SDN处百家争鸣百花齐放时期

在"2013全球IPv6下一代互联网高峰会议"SDN研讨专场中,清华大学网络体系架构和IPv6研究室主任,中国SDN与开放网络专委会常务副主任委员毕军教授在发表主题演讲时表示,SDN还处在百家争鸣,百花齐放的阶段,OpenFlow不能全面代表SDN。     

百家争鸣 百花齐放——RSA Conference Keynotes

思科介绍了在网络安全方面的战略、McAfee分析了新型的攻击场景以及现阶段防护的思路、TippingPoint专注在如何更灵活的设置Policy等一些技术上，RSA2009的技术演讲引人入胜。     

汽车隔音：百花齐放并未引来百家争鸣

目前,无论是汽车（音响）改装领域,还是专业汽车隔音领域,各种品牌、各个层次的隔音产品品牌层出不穷。十分活跃,但这种市场表面呈现出的百花齐放的兴旺局面并未引来百家争鸣。     

电子商务 百花齐放

近来,电子商务新闻频传,许多新老站点纷纷借“e”缕春风,推出自己宏伟的发展计划,其中许多值得我们玩味……     

百家争鸣 卓绝群伦

卓振机房环境监控系统,是基于数字化、网络化、智能化的监控系统,由监控系统管理平台、嵌入式环境监控主机、数据采集模块、各种传感器、系统报警设备及前端被监测设备组成。总体架构基于TCP／IP网络和现场总线,中间不需要任何协议转换模块、多功能串口卡、工控机等。     

开源认证 百家争鸣

随着开源运动的不断深入,来自政府的、组织的、厂商的各种培训认证层出不穷,形式了如今开源认证百家争鸣的局面。     

平板电脑百花齐放

尽管2010年国内市场上号称挑战iPad的产品不少,但拼凑个硬件平台再装上一个低版本Android系统的产品是大多数,这样的平板电脑连一部靠谱的智能手机都比不上,哪里谈得到挑战iPad。     

数据库市场百花齐放

虽然RC版本的SQL Server2008并没有在社区带动大的热潮，但微软应对SQL注八攻击的三个工具（Scrawlr、URLScan 3．0 Beta、Source Code Analyzer for SQL Injection）却格外引人注目。自今年4月份开始，全球基于ASP和ASPNET的网站其数据安全频繁受到威胁，SQL注入攻击是直接主因。为此，     

开源数据库 百花齐放

在开源领域，有众多的开源数据库项目，媲美商业数据库的MySQL、企业级数据库PostgreSQL、嵌入式数据库Berkeley DB都为开源运动的深入发展添砖加瓦，在狭小的开源世界里，数据库也是百花齐放。     

数据库市场百花齐放

SQL Server2008总算发布了RTM版本,产品共包括7个版本。虽然相对SQL Server2005补充了诸如非结构信息、流数据和空间数据的管理措施,但价格保持不变。     

2N Period submicron grating at the inner wall of a metal cylinder

The aim of the present contribution is to set up and demonstrate the chain of processes leading to the Ni-master of a circular cylinder having an integer number of long grating lines of submicron period at its wall. Microelectronics 2D microstructuring technologies were adapted in order to print a photoresist integer period number on a glass cylinder flank by the projection of a radial planar phase-mask grating. The next step is the galvanic growth of nickel on the photoresist corrugation. Subsequently, the manufacturing of cylindrical gratings will be enabled by an injection moulding process.     

Let’s Get Physical! In, Out and Around the Gaming Circle of Physical Gaming at Home

Physical gaming is a genre of computer games that has recently been made available for the home. But what does it mean to bring games home that were originally designed for play in the arcade? This paper describes an empirical study that looks at physical gaming and how it finds its place in the home. We discuss the findings from this study by organizing them around four topics: the adoption of the game, its unique spatial needs, the tension between visibility and availability of the game, and what it means to play among what we describe as the gaming circle, or players and non-players alike. Finally, we discuss how physical gaming in the home surfaces questions and issues for householders and researchers around adoption, gender and both space and place.     

中高职衔接学生学习倦怠影响因素与应对策略研究

中高职衔接是实现职校学生可持续发展的重要途径。网络技术专业对188名大学生进行调查,分析了中高职衔接学生在步入高职后导致学习倦怠的影响因素,探究了专业教师教学、教学内容、学习环境、学习方法和心态管理等各种因子之间的相关性。研究表明关注这些因子并采取有效措施,对提高中高职衔接学生学习积极性具有重要价值,研究结果为我国中高职顺利衔接提供重要的借鉴和参考。     

Design and use of a hypermedia system at the University level

Abstract This paper reports on an experiment in which a whole semester course in psychology was replaced by a mixed formula consisting of a CD-ROM complemented by a series of seminars and workshops. The CD-ROM was conceived as a collection of documents (hypertexts, research data, references, videos and activities) linked together with genuine Netscape facilities. Students were invited to search through these documents for information to answer questions (called challenges ) on the topic. A multiple-choice questionnaire accompanied each challenge in order to foster students' self-evaluation. The seminars, held every other week, served both as forums to discuss each of the topics under the guidance of an expert. Careful analysis of students' answers to two questionnaires at the beginning and end of the course and during interviews, showed that such a formula was favourably accepted by a large majority of students, although it lead to more anxiety and work load than a traditional course. Positive effects were also observed on learning.     

Identification and dynamic inversion-based control of a pressurizer at the Paks NPP

The paper presents the design of a pressure controlling tank located in the primary circuit of a Nuclear Power Plant. All steps from modeling through control design to implementation are detailed. Based on first engineering principles a second-order Wiener model is formulated and its unknown parameters are identified. The control design is based on a dynamic inversion method. The performance of the designed closed-loop system is tuned by an error feedback. The implemented controller is of a distributed structure including measurement and control PLCs, a continuous power controller and a special supervisor module. The nominal stability of the controller in the networked environment is analyzed by using the maximum allowable transmit interval. The hardware and software design and implementation obey the safety-critical requirements imposed by the special nature of the plant.     

Is that a bot running the social media feed? Testing the differences in perceptions of communication quality for a human agent and a bot agent on Twitter

Due to the growth and popularity of Twitter, automated programs that can tweet are increasingly developed and employed. In line with the Computers Are Social Actors (CASA) paradigm (Reeves & Nass, 1996), findings suggest that Twitterbots are perceived as credible, attractive, competent in communication, and interactional. Additionally, there were no differences in the perceptions of source credibility, communication competence, or interactional intentions between the bot and human Twitter agents. However, the source of the human Twitter agent was rated higher in attraction (social and task) than was the Twitterbot. Results are discussed in light of CASA. Implications for organizations that might employ Twitterbots are also addressed.     

Computers and the 16th-century Chanson a pilot project at the University of Chicago

Conclusions One cardinal principle guided our evaluation of the data provided for us by the computer: never to be deluded into believing that the computer was in any way capable of analyzing a piece of music. Rather, we used the information made available by the computer as a means of substantiating or explaining the insights into a given composition that we gained by means of a direct confrontation with the music. In this way, the data supplied by the computer proved to be very useful in explaining why a particular portion of a chanson generates a sense of tension, while another section of the same piece creates a feeling of rest. Similarly, the electronically derived information was particularly helpful in setting up stylistic profiles of the various composers whose chansons were included in our sampling. In fact, the computer output was instrumental in helping to settle more than one problem of conflicting attributions, largely on the basis of these stylistic profiles. Like any other computerized process, our program elicited from the computer no analytical operation that could not have been done without the assistance of the computer. Very little precise measurement has been done in the analysis of the music of the Renaissance, however, and for good reason: the compilation of statistical data of the type we have described takes so much time that it can be considered feasible only with mechanical assistance. The ability we gained to apply to the chanson repertory a somewhat more precise system of analytical measurement was the most encouraging aspect of the pilot project. candidate for the Ph.D. in Physics     

Is the Amik Basin (SE Turkey) a triple-junction area? Analyses of SPOT XS imagery and seismicity

In the eastern Mediterranean, plate motions occur between the Arabia/Anatolia, Africa/Arabia and Anatolia/Africa boundaries along the Amanos Fault, the Dead Sea Fault and the Cyprus Arc, and the extension of the latter on land. Detailed enhancement and classification procedures applied to SPOT XS imagery of the Hatay region, and centred on the Quaternary Amik Basin, have revealed a prominent NE–SW-trending tectonic lineament. Recent seismicity suggests that this NE–SW-trending lineament dies out in the Quaternary Amik Basin in the east and continues to the Cyprus Arc to the south-west. Structural lineament extensions derived from SPOT XS imagery using linear edge enhancement and unsupervised classification methods and the distribution of seismicity in the Hatay region show that this region has been affected by the East Anatolian Fault Zone, the Dead Sea Fault Zone and the Cyprus–Antakya Transform fault. These fault associations accommodate northerly movement of the African and Arabian plates toward the Eurasian plate. The Amik Basin appears to have been formed by interaction among the Amanos Fault interpreted here as a continuation of the East Anatolian Fault the left-lateral Dead Sea Fault, and the left-lateral Cyprus–Antakya transform fault. Active faults belonging to the aforementioned structural zones meet one another to form a triple junction at the Amik Basin near Antakya.     

Base64 encoding and decoding at almost the speed of a memory copy

Many common document formats on the Internet are text-only such as email (MIME) and the Web (HTML, JavaScript, JSON, and XML). To include images or executable code in these documents, we first encode them as text using base64. Standard base64 encoding uses 64 ASCII characters, ie, both lower and upper case Latin letters, digits and two other symbols. We show how we can encode and decode base64 data at nearly the speed of a memory copy (memcpy ) on recent Intel processors, as long as the data does not fit in the first-level (L1) cache. We use the single-instruction-multiple-data instruction set AVX-512 available on commodity processors. Our implementation generates several times fewer instructions than previous single-instruction-multiple-data-accelerated base64 codecs. It is also more versatile, as it can be adapted, even at runtime, to any base64 variant by only changing constants.