Application of Internet of Things Micropower Smart Switch in Temperature Monitoring

This study uses the smart phone with the Android system to construct a cloud-side smart switch system in the client-server architecture with the Android open platform system, using microprocessors (MCU 16F690) as the thermostat controller and combined with Raspberry Pi. The computing technology extends the control of the constant temperature from the local to the cloud, allowing the user to view the temperature status recorded by the cloud server using the smart phone application (App) or web browser. It can even remotely control the heating power of the smart switch for the heating device in the Internet control environment and use the proportional-integral-derivative (PID) control and the pulse-width modulation (PWM) technology to achieve intelligent constant temperature control. The proposed control system uses the expert PID control as the core to calculate the duty cycle of the PWM signal to control the power output of the smart switch for the constant temperature water tank. The experiment results verify the effectiveness of the proposed system.     

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.     

Effect of processing on the texture and structure of raspberry (cv. Heritage) and blackberry (cv. Thornfree)

This paper reports separate studies of the effect of pre-treatments (CaCl₂, low methoxyl pectin (LMP), and combined solutions) and the effect of freezing method (at four different rates) and thawing mode (at two different rates) on objective parameters, structure and sensory characteristics of fresh raspberries and blackberries. After that, the effect of a complete freezing process combining the best pre-treatments with the best freezing/thawing conditions found for each fruit was investigated. Kramer Shear Cell (KSC), back extrusion, compression and multiple penetration tests were used to measure fruit texture objectively. For calcium and LMP pre-treatments, which were applied separately, texture parameters were significantly higher in samples treated at the highest concentrations (100 mM of CaCl₂ for both fruits and 0.3 and 3% of LMP for raspberry and blackberry, respectively) compared to fresh controls. Blackberry structure was more susceptible than raspberry structure to the effect of pre-treatments. For the combined pre-treatments, the highest texture parameters were found in the samples treated with CaCl₂ (100 mM) and LMP (0.1%) in the case of raspberries and CaCl₂ (100 mM) and LMP (3%) in the case of blackberries. Combined pre-treatment did not increase firmness with respect to that of samples treated only with calcium, which indicates that CaCl₂ preserved the raspberry structure more efficiently during processing. Fruits frozen by forced convection with liquid nitrogen vapour at –40 °C were significantly firmer. Raspberries should be thawed at 5 °C, whereas blackberries may be thawed at room temperature. Sensory analysis showed that the blackberry structure was more resistant to freezing. In both fruits, over the complete process parameter values were again highest in the samples treated with 100 mM CaCl₂, applied either separately or in combination with LMP. In raspberry, panellists detected no significant differences between sensory texture parameters of the different samples, and in blackberry, panellists found no significant differences between any of the sensory characteristics. Multiple penetration maximum force (F _MP) was the parameter that best expressed product firmness for both fresh and frozen raspberries, whereas compression slope (S _C) best reflected changes in blackberries. SEM mainly corroborated results from objective texture parameters.     

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.     

Effect of in vitro digestion upon the antioxidant capacity of aqueous extracts of Agrimonia eupatoria, Rubus idaeus, Salvia sp. and Satureja montana

An in vitro digestion/Caco-2 cell culture model was used to assess the stability and bioavailability of phenolic compounds in aqueous extracts of four herbal infusions, traditionally used as functional drinks in Portugal. Alterations in antioxidant power were monitored by ABTS⁺, whereas the profile of phenolic compounds was ascertained by HPLC-DAD. The bioavailability of rutin - an important flavonoid present in such extracts, and thus a representative of those compounds, was assessed across Caco-2 cells via LC-MS/MS. Our results indicate that several antioxidant compounds are not affected by the (simulated) digestive process, whereas others undergo decreases in their activity throughout said process; a few have their antioxidant capacity hampered under stomach-like conditions. It was also found that rutin can be transported across the Caco-2 cell barrier.     

C2P:基于Pi演算的协议C代码形式化抽象方法和工具

形式化方法为安全协议分析提供了理论工具,但经过形式化验证过的协议标准在转换为具体程序实现时,可能无法满足相应的安全属性.为此,提出了一种检测安全协议代码语义逻辑错误的形式化验证方法.通过将协议C源码自动化抽象为Pi演算模型,基于Pi演算模型对协议安全属性形式化验证.最后给出了方案转换的正确性证明,并通过对Kerbero...     

基于图像识别的分类垃圾桶设计与仿真

垃圾分类是保护生态环境、促进经济发展的有效措施。以Arduino和Raspberry Pi为控制板结合Inception V3垃圾图像识别算法,针对厨余、可回收、其他、有害四类垃圾设计出垃圾识别准确率可达97%的分类垃圾桶。为验证该分类系统的可行性,进行了垃圾分类仿真实验,结果表明,编写的分类程序满足设计要求,系统可稳定运行,垃圾识别精准度高。     

覆盆子中有机酸含量的测定

覆盆子为药食两用果实,具有抗衰老、调节生殖系统、促进细胞免疫机能、减肥之功效。本研究利用HPLC法对覆盆子干果中有机酸含量进行测定,测定的色谱条件为：柱温30 ℃,流动相为0.05 mmol H2SO4,流速0.5 mL/min,检测波长210 nm,进样量10 μL,色谱柱为C18柱,在设定的色谱条件下覆盆子干果处理液峰面积与有机酸标品线性关系良好,相关系数在0.9998~0.9999之间,精密度实验各有机酸RSD值在0.30~0.90%之间,重现性实验各有机酸RSD值在0.42~3.69%之间,加标回收率在97.86~102.35%之间,此方法用于测定覆盆子干果中有机酸含量准确、可行。     

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.     

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.