浅析火灾自动报警系统使用中存在的问题

本文通过对城市现有的一些现代化建筑内的火灾自动报警系统的现状以及将来发展的趋势进行分析,找出对火灾自动报警系统使用、管理、维修以及重视程度等方面的弊端,提出一点相关的解决办法。     

声光双控节能灯电路设计

为解决工厂长明灯现象,设计了一种声光双控节能电路供楼道照明灯用,其功能:夜间有人上下楼时,照明灯自动点亮,灯亮后延时2～3分钟,会自动熄灭;白天照明灯受人走动的控制,灯不会点亮。整个电路由电源电路,放大电路,处理电路(声控电路、光控电路)及延时电路等部分组成。     

汽车扭簧疲劳试验机的设计

针对汽车扭簧疲劳断裂特点,设计了一种基于曲柄摇杆机构的扭簧耐久测试机;采用PLC编程,在扭簧耐久测试中对其进行控制和计数。测试数据表明该机器设计结构简单,操作方便,运行可靠,测试结果合理。     

用于先进PCB制造技术的堆叠封装技术研究

球栅阵列封装器件和芯片尺寸封装器件的研究和应用使得印刷电路板的组装密度和性能得到了提高,达到了二维组装密度的极限。但如同之前的通孔直插器件和表面贴装器件一样,它们在电学、机械、热性能、尺寸、质量和可靠性方面达到最大值。目前,3D多芯片堆叠组装正在成为未来先进印刷电路板制造工艺的发展方向。按照结构特征可把其分为芯片堆叠封装和封装堆叠封装,重点对其中成本最低、性能最先进的元器件堆叠封装技术进行了研究。     

数控机床故障诊断与维修课程“做中学”教学模式的研究与实践

项目教学法是行动导向教学法中的一种,强调"教、学、做"相统一,重在"做中学"。通过结合实例,详细介绍了项目教学法在数控机床故障诊断与维修课程中的具体应用,包括学习项目的确定、具体实施过程及课程评价方法。通过实施"做中学"的教学模式,学生能够把理论知识与实践操作有机地结合起来,能有效地培养他们的团结合作、分析问题和解决问题等综合能力。     

煤矿综机现状与发展趋势分析

本文首先对我国煤矿综机发展现状进行了介绍,在对国内外存在差距进行分析的同时,对煤矿综机发展趋势进行了探讨,并提出了有关建议。     

一种基于RFID的AGV电磁导引新方式

针对传统电磁导引方式存在的缺陷,提出了双线轨道和节点RFID导向方法;进一步降低地面和系统成本,提高了路径设计及更改的灵活性;利用RFID中定位及存储关键词等方式增强了AGV自主导引能力;最后展望了新导引方式及AGVS在物联网中的应用前景和使用方式。     

Ability of crime,demographic and business data to forecast areas of increased violence

ABSTRACT

Identifying geographic areas and time periods of increased violence is of considerable importance in prevention planning. This study compared the performance of multiple data sources to prospectively forecast areas of increased interpersonal violence. We used 2011–2014 data from a large metropolitan county on interpersonal violence (homicide, assault, rape and robbery) and forecasted violence at the level of census block-groups and over a one-month moving time window. Inputs to a Random Forest model included historical crime records from the police department, demographic data from the US Census Bureau, and administrative data on licensed businesses. Among 279 block groups, a model utilizing all data sources was found to prospectively improve the identification of the top 5% most violent block-group months (positive predictive value = 52.1%; negative predictive value = 97.5%; sensitivity = 43.4%; specificity = 98.2%). Predictive modelling with simple inputs can help communities more efficiently focus violence prevention resources geographically.     

质量管理体系在高精大型机床制造、服务中的实际应用

高精大型机床制造、服务过程中常遇到某些实际问题，文章结合ISO9000标准质量管理八大管理原则中某些原则的实际应用对其进行分析，并阐述尤其是在为用户服务方面，采取多种行之有效的实施办法，取得了直接的效果，而在技术创新开发新产品中抓住机遇，迎合市场需求，能让开发高精大型机床产品取得成功。     

An enhanced dynamic hash TRIE algorithm for lexicon search

Information retrieval (IR) is essential to enterprise systems along with growing orders, customers and materials. In this article, an enhanced dynamic hash TRIE (eDH-TRIE) algorithm is proposed that can be used in a lexicon search in Chinese, Japanese and Korean (CJK) segmentation and in URL identification. In particular, the eDH-TRIE algorithm is suitable for Unicode retrieval. The Auto-Array algorithm and Hash-Array algorithm are proposed to handle the auxiliary memory allocation; the former changes its size on demand without redundant restructuring, and the latter replaces linked lists with arrays, saving the overhead of memory. Comparative experiments show that the Auto-Array algorithm and Hash-Array algorithm have better spatial performance; they can be used in a multitude of situations. The eDH-TRIE is evaluated for both speed and storage and compared with the naïve DH-TRIE algorithms. The experiments show that the eDH-TRIE algorithm performs better. These algorithms reduce memory overheads and speed up IR.