104 research outputs found

    Optimization Research of Generation Investment Based on Linear Programming Model

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    AbstractLinear programming is an important branch of operational research and it is a mathematical method to assist the people to carry out scientific management. GAMS is an advanced simulation and optimization modeling language and it will combine a large number of complex mathematical programming, such as linear programming LP, nonlinear programming NLP, MIP and other mixed-integer programming with the system simulation. In this paper, based on the linear programming model, the optimized investment decision-making of generation is simulated and analyzed. At last, the optimal installed capacity of power plants and the final total cost are got, which provides the rational decision-making basis for optimized investments

    A Filter Algorithm with Inexact Line Search

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    A filter algorithm with inexact line search is proposed for solving nonlinear programming problems. The filter is constructed by employing the norm of the gradient of the Lagrangian function to the infeasibility measure. Transition to superlinear local convergence is showed for the proposed filter algorithm without second-order correction. Under mild conditions, the global convergence can also be derived. Numerical experiments show the efficiency of the algorithm

    RH-Map: Online Map Construction Framework of Dynamic Objects Removal Based on Region-wise Hash Map Structure

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    Mobile robots navigating in outdoor environments frequently encounter the issue of undesired traces left by dynamic objects and manifested as obstacles on map, impeding robots from achieving accurate localization and effective navigation. To tackle the problem, a novel map construction framework based on 3D region-wise hash map structure (RH-Map) is proposed, consisting of front-end scan fresher and back-end removal modules, which realizes real-time map construction and online dynamic object removal (DOR). First, a two-layer 3D region-wise hash map structure of map management is proposed for effective online DOR. Then, in scan fresher, region-wise ground plane estimation (R-GPE) is adopted for estimating and preserving ground information and Scan-to-Map Removal (S2M-R) is proposed to discriminate and remove dynamic regions. Moreover, the lightweight back-end removal module maintaining keyframes is proposed for further DOR. As experimentally verified on SemanticKITTI, our proposed framework yields promising performance on online DOR of map construction compared with the state-of-the-art methods. And we also validate the proposed framework in real-world environments

    A comprehensive insight into functional profiles of free-living microbial community responses to a toxic Akashiwo sanguinea bloom.

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    Phytoplankton blooms are a worldwide problem and can greatly affect ecological processes in aquatic systems, but its impacts on the functional potential of microbial communities are limited. In this study, a high-throughput microarray-based technology (GeoChip) was used to profile the functional potential of free-living microbes from the Xiamen Sea Area in response to a 2011 Akashiwo sanguinea bloom. The bloom altered the overall community functional structure. Genes that were significantly (p < 0.05) increased during the bloom included carbon degradation genes and genes involved in nitrogen (N) and/or phosphorus (P) limitation stress. Such significantly changed genes were well explained by chosen environmental factors (COD, nitrite-N, nitrate-N, dissolved inorganic phosphorus, chlorophyll-a and algal density). Overall results suggested that this bloom might enhance the microbial converting of nitrate to N2 and ammonia nitrogen, decrease P removal from seawater, activate the glyoxylate cycle, and reduce infection activity of bacteriophage. This study presents new information on the relationship of algae to other microbes in aquatic systems, and provides new insights into our understanding of ecological impacts of phytoplankton blooms

    High-Efficiency Asymmetric Transmission of Circularly Polarized THz waves using a Dielectric Herringbone Metasurface

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    An interesting topic is that of metamaterials imparting chiral responses which invoke a disparity between opposite handednesses of circularly polarised (CP) light. Most chiral metamaterials are either 3D-helical structures [1] or stacked metallic structures with twisted orientations [2]. These structures allow selective transmission of one CP whilst prohibiting or reflecting the other, termed Circular Dichroism. However, for 2D chiral metamaterials, this is not so. Instead, the cross-polarisation conversion of one CP to another is different. The original work in [3] used an anisotropic lossy planar-chiral “fish-scale” structure to exhibit this effect, termed Asymmetric Transmission (AT). However, these responses are small with efficiencies less than 25%. Works to improve efficiency used 3D arrangements. Work in [4] achieved much higher efficiency than for the 2D planar-chiral structures, but due to the metallic construction absorption losses were unavoidable; such losses were given as 37%. Here, we propose a means of achieving AT using a loss-free mechanism at 1THz frequency by constructing Monolithic Herringbone metamaterials from a dielectric medium [5]. This device works by a spin-selective interference of CP light, due to Pancharatnam-Berry (PB) phases, in conjunction with a propagative dynamic phase (Fig. 2) causing constructive interference for TRL and destructive for TLR Jones matrix components. An analytical derivation (Fig. 1a) was found to agree well with numerical simulations (Fig. 1b) for the design. These results indicate a conversion efficiency of LCP to RCP (TRL) exceeding 80%. Fabrication of Intrinsic Silicon was used for the devices (Fig. 2) and THz Time Domain Spectroscopy (THz-TDS) was used to characterise the samples, showing a 60% spin-conversion efficiency (Fig. 3). Such a device is robust and is not easily degraded by errors in fabrication

    Pancharatnam-Berry Phase Induced Spin-Selective Transmission in Herringbone Dielectric Metamaterials

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    A dielectric metamaterial approach for achieving spin‐selective transmission of electromagnetic waves is proposed. The design is based on spin‐controlled constructive or destructive interference between propagating phase and Pancharatnam–Berry phase. The dielectric metamaterial, consisting of monolithic silicon herringbone structures, exhibits a broadband operation in the terahertz regime

    LUCIDENIC ACID A INHIBITS THE BINDING OF HACE2 RECEPTOR WITH SPIKE PROTEIN TO PREVENT SARS-COV-2 INVASION

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    High infection caused by mutations of SARS-CoV-2 calls for new prevention strategy. Ganoderma lucidum known as a superior immunoenhancer exhibits various antiviral effects, whether it can resist SARS-CoV-2 remains unclear. Herein, virtual screening combined with in vitro hACE2 inhibition assays were used to investigate its anti SARS-CoV-2 effect. Potential 54 active components, 80 core targets and 20 crucial pathways were identified by the component-target-pathway network. The binding characters of these components to hACE2 and its complexes with spike protein including omicron variant was analyzed by molecular docking. Lucidenic acid A was selected as the top molecule with high affinity to all receptors by forming hydrogen bonds. Molecular dynamics simulation showed it had good binding stability with the receptor proteins. Finally, in vitro FRET test demonstrated it inhibited the hACE2 activity with IC50 2 μmol/mL. Therefore, lucidenic acid A can prevent the virus invasion by blocking hACE2 binding with SARS-CoV-2

    Robot-assisted percutaneous screw fixation in the treatment of navicular fracture

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    BackgroundLong recovery time, large scar, postoperative swelling and pain are possible side effects of open reduction internal fixation (ORIF) for tarsal navicular fractures. Early exercise instruction is made possible by the use of an intraoperative robot-assisted percutaneous invasive closed reduction internal fixation. The goal of the trial was to determine whether percutaneous screw internal fixation with robot assistance might be used to treat navicular fractures.Methods27 patients with navicular fractures had surgical treatment between June 2019 and December 2021. Of those, 20 instances were treated with ORIF, while 7 cases had robot-assisted percutaneous screw internal fixation. At the final follow-up, the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score and the visual analogue scale (VAS) score were compared to determine outcomes and function.ResultsFollow-up was obtained in all 27 patients after surgery, with a mean follow-up time of 21.81 months, ranging from 15 to 29 months . In the 7 instances of robot-assisted group, percutaneous guide wire insertion and screw placement only needed one attempt and the depth and position of the implant were both satisfactory. In the ORIF group, there were two patients who sustained cutaneous nerve injuries. The AOFAS score and the VAS score of the group receiving robot-assisted navigation percutaneous screw fixation were 92.25 ± 2.22 and 0.75 ± 0.25 respectively at the last follow-up, while 82.25 ± 7.15 and 0.50 ± 0.29 were the respective values for the ORIF group.ConclusionIntraoperative robot-assisted percutaneous closed reduction internal fixation for tarsal navicular fractures can accomplish exact localization of fracture site, reduce soft tissue damage and operative time. According to current view, this method offers fewer complications, a faster recovery after surgery, and more patient satisfaction
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