Predictive Current Control of Doubly Fed Induction Generators

This paper presents a predictive current control strategy for doubly-fed induction generators (DFIG). The method predicts the DFIG’s rotor current variations in the synchronous reference frame fixed to the stator flux within a fixed sampling period. This is then used to directly calculate the required rotor voltage to eliminate the current errors at the end of the following sampling period. Space vector modulation is used to generate the required switching pulses within the fixed sampling period. The impact of sampling delay on the accuracy of the sampled rotor current is analyzed and detailed compensation methods are proposed to improve the current control accuracy and system stability. Experimental results for a 1.5 kW DFIG system illustrate the effectiveness and robustness of the proposed control strategy during rotor current steps and rotating speed variation. Tests during negative sequence current injection further demonstrate the excellent dynamic performance of the proposed PCC method.

A Fast Algorithm for Sparse Support Vector Machines for Mobile Computing Applications

This research presents a fast algorithm for projected support vector machines (PSVM) by selecting a basis vector set (BVS) for the kernel-induced feature space, the training points are projected onto the subspace spanned by the selected BVS. A standard linear support vector machine (SVM) is then produced in the subspace with the projected training points. As the dimension of the subspace is determined by the size of the selected basis vector set, the size of the produced SVM expansion can be specified. A two-stage algorithm is derived which selects and refines the basis vector set achieving a locally optimal model. The model expansion coefficients and bias are updated recursively for increase and decrease in the basis set and support vector set. The condition for a point to be classed as outside the current basis vector and selected as a new basis vector is derived and embedded in the recursive procedure. This guarantees the linear independence of the produced basis set. The proposed algorithm is tested and compared with an existing sparse primal SVM (SpSVM) and a standard SVM (LibSVM) on seven public benchmark classification problems. Our new algorithm is designed for use in the application area of human activity recognition using smart devices and embedded sensors where their sometimes limited memory and processing resources must be exploited to the full and the more robust and accurate the classification the more satisfied the user. Experimental results demonstrate the effectiveness and efficiency of the proposed algorithm. This work builds upon a previously published algorithm specifically created for activity recognition within mobile applications for the EU Haptimap project [1]. The algorithms detailed in this paper are more memory and resource efficient making them suitable for use with bigger data sets and more easily trained SVMs.

Inverse Class-E Amplifier With Transmission-Line Harmonic Suppression

This paper reports on the design methodology and experimental characterization of the inverse Class-E power amplifier. A demonstration amplifier with excellent second and third harmonic-suppression levels has been designed, constructed, and measured. The circuit fabricated using a 1.2-min gate-width GaAs MESFET is shown to be able to deliver 22-dBm output power at 2.3 GHz. The amplifier achieves a peak power-added efficiency of 64 % and drain efficiency of 69 %, and exhibits 11.6 dB power gain when operated from a 3-V supply voltage. Comparisons of simulated and measured results are given with good agreement between them being obtained. Experimental results are presented for the amplifier's response to Gaussian minimum shift keying modulation, where a peak error vector modulation value of 0.6% is measured.

Waterfront retrieved. Buenos Aires’ contrasting leisure experience

The southern waterfront of the city of Buenos Aires has been recovered. Now that more than 20 years have passed since the projects began, we are able to get some perspective on these developments and can confront them with the integral history of this area. The areas of Puerto Madero, Costanera Sur, Reserva Ecológica and Santa María del Plata have distinctive characteristics and these are reflected in urban landscape, architecture and especially through the use of these spaces. Real estate developments cohabit with public space, tourism with local leisure facilities, and the most expensive office floors with local choripan1 stands, all of these in a development in which the state, the municipality, international corporations and real estate companies have collaborated and discussed to produce a hybrid new space for the city.

Church of St George and St Thomas

Abstract: A vibrant inner city parish needed space for meetings, language classes, children’s play and other support accommodation as well as a clearer link between the interior of the listed church and the space outside.

The project builds itself about the entrance to the church. The form is manipulated such that the intervention recedes from those entering the church, drawing them into the plan before becoming readable as an addition. The resultant poché between this entrance sequence and the fabric of the church is hollowed out to provide the required accommodation. These rooms are insulated and lined in cork to allow for their use separate to the main body of the church. With budget at a premium the construction methodology was developed from an analysis of traditional Irish boat building techniques, which allowed the use of the solid timber to act as the primary structure with no additional material support.

Constructed in solid walnut the intervention reads with the existing brick interior and yet is clearly identifiable as a contemporary addition.

Aims / Objectives Questions

1 To accommodate new space inside an existing protected structure.
2 To form a new threshold between interior and exterior.
3 To develop an affordable means of construction that would be durable and rapid to erect.
4 To make a contemporary addition in sympathy with the qualities of the existing protect structure, in line with best conservation practice and research.
5 Traditional forms of construction as a model for contemporary technologies.

Allometric analysis of Sitka spruce branches:Mechanical versus hydraulic design principles

The geometry of tree branches can have considerable effect on their efficiency in terms of carbon export per unit carbon investment in structure. The purpose of this study was to evaluate different design criteria using data describing the form of Picea sitchensis branches. Allometric analysis of the data suggests that resources are distributed to favour shoots with the greatest opportunity for extension into new space, with priority to the extension of the leader. The distribution of allometric relations of links (branch elements) was tested against two models: the pipe model, based on hydraulic transport requirements, and a static load model based on the requirement of shoots to provide mechanical resistance to static loads. Static load resistance required the load parameter to be proportional to the link radius raised to the power of 4. This was shown to be true within a 95% statistical confidence limit. The pipe model would require total distal length to be proportional to link radius squared but the measured branches did not conform well to this model. The comparison suggests that the diameters of branch elements were more related to the requirements for mechanical load. The cost of following a hydraulic design principle (the pipe model) in terms of mechanical efficiency was estimated and suggested that the pipe model branch would not be mechanically compromised but would use structural resources inefficiently. Resource allocation among branch elements was found to be consistent with mechanical stability criteria but also indicated the possibility of allocation based on other criteria, such as potential light interception by shoots. The evidence suggests that whilst branch topology increments by reiteration of units of morphogenesis, the geometry follows a functional design pattern.

Additional Accommodation Church of St George and St Thomas

A vibrant inner city parish needed space for meetings, language classes, children’s play and other support accommodation as well as a clearer link between the interior of the listed church and the space outside.

The project builds itself about the entrance to the church. The form is manipulated such that the intervention recedes from those entering the church, drawing them into the plan before becoming readable as an addition. The resultant poché between this entrance sequence and the fabric of the church is hollowed out to provide the required accommodation. These rooms are insulated and lined in cork to allow for their use separate to the main body of the church. With budget at a premium the construction methodology was developed from an analysis of traditional Irish boat building techniques, which allowed the use of the solid timber to act as the primary structure with no additional material support.

Constructed in solid walnut the intervention reads with the existing brick interior and yet is clearly identifiable as a contemporary addition.

Aims / Objectives Questions

1 To accommodate new space inside an existing protected structure.
2 To form a new threshold between interior and exterior.
3 To develop an affordable means of construction that would be durable and rapid to erect.
4 To make a contemporary addition in sympathy with the qualities of the existing protect structure, in line with best conservation practice and research.
5 Traditional forms of construction as a model for contemporary technologies.


Principal Investigator: Clancy Moore Architects –Colm Moore

Co-investigator(s): Andrew Clancy, Mathew O’Malley

Funding partner/ Client: Select Vestry of St George and St Thomas

Finance. €35’000

Date (start – finished) Start June 2008 – Completed December 2008

Documents and Dependencies: an Exploration of Vector Space Models for Semantic Composition

In most previous research on distributional semantics, Vector Space Models (VSMs) of words are built either from topical information (e.g., documents in which a word is present), or from syntactic/semantic types of words (e.g., dependency parse links of a word in sentences), but not both. In this paper, we explore the utility of combining these two representations to build VSM for the task of semantic composition of adjective-noun phrases. Through extensive experiments on benchmark datasets, we find that even though a type-based VSM is effective for semantic composition, it is often outperformed by a VSM built using a combination of topic- and type-based statistics. We also introduce a new evaluation task wherein we predict the composed vector representation of a phrase from the brain activity of a human subject reading that phrase. We exploit a large syntactically parsed corpus of 16 billion tokens to build our VSMs, with vectors for both phrases and words, and make them publicly available.

Vector representation of directional modulation transmitters

Directional Modulation (DM) is a recently proposed technique for securing wireless communication. In this paper we point out that modulation-directionality is a consequence of varying the beamforming network, either in baseband or in the RF stage, at the information rate In order to formalize and extend on previous analysis and synthesis methods a new theoretical treatment using vector representations of directional modulation (DM) systems is introduced and used to obtain the necessary and sufficient con

'Prying open the space for social work in the new millennium: four theoretical perspectives on transformative practice'

Houston S, Skehill C, Pinkerton J & Campbell J (2005) Social Work and Social Sciences Review 12 (1) 35-52.