147 research outputs found

    Application of project management method in offshore engineering

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    Performance Investigation of the Impact Mechanisms of Turbulence Image Mathematical Properties

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    Abstract: In this research, fuzzy gray degrees were established to quantitatively evaluate the impact mechanisms in the image properties of turbulence motion locus. Through selecting different impact mechanisms during image acquirement and establishing factor-parameters array, the mathematical model of fuzzy gray evaluating system can therefore be structured. After calculating those fuzzy gray relational degrees between those factor-parameters and image properties, the external impact on image properties can be quantized systematically. By repeatedly experiments their impact disciplines are determined, this paper also provides technical references and new research ideas for following turbulence monitoring in practice as well. Copyrigh

    A New Vehicle Image Dynamic Tracking Approach

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    Abstract: For the purpose of moving target’s detecting, a new image tracking approach based on the changing factor of reference background learning and the direction predicting operator is presented. The high-speed moving vehicle is used as the detecting target for establishing a changing factor, on this basis the image sequence’s reference background learning is conducted, then by cross-correlation matching and coordinate transforming the moving target-vehicle is coordinate-positioned and speed-determined, combining with the direction predicting operator the moving direction of the target vehicle is predicted, thus the vehicle imagetracking can be realized. Through tracking experiment and performance comparison it is proved that by this new approach an accurate and stable tracking results of moving vehicle can be gotten; a new idea can also be provided for the research of moving target’s image-monitoring. Copyright © 2014 IFSA Publishing, S. L

    Comparative study of typical asphalt binders in Xinjiang region modified with warm mix additives

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    Xinjiang’s representative asphalt binders, such as Karamay and Tahe asphalt, lack sufficient research on warm-mix additive modification effects. Given their unique microstructure and molecular composition differences, comprehensive investigations are essential for a nuanced understanding of these binders. This study added Sasobit and Evotherm warm mix additives to Karamay 90# asphalt and Tahe 90# asphalt, respectively. The evaluation of diverse warm mix additives’ impact on diverse asphalt binders involved viscosity, softening point, penetration tests, Fourier transform infrared (FTIR) and analysis of saturate, aromatic, resin, and asphaltene (SARA) fractions. Additionally, molecular models of asphalt were constructed using Materials Studio software, based on the SARA test data. Molecular models of Sasobit and Evotherm were also developed, representing organic wax and a cationic quaternary ammonium surfactant, respectively. Conducting molecular dynamics simulations of warm mix additives and two asphalt molecules yielded valuable insights into solubility parameters and the radial distribution function (RDF). This approach enabled a thorough and comparative exploration of the modification mechanisms employed by various warm mix additives on different asphalt types at a molecular scale. The results indicate that, Evotherm excelled in enhancing high-temperature asphalt performance, while Sasobit surpassed it in low-temperature. The viscosity reduction by Sasobit proved more effective for K90, while for T90 asphalt, the trend was reversed with Evotherm exhibiting superior performance. The solubility parameter in MD simulations consistently correlates with asphalt viscosity results. Sasobit showed enhanced compatibility with K90 asphalt, while T90 asphalt demonstrated greater suitability for modification with Evotherm

    USB-NeRF: Unrolling Shutter Bundle Adjusted Neural Radiance Fields

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    Neural Radiance Fields (NeRF) has received much attention recently due to its impressive capability to represent 3D scene and synthesize novel view images. Existing works usually assume that the input images are captured by a global shutter camera. Thus, rolling shutter (RS) images cannot be trivially applied to an off-the-shelf NeRF algorithm for novel view synthesis. Rolling shutter effect would also affect the accuracy of the camera pose estimation (e.g. via COLMAP), which further prevents the success of NeRF algorithm with RS images. In this paper, we propose Unrolling Shutter Bundle Adjusted Neural Radiance Fields (USB-NeRF). USB-NeRF is able to correct rolling shutter distortions and recover accurate camera motion trajectory simultaneously under the framework of NeRF, by modeling the physical image formation process of a RS camera. Experimental results demonstrate that USB-NeRF achieves better performance compared to prior works, in terms of RS effect removal, novel view image synthesis as well as camera motion estimation. Furthermore, our algorithm can also be used to recover high-fidelity high frame-rate global shutter video from a sequence of RS images

    PTENless means more

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    AbstractRecent studies indicate that certain key molecules that are vital for various developmental processes, such as Wnt, Shh, and Notch, cause cancer when dysregulated. PTEN, a tumor suppressor that antagonizes the PI3 kinase pathway, is the newest one on the list. The biological function of PTEN is evolutionarily conserved from C. elegans to humans, and the PTEN-controlled signaling pathway regulates cellular processes crucial for normal development, including cell proliferation, soma growth, cell death, and cell migration. In this review, we will focus on the function of PTEN in murine development and its role in regulating stem cell self-renewal and proliferation. We will summarize the organomegaly phenotypes associated with Pten tissue-specific deletion and discuss how PTEN controls organ size, a fundamental aspect of development. Last, we will review the role of PTEN in hormone-dependent, adult-onset mammary and prostate gland development

    Revisiting Rolling Shutter Bundle Adjustment: Toward Accurate and Fast Solution

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    We propose a robust and fast bundle adjustment solution that estimates the 6-DoF pose of the camera and the geometry of the environment based on measurements from a rolling shutter (RS) camera. This tackles the challenges in the existing works, namely relying on additional sensors, high frame rate video as input, restrictive assumptions on camera motion, readout direction, and poor efficiency. To this end, we first investigate the influence of normalization to the image point on RSBA performance and show its better approximation in modelling the real 6-DoF camera motion. Then we present a novel analytical model for the visual residual covariance, which can be used to standardize the reprojection error during the optimization, consequently improving the overall accuracy. More importantly, the combination of normalization and covariance standardization weighting in RSBA (NW-RSBA) can avoid common planar degeneracy without needing to constrain the filming manner. Besides, we propose an acceleration strategy for NW-RSBA based on the sparsity of its Jacobian matrix and Schur complement. The extensive synthetic and real data experiments verify the effectiveness and efficiency of the proposed solution over the state-of-the-art works. We also demonstrate the proposed method can be easily implemented and plug-in famous GSSfM and GSSLAM systems as completed RSSfM and RSSLAM solutions

    Bronchoscopic ethanol injection combined with cryotherapy is an effective treatment for benign airway stenosis caused by endotracheal intubation or tracheotomyc

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    The benign tracheal stenosis is a challenge in interventional pulmonary disease. Bronchoscopic ethanol injection (BEI) is always used in airway stenosis caused by malignant tracheal tumor. The efficacy and safety of BEI in benign airway stenosis has not been studied before. To compare the safety and efficacy between bronchoscopic icryotherapy and BEI combined with bronchoscopic cryotherapy in the treatment of benign tracheal stenosis. A retrospective study included 61 patients with tracheal stenosis caused by endotracheal intubation and tracheotomy from July 2010 to June 2015 was made. 33 patients received repeated bronchoscopic cryotherapy alone were in Group A, 29 patients underwent repeated cryotherapy combined with BEI were in Group B. Dyspnea index, tracheal diameter were collected before and after treatment. Efficacy and complications were compared in two groups. The changes of tracheal diameter, dyspnea index were significant before and after treatment in both groups (P < 0.05). The long-term cure rate was higher in group B than that in group A (100% vs 84.8%). The average duration for dilated airway stable was much shorter in group B than group A (166±28 days vs 278±32 days, P < 0.05). The average cryotherapy session performed in group B was significantly less than that in group A (22.1±4.7 vs 34.9±6.5, P < 0.05). Meanwhile the complications in group A were seldom, the incidence of complications related to BEI were low in group B (mild chest pain 7.1%, bleeding 3.6% and cough 10.7%). BEI combined with bronchoscopic cryotherapy is an effective minimally invasive choice for releasing the airway obstructive symptoms
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