接入网络建设:回顾历史,展望末来

对于大多数最终用户来说,过去几十年,接入网几乎没有什么经变化.最近几十年,尽管美国各大运营商在现有网络的升级上不惜代价,但主要还是用于骨干网的扩容,以满足数据、互联网业务带宽需求的急剧增长.     

Looking ahead: Joint small group detection and tracking in crowd scenes

Small group detection and tracking in crowd scenes are basis for high level crowd analysis tasks. However, it suffers from the ambiguities in generating proper groups and in handling dynamic changes of group configurations. In this paper, we propose a novel delay decision-making based method for addressing the above problems, motivated by the idea that these ambiguities can be solved using rich temporal context. Specifically, given individual detections, small group hypotheses are generated. Then candidate group hypotheses across consecutive frames and their potential associations are built in a tree. By seeking for the best non-conflicting subset from the hypothesis tree, small groups are determined and simultaneously their trajectories are got. So this framework is called joint detection and tracking. This joint framework reduces the ambiguities in small group decision and tracking by looking ahead for several frames. However, it results in the unmanageable solution space because the number of track hypotheses grows exponentially over time. To solve this problem, effective pruning strategies are developed, which can keep the solution space manageable and also improve the credibility of small groups. Experiments on public datasets demonstrate the effectiveness of our method. The method achieves the state-of-the-art performance even in noisy crowd scenes.     

30 years of adaptive neural networks: perceptron, Madaline, andbackpropagation

Fundamental developments in feedforward artificial neural networks from the past thirty years are reviewed. The history, origination, operating characteristics, and basic theory of several supervised neural-network training algorithms (including the perceptron rule, the least-mean-square algorithm, three Madaline rules, and the backpropagation technique) are described. The concept underlying these iterative adaptation algorithms is the minimal disturbance principle, which suggests that during training it is advisable to inject new information into a network in a manner that disturbs stored information to the smallest extent possible. The two principal kinds of online rules that have developed for altering the weights of a network are examined for both single-threshold elements and multielement networks. They are error-correction rules, which alter the weights of a network to correct error in the output response to the present input pattern, and gradient rules, which alter the weights of a network during each pattern presentation by gradient descent with the objective of reducing mean-square error (averaged over all training patterns)     

初心如磐奋楫笃行而立之年再出发

"极不平凡"贯穿着2020年一整年,中国经济交出了令世界瞩目的答卷:率先控制疫情、率先复工复产、率先实现经济增长由负转正.2020年,印制电路板(PCB)人同样交出了一份满意的答卷,大家齐心抗疫,克服重重困难,加足马力全力生产,保就业、稳经济、促发展."电子产品之母"不辱使命!     

Looking back and to the future - leadership from a Swedish perspective

This paper describes the current situation and trends related to leadership from a Swedish perspective and from the author's personal viewpoint. The paper also identifies several key elements in creating a positive working environment and discusses the current and future challenges facing research leaders     

Looking back: how practical experience in the classroom taught me aprofessional approach on the job

The author discusses his experience as a graduate student in the Technical Communication Program at Oklahoma State University (OSU). He discusses activities that he found particularly valuable being an intern, namely, participating in the Society for Technical Communication (STC), writing for publication, and giving oral presentations     

Looking Forward: New Ideas, New Opportunities

The editor in chief discusses upcoming special issues, topic trends in multimedia, article submissions in 2007, and our volunteers' efforts.     

亲历中国科幻30年：个人史与社会史

吴岩简介 吴岩（1962-）,北京市人,科幻作家。,北京师范大学教育学部副教授、文学院兼职副教授：中国科普作家协会科学文艺委员会副主任委员。著有《心灵探险》、《生死第六天》、《抽屉里的青春》等科幻小说：主持国家社科基金“科幻文学理论和学科体系建设”,主编“科幻新概念理论丛书”、“科幻文学理论和学科体系建设丛书”、     

光网络30年:回顾与展望

作为信息网络基础架构的核心一环,光网络具有不可替代的重要地位.首先回顾了光网络的诞生过程并总结了其30年研究和发展历程中具有重大意义的里程碑事件,并根据未来网络需求探讨了光网络发展所面临的挑战和可能的发展方向.     

Beyond interactivity: critical/cultural surveillance scholarship, 10 years after Andrejevic

Mark Andrejevic’s iSpy: Surveillance and Power in the Interactive Era identified the potential for critical/cultural studies to examine advances in surveillance technologies by considering their relationship with cultures and discourses. Almost 10 years after iSpy, critical/cultural projects have expanded Andrejevic’s vision to account for new surveillance innovations (e.g. biometric technology and body scanners), new cultural contexts (e.g. of terrorist threat conception), and new moments of resistance (e.g. the recent revelation of National Security Agency monitoring). I review here five of these projects, published between 2010 and 2015, and summarize current conversations in critical/cultural surveillance studies as they implicate ongoing communication theory and research. These projects demonstrate that Andrejevic’s formative vision of surveillance as control of consumer agency illuminates evolving control in other arenas. This control subjects certain people to more surveillance and less security, along racialized, gendered, and classed lines. In particular, I trace how discourses are used to encourage consent and formulate resistance to surveillance in these projects.     

ZnCdO: Status after 20 years of research

With the increasing attention devoted to ZnO in the late nineties, the discovery of ZnCdO as a means of reducing its bandgap towards visible wavelengths promised it a bright future in optoelectronics, which should run in parallel to its possible applications as a transparent conducting oxide. This review will cover the developments achieved so far in the growth of ZnCdO, in the understanding of its structural properties, paying special attention to the competition between wurtzite and rocksalt phases, as well as in the analysis of its optical and electronic properties. Finally, some of the devices demonstrated with ZnCdO will be reviewed together with the difficulties they have encountered.     

Tubes: still vital after all these years

Though barely acknowledged in this solid-state world, vacuum tubes still rule where frequency is measured in gigahertz and power levels range upward from the kilowatt level. The author discusses the pros and cons of solid state devices and electron tubes. The benefits of tubes of solid state devices are outlined. Reliability and cathode exhaustion are also discussed     

Looking for New DNA: The World Around IMT-advanced

Technology, such as IMT-2000 and IMT-A, plays an important role in our society. A number of prominent authors and thinkers have judged the impact of technology as being increasingly radical. This paper connects different visions on technology, thereby bringing different perspectives on innovation into line. An important motivation for this paper has been the predominantly instrumental vision on technology that is present at most European governments. The paper shows that this is an imbalanced vision that neglects the renewing and radical power of technology. On the other hand, the paper focuses on the required skills (‘DNA’) that are needed to help companies bridge the gap from radical innovation to user centred innovation. The paper concludes with an example from personal network technology, illustrating the main concepts and claims.