Additive manufacturing technologies : 3D printing, rapid prototyping, and direct digital manufacturing

This book covers in detail the various aspects of joining materials to form parts. A conceptual overview of rapid prototyping and layered manufacturing is given, beginning with the fundamentals so that readers can get up to speed quickly. Unusual and emerging applications such as micro-scale manufacturing, medical applications, aerospace, and rapid manufacturing are also discussed. This book provides a comprehensive overview of rapid prototyping technologies as well as support technologies such as software systems, vacuum casting, investment casting, plating, infiltration and other systems. This book also: Reflects recent developments and trends and adheres to the ASTM, SI, and other standards Includes chapters on automotive technology, aerospace technology and low-cost AM technologies Provides a broad range of technical questions to ensure comprehensive understanding of the concepts covered.

Identifying Heel Contact and Toe-Off Using Forceplate Thresholds With a Range of Digital-Filter Cutoff Frequencies

Analysis of human gait requires accurate measurement of foot-ground contact, often determined using either foot-ground reaction force thresholds or kinematic data. This study examined the differences in calculating event times across five vertical force thresholds and validated a vertical acceleration-based algorithm as a measure of heel contact and toe-off.

Digital literacies in the middle years of schooling

This paper uses Glister's interpretation of digital literacy whilst acknowledging that a computer is not the only means for the delivety of digital texts. I will explore how we can support student teachers to develop understandings about the teaching in the middle years in order to work with students in schools to successfully read digital texts, create digital texts, search, fmd and use information in the digital world and to become critical users of digital texts. Students in the middle years of schooling are facing increasingly sophisticated literacy demands of new technologies that go well beyond that of the traditional printed page as they interact with information communicated through a range of digital media both inside and outside of school. At best new technologies can open doors to students for researching and accessing a world far beyond their own environment, empowering them to direct and control their own learning and produce quality work.

Information warfare : corporate attack and defence in a digital world

This text introduces the concepts of information warfare from a non-military, organizational perspective. It is designed to stimulate managers to develop policies, strategies, and tactics for the aggressive use and defence of their data and knowledge base. The book covers the full gambit of information warfare subjects from the direct attack on computer systems to the more subtle psychological technique of perception management. It provides the framework needed to build management strategies in this area. The topics covered include the basics of information warfare, corporate intelligence systems, the use of deception, security of systems, modes of attack, a methodology to develop defensive measures, plus specific issues associated with information warfare.

Ethical considerations and guidelines in web analytics and digital marketing : a retail case study

Within the information economy customers utilise the media that interests them, view the news that affects them and read about the people that inspire them. Web analytics enables an organisation to collect customers' data as they interact with an organisation. Then with analysis of the captured data, organisations can offer a unique online experience, tailored to the customer's individual preferences and create direct marketing campaigns that target individual consumers. This paper discusses the ethical considerations of collecting customer data and highlights how ethical guidelines can better inform organisational behaviour.

Digital natives? : new and old media and children’s language acquisition

The current generation of young children has been described as “digital natives”, having been born into a ubiquitous digital media environment. They are envisaged as educationally independent of the guided interaction provided by “digital immigrants”: parents and teachers. This paper uses data from the multiples waves of the Longitudinal Study of Australian Children (LSAC) to study the effect of various media on children’s development of vocabulary and traditional literacy. Previous research has suggested that time spent watching television is associated with less time spent reading, and ultimately, with inferior educational outcomes. The early studies of the “new” digital media (computers, games consoles, mobile phones, the Internet, etc.) assumed these devices would have similar effects on literacy outcomes to those associated with television. Moreover, these earlier studies relied on poorer measures of time spent in media use and usually did not control for the context of the child’s media use. Fortunately, LSAC contains measures of access to digital devices; parental mediation practices; the child’s use of digital devices as recorded in time use diaries; direct measures of the child’s passive vocabulary; and teachers’ ratings of the child’s literacy. The analysis presented shows the importance of the parental context framing the child’s media use in promoting the acquisition of vocabulary, and suggests that computer (but not games) use is associated with more developed language skills. Independently of these factors, raw exposure to television is not harmful to learning, as previously thought.

Hydrograph separation and development of empirical relationships using single-parameter digital filters

A reliable hydrograph separation method is necessary for surface runoff modeling and hydrological studies. This paper investigates and compares the separation characteristics of two single-parameter digital filters, which are herein referred to as the one-parameter algorithm and the conceptual method. The application of the one-parameter algorithm was found to be restricted to low and medium baseflow separations, with a maximum separation limit of 50% of the total runoff hydrograph. The one-parameter algorithm was also observed to produce unrealistic sharp peaks under the peaks of the measured hydrograph when recession constant is smaller than 0.96. On the other hand, the conceptual method is applicable even for catchments fed largely by groundwater discharge. However, a reliable estimation of recession constant is a prerequisite for applying the conceptual method for large baseflow separations. Based on the hydrograph separation results, useful empirical relationships were developed for a partially urbanized watershed to estimate total runoff and direct runoff from the measured rainfall depth. The relationships between rainfall depth and total runoff depth and rainfall depth and direct runoff depth were found to be well represented by linear equations. The empirical relationships were then applied to estimate the long-term contribution of baseflow and surface runoff to total runoff at the study site. Baseflow was found to contribute about 58–61% of the annual total runoff.

Generation of total runoff hydrographs using a method derived from a digital filter algorithm

A reliable prediction of the total runoff hydrograph is necessary for water resources management. This study investigates two approaches to generate total runoff hydrograph by adding baseflow to direct runoff hydrographs. The first approach uses a method, derived from a digital filter algorithm for hydrograph separation, to generate baseflow hydrographs from direct runoff hydrographs. The method appears to perform well in producing the overall shape of the total runoff hydrographs and the acceptable mass balance errors for a year of water cycle. For application, the recession baseflow constant needs to be estimated reliably and the initial baseflow could be approximated to the long-term mean dry weather flow. The second approach assumes a constant baseflow rate. Although this approach is still capable of producing the overall hydrograph shape, it yields high mass balance errors in the total runoff hydrographs for both monthly and long-term periods. Further analysis shows that two-third of the mass balance errors are contributed from periods with direct runoff, implying that the constant baseflow assumption could introduce significant errors into the computations of total runoff hydrograph

Digital library service quality assessment model

With the introduction of digital library services, the quality of service (QoS) has become paramount importance for evaluating the performance of the digital library service provisioning. Various models and frameworks have been proposed to evaluate digital library QoS. However, the prevalent research concentration in QoS for digital library is on the dimensions of the perspective of users’ perception. In this paper, we address the same research problem from a different dimension which is from the perspective of the digital service providers. To this end, we propose a new model suitable for evaluating the performance of digital library services. We argue that the level of QoS provided by the digital service providers have direct impact on the perception and satisfaction of the digital service end-users.