Connective Ethnography for the Exploration of e-Science

E-science comprises diverse sites, connected in complex and heterogeneous ways. While ethnography is well established as a way of exploring the detail of the knowledge production process, some strategic adaptations are prompted by this spatial complexity of e-science. This article describes a study that focused on the biological discipline of systematics, exploring the ways in which use of a variety of information and communication technologies has become a routine part of disciplinary practice. The ethnography combined observation and interviews within systematics institutions with mailing list participation, exploration of web landscapes, and analysis of expectations around information and communications technologies as portrayed in policy documents. Exploring connections among these different activities offers a means of understanding multiple dimensions of e-science as a focus of practice and policy. It is important when studying e-science to engage critically with claims about the transformative capacity of new technologies and to adopt methodologies that remain agnostic in the face of such claims: A connective approach to ethnography offers considerable promise in this regard.     

Mapping the e-science landscape in South Korea using the webometrics method

There is a burgeoning interest among social scientists in the development of e-science technologies and research practices around world. However, the international social science research literature has not systematically examined e-science approaches in Asia in general and Korea in particular. This article presents empirical findings from a webometrics analysis of the semantic variation, disciplinary scope, and institutional structure of e-science programs in South Korea. The findings suggest that some e-science terms, including cyberinfrastructure, have prominent Korean web presences. At the same time, Korean government-sponsored national e-science centers and their affiliates do not have a strong web presence and do not actively participate in the hyperlink network that connects e-science-related institutional websites. Instead, they have a closed network among themselves. This result stems from the institutional dynamics within Korea's public and private e-science research communities.     

高性能虚拟网络VegaNet

现有网络研究的实验一般在模拟工具或原型系统上完成.然而,这些实验环境与真实网络环境总有较大的差别,主要包括没有真实用户流量、缺乏真实网络中的丰富网络事件、没有运行真正的协议栈软硬件平台等.另一方面,对于运营网络的研究,研究者经常希望分析网络事件发生前后的网络状况,例如更改拓扑或配置,注入网络故障等,显然这些措施难以在真实运营网络中实施.针对上述问题设计了一种为网络研究提供真实实验环境以及对核心网络进行模拟分析的高性能虚拟网络VegaNet(Virtual Gigabit Network).文中详细介绍了VegaNet结构模型及设计实现.目前,已完成VegaNet在CERNET2清华校园网的初步部署.实验表明,VegaNet能提供一个接近于真实网络状况的网络实验环境,并能灵活支持对核心网络的模拟分析.     

基于LP和DFB结构的离散Contourlet遥感影像融合算法及在QuickBird中的试验研究

针对目前最新发展的Contourlet变换能够比小波变换提供更丰富的方向和形状基,适合进行多尺度边缘增强的特点,利用Contourlet变换用于融合遥感全色和多光谱影像的算法,即利用LP（Laplacian Pyramid）捕获影像的低频分量,利用DFB（Directional Filter Bank）获得影像的高频分量,再对得到的低频近似系数和高频细节系数按照融合规则,采用算术平均和加权算子构造融合影像对应的对比度金字塔;最后,通过逆塔形变换重构融合影像。提出一种基于塔形方向滤波器组PDFB（Pyramidal Directional Filter Bank）的影像融合方法,算法一方面将Contourlet变换这一新的数学工具引入到影像融合中,另一方面对目前高分辨率影像数据源QuickBird进行了融合实验。此外,利用熵、扭曲度、偏差指数、相关系数、标准差等参量,对此融合方法的融合性能进行了评价与分析。实验结果表明：提出的融合算法能在保留多光谱影像光谱信息的同时增强了融合影像的空间细节表现能力和信息量,该算法是有效可行的。     

Gossiping protocols for hybrid grid resource scheduling

Grid resource providers can use gossiping to disseminate their available resource state to remote regions of the grid to attract application load. Pairwise gossiping protocols exchange information about limited subsets of other resources between pairs of potentially remote participants. In epidemic gossiping protocols, the provider disseminates information to multiple neighbors, who in turn forward it to their neighbors, and so on. One important metric for these protocols is their coverage, which characterizes how many and which resources receive the information. Coverage characteristics of epidemic protocols are non-uniform, concentrated within the vicinity of a disseminating node; they can exhibit bi-modal behavior where information either reaches distant nodes or dies out quickly. Pairwise gossiping protocols, on the other hand, provide a more uniform coverage, but it can take longer for the dissemination to reach desired uniformity. In this paper, we study performance characteristics of three gossiping protocols: (1) epidemic gossiping, (2) pairwise gossiping, and (3) adaptive information dissemination (which is based on a form of epidemic gossiping). We report experimental results based on our simulation framework that compare the three protocols in terms of packet overhead and query satisfaction rates. We show that pairwise gossiping protocols work best when resource distribution on the grid is uniform, and that they can be configured to perform well in support of grid scheduling. We also verify this behavior under typical node failures of real-world production grids.     

一种分布式持久性内存文件系统的一致性机制

持久性内存(persistent memory, PM)和远程直接内存访问(remote direct memory access, RDMA)具有高带宽、低延迟的硬件性能,这为设计高性能的分布式存储系统提供了新的机遇.然而,它们这些新的特性为高效的数据一致性管理引出了诸多问题：一方面,持久性内存数据一致性依赖于CPU主动执行硬件指令刷写缓存实现,而这类指令开销极高,严重影响CPU处理性能;另一方面,RDMA在服务器端CPU不参与的情况下直接读写服务器端内存,因此服务器端CPU无法主动感知数据写入事件以执行数据刷写操作,一旦系统崩溃会造成数据不一致的问题.针对以上2个问题,提出一种分布式持久性内存文件系统的一致性机制(crash consistency mechanism, CCM)：首先设计实现了基于操作日志的一致性保障策略,通过将每次操作的元信息记录至日志,并持久化,以保障系统的一致性状态;其次,设计了一种客户端对服务器端的远程写一致性策略,在完成数据传输的同时使服务器端CPU主动执行数据刷写;最后实现了一种服务器端的数据异步持久化,以提高系统的处理能力.测试结果表明,基于CCM的文件系统写吞吐可达到网络裸带宽的88%.相比于现有系统Octopus,CCM性能下降控制在1%以内.     

Unconscious emotions: quantifying and logging something we are not aware of

Lifelogging tools aim to precisely capture daily experiences of people from the first-person perspective. Although there have been numerous lifelogging tools developed for users to record the external environment around them, the internal part of experience characterized by emotions seems to be neglected in the lifelogging field. However, the internal experiences of people are important and, therefore, lifelogging tools should be able to capture not only the environmental data, but also emotional experiences, thereby providing a more complete archive of past events. Moreover, there are implicit emotions that cannot be consciously experienced, but still influence human behaviors and memories. It has been proven that conscious emotions can be recognized from physiological signals of the human body. This fact may be used to enhance life-logs with information about unconscious emotions, which otherwise would remain hidden. On the other hand, it is not clear if unconscious emotions can be recognized from physiological signals and differentiated from conscious emotions. Therefore, an experiment was designed to elicit emotions (both conscious and unconscious) with visual and auditory stimuli and to record cardiovascular responses of 34 participants. The experimental results showed that heart rate responses to the presentation of the stimuli are unique for every category of the emotional stimuli and allow differentiation between various emotional experiences of the participants.     

Co-Constructing Non-Mutual Realities: Delay-Generated Trouble in Distributed Interaction

The use of remote communication technologies to carry out dailywork is becoming increasingly common, and their use in certainsettings is already commonplace. Yet, in spite of the fact thatsignificant sums are being spent on the acquisition oftechnologies to support distributed work, we are only beginningto understand the intricacies of these interactions. This paperidentifies and analyzes one particular limitation of video-basedteleconferencing, the impact of an audio and video delay ondistributed communication. It offers a detailed microanalysis ofone distributed team's use of videoconferencing to support remoteteamwork. We explore through this analysis the impact whichtechnology-generated delays may have on shared meaning-makingbetween remote participants. We draw conclusions about thesignificance of our findings for understanding talk, interactionand collaboration across remote links, and conclude withrecommendations for designers, users and implementers.     

一种基于灰度直方图的遥感影像阴影自动检测方法

在高分辨率全色遥感影像中,阴影的存在既给目标识别带来了困难,又包含了地物的层次和高度信息。本文运用灰度统计直方图的势函数对全色遥感影像的灰度统计直方图函数进行拟合,使用一阶差分找到直方图势函数的第一个谷点,以该谷点对应的灰度值对原始影像做阈值分割完成阴影检测。实验表明,在各种复杂地物环境下,本文方法都能能完成灰度分割阚值的自动选取,其阴影检测结果是快速有效的。     

Providing Dynamic Visual Information for Collaborative Tasks: Experiments With Automatic Camera Control

One possibility presented by novel communication technologies is the ability for remotely located experts to provide guidance to others who are performing difficult technical tasks in the real world, such as medical procedures or engine repair. In these scenarios, video views and other visual information seem likely to be useful in the ongoing negotiation of shared understanding, or common ground, but actual results with experimental systems have been mixed. One difficulty in designing these systems is achieving a balance between close-up shots that allow for discussion of detail and wide shots that allow for orientation or establishing a mutual point of focus in a larger space. Achieving this balance can be difficult without disorienting or overloading task participants. In this article we present results from two experiments involving three automated camera control systems for remote repair tasks. Results show that a system providing both detailed and overview information was superior to systems providing only one or the other in terms of performance but that some participants preferred the detail-only system.     

分布式网络化测试系统的中心服务器技术与研究

为了实现测试系统的网络化、开放化和标准化,基于传感器振动测试平台远程实物实验系统提出一种具有开放与互联能力的分布式网络化测试系统体系结构,并在逻辑上将该体系结构划分为测控中心服务器、测试服务器和标定服务器。中心服务器是分布式网络测试系统的核心逻辑组成单元,是系统中事务响应和处理中心。该服务器向上服务于测试用户,提供测试请求响应服务;向下管理、控制和协调测试服务器与标定服务器进行工作,完成具体的测试请求和测试服务。文章给出了中心服务器的组建方案,并重点阐述了中心服务器的体系结构、组件应用技术及组件接口,同时也对其关键技术进行了介绍。     

Remote sensing and developing countries,training and technology transfer Europe-Africa

The use of space remote sensing is certainly important for developing countries, but the questions still remain of how to introduce it effectively and in the long term and what the contribution of training is.

This paper attempts to provide analysis on efforts in space remote sensing from developing countries, particularly Europe and Africa. It highlights two essential points: 1. The training. 2. The actual state of space remote sensing applications.

The study shows that the actual use of this technology in Africa is still rare in comparison to the number of trained participants. It also shows that there is no direct correlation between the percentages of those trained and the number of ongoing national projects.

It appears that a national and global policy is essential to ensure durability. Demonstrations, financial analysis and assessments are needed to sensitize the government decision-makers.     

Disaster Exercise Outcomes for Professional Emergency Personnel and Citizen Volunteers

It has long been argued in the research literature that conducting disaster exercises produces a variety of benefits that promote effective emergency management. In spite of nearly universal acceptance of the claim, there are few empirical studies that have explored the effects of exercises on participants. This paper reviews the role of exercises in the creation of community disaster preparedness, while making explicit the links among planning, training and exercising. Using a quasi‐experimental design, the effects of disaster exercise participation on perceptions of response knowledge and teamwork are studied for police officers, fire‐fighters and civilian volunteers. The exercise studied involved an annual airport disaster drill required for continuing certification. It was found that participation enhanced the perceptions of response knowledge and teamwork for all three types of participants.     

Designing for e-science: Requirements gathering for collaboration in CiteSeer

It is unclear if and how collaboratories have enhanced distributed scientific collaboration. Furthermore, little is known in the way of design strategies to support such collaboration. This paper presents findings from an investigation into requirements for collaboration in e-science in the context of CiteSeer, a search engine and digital library of research literature in the computer and information science disciplines. Based on a survey and follow-up interviews with CiteSeer users, we present four novel implications for designing the CiteSeer collaboratory. First, visualize query-based social networks to identify scholarly communities of interest. Second, provide online collaborative tool support for upstream stages of scientific collaboration. Third, support activity awareness for staying cognizant of online scientific activities. Fourth, use notification systems to convey scientific activity awareness. We discuss how these implications can broadly enhance e-science usability for collaboratory infrastructures based on digital libraries.     

基于声誉的分布式联邦学习节点选择算法

由于隐私泄露的风险越来越大,而采集的数据中的通常包含大量隐私信息,使数据的采集者不愿意共享自己的数据,造成“数据孤岛”,联邦学习能够实现数据不离本地的数据共享,但其在多机构数据共享中还存在一些问题,一方面中央服务器集中处理信息造成昂贵的成本,易产生单点故障,另一方面,对于多机构数据共享而言,参与节点中混入恶意节点可能影响训练过程,导致数据隐私泄露,基于上述分析,本文提出了一种将区块链和联邦学习相结合的以实现高效节点选择和通信的新的分布式联邦学习架构,解放中央服务器,实现参与节点直接通信,并在此架构上提出了一种基于信誉的节点选择算法方案（RBLNS）,对参与节点进行筛选,保证参与节点的隐私安全。仿真结果表明,RBLNS能够显着提高模型的实验性能。     

一种基于PCA的远程匿名证明改进方案

远程证明是可信计算的关键技术之一,可以验证平台身份和配置信息的可信性,而现有远程证明方案存在一定的缺陷。本文在分析现有基于匿名属性证书的远程匿名证明方案的基础上,提出了改进方案。针对原方案中存在的在匿名属性证书申请过程中未验证证书颁发实体的问题,对证书申请方案进行了改进,采用会话密钥对PCA签名,保证了证书颁发实体的真实性;针对远程证明协议存在恶意用户接入的问题,在改进方案中引入假名机制,即保证了用户身份的匿名性,又防止了具有不良历史记录用户的非法接入。     

Swiping paper: the second hand, mundane artifacts, gesture and collaboration

It is widely recognised that paper remains a pervasive resource for collaboration and yet there has been uncertain progress in developing technologies that aim to enhance paper documents with computational capabilities. In this article, we discuss the design of a technology that interweaves developments in hardware and materials, electronics and software, and seeks to create new affinities between digital content and paper. The design of the technology drew from findings from naturalistic studies of the uses of paper, particularly when considering how ‘users’ might ‘interact’ with the augmented technology. We briefly review these studies and discuss the results of an evaluation of the emerging technology. Analysis of the fine details of the conduct of participants in these assessments suggest how, even when we design simple forms of interaction with a device, these can be shaped and transformed by the participation and collaboration of others.     

Selected challenges in computer networking

The convergence of computing and networking is nowhere more evident than in the phenomenal growth of the World Wide Web. In another sense, though, computer networking is being pulled in two opposite directions. On the one hand, the Web's popularity and growth has been fueled largely by desktop applications consuming bandwidth-intensive images and video. On the other hand, thin-client computers are becoming more commonly used as edge-of-network devices, often connected by wireless technology. There is also an increasing mismatch between fiber-optic transmission bandwidths and computer speeds, pushing computing further away from the network core. Are there ways to close, or at least manage, this growing schism-whether through novel hardware solutions or the programmability of network infrastructures? Can we better integrate these edge-of-network devices and make them full-fledged network participants? The paper discusses programmable network challenges