"大学英语"课程进行网络自主学习,是新时代"大学英语"教学改革的发展方向,资源库的建设是进行网络自主学习的重要保障.将大数据技术应用到资源库的建设,可以使资源配置科学化、合理化、智能化,能有效培养学生的自主学习能力,提高"大学英语"课程的教学质量.文章基于大数据背景,对高校网络资源库的建设进行了分析与研究.

大学英语网络自主学习平台建设是辅以先进的计算机网络技术和智能化技术,利用海量的英语学习资源库来激发学生的自主学习积极性,减轻课堂教学压力,实现传统教学模式的改变.让大学英语教学向自主化、特色化、专业化、信息化的现代网络教育模式迈进.

Emerging Internet of Things(IoT) applications are moving from silo and small scale sensor data sharing to composite and large scale ones. With the rapid growth of application scale, IoT applications is going to leverage cloud infrastructure for scalable solutions and real-time services. Thus large volumes of heterogeneous and high frequency sensor data are fed into IoT cloud services for real-time actionable insight, which raises great challenges of performance and adaptability on cloud solutions. In this paper, we propose a streaming based processing infrastructure for high throughput and low latency IoT real-time analytics services. A data adaptive mechanism is also introduced for heterogeneous data stream integration, interpreting and processing with application logics, as well as context stream. We implemented the proposed mechanisms with spark streaming, and deployed real time IoT analytics service in cloud. Experiment results show that the service has a good scalability and high throughput for IoT data analytics.

In smart building systems, the automatic control of devices relies on matching the sensed environment information to customized rules. With the development of wireless sensor and actuator networks (WSANs), low-cost and self-organized wireless sensors and actuators can enhance smart building systems, but produce abundant sensing data. Therefore, a rule engine with ability of efficient rule matching is the foundation of WSANs based smart building systems. However, traditional rule engines mainly focus on the complex processing mechanism and omit the amount of sensing data, which are not suitable for large scale WSANs based smart building systems. To address these issues, we build an efficient rule engine. Specifically, we design an atomic event extraction module for extracting atomic event from data messages, and then build a β-network to acquire the atomic conditions for parsing the atomic trigger events. Taking the atomic trigger events as the key set of MPHF, we construct the minimal perfect hash table which can filter the majority of the unused atomic event with O(1) time overhead. Moreover, a rule engine adaption scheme is proposed to minimize the rule matching overhead. We implement the proposed rule engine in a practical smart building system. The experimental results show that the rule engine can perform efficiently and flexibly with high data throughput and large rule set.

多媒体教室是高校教学中一个重要教学场所,它在高校教学中起着激发学生学习兴趣和提高教师教学质量的作用.网络化中控系统可以最大限度发挥高校多媒体教室的作用,利用网络集中化管理可以提高多媒体教室的管理效率.

高校语言实验室是外语教学中一个重要的综合训练基地.它在外语教学中起着提高学生语言运用能力和培养其语言创造力的重要作用.一套好的语言实验室设计方案和科学的管理系统可以最大限度发挥语言实验室的作用,提高语言教学的效果和改善语言教学的质量.

Push notification is an important approach to distribute interesting information to users timely. With the fast development of mobile devices and mobile applications, push notification is getting more and more popular. The convergence of mobile and IoT also bring new challenges on how the system can handle the mixed push channels designed for M2M communication and human interaction, and enable the effective interaction with both human and IoT devices involved. IoT devices may push notifications of sensor data in a high frequency. To enable push notification for both of mobile devices and IoT devices, the push notification system is required to achieve high throughput to handle the frequent notifications, and support content matching to filter out the undesired notifications. To enable effective push notification with both human and IoT devices involved, the system is required to understand the users' interests for notifications with the IoT devices providing the users' contexts. That is to say users need an intelligent push notification system. In this paper we propose a high performance context-aware push notification system for the converged mobile and IoT messaging. We designed high performance content matching engine as the core to enable efficient message dispatching for push notification according to highly personalized interest to ensure IoT messages to be involved in push notification. A user's interest of notifications is highly related with his context. Therefore, based on the content-matching engine, a framework for efficient context information fusion is built to support various types of context-aware push notification, towards intelligent push notification. Also we designed shared connection scheme to reduce the resource cost. Based on the content-match engine and context-aware features, the proposed push notification service can support both of group push notification and bi-directional push notification. Tests are conducted for performance evaluation.

With the leap of information technology, the traditional mode of laboratory management has lagged behind the requirements of modern universities intelligent campus. The application of RFID technology not only can solve the problem of laboratory information aut omation with fast, accurate and safe information handling process; it also can reduce the intensity of laboratory managers and simplify ma nagement processes to achieve more intelligent impacts in university laboratory management.

五轴联动机床未来发展趋势 中捷机床有限公司龙门设计室主任 赵国涛 五轴联动机床是一种科技含量高、精密度高、专门用于加工复杂曲面的机床,这种机床对一个国家的航空、航天、军事、科研、精密器械及高精医疗设备等等行业有着举足轻重的影响力.

主要研究了当网络中出现带宽请求时计算流量工程路径的问题。许多研究者超越传统IP网络中最短路径的思想,开发了各种复杂的路径选择算法。虽然这些算法在中度网络负载下表现良好,但在高负载条件下,往往存在网络性能不稳定的风险。此外,这些复杂的算法往往是计算密集型的。文章提出了一个复杂度较低的流量工程路径计算算法,该算法不仅在中度负载条件下提高了网络的利用率,而且在高负载的情况下也能保持网络性能的稳定。实验表明,该算法与其它算法相比降低了复杂度,具有较高的性能。

In Wireless Audio Sensor Networks (WASNs), many applications such as target tracking, data fusion and localization, often require precise synchronization among audio streams. Extensive researches have focused on the centralized control under the assumption that the cluster head is power supplied. However, the cluster head is usually battery-powered, especially in the wild environment. In this paper, we propose a distributed audio synchronization scheme which can share the task of the cluster head with all the reporting sensors. At the sensor, by dynamically detecting and marking the endpoint of the audio streams, we can determine the start point of the audio synchronization effectively with little effect of the interference in the communication. At the cluster head, by aligning and adjusting the marked endpoint, we synchronize the reported audio streams precisely. Experiment results show that the proposed scheme can synchronize the audio streams under different conditions with low energy cost.

FIDIA C series CNC system have two sets of measurement feedback system,including full closed loop and loop.In its manufacture and usage life cycle,manually switch is need,which process is tedious,error-prone,having extensive experience of commissioning,maintenance personnel to operate.This article studies the FIDIA C series CNC system interface development technology and measuring system switching mechanism,the system interface integrates visual operation softkeys,combines with AUCOL programming language,develops a measurement feedback system for automatic switching function.Practical application in GMC820u five axis machine tool indicates that the function ensures stable operation of machine tool,and greatly shortens switching time,improves work efficiency.

In Wireless Multimedia Sensor Networks (WMSNs), data fusion and collaborative in-network processing operations often require effective multimedia synchronization control. Extensive researches have been done in the traditional networks. Most of these works assume that there exists a powerful synchronization controller in the network. However, for WMSNs, the in-network processing of the multimedia content is usually performed based on the resource-constrained sensors. Traditional synchronization control algorithms fail to run on the low-end hardware platform. In this paper, we propose an adaptive synchronization control scheme with multi-level buffer to address this problem. Main contributions of this paper are as follows. (i) To overcome the resource constraint of WMSNs, we perform the synchronization control in a distributed way by combining the sensors in the stream transmission path. (ii) By evaluating the current network state, we adjust the level number of the buffer adaptively to balance the delay and delay jitter. (iii) Through analyzing the buffer state of each level, we propose an efficient packet scheduling scheme to reduce the delay jitter actively. (iv) We implement the proposed scheme and verify its effectiveness in our practical WMSNs platform. The experiment results show that the proposed scheme can maintain the streams synchronization effectively with the low-end sensors.

本文首先以大推力直线电机为基础,对大推力永磁同步直线电机进行了详细的介绍,同时对其进行了相关性的测试;通过前馈+PID算法对系统参数进行相应的调节,最大程度的得到一个较为理想的响应曲线,同时减小系统的跟随误差。测试结果显示,运用这种控制方式能够保证进给系统在一定程度上具有一个理想的静态性能和动态性能。

<正>一台拥有为加工复杂形状的工件而进行数道工序、不同方式的加工性能的机械称之为复合加工机床。为达到同样目的,也有将控制坐标多轴化、扩大加工功能、多机能化的使用方法。总之是用工序集成的方法提高生产效率,提高机床的附加价值。于是,这里就把前者的在一台机床内实现不同品种为加工复杂形状加工的机床和后者的多坐标控制机床两者通称为复合加工机床。而今复合加工机床成为世界机床发展方向,目前,世界上越来越多的复杂零件采用复合机床进行

Video surveillance system, which can provide real-time display of the monitored scene and video playback, has been employed in many areas including commercial security, accident investigation, law enforcement, and emergency response. However, audio which carries important information not available in video is usually not taken seriously and used effectively. In this paper, we develop an enhanced surveillance platform by organically integrating the low-power wireless audio sensor network (WASN) with the traditional visual surveillance network. We can obtain more comprehensive and precise monitoring without the limitation of the line-of-sight and lighting condition. Moreover, this platform is designed and built for providing key support to varieties of applications in wireless multimedia sensor networks. This paper describes the platform architecture, including design, implementation, and performance. We describe the hardware and software components of the audio/video sensors. Then, we present the multimedia synchronization mechanism in the heterogeneous network which is the foundation of applications in the proposed platform. Besides, we describe a sample application and data management mechanism that we have implemented to show the usefulness of our platform. Our experiments include an in-depth analysis of the bottlenecks within the platform as well as measurements for the various components.

<正>慢性支气管炎简称慢支,是严重危害人民健康的常见病和多发病,尤以老年人多见,50岁以上者高达15%左右。慢性支气管炎是指气管、支气管黏膜及其周围组织的慢性非特异性炎症,秋冬季节为发病高峰。