一种快速、有效的量化与基于小波的图像压缩

量化是利用小波变换的图像压缩编码技术的关键环节之一。矢量量化和标量量化各有长短,该文将这二者有机地结合起来,称为混合量化(HQ—Hybrid Quantization)。它既有矢量量化的高效率,又具有标量量化的简单性,不需要进行码书训练,不要做乘除法。并用标准测试图像与其它方法的压缩结果进行了比较。     

Scheduling data-flow graphs via retiming and unfolding

Loop scheduling is an important problem in parallel processing. The retiming technique reorganizes an iteration; the unfolding technique schedules several iterations together. We combine these two techniques to obtain a static schedule with a reduced average computation time per iteration. We first prove that the order of retiming and unfolding is immaterial for scheduling a data-flow graph (DFG). From this nice property, we present a polynomial-time algorithm on the original DFG, before unfolding, to find the minimum-rate static schedule for a given unfolding factor. For the case of a unit-time DFG, efficient checking and retiming algorithms are presented     

神经网络非线性系统自适应控制的研究

提出了一种新的神经网络非线性系统自适应控制方法采用改进的ＢＰ算法，避免了选取学习速率的麻烦仿真结果表明：该方法对非线性系统及突加外干拢、参数突变具有较强的自适应能力     

Quantification of overaging hardening kinetics of aluminum alloys

The overaging hardening kinetics in several aluminum alloys has been quantified, based on a relation between hardness and time for precipitation-hardened alloys. The relation takes into account precipitate coarsening and Orowan bowing mechanisms. Hardness-time curves from literature data for Al-2.5Cu-1.5Mg-(Si,Ag) (wt pct) alloys at 200° C and for an Al-1.23Mg-1.64Cu-6.15Zn (wt pct) alloy at 120° C are analysed, which are found to obey the overaging kinetics relation.     

氧分压对反应磁控溅射ZrO2薄膜光学透射率的影响

从氧空位、表面粗糙度及晶界三方面,讨论了氧分压对射频反应磁控溅射ZrO2薄膜光学透射率的影响.结果表明,随氧分压增大,氧空位的减少使单斜相逐渐占优,缺氧状况的改善使薄膜透射率逐渐升高;高氧分压下,出现颗粒聚集现象,表面粗糙度大幅增加及晶粒的聚集长大,使薄膜透射率下降.     

关于标准生成吉布斯自由能的一种计算方法及绘图实例

根据目前国际上流行的数学和工程计算软件IVIATCAB能很好地帮助工程师和科学家解决实际工程和技术问题的特点，针对热力学标准生成吉布斯自由能对材料合成和加工过程中的物质的反应和相变分析具有密切关系的情况，介绍了一种用MATLB软件计算标准生成吉布斯自由能及绘图的简便方法，并通过实例进行了说明。     

商务英语教学中英语知识与商务知识的关系

分析了商务英语教学中英语知识与商务知识的关系，对“二分法”认为英语知识高于商务知识的观点进行了商榷，并根据商务英语的基本目的和中国在校大学生普遍缺乏工作经验的实际情况，提出了在实际教学中应坚持“两手抓，两手都要硬”的教学方法。     

谐波、电压波动和闪烁校准系统的研究

在电磁兼容领域中为了保障由电子产品产生的谐波电流、电压波动和闪烁测试系统的准确度,需要对测试系统进行校准.本文首先对谐波电流、电压波动和闪烁的测试系统进行了系统的分析,然后重点研究了根据国家标准构建的由3091LD Ac load和FLUCK 6100A电能标准源组成的校准系统,确定校准项目,并对谐波电流、电压波动和闪烁测量系统的校准方法进行了研究.     

Effects of Magnetic Heat Treatment on Magnetostiction Properties of Tb0.3 Dy0.7 Fe1.95 Alloy

The effects of magnetic heat treatment on magnetostriction properties of Tb0.3Dy0.7Fe1.95 alloy were investigated.The directionally solidified alloy was heated to various temperatures near Curie temperature TC in vacuum, kept for a certain time under the application of magnetic field and then cooled to room temperature.The magnetostriction coefficient was measured by a resistance strain gage.The crystal structure was analyzed by X-ray diffraction (XRD).The experimental results show that the magnetostriction coefficient obviously increases and the grains orientations along the axis changed somewhat as the field of 1 T vertical to axis of the rod-shaped specimen is applied for 5 min at the heating temperature slightly lower than TC.     

SiCp/Cu复合材料切削加工性及其加工表面微观结构研究

通过应变测力仪，测量每一组切削用量参数下Cu及SiCp／Cu复合材料的切削力，并用电子显微镜观察分析切削表面的微观结构。研究表明：由于SiC颗粒对位错运动的阻碍，在SiCp／Cu界面处形成位错塞集群，产生应力集中，使SiCp／Cu复合材料切削过程呈典型的脆性分离；切削力随背吃刀量和进给量的增大而增大，随切削速度的增大而减小。