System- and Data-Driven Methods and Algorithms

An increasing complexity of models used to predict real-world systems leads to the need for algorithms to replace complex models with far simpler ones, while preserving the accuracy of the predictions. This two-volume handbook covers methods as well as applications. This first volume focuses on real-time control theory, data assimilation, real-time visualization, high-dimensional state spaces and interaction of different reduction techniques

THE FERRY SERVICE OFFER AN ANALYSIS OF FERRY SERVICES OPERATING FROM AND WITHIN THE UNITED KINGDOM

The objective of this study is to investigate the market offer of passenger-car ferry services within and from the United Kingdom. The study is approached from the pomt of view of the provider of the ferry service offer. Initially, it seeks to analyse the existing ferry services offered within and from the United Kingdom by the various operators, and subsequently undertakes an empirical investigation based on the appropriate marketing and management theory. The role of the consumer is, of course, crucial to an understanding of the marketing of ferry services. However, this particular study focuses on the supply of the ferry offer, and may be seen as complementary to earUer studies of ferry consumers and benefits sought. A comparison of on-board facilities and services on 70 ferries operating in the UK in 1994 resulted in the development of a basehne model explaining differences between services according to a wide range of criteria. This led to the development of a conceptual model of the ferry service offer using concepts from services marketing and corporate culture theory. Using cluster analysis it was concluded that the ferry service offer can be described in terms of core, augmented, and inter-product levels. In addition to these three ferry service offer levels the preferred service provider of each particular ferry service element has been identified. Using multiple discriminant analysis it was concluded that the augmented ferry service offer can be explained by differences among Miles & Snow corporate culture types (prospectors, analysers, and defenders). Combining these results, this study provides an explanation of the ferry service offer in terms of product level, preferred provider, and dominant corporate culture, which should prove of both practical and theoretical value

Modeling and simulation of arterial walls with focus on damage and residual stresses

Die vorliegende Arbeit behandelt die kontinuumsmechanische Modellierung von Arterienwänden. Ein Schwerpunkt liegt in der Konstruktion von anisotropen Schädigungsmodellen zur Beschreibung von Schädigungseffekten in Arterienwänden, wie sie bei therapeutischen Maßnahmen auftreten. Solche Schädigungseffekte gelten als einer der wesentlichen Faktoren für eine erfolgreiche Behandlung von atherosklerotisch degenerierten Arterien mittels Ballonangioplastie. Ein weiterer Schwerpunkt liegt in der Erarbeitung eines numerischen Modells zur Berücksichtigung von Eigenspannungen in Arterienwänden. Eigenspannungen beeinflussen die Spannungsverteilung in Umfangsrichtung derart, dass sie zu einer Verringerung der Spannungsgradienten in der Arterienwand beitragen. Hierauf aufbauend wird ein neuer Ansatz zur Implementierung von Eigenspannungen vorgeschlagen. Alle Modelle werden an experimentelle Daten angepasst und auf die numerische Simulation von patientenspezifischen Arterienwänden angewendet. Die Quasi-Inkompressibilität des Materials wird zum einen durch die Verwendung einer Penalty-Methode und zum anderen über einen Augmented-Lagrange Ansatz erfüllt. Beide Methoden werden hinsichtlich ihres Einflusses auf die Robustheit numerischer Simulationen untersucht.The present work deals with the continuum-mechanical modeling and analysis of arterial walls. One focus is on the construction of anisotropic damage models that are able to reflect damage effects in arterial tissues under therapeutic loading. Damage effects are assumed to be a main contributor to the success of a balloon angioplasty, which is a method of treatment of atherosclerotic arteries. Another main focus is on the elaboration of a numerical model for the incorporation of residual stresses in arterial walls. Residual stresses influence the circumferential stress distribution in such a way that they prevent large stress gradients in the arterial wall. Thus, a novel approach for the implementation of residual stresses is proposed. All models are adjusted to experimental data and applied to numerical simulations of patient-specific arterial walls. The quasi-incompressibility constraint is ensured by using the Penalty-Method and the Augmented-Lagrange-Method, which are analyzed with respect to their computational robustness

Improvisation, Computers, and Interaction : Rethinking Human-Computer Interaction Through Music

Interaction is an integral part of all music. Interaction is part of listening, of playing, of composing and even of thinking about music. In this thesis the multiplicity of modes in which one may engage interactively in, through and with music is the starting point for rethinking Human-Computer Interaction in general and Interactive Music in particular. I propose that in Human-Computer interaction the methodology of control, interaction-as-control, in certain cases should be given up in favor for a more dynamic and reciprocal mode of interaction, interaction-as-difference: Interaction as an activity concerned with inducing differences that make a difference. Interaction-as-difference suggests a kind of parallelity rather than click-and-response. In essence, the movement from control to difference was a result of rediscovering the power of improvisation as a method for organizing and constructing musical content and is not to be understood as an opposition: It is rather a broadening of the more common paradigm of direct manipulation in Human-Computer Interaction. Improvisation is at the heart of all the sub-projects included in this thesis, also, in fact, in those that are not immediately related to music but more geared towards computation. Trusting the self-organizing aspect of musical improvisation, and allowing it to diffuse into other areas of my practice, constitutes the pivotal change that has radically influenced my artistic practice. Furthermore, is the work-in-movement (re-)introduced as a work kind that encompasses radically open works. The work-in-movement, presented and exemplified by a piece for guitar and computer, requires different modes of representation as the traditional musical score is too restrictive and is not able to communicate that which is the most central aspect: the collaboration, negotiation and interaction. The Integra framework and the relational database model with its corresponding XML representation is proposed as a means to produce annotated scores that carry past performances and version with it. The common nominator, the prerequisite, for interaction-as-difference and a improvisatory and self-organizing attitude towards musical practice it the notion of giving up of the Self. Only if the Self is able and willing to accept the loss the priority of interpretation (as for the composer) or the faithfulness to ideology or idiomatics (performer). Only is one is willing to forget is interaction-as-difference made possible. Among the artistic works that have been produced as part of this inquiry are some experimental tools in the form of computer software to support the proposed concepts of interactivity. These, along with the more traditional musical work make up both the object and the method in this PhD project. These sub-projects contained within the frame of the thesis, some (most) of which are still works-in-progress, are used to make inquiries into the larger question of the significance of interaction in the context of artistic practice involving computers

Essays on entry and market profitability in the UK pharmaceuticals

This thesis applies economic methods developed in industrial organization to assess entry barriers and profitability of the pharmaceutical market in the UK. The thesis has two parts. The first part investigates whether incumbent firms strategically proliferate product varieties to delay and deter entry of competitors, and whether such strategy is effective to be a barrier. Three sets of regressions are employed: a non-monotonicity test between number of products and market size, as proposed by Ellison and Ellison (2011); a hazard rate model of entry probability, with focus on whether entry can be influenced by product varieties; and a regression of incumbent’s market share post entry to test whether their share is positively correlated with product varieties built prior to entry. The results suggest that product proliferation can be a barrier to entry in the UK, however, evidence on incumbents’ strategic incentive is inconclusive. The second part of the thesis focuses on antibiotic market. With the use of antibiotics, bacteria start to develop resistance, which has became a global crisis in healthcare. Despite the need for new entries because old molecules are losing effectiveness, research firms are leaving this market. We use nested logit and random coefficients logit model to estimate the price elasticity of demand between drugs in order to assess the profitability of the market and to evaluate policy interventions of shifting consumption away from molecules that cause higher resistance. We find that price-cost margin of this market is 35.2% on average but varies by molecules and drug types (branded/generics). We also find that some interventions can be effective to shift demand but with prices to pay

The geology and structure of the Bushveld Complex metamorphic aureole in the Olifants River area.

Thesis (Ph.D.)-University of Natal, Durban, 1998.The contact metamorphic aureole of the Rustenburg Layered Suite of the Bushveld Complex extends to a depth of over 5 km into the underlying mainly argillaceous Pretoria Group. When compared to other parts of the metamorphic aureole, the Olifants River area is unique in that it is characterised by a high degree of syn-Bushveld Complex deformation and very coarse grained pelitic assemblages. This is believed to have resulted from a combination of greater magma thickness, a deeper emplacement depth and a high degree of subsidence related deformation that was focused along the Thabazimbi-Murchison Lineament. This area also contains a laterally extensive and deformed quartz-feldspar porphyry sill, the Roodekrans Complex that is shown to represent a hypabyssal equivalent of the volcanic Rooiberg Group. There are three main metamorphic zones. A wide andalusite zone dominated by staurolite, garnet and cordierite assemblages. This is followed by a narrow fibrolite zone without staurolite, and a wide inner aureole of migmatite. The migmatite zone is characterised by garnet-cordierite-aluminosilicate assemblages with corundum, spinel and orthopyroxene assemblages at the highest grades. Metamorphic pressure and temperature estimates indicate pressures of between 3 kb and 4 kb in the lower part of the andalusite zone at temperatures of approximately 550°C. Porphyroblast-matrix relationships reveal a close link between deformation and metamorphism resulting in a spectrum of textural relationships developed as a result of inhomogeneous strain. Porphyroblasts in low strain domains preserve textures of “static type" growth whereas syntectonic textures are found in foliated rocks. Pre-tectonic porphyroblasts in many foliated domains indicate that deformation outlasted porphyroblast growth and increased in intensity and extent with time. Retrograde porphyroblasts are post-tectonic. Evidence is presented for both rotation and non-rotation of porphyroblasts in relation to geographical coordinates during extensional top-to-south, down-dip shear in the floor. The unique structural setting in this area triggered the growth of large diapiric structures in the floor of the Rustenburg Layered Suite that are preserved as periclinal folds on the margin and within the northeastern Bushveld Complex. Extreme gravitational loading and heating of the floor by a thickness of up to 8 km of mafic magma resulted in the generation of evenly spaced, up to 7 km diameter wall-rock diapirs that penetrated the overlying magma chamber. Diapiric deformation is restricted to rocks above a decollement zone that is developed along competency contrasts and corresponds approximately with the 550 °C peak metamorphic isotherm. Strongly lineated, boudinaged and foliated rocks are developed in the interpericlinal domains between adjacent periclines. Migmatites in these domains are characterised by conjugate extensional ductile shears and associated asymmetrical boudinage suggesting bulk deformation by pure shear processes. The extension lineation was produced by lateral extension along flow lines directed toward dome culminations. Each of the four diapiric periclines is cut by a different erosional section enabling reconstruction of a typical diapir geometry. At the highest structural levels, periclines have bulbous shapes with overturned limb geometries forming overhangs. The surrounding layered igneous rocks are locally deformed into a series of outward verging folds that define a broad rim syncline. Deformation within the pericline cores is represented by constrictional deformation that produced radial curtain-type folds with steeply plunging lineations and concentrically orientated folds in the outer shell. Diapirism is closely linked to magma emplacement mechanisms. Floor folds in the country rocks were initiated in the interfinger areas of a fingered intrusion. With further magma additions and the coalescence of intrusion fingers into a single sheet, interfinger folds matured into large diapiric periclines which rose to the upper levels of the magma chamber. Strain rates estimated from strain analyses, pericline geometry and model cooling calculations are in the order of 10-14 S-1, corresponding to diapiric uplift rates of 0.6 cm/yr. Diapirism is broadly compatible with a N-S extension in the Olifants River area during emplacement of the Rustenburg Layered Suite. On a regional scale, this is indicated by existence of a major EW dyke swarm that coincides with the long axis of the Bushveld Complex. The accommodation of the Bushveld Complex into the Kaapvaal Craton was facilitated by a combination of craton-wide extension that accompanied plume related magmatic underplating, and loading of the Bushveld Complex. Isostatic adjustment in response to Bushveld Complex subsidence resulted in further development of large basement domes around the perimeter of the Bushveld Complex.Big maps not scanned

A distributed simulation model of a reconstructed ancient water harvesting system in the Negev Desert.

This thesis addresses the problems of evaluating a water harvesting catchment system in the arid environment of the Negev Desert, Israel. A general interpretation of arid hillslope hydrological response is developed called Contiguous Area Contribution. Whilst agreeing with humid area concepts of partial area contribution, it focusses on the different nature of arid slope contributions to stormflow where frequent and rapid overland flow generation intercepts channels by downslope expansion and extension of flow-lines. The physical system at Avdat is geometrically represented as a flow net of hillslope and channel cascades for kinematic routing. A survey of the micro-morphology and surface materials enables hillslope areas to be classified into six broad units on the basis of their textural characteristics. These units are used to quasi-distribute process data sampled at locations within them. The process of infiltration is discussed and different mathematical models examined using results from a limited number of field measurements with runon/runoff apparatus. The best-fit is provided by the storage model of Green and Ampt and not the Hortonian models of Philip and Kostiakov. Initial infiltration rates vary from 85 to 18 mm hr-1 and steady- state rates from 60 to 6 mm hr-1. The inclusion of detention storage in early time period observations is shown to be a significant problem in modelling. For flow routing, an alternative approach to assuming sheetflow is presented using cross-slope microtopographic profiles to provide an estimate of surface geometry for flow across micro-rough surfaces. Measurements of flow velocity for different discharges are made using the runon/runoff apparatus. By assuming sheetflow, a lower value of Manning's n is predicted if velocity and flow dimensions are known. For a given n, the assumption of sheetflow predicts a lower velocity for a given discharge. The values of n derived at Avdat range from 0.18 to 1.36 with a mean of 0.64 when a micro-rough surface is retained, and 0.12 to 0.62 with a mean of 0.36 if sheetflow is assumed, values considerably higher than those usually adopted from channel studies. A distributed model is developed to handle surface runoff processes at a range of scales from the small plot to the complete catchment. In a detailed sensitivity analysis, the range of physical and process parameters derived for Avdat show sensitivity of the runoff processes to particular parameters and their combination. For the selected range, flow boundary shape is the most significant influence on the shape of flow hydrographs resulting in quicker, higher peaks if a micro-rough flow geometry is assumed. The model is used at the plot scale to examine the problem of including detention storage in infiltration model parameters, at the cascade scale to show the effect of runoff production enhancing and inhibiting slope areas, and at the sub-catchment scale to assess the predictive ability of the model using the limited process parameter data-set. With three sub-catchments, prediction errors were good volumetrically ranging from 6% to 14% for the high intensity, short duration rainstorm, but deteriorated for the long duration, varied intensity storm with predicting high overestimates. Three sub-catchments consistently under-predicted and one over-predicted. In most, the rising and falling limbs were lagged relative to the observed hydrographs