复杂分支和同步模式的Pi演算描述

Pi演算是一种描述和分析动态并发系统的计算模型。对Pi演算进行研究后,提出了以Pi演算作为工作流形式化的基础,并利用Pi演算对复杂分支和同步工作流模式进行了详细的描述。     

基于树莓派的人脸识别考勤系统的开发与实现

提出一种基于树莓派的人脸识别考勤系统,该系统通过使用人脸识别云服务可实时地对人员进行考勤.文中详细描述了该系统的搭建和实现过程,为相关产品提供了一套很好的解决方案.对所设计的系统进行模拟测试,其测试结果达到了设计目标.     

广西桂林甑皮岩遗址陶器的科学研究

甑皮岩遗址为中国华南地区的新石器时代早期遗址，出土了大量的陶器和石器。而在它最早一期距今12，000年左右的文化层中出土了更早期的粘土制品，经过热释光方法的测定，可以确定它未经过250℃以上温度的烧制。应该属于陶器形成过程中的阶段产物，也可以称之为陶器的雏形。这是以往考古发掘中绝无仅有的重大发现，将对研究陶器起源问题提供重要线索。本文除了对这种粘土制品进行科学研究，还研究了其后期陶片化学组成、晶相组成以及烧戍温度等属性。甑皮岩陶器的制作原料经过了从随机取土到随机选土，到进行初步处理的阶段。陶片中含有石英、长石、方解石、绢云母等各种矿物颗粒，还含有一定量的炭。陶器的烧成温度一般在800～840℃之间．均为无窑烧成。     

基于ZigBee网络的电厂循环水在线监测系统设计

目前,火电厂循环水水质监测主要是离线方式,在人工采样测量参数之后,对相关设备进行调整操作。缺点是测量工作量大,调节精度不够而且不及时,导致参数不能维持在稳定的范围内。该文通过ZigBee技术和树莓派(Raspberry Pi)构建循环水在线监测系统,实现实时动态地将数据传送至在线监测平台,使水质参数测量更具客观性和科学性,为设备调整的控制决策提供准确的依据。     

面向智慧医疗的家庭健康跟踪系统

智慧医疗是物联网的重点应用领域,家庭健康跟踪系统是实现智慧医疗的重要组成部分.本文在开源硬件平台Raspberry Pi和Arduino的基础之上,设计和实现了一款家庭健康跟踪系统.该系统利用Arduino实现健康生理信息的采集、集成和蓝牙传输,在Raspberry PI平台上利用QT实现健康状况的分析,并最终在LCD屏幕上实现健康状况的可视化.最后,通过原型系统实现和测试,证明了该系统的可行性和有用性.本文设计的家庭健康跟踪系统具备操作简单、可扩展性强和成本低等特点,可为智慧医疗的全面实现提供基础.     

结合Petri网和Pi演算的协同业务过程建模

协同业务过程使组织业务过程同其他组织的业务过程间进行交互和协作,以形成相对稳定的过程视图,从而满足共同的商业目标。为确保过程模型的正确性,采用形式化方法对协同业务过程进行建模变得越来越重要。将Petri网和Pi演算进行交叉应用,提出了一种协同业务过程的建模方法。该方法采取关注点分离的原则,一方面,从控制流角度,针对协同业务过程面向流的特点,提出公共视图,使用Petri网直观描述参与协同组织的业务过程的静态结构和状态转换;另一方面,从交互角度,针对协同业务过程面向协作的特点,提出协作视图,使用Pi演算描述业务过程间的交互。为建立Petri网和Pi演算间的关联,提出了进程标号迁移系统。与传统的业务过程建模方法相比,该方法能有效支持协同业务过程具有的个性化特征。     

A note on scaling the Linpack benchmark

Dimensional analysis yields a new scaling formula for the Linpack benchmark. The computational power r(_p0,_q0)$r(p_0,q_0)$ on a set of processors decomposed into a (_p0,_q0)$(p_0,q_0)$ grid determines the computational power r(p,q)$r(p,q)$ on a set of processors decomposed into a (p,q)$(p,q)$ grid by the formula r(p,q)=(p/_p0)^α(q/_q0)^βr(_p0,_q0)$r(p,q)=(p/p_0{)}^{\alpha }(q/q_0{)}^{\beta }r(p_0,q_0)$. The two scaling parameters α$\alpha$ and β$\beta$ measure interprocessor communication overhead required by the algorithm. A machine that scales perfectly corresponds to α=β=1$\alpha =\beta =1$; a machine that scales not at all corresponds to α=β=0$\alpha =\beta =0$. We have determined the two scaling parameters by imposing a fixed-time constraint on the problem size such that the execution time remains constant as the number of processors changes. Results for a collection of machines confirm that the formula suggested by dimensional analysis is correct. Machines with the same values for these parameters are self-similar. They scale the same way even though the details of their specific hardware and software may be quite different.     

基于Raspberry Pi的家庭附网存储系统的设计与实现

为解决当前家庭用户大量数据下载、存储和共享的问题,提出了一种新的基于树莓派硬件平台的家庭附网存储系统.设计搭载了基于Debian的Linux操作系统,提供了基于CIFS/SMB、NFS和F1P协议的网络异构系统的文件共享,并实现了多种方式的脱机下载.系统将RAID技术和LVM技术相结合,并且利用Bypy同步百度云空间,提高了设备中数据的读写速率和系统的安全性,同时采用B/S模式的Web管理系统,用户可以通过浏览器对NAS设备进行控制和管理.通过测试数据表明,系统稳定可靠,具有数据传输速度快、安全性高、可扩展性好等优点.     

Non-intrusive plasma diagnostics for the deposition of large area thin film silicon

Plasma diagnostics for large area, industrial RF parallel-plate reactors can be useful for process optimization and monitoring, provided that their implementation is practical and non-intrusive. For instance, Fourier transform infrared (FTIR) absorption spectroscopy and/or time-resolved optical emission spectroscopy (OES) can easily be retro-fitted into the pumping line of a reactor. Both techniques were used to measure the fractional depletion of silane in silane/hydrogen plasmas. By means of a simple analytical plasma chemistry model, it is shown that the silane depletion is related to the silicon thin film properties such as microcrystallinity. Uses of the diagnostics are demonstrated by two examples: (i) the optimal plasma parameters for high deposition rate of microcrystalline silicon, along with efficient gas utilization, are shown to be high input concentration and strong depletion of silane; and (ii) the optimal reactor design, in terms of fast equilibration of the plasma chemistry, is shown to be a closed, directly-pumped showerhead reactor containing a uniform plasma.     

Variation of total phenolics, anthocyanins, ellagic acid and radical scavenging capacity in various raspberry (Rubus spp.) cultivars

The aim of this study was to assess the level of some phytochemicals in 19 raspberry cultivars grown in Lithuania. The content of total ellagic acid measured after 20 h acidic hydrolysis of investigated raspberry cultivars, varied from 119.8 (cv. ‘Pokusa’) to 323.5 mg/100 g (cv. ‘Bristol’). The content of total phenolics ranged from 278.6 (cv. ‘Pokusa’) to 714.7 mg/100 g (cv. ‘Bristol’). The total anthocyanins content varied from 2.1 (yellow cv. ‘Beglianka’) to 325.5 mg/100 g (black cv. ‘Bristol’). The radical scavenging capacity of the tested raspberry cultivars highly correlating with their total phenolics and total ellagic acid content (r = 0.90 and 0.92, respectively). The results of this study expand the knowledge about variation in the content of valuable bioactive compounds in raspberries and may help for the selection and validation of the most productive cultivars.