archives@tulane.edu / The wavelength dependent abstraction energy profiles for CH_3 CH_2 CH_3/CH_3 CH_2 CH_2 CH_3+Br are studied using a gas expansion containing 〖Br〗_2 and either propane or butane abstraction targets. Laser-induced photolysis of cold 〖Br〗_2 in the visible region produces a narrow, tunable distribution of Br atoms whose collisional kinetic energies can be scanned up to and beyond the thermodynamic threshold of the reaction to yield HBr or DBr as photolytic reaction products. Femtosecond laser ionization allows the reactive products to be efficiently monitored over all product quantum states. Both the observed HBr and DBr reaction thresholds are consistent with thermodynamic and calculated values with no apparent barrier to reaction. Studies addressing the site-specific reaction behavior for selectively deuterated propane and butane molecules is presented and discussed. Future applications of the approach are discussed such as state-dependent detection methods, and ultra-cold nozzle expansions. / 1 / Shane J. G. McGlynn

Search is an important aspect of Artificial Intelligence and many advances have been achieved in finding optimal solutions for a variety of search problems. Up until recently most search problems were solved using a serial-single threaded approach. Speed is extremely important and one way to decrease the amount of time needed to find a solution is to use better hardware. A single threaded approach is limited in this way because newer processors are not much faster than previous generations. Instead industry has added more cores to allow more threads to work at the same time. In order to solve this limitation and take advantage of newer multi-core processors, many parallel approaches have been developed. The best approach to parallel search is an algorithm named Parallel Best-N Block First Search (PBNF). PBNF relies on an abstraction function to divide up the work in a way that allows threads to work efficiently with little contention. This thesis studies the way this abstraction function chooses to build the abstraction and demonstrates that better abstractions can be built. This abstraction focuses on goal variables on ways to keep the number of abstract states as small as possible while adding as many variables as feasible.

No description available.

Today's autonomous robots come in a variety of shapes and sizes from all terrain vehicles clambering over rubble, to robots the size of coffee cups zipping about a laboratory. The diversity of these robots is extraordinary; but so is the diversity of the software created to control them even when the basic tasks many robots undertake are practically the same (such as obstacle detection, tracking, or path planning). It would be beneficial if some reuse of these coded sub-tasks could be achieved. However, most of the present day robot software is monolithic, very specialised and not at all modular, which hinders the reuse and sharing of code between robot platforms. One difficulty is that the hardware details of a robot are usually tightly woven into the high-level controllers. When these details are not decoupled and explicitly encapsulated, the entire code set must be revised if the robot platform changes. An even bigger challenge is that a robot is a context-aware device. Hence, the possible interpretations of the state of the robot and its environment vary along with its context. For example, as the robots differ in size and shape, the meaning of concepts such as direction, speed, and distance can change { objects that are considered far from one robot, might seem near to a much larger robot. When designing reusable robot software, these variable interpretations of the environment must be considered. Similarly, so must variations in context dependent robot instructions { for example, `move fast' has different abstractions; a `virtual robot' layer to manage the robot's platform abstractions; and high-level abstraction components that are used to describe the state of the robot and its environment. The prototype is able to support binary code portability and dynamic code extensibility across a range of different robots (demonstrated on eight diverse robot platform configurations). These outcomes significantly ease the burden on robot software developers when deploying a new robot (or even reconfiguring old robots) since high-level binary controllers can be executed unchanged on different robots. Furthermore, since the control code is completely decoupled from the platform information, these concerns can be managed separately, thereby providing a flexible means for managing different configurations of robots. These systems and techniques all improve the robot software design, development, and deployment process. Different meanings depending on the robot's size, environmental context and task being undertaken. What is needed is a unifying cross-platform software engineering approach for robots that will encourage the development of code that is portable, modular and robust. Toward this end, this research presents a complete abstraction model and implementation prototype that contain a suite of techniques to form and manage the robot hardware, platform, and environment abstractions. The system includes the interfaces and software components required for hardware device and operating system abstractions; a `virtual robot' layer to manage the robot's platform abstractions; and high-level abstraction components that are used to describe the state of the robot and its environment. The prototype is able to support binary code portability and dynamic code extensibility across a range of different robots (demonstrated on eight diverse robot platform configurations). These outcomes significantly ease the burden on robot software developers when deploying a new robot (or even reconfiguring old robots) since high-level binary controllers can be executed unchanged on different robots. Furthermore, since the control code is completely decoupled from the platform information, these concerns can be managed separately, thereby providing a flexible means for managing different configurations of robots. These systems and techniques all improve the robot software design, development, and deployment process.

Au-delà de l'importance de l'espace dans l’œuvre de Michelangelo Antonioni, considérer le mur permet de mettre en évidence le rapport entre le corps sensible des personnages et leur environnement à partir de cet élément à échelle humaine et de découvrir que le mur apparaît également dans des configurations qui ne font plus appel à la notion de volume, mais à celle, métacinématographique, d'écran. En examinant les différents aspects que le terme « mur » recouvre dans l’œuvre, mon propos s'attache à démontrer que si le mur devient catégorie esthétique c'est par son omniprésence à l'écran mais aussi par sa capacité à s'étendre à toutes les dimensions de la fable. La thèse s'organise selon deux idées-cinéma : le mur-objet – qui considère le mur selon son acception la plus concrète – et le mur-écran – pour souligner la proximité du mur, devenu surface, avec l'écran cinématographique. À chaque étape, des lignes transversales sont tendues vers d'autres œuvres et d'autres arts. À partir du mur, élément en apparence stable et immuable, se dévoile un mouvement de libération inhérent à l’œuvre. Les murs sont surfaces de déplacements, formes en mouvement qui entraînent les personnages le long des lignes de déterritorialisation qu'ils proposent. Comme dans sa réalité concrète entre deux espaces, le mur se situe toujours à une limite. Penser le mur, c'est se confronter à cette limite, lieu de basculement, lieu d'instabilité. / Beyond the importance of spaces in Michelangelo Antonioni's work, considering the wall allows to highlight the relationships between the characters' sensitive bodies and their environment from this human scale element and to discover that the wall also appears in configurations which do not depend on the notion of volume but on the metacinematographic notion of screen. By studying the various aspects the term "wall" recovers, I attempt to demonstrate that the wall becomes esthetic category by its omnipresence but also by its capacity to extend in all the dimensions of the fable. The thesis is organized according to two ideas-cinemas: the wall-object - which considers the wall according to its most concrete meaning - and the wall-screen - to underline the closeness of the wall, as a surface, with the film screen. In every stage, transverse lines are tightened towards other works and other arts. From this seemingly stable and unchanging element unfold a movement of liberation inherent to the work. Walls are surfaces of movements, forms in movement which lead the characters along the lines of deterritorialisation they propose. As in its concrete reality between two spaces, the wall is always on a limit. Considering the wall is confronting with this limit, this place of shift and instability.

This paper presents the Temporal Abstract Behavior Representation Model (TABRM). Current techniques for representing behaviors suffer from a lack of abstract representation capability and do not possess the robustness to be used in diverse environments. Without abstraction, the representation of behaviors becomes computationally complex due to the wealth of detail required to enumerate all attributes associated with the environment and the potential courses of action. As a result existing behavior representations tend to be restricted to a limited number of environments or behaviors. TABRM addresses these limitations by using abstraction to define a small number of abstract behaviors and environments. Through the use of abstracted behaviors and environments, TABRM is able to operate using a small decision tree to determine the most appropriate behavior for a given environment. TABRM translates detailed environments into an abstract representation, determines an appropriate abstract behavior, and translates the results back to the detailed environment to produce suitable actions. Decision making within the abstract realm allows an appropriate behavior to be selected regardless of the actual detailed environment. This provides robustness in the model, which is demonstrated within this paper through the application of the model to a range of behavioral domains.

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / This paper illustrates a Windows computer application program which uses the object-oriented paradigm as a basis. The objective of the application program is to control the setup of equipment involved in routing a telemetry signal. This design uses abstract classes as high level building blocks from which site specific classes are derived. It is the next generation to the software portion of a system described by Eugene L. Law. The object-oriented design method, as presented by Grady Booch in his book Object-Oriented Analysis and Design with Applications, is the design tool.

No description available.

No description available.

The promoters of the large groundwater developments implemented in the 1970's paid little attention to the effects of pumping on soil moisture. A field study, conducted in 1979 in the Tern Area of the Shropshire Groundwater Scheme, revealed that significant quantities of the available moisture could be removed from the root zone of vegetation when drawdown of shallow watertables occurred. Arguments to this effect, supported by the field study evidence, were successfully presented at the Shropshire Groundwater Scheme public inquiry. The aim of this study has been to expand the work which was undertaken in connection with the Shropshire Groundwater Scheme, and to develop a method whereby the effects of groundwater pumping on vegetation can be assessed, and hence the impacts minimised. Two concepts, the critical height and the soil sensitivity depth, formulated during the initial work are at the core of the Environmental Impact Assessment method whose development is described. A programme of laboratory experiments on soil columns is described, as is the derivation of relationships for determining critical heights and field capacity moisture profiles. These relationships are subsequently employed in evaluating the effects of groundwater drawdown. In employing the environmental assessment technique, digitised maps of relevant features of the Tern Area are combined to produce composite maps delineating the extent of the areas which are potentially sensitive to groundwater drawdown. A series of crop yield/moisture loss functions are then employed to estimate the impact of simulated pumping events on the agricultural community of the Tern Area. Finally, guidelines, based on experience gained through evaluation of the Tern Area case study, are presented for use in the design of soil moisture monitoring systems and in the siting of boreholes. In addition recommendations are made for development of the EIA technique, and further research needs are identified.