利用数据中心构建数字化钻井施工模式

世界石油钻井技术不断向信息化、智能化方向发展,为适应钻井技术的发展,构建了数字化钻井施工模式框架。从井场信息采集设施、井场网络环境、井场信息采集处理软件、井场工程监测软件等方面阐述了数字化钻井队的构建方法,从钻井数据库设计、数据流向及数据加载、数据发布等方面阐述了钻井数据中心的构成,从钻井设计系统、钻井远程监测系统、井眼轨迹控制系统以及专家系统等方面描述了钻井辅助决策平台主要功能。除了理论研究之外,还简要介绍了研究成果在现场的应用情况。这些研究成果是国内"数字油田"建设的基础,必将促进钻井行业的信息技术发展。     

WCDMA的MBMS技术

主要介绍了基于WCDMA的MBMS技术,给出了其网络架构和技术难点,并对其应用给无线网络带来的影响作了一定深度的探讨。     

3G中的QoS结构及无线资源分配策略

在3G（第3代移动通信系统）中，为了给不同类型的业务提供不同级别的端到端QoS，网络资源必须进行合理分配。QoS和资源分配是密不可分的，而无线资源分配显得尤为重要。文中提出了UMTS的QoS结构，分3部分对空中接口部分的QoS（即无线资源分配策略问题）进行了讨论：首先提出了一种RRA算法，接着讨论了W－CDMA和TD－CDMA系统的无线资源分配问题，最后讨论了下行链路及上行链路的呼叫允许控制（CAC）。     

Design Methodology of the Structure of Postal Express Mail Networks of Aviation Channels in China

1　ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｏｒｄｅｒｔｏｉｍｐｒｏｖｅｔｈｅｑｕａｌｉｔｙｏｆｐｏｓｔａｌｓｅｒｖｉｃｅａｎｄｔａｋｅａｄｖａｎｔａｇｅｏｆａｕｔｏｍａｔｅｄｍａｉｌｓｏｒｔｉｎｇｅｑｕｉｐ ｍｅｎｔｓ,ｉｔｈａｓｂｅｅｎｄｅｔｅｒｍｉｎｅｄｔｏｃｏｎｓｔｒｕｃｔｔｈｅｐｏｓｔａｌａｒｅａｃｅｎｔｅｒｏｆｆｉｃｅｓｙｓｔｅｍｉｎＣｈｉｎａＰｏｓｔａｌＳｅｒ ｖｉｃｅ (ＣＰＳ) .ＴｈｅｃｒｕｘｏｆｔｈｅｐｒｏｂｌｅｍｆａｃｅｄｂｙＣＰＳｉｓｔｏｒｅｄｅｓｉｇｎｔｈｅｐｏｓｔａｌｃｏｍｍｕｎｉｃａ…     

CX6112车铣复合机床设计方案的研究与探讨

文章较系统地论述了车铣复合机床设计方案的形成过程，同时分析了该设计方案的持点，并简要介绍了该产品的主要技术参数和用途，简评了该产品的技术水平。     

紧凑 Tokamak(球形环)聚变堆第一壁及中心导体柱上中子负荷及核热计算与分析

采用通用蒙特卡罗粒子输运程序ＭＣＮＰ／３８计算低环径比Ｔｏｋａｍａｋ（紧凑环或球形环）聚变堆第一壁及中心导体上的中子壁负荷分布和核热沉积分布，并与常规Ｔｏｋａｍａｋ堆第一壁上中子壁负荷分布和核热沉积分布进行比较、分析。结果表明，在中子壁负荷归一化为１ＭＷ／ｍ２时，与常规Ｔｏｋａｍａｋ相比，在低环径比Ｔｏｋａｍａｋ堆第一壁及中心柱表面上中子壁负荷分布峰值并不比常规Ｔｏｋａｍａｋ堆第一壁上的峰值高，而且低于低环径比Ｔｏｋａｍａｋ堆整个第一壁上的平均值，而中心柱上的核热沉积峰值稍高于常规Ｔｏｋａｍａｋ堆第一壁上的核热沉积峰值，但对较高中子壁负荷情况，中心导体柱上的核热沉积和辐照损伤仍可能是比较严重和值得特别研究的问题。     

DX centers in AlxGa1-xAs bulk alloy,AlAs/GaAs ordered,and disordered superlattices

Properties of theDX centers in Al_0.5Ga_0.5As bulk alloy (b-AL), (AlAs)₂ (GaSa)₂ ordered superlattice (o-SL) and (AlAs) _m (GaAs) _n disordered superlattice (d-SL) (m = 1, 2, 3,n = 1, 2, 3) with the same macroscopic composition were measured and compared. By deconvolution of deep level transient spectroscopy (DLTS) spectrum due to theDX center, we have found a decrease in the number of separate peaks in DLTS spectrum in an intentionally atomic ordered arrangement. Visiting Scholar of the Japan Society for the Promotion of Science. On leave from Department of Electrical Engineering, San Jose State University, San Jose, California 95192-0084, USA.     

Engset multi‐rate state‐dependent loss models with QoS guarantee

We consider a single link loss system of quasi‐random input, described by the Engset multirate loss model (EnMLM). Blocked calls may once reattempt to be connected to the system requiring less bandwidth; then the system is described by the single retry model for finite sources (f‐SRM). The EnMLM and the f‐SRM are extended with the single threshold finite source model (f‐STM), where calls may attempt to be connected to the system with less bandwidth requirements, according to the link occupancy, before blocking occurs. We focus on CBP equalization in the EnMLM, f‐SRM and f‐STM, under the bandwidth reservation (BR) policy. For this analysis, we apply two approximate methods, the Roberts' method and the method of reverse transition rates (RTR), which lead to a recursive CBP calculation. We evaluate the accuracy of the above models under the BR policy by comparing the analytical with simulation CBP results, based on the relative approximation errors (RAE). The results are highly satisfactory because they show that the proposed models (formulas) lead to small RAE. Copyright © 2005 John Wiley & Sons, Ltd.     

Multiobjective dynamic load-dispatching method for optimal operation of power systems

A new practical method is proposed which gives a quasi-optimal solution of the dynamic load-dispatching problem formulated by a multiconstraint multiobjective optimization problem. Here, the multiple constraints are rate reserve constraints and power flow ones, and the multiple objectives are fuel cost and CO₂ emission. The proposed method is an integration of the following three techniques: (1) “Group Dispatch Scheme,” which is developed by the authors, is used to satisfy a violated constraint easily. This scheme consists of three steps. The first step is to classify all generators into two groups. One is the group which should be more loaded to satisfy the violated constraint, and the other is the should-be less loaded group. The second step is to add some load to the former group, and to subtract the same load from the latter. The third step is to dispatch each group load to each groups generators, respectively; (2) the dynamic load-dispatching algorithm is used which provides, in practical time, quasi-optimal generation trajectories; (3) the conventional weighting parametric method is used to obtain a Pareto optimal solution of multiobjective problems. The effectiveness of the method is clarified by a computer simulation on the actual power system of Kansai Electric Power Company.     

An empirical InSAR-optical fusion approach to mapping vegetation canopy height

Exploiting synergies afforded by a host of recently available national-scale data sets derived from interferometric synthetic aperture radar (InSAR) and passive optical remote sensing, this paper describes the development of a novel empirical approach for the provision of regional- to continental-scale estimates of vegetation canopy height. Supported by data from the 2000 Shuttle Radar Topography Mission (SRTM), the National Elevation Dataset (NED), the LANDFIRE project, and the National Land Cover Database (NLCD) 2001, this paper describes a data fusion and modeling strategy for developing the first-ever high-resolution map of canopy height for the conterminous U.S. The approach was tested as part of a prototype study spanning some 62,000 km² in central Utah (NLCD mapping zone 16). A mapping strategy based on object-oriented image analysis and tree-based regression techniques is employed. Empirical model development is driven by a database of height metrics obtained from an extensive field plot network administered by the USDA Forest Service-Forest Inventory and Analysis (FIA) program. Based on data from 508 FIA field plots, an average absolute height error of 2.1 m (r = 0.88) was achieved for the prototype mapping zone.