常见食物中毒质谱图数据库系统平台建设

食物中毒事件具有群发性、复杂性、突发性和危害严重等特点,确证引起食物中毒的病因对食物中毒事件处理具有现实意义.色谱质谱联用系统作为国际上通用的未知物质快速检测及确认手段被广泛的应用于未知物质的检测及确认领域中,质谱图数据库系统是应用质谱方法确认中毒物质的关键系统,针对食物中毒的特点,开发了常见食物中毒质谱图数据库系统.系统采用流行的B\S三层结构,数据库可以存储不同仪器以不同采集方式采集的质谱图数据,同时还加载了相关化合物的理化性质、毒理学资料和临床症状等信息;并通过网络实现应急平台的资源共享,同时具有质谱谱图的快速搜索功能,为不明原因食物中毒辅助诊断提供重要的技术措施,为大规模食物中毒的预警提供重要信息,为突发公共卫生事件应急反应机制提供决策支持.     

pPre_ITMS:基于机器学习方法的串联质谱数据预处理系统

串联质谱技术被广泛应用于高通量的蛋白质鉴定.质谱中噪音峰和同位素峰的存在会降低蛋白质鉴定的准确性,同时增加计算负担.pPre_ITMS系统是针对离子阱数据,利用机器学习中的最大期望方法和决策树方法分别识别出质谱中的噪音基线和同位素峰的预处理系统.此外,pPre_ITMS系统采用三层独立模型增强系统鲁棒性,并提供了手动调节功能.利用pPre_ITMS系统可以简单、快速且可视化地对离子阱数据进行预处理.     

基于卷积神经网络的无人机油气管线巡检监察系统

为满足深埋式油气管道巡检监察需求,以及解决常规人工巡检手段效率低、时效性差、安全性低等问题,通过结合无人机飞行平台、卷积神经网络算法及计算机系统集成技术,设计并开发了一套基于卷积神经网络的无人机油气管线巡检监察系统,为油气管线的巡检监察工作提供技术支撑.本文首先介绍了巡检监察系统的总体设计方案、及作业流程进行了介绍;其次对系统组成进行了详细介绍,整个系统由无人机飞行平台、神经网络目标检测系统、无人机巡检监察管理系统以及无人机巡检执法终端四大子系统组成,无人机飞行平台以油动固定翼无人机为飞行载体,搭载高清相机进行数据采集,神经网络目标检测系统对影像数据进行自动检测、识别、搜索沿线工程车辆和管线隐患的目标,无人机巡检监察管理系统实现数据信息的存储管理及分发推送,无人机巡检执法终端接收隐患目标推送信息并进行现场快速执法;最后,对该系统的应用情况及后续的发展方向进行了总结和展望.目前,该系统成功应用于河南、甘肃等省份的油气管线巡检监察作业中,结果表明系统满足油气管线巡检监察的业务需求.     

基于多级数据处理的RFID中间件开发

针对大规模无线射频识别(RFID)应用中产生的海量标签信息处理问题,设计一种基于多级数据处理的嵌入式RFID中间件系统。该系统包含数据采集和数据处理2个子系统,对海量标签信息进行分层过滤、分类、重组等操作,从中获得有价值的信息与事件,并以多种形式提供给用户。仿真实验结果表明,该系统可以在一定程度上提高数据处理的效率和准确性,进而提升大规模RFID应用的性能。     

基于GIS的土地执法监察系统设计与实现

为了推进土地执法监察信息化,以ArcGIS API for JavaScript和ArcGIS Runtime SDK for Android为WebGIS和移动GIS开发框架,基于REST服务,构建Web端土地管理系统和移动执法巡查系统。该系统支持国土数据可视化、案件查询、轨迹记录、案件审查等功能,解决国土执法监察中数据传输慢、处理不及时、缺少监管等问题。充分利用移动GIS的移动性、便携性、实时性特点和WebGIS的跨平台多用户特点,建立土地执法监察GIS系统,将执法数据进行高效整合和服务共享,为提高土地执法监察效率提供技术支持。     

大规模数据中心监控数据并发处理

在大规模数据中心场景下,采集系统要实时并发处理大规模数据来保证监控数据的实时性。论文首先描述了大规模数据中心监控数据的规模,并指出监控数据的并发处理中存在的问题,然后针对问题提出关键技术和解决方案,进而基于上述研究结果进行架构设计。经过实验验证Storm应用于大规模数据中心监控数据的并发处理业务,可以保证监控数据的实时性,并且系统具备一定的扩展性。     

基于大规模廉价计算平台的海量数据处理系统的研究*

提出一种基于大规模廉价计算平台的海量数据处理模型,吸取了Map/Reduce计算模式和大规模分布式数据存储机制Bigtable的基本思想,实现了以数据为中心的计算密集型的经济性超级计算系统平台。系统选择电信部门的大规模业务数据为分析对象,对电信通话和数据业务的大规模数据集进行处理,从而向运营商和普通用户提供有价值的数据分析服务。该平台适用于其他多种海量数据的分布式处理,为其他的各种应用提供了一个具有良好参考价值的示范。     

MapReduce:新型的分布式并行计算编程模型

MapReduce是Google提出的分布式并行计算编程模型,用于大规模数据的并行处理。Ma-pReduce模型受函数式编程语言的启发,将大规模数据处理作业拆分成若干个可独立运行的Map任务,分配到不同的机器上去执行,生成某种格式的中间文件,再由若干个Reduce任务合并这些中间文件获得最后的输出文件。用户在使用MapReduce模型进行大规模数据处理时,可以将主要精力放在如何编写Map和Reduce函数上,其它并行计算中的复杂问题诸如分布式文件系统、工作调度、容错、机器间通信等都交给MapReduce系统处理,在很大程度上降低了整个编程难度。MapReduce日益成为云计算平台的主流编程模型。Apache Hadoop项目提供开源的MapReduce系统还有待进一步完善。     

数据划分优化的并行k-means算法

针对大规模文本聚类中对聚类算法执行效率的要求,提出了一个内容相关的纵向数据划分策略FTDV,并基于该策略提出了数据划分优化的并行DVP k-means算法,提高了常规并行k-means算法的并行化程度,达到了优化算法执行效率的目的。在实验中,与常规并行k-means算法和基于关键方向分解的PDDP k-means算法进行比较,DVP k-means具有更好的并行性和对数据规模的适应性,且可以生成更高质量的聚簇。     

大规模并行文件系统中的数据可靠性机制

把分布式的备份思想应用到大规模并行文件系统中，在使用冗余机制构建数据的系统中提供快速恢复机制。并使用马尔可夫模型建立了一个平均直到数据丢失时间的分布模型，指导如何在数据可靠性需求和冗余数据开销之间进行平衡。根据可靠性模型分析，在快速恢复机制下，使用m-n机制，只要n≥m＋2，并且恢复数据所需的计算时间与磁盘I／O时间相比可以忽略不计，就可以满足大规模存储系统对町靠性的需求。     

Gas desorption electron stimulated during operation of field emitter-phosphor screen pairs

Gas desorption from a field emitter array (FEA) cathode and phosphor screen anode in a flat panel display during a lifetime operation can affect cathode electron emission and degrade display performance and uniformity. We have measured the outgassing products from selected FEA-phosphor pairs in an ultrahigh vacuum system equipped with a calibrated quadrupole rresidual gas analyzer. Different low voltage phosphors and blank anodes were studied. A Spindt-type FEA was used as the electron source. A unique carousel was used so the desorption from all these different anodes could be measured without intervening vacuum breaks; this allowed the desorption from the different anodes to be directly compared with each other. Quantitative outgassing rates are given and the implications of the results for the pumping of the flat panel and emission from the FEAs are discussed.     

Structural changes in PMMA under hard X-ray irradiation

 We describe here initial studies of several commercially available poly(methylmethacrylate)s, PMMAs, both before and after exposure to hard X-rays. In order to gain knowledge about the chemical changes that occur during resist preparation (gluing to substrate, etc.) and exposure, several analytical spectroscopic, chromatographic, and thermal methods have been applied. Gas Chromatography-Mass Spectrometry (GC-MS) has been used to observe in the PMMA (before and after exposure) trapped volatiles, such as MMA monomer. Thermal analysis methods were employed to gain knowledge about the effects of pre-exposure annealing of PMMA on radiation-induced swelling. In addition, gel permeation chromatography (GPC) and matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOFMS) were used to obtain information concerning polymer/oligomer characteristics. Received: 25 August 1997/Accepted: 5 September 1997     

Structural optimization of modular product families with application to car space frame structures

This paper extends classical structural optimization from single-product optimization to optimization of a whole family of products that have common modules. It integrates the family commonality problem with the finite element models of the structures. A general mathematical frame where optimization is seen as a balance between cost and performance is given. The most obvious cost function is mass, while performance is taken to be a weighted sum of compliances. As a case study, a car product family consisting of three products is presented. These three products are a base model, a seven-seat version, and a pickup version. The study shows how optimal results are effected by requiring modules to be shared between products. Loads emanating from prescribed acceleration fields that simulate crash situations are used. This is a proof-of-concept paper which is a first step toward including more general manufacturing costs than mass and performance measures other than compliance.     

面向大规模定制汽车产品配置器的关键技术研究

在阐述了面向大规模定制的产品配置技术理论的基础上,制定了一种产品配置的设计方案;以汽车产品为实例,详细介绍了汽车产品配置规则,建立了汽车产品配置的流程;针对汽车产品构建了一种基于PDM的产品配置器,为汽车产品实现面向大规模定制的配置奠定了基础.     

Time-bound product returns and optimal order quantities for mass merchandisers

The return guidelines for a mass merchandiser usually entail a grace period, a markdown on the original price and the condition of the returned items. This research utilises eight scenarios formed from the variation of possible return guidelines to model the cost functions of single-product categories for a typical mass merchandiser. Models for the eight scenarios are developed and solved with the objective of maximising the expected profit so as to obtain closed form solutions for the associated optimal order quantity. An illustrative example and sensitivity analysis are provided to demonstrate the applicability of the model. Our results show that merchandisers who allow for returns within a time window, albeit with a penalty cost imposed and the returned products being recoverable, should plan for larger order amounts as such products do not affect the business. Similarly, the merchandisers who allow for returns beyond a grace period and without any penalty charges, but where the returned products are irrecoverable, should manage their stocks in this category more judiciously by ordering as little as possible so as to limit the number of returns and carefully consider the effects of their customer satisfaction-guaranteed policies, if any.     

面向大规模定制的软件开发模式

在领域工程、基于构件的软件工程和并行工程的基础上，提出了面向大规模定制的软件开发模式。该模式以大规模开发标准软件的效益满足用户的个性化需求。介绍了面向大规模定制的软件开发过程，面向大规模定制的软件产品族体系结构，以及面向大模型定制软件开发的产品集成过程模型。最后介绍了一种面向大规模定制的敏捷软件开发组织。     

Enhancement of thermal uniformity for a microthermal cycler and its application for polymerase chain reaction

Thermal uniformity is essentially important for micro reactors which require precise control of critical reaction temperatures. Accordingly, we report a new approach to increase the temperature uniformity inside a microthermal cycler, especially for polymerase chain reaction (PCR). It enhances the thermal uniformity in the reaction region of a PCR chip by using new array-type microheaters with active compensation (AC) units. With this approach, the edges of the microthermal cyclers which commonly have significant temperature gradients can be compensated. Significantly, the array-type microheaters provide higher uniformity than conventional block-type microheaters. Besides, experimental data from infrared (IR) images show that the percentages of the uniformity area with a thermal variation of less than 1 °C are 63.6%, 96.6% and 79.6% for three PCR operating temperatures (94, 57 and 72 °C, respectively) for the new microheaters. These values are significantly better than the conventional block-type microheaters. Finally, the performance of this proposed microthermal cycler is successfully demonstrated by amplifying a detection gene associated with Streptococcus Pneumoniae (S. Pneumoniae). The PCR efficiency of the new microthermal cycler is statistically higher than the block-type microheaters. Therefore, the proposed microthermal cycler is suitable for DNA amplification which requires a high temperature uniformity and is crucial for micro reactors with critical thermal constraints.     

Microcomputer-assisted temperature programmed desorption studies

An IBM-PC assisted ultra-high vacuum system for temperature programmed desorption studies is described. With the use of a self-constructed interface board and a commercial IEEE interface, the microcomputer controls the heating of the adsorbent and stores the partial pressure-temperature-time data from a quadrupole mass spectrometer and thermocouple. Hardware and software details are presented and discussed. Applications of the system are illustrated by the results of carbon monoxide desorption from CdTe(110) surface.     

Thermal deformation of microstructure diffuser plate in LED backlight unit

Thermal deformations of a microstructure diffuser plate in an LED backlight unit subjected to a long period of illumination were studied. Mechanical properties of the microstructure diffuser plate in the LED backlight unit were determined and verified. Rather than using data from the relevant literature, accurate finite element solutions were obtained by using a microtensile test and thermo‐mechanical analyzer to calculate the Young's modulus, Poisson's ratio, and thermal expansion coefficient of the microstructure diffuser plate. The measured mechanical properties were used as input data in finite element simulations. Comparisons of the finite element analysis results with the experimental measurements made using strain gauge yielded differences of less than 3%. Thermal warpage phenomena of the microstructure diffuser plate at various temperatures are discussed. Thermal deformations are also compared between the conventional diffuser plate and the microstructure diffuser plate.