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991.
为了提高油田钻井时效及质量,降低钻进成本,开发了基于网络通信技术的钻井井场生产无线监控系统;系统通过网络将井场数据无线传输给基地存储,基地通过网络将各类生产指令下达到井场,实现生产一线、科研、管理信息共享,共同监视钻井施工过程,实时综合分析数据,自动预警,及时调整钻井工艺,预防事故发生,具有较强的应用价值。 相似文献
992.
MPEG音频编码标准的实现算法比较复杂,而目前对该算法的优化大部分集中在在对算法的简化上,以减少运算量,在这方面已经有了很大的发展,通过从算法编码实现上,讨论对MP2编码算法的优化. 相似文献
993.
Xie X Mirmehdi M 《IEEE transactions on pattern analysis and machine intelligence》2007,29(8):1454-1464
We present an approach to detecting and localizing defects in random color textures which requires only a few defect free samples for unsupervised training. It is assumed that each image is generated by a superposition of various-size image patches with added variations at each pixel position. These image patches and their corresponding variances are referred to here as textural exemplars or texems. Mixture models are applied to obtain the texems using multiscale analysis to reduce the computational costs. Novelty detection on color texture surfaces is performed by examining the same-source similarity based on the data likelihood in multiscale, followed by logical processes to combine the defect candidates to localize defects. The proposed method is compared against a Gabor filter bank-based novelty detection method. Also, we compare different texem generalization schemes for defect detection in terms of accuracy and efficiency. 相似文献
994.
SNMPv1 is very successful due to its simplicity,flexibility,and extensibility,However,simplicity can also be a drawback,In SNMPv1,a manager can only reteieve one piece of information at a time,and an agent merely reports one protocol operation.These two interactions enlarge the number of protocol exchanges between a manager and an agent.SNMPv2 permits the retrieval of large data blocks,but the errors can only be handled one by one.These errors continually occur in a multivendor network.This paper proposes an error handling method in SNMPv2 protocol operations.In this method,all errors within a received PDU(Protocol Data Unit) can be detected by the agent simultaneously. 相似文献
995.
Stephen R. Schach Tokunbo O. S. Adeshiyan Daniel Balasubramanian Gabor Madl Esteban P. Osses Sameer Singh Karlkim Suwanmongkol Minhui Xie Dror G. Feitelson 《Software Quality Journal》2007,15(1):99-113
Both common coupling and pointer variables can exert a deleterious effect on the quality of software. The situation is exacerbated
when global variables are assigned to pointer variables, that is, when an alias to a global variable is created. When this
occurs, the number of global variables increases, and it becomes considerably harder to compute quality metrics correctly.
However, unless aliasing is taken into account, variables may incorrectly appear to be unreferenced (neither defined nor used),
or to be used without being defined. These ideas are illustrated by means of a case study of common coupling in the Linux
kernel.
相似文献
Stephen R. SchachEmail: |
996.
异构数据源的集成技术 总被引:8,自引:0,他引:8
本综述了异构数据源集成技术的发展必然性、发展历史、现状和将来。按照集成技术出现时间的顺序首先介绍了最通用的ODBC方案,然后介绍了两种对关系数据库进行集成的传统方法:有全局模式的集成策略和无全局模式的集成策略,最后着重叙述了新时期出现的几种有代表性的数据集成方法。 相似文献
997.
998.
More and more universities and colleges are providing online courses not only for on-campus students but also for off-campus students. Tutors have to consider the differences between on- and off-campus students in order to improve effective instruction. Comparisons are made in this paper between on- and off-campus performances in online learning from four areas: learning time, path of browsing courseware, intercommunication and adaptability towards online learning. The last two areas are emphasized. Multiple approaches were adopted to collect data, which include questionnaires, posted documents, online logs, interviews and observations. This study shows that the rush time of online learning, paths of browsing courseware and favourite intercommunication means of on- and off-campus students are similar. But there are also some differences between these two groups such as competence of self-learning, enthusiasm of interpersonal exchange, dependence on tutors, feeling of learning stress, etc. 相似文献
999.
This paper deals with the J-spectral factorization for general discrete rational matrices. A simple approach based on the Kalman filtering in Krein space is proposed. The main idea is to construct a stochastic state space filtering model in Krein space such that the spectral matrix of the output is equal to the rational matrix to be factorized. The spectral factor is then easily derived by using the generalized Kalman filtering in Krein space, which is similar to the H2 spectral factorization. Our approach unifies the treatment of the H2 spectral factorization and the J-spectral factorization. The applications of the derived results in H∞ and risk-sensitive estimation for both nonsingular and singular systems are demonstrated. 相似文献
1000.