一种自动道路交通参数采集处理系统

本文叙述了一种自动道路交通参数采集系统，该系统可采集道路的交通流量，车头距，速度，占有率和密度等交通参数，并分析了这种参数互相间的关系以及如何利用这些参数判定道路的运行状况。     

Robust H∞ controller design for sampled-data systems with parametric uncertainties

This article investigates the problem of robust H∞ controller design for sampled-data systems with time-varying norm-bounded parameter uncertainties in the state matrices. Attention is focused on the design of a causal sampled-data controller, which guarantees the asymptotical stability of the closed-loop system and reduces the effect of the disturbance input on the controlled output to a prescribed H∞ performance bound for all admissible uncertainties. Sufficient condition for the solvability of the problem is established in terms of linear matrix inequalities (LMIs). It is shown that the desired H∞ controller can be constructed by solving certain LMIs. An illustrative example is given to demonstrate the effectiveness of the proposed method.     

Scientific big data and Digital Earth

Big data has been a focus of research in sci- ence, technology, economics, and social studies. Many countries have already incorporated big data research into their national strategies. This paper elaborates upon the origin, connotation, and development of big data from both a spatial and temporal perspective. It proposes that scien- tific big data will become a new solution in scientific research as the paradigm changes from being model-driven to data-driven. This paper defines the concept of ＂scientific big data＂ and proposes strategies for solving ＂big data problems＂. Theoretical frameworks and data systems for Digital Earth are discussed with a clear conclusion that scientific big data is a prominent feature of Digital Earth. As an example, spatial cognition of the formation mecha- nism of China＇s Heihe-Tengchong Line--a geo-demo- graphic demarcation line dividing China into two parts--is discussed within the context of big data computation and analysis for Digital Earth.     

CT关键征象联合临床指标鉴别诊断甲状腺TI-RADS 4-5类结节性质

目的:探讨CT关键征象-临床指标联合诊断模型鉴别诊断甲状腺影像报告及数据系统(TI-RADS)4-5类结节的良、恶性的价值。方法:搜集本院超声诊断为TI-RADS 4-5类且于CT下清晰显示的甲状腺结节患者319例(369个结节)及术前2周内的临床血清学检查资料，以术后病理结果作为诊断的金标准。分别绘制CT关键征象模型、临床指标模型及CT关键征象-临床指标联合模型的受试者工作特征曲线(ROC)并计算曲线下面积(AUC),比较3者的诊断效能。结果:全部的甲状腺结节中，恶性296个，良性73个，联合诊断模型AUC为0.888,灵敏度77.36%,特异度91.78%;CT关键征象模型AUC为0.846,灵敏度73.99%,特异度90.41%;临床指标模型AUC为0.691,灵敏度为54.05%,特异度为79.45%;联合诊断模型的诊断效能与单独检查诊断效能相比，差异具有统计学意义(P<0.05)。结论:在超声诊断的TI-RADS 4-5类的甲状腺结节中，CT关键征象-临床指标联合诊断模型的诊断准确率相对较高。