14,715 research outputs found

    A Joint Intensity and Depth Co-Sparse Analysis Model for Depth Map Super-Resolution

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    High-resolution depth maps can be inferred from low-resolution depth measurements and an additional high-resolution intensity image of the same scene. To that end, we introduce a bimodal co-sparse analysis model, which is able to capture the interdependency of registered intensity and depth information. This model is based on the assumption that the co-supports of corresponding bimodal image structures are aligned when computed by a suitable pair of analysis operators. No analytic form of such operators exist and we propose a method for learning them from a set of registered training signals. This learning process is done offline and returns a bimodal analysis operator that is universally applicable to natural scenes. We use this to exploit the bimodal co-sparse analysis model as a prior for solving inverse problems, which leads to an efficient algorithm for depth map super-resolution.Comment: 13 pages, 4 figure

    A New Strategy to Stabilize Oxytocin in Aqueous Solutions: I. The Effects of Divalent Metal Ions and Citrate Buffer

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    In the current study, the effect of metal ions in combination with buffers (citrate, acetate, pH 4.5) on the stability of aqueous solutions of oxytocin was investigated. and divalent metal ions (Ca2+, Mg2+, and Zn2+) were tested all as chloride salts. The effect of combinations of buffers and metal ions on the stability of aqueous oxytocin solutions was determined by RP-HPLC and HP-SEC after 4 weeks of storage at either 4°C or 55°C. Addition of sodium or potassium ions to acetate- or citrate-buffered solutions did not increase stability, nor did the addition of divalent metal ions to acetate buffer. However, the stability of aqueous oxytocin in aqueous formulations was improved in the presence of 5 and 10 mM citrate buffer in combination with at least 2 mM CaCl2, MgCl2, or ZnCl2 and depended on the divalent metal ion concentration. Isothermal titration calorimetric measurements were predictive for the stabilization effects observed during the stability study. Formulations in citrate buffer that had an improved stability displayed a strong interaction between oxytocin and Ca2+, Mg2+, or Zn2+, while formulations in acetate buffer did not. In conclusion, our study shows that divalent metal ions in combination with citrate buffer strongly improved the stability of oxytocin in aqueous solutions

    Probability of improvement methods for constrained multi-objective optimization

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    This paper shows how the simultaneous consideration of multiple Kriging models can lead to useful metrics for the selection of design vectors in constrained multiobjective optimization. The savings in computational cost with such methods make them particularly useful for optimal electromagnetic design

    The potential for using a free-growth system in the rehabilitation of poorly performing pole-stage broadleaf stands

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    peer-reviewedThis paper is a literature review of the free-growth system, which may have potential for the rehabilitation of some poorly-performing pole-stage broadleaf stands. It involves releasing of a selected number of good quality stems from crown competition as a basis for the final crop. Generally, only stems with crowns adjacent to the potential final crop trees are removed. The aim is to increase diameter growth of the selected stems and thereby shorten the rotation length needed to achieve a given diameter. The treatment may result in a greater incidence of epicormic shoots, particularly in oak (Quercus spp.). To maintain stem quality, epicormics may need to be removed, which may make the free-growth system uneconomic. There is, however, some evidence to believe that this may not be the case. In addition, the free-growth system may also be applicable in species less prone to epicormics, such as ash (Fraxinus excelsior L.) and sycamore (Acer pseudoplatanus L.). The free-growth system may prove to be a useful system for the rehabilitation of poorly performing pole-stage broadleaf stands and, with the advent of Chalara ash dieback (caused by Hymenoscyphus pseudoalbidus V. Queloz et al.) in Ireland, may gain greater use for its ability to reduce rotation lengths.COFOR

    Apolipoprotein AIV gene variant S347 is associated with increased risk of coronary heart disease and lower plasma apolipoprotein AIV levels

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    The impact of common variants in the apolipoprotein gene cluster (APOC3-A4-A5) on prospective coronary heart disease (CHD) risk was examined in healthy UK men. Of the 2808 men followed over 9 years, 187 had a clinically defined CHD event. Examination of 9 single nucleotide polymorphisms (SNPs) in this group revealed that homozygotes for APOA4 S347 had significantly increased risk of CHD [hazard ratio (HR) of 2.07 (95%CI 1.04 to 4.12)], whereas men homozygous for APOC3 1100T were protected [HR 0.28 (95%CI 0.09 to 0.87)]. In stepwise multiple regression analysis, after entering all the variants and adjusting for established risk factors APOA4 T347S alone remained in the model. Using all nine SNPs, the highest risk-estimate haplotypes carried APOA4 S347 and rare alleles of the two flanking intergenic markers. The protective effect of APOC3 1100T could be explained by negative linkage disequilibrium with these alleles. To determine the association of APOA4 T347S with apoAIV levels, the relationship was examined in 1600 healthy young European men and women. S347 homozygotes had significantly lower apoAIV plasma levels (13.64±0.59 mg/dL) compared with carriers of the T347 allele (14.90±0.12 mg/dL) (P=0.035). These results demonstrate that genetic variation in and around APOA4, independent of the effects of triglyceride, is associated with risk of CHD and apoAIV levels, supporting an antiatherogenic role for apoAIV

    External examining: fit for purpose?

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    In a context of international concern about academic standards, the practice of external examining is widely admired for its role in defending standards. Yet a contradiction exists between this faith in examining and continuing concerns about standards. This article argues that external examining rests on assumptions about standards which are significantly open to challenge. Six assumptions relating to the conceptual context, the operation and the nature of examiners themselves are analysed drawing on a review of the available evidence. The analysis challenges the notion of a consensus on standards and the potential to vest in individuals the ability to represent that consensus when judging the comparability of academic standards in a stable and appropriate way. The issues raised have relevance to the UK and to other national systems using external examiners or seeking to guarantee academic standards by, in some cases, adopting quality assurance approaches developed in the UK

    Banking reform

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    Bank failures ; Savings and loan associations ; Bank supervision ; Deposit insurance

    Learning Co-Sparse Analysis Operators with Separable Structures

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    In the co-sparse analysis model a set of filters is applied to a signal out of the signal class of interest yielding sparse filter responses. As such, it may serve as a prior in inverse problems, or for structural analysis of signals that are known to belong to the signal class. The more the model is adapted to the class, the more reliable it is for these purposes. The task of learning such operators for a given class is therefore a crucial problem. In many applications, it is also required that the filter responses are obtained in a timely manner, which can be achieved by filters with a separable structure. Not only can operators of this sort be efficiently used for computing the filter responses, but they also have the advantage that less training samples are required to obtain a reliable estimate of the operator. The first contribution of this work is to give theoretical evidence for this claim by providing an upper bound for the sample complexity of the learning process. The second is a stochastic gradient descent (SGD) method designed to learn an analysis operator with separable structures, which includes a novel and efficient step size selection rule. Numerical experiments are provided that link the sample complexity to the convergence speed of the SGD algorithm.Comment: 11 pages double column, 4 figures, 3 table
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