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.

补肾填精汤治疗多囊卵巢综合征-胰岛素抵抗伴维生素D缺乏临床研究

目的:观察补肾填精汤治疗多囊卵巢综合征(polycystic ovary syndrome,PCOS)-胰岛素抵抗(insulin resistance,IR)伴维生素D缺乏的临床疗效。方法:将90例PCOS-IR患者按照随机数字表法分为中药组、西药组及中西医组,每组各30例。西药组给予盐酸二甲双胍缓释片治疗,中药组给予补肾填精汤治疗,中西医组给予盐酸二甲双胍缓释片联合补肾填精汤治疗。测定各组患者治疗前后空腹胰岛素(fasting serum lisulin,FINS)、空腹血糖(fasting blood-glucose,FBG)、25-羟基维生素D_(3)[25-dihydroxyvitamin D3,25-(OH)D_(3)]水平、性激素水平[雌二醇(estradiol,E2)、促卵泡生成素(follicle stimulating hormone,FSH)、黄体生成素(luteinizing hormone,LH)、总睾酮(testosterone,T)]及炎性因子水平[白细胞介素(interleukin-6,IL-6)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)],计算HOMA-IR。比较各组患者的临床疗效、HCG日子宫内容形态、子宫内膜厚度、Salle评分及治疗前后中医证候积分变化情况,分析各组患者体质量指数、血清指标与25-(OH)D_(3)的相关性。结果:中药组有效率90.0%,中西医组有效率93.4%,西药组有效率86.7%,各组有效率比较,差异无统计学意义(P>0.05)。各组患者治疗后中医证候积分低于本组治疗前(P<0.05),治疗后中药组与中西医组比较,差异无统计学意义(P>0.05);治疗后中西医组、中药组与西药组比较,差异均有统计学意义(P<0.05)。各组患者治疗后血清指标与本组治疗前比较,差异无统计学意义(P>0.05);与中药组比较,中西医组治疗后T、HOMA-IR水平降低,与西药组比较,中西医组治疗后血清25-(OH)D_(3)水平升高,TNF-α水平降低,差异均有统计学意义(P<0.05)。将所有患者治疗前体质量指数、性激素、HMOA-IR、炎症因子与25-(OH)D_(3)进行相关性分析,结果显示,HOMA-IR与25-(OH)D_(3)呈正相关(P<0.05)。进一步分析,中药组及中西医组治疗后,25-(OH)D_(3)水平上调,T水平下降,且T水平与25-(OH)D_(3)呈负相关(P<0.05)。中西医组Salle评分高于中药组及西药组,差异具有统计学意义(P<0.05);各组内膜厚度比较,差异无统计学意义(P>0.05);中西医组A型内膜率高于西药组及中药组,差异具有统计学意义(P>0.05)。结论:补肾填精汤和(或)联用盐酸二甲双胍缓释片治疗PCOS-IR,可不同程度改善患者的临床症状,下调炎症因子及LH、T水平,改善胰岛素抵抗及25-(OH)D_(3)缺乏,促进子宫内膜修复,其作用机制可能是胰岛素抵抗、T水平与25-(OH)D_(3)水平存在关联性。

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.

安徽省乒乓球传统学校教练员执教能力评价指标体系构建研究

在体教融合背景下,传统体育特色学校是彰显学校体育特色与培养后备人才的新领地。本文采用文献资料法、德尔菲法、问卷调查法、层次分析法、数理统计法等研究方法,构建出由乒乓球教学训练能力、竞赛指导能力、组织管理能力、社交能力、执教经历、科研学习能力6个二级指标与41个三级指标的评价体系,旨在为提升安徽省乒乓球传统学校教练员执教能力提供理论参考。

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.

传统穿斗木结构榫卯节点附加黏弹性阻尼器振动台试验

通过对一个两层、足尺、长宽高为3．8m×3．6m×3．9m的穿斗式木结构房屋模型的榫卯节点附加黏弹性阻尼器进行振动台试验，研究了结构的抗震性能，并对0．07g、0．4g两种峰值加速度下进行了榫卯节点附加阻尼器和未附加阻尼器的进行了振动台对比试验。试验结果表明：榫卯节点附加了黏弹性阻尼器后节点刚度增大，减小了半刚性榫卯节点的转动能力，并使结构在地震激励作用下的变形恢复能力得到了大幅提高，经过多次重复地震，即使经历0．95g的地震激励后，结构模型也未发生明显倾斜破坏；结构一层柱顶榫卯节点最先发挥减震耗能作用，动力放大系数随着地震激励增加呈减小趋势，由于结构两个方向刚度及质量分布的不均匀，X、Y，方向动力放大系数有差异，X方向动力放大系数在1．2519-0．7775之间，Y向1．8779-1．1152之间。榫卯节点附加黏性阻尼器达到了小震下减小层间位移角，大震下增强榫卯节点变形恢复能力的目的。

火焰原子吸收光谱法测定中成药中微量元素

利用火焰原子吸收光谱法测定了中成药复方半夏片中14种微量元素.Ca、Mg、Fe、Zn、K、Na、Mn、Cu、Co、Sr、Cr、N i、Cd、Pb的含量分别为365.4、162.0、1 035.8、24.74、599.9、149.1、42.1、22.8、3.88、12.8、20.26、7.15和10.77μg.g-1,Cd未检出.详细研究了消化液种类、HNO3和HC lO4的比例、消化体积及消化时间对测定结果的影响.

传统方法加固馆藏浮放文物抗震性能试验

为探索馆藏浮放文物的有效抗震加固方法,采用振动台试验手段,研究了传统方法加固浮放文物的抗震性能。基于故宫博物院某展柜原型尺寸,制作了1:1比例陈列柜模型。在陈列柜内浮放一轻质陶瓷文物,分别考虑采用砂子、塑料卡、鱼线、橡皮泥及磁铁加固文物,进行了振动台试验。通过白噪声激励,获得了陈列柜基频分布;通过输入不同强度、不同类型的地震波,获得了不同方法加固条件下陈列柜和文物的位移响应、加速度响应和和动力放大系数,评价了不同方法的加固效果。结果表明:陈列柜的基频与输入地震波相差较大,这是陈列柜震害不明显的主要原因之一;传统方法加固文物后,输入地震波的加速度仍有一定放大,但是与加固前文物相比,文物的位移和加速度响应均有所减小,且文物因摇晃幅度而产生倾覆的可能性减小。此外,从减小文物加速度响应峰值角度考虑,橡皮泥和鱼线加固文物效果优于其它方法。试验结果可为文物防震保护研究提供较全面的参考。

土坯围护墙-木结构民居抗震加固振动台试验研究

土坯围护墙-木结构传统民居在我国分布量大面广,实际震害表明该类型民居除木结构节点容易发生破坏外,围护墙体经常出现开裂、外闪,甚至倒塌现象.对此提出的加固措施包括:对木结构榫卯节点采用扁铁、薄钢片和角钢进行加固;在土坯墙体内外水平刻槽并设置配筋砂浆带,以增强土坯墙体水平抗剪能力,及与木结构之间可靠拉接.为验证以上措施的有效性,制作了单层两开间、1/2缩尺房屋加固模型,并进行了模拟地震振动台试验.试验结果表明:7度设防地震作用时墙体未见破坏,8度设防地震作用时墙体有轻微裂缝,8度罕遇地震作用时模型最大位移角达到1/61,墙体开裂较多,但由于约束较好,未有土坯剥落现象,并可以继续承载.试验过程中,加固后的木结构自始至终没有发生破坏,且与土坯围护墙体协同工作良好,总体上实现了"小震不坏、中震可修、大震不倒"的设防目标.

青藏铁路北麓河试验段块石路基与普通路基的地温特征

基于青藏铁路北麓河试验段块石路基与普通路基3个完整冻融循环周期内的地温数据,对比分析了两种路基下原天然地面处与原冻土天然上限处的地温变化过程以及路基不同部位下部土体的地温年际间变化过程。试验结果表明:块石路基下降温趋势明显且低于普通路基,原天然地面处低0.4～0.9℃,原天然冻土上限处低0.3～0.6℃。块石路基下部土体降温范围与降温幅度均大于普通路基,块石路基右路肩下部土体降温范围大于普通路基3 m,块石路基中心下部土体降温范围大于普通路基2 m。块石路基下部土体通过块石层与外界气体发生热交换强度不一致,右路肩下部最强,路基中心下部次之,左路肩下部最弱。

土坯墙承重民居抗震加固振动台试验研究

传统土坯墙承重民居由于材料自身缺陷、施工粗糙及缺乏抗震构造措施等原因.地震时经常发生严重损毁甚至倒塌。当前国内全面实施美丽乡村建设,对此类房屋进行抗震加固很有必要。提出的加固措施是在土坯墙体内外设置厚度较薄的水平和竖向配筋砂浆带,形成格栅配筋网,以约束土坯墙体并增强房屋的整体抗震性能。为验证以上措施的有效性,制作了单层单开间、1/2缩尺房屋加固模型,并进行了模拟地震振动台试验。试验表明:小震时格栅配筋带有效抑制了裂缝的出现和发展;大震时虽然墙体开裂较多.但由于约束较好,土坯未有剥落现象,8度大震时模型最大位移角达到1/195,总体上可以满足"小震不坏、中震可修、大震不倒"的设防目标。

传统民居穿斗式木构架抗震性能振动台试验研究

为研究西南地区木结构传统民居的抗震性能,对一个位于7度抗震设防烈度地区的两层、两跨穿斗式木构架进行模拟地震振动台试验。试验中选用3条天然波和1条人工波作为输入地震波,对模型结构的动力特性、加速度响应、位移响应、地震剪力及耗能能力进行分析。研究结果表明:随着输入加速度峰值的增加,模型结构自振频率减小,阻尼比增大。在加速度峰值为0.22g的地震作用后,模型结构X向和Y向的一阶自振频率分别降低了10.69%和19.97%,相应阻尼比分别增大到16.06%和17.47%。结构各层加速度放大系数随着加速度峰值的增加而降低,檐柱顶处的加速度放大系数在整个结构中最小,说明檐柱顶处榫卯节点在振动过程中减震作用明显。在加速度峰值为0.22g的地震作用下,结构最大层间位移角为1/53,此时未见模型有显著破坏,表明模型木构架具有良好的整体变形能力和抗倒塌能力。整个试验过程中,一层柱架耗能作用最大,柱脚耗能作用最小。