Context. A portal in computer graphics is an opening which connects two spaces together. Portals can be used for occlusion culling for indoor environments or wormhole-like effects. This thesis address the latter and focus on how objects interact with such portals. Objectives. The objectives are to provide a solution to how objects can interact with complex portals in real-time with focus on visual (and physical) correctness and also present a background to how simple and complex portals work. Methods. A hybrid approach of a geometry and image technique is used to render portals. Intersection techniques and a technique related to constructive solid geometry is used to solve object-portal interactions. The research methodology used is implementation and simple analysis of the results is performed. Results. The results show that the implementation of the object-portal interaction scales exponentially. In the worst case it has a complexity of O(n² * m²) where n and m are the number of triangles in the object and portal respectively. Increasing the number of triangles in the object shape is more costly than increasing the number of triangles in the portal shape by the same amount. The results were not compared to previous knowledge as no results have been published of other object-portal interaction methods. The rendering of portals scales linearly with the number of triangles used to represent it. Conclusions. This thesis extends the state-of-the-art portal rendering system and adds a solution to object-portal interaction of complex shapes. It also provides a detailed background into the fundamentals of portals and their nature. The thesis is of interest to those who want object-portal interaction of both simple and complex portals used in gameplay and special effects without restriction on portal placement and shape, with the exception that portals may not have holes in their shape in the direction an intersecting object is moving.

>Magister Scientiae - MSc / A Steiner triple system of order v is a collection of subsets of size three from a set of v-elements such that every pair of the elements of the set is contained in exactly one 3-subset. In this study, we discuss some known Steiner triple systems and their automorphism groups. We also construct block intersection graphs of the Steiner triple systems of our consideration and compare their automorphism groups to the automorphism groups of the Steiner triple systems.

People detection has been an attractive technology in computer vision. There are many useful applications in our daily life, for instance, intelligent surveillance and driver assistance system. People detection is a challenging matter as people adopt a wide range of poses, wear diverse clothes, and are visible in different kind of backgrounds with significant changes in illumination. In this thesis, some advanced techniques and powerful tools are presented in order to design a robust people detection system. First a baseline model is implemented by combining the Histogram of Oriented Gradients descriptor and linear Support Vector Machines. This baseline model obtains a good performance on the well-known INRIA dataset. Second an advanced model is proposed which has a two-layer cascade framework that achieves both accurate detection and lower computational complexity. For the first layer, the baseline model is used as a filter to generate several candidates. In this procedure, most positive samples survived and the majority of negative samples are rejected according to a preset threshold. The second layer uses a more discriminative model. We combine the Variational Local Binary Patterns descriptor, and the Histogram of Oriented Gradients descriptor as a new discriminative feature. Furthermore multi-scale feature descriptors are used to improve the discriminative power of the Variational Local Binary Patterns feature. Then we perform Feature Selection using the Feature Generating Machine in order to generate a concise descriptor based on this concatenated feature. Moreover Histogram Intersection Kernel Support Vector Machines is employed as an efficient tool of classification. The bootstrapping algorithm is used in the training procedure to exploit the information of the dataset. Finally our approach has a good performance on the INRIA dataset, with results superior to the baseline model.

La Carretera Panamericana Sur km. 37.5 y el Puente Arica, es una intersección vial tipo Diamante Convencional partido sin semáforos, ubicado en el distrito de Lurín y provincia de Lima. Esta intersección presenta congestionamiento vehicular ocasionando pérdida de horas hombre. Debido a esto, se determinó los niveles de servicio actuales, a través del software Synchro 8.0, mediante aforos vehiculares tomados en campo. Los niveles de servicio obtenidos fueron muy bajos y demoras elevadas. Como consecuencia se plantearon y modelaron con el software Synchro 8.0 diferentes propuestas para solucionar la congestión vehicular, tales como; Implementación de cruceros semafóricos con diferentes diseños, implementación de mini óvalos dentro de la intersección y en los extremos de la intersección, y un intercambio vial de tipo Diamante Divergente. La propuesta de solución se inicia con la comparación de resultados obtenidos de las alternativas para el escenario actual y proyectado a 5 y 10 años. En consecuencia, se obtuvieron dos propuestas que solucionan la congestión vehicular actual y proyectada a 5 años. La primera es la implementación de cruceros semafórico con un carril exclusivo para el giro libre a la derecha y la segunda es la implementación de un novedoso intercambio vial de tipo Diamante Divergente, mientras que las demás propuestas no son sostenibles en la proyección del tránsito futuro. Por otro lado, si bien es cierto que ambas propuestas mejoran y dan solución al problema planteado la segunda presenta mejores niveles de servicio y menores demoras en la proyección a 10 años. / The South Pan American Highway km. 37.5 and the Arica Bridge, is a Conventional Diamond-type road intersection without traffic lights, located in the district of Lurín and province of Lima. This intersection presents vehicular congestion causing loss of man-hours. Due to this, the current service levels were determined, through Synchro 8.0 software, through vehicle capacities taken in the field. The service levels obtained were very low and delays were high. As a consequence, different proposals were proposed and modeled with Synchro 8.0 software to solve vehicular congestion, such as; Implementation of traffic lights with different designs, implementation of mini ovals within the intersection and at the ends of the intersection, and a Divergent Diamond road interchange. The solution proposal begins with the comparison of results obtained from the alternatives for the current scenario and projected at 5 and 10 years. Consequently, two proposals were obtained that solve the current and projected vehicular congestion at 5 years. The first is the implementation of traffic light cruises with an exclusive lane for the free right turn and the second is the implementation of a new Divergent Diamond interchange, while the other proposals are not sustainable in the projection of future traffic. On the other hand, although it is true that both proposals improve and solve the problem posed, the second presents better levels of service and less delays in the 10-year projection. / Tesis

Plant efficiency and profitability are becoming increasingly important and operating at the most optimal point is a necessity. The definition of proper operational bounds on output variables such as product quality, production rates etc., is critical for plant optimisation. The use of operational bounds that do not lie within the region of the output operational space of the plant can result in the control system attempting to operate the plant in a non attainable region. The use of operational bounds that lie within the bounds of the output operational space of the plant and if the output operational space is non convex can also result in the control system attempting to operate the plant in a non attainable region. This results in non feasible optimisation. A numerical intersection algorithm has been developed that identifies the feasible region of operation known as the desired operational space. This is accomplished by finding the intersection of the required operational space and the achievable output operational space. The algorithm was simulated and evaluated on a case study under various scenarios. These scenarios included specifying operational bounds that lie partially within the bounds of the achievable operational space and also specifying operational bounds that lie within the bounds of the operational space which was non convex. The results yielded a desired operational space with bounds that were guaranteed to lie within an attainable region on the output operational space. The desired operational space bounds were also simplified into a rectangle with high and low limits that can be readily used in control systems. / Dissertation (MEng)--University of Pretoria, 2012. / Chemical Engineering / unrestricted

Multicultural theorists argue that foundational theories of identity development fail to capture the experiences of ethnic and sexual minorities. Likewise, models of ethnic and sexual identity, separately, may not capture experiences of lesbian, gay, bisexual, transgender, queer, or questioning (LGBTQ) ethnic minorities. Intersectional models have been proposed that consider the interaction of identity statuses in their real-world context. However, more empirical support for such models is needed. This study represents a preliminary investigation into patterns of identification, values, attitudes, behaviors, and sense of belonging of these LGBTQ ethnic minorities. The patterns that emerged were varied and complex. Demographic questions were structured in a way that allowed participants to describe with complexity their identities, and the intersections among them. Four distinct groups were identified using Q-sort methodology. Both commonalities and important group differences emerged.

Indiana University-Purdue University Indianapolis (IUPUI) / Autonomous vehicles currently dominate the automobile field for their impact on humanity and society. Connected and Automated Vehicles (CAV’s) are vehicles that use different communication technologies to communicate with other vehicles, infrastructure, the cloud, etc. With the information received from the sensors present, the vehicles analyze and take necessary steps for smooth, collision-free driving. This the sis talks about the cruise control system along with the intersection collision avoidance system based on Petri net models. It consists of two internal controllers for velocity and distance control, respectively, and three external ones for collision avoidance. Fault-tolerant redundant controllers are designed to keep these three controllers in check. The model is built using a PN toolbox and tested for various scenarios. The model is also validated, and its distinct properties are analyzed.

Two entities, town and university, each playing different functional roles, different in scale and structure, come together at one point. The architecture of that point is a transitional condition. Each element has integrity on its own, and at the same time is a part of the system. The primary requirement for the architecture of this place is to be elegant and thoughtful. This idea is addressed in five scales within the project: the axis, the street, the paths, the wall, and the room. / Master of Architecture

In Chapter 1, we present the background for transient absorption spectroscopy through the polarization response of a material to an electric field which gives rise to linear and non-linear processes. We then discuss a theoretical description of how vibrational coherences are formed via four-wave mixing and impulsive excitation. We also describe signatures of coherent wavepackets in transient absorption and the application of vibrational coherences, specifically to observe non-radiative processes. We then summarize two previous studies using impulsive transient absorption on cresyl violet, the differences in the coherent dynamics reported, and the motivations behind the experiments presented in this work. Chapter 2 pertains to the apparatus used to perform the transient absorption experiments. We detail the source for the generation of ultrashort laser pulses (durations of less than 10 fs) used for the pump and probe from an argon-based white-light filament and non-colinear optical parametric amplifier. Two-dimensional shearing interferometry, the method used to measure the ultrashort pulses across a large portion of the visible spectrum (500-750 nm), is discussed. The retrieved temporal, spectral, and phase profiles of the pump and probe pulses are presented. Finally, the sample preparation for cresyl violet is described as well as the detection method and data processing used to generate the figures throughout this work. In Chapter 3, we present the results of impulsive transient absorption spectroscopy of cresyl violet perchlorate under four pump conditions. First, we report a study on controlling the formation of vibrational coherences on the ground or excited electronic states of cresyl violet by tuning the pump conditions from an off-resonant to a resonant scheme. The decay of the electronic population and positions of the stimulated emission and excited-state absorption maximums shows a dependence on the pump wavelength. Higher excitation frequencies blueshifts the stimulated emission 18 meV and red shifts excited-state absorption by 4 meV at early times compared to only 13 meV and 2 meV when using lower excitation frequencies. Coherent vibrations are observed and persist for approximately 6 ps after excitation, with phase flips appearing at 593 nm, the absorption maximum, after off-resonant excitation and at the emission (619 nm) and excited-state absorption (500 nm) maximums after resonant excitation. The ground- and excited-state vibrational modes are characterized by Fourier transform Raman spectroscopy. The excited-state vibration spectrum is shown to share nearly identical features as the ground-state, with each vibration slightly red-shifted, 2-10 cm-1, from the corresponding mode in the ground-state, particularly a prominent peak appearing at 594 cm-1 in the ground-state and 589 cm-1 in the excited-state. Next, two additional pump conditions using broadband and partially resonant pump pulses are explored to replicate the conflicting reports of non-adiabatic crossings in cresyl violet. Constant phase-flips observed in the control studies are replaced with phase flips that appear and disappear over several picoseconds. The Fourier Raman spectrum of the coherent signal after broadband excitation displays a mix of ground- and excited-state features, particularly prominent peaks at both 589 cm-1 and 594 cm-1. In Chapter 4, we analyze the coherent signals after broadband excitation using a Fourier filtering technique to isolate the ground- or excited-state coherent dynamics by carefully selecting representative vibrational modes for each state. Using a narrow filter to isolate the 589 cm-1 and 595 cm-1 features in the broadband Fourier Raman spectrum successfully isolates coherent vibrations with phase flips at either the emission and excited-state absorption maximums or the ground-state absorption maximum, respectively. A filter that includes both features generates apparent phase-flips that only appear for ~1ps and at probe wavelengths that do not correspond to the emission or absorption maximums. In Chapter 5, we present a simulation of the coherent signals using a model of two wavepackets with carrier frequencies of 589 cm-1 and 595 cm-1 and dephasing rates of 2 and 3 ps, respectively. Comparison to the broadband pump conditions and Fourier filtered coherent oscillations shows that the complex temporal dynamics observed are adequately described by the linear interference of two vibrational coherences evolving on different electronic potential energy surfaces, without the need to invoke non-adiabatic dynamics. / Chemistry

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