Commercial digital image libraries,digital images and digital discontent

Publications such as consumer magazines rely heavily on image libraries as sources for the images they use in their issues. Traditionally, magazine editorial staff have discussed their image requirements over the telephone with library staff and the library has conducted the search. Many libraries have now developed Web sites and their customers search them for images themselves. A minority have e-commerce capabilities, and enable customers to purchase and download digital images from their sites. This survey found that magazine staff do not often choose to search digital libraries, preferring instead to continue to contact the library by telephone. Most also choose not to buy the use of digital images, but prefer to continue to work with conventional transparencies and slides. The reasons for these preferences, and the reasons they are unlikely to change in the short term, are explored.     

Bionic digital brain realizing the digital twin-cutting process

A digital twin (DT) is an effective means of achieving physical and information fusion and has great potential for achieving a new paradigm of cutting process (CP) intelligence. This paper traces the relevant studies of digital technology in manufacturing and proposes a bionic digital brain (BDB) as the intelligent core of a digital twin-cutting process (DTCP) framework. The BDB was built with digital neurons (DN) as the basic functional unit, and the reaction mechanism between the DN stimulated the BDB to compute intelligently in real time (RT). The left brain obtains the prophetic theoretical processing information through the DN. The right brain receives actual perceptive processing information through the DN. After the corpus callosum fuses the left and right brain information, the DN outputs the optimal control solutions in RT to ensure demand. The details of monitoring, predicting, optimizing, and controlling the CP based on this framework are described in detail through a case study, demonstrating the powerful information processing capability of the BDB and the RT precision intelligent machining effects. The developed DTCP system confirmed the feasibility and effectiveness of the proposed framework. It provided a theoretical and technical reference for applying and promoting DT technology in the CP.     

Teaching digital library concepts using digital library applications

Many digital library topics may be taught using digital library applications, in the context of project-based digital library courses. Several digital library applications exist, and these applications are used as teaching tools to illustrate the functionality of digital libraries as well as the design decisions that go into them. Using digital library applications as teaching tools provides a valuable learning experience for students, and may provide useful feedback to the developers of DL applications. This paper identifies and explores DL topics that may most effectively be taught using DL applications, in the context of project-based DL courses.     

手机及小型手持数字设备数字取证研究综述

现代社会以手机和个人数字助理为代表的小型手持电子设备已经成为人们不可或缺的日常工具。随着信息和通信技术的发展,这些手持设备功能越来越增强,普及度越来越高,在各类案件中都可以见到这类数字手持设备的身影。因而对于这一类小型数字电子设备取证成为紧迫性的新研究领域。对这一类数字取证现状和相应工具作一综述。     

Debunking the ‘digital native’: beyond digital apartheid,towards digital democracy

This paper interrogates the currently pervasive discourse of the ‘net generation’ finding the concept of the ‘digital native’ especially problematic, both empirically and conceptually. We draw on a research project of South African higher education students' access to and use of Information and Communication Technologies (ICTs) to show that age is not a determining factor in students' digital lives; rather, their familiarity and experience using ICTs is more relevant. We also demonstrate that the notion of a generation of ‘digital natives’ is inaccurate: those with such attributes are effectively a digital elite. Instead of a new net generation growing up to replace an older analogue generation, there is a deepening digital divide in South Africa characterized not by age but by access and opportunity; indeed, digital apartheid is alive and well. We suggest that the possibility for digital democracy does exist in the form of a mobile society which is not age specific, and which is ubiquitous. Finally, we propose redefining the concepts ‘digital’, ‘net’, ‘native’, and ‘generation’ in favour of reclaiming the term ‘digitizen’.     

A novel digital information service for federating distributed digital entities

We investigate the performance and the scalability metrics of a Digital Information Service framework that is used for unifying and federating online digital entities by retrieving and managing information located on the web. The Digital Information Service consists of tools and web services for supporting Cyberinfrastructure based scientific research. This system supports a number of existing online Web 2.0 research tools (social bookmarking, academic search, scientific databases, journal and conference content management systems) and aims to develop added-value community building tools that leverage the management and federation of digital entities and their metadata obtained from multiple services. We introduce a prototype implementation and present its evaluation. As the results indicate, the proposed system achieves federation and unification of digital entities coming from different sources with negligible processing overheads.     

Paper-based digital microfluidics

In this paper, a new fabrication method for digital microfluidics is proposed. In which, paper, graphite, and adhesive tape are used as substrate, electrodes, and dielectric layer, respectively. The graphite is sprayed over a template on the paper substrate. Two different water repellants are used as the hydrophobic layer, which replace with expensive materials such as Teflon-AF^®. The paper substrate is low cost, available, and flexible. The proposed device is disposable, and its fabrication procedure is simple, fast, and low cost which allows creation of a new device for each individual experiment. Therefore, problems such as adsorption and dielectric breakdown will not occur in this type of digital microfluidics. This device can perform two types of droplet operations, merging and moving on droplets in volumes of 15–50 μL.     

便携式数字声级计

在介绍声级测量的基础上，论述了便携式数字声级计的工作原理、主要电路及特点。与传统的指针式声级计相比，便携式数字声级计的制造成本几乎没有增加，可声级计的功能、附加值却大为增加，提高了产品的竞争力和市场占有率。     

Detecting digital chameleons

Conversations are characterized by an interactional synchrony between verbal and nonverbal behaviors [Kendon, A. (1970). Movement coordination in social interaction: some examples described. Acta Psychologica, 32(2), 101–125]. A subset of these contingent conversational behaviors is direct mimicry. During face to face interaction, people who mimic the verbal [Giles, H., Coupland, J., & Coupland, N. (1991). Accommodation theory: Communication, context, and consequence. In Giles, H., Coupland, J., & Coupland, N. Contexts of accommodation. Developments in applied sociolinguistics. Cambridge: Cambridge University Press] and nonverbal behaviors [Chartrand, T. L., & Bargh, J. A. (1999). The chameleon effect: the perception-behavior link and social interaction. Journal of Personality and Social Psychology, 76, 893–910] gain social advantage. Most research examining mimicry behavior in interaction examines ‘implicit mimicry’ in which the mimicked individual is unaware of the behavior of the mimicker. In this paper, we examined how effective people were at explicitly detecting mimicking computer agents and the consequences of mimic detection in terms of social influence and interactional synchrony. In Experiment 1, participant pairs engaged in a “one-degree of freedom” Turing Test. When the computer agent mimicked them, users were significantly worse than chance at identifying the other human. In Experiment 2, participants were more likely to detect mimicry in an agent that mirror-mimicked their head movements (three degrees of freedom) than agents that either congruently mimicked their behaviors or mimicked those movements on another rotational axis. We discuss implications for theories of interactivity.     

基于数字水印和数字签名的电子支票支付系统

探讨了当前电子商务支付中电子支票的安全问题,分析了其发展的形势及存在的安全缺陷,提出了一种结合数字水印和数字签名的安全保障机制。该机制采用了双重身份认证方案和水印内容认证方案,使得非法接触以及修改电子支票,伪造其内容都是不可能的。分析表明,该方案使得电子支票具有认证精度高、可信度高、安全性强等特点。     

多通道雷达数字接收机数字下变频设计

提出一种基于时分复用原理的双频段多通道数字接收机DDC模块的设计方法,并利用FPGA的数控振荡器和FIR滤波器的IP核完成了DDC模块的设计与实现。仿真结果表明,该设计实现了数字混频、抽取和滤波的功能,与其他设计方案对比表明,本方案有效地减少了FPGA资源的使用量,降低了硬件设计的复杂度,节约了硬件成本。     

Convex digital solids

A definition of convexity of digital solids is introduced. Then it is proved that a digital solid is convex if and only if it has the chordal triangle property. Other geometric properties which characterize convex digital regions are shown to be only necessary, but not sufficient, conditions for a digital solid to be convex. An efficient algorithm that determines whether or not a digital solid is convex is presented.     

From simple digital twin to complex digital twin part II: Multi-scenario applications of digital twin shop floor

The shop floor has always been an important application object for the digital twin. It is well known that production, process, and product are the core business of the shop floor. Therefore, the digital twin shop floor covers multi-dimensional information and multi-scale application scenarios. In this paper, the digital twin shop floor is constructed according to the modeling method of the complex digital twin proposed in Part I. The digital twin shop floor is firstly divided into several simple digital twins that focus on scenarios of different scales. Two simple application scenarios are constructed, including tool wear prediction and spindle temperature prediction. Main functions in different application scenarios, such as data acquisition, data processing, and data visualization, are implemented and encapsulated as components to construct simple digital twins. Secondly, ontology models, knowledge graphs, and message queues are used to assemble these simple digital twins into the complex digital twin shop floor. And two complex application scenarios are constructed, including machining geometry simulation considering spindle temperature and production scheduling considering tool wear. The implementation of the complex digital twin shop floor demonstrates the feasibility of the proposed modeling method.     

Three-dimensional digital planes

Definitions of 3-D digital surface and plane are introduced. Many geometric properties of these objects are examined. In particular, it is shown that digital convexity is neither a necessary nor a sufficient condition for a digital surface element to be a convex digital plane element, but it is both necessary and sufficient for a digital surface to be a digital plane. Also algorithms are presented to determine whether or not a finite set of digital points is a (convex) digital plane element.     

Unlocking digital music

So why is all this happening, and why now? Surely DRM's interminablebad press and poor consumer perception could not have led tothis move towards the abandonment of DRM in favour of nakeddigital content. Or could it?     

Towards a digital library theory: a formal digital library ontology

Digital libraries (DLs) have eluded definitional consensus and lack agreement on common theories and frameworks. This makes comparison of DLs extremely difficult, promotes ad-hoc development, and impedes interoperability. In this paper we propose a formal ontology for DLs that defines the fundamental concepts, relationships, and axiomatic rules that govern the DL domain, therefore providing a frame of reference for the discussion of essential concepts of DL design and construction. The ontology is an axiomatic, formal treatment of DLs, which distinguishes it from other approaches that informally define a number of architectural variants. The process of construction of the ontology was guided by 5S, a formal framework for digital libraries. To test its expressibility we have used the ontology to create a taxonomy of DL services and to reason about issues of reusability, extensibility, and composability. Some practical applications of the ontology are also described including: the definition of a digital library services taxonomy, the proposal of a modeling language for digital libraries, and the specification of quality metrics to evaluate digital libraries. We also demonstrate how to use the ontology to formally describe DL architectures and to prove some properties about them, thus helping to further validate the ontology.     

基于FPGA的宽带数字接收机变带宽数字下变频器设计

基于FPGA芯片Stratix II EP2S60F672C4设计了一个适用于宽带数字接收机的带宽可变的数字下变频器(VB-DDC)。该VB-DDC结合传统数字下变频结构与多相滤波结构的优点,实现了对输入中频信号的高效高速处理,同时可以在较大范围内对信号处理带宽灵活配置。硬件调试结果验证了本设计的有效性。     

Multirate digital filters

This paper provides a review of recent developments in multirate digital filters and attempts to fill a long existing gap between multirate digital filters and multirate sampled-data feedback control systems.