1,565 research outputs found

    Hardware accelerator for anti-aliasing Wu's line algorithm using FPGA

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    Digital images are suffering from the stair-step effect because they are built from small pixels. This effect termes aliasing and the method uses to decrease so-called anti-aliasing. This paper offers a hardware accelerator of an anti-aliasing algorithm using HLS (high level synthesis) along straight-line segments or edges. These straight-line segments are smoothed by modifying the intensity of the pixel. The hardware implementation of two different architectures which is based on Zynq FPGA are presented in this work. The first architecture is built from one core while the second architecture is built from multi-core and uses a parallel technique to speed up the algorithm by dividing line segments into sub-segments and drawing them after smoothing instantaneously to formulate the main line. This parallel usage leads to a very fast execution of Wu's algorithm which is represented one-tenth hardware runtime for one core only. Also, the optimized resource utilization and power consumption for different cores have been compared, through single-core design which utilizes 8% and consumes 1.6 W, while utilized resources using 10 cores are 77% with a power consumption of 2 W

    Assessment of Post-Restrained Shrinkage Mechanical Properties of Concrete

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    Restrained shrinkage induced cracks can cause issues with serviceability, structural integrity and durability in concrete, but are difficult to predict. This paper proposes a simple, and economical test rig for restrained shrinkage and associated procedures to assess the post-shrinkage mechanical properties (compressive and flexural strength) of concrete. The results show that the restraining factor of the proposed rig is dependent on the time and the stiffness of the concrete. Results of residual mechanical properties show that restrained shrinkage induced cracks can affect the mechanical behaviour (flexural and compressive strength and stiffness) of concrete by up to 21%

    Calcium-sensing receptor activation increases cell-cell adhesion and ß-cell function

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    Background/Aims: The extracellular calcium-sensing receptor (CaR) is expressed in pancreatic β-cells where it is thought to facilitate cell-to-cell communication and augment insulin secretion. However, it is unknown how CaR activation improves β-cell function. Methods: Immunocytochemistry and western blotting confirmed the expression of CaR in MIN6 β-cell line. The calcimimetic R568 (1µM) was used to increase the affinity of the CaR and specifically activate the receptor at a physiologically appropriate extracellular calcium concentration. Incorporation of 5-bromo-2’-deoxyuridine (BrdU) was used to measure cell proliferation, whilst changes in non-nutrient-evoked cytosolic calcium were assessed using fura-2-microfluorimetry. AFM-single-cell-force spectroscopy related CaR-evoked changes in epithelial (E)-cadherin expression to improved functional tethering between coupled cells. Results: Activation of the CaR over 48hr doubled the expression of E-cadherin (206±41%) and increased L-type voltage-dependent calcium channel expression by 70% compared to control. These changes produced a 30% increase in cell-cell tethering and elevated the basal-to-peak amplitude of ATP (50µM) and tolbutamide (100µM)-evoked changes in cytosolic calcium. Activation of the receptor also increased PD98059 (1-100µM) and SU1498 (1-100µM)-dependent β-cell proliferation. Conclusion: Our data suggest that activation of the CaR increases E-cadherin mediated functional tethering between β-cells and increases expression of L-type VDCC and secretagogue-evoked changes in [Ca2+]i. These findings could explain how local changes in calcium, co-released with insulin, activate the CaR on neighbouring cells to help ensure efficient and appropriate secretory function

    Comparative performance of optical amplifiers: Raman and EDFA

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    The in-line optical signal amplification is often used in optical communication systems to accomplish longer transmission distances and larger capacity. In this proposed paper, the operation of two types of optical amplifiers for 16×10 Gbps wavelength division multiplexing system had been examined by changing transmission distance from 10 to 200 km with a dispersion equals to 16.75 ps/nm/km. The analysis and design of such systems ordinarily includes many signal channels, nonlinear devices, several topologies with many noise sources, is extremely complex and effort-exhaustive. Therefore, theoretical studies with simulation CAD software of systems are become necessity to predict and optimize system performance. The comparison between EDFA and Raman has already explored by many researchers in varying ways in this work and to achieve obove objectives, the OptiSystem software was used to design the proposed fiber optic communications system and to simulate results. Performance for the present system was evaluated for parameters like bit error rate (BER), quality factor (QF), total gain with eye opening factor. It was saw that EDFA provides better results, in the maximal transmission distance 64% better than Raman amplifier, 57.5% for gain and 26.7% for maximum quality factor. As a future study a hybrid amplifier can produce better quality of amplification

    Initiation of Cracks in Dental Amalgam

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    The force required to initiate cracks in dental amalgam beams was measured and related to the microstructure. The force measured was dependent on age and on the distribution of phases on the tension side of the beam. The Ag-Cu phase is most resistant to failure in Dispersalloy and an experimental alloy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67365/2/10.1177_00220345750540060601.pd

    A piecewise-linear reduced-order model of squeeze-film damping for deformable structures including large displacement effects

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    This paper presents a reduced-order model for the Reynolds equation for deformable structure and large displacements. It is based on the model established in [11] which is piece-wise linearized using two different methods. The advantages and drawbacks of each method are pointed out. The pull-in time of a microswitch is determined and compared to experimental and other simulation data.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

    The Effect of Time-Delay Feedback Controller on an Electrically Actuated Resonator

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    This paper presents a study of the effect of a time-delay feedback controller on the dynamics of a Microelectromechanical systems (MEMS) capacitor actuated by DC and AC voltages. It is shown that negative time-delay feedback control gain can lead to an unstable system, even if AC voltage is relatively small compared to DC voltage. Perturbation method is utilized to present analytically the nonlinear dynamic characteristics of the MEMS capacitor. Agreements among the results of a shooting technique, long-time integration, basin of attraction analysis with the perturbation method are achieved

    Design and implementation of PSO/ABC tunned PID controller for Buck converters

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    In the recent years, Buck converters have been widely involved in a variety of the everyday applications such as smartphones and PCs. Buck converters can provide better and steadier performance when integrating a control system in the design. Therefore, it is interesting to work on this integration and gain the required efficiency in term of the gained voltage. In this paper, PID controller is adopted to control the output voltage of the Buck converter. An optimization is achieved on the performance of the Buck converter using two bio-inspired algorithms namely, Particle Swarm Optimization (PSO) and Artificial Bee Colony (ABC). The voltage controlled Buck converter system is simulated using MATLAB environment to validate the proposed PID controller system. In this study, the voltage regulation process of Buck converter is investigated based on many working disturbances such as the change in the supply voltage, reference voltage, and load resistance in order to verify the robustness of the proposed PID controller. Finally, the feedabck voltage control system of the Buck converter is implemented experimentaly in real-time to validatde the simulated PID controller
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