A wavelet-based multi-dimensional temporal recurrent neural network for stencil printing performance prediction

The solder paste printing (SPP) is a critical procedure in a surface mount technology (SMT) based assembly line, which is one of the major attributes to the defect of the printed circuit boards (PCBs). The quality of SPP is influenced by multiple factors, such as the squeegee speed, pressure, the stencil separation speed, cleaning frequency, and cleaning profile. During printing, the printer environment is dynamically varying due to the physical change of solder paste, which can result in a dynamic variation of the relationships between the printing results and the influential factors. To reduce the printing defects, it is critical to understand such dynamic relationships. This research focuses on determining the printing performance during printing by implementing a wavelet filtering-based temporal recurrent neural network. To reduce the noise factor in the solder paste inspection (SPI) data, this research applies a three-dimensional dual-tree complex wavelet transformation for low-pass noise filtering and signal reconstruction. A recurrent neural network is utilized to model the performance prediction with low noise interference. Both printing sequence and process setting information are considered in the proposed recurrent network model. The proposed approach is validated using practical dataset and compared with other commonly used data mining approaches. The results show that the proposed wavelet-based multi-dimensional temporal recurrent neural network can effectively predict the printing process performance and can be a high potential approach in reducing the defects and controlling cleaning frequency. The proposed model is expected to advance the current research in the application of smart manufacturing in surface mount technology.     

Value drivers of blockchain technology: A case study of blockchain-enabled online community

There is growing recognition that blockchain technology has significant potential to alter how organizations and people work and communicate. However, theoretical guidance concerning how organizations leverage blockchain technology to enhance value creation for users is still limited. Grounded in the socio-technical perspective and leveraging the rich data obtained from case analyses of blockchain-enabled online communities, this paper develops a theoretical model to identify the core value drivers that blockchain enables for online communities. The core value drivers include: a reputation-value system, data ownership mechanisms, and verification & tracking mechanisms. Our findings suggest that these three value drivers enhance value creation of online communities by motivating participation and protecting contributions.     

基于跨临界CO2热泵的茶叶生产能源系统负荷削减潜力

乡村产业中的化石能源设备逐渐被电能技术替代，引起了乡村负荷波动增大、部分时段产生集中高负荷的问题。为了解决以上问题，将低品位清洁能源应用至乡村的茶叶生产中，针对烘茶全过程的工艺要求提出了跨临界CO₂热泵烘茶技术；并以某茶叶生产乡村为对象，对其代表台区的全年日用电量及产茶日负荷进行了分析，得出采用CO₂热泵烘茶后其负荷得到大幅度削减，整体可降低至原负荷的39.6%~46.8%，峰值负荷与平时负荷的比值由原本的13.6降至5.4~6.2。跨临界CO₂热泵应用至农产品生产中可有效缓解乡村供电压力。     

基于STM32单片机的大学生体能监测仪设计与实现

体能监控仪作为生命体征监测设备,对于辅助大学生完成体能训练有很大帮助;基于STM32单片机技术,设计开发集成了多种传感器的一种大学生体能监测装备,它能够有效的检测包括心率检测、人体的步数、运动圈速、消耗卡路里等信息;该设计采用了STM32作为主控芯片,采用模块化的设计思路;在系统硬件设计方面,设计了包括STM32控制系统、心率获取电路、三轴传感器电路、显示电路以及按键电路等;同时将软件模块拆分成了初始化子程序、心率获取子程序,步数获取子程序,显示子程序等;Proteus仿真结果显示,使用STM32单片机技术设计的体能监测系统,能够运行稳定,测量心率范围60次/min~180次/min,可在心率异常时报警,同时检测步数的准确率达98%,满足体能监测任务需要,实验结果符合预期;为STM32单片机在体育运动研究信息化中应用提供参考。     

矿井风门漏风监测系统的研究及应用

为了有效监控煤矿井下风门是否漏风、保证煤矿风量的充足,采用压差法测风技术和软件控制技术,开发了风门漏风监测系统。系统通过在线监测风门两侧的压差实时动态掌握在用风门良好状态,对漏风风门及时报警。     

环境检测技术存在的问题及对策分析

环境检测技术对于环境的决策及监管有着很大的影响,但目前在我国的环境检测技术仍然还存在一定的问题,仍然有待完善。因此,本文针对环境检测技术现存问题进行了研究分析,并且提出了一些相应的有效对策。     

Popularity of patent commercialization policies: Iran as a case

Commercialization of technologies has attracted increasing attention over the past years due to its role in improving national competitiveness. Iran has not been an exception as the country's policy-makers have been actively engaged in crafting national policies to facilitate and promote commercialization of technologies. The popularity of the existing policies in this field, however, has not been properly researched. Our research, by following a survey study methodology, aims for the first time to address this gap. The study looks at popularity of governmental policies aimed at supporting commercialization of patented technologies in Iran, based on the careful study of 10 cases of successfully commercialized patented technologies in Iran. Our results indicate that the commercialization process of the studied patented technologies was very much affected by some company/technology-specific characteristics. The study shows that the two policy measures with the highest perceived popularity were the financial supports and the services offered by incubation centers. Our results also show that some of the existing supportive policy measures did not serve the intended purposes and some other measures need to be fine-tuned, as far as the studied cases are concerned, such as frequently held invention and innovation exhibitions and the government-supported media coverage.