煤矿物联网中智能终端的设计与实现

智能终端是在煤矿物联网技术下通过感知井下人员周围环境提高煤矿安全生产水平的具体实现。介绍了智能终端的软硬件设计,采用低功耗GS1011智能芯片为硬件核心,以μ-velosity嵌入式操作系统为软件平台,实现井下环境参数采集、双向通信并为地面上位机提供定位信息。测试结果表明,智能终端完成了对周围环境的主动感知。     

Remote sensing image classification based on neural network ensemble algorithm

The amounts and types of remote sensing data have increased rapidly, and the classification of these datasets has become more and more overwhelming for a single classifier in practical applications. In this paper, an ensemble algorithm based on Diversity Ensemble Creation by Oppositional Relabeling of Artificial Training Examples (DECORATEs) and Rotation Forest is proposed to solve the classification problem of remote sensing image. In this ensemble algorithm, the RBF neural networks are employed as base classifiers. Furthermore, interpolation technology for identical distribution is used to remold the input datasets. These remolded datasets will construct new classifiers besides the initial classifiers constructed by the Rotation Forest algorithm. The change of classification error is used to decide whether to add another new classifier. Therefore, the diversity among these classifiers will be enhanced and the accuracy of classification will be improved. Adaptability of the proposed algorithm is verified in experiments implemented on standard datasets and actual remote sensing dataset.     

Holography: a behavior‐based profiler for malware analysis

Behavior‐based detection and signature‐based detection are two popular approaches to malware (malicious software) analysis. The security industry, such as the sector selling antivirus tools, has been using signature and heuristic‐based technologies for years. However, this approach has been proven to be inefficient in identifying unknown malware strains. On the other hand, the behavior‐based malware detection approach has a greater potential in identifying previously unknown instances of malicious software. The accuracy of this approach relies on techniques to profile and recognize accurate behavior models. Unfortunately, with the increasing complexity of malicious software and limitations of existing automatic tools, the current behavior‐based approach cannot discover many newer forms of malware either. In this paper, we implement ‘holography platform’, a behavior‐based profiler on top of a virtual machine emulator that intercepts the system processes and analyzes the CPU instructions, CPU registers, and memory. The captured information is stored in a relational database, and data mining techniques are used to extract information. We demonstrate the breadth of the ‘holography platform’ by conducting two experiments: a packed binary behavior analysis and a malvertising (malicious advertising) incident tracing. Both tasks are known to be very difficult to do efficiently using existing methods and tools. We demonstrate how the precise behavior information can be easily obtained using the ‘holography platform’ tool. With these two experiments, we show that the ‘holography platform’ can provide security researchers and automatic malware detection systems with an efficient malicious software behavior analysis solution. Copyright © 2011 John Wiley & Sons, Ltd.     

Rubber-assisted embossing of polymer thin films using molds with through-thickness microchannels

A flexible microfluidic chip is difficult to fabricate using the standard hot embossing technology. In this study, rubber-assisted embossing of polymer thin films using molds with through-thickness microchannels was investigated. The polymer film was thermoformed into the microchannels by rubber as a soft counter-tool. Different processing conditions, as well as material selections, affecting the thickness uniformity and replicated depth were examined. Results indicated that smoother surfaces on the embossed articles were created, and the thickness uniformity and the depth of the embossed channel were significantly affected by the embossing temperature, the embossing pressure, and the rubber hardness. The embossed film was sealed on one side with a layer of transparent adhesive film to form closed microchannels, and desired 3-D flow characteristics were obtained with this flexible microfluidic chip.     

鄂尔多斯盆地东南部长7油层组沉积相研究

为了明确鄂尔多斯盆地东南部长7油层组沉积体系类型和沉积相展布特征,总结其沉积演化规律,以沉积学的基本原理和方法为指导,综合运用地球化学、盆地分析等理论和方法,通过野外露头、钻井、测井等资料的综合分析,认为鄂尔多斯盆地东南部长7油层组主要发育三角洲和湖泊沉积体系,可进一步划分为3类亚相,其中以三角洲前缘和深湖2种亚相为主．     

苦参愈伤组织诱导及继代培养条件研究

目的：研究苦参愈伤组织诱导与继代培养,为药用成分苦参碱及氧化苦参碱的来源提供新途径.方法：考察了不同外植体和激素组合对苦参愈伤组织诱导的影响和苦参愈伤组织增殖继代的最佳培养条件.结果：分别以幼芽、根、茎段、叶片为外植体,在MS＋1.0mg/L 2,4-D＋1.0mg/L 6-BA＋1.0mg/L NAA激素组合下苦参愈伤组织的诱导率分别为94.12%、74.19%、35.71%、23.08%;在MS＋0.5mg/L 2,4-D＋0.1mg/L 6-BA＋0.5mg/L NAA激素组合下,苦参愈伤组织增殖率最高,为25.3%.结论：幼芽为苦参愈伤组织诱导最佳外植体.不同激素组合对愈伤组织诱导率的影响不大,但对其增殖的影响较大,其中NAA具有显著影响.     

基于AD2S83对电动舵机低速及动态性能的改进

目前被广为应用的一类电动舵机需将传感器输出的交流位置信号通过解调和微分获得反馈需要的直流位置和速度信号.解调和微分电路会降低系统相角裕度和放大噪声,导致系统开环增益受到限制无法继续提高,使舵机低速运行时发生爬行现象,且舵机通频带较窄.针对此问题,采用旋转变压器——数字转换器AD2S83来取代解调和微分电路,直接得到直流位置信号和速度信号,通过提升系统的开环增益,改善舵机的低速和动态性能.实验结果表明,AD2S83的引入使该类电动舵机的低速和动态性能得到了明显的提升.     

枯草芽孢杆菌谷氨酰胺转氨酶的异源表达

以野生型枯草芽孢杆菌基因组DNA为模板,PCR扩增获得带有sD序列及谷氨酸棒状杆菌信号肽AS0949的BTG基因。将其与大肠杆菌-谷氨酸棒状杆菌穿梭表达载体pXMJ19连接,构建重组质粒pXMJ19-Sbtf转化谷氨酸棒状杆菌ATCC13032。经IPTG诱导后该重组茵发酵液具有交联酪蛋白的能力,表明该重组茵能够实现分泌表达。     

烟丝组分的吸湿模型研究

为了研究烟丝主要组分的吸湿平衡规律,用GAB模型获得的叶丝、梗丝、膨胀烟丝在25℃环境下,在45%～75%平衡相对湿度范围内的吸湿平衡,得到优异的拟合精度.结果表明,用GAB吸湿模型计算的叶丝、梗丝、膨胀烟丝的单层含水率（干基）分别为6.14%,7.04%,5.92%.以水活度0.65为安全贮存的临界点,对应于吸湿过程,用GAB模型估计25℃时叶丝、梗丝、膨胀烟丝的安全含水率（干基）分别为16.69%,18.30%,15.00%.研究结果为各组分加工过程各阶段的含水率设计提供了参考.     

垫条宽度对混凝土劈拉试验破坏形态的影响

通过有限元计算和试验,探讨了垫条宽度对混凝土劈裂抗拉试验的影响.结果表明:当垫条宽度与立方体试件边长的比值k在0.167～0.600时,有效缓解了加载部位的应力集中,能保证立方体试件在端面中心处起裂.