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71.
72.
新形势下的钻井信息化 总被引:3,自引:1,他引:2
介绍了我国石油行业在新的发展形势和管理模式下,钻井领域进行信息化的重要任务。在理清钻井业务流程的基础上,提出了以“钻井数据中心”为核心的钻井信息系统框架。从自动采集和人工采集两个方面阐明了钻井数据采集的范围和方式;从井筒网络、井场局域网、远程传输网和企业网等方面介绍了钻井信息化立体网络的构成,还介绍了钻井数据与甲方数据中心的数据交换方式、钻井数据中心的构建方法、以及钻井数据中心所支持的上层应用系统设计内容。提出了钻井信息化的发展方向,对我国钻井行业信息化有一定的指导意义。 相似文献
73.
基于Agent的分布式查询优化研究 总被引:8,自引:0,他引:8
Internet上异构的软硬件环境以及多种并行机制对分布式查询优化技术提出了新的挑战,文章将分布式人工智能与数据库管理系统两个研究领域相结合,给出了基于Agent的分布式查询优化系统模型,在该系统中,Agent采用了典型的慎思型体系结构,即BDI模.Agent具有信念库,目标库并在此基础上进行学习和推理,多个Agent之间通过协调,协作以及协商以支持分布式数据库系统的动态查询优化和规划的执行,提高系统的查询效率。 相似文献
74.
实现各类目标和背景下动态场景的计算机编辑和生成,首先应对组成动态场景的要素进行分析,即目标,目标运动规律和特殊事件四个要素,然后通过编程由四个模块完成相应功能。目标,背景编辑模块可对目标,背景图像进行各种处理,并对重要特征量进行计算,运动路径模块可指定目标的运行规律,包括路线,大小和角度变化等。特殊事件模块可加入独立目标的各类典型事件,如运动的干扰物等。最后通过动态场景合成由计算机自动生成所需的动态场景图像。所需的原始目标,背景图像来源于图像数据库管理系统,通过索引项可便携地找到。 相似文献
75.
George P. Naughton Christopher C. Caudill Christopher A. Peery Tami S. Clabough Michael A. Jepson Theodore C. Bjornn Lowell C. Stuehrenberg 《河流研究与利用》2007,23(1):99-111
Previous studies of Pacific salmonid passage over Snake River dams indicated slowed passage at transition pools, the transition area between the fishway entrance and the fish ladder. In 2001 and 2002, we conducted an experiment to determine if modified weirs affected adult salmon and steelhead passage times and route selection through the Lower Granite Dam transition pool. Fish attraction flows through the lower ladder weirs were experimentally increased using removable panels. During the experiment we monitored radio‐tagged adult Chinook salmon and steelhead to determine passage routes and times through the transition pool. The weir treatment increased the number of spring–summer Chinook salmon passing straight through the transition pool compared to those exiting the transition pool to the collection channel or tailrace. Mean passage times through the transition pool differed among routes and were significantly lower during treatment periods for the exit‐to‐collection channel route in spring‐summer Chinook salmon, but not for other routes. Passage times among routes differed in steelhead, but there was no evidence of treatment effects on route use or passage time. Fall Chinook exhibited similar trends in route use and passage time to spring–summer Chinook, but differences were not significant, perhaps because of relatively small sample size. Total dam passage times did not differ by treatment or route for any run. Fish depth during passage of the transition pool suggested that most fish passed through submerged orifices and supported the hypothesis that increased water velocity through these orifices caused the increase in straight‐through passage in spring–summer Chinook. Collectively, the results suggested the weir modifications provided improvement to passage through the transition pool for spring–summer Chinook and no evidence of negative effects on other runs. The results from this study were used to develop new design criteria and modifications of the Lower Granite Dam fishway. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
76.
本文对网上成绩考核系统进行了总体设计.其中,设计了校园网的网络结构模型、网上成绩考核系统的模块结构及其数据库和数据表. 相似文献
77.
分析了太钢电弧炉变压器高压侧相间过电压的产生原因,比较了用于限制过电压的避雷器的两种接法.结论是用四垦接法MOA限制过电压的效果较显著. 相似文献
78.
G. Dong 《Annals of Mathematics and Artificial Intelligence》1993,7(1-4):107-127
LDL is one of the recently proposed logical query languages, which incorporate set, for data and knowledge base systems. Since LDL programs can simulate negation, they are not monotonic in general. On the other hand, there are monotonic LDL programs. This paper addresses the natural question of “When are the generally nonmonotonic LDL programs monotonic?” and investigates related topics such as useful applications for monotonicity. We discuss four kinds of monotonicity, and examine two of them in depth. The first of the two, called “ω-monotonicity”, is shown to be undecidable even when limited to single-stratum programs. The second, called “uniform monotonicity”, is shown to implyω-monotonicity. We characterize the uniform monotonicity of a program (i) by a relationship between its Bancilhon-Khoshafian semantics and its LDL semantics, and (ii) with a useful property called subset completion independence. Characterization (ii) implies that uniformly monotonie programs can be evaluated more efficiently by discarding dominated facts. Finally, we provide some necessary and/or sufficient, syntactic conditions for uniform monotonicity. The conditions pinpoint (a) enumerated set terms, (b) negations of membership and inclusion, and (c) sharing of set terms as the main source for nonuniform monotonicity. 相似文献
79.
This article is based on experiences with data and text mining to gain information for strategic business decisions, using host-based analysis and visualisation (A/V), primarily in the field of patents. The potential advantages of host-based A/V are pointed out and the features of the first such A/V software, STN®AnaVist™, are described in detail. Areas covered include the user interfaces, initial set of documents for A/V, data mining, text mining, reporting, and suggestions for further development. 相似文献
80.