8数码问题求解算法的改进与实现

8数码问题源于一古老的智力游戏,随着人工智能的发展,产生了许多可以使用计算机对8数码求解的算法,其中基于启发式搜索的A*算法堪称经典。但传统的A*算法在对8数码问题求解时需要消耗巨大的时间成本。文章通过对A*算法中启发函数及open表结构的改进,得出了一个针对8数码问题求解的高效算法,该算法能针对任意布局的8数码问题在保证求解速度的情况下获得较佳的结果。     

8数码问题求解算法的改进与实现

8数码问题源于一古老的智力游戏,随着人工智能的发展,产生了许多可以使用计算机对8数码求解的算法,其中基于启发式搜索的A*算法堪称经典.但传统的A*算法在对8数码问题求解时需要消耗巨大的时间成本.文章通过对A*算法中启发函数及open表结构的改进,得出了一个针对8数码问题求解的高效算法,该算法能针对任意布局的8数码问题在保证求解速度的情况下获得较佳的结果.     

基于A*算法的动态路径诱导算法研究

城市交通路径诱导系统是智能交通系统的重要组成部分,而最优路径算法作为路径诱导系统的重要部分,一直是计算机科学、运筹学、地理信息科学等学科的一个研究热点;本文在研究传统的静态路径算法的基础上,采用改进的A*算法,以西安市电子地图为基础,研究出实现动态交通网络中路径诱导的方案。     

基于Dijkstra算法的快递车辆配送路径优化

针对目前快递车辆运输成本问题,研究了如何利用Dijkstra算法来迅速寻找出快递车辆配送派件过程中的最短路,并与解决该类问题常用的遗传算法,蚁群算法和A*算法进行了比较分析。证明了Dijkstra算法可以准确迅速地寻找出快递配送车辆派件过程中的最短路,从而有效的帮助快递公司降低运输成本。     

基于A4纸的摄像机标定算法

摄像机标定技术是三维重建的第一步,文章结合三维重建对计算机标定精度要求不是很高的具体需求,在张正友提出的基于平面模板的标定方法基础上,提出了一种基于A4纸的摄像机标定算法。经实验验证,文章所采用的算法标定精度较高,鲁棒性较好。     

基于定长窗分层检测的音频分割算法

音频分割是音频分析、检索等应用的基础.△BIC算法是一种重要的音频分割算法,传统的△BIC及其改进算法采用窗口增长方式遍历音频流顺次检测跳变点,计算量大且准确率低.本文提出基于定长窗分层检测的音频分割算法,采用定长窗滑动遍历音频流,窗内自顶向下分层次地计算△BIC检测跳变点,最后用局部极值判定方法验证检测到的候选跳变点.实验结果表明,本文算法分割性能良好.     

二阶隐马尔科夫模型的原理与实现

文中简述了二阶隐马尔科夫模型(second-order markov model)的基本原理和实现中的问题,并给出了一种新的Viterbi算法:新算法是利用MAP路径估计(Maximum A Posteriori Path)改进Viterbi算法。     

基于改进聚类分析算法的供应商选择研究

通过比较几种数据挖掘算法以及结合供应商选择的实际情况,提出一种适用于选择供应商的改进层次凝聚数据挖掘算法.然后具体以某制造企业为例,运用该算法证明可行性.     

基于DSP TMS320LF2407A的浮点数开平方算法的研究

研究DSP TMS320LF2407A浮点数开平方的理论方法,采用改进Newton下山算法为Newton迭代法提供了更为精确的初值,从而使得收敛速度加快,精度更高。在DSP TMS320LF2407A上编写了一套算法,计算结果与理论分析基本吻合。该算法思路新颖,精度高,速度快,可移植到其它浮点数运算的单片机上。     

一种闭环的GMSK位同步方法

本文主要讲述了一种闭环的GMSK位同步方法,这种方法是用一路复系数PAM信号来近似GMSK信号,经过线性近似以后就可以采用平方时恢复算法来进行位定时误差估计,将位定时误差的估计结果再送入环路滤波器和NCO,最后利用NCO来控制A/D时钟。本文在给出了误差估计方法、环路滤波器和NCO的模型以后,再结合A/D,DDS构成了一个模拟与数字相结合的锁相环,实现了GMSK位同步。     

Road pricing in a free society

Improved road pricing would be an indispensable element in a road system run on commercial principles, with charges for road use not co-mingled with taxes, and with no discrimination against private road providers. But pricing imposed by a monopoly supplier, to 'restrain' motorised mobility, is unacceptable in a free society.     

Interpretation of Cointegrating Coefficients in the Cointegrated Vector Autoregressive Model*

Regression coefficients are interpreted by a counterfactual experiment. For simultaneous equations this experiment can be implemented if the coefficients are identified, and throws some light on the role of instruments and the method of indirect least squares. This paper discusses another counterfactual experiment in the vector autoregressive model in order to interpret the coefficients of an identified cointegrating relation. The dynamics of the model is used to implement a long‐run change by changing the current values. The counterfactual experiment can be conducted precisely when the cointegrating relation is identified.     

市政桥梁路面铺装层病害防治措施

市政桥梁路面的铺装层属于工程施工中较为薄弱的施工环节,并且很容易受到各种因素影响,桥梁路面通车不久其铺装层便有裂缝和脱落等现象出现,交通安全受到阻碍,进而使得路面服务质量降低,造成整个桥梁美观受到影响。本文主要分析了市政桥梁工程路面铺装层常见病害问题,并简要分析了这些病害形成的原因,提出了一些防止病害的有效措施,以确保铺装层病害问题得到妥善解决。     

配电线路故障定位算法及系统实现

本文提出一种基于支路-节点的配电网线路故障定位矩阵算法,基于此算法形成配电线路故障定位系统。经过模拟现场试点运行,表明该系统便于监控人员在发生配电线路故障时,迅速判断出故障区段,节约维修时间,对配电网络的安全稳定运行起到有效的作用。     

Short and long-run cost efficiency in Indian public bus companies using Data Envelopment Analysis

State Transport Undertakings (STUs) are key players in providing mass road transport in India. Given that they operate under high levels of government imposed regulatory constraints, it is imperative to study their efficiency levels. Given that capital is a relatively scarce resource in developing countries like India, it is important to obtain efficiency in the short-run where some inputs are fixed as well as over the long run, where all inputs are variable. The technique used for capturing efficiency is Data Envelopment Analysis (DEA). A key possible limitation of DEA models based on physical inputs and outputs is that for an inefficient firm, reduction in some or all inputs may be recommended. It may often be desirable for an inefficient firm to increase some less expensive inputs while reducing the use of relatively expensive ones. Hence, when market price data is available, it is advisable to use the cost variant of DEA. Also, it is possible to determine variable cost efficiency in the short run when some inputs cannot be varied. Such inputs are referred to as “quasi-fixed” inputs. In this paper, we examine short and long term efficiencies of select bus companies in India known as State Transport Undertakings (STUs) over a period of 10 years. Fleet strength has been used as the quasi-fixed input. It is possible to ascertain, through a comparison of shadow price of the quasi-fixed input, vis-à-vis its market price, as to whether the quantity of this input is sub-optimally small or large. It is found that by adopting efficiency enhancing practices, STUs can cumulatively reduce their operating costs to the extent of 9123.35 million dollars. Also the tendency to minimize costs is found to be declining over time. In the short run some STUs are found to operate with a sub optimally low fleet size.     

湖南省国省干线公路路面改造中反射裂缝的处治研究

旧水泥砼路面加铺沥青砼面层非常容易形成反射裂缝。文章介绍了常用的反射裂缝防治措施。结合湖南省国省干线公路路面改造中对原有水泥砼路面处治方案,分析了原旧水泥砼路面处治方案对消除反射裂缝的效果,结合工程实例,提出了尽量少采用整体利用原有水泥砼路和尽量多采用共振机械碎石化原有水泥砼路面。     

城市出行信息环境分层规划方法

认为出行信息环境的服务水平是影响城市交通效率的重要因素之一,有效的出行信息传递能够显著提高路网的整体效率。系统分析了我国城市出行信息环境现状,在出行信息需求分析的基础上,建立了包含城市路网、交通方式与路线三个层面的出行信息环境分层规划方法,并提出了具体的出行信息环境优化对策。     

An EM algorithm for the estimation of parametric and nonparametric hierarchical nonlinear models

It is shown how to implement an EM algorithm for maximum likelihood estimation of hierarchical nonlinear models for data sets consisting of more than two levels of nesting. This upward–downward algorithm makes use of the conditional independence assumptions implied by the hierarchical model. It cannot only be used for the estimation of models with a parametric specification of the random effects, but also to extend the two-level nonparametric approach – sometimes referred to as latent class regression – to three or more levels. The proposed approach is illustrated with an empirical application.     

嵌岩桩在铁路桥梁施工中的应用

随着现代成桩工艺、桩体结构的检测技术与桩的承载力等方面的进步和提高,桩与桩基础得到越来越广泛的应用,当桥梁上部结构荷载较大,而适合作为持力层的岩层又埋藏较浅,或虽然可作为持力层的土层埋藏不深但其下又存在软弱下卧层,用天然浅基础不能满足结构物对地基强度、变形和稳定性方面的要求时,嵌岩桩作为桩基础的一种形式往往是常用的一种基础。本文结合武广客运专线桥梁基础的施工,对嵌岩桩在铁路桥梁施工中的注意事项加以论述。     

The Brexit can is kicked again – where do we go next?

? The UK and EU have agreed to kick the can further along the road, extending the Article 50 period to 31 October. But our analysis of the various political scenarios suggests that the chances of Parliament using the extra time to form a consensus are low, particularly if MPs believe that further extensions are possible. Should the EU make clear that it has run out of road along which to kick the can, Parliament will be forced to choose between the three options it has always had – in this situation we would still see an “orderly” Brexit as most likely, with a sizeable risk of “no deal” and a low probability on “no Brexit”.