Machine translation of non-literary texts: Some Canadian experiences

A survey was carried out of past and current Canadian experiences with machine-aided translation (MAT) systems of non-literary texts in one government institution and three industrial settings. Each organization requires a great deal of translation and had conducted several experiments in the use of MAT. The survey supports positive conclusions about the prospects for expanded use of computers in translation.The authors express their thanks to all those who helped in the preparation of this paper. We are particularly grateful to the staff of the translation departments of the organizations mentioned in the paper for their kind cooperation and their willingness to answer our questions: Chantal Delorme ofIBM Canada, Lorraine Desmarais and Mr. Plamondon of Bell Canada, Pierre Tellier of the Department of the Secretary of State, Maria Russo and Raymond Lapointe of the Xerox Corporation. Furthermore we thank Prof. Graeme Hirst for helpful discussion.     

LayTracks: a new approach to automated geometry adaptive quadrilateral mesh generation using medial axis transform

A new mesh generation algorithm called ‘LayTracks’, to automatically generate an all quad mesh that is adapted to the variation of geometric feature size in the domain is described. LayTracks combines the merits of two popular direct techniques for quadrilateral mesh generation—quad meshing by decomposition and advancing front quad meshing. While the MAT has been used for the domain decomposition before, this is the first attempt to use the MAT, for the robust subdivision of a complex domain into a well defined sub‐domain called ‘Tracks’, for terminating the advancing front of the mesh elements without complex interference checks and to use radius function for providing sizing function for adaptive meshing. The process of subdivision of a domain is analogous to, formation of railway tracks by laying rails on the ground. Each rail starts from a node on the boundary and propagates towards the medial axis (MA) and then from the MA towards the boundary. Quadrilateral elements are then obtained by placing nodes on these rails and connecting them inside each track, formed by adjacent rails. The algorithm has been implemented and tested on some typical geometries and the quality of the output mesh obtained are presented. Extension of this technique to all hexahedral meshing is discussed. Copyright © 2004 John Wiley & Sons, Ltd.     

MAT271质谱计测控程序研制

在通用计算机上安装PCI-GPIB接口卡,用Visual Basic编写程序,实现了在Windows系统下对MAT271质谱计的数据获取和仪器控制。该测控程序实现了磁场、高压的控制和测量,样品压强、放大器信号的测量,气体组分扫描、气体同位素分析等功能。可以使原来只能显示和打印的数据能够以Excel格式保存到电脑硬盘,便于数据转移及数据处理。并且通过室外空气的重复性测试,表明仪器的性能与原程序时一致。     

人CD271基因的克隆及原核表达

目的克隆人CD271基因,并在大肠杆菌中表达。方法采用RT-PCR技术从人REH细胞系中扩增CD271基因,将其克隆入pET22b表达载体,转化大肠杆菌BL21(DE3),IPTG诱导表达,并对表达产物进行纯化及Western blot鉴定。结果重组表达质粒pET22b/CD271经双酶切鉴定,可见1197bp的目的基因条带。表达产物经SDS-PAGE分析,在相对分子质量约75000处可见表达条带。IPTG浓度为0.5mmol/L时,目的蛋白表达量最高。纯化后蛋白纯度为82.5%。Western blot检测表明纯化后的蛋白具有良好的反应原性。结论已成功克隆了人CD271基因,并在大肠杆菌中获得表达。     

Potential Effect of CD271 on Human Mesenchymal Stromal Cell Proliferation and Differentiation

The Low-Affinity Nerve Growth Factor Receptor (LNGFR), also known as CD271, is a member of the tumor necrosis factor receptor superfamily. The CD271 cell surface marker defines a subset of multipotential mesenchymal stromal cells and may be used to isolate and enrich cells derived from bone marrow aspirate. In this study, we compare the proliferative and differentiation potentials of CD271⁺ and CD271⁻ mesenchymal stromal cells. Mesenchymal stromal cells were isolated from bone marrow aspirate and adipose tissue by plastic adherence and positive selection. The proliferation and differentiation potentials of CD271⁺ and CD271⁻ mesenchymal stromal cells were assessed by inducing osteogenic, adipogenic and chondrogenic in vitro differentiation. Compared to CD271⁺, CD271⁻ mesenchymal stromal cells showed a lower proliferation rate and a decreased ability to give rise to osteocytes, adipocytes and chondrocytes. Furthermore, we observed that CD271⁺ mesenchymal stromal cells isolated from adipose tissue displayed a higher efficiency of proliferation and trilineage differentiation compared to CD271⁺ mesenchymal stromal cells isolated from bone marrow samples, although the CD271 expression levels were comparable. In conclusion, these data show that both the presence of CD271 antigen and the source of mesenchymal stromal cells represent important factors in determining the ability of the cells to proliferate and differentiate.     

分层多种示踪剂井间监测技术在坨11南断块的应用

简介了题示示踪剂井间监测技术的原理、示踪剂用量设计及所得资料解释方法。在胜坨油田11南断块沙二8砂层组,相隔22或23天,将3组不同的非分配型 分配型示踪剂分别注入3-9-271注水井的沙二81、沙二82、沙二83层,在周围生产不同层位的9口采油井进行监测。以沙二81层为例说明示踪剂产出浓度曲线拟合效果较好。监测资料表明沙二8层的平面和纵向非均质性均较强,有几口井内有窜槽现象。由监测资料确定了3个小层的主要水驱方向。通过监测数据的综合解释,得到该井组的井间高渗层渗透率、厚度、喉道半径、主流通道、波及体积及系数等储层参数,表明井间主流道均为长期注水冲刷形成的高渗层。井区非均质性强,83层尤其突出。根据综合解释结果修正地质模型,应用示踪数值模拟方法,得到了井组3个小层的剩余油饱和度分布图。图6表5参3。     

基于MAT96本构模型的钢筋混凝土结构爆破拆除数值模拟

采用有限元分析软件ANSYS/LS-DYNA,分析了基于MAT96本构模型的钢筋混凝土结构爆破拆除过程。混凝土实体单元的单轴压缩模拟试验表明,材料的峰值抗拉强度为2.4 MPa,抗压强度为30.0 MPa,无围压压缩强度约为拉伸强度的12倍;在三轴压缩模拟试验中,随着围压升高,混凝土的抗压强度显著增加、变形显著增大,其模拟结果与真实混凝土试验相近。基于MAT96本构关系的混凝土试件在拉伸模拟试验中呈现的是混凝土的劈裂破坏,而压缩呈现的是对角线破坏,类似于混凝土材料实验室破坏模式,验证了MAT96材料本构关系与混凝土吻合较好。结合整体式建模模拟钢筋混凝土结构爆破拆除倒塌过程,基于计算结果,分析了建筑物在倒塌过程中的前冲、后坐、鼓胀等问题,并对整个倒塌过程做出了定量描述。通过与工程实践相对比,得知模拟结果较符合实际情况,对钢筋混凝土结构建筑物的拆除爆破工程具有指导意义。     

Biological Characteristics of Verticillium dahliae MAT1-1 and MAT1-2 Strains

Verticillium dahliae is a soil-borne plant pathogenic fungus that causes Verticillium wilt on hundreds of dicotyledonous plant species. V. dahliae is considered an asexually (clonal) reproducing fungus, although both mating type idiomorphs (MAT1-1 and MAT1-2) are present, and is heterothallic. Most of the available information on V. dahliae strains, including their biology, pathology, and genomics comes from studies on isolates with the MAT1-2 idiomorph, and thus little information is available on the MAT1-1 V. dahliae strains in the literature. We therefore evaluated the growth responses of MAT1-1 and MAT1-2 V. dahliae strains to various stimuli. Growth rates and melanin production in response to increased temperature, alkaline pH, light, and H₂O₂ stress were higher in the MAT1-2 strains than in the MAT1-1 strains. In addition, the MAT1-2 strains showed an enhanced ability to degrade complex polysaccharides, especially starch, pectin, and cellulose. Furthermore, several MAT1-2 strains from both potato and sunflower showed increased virulence on their original hosts, relative to their MAT1-1 counterparts. Thus, compared to MAT1-1 strains, MAT1-2 strains derive their potentially greater fitness from an increased capacity to adapt to their environment and exhibit higher virulence. These competitive advantages might explain the current abundance of MAT1-2 strains relative to MAT1-1 strains in the agricultural and sylvicultural ecosystems, and this study provides the baseline information on the two mating idiomorphs to study sexual reproduction in V. dahliae under natural and laboratory conditions.     

The TR-UWB receiver based on spatial diversity

This paper presents a new Transmitted Reference (TR) Ultra-WideBand (UWB) receiver based on Spatial Diversity (SD), which employs Multi-Antenna Technology (MAT) to improve the performance of TR-UWB receiver. According to the amplitude of correlator output of every antenna branch, this paper analyzed the performances of the proposed TR-UWB receiver employing three different kinds of combina-tion strategies, i.e., Maximum Ratio Combination (MRC), Equal Gain Combination (EGC), and Selective Combination (SC), which are different from conventional ones, and theoretically proved that the performance of EGC is better than MRC. Simulation results verify that when EGC is adopted and BER=10–3, increasing three antennas provides Signal to Noise Ratio (SNR) gain of about 3 dB in CM4 channel and SNR gain of about 2 dB in CM2 channel.     

联合采用多代理和禁忌方法的系统恢复策略

将多代理技术MAT的分布式信息处理和禁忌方法TSM有机结合,形成了一种新型分布式电力系统恢复模型。模型由多结点智能代理GIAGs(crunode intelligent agents)和一个智能控制代理ICAG(intelligent control agent)组成,通过多个CIAGs间交互协商处理及ICAG的基于TSM的协同求解,能够实现快速恢复决策。仿真结果表明,该模型不仅能够快速获得恢复优化策略,而且对网络拓扑结构变化具有较强的适应性。