共查询到20条相似文献，搜索用时 46 毫秒
1.
系统以C8051F020单片机为控制核心,由MCU模块、键盘输入模块、液晶显示模块、温度传感器模块等功能模块组成。检测系统结构简单,并进行了抗干扰设计,使其具有较好的抗干扰能力,保证系统可靠工作。 相似文献
2.
3.
介绍一种新型同步电动机励磁恒功率因数闭环调节装置。本装置利用单片机内部A/D转换器采集定子电压和定子电流,通过功率计算出功率因数,再利用单片机的PCA输出6路触发脉冲控制可控硅整流桥,改变同步电动机的励磁电流,从而改变同步电动机的功率因数,实现功率因数闭环调节。 相似文献
4.
本文设计的是以16位低功耗C8051F040单片机为控制芯片的简易电磁控制运动装置,整个系统包含键盘模块、液晶显示模块、角度采样模块、恒流源模块、单片机控制模块、单摆机械装置模块、电磁控制模块等。由角度传感器、单片机以及恒流源构成闭环反馈控制,通过PID控制使电磁控制装置的磁场变化频率和单摆固有频率基本相等,以达到单摆的自由谐振,能够在允许误差范围内摆到指定角度及周期。 相似文献
5.
如何提高数字程控交换机的维修能力,正在受到邮电通信部门的重视。本文就占数字程控交换机维护量80％以上的用户板的测试和维修问题,提出了一种实用的用户板检测系统,它可以实现用户电路的摘挂机识别、振铃、送、受话功能检测. 相似文献
6.
储油罐底外边缘板相对于混凝土基座立体位移的运动形态和环境变化对罐底外边缘造成腐蚀造成严重影响。本文从储油罐底外边缘板的腐蚀状况、腐蚀原因分析、防护改进措施等三方面对储油罐底外边缘板的腐蚀与防护进行初步探析。 相似文献
7.
外墙外保温装饰一体化系统材料损耗小,建筑垃圾少.外保温装饰一体板由工厂加工生产,施工现场安装,其材料边角料可回收再次利用,从而减少了建筑垃圾的产生,而且降低了施工劳动强度,简化了工序,有效节约施工成本,减少了作业环境和工人施工带来的不确定性;施工工期与传统工艺比较可缩短30％-40％,从而降低了大型垂直机械设备、外脚手... 相似文献
8.
可变数据出版凭借其为客户提供内容高度可定制的个性化印件特点,在直邮广告、可变数据打印、个性化短版印刷以及网络出版市场表现优异,市场需求增长强劲,市场容量不断扩大。然而,尽管市场强势增长,可变数据出版技术发展却相对滞后,国内外厂商虽推出了不少可变数据出版软件,但在可变数据的前端数据处理、后端输出以及与印刷流程结合方面的能力依然不足,急需基于现有可变数据出版技术对现有可变数据出版解决方案进行优化。通过对可变数据出版关键技术的分析,本文提出了可变数据出版系统优化的关键点和优化方法,并依托InDesign开放平台,开发了一种基于InDesign的可变数据出版插件,构建了基于InDesign的可变数据出版系统。 相似文献
9.
本文结合中国石油QHSE报告系统的设计和开发,分析阐述了一个实际应用的数据仓库项目的分析和建设过程,给出了数据仓库项目设计和实施方案。重点研究了如何从技术层次上实现数据仓库平台源文件处理、数据抽取、数据转换、数据加载的ETL过程。 相似文献
10.
介绍了一个基于 VFP的通用报表生成工具。该工具功能强大 ,可生成各种类型的报表 ,且操作简便 ,易调用 ,采用 Excel作为报表表头格式设计和报表输出工具 ,充分利用Excel强大的表格编辑功能和统计分析功能 ,满足了用户不同的报表格式和对数据进行再挖掘的需求。该工具已经用于多个 MIS系统中。 相似文献
11.
《Telecommunications Policy》2022,46(9):102403
Trade in digital goods and services have witnessed increasing growth in recent years, accompanied by a corresponding increase in data flows across national boundaries. At the same time, governments around the world have enacted data policies that restrict such cross border data flows in their effort to claim sovereignty over data generated from within their countries. However, scholars have long proclaimed that any restrictions to the Internet and associated digital trade will have serious economic consequences. Given this context, we analyze the impact of data policies that impose restrictions on digital trade, specifically on cross border data flows. We construct Market Data Restrictions Index (MDRI), that measures the data restrictions faced by an exporting country from their trade partners. We use a variation of random effect model on a panel data set consisting of 60 countries that contribute to more than 50 percent of IT services export during the period 2006–2017. The results indicate that apart from variables such as Foreign Direct Investment, and Service Value Added, the MDRI of partner countries has a moderate negative effect on IT services export. If countries move from liberal policies to stringent data restrictions, the economies of the country that exports its ICT services to these partner countries is affected substantially. Hence government regulators shall be cautious in imposing stringent data restrictions as it affects global digital trade. 相似文献
12.
全文分析了GPS高程系统与我国现行高程系统的区别与联系;叙述了GPS高程拟合常用方法,对影响GPS高程拟合精度的因素进行了分析,提出了提高精度的方法。 相似文献
13.
根据GPS的基本原理,探讨GPS技术在工程水准测量应用中的方法和要求,并根据两次大型工程的实测资料分析GPS水准测量的高程精度,讨论GPS水准测量在工程施工方面的应用前景。 相似文献
14.
利用GPS技术建立桥梁变形监测网 总被引：1，自引：0，他引：1
将GPS技术应用于大型桥梁的变形监测,是未来发展的趋势。本文结合桥梁工程变形的特点,阐述了GPS桥梁变形监测方案的设计原则和实施步骤。 相似文献
15.
本文介绍了GPS同步时钟的基本结构.分析了GPS同步时钟技术在双端行波故障测距及事件顺序记录中的应用.对于推动电力系统时间同步技术的发展具有重要的意义. 相似文献
16.
GPS高程拟合模型确定 总被引：1，自引：0，他引：1
本文阐述了两种进行GPS水准拟合的数学模型:多项式拟合模型和多面函数曲面拟合模型.通过实例验证,结果满足四等几何水准的测量要求,并提出了GPS高程拟合模型确定的几点结论. 相似文献
17.
This paper analyzes the effects of cross-border mergers and acquisitions on innovation activities in target firms. The empirical analysis is based on survey and ownership data for a large sample of small- and medium-sized German firms. After controlling for endogeneity and selection bias, we find that foreign acquisitions have a large negative impact on the propensity to perform innovation activities and a negative impact on average R&D expenditures in innovative firms. Furthermore, innovation output, measured as product and process innovations, and the share of sales from product innovations, is not significantly affected by a foreign acquisition for a given amount of innovation efforts. Hence, the estimation results do not provide any evidence of significant technology transfer through foreign acquisitions in form of a higher innovation success. 相似文献
18.
19.
北部湾（广西）经济区CORS系统应用分析 总被引：1，自引：0，他引：1
本文对GPS连续运行参考站(CORS)在北部湾(广西)经济区的建设情况进行了阐述,针对在工程运用上遇到的问题进行分析并提出了解决的办法. 相似文献
20.
《Telecommunications Policy》2022,46(1):102242
A comprehensive exploration into the routine/non-routine job implications of information and communication technology (ICT) is crucial for tackling routine-replacing technological change challenges in the digital era. To this end, we propose an integrated input-output (IO) analytical framework to detangle the intertwined relations between ICT and non-ICT sectors, and further incorporate structural path analysis (SPA) and structural decomposition analysis (SDA) to examine the extent to which and how ICT sub-sectors drive the formations and changes of embodied routine/non-routine jobs in ICT. An empirical study using China's national IO tables from World Input-Output Database and the matched occupational employment data derived from 2000 and 2010 Population Census is conducted. We find that China's ICT growth over 2000–2010 has not led to a decline in jobs, which still holds true for both ICT manufacturing and ICT service, as well as for routine/non-routine jobs. We also find an increase in the embodied employment share of non-routine relative to routine jobs. The typical paths “source sector → (intermediate sector) → ICT final demand” generate many routine/non-routine jobs, which are primarily lied in the zero and first rounds. The decomposition results show that the declining sectoral routine/non-routine job coefficients drives the decline of both ICT embodied routine and non-routine jobs (especially the former), which is completely offset by the rising final demand of ICT. The proposed integrated IO analytical framework could also be applied to other indicators and extended to multi-country/region analysis. 相似文献