Congestion control in wireline networks has been studied extensively since the seminal work by Mazumdar et al in 1998. It is well known that this global optimization problem can be implemented in a distributed manner. Stability and fairness are two main design objectives of congestion control mechanisms. Most literatures make the assumption that the number of flows is fixed in the network and each flow has infinite backlog for transfer in developing congestion control schemes. However, this assumption may not hold in reality. Thus, there is a need to study congestion control algorithm in the presence of dynamic flows. It is only until recently that short-lived flows have been taken into account. In this thesis, we study utility maximization problems for networks with dynamic flows. In particular, we consider the case where each class of flows arrives according to a Poisson process and has a length given by a certain distribution. The goal is to maximize the long-term expected system utility, which is a function of the number of flows and the rate (identical within a given class) allocated to each flow. Our investigation shows that, as long as the average work brought by the arrival processes is strictly within the network stability region, the fairness and stability issues are independent. While stability can be guaranteed by, for example, a FIFO policy, utility maximization becomes an unconstrained optimization. We also provide a queueing interpretation of this seemingly surprising result and show that not all utility functions make sense under dynamic flows. Finally, we use simulation results to show that our algorithm indeed maximizes the expected system utility.

The objective of this research is to assess the performance of two popularReynolds-averaged Navier-Stokes (RANS) models, standard k-E and k-w, andto suggest modifications to improve model predictions for high-speed flows. Numerical simulations of turbulent ow past a at plate are performed at M1 = 2:25; 7:2.The results from these two Mach number cases are compared with Direct NumericalSimulation (DNS) results from Pirozzoli et al. (2004) and experimental results fromHorstman & Owen (1975). The effect of the Boussinesq coefficient (Cu) and turbulenttransport coefficients (sigmak; sigmaE; sigma; sigma*) on the boundary layer ow is examined. Further,the performance of a new model with realizability-based correction to Cu and corresponding modifications to sigma; sigma* is examined. The modification to Cu is based oncontrolling the ratio of production to dissipation of kinetic energy (P/E=1). The firstchoice of P/E = 1 ensures that there is no accumulation of kinetic energy in stagnation or free-stream regions of the ow. The second choice of P/E= 1:6 holds underthe assumption of a homogeneous shear ow. It is observed that the new model'sperformance is similar to that of the existing RANS models, which is expected for asimple ow over a at plate. Finally, the role of turbulent Prandtl number (Prt) intemperature and density predictions is established. The results indicate that the k-wmodel's performance is better compared to that of the standard k-E model for highMach number flows. A modification to Cu must be accompanied with correspondingchanges to sigmak; sigmaE; sigma; sigma* for an accurate log-layer prediction. The results also indicate that a Prt variation is required across the boundary layer for improved temperatureand density predictions in high-speed flows.

We study approximation techniques for incompressible flows with heterogeneous properties. Speci cally, we study two types of phenomena. The first is the flow of a viscous incompressible fluid through a rigid porous medium, where the permeability of the medium depends on the pressure. The second is the ow of a viscous incompressible fluid with variable density. The heterogeneity is the permeability and the density, respectively. For the first problem, we propose a finite element discretization and, in the case where the dependence on the pressure is bounded from above and below, we prove its convergence to the solution and propose an algorithm to solve the discrete system. In the case where the dependence is exponential, we propose a splitting scheme which involves solving only two linear systems. For the second problem, we introduce a fractional time-stepping scheme which, as opposed to other existing techniques, requires only the solution of a Poisson equation for the determination of the pressure. This simpli cation greatly reduces the computational cost. We prove the stability of first and second order schemes, and provide error estimates for first order schemes. For all the introduced discretization schemes we present numerical experiments, which illustrate their performance on model problems, as well as on realistic ones.

ABSTRACT All the current moving in the financial market would be affected by the business cycle and the price the asset, Do all the investor realize the knowledge of the financial asset, and allocate their asset rationally or emotionally, even take the advice of the sales representative¡H After reading studies of mutual fund, For the purpose of realize the determinants of money flow, we combine the experience and econometrics and the opinion of market participants to undertake this study. In this study, we investigate the determinants of mutual fund flows from aggregate viewpoint. The empirical results are as follows: 1.The initial public offering of new fund have positive influence on the aggregate flow, no evidence that aggregate mutual fund flows have been affected by the stock return. 2.The stock returns with 1 month lag show no evidence to influence the flows, 3.Long-term real interest have obviously negative influence on the aggregate mutual fund and while short-tern interest does not. 4.Personal income positively related to aggregate mutual fund flows but not obvious for 1-month lagged income.

Regulators only require banks to manage their short-term exchange rate risk stringently. A possible reason is that the prevailing capital-market methodology cannot determine the long-term exchange rate risk. Using the real performance of operating incomes, this paper investigates the impact of fluctuating foreign currencies on the values of Taiwanese banking institutions, and decomposes the overall exchange rate risk into short-term and long-term components. We not only overcome the deficiency of prior studies that have limited success in detecting significant currency exposure, but also measure correct economic exposure that firms are confronted with. Comparing with the capital market approach, we find the evidence of the relative strength of cash flows to detect currency exposure. After controlling for the impact of interest rates, we find that, over the time period examined, 61.54% of the sample firms have a significant currency exposure, which is larger than those documented by prior research. Our result also shows that the existence of significant long-term exchange rate risk is prevalent among Taiwanese banking institutions. Furthermore, US dollar (the currency of a nation which is Taiwan¡¦s largest exporting country) has an opposite effect as opposed to Japanese Yen (the currency of a nation which is Taiwan¡¦s largest importing partner). Our results have policy implications that banking institutions should manage long-term currency exposure.

Abstract In the researches of image tracking to restore an object¡¦s position or velocity in the space, it is expectable that increasing numbers of camera can reduce the error. In fact, this phenomenon happens in practical applications. But so far, the physical theory behind this effect has not been fully known. Therefore, based on this motivation, this thesis tends to lay the physical foundation of specific machine vision problem using the statistical probability concept. Extensive error analysis and computer simulation for motion vector of translation movement solved by the least squares technique are conducted by incorporating Gaussian noised into optical flow components. It is expected to provide an effective theoretical model for further developments. Keywords¡GImage tracking, The least squares method, Gauss distribution, Error analysis.

This study examines the survival of individual subsidiary in an inter-subsidiary perspective within the ever-increasing competitive environment in the Greater China region between Mainland Chinese subsidiaries and Taiwanese subsidiaries. 80 Taiwanese Multinational Enterprises¡¦ (MNEs¡¦) participated in this study and the researcher specifically looked at the two sub-frameworks, data collected were empirically tested. In the first sub-framework, it examines the influences of inter-subsidiary competition for strategic positions on subsidiary survival with respect to its strategic importance, resource asymmetry, and some characteristics of value activities. In the second sub-framework, it examines the influences of competition on knowledge flow positions with respect to knowledge flows and intellectual capital. The results showed that these determinants have different effects on subsidiary survival. Specifically, in the first sub-framework, the strategic importance and advantages of intangible resources enhances a focal subsidiary¡¦s survival, whereas local responsiveness, advantages on physical resources, similarity and mobility of value activities decreases its survival. On the other hand, in the second sub-framework, determinants of knowledge flows specifically on knowledge inflows, knowledge transfer, and absorption capacity of a specific peer subsidiary decreases its survival rate. Further, determinants on intellectual capital such as application capabilities on organizational capital and human capital are seen as positive factors. Finally, this study discusses the implications of inter-subsidiary competition for these factors in determining a focal subsidiary¡¦s survival.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (p. 57-59).

The lower continental slope of Morocco’s west coast consists of Triassic-age salt manifested in the form of diapirs, tongues, sheets, and canopies, and both extensional and compressional structures that result from salt movements. Salt diapirism and regional tectonics greatly influenced a broad spectrum of depositional processes along the margin. Mapping of a 1064-km² (411-mi²) seismic survey acquired in the Safi Haute Mer area reveals that Jurassic to Holocene salt mobilization has induced sedimentation that manifests itself in gravity slumps and slides and debris flows. An east-west–trending structural anticline located downdip of the salt-influenced region, was activated during the Atlas uplift (latest Cretaceous) and shaped much of the lower continental slope morphology from Tertiary time until present. The largest of the mass transport deposits (MTC) is a 500-m (1640-ft)-thick Cretaceous-age unit that spans an area of up to 20,000 km2 (7722 mi2). Seismic facies composing the MTC are (1) chaotic, mounded reflectors; (2) imbricated continuous to discontinuous folded reflector packages interpreted to represent internal syn-depositional thrusts; and (3) isolated, thick packages of continuous reflectors interpreted to represent transported megablocks (3.3 km2 [1.3 mi2]). The latter show well preserved internal stratigraphy. The MTCs originated from an upslope collapse of a narrow shelf during the earliest phases of the Alpine orogeny. Seismic geomorphologic analysis of the non-salt-deformed sections reveal numerous linear features that are interpreted as migrating Mesozoic-age deepmarine sediment waves. Three styles of sediment waves have been identified. These include: (1) type J1—small (less than 17 m thick) and poorly imaged, Jurassic in age, ridges that have wavelengths of up to 12 km and crest-to-crest separations of less than 1 km; (2) type K1—early Aptian constructional sediment waves (~110 m thick) that appear to show some orientation and size variations which suggest an influence on currents by salt-influenced seafloor topography, and (3) type K2—latest Albian and earliest post-Albian sediment waves exhibiting wave heights of 40 m and crest-to-crest separations of 1 km, that are continuous across the entire study area and show evidence of up-slope migration. / text

In many natural and laboratory conditions, plasmas are often in the non-equilibrium state due to presence of stationary flows, when one particle species (or a special group, such as group of high energy particles, i.e., beam) is moving with respect to the other plasma components. Such situations are common for a number of different plasma applications such as diagnostics with emissive plasma probes, plasma electronics devices and electric propulsion devices. The presence of plasmas flows often leads to the instabilities in such systems and subsequent development of large amplitude perturbations. The goal of this work is to develop physical insights and numerical tools for studies of ion sound instabilities driven by the ion flow in a system of a finite length. The ion sound waves are modified by the presence of ion beam resulting in negative and positive energy modes. The instability develops due to coupling of negative and positive energy modes mediated by reflections from the boundary. It is shown that the wave dispersion due to deviation from quasi-neutrality is crucial for the stability. In finite length system, the dispersion is characterized by the length of the system measured in units of the Debye length. The instability is studied analytically and the results are compared with direct initial value numerical simulations. The numerical tools to simulate these systems are developed based on Godunov and multiple shooting methods. The initial value simulations show the time dependent evolution from which the growth rates were determined for different parameters of the system. The results of the simulations were benchmarked against the analytical results in some limiting cases. In the pursuit of simulation efficiency, the parallelization of the code was investigated for two basic types of parallel systems: shared and distributed memory. The OpenMP and MPI library were used correspondingly.