Epidemiology and public health; a text and reference book for physicians, medical students and health workers,

Bibliography at end of each chapter.

Ad quadratum; a study of the geometrical bases of classic & medieval religious architecture, with special reference to their application in the restoration of the cathedral of Nidaros (Throndhjem) Norway,

"Rules of religious architecture were a secret science in the middle ages, just as they were in classic times ... Through this secrecy, the rules became forgotten ... It is this forgotten science which we have discovered, and which we develop in this work."--p. xxii.

Mode Localization in a Nearly Cyclic Symmetric System

Thesis (Ph.D.)--University of Washington, 2016-06

Exact solution, scaling behaviour and quantum dynamics of a model of an atom-molecule Bose-Einstein condensate

0We study the exact solution for a two-mode model describing coherent coupling between atomic and molecular Bose-Einstein condensates (BEC), in the context of the Bethe ansatz. By combining an asymptotic and numerical analysis, we identify the scaling behaviour of the model and determine the zero temperature expectation value for the coherence and average atomic occupation. The threshold coupling for production of the molecular BEC is identified as the point at which the energy gap is minimum. Our numerical results indicate a parity effect for the energy gap between ground and first excited state depending on whether the total atomic number is odd or even. The numerical calculations for the quantum dynamics reveals a smooth transition from the atomic to the molecular BEC.

Behaviour of the energy gap in a model of Josephson coupled Bose-Einstein condensates

In this work we investigate the energy gap between the ground state and the first excited state in a model of two single-mode Bose-Einstein condensates coupled via Josephson tunnelling. The ene:rgy gap is never zero when the tunnelling interaction is non-zero. The gap exhibits no local minimum below a threshold coupling which separates a delocalized phase from a self-trapping phase that occurs in the absence of the external potential. Above this threshold point one minimum occurs close to the Josephson regime, and a set of minima and maxima appear in the Fock regime. Expressions for the position of these minima and maxima are obtained. The connection between these minima and maxima and the dynamics for the expectation value of the relative number of particles is analysed in detail. We find that the dynamics of the system changes as the coupling crosses these points.

A reference architecture for instructional educational software

Our extensive research has indicated that high-school teachers are reluctant to make use of existing instructional educational software (Pollard, 2005). Even software developed in a partnership between a teacher and a software engineer is unlikely to be adopted by teachers outside the partnership (Pollard, 2005). In this paper we address these issues directly by adopting a reusable architectural design for instructional educational software which allows easy customisation of software to meet the specific needs of individual teachers. By doing this we will facilitate more teachers regularly using instructional technology within their classrooms. Our domain-specific software architecture, Interface-Activities-Model, was designed specifically to facilitate individual customisation by redefining and restructuring what constitutes an object so that they can be readily reused or extended as required. The key to this architecture is the way in which the software is broken into small generic encapsulated components with minimal domain specific behaviour. The domain specific behaviour is decoupled from the interface and encapsulated in objects which relate to the instructional material through tasks and activities. The domain model is also broken into two distinct models - Application State Model and Domainspecific Data Model. This decoupling and distribution of control gives the software designer enormous flexibility in modifying components without affecting other sections of the design. This paper sets the context of this architecture, describes it in detail, and applies it to an actual application developed to teach high-school mathematical concepts.

Developing a research framework for understanding the social realities, with special reference to Sri Lankan entrepreneurs

This paper identifies and examines issues of relevance for increasing effectiveness of entrepreneurial management research. These issues emerged from research into entrepreneurial behaviour and underlying motivations in Sri Lanka. Understanding of socially- and culturally-bound social actors, social actions and social outputs in entrepreneurial activity requires context-sensitivity, expressed through cognisance of institutional characteristics, the interface between cultural values and business, and historical and cultural forces which impact on entrepreneurship. We suggest that this requires exploration through bottom-up translations of actions consistent with the beliefs and values of the actors involved, employing qualitative methodology to ground the reality of human behaviour in deep-rooted cultural and social contexts. Thorough interpretation of holistic case studies that are capable of capturing the actors' viewpoints brings appropriate insights to the field of entrepreneurship.

The impact of supply chain performance measurement systems on dynamic behaviour in supply chains

The amplification of demand variation up a supply chain widely termed ‘the Bullwhip Effect’ is disruptive, costly and something that supply chain management generally seeks to minimise. Originally attributed to poor system design; deficiencies in policies, organisation structure and delays in material and information flow all lead to sub-optimal reorder point calculation. It has since been attributed to exogenous random factors such as: uncertainties in demand, supply and distribution lead time but these causes are not exclusive as academic and operational studies since have shown that orders and/or inventories can exhibit significant variability even if customer demand and lead time are deterministic. This increase in the range of possible causes of dynamic behaviour indicates that our understanding of the phenomenon is far from complete. One possible, yet previously unexplored, factor that may influence dynamic behaviour in supply chains is the application and operation of supply chain performance measures. Organisations monitoring and responding to their adopted key performance metrics will make operational changes and this action may influence the level of dynamics within the supply chain, possibly degrading the performance of the very system they were intended to measure. In order to explore this a plausible abstraction of the operational responses to the Supply Chain Council’s SCOR® (Supply Chain Operations Reference) model was incorporated into a classic Beer Game distribution representation, using the dynamic discrete event simulation software Simul8. During the simulation the five SCOR Supply Chain Performance Attributes: Reliability, Responsiveness, Flexibility, Cost and Utilisation were continuously monitored and compared to established targets. Operational adjustments to the; reorder point, transportation modes and production capacity (where appropriate) for three independent supply chain roles were made and the degree of dynamic behaviour in the Supply Chain measured, using the ratio of the standard deviation of upstream demand relative to the standard deviation of the downstream demand. Factors employed to build the detailed model include: variable retail demand, order transmission, transportation delays, production delays, capacity constraints demand multipliers and demand averaging periods. Five dimensions of supply chain performance were monitored independently in three autonomous supply chain roles and operational settings adjusted accordingly. Uniqueness of this research stems from the application of the five SCOR performance attributes with modelled operational responses in a dynamic discrete event simulation model. This project makes its primary contribution to knowledge by measuring the impact, on supply chain dynamics, of applying a representative performance measurement system.

The hydrodynamic behaviour and mass transfer characteristics of single droplets in a pulsed sieve plate column

The literature relating to the performance of pulsed sieve plate liquid-liquid extraction columns and the relevant hydrodynamic phenomenon have been surveyed. Hydrodynamic behaviour and mass transfer characteristics of droplets in turbulent and non-turbulent conditions have also been reviewed. Hydrodynamic behaviour, i.e. terminal and characteristic velocity of droplets, droplet size and droplet breakup processes, and mass transfer characteristics of single droplets (d≤0.6 cm) were investigated under pulsed (mixer-settler & transitional regimes) and non-pulsed conditions in a 5.0 cm diameter, 100 cm high, pulsed sieve plate column with three different sieve plate types and variable plate spacing. The system used was toluene (displaced) - acetone - distilled water. Existing photographic techniques for following and recording the droplet behaviour, and for observing the parameters of the pulse and the pulse shape were further developed and improved. A unique illumination technique was developed by which a moving droplet could be photographed using cine or video photography with good contrast without using any dye. Droplet size from a given nozzle and droplet velocity for a given droplet diameter are reduced under pulsing condition, and it was noted that this effect is enhanced in the presence of sieve plate. The droplet breakup processes are well explained by reference to an impact-breakup mechanism. New correlations to predict droplet diameter based on this mechanism are given below.vskip 1.0cm or in dimensionless groups as follows:- (We)crit= 3.12 - 1.79 (Eo)crit A correlation based on the isotropic turbulence theory was developed to calculate droplet diameter in the emulsion regime.vskip 1.0cm Experimental results show that in the mixer-settler and transitional regimes, pulsing parameters had little effect on the overall dispersed phase mass transfer coefficient during the droplet formation and unhindered travel periods.

Individual and group differences in driving behaviour

Road traffic accident involvement rates show that younger males are over represented in accidents. A number of studies have shown individual differences in accident involvement. Questionnaire-based methods to investigate individual and group differences in driver stress and risk perceptions reported in chapter 2 and 3 revealed that neuroticism was associated with; heightened perception of personal risk, driver stress, and inefficient coping strategies. Younger drivers and female drivers reported higher levels of stress. Young male drivers assessed their personal risk and driving abilities less realistically than did other age and sex groups. Driving simulator-based methods reported in chapter 4 revealed that young drivers and male drivers; drive faster, overtake more often, and commit more `high risk' overtakes than do other age and sex groups. Middle-aged and elderly drivers were poorer at maintaining a fixed distance from a lead `vehicle'. Older drivers adopt a slower, more cautious driving style, but appear to be worse at controlling distance from a `lead' vehicle. Results are consistent with individual and group differences in accident involvement rates. Findings are discussed with reference to the implementation of driver education programs to reduce stress, the adoption of more realistic perceptions of risk among younger drivers, and the training of compensation strategies to counteract age-related changes in older drivers.

The role of the English language in the context of national development vision 2025 with specific reference to agriculture in Tanzania

After thirty years of vacillation, the Tanzanian government has made a firm decision to Swahilize its secondary education system. It has also embarked on an ambitious economic and social development programme (Vision 2025) to transform its peasant society into a modern agricultural community. However, there is a faction in Tanzania opposed to Kiswahili as the medium of education. Already many members of the middle and upper class their children to English medium primary schools to avoid the Kiswahili medium public schools and to prepare their children for the English medium secondary system presently in place. Within the education system, particularly at university level, there is a desire to maintain English as the medium of education. English is seen to provide access to the international scientific community, to cutting edge technology and to the global economy. My interest in this conflict of interests stems from several years' experience teaching English to students at Sokoine University of Agriculture. Students specialise in agriculture and are expected to work with the peasant population on graduation. The students experience difficulties studying in English and then find their Kiswahili skills insufficient to explain to farmers the new techniques and technologies that they have studied in English. They are hampered by a complex triglossic situation in which they use their mother tongue with family and friends, Kiswahili, the national language for early education and most public communication within Tanzania, and English for advanced studies. My aim in this thesis was - to study the language policy in Tanzania and see how it is understood and implemented; - to examine the attitudes towards the various languages and their various roles; - to investigate actual language behaviour in Tanzanian higher education. My conclusion is that the dysfunctionality of the present study has to be addressed. Diglossic public life in Tanzania has to be accommodated. The only solution appears to be a compromise, namely a bilingual education system which supports from all cases of society by using Kiswahili, together with an early introduction of English and its promotion as a privileged foreign language, so that Tanzania can continue to develop internally through Kiswahili and at the same time retain access to the globalising world through the medium of English.

Differential perception of innovation with particular reference to the organisational context

Differential perception of innovation is a research area which has been advocated as a suitable topic for study in recent years. It developed from the problems encountered within earlier perception of innovation studies which sought to establish what characteristics of an innovation affected the ease of its adoption. While some success was achieved In relating perception of innovation to adoption behaviour, variability encountered Within groups expected - to fercelve innovation similarly suggested that the needs and experiences of the potential adopter were significantly affecting the research findings. Such analysis being supported by both sociological and psychological perceptual research. The present study sought to identify the presence of differential perception of innovation and explore the nature of the process. It was decided to base the research in an organisational context and to concentrate upon manufacturing innovation. It has been recognised that such adoption of technological innovation is commonly the product of a collective decision-making process, involving individuals from a variety of occupational backgrounds, both in terms of occupational speciality and level within the hierarchy. Such roles appeared likely to significantly influence perception of technological innovation, as gathered through an appropriate measure and were readily identifiable. Data vas collected by means of a face-to-face card presentation technique, a questionnaire and through case study material. Differential perception of innovation effects were apparent In the results, many similarities and differences of perception being related to the needs and experiences of the individuals studied. Phenomenological analysis, which recognises the total nature of experience in infiuencing behaviour, offered the best means of explaining the findings. It was also clear that the bureaucratic model of role definition was not applicable to the area studied, it seeming likely that such definitions are weaker under conditions of uncertainty, such as encountered in innovative decision-making.

Nonlinear soliton propagation in a few mode optical fibre

We experimentally demonstrate adiabatic soliton propagation in the fundamental mode of a few mode optical fibre and more complex behaviour in a higher order mode, indicating that the impact of nonlinearities differs for each mode.

Polarisation mode coupling of excessively tilted fibre Bragg gratings with directional transverse loading

We report a distinctive polarisation mode coupling behaviour of tilted fibre Bragg gratings (TFBGs) with tilted angle exceeding 45°. The ex-45° TFBGs exhibit pronounced polarisation mode splitting resulted from grating structure asymmetry induced birefringence. We have studied and analysed the property of ex-45° TFBGs under transverse load applied to their equivalent fast- and slow-axis. The results show that the coupling between the orthogonally polarised modes takes place only when the load is applied to its fast-axis, giving a prominent directional loading response. This transverse load related polarisation property may be exploitable for implementation of optical fibre vector sensors capable of measuring the magnitude and orientation of the applied transverse load.

The single-phase induction motor:a critical appraisal of the rotating-field and cross-field theories with particular reference to skin effect

The purpose of this thesis is twofold: to examine the validity of the rotating-field and cross-field theories of the single-phase induction motor when applied to a cage rotor machine; and to examine the extent to which skin effect is likely to modify the characteristics of a cage rotor machine. A mathematical analysis is presented for a single-phase induction motor in which the rotor parameters are modified by skin effect. Although this is based on the usual type of ideal machine, a new form of model rotor allows approximations for skin effect phenomena to be included as an integral part of the analysis. Performance equations appropriate to the rotating-field and cross-field theories are deduced, and the corresponding explanations for the steady-state mode of operation are critically examined. The evaluation of the winding currents and developed torque is simplified by the introduction of new dimensionless factors which are functions of the resistance/reactance ratios of the rotor and the speed. Tables of the factors are included for selected numerical values of the parameter ratios, and these are used to deduce typical operating characteristics for both cage and wound rotor machines. It is shown that a qualitative explanation of the mode of operation of a cage rotor machine is obtained from either theory; but the operating characteristics must be deduced from the performance equations of the rotating-field theory, because of the restrictions on the values of the rotor parameters imposed by skin effect.