147 research outputs found

    Solving Partial Differential Equation Using FPGA Technology

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    This chapter introduces the method of using CNN technology on FPGA chips to solve differential equation with large space, with lager computing space, while limitation of resource chip on FPGA is needed, we have to find solution to separate differential space into several subspaces. Our solution will do: firstly, division of the computing space into smaller areas and combination of sequential and parallel computing; secondly, division and combination of boundary areas that are required to be continuous to avoid losing temporary data while processing (using buffer memory to store); and thirdly, real-time data exchange. The control unit controls the activities of the whole system set by the algorithm. We have configured the CNN chip for solving Navier-Stokes equation for the hydraulic fluid flow successfully on the Virtex 6 chip XCVL240T-1FFG1156 by Xilinx and giving acceptance results as well

    LAPFormer: A Light and Accurate Polyp Segmentation Transformer

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    Polyp segmentation is still known as a difficult problem due to the large variety of polyp shapes, scanning and labeling modalities. This prevents deep learning model to generalize well on unseen data. However, Transformer-based approach recently has achieved some remarkable results on performance with the ability of extracting global context better than CNN-based architecture and yet lead to better generalization. To leverage this strength of Transformer, we propose a new model with encoder-decoder architecture named LAPFormer, which uses a hierarchical Transformer encoder to better extract global feature and combine with our novel CNN (Convolutional Neural Network) decoder for capturing local appearance of the polyps. Our proposed decoder contains a progressive feature fusion module designed for fusing feature from upper scales and lower scales and enable multi-scale features to be more correlative. Besides, we also use feature refinement module and feature selection module for processing feature. We test our model on five popular benchmark datasets for polyp segmentation, including Kvasir, CVC-Clinic DB, CVC-ColonDB, CVC-T, and ETIS-LaribComment: 7 pages, 7 figures, ACL 2023 underrevie

    Refinement of an inverse analysis procedure for estimating tensile constitutive law of UHPC

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    As regard to cementitious composite materials added a certain dosage of fiber, estimation of tensile constitutive law through inverse analysis methods is no longer extraordinary. However, development or improvement to achieve an effective method for estimating such a tensile behavior of fiber reinforced concrete (FRC) or Ultra high-performance concrete (UHPC) is still an interesting topic to researchers. In this respect, the paper presents a development of inverse analysis method developed by Lopez to obtain the stress-strain behavior of UHPC from the four-point bending test. By applying optimization algorithm into the iterative procedure of method, an improvement could be obtained for the inverse analysis with a high degree of automation in calculation. A post-process treatment for inverse analysis results is also proposed to bring a finer agreement between the tensile behavior curve obtained by the inverse analysis and result curve of uniaxial tensile test (UTT). The effectivity of process is shown through a comparison between the result obtained by the proposed method and the result in Lopez’s public paper

    Refinement of an inverse analysis procedure for estimating tensile constitutive law of UHPC

    Get PDF
    As regard to cementitious composite materials added a certain dosage of fiber, estimation of tensile constitutive law through inverse analysis methods is no longer extraordinary. However, development or improvement to achieve an effective method for estimating such a tensile behavior of fiber reinforced concrete (FRC) or Ultra high-performance concrete (UHPC) is still an interesting topic to researchers. In this respect, the paper presents a development of inverse analysis method developed by Lopez to obtain the stress-strain behavior of UHPC from the four-point bending test. By applying optimization algorithm into the iterative procedure of method, an improvement could be obtained for the inverse analysis with a high degree of automation in calculation. A post-process treatment for inverse analysis results is also proposed to bring a finer agreement between the tensile behavior curve obtained by the inverse analysis and result curve of uniaxial tensile test (UTT). The effectivity of process is shown through a comparison between the result obtained by the proposed method and the result in Lopez’s public paper

    ENERGY-ENVIRONMENT ISSUE IN TRANSPORT OF VIETNAM

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    Joint Research on Environmental Science and Technology for the Eart

    Vortex flow generator utilizing synthetic jets by diaphragm vibration

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    This paper develops a millimeter scale fully packaged device in which a vortex flow of high velocity is generated inside a chamber. Under the actuation by a lead zirconate titanate (PZT) diaphragm, a flow circulates with increasing velocity after each actuating circle to form a vortex in a cavity named as the vortex chamber. At each cycle, the vibration of the PZT diaphragm creates a small net air flow through a rectifying nozzle, generates a synthetic jet which propagates by a gradual circulation toward the vortex chamber and then backward the feedback chamber. The design of such device is firstly conducted by a numerical analysis whose results are considered as the base of our experimental set-up. A vortex flow generated in the votex chamber was observed by a high-speed camera. The present approach which was illustrated by both the simulation and experiment is potential in various applications related to the inertial sensing, fluidic amplifier and micro/nano particle trapping and mixing

    Value Creation through Urban Data Platforms: A Conceptual Framework

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    In the context of smart cities, data-driven innovation and digital transformation have received increasing attention from practitioners and academics. The data-centric nature of smart city transformations highlights the essential role of urban data platform (UDP) to manage large and heterogeneous urban data sets and to facilitate interaction among data providers and users in a city ecosystem. To realize value creation through UDP, a comprehensive understanding of the key UDP dimensions and how they influence UDP adoption, use, and value creation are required. For this purpose, we first identify key UDP dimensions through a literature review. Second, by exploring and discussing their relationships with an expert panel, we develop a framework for understanding value creation through UDPs. By identifying key dimensions of UDP and their effects on value creation through UDP, the proposed framework provides a systematic and comprehensive approach for understanding UDP adoption, use, and value creation. Thereby, this study helps city policymakers and business developers in realizing value from UDPs in city ecosystem

    A closed device to generate vortex flow using PZT

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    This paper reports for the first time a millimeter scale fully packaged device which generates a vortex flow of high velocity. The flow which is simply actuated by a PZT diaphragm circulates with a higher velocity after each actuating circle to form a vortex in a desired chamber. The design of such device is firstly conducted by a numerical analysis using OpenFOAM. Several numerical results are considered as the base of our experiment where a flow vortex is observed by a high speed camera. The present device is potential in various applications related to the inertial sensing, fluidic amplifier and micro/nano particle trapping and mixing

    Digital Security Governance: What Can We Learn from High Reliability Organizations (HROs)?

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    With the growing digitalization of businesses, digital security governance (DSG) is becoming central to organizational survival strategies. However, many organizations fail to establish successful DSG practices and, consequently, fail to understand how DSG can lower the severity of cybersecurity failures. This paper aims to contribute to filling this gap. By putting the five principles of the High Reliability Organization (HRO) central to the design of our qualitative investigation, we engage in interviewing forty-two chief information security officers (CISOs) and chief information officers (CIOs) of large organizations in the Netherlands about their views on why organizations fail to successfully achieve DSG. Our data show that HRO principles are partly relevant but lacking in DSG approaches, which potentially increases security failure. We conclude this paper by discussing these findings in light of future research and practice

    A study of ion wind generator using parallel arranged electrode configuration for centrifugal flow mixer

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    Ion wind is recently applied in various research areas such as the biomedical engineering, microfluidic mixing and particle manipulation. In this work, a bipolar ion wind generator configured by parallel arranged electrodes is used for centrifugal mixing applications. With the proposed configuration, negative and positive ion winds are simultaneously generated, mixed and then neutralized by each other while travelling toward liquid surface. The efficiency of the device was investigated both computationally and experimentally. The mixing of liquid occurred in different ways when the system is activated by either direct or alternating currents. Furthermore, the mixing is dependent on the dimension of electrode tip
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