6,116 research outputs found

    Expert Finding by Capturing Organisational Knowledge from Legacy Documents

    No full text
    Organisations capitalise on their best knowledge through the improvement of shared expertise which leads to a higher level of productivity and competency. The recognition of the need to foster the sharing of expertise has led to the development of expert finder systems that hold pointers to experts who posses specific knowledge in organisations. This paper discusses an approach to locating an expert through the application of information retrieval and analysis processes to an organization’s existing information resources, with specific reference to the engineering design domain. The approach taken was realised through an expert finder system framework. It enables the relationships of heterogeneous information sources with experts to be factored in modelling individuals’ expertise. These valuable relationships are typically ignored by existing expert finder systems, which only focus on how documents relate to their content. The developed framework also provides an architecture that can be easily adapted to different organisational environments. In addition, it also allows users to access the expertise recognition logic, giving them greater trust in the systems implemented using this framework. The framework were applied to real world application and evaluated within a major engineering company

    Quantifying mixed-state quantum entanglement by optimal entanglement witness

    Full text link
    We develop an approach of quantifying entanglement in mixed quantum states by the optimal entanglement witness operator. We identify the convex set of mixed states for which a single witness provides the exact value of an entanglement measure, and show that the convexity, properties, and symmetries of entanglement or of a target state considerably fix the form of the optimal witness. This greatly reduces difficulty in computing and experimentally determining entanglement measures. As an example, we show how to experimentally quantify bound entanglement in four-qubit noisy Smolin states and three-qubit Greenberger-Horne-Zeilinger (GHZ) entanglement under white noise. For general measures and states, we provide a numerical method to efficiently optimize witness.Comment: Supplemental material is include

    Minimax optimization of entanglement witness operator for the quantification of three-qubit mixed-state entanglement

    Full text link
    We develop a numerical approach for quantifying entanglement in mixed quantum states by convex-roof entanglement measures, based on the optimal entanglement witness operator and the minimax optimization method. Our approach is applicable to general entanglement measures and states and is an efficient alternative to the conventional approach based on the optimal pure-state decomposition. Compared with the conventional one, it has two important merits: (i) that the global optimality of the solution is quantitatively verifiable, and (ii) that the optimization is considerably simplified by exploiting the common symmetry of the target state and measure. To demonstrate the merits, we quantify Greenberger-Horne-Zeilinger (GHZ) entanglement in a class of three-qubit full-rank mixed states composed of the GHZ state, the W state, and the white noise, the simplest mixtures of states with different genuine multipartite entanglement, which have not been quantified before this work. We discuss some general properties of the form of the optimal witness operator and of the convex structure of mixed states, which are related to the symmetry and the rank of states

    Generating Individual Patient Preferences for the Treatment of Osteoarthritis Using Adaptive Choice-Based Conjoint (ACBC) Analysis.

    Get PDF
    INTRODUCTION: To explore how adaptive choice-based conjoint (ACBC) analysis could contribute to shared decision-making in the treatment of individual patients with osteoarthritis (OA). METHODS: In-depth case study of three individuals randomly selected from patients with OA participating in an ACBC analysis exercise. Eleven members of a research users' group participated in developing an ACBC task on medication preferences for OA. Individual medication priorities are illustrated by the detailed analysis of ACBC output from three randomly selected patients from the main sample. RESULTS: The case study analysis illustrates individual preferences. Participant 1's priority was avoidance of the four high-risk side effects of medication, which accounted for 90% of the importance of all attributes, while the remaining attributes (expected benefit; way of taking medication; frequency; availability) accounted only for 10% of the total influence. Participant 3 was similar to participant 1 but would accept a high risk of one of the side effects if the medication were available by prescription. In contrast, participant 2's priority was the avoidance of Internet purchase of medication; this attribute (availability) accounted for 52% of the importance of all attributes. CONCLUSIONS: Individual patients have preferences that likely lead to different medication choices. ACBC has the potential as a tool for physicians to identify individual patient preferences as a practical basis for concordant prescribing for OA in clinical practice. Future research needs to establish whether accurate knowledge of individual patient preferences for treatment attributes and levels translates into concordant behavior in clinical practice

    Electron interactions in an antidot in the integer quantum Hall regime

    Full text link
    A quantum antidot, a submicron depletion region in a two-dimensional electron system, has been actively studied in the past two decades, providing a powerful tool for understanding quantum Hall systems. In a perpendicular magnetic field, electrons form bound states around the antidot. Aharonov-Bohm resonances through such bound states have been experimentally studied, showing interesting phenomena such as Coulomb charging, h/2e oscillations, spectator modes, signatures of electron interactions in the line shape, Kondo effect, etc. None of them can be explained by a simple noninteracting electron approach. Theoretical models for the above observations have been developed recently, such as a capacitive-interaction model for explaining the h/2e oscillations and the Kondo effect, numerical prediction of a hole maximum-density-droplet antidot ground state, and spin density-functional theory for investigating the compressibility of antidot edges. In this review, we summarize such experimental and theoretical works on electron interactions in antidots.Comment: 73 pages, 28 figures, to be published in Physics Reports. The resolution of some figures is reduced in this uploa

    Magnetic Quantum Dot: A Magnetic Transmission Barrier and Resonator

    Full text link
    We study the ballistic edge-channel transport in quantum wires with a magnetic quantum dot, which is formed by two different magnetic fields B^* and B_0 inside and outside the dot, respectively. We find that the electron states located near the dot and the scattering of edge channels by the dot strongly depend on whether B^* is parallel or antiparallel to B_0. For parallel fields, two-terminal conductance as a function of channel energy is quantized except for resonances, while, for antiparallel fields, it is not quantized and all channels can be completely reflected in some energy ranges. All these features are attributed to the characteristic magnetic confinements caused by nonuniform fields.Comment: 4 pages, 4 figures, to be published in Physical Review Letter

    Moments of spectral functions: Monte Carlo evaluation and verification

    Full text link
    The subject of the present study is the Monte Carlo path-integral evaluation of the moments of spectral functions. Such moments can be computed by formal differentiation of certain estimating functionals that are infinitely-differentiable against time whenever the potential function is arbitrarily smooth. Here, I demonstrate that the numerical differentiation of the estimating functionals can be more successfully implemented by means of pseudospectral methods (e.g., exact differentiation of a Chebyshev polynomial interpolant), which utilize information from the entire interval (β/2,β/2)(-\beta \hbar / 2, \beta \hbar/2). The algorithmic detail that leads to robust numerical approximations is the fact that the path integral action and not the actual estimating functional are interpolated. Although the resulting approximation to the estimating functional is non-linear, the derivatives can be computed from it in a fast and stable way by contour integration in the complex plane, with the help of the Cauchy integral formula (e.g., by Lyness' method). An interesting aspect of the present development is that Hamburger's conditions for a finite sequence of numbers to be a moment sequence provide the necessary and sufficient criteria for the computed data to be compatible with the existence of an inversion algorithm. Finally, the issue of appearance of the sign problem in the computation of moments, albeit in a milder form than for other quantities, is addressed.Comment: 13 pages, 2 figure

    Neuropilin 1 Involvement in Choroidal and Retinal Neovascularisation

    Get PDF
    Purpose Inhibiting VEGF is the gold standard treatment for neovascular age-related macular degeneration (AMD). It is also effective in preventing retinal oedema and neovascularisation (NV) in diabetic retinopathy (DR) and retinal vein occlusions (RVO). Neuropilin 1 (Nrp1) is a co-receptor for VEGF and many other growth factors, and therefore a possible alternative drug target in intra ocular neovascular disease. Here we assessed choroidal and retinal NV in an inducible, endothelial specific knock out model for Nrp1. Methods Crossing Nrp1 floxed mice with Pdgfb-CreERT2 mice produced tamoxifen-inducible, endothelial specific Nrp1 knock out mice (Nrp1ΔEC) and Cre-negative, control littermates. Cre-recombinase activity was confirmed in the Ai3(RCL-EYFP) reporter strain. Animals were subjected to laser-induced CNV (532 nm) and spectral domain-optical coherence tomography (SD-OCT) was performed immediately after laser and at day 7. Fluorescein angiography (FA) evaluated leakage and postmortem lectin staining in flat mounted RPE/choroid complexes was also used to measure CNV. Furthermore, retinal neovascularisation in the oxygen induced retinopathy (OIR) model was assessed by immunohistochemistry in retinal flatmounts. Results In vivo FA, OCT and post-mortem lectin staining showed a statistically significant reduction in leakage (p<0.05), CNV volume (p<0.05) and CNV area (p<0.05) in the Nrp1ΔEC mice compared to their Cre-negative littermates. Also the OIR model showed reduced retinal NV in the mutant animals compared to wild types (p<0.001). Conclusion We have demonstrated reduced choroidal and retinal NV in animals that lack endothelial Nrp1, confirming a role of Nrp1 in those processes. Therefore, Nrp1 may be a promising drug target for neovascular diseases in the eye

    Consumer Awareness and Perception of Organic Vegetables in Baguio City and La Trinidad, Benguet, Northern Philippines

    Get PDF
    Food consumption patterns are changing as a result of health and environmental issues, especially in the Cordillera Region which is known as producer and supplier of conventionally produced vegetables. The study aimed to determine the awareness and perception of consumers regarding organic vegetables and determine the factors affecting purchase/consumption of organic products. The data for the study was gathered through a survey of 200 household respondents from the selected barangays (villages) in Baguio City and La Trinidad, Benguet. Result shows that 70% of the household respondents were aware about organic products. Among these, 68% are moderately aware, 28% have high awareness, and only 4% have low awareness on organic vegetables. The awareness of consumers is not a guarantee that they are consumers of organic vegetables. Out of the 141 respondents who are aware, only 115 are consumers. Perception about organic products is based on the information they acquired from their friends, neighbors, relatives, officemates, radio and TV programs, seminars, programs, and the internet. Factors affecting the purchase/ consumption of organic vegetables are price, income, health benefits, nutrient contents, and safety of the product. Respondents perceived that organic vegetables are more nutritious, healthier, safe, clean, naturally grown, and free from poisonous chemicals. In order to create awareness and greater demand for organic products, there should be a massive information dissemination about organic products, the health benefits derived from consumption, and the benefit of organic production to the environment. This could be done through seminars, mothers’ classes in the barangay, and the use of media, flyers, and brochures
    corecore