1522 research outputs found
Sort by
A Study of Riordan Arrays with Applications to Continued Fractions, Orthogonal Polynomials and Lattice Paths
Get PDFWe study integer sequences using methods from the theory of continued fractions, or-
thogonal polynomials and most importantly from the Riordan groups of matrices, the
ordinary Riordan group and the exponential Riordan group. Firstly, we will intro-
duce the Riordan group and their links through orthogonal polynomials to the Stieltjes
matrix. Through the context of Riordan arrays we study the classical orthogonal
polynomials, the Chebyshev polynomials. We use Riordan arrays to calculate determi-
nants of Hankel and Toeplitz-plus-Hankel matrices, extending known results relating
to the Chebyshev polynomials of the third kind to the other members of the family of
Chebyshev polynomials. We then define the form of the Stieltjes matrices of important
subgroups of the Riordan group. In the following few chapters, we develop the well es-
tablished links between orthogonal polynomials, continued fractions and Motzkin paths
through the medium of the Riordan group. Inspired by these links, we extend results
to the Lukasiewicz paths, and establish relationships between Motzkin, Schr¨oder and
certain Lukasiewicz paths. We concern ourselves with the Binomial transform of inte-
ger sequences that arise from the study of Lukasiewicz and Motzkin paths and we also
study the effects of this transform on lattice paths. In the latter chapters, we apply
the Riordan array concept to the study of sequences related to MIMO communica-
tions through integer arrays relating to the Narayana numbers. In the final chapter,
we use the exponential Riordan group to study the historical Euler-Seidel matrix. We
calculate the Hankel transform of many families of sequences encountered throughout
Development of Molecularly Imprinted Polymers for Corticosteroids
Get PDFThe aim of this research was to prepare a series of molecularly imprinted polymers (MIPs) for corticosteroid templates using bulk and precipitation polymerisation strategies. Initially, a systematic study was undertaken, investigating the factors affecting the synthesis of MIPs by precipitation polymerisation. Careful optimisation of polymerisation parameters, including the monomer concentration, initiator type and solvent, allowed for a high degree of control over particle size and morphology. Preequilibrium interactions between the primary target budesonide (BDN) and functional monomers were investigated using NMR studies and showed weak interactions with dissociation constants, kdiss, ranging from 0.534-1.47 M Due to this weak functional monomer-template interaction, polymers were prepared in bulk format using a target analogue approach utilising hydrocortisone-17-butyrate (HCB) as a low-cost alternative to BDN. The HCB imprinted ground bulk polymers demonstrated imprinting factors (IF) as high as 7.5 for the template. Selectivity studies on six steroidal analogues showed that recognition was driven by shape and size selectivity as well as hydrophobic interactions, with IF values ranging from 1.2-9.5 in both organic and aqueous based systems. Applications of the imprinted polymers were demonstrated by solid-phase extraction (SPE) and analytical column chromatography. SPE studies utilising HCB imprinted polymers displayed a seven-fold increase in the specific retention of BDN. Precipitated prednisolone imprinted polymers achieved chromatographic separation between the template and hydrocortisone, a close structural analogue. Selectivity factors as high as 1.4 and a resolution value of 0.75 were achieved. Two custom functional monomer strategies were utilised towards enhancing MIP performance. The synthesis of tailor-made monomers based on derivatised cyclodextrins (CD) achieved a substitution of 2.5 polymerisable vinyl groups per CD. This derivatised CD was used to prepare precipitated polymers (0.3-7.2 μm) in a 40% aqueous acetonitrile porogen. A polymerisable hydrocortisone methacrylate monomer was successfully synthesised for use in semi-covalent imprinting which produced discrete microspherical beads (1.2-5.1 μm) using divinylbenzene as the crosslinker
Methods of enhancing botanical diversity within field margins of intensively managed grassland: a 7-year field experiment
Get PDFP>1. Increased intensification in agricultural grasslands has led to well-documented declines in the associated flora. Manipulation of field margins for biodiversity enhancement in arable systems has been extensively investigated. However, there is a paucity of corresponding long-term research within intensively managed grasslands. 2. We investigated a combination of establishment and management methods to enhance botanical diversity of newly established field margins in intensively managed grasslands. Three methods of field margin establishment were investigated including fencing, natural regeneration by rotavation, or seeding with a wildflower mixture. Subsequent sward management by either grazing or mowing was tested at three margin widths. Success of establishment was addressed in terms of persistence of species richness, plant community composition and incidence of noxious weeds. 3. Seeding with a wildflower mixture was the most successful establishment method to enhance plant species richness and this effect persisted throughout the 7 years of the experiment ( = 16 center dot 4 +/- 0 center dot 43 SE plant species richness per 1 x 3 m2 quadrat). Mown ( = 6 center dot 01 +/- 0 center dot 30 SE) and rotavated ( = 9 center dot 7 +/- 0 center dot 34 SE) treatments contained significantly fewer plant species; grazed controls contained 9 center dot 83 +/- 0 center dot 24 species. 4. Grazing led to a significant, but modest increase in species richness in fenced and rotavated plots compared to the mowing treatment, but had no effect in seeded plots. Grazing also led to an increased frequency and cover of competitive grasses in the seeded treatment. 5. Although margin width was not found to significantly influence species richness, there was increased herb cover and reduced abundance of noxious weeds in the wider seeded margins. 6.Synthesis and applications. The choice of establishment method and subsequent management of grassland field margins significantly affected their conservation value. The botanical diversity of margins within intensively managed pasture can be enhanced by sowing wildflower seed mixtures. This diversity can be maintained over time through appropriate management, i.e. either the reduction of high grazing pressure by seasonal fencing, or annual mowing. Management approaches that involve minimal change are currently adopted in many agri-environment schemes (such as fencing and/or the cessation of nutrient inputs) but did not produce swards of conservation value in this study
Blues, Funk, Rhythm and Blues, Soul Hip-hop and Rap: A Research and Information Guide: A Review / Essay in Reference Reviews
No full texteBooks - Tipping Points and Milestones
No full text“Without a doubt,the eBook is practically the
biggest thing that’s hit the publishing industry since
the invention of movable type”
(Philip Ruppel, CEO McGraw-Hill, 2011)
“inexorable rise of the eBook”
(CIBER, UC
Riordan arrays, orthogonal polynomials as moments, and Hankel transforms
Get PDFTaking the examples of Legendre and Hermite orthogonal polynomials, we show
how to interpret the fact that these orthogonal polynomials are moments of other
orthogonal polynomials in terms of their associated Riordan arrays. We use these
means to calculate the Hankel transforms of the associated polynomial sequences
Information and communication technologies and social network sites : The digital world of adolescents
Get PDFAt present, it is hard to imagine many adolescents in Ireland experiencing life without Information and Communication Technologies (ICTs) and Social Network Sites (SNSs) in their everyday social and leisure pursuits. Many have access to a range of ICTs and most are registered with at least one Social Network Site. To date however, limited academic attention has been given to the context of ICT and Social Network Site use in Irish adolescents’ lives. The aim of this research is to contribute to the understanding of Irish adolescents’access to and use of ICTs and SNSs with particular emphasis on the Social Network Site ‘Bebo’. This research utilised a method triangulation approach implemented in the South-East of Ireland with transition year students as the sample base. The initial research involved a questionnaire and logbook based survey of four hundred and ten students based in eleven secondary schools. Next, digital ethnography was utilised to examine key concepts surrounding Social Network Site practice. This was augmented by questionnaires and focus group interviews. A sample of one hundred and eight students from three secondary schools were utilised in this Phase. The data retrieved from both Phases, provided for an in-depth examination of adolescent’s day-to-day use of the Social Network Site ‘Bebo’ and a comprehensive overview of their access to, use and engagement with ICTs and SNSs. It would appear from the research findings that ICTs and SNSs have both a space and place in the lives of many adolescents, and are becoming increasingly important in their daily social and leisure experiences. It would also seem that there is a shift towards a domestication of ICTs in the family home. In addition, SNSs seem to be changing the means in which adolescents communicate and search for information on a daily basis. These sites appear to be altering socialisation processes, allowing adolescents both to foster new relationships and fabricate a real or virtual image online. Other important issues explored include the digital divide, communication practices and risk behaviours online and parental mediation practices
Validation of Networked Automotive Control Systems Using Global Predicates
Get PDFVehicles consist of many connected networks of electronic control units (ECUs). Automotive application software (e.g. traction control system, climate control, engine management) is distributed across many separate ECUs, making
application testing and system integration very difficult. The main difficulty is in constructing a global application state, due to the asynchronous independent operation of each ECU.
The aim of this research is to make the system integration more efficient by creating a global application state based on analysis of application test results. To achieve this goal, a prototype program was developed to construct global states and to analyse these global states. The prototype collects ECU state and network interaction data using the Vector CANoe tool. From these data a lattice of consistent global application states is constructed. The global state lattice can then be used as the basis for analysing ECU signal consistency across ECUs and identifying the potential for erroneous system states to be entered.
Test results from the prototype demonstrate the validity of the theoretical approach despite the disadvantage of the state space explosion associated with large distributed systems
Scaling Instant Messaging Communication Services: A Comparison of Blocking and Non-Blocking techniques
Get PDFDesigning innovative communications services that
scale to facilitate potential new usage patterns can pose
significant challenges. This is particularly the case if these
services are to be delivered over existing protocols and
interoperate with legacy services. This work explores design
choices for such a service: large scale message delivery to
existing Instant Messaging users. In particular we explore
message throughput, accuracy and server load for several
alternative implementation strategies. These strategies focus on
approaches to concurrency, with best practice in current and
emerging techniques thoroughly benchmarked. Specifically, a
conventional Java Executor approach is compared with a
functional approach realised through Scala and its Actors
framework. These could be termed “blocking I/O” technology.
A third approach has also been measured - a “non-blocking
I/O” based on an alternative to Java Virtual Machine
approaches - employing Node.js and Javascript. We believe
that some of the results are startling
An Analysis and Investigation into the Elite Player Pathways of the Irish Rugby Football Union
No full textIn today’s increasingly competitive world of professional rugby, clubs, provinces and national teams have recognised the importance and need for rugby academies in order to obtain ultimate success whether it is at a domestic level or on the world stage (Spamer, 2009). The purpose of this study was to analyse and investigate the Elite Player pathway systems of the Irish Rugby Football Union. Williams and Reilly (2000) explain that in order to remain competitive, sporting organisations and clubs must invest considerable amounts of money in their quest to identify and nurture potentially elite players. Abbott and Collins (2002) are of the opinion that early identification of individuals has become important across all sporting domains. Since the dawn of the professional rugby era in 1995, rugby in Ireland has become a real career path for many schoolboy players and competition for provincial and national selection at school level has become increasingly tough (Spamer, 2009). Currently Ireland has four representative professional rugby teams; each province has their own academy where the focus is to provide the best environment for young Irish players to develop their skills, disciplines, knowledge and attitude to achieve their full playing potential of the game. Full time academy players typically join the academies around 18 years of age; these players are contracted for three years subject to annual review. The primary objective of this study was to identify and examine the recruitment and talent identification methods used by the IRFU. Quantitative research was undertaken and data was obtained through the use of questionnaires which were distributed to current (n=61) and past players (n=139) with a return rate of current (n= 44) and past (n= 15) The study employed a largely qualitative methodology, interviewing nineteen elite young rugby players (18-22 years of age) and four Head coaches. The study revealed that on average 32% of the total academy players have graduated to their respective current provincial senior squad in the period 2004 -2010. Within the particular Irish context, this country is known for its incredibly competitive attitude worldwide. Current findings show that 60% of past players have come through the elite player pathway and graduated to a development contract; while 20% of former academy players went on to win senior international caps for Ireland. However, this “never say die” is unfortunately not enough to consistently guarantee success in the sports arena. To further increase the IRFU’s pool of knowledge in a constructive and meaningful way, accurate methods of talent identification and development need to be developed