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Showing papers by "Dublin City University published in 2005"


Book ChapterDOI
04 Dec 2005
TL;DR: A new identity-based signcryption (IBSC) scheme built upon bilinear maps is described that is more efficient than all others proposed so far and also faster than all known pairing-based IBS methods.
Abstract: In this paper we describe a new identity-based signcryption (IBSC) scheme built upon bilinear maps. This scheme turns out to be more efficient than all others proposed so far. We prove its security in a formal model under recently studied computational assumptions and in the random oracle model. As a result of independent interest, we propose a new provably secure identity-based signature (IBS) scheme that is also faster than all known pairing-based IBS methods.

520 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of laser power (1.2-1.43kW), welding speed (30-70 cm/min) and focal point position (−2.5 to 0mm) on the heat input and the weld-bead geometry (i.e. penetration, welded zone width, and heat affected zone width (W HAZ )) was investigated using response surface methodology (RSM).

368 citations


Journal ArticleDOI
TL;DR: Benefits from vibration training may be greater in elite athletes than non-elite athletes and the employment of a greater exercise intensity and volume within a vibration training programme may facilitate a larger enhancement in strength and power.
Abstract: Vibration has been combined with conventional resistance training in an attempt to attain greater gains in neuromuscular performance than from conventional resistance training alone. Although there is a lack of strictly controlled studies on the vibration training effect, current findings in this area suggest that vibration may have a beneficiary acute and/or chronic training effect on strength and power enhancement. However, the effect of vibration on strength and power development appears dependent upon the vibration characteristics (method of application, amplitude and frequency) and exercise protocols (training type, intensity and volume) employed. Vibration amplitude and frequency determine the load that vibration imposes on the neuromuscular system. This vibration load should be in an optimal range to elicit strength and power enhancement. To activate the muscle most effectively, vibration frequency should be in the range of 30-50 Hz. It is less clear to what the optimal amplitude should be, but smaller amplitudes may be insufficient to elicit an enhancement. It should also be noted that the method of vibration application (i.e. vibration applied directly or indirectly to a targeted muscle) may have an influence on the magnitude of amplitude and frequency that are delivered to the muscle and, therefore, may have an influence on vibration training effect. The employment of a greater exercise intensity and volume within a vibration training programme may facilitate a larger enhancement in strength and power. In addition, benefits from vibration training may be greater in elite athletes than non-elite athletes. Further studies are required to examine these inter-dependencies, especially in relation to chronic adaptation to dynamic exercises, which are the most relevant response to practitioners, but where the least amount of research has been undertaken.

333 citations


Journal ArticleDOI
TL;DR: Among the variety of biomimetic recognition schemes utilizing supramolecular approaches molecularly imprinted polymers have proven their potential as synthetic receptors in numerous applications ranging from liquid chromatography to assays and sensor technology as mentioned in this paper.

257 citations


Journal ArticleDOI
TL;DR: The data suggest that the Th2 responses induced by the helminth F. hepatica are mediated through the secretion of molecules, one of which is TPx, that induce the recruitment and alternative activation of macrophages.
Abstract: Alternatively activated macrophages (AAMφ) are primarily associated with the chronic stages of parasitic infections and the development of a polarized Th2 response. We have shown that Fasciola hepatica infection of BALB/c mice induces a polarized Th2 response during both the latent and chronic stage of disease. The activation status of macrophages was analyzed in this model of helminth infection by evaluating the expression of genetic markers of alternative activation, namely, Fizz1, Ym1, and Arg1. AAMφ were recruited to the peritoneum of mice within 24 h of F. hepatica infection and after intraperitoneal injection of parasite excretory-secretory (ES) products. Administration of a recombinant antioxidant thioredoxin peroxidase (TPx), which is contained within the ES products, also induced the recruitment of AAMφ to the peritoneum. In vitro studies showed that this recombinant TPx directly converts RAW 264.7 macrophages to an alternatively activated phenotype characterized by the production of high levels of interleukin-10 (IL-10), prostaglandin E2, corresponding with low levels of IL-12. Our data suggest that the Th2 responses induced by the helminth F. hepatica are mediated through the secretion of molecules, one of which is TPx, that induce the recruitment and alternative activation of macrophages.

255 citations


Journal ArticleDOI
TL;DR: A novel audio-visual feature-based framework for event detection in broadcast video of multiple different field sports and the results suggest that high event retrieval and content rejection statistics are achievable.
Abstract: In this paper, we propose a novel audio-visual feature-based framework for event detection in broadcast video of multiple different field sports. Features indicating significant events are selected and robust detectors built. These features are rooted in characteristics common to all genres of field sports. The evidence gathered by the feature detectors is combined by means of a support vector machine, which infers the occurrence of an event based on a model generated during a training phase. The system is tested generically across multiple genres of field sports including soccer, rugby, hockey, and Gaelic football and the results suggest that high event retrieval and content rejection statistics are achievable.

251 citations


Journal ArticleDOI
TL;DR: The authors examined the perceptions of first-year students as they commence their study of accounting at an Irish university and explored a range of factors which impact on students' learning: their motives for entering higher education, their rationale for selecting an accounting program, their preparedness for further study and their expectations.
Abstract: Framed by the accounting education change debate and growing national concern regarding student attrition, this paper examines the perceptions of first‐year students as they commence their study of accounting at an Irish university. It explores a range of factors which impact on students' learning: their motives for entering higher education, their rationale for selecting an accounting programme, their preparedness for further study and their expectations. The findings offer accounting educators the opportunity to have a greater sensitivity to, and a better understanding of, their students. This will enable better‐informed curriculum, teaching and assessment within the accounting discipline, aiding students' transition to higher education and leading to higher quality learning.

234 citations


Book ChapterDOI
14 Feb 2005
TL;DR: It is described, in detail sufficient for easy implementation, a fast method for calculation of the Tate pairing, as required for pairing-based cryptographic protocols.
Abstract: We describe, in detail sufficient for easy implementation, a fast method for calculation of the Tate pairing, as required for pairing-based cryptographic protocols. We point out various optimisations and tricks, and compare timings of a pairing-based Identity Based Encryption scheme with an optimised RSA implementation.

218 citations


Book ChapterDOI
14 Feb 2005
TL;DR: In this paper, a new two-party identity-based key agreement scheme was proposed, which is inspired by the key pair derivation algorithm first proposed by Sakai and Kasahara.
Abstract: We present a new two-party identity-based key agreement that is more efficient than previously proposed schemes. It is inspired on a new identity-based key pair derivation algorithm first proposed by Sakai and Kasahara. We show how this key agreement can be used in either escrowed or escrowless mode. We also describe conditions under which users of different Key Generation Centres can agree on a shared secret key. We give an overview of existing two-party key agreement protocols, and compare our new scheme with existing ones in terms of computational cost and storage requirements.

217 citations


Journal ArticleDOI
TL;DR: In this article, a two-step vapor phase transport method on sapphire was used to obtain high energy excitonic emission at low temperatures close to the band-edge which was assigned to the surface exciton in ZnO at $\ensuremath{\sim}3.366\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$.
Abstract: We report ZnO nanowire/nanowall growth using a two-step vapor phase transport method on $a$-plane sapphire. X-ray diffraction and scanning electron microscopy data establish that the nanostructures are vertically well aligned with the $c$ axis normal to the substrate and have a very low rocking curve width. Photoluminescence data at low temperatures demonstrate the exceptionally high optical quality of these structures, with intense emission and narrow bound exciton linewidths. We observe a high energy excitonic emission at low temperatures close to the band-edge which we assign to the surface exciton in ZnO at $\ensuremath{\sim}3.366\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$. This assignment is consistent with the large surface to volume ratio of the nanowire systems and indicates that this large ratio has a significant effect on the luminescence even at low temperatures. The band-edge intensity decays rapidly with increasing temperature compared to bulk single crystal material, indicating a strong temperature-activated nonradiative mechanism peculiar to the nanostructures. No evidence is seen of the free exciton emission due to exciton delocalization in the nanostructures with increased temperature, unlike the behavior in bulk material. The use of such nanostructures in room temperature optoelectronic devices appears to be dependent on the control or elimination of such surface effects.

188 citations


Journal ArticleDOI
TL;DR: The working group’s vision for the evolution of digital libraries and the role that personalisation and recommender systems will play are outlined, and a series of research challenges and specific recommendations and research priorities for the field are presented.
Abstract: Widespread use of the Internet has resulted in digital libraries that are increasingly used by diverse communities of users for diverse purposes and in which sharing and collaboration have become important social elements. As such libraries become commonplace, as their contents and services become more varied, and as their patrons become more experienced with computer technology, users will expect more sophisticated services from these libraries. A simple search function, normally an integral part of any digital library, increasingly leads to user frustration as user needs become more complex and as the volume of managed information increases. Proactive digital libraries, where the library evolves from being passive and untailored, are seen as offering great potential for addressing and overcoming these issues and include techniques such as personalisation and recommender systems. In this paper, following on from the DELOS/NSF Working Group on Personalisation and Recommender Systems for Digital Libraries, which met and reported during 2003, we present some background material on the scope of personalisation and recommender systems in digital libraries. We then outline the working group's vision for the evolution of digital libraries and the role that personalisation and recommender systems will play, and we present a series of research challenges and specific recommendations and research priorities for the field.

Journal ArticleDOI
TL;DR: In this paper, a quick quench compocaster was used to obtain a uniform distribution of SiC particles in the aluminium matrix, which was found to improve the uniformity of the SiC distribution significantly.

Journal ArticleDOI
TL;DR: This work reviews several approaches taken towards gaining a clear understanding of both the mechanism of energy and electron transfer processes and how these processes can be manipulated, with particular focus on the physical techniques employed.
Abstract: Rational design of supramolecular systems for application in photonic devices requires a clear understanding of both the mechanism of energy and electron transfer processes and how these processes can be manipulated. Central to achieving these goals is a detailed picture of their electronic structure and of the interaction between the constituent components. We review several approaches that have been taken towards gaining such understanding, with particular focus on the physical techniques employed. In the discussion, case studies are introduced to illustrate the key issues under consideration.

Journal ArticleDOI
TL;DR: In this paper, a new compressible conducting material has been developed by coating polyurethane (PU) foam with inherently conducting polypyrrole (PPy), and the optimised conditions for preparation of the conducting foam have been investigated.
Abstract: A new compressible conducting material has been developed by coating polyurethane (PU) foam with inherently conducting polypyrrole (PPy). The optimised conditions for preparation of the conducting foam have been investigated. Evaluation of the conducting foam shows that a linear relationship exists between the conductance and the stress applied. Parameters such as sensitivity, dynamic range, repeatability of this pressure sensor are discussed. The use of this soft pressure sensor in a prototype breath monitor is also reported.

Journal ArticleDOI
TL;DR: It is suggested that cyclic strain inhibits SMC growth while enhancing SMC apoptosis, in part, through regulation of Notch receptor and downstream target gene expression.
Abstract: Notch signaling has been shown recently to regulate vascular cell fate in adult cells. By applying a uniform equibiaxial cyclic strain to vascular smooth muscle cells (SMCs), we investigated the role of strain in modulating Notch-mediated growth of SMCs in vitro. Rat SMCs cultured under conditions of defined equibiaxial cyclic strain (0% to 15% stretch; 60 cycles/min; 0 to 24 hours) exhibited a significant temporal and force-dependent reduction in Notch 3 receptor expression, concomitant with a significant reduction in Epstein Barr virus latency C promoter-binding factor-1/recombination signal-binding protein of the Jκ immunoglobulin gene–dependent Notch target gene promoter activity and mRNA levels when compared with unstrained controls. The decrease in Notch signaling was Gi-protein– and mitogen-activated protein kinase–dependent. In parallel cultures, cyclic strain inhibited SMC proliferation (cell number and proliferating cell nuclear antigen expression) while significantly promoting SMC apoptosis (annexin V binding, caspase-3 activity and bax/bcl-x L ratio). Notch 3 receptor overexpression significantly reversed the strain-induced changes in SMC proliferation and apoptosis to levels comparable to unstrained control cells, whereas Notch inhibition further potentiated the changes in SMC apoptosis and proliferation. These findings suggest that cyclic strain inhibits SMC growth while enhancing SMC apoptosis, in part, through regulation of Notch receptor and downstream target gene expression.

Journal ArticleDOI
TL;DR: In this paper, the authors examined the capital structure of new technology-based firms and found that the use of debt is rare and equity financing is the prime source of external finance.

Book ChapterDOI
20 Jul 2005
TL;DR: This paper compares fusion methods based on normalised score and rank that use either the average, weighted average or maximum of retrieval results from a discrete Jelinek-Mercer smoothed language model with a simple probability-based combination of the language model results.
Abstract: It is now accepted that the most effective video shot retrieval is based on indexing and retrieving clips using multiple, parallel modalities such as text-matching, image-matching and feature matching and then combining or fusing these parallel retrieval streams in some way. In this paper we investigate a range of fusion methods for combining based on multiple visual features (colour, edge and texture), for combining based on multiple visual examples in the query and for combining multiple modalities (text and visual). Using three TRECVid collections and the TRECVid search task, we specifically compare fusion methods based on normalised score and rank that use either the average, weighted average or maximum of retrieval results from a discrete Jelinek-Mercer smoothed language model. We also compare these results with a simple probability-based combination of the language model results that assumes all features and visual examples are fully independent.

Journal ArticleDOI
TL;DR: In this article, the authors examined Irish secondary school students' perceptions of the work of an accountant and the accounting profession and found that they hold a traditional view of the profession considering it to be boring, definite, precise and compliance driven.
Abstract: Research shows that the perceptions that people hold are an important influence on career decisions. This study examines Irish secondary school students' perceptions of the work of an accountant and the accounting profession. Students are found to hold a traditional view of the profession considering it to be boring, definite, precise and compliance driven. Students who are studying accounting in school have less negative views than those not studying the subject. Females view accounting as more definite, precise and compliance driven than males. Students' perceptions are influenced by the study of the subject at school, the factual media and teachers. They believe that society holds the profession in high esteem but lower than some other professions. These findings suggest that if the profession is to be successful in attracting students who have the skills and attributes to become effective accountants, it must seek to influence students' perceptions of accounting by providing them with a reali...

Journal ArticleDOI
TL;DR: In this article, the plasmonic enhancement effect of metal surfaces or particles in the vicinity of a fluorophore can dramatically alter the fluorescence emission and absorption properties of the fluorophores.
Abstract: In this work we report on the so-called plasmonic enhancement effect, whereby the presence of metallic surfaces or particles in the vicinity of a fluorophore can dramatically alter the fluorescence emission and absorption properties of a fluorophore. The effect, which is associated with the surface plasmon resonance of the metallic surface, depends on parameters such as metal type, particle size, fluorophore type, and fluorophore-particle separation. This work focuses on the creation of metal nanoparticle arrays by a lithographic process and on optimisation strategies to maximise the fluorescence enhancement of dyes in the vicinity of the nanoparticles, for important applications such as fluorescence-based biochip platforms. Ordered arrays of metallic nano-islands were fabricated on glass substrates by a process of natural lithography using monodisperse polystyrene nanospheres. The metal particle dimensions were tailored in order to tune the plasmon resonance wavelength to match the spectral absorption of the fluorophore. The fluorophore, Cy5 dye, which is widely used in optical immunoassays and has a medium quantum efficiency (∼0.3), was used in this preliminary study of the plasmonic enhancement effect. The morphology of the metallic arrays was investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Absorption and emission spectroscopies were used to elucidate the enhancement effect and its dependence on metal island morphology. Results were correlated with existing theoretical models. The applicability of this important technique to sensor platforms, such as fluorescence-based biochips, is also discussed.

Journal ArticleDOI
TL;DR: End-stage renal disease and its ensuing treatments negatively affect quality of life and nurses aware of this evidence can explore new ways to assess more accurately and identify specific problem areas for individual patients and take action to ameliorate these.
Abstract: Aim. The aims of the study were (a) to measure the overall quality of life of people receiving haemodialysis, (b) to compare the quality of life of the sample with that of the general population and (c) to identify any differences between the quality of life of people who are adequately dialysed and those inadequately dialysed, as determined by Kt/Vurea (dialysis adequacy) measurements. Background. End stage renal disease is a progressive, debilitating, chronic illness requiring nursing and medical interventions. The development of the disease affects quality of life, potentially influencing physical and mental health, functional status, independence, general well-being, personal relationships and social functioning. Method. A descriptive, cross-sectional, survey was carried out of the quality of life of patients undergoing haemodialysis treatment at a hospital in the Republic of Ireland. A non-probability sample of 97 patients was chosen. Health-related quality of life was assessed using the 36-item Short Form Health Survey questionnaire. Findings. Patients receiving haemodialysis identified limitations in a number of areas including vitality, physical functioning and physical role limitations. They also reported significantly lower physical functioning when compared with general population norm-based scores. Differences were also found in mental health scores between patients who were well-dialysed and those less well-dialysed. Conclusion. End-stage renal disease and its ensuing treatments negatively affect quality of life. Nurses aware of this evidence can explore new ways to assess more accurately and identify specific problem areas for individual patients and take action to ameliorate these.

Journal ArticleDOI
TL;DR: In this paper, the authors interviewed senior corporate managers and reviewed the literature to find the right balance between corporate creativity and efficiency in order to turn innovation into commercial reality, and they found that a key factor in boosting innovativeness is establishing the right organizational climate to nurture the creative potential of employees and make use of their knowledge of customers, competitors, and processes.
Abstract: Purpose – Advising top management how to find the right balance between corporate creativity and efficiency in order to turn innovation into commercial reality.Design/methodology/approach – The author interviewed senior corporate managers and reviewed the literature.Findings – Inventiveness is required in everything that is done by the company, not just in marketing or in new product development. A key factor in boosting innovativeness is establishing the right organizational climate to nurture the creative potential of employees and make use of their knowledge of customers, competitors, and processes. When leveraging the best innovation practices of other companies look to their philosophy and values.Research limitations/implications – More interviews and a study to determine long‐term success factors would be advisable.Practical implications – Key practices: place people and ideas at the heart of management philosophy; give people room to grow, to try and learn from mistakes; build a strong sense of ope...

Journal ArticleDOI
TL;DR: It is suggested that Notch promotes changes in hVSMC phenotype via activation of CBF-1/RBP-Jkappa-dependent pathways in vitro and contributes to the phenotypic response of VSMCs to cyclic strain-induced changes in VSMC differentiation.
Abstract: Vascular smooth muscle cell (VSMC) phenotypic modulation is a key factor in vascular pathology. We have investigated the role of Notch receptor signaling in controlling human vascular smooth muscle...

Journal ArticleDOI
TL;DR: A novel approach is proposed to uniquely optimise each transform in order to minimise perspective distortions, which ensures the rectified images resemble the original images as closely as possible.

Journal ArticleDOI
TL;DR: The electropolymn. of Ru and Os bis-terpyridine complexes that form rod-like polymers with bithienyl, quaterthienyl or hexathienyl bridges were studied in this article.
Abstract: The electropolymn. of Ru and Os bis-terpyridine complexes that form rodlike polymers with bithienyl, quaterthienyl, or hexathienyl bridges were studied. Absorption spectroscopy, SEM, and cyclic voltammetry were used to characterize the monomers and resulting polymer films. The abs. d.c. cond. of the quaterthienyl-bridged {Ru(tpy)2} and {Os(tpy)2} polymers is unusually large and independent of the identity of the metal center at 1.6 × 10-3 S cm-1. The max. cond. occurs at the formal potential of each redox process, which typically is obsd. for systems where redox conduction is the dominant charge transport mechanism. Significantly, the d.c. cond. of the metal-based redox couple obsd. in these polymers is 2 orders of magnitude higher than that of a comparable nonconjugated system.

Journal ArticleDOI
TL;DR: In this paper, the optimization capabilities in design-expert software were used to optimize the keyhole parameters (i.e., maximize penetration, minimize the heat input, width of welded zone, and width of heat-affected zone (W HAZ )) in CW CO 2 laser butt-welding of medium carbon steel.

Journal ArticleDOI
TL;DR: It is shown that SPCE does not lead to any improvement, but that the metal film actually reduces the sensitivity of fluorescence detection.
Abstract: Surface-plasmon coupled emission (SPCE) has emerged as a new and potentially powerful tool for highly sensitive fluorescence detection. In the case of SPCE, the fluorescence is collected through a semi-transparent thin metal film deposited on glass. We present a theoretical analysis of SPCE, studying the potential enhancement of the fluorescence collection efficiency, brightness, quantum-yield, and photostability. The results are compared with fluorescence detection on a pure glass surface. It is shown that SPCE does not lead to any improvement, but that the metal film actually reduces the sensitivity of fluorescence detection.

Journal ArticleDOI
TL;DR: In this article, the degree of independence varies as a function of the need to make a credible commitment in areas subject to market opening and the complexity of policy in particular areas, and they demonstrate that these institutions enjoy varying degrees of independence.
Abstract: A common feature of contemporary political systems is the increasing amount of delegation from governments to non-majoritarian institutions. Governments may decide to delegate authority to such institutions for reasons relating to credible commitments, political uncertainty and policy complexity. this article focuses on independent administrative authorities (autorites administratives independantes) in France. We demonstrate that these institutions enjoy varying degrees of independence. We find that the degree of independence varies as a function of two factors: the need to make a credible commitment in areas subject to market opening and the complexity of policy in particular areas.

Journal ArticleDOI
TL;DR: Cyclic strain promotes BAEC migration and tube formation in a Gi-protein-dependent PTK-independent manner, and is demonstrated for the first time a putative role for MMP-9 in both strain- induced events, whilst RGD-dependent integrins and uPA appear only to be involved in strain-induced tube formation.

Proceedings ArticleDOI
13 Jun 2005
TL;DR: RIDAN is a novel architecture that uses knowledge-based intrusion detection techniques to detect, in real-time, attacks that an adversary can perform against the routing fabric of a mobile ad hoc network.
Abstract: A mobile ad hoc network is a collection of nodes that are connected through a wireless medium and form rapidly changing topologies. The widely accepted existing routing protocols designed to accommodate the needs of such self-organised networks do not address possible threats aimed at the disruption of the protocol itself. The assumption of a trusted environment is not one that can be realistically expected; hence several efforts have been made towards the design of a secure routing protocol for ad hoc networks. The main problems with this approach are that it requires changes to the underlying routing protocol and that manual configuration of the initial security associations cannot be completely avoided. We propose RIDAN, a novel architecture that uses knowledge-based intrusion detection techniques to detect, in real-time, attacks that an adversary can perform against the routing fabric of a mobile ad hoc network. Our system is designed to take countermeasures minimising the effectiveness of an attack and maintaining the performance of the network within acceptable limits. RIDAN does not introduce any changes to the underlying routing protocol since it operates as an intermediate component between the network traffic and the utilised protocol with minimum processing overhead. We have developed a prototype that was evaluated in AODV-enabled networks using the ns-2 network simulator.

Journal ArticleDOI
TL;DR: In this paper, a novel aqueous-based nanoparticulate polyaniline (PANI), doped with dodecylbenzenesulfonic acid (DBSA), was demonstrated for H2O2 sensing.
Abstract: The biosensor described here uses a novel aqueous-based nanoparticulate polyaniline (PANI), doped with dodecylbenzenesulfonic acid (DBSA). The nanoparticles were applied to a glassy carbon electrode surface by electrodeposition techniques, and horseradish peroxidase (HRP) was subsequently electrostatically adsorbed to the nanoparticle-modified surface. This biosensor format was demonstrated for H2O2 sensing. Electrodeposited polymer nanoparticles resulted in highly ordered conductive nanostructured films, which were examined by scanning electron microscopy (SEM), atomic force microscopy (AFM), profilometry and spectroelectrochemistry. The surface of the films were characterized by a uniform array of nanoparticulate PANI (nanoPANI/DBSA) nodules and were shown to have a thickness of 350 nm. Physical techniques have shown that the nanofilms possess properties which allow for uniform electrostatic adsorption of protein to take place. This effective biosensor format, exhibits higher signal-to-background ratios and shorter response times than previous PANI biosensor configurations.