A physical map of the human Y chromosome

The non-recombining region of the human Y chromosome (NRY), which comprises 95% of the chromosome, does not undergo sexual recombination and is present only in males. An understanding of its biological functions has begun to emerge from DNA studies of individuals with partial Y chromosomes, coupled with molecular characterization of genes implicated in gonadal sex reversal, Turner syndrome, graft rejection and spermatogenic failure. But mapping strategies applied successfully elsewhere in the genome have faltered in the NRY, where there is no meiotic recombination map and intrachromosomal repetitive sequences are abundant. Here we report a high-resolution physical map of the euchromatic, centromeric and heterochromatic regions of the NRY and its construction by unusual methods, including genomic clone subtraction and dissection of sequence family variants. Of the map's 758 DNA markers, 136 have multiple locations in the NRY, reflecting its unusually repetitive sequence composition. The markers anchor 1,038 bacterial artificial chromosome clones, 199 of which form a tiling path for sequencing.     

A physical map of the mouse genome

A physical map of a genome is an essential guide for navigation, allowing the location of any gene or other landmark in the chromosomal DNA. We have constructed a physical map of the mouse genome that contains 296 contigs of overlapping bacterial clones and 16,992 unique markers. The mouse contigs were aligned to the human genome sequence on the basis of 51,486 homology matches, thus enabling use of the conserved synteny (correspondence between chromosome blocks) of the two genomes to accelerate construction of the mouse map. The map provides a framework for assembly of whole-genome shotgun sequence data, and a tile path of clones for generation of the reference sequence. Definition of the human-mouse alignment at this level of resolution enables identification of a mouse clone that corresponds to almost any position in the human genome. The human sequence may be used to facilitate construction of other mammalian genome maps using the same strategy.     

Integration of cytogenetic landmarks into the draft sequence of the human genome

We have placed 7,600 cytogenetically defined landmarks on the draft sequence of the human genome to help with the characterization of genes altered by gross chromosomal aberrations that cause human disease. The landmarks are large-insert clones mapped to chromosome bands by fluorescence in situ hybridization. Each clone contains a sequence tag that is positioned on the genomic sequence. This genome-wide set of sequence-anchored clones allows structural and functional analyses of the genome. This resource represents the first comprehensive integration of cytogenetic, radiation hybrid, linkage and sequence maps of the human genome; provides an independent validation of the sequence map and framework for contig order and orientation; surveys the genome for large-scale duplications, which are likely to require special attention during sequence assembly; and allows a stringent assessment of sequence differences between the dark and light bands of chromosomes. It also provides insight into large-scale chromatin structure and the evolution of chromosomes and gene families and will accelerate our understanding of the molecular bases of human disease and cancer.     

A physical map of the chicken genome

Strategies for assembling large, complex genomes have evolved to include a combination of whole-genome shotgun sequencing and hierarchal map-assisted sequencing. Whole-genome maps of all types can aid genome assemblies, generally starting with low-resolution cytogenetic maps and ending with the highest resolution of sequence. Fingerprint clone maps are based upon complete restriction enzyme digests of clones representative of the target genome, and ultimately comprise a near-contiguous path of clones across the genome. Such clone-based maps are used to validate sequence assembly order, supply long-range linking information for assembled sequences, anchor sequences to the genetic map and provide templates for closing gaps. Fingerprint maps are also a critical resource for subsequent functional genomic studies, because they provide a redundant and ordered sampling of the genome with clones. In an accompanying paper we describe the draft genome sequence of the chicken, Gallus gallus, the first species sequenced that is both a model organism and a global food source. Here we present a clone-based physical map of the chicken genome at 20-fold coverage, containing 260 contigs of overlapping clones. This map represents approximately 91% of the chicken genome and enables identification of chicken clones aligned to positions in other sequenced genomes.     

基于RFID供应链的双轨迹克隆检测方法

针对传统基于射频识别技术(radio frequency identification,RFID)的克隆检测方法面对供应链动态变化、标签误读的局限性,提出一种简单、有效的基于轨迹的克隆检测方法.该方法通过在标签中写入验证序列,使得随着标签随产品在供应链中流动,正版标签和克隆标签因验证序列的不断更新而出现不同,而且标签中的验证序列随时间变化会呈现一定的规律,于是形成一条序列轨迹,结合标签事件信息中业务动作的一致性形成2条轨迹,即双轨迹.该方案通过评估2条轨迹的正确性来发现克隆,在评估克隆存在时充分考虑了标签误读、误写、事件丢失以及错误运输.使用Arena对供应链进行建模和仿真.仿真表明,该方案对供应链动态变化具有灵活性,同时在牺牲较小通信量的情况下,有效地提高了检测性能.     

基于RFID阵列的无轨AGV系统的研究与设计

为改进有轨自动导航小车(AGV)的不足,研究一种基于RFID阵列的无轨AGV系统。该系统包括RFID阵列地板、无线通信网络、上位机、运行场地地图、小车运行控制系统;AGV安装若干RFID读卡器,运行在RFID阵列地板上,运行时通过读取地板下RFID电子标签的ID号,并通过无线通信网络发送到上位机;上位机构建和存储RFID阵列地板地图,上机位将接收到的ID号与存储的地图进行对照,计算出小车当前的位置的运行姿态,依据预设的运行路径生成AGV当前的控制指令并通过无线网络发送小车,控制小车的运行。系统通过利用RFID与地图实现定位,上位机生成控制指令的方式,实现AGV无轨运行。验证测试结果表明,AGV在预设运行路径上行驶,平均定位精度5cm,实用性好,稳定性高。     

克隆含有MT-Ⅰ和MT-Ⅱ基因的染色体DNA片段及其内切酶图谱的鉴定

用小鼠MT-ⅠcDNA作为探针,从129小鼠的基因组库中获得含MT-Ⅰ基因的DNA片段。从6.8×10⁵的噬菌斑中挑出4个阳性噬菌体克隆,分别命名为1-1, 2-1, 1-6和4-3。在这4个克隆中1-1和2-1的阳性信号更强些。应用插入片段的末端引物作为探针进行杂交结合部分酶切的方法,对这2个克隆的插入片段进行了限制性内切酶酶切图谱分析,确定了克隆1-1和2-1的酶切图谱及MT-Ⅰ基因在2个克隆DNA中的位置。并进一步发现和证明了在2个克隆中含有MT-Ⅱ基因。     

从SNP到标签SNP的算法实现与讨论

由于对全部的SNP位点都进行基因分型的成本过于昂贵，而少量的标签SNP就能够提供与全部1500万个SNP位点大致相同的图谱信息．因此，如何选择标签SNP就显得十分重要，本文中所实现的选择标签SNP的算法是以连锁不平衡（Linkage Disequilibrium，LD）为基础的．     

A physical map of the human genome

The human genome is by far the largest genome to be sequenced, and its size and complexity present many challenges for sequence assembly. The International Human Genome Sequencing Consortium constructed a map of the whole genome to enable the selection of clones for sequencing and for the accurate assembly of the genome sequence. Here we report the construction of the whole-genome bacterial artificial chromosome (BAC) map and its integration with previous landmark maps and information from mapping efforts focused on specific chromosomal regions. We also describe the integration of sequence data with the map.     

基于GIS地图的移动机器人路径规划

针对移动机器人路径规划实现条件的限制,提出基于GIS (geographic information system)地图的移动机器人路径规划.该方法应用改进A*算法,较好地实现了移动机器人的最优路径规划.在任意给定的地图中,只要确定了机器人的起点和终点,就可以找到该机器人在实际工作环境中符合需求的路径规划轨迹.应用VC++编程进行实验,证明了该方法的有效性.     

变电站智能巡检机器人全局路径规划设计

针对国内变电站智能巡检机器人行走路线的特点,建立半结构化的道路模型。提出将改进的Dijkstra算法与模拟退火算法相结合,应用到变电站智能巡检机器人的全局路径规划中,在数据库技术的基础上采用VC++对上述算法进行软件设计与实现,构建具有全局路径规划功能的电子地图系统。该系统已在变电站的智能巡检机器人系统平台下进行实验并投入使用,现场运行结果证明该方法高效可行。     

基于优化PSO的LU循环分块方法

循环分块技术可以提高Cache的命中率,而循环分块的规模是该技术的决定性因素。利用粒子群优化算法可以优化循环分块的规模,获取合适规模的分块,提高循环分块的效率。首先研究了LU分解算法,然后讨论了传统粒子群优化算法并针对用于循环分块方面的不足加以改进,最后把优化的粒子群优化算法用于LU分解算法之中,从而提出了一个PSO-LU循环分块算法。仿真实验结果表明,和原始基准测试程序相比,所提循环分块算法比性能有所提升,更充分地提高高速缓存运算效率。     

基于环境剖分的层次拓扑地图及路径规划

针对基于拓扑地图的移动机器人路径规划问题,提出一种层次拓扑地图及相应的路径规划方法——边界方位法。层次拓扑地图分为剖分层和边界层,剖分层以环境剖分为拓扑节点,边界层以剖分的边界为拓扑节点。边界方位法首先在剖分层生成由剖分构成的路径序列,再将边界层转化为由边界构成的路径序列,最后根据机器人当前位置及边界之间的方位荚系实时生成实际路径。由于定义了边界之间的方位关系,使得机器人能够根据边界序列路径中的下一边界与当前边界的方位关系确定当前的运动方向,从而实现了实际路径的优化。理论分析和仿真实验均表明,该方法在增加少量存储信息的基础上,获得了较好的路径规划效果。     

地图加权遗传算法的油井自动巡检机器人路径规划

针对油井巡检机器人与障碍物的接触率高,造成设备故障率高增加石油生产成本问题,提出基于地图加权的遗传算法。首先将地图进行栅格化,建立栅格地图模型,并进行加权设置。其次引入遗传算法模型进行路径规划,将每次路径规划结果存入染色体中并计算路径长度,最后筛选最大权值中的路径最短染色体,并绘制路线。在参数设定相同的条件下,采用基于地图加权的遗传算法、经典遗传算法进行比对实验,仿真结果表明,基于地图加权的遗传算法优先选择了不靠近障碍物的栅格的情况下完成了路径规划任务,机器人与障碍物的接触率下降了74.91%,时间和路程仅增加0.3179 s与32%。     

基于激光同步定位与建图的移动机器人路径寻优方法

针对未知场景下移动机器人路径寻优问题,提出一种基于改进蚁群算法的激光SLAM移动机器人路径寻优方法。该方法由场景重构和路径寻优组成,利用激光雷达传感器观测特征物信息对广义卡尔曼滤波估计值更新,建立场景理解信息点云构造二维栅格地图,根据场景重构地图信息结合改进的蚁群算法进行路径优化。在复杂场景下,通过激光SLAM移动机器人实验表明,改进蚁群算法的激光SLAM移动机器人在多种复杂场景路径寻优和运行消耗时间等方面取得了较好的效果。     

Dscam2 mediates axonal tiling in the Drosophila visual system

Sensory processing centres in both the vertebrate and the invertebrate brain are often organized into reiterated columns, thus facilitating an internal topographic representation of the external world. Cells within each column are arranged in a stereotyped fashion and form precise patterns of synaptic connections within discrete layers. These connections are largely confined to a single column, thereby preserving the spatial information from the periphery. Other neurons integrate this information by connecting to multiple columns. Restricting axons to columns is conceptually similar to tiling. Axons and dendrites of neighbouring neurons of the same class use tiling to form complete, yet non-overlapping, receptive fields. It is thought that, at the molecular level, cell-surface proteins mediate tiling through contact-dependent repulsive interactions, but proteins serving this function have not yet been identified. Here we show that the immunoglobulin superfamily member Dscam2 restricts the connections formed by L1 lamina neurons to columns in the Drosophila visual system. Our data support a model in which Dscam2 homophilic interactions mediate repulsion between neurites of L1 cells in neighbouring columns. We propose that Dscam2 is a tiling receptor for L1 neurons.     

基于电子地图的路径规划的分析解决方案

路径规划问题被广泛应用于汽车导航系统、交通监控系统及各种应急系统中．在已有的基于ShapeFile格式的电子地图上，需增添路径规划的功能；并且提出如有较多道路附属信息，能设计出最优路径．同时提出一种存储道路数据的数据结构，然后采用启发式算法，实现信息可扩展的路径解决方案．将代码加入到已有系统中，经过验证，能准确高效地将路径展示Ⅲ来．     

调整数组大小—一种减少Cache失效率的有效方法

循环分块是提高Ｃａｃｈｄ命中率的有效途径，但循环分块后仍然存在Ｃａｃｈｅ的干扰失效问题。循环分块的副作用也是影响程序效率的一个重要因素。本文提出了一种副作用较小的调整数组大小的新的消除Ｃａｃｈｅ干扰失效的方法。     

基于seq2seq模型的标签推荐方法

针对NPM平台上存在大量的软件包没有标签或标记不完善的问题, 提出一种基于seq2seq模型的深度学习方法为软件包推荐标签. 首先, 利用ECMAScript工具分析软件包的源码构建出包的函数调用图, 遍历函数调用图从而将软件包转换成一组具有包语义信息的函数调用序列; 其次, 训练seq2seq模型, 并将训练好的模型用于软件包的标签推荐工作, 该模型能将包的函数调用序列映射到一组预测的标签序列上, 从而完成软件包的标签推荐. 实验结果表明, 该方法能为软件包推荐一组合理的标签, 准确率达82.6%.     

一种改进工业自动导引车路径规划算法

为了解决当前工业自动导引车(automated guided vehicle,AGV)栅格地图下路径规划算法存在路径转弯较多、弯曲度较大、搜路时间较长且距离障碍物近等问题,基于A?算法提出了一种改进路径规划算法.首先,通过在全局地图中设置路径关键节点,生成关键点拓扑地图,并利用Floyd算法进行最短路径规划,输出路径节点集合;其次,利用A?算法对集合中相邻节点进行路径规划,并将生成的路径进行拼接;最后,通过引入贝塞尔曲线对拼接路径进行平滑处理,以获取全局路径.实验结果表明:本文算法规划的路径转弯更少、弯曲度更小、搜索时间更短且能完全避开障碍物行走,更符合工业AGV的应用环境.