关键词： 便携式光笔测量系统   视觉坐标测量   图像处理   数学形态算法   回光反射标志点  

摘要： 介绍了一种便携式光笔三坐标视觉测量系统,在分析测量系统成像特点的基础上,提出了一种基于数学形态学算法的图像数字处理方法,即通过在CCD摄像机镜头上加滤光片来隔离背景对图像产生亮斑的干扰。数学形态算法以光笔上被测特征点在CCD摄像机像面上的光斑图像轮廓所占的像素个数为基准,剔除过大和过小的图像轮廓,进而采用基于本算法的特征点图像识别方法来实现目标图像的获取,从而实现椭圆形光斑图像的识别。本文给出了该方法的具体实现过程,试验结果表明,该方法能够对背景复杂和灰度分布不均匀的图像实行有效的图像分割,实现目标图像和背景图像的分离,加快图像分析和处理速度,提高系统测量的效率和稳定性。

关键词： 数学优化算法   水网络优化   智能算法  

摘要： 基于超结构的多杂质用水网络优化模型具有维数高、非线性和非凸性等特点,是目前节水技术研究的难点之一,数学优化算法是解决这一问题的主要工具。介绍了数学优化算法中的经典数学规划法、智能算法和智能混合算法解决多杂质水网络优化问题的研究进展。智能混合算法通用性高,较其他算法具有更强的全局和局部寻优能力,更适用于多杂质水网络的优化。开发智能混合算法,综合考虑换热网络和着眼企业现场条件是今后水网络优化研究的重点。

关键词： Encryption   Chaos   DNA encoding   Cryptanalysis   Equivalent keys  

摘要： Recently a new image encryption method based on DNA encoding and chaotic systems has been proposed. In this paper, several weaknesses of this cryptosystem are pointed out. Equivalent mathematical model of the cryptosystem is designed and algebraic analysis is given. Moreover reduction of the key space has been reached by finding equivalent keys. A recovering scheme is finally given with a lower complexity than the actual decryption scheme.

关键词： Adjoint ideal   Conductor   Groebner basis   Integral closure  

摘要： Let l be an irreducible affine plane algebraic curve defined by a polynomial f is an element of K[x, y]. Assume that f is monic with respect to y and that the function field K(l) of the curve is separable over K(x). In this paper we give a simple algorithm to compute a lexicographic Groebner basis of the adjoint ideal Adj(l) of l from a basis, as a K[x]- module, of the integral closure K[(l) over bar] of the coordinate ring K[l].

关键词： Bin packing   Item fragmentation   Mathematical programming   Branch-and-price  

摘要： In this paper we consider a class of bin packing problems from the literature having the following distinctive feature: items may be fragmented at a price. Problems of this kind arise in diverse application fields like logistics and telecommunications, and have already been extensively tackled from an approximation point of view. We focus on the case in which splitting produces no overhead, a fixed number of bins is given and the number of fragments or fragmentations needs to be minimized. We first investigate the theoretical properties of the problem. Then we elaborate on them to devise mathematical programming models and algorithms, yielding both exact optimization algorithms and effective heuristics. An extensive experimental campaign proves that our approach is very effective, and highlights which features make an instance computationally harder to solve. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： 三角剖分   数学形态学   拓扑规则   修补算法  

摘要： 三角剖分技术被广泛的应用在逆向工程、三维有限元预处理、医学成像等不同的领域,是当前几何造型、计算机图形学中的主要研究领域之一。而针对散乱点云数据在剖分过程中所产生的缺陷,则采用数学形态学的方法对其进行修复,同时运用基于拓扑规则的算法对该区域进行局部的修改,从而生成新的三角网格。

关键词： Individual cell-based model   Population dynamics   Cell division   Apoptosis   Clonal contraction  

摘要： We formulate and analyze an algorithm of cell fate decision that describes the way in which division vs. apoptosis choices are made by individual T cells during an infection. Such model involves a minimal number of known biochemical mechanisms: it basically relies on the interplay between cell division and cell death inhibitors on one hand, and membrane receptors on the other. In spite of its simplicity, the proposed decision algorithm is able to account for some significant facts in immune response. At the individual level, the existence of T cells that continue to replicate in the absence of antigen and the possible occurrence of T cell apoptosis in the presence of antigen are predicted by the model. Moreover, the latter is shown to yield an emergent collective behavior, the observed delay in clonal contraction with respect to the end of antigen stimulation, which is shown to arise just from individual T cell decisions made according to the proposed mechanism. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Second-order learning algorithm   Discrete algebraic Lyapunov equation   Extended Hamiltonian algorithm   Positive definite symmetric matrix   Euclidean gradient   Riemannian gradient  

摘要： In this paper, we use a second-order learning algorithm for solving the numerical solution of the discrete algebraic Lyapunov equation. Specifically, Extended Hamiltonian algorithm based on the manifold of positive definite symmetric matrices is provided. Furthermore, this algorithm is compared with the Euclidean gradient algorithm, the Riemannian gradient algorithm and the two traditional iteration methods. Simulation examples show that the convergence speed of the Extended Hamiltonian algorithm is the fastest one among these algorithms. (C) 2014 Elsevier Inc. All rights reserved.

关键词： Skewness   Kurtosis   Mixture of Gaussians   Moment matching   Maximum likelihood   EM algorithm   C13   C15   C16   C44  

摘要： An analogue can be made between: (a) the slow pace at which species adapt to an environment, which often results in the emergence of a new distinct species out of a once homogeneous genetic pool and (b) the slow changes that take place over time within a fund, mutating its investment style. A fund's track record provides a sort of genetic marker, which we can use to identify mutations. This has motivated our use of a biometric procedure to detect the emergence of a new investment style within a fund's track record. In doing so, we answer the question: What is the probability that a particular PM's performance is departing from the reference distribution used to allocate her capital? The EF3M algorithm, inspired by evolutionary biology, may help detect early stages of an evolutionary divergence in an investment style and trigger a decision to review a fund's capital allocation.

关键词： flowshop scheduling   parallel machines   mixed integer linear programming model   hunting search metaheuristic algorithm  

摘要： Majority of researches in no-wait flowshop scheduling assume that there is only one machine at each stage. But, factories commonly duplicate machines in parallel for each operation. In this case, they balance the speed of the stages, increase the throughput of the shop floor and reduce the impact of bottleneck stages. Despite their importance, there is no paper to study the general no-wait flowshop with parallel machines. This paper studies this problem where the objective is to minimise makespan. Since there is no mathematical model for the problem, we first mathematically formulate it in form of two mixed integer linear programming models. By the models, the small instances are optimally solved. We then propose a novel hunting search metaheuristic algorithm (HSA) to solve large instances of the problem. HSA is derived based on a model of group hunting of animals when searching for food. A set of experimental instances are carried out to evaluate the algorithm. The algorithm is carefully evaluated for its performance against an available algorithm by means of statistical tools. The related results show that the proposed HSA provides sound performance comparing with other algorithms.