The reserve growth potential of existing conventional oil reservoirs is huge. This research, through numerical simulation, aims to evaluate pattern size reduction as a strategy for improving waterflood recovery in undersaturated oil reservoirs. A plethora of studies have reported improvements in waterflood recovery resulting from pattern size reduction in heterogeneous reservoirs. The dependence of waterflood recovery on pattern size was attributed to factors such as areal reservoir discontinuity, preferential flooding directions, “wedge-edge” oil recovery, irregular pattern geometry, communication with water-bearing zones, vertical reservoir discontinuity, and project economics (Driscoll, 1974). Though many of these publications relied on decline curve analysis in estimating ultimate oil recovery, simulations completed in this thesis support their findings, specifically for compartmentalized reservoirs, fractured reservoirs, and layered reservoirs. Geostatistically-generated permeability fields were employed in the creation of various types of reservoir models. These models were populated with vertical production and injection wells. Sensitivity analysis was then performed on three development scenarios: 160, 40, and 10 acre five-spots. Based on assigned production and injection constraints, the quantity of oil recovered at simulation termination was used to calculate ultimate recovery efficiency. In homogeneous reservoir models, simulation results suggest that waterflood recovery was independent of pattern size. Similar results were also obtained from models with highly-variable non-zero permeabilities. On the other hand, pattern size reduction was found to enhance oil recovery from reservoir models with a high degree of permeability anisotropy. In such reservoirs, recovery was found to be highly dependent on bottom-hole injection pressures. The higher the injection pressure the larger the quantity of oil bypassed by widely spaced patterns. Likewise, high infill potential exists for reservoir models exhibiting areal discontinuity. In these types of models, the improvement in waterflood recovery resulting from pattern size reduction was directly related to the percentage of imbedded zero-permeability grid blocks. Ultimate oil recovery depended on the percolation of permeable grid blocks between production and injection wells. Increasing well density also enhanced waterflood recovery in vertically discontinuous reservoir models. In such layered reservoirs, the amount oil unswept with large patterns was considerably diminished because of the improved injection profiles associated with tighter patterns. / text

Abstract This study is to examine the phenomena caused by rolling action of a nano-particle against the work surface. The analysis was done by the molecular dynamics method. The distributed computing scheme was adopted in these simulations to increase the computing efficiency. The study includes the interfacial force between the nano-particle, the work and the roughness of the work surface, and the damage layer thickness of the work surface. It is done by first identifying the main factors, and then to understand how the phenomena is affected by these factors. Finally, the results of these simulations were discussed. The results show that the interactive force most comes from the breaking process between the work surface and the nano-particle. When the nano-particle¡¦s rolling speed is increased, the interactive force is enhanced. But if the speed has reached a high value, the interactive force will be saturated. The interactive force is not significantly affected by temperature. When the adhesive strength between the nano-particle and the work is higher, the interactive force is higher. The roughness of the work surface is affected by the rolling speed of the nano-particle, the temperature, and the adhesive strength between the nano-particle and the work. If the temperature or the interactive force is higher, the roughness of the work surface is higher. If the rolling speed is higher, the roughness of the work surface will increase. But if the rolling speed has reached a high value, the roughness of the work surface will not increase. The damage layer thickness of the work surface is little affected by the rolling speed of the nano-particle or temperature or the adhesive strength between the nano-particle and the work surface.

Research shows that interracial relationships are more likely to dissolve than same-race relationships (Bratter and King, 2008), with evidence suggesting social disapproval may play a role (Lehmiller and Agnew, 2006). However, people seem to overlook external attributions for failures and minimize internal attributions for successes when judging interracial relationships (Ellithorpe, Colvin, Missel, and Sinclair, 2012), thus making the ultimate attribution error. To test whether individuals make this error, 642 participants read one of 16 vignettes manipulating the race (Caucasian vs. African American) of relationship partners and the opinions of their parents (Approving vs. Disapproving). Participants predicted the likelihood of relationship success and indicated reasons for potential relationship outcomes. Participants were more likely to predict success for relationships that had approval, but were significantly more likely to predict failure for interracial relationships. Consistent with ultimate attribution error theory, individuals scoring high in prejudice were more likely to make these attribution patterns.

This thesis studies the present methods used to predict the ultimate tripping strength of stiffened panels under compressive axial stress. The current methods involve the use of a bifurcation, or eigenvalue, approach to predicting failure stress. The effects of initial transverse eccentricity of the stiffener are ignored using such a method. Six panels were modeled and tested with ABAQUS, a finite element software package, and the results were compared to output from ULSAP, a closed-form ultimate strength analysis program. The ultimate strengths predicted by ABAQUS changed with the influence of initial deflection of the stiffener flange, while the results from ULSAP did not change. This thesis attempts to use beam-column analysis on the imperfect stiffener flange to predict the tripping strength. It was determined that the procedure presented in this thesis does not accurately model the true failure mode of stiffeners in tripping. The resulting ultimate strengths are extremely conservative and neglect the importance of the stiffener web's role in tripping. Future work is recommended to expand on these findings and to incorporate the influence of the stiffener web into a beam-column solution. / Master of Science

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Systems involving quantisation arise in many areas of engineering, especially when digital implementations are involved. In this thesis we consider different aspects of quantisation in feedback control systems. We study two topics of interest: (a) quantisers that quadratically stabilise a given system and are efficient in the use of their quantisation levels and (b) the derivation of ultimate bounds for perturbed systems, especially when the perturbations arise from the use of quantisers. In the first part of the thesis we address problem (a) above. We consider quadratic stabilisation of discrete-time multiple-input systems by means of quantised static feedback and we measure the efficiency of a quantiser via the concept of quantisation density. Intuitively, the lower the density of a quantiser is, the more separated its quantisation levels are. We thus deal with the problem of optimising density over all quantisers that quadratically stabilise a given system with respect to a given control Lyapunov function. Most of the available results on this problem treat single-input systems, and the ones that deal with the multiple-input case consider only two-input systems. In this thesis, we derive several new results for multiple-input systems and also provide an alternative approach to deal with the single-input case. Our new results for multiple-input systems include the derivation of the structure of optimal quantisers and the explicit design of multivariable quantisers with finite density that are able to quadratically stabilise systems having an arbitrary number of inputs. For single-input systems, we provide an alternative approach to the analysis and design of optimal quantisers by establishing a link between the separation of the quantisation levels of a quantiser and the size of its quantisation regions. In the second part of the thesis we address problem (b) above. In the presence of perturbations, asymptotic stabilisation may not be possible. However, there may exist a bounded region that contains the equilibrium point and has the property that the system trajectories converge to this bounded region. When this bounded region exists, we say that the system trajectories are ultimately bounded, and that this bounded region is an ultimate bound for the system. The size of the ultimate bound quantifies the performance of the system in steady state. Hence, it is important to derive ultimate bounds that are as tight as possible. This part of the thesis addresses the problem of ultimate bound computation in settings involving several scalar quantisers, each having different features. We consider each quantised variable in the system to be a perturbed copy of the corresponding unquantised variable. This turns the original quantised system into a perturbed system, where the perturbation has a natural \emph{componentwise} bound. Moreover, according to the type of quantiser employed, the perturbation bound may depend on the system state. Typical methods to estimate ultimate bounds are based on the use of Lyapunov functions and usually require a bound on the norm of the perturbation. Applying these methods in the setting considered here may disregard important information on the structure of the perturbation bound. We therefore derive ultimate bounds on the system states that explicitly take account of the componentwise structure of the perturbation bound. The ultimate bounds derived also have a componentwise form, and can be systematically computed without having to, e.g. select a suitable Lyapunov function for the system. The results of this part of the thesis, though motivated by quantised systems, apply to more general perturbations, not necessarily arising from quantisation. / PhD Doctorate

Many leisure researchers have examined the recreation specialization construct with the belief that recreationists progress along a specialization continuum, from low to high, the longer they participate in an activity. Building on other researchers' conclusions that recreationists do not necessarily progress over time, this study sought to better understand whether people truly desire to progress. Competition, sociability, and skill development variables were proposed as measures that would more accurately describe an intermediate career trajectory of specialization. This intermediate career trajectory of specialization was called flatlining, because recreationists progress to their desired level of specialization and then maintain a flat, or non-progressing, style of involvement on the specialization continuum. Behavior, skill and knowledge, and commitment variables were also used to measure recreation specialization. A three-level self-classification measure was used to predict group membership, and this classification was used to evaluate both groups of variables. The behavior, skill and knowledge, and commitment variables did a very good job of predicting level of specialization. The competition, sociability, and skill development variables did a good job of predicting the high and low levels of specialization, but did a very poor job of predicting the flatlining level of specialization. Motivations to participate were also studied. This study's failure to accurately predict the flatlining career trajectory highlights the need for further research on the phenomenon.

The effects of work¡¦s surface wavelength on the ultimate surface roughness are considered in this study. Both the experimental and theoretical studies will be done in this study. In the experimental study, the relationships between ultimate surface roughness and various operating parameters will be examined. In the theoretical study, a mathematical model relating the machining rate and various machining parameters are proposed. In the mathematical model, qualitative and quantitative properties of machining rate under various surface geometric condition are obtained by the aid of computer simulation. For the experimental study, a series of experiments will be done to investigate the effects of various factors on the ultimate surface roughness of different work¡¦s surface wavelength.The factors may include the the tool speed, the tool¡¦s surface irregularity, and the particle density of slurry. The comouter simulation indicates that the removal rate is non-linear proportional to tool speed and normal load. Besides, results also showed that the difference of removal rate between peak and valley of surface profile always decreases as the work¡¦s surface wavelength increases. The experimental study confirmed that the relationship between ultimate roughness and wavelength does exist in the specific range of work¡¦s surface wavelength . The model appears to be consistent with currently available experimental data.

Many leisure researchers have examined the recreation specialization construct with the belief that recreationists progress along a specialization continuum, from low to high, the longer they participate in an activity. Building on other researchers' conclusions that recreationists do not necessarily progress over time, this study sought to better understand whether people truly desire to progress. Competition, sociability, and skill development variables were proposed as measures that would more accurately describe an intermediate career trajectory of specialization. This intermediate career trajectory of specialization was called flatlining, because recreationists progress to their desired level of specialization and then maintain a flat, or non-progressing, style of involvement on the specialization continuum. Behavior, skill and knowledge, and commitment variables were also used to measure recreation specialization. A three-level self-classification measure was used to predict group membership, and this classification was used to evaluate both groups of variables. The behavior, skill and knowledge, and commitment variables did a very good job of predicting level of specialization. The competition, sociability, and skill development variables did a good job of predicting the high and low levels of specialization, but did a very poor job of predicting the flatlining level of specialization. Motivations to participate were also studied. This study's failure to accurately predict the flatlining career trajectory highlights the need for further research on the phenomenon.

This diploma thesis concerns comparison of different categories regarding the offensive phase of the frisbee ultimate match. The theoretical part deals with the offensive play skills of the individuals, that are important for this phase of the game. It also concerns team skills and tactics essential for mastering the game at a high level. Marginal defense systems are mentioned as well. The research part deals with comparison of different offensive procedure, representation of offensive tactics, percentage success of the particular types of offensive play, all in the categories OPEN, WOMEN, MIXED. For the researcg, a video analysis from the 2015 European Championship of Nations was used. Key word Frisbee ultimate, category OPEN, category WOMEN, category MIXED, horizontal lane, vertical lane, zone defense game, short lane, split stack