In order to understand tidal circulation and oceanic current for the seas around Taiwan, this study use a baroclinic unstructured grid model to build a high resolution model. This model use semi-implicit method to solve the dynamic of ocean movement and larger time step can be used to calculate. Unstructured grid can be used to resolve complex coastline and variation of depth. TaiDBMv6 depth data were chosen to describe the depth distribution and grid mesh size were determined by local depth, minimum mesh size is about 0.75 minutes, and maximum 13 minutes. Tidal boundaries use 8 constituents derived from FES2004 and calibrated with 34 tide station records. Data of 2009 were used to evaluate the model results. The average of all station root mean square error was 10.1 cm. Station at east side of Taiwan have smaller errors, which almost lower than 5 cm. The maximum error can be found inside Taiwan Strait, about 25cm, mainly caused by lack of depth data near the coastal area. For oceanic current model, GFS and NFS-MC CWB wind forecast were used as meteorology input. Initial fields and boundary condition are derived from HYCOM results. Nudging of salinity and temperature also were used to stabilize the model. Transport of Kuroshio of 2009 is about 17.0¡Ó3.2Sv. Maximum value is about 28.6Sv, occurred in summer. Minimum value is about 8.3Sv, occurred in winter.

The amount of information on the internet is increasing every day and it is very difficult to find exact information from big list of search results. Users typically generate query specifying keywords and the search engine displays documents, what contains keywords what were set by user. Search within unstructured data starts from data processing: first of all documents are braked into sentences, then words and word groups are analyzed semantically and syntactically, to obtain facts. Facts describe objects of real world. Facts obtained from unstructured data will be stored into database, and unstructured data will be transformed into structured data. Afterwards it will be easy to analyze, conjunct, filter or do other manipulations with structured data.

Replication is a popular technique for increasing data availability and improving perfor- mance in peer-to-peer systems. Maintaining freshness of replicated data is challenging due to the high cost of update management. While updates have been studied in structured networks, they have been neglected in unstructured networks. We therefore confront the problem of maintaining fresh replicas of data in unstructured peer-to-peer networks. We propose techniques that leverage path replication to support efficient lazy updates and provide freshness for cached data in these systems using only local knowledge. In addition, we show that locally available information may be used to provide additional guarantees of freshness at an acceptable cost to performance. Through performance simulations based on both synthetic and real-world workloads from big data environments, we demonstrate the effectiveness of our approach.

The thesis presents work across three different subjects of investigations into the modelling of spray development and its interaction with non-reactive and reactive flow. The first part of this research is aimed to create a new and robust family of convective scheme to capture the interface between the dispersed and the carrier phases without the need to build up the interface boundary. The selection of Weighted Average Flux (WAF) scheme is due to this scheme being designed to deal with random flux scheme which is second-order accurate in space and time. The convective flux in each cell face utilizes the WAF scheme blended with Switching Technique for Advection and Capturing of Surfaces (STACS) scheme for high resolution flux limiters. However in the next step, the high resolution scheme is blended with the scheme to provide the sharpness and boundedness of the interface by using switching strategy. The proposed scheme is tested on capturing the spray edges in modelling hollow cone type sprays without need to reconstruct two-phase interface. A test comparison between TVD scheme and WAF scheme using the same flux limiter on convective flow on hollow cone spray is presented. Results show that the WAF scheme gives better prediction than the TVD scheme. The only way to check the accuracy of the presented models are evaluations according to physical droplets behaviour and its interaction with air. In the second part, due to the effect of evaporation the temperature profile in the released fuel vapour has been proposed. The underlying equation utilizes transported vapour mass fraction. It can be used along with the solution of heat transfer inside a sphere. After applying boundary conditions, the equation can provide a solution of existing conditions at liquid-gas interface undergoing evaporation and it is put in a form similar to well-known one-third rule equation. The resulting equation is quadratic type that gives an accurate prediction for the thermo-physical properties due to the non-linear relation between measured properties and temperature. Comparisons are made with one-third rule where both equations are implemented in simulating hollow cone spray under evaporation conditions. The results show the presumed equation performs better than one-third rule in all comparisons. The third part of this research is about a conceptual model for turbulent spray combustion for two combustion regimes that has been proposed and tested for n-heptane solid cone spray type injected into a high-pressure, high-temperature open reactor by comparing to the available experimental data and to results obtained using two well known combustion models named the Combined Combustion Model (CCM) and the unsteady two-dimensional conditional moment closure (CMC) model. A single-zone intermittent beta-two equation turbulent model is suggested to characterise the Lumped zone. This model can handle both unburned and burned zones. Intermittency theory is used to account for the spatially non-uniform distribution of viscous dissipation. The model suggests that the Lumped zone can be identified by using the concept of Tennekes and Kuo-Corrsion of isotropic turbulence that suggests that dissipative eddies are most probably formed as vortex tubes with a diameter of the order of Kolmogorov length scale and a space of the order of Taylor length scale. Due to the complexity of mixture motion in the combustion chamber, there exist coherent turbulent small scale structures containing highly dissipative vortices. The small size eddies play an important role in extinguishing a diffusion spray flame and have an effect on the combustion reaction at molecular scale because small scales turbulence increase heat transfer due to the dissipation. A common hypothesis in constructing part of the model is if the Kolmogorov length scale is larger than the turbulent flame thickness. The Lumped strategy benefits from capturing small reactive scales information provided by numerics to improve the modelling and understand the exact implementation of the underlying chemical hypothesis. The Lumped rate is estimated from the ratio of the turbulent diffusion to reaction flame thickness. Three different initial gas temperature test cases are implemented in simulations. Lumped spray combustion model shows a very good agreement with available experimental data concerning auto-ignition delay points.

A discrete adjoint method is developed and demonstrated for aerodynamic design optimization on unstructured grids. The governing equations are the three-dimensional Reynolds-averaged Navier-Stokes equations coupled with a one-equation turbulence model. A discussion of the numerical implementation of the flow and adjoint equations is presented. Both compressible and incompressible solvers are differentiated, and the accuracy of the sensitivity derivatives is verified by comparing with gradients obtained using finite differences and a complex-variable approach. Several simplifying approximations to the complete linearization of the residual are also presented. A first-order approximation to the dependent variables is implemented in the adjoint and design equations, and the effect of a "frozen" eddy viscosity and neglecting mesh sensitivity terms is also examined. The resulting derivatives from these approximations are all shown to be inaccurate and often of incorrect sign. However, a partially-converged adjoint solution is shown to be sufficient for computing accurate sensitivity derivatives, yielding a potentially large cost savings in the design process. The convergence rate of the adjoint solver is compared to that of the flow solver. For inviscid adjoint solutions, the cost is roughly one to four times that of a flow solution, whereas for turbulent computations, this ratio can reach as high as ten. Sample optimizations are performed for inviscid and turbulent transonic flows over an ONERA M6 wing, and drag reductions are demonstrated. / Ph. D.

Yes / Researchers have used the simulation technique to develop new networks and test, modify, and optimize existing ones. The scientific community has developed a wide range of network simulators to fulfil these objectives and facilitate this creative process. However, selecting a suitable simulator appropriate for a given purpose requires a comprehensive study of network simulators. The current literature on network simulators has limitations. Limited simulators have been included in the studies with functional and performance criteria appropriate for comparison not been considered, and a reasonable selection model for selecting the suitable simulator has not been presented. To overcome these limitations, we studied twenty-three existing network simulators with classifications, additional comparison parameters, system limitations, and comparisons using several criteria. / This work was supported by the Petroleum Technology Development Fund (PTDF) Nigeria with grant number PTDF/ED/PHD/MAS/179/17.

Several different time-integration algorithms for the Euler equations are investigated on two distributed-memory parallel computers using an explicit message-passing paradigm: these are classic Euler Explicit, four-stage Jameson-style Runge-Kutta, Block Jacobi, Block Gauss-Seidel, and Block Symmetric Gauss-Seidel. A finite-volume formulation is used for the spatial discretization of the physical domain. Both two- and three-dimensional test cases are evaluated against five reference solutions to demonstrate accuracy of the fundamental sequential algorithms. Different schemes for communicating or approximating data that are not available on the local compute node are discussed and it is shown that complete sharing of the evolving solution to the inner matrix problem at every iteration is faster than the other schemes considered. Speedup and efficiency issues pertaining to the various time-integration algorithms are then addressed for each system. Of the algorithms considered, Symmetric Block Gauss-Seidel has the overall best performance. It is also demonstrated that using parallel efficiency as the sole means of evaluating performance of an algorithm often leads to erroneous conclusions; the clock time needed to solve a problem is a much better indicator of algorithm performance. A general method for extending one-dimensional limiter formulations to the unstructured case is also discussed and applied to Van Albada’s limiter as well as Roe’s Superbee limiter. Solutions and convergence histories for a two-dimensional supersonic ramp problem using these limiters are presented along with computations using the limiters of Barth & Jesperson and Venkatakrishnan — the Van Albada limiter has performance similar to Venkatakrishnan’s. / Ph. D.

This study explores therapists' spiritual experience, personally and within the therapeutic relationship. It focuses on the lived experience of therapists and the different meanings made of what is experienced. The purpose of this research is to bring into the light spiritual experiences of therapists and how they are experienced in the therapeutic process. It contributes to current debate about spiritual experience in the day- to- day practice of psychotherapy. The methodology of phenomenological hermeneutics is chosen as it provides the means to study therapists' lived experience. The study is guided by the philosophical thinking of Heidegger, Gadamer and Van Manen.The findings of this study reveal different types of spiritual experience. These include non-ordinary states of consciousness where there is a feeling sense of being beyond the boundaries of linear time and space. Experiences involve noticing subtle body feelings before they manifest in everyday consciousness. They include hearing and seeing phenomena that may normally be overlooked or disavowed in psychotherapy. The findings show therapists' ability to notice, explore and utilize subtle body phenomena was a combination of their own capabilities, their spiritual practice, and years of experience as therapists. The therapist's body appeared to be like a doorway into experiences that had transformative effects on both therapists and clients. The meanings made of experiences reflected therapists' spiritual and cultural beliefs. These beliefs meant that therapists are attuned to something bigger than everyday identity that gave meaning and purpose to the work and was a rich source of wisdom and guidance, comfort and a sense of being held in the work. Specific attitudes and qualities of presence are revealed that reflect therapists' spiritual beliefs. Participants described experiences that emerged out of the context of the therapeutic relationship but could not be explained clinically. The findings show therapists' world views, their spiritual and cultural beliefs and capacity to experience the unknown, bring a richness and diversity of meanings to the therapeutic relationship that includes the wider contexts of culture and the environment. This study explores current thinking about spiritual experience in psychotherapy and its effects on the therapist. It raises issues for further discussion relating to the role of therapists' spiritual experience in contemporary psychotherapy.

The intrinsic flexibility of unstructured meshes is compelling for numerical ocean modeling. Complex topographic features, such as coastlines, islands and narrow straits, can faithfully be represented by locally increasing the mesh resolution and because there is no constraint on the mesh topology. In that respect, the finite element method is particularly promising. Not only does it allow for naturally handling unstructured meshes but it also offers additional flexibility in the choice of interpolation and is sustained by a rich and rigorous mathematical framework. This doctoral research was carried out under the auspices of the SLIM (Second-generation Louvain-la-Neuve Ice-ocean Model) project, the objective of which is to develop an ocean general circulation model using the finite element method. This PhD dissertation deals with one-, two- and three-dimensional finite element ocean modeling. We chiefly focus on the accurate representation of some selected oceanic processes and we devote much effort toward using a consistent finite element method to solve the underlying equations. We first concentrate on the finite element solution to a one-dimensional benchmark for the propagation of Poincaré waves with particular emphasis on the discontinuous Galerkin method and a physical justification for computing the numerical fluxes. We then compare three finite element formulations (vorticity - streamfunction, velocity - pressure and free-surface) for the solution to geophysical fluid flow instabilities problems. The prominent -- and remaining -- part of this work deals with three-dimensional ocean modeling on moving meshes. It covers the selection of the right elements for the vertical velocity and tracers through achieving strict tracer conservation and local consistency between the elevation, continuity and tracer equations. The ensuing three-dimensional model is successfully validated against a realistic tidal flow around a shallow-water island. New physical insights are proposed as to the physical processes encountered in such flows.

Turbulent flows present structures with a wide range of scales. The computation of the complete physics of a turbulent flow (termed DNS) is very expensive and is, for the time being, limited to low and medium Reynolds number flows. As a way to capture high Reynolds number flows, a part of the physics complexity has to be modeled. Large eddy simulation (LES) is a simulation strategy where the large turbulent eddies present on a given mesh are captured and the influence of the non-resolved scales onto the resolved ones is modeled. The present thesis reports on the development and validation of a methodology in order to apply LES for complex wall-bounded flows. Discretization methods and LES models, termed subgrid scale models (SGS), compatible with such a geometrical complexity are discussed. It is proved that discrete a kinetic energy conserving discretization of the convective term is an attractive solution to perform stable simulations without the use of an artificial dissipation, as upwinding. The dissipative effect of the SGS model is thus unaffected by any additional dissipation process. The methodology is first applied to a developed parallel fourth-order incompressible flow solver for cartesian non-uniform meshes. In order to solve the resulting Poisson equation, an efficient multigrid solver is also developed. The code is first validated using DNS (Taylor-Green vortex, channel flow, four-vortex system) and LES (channel flow), and finally applied to the investigation of an aircraft two-vortex system in ground effect. The methodology is then applied to improve a RANS-based industrial unstructured compressible flow solver, developed at CENAERO, to perform well for LES applications. The proposed modifications are tested successfully on the unsteady flow past a sphere at Reynolds of 300 and 10000, corresponding to the subcritical regime.