Remote fieldwork: using portable wireless networks and backhaul links to participate remotely in fieldwork

Fieldwork is an important means of contextualising knowledge and developing subject-specific and generic transferable skills. However, field locations are not always accessible. To address this problem we present a remote fieldwork approach that makes use of a portable wireless network and other mobile technologies to support fieldwork at a distance. As well as improving access to fieldwork, this approach can also be used to provide communication tools to fieldworkers, enabling them to share their findings and talk to their colleagues while in the field. This paper presents the portable communications toolkit we have developed and reports on three recent trials

Performance evaluation of an open distributed platform for realistic traffic generation

Network researchers have dedicated a notable part of their efforts to the area of modeling traffic and to the implementation of efficient traffic generators. We feel that there is a strong demand for traffic generators capable to reproduce realistic traffic patterns according to theoretical models and at the same time with high performance. This work presents an open distributed platform for traffic generation that we called distributed internet traffic generator (D-ITG), capable of producing traffic (network, transport and application layer) at packet level and of accurately replicating appropriate stochastic processes for both inter departure time (IDT) and packet size (PS) random variables. We implemented two different versions of our distributed generator. In the first one, a log server is in charge of recording the information transmitted by senders and receivers and these communications are based either on TCP or UDP. In the other one, senders and receivers make use of the MPI library. In this work a complete performance comparison among the centralized version and the two distributed versions of D-ITG is presented

Speaker Recognition in the VoIP Environment

Tato práce popisuje použití systémů pro rozpoznávání mluvčího v~prostředí VoIP, úspěšnost systému a přístupy k jejímu zlepšení. Popisuje architekturu těchto systémů, metriky pro vyhodnocení jejich úspěšnosti a klíčové komponenty VoIP z hlediska rozpoznávání mluvčího. Je zde popsáno vytvoření simulace VoIP prostředí, úspěšnost systému je vyhodnocena na datech pocházejících z různých druhů VoIP prostředí a výsledky jsou demostrovány. Adaptace a kalibrace systému je provedena a jejich přínosy zhodnoceny.This work describes using speaker recognition systems in the VoIP environment, system performance and approaches to improving it. System architecture, evaluation metrics and VoIP technology key components from the view of speaker recognition are described. VoIP environment simulation is described. Speaker recognition system's performance is evaluated on data sets from various kinds of VoIP environments and the results are demonstrated. System adaptation and calibration is performed and their benefits are discussed.

Renewable power for lean desktops in media applications

An integration of solar microgeneration to supply a low-power IT desktop, using the Power over Ethernet standards IEEE 802.3af/at as a low power distribution network avoiding transformer losses from DC generation to mains power AC and back to low-voltage DC and hence maximising efficiency. The resulting design points to applications in media technology where reducing grid power consumption is critical for improving sustainability, or where there are supply constraints, and indicates new directions in how we manage and consume power for IT devices

Should Australian courts give more witnesses the right to Skype?

Millions of people use Skype, a common form of social media that permitspeople to talk to each other over the internet. Courts in Australia havepermitted witnesses in at least a few instances to testify by Skype to date. Thisarticle examines whether Australian courts should permit witnesses to testifyby Skype more often. The article considers using videoconferencing, asopposed to Skype, and security issues associated with Skype. It alsoconsiders the impact that Skype may have upon considering witness credibility.Ultimately, it argues that Australian judicial officers may want to considerpermitting witnesses to testify by Skype if testifying by videoconference is notpossible, on a case by case basis. The authors believe that this is the firstscholarly article in Australia to focus on the issue of witnesses testifying bySkype

Emerging technologies for learning (volume 1)

Collection of 5 articles on emerging technologies and trend

Quality of service and availability in a full mesh WAN using IP/MPLS : Case study: the network at the Department of Justice in Argentina

At the Argentine Department of Justice (Ministerio Público Fiscal de la República Argentina), a project is developed to set up a WAN with national coverage, quality of service, and IP/MPLS/VPN links. The project focuses on quality of service, a direct result from the selected technology. In previous work, studies explored these issues. Hence, the project enabled the implementation of the examined theory. The advantages of MPLS technology are evaluated to determine quality standards in VoIP, videoconference, mission critical appli-cations, e-mail, web access, and others. Other aspects of LANs are analyzed to obtain an availability level compatible to the required needs. The Project in-clude practical recommendations to adequate the LAN to the desired availability levels.IV Workshop Arquitectura, Redes y Sistemas Operativos (WARSO)Red de Universidades con Carreras en Informática (RedUNCI

Subjective Audio Quality over a Secure IEEE 802.11n Draft 2.0 Wireless Local Area Network

This thesis investigates the quality of audio generated by a G.711 codec and transmission over an IEEE 802.11n draft 2.0 wireless local area network (WLAN). Decline in audio quality due to additional calls or by securing the WLAN with transport mode Internet Protocol Security (IPsec) is quantified. Audio quality over an IEEE 802.11n draft 2.0 WLAN is also compared to that of IEEE 802.11b and IEEE 802.11g WLANs under the same conditions. Audio quality is evaluated by following International Telecommunication Union Telecommunication Standardization Sector (ITU-T) Recommendation P.800, where human subjects rate audio clips recorded during various WLAN configurations. The Mean Opinion Score (MOS) is calculated as the average audio quality score given for each WLAN configuration. An 85% confidence interval is calculated for each MOS. Results suggest that audio quality over an IEEE 802.11n draft 2.0 WLAN is not higher than over an IEEE 802.11b WLAN when up to 10 simultaneous G.711 calls occur. A linear regression of the subjective scores also suggest that an IEEE 802.11n draft 2.0 WLAN can sustain an MOS greater than 3.0 (fair quality) for up to 75 simultaneous G.711 calls secured with WPA2, or up to 40 calls secured with both WPA2 and transport mode IPsec. The data strongly suggest that toll quality audio (MOS ≥ 4.0) is not currently practical over IEEE 802.11 WLANs secured with WPA2, even with the G.711 codec