钢丝绳无损探伤技术研究与发展

钢丝绳是矿山煤炭运输、提升等设备中不可缺少的关键部件之一,并直接关系到工作设备的安全性。所以,钢丝绳的探伤研究非常重要。本文对钢丝绳无损探伤技术现状进行了分析,对于指导钢丝绳探伤研究具有一定的参考意义。     

A new approach to assessing model risk in high dimensions

A central problem for regulators and risk managers concerns the risk assessment of an aggregate portfolio defined as the sum of d individual dependent risks $X_i$. This problem is mainly a numerical issue once the joint distribution of $\left(X_1\text{,}{X}_2\text{,}\dots \text{,}{X}_d\right)$ is fully specified. Unfortunately, while the marginal distributions of the risks $X_i$ are often known, their interaction (dependence) is usually either unknown or only partially known, implying that any risk assessment of the portfolio is subject to model uncertainty.Previous academic research has focused on the maximum and minimum possible values of a given risk measure of the portfolio when only the marginal distributions are known. This approach leads to wide bounds, as all information on the dependence is ignored. In this paper, we integrate, in a natural way, available information on the multivariate dependence. We make use of the Rearrangement Algorithm (RA) of Embrechts et al. (2013) to provide bounds for the risk measure at hand. We observe that incorporating the information of a well-fitted multivariate model may, or may not, lead to much tighter bounds, a feature that also depends on the risk measure used. In particular, the risk of underestimating the Value-at-Risk at a very high confidence level (as used in Basel II) is typically significant, even if one knows the multivariate distribution almost completely.Our results make it possible to determine which risk measures can benefit from adding dependence information (i.e., leading to narrower bounds when used to assess portfolio risk) and, hence, to identify those situations for which it would be meaningful to develop accurate multivariate models.     

Automating Linguistics-Based Cues for Detecting Deception in Text-Based Asynchronous Computer-Mediated Communications

The detection of deception is a promising but challenging task. A systematic discussion of automated Linguistics Based Cues (LBC) to deception has rarely been touched before. The experiment studied the effectiveness of automated LBC in the context of text-based asynchronous computer mediated communication (TA-CMC). Twenty-seven cues either extracted from the prior research or created for this study were clustered into nine linguistics constructs: quantity, diversity, complexity, specificity, expressivity, informality, affect, uncertainty, and nonimmediacy. A test of the selected LBC in a simulated TA-CMC experiment showed that: (1) a systematic analysis of linguistic information could be useful in the detection of deception; (2) some existing LBC were effective as expected, while some others turned out in the opposite direction to the prediction of the prior research; and (3) some newly discovered linguistic constructs and their component LBC were helpful in differentiating deception from truth.     

网页指纹查重技术的研究

网页查重技术是浏览获取有用信息的关键技术,传统的查重方法中,选取关键词在网页中出现的频率来判断网页是否重复,如果关键词相近,可能造成查重误判的情况。本文提出网页本身特有的指纹技术,设计新的查重算法,通过与网页特征库中的指纹比较,完成网页的查重工作,提高查重的准确率。     

浅层地震勘探在城市活断层探测中的应用研究

本文通过在上海市用浅层地震纵波反射方法探测太仓-奉贤隐伏断裂的实例,阐述了在覆盖层较厚、人口密集、环境干扰较强条件下的地震勘探方法技术。     

跑道入侵与民航客运量的相关性及预防策略

在对相关数据进行整理的基础上,对跑道入侵事件和民航客运量进行相关性分析,得出两者之间的函数关系,并建立了跑道入侵与年份之间的回归关系。结论表明,随着民航旅客运输量的增加,跑道入侵事件呈逐步上升的状态。从强化跑道入侵风险管控、加强跑道入侵监管力度、改进跑道安全监测技术三个方面,提出了对跑道入侵的预防策略。     

浅析纺织品禁用偶氮染料检测的若干问题

本文针对纺织品禁用偶氮染料检测的热点难点问题,做了简要介绍分析并提出了具体的解决方案。     

浅析桩基础钻芯法检测技术

钻芯法检测是检测方法中应用最为普遍的一种方法。本文从抽芯检测方案的制定、钻孔抽芯的施工要点、钻孔抽芯检测的质量评定等方面详细介绍了桩基础钻芯法检测技术,对于同类工程的检测具有一定的参考价值。     

网上信息侦听与分析系统的设计

互联网带给人们便利的同时,各种非法信息也迅速蔓延,为有效地屏蔽网络上的非法信息,本文提出了在Linux平台下对接收到的网络数据包进行分析,过滤各种不良信息的一种解决方案。该方案描述了网上侦听与分析系统的总体结构和整体设计概念,解析了系统实现的流程,给出了模块之间的相互关系,对各个模块的功能进行了描述,体现了系统的设计思想。     

基于非参量累积和的合作频谱感知

针对认知无线电网络中频谱感知的检测时延降低问题,提出了基于非参量累积和的合作频谱感知算法。本地认知用户预处理频谱观测数据,获得观测数据相对于信念值的正向漂移和负向漂移。为了缩短检测延迟,认知用户只将数据的正向漂移同步传输至融合中心。融合中心融合正向漂移得到判决信息,采用非参量累积和算法依时间序列顺序累加判决信息,判断主用户是否正在使用授权频段。为了解决不传输负向漂移引起的虚警问题,改进算法提出融合中心可以保留首次判决,经过等待时间间隔后再作出最终判决。相对于传统的软融合算法,改进融合规则的合作频谱感知算法具有较低的检测延迟。