1,439 research outputs found

    Making information accessible for the conservation and use of biodiversity. A novel initiative to facilitate access to information and use of agricultural and tree biodiversity

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    Poster presented at Science Week 2014 - Bioversity International HQ, Rome (Italy), 24-27 Feb 201

    Dynamic evolving neural-fuzzy inference system for rainfall-runoff (R-R) modelling

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    Dynamic Evolving Neural-Fuzzy Inference System (DENFIS) is a Takagi-Sugeno-type fuzzy inference system for online learning which can be applied for dynamic time series prediction. To the best of our knowledge, this is the first time that DENFIS has been used for rainfall-runoff (R-R) modeling. DENFIS model results were compared to the results obtained from the physically-based Storm Water Management Model (SWMM) and an Adaptive Network-based Fuzzy Inference System (ANFIS) which employs offline learning. Data from a small (5.6 km2) catchment in Singapore, comprising 11 separated storm events were analyzed. Rainfall was the only input used for the DENFIS and ANFIS models and the output was discharge at the present time. It is concluded that DENFIS results are better or at least comparable to SWMM, but similar to ANFIS. These results indicate a strong potential for DENFIS to be used in R-R modeling

    PV cell angle optimization for energy generation-consumption matching in a solar powered cellular network

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    An inherent problem of solar-energy-powered-smallcell base stations (SBSs) is that the energy generation of the photovoltaic (PV) cell does not match the energy consumption of the SBS in time. In this paper, we propose to optimize the PV cell orientation angle to achieve a good match between the energy generation and consumption profiles on a daily time scale. The optimization is formulated as an integer linear programming problem. We also derive an expression for the correlation between the energy generation and consumption profiles to evaluate their general interaction independent of the exact PV cell or SBS deployment setup. The numerical evaluation of the proposed angle optimization in a business area in London in summer/winter shows that the optimal PV cell orientation in summer contradicts the conventional assumption of south facing being optimal in the northern hemisphere. Instead, a southwest orientation should be chosen in summer due to its ability to shift the energy generation peak towards the energy consumption peak in the afternoon at a SBS in central London. This is in accordance with the prediction given by our derived correlation between the solar energy generation and consumption profiles

    UNDERSTANDING THE SOURCES OF STUDENTS’ SELF-EFFICACY DEVELOPMENT IN A CHINESE HIGHER VOCATIONAL INSTITUTE

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    ABSTRACT Self-efficacy theory (Bandura, 1997) posits that if individuals believe they have the capability to perform well in their endeavours, they are more inclined to be motivated, invest more effort and persist in the face of adversity (Klassen & Usher, 2010; Pajares & Schunk, 2001; Zimmerman, 2000). The study of efficacy beliefs is still a relatively new area of research in Chinese society (Kwan, Hui & McGee, 2010) and research into the influence of perceived self-efficacy or one’s efficacy belief on academic achievements is limited, especially in the context of vocational education. The purpose of this study is to understand the development of efficacy beliefs of Chinese students in vocational education. This study adopted a qualitative approach using face to face interviews in the data collection, and thematic analysis was used to analyse data collected from participants who were studying on a Sino-Australian hotel management programme at a higher vocational institute in China. The findings from this study indicated that the major sources of self-efficacy development are consistent with Bandura’s (1997) four hypothesized sources of self-efficacy. The findings also indicated that Influences of these sources of self-efficacy can be both positive in increasing perceived self-efficacy and negative by undermining efficacy beliefs development, depending on varying conditions such as how the information is valued and interpreted, and the timing of information received. Self-talk was found in this study as self-encouragement as well as a copying strategy to overcome anxieties and stressful situations. Participants also reported the beneficial influence of collective efficacy in the foreign component of their Sino-Joint Venture programmes as well as on their internship workplace. This study found that despite some participants’ with self-reported low perceived self-efficacy in certain domains, expressed the willingness and necessity to persevere with more effort to gain a chance of success. The findings also indicated that the participants generally believe that effort investment is necessary for achievement; however it is also necessary to first have belief in their capabilities. The implications are that the development of self-efficacy beliefs is important to help them make sense of their commitment to hard work and that the development of collective efficacy at the institutional level can change how vocational education is perceived in China. Key words: Chinese students; collective efficacy; effort investment; internship; mastery experience; perceived self-efficacy; physical and emotional status; qualitative research; relational efficacy, self-efficacy beliefs; sources of self-efficacy; vicarious experience; self-talk; social cognitive theory; vocational education

    Mechano-responsive polymer solutions based on CO2 supersaturation: shaking-induced phase transitions and self-assembly or dissociation of polymeric nanoparticles

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    Mechanical stimulation of supersaturated aqueous CO2 solutions is accompanied by a pH increase within seconds. In solutions of tailored homo- and AB diblock copolymers this is exploited to induce micelle formation, or, taking advantage of an aqueous upper critical solution temperature transition, nanoparticle disassembly

    Band Structure Mapping of Bilayer Graphene via Quasiparticle Scattering

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    A perpendicular electric field breaks the layer symmetry of Bernal-stacked bilayer graphene, resulting in the opening of a band gap and a modification of the effective mass of the charge carriers. Using scanning tunneling microscopy and spectroscopy, we examine standing waves in the local density of states of bilayer graphene formed by scattering from a bilayer/trilayer boundary. The quasiparticle interference properties are controlled by the bilayer graphene band structure, allowing a direct local probe of the evolution of the band structure of bilayer graphene as a function of electric field. We extract the Slonczewski-Weiss-McClure model tight binding parameters as γ0=3.1\gamma_0 = 3.1 eV, γ1=0.39\gamma_1 = 0.39 eV, and γ4=0.22\gamma_4 = 0.22 eV.Comment: 12 pages, 4 figure

    The detection of cervical intraepithelial neoplasia by electrical impedance spectroscopy: The effects of acetic acid and tissue homogeneity

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    Objective. To evaluate the efficacy of an electrical impedance probe (Epitheliometer) in the diagnosis of high grade cervical intraepithelial neoplasia (CIN) in women referred with cervical smear abnormalities and to assess the effect of acetic acid (AA) and tissue boundaries on the measurements. Methods. A prospective observational study was undertaken in the colposcopy clinic. One hundred and sixty-five women, either with a clinical indication or abnormal cervical cytology, were recruited into the study. A pencil type probe was used to record impedance spectra from 12 points on the cervix before and after the application of 5% AA. Spectra were also recorded from tissue boundaries. Colposcopic examinations, including probe positioning, were video recorded to allow for correlations between histopathological diagnosis of colposcopically directed biopsies, colposcopic impression and the diagnosis based on impedance measurements. Results. Receiver operating characteristic (ROC) curves were derived. The areas under the curves (AUCs) to discriminate original squamous from high grade CIN were 0.80 (pre AA) and 0.79 (post AA). Comparison of these curves showed no significant difference, indicating that application of AA does not produce a large change in spectra. The probe Could distinguish tissue boundaries from homogeneous tissue points. Conclusion. The Epitheliometer has the potential to be used as an adjunct to colposcopy in the diagnosis of high grade CIN. It has the advantage of real time results, decreasing the need for diagnostic cervical biopsies, and facilitates a wider use of the 'see and treat' policy without the risk of overtreatment. (C) 2009 Elsevier Inc. All rights reserved

    DotAligner:Identification and clustering of RNA structure motifs

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    Abstract The diversity of processed transcripts in eukaryotic genomes poses a challenge for the classification of their biological functions. Sparse sequence conservation in non-coding sequences and the unreliable nature of RNA structure predictions further exacerbate this conundrum. Here, we describe a computational method, DotAligner, for the unsupervised discovery and classification of homologous RNA structure motifs from a set of sequences of interest. Our approach outperforms comparable algorithms at clustering known RNA structure families, both in speed and accuracy. It identifies clusters of known and novel structure motifs from ENCODE immunoprecipitation data for 44 RNA-binding proteins

    Electronic energy level alignment at metal-molecule interfaces with a GW approach

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    Using density functional theory and many-body perturbation theory within a GW approximation, we calculate the electronic structure of a metal-molecule interface consisting of benzene diamine (BDA) adsorbed on Au(111). Through direct comparison with photoemission data, we show that a conventional G0_0W0_0 approach can underestimate the energy of the adsorbed molecular resonance relative to the Au Fermi level by up to 0.8 eV. The source of this discrepancy is twofold: a 0.7 eV underestimate of the gas phase ionization energy (IE), and a 0.2 eV overestimate of the Au work function. Refinements to self-energy calculations within the GW framework that account for deviations in both the Au work function and BDA gas-phase IE can result in an interfacial electronic level alignment in quantitative agreement with experiment
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