33 research outputs found

    Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

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    无线传感器网络,作为全球未来十大技术之一,集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术,可实时感知、采集、处理、传输网络分布区域内的各种信息数据,在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议,并针对大规模的无线传感器网络设计了一种树状路由协议,它根据节点地址信息来形成路由,从而简化了复杂繁冗的路由表查找和维护,节省了不必要的开销,提高了路由效率,实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR(AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位:工学硕士院系专业:信息科学与技术学院通信工程系_通信与信息系统学号:2332007115216

    Simulation results of a small animal liquid xenon PET detector

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    International audienceMonte Carlo simulations of a novel concept PET detector for small animal imaging are presented. The scintillation medium of the detector is liquid xenon whose characteristics in terms of detection rival with the common scintillator crystals. Moreover, the axial geometry of the detector enables depth of interaction measurement. A detector module has been built and an experimental test bench has been developed. Simulations of the test bench enabled to determine the methods to use for analysing the experimental data. Moreover, they indicate the spatial resolution in the axial direction and the energy resolution which can be expected from the detector. The results show an axial resolution of 2.87plusmn0.12 mm and an energy resolution of 7.59plusmn0.34%

    Simulation results of a small animal liquid xenon PET detector

    No full text
    International audienceMonte Carlo simulations of a novel concept PET detector for small animal imaging are presented. The scintillation medium of the detector is liquid xenon whose characteristics in terms of detection rival with the common scintillator crystals. Moreover, the axial geometry of the detector enables depth of interaction measurement. A detector module has been built and an experimental test bench has been developed. Simulations of the test bench enabled to determine the methods to use for analysing the experimental data. Moreover, they indicate the spatial resolution in the axial direction and the energy resolution which can be expected from the detector. The results show an axial resolution of 2.87plusmn0.12 mm and an energy resolution of 7.59plusmn0.34%

    A Preamplifier-discriminator circuit based on a Common Gate Feedforward TIA for fast time measurements using diamond detectors

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    International audienceThis paper describes the design and simulation of a preamplifier-discriminator circuit based on a common-gate feedforward TIA architecture and a Leading Edge Discriminator for fast time measurements. The goal is to validate the use of such circuits with the new generation of radiation detectors based on diamond. The circuit has been designed in a 130 nm 1P8M CMOS technology and it is intended to be used as Front-End-Electronics (FEE) for the measure of the time of flight (TOF) using diamond detectors in order to realize a beam tagging hodoscope

    A low crosstalk 768-channel of 14-bit analog to digital converters for high resolution array of detectors

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    International audienceThis paper reports the design and measurement results of a 768-channel of 14-bit analog to digital converters. Each channel&rsquo;s layout pitch is only 8.5&micro;m with a sampling rate from 40KS/s up to 100KS/s. Testing results show a crosstalk about only +/- 1 LSB. The architecture of the circuit and the structure of the layout make it extensible to exceptionally large format of detectors beyond 1000 channels. The circuit is produced to be used as a side element for multi-channel readout systems or alternatively as an IP to be transferred inside very dense integrated circuits.For many physics and photonics applications, silicon detectors are increasingly used, and their density will continue to grow for next generations. This creates the need of very dense readout circuits in which the analog to digital stage will play a crucial role. The reduced pitch makes the layout particularly challenging for high resolution mixed signal circuits as converters. We report here the results of 14-bit array of analog to digital converters compatible with pixels&rsquo; pitch of 8.5&micro;m. The crosstalk is measured about +/- 1 LSB. This hybrid architecture of converter dissipates in total 110&micro;W/channel when sampling at 40KHz rate. Each channel includes its own reference voltage buffers. This strategy paves the way for more dense arrays beyond one thousand channels of 14-bit resolution in the future. This prototype was produced in a 130nm process, and the total surface of the die is 6mm*4mm. The integral non-linearity (INL) is +5/-9 LSB over a single-ended dynamic range from 0.6V to 2.9V with a power supply of 3.3V. The noise is less than 4 LSB rms when all the channels are fully working. We show the die photograph in an additional document.</p

    A low crosstalk 768-channel of 14-bit analog to digital converters for high resolution array of detectors

    No full text
    International audienceThis paper reports the design and measurement results of a 768-channel of 14-bit analog to digital converters. Each channel&rsquo;s layout pitch is only 8.5&micro;m with a sampling rate from 40KS/s up to 100KS/s. Testing results show a crosstalk about only +/- 1 LSB. The architecture of the circuit and the structure of the layout make it extensible to exceptionally large format of detectors beyond 1000 channels. The circuit is produced to be used as a side element for multi-channel readout systems or alternatively as an IP to be transferred inside very dense integrated circuits.For many physics and photonics applications, silicon detectors are increasingly used, and their density will continue to grow for next generations. This creates the need of very dense readout circuits in which the analog to digital stage will play a crucial role. The reduced pitch makes the layout particularly challenging for high resolution mixed signal circuits as converters. We report here the results of 14-bit array of analog to digital converters compatible with pixels&rsquo; pitch of 8.5&micro;m. The crosstalk is measured about +/- 1 LSB. This hybrid architecture of converter dissipates in total 110&micro;W/channel when sampling at 40KHz rate. Each channel includes its own reference voltage buffers. This strategy paves the way for more dense arrays beyond one thousand channels of 14-bit resolution in the future. This prototype was produced in a 130nm process, and the total surface of the die is 6mm*4mm. The integral non-linearity (INL) is +5/-9 LSB over a single-ended dynamic range from 0.6V to 2.9V with a power supply of 3.3V. The noise is less than 4 LSB rms when all the channels are fully working. We show the die photograph in an additional document.</p

    Diamond Dosimeter for in Vivo Dosimetry for Synchrotron Radiotherapy

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    International audienceA significant proportion of cancer patients benefit from radiotherapy . Besides conventional x-ray radiation, synchrotron has proven to offer significant advantages in radiotherapy by using high dose rate coherent x-rays beams. Indeed, High coherence allowing to produce micrometric fields to explore limits of a concept called dose-volume effect. The other important characteristics of synchrotron radiation (high dose rate) permits to take advantage of the so-called flash effect.The first phase I/II clinical study of synchrotron radiotherapy at the European Synchrotron Radiation Facility (ESRF) demonstrated the feasibility and safety of this technique. this method requires some development. One of them, in-vivo dosimetry (the real time dose delivered during the treatment), is particularly challenging, because of the high dose rate and low energy flux.A new approach based on pixelised diamond detectors ,already validated for one point dosimetry in synchrotron radiation[1], will be developed.Before the full conception of one dimension dosimeter, first step is to characterize diamond detectors responses in synchrotron radiation (incident photons energy between 30 and 150 keV and an high dose rate which can reach 10 000 Gy/s) and show the project’s viability.For this reason, some preliminary tests was performed on different diamond detectors (two mono-crystalline and one polycrystalline), to show their response for different energy and dose rate, already developed at LPSC (Laboratoire de Physique Subatomique et Cosmologie) and this presentation will focus on these tests.[1]: Livingstone J. et al. Characterization of a synthetic single crystal diamond detector for dosimetry in spatially fractionated synchrotron x-rays fields. 201

    DOSIMETRY, DIAMOND DETECTOR, SYNCHROTRON RADIATION

    No full text
    National audienceA significant proportion of cancer patients benefit from radiotherapy. Besides conventional x-ray radiation, synchrotron has proven to offer significant advantages in radiotherapy by using high dose rate coherent x-rays beams. Indeed, High coherence allowing to produce micrometric fields to explore limits of a concept called dose-volume effect. The other important characteristics of synchrotron radiation (high dose rate) permits to take advantage of the so-called flash effect. The first phase I/II clinical study of synchrotron radiotherapy at the European Synchrotron Radiation Facility (ESRF) demonstrated the feasibility and safety of this technique. this method requires some development. One of them, in-vivo dosimetry (the real time dose delivered during the treatment), is particularly challenging, because of the high dose rate and low energy flux. A new approach based on pixelised diamond detectors, already validated for one point dosimetry in synchrotron radiation[1], will be developed. Before the full conception of one dimension dosimeter, first step is to characterize diamond detectors responses in synchrotron radiation (incident photons energy between 30 and 150 keV and an high dose rate which can reach 10 000 Gy/s) and show the project's viability. For this reason, some preliminary tests were performed on different diamond detectors (two mono-crystalline and one polycrystalline), to show their response for different energy and dose rate, already developed at LPSC (Laboratoire de Physique Subatomique et Cosmologie) and this presentation will focus on these tests
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