M.Ing. / Spoornet currently has a fleet of more than 1500 electric locomotives in service. The majority of electric locomotives are resistor controlled but there are many chopper as well as thyristor controlled locomotives which all incorporate direct current (dc) traction motors. In recent years Spoornet has also bought locomotives employing alternating current (ac) traction motors. Because locomotives are very expensive and the running costs are high it is important that these locomotives must be available and reliable. Most of the newer generation locomotives, which are the semiconductor controlled locomotives, must be in service for at least another 20 years. The availability and reliability are often influenced by delayed design problems as well as problems arising due to changes in the total system configuration. One way of solving these problems, or at least understanding them, is by employing computer simulations. The availability and reliability can also be improved by using new technologies which were not originally employed on the locomotives. By doing computer simulations the optimal solution can be obtained when introducing new technologies on the locomotive. A good example of this type of application within Spoornet is given in [6], where simulation models for high technology locomotives were developed which were suitable to be used in the assessment of electromagnetic compatibility between modern power electronic locomotives and the railway signaling system. However, these models are also suited to be used in other applications. These models make use of the ATP-EMTP simulation program.

Wong Ngai-ning. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 65-67). / Abstracts in English and Chinese. / Abstract --- p.ii / Content --- p.iv / List of Table --- p.v / List of Figures --- p.v / Acknowledgement --- p.vii / Dedication --- p.viii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Related work --- p.2 / Chapter 1.2 --- Background --- p.6 / Chapter 1.3 --- Contribution --- p.23 / Chapter 1.4 --- Thesis roadmap --- p.24 / Chapter 2 --- The Capacitance method --- p.25 / Chapter 2.1 --- Theoretical Comparison --- p.29 / Chapter 3 --- Collision detection --- p.32 / Chapter 3.1 --- Searching the hierarchy --- p.33 / Chapter 3.2 --- Neighborhood algorithm --- p.35 / Chapter 3.3 --- Regional sphere tree update --- p.38 / Chapter 4 --- Implementation --- p.41 / Chapter 4.1 --- System Architecture --- p.41 / Chapter 4.2 --- Multi-contact latency --- p.45 / Chapter 5 --- Result and Analysis --- p.46 / Chapter 5.1 --- Pre-computation --- p.46 / Chapter 5.2 --- Relation matrix Establishment --- p.47 / Chapter 5.3 --- Sphere tree construction --- p.49 / Chapter 5.4 --- Regional sphere tree update --- p.50 / Chapter 5.5 --- Graphic result --- p.52 / Chapter 6 --- Conclusion and Future work --- p.62 / Chapter 6.1 --- Conclusion --- p.62 / Chapter 6.2 --- Future work --- p.64 / Reference --- p.65 / Appendix A --- p.68 / Appendix B --- p.70

by Ping-Fu Fung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 98-102). / Abstract also in Chinese. / Abstract --- p.iv / Acknowledgements --- p.vi / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Medical Visualization System --- p.4 / Chapter 1.1.1 --- Data Acquisition --- p.4 / Chapter 1.1.2 --- Computer-aided Medical Visualization --- p.5 / Chapter 1.1.3 --- Existing Systems --- p.6 / Chapter 1.2 --- Research Goal --- p.8 / Chapter 1.2.1 --- System Architecture --- p.9 / Chapter 1.3 --- Organization of this Thesis --- p.10 / Chapter 2 --- Volume Visualization --- p.11 / Chapter 2.1 --- Sampling Grid and Volume Representation --- p.11 / Chapter 2.2 --- Priori Work in Volume Rendering --- p.13 / Chapter 2.2.1 --- Surface VS Direct --- p.14 / Chapter 2.2.2 --- Image-order VS Object-order --- p.18 / Chapter 2.2.3 --- Orthogonal VS Perspective --- p.22 / Chapter 2.2.4 --- Hardware Acceleration VS Software Acceleration --- p.23 / Chapter 2.3 --- Chapter Summary --- p.29 / Chapter 3 --- IsoRegion Leaping Technique for Perspective Volume Rendering --- p.30 / Chapter 3.1 --- Compositing Projection in Direct Volume Rendering --- p.31 / Chapter 3.2 --- IsoRegion Leaping Acceleration --- p.34 / Chapter 3.2.1 --- IsoRegion Definition --- p.35 / Chapter 3.2.2 --- IsoRegion Construction --- p.37 / Chapter 3.2.3 --- IsoRegion Step Table --- p.38 / Chapter 3.2.4 --- Ray Traversal Scheme --- p.41 / Chapter 3.3 --- Experiment Result --- p.43 / Chapter 3.4 --- Improvement --- p.47 / Chapter 3.5 --- Chapter Summary --- p.48 / Chapter 4 --- Parallel Volume Rendering by Distributed Processing --- p.50 / Chapter 4.1 --- Multi-platform Loosely-coupled Parallel Environment Shell --- p.51 / Chapter 4.2 --- Distributed Rendering Pipeline (DRP) --- p.55 / Chapter 4.2.1 --- Network Architecture of a Loosely-Coupled System --- p.55 / Chapter 4.2.2 --- Data and Task Partitioning --- p.58 / Chapter 4.2.3 --- Communication Pattern and Analysis --- p.59 / Chapter 4.3 --- Load Balancing --- p.69 / Chapter 4.4 --- Heterogeneous Rendering --- p.72 / Chapter 4.5 --- Chapter Summary --- p.73 / Chapter 5 --- User Interface --- p.74 / Chapter 5.1 --- System Design --- p.75 / Chapter 5.2 --- 3D Pen Input Device --- p.76 / Chapter 5.3 --- Visualization Environment Integration --- p.77 / Chapter 5.4 --- User Interaction: Interactive Navigation --- p.78 / Chapter 5.4.1 --- Camera Model --- p.79 / Chapter 5.4.2 --- Zooming --- p.81 / Chapter 5.4.3 --- Image View --- p.82 / Chapter 5.4.4 --- User Control --- p.83 / Chapter 5.5 --- Chapter Summary --- p.87 / Chapter 6 --- Conclusion --- p.88 / Chapter 6.1 --- Final Summary --- p.88 / Chapter 6.2 --- Deficiency and Improvement --- p.89 / Chapter 6.3 --- Future Research Aspect --- p.91 / Appendix --- p.93 / Chapter A --- Common Error in Pre-multiplying Color and Opacity --- p.94 / Chapter B --- Binary Factorization of the Sample Composition Equation --- p.96

在這篇論文中，我們提出了在醫學模擬應用的血管或傷口上作相互作用的粒子血流變模型框架。通過平滑粒子流體動力學（SPH）制定的非牛頓流體，進行了血液流變學的模擬。通過建模血管壁結構虛擬粒子，流體 - 結構相互作用（FSI）是一個純粹的拉格朗日(Lagrange)顆粒模型進行建模的血管或血液的交互。我們的建議的方法基於純粹的非網格方法，可用於常見的動脈瘤和血管狹窄等病症的建立上。如需模擬開放性傷口在手術部位中發生較大的變形情況時，我們則採用質量 - 彈簧系統進行血顆粒的交互，此交互框架可應用到幾個開放性手術模擬，如骨科或胃鏡檢查為基礎的手術。無論是常見的醫療圖像：如CT血管造影（CTA）、磁共振血管造影（MRA）或基於網格的數據也可以 作為系統輸入的數據。血栓形成與溶解模型也被集成到這個流固耦合框架中。實驗結果證明採用我們建議的粒子互相作用框架在模擬血管中的凝血過程是可行的。受益於簡潔的拉格朗日粒子交互作用模擬，我們的系統可以保持在互動幀速率中。 / 首先，我們在這篇論文中建議把無網格流變模擬框架應用於血管手術的建模中。於非牛頓粘性流動的假設下，我們建立了血液結構的一般模型方程：以平滑粒子流體動力學實現多血粘度模型與低彈性血管壁模型。血流動力學和軟組織都可以於相同的拉格朗日粒子為基礎下模擬。在這個意義上說，通過延伸平滑粒子流體動力學的密度和動量求和不管顆粒的性質下，本論文提出了一個有效的流體 - 固體交互作用模型。該模型是特別有利於整合多種類型的介質（包括固體或液體）的。在這方面，我們進一步提出了一個與流體相關的血塊凝集溶解模型，可以適用於許多不同種類的醫學模擬：例如血栓栓塞。 / 其次，本論文亦提出了如何基於粒子的血液建模框架的前提下，擴展到大變形的軟組織互動。我們是以耦合雙向階段性質量 - 彈簧系統與固體顆粒，去代替無網格粒子固體的建模，用以維持真正人體組織的高保真度，此方法可以實現類似軟組織的皮膚或真皮的交互式模擬。而耦合血顆粒與平滑粒子方面，則由一個聰明的碰撞模塊處理，使得利用模擬皮膚表面之上，可以模擬出真實的表皮出血現象。該模型的動態計算進一步以物理學處理單元加速；而渲染的模型則是通過一個強大的圖形處理單元為基礎的立方體運行（marching cubes）的方法來實現。該模型已應用於全身血液管理培訓中。 / In this thesis, we propose particle-based rheological modeling frameworks for blood-vessel and blood-wound interaction in medical simulation applications. The effect of blood rheology has been simulated through a smoothed particle hydrodynamics (SPH) formulation of non-Newtonian flow. By modeling the vessel wall structure as virtual particles, a pure Lagrange particle formulation for fluid-structure interaction (FSI) is proposed for modeling the blood-vessel or blood-device interaction. Our proposed framework synthesizes common vascular complication sites such as stenosis and aneurysm based on purely mesh-less approach. For larger deformation situations happened in surgical sites such as open wound, we adopt a mass-spring system to interact with the blood particles; the blood-wound interaction framework can be applied to several open surgery simulations such as orthopedics or endoscopy-based interventions. Input of the data can be obtained from either common medical modalities like computed tomographic angiography (CTA), magnetic resonance angiography (MRA) or processing mesh-based data. A thrombus (clot) formation-dissolution model is also integrated into this fluid-solid interaction framework. Results have demonstrated the feasibility of employing our proposed particle framework in simulating blood-vessel interaction in the clotting process which is essential to vascular procedure simulations. Having benefited from the elegant formulation of Lagrangian particle interaction; the simulation can be maintained at interactive frame-rates. / In this thesis, first, a meshless rheological modeling framework for medical simulation of vascular procedures is proposed. Instead of assuming a Newtonian non-viscous flow, we have built our model based on the general constitutive equation of blood. The multi-regime of viscosity in blood model with a hypoelastic model of vessel wall has been realized under a SPH formulation. The hemodynamic and the soft tissue can all be simulated under the same Lagrangian particle-based formulation. In this sense, an efficient formulation of fluid-solid interaction is proposed through extending SPH summations of density and momentum regardless the nature of particles. This model is particularly beneficial to the integration of multiple types of media (including solids or fluids). With this regards, we further propose a flow related clot aggregation-dissolution model which can be applicable to many different kinds of medical simulation e.g. thrombo-embolization. / Second, the proposed particle-based blood modeling framework has been extended to interact with large deformation of soft tissue. Instead of modeling the solid as meshless particles, a bi-phasic mass-spring system is coupled with solid particles so that an interactive simulation of skin or dermis like soft tissue can be realized with high fidelity to real human tissue. To couple with the SPH formulation of blood particles, a smart collision handling module is exploited so that a realistic bleeding simulation on top of the skin surface can be created. The dynamic computation of this model is further accelerated by the physics processing unit; while the rendering of the model is realized through a robust graphics processing unit based marching cube approach. The proposed model has been applied to provide general blood management training. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Chui, Yim Pan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 98-113). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / Abstract --- p.ii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Related works on physically based fluid-structure models --- p.7 / Chapter 2.1 --- Eulerian grid-based methods --- p.8 / Chapter 2.2 --- Lagrangian grid-based methods --- p.9 / Chapter 2.3 --- Lagrangian meshfree methods --- p.11 / Chapter 2.4 --- Fluid-structure interaction (FSI) --- p.12 / Chapter 2.5 --- Endovascular simulation --- p.14 / Chapter 2.6 --- Overview of Our Model --- p.15 / Chapter 3 --- Meshless blood-clot interaction --- p.16 / Chapter 3.1 --- Basic equations of fluid dynamics --- p.17 / Chapter 3.2 --- SPH basics --- p.18 / Chapter 3.3 --- SPH Rheological hemodynamics of blood --- p.20 / Chapter 3.4 --- SPH modeling of the hypoelastic vessel --- p.26 / Chapter 3.5 --- Fluid-solid interaction model --- p.28 / Chapter 3.6 --- Flow-related clot aggregation-dissolution model --- p.33 / Chapter 3.7 --- Time integration --- p.36 / Chapter 3.8 --- Hardware-friendly formulation --- p.37 / Chapter 3.9 --- Results --- p.39 / Chapter 3.9.1 --- Classical Dam-break problem --- p.41 / Chapter 3.9.2 --- Poiseuille flow --- p.43 / Chapter 3.9.3 --- Couette flow --- p.45 / Chapter 3.9.4 --- Mechanical model with material strength --- p.47 / Chapter 3.9.5 --- Hemoelastic feedback system --- p.49 / Chapter 3.9.6 --- Clotting in a stenosed vessel --- p.52 / Chapter 3.9.7 --- Timing results --- p.53 / Chapter 4 --- Meshless modeling of thrombo-embolization --- p.55 / Chapter 4.1 --- Modeling framework for thrombus formation within blood vessel . --- p.60 / Chapter 4.2 --- Geometric Modeling and Flow Simulation --- p.61 / Chapter 4.2.1 --- Data processing on vascular data --- p.61 / Chapter 4.2.2 --- Blood-Vessel particle distribution --- p.62 / Chapter 4.2.3 --- Blood-structure Interaction --- p.65 / Chapter 4.3 --- Visualization and Thrombosis Simulation --- p.66 / Chapter 4.3.1 --- Flow Visualization --- p.66 / Chapter 4.3.2 --- Thromb-Embolization Simulation --- p.68 / Chapter 4.4 --- Conclusion and discussion --- p.72 / Chapter 5 --- Lagrangian modeling framework for bleeding simulation --- p.76 / Chapter 5.1 --- SPH-based bleeding model --- p.78 / Chapter 5.2 --- Biphasic Soft-tissue deformation --- p.79 / Chapter 5.3 --- Interaction between blood and soft tissue --- p.83 / Chapter 5.4 --- Integrated training for blood management --- p.87 / Chapter 6 --- Discussion and Conclusion --- p.93 / Bibliography --- p.98

Choi Kup Sze. / "June 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 122-127). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Wai Yin Yee = 遺傳演算法的應用連續影像之人體動作捕捉 / 韋燕儀. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 113-115). / Text in English; abstracts in English and Chinese. / Wai Yin Yee = Yi zhuan yan suan fa de ying yong lian xu ying xiang zhi ren ti dong zuo bu zhuo / Wei Yanyi. / Abstract --- p.ii / 摘要 --- p.iv / Acknowledgement --- p.vi / Content --- p.vii / List of Figures --- p.x / List of Tables --- p.xviii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Human Motion Capture --- p.1 / Chapter 1.1.1 --- Optical Motion Capture --- p.3 / Chapter 1.1.2 --- Monocular Motion Capture --- p.4 / Chapter 1.2 --- Proposed Human Motion Capture System --- p.6 / Chapter 1.3 --- Organization --- p.8 / Chapter Chapter 2 --- Introduction of Genetic Algorithms --- p.10 / Chapter 2.1 --- Traditional Search Methods & Genetic Algorithms --- p.11 / Chapter 2.2 --- Mechanism of Genetic Algorithms --- p.14 / Chapter 2.3 --- A Simple Genetic Algorithm --- p.16 / Chapter 2.3.1 --- Initialization --- p.16 / Chapter 2.3.2 --- Evaluation --- p.17 / Chapter 2.3.3 --- Selection --- p.18 / Chapter 2.3.4 --- Genetic Operation --- p.19 / Chapter 2.3.5 --- Termination --- p.23 / Chapter 2.4 --- Convergence Proof for GA --- p.24 / Chapter 2.5 --- Proposed Modified Genetic Algorithm --- p.26 / Chapter 2.6 --- Effectiveness of the Proposed Modified GA on Function Optimization --- p.28 / Chapter 2.6.1 --- Function 1 - Unimodal function --- p.28 / Chapter 2.6.2 --- Function 2 - Sine function --- p.35 / Chapter 2.6.3 --- Function 3 - Foxhole function --- p.39 / Chapter 2.6.4 --- Function 4 - Discrete function --- p.41 / Chapter Chapter 3 --- Pre-processing I - Articulated Stick Model --- p.44 / Chapter 3.1 --- Background Knowledge of Human Skeleton --- p.44 / Chapter 3.2 --- Simplified Humanoid Articulated Stick Model --- p.44 / Chapter Chapter 4 --- Pre-Processing II - Reference Lengths & 2-D Frame Scale --- p.48 / Chapter 4.1 --- Optimization Approach --- p.54 / Chapter 4.1.1 --- Parameters Range --- p.62 / Chapter 4.1.2 --- GA Formulation --- p.63 / Chapter 4.2 --- Triangulation approach --- p.63 / Chapter 4.3 --- Experiments & Discussion --- p.66 / Chapter 4.3.1 --- Experiment One: Synthetic sequences --- p.67 / Chapter 4.3.2 --- Experiment Two: Real image sequences --- p.71 / Chapter Chapter 5 --- Pre-Processing III - Possible Depths --- p.76 / Chapter Chapter 6 --- Resolving Depth Ambiguity by GA --- p.83 / Chapter 6.1 --- Smoothness Assumption --- p.83 / Chapter 6.2 --- Kinematic Constraint --- p.85 / Chapter 6.3 --- GA Formulation --- p.85 / Chapter 6.4 --- Proposed Constrained GA --- p.86 / Chapter 6.5 --- Implementation and Experiments --- p.87 / Chapter 6.5.1 --- Experiment One: Synthetic sequences --- p.88 / Chapter 6.5.2 --- Experiment Two: Real image sequences --- p.105 / Chapter Chapter 7 --- Conclusion --- p.111 / Bibliography --- p.113 / Appendix A Description of Rotating Angles --- p.116

Thesis (M. Sc) --University of Limpopo, 1999 / refer to ducument

Background. Extensive studies have been conducted to simulate blood flow in the human vasculature using nonlinear equations of pulsatile flow in collapsible tube plus a network of vessels to represent the whole vasculature and the cerebral circulation. For non-linear models numerical solutions are obtained for the fluid flow equations. Methods. Equations of fluid motion in collapsible tubes were developed in the presence of gravitational force (Gforce). The Lax-Wendroff and MacCormack methods were used to solve the governing equations and compared both in terms of accuracy, convergence, and computer processing (CPU) time. A modified vasculature of the whole body and the cerebral circulation was developed to obtain a realistic simulation of blood flow under different conditions. The whole body vasculature was used to validate the simulation in terms of input impedance and wave transmission. The cerebral vasculature was used to simulate conditions such as presence of G-force, blockage of Internal Carotid Artery (ICA), and the effects on cerebral blood flow of changes in mean and pulse pressure. Results. The simulation results for zero G-force were in very good agreement with published experimental data as was the simulation of cerebral blood flow. Both numerical methods for solutions of governing equations gave similar results for blood flow simulations but differed in calculation performance and stability depending on levels of G-force. Simulation results for uniform and sinusoidal G-force are also in good agreement with published experimental results, Blood flow was simulated in the presence of a single (left) carotid artery obstruction with varying morphological structures of the Circle of Willis (CoW). This simulation showed significant differences in contralateral blood flow in the presence or absence of communicating arteries in the CoW. It also was able to simulate the decreases in blood flow in the cerebral circulation compartment corresponding to the visual cortex in the presence of G-force. This is consistent with the known loss of vision under increased acceleration. Conclusions. This study has shown that under conditions of gravitational forces physiological changes in blood flow in the systemic and cerebral vasculature can be simulated realistically by solving the one-dimentional fluid flow equations and non-linear vascular properties numerically. The simulation was able to predict changes in blood flow with different configurations and properties of the vascular network.

A variety of general circulation model experiments are performed to investigate the influence of seasonality and topography on the strength of baroclinic eddies in the Martian atmosphere. Three different models are used: a full physics model, a simplified physics model, and a zonally symmetric simplified physics model. All three models are sigma coordinate, finite difference global atmospheric circulation models that have been adapted to the Martian regime. The full physics model has previously been tested extensively by researchers at the NASA Ames Research Center. The simplified physics model replaces many of the atmospheric physics routines with simple parameterizations; most importantly, the radiation code is replaced by Newtonian cooling. A Newtonian cooling code with a radiative time constant that varies in height and latitude produces superior results to one with a radiative time constant that is the same everywhere throughout the atmosphere. It is found that baroclinic eddy activity is extremely sensitive to the mean meridional temperature gradient in the simplified model. A power law fit gives an exponent of approximately six. The baroclinic eddy activity is also sensitive to the maximum growth rate in the Eady model of baroclinic activity. This is due to the close connection between the meridional temperature gradient and the maximum growth rate. Baroclinic adjustment theory, which predicts how baroclinic eddies will react to changes in the mean circulation, does not appear to be valid in the Martian regime, according to the simplified model. This finding may be related to the differences in the relative strengths of the baroclinic eddies and the mean circulation on Earth and Mars. The simplified model indicates that seasonality is more important than topography in creating stronger eddies in the northern hemisphere winter than in the southern hemisphere winter. However, the effects of topography in the simplified model may not be adequately matching the effects of topography in the full physics model, particularly in the southern hemisphere. / Graduation date: 2001

This thesis presents elastic finite difference simulations of two dimensional wavefield propagation for line-9, recorded during the 1993 part of the multi-institutional, multi-year Mendocino Triple Junction (MTJ) Seismic Experiment. Line-9 is a high-resolution, large-aperture seismic profile oriented in north-south direction, extending from the subduction regime north of the MTJ to the transform regime south of the MTJ. Snapshots of the wavefield are recorded during the simulation to create a movie which assists with the analysis of the synthetic seismograms. The simulations are computed on a 64 processor CM-5 parallel supercomputer. First a velocity model obtained by the Mendocino Working Group is examined. The model is based on information from depth-migrated single-fold reflection profiles and tomographic inversion of first arrivals. The synthetic seismic sections show acceptable first arrival traveltime fit but fail to correctly model secondary arrivals and amplitude variations of the wavefield. Based on the shortcomings of the initial model an alternative model for the north-south line is proposed. The new model introduces several distinct structures, like a subducted Gorda plate, a slabless window, and a wedge shaped low velocity zone between Franciscan material and Gorda plate. The big difference between the two models is that the initial model is too smooth to contain any discontinuities and cannot account for any reflection arrivals. In addition all structures in the lower crust of the alternative models are located about 4 km deeper than the equivalent velocities in the initial model. The seismic sections of the alternative model show much improved traveltime and amplitude fit. Also, some characteristics of the wavefield observed in the field data (e.g. traveltime oscillations, amplitude variations, and discontinuous arrivals) are also observed in the synthetic seismograms.. The position of the southern end of the Gorda plate (SEDGE) is at 80 km in the model (39.7°N). Because of the limited resolution it is not possible to resolve whether the Gorda plate just north of the SEDGE is fragmented or continuous. To add attenuation by scattering or coda waves generation to the model, the effects of a stochastic velocity description for Franciscan rocks on the wavefield are explored. The best velocity contrast between sandstones and melange units in a bimodal, seifaffine, sinuous connected model is determined as 0.5 km/s. Stochastic models of this kind successfully model background noise and coda waves and to some degree discontinuous phases, amplitude variations, and traveltime oscillations. They cannot, however, account for the full range of characteristics observed in the field data. For this, additional large scale velocity variations must be added to the model. For the final model, the (deterministic) alternative model and the statistical description of Franciscan rocks are combined. The resulting wavefield shows good amplitude and traveltime fit and the observed wavefield characteristics are similar to the characteristics of the field data. / Graduation date: 1997 / Best scan available for figures.