split into two subcases. If the cardinality of an input alphabet is bound by some constant, then the order of Shannon function of experiment complexity is the same for al k; otherwise there emerges a lower bound of the order nk.

scholarly journals Power Matrices and Dunn--Belnap Semantics: Reflections on a Remark of Graham Priest

2014 ◽  
Vol 11 (1) ◽  
Author(s):  
Lloyd Humberstone
Keyword(s):  
Equational Logic ◽  
Consequence Relations ◽  
Consequence Relation ◽  
Power Matrix ◽  
Matrix Construction ◽  
The Given ◽  
The Universe ◽  
Power Algebras ◽  
Graham Priest ◽  
Natural Way

The plurivalent logics considered in Graham Priest's recent paper of that name can be thought of as logics determined by matrices (in the `logical matrix' sense) whose underlying algebras are power algebras (a.k.a. complex algebras, or `globals'), where the power algebra of a given algebra has as elements \textit{subsets} of the universe of the given algebra, and the power matrix of a given matrix has has the power algebra of the latter's algebra as its underlying algebra, with its designated elements being selected in a natural way on the basis of those of the given matrix. The present discussion stresses the continuity of Priest's work on the question of which matrices determine consequence relations (for propositional logics) which remain unaffected on passage to the consequence relation determined by the power matrix of the given matrix with the corresponding (long-settled) question in equational logic as to which identities holding in an algebra continue to hold in its power algebra. Both questions are sensitive to a decision as to whether or not to include the empty set as an element of the power algebra, and our main focus will be on the contrast, when it is included, between the power matrix semantics (derived from the two-element Boolean matrix) and the four-valued Dunn--Belnap semantics for first-degree entailment a la Anderson and Belnap) in terms of sets of classical values (subsets of {T, F}, that is), in which the empty set figures in a somewhat different way, as Priest had remarked his 1984 study, `Hyper-contradictions', in which what we are calling the power matrix construction first appeared.

scholarly journals State Complexity of Neighbourhoods and Approximate Pattern Matching

2018 ◽  
Vol 29 (02) ◽  
pp. 315-329 ◽  
Author(s):  
Timothy Ng ◽  
David Rappaport ◽  
Kai Salomaa
Keyword(s):  
Lower Bound ◽  
Pattern Matching ◽  
Finite Automaton ◽  
The State ◽  
Worst Case ◽  
State Complexity ◽  
Approximate Pattern Matching ◽  
The Given ◽  
Nondeterministic Finite Automaton ◽  
Distance Formula

The neighbourhood of a language [Formula: see text] with respect to an additive distance consists of all strings that have distance at most the given radius from some string of [Formula: see text]. We show that the worst case deterministic state complexity of a radius [Formula: see text] neighbourhood of a language recognized by an [Formula: see text] state nondeterministic finite automaton [Formula: see text] is [Formula: see text]. In the case where [Formula: see text] is deterministic we get the same lower bound for the state complexity of the neighbourhood if we use an additive quasi-distance. The lower bound constructions use an alphabet of size linear in [Formula: see text]. We show that the worst case state complexity of the set of strings that contain a substring within distance [Formula: see text] from a string recognized by [Formula: see text] is [Formula: see text].

scholarly journals Computing the Angularity Tolerance

1998 ◽  
Vol 08 (04) ◽  
pp. 467-482 ◽  
Author(s):  
Mark De Berg ◽  
Henk Meijer ◽  
Mark Overmars ◽  
Gordon Wilfong
Keyword(s):  
Restricted Problem ◽  
Dimensional Space ◽  
Similar Time ◽  
3 Dimensional ◽  
Computational Metrology ◽  
The Given ◽  
Time Bounds ◽  
Extract Information

In computational metrology one needs to compute whether an object satisfies specifications of shape within an acceptable tolerance. To this end positions on the object are measured, resulting in a collection of points in space. From this collection of points one wishes to extract information on flatness, roundness, etc. of the object. In this paper we study one particular feature of objects, the angularity. The angularity indicates how well a plane makes a specified angle with another plane. We study the problem in 2-dimensional space (where the planes become lines) and in 3-dimensional space. In 2-dimensional space the problem is equivalent to computing the smallest wedge of the given angle that contains all the points. We give an O(n2 log n) algorithm for this problem. In 3-dimensional space we study the more restricted problem where one of the planes is known (a datum plane). In this case the problem is equivalent to asking for the smallest width 3-dimensional strip that contains all the points and makes a given angle with the datum plane. We give an O(n log n) algorithm to solve this version. We also show that in the case of uncertainty in the measured points, upperbounds and lowerbounds on the width can be computed in similar time bounds.

Matrix Perturbation and Optimal Partition Invariancy in Linear Optimization

2015 ◽  
Vol 32 (03) ◽  
pp. 1550013 ◽  
Author(s):  
Alireza Ghaffari-Hadigheh ◽  
Nayyer Mehanfar
Keyword(s):  
Linear Optimization ◽  
Optimal Solution ◽  
Singular Values ◽  
Coefficient Matrix ◽  
Optimal Partition ◽  
Matrix Perturbation ◽  
Optimal Value ◽  
Special Perturbation ◽  
Transition Points ◽  
The Given

Understanding the effect of variation of the coefficient matrix in linear optimization problem on the optimal solution and the optimal value function has its own importance in practice. However, most of the published results are on the effect of this variation when the current optimal solution is a basic one. There is only a study of the problem for special perturbation on the coefficient matrix, when the given optimal solution is strictly complementary and the optimal partition (in some sense) is known. Here, we consider an arbitrary direction for perturbation of the coefficient matrix and present an effective method based on generalized inverse and singular values to detect invariancy intervals and corresponding transition points.

A Task Driven Approach to Unified Synthesis of Planar Four-Bar Linkages Using Algebraic Fitting of a Pencil of G-Manifolds

2013 ◽  
Author(s):  
Q. J. Ge ◽  
Ping Zhao ◽  
Anurag Purwar
Keyword(s):  
Least Squares ◽  
Singular Values ◽  
Geometric Constraints ◽  
Motion Generation ◽  
Motion Approximation ◽  
Value Decomposition ◽  
Four Bar Linkage ◽  
The Given ◽  
Best Fit ◽  
Additional Constraints

This paper studies the problem of planar four-bar motion approximation from the viewpoint of extraction of geometric constraints from a given set of planar displacements. Using the Image Space of planar displacements, we obtain a class of quadrics, called Generalized- or G-manifolds, with eight linear and homogeneous coefficients as a unified representation for constraint manifolds of all four types of planar dyads, RR, PR, and PR, and PP. Given a set of image points that represent planar displacements, the problem of synthesizing a planar four-bar linkage is reduced to finding a pencil of G-manifolds that best fit the image points in the least squares sense. This least squares problem is solved using Singular Value Decomposition. The linear coefficients associated with the smallest singular values are used to define a pencil of quadrics. Additional constraints on the linear coefficients are then imposed to obtain a planar four-bar linkage that best guides the coupler through the given displacements. The result is an efficient and linear algorithm that naturally extracts the geometric constraints of a motion and leads directly to the type and dimensions of a mechanism for motion generation.

scholarly journals Ограничение допустимой коэрцитивной силы, вызванное полем рассеяния магнита

2019 ◽  
Vol 89 (7) ◽  
pp. 1055
Author(s):  
Н.С. Моисеева ◽  
И.И. Резчикова ◽  
Д.В. Королев ◽  
Р.Б. Моргунов ◽  
В.П. Пискорский
Keyword(s):  
Rare Earth ◽  
Lower Bound ◽  
Coercive Force ◽  
Rare Earth Alloys ◽  
Working Temperature ◽  
Technical Requirements ◽  
The Given

AbstractIt is shown that the shape of a sample determines the allowed lower-bound limit of the coercive force of material that can be used for fabrication of magnets with the given shape. Rings with radial magnetization are used as examples to show that such samples can be made of only rare-earth alloys with the coercive force that is sufficiently high to satisfy technical requirements at the maximum allowed working temperature of the magnet.

scholarly journals Colorful Subhypergraphs in Kneser Hypergraphs

10.37236/3573 ◽  
2014 ◽  
Vol 21 (1) ◽  
Author(s):  
Frédéric Meunier
Keyword(s):  
Lower Bound ◽  
Chromatic Number ◽  
Bipartite Graphs ◽  
Uniform Hypergraph ◽  
Proper Coloring ◽  
Kneser Graph ◽  
Complete Bipartite Graphs ◽  
Definition Of ◽  
Ky Fan

Using a $\mathbb{Z}_q$-generalization of a theorem of Ky Fan, we extend to Kneser hypergraphs a theorem of Simonyi and Tardos that ensures the existence of multicolored complete bipartite graphs in any proper coloring of a Kneser graph. It allows to derive a lower bound for the local chromatic number of Kneser hypergraphs (using a natural definition of what can be the local chromatic number of a uniform hypergraph).

An approach to concurrent engineering

1998 ◽  
Vol 212 (1) ◽  
pp. 13-27 ◽  
Author(s):  
D T Pham ◽  
S S Dimov
Keyword(s):  
Carrying Capacity ◽  
Concurrent Engineering ◽  
Deductive Reasoning ◽  
Design Models ◽  
New Approach ◽  
Wide Range ◽  
Manufacturing Information ◽  
Form Features ◽  
The Given ◽  
Natural Way

This paper presents a new approach to concurrent engineering, focusing on simultaneous product design and process planning. The key elements in this approach are (a) a framework for structuring manufacturing information and maximizing the information-carrying capacity of the design models, (b) a procedure for intelligently mapping form features on to pertinent manufacturing considerations and (c) a procedure for utilizing the available manufacturing information about components already machined within the given manufacturing environment. The proposed approach provides a natural way for conveying manufacturing information to the designer. Its distinguishing feature is the application of a wide range of artificial intelligence techniques for knowledge acquisition and deductive reasoning.

Two terms in the lower bound for the superheating field in a semi-infinite film in the weak-κ limit

2002 ◽  
Vol 13 (5) ◽  
pp. 517-544 ◽  
Author(s):  
P. DEL CASTILLO
Keyword(s):  
Lower Bound ◽  
Half Space ◽  
Ginzburg Landau ◽  
Landau Model ◽  
Formal Expansion ◽  
Formal Solutions ◽  
Natural Way ◽  
Formal Construction

Dorsey et al. [8] have constructed formal solutions for the half-space Ginzburg–Landau model, when κ is small. Dorsey et al. deduce a formal expansion for the superheating field in powers of κ½ up to order 4. In this paper, we show how the formal construction gives a natural way for constructing a subsolution for the Ginzburg–Landau system. We improve the result obtained by Bolley & Helffer [2], and take a step in the proof of the Parr Formula [13], getting two terms in the lower bound for the superheating field as κ → 0.

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