TF1000ms固井设备自动监控系统

TF1000ms固井设备监控系统能实现油田钻井固井施工过程全智能自动控制,是针对油田勘探的恶劣环境而设计开发的,基于PC104嵌入式计算机系统系统设计。介绍了工作原理,方法和系统功能,分析和试验了系统的可靠性,控制精度和抗环境的能力,该仪表系统能在低温－40℃至高温55℃范围内正常工作,系统按单机单泵和双机双泵两种形式设计,试验和应用结果表明,该系统完全满足了油田固井生产的需要,且市场前景可观。     

VPN及其安全技术研究

VPN(虚拟专用网)是在公共网的基础上建立的适合用户需求的虚拟网络，它可以节省费用，同时又具有高度安全性。介绍了VPN的相关技术，尤其是隧道技术，并分析了基于各层协议(第2层隧道协议PPTP／L2TF和第3层隧道协议IPSec)建立隧道的过程、方法和优缺点。     

基于二次TF* IDF的互信息文本特征选择算法研究

在分析传统互信息法缺陷的基础上,提出一种基于二次TF*IDF的互信息特征选择算法,对仅在一个类别中出现的特征词的重要程度给予再次的衡量,解决了互信息值相等而无法进行有效特征选择的问题。利用贝叶斯分类器对该方法进行验证的结果表明该算法在文本分类效率和正确率上比原有方法有一定的提高。     

基于微博扩展的用户兴趣主题挖掘算法

为解决基于微博的用户兴趣建模存在建模不全面的问题,提出一种基于微博扩展的用户兴趣主题挖掘算法。通过结合用户自身兴趣及用户关注人的兴趣来扩充微博用户兴趣,将兴趣分为长期兴趣、过期兴趣、近期兴趣,利用改进的TF． IDF算法分析相关微博内容,利用基于时间及文档频率加权的主题词重要度计算兴趣主题词得分,得出综合全面的用户兴趣。实验结果表明,综合分析用户及用户关注人的兴趣,可以有效得到真实、全面、包含潜在兴趣的用户个人兴趣。     

文献搜索引擎中特征项及权重的应用

针对目前用户在使用搜索引擎过程中,检索结果冗余、效率低下等问题,本文在对文献垂直搜索系统中Lucene.Net的索引算法研究基础上,结合用户实际专业检索需求,改变其算法中的激励因子,实验结果证明该方法确能提高搜索结果的相关度.     

New doctors ranking system based on VIKOR method

Nowadays, we can use different websites that help us make decisions about various aspects of our lives. However, privacy protection prevents websites from providing personalised guidelines to users. We propose a novel doctor‐ranking system (DRS) based on multi‐criteria group decision‐making (MCGDM) method to address the problems of privacy protection. The following aspects differentiate our proposed DRS model from previous works: (a) textual information reviews are used to identify user preferences and complementary criteria, (b) criteria weights are determined by term frequency inverse document frequency (TF‐IDF) instead of Delphi method or expert opinion, (c) intuitionistic fuzzy sets (IFSs) are used to replace sentiment analysis to express subjective user criteria, and (d) VIsekriterijumsko KOmpromisno Rangiranjie (VIKOR) method for MCGDM with IFSs is used to solve the doctor‐ranking problem. We apply our proposed model to datasets from Haodf.com to compare the performance of our method with that of sentiment analysis and technique for order performance by similarity to ideal solution (TOPSIS) methods. The experimental results show that our method provides accurate ranking and increases the reliability of DRS.     

Preliminary analysis of compatibility with low activation martensitic steel blanket for the fusion experimental breeder: Impact of ferromagnetic behavior on plasma burning cycle

The reduced activation ferritic martensitic steels is considered a candidate for the first wall (FW) blanket structural material because of its safety environmental advantages [R.L. Klueh, D.S. Geiles, et al., Ferritic/martensitic steels overview of recent results, J. Nucl. Mater. 307-312 (2002) 455-465; T. Muroga, M. Gasparotto, S.J. Zinkle, Overview of materials research for fusion reactors, Fusion Eng. Des. 61-62 (2002) 3-25]. An engineering design analysis concerning the electromagnetic issues is performed. Preliminary analysis results show that design effort of the fusion reactor can cope with the effect of the ferromagnetic FW blanket on the electromagnetic forces, which increases by 28-38% during a major plasma disruption and overcome the influence of the poloidal field, which reduces by 10-20%, comparing with the austenitic steel blanket. Both the effect and influence depend on the saturation magnetic susceptibility and blanket configurations.     

TFPI-1抑制作用的模型化研究

TFPI-1在凝血动力系统中起着重要的调节作用,主要对FV∏α-TF的抑制过程作用显著.根据生物学实验建立一个关于TFPI-1,FV∏α-TF和FXα等因子的凝血动力数学模型.通过对模型的分析和数值模拟得到了一些与临床医学及实验相吻合的结论,展现出模型化方法的重要作用及预测能力.     

An improved tie force method for progressive collapse resistance design of reinforced concrete frame structures

Progressive collapse of structures refers to local damage due to occasional and abnormal loads, which in turn leads to the development of a chain reaction mechanism and progressive and catastrophic failure. The tie force (TF) method is one of the major design techniques for resisting progressive collapse, whereby a statically indeterminate structure is designed through a locally simplified determinate structure by assumed failure mode. The method is also adopted by the BS8110-1:1997, Eurocode 1, and DoD 2005. Due to the overly simplified analytical model used in the current practical codes, it is necessary to further investigate the reliability of the code predictions. In this research, a numerical study on two reinforced concrete (RC) frame structures demonstrates that the current TF method is inadequate in increasing the progressive collapse resistance. In view of this, the fundamental principles inherent in the current TF method are examined in some detail. It is found that the current method fails to consider such important factors as load redistribution in three dimensions, dynamic effect, and internal force correction. As such, an improved TF method is proposed in this study. The applicability and reliability of the proposed method is verified through numerical design examples.     

Network Sorting Algorithm of Multi-Frequency Signal with Adaptive SNR

An signal noise ratio (SNR) adaptive sorting algorithm using the time-frequency (TF) sparsity of frequency-hopping (FH) signal is proposed in this paper.Firstly,the Gabor transformation is used as TF transformation in the system and a sorting model is established under undetermined condition;then the SNR adaptive pivot threshold setting method is used to find the TF single source.The mixed matrix is estimated according to the TF matrix of single source.Lastly,signal sorting is realized through improved subspace projection combined with relative power deviation of source.Theoretical analysis and simulation results show that this algorithm has good effectiveness and performance.