Silicon photomultipliers (SiPMs) attract extensive attentions for detecting optical photons in high energy physics and medical imaging due to its high gain, high photon detection efficiency (PDE), low operation voltag...
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Silicon photomultipliers (SiPMs) attract extensive attentions for detecting optical photons in high energy physics and medical imaging due to its high gain, high photon detection efficiency (PDE), low operation voltage and fast timing response. We use a binary optical element (BOE) made of the silicon flexible optical material to transform the incident light intensity expressed as Gaussian distribution into uniform in space, making the incident photons be detected by the SiPM evenly. In this way, we can make full use of all cells of the SiPM, and more cells operating means more photons being detected for a certain pulse, which can increase the count rate of the incident photons and therefore improve the detection efficiency of the SiPM. Also, by comparing the outputs of the SiPM in different light intensity inputs, we can obtain the best light intensity fit for the SiPM along with the suitable scintillator and surface treatment for the positron emission tomography (PET) imaging based on the SiPM. In our experiments, we use the laser pulse as the SiPM input, whose light intensity can be expressed as Gaussian distribution in space, and then compare the readouts of the SiPM with and without the BOE. As expected, by using the BOE, the timing resolution and energy resolution of the SiPM are better than those without using it for some certain light intensity.
The design of on-line fault detection, identification and reconfiguration(FDIR) for three-axis-stabilized satellite attitude control system with reaction wheel(RW) fault was presented. Firstly, the fault pattern of RW...
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The design of on-line fault detection, identification and reconfiguration(FDIR) for three-axis-stabilized satellite attitude control system with reaction wheel(RW) fault was presented. Firstly, the fault pattern of RW was analyzed and a parameterized description for fault was established based on its dynamic model. Then, local FDI was used to diagnose the fault of RW by parameter identification. Based on the method of dynamic inversion, by introducing the model of reaction wheel, the reconfigurable controller was obtained to deal with RW fault. Finally, numerical simulation results with three fault patterns demonstrate that the proposed approach is effective and feasible.
Polycrystalline silicon (poly-Si) thin-film is fabricated on Al-coated planar glass substrates at the temperature below 100 °C, using aluminium-induced crystallized (AIC) amorphous silicon (a-Si) deposited by dc-...
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A quick 3D needle segmentation algorithm for 3D US data is described in this paper. The algorithm includes the 3D Quick Randomized Hough Transform (3DGHT), which is based on the 3D Randomized Hough Transform and coars...
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This paper introduced a novel high performance algorithm and VLSI architectures for achieving bit plane coding (BPC) in word level sequential and parallel mode. The proposed BPC algorithm adopts the techniques of co...
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This paper introduced a novel high performance algorithm and VLSI architectures for achieving bit plane coding (BPC) in word level sequential and parallel mode. The proposed BPC algorithm adopts the techniques of coding pass prediction and parallel & pipeline to reduce the number of accessing memory and to increase the ability of concurrently processing of the system, where all the coefficient bits of a code block could be coded by only one scan. A new parallel bit plane architecture (PA) was proposed to achieve word-level sequential coding. Moreover, an efficient high-speed architecture (HA) was presented to achieve multi-word parallel coding. Compared to the state of the art, the proposed PA could reduce the hardware cost more efficiently, though the throughput retains one coefficient coded per clock. While the proposed HA could perform coding for 4 coefficients belonging to a stripe column at one intra-clock cycle, so that coding for an NxN code-block could be completed in approximate N2/4 intra-clock cycles. Theoretical analysis and experimental results demonstrate that the proposed designs have high throughput rate with good performance in terms of speedup to cost, which can be good alternatives for low power applications.
Aero-optic effects cause distortions, including blurring, vibration, deformation and spatial shifting, of the objects in the image obtained by the infra-red sensor. Contributions of this paper are in the following two...
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To overcome the main drawbacks of global minimal for active contour models (L. D. Cohen and Ron Kimmel) that the contour is only extracted partially for low SNR images, Method of boundary extraction based on Schrö...
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To overcome the main drawbacks of global minimal for active contour models (L. D. Cohen and Ron Kimmel) that the contour is only extracted partially for low SNR images, Method of boundary extraction based on Schrödinger Equation is proposed. Our Method is based on computing the numerical solutions of initial value problem for second order nonlinear Schrödinger equation by using discrete Fourier Transformation. Schrödinger transformation of image is first given. We compute the probability P(b,a) that a particle moves from a point a to another point b according to I-Type Schrödinger transformation of image and obtain boundary of object by using quantum contour model.
In this paper, a modular approach is proposed for a class of strict-feedback stochastic nonlinear systems with uncertain Wiener noises and constant unknown parameters. Both the adaptive Backstepping procedure and inpu...
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In this paper, a modular approach is proposed for a class of strict-feedback stochastic nonlinear systems with uncertain Wiener noises and constant unknown parameters. Both the adaptive Backstepping procedure and input-to-state stable(ISS) controller of global stabilization in probability are designed to guarantee that the system states are bounded and has adaptive stabilization while the covariance of Wiener noises is uncertain. According to Swapping technique, we develop two filters and convert dynamic parametric models into static ones to which the gradient update law is designed.
In this paper, a modular design approach of adaptive tracking is proposed for parameter-strict-feedback stochastic nonlinear systems with standard Wiener noises and constant unknown parameters. Both the adaptive backs...
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In this paper, a modular design approach of adaptive tracking is proposed for parameter-strict-feedback stochastic nonlinear systems with standard Wiener noises and constant unknown parameters. Both the adaptive backstepping procedure and input-to-state stable (ISS) controller of global stabilization in probability are designed separately to ensure the output-feedback tracking can be achieved. According to swapping technique, we develop two filters and convert dynamic parametric models into a static one to which the gradient update law is chosen. The transient performance shows the tracking error is bounded.
In this paper, we present the passive wireless sensor network based on the surface acoustic wave(SAW) resonators. The sensor node consists of the SAW sensor that is small, light, reliable, stable, sensitive, wireless ...
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In this paper, we present the passive wireless sensor network based on the surface acoustic wave(SAW) resonators. The sensor node consists of the SAW sensor that is small, light, reliable, stable, sensitive, wireless and passive, so the battery is needless and its life-span is infinite. The sink node gathers data from the sensor nodes, processes the data with intelligent algorithms and transmits the needed data to the exterior network timely. The basic structure and the realization of the passive wireless sensor network are elaborated. The five main characteristics of the passive wireless sensor network, that is passive sensor nodes, simple and small sensor nodes, organized sensor nodes, intelligent sink nodes, high security, good extendibility, are explained concretely. Specially, the key techniques in our research, such as coding and decoding techniques of the sensor node, signal frequency measurement techniques of the sensor node, intelligent signal processing techniques, measurement error compensation techniques and network security techniques, are discussed exhaustively. In the end, we point out the problems at present and forecast the application prospect and research direction in the future.
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