VictorJuiz/thesis huggingface dataset:
Dynamic Layer Multicast Congestion Control
Keywords: Computer Science.
Routing > Computer network management
Multicasting > Computer networks
Thesis

Multicast is a routing protocol that allows broadcast of internet data from one sender to multiple receivers. This requires a congestion control protocol that will determine the appropriate rate for each of the recipients of the data stream. Multicast is currently implemented in a way that requires a large latency for a client to leave a multicast session. This long latency hinders existing congestion control protocols by lengthening their reaction time in the face of congestion. This thesis reports on joint work done on a protocol which uses dynamic layers, which make the reactivity of the protocol independent of the leave latency.
The original parts of this thesis are the experimental results and the analysis of the algorithm. The protocol, called Dynamic Layer Congestion Control (DLCC), is responsive to dynamically changing network conditions and scalable to a large number of receivers. It requires no receiver-to-receiver coordination, and can be made to compete fairly against TCP flows. Experimental simulations illustrate its behavior, and show how it can be tuned empirically to compete fairly against TCP sessions.
Improving SSL’s Performance in Software
Keywords: Computer Science.
Computer networks > Security measures
World Wide Web > -Security measures
Computer network protocols
Thesis

The paper focuses on an algorithmic approach for speeding up SSL’s performance on a web server. Our approach improves the performance of SSL’s handshake protocol by up to a factor of three for 1024-bit RSA keys. It is especially well-suited for heavily-loaded web servers handling many concurrent SSL sessions. We improve the server’s performance by batching the SSL handshake protocol. That is, we show that b SSL handshakes can be done faster as a batch than doing the b handshakes separately one after the other. Experiments show that taking b = 4 leads to optimal results, namely a speedup of a factor of 3. Our starting point is a technique due to Fiat for batching RSA decryptions.
Structure and thermochronology of the metamorphic core of the Brooks Range, Alaska
Keywords: Geological and Environmental Sciences.
Geology, Stratigraphic > Mesozoic.
Geology, Structural > Alaska > Brooks Range.
Metamorphism (Geology) > Alaska.
Rock deformation.
Metamorphic rocks > China > Brooks Range.

Folded maps: Pl. 1. Geological map of the Sishakshinovik Pass area, Gates of the Arctic National Park, Brooks Range, Alaska. Scale 1:40,000
Pl. 2. Geological map of Mt. Igikpak, Gates of the Arctic National Park, Brooks Range, Alaska. Scale 1:50,000.
Pore Level Modelling of Three Phase Flow Through Oil-Wet Porous Media
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

This work is an extension of Darryl H. Fenwick's work on network modelling of three-phase flow in porous media. A theoretical analysis of the two-phase and three-phase configurations under both water-wet and oil-wet conditions are presented. Then three-phase relative permeabilities for three different fluid systems are computed. The results for oil-wet and water-wet media are compared.
Micromodel Studies of Three Phase Flow in Porous Media
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

This report is concerned with the flow of oil, water and gas in a water-wet porous medium at the pore level. Silicon micromodels which were an exact replica of a Berea sandstone are used to represent a heterogenous porous medium. The interaction of three phases in a micromodel has been studied to provide quantitative information about pore-scale displacement processes. The motivation was to obtain important parameters that must be included in the development of a mathematical model for three-fluid constitutive relationship.These observed displacement mechanisms can subsequently be used to calculate three phase relative permeabilities and capillary pressures from a pore network model. Double drainage was by far the most readily observed displacement mechanism in the air/hexane/water system studied. Generally, the imbibition mechanisms, including double imbibition were not readily observed. For double imbibition, this could be ascribed to the fact that the mechanism occurred very quickly and it was very difficult to capture the events when they occurred. The other double displacement combinations were unfavorable as there was a strong affinity between the gas and its surrounding oil.The oil layers which resided between the wetting phase (water) and the non-wetting phase (gas) were stable and oil recovery was high.
A Study of In-Situ Combustion on Saudi Tar
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

This study has been conducted to investigate possibilities of applying the process of in-situ combustion to mobilize the tar zone present in several oil reservoirs in Saudi Arabia. These reservoirs are isolated from the pressure support of the large aquifers underlying many oil reservoirs in Saudi Arabia. The tar zone separating oil from the aquifer is about 6 inches thick; which if it could be mobilized, would lead to better recovery factors from pressure maintenance and waterflood below.
Boundary Effects in the Successive Upscaling of Absolute Permeability
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

Reservoir descriptions generated by geostatistical techniques are usually done on a very fine scale and have far too many cells for any present day flow simulator to handle. The pressure-solver method is widely used in the petroleum industry to upscale such fine scale realizations into coarser ones with fewer cells. However, this method makes the assumption of constant pressure and no-flow boundary conditions. These assumptions can introduce errors in the upscaling process, resulting in an incorrect estimate of the effective permeability. This study determines the extent of these errors and outlines the conditions in which permeability upscaling by pressure-solver method works and others in which it fails. A range of geostatistical realizations have been studied and certain geometric and geostatistical parameters of these realizations have been highlighted which appear to have the greatest effect on the upscaling process.
Pipe Network Optimization in Multiphase Flow
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

The two-phase flow problem at hand consists of a pipe network in three dimensions. Given the pressure at the inlet node and the amount of liquid and gas flow rates in the inlet pipe, the problem requires the determination of the pressure value at the other nodes. The total pressure drops along the common pipe legs should be equal. Beggs and Brill's method is used for computing the pressure drops.
Using Artificial Neural Network and Sequential Predictive Probability Method to Mechanize Interpretation of Well Test Data
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

We propose a robust way of achieving a well test interpretation by combining the sequential predictive probability method with an artificial neural network approach. The sequential predictive probability method considers all possible reservoir models and determines which candidate model or models best predict the well response. This method is dependent on obtaining good initial estimates for the parameters governing the candidate reservoir models, which is achieved by applying the artificial neural network approach. We use the neural network to identify the characteristic components of the pressure derivative curve corresponding to the flow regimes known to be in each candidate model. Reservoir parameters are then computed using the data in the identified range of the corresponding behavior.As a final step, the candidate models and their initial estimates are evaluated using the sequential probability method. The method discriminates between the candidate models and simultaneously performs nonlinear regression to compute the best estimates of reservoir parameters.The trained neural network was able to identify the characteristic components of the derivative curve in most cases. The algorithm written to interpret the neural network signals into flow regimes required special procedures to take care of the misclassification from the neural network. The initial estimates of reservoir parameters from the neural network were found to be reasonably close to the eventual estimates from the sequential predictive probability method.
Earth-Tide Effects on Downhole Pressure Measurements
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

Earth-tide effects have been used to derive reservoir parameters by hydrologists and petroleum engineers. Most of the work done on this subject ignores the effect of dilatation of the matrix structure due to earth tides on downhole pressure response. In this work, we derive an equation which considers the effect of dilatation of matrix structure due to earth tides on downhole pressure measurements. We consider a few reservoir models and obtain the expected pressure response to earth tides for simple configurations. We compare our results with results which do not consider the effect of dilatation of the matrix structure. Field data which shows the effect of earth tides on downhole pressure measurements is processed to derive estimates of reservoir parameters using this method.
Simulation of Tracer Flow Through Heterogeneous Porous Media
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

Improved finite-difference techniques for simulating tracer flows through heterogeneous porous media are developed. These numerical techniques are then used to perform a series of numerical experiments that investigates the combined use of a discrete geologic model and apparent-mixing parameters to represent heterogeneous permeability fields.Several multidimensional extensions of the one-dimensional, total variation diminishing (TVD), approach to developing flux-limiting functions for high-order finite-difference schemes are investigated. These extensions include using the TVD technique independently in each coordinate direction (TVD), using the TVD technique in successive coordinate sweeps (ADTVD), and using a new class of upstream stable (US) flux-limiting techniques. Additionally, a flux limiter based on a third-order finite-difference scheme is introduced. New algorithms are developed to allow the use of high-throughput (HT) timestepping with flux-limited techniques and to improve the use of HT timestepping for problems with physical dispersion/diffusion. The use of multidimensional TVD extensions combined with HT timestepping give numerical models that are more accurate and more efficient than previous finite-difference models.Two sets of numerical experiments are performed that investigate the representation of permeability heterogeneities. The first experiment explores the effects of changes in the geologic representation scale (GRS). This experiment shows that reservoir response may continue to change as the GRS is decreased, and indicates that apparent mixing due to sub-GRS heterogeneity must be represented implicitly through apparent-mixing parameters, such as dispersivity. The second numerical study demonstrates a case for which the effects of small and large scale heterogeneities can be represented by a combination of explicit representation through varying gridblock permeabilities and implicit representation through apparent-mixing parameters.Furthermore, the properties of the non-represented permeability field are found to be related to the values of the apparent-mixing parameters. Thus, the non-represented permeability field may be used to determine if apparent-mixing parameters can successfully represent sub-GRS permeability heterogeneity. Finally, it is suggested that the robustness of apparent-mixing parameters can be improved by decoupling the GRS from the scale used to average apparent-mixing parameters.
Ultrasonic Rate Measurement of Multiphase Flow
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

One of the most important tools in production logging and well testing is the downhole flowmeter. Unfortunately, existing tools are inaccurate outside of an idealized single phase flow regime. Spinner tools are inaccurate at extremely high or low flow rates and when the flow rate is variable. Radioactive tracer tools have similar inaccuracies and are extremely sensitive to the flow regime. Both tools completely fail in the presence of multiphase flow, whether gas/oil, gas/water or fluid/solid. (Bennett et al., 1991, Hill and Oolman, 1982, Hill, 1990 and McKinley, 1982) Downhole flow metering is important for locating producing zones and thief zones and monitoring production and injection rates. The effects of stimulation can also be determined. (Leach et al., 1974) This goal of this project is the investigation of accurate downhole flow metering techniques for all single phase flow regimes and multiphase flows. The measurement method investigated in this report is the use of ultrasound. There are two ways to use ultrasound for fluid velocity measurement. The first method, examined in Chapter 2, is the contrapropagation, or transit-time, method which compares travel times with and against fluid flow. Chapter 3 details the second method which measures the Doppler frequency shift of a reflected sound wave in the moving fluid.
Electronic Democracy: Promises, Prospects, and Problems and Its Potential for Development at Dartmouth College
Keywords: Stanford University. Program in Science Technology and Society
Honors theses
Thesis

This essay was inspired by my work at Stanford from 1988 to 1990, when I headed the student government commission responsible for running student government elections at Stanford. One of my accomplishments during that period of time was the computerization of Stanford's student government elections. Rather than marking their choices on paper ballots,
students sat down in front of Macintosh computers and used software specially designed for the election to register their choices. The use of computers for voting and tabulating election results was well-received by the student body and the voting system generated considerable interest from state and local officials and the press. In the summer of 1989 I began to consider the larger implications of my work at Stanford and to formulate this project as an attempt to understand what role computers might play in the electoral process in a society where people are expected to own and use a home personal computer.
In November 1989, I contacted the Student Assembly office at Dartmouth and explained my interest in using Dartmouth's unique computing resources to model an operational electronic democracy. I believed that the Assembly would use computerized polls to gather student opinion before making decisions or creating policy and that I would be able to
observe the use of computerized polling at Dartmouth and its effect on voter participation and awareness. By March of 1990, the Assembly endorsed my proposal and suggested that Dartmouth's Kiewit Computing Center develop the software needed to run computerized polls over Dartmouth's computer network. In June, Kiewit began work on the software and named it
"Questor ."
Though a working prototype of the Questor software had been created by January of 1991, the Questor project was not completed in time for me to conduct the experiments I originally intended as the focus of my thesis. Accordingly, I altered the focus of this project to an analysis of the potentials and problems associated with computerized voting and electronic democracy in society at large. However, I often make references to the technology being employed at Dartmouth, because Dartmouth is probably the only community in this country in which the plausibility of many of the assertions and hypotheses put forth in this paper can be tested.
Decline Curve Derivative Analysis for Homogeneous and Composite Reservoirs
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Stanford Geothermal Program
Thesis

In this study, the rate decline and rate decline derivatives of a constant pressure well are presented for infinite, constant pressure outer boundary, and closed outer bound by homogeneous reservoirs. A rate derivative type curve is provided for these cases as well. The effects of the dimensionless reservoir exterior radius are discussed. Rate decline and rate decline derivatives of a constant pressure well in an infinite composite reservoir are also presented. For composite reservoirs, the effects of mobility ratios and discontinuity distance on both rate decline and rate decline derivatives are presented. Type curves for dimensionless wellbore flowrate derivatives for infinite composite reservoirs are provided. A new correlating group for the derivative type curve is provided, and is different than the correlating group for the rate type curve presented in the past. Finally, an analysis method that comprises type curve and derivative type curve matching to determine the dimensionless variables is proposed and demonstrated with a simulated example.
Analysis of Injection-Backflow Tracer Tests
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

Tracer tests have been an important technique for determining the flow and reservoir characteristics in various rock matrix systems. While the interwell tracer tests are aimed at the characterization of the regions between the wells, single-well injection-backflow tracer tests may be useful tools of preliminary evaluation, before implementing long term interwell tracer tests. This work is concerned with the quantitative evaluation of the tracer return profiles obtained from single well injection-backflow tracer tests. First, two mathematical models of tracer transport through fractures, have been reviewed. These two model are based on two different principles: Taylor Dispersion along the fracture and simultaneous diffusion in and out of the adjacent matrix. Then the governing equations for the transport during the injection backflow tests have been solved. Finally the results were applied to field data obtained from Raft River and East Mesa geothermal fields. In order to determine the values of the parameters of the models that define the transport mechanisms through fractures a nonlinear optimization technique was employed.
Transcending the Problems of the Black Graphic Designer to Success in the Marketplace
Keywords: Graphic Design
African American Graphic Designers
Black Artists
Graphic design business
Graphic design education
Design Diversity and Inclusion
Diversity Equality and Inclusion
African American Studies
mixed-race studies
Cheryl D. Miller
Pratt Institute
Thesis

There are few black graphic designers in the marketplace today [1985]. For many years it has been the concern of the writer as to the reason why. With so many fields and opportunities now open to blacks, it's almost unbelievable that their presence in the graphic design industry is slight. In addition, the writer has encountered numerous young black graphic design students who have been misguided. These students suffer tremendous hardships due to the lack of resources, professional training , and accurate information
about the industry. It is the hope of the writer that the findings of the thesis will aid in any capacity to increase the visibility of qualified blacks in the graphic design marketplace.
An Investigation of Pressure Effects on Combustion Tire Runs
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

The phenomena involved in in-situ combustion processes are usually studied by analyzing the results of laboratory combustion tube experiments. This type of experiment has been conducted for the last 35 years and an effort has been made to analyze all significant parameters. Among these parameters, little has been shown in the literature about the effects of pressure on the phenomena related to the in-situ combustion process.This report shows the results of a combustion tube run, carried out in the laboratory of the Petroleum Engineering Department at Stanford University, in which the operating pressure was the only parameter varied during the run, from 100 psi to 300 psi. A set of programs for an HP-41CV calculator was elaborated and used to analyze the effects of pressure. A discussion about the results is provided and the programs are also attached to this work.
Elastic Properties of Unconsolidated Sands Under Pressure and Temperature
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

The phenomenon of formation compaction and surface subsidence has been associated in many cases to fluid withdrawal. Different studies have been conducted by many researchers in order to get a better understanding of this behavior in some formations, which generally create irreversible environmental distorsions. Laboratory tests were conducted to establish a relationship between the most important parameters that are usually considered t o define the mechanical properties of a formation, such as Poisson's ratio, Young's and shear modulus and compressibility.Measurements of deformation, as well as the travel time of seismic waves under different conditions of pressure and temperature, were taken to define the behavior of unconsolidated sands. Due to the high compressibility of this material, changes in the length of the sample were considered in the evaluation of the compressional and shear velocities from the measured travel time data.
A Higher Order Finite Difference Method in Reservoir Stimulation
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

A fourth order compact implicit differencing scheme which is known as the Babuska-Marchuk method is generalized for irregular grid system in both Cartesian and cylindrical coordinates, as its original form is valid only for uniform grid systems in Cartesian coordinates. Although the methods are represented as 3-point formulas, they have O(h3) local accuracy in general as compared with O(h) for the conventional 3-point schemes. The extended scheme for two dimensional spatial operator is also obtained. In this case the method results in a new 9-point formula. The application of the methods to reservoir simulation is then explained. The effectiveness of the methods is demonstrated by numerical examples for two test problems, a pressure drawdown problem and the Buckley-Leverett problem.