共查询到20条相似文献,搜索用时 60 毫秒
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介绍了一种十级12位50M Sample/sCMOS流水线A/D转换器的设计。该设计方案采用了全差分采样/保持电路和折叠式共源共栅运算放大器,保证了处理模拟信号的精度与速度。自举MOS开关和双差分动态比较器的使用,提高了电路的精度与速度,每级电路基本一致.简化了电路设计。 相似文献
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适用于流水线ADC采样保持电路的设计 总被引:1,自引:0,他引:1
文章介绍了一种适用于10位40MS/s流水线AID转换器的采样/保持(S/H)电路.整个电路的设计基于TSMC的0.25um工艺,在电源电压为2.5V的情况下,采样信号全差分幅度为1V.通过采用全差分flip-around结构,而非传统的电荷传输构架,因而在同等精度下,大大降低了功耗.为了达到高精度,高采样速率的要求,该S/H电路采用高增益,宽带宽的的两级运算放大器. 相似文献
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详细介绍了MAXIM公司生产的串行A/D转换器MAX1270,给出了其与单片机AT89S52的接口电路以及汇编语言A/D转换程序。将其应用于毛细管电泳电导检测系统的数据采集,转换速度和转换精度完全满足要求。 相似文献
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针对MOEA/D算法中差分进化操作收敛精度不高且速度较慢的不足,提出了一种综合基于可控支配域的向量差生成策略和基于主成分的动态缩放因子的新型差分进化模型,均衡显性与隐性搜索引导;并实现了一种基于新型差分进化模型的MOEA/D改进算法(MOEA/D-iDE)。新型差分进化是借助基于可控支配域的非支配排序对邻域进行分层,根据分层信息生成与不同进化阶段相匹配的向量差,实现对种群收敛速度的显性引导;同时对决策空间进行主成分分析,动态调整差分进化缩放因子,实现对种群收敛精度的隐性引导。实验选取ZDT、DTLZ和WFG等为测试问题,以IGD+,ER作为评价指标,将MOEA/D-iDE算法与6个同类算法进行对比实验,结果表明新算法在保证多样性的同时具有更好的收敛速度与精度,从而验证了新型差分进化模型的有效性。 相似文献
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介绍隔离型高精度D/A转换器的设计方法由单片机89C52产生PWM,经过光电隔离和一个双RC电路,将数字信号转换为直流电压信号,再经过电压/电流转换电路(V/I),输出0~20 mA电流信号;通过软件校正,达到较高的精度. 相似文献
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以9自由度液压机械臂为研究对象,建立求解位姿逆解的非线性方程组.以末端执行器位姿误差最小为优化指标建立目标函数,将非线性方程求解问题转化为最优化问题,并应用差分进化(DE)算法求解该问题.首先,为了避免位置和姿态收敛精度的不同,引入自适应权值系数进行平衡.然后,为克服基本DE算法难以平衡全局探索能力和局部开发能力的缺陷,结合DE/rand/1/bin和DE/best/1/bin两种进化模式,改进自适应变异差分进化(SAMDE)算法,提高了算法的收敛精度和收敛速度.最后,采用对称映射法对不满足关节角边界范围的个体进行处理,提高了收敛精度.开展了与基本DE算法的对比试验,仿真结果表明,该算法的收敛精度和收敛速度优于基本差分进化算法,且能够大幅度提高算法的稳定性. 相似文献
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简单介绍了SAR A/D基本结构.基于该结构,设计了采用两级差分放大器作为前置放大,最后采用一级差分输入的自偏压差分放大器输出结果.该电路采用0.18um工艺实现,对其进行了仿真,得到的仿真结果和波形说明了该比较器可应用于逐次逼近结构的模数转换器. 相似文献
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研究、分析了测量过程中的A/D转换精度问题 ,得出了使用低位A/D转换器获得和高位A/D转换器相当的转换精度的设计思想及实现电路 相似文献
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J. MacGregor 《Performance Evaluation》2003,52(4):237-267
An exact solution for the M/G/c/K model is only possible for special cases, such as exponential service, a single server, or no waiting room at all. Instead of basing the approximation on an infinite capacity queue as is often the case, an approximation based on a closed-form expression derivable from the finite capacity exponential queue is presented. Properties of the closed-form expression along with its use in approximating the blocking probability of M/G/c/K systems are discussed. Extensive experiments are provided to test and verify the efficacy of our approximate results. 相似文献
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Roger W Hockney 《Parallel Computing》1985,2(1):1-14
We report performance measurements made on the 2-CPU CRAY X-MP at ECMWF, Reading. Vector (SIMD) performance on one CPU is interpreted by the two parameters (), and we find for dyadic operations using FORTRAN . All vector triadic operations produce ; and a triadic operation with two vectors and one scalar gives r∞ = 148 Mflop/s and . MIMD performance using both CPUs on one job is interpreted with the two parameters (), where is the amount of arithmetic that could have been done during the time taken to synchronize the two CPUs. We find, for dyadic operations using the TSKSTART and TSKWAIT synchronization primitives, that r∞ = 130 Mflop/s and . This means that a job must contain more than ~ 6000 floating-point operations if it is to run at more than 50% of the maximum performance when split between both CPUs by this method. Less expensive synchronization methods using LOCKS and EVENTS reduces to 4000 flop and 2000 flop respectively. A simplified form of LOCK synchronization written in CAL code further reduces to 220 flop. This is probably the minimum possible value for synchronization overhead on the CRAY X-MP. 相似文献
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Consideration was given to the discrete-time queuing system with inversive servicing without interrupts, second-order geometrical
arrivals, arbitrary (discrete) distribution of the customer length, and finite buffer. Each arriving customer has length and
random volume. The total volume of the customers sojourning in the system is bounded by some value. Formulas of the stationary
state probabilities and stationary distribution of the time of customer sojourn in the system were established. 相似文献
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Kazuko Morizawa Hiroyuki Nagasawa Noriyuki Nishiyama 《Computers & Industrial Engineering》1994,27(1-4):23-26
“Complex Random Sample Scheduling(CRSS)” was proposed in this paper as an efficient heuristic method for solving any permutation scheduling problems. To show the effectiveness of the proposed CRSS, it was applied to an N-job, M-machine, permutation flowshop scheduling problem to minimize makespan, N/M/F/Fmax. Numerical experiments made it clear that the proposed CRSS provides a schedule very close to the near-optimal schedule obtained by the existing promising heuristic methods such as taboo search and simulated annealing, within less computation time than these heuristic methods. 相似文献
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T. C. E. Cheng 《Computers & Industrial Engineering》1992,22(4):495-499
Several efficient algorithms of O(n log n) computational complexity, for the Johnson's rule to schedule a set of simultaneously available jobs on two machines in a flowship to minimize the maximum job flowtime have appeared in the literature. A modified version of one of these algorithms is presented which not only simplifies the programming effort for implementation but is also able to generate all possible optimal sequences obtainable from Johnson's rule. 相似文献
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H.G. Perros 《Performance Evaluation》1983,3(2):83-93
We obtain the exact analytic expression of the probability distribution of the number of units in a single server queue with Poisson arrivals and Coxian service time distribution (notated as M/Ck/1). A recursive procedure for calculating this probability distribution is given. The well-known queues M/Ek/1 and M/D/1 are re-derived as special cases of the M/Ck/1 queue. Finally, the cases of M/C2/1 and M/C3/1 are fully worked out. 相似文献
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