基于Luv色度坐标图像分割方法的孔洞参数计算

针对成像测井解释中孔洞参数定量计算的准点，提出用基于Luv色度坐标进行图像分割的方法来定量计算孔洞的面积、面孔率等相关参数。采用该方法得到的孔洞结果目标区域完整，可以方便地计算出孔洞面积和面孔率等参数。     

新抗冲型ACR的合成与研究

采用种子乳液聚合法制备了含有PBA＼PMMA＼PS三种组分的丙烯酸酯类抗冲型改性剂ACR，在ACR的幔层结构中引入接枝剂甲基丙烯酸烯丙酯（ALMA）来完善幔层结构，从而实现核一壳之间良好的结合，用红外光谱（FTIR）和差示扫描量热法（DSC）对ACR的组成和结构进行表征。研究结果表明：由PBA＼PMMA＼PS三组分构成的ACR在抗冲击性能上要略优于由简单的PBA＼PMMA构成的ACR，苯乙烯单体（St）最多可以取代大约1／3壳层的甲基丙烯酸甲酯（MMA），甲基丙烯酸烯丙酯（ALMA）的引入对幔层结构的完善起了显著的作用。     

Minimum-Energy Translational Trajectory Generation for Differential-Driven Wheeled Mobile Robots

Mobile robots can be used in many applications, such as exploration, search and rescue, reconnaissance, security, and cleaning. Mobile robots usually carry batteries as their energy source and their operational time is restricted by the finite energy available from the batteries. Therefore, energy constraints are critical to the service time of mobile robots. This paper investigates the minimum-energy control problem for translational trajectory generation, which minimizes the energy drawn from the batteries. Optimal control theory is used to find the optimal velocity trajectory in analytic form. To demonstrate energy efficiency obtainable, we performed simulations of minimum-energy velocity control and compared the results with loss-minimization control and energy-optimal trapezoidal velocity profiles. Simulation results showed that significant energy savings can be achieved, of up to 9% compared with loss-minimization control and up to 10% compared with energy-optimal trapezoidal velocity profile. We also performed an actual robot experiment using Pioneer 3-AT platform to show the validity of the proposed minimum-energy velocity control. The experimental results revealed that the proposed minimum-energy velocity control can save the battery energy up to 10% compared with loss-minimization control. Categories (3): Robot control, (5): RobotMotion Planning     

An accurate and practical buffer allocation model for the buffer cache based on marginal gains

A new dynamic buffer allocation strategy based on the notion of marginal gains is presented for the buffer cache that is used by the operating system to store frequently accessed disk blocks in main memory, and the performance of the proposed strategy is compared with those of previous allocation strategies. In the proposed strategy, marginal gain values are predicted by exploiting functions that approximate the expected number of buffer hits per unit time. Experimental results from both trace-driven simulation and an actual implementation in the FreeBSD operating system show that the proposed strategy accurately predicts the marginal gain values for various workloads resulting in significantly improved buffer hit ratios.     

晶体硅薄膜电池制备技术及研究现状

晶体硅薄膜太阳电池近些年来得到广泛的研究和初步的商业化探索。根据所采用的晶体硅薄膜沉积工艺中温度范围的不同，晶体硅薄膜电池研究可分为高温路线和低温路线两个不同发展方向。本文分别从这两个方向综述了目前国外晶体硅薄膜电池制备技术的最新进展，最新实验室研究结果。报导了晶体硅薄膜电池商业化进展状况，指出了晶体硅薄膜电池实现产业化必须解决的问题。     

Ti-45Al-10Nb合金的高温氧化行为

研究了Ti—45A1—10Nb(原子分数，％)合金在800-960℃在氧气和空气中的氧化行为．结果表明，该合金具有较好的高温抗氧化性能，其氧化增重速率与铁基耐热不锈钢相似或略优．与Ti—50A1合金相反，Ti-45A1-10Nb合金在空气中的氧化增重速率明显低于在纯氧中的氧化增重速率．X射线衍射与能谱分析表明，Ti-45Al一10Nb合金在氧气中的氧化产物主要有TiO2和Al2O3，但在空气中的氧化产物中有TiN相．这是降低氧化速率的主要原因，同时，合金元素Nb稳定了氧化层中的TiN相，因而提高了合金在空气中的抗氧化性能．     

压电振子径厚耦合振动的二维等效电路研究

提出了一种轴向极化压电圆环和圆片的径厚二维耦合等效电路模型。应用这一模型分析了它们的耦合振动,比较了不同尺寸比例下耦合振动与单一模式振动的异同,发现这种方法比一维等效电路方法能在较宽尺寸范围内更准确的分析压电振子的振动问题。有限元计算和试验测量结果验证了这一模型对压电振子频率计算的准确性。     

An Area Optimization Method for Digital Filter Design

In this paper, we propose an efficient design method for area optimization in a digital filter. The conventional methods to reduce the number of adders in a filter have the problem of a long critical path delay caused by the deep logic depth of the filter due to adder sharing. Furthermore, there is such a disadvantage that they use the transposed direct form (TDF) filter which needs more registers than those of the direct form (DF) filter. In this paper, we present a hybrid structure of a TDF and DF based on the flattened coefficients method so that it can reduce the number of flip‐flops and full‐adders without additional critical path delay. We also propose a resource sharing method and sharing‐pattern searching algorithm to reduce the number of adders without deepening the logic depth. Simulation results show that the proposed structure can save the number of adders and registers by 22 and 26%, respectively, compared to the best one used in the past.     

EPON媒体接入控制的关键技术研究

文章简要介绍了基于以及太网的无源光网络（EPON）这种新型的接入网技术，将其与基于ATM技术的无源光网络（APON）的优缺点进行了比较，并对其媒体接入控制（MAC）的关键技术测距及上行接入进行了讨论，初步提出了光网络单元（ONU）的软、硬件实现方案。