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档案资料是文献信息资源宝库中一个很重要的组成部分。随着Internet的迅速普及,如何运用网络对档案信息资源进行挖掘、开发和利用,成为信息资源开发者和信息资源利用者共同关心的问题。其中,如何收集档案资料资源,处理档案资料的所属(著作)权等问题,是档案信息资源开发面,临的现实问题。 相似文献
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A low cost of die area and power consumption CMOS image sensor readout circuit with fixed pattern noise(FPN) cancellation is proposed.By using only one coupling capacitor and switch in the double FPN cancelling correlative double sampling(CDS),pixel FPN is cancelled and column FPN is stored and eliminated by the sampleand-hold operation of digitally programmable gain amplifier(DPGA).The bandwidth balance technology based on operational amplifier(op-amp) sharing is also introduced to decrease the power dissipation of traditional multi-stage switched capacitor DPGA.The circuit is designed and simulated using 1P6M 0.18 μm 1.8 V/3.3 V process.Simulation results indicate that the proposed CDS scheme can achieve an FPN of less than 1 mV.The total sampling capacitor per column is 0.9 pF and no column-wise power is dissipated.The die area and FPN value are cut by 70% and 41% respectively compared with amplifier-based CDS.The op-amp sharing gain stage can achieve a 12-bit precision and also implement an 8-bit gain controlling within a gain range of 24 dB.Its power consumption is 1.4 mW,which is reduced by 57% compared with traditional schemes.The proposed readout circuit is suitable for the application of low power cost-sensitive imaging systems. 相似文献
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A high speed column-parallel CDS/ADC circuit with nonlinearity compensation is proposed in this paper.The correlated double sampling (CDS) and analog-to-digital converter (ADC) functions are integrated in a threephase column-parallel circuit based on two floating gate inverters and switched-capacitor network.The conversion rate of traditional single-slope ADC is speeded up by dividing quantization to coarse step and fine step.A storage capacitor is used to store the result of coarse step and locate the section of ramp signal of fine step,which can reduce the clock step from 2 n to 2 (n/2+1).The floating gate inverters are implemented to reduce the power consumption.Its induced nonlinear offset is cancelled by introducing a compensation module to the input of inverter,which can equalize the coupling path in three phases of the proposed circuit.This circuit is designed and simulated for CMOS image sensor with 640×480 pixel array using Chartered 0.18μm process.Simulation results indicate that the resolution can reach 10-bit and the maximum frame rate can reach 200 frames/s with a main clock of 10MHz.The power consumption of this circuit is less than 36.5μW with a 3.3V power supply.The proposed CDS/ADC circuit is suitable for high resolution and high speed image sensors. 相似文献
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档案馆有着得天独厚的档案资源优势,如何充分发挥这种优势,更好地为经济建设和社会各项事业服务,是新形势下档案馆开发利用工作面临的新课题。 相似文献
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