Windows操作系统的文件操作监控技术

论文详细描述目前网络安全防范方面的一种新的系统监控思路———文件操作监控技术,传统的方式中对网络入侵的检测是通过IDS以及网络连接情况的监控,现已被入侵者所熟悉,入侵者往往能采用各种应对手段来逃避检测系统的追查。但是当系统被入侵后,入侵者会不可避免的在某些文件上留下痕迹,而文件操作监控技术就是利用对系统文件的监控来实现侦测入侵情况的有效的新方法.     

使用Gantt图建立EPC工作流模型的研究

论文结合建筑工程项目的特点,讨论如何使用广义Gantt图建立基于EPC的工作流过程模型,旨在为建筑工程项目的工作流管理提供一个新的思路。     

在线钠度计的研制

为了测定水汽中钠离子含量，保证热力设备的高效运行。根据能斯特方程的测量原理，研制了在线钠度计。文章介绍了仪器的分析流路，工作过程。并对仪器的硬件电路和标定子程序的设计进行了较详细的论述。实验表明该仪器具有自动化程度高，测量准确的优点，具有良好的应用前景。     

基于Rhino3D平台的鞋楦二、三维互转换的设计与实现

本文介绍了一种基于Rhino3D开发平台的鞋楦二、三维之间相互转换的设计，该设计使得鞋楦二维到三维和三维到二维的转换得到统一实现。并且满足转换前后，二维鞋样和三维鞋样的面积近似相等，边界线相互对应且长度保持相等，鞋样上网格点的位置相互对应。该设计利用VC 语言编程在Rhino3D操作平台上实现并给出了转换的直观效果，验证了该设计的可实施性。     

A fuzzy constraint satisfaction approach for electronic shopping assistance

The Internet and World Wide Web offer an additional channel for consumers to find, select, and buy products. However, unlike shopping in the traditional store, consumers have no direct contact with human clerks to get the required information in the electronic store. The objective of this paper is to propose a fuzzy constraint satisfaction approach to help buyers find fully satisfactory or replacement products in electronic shopping. For the buyer who can give precise product requirements, the proposed approach can generate product-ranking lists based on the satisfaction degrees of each product to the given requirements. For the buyer who may not input accurate requirements, a similarity analysis approach is proposed to assess buyer requirements automatically during his browsing process. The proposed approach could help buyers find the preferred products on the top of the ranking list without further searching the remaining pages. The experimental results show the applicability of the proposed approach for electronic shopping assistance.     

High Temperature Schottky Barrier on n-Type SrTiO3 and Its Sensitivity to Ambient Gases

Metal or oxide electrodes (Pt, Au, Ag, (La, Sr)CoO₃) were deposited on single crystals of 0.02 mol% Nb doped SrTiO₃ by pulsed laser deposition. Current-voltage and capacitance-voltage responses were measured using three-terminal electrode configuration. Under high oxygen partial pressures, clear rectification behaviors were observed. Diffusion model well explained the current vs. voltage relationship with ideality factors close to unity. The barrier height varied reversibly with oxygen partial pressure, and was almost independent of the electrode materials, which suggested that the Fermi level at the interface was pinned by the surface states. The origin of the surface states was discussed in terms of oxygen adsorption or oxidative formation of metal vacancies around the surface. Chemical interaction between the surface and oxygen and resulting cation rearrangement was concluded to play an important role from the long stabilization time on oxygen partial pressure change. The water vapor pressure dependence of the barrier height was also explained by competitive adsorption of oxygen and water.     

Sensorless flux-weakening control of permanent-magnet brushless machines using third harmonic back EMF

The sensorless control of brushless machines by detecting the third harmonic back electromotive force is a relatively simple and potentially low-cost technique. However, its application has been reported only for brushless dc motors operating under normal commutation. In this paper, the utility of the method for the sensorless control of both brushless dc and ac motors, including operation in the flux-weakening mode, is demonstrated.     

Experiments and simulations of short-pulse laser-pumped extreme ultraviolet lasers

Recent experimental work on the development of extreme ultraviolet lasers undertaken using as the pumping source the VULCAN laser at the Rutherford Appleton Laboratory is compared to detailed simulations. It is shown that short duration (/spl sim/picosecond) pumping can produce X-ray laser pulses of a few picosecond duration and that measurement of the emission from the plasma can give an estimate of the duration of the gain coefficient. The Ehybrid fluid and atomic physics code developed at the University of York is used to simulate X-ray laser gain and plasma emission. Two postprocessors to the Ehybrid code are utilized: 1) to raytrace the X-ray laser beam amplification and refraction and 2) to calculate the radiation emission in the kiloelectronvolt photon energy range. The raytracing and spectral simulations are compared, respectively, to measured X-ray laser output and the output of two diagnostics recording transverse X-ray emission. The pumping laser energy absorbed in the plasma is examined by comparing the simulations to experimental results. It is shown that at high pumping irradiance (>10/sup 15/ Wcm/sup -2/), fast electrons are produced by parametric processes in the preformed long scalelength plasmas. These fast electrons do not pump the population inversion and so pumping efficiency is reduced at high irradiance.     

Bone Formation Process of β-TCP Ceramics with Tetracycline Tracing

To study the new bone formation in the bone defect area after implantation, the tetracycline tracing method was used. The results show that new bone formed in 1 month, and the formation rate of new bone was very high (8. 164 μm/day), considerably faster than that of control groups (3.219 μm/day). The new bone grew up quickly and β_TCP particles were surrounded by double fluorescence bands which became more obvious. The new bone formation rate was maximal at 2 months, and then gradually reduced. The rate was steady at 4 months, and then reduced to resembling as the normal physiologic metabolism of bone, which indicated the implanted materials were completely replaced by bone. Calcium phosphate materials had the ability of osteoconduction.