Accelerated generation of holograms with ultra-low memory symmetrically high-compressed look-up table

Computer-generated holography technology has been widely applied,and as research in this field deepens,the demand for memory and computational power in small AR and VR devices continues to increase.This paper presents a hologram generation method,i.e.,a symmetrically high-compressed look-up table method,which can reduce memory usage by50%.In offline computing,half of the basic horizontal and vertical modulation factors are stored,halving the memory requirements without affecting inline speed.Currently,its potential extends to various holographic applications,including the production of optical diffraction elements.

A general purpose exact Rayleigh scattering look-up table for ocean color remote sensing

The current exact Rayleigh scattering calculation of ocean color remote sensing uses the look-up table （LUT）, which is usually created for a special remote sensor and cannot be applied to other sensors. For practical application, a general purpose Rayleigh scattering LUT which can be applied to all ocean color remote sensors is generated. An adding-doubling method to solve the vector radiative transfer equation in the plane-parallel atmosphere is deduced in detail. Compared with the exact Rayleigh scattering radiance derived from the MODIS exact Rayleigh scattering LUT, it is proved that the relative error of Rayleigh scattering calculation with the adding-doubling method is less than 0.25%, which meets the required accuracy of the atmospheric correction of ocean color remote sensing. Therefore, the adding-doubling method can be used to generate the exact Rayleigh scattering LUT for the ocean color remote sensors. Finally, the general purpose exact Rayleigh scattering LUT is generated using the adding-doubling method. On the basis of the general purpose LUT, the calculated Rayleigh scattering radiance is tested by comparing with the LUTs ofMODIS, SeaWiFS and the other ocean color sensors, showing that the relative errors are all less than 0.5%, and this general purpose LUT can be applied to all ocean color remote sensors.

Fine Doppler shift acquisition algorithm for BeiDou software receiver by a look-up table

The BeiDou software receiver uses the fast Fourier transform(FFT)to perform the acquisition.The Doppler shift estimation accuracy should be less than 500 Hz to ensure satellite signals to enter a locked state in the tracking loop.Since the frequency step is usually 500 Hz or larger,the Doppler shift estimation accuracy cannot guarantee that satellite signals are brought into a stable tracking state.The straightforward solutions consist in increasing the sampling time and using zero-padding to improve the frequency resolution of the FFT.However,these solutions intensify the complexity and amount of computation.The contradiction between the acquisition accuracy and the computational load leads us to research for a more simple and effective algorithm,which achieves fine acquisition by a look-up table.After coarse acquisition using the parallel frequency acquisition(PFA)algorithm,the proposed algorithm optimizes the Doppler shift estimation through the look-up table method based on the FFT results to improve the acquisition accuracy of the Doppler shift with a minimal additional computing load.When the Doppler shift is within the queryable range of the table,the proposed algorithm can improve the Doppler shift estimation accuracy to 50 Hz for the BeiDou B1I signal.

Performance of global look-up table strategy in digital image correlation with cubic B-spline interpolation and bicubic interpolation

Global look-up table strategy proposed recently has been proven to be an efficient method to accelerate the interpolation, which is the most time-consuming part in the iterative sub-pixel digital image correlation （DIC） algorithms. In this paper, a global look-up table strategy with cubic B-spline interpolation is developed for the DIC method based on the inverse compositional Gauss-Newton （IC-GN） algorithm. The performance of this strategy, including accuracy, precision, and computation efficiency, is evaluated through a theoretical and experimental study, using the one with widely employed bicubic interpolation as a benchmark. The global look-up table strategy with cubic B-spline interpolation improves significantly the accuracy of the IC-GN algorithm-based DIC method compared with the one using the bicubic interpolation, at a trivial price of computation efficiency.

Research of NO_(2) vertical profiles with look-up table method based on MAX-DOAS

Obtaining the vertical distribution profile of trace gas is of great significance for studying the diffusion procedure of air pollution.In this article,a look-up table method based on multi-axis differential optical absorption spectroscopy(MAX-DOAS)technology is established for retrieving the tropospheric NO_(2) vertical distribution profiles.This method retrieves the aerosol extinction profiles with minimum cost function.Then,the aerosol extinction profiles and the atmospheric radiation transfer model(RTM)are employed to establish the look-up table for retrieving the NO_(2) vertical column densities(VCDs)and profiles.The measured NO_(2) differential slant column densities(DSCDs)are compared with the NO_(2) DSCDs simulated by the atmospheric RTM,and the NO_(2) VCDs,the weight factor of NO_(2) in the boundary layer,and the boundary layer height are obtained by the minimization process.The look-up table is established to retrieve NO_(2) VCDs based on MAX-DOAS measurements in Huaibei area,and the results are compared with the data from Copernicus Atmospheric Monitoring Service(CAMS)model.It is found that there are nearly consistent and the correlation coefficient R2 is more than 0.86.The results show that this technology provides a more convenient and accurate retrieval method for the stereoscopic monitoring of atmospheric environment.

WinoNet:Reconfigurable look-up table-based Winograd accelerator for arbitrary precision convolutional neural network inference

To solve the hardware deployment problem caused by the vast demanding computational complexity of convolutional layers and limited hardware resources for the hardware network inference,a look-up table(LUT)-based convolution architecture built on a field-programmable gate array using integer multipliers and addition trees is used.With the help of the Winograd algorithm,the optimization of convolution and multiplication is realized to reduce the computational complexity.The LUT-based operator is further optimized to construct a processing unit(PE).Simultaneously optimized storage streams improve memory access efficiency and solve bandwidth constraints.The data toggle rate is reduced to optimize power consumption.The experimental results show that the use of the Winograd algorithm to build basic processing units can significantly reduce the number of multipliers and achieve hardware deployment acceleration,while the time-division multiplexing of processing units improves resource utilization.Under this experimental condition,compared with the traditional convolution method,the architecture optimizes computing resources by 2.25 times and improves the peak throughput by 19.3 times.The LUT-based Winograd accelerator can effectively solve the deployment problem caused by limited hardware resources.

The establishment of crystal position look-up table for positron emission tomography with block detectors

A method has been developed to establish the crystal position look-up table for positron emission tomography with block detectors. It is based on the principle that the counts in crystal position histogram obey the Gaussian mixture model (GMM). This method has taken full consideration of the characteristics of the GMM and the detector itself. The experimental results have proved that it is simple, reliable, and universal.

CRC Look-up Table Optimization for Single-Bit Error Correction

Many communication systems use the cyclic redundancy code （CRC） technique for protecting key data fields from transmission errors by enabling both single-bit error correction and multi-bit error detection. The look-up table design is very important for the error-correction implementation. This paper presents a CRC look-up table optimization method for single-bit error correction. The optimization method minimizes the address length of the pre-designed look-up table while satisfying certain restrictions. The circuit implementation is also presented to show the feasibility of the method in the application specific integrated circuit design. An application of the optimization method in the generic framing procedure protocol is implemented using field programmable gatearrays. The result shows that the memory address length has been minimized, while keeping a very simple circuit implementation.

Differential Spatial Modulation Mapping Algorithms

Differential spatial modulation(DSM)is a multiple-input multiple-output(MIMO)transmission scheme.It has attracted extensive research interest due to its ability to transmit additional data without increasing any radio frequency chain.In this paper,DSM is investigated using two mapping algorithms:Look-Up Table Order(LUTO)and Permutation Method(PM).Then,the bit error rate(BER)performance and complexity of the two mapping algorithms in various antennas and modulation methods are verified by simulation experiments.The results show that PM has a lower BER than the LUTO mapping algorithm,and the latter has lower complexity than the former.

Device and circuit analysis of a sub 20 nm double gate MOSFET with gate stack using a look-up-table-based approach

In this paper, we explore the possibility of mapping devices designed in TCAD environment to its modeled version developed in cadence virtuoso environment using a look-up table （LUT） approach. Circuit simu- lation of newly designed devices in TCAD environment is a very slow and tedious process involving complex scripting. Hence, the LUT based modeling approach has been proposed as a faster and easier alternative in ca- dence environment. The LUTs are prepared by extracting data from the device characteristics obtained from device simulation in TCAD. A comparative study is shown between the TCAD simulation and the LUT-based alternative to showcase the accuracy of modeled devices. Finally the look-up table approach is used to evaluate the perform- ance of circuits implemented using 14 nm nMOSFET.

Accurate and fast table look-up models for leakage current analysis in 65nm CMOS technology

Novel physical models for leakage current analysis in 65 nm technology are proposed. Taking into consideration the process variations and emerging effects in nano-scaled technology, the presented models are capable of accurately estimating the subthreshold leakage current and junction tunneling leakage current in 65 nm technology. Based on the physical models, new table look-up models are developed and first applied to leakage current analysis in pursuit of higher simulation speed. Simulation results show that the novel physical models are in excellent agreement with the data measured from the foundry in the 65 nm process, and the proposed table look-up models can provide great computational efficiency by using suitable interpolation techniques. Compared with the traditional physical-based models, the table look-up models can achieve 2.5X speedup on average on a variety of industry circuits.

结晶紫选择电极的制备及催化电位法测定碘的研究

根据磷酸介质中碘离子 ( I-)催化高碘酸钠氧化结晶紫的氧化还原反应 ,应用自制的结晶紫选择电极跟踪反应中结晶紫的浓度变化 ,对催化电位法测定碘进行了研究。测定碘离子的线性范围为 0 .2 0～ 5.5μg/ 2 5m L,方法检出限为 4 .1× 1 0 -9g/ m L。该方法应用于测定食盐和饮用水中碘含量 ,RSD<4 .1 %( n=6 ) ,平均回收率为 95.1 %。

中西医结合治疗水痘患儿26例临床观察

目的:探讨分析清解透表汤加减治疗水痘患儿的临床疗效与安全性。方法:选取收治的52例水痘患儿,随机分为治疗组与对照组,两组均为26例。对照组静脉滴注阿昔洛韦;治疗组在对照组治疗基础上加服清解透表汤,比较两组患者的临床疗效、恢复情况及出院后的随访指标。结果:总有效率治疗组为96.2%,对照组为76.9%,两组比较,差异有统计学意义(P<0.05);治疗组体温恢复正常的平均时间、疱疹愈合的平均时间、平均住院时间、皮疹消退的平均时间显著少于对照组(P<0.05)。结论:清解透表汤加减治疗水痘患儿的临床疗效较佳,且用药的安全性高。

非立方晶系电子衍射花样的ξ表法

提出了一种不使用仪器常数Lλ可鉴定非立方晶系电子衍射花样(EDP)选区物相及确定其指数{hkl}的新方法———相对d值表法(简称ξ表法)。由于省去了繁琐的Lλ测定,在一般情况下,ξ表法较传统的d值表法[1]简便,精度也得到了提高。

几种稀土金属间化合物的配制及结构测定

用高频熔炼的方法配制了三个稀土金属间化合物即 (K ,M ,N) .采用X射线衍射法测定了它们的晶体结构 ,结果表明 :K(NdAl1 .75Si0 .2 5)属于立方晶系 ,点阵参数a =7.986× 10 - 1 0 m ;化合物M(NdAl2 Si2 )和N(NdAl1 .2 5Si0 .75)是六方晶系 ,其点阵参数分别为a =4.2 3× 10 - 1 0 m、c =6.71× 10 - 1 0 m ,N和a =4.2 76× 10 - 1 0 m、c =4.2 0 4× 10 - 1 0 m .

同系因子1/N在元素周期表中的应用

将同系因子１／Ｎ用于元素周期表，以Ｎ为周期序数，Ｐ作为各元素或其化合物的性能，利用公式Ｐ＝ａ＋ｂ／Ｎ对周期表中各元素及化合物３０多种性能进行拟合，得到了良好的结果．

基于STC15单片机逻辑IC检测器的设计与实现

利用逻辑电平的输入输出非"0"即"1"的特点,采用51单片机,将其I/O口与逻辑芯片全部引脚相连,根据逻辑芯片的功能及真值表,使与逻辑芯片输入端相连的I/O口,输出相应的逻辑电平,然后通过与逻辑芯片输出相连的I/O口,获取其相应的输出电平,再与真值表相比对,得出此逻辑芯片的功能好坏。选用增强型的51单片机,具有推挽的功能,能使其I/O口在输出"1"或"0"时,可以流出或流入更大的电流,因此可直接用推挽模式的I/O口,给逻辑芯片提供电源,简化了电路设计的难度。显示部分,选用分辨率较高的中文液晶12864,能使操作使用更加直观明了,同时因其是点阵式液晶,可加入显示芯片管脚图的功能,进一步方便了使用者。

交叉型报表技术在GIS中的应用

分析了交叉型报表模版单元的内部结构,探寻了将ＳＱＬ语句嵌入交叉型报表表模版的基本单元,实现了报表快速自动创建的技术。

基于Pt100运用查表法实现的高温温度计设计

针对高温温度计存在体积大、成本高、操作复杂及实际测量依赖电脑而不能独立工作等缺点,研究了温度数据的采集、传输、显示等问题,设计出以STC89C52为核心,基于Pt100温度传感器和液晶1602显示的铂电阻高温温度计。该温度计的测量范围从-200～+500℃,精度为1℃。实验表明,该高温温度计具有测温范围广、性能稳定、工作可靠、扩展能力强和可独立工作等特点。

基于多种探测算法结果分级融合的PET探测器晶体查找表建立算法

高分辨率是现代正电子发射型断层显像仪(Positron Emission Tomography,PET)设备最重要的技术指标之一,高分辨率PET探测器通常由海量闪烁晶体组成,这使得探测器校准时,晶体查找表建立的工作量大幅增加,从而对相关自动化算法的鲁棒性提出了更高的要求。目前,晶体阵列的矫正主要依赖固定放射源对探测器晶体阵列成像得到的光子二维位置直方图。高分辨率PET探测器的晶体阵列中晶体个数增多,尺寸变小,导致二维位置直方图信噪比下降,且非线性形变更加复杂,使已有的晶体查找表建立算法都无法得到理想的自动化效率。在测试了多种前沿的晶体查找表建立算法后发现,某些算法的结果之间有很强的互补性,可以通过将多种算法结果相融合的方法得到优于单一探测算法的结果。因此提出了一种基于多种探测算法结果分级融合的晶体查找表建立算法,在实现过程中选取了三种互补性较强的晶体探测方法,分级融合其结果,大幅度降低了二维位置直方图上晶体分割的出错概率,获得了鲁棒的结果。