• Title/Summary/Keyword: Chris

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ROTATION IMPLEMENTATION OF A CIRCULAR CYLINDER IN INCOMPRESSIBLE FLOW VIA STAGGERED GRID APPROACH

  • Xiao Mingqing;Lin Yuan;Myatt James H.;Camphouse R. Chris;Banda Siva S.
    • Journal of applied mathematics & informatics
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    • v.22 no.1_2
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    • pp.67-82
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    • 2006
  • In this paper, we present a finite difference method for the implementation of the rotation of a circular cylinder in the incompressible flow field by solving the two-dimensional unsteady Navier-Stokes equations. The approach is to use staggered grid method so that the accuracy and order of convergence of the associated algorithms can be maintained. The proposed method is easy to be implemented and is effective. A set of simulations for the flow dynamics is provided to show the computational results.

Does Aging Matter? The Efficacy of Carpal Tunnel Release in the Elderly

  • Fung, Bettina Wai Yan;Tang, Chris Yuk Kwan;Fung, Boris Kwok Keung
    • Archives of Plastic Surgery
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    • v.42 no.3
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    • pp.278-281
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    • 2015
  • Open release remains the gold standard in the treatment of carpal tunnel syndrome in cases where conservative treatment fails. However, the efficacy of carpal tunnel release in the elderly has been debated in the literature throughout the years. This review aims to review the current evidence pertaining to the efficacy of carpal tunnel release in the elderly. Based on the current evidence, the outcome of carpal tunnel release is unpredictable in the elderly. Elderly patients are also less satisfied with the operation compared to younger patients. The authors recommend that these messages be conveyed to elderly patients before surgery. Moreover, open carpal tunnel release should be offered in the early stages of treatment whenever operative management is indicated.

Where is the Lesion? Glomus Tumours of the Hand

  • Tang, Chris Yuk Kwan;Tipoe, Timothy;Fung, Boris
    • Archives of Plastic Surgery
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    • v.40 no.5
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    • pp.492-495
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    • 2013
  • Glomus tumours are vascular hamartomas that are commonly found in the hand, particularly the subungual region. They appear as solitary or multiple tumours, and often present as a bluish discoloration of the nail plate. Different diagnostic tests are outlined, as well as imaging studies such as magnetic resonance imaging and ultrasound. Misdiagnosis and delayed diagnosis of these tumours are common, while a familial tendency is a potential risk factor but not yet proven. Complete surgical excision often results in complete symptomatic relief, while recurrences are largely due to incomplete excision or the growth of a new glomus tumour. This article aims to review the key aspects of glomus tumours and provide a diagnostic algorithm so that the lesion can be recognized and treated earlier.

Phenotypes of Integrase-Mutated Human Immunodeficiency Virus Type-1(HIV-1)

  • ;Chris M. Farnet;William A. Haseltine
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1993.04a
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    • pp.92-92
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    • 1993
  • Point mutations in a highly conserved central region of the HIV-1 integrase protein were analyzed for their effects on viral replication and virion morphogenesis. Conservative amino acid replacements of two amino acid residues invariant un retroviral integrases, D116 and E152 of HIV-1, as well as the highly conserved amino acid S147, completely blocked viral replication in two CD4$\^$+/ human T cell lines. Mutation of four other highly conserved amino acids in the region had no detectable effect on viral replication, while Mutations at two positions, N117 and Y143, resulted in viruses with a delayed replication phenotype. Characteristic and reproducible defects id virion core structure were observed by electron microscopic analysis of sore of the replication defective integrase point mutants, indicating that mutant integrase proteins can interfere with the process of virion core maturation.

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Social Influence on Knowledge Worker's Adoption of Innovative Information Technology

  • Yang, Hee-Dong;Moon, Yun-Ji;Rowley, Chris
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2008.10b
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    • pp.457-462
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    • 2008
  • User perceptions toward information technology (IT) are crucial to successful implementation. The purpose of our study is to improve the understanding of the impact of social influences on different types of users' perceptions and adoption of IT. To do this our study refines and expands the operationalization of the social influence construct to include four components: "subjective norm", "image","visibility", "voluntariness". We use this to examine influences by type of user (knowledge worker versus university student) and IT (innovative versus mature). The key finding is that when knowledge workers consider adopting innovative IT they are sensitive to general perceptions of its usefulness. Our results have implications for management enquiry and practice.

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Comparison of Intelligent Charging Algorithms for Electric Vehicles to Reduce Peak Load and Demand Variability in a Distribution Grid

  • Mets, Kevin;D'hulst, Reinhilde;Develder, Chris
    • Journal of Communications and Networks
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    • v.14 no.6
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    • pp.672-681
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    • 2012
  • A potential breakthrough of the electrification of the vehicle fleet will incur a steep rise in the load on the electrical power grid. To avoid huge grid investments, coordinated charging of those vehicles is a must. In this paper, we assess algorithms to schedule charging of plug-in (hybrid) electric vehicles as to minimize the additional peak load they might cause. We first introduce two approaches, one based on a classical optimization approach using quadratic programming, and a second one, market based coordination, which is a multi-agent system that uses bidding on a virtual market to reach an equilibrium price that matches demand and supply. We benchmark these two methods against each other, as well as to a baseline scenario of uncontrolled charging. Our simulation results covering a residential area with 63 households show that controlled charging reduces peak load, load variability, and deviations from the nominal grid voltage.

Improved phenomenological modelling of transient thermal strains for concrete at high temperatures

  • Nielsen, Claus V.;Pearce, Chris J.;Bicanic, Nenad
    • Computers and Concrete
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    • v.1 no.2
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    • pp.189-209
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    • 2004
  • Several extensions to the Thelandersson phenomenological model for concrete under transient high temperatures are explored. These include novel expressions for the temperature degradation of the elastic modulus and the temperature dependency of the coefficient of the free thermal strain. Furthermore, a coefficient of thermo mechanical strain is proposed as a bi-linear function of temperature. Good qualitative agreement with various test results taken from the literature is demonstrated. Further extensions include the effects of plastic straining and temperature dependent Poisson's ratio. The models performance is illustrated on several simple benchmark problems under uniaxial and biaxial stress states.

Some effects of audio-visual speech in perceiving Korean

  • Kim, Jee-Sun;Davis, Chris
    • Annual Conference on Human and Language Technology
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    • 1999.10e
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    • pp.335-342
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    • 1999
  • The experiments reported here investigated whether seeing a speaker's face (visible speech) affects the perception and memory of Korean speech sounds. In order to exclude the possibility of top-down, knowledge-based influences on perception and memory, the experiments tested people with no knowledge of Korean. The first experiment examined whether visible speech (Auditory and Visual - AV) assists English native speakers (with no knowledge of Korean) in the detection of a syllable within a Korean speech phrase. It was found that a syllable was more likely to be detected within a phrase when the participants could see the speaker's face. The second experiment investigated whether English native speakers' judgments about the duration of a Korean phrase would be affected by visible speech. It was found that in the AV condition participant's estimates of phrase duration were highly correlated with the actual durations whereas those in the AO condition were not. The results are discussed with respect to the benefits of communication with multimodal information and future applications.

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Synthesis of Host Polymers and Guests for Electrophosphorescence

  • Watkins Scott E.;Chan, Khai Leok;Cho, Sung-Yong;Evans Nicholas R.;Grimsdale Andrew C.;Holmes Andrew B.;Mak Chris S.K.;Sandee Albertus J.;Williams Charlotte K.
    • Macromolecular Research
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    • v.15 no.2
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    • pp.129-133
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    • 2007
  • Significant progress has been realized in the design and synthesis of light emitting polymers that emit over the entire visible spectrum. However, up to seventy-five percent of charge recombination events can lead to triplet states that decay non-radiatively. Following the pioneering work in the field of small molecule organic light emitting devices, it has been found that solution processible iridium polymer complexes can be used to harness the wasted triplet energy. In this paper, new results with respect to the electrophosphorescence of solution processible tethered iridium polymer derivatives are presented. Furthermore, our approaches to the design of new high triplet energy conjugated polymer hosts are also reported.