Search results for "Tangle"
showing 10 items of 420 documents
A GRASP algorithm for constrained two-dimensional non-guillotine cutting problems
2005
This paper presents a greedy randomized adaptive search procedure (GRASP) for the constrained two-dimensional non-guillotine cutting problem, the problem of cutting the rectangular pieces from a large rectangle so as to maximize the value of the pieces cut. We investigate several strategies for the constructive and improvement phases and several choices for critical search parameters. We perform extensive computational experiments with well-known instances previously reported, first to select the best alternatives and then to compare the efficiency of our algorithm with other procedures.
Out-of-plane transport of 1T-TaS2/graphene-based van der Waals heterostructures
2021
Due to their anisotropy, layered materials are excellent candidates for studying the interplay between the in-plane and out-of-plane entanglement in strongly correlated systems. A relevant example is provided by 1T-TaS2, which exhibits a multifaceted electronic and magnetic scenario due to the existence of several charge density wave (CDW) configurations. It includes quantum hidden phases, superconductivity and exotic quantum spin liquid (QSL) states, which are highly dependent on the out-of-plane stacking of the CDW. In this system, the interlayer stacking of the CDW is crucial for the interpretation of the underlying electronic and magnetic phase diagram. Here, thin-layers of 1T-TaS2 are …
Deconvolution of the Effects of Binary Associations and Collective Assemblies on the Rheological Properties of Entangled Side-Chain Supramolecular Po…
2019
The properties and function of supramolecular polymer networks are determined not only by pairwise interchain transient associations but also by chain entanglement and nanoscopic phase separation of the associative groups. To unravel the impact and interplay of these different factors, we devise a set of model supramolecular polymer networks in which the number of entanglements and the density of associative groups are systematically varied. Rheological data show that by increasing the density of associative groups, the plateau modulus grows to a steady level and extends over a distinct frequency range. This is credited to the presence of binary associations with unique partner exchange tim…
GRASP and Path Relinking for the Two-Dimensional Two-Stage Cutting-Stock Problem
2007
We develop a greedy randomized adaptive search procedure (GRASP) for the constrained two-dimensional two-stage cutting-stock problem. This is a special cutting problem in which the cut is performed in two phases. In the first phase, the stock rectangle is slit down its width into different vertical strips and in the second phase, each of these strips is processed to obtain the final pieces. We propose two different algorithms based on GRASP methodology. One is “piece-oriented” while the other is “strip-oriented.” Both procedures are fast and provide solutions of different structures to this cutting problem. We also propose a path-relinking algorithm, which operates on a set of elite soluti…
Constructive procedures to solve 2-dimensional bin packing problems with irregular pieces and guillotine cuts
2015
Abstract This paper presents an approach for solving a new real problem in cutting and packing. At its core is an innovative mixed integer programme model that places irregular pieces and defines guillotine cuts. The two-dimensional irregular shape bin packing problem with guillotine constraints arises in the glass cutting industry, for example, the cutting of glass for conservatories. Almost all cutting and packing problems that include guillotine cuts deal with rectangles only, where all cuts are orthogonal to the edges of the stock sheet and a maximum of two angles of rotation are permitted. The literature tackling packing problems with irregular shapes largely focuses on strip packing i…
A tabu search algorithm for a two-dimensional non-guillotine cutting problem
2007
In this paper we study a two-dimensional non-guillotine cutting problem, the problem of cutting rectangular pieces from a large stock rectangle so as to maximize the total value of the pieces cut. The problem has many industrial applications whenever small pieces have to be cut from or packed into a large stock sheet. We propose a tabu search algorithm. Several moves based on reducing and inserting blocks of pieces have been defined. Intensification and diversification procedures, based on long-term memory, have been included. The computational results on large sets of test instances show that the algorithm is very efficient for a wide range of packing and cutting problems.
Handling precedence constraints in scheduling problems by the sequence pair representation
2015
In this paper, we show that sequence pair (SP) representation, primarily applied to the rectangle packing problems appearing in the VLSI industry, can be a solution representation of precedence constrained scheduling. We present three interpretations of sequence pair, which differ in complexity of schedule evaluation and size of a corresponding solution space. For each interpretation we construct an incremental precedence constrained SP neighborhood evaluation algorithm, computing feasibility of each solution in the insert neighborhood in an amortized constant time per examined solution, and prove the connectivity property of the considered neighborhoods. To compare proposed interpretations…
Silence of Binary Kerr Black Holes
2020
A nontrivial S matrix generally implies a production of entanglement: starting with an incoming pure state, the scattering generally returns an outgoing state with nonvanishing entanglement entropy. It is then interesting to ask if there exists a nontrivial S matrix that generates no entanglement. In this Letter, we argue that the answer is the S-matrix for the scattering of classical black holes. We study the spin entanglement in the scattering of arbitrary spinning particles. Augmenting the S-matrix with Thomas–Wigner rotation factors, we derive the entanglement entropy from the gravitational induced 2→2 amplitude. In the Eikonal limit, we find that the relative entanglement entropy, defi…
Universal N -Partite d -Level Pure-State Entanglement Witness Based on Realistic Measurement Settings
2019
Entanglement witnesses are operators that are crucial for confirming the generation of specific quantum systems, such as multipartite and high-dimensional states. For this reason, many witnesses have been theoretically derived which commonly focus on establishing tight bounds and exhibit mathematical compactness as well as symmetry properties similar to that of the quantum state. However, for increasingly complex quantum systems, established witnesses have lacked experimental achievability, as it has become progressively more challenging to design the corresponding experiments. Here, we present a universal approach to derive entanglement witnesses that are capable of detecting the presence …
Embedding Quantum into Classical: Contextualization vs Conditionalization
2014
We compare two approaches to embedding joint distributions of random variables recorded under different conditions (such as spins of entangled particles for different settings) into the framework of classical, Kolmogorovian probability theory. In the contextualization approach each random variable is "automatically" labeled by all conditions under which it is recorded, and the random variables across a set of mutually exclusive conditions are probabilistically coupled (imposed a joint distribution upon). Analysis of all possible probabilistic couplings for a given set of random variables allows one to characterize various relations between their separate distributions (such as Bell-type ine…