A scalable multi-core architecture with heterogeneous memory structures for Dynamic Neuromorphic Asynchronous Processors (DYNAPs)

Neuromorphic computing systems comprise networks of neurons that use asynchronous events for both computation and communication. This type of representation offers several advantages in terms of bandwidth and power consumption in neuromorphic electronic systems. However, managing the traffic of asynchronous events in large scale systems is a daunting task, both in terms of circuit complexity and memory requirements. Here we present a novel routing methodology that employs both hierarchical and mesh routing strategies and combines heterogeneous memory structures for minimizing both memory requirements and latency, while maximizing programming flexibility to support a wide range of event-based neural network architectures, through parameter configuration. We validated the proposed scheme in a prototype multi-core neuromorphic processor chip that employs hybrid analog/digital circuits for emulating synapse and neuron dynamics together with asynchronous digital circuits for managing the address-event traffic. We present a theoretical analysis of the proposed connectivity scheme, describe the methods and circuits used to implement such scheme, and characterize the prototype chip. Finally, we demonstrate the use of the neuromorphic processor with a convolutional neural network for the real-time classification of visual symbols being flashed to a dynamic vision sensor (DVS) at high speed.Comment: 17 pages, 14 figure

Use and perceptions of second life by distance learners: comparison with other communication media

Research has demonstrated that the use of communication media in distance education can reduce the feeling of distance and isolation from peers and tutor, and provide opportunities for collaborative learning activities (Bates, 2005). The use of virtual worlds (VW) in education has increased in recent years, with Second Life (SL) being the most commonly used VW in higher education (Wang & Burton, 2012). There is a paucity of information available on students’ use and perceptions of SL in relation to other online communication media available to the distance learner. Consequently, in the study described here, this area was explored with a group of students registered in a part-time distance education Master’s program at a large UK University open to international students. A self-completion survey was designed to assess students’ use and perceptions of using SL compared with other communication media. The majority of students rated SL lower than other forms of communications media such as email, WebCT discussion boards, Skype, and Wimba for facilitating communication, promoting the formation of social networks, fostering a sense of community, and benefiting their learning.  It is possible that the results of this study were influenced by the lower frequency of use of SL in this program compared to other work reported on this subject. Further work is required to evaluate the effect of frequency of use of SL and availability of alternative communication media on students’ use and perceptions of this virtual world

Using asynchronous discussion tools in engineering education

This paper considers a number of uses of asynchronous discussion in engineering education, highlighting the benefits to learners and the issues which need to be considered. The main context is the use of computer conferencing by distance learners of technology at the UK Open University. The paper focuses on two courses where computer conferencing has been used in different ways: for optional peer support; and for assessed group activities. A number of questions about the use of asynchronous discussion are considered in the light of experience from these two contexts. The paper also indicates where more research is needed, considers how this research might be carried out, and discusses the difficulties involved

Lyceum: internet voice groupware for distance learning

This paper describes the design, implementation and deployment of Lyceum, a groupware system providing students and tutors with real time voice conferencing and visual workspace tools, over the standard internet. Lyceum uses a Java client/server architecture to tackle a formidable set of networking requirements: multi-way voice communication with synchronous shared displays, scalable to hundreds of simultaneous users, running over normal modem connections via unknown internet service providers, on home PCs. Additionally, the design had to support multiple courses with different requirements. We describe the interdisciplinary requirements analysis, and iterative design process, by which an academic course team was able to specify and evaluate prototypes. We present the systemís architecture, describe the technical successes and failures from Lyceumís first large scale deployment, and summarise its affordances for interaction and learning

What did the Romans ever do for us? ‘Next generation’ networks and hybrid learning resources

Networked learning is fundamentally concerned with the use of information and communication technologies (ICT) to link people to people and resources, to support the process of learning. This paper explores some current and forthcoming changes in ICT and some potential implications of these developments for networked learning. Whilst we aim to avoid taking a technologically determinist stance, we explore the potential for future practice and how some educational and pedagogic practices are evolving to exploit and shape the digital environment. We argue that we can change both the ways in which connections between people (learners and other learners; learners and tutors) are made and the nature of the resources that learning communities (particularly distributed communities) can engage with. In doing this we draw on two strands of work. Firstly, we draw on the ‘IBZL Education’ a UK Open University initiative to develop new scholarship in the context of STEM (Science, Technology, Engineering and Mathematics) through which educators are encouraged to think about technological change in the next five to ten years and ways in which we can intervene and shape these developments. We use problem-based learning as an example of a learning experience that can be difficult to implement in a networked learning environment. IBZL identified two broad strands of significant technological development. 'Superfast' broadband networks that are capable of supporting novel applications are being rolled in the UK (and elsewhere). Also, boundaries between the real and virtual worlds are becoming blurred as in the ‘internet of things’ where, for example, RFID tags enable information about the real world to be brought into the virtual one. We use the term ‘artefact’ to describe designed components, whether entirely digital, such as a computer forum, or material, such as a tablet PC. Networked ‘hybrid’ technologies of virtual and material components have may great potential for use in education. Secondly, we illustrate how these changes may be beginning to happen in distance education using the example of TU100 My Digital Life, a new introductory Open University. . TU100 Students use an electronics board in their own homes to work on a programming problem in collaboration other students through a tutor-led tutorial in a web conferencing system. We also note some of the evident complexity that establishing such resources as part of wider infrastructures of networked learning would be likely to involve

Virtual pedagogical model: development scenarios

info:eu-repo/semantics/publishedVersio

Middleware’s message : the financial technics of codata

In this paper, I will argue for the relevance of certain distinctive features of messaging systems, namely those in which data (a) can be sent and received asynchronously, (b) can be sent to multiple simultaneous recipients and (c) is received as a “potentially infinite” flow of unpredictable events. I will describe the social technology of the stock ticker, a telegraphic device introduced at the New York Stock Exchange in the 1860s, with reference to early twentieth century philosophers of synchronous experience (Bergson), simultaneous sign interpretations (Mead and Peirce), and flows of discrete events (Bachelard). Then, I will show how the ticker’s data flows developed into the 1990s-era technologies of message queues and message brokers, which distinguished themselves through their asynchronous implementation of ticker-like message feeds sent between otherwise incompatible computers and terminals. These latter systems’ characteristic “publish/subscribe” communication pattern was one in which conceptually centralized (if logically distributed) flows of messages would be “published,” and for which “subscribers” would be spontaneously notified when events of interest occurred. This paradigm—common to the so-called “message-oriented middleware” systems of the late 1990s—would re-emerge in different asynchronous distributed system contexts over the following decades, from “push media” to Twitter to the Internet of Things

Analytical Bit Error Rate Performance of DS-CDMA Ad Hoc Networks using Large Area Synchronous Spreading Sequences

The performance of large area synchronous (LAS) direct sequence code division multiple access (DS-CDMA) assisted ad hoc networks is investigated in the context of a single-hop infinite mesh of rectilinearly located ad hoc nodes. It is shown that LAS DS-CDMA exhibits a significantly better performance than the family of traditional spreading sequences used in a quasisynchronous DS-CDMA scenario having a low number of resolvable multipath components and a sufficiently high number of RAKE receiver branches. The benefits of LAS codes in ad hoc networks are multifold: (i) Their performance is noise-limited, rather than interference-limited, provided that the multipath and multi-user interference arrives within their interference free window. (ii) Under the same conditions LAS codes are robust against the ‘near–far’ effects imposed by ad hoc networks operating without base-station-aided power control, without accurate synchronisation and without implementationally complex interference cancellers

Analytical BER Performance of DS-CDMA Ad Hoc Networks using Large Area Synchronized Spreading Codes

The family of operational CDMA systems is interference-limited owing to the Inter Symbol Interference (ISI) and the Multiple Access Interference (MAI) encountered. They are interference-limited, because the orthogonality of the spreading codes is typically destroyed by the frequency-selective fading channel and hence complex multiuser detectors have to be used for mitigating these impairments. By contrast, the family of Large Area Synchronous (LAS) codes exhibits an Interference Free Window (IFW), which renders them attractive for employment in cost-efficient quasi-synchronous ad hoc networks dispensing with power control. In this contribution we investigate the performance of LAS DS-CDMA assisted ad hoc networks in the context of a simple infinite mesh of rectilinear node topology and benchmark it against classic DS-CDMA using both random spreading sequences as well as Walsh-Hadamard and Orthogonal Gold codes. It is demonstrated that LAS DS-CDMA exhibits a significantly better performance than the family of classic DS-CDMA systems operating in a quasi-synchronous scenario associated with a high node density, a low number of resolvable paths and a sufficiently high number of RAKE receiver branches