An Efficient Algorithm for Haplotype Inference on?Pedigrees with a Small Number of Recombinants

Combinatorial (or rule-based) methods for inferring haplotypes from genotypes on a pedigree have been studied extensively in the recent literature. These methods generally try to reconstruct the haplotypes of each individual so that the total number of recombinants is minimized in the pedigree. The problem is NP-hard, although it is known that the number of recombinants in a practical dataset is usually very small. In this paper, we consider the question of how to efficiently infer haplotypes on a large pedigree when the number of recombinants is bounded by a small constant, i.e. the so called k-recombinant haplotype configuration (k-RHC) problem. We introduce a simple probabilistic model for k-RHC where the prior haplotype probability of a founder and the haplotype transmission probability from a parent to a child are all assumed to follow the uniform distribution and k random recombination events are assumed to have taken place uniformly and independently in the pedigree. We present an O(mnlog? ^k+1 n) time algorithm for k-RHC on tree pedigrees without mating loops, where m is the number of loci and n is the size of the input pedigree, and prove that when 90log?n<m<n ³, the algorithm can correctly find a feasible haplotype configuration that obeys the Mendelian law of inheritance and requires no more than k recombinants with probability $1 -O(k^{2}\frac{\log^{2}n}{mn}+\frac{1}{n^{2}})$ . The algorithm is efficient when k is of a moderate value and could thus be used to infer haplotypes from genotypes on large tree pedigrees efficiently in practice. We have implemented the algorithm as a C++ program named Tree-k-RHC. The implementation incorporates several ideas for dealing with missing data and data with a large number of recombinants effectively. Our experimental results on both simulated and real datasets show that Tree-k-RHC can reconstruct haplotypes with a high accuracy and is much faster than the best combinatorial method in the literature.     

An investigation of the effects of mix strength on the fracture and fatigue behavior of concrete mortar

This paper examines the effects of mix compressive strength (30, 35 and 40 MPa) on the fracture initiation toughness, resistance-curve behavior and fatigue crack growth behavior of concrete mortar. The fracture initiation toughness and the resistance-curve behavior are shown to increase with increasing mix strength. The observed resistance-curve behavior is then attributed largely to the effects of ligament bridging, which are predicted using small- and large-scale bridging models. In contrast, the fatigue crack growth resistance is shown to decrease with increasing mix strength. An extended multiparameter framework was used for the modeling of fatigue crack growth. Finally, the implications of the results are discussed for the design of concrete mixtures with attractive combinations of strength, fracture toughness and fatigue crack growth resistance.     

Stable multiwavelength dispersion-tuned actively mode-locked erbium-doped fiber ring laser using nonlinear polarization rotation

We demonstrate a stable multiwavelength actively mode-locked erbium-doped fiber laser at 10 GHz based on a dispersion cavity and nonlinear polarization rotation (NPR) effect. The dispersion cavity allows simultaneous multiple wavelengths to satisfy the round-trip condition and smooth wavelength tuning, while the NPR ensures the stable operation and supermode noise suppression. A simple model is developed to explore the optimal setting of the cavity. Simultaneous dual- and five-wavelength operation is experimentally investigated.     

基于GIS的城市管网管理系统的设计与实现

本文介绍了采用MapX开发城市管网信息系统的具体过程,并对系统的设计原则、结构设计及功能设计等方面的内容进行了深入分析;为城市规划及管理部门提供了科学管理、科学建设城市的决策依据。     

SQL注入攻击全面预防办法及其应用

介绍了SQL注入攻击原理,以ASP+SQLServer型网站为基础,从应用服务器、数据服务器、功能代码本身三个方面详细介绍了如何避免SQL注入攻击。尤其在功能程序本身方面,在前人提出的检测/防御/备案通用模型基础上,提出一个改良的SQL注入攻击通用检验模型。该模型只在服务器端设置一级检查,对攻击者进行备案,攻击次数过多的用户的请求服务器将不予理会,而且被抽象出来以单独函数形式存在,使用时直接调用即可,适用于所有页面。     

碳纳米管冷阴极大电流发射机理的研究

本文对碳纳米管冷阴极的场致发射机理进行了理论和实验研究.研究发现,如果场致发射冷阴极的发射面积很小,有可能得到较大的发射电流密度.当发射面积增加时,冷阴极的平均发射电流密度迅速下降,很难得到大的束电流.研究表明,在碳纳米管冷阴极的场致发射现象中,边沿场的场致发射现象起着非常重要作用.如果仅仅增加发射面积,边沿发射电流增加不多,这导致了平均发射电流密度的下降.因此,在阴极结构中增加发射体的边沿,则可有效提高阴极的发射电流.     

深度图像的平滑

由于受到各种干扰，结构光方法获取的深度图像重建结果中包含大量的毛刺，本文将平面图像平滑的方法拓展到深度图像领域，通过分析噪声模型，我们利用中值滤波器和高斯滤波器对深度图像进行三维平滑。结合去噪电路，取得了满意的重建效果。     

作业成本法在焦家金矿高水材料厂的应用研究

介绍了作业成本法的概念、计算原理、核算过程及数学模型；通过应用作业成本法对焦家金矿高水材料厂产品成本的计算、分析，其计算结果与实际相符；为管理者决策提供了依据。     

MR阻尼器在斜拉索被动控制中最优型号研究

以全索全时段振动响应的均方根(RMS)评价MR阻尼器对斜拉索的减振效果.计算结果表明MR阻尼器型号是影响斜拉索减振效果的最主要因素.斜拉索的减振效果在选用合适的MR阻尼器时达到最佳.本文进而研究了MR阻尼器的最优型号与阻尼器安装位置、施加的电压、斜拉索基频(张力、索长、质量)、激励荷载(类型、频率、幅值)等各种因素的关系,为MR阻尼器合理选型提供了优化设计的方法.     

DTM350-600磨煤机大轴断裂分析

针对陕西渭河发电有限责任公司5号炉磨煤机乙磨大轴断裂失效进行了金属分析。结果表明应加强制造质量监控和实施设备全过程金属监督。