Efficient Hierarchical Algorithm for Mixed Mode Placement in Three Dimensional Integrated Circuit Chip Designs

Hierarchical art was used to solve the mixed mode placement for three dimensional(3-D)integrated circuit design.The 3-D placement flow stream includes hierarchical clustering,hierarchical 3-D floorplanning, vertical via mapping,and recursive two dimensional(2-D)global/detailed placement phases.With state-of-the-art clustering and de-clustering phases,the design complexity was reduced to enhance the placement algorithm efficiency and capacity.The 3-D floorplanning phase solved the layer assignment problem...     

Smart Image Sensor with Integrated Low Complexity Image Processing for Wireless Endoscope Capsules

A smart image sensor was developed which integrates a digital pixel image sensor array with an image processor designed for wireless endoscope capsules. The camera-on-a-chip architecture and its on-chip functionality facilitate the design of the packaging and power consumption of the integrated capsule. The power reduction techniques were carried out at both the architectural and circuit level. Gray coding and power gating in the sensor array to eliminate almost 50% of the switch activity on the data bus and more than 99% of the power dissipation in each pixel at a transmitting rate of 2 frames per second. Filtering and compression in the processor reduces the data transmission by more than 2/3. A parallel fully pipelined architecture with a dedicated clock management scheme was implemented in the JPEG-LS engine to reduce the power consumption by 15.7%. The smart sensor has been implemented in 0.18 μm CMOS technology.     

基于混合遗传算法的区域大系统多目标水资源优化配置模型

针对区域水资源优化配置中重水量轻水质、重国民经济需水轻生态环境需水的特点,基于大系统总体优化配置理论与方法,综合考虑生态环境需水和水质因素,构建了基于混合遗传算法的区域大系统多目标水资源优化配置模型.运用混合遗传模拟退火算法对模型进行求解,将所提配置模型及方法应用于海河流域大清河,计算表明2010年P=50{\%}、75{\%}、95{\%}时不同保证率情况下生活和生态环境需水均能满足需求,系统协调度均大于0.84.     

一类新的抛物方程混合体积元方法

与标准的混合体积元方法不同,用梯度算子作用压力方程后,将两个方程均在对偶单上积分,得到新的混合体积元格式,且得到了速度H(div)模和压力L2模的最优误差估计.     

燃用橡胶籽生物柴油柴油机的性能与排放特性

按体积比将20%的橡胶籽油生物柴油与80%的-10^#柴油混合配制了B20生物柴油,12150ZL型涡轮增压柴油机和福田风景BT6516B1DBA型面包柴油车上研究了燃用B20时的外特性、负荷特性、万有特性以及自由加速烟度与排放特性。结果表明,与燃用-10^#柴油相比,柴油机燃用B20时燃油消耗升幅不高于1.7%,而功率和转矩分别升高0.16%～1.16%和0.07%～1.17%,最大爆发压力变化不大,并且排气温度和烟度值均有所降低。燃用B20有助于降低污染物排放,与燃用-10^#柴油相比,自由加速烟度的净化率达15.79%。     

强耐久性HPC配合比设计优化方法

对全计算法等三种高性能混凝土配合比方法进行了分析,提出了一种充分考虑混凝土耐久性的配合比优化设计方法。针对普遍存在的对耐久性评价模糊问题,建立了以最大表观密度为目标函数的优化模型,通过表观密度和孔隙分布判断所配制混凝土的耐久性能,是否与使用环境相适应以及满足混凝土工作性、强度和耐久性等三方面性能要求。实例证明了本文方法的可行性。     

Soft initial-rotation and H∞ robust constant rotational speed control for rotational MEMS gyro

A novel soft initial-rotation control system and an H∞ robust constant rotational speed controller (RCRSC) for a rotational MEMS (micro-electro-mechanical system) gyro are presented. The soft initial-rotation control system can prevent the possible tumbling down of the suspended rotor and ensure a smooth and fast initial-rotation process. After the initial-rotation process, in order to maintain the rotational speed accurately constant, the RCRSC is acquired through the mixed sensitivity design approach. Simulation results show that the actuation voltage disturbances from the internal carrier waves in the gyro is reduced by more than 15.3 dB, and the speed fluctuations due to typical external vibrations ranging from 10 Hz to 200 Hz can also be restricted to 10−3 rad/s order.     

方管内混合对流与管壁导热耦合换热的数值模拟

针对方管内空气混合对流时的流固耦合换热问题,提出将壁面导热作为边界条件进行处理的壁面导热与流动耦合简化计算方法,推导了计算公式,并采用SIMPLER算法进行了数值模拟.算法忽略壁面沿厚度方向的导热,假设管壁温度沿轴向一维分布,采用热量平衡法建立边界单元的能量守恒方程,将固体区域的导热简化为流体区域的边界条件,以提高计算的精度和可靠性.计算结果表明,受二次流影响,沿通道周向热量从加热面同时沿顺时针和逆时针方向迅速向两边传递,各壁面最大温差小于0.5℃,在轴向归一化长度为2～4时壁面轴向导热热流密度出现最值.平均Nusselt数Num随Reynolds数Re及方管倾斜角度θ的增大而增大,最优倾角在-30°和0°之间变化,但当Re＞1 500时,Num随θ的变化近似保持不变.计算结果与实验数据吻合良好,最大偏差小于±28.7％.     

一类奇异分数阶微分方程边值问题解的存在唯一性

本文应用混合单调算子理论研究了一类奇异分数阶微分方程边值问题正解的存在性与唯一性。     

凸多面体不确定混合时滞系统的均方指数稳定

文章讨论了一类凸多面体不确定系统的均方指数稳定性问题,考虑了带有Markov跳变参数系统中同时具有时变与分布时滞的混合时滞情形,通过基于二次稳定的概念构造系统的Lyapunov-Krasovskii候选函数,得出该类带有混合时滞的凸多面体不确定系统的均方指数稳定的充分条件;最后通过数值例子验证了该方法的可行性与有效性.