Pipelined Two-Operand Modular Adders

Pipelined two-operand modular adder (TOMA) is one of basic components used in digital signal processing (DSP) systems that use the residue number system (RNS). Such modular adders are used in binary/residue and residue/binary converters, residue multipliers and scalers as well as within residue processing channels. The design of pipelined TOMAs is usually obtained by inserting an appriopriate number of latch layers inside a nonpipelined TOMA structure. Hence their area is also determined by the number of latches and the delay by the number of latch layers. In this paper we propose a new pipelined TOMA that is based on a new TOMA, that has the smaller area and smaller delay than other known structures. Comparisons are made using data from the very large scale of integration (VLSI) standard cell library

Implementing intelligent pedagogical agents in virtual worlds: Tutoring natural science experiments in OpenWonderland

Intelligent Pedagogical Agents (IPAs) can be thought of as embodied intelligent agents that are designed for pedagogical purposes to support learning. They can be designed in particular for virtual worlds. Virtual worlds are becoming an interesting medium for engineering education for the properties of visual collaboration abilities providing authentic learning experiences and for the opportunity of providing active learning. However, virtual worlds need more educational support to be more inhabited with increased learning services. Incorporating intelligent pedagogical agents into virtual worlds adds such learning support by adding intelligence, improving believability, and the opportunity to increase communication with an artificial educator. However the implementation of intelligent pedagogical agents and adopting them in a virtual world require several efforts with different aspects of implementation. This paper reports our first prototype implementation of an IPA interacting with a learner and a learning object in natural science experiment in a virtual world while providing supporting multi-modal communication abilities. The IPA has features of text chat based on the Artificial Intelligence Markup Language (AIML), a text-to-speech synthesis function, and non-verbal communication abilities through gesture animation. The implementation is presented through explained scenarios of the IPA tutoring an experiment or monitoring a learner avatar interaction with a learning object in a Virtual World. The IPA & the learning scenarios are implemented in the open source of Open Wonderland

Simulating Interactive Learning Scenarios with Intelligent Pedagogical Agents in a Virtual World through BDI-Based Agents

Intelligent Pedagogical Agents (IPAs) are designed for pedagogical purposes to support learning in 3D virtual learning environments. Several benefits of IPAs have been found adding to support learning effectiveness. Pedagogical agents can be thought of as a central point of interaction between the learner and the learning environment. And hence, the intelligent behavior and functional richness of pedagogical agents have the potential to reward back into increased engagement and learning effectiveness. However, the realization of those agents remains to be a challenge based on intelligent agents in virtual worlds. This paper reports the challenging reasons and most importantly an approach for simplification. A simulation based on BDI agents is introduced opening the road for several extensions and experimentation before implementation of IPAs in a virtual world can take place. The simulation provides a proof-of concept based on three intelligent agents to represent an IPA, a learner, and learning object implemented in JACK and Jadex intelligent agent platforms. To that end, the paper exhibits the difficulties, resolutions, and decisions made when designing and implementing the learning scenario in both domains of the virtual world and the agent-based simulation while comparing the two agent platforms

Filament formation associated with spirochetal infection: a comparative approach to Morgellons disease

Bovine digital dermatitis is an emerging infectious disease that causes lameness, decreased milk production, and weight loss in livestock. Proliferative stages of bovine digital dermatitis demonstrate keratin filament formation in skin above the hooves in affected animals. The multifactorial etiology of digital dermatitis is not well understood, but spirochetes and other coinfecting microorganisms have been implicated in the pathogenesis of this veterinary illness. Morgellons disease is an emerging human dermopathy characterized by the presence of filamentous fibers of undetermined composition, both in lesions and subdermally. While the etiology of Morgellons disease is unknown, there is serological and clinical evidence linking this phenomenon to Lyme borreliosis and coinfecting tick-borne agents. Although the microscopy of Morgellons filaments has been described in the medical literature, the structure and pathogenesis of these fibers is poorly understood. In contrast, most microscopy of digital dermatitis has focused on associated pathogens and histology rather than the morphology of late-stage filamentous fibers. Clinical, laboratory, and microscopic characteristics of these two diseases are compared

The Quaternary Geologic History of the Canadian Rocky Mountains

The Canadian Rocky Mountains figured prominently during the glacial history of western Canada. First as a western limit or boundary to the Laurentide Ice Sheet, second as an eastern margin of the Cordilleran Ice Sheet, and finally as a centre of local Montane ice. Throughout the Quaternary, complex interactions of glacier ice from these three ice sources markedly changed the physical form of the Rocky Mountains, Trench and Foothills areas. Investigations into the Quaternary history of this region have been ongoing since the beginning of the last century. Since about 1950, the number of studies performed in this area have increased significantly. This paper briefly reviews the historical accomplishments of Quaternary work in the region up to the period of about 1950. From this time to the present, individual study efforts are examined in detail according to the three geographic regions: 1) the northern Rocky Mountains (from the Liard Plateau south to the McGregor Plateau), 2) the central Rocky Mountains (from the McGregor Plateau south to the Porcupine Hills) and 3) the southern Rocky Mountains (from the Porcupine Hills south to the international border). In the northern region, geologic data suggest a maximum of two Rocky Mountain glaciations and only one Laurentide glaciation and no ice coalescence. In the central region, three of four Rocky Mountain events, and at least two Laurentide events are known. Only in the central region is there good evidence for ice coalescence, but the timing of this event is not clearly established. In the south, at least three Rocky Mountain episodes and a variable number of Laurentide episodes are recognized. There is no evidence for ice coalescence. A number of facts support the proposal that Cordilleran ice crossed the Continental Divide and joined with local Montane ice at several locations. However, this expansion of western ice occurred before the Late Wisconsinan in all areas but Jasper. In general, the chronological data presented suggest that the Late Wisconsinan glaciation in the Rocky Mountains was a short-lived event which started around or after 20 ka years ago and ended before 12 ka ago.Les montagnes Rocheuses ont constitué un cas particulier au cours de l'évolution glaciaire de l'ouest du Canada. Elles ont d'abord formé la limite occidentale de l'Inlandsis laurentidien, puis la limite orientale de l'Inlandsis de la Cordillère et finalement le centre d'une glaciation alpine locale. Tout au long du Quaternaire, les interactions complexes des glaces à partir de ces trois sources ont modifié de façon sensible l'aspect physique des Rocheuses, du sillon et du piémont. Les études sur l'évolution géologique de la région ont commencé au début du siècle dernier; beaucoup plus nombreuses depuis 1950, elles se sont également diversifiées. On résume d'abord les réalisations jusqu'aux années 50, puis on se penche plus particulièrement sur les travaux accomplis depuis lors dans : 1) la partie septentrionale (du plateau du Liard au plateau du McGregor, au sud); 2) la partie centrale (du plateau du McGregor aux collines Porcupine, au sud); et 3) la partie méridionale (des collines Porcupine à la frontière des É-U., au sud). Dans la partie septentrionale, les données géologiques montrent l'existence d'au plus deux glaciations issues des Rocheuses, une seule glaciation laurentidienne et aucune coalescence des glaces. Dans la partie centrale, on reconnaît l'existence de trois ou quatre glaciations issues des Rocheuses et au moins deux glaciations d'origine laurentidienne. On y observe des indices sur la coalescence des glaces, mais on ne sait pas exactement quand elle s'est produite. Dans le sud, on reconnaît l'existence d'au moins trois glaciations issues des Rocheuses et d'un nombre variable de glaciations d'origine laurentidienne. Il n'y aurait pas eu de coalescence. Un certain nombre de faits appuient l'hypothèse selon laquelle les glaces cordillérennes auraient traversé la ligne de partage des eaux en plusieurs points pour se joindre aux glaces alpines locales. Cependant, cette extension des glaces venant de l'ouest s'est produite avant le Wisconsinien supérieur dans tous les secteurs, sauf à Jasper. De façon générale, les données chronologiques indiquent que la glaciation du Wisconsinien supérieur a été de courte durée dans les Rocheuses (de 20 ka à 12 ka environ).Die kanadischen Rocky Mountains stellen einen Sonderfall in der glazialen Geschichte von Westkanada dar. Zuerst als eine westiiche Grenze oder Trennungslinie zur laurentidischen Eisdecke, dann als ein ôstlicher Rand der Kordilleren-Eisdecke, und schlieBlich als das Zentrum einer lokalen alpinen Vereisung. Während des ganzen Quaternärs haben komplexe Interaktionen von Gletschereis aus diesen drei Eisquellen die physikalische Form der Rocky Mountains, der Trench und Foothill-Gebiete signifikant veràndert. Untersuchungen der Quatemàr-Geschichte dieses Gebiets finden seit dem Beginn des letzten Jahrhunderts statt. Dieser Aufsatz gibt einen kurzen Ùberblick ùber die historischen Leistungen der Arbeit zum Quaternàr in dem Gebiet bis in die 50ger Jahre. Von diesem Zeitpunkt an bis heute werden individuelle Forschungs-bemùhungen im Detail untersucht und zwar zu drei geographischen Gebieten: nôrdlichen, zentralen und sûdlichen Rocky Mountains. Im nôrdlichen Gebiet weisen die geologischen Daten auf maximal zwei Rocky Mountain-Vereisungen und nur eine laurentidische Vereisung und auf keinen Eiszusammen-schluB. Im mittleren Gebiet sind drei von vier Rocky Mountain-Vereisungen und mindesten zwei laurentidische Vereisungen bekannt. Nur im mittleren Gebiet findet man einen klaren Nachweis fur EiszusammenschluB aber die Zeit fur diesen Vorgang kann nicht klar bes-timmt werden. Im Sùden kônnen mindestens drei Rocky Mountain-Vereisungen und eine variable Zahl von laurentidischen Vereisungen erkannt werden. Es gibt keinerlei Hinweis auf EiszusammenschluB. Eine Reihe von Fakten stùtzen die These, daB Eis von den Kordil-leren die Wasserscheidelinie ùberquerte und sich an einigen Plàtzen mit lokalem alpinem Eis vereinigte. Jedoch geschah dièse Ausdehnung westlichen Eises vor dem spâten Wisconsinum in alien Gebieten auBer in Jasper. Im allgemeinen zeigen die vorgelegten chronologischen Daten, daB die Spàt-Wisconsinum-Vereisung in den Rocky Mountains ein kurzlebiges Ereignis war, das vor etwa 20 ka Jahren oder danach begann und vor 12 ka Jahren endete

Reducing the Environmental Impact of Bitumen Extraction with ES-SAGD Process

Steam Assisted Gravity Drainage (SAGD) is a proven enhanced oil recovery technique for oil sand extraction. However, the environmental and economic challenges associated with excessive greenhouse gas emissions due to the combustion of significant amount of natural gas and consumption of large amount of fresh water for steam generation limit the application of this technology. To address these issues, various SAGD modifications have been developed, among those, SAGD with solvent co-injection is one of the most prospective techniques. In this experimental study, the effectiveness of base SAGD and Expanding Solvent SAGD (ES-SAGD) was tested on a Peace River bitumen. All experiments were conducted using a two-dimensional cylindrical physical model. In order to investigate the influence of in-situ asphaltene precipitation on the performance of ES-SAGD process, three different types of solvent were considered as hydrocarbon additives; asphaltene soluble (toluene), asphaltene insoluble (n-hexane), and solvent with intermediate solubility parameter (cyclohexane). Different strategies for solvent injection were examined. In all experiments, temperature profiles at 47 different positions, produces oil and water were monitored continuously. Viscosity and API gravity of original and produced oil samples were measured. This study reveals that co-injection of hydrocarbon solvents with steam enhances the efficiency of SAGD process in terms of oil production, level of oil upgrading, steam to oil ratio and energy consumption. It was also concluded that selection the solvent type and injection strategy are important parameters for the design of hybrid SAGD process

Air Force Institute of Technology Research Report 2006

This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, Mathematics, Statistics and Engineering Physics