基于内容寻址的对象存储系统设计与实现

基于对象存储的理论并结合现代媒体企业的存储需求,设计并实现了一种应用于连续媒体数据归档的、按内容寻址的存储系统.在CAS中采用了高速索引技术对数据对象进行快速定位和访问,用生成的数据对象的内容地址,来惟一地标识该数据对象,使得能够快速、准确地定位、访问数据对象.以设备驱动的方式构建CAS设备,遵循动态内核驱动标准,能够灵活、方便地挂载和卸载CAS设备.对CAS原型系统进行了性能测试,结果表明,CAS在内容获取时有很好的性能.CAS系统提供开放的系统接口,便于和媒体资产管理系统进行集成,可以满足媒体企业的归档存储需求.     

Uncertainty Analysis in Software Reliability Modeling by Bayesian Analysis with Maximum-Entropy Principle

In software reliability modeling, the parameters of the model are typically estimated from the test data of the corresponding component. However, the widely used point estimators are subject to random variations in the data, resulting in uncertainties in these estimated parameters. Ignoring the parameter uncertainty can result in grossly underestimating the uncertainty in the total system reliability. This paper attempts to study and quantify the uncertainties in the software reliability modeling of a single component with correlated parameters and in a large system with numerous components. Another characteristic challenge in software testing and reliability is the lack of available failure data from a single test, which often makes modeling difficult. This lack of data poses a bigger challenge in the uncertainty analysis of the software reliability modeling. To overcome this challenge, this paper proposes utilizing experts' opinions and historical data from previous projects to complement the small number of observations to quantify the uncertainties. This is done by combining the maximum-entropy principle (MEP) into the Bayesian approach. This paper further considers the uncertainty analysis at the system level, which contains multiple components, each with its respective model/parameter/ uncertainty, by using a Monte Carlo approach. Some examples with different modeling approaches (NHPP, Markov, Graph theory) are illustrated to show the generality and effectiveness of the proposed approach. Furthermore, we illustrate how the proposed approach for considering the uncertainties in various components improves a large-scale system reliability model.     

120t转炉托圈制造工艺分析

对120 t转炉托圈制造工艺,从方案的选择,制造工艺,使用效果等进行了详细分析。120 t转炉托圈的制造工艺是合理的,实现了当月投产,当月达产的目标。     

亚45 nm技术节点平面式硅基CMOS电路制作的材料选择

随着45nm技术的临近，减小单个晶体管尺寸以提高晶体管集成度的方法逐渐达到物理极限。传统掺杂多晶硅，二氧化硅栅结构因硼杂质扩散穿透、多晶硅耗尽和电子隧穿等效应使深亚微米器件的性能退化。此外，沟道载流子迁移率退化也阻碍Si基MOS性能的提升。因此，需采用高k介质、金属栅和应变硅等新材料、新技术以改善Si基MOS管性能。本文在介绍这3种新材料优势的同时，分析了适合未来平面式硅基CMOS技术中的高介电常数材料和金属栅材料的种类，指出了未来电路中新材料的进一步发展方向。     

掺氮对300 mm单晶硅中流动图形缺陷和氧化诱生层错的影响

采用直拉法生长普通硅单晶和掺氮硅单晶,研究两种晶体中空位型原生缺陷（voids）和氧化诱生层错（OSFs）的行为。从两种晶体的相同位置取样,并对样品进行Secco腐蚀、1100℃湿氧氧化和铜缀饰实验。实验结果表明,在掺氮硅单晶中与较大尺寸的voids相关的流动图形缺陷（FPDs）的密度变小,氧化诱生层错环（OSF-ring）向样片中心处移动,同时宽度变大。这说明在直拉硅中掺氮可以抑制大尺寸voids的产生,同时可以缩小空位型缺陷区的范围,而且V/I过渡区（OSF-ring）的范围变大。     

Face recognition using a kernel fractional-step discriminant analysis algorithm

Feature extraction is among the most important problems in face recognition systems. In this paper, we propose an enhanced kernel discriminant analysis (KDA) algorithm called kernel fractional-step discriminant analysis (KFDA) for nonlinear feature extraction and dimensionality reduction. Not only can this new algorithm, like other kernel methods, deal with nonlinearity required for many face recognition tasks, it can also outperform traditional KDA algorithms in resisting the adverse effects due to outlier classes. Moreover, to further strengthen the overall performance of KDA algorithms for face recognition, we propose two new kernel functions: cosine fractional-power polynomial kernel and non-normal Gaussian RBF kernel. We perform extensive comparative studies based on the YaleB and FERET face databases. Experimental results show that our KFDA algorithm outperforms traditional kernel principal component analysis (KPCA) and KDA algorithms. Moreover, further improvement can be obtained when the two new kernel functions are used.     

扫描电镜中的电子反射镜像现象及应用

观察非导电样品在扫描电镜（SEM）中产生的电子镜现象。研究了电子镜出现的条件，监测了电子镜像出现过程中表面电势Es和吸收电流Ia的变化。结果表明，当Es达到7kV～9kV时出现了电子镜像。当电子总发射产额σ≌1，Es≌4kV，及Ia≌0时，形成了稳定而无畸变的电子镜像。利用电子镜现象可确定电子散射率及入射电子能量的临界值E2，以及评价非导电样品导电性能。     

重庆市污水源热泵应用前景分析

文章介绍了城市污水的主要热特性以及污水源热泵的优势，结合重庆市的污水排放情况，分析了在重庆市运用污水源热泵的方案，并简要分析了在重庆市采用污水源热泵所产生的效益，最后得出污水源热泵在重庆市具有良好的应用前景的结论。     

新型孔洞式全热滑轨技术在推钢式加热炉上的应用

介绍了新型孔洞式全热滑轨技术的原理、特点及其在推钢式加热炉上的应用。     

玲珑金矿田金矿成矿地质背景特征研究

通过研究前人关于玲珑金矿田的大量科研文献,从地层和岩浆岩的成生时代、控矿构造特征,系统地分析了玲珑金矿田内金矿产出的地质背景,指出了玲珑金矿田内的找矿方向,为东山矿床深部探、找矿方案设计提供了基础依据.