The rapid proliferation of 3D volume data, including MRI and CT scans, is prompting the search within computer graphics for more effective volume visualisation techniques. Partially because of the traditional association with medical subjects, concepts borrowed from the domain of scientific illustration show great promise for enriching volume visualisation. This thesis describes the first general system dedicated to creating user-directed, variable-detail, scientific illustrations directly from volume data. In particular, using volume segmentation for explicit abstraction in non-photorealistic volume renderings is a new concept. The unique challenges and opportunities of volume data require rethinking many non-photorealistic algorithms that traditionally operate on polygonal meshes. The resulting 2D images are qualitatively different from but complementary to those normally seen in computer graphics, and inspire an analysis of the various artistic implications of volume models for scientific illustration.

This paper is intended to serve as a supporting document for the exhibition This Site Is Under Construction that was held at the University of Waterloo Art Gallery, University of Waterloo, April 17th – May 14th, 2010. The work explores the ways in which we constitute and mediate our specific place in a space that is constantly changing. It is concerned with notions surrounding how we make and perceive images now in our computerized visual culture and the ways in which we can mark a subjective painting aesthetic and visual vocabulary. The painting installation, “This Site Is Under Construction”, investigates the effects of new media and digitization on experiential perception, and the nature of making and re-configuring images. The title alludes not only to the on-line, virtual space of the computer, but also to the physical spaces of building and urban development sites. The subjects for the paintings are spaces in flux – specific locales of construction and building sites that are in-between states of development – placing emphasis on the mechanized devices that fabricate the new structures. The paintings themselves reveal seemingly spontaneous and optically warped immersive spaces; alternative architectural environments which subvert interpretations of two-dimensional and three-dimensional forms of visual presentation and recognition. The work aims to contrast outward appearance and illusionistic staging as it relates to both the picture and its support.

Pipelined circuits operate as an assembly line that starts processing new instructions while older ones continue execution. Control properties specify the correct behaviour of the pipeline with respect to how it handles the concurrency between instructions. Control properties stand out as one of the most challenging aspects of pipelined circuit verification. Their verification depends on the datapath and memories, which in practice account for the largest part of the state space of the circuit. To alleviate the state explosion problem, abstraction of memories and datapath becomes mandatory. This thesis provides a methodology for an efficient abstraction of the datapath under all possible control-visible behaviours. For verification of control properties, the abstracted datapath is then substituted in place of the original one and the control circuitry is left unchanged. With respect to control properties, the abstraction is shown conservative by both language containment and simulation. For verification of control properties, the pipeline datapath is represented by a network of registers, unrestricted combinational datapath blocks and muxes. The values flowing through the datapath are called parcels. The control is the state machine that steers the parcels through the network. As parcels travel through the pipeline, they undergo transformations through the datapath blocks. The control- visible results of these transformations fan-out into control variables which in turn influence the next stage the parcels are transferred to by the control. The semantics of the datapath is formalized as a labelled transition system called a parcel automaton. Parcel automata capture the set of all control visible paths through the pipeline and are derived without the need of reachability analysis of the original pipeline. Datapath abstraction is defined using familiar concepts such as language containment or simulation. We have proved results that show that datapath abstraction leads to pipeline abstraction. Our approach has been incorporated into a practical algorithm that yields directly the abstract parcel automaton, bypassing the construction of the concrete parcel automaton. The algorithm uses a SAT solver to generate incrementally all possible control visible behaviours of the pipeline datapath. Our largest case study is a 32-bit two-wide superscalar OpenRISC microprocessor written in VHDL, where it reduced the size of the implementation from 35k gates to 2k gates in less than 10 minutes while using less than 52MB of memory.

A series of tetravalent zirconium and hafnium complexes were supported by diarylamido-phosphino [PNP]- (bis(o-diisopropylphosphinophenyl)amide) ligand. The reaction of MCl4(THF)2 (M = Zr, Hf) with [PNP]Li in toluene at room temperature generates [PNP]MCl3 as solid in 60 % yield. Polyalkyl complexes which are lack of £]-hydrogen have been achieved in synthesis of [PNP]MR3 (R = Me, CH2SiMe3) or [PNP]M(CH2SiMe3)2(E) (E = Cl, Me) since we could control the desired product from steric effect. An X-ray diffraction study of [PNP]ZrCl3 showed it to be a chloride-bridged binuclear species {[PNP]MCl2(£g-Cl)}2 in which both metal atoms are 7-coordinate whereas that of [PNP]MCl3(THF) revealed a mononuclear, 7-coordinate core structure. The phosphine fluxional exchange were found in those complexes, monitoring variable temperature 31P NMR, their fluxionality were calculated by line shape analysis. By heating [PNP]M(CH2SiMe3)2(Cl) in solution, we can afford new alkylidene complexes [PNP]M(Cl)(=CHSiMe3) via intramolecular £\-abstraction. Through Eyring plot analysis, the activation energy of [PNP]Zr(CH2SiMe3)2(Cl) £\-abstraction is ∆H‡ = 16.49(19) kcal/mol and ∆S‡ = −25.64(19) cal/mol•K; [PNP]Hf(CH2SiMe3)2(Cl) £\-abstraction is ∆H‡ = 18.70(36) kcal/mol and ∆S‡ = −23.12(36) cal/mol•K. The mixture [PNP]Hf(=CHSiMe3)(Cl) could not isolate with any purification, but [PNP]Hf(=CHSiMe3)(CH2SiMe3) obtained through directly alkylation. Here we also identified multiple alkylidene derivatives of [PNP]M(=CHSiMe3)(X) (X = Cl, CH2SiMe3). The X-ray structured and solution NMR data of those alkylidene complexes can be ascribed to evidence of £\-agostic interaction with metal center. A novel zwitterionic complex [PNP]Zr(£g2-CHSiMe3)2(AlMe2) was characterized by X-ray and been received a bisalkylidene complex which was synthesized through addition Lewies acid (AlMe3) into [PNP]Zr(=CHSiMe3)(CH2SiMe3). Group 4 alkylidene was acting as catalyst to metathesize ethylene or norbornene. The complexes [PNP]M(=CHSiMe3)(Cl) have highly streotic selectivity catalyst for ring-opening metathesis polymerization (ROMP) of norbornene. It is important to emphasize the great significance of the catalyst discoveries and improvements for both academic research and industry.

The ability to recognize sameness among objects and events is a prerequisite for abstraction and forming concepts about what one has learned; thus, identity and nonidentity learning can be considered the backbone of higher-order human cognitive abilities. Discovering identity relations between the constituent properties of objects is an important ability that often characterizes the comparisons that humans make so it is important to devote attention to understanding how nonhuman primates process and conceptualize part-identity as well as whole-identity. Because the ability to generalize the results of learning is to what concepts ultimately reduce, the series of experiments herein first investigated responding to part-identity and -nonidentity and whole-identity and -nonidentity and then explored the generality of such learning to the formation of concepts about color, shape, and cardinal number. The data from Experiments 1, 2, and 3 indicated that the two orangutans learned to respond concurrently to color whole-identity and -nonidentity and they responded faster to color whole-identity. Additionally, both subjects learned to respond concurrently to color and shape part- and whole-identity and for the most part, it was easier for them to do so with color part- and whole-identity problems than shape part- and whole-identity problems. Further, their learned responses to color and shape part- and whole-identity fully transferred to novel color part-identity problems for both subjects and fully transferred to novel color and shape whole-identity problems for one orangutan. The data from Experiments 4, 5, and 6 showed that one subject learned to judge numerical identity when both irrelevant dimensions were cue-constant, but the subject did not do the same when one or more irrelevant dimensions were cue-ambiguous. Further, the subject's accuracy was affected by the numerical distance and the numerical total of comparisons during acquisition of the conditional discrimination. The subject subsequently formed a domain-specific concept about numerical identity as evinced by the transfer of learning to novel numerosities instantiated with novel, cue-constant element colors and shapes and novel numerosities instantiated with cue-constant, familiar element colors and shapes. Given the adaptive significance of using concepts, it is important to investigate if and how nonhuman primates form identity concepts for which they categorize or classify the stimuli around them. This dissertation provided evidence about the extent to which orangutans learned to respond to color, shape, and number identity and nonidentity and subsequent concept formation from such learning. The findings from this study will help in understanding the convergence and divergence in the expression abstraction in the primate phylogeny, thus, informing our understanding about the origins and mechanisms of cognition in human and nonhuman primates.

Mémoire d'orthophonie : Médecine : Nantes : 2008. / Bibliogr.

The following graduate report is an overview of my artistic endeavors spanning the past three years at the University of Texas at Austin. While at UT, I have concentrated on making paintings that focus on the relationship between abstraction, representation, and entropy. Using banal, often overlooked cultural objects as subject matter, I paint ambiguous scenes that teeter between disintegration and formation. Representations of banal detritus within an ambiguous natural space become a metaphor for memory, culture, and life and death alluding to unseen forces and, ultimately, a lack of control. Using a combination of random and deliberate decisions, I aim to create a commentary about the unpredictable yet conformist aspects of the world in which we participate. / text

The research presented herein explores three aspects of asymmetric catalysis: (1) the development of new catalytic enantioselective reactions, (2) the application of stereoselective catalysis to natural product total synthesis, and (3) the design and synthesis of new chiral catalysts. / Chemistry and Chemical Biology

The programming language and underlying hardware determine application performance, and both are undergoing revolutionary shifts. As applications have become more sophisticated and capable, programmers have chosen managed languages in many domains for ease of development. These languages abstract memory management from the programmer, which can introduce time and space overhead but also provide opportunities for dynamic optimization. Optimizing memory performance is in part paramount because hardware is reaching physical limits. Recent trends towards chip multiprocessor machines exacerbate the memory system bottleneck because they are adding cores without adding commensurate bandwidth. Both language and architecture trends add stress to the memory system and degrade application performance. This dissertation exploits the language abstraction to analyze and optimize memory efficiency on emerging hardware. We study the sources of memory inefficiencies on two levels: heap data and hardware storage traffic. We design and implement optimizations that change the heap layout of arrays, and use program semantics to eliminate useless memory traffic. These techniques improve memory system efficiency and performance. We first quantitatively characterize the problem by comparing many data compression algorithms and their combinations in a limit study of Java benchmarks. We find that arrays are a dominant source of heap inefficiency. We introduce z-rays, a new array layout design, to bridge the gap between fast access, space efficiency and predictability. Z-rays facilitate compression and offer flexibility, and time and space efficiency. We find that there is a semantic mismatch between managed languages, with their rapid allocation rates, and current hardware, causing unnecessary and excessive traffic in the memory subsystem. We take advantage of the garbage collector's identification of dead data regions, communicating information to the caches to eliminate useless traffic to memory. By reducing traffic and bandwidth, we improve performance. We show that the memory abstraction in managed languages is not just a cost to be borne, but an opportunity to alleviate the memory bottleneck. This thesis shows how to exploit this abstraction to improve space and time efficiency and overcome the memory wall. We enhance the productivity and performance of ubiquitous managed languages on current and future architectures. / text

Η παρούσα διπλωματική εργασία πραγματεύεται το θέμα της αυτόματης εξαγωγής περίληψης από κείμενο ελληνικής γλώσσας. Η ανάκτηση πληροφορίας είναι ένας τομέας της επεξεργασίας φυσικής γλώσσας η οποία αποτελεί υποτομέα της Τεχνητής Νοημοσύνης. Σκοπός της είναι η ανάκτηση σημαντικών πληροφοριών από μεγάλες συλλογές δεδομένων. Ο συγκεκριμένος τομέας που συγκεντρώνεται στην εξαγωγή συνοπτικών περιλήψεων από κείμενα καλείται Αυτόματη Εξαγωγή Περίληψης Κειμένου. Το πρόγραμμα αφαιρεί τις πλεονάζουσες πληροφορίες από το κείμενο εισόδου και παράγει ένα μικρότερο, απαλλαγμένο από πλεονασμούς, κείμενο εξόδου. Το κείμενο αυτό είναι ένα extract από το αρχικό κείμενο. Με αυτό εννοούμε ότι καμία από τις νέες προτάσεις δεν παράγεται από την αρχή, αντ' αυτού, αρχικές μη τροποποιημένες προτάσεις χρησιμοποιούνται για να σχηματιστεί η περίληψη. Οι πιο σημαντικές προτάσεις επιλέγονται με την εφαρμογή κριτήριων που έχουν ειδικά σχεδιαστεί για να βαθμολογήσουν τη κάθε πρόταση. Το αποτέλεσμα συγκρίνεται με «ανθρώπινα» κατασκευασμένες περιλήψεις και με κάποια γνωστά προγράμματα αυτόματης σύνοψης κειμένου. / This diploma dissertation is about automatic text summarization for the Greek language. Information retrieval is a field of natural language processing which is a subfield of Artificial Intelligence. Its purpose is to retrieve important information out of large collections of data. The specific domain that concentrates on text-data and the extraction of short summaries is called automatic text summarization. A computer program that summarizes a text. The summarizer removes redundant information from the input text and produces a shorter non-redundant output text. The output text is an extract from the original text. With extract, we mean that no sentence is produced from scratch, but instead original sentences are used to form the summary. The most important sentences are chosen by application of some criteria that are specially designed to rank each sentence. The results are compared to human made summaries and to some well-known summarization programs.