Engineering Commons^™

Optimisation Of Multicast Routing In Wireless Mesh Networks, Brian Keegan, Karol Kowalik, Mark Davis

Conference papers

In recent years Wireless Mesh Networks have been deployed and grown in popularity in many metropolitan areas. The deployment of such networks has allowed clients to gain access to publicly available broadband networks. The implementation of wireless mesh networks requires that backhaul services (traditionally carried by wired networks) be maintained via wireless mesh points. Because of their structure, wireless mesh networks provide an excellent means for targeting a large group of end users or simply to relay data. This may be achieved by means of broadcasting or more specifically multicasting. The lack of standards and support for multicasting over wireless …

Investigation Of Across-Layer Modification To The Dsr Routing Protocol In Wireless Mesh Networks, Mustafa Ramadhan, Mark Davis

Conference papers

This work introduces a cross-layer modification to the DSR protocol that increases the global throughput in wireless mesh networks. In our modified DSR protocol we have introduced the Access Efficiency metric as an alternative to the hop-count metric in order to improve the route selection mechanism. The selected path in the route selection mechanism is identified by choosing the path with the highest minimum Access Efficiency value. We have employed the OPNET modeller as a simulator to examine two different patterns of traffic for a series of randomly generated network topologies. Each topology was simulated twice. One simulation used the …

Effects Of Lline Rate On Vvideo Qos Over Wireless Networks: An Experimental Approach, Stuart Wallace, Mark Davis

Conference papers

Video streaming over Wireless Local Area Networks (WLANS) is becoming an increasingly popular service. However, end user OoS is highly influenced by many factors. These include the video codec used, the packetization scheme, error concealment and correction techniques, the complexity of the video, propagation losses, and the line rate. In this paper the effect of the line rate on the capacity of the network when streaming multimedia content is analyzed experimentally. It is shown that as the line rate decreases the bandwidth load of the video stream dramatically increases leading to poor QoS at the client side. As automatic line …

An Investigation Of The Correlation Between Passive Monitoring And Activie Probing Techniques Used In Wlan Mesh Networks, Chenzhe Zhang, Mark Davis

Conference papers

In recent years, Wireless Mesh Networks (WMNs) have emerged as a promising solution to provide low cost networks that extend Internet access and other networking services. Mesh routers form the backbone connectivity through cooperative routing in an often unstable wireless medium. Therefore, the techniques used to monitor and manage the performance metrics to help optimize the link performance in WMNs. This paper presents an assessment of the correlation between passive monitoring and active probing techniques used for link performance measurement in WMNs. This paper presents an assessment of the correlation between passive monitoring and active probing techniques used for link …

Control Of Double Fed Induction Generator Wind Turbine During Network Voltage Unbalance Conditions, Joseph Kearney, Michael Conlon

Conference papers

The behaviour of Double-Fed Induction Generators to supply network voltage unbalance is investigated. The paper describes a method to control the rotor-side converter in a DFIG when subjected to the effects of network voltage unbalance conditions. A parallel control scheme is implemented to control the positive and negative sequence components independently. A DFIG model is implemented in Matlab/Simulink and simulations show the reduction in power and torque oscillations and a reduction in the high unbalanced currents generated as a result of the applied voltage unbalance.

Barriers To Innovation In Public-Private Partnership (Ppp), Louis Gunnigan, David Eaton

Conference papers

This paper sets out to identify barriers to greater use of innovation in PPP projects. Using a series of in-depth interviews with participants on two closely related PPP projects, data were gathered and analysed to compare the success of the projects in relation to innovation. The views of the participants relating to the approach to innovation were recorded and were examined relative to the views on innovation expressed in published documentation relating to these projects. The research showed that two different types of innovation could be identified – namely cost reducing innovation and product enhancing innovation. It also showed that, …

The Role Of 3pls Internet Technology In Supporting Extended Enterprise: An Exploratory Survey, Pietro Evangelista, Emilio Esposito, Edward Sweeney, Erica Staller

Conference papers

It is well accepted that ICT and Internet technology have the potential to facilitate firms’ innovation processes as it offers new and more effective support to conduct business operations. This is particularly true in the context of Extended Enterprise (EE) concept where new technologies are critical in ensuring the effective integration of physical and information flows among participating companies (Dresner et al., 1999). The role of third party logistics providers (3PLs) in logistics outsourcing has evolved along the last few years (McKinnon, 1999). Such companies are transforming their business configuration from simple transport service providers to supply chain integrators. Internet …

The Role Of Micro Wind Generation In Ireland’S Energy Future, Keith Sunderland, Michael Conlon

Conference papers

This paper defines the current position for micro-generation, with particular reference to the potential for micro-wind units, in the Irish electricity supply system. A network model is developed using the Distflow method of load flow analysis and is applied to consider the appropriate level of micro-generation penetration.

An Evaluation Of A Conservative Transmit Power Control Mechanism On An Indoor 802.11 Wireless Mesh Testbed, Karol Kowalik, Marek Bykowski, Brian Keegan, Mark Davis

Conference papers

Power control techniques for IEEE 802.11 wireless networks have already gained considerable attention. Such techniques are particularly attractive because they can improve various aspects of wireless network operation such as interference mitigation, spatial reuse in dense wireless deployments, topology control, and link quality enhancement. In this paper we propose a novel delivery ration based Conservative Transmit Power Control (ConTPC) mechanism. Our implementation is conservative when it comes to deciding if the transmit power should be reduced for a given link. This is because we do not want poor quality wireless links to further reduce their quality and be overwhelmed by …

A Vowel-Stress Emotional Speech Analysis Method, Charlie Cullen, Brian Vaughan, Spyros Kousidis

Conference papers

The analysis of speech, particularly for emotional content, is an open area of current research. This paper documents the development of a vowel-stress analysis framework for emotional speech, which is intended to provide suitable assessment of the assets obtained in terms of their prosodic attributes. The consideration of different levels of vowel-stress provides means by which the salient points of a signal may be analysed in terms of their overall priority to the listener. The prosodic attributes of these events can thus be assessed in terms of their overall significance, in an effort to provide a means of categorising the …

Practical Issues Of Power Control In Ieee 802.11 Wireless Devices, Karol Kowalik, Marek Bykowski, Brian Keegan, Mark Davis

Conference papers

Power control techniques for IEEE 802.11 wireless networks have already gained much attention. Such techniques are particularly attractive because they can improve various aspects of wireless network operations such as interference mitigation, spatial reuse in dense wireless deployments, topology control, and link quality enhancement. However, until recently implementing such advanced power control using off-the-shelf wireless devices was not considered possible. For example, Abdesslem et al. [1] stated that “many novel power control solutions cannot be efficiently implemented over existing IEEE 802.11 cards”. However, in this paper we demonstrate that power control is now feasible and can be implemented in current …

A Real-Time Framework For Video Time And Pitch Scale Modification, Ivan Damnjanovic, Dan Barry, David Dorran, Josh Reiss

Conference papers

A framework is presented which addresses the issues related to the real-time implementation of synchronised video and audio time-scale and pitch-scale modification algorithms. It allows for seamless real-time transition between continually varying, independent time-scale and pitch-scale parameters arising as a result of manual or automatic intervention. We illuminate the problems which arise in a real-time context as well as provide novel solutions to prevent artefacts, minimise latency, and improve synchronisation. The time and pitch scaling approach is based on a modified phase vocoder with optional phase locking and an integrated transient detector which enables high quality transient preservation in real-time. …

Emotional Speech Corpus Construction, Annotation And Distribution, Brian Vaughan, Charlie Cullen, Spyros Kousidis, John Mcauley

Conference papers

This paper details a process of creating an emotional speech corpus by collecting natural emotional speech assets, analysisng and tagging them (for certain acoustic and linguistic features) and annotating them within an on-line database. The definition of specific metadata for use with an emotional speech corpus is crucial, in that poorly (or inaccurately) annotated assets are of little use in analysis. This problem is compounded by the lack of standardisation for speech corpora, particularly in relation to emotion content. The ISLE Metadata Initiative (IMDI) is the only cohesive attempt at corpus metadata standardisation performed thus far. Although not a comprehensive …

An Integrated Approach To The Teaching Of Numerical Methods To Engineering Students, Garrett Keane, Michael Carr, Patrick Carroll

Conference papers

In Technological University Dublin, historically, numerical methods were taught to engineering students using a format of traditional mathematics lectures, to a large class group consisting of students from five different engineering disciplines, complemented by small class tutorials. Assessment was by a single, written exam only.

In order to improve the overall effectiveness of the students’ learning experience, it was deemed beneficial to also introduce practical computing classes in which the students would be required to apply the general mathematical methods covered in lectures to discipline-specific examples.

Three different practical computing assignments were devised for the students to undertake, and 20% …

Changing Training Needs Arising From The Introduction Of Off-Site Construction Techniques, Louis Gunnigan, John Mcdonagh

Conference papers

The objective of this paper is to examine the changes in training needs arising from the increase of off-site construction in the Republic of Ireland. The methodology employed was a case study using a participant observation research technique. For a period of three weeks, the researcher observed the construction of residential housing, constructed using off-site techniques. From the practices observed and from interviews with the operatives on-site, an account of the differences in skills required between those employed in traditional construction and off-site construction was compiled. Each of the different trades involved in traditional construction was addressed and a comprehensive …

Implementing Ecommerce In The Irish Construction Industry, Alan V. Hore, Roger West

Conference papers

The current methods of ordering, delivering and invoicing of materials in the construction in-dustry is enormously inefficient, with vast quantities of paperwork, duplication of effort, scanning, re-keying and resolving mismatches between invoices, delivery dockets and purchase orders. The objective of this pa-per is to set out the progress that is being made by the Construction IT Alliance (CITA) in Ireland to support the implementation of eCommerce in the Irish construction industry. The authors will present the result of a pilot project in 2006 which demonstrated that the technology necessary for implementing an electronic supply chain exists and could be deployed …

Emotional Speech Corpora For Analysis And Media Production, Charlie Cullen, Brian Vaughan, Spyros Kousidis

Conference papers

Research into the acoustic correlates of emotional speech as part of the SALERO project has led to the construction of high quality emotional speech corpora, which contain both IMDI metadata and acoustic analysis data for each asset. Research into semi-automated, re-usable character animation has considered the development of online workflows based on speech corpus assets that would provide a single point of origin for character animation in media production. In this paper, a brief description of the corpus design and construction is given. Further, a prototype workflow for semi-automated emotional character animation is also provided, alongside a description of current …

Linear Prediction: The Problem, Its Solution And Application To Speech, Alan O'Cinneide, David Dorran, Mikel Gainza

Conference papers

Linear prediction is a signal processing technique that is used extensively in the analysis of speech signals and, as it is so heavily referred to in speech processing literature, a certain level of familiarity with the topic is typically required by all speech processing engineers. This paper aims to provide a well-rounded introduction to linear prediction, and so doing, facilitate the understanding of the technique. Linear prediction and its mathematical derivation will be described, with a specific focus on applying the technique to speech signals. It is noted, however, that although progress in linear prediction has been driven primarily by …

Proposal For A Construction Industry Digital Competency Centre For Ireland, Alan V. Hore

Conference papers

The Irish construction industry is facing a series of fundamental challenges that is affecting every player in the AEC lifecycle from architects to owners to tenants. Despite technology advances in recent years, the Irish construction industry lags behind other industries in respect to Information Communications Technology (ICT) investments. Despite a pressing need for innovation, procurement and tendering procedures in Ireland largely discourages new ideas and puts further pressure on wafer-thin margins that characterise the construction sector. This paper will reflect on the deliverables of the Construction Information Technology Alliance (CITA) in Ireland, which was formed in partnership between the Technological …

Implications Of Future Heavier Trucks For Europe's Bridges, Colin C. Caprani, Bernard Enright, Eugene O'Brien

Conference papers

European road freight transport has increased by 38% between 1995 and 2005 and this strong growth trajectory seems likely to continue into the future. To address this growth without compromising the competitativeness of European transport, some countries are contemplating the introduction of longer and heavier trucks, with up to 8 axles and gross weights of up to 60 t. This has the advantage of reducing the number of vehicles for a given volume or mass of freights, reducing labour, fuel and other costs. However, many roads authorities are concerned about the implications for Europe's bridge infrastructure. For bridge loading, it …

Linguatag: An Emotional Speech Analysis Application, Charlie Cullen, Brian Vaughan, Spyros Kousidis

Conference papers

The analysis of speech, particularly for emotional content, is an open area of current research. Ongoing work has developed an emotional speech corpus for analysis, and defined a vowel stress method by which this analysis may be performed. This paper documents the development of LinguaTag, an open source speech analysis software application which implements this vowel stress emotional speech analysis method developed as part of research into the acoustic and linguistic correlates of emotional speech. The analysis output is contained within a file format combining SMIL and SSML markup tags, to facilitate search and retrieval methods within an emotional speech …

Metadata Visualisation Techniques For Emotional Speech Corpora, Charlie Cullen, Brian Vaughan, Spyros Kousidis

Conference papers

Our research in emotional speech analysis has led to the construction of dedicated high quality, online corpora of natural emotional speech assets. Once obtained, the annotation and analysis of these assets was necessary in order to develop a database of both analysis data and metadata relating to each speech act. With annotation complete, the means by which this data may be presented to the user online for analysis, retrieval and organization is the current focus of our investigations. Building on an initial web interface developed in Ruby on Rails, we are now working towards a visually driven GUI built on …

Throughput Enhancement Through Combined Fragmentation And Rate Method In Ieee 802.11b Wlans, Marek Bykowski, Karol Kowalik, Brian Keegan, Mark Davis

Conference papers

IEEE 802.11 allows for fragmentation tuning and rate selection. Their combined usage is referred sometimes to link adaptation. However, the algorithms of link adaptation are beyond the 802.11 standards. In this paper we investigate the benefits arising from proper use of link adaptation. Particularly, we develop a mathematical model describing the fragmented transmission in 802.11b. We examine potential benefits of it over AWGN and fading channels. More significantly we combine fragmentation tuning with bit-rate selection to yield the highest achievable throughput performance for any given channel conditions. Finally, we propose an algorithm that performs the optimal link adaptation.

Interaction Of Rf-Hyperthermia Applicator With High Fidelity Human Body Model, Sergio Curto, T.S. P. See, Z. N. Chen, Patrick Mcevoy, Max Ammann

Conference papers

A compact patch antenna working at the 434 MHz ISM frequency band is proposed as an RF-Hyperthermia applicator. The electromagnetic interaction in terms of S11, SAR and E-Field distribution of the antenna with a High Fidelity human body model is investigated. This analysis provides useful information for engineers and clinical staff to develop more efficient and smaller antennas for medical applications, in particular for RF-Hyperthermia cancer therapy, where the size of the antenna determines tumor accessibility.

Rfid: An Ideal Technology For Ubiquitous Computing?, Ciaran O'Driscoll, Daniel Maccormac, Mark Deegan, Fredrick Mtenzi, Brendan O'Shea

Conference papers

This paper presents a review of RFID based approaches used for the development of smart spaces and smart objects. We explore approaches that enable RFID technology to make the transition from the recognized applications such as retail to ubiquitous computing, in which computers and technology fade into the background of day to day life. In this paper we present the case for the use of RFID technology as a key technology of ubiquitous computing due to its ability to embed itself in everday objects and spaces. Frameworks to support the operation of RFID-based smart objects and spaces are discussed and …

Machine Annotation Of Sets Of Traditional Irish Dance Tunes, Bryan Duggan, Mikel Gainza, Padraig Cunningham

Conference papers

A set in traditional Irish music is a sequence of two or more dance tunes in the same time signature, where each tune is repeated an arbitrary number of times. A turn in a set represents the point at which either a tune repeats or a new tune is introduced. Tunes in sets are played in a segue (without a pause) and so detecting the turn is a significant challenge. This paper presents the MATS alogrithm, a novel algorithm for identifying turns in sets of traditional Irish music. MATS works on digitised audio files of monophonic flute and tin-whistle music. …

Violin Timbre Space Features, Jane Charles, Derry Fitzgerald, Eugene Coyle

Conference papers

Signal processing techniques, from which the quality of a violinist's playing can be assessed by a computer are presented in this paper

Time And Pitch Scale Modification: A Real-Time Framework And Tutorial, Dan Barry, David Dorran, Eugene Coyle

Conference papers

A framework is presented which is designed to address the issues related to the real-time implementation of time-scale and pitch scale modification algorithms. This framework can be used as the basis for the developments of applications which allow for a seamless real-time transition between continually varying time scale and pitch-scale parameters which arise as a result of manual or automatic intervention.

Pitch Tracking And Voiced/Unvoiced Detection In Noisy Environment Using Optimat Sequence Estimation, Moshe Wasserblat, Mikel Gainza, David Dorran, Yuval Domb

Conference papers

This paper addresses the problem of pitch tracking and voiced/unvoiced detection in noisy speech environments. An algorithm is presented which uses a number of variable thresholds to track pitch contour with minimal error. This is achieved by modeling the pitch tracking problem in such a way that allows the use of optimal estimation methods, such MLSE. The performance of the algorithm is evaluated using the Keele pitch detection database with realistic background noise. Results show best performance in comparison to other state of the art pitch detector and successful pitch tracking is possible in low signal to noise conditions.

Structural Segmentation Using Set Accented Tones, Cillian Kelly, Mikel Gainza, David Dorran, Eugene Coyle

Conference papers

An approach which efficiently segments Irish Traditional Music into its constituent structural segments is presented. The complexity of the segmentation process is greatly increased due to melodic variation existent within this music type. In order to deal with these variations, a novel method using ‘set accented tones’ is introduced. The premise is that these tones are less susceptible to variation than all other tones. Thus, the location of the accented tones is estimated and pitch information is extracted at these specific locations. Following this, a vector containing the pitch values is used to extract similar patterns using heuristics specific to …