On Combinational Networks with Restricted Fan-Out

Fan-out-free networks of AND, OR, NOT, EXOR, and MAJORITY gates are considered. Boolean functions for which such networks exist are defined to be fan-out free. The paper solves the following problems regarding the fan-out-free networks and functions. 1) Characterization of the class of fan-out-free functions: The characterization given is constructive in the sense that if a given function is fan-out free one obtains a fan-out-free network to realize it. 2) Counting the class of fan-out-free functions: After establishing a correspondence between a fan-out-free function and a normalized network realizing it, a series of formulas are developed to count distinct normal networks for any subset of the five gates mentioned above. 3) Fault Diagnosis: Methods are developed to detect multiple faults and to locate single faults in arbitrary fan-out-free networks

Students’ attitude to educational loan repayments: A structual modelling approach

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Educational loan defaulting is a problem increasing on a worldwide scale. In Malaysia, the default rate is almost 50% in the case of loans advanced to students in higher education. With this in mind, for the first time, this study analyses this chronic problem in-depth with consideration to primary data collected from a cross-section of students currently studying in public universities in Malaysia. With help from the Theory of Planned Behaviour, the empirical analysis establishes that loan defaults are influenced by a complex interaction of personal-, social- and psychology-related variables: students’ attitude, intention to repay loan, parental influence, perceptions that loan repayment will affect quality of life after graduation, perceptions towards loan agreement, and an awareness of loan repayment issues created by the media. This study succeeds in disentangling the precise impact of such variables in regard to loan defaults. The findings are of great relevance to government-funding agencies, which can better plan the loan advancement and recovery process once they understand the true reasons behind defaults. The novel method utilised for the first time with the objective to study the default issue should also be useful to academic researchers seeking to conduct similar studies in the context of other countries. This study should also assist policy makers in planning long-term strategies in terms of assessing, designing and evaluating new loan schemes. Developing countries, such as Malaysia, face competing demands on their limited financial resources. An increase in the recovery rate will bring in funds that can be lent to additional students or used for strengthening educational infrastructure. These measures add useful value to the social and economic set-up of the country

Expanding Thurston Maps

We study the dynamics of Thurston maps under iteration. These are branched covering maps $f$ of 2-spheres $S^2$ with a finite set $\mathop{post}(f)$ of postcritical points. We also assume that the maps are expanding in a suitable sense. Every expanding Thurston map $f\: S^2 \to S^2$ gives rise to a type of fractal geometry on the underlying sphere $S^2$. This geometry is represented by a class of \emph{visual metrics} $\varrho$ that are associated with the map. Many dynamical properties of the map are encoded in the geometry of the corresponding {\em visual sphere}, meaning $S^2$ equipped with a visual metric $\varrho$. For example, we will see that an expanding Thurston map is topologically conjugate to a rational map if and only if $(S^2, \varrho)$ is quasisymmetrically equivalent to the Riemann sphere $\widehat{\mathbf{C}}$. We also obtain existence and uniqueness results for $f$-invariant Jordan curves $\mathcal{C}\subset S^2$ containing the set $\mathop{post}(f)$. Furthermore, we obtain several characterizations of Latt\`{e}s maps.Comment: 492 pages, 51 figure

Fluorocarbon Complexes of the Transition Metals

Reactions of transition metal carbonyl and cyclopentadienyl complexes with disulphides and acetylenes bearing fluorocarbon substituents have been investigated. Photolytic reactions of disulphides RSSR, R = CF3, C6F5 are considered to proceed via RS radicals and with dimeric complexes monomers have been obtained e. g. [CpMo(CO)3]2 -RS→CpMo(CO)3SR Use of closed reaction systems has enabled the identification of thermally unstable compounds such as Mn(CO)5SCF3 and CpNi(CO)SR which decarbonylate readily in an open system to di-or polymeric mercapto bridged complexes e.g. 2Mn(CO)5SCF3→ [Mn(CO)4SCF3]2 + 2C0 The dimers in many cases exhibit isomerism due to inversion at sulphur and this has been studied by i.r. and n.m.r. spectroscopy. The photolytic reactions of disulphides and monomeric carbonyls e. g. Fe(CO)5, Mo(CO)6, gave dimeric mercapto-bridged compounds directly, e.g. [Fe(CO)3SCF3]2 [Mo(CO)4SCF3]2, but in the absence of u. v. light CpCo(CO)2 and C6F5SSC5F4 gave CpCo(CO)(SC6F5)2 which can be decarbonylated to [CpCoSC6F5]2, illustrating that monomeric carbonyls can react with disulphides to give sulphur bridged dimers via an oxidative addition reaction. Possible mechanisms of these reactions and steric and electronic effects of the substituent on sulphur are discussed. Reactions of these organothic derivatives with acetylenes CF3C=CCF3 and CF3C=CH gave a variety of novel complexes. Complexes CrMo(CO)3SCF3, M = Mo, W,were observed to undergo CO substitution by CF3C2CF3 to give CpM(C0)2(CF3C2CF3)SCF3, the variable temperature n.m.r. spectra of which have been interpreted in terms of restricted rotation of the SCF3, ligand. Similar complexes were obtained with CH3C=CCH3 and PhC=CPh. In contrast CpMo(CO)3SCF3 and CF3C=CH gave the cyclopentadienone derivative CpMo(CO)[ (CF3C2H)2CO]SCF3 which was photochemically decarbonylated to [CpMo[(CF3C2H)2CO]SCF3]2. Insertion of CF3C=CCF3 into the Mn-S bond of [Mn(CO)4SC6F5]2 gave Mn(CO)4C(CF3)=C(CF3)SC6F5 while CF3C=CH gave Mn(CO)4(CF3C2H)2SC6F5. With excess acetylene the former yielded Mn(CO)3[C4(CF3)4SC6F5] which has been shown by X-ray studies to contain a non-planar heterocyclic sulphonium ion [C4(CF3)4SC6F5] bonded to an Mn(CO)3 species. Several other examples of acetylene insertion into M-S bonds were observed but with [Fe(CO)3SR]2 insertion into the Fe-Fe bond gave complexes [Fe(CO)3SR]2CF3C2R' , R'= CF3, H. X-ray studies of [Fe(CO)3SCF3]2CF3C2CF3 have revealed that this results in a significant change in the Fe2S2 ring geometry which allows the formation of the syn (axial, axial) isomer not observed in the parent complexes. [CpCoSR]2 and CF3C=CCF3 in contrast gave CpCoC6(CF3)6 containing a tetrahapto hexakis(trifluoromethyl)benzene ligand. Attempts have been made to rationalise the various reaction types in terms of the properties of possible reaction intermediates. Reactions of certain cyclopentadienyl-nickel complexes with hexa-fluorobut-2-yne gave products resulting from condensation of the acetylene and a cyclopentadienyl ligand, e. g. Cp2Ni + CF3C=CCF3-->CpNi[(C5H5)C4(CF3)4] while in other cases cyclooligomerisation of the acetylene was observed. These reactions have been rationalised in terms of acetylene coordination promoting a pi-d rearrangement of a cyclopentadienyl ligand. Several complexes were isolated in which a pi-cyclopentadienyl ligand appears to have been replaced by a nickelacyclopentadiene ring, CpNiC4(CF3)4, e.g. Cp2Ni3C6(CF3)6, CpNi2[C4(CF3)4(C5H5)C2F3Cl] and [C5H5NiC2(CF3)2]4. The crystal structure of the last has been solved and suggests that the molecule is formed by a Diels-Alder addition of the nickelacyclopentadiene ring of a dinuclear intermediate [CpNiC2(CF3)2]2 to the 1,2 positions of a cyclopentadienyl ring of a second dimeric species. The reactions of CpMo(CO)3X, X = Cl, Br, I, with acetylenes . RC=CR, R = CF3, CH3, have been found to give sixteen electron molybdenum complexes CpMo(RC2R)2X and with R = CH3 tetramethylquinone was also obtained. Variable temperature n.m.r. studies suggest that the coordinated acetylenes undergo an intramolecular exchange reaction at temperatures above -25C, R = CF3, +15C, R = CH3 CpMo(CO)3X and PhC=CPh gave sixteen electron complexes CpMo(C0)(PhC2Ph)X at low temperatures (< 50 C) or on photolysis in pentane. At higher temperatures the tetraphenylcyclobutadiene derivatives CpMo(CO)(PhC)4X were obtained. Brief studies of reactions of acetylenes with transition metal trifluorophosphine complexes suggest that in certain cases the latter react in a similar manner to analogous carbonyl derivatives. CpCo(PF3)2 and CF3C=CCF3 gave CpCo[C4(CF3)4PF3] according to mass spectral evidence and this undergoes stepwise hydrolysis to [CpCoC4(CF3)4PO2H] via CpCo[C4(CF3)4POF]. An X-ray study of the terminal hydrolysis product has revealed a structure containing a heterocyclic P(v) ring pi-bonded to a cyclopentadienyl-cobalt moiety. This is analogous to CpCo[C4(CF3)4CO] obtained from the reaction of CpCo(CO)2 ana CF3C=CCF3

Religious influences on the Thatcherite enterprise culture

During the 1980s, the government of Great Britain, led by Margaret Thatcher, promoted a political and economic ideology known in the demotic as the Thatcherite Enterprise Culture. This set of beliefs and actions included an encouragement of hard work, thrift, self-responsibility, and self-employment, as well as legislating for the support of small firms, privatisation, free markets and a strong - but minimal - central state. Behind the Enterprise Culture lay a religious paradigm, explicitly called upon by its chief creators, including Margaret Thatcher. The thesis builds an ideal-type of the Thatcherite Enterprise Culture, following a Weberian methodology, to form the major object of study. The work aims to discover whether the ideal-type under analysis is theologically coherent, and whether it can justifiably claim to be a continuation of Christian thought in this area. This thesis examines the development of Western European philosophy and theology as it relates to the key aspects of the Thatcherite Enterprise Culture, beginning with the Ancient Greeks and concluding with the Victorian Age of Enterprise. The historical review demonstrates that the Thatcherite Enterprise Culture is generally discontiguous with the tradition of religious thought, and in some instances is essentially in direct contradiction with important aspects of the tradition, such as the significance of the Incarnation. A review of the theological works of the Thatcherite Enterprise Culture and its critics adds to the findings of the historical examination, indicating further flaws and contradictions within Enterprise Theology. Critics of Enterprise Theology are found to be much more consistent with mainstream Christian Theology

ASMOD 2018: Proceedings of the International Conference on Advances in Statistical Modelling of Ordinal Data

[English]:This volume collects the peer-reviewed contributions presented at the 2nd International Conference on “Advances in Statistical Modelling of Ordinal Data” - ASMOD 2018 - held at the Department of Political Sciences of the University of Naples Federico II (24-26 October 2018). The Conference brought together theoretical and applied statisticians to share the latest studies and developments in the field. In addition to the fundamental topic of latent structure analysis and modelling, the contributions in this volume cover a broad range of topics including measuring dissimilarity, clustering, robustness, CUB models, multivariate models, and permutation tests. The Conference featured six distinguished keynote speakers: Alan Agresti (University of Florida, USA), Brian Francis (Lancaster University, UK), Bettina Gruen (Johannes Kepler University Linz, Austria), Maria Kateri (RWTH Aachen, Germany), Elvezio Ronchetti (University of Geneva, Switzerland), Gerhard Tutz (Ludwig-Maximilians University of Munich, Germany). The volume includes 22 contributions from scholars that were accepted as full papers for inclusion in this edited volume after a blind review process of two anonymous referees./ [Italiano]: Il volume raccoglie i contributi presentati alla seconda Conferenza Internazionale “Advances in Statistical Modelling of Ordinal Data” - ASMOD 2018 – che si è svolta presso il Dipartimento di Scienze Politiche, Università di Napoli Federico II, nei giorni 24-26 ottobre 2018. La Conferenza ha visto la presentazione di studi sia teorici che applicati al fine di condividere i più recenti sviluppi scientifici nel campo. Oltre al tema fondamentale dell'analisi delle strutture latenti e dei modelli, i contributi richiamano una vasta gamma di argomenti, tra cui misure di dissimilarità, metodi di clustering, analisi di robustezza, modelli CUB, modelli multivariati e test di permutazione. In particolare, questa pubblicazione contiene le relazioni invitate di studiosi riconosciuti a livello internazionale: Alan Agresti (Università della Florida, USA), Brian Francis (Università Lancaster, Regno Unito), Bettina Gruen (Johannes Kepler University Linz, Austria), Maria Kateri (RWTH Aachen, Germania), Elvezio Ronchetti (Università di Ginevra, Svizzera), Gerhard Tutz (Università Ludwig-Maximilians di Monaco, Germania). Il volume include, inoltre, 22 contributi di studiosi che sono stati accettati dopo un processo di revisione anonima

Latent class approaches for modelling multiple ordinal items

The modelling of the latent class structure of multiple Likert items is reviewd. The standard latent class approach is to model the absolute Likert ratings. Commonly, an ordinal latent class model is used where the logits of the profile probabilities for each item have an adjacent category formulation (DeSantis et al., 2008). an alternative developed in this paper is to model the relative orderings, using a mixture model of the relative differences between pairs of Likert items. This produces a paired comparison adjacent category log-linear model (Dittrich et al., 2007; Francis and Dittrich, 2017), with item estimates placed on a (0,1) “worth” scale for each latent class. The two approaches are compared using data on environmental risk from the International Social Survey Programme, and conclusions are presented