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Accelerated generation of holograms with ultra-low memory symmetrically high-compressed look-up table
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作者 杨燕 朱建英 +1 位作者 孙敏远 毕勇 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期466-471,共6页
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... 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. 展开更多
关键词 computergenerated hologram look-up table HOLOGRAPHY
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A general purpose exact Rayleigh scattering look-up table for ocean color remote sensing 被引量:5
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作者 HE Xianqiang PAN Delu +1 位作者 BAI Yan GONG Fang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2006年第1期48-56,共9页
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 practica... 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. 展开更多
关键词 ocean color Rayleigh scattering look-up table radiative transfer adding-doubling method
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Fine Doppler shift acquisition algorithm for BeiDou software receiver by a look-up table 被引量:3
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作者 QIU Wenqi ZENG Qingxi +1 位作者 GAO Chang LYU Chade 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第3期612-625,共14页
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 t... 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. 展开更多
关键词 fine acquisition fast Fourier transform(FFT) table look-up parallel frequency acquisition(PFA) BEIDOU
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Performance of global look-up table strategy in digital image correlation with cubic B-spline interpolation and bicubic interpolation 被引量:4
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作者 Zhiwei Pan Wei Chen +3 位作者 Zhenyu Jiang Liqun Tang Yiping Liu Zejia Liu 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2016年第3期126-130,共5页
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 (... 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. 展开更多
关键词 Digital image correlation Inverse compositional Gauss-Newton algorithm Cubic B-spline interpolation Bicubic interpolation Global look-up table
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WinoNet:Reconfigurable look-up table-based Winograd accelerator for arbitrary precision convolutional neural network inference
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作者 Wang Chengcheng Li He +3 位作者 Cao Yanpeng Song Changjun Yu Feng Tang Yongming 《Journal of Southeast University(English Edition)》 EI CAS 2022年第4期332-339,共8页
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 convo... 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. 展开更多
关键词 quantized neural networks look-up table(LUT)-based multiplier Winograd algorithm arbitrary precision
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Research of NO_(2) vertical profiles with look-up table method based on MAX-DOAS
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作者 Yingying Guo Suwen Li +2 位作者 Fusheng Mou Hexiang Qi Qijin Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第1期332-338,共7页
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 a... 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. 展开更多
关键词 multi-axis differential optical absorption spectroscopy look-up table method the cost function NO_(2)vertical profile
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The Periodic Table of Elementary Particles for Baryonic Matter and Dark Matter: Upward-Going ANITA Events
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作者 Ding-Yu Chung 《Journal of Modern Physics》 2018年第13期2308-2319,共12页
This paper posits that the upward-going ANITA events are derived from the cosmic ray of the baryonic-dark matter (BDM) Higgs boson. In the extended standard model (ESM) for baryonic matter and dark matter, the spontan... This paper posits that the upward-going ANITA events are derived from the cosmic ray of the baryonic-dark matter (BDM) Higgs boson. In the extended standard model (ESM) for baryonic matter and dark matter, the spontaneous symmetry breaking through the Higgs mechanism for the symmetrical massless baryonic matter left-handed neutrinos and massless dark matter right-handed neutrinos produced massless baryonic matter left-handed neutrinos, sterile massive dark matter neutrinos, and the BDM Higgs boson. The BDM Higgs boson is the composite of the high-mass tau neutrino and the high-mass dark matter neutrino. During the passage through the high-density part of the Earth, the BDM Higgs boson is transformed into the oscillating BDM Higgs boson between the composite of the high-mass tau neutrino and the high-mass dark matter neutrino and the composite of the high-mass tau neutrino and the low-mass dark matter neutrino. The oscillating BDM Higgs boson decays into the high-mass tau neutrino with the extra energy and the low-mass dark matter neutrino (27 eV) in the low-density water-ice layer of the Earth. The high-mass tau neutrino is converted into ultra-high-energy tau neutrino which decays into tau lepton through the charged-current interactions, and tau lepton emerges from the surface of ice. Based on the periodic table of elementary particles, the calculated value for the high-mass tau neutrino with the extra energy is 0.47 EeV in good agreement with the observed 0.56 and 0.6 EeV. The periodic table of elementary particles for baryonic matter, dark matter, and gravity is based on the seven principal mass dimensional orbitals for stable baryonic matter leptons (electron and left-handed neutrinos), gauge bosons, gravity, and dark matter and the seven auxiliary mass dimensional orbitals for unstable leptons (muon and tau) and quarks, and calculates accurately the masses of all elementary particles and the cosmic rays by using only five known constants. 展开更多
关键词 ANITA Periodic table of Elementary Particles HIGGS BOSON Baryonic-Dark MATTER HIGGS BOSON Cosmic RAYS Upward-Going DARK MATTER Baryonic MATTER extended Standard Model
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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
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作者 曹珍珍 安洁 +1 位作者 郭小晶 颊小芳 《河南中医》 2024年第6期903-909,共7页
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... 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。 展开更多
关键词 多囊卵巢综合征 胰岛素抵抗 补肾填精汤 盐酸二甲双胍缓释片 中西医结合疗法
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Differential Spatial Modulation Mapping Algorithms
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作者 WANG Chanfei CHAI Jianxin XU Yamei 《ZTE Communications》 2024年第3期116-122,共7页
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... 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. 展开更多
关键词 spatial modulation(SM) multiple-input multiple-output(MIMO) look-up table Order(LUTO) Permutation Method(PM) mapping algorithm
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The establishment of crystal position look-up table for positron emission tomography with block detectors 被引量:2
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作者 CHAI Pei1,2 & SHAN BaoCi1 1 Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China 2 Graduate University of Chinese Academy of Sciences, Beijing 100049, China 《Science China(Technological Sciences)》 SCIE EI CAS 2009年第8期2418-2423,共6页
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 Ga... 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. 展开更多
关键词 POSITRON emission TOMOGRAPHY POSITION look-up table 2-D POSITION HISTOGRAM
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CRC Look-up Table Optimization for Single-Bit Error Correction 被引量:1
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作者 潘赟 葛宁 董在望 《Tsinghua Science and Technology》 SCIE EI CAS 2007年第5期620-623,共4页
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-... 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. 展开更多
关键词 cyclic redundancy code look-up table OPTIMIZATION single-bit error correction genetic framing procedure
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Device and circuit analysis of a sub 20 nm double gate MOSFET with gate stack using a look-up-table-based approach
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作者 S Chakraborty A Dasgupta +3 位作者 R Das M Kar A Kundu C K Sarkar 《Journal of Semiconductors》 EI CAS CSCD 2017年第12期37-41,共5页
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 o... 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. 展开更多
关键词 14 nm double gate MOSFET look-up table VerilogA
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Accurate and fast table look-up models for leakage current analysis in 65nm CMOS technology
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作者 薛冀颖 李涛 余志平 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2009年第2期42-47,共6页
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... 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. 展开更多
关键词 leakage current 65 nm technology table look-up model INTERPOLATION
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高能物理计算环境中KVM虚拟机的性能优化与应用 被引量:10
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作者 黄秋兰 李莎 +1 位作者 程耀东 陈刚 《计算机科学》 CSCD 北大核心 2015年第1期67-70,共4页
高能物理是典型的高性能计算的应用,对CPU计算能力要求很高,并且CPU利用率的高低直接影响高能物理的计算效率。虚拟化技术在实现资源共享和资源高利用率方面表现出很大的优势。基于KVM(Kernel-based Virtual Machine)虚拟机进行性能测... 高能物理是典型的高性能计算的应用,对CPU计算能力要求很高,并且CPU利用率的高低直接影响高能物理的计算效率。虚拟化技术在实现资源共享和资源高利用率方面表现出很大的优势。基于KVM(Kernel-based Virtual Machine)虚拟机进行性能测试和性能优化。首先对KVM虚拟机的处理器、磁盘IO和网络IO等参数进行测试,给出虚拟机和物理机的性能差异和定量分析,然后从KVM虚拟机架构上分析影响KVM性能的各种因素,从硬件级、内核级对影响性能的因素包括扩展页表EPT(Extented Page Table)和CPU的亲和性(CPU affinity)展开研究,以对KVM进行性能优化。优化结果表明,KVM的CPU性能的损失率可以降低至3%左右。最后,给出了高能物理计算的虚拟集群,结果显示虚拟机群的计算性能能够满足高能物理计算的需求。 展开更多
关键词 高性能计算 KVM CPU亲和性 扩展页表
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地震模拟振动台扩展系统理论分析及试验研究 被引量:4
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作者 李青宁 程麦理 +3 位作者 尹俊红 闫磊 韩春 周春娟 《振动与冲击》 EI CSCD 北大核心 2015年第7期81-84,共4页
为利用单振动台进行空间大跨度结构动力试验,提出地震模拟振动台扩展系统概念。根据达朗贝尔原理对系统子台进行动力平衡分析,建立振动台扩展系统理论分析模型,通过考虑振动过程中上部结构对子台的动力影响,合理确定动力方程关键参数,... 为利用单振动台进行空间大跨度结构动力试验,提出地震模拟振动台扩展系统概念。根据达朗贝尔原理对系统子台进行动力平衡分析,建立振动台扩展系统理论分析模型,通过考虑振动过程中上部结构对子台的动力影响,合理确定动力方程关键参数,改变系统参量可实现结构多点激励研究。设计并制作振动台扩展系统,试验结果表明,系统子台反应有明显时滞、增幅效应。试验及算例表明,该理论正确,方法可行,对地震模拟振动台试验系统的发展有实际意义。 展开更多
关键词 振动台 扩展系统 子母台 理论分析 试验研究
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杂合灰色聚类与扩展优势粗集的概率决策方法 被引量:7
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作者 菅利荣 刘思峰 谢乃明 《系统工程学报》 CSCD 北大核心 2010年第4期554-560,共7页
为了能够由多标准信息表获取最小的知识表达,提出了一种灰色定权聚类与扩展优势粗糙集杂合的方法,杂合方法建立的基本思路为:首先运用灰色定权聚类方法将由不同量纲偏好属性组成的多标准信息表生成多标准决策表,接下来应用扩展优势粗糙... 为了能够由多标准信息表获取最小的知识表达,提出了一种灰色定权聚类与扩展优势粗糙集杂合的方法,杂合方法建立的基本思路为:首先运用灰色定权聚类方法将由不同量纲偏好属性组成的多标准信息表生成多标准决策表,接下来应用扩展优势粗糙集方法进行概率决策分析,并导出偏好概率决策模型.该方法被应用于区域关键技术的评价选择中,获取的偏好概率决策规则可为决策者提供决策参考. 展开更多
关键词 灰色定权聚类 扩展优势粗糙集 多标准决策表 概率决策
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硬盘分区链表结构分析与应用 被引量:7
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作者 姚罡 李大军 梅顺良 《微计算机信息》 北大核心 2006年第03X期206-208,222,共4页
硬盘分区表对整个硬盘的组织和管理有着极其重要的作用。本文详细介绍了硬盘上的主引导扇区和分区结构,进一步分析了每个结点的数据结构和各分项所起的作用。并通过扩展INT13H,实际分析了一块硬盘的结构。基于以上分析,文章最后提供了... 硬盘分区表对整个硬盘的组织和管理有着极其重要的作用。本文详细介绍了硬盘上的主引导扇区和分区结构,进一步分析了每个结点的数据结构和各分项所起的作用。并通过扩展INT13H,实际分析了一块硬盘的结构。基于以上分析,文章最后提供了一个实际应用。 展开更多
关键词 主引导扇区 分区链表 扩展INT 13H
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VR-Forces仿真系统功能扩展与数据交互 被引量:5
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作者 高化猛 余本俊 《装备指挥技术学院学报》 2010年第4期116-120,共5页
分析了VR-Forces仿真系统程序结构、类层次结构、类工厂机制、应用程序接口。应用面向对象设计方法,通过派生子类和类工厂机制,实现VR-Forces对象管理类和远程控制函数的功能扩展。针对VR-Forces与其他仿真程序数据交互困难的问题,提出... 分析了VR-Forces仿真系统程序结构、类层次结构、类工厂机制、应用程序接口。应用面向对象设计方法,通过派生子类和类工厂机制,实现VR-Forces对象管理类和远程控制函数的功能扩展。针对VR-Forces与其他仿真程序数据交互困难的问题,提出一种新的基于注册表和远程控制函数的数据交互机制。实际运行表明,派生子类接口得到扩展,新的数据交互机制解决了fed文件共享、数据并发存取、软件版本冲突、重复定义等难题,VR-Forces功能得到扩展,数据交互更安全。 展开更多
关键词 功能扩展 数据交互 仿真系统 注册表
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基于多级滞环控制器的永磁同步电机直接转矩控制 被引量:20
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作者 肖萌 史婷娜 +1 位作者 王志强 夏长亮 《中国电机工程学报》 EI CSCD 北大核心 2017年第14期4201-4211,共11页
该文提出一种多级滞环控制器与基于离散占空比的扩展开关表相结合的新型直接转矩控制策略。该策略可以在保证系统具有快速响应能力的前提下有效地降低磁链和转矩波动。所提出的多级滞环控制器将转矩、磁链误差大小划分成若干等级,从而... 该文提出一种多级滞环控制器与基于离散占空比的扩展开关表相结合的新型直接转矩控制策略。该策略可以在保证系统具有快速响应能力的前提下有效地降低磁链和转矩波动。所提出的多级滞环控制器将转矩、磁链误差大小划分成若干等级,从而能够更详尽的描述系统需要增、减转矩或磁链的程度。文中对占空比进行离散化处理,在此基础上生成不同幅值、不同相角的矢量作为备选矢量,丰富和扩展了传统DTC开关表。此外,本文采用倒三角矩阵存储备选矢量集合,并采用"二次寻优"的方法准确、快速地从扩展开关表中选出目标矢量。最后对本文算法的可行性与有效性进行了实验验证。 展开更多
关键词 永磁同步电机 直接转矩控制 多级滞环控制器 占空比:扩展开关表 倒三角矩阵
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基于VMFUNC的虚拟机自省触发机制 被引量:2
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作者 刘维杰 王丽娜 +1 位作者 谈诚 徐来 《计算机研究与发展》 EI CSCD 北大核心 2017年第10期2310-2320,共11页
虚拟化技术作为云计算的基础得到了广泛应用,但随之而来的虚拟机安全问题日趋严重.虚拟机自省作为一种从外部监控虚拟机内部运行状态的方法,为解决虚拟机安全问题提供了新视角,但同时也引入了巨大开销,阻碍了实际应用.提出了一种基于VMF... 虚拟化技术作为云计算的基础得到了广泛应用,但随之而来的虚拟机安全问题日趋严重.虚拟机自省作为一种从外部监控虚拟机内部运行状态的方法,为解决虚拟机安全问题提供了新视角,但同时也引入了巨大开销,阻碍了实际应用.提出了一种基于VMFUNC的虚拟机自省(virtual machine introspection,VMI)触发机制.该机制借助CPU硬件特性VM-Function以及RDTSC指令模拟,将调用时产生VM Exit开销降至最低;利用VMFUNC的功能为目标虚拟机切换备用扩展页表,避免VMI程序运行时对虚拟机执行的中断;通过重载VMFUNC指令和Xentrace的功能实现高效的触发与信息传递机制,主动触发VMI程序运行,克服了VMI程序常驻带来的大量资源消耗.实现了虚拟机自省即服务系统,并进行了实验验证.结果表明:本系统带来额外性能开销不超过2%,使VMI在实际云环境中的广泛应用成为了可能. 展开更多
关键词 云计算安全 虚拟机自省 VMFUNC 扩展页表指针切换 虚拟机自省即服务
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