A refined search tree technique for Dominating Set on planar graphs

We establish a refined search tree technique for the parameterized DOMINATING SET problem on planar graphs. Here, we are given an undirected graph and we ask for a set of at most k vertices such that every other vertex has at least one neighbor in this set. We describe algorithms with running times O(8^kn) and O(8^kk+n³), where n is the number of vertices in the graph, based on bounded search trees. We describe a set of polynomial time data-reduction rules for a more general “annotated” problem on black/white graphs that asks for a set of k vertices (black or white) that dominate all the black vertices. An intricate argument based on the Euler formula then establishes an efficient branching strategy for reduced inputs to this problem. In addition, we give a family examples showing that the bound of the branching theorem is optimal with respect to our reduction rules. Our final search tree algorithm is easy to implement; its analysis, however, is involved.     

Solving constrained combinatorial optimization problems via importance sampling in the grand canonical ensemble

Combinatorial optimization problems are usually NP-hard. These problems are generally tackled by heuristic or branch-and-bound methods. The aim of this paper is to tackle constrained combinatorial optimization problems by importance Monte Carlo sampling. For this, we show that every constrained combinatorial optimization problem can be represented by a thermodynamical system in a suitable grand canonical ensemble given by the quantities of temperature, volume, and chemical potential. In order to find optimum solutions of the optimization problem, the grand canonical Monte Carlo method can be applied to the corresponding thermodynamical system. This method will amount to importance sampling, i.e. good feasible solutions of the optimization problem will be preferably sampled, provided that the intensive quantities of temperature and chemical potential are appropriately chosen. Our approach extends the standard importance sampling approach in the canonical ensemble to tackle unconstrained combinatorial optimization problems. The knapsack problem is considered as a prototype example.     

包装行业与电子商务的关系

结合包装业实际.分析了包装行业发展电子商务的意义,提出了发展包装电子商务的一些基本设想.     

用振动测量数据最优修正质量矩阵

在实际工程中，由有限元模型得到的计算值与通过试验获得的测量值之间往往存在偏差，为了能够精确预测结构的动力响应，依据测量信息修正存在的动力模型是非常必要的。运用代数特征值反问题的理论和方法，研究了满足正交性条件的质量矩阵的修正问题，得到了Frobenius范数意义下的最优修正矩阵。     

非线性时域识别方程的不适定性与正则化方法研究

研究了非线性时域识别方程的不适定性及其正则化求解方法。雅可比矩阵的性态能够反映非线性识别方程的性态，因此雅可比矩阵的条件数是非线性识别方程的不适定性的度量。阻尼最小二乘法只是一种强迫正定的计算方法，其识别结果仍然对测试噪声很敏感，解决该问题的有效途径是将阻尼最小二乘法与正则化方法两者结合使用。算例表明，将先验的参数预估值引入Tikhonov镇定泛函可以得到稳定的参数解，且识别误差与原始数据的测试噪声基本保持在同一水平。     

模拟退火算法在单目标规划问题中的应用

模拟退火算法是一种用于解决连续、有序离散和多模态优化问题的随机优化技术。它对于非常复杂，高度非线性的大型系统优化的求解，表现出比其他传统优化算法更加独特和优越的性能。现介绍了模拟退火算法的原理、数学模型及其求解步骤，并以一实例来说明模拟退火算法在解决组合优化问题时的有效性和优越性。     

宽带网综合布线系统若干问题探讨

当前信息化建设事业迅速发展，宽带网络的建设将成为人们关注的热点和今后工程建设的投资重点，“最后一公里”宽带接入网的组网方式厦其选用的接入产品更是目前讨论的焦点话题。本文提出宽带网建设要本着积极创新，求真务实，还应该遵循四大建网原则、“最后一公里”宽带接入网四种主流接入方式厦五大不同用户群的建设宽网要求和宽带网的产品选用参考的三大原则。     

新建煤矿监测监控系统中值得注意的几个问题

论述了建设煤矿监测监控系统的意义，计算机控制系统的一般构成和分类，提出了在新建煤矿监测监控系统时应该注意的几个问题。     

Incorporating social anxiety into a model of college problem drinking: Replication and extension.

Although research has found an association between social anxiety and alcohol use in noncollege samples, results have been mixed for college samples. College students face many novel social situations in which they may drink to reduce social anxiety. In the current study, the authors tested a model of college problem drinking, incorporating social anxiety and related psychosocial variables among 228 undergraduate volunteers. According to structural equation modeling (SEM) results, social anxiety was unrelated to alcohol use and was negatively related to drinking consequences. Perceived drinking norms mediated the social anxiety-alcohol use relation and was the variable most strongly associated with problem drinking. College students appear to be unique with respect to drinking and social anxiety. Although the notion of social anxiety alone as a risk factor for problem drinking was unsupported, additional research is necessary to determine whether there is a subset of socially anxious students who have high drinking norms and are in need of intervention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

网页设计实践存在的问题及对策

《网页设计》实践很讲究创新,同时它的技术性又很强,要求学生在实践时要尽可能掌握知识和熟练相关操作,然而,学生由于疏忽或者在知识上的缺陷,在实践中暴露了一些问题。文章就这些问题进行归类及做出原因分析,并归纳了网页实践的经验教训。