While administrators, faculty and students of community colleges have embraced web-based instruction, it is essential to understand the progress and success of such instruction. The primary purpose of the study was to investigate whether there were differences in completion and passing rates between courses offered in traditional classroom and web-based instructional formats that were taught by the same instructor(s) at least once using both instructional media. The secondary related purpose was to determine whether there were differences in completion and passing rates among courses taught in different academic disciplines, including both traditional and web-based courses. The population consisted of 3,601 students enrolled in courses offered in both instructional delivery formats during the academic years 1998 through 2002. The findings demonstrated that the proportion of female students enrolled in identical courses offered in the web-based format was higher than the proportion of their male counterparts enrolled in the same instructional format. Approximately two-thirds of the students enrolled in courses offered via the web-based format in this study were 23 years and older as compared with students 22 years and younger. Differences in both completion and passing rates were found between the traditional and web-based formats. In both instances the rates for traditional instruction were higher. When course grade point averages (GPAs) were compared in both formats, courses offered in the traditional classroom setting had higher mean GPAs as compared with the mean GPAs of identical courses taught by the same instructor or instructors in the web-based delivery method. Regarding differences among academic divisions, for the courses offered in the traditional format, no differences in the mean course completion rates were found. However, there were differences for identical courses offered in the web-based format. The study's findings revealed that there were differences in the mean passing rates for courses offered in traditional format. When the GPAs were compared among the seven academic divisions, differences were found for courses offered in the traditional format. Despite no differences found in course completion rates between younger and older students in web-based instructional format, significant differences were found in identical courses offered in the traditional setting.

Twentieth-century American literature incorporates interracial and biracial themes that bring to light the often unnamed and unrecognized biracial identities of many Americans. Unfortunately, despite the potential value for a deeper understanding of the construction of race, these themes have seldom been seriously considered in the context of reevaluating the nature of the system that creates racial labels and categories until the recent emergence of postmodern critical theories. This thesis examines the black-white interracial themes and biracial protagonists in Nella Larsen's Quicksand (1928) and Danzy Senna's Caucasia (1998) in order to explore the texts' representations of systems of hegemonic power that create racial labels and categories. I discuss the binary sociopolitical construction of race in the United States (blackwhite) and the complexity of biracial identities as a foundation for my examination of literary representations of biracial subjectivity, racial passing, primitive exoticism, and the intersections between race, class and gender. I conclude that a study of the interracial theme in literature is a dive into the chasm between margin and center, the enunciative split between the binary racial signifiers black and white. Therefore, representations of biracial subjectivity provide a unique vantage point for surveillance of the complexities of the human struggle to gain and maintain power.

Graph Neural Networks and Transformers are very powerful frameworks for learning machine learning tasks. While they were evolved separately in diverse fields, current research has revealed some similarities and links between them. This work focuses on bridging the gap between GNNs and Transformers by offering a uniform framework that highlights their similarities and distinctions. We perform positional encodings and identify key properties that make the positional encodings node embeddings. We found that the properties of expressiveness, efficiency and interpretability were achieved in the process. We saw that it is possible to use positional encodings as node embeddings, which can be used for machine learning tasks such as node classification, graph classification, and link prediction. We discuss some challenges and provide future directions.

This study considers software techniques for improving performance on clusters of workstations and approaches for designing message-passing middleware that facilitate scalable, parallel processing. Early binding and overlapping of communication and computation are identified as fundamental approaches for improving parallel performance and scalability on clusters. Currently, cluster computers using the Message-Passing Interface for interprocess communication are the predominant choice for building high-performance computing facilities, which makes the findings of this work relevant to a wide audience from the areas of high-performance computing and parallel processing. The performance-enhancing techniques studied in this work are presently underutilized in practice because of the lack of adequate support by existing message-passing libraries and are also rarely considered by parallel algorithm designers. Furthermore, commonly accepted methods for performance analysis and evaluation of parallel systems omit these techniques and focus primarily on more obvious communication characteristics such as latency and bandwidth. This study provides a theoretical framework for describing early binding and overlapping of communication and computation in models for parallel programming. This framework defines four new performance metrics that facilitate new approaches for performance analysis of parallel systems and algorithms. This dissertation provides experimental data that validate the correctness and accuracy of the performance analysis based on the new framework. The theoretical results of this performance analysis can be used by designers of parallel system and application software for assessing the quality of their implementations and for predicting the effective performance benefits of early binding and overlapping. This work presents MPI/Pro, a new MPI implementation that is specifically optimized for clusters of workstations interconnected with high-speed networks. This MPI implementation emphasizes features such as persistent communication, asynchronous processing, low processor overhead, and independent message progress. These features are identified as critical for delivering maximum performance to applications. The experimental section of this dissertation demonstrates the capability of MPI/Pro to facilitate software techniques that result in significant application performance improvements. Specific demonstrations with Virtual Interface Architecture and TCP/IP over Ethernet are offered.

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Current design methods in transportation engineering do not simultaneously address the levels of risk and service associated with the design and use of various highway geometric elements. Passing sight distance (PSD) is an example of a geometric element designed with no risk measures. PSD is provided to ensure the safety of passing maneuvers on two-lane roads. Many variables decide the minimum length required for a safe passing maneuver. These are random variables and represent a wide range of human and vehicle characteristics. Also, current PSD design practices replace these random variables by single-value means in the calculation process, disregarding their inherent variations. The research focuses on three main objectives. The first goal is to derive a PSD distribution that accounts for the variations in the contributing parameters. Two models are devised for this purpose, a Monte-Carlo simulation model and a closed form analytical estimation model. The results of both models verify each other and differ by less than 5 percent. Using the PSD distribution, the reliability index of the current PSD criteria are assessed. The second goal is to attach risk indices to the various PSD lengths of the obtained distribution. A unique microscopic simulation is devised to replicate passing maneuvers on two-lane roads. Using the simulation results, the author is able to assess the risk of various PSD lengths for a specific design speed. The risk index of the AASHTO Green Book and the MUTCD PSD standards are also obtained using simulation. With risk measures attached to the PSD lengths, a trade-off analysis between the level of service and risk is feasible to accomplish. The last task is concerned with applying the Highway Capacity Manual concepts to assessing the service measures of the different PSD lengths. The results of the final trade-off analysis show that for a design speed of 50 mph, the AASHTO Green Book and the MUTCD standards overestimate the PSD requirements. The criteria can be reduced to 725 ft and still be within an acceptable risk level. / Ph. D.

My thesis is an attempt to examine and study the in-between spaces between buildings.With my design as a vehicle, taking an entire block of Blacksburg, I have tried to explore the idea by which one could offer a transitional moment between buildings. The in-between spaces provide an opportunity to intervene and choreograph a space which re-engages the dweller through repetitive distractions. The design combines residential spaces with commercial establishments creating a mixed use condition in a city block which in its density, constantly alternates between the public and private realms. The resultant spaces between the buildings are spaces which are a combination of the planned and the improvised, in a constant state of flux forming the "passing place". The spaces could create subtle interconnections which can be exploited and temporal experiences could be defined through architectural interpretation of transitional spaces.Mixing uses is one approach in architecture that assists in making lively thresholds. I project the idea of a deliberate hetrogeneity in architecture, where opposing objects are placed together as a part of a strategy to create complex and compelling buildings and their in-between spaces. / Master of Architecture

[EN] The quality of traffic on two-lane roads is closely linked to the possibility of making the overtaking maneuver that is especially critical in addition to the level of risk posed to do it. Options to facilitate overtaking are providing a path with geometric conditions for overtaking can be performed on the road with enough opportunities or provide a cross section that facilitates this advancement by auxiliary lanes. In this research, the second option with passing and climbing lanes was discussed. To characterize the passing maneuver on steep grades an experimental study that allowed access to data and important information for calibrating TWOPAS, a microscopic traffic simulation model of two-lane roads, which is main element of the Traffic Analysis Module (TAM) that integrates the Interactive Highway Safety Design Model (IHSDM) was developed. TWOPAS was validated in other two-lane road with very different characteristics to the road considered during calibration thereby evaluating the usefulness of this simulation model was completed. Considering a target of this research the TWOPAS was applied in the analysis of auxiliary lanes in a multitude of scenarios, around 98,000, where traffic volumes, longitudinal gradients, initiation and length of the auxiliary lane and percentage of trucks were varied; the influence of random variation of traffic generated wealth of information for the scope of this paper and considered for further analysis. A computational tool, the PEMAT, which allows automatic execution of TWOPAS (TAM), capturing the results of each simulation and generating outputs in terms of operational indicators was created. Among the results of the analysis of auxiliary lanes are factors to consider the effect of passing and climbing lanes in the Percentage Time Spent Following (PTSF) and the Average Travel Speed (ATS) to adapt the procedure of Highway Capacity Manual (HCM) in 2010 and to estimate the level of service on two-lane road sections with individual auxiliary lanes. The manuals for the calculation of the capacity and level of service on conventional roads does not cover the diversity of geometric and traffic conditions so that a procedure for analyzing the transit operation in any conventional road was proposed to facilitate overtaking by consideration of a number of auxiliary lanes in both directions of traffic simulation model with TWOPAS; thus overtaking can be solved for any configuration of road and transit improvements in methods in manuals or technical guidance. / [ES] La calidad de la circulación en carreteras convencionales está estrechamente vinculada con la posibilidad de realizar la maniobra de adelantamiento que es especialmente crítica además por el nivel de riesgo que supone realizarla. Las opciones para facilitar el adelantamiento son proveer en el trazado las condiciones geométricas para que el adelantamiento se pueda realizar a lo largo de la vía con suficientes oportunidades pero cuando esta se dificulta se dispone de la alternativa de proveer una sección transversal que facilite este adelantamiento mediante los carriles auxiliares. En este trabajo de investigación se abordó esta segunda opción con los carriles de adelantamiento y de ascenso. Para caracterizar la maniobra de adelantamiento en pendientes ascendentes se hizo un estudio experimental que permitió disponer de datos y extraer información importante para la calibración de un modelo de simulación microscópica del tránsito en carreteras convencionales denominado TWOPAS, el cual es elemento principal del Traffic Analysis Module (TAM) que integra el Interactive Highway Safety Design Model (IHSDM). TWOPAS fue validado en otra carretera convencional de características bien diferentes a la considerada en la calibración que completó la evaluación de la utilidad de este modelo de simulación. Orientado hacia el objetivo de este trabajo de investigación se aplicó el TWOPAS en el análisis de carriles auxiliares en una multiplicidad de escenarios, alrededor de 98.000, en los cuales se variaron los volúmenes de tránsito, pendientes longitudinales, inicio y longitud del carril auxiliar, porcentaje de camiones y considerando la influencia de la variación aleatoria del tránsito que generó gran cantidad de información para el alcance de este trabajo y para nuevos análisis. Se creó una herramienta computacional, el PEMAT, que permite la ejecución automática del TWOPAS (TAM), la captura de los resultados de cada simulación y la generación de las salidas en términos de indicadores operacionales. Entre los resultados obtenidos del análisis de carriles auxiliares están factores para considerar el efecto de carriles de adelantamiento y ascenso en el Porcentaje de Tiempo Consumido en el Seguimiento (PTSF) y la Velocidad Media de Recorrido (ATS) para adaptar el procedimiento del Highway Capacity Manual (HCM) de 2010 para estimar el nivel de servicio en tramos de carretera convencional con carriles auxiliares individuales. Los manuales para el cálculo de la capacidad y el nivel de servicio en carreteras convencionales no cubre la diversidad de condiciones geométricas y de tránsito por lo que se propuso un procedimiento para adelantar el análisis de la operación del tránsito en cualquier carretera convencional para facilitar el adelantamiento mediante la consideración de una serie de carriles auxiliares en los dos sentidos de circulación de dicha vía sustentado en la aplicación de la simulación con el modelo TWOPAS de manera que puede atenderse la necesidad de demanda de adelantamiento para cualquier configuración de carretera y condición de tránsito mejorando los métodos contemplados en los manuales o guía técnicas. / [CA] La qualitat de la circulació en carreteres convencionals està estretament vinculada amb la possibilitat de realitzar la maniobra d'avançament que és especialment crítica a més per el nivell de risc que suposa el realitzar-la. Les opcions per facilitat l'avançament son proveir en el traçat les condicions geomètriques per a que l'avançament es puga realitzar al llarg de la via amb suficients oportunitats però quan aquesta es dificulta es disposa de l'alternativa de proveir una secció transversal per facilitar aquest avançament mitjançant els carrils auxiliars. En aquest treball d'investigació es va abordar aquesta segona opció amb els carrils d'avançament i d'ascens. Per caracteritzar la maniobra d'avançament en pendent ascendent es va fer un estudi experimental que va possibilitar disposar de dades i extraure informació important per a la calibració d'un model de simulació microscòpica del trànsit en carreteres convencionals denominat TWOPAS, el qual es element principal del Traffic Analysis Module (TAM) que integra l'Interactive Highway Safety Design Model (IHSDM). TWOPAS va ser validat en un altra carretera convencional de característiques ben diferents a la considerada en la calibració que va completar la avaluació de la utilitat de aquest model de simulació. Orientat a l'objectiu d'aquest treball d'investigació es va aplicar el TWOPAS en l'anàlisi de carrils auxiliars en una multiplicitat d'escenaris, voltant els 98.000, en els quals es variaren els volums de trànsit, pendents longitudinals, inici i longitud del carril auxiliar, percentatge de camions i tenint en compte la influència de la variació aleatòria del trànsit que va generar gran quantitat d'informació per al alcans d'aquest treball i per a nous anàlisis. Es va crear una ferramenta computacional, el PEMAT, que permet la execució automàtica del TWOPAS (TAM), la captura dels resultats de cada simulació i la generació de les eixides en terminis d'indicadors operacionals. Entre els resultats obtinguts de l'anàlisi de carrils auxiliars estan factors per considerar l'efecte de carrils d'avançament i ascens en el Percentatge de Temps Consumit en el Seguiment (PTSF) i la Velocitat Mitjana de Recorregut (ATS) per a adaptar el procediment del Highway Capacity Manual (HCM) de 2010 per a estimar el nivell de servici en trams de carretera convencional amb carrils auxiliars individuals. Els manuals per al càlcul de la capacitat i el nivell de servici en carreteres convencionals no cobreixen la diversitat de condicions geomètriques i de trànsit per el que es va proposar un procediment per avançar l'anàlisi de la operació del trànsit en qualsevol carretera convencional per a facilitat l'avançament mitjançant la consideració d'una sèrie de carrils auxiliars en els dos sentits de circulació d'eixa via sustentat en l'aplicació de la simulació amb el model TWOPAS de manera que es puga atendre la necessitat de demanda d'avançaments per a qualsevol configuració de carretera i condició de trànsit millorant els mètodes contemplats en els manuals o guies tècniques. / Valencia Alaix, VG. (2016). ELABORACIÓN DE PROCEDIMIENTOS PARA FACILITAR EL ADELANTAMIENTO EN CARRETERAS CONVENCIONALES APLICANDO SIMULACIÓN [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62413