909 research outputs found
Introduction to hyperconvex spaces
No full textThe notion of hyperconvexity is due to Aronszajn and Panitchpakdi (1956) who proved that a hyperconvex space is a nonexpansive absolute retract, i.e. it is a nonexpansive retract of any metric space in which it is isometrically embedded. The corresponding linear theory is well developed and associated with the names of Gleason, Goodner, Kelley and Nachbin (see for instance. The nonlinear theory is still developing. The recent interest into these spaces goes back to the results of Sine and Soardi who proved independently that fixed point property for nonexpansive mappings holds in bounded hyperconvex spaces. Since then many interesting results have been shown to hold in hyperconvex spaces
Douglas-Rachford Method for Non-Convex Feasibility Problems
No full textThe Douglas-Rachford method has been employed successfully to solve a variety of non-convex feasibility problems. In particular, it shows surprising stability when applied to finding the intersections of hypersurfaces. We prove local convergence in the generalization of a case prototypical of the phase retrieval problem. In so doing, we also discover phenomena which may inhibit convergence. Finally we illustrate an application to solving boundary valued ordinary differential equations.
This talk includes discoveries from three closely related works:
1. With Brailey Sims, Matthew Skerritt. ''Computing Intersections of Implicitly Specified Plane Curves.'' To appear in Journal of Nonlinear and Convex Analysis.
2. With Jonathan M. Borwein, Brailey Sims, Anna Schneider, Matthew Skerritt. ''Dynamics of the Douglas-Rachford Method for Ellipses and p-Spheres.'' Submitted to Set Valued and Variational Analysis.
3. With Bishnu Lamichhane and Brailey Sims. ''Application of Projection Algorithms to Differential Equations: Boundary Value Problems,'' in preparation with plans to submit to ANZIAM Journal.Non UBCUnreviewedAuthor affiliation: University of NewcastleGraduat
Visualisation of amphetamine contamination in fingerprints using tof-sims technique
No full textTime-of-flight secondary ion mass spectrometry (TOF-SIMS) was applied to detect traces of amphetamine on fingerprints. In the present study, three different lift tapes and latent powder fingerprints were tested. The obtained results show that it is possible to identify traces of a drug as well as its distribution over the tested fingerprint after its transfer from the primary base onto an adhesive lifter (secondary base). Moreover, images obtained by the TOF-SIMS technique enable the observation of very small areas of the analysed fingerprint as well as the identification of micro-objects (residues of a contaminant) that were left on the fingerprint. The use of the black latent fingerprint powder did not interfere with the TOF-SIMS analysis, which makes it possible to effectively use this technique to study the traces of substances on the revealed fingerprints.ChemE/Advanced Soft Matte
Universal Processor Architecture for Biomedical Implants: The SiMS Project
No full textHEALTHCARE in the 21st century is changing rapidly. In advanced countries, in particular, healthcare is moving from a public to a more personalized nature. However, the costs of healthcare worldwide are increasing every year. Better use of technology can and should be used to get control of these costs. At the same time, implants have clearly benefitted from the astounding technology-miniaturization trends of late, boasting smaller sizes, lower power consumption and increased performance of the transistor devices. However, such advances do not come for free. Adverse effects in current implant designs are being witnessed, such as increasing power consumption, absence of design for reliability and highly application-specific nature. Operating under the assumption that implants will constitute an important means towards improved, personal healthcare and, in view of the aforementioned design phenomena, we believe that a new paradigm in implant design is required. This dissertation establishes the concept of Smart implantable Medical Systems (SiMS). SiMS is a systematic approach – a framework – for providing biomedical researchers and, hopefully, industry with a toolbox of ready-to-use, highly reliable implant sub-systems and models in order to construct optimal implants for various medical applications. The SiMS framework has to guarantee essential attributes, such as high dependability, modular design, ultra-low power consumption and miniature size. Having defined the SiMS framework, this dissertation is, then, concerned with exploring the optimal microarchitectural details of a crucial SiMS component: the SiMS processor. Contrary to the current state of the art, this processor aspires to be a new universal, low-power and low-cost processor and capable of efficiently serving a wide range of diverse implant applications.Computer Science and EngineeringElectrical Engineering, Mathematics and Computer Scienc
'A bright memory to remain' : the life and works of Charles Sims RA (1873-1928)
No full textThis thesis investigates the life and work of the English painter Charles Sims RA (1873-1928). It takes the form of a monograph and examines key themes of Sims' career within a chronological framework. The study makes consistent reference to the Sims Archive — the artist's studio contents recently brought to light by the author in negotiation with the artist's family and currently in the possession of Northumbria University. For the first time Sims' working practices and motivations have been explored in detail, thus contributing to knowledge of this particular neglected painter and more generally allowing some additional insight into the problems besetting and opportunities afforded to British artists of his generation. Sims' career spanned a transitional period in British art history which is currently being reassessed by art historians: the debates surrounding the effects of European modernism on British art, the inevitable impact of the Great War and the search during the 1920s for a visual language appropriate to modern life. Sims negotiated disparate experiences and preoccupations in an interesting way, and produced a stylistically diverse body of work in his continued search, I argue, for an alternative to modern reality. He attempted the combination of ancient religions, past art and modern experience into pictorial idylls that were simultaneously familiar and unattainable. The thesis aims to explore Sims' inspiration and reassesses his career within the context of his better known contemporaries by cross-referencing information held in national and international collections, libraries and archives with the hitherto unseen material here
Synthesis of furanosesquiterpenoid natural products
No full textThe effect of addition of a catalytic quantity of a crown ether in the reaction of a phosphonate anion with a carbonyl compound (Wadsworth-Emmons reaction) has been studied and found to greatly facilitate this reaction. This modification of the Wadsworth-Emmons reaction, using a catalytic amount of 15-crown-5, has been employed in the synthesis of the naturally occurring furanosesquiterpene Pallescensin-E. The structure of this compound has been confirmed by comparison of its spectral data with that of the synthesised isomer, 4,l0-dihydro-7,8-dimethyl 10H-benzof4,5Jcycloheptafl,2-bJ furan.Homosesquirosefuran, an analogue of the naturally occurring furanosesquiterpene Sesquirosefuran, has been synthesised via the dianion of methylacetoacetate.An approach to the synthesis of Pinguisone (a component of the essential oil of the liverwort Aneura pinguis)has been attempted employing two Diels-Alder reactions to generate the four cis-methyl groups found in the natural product.In a study of the reaction of n-(2-methylallyl)nickel bromide complex with a range of epoxides, this complex was found not only to react with reactive epoxides (e.g. styrene epoxide) but also with less reactive propylene epoxide.Substrates for possible intramolecular n-allylnickel cyclisation to generate an a-methylene-6-valerolactone ring system have been prepared
Library licensing and criminal law: The Aaron Swartz case
No full textReviews the ways that library licenses for subscription content contributed to criminal charges against activist Aaron Swartz, when he downloaded content from JSTOR on the MIT campus. (Author Note: This piece predates Swartz's death by suicide in 2013.)Sims, Nancy, A. (2011). Library licensing and criminal law: The Aaron Swartz case. Retrieved from the University Digital Conservancy, 10.5860/crln.72.9.8637
Sim-biosis : di-simulando "The Sims"
No full textThe Sims (2000-2003) is a fascinating computer game that allows the user to simulate human behaviour and the triviality of everyday interactions. This essay makes sense of the appeal of what superficially looks like a virtual dollhouse. The researchers conclude that The Sims is an example of a new form of interactive narrative that allows the user to play an array of possible roles: spectator, player and intertextual author
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