627 research outputs found

    Research on Trust-Role Access Control Model in Cloud Computing

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    A Study on the Effects of Local Added Masses on the Natural and the Sound Radiation Characteristics of Thin Plate Structures

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    As panel-like structures are widely used in industrial products such as high speed trains, automobiles, and ships, the effects of additional attachments (e.g. lumped mass, rib-stiffeners) to the panels on their dynamic/acoustic characteristics have been investigated analytically, numerically, experimentally or combining two or all the methods in the past decades. The present study focuses on highlighting the differences among local mass effects on the vibration and the radiation behaviour of flexible modes of the flat panel structures. A simple model comprising a local mass attached to a rectangular plate surface is set up, allowing us a deep insight into how the local mass affects the inherent mode parameters and the corresponding vibration and radiation characteristics of panel structures. The influential phenomena are first investigated analytically and then verified using FE-numerical simulations. The results show that: (1) the dynamic modal parameters of flat panel structures show different sensitivity to the values of the added mass and its locations; (2) the vibration and radiation characteristics of elastic modes with the same order can be affected in quite different degrees by the same local mass attachment; and (3) the modal acoustic interactions of thin plates can be significantly affected by the local mass attachments

    Mobile Internet based M-Commerce Management Architecture & System

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    The mobile Internet exits already in very many forms on the market. However, there are definitely still a lot of possibilities to improve the current concepts and solution, and thus a lot of room for future R&D activities. This paper is divided five parts as followings: First of all, introduction; Secondly, the basic concept of mobile Internet is introduced, and its’ develop- ment status is described simply; Thirdly, the process of come into being M-commerce based on Internet and the existing modes of M-commerce are discussed respectively; the differences between E-commerce and Mcommerce are also shown in the paper; Fourthly, an M-commerce system model is presented, the model involves its’ basic elements such as hierarchical architecture, management mechanism, system decision-making, application procedure etc; Fifthly, development trend and application fields for coming the new economics times are forecasted; Finally, how to build a M-commerce management system and make applications for business via CERNET** (one of the biggest Internet platform in China) are introduced primarily in end of the paper

    Steering of magnetotactic bacterial microrobots by focusing magnetic field for targeted pathogen killing

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    International audienceTargeted steering of magnetotactic bacterial microrobots is a growing tendency for their various biomedical applications. However, real-time monitoring during their movements and targeted cell killing in specific locations remains challenging. Here, we steered bacterial microrobots to target and attach to Staphylococcus aureus that was subsequently killed in a magnetic target device, which can realize guiding, mixing, and killing for targeted therapy. The generated focusing magnetic field was applied to magnetotactic bacterial microrobots, and the realizability of control strategies was analyzed. We successfully guided magnetotactic bacterial microrobots in microfluidic chips without real-time monitoring of their location. After mixing with microrobots under a rotating magnetic field for their attachment, the pathogen was killed under a swinging magnetic field. These results suggest that targeted therapy with these microrobots by using a magnetic target device is a promising approach

    Geometric Prior Based Deep Human Point Cloud Geometry Compression

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    The emergence of digital avatars has raised an exponential increase in the demand for human point clouds with realistic and intricate details. The compression of such data becomes challenging with overwhelming data amounts comprising millions of points. Herein, we leverage the human geometric prior in geometry redundancy removal of point clouds, greatly promoting the compression performance. More specifically, the prior provides topological constraints as geometry initialization, allowing adaptive adjustments with a compact parameter set that could be represented with only a few bits. Therefore, we can envisage high-resolution human point clouds as a combination of geometric priors and structural deviations. The priors could first be derived with an aligned point cloud, and subsequently the difference of features is compressed into a compact latent code. The proposed framework can operate in a play-and-plug fashion with existing learning based point cloud compression methods. Extensive experimental results show that our approach significantly improves the compression performance without deteriorating the quality, demonstrating its promise in a variety of applications

    Modeling the role of p53 pulses in DNA damage- induced cell death decision

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    <p>Abstract</p> <p>Background</p> <p>The tumor suppressor p53 plays pivotal roles in tumorigenesis suppression. Although oscillations of p53 have been extensively studied, the mechanism of p53 pulses and their physiological roles in DNA damage response remain unclear.</p> <p>Results</p> <p>To address these questions we presented an integrated model in which Ataxia-Telangiectasia Mutated (ATM) activation and p53 oscillation were incorporated with downstream apoptotic events, particularly the interplays between Bcl-2 family proteins. We first reproduced digital oscillation of p53 as the response of normal cells to DNA damage. Subsequent modeling in mutant cells showed that high basal DNA damage is a plausible cause for sustained p53 pulses observed in tumor cells. Further computational analyses indicated that p53-dependent PUMA accumulation and the PUMA-controlled Bax activation switch might play pivotal roles to count p53 pulses and thus decide the cell fate.</p> <p>Conclusion</p> <p>The high levels of basal DNA damage are responsible for generating sustained pulses of p53 in the tumor cells. Meanwhile, the Bax activation switch can count p53 pulses through PUMA accumulation and transfer it into death signal. Our modeling provides a plausible mechanism about how cells generate and orchestrate p53 pulses to tip the balance between survival and death.</p

    The Emerging of Hydrovoltaic Materials as a Future Technology: A Case Study for China

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    Water contains tremendous energy in various forms, but very little of this energy has yet been harvested. Nanostructured materials can generate electricity by water-nanomaterial interaction, a phenomenon referred to as hydrovoltaic effect, which potentially extends the technical capability of water energy harvesting. In this chapter, starting by describing the fundamental principle of hydrovoltaic effect, including water-carbon interactions and fundamental mechanisms of harvesting water energy with nanostructured materials, experimental advances in generating electricity from water flows, waves, natural evaporation, and moisture are then reviewed. We further discuss potential applications of hydrovoltaic technologies, analyze main challenges in improving the energy conversion efficiency and scaling up the output power, and suggest prospects for developments of the emerging technology, especially in China

    Consumers' decoy effect when purchasing pork with traceability technologies

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    Despite government investment, policy guidance, and publicity, it has been difficult to establish a traceable food market in China over the past 2 decades. Once a food safety problem occurs, it is difficult to implement effective traceability, recall, and accountability along the food supply chain. How to use the decoy effect to promote the development of China traceable food market? As bounded rationality, a decoy effect exists when adding an alternative to a choice set increases the chance an existing alternative to be chosen. However, few studies have examined the decoy effect in food purchases. Based on consumers in Wuxi, Jiangsu Province, China, we show the decoy effect in traceable pork hindquarter purchases and that the effects differ across product quality and price attributes. The effects are heterogeneous across consumers and are less likely to occur among those who had a personal annual income of more than 50,000 yuan (USD $7,000), were married, and had minor children in the family. These findings have implications on leveraging the influence of the decoy effect on consumer behavior and facilitating the construction of food traceability systems
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