静态形式验证在跨时钟域和复位验证中的应用

Soc芯片的各个复杂功能模块中通常包含多个时钟域和复位域,跨时钟域信号路径设计的错误可能引起亚稳态问题进而导致设计故障。本文介绍了亚稳态的危害、以及传统的验证方法。相对于传统动态仿真方法耗时、容易遗漏的缺点,静态形式验证利用数学方法进行穷举,可以高效、快速、完备的检查可能出现的所有场景,提高验证的质量和效率。本文通过实例,利用静态形式验证技术对不同规模的设计中存在的跨时钟域和复位问题进行检视,并对验证结果进行了对比和分析。

天地一体化信息网络域间协议实验平台

域间协议是快速实现天地一体化信息网络中各类卫星系统及天地异构网络间互联的关键。然而,天地一体化信息网络的天、地网络拓扑的极大差异性使直接部署现有域间协议可能面临性能问题。为验证域间协议的工作性能,设计了一种天地一体化信息网络协议验证平台,采用虚拟网络技术高效模拟大规模、高动态的空间网络以及现有地面网络。实验结果显示,随着空间网络的拓扑规模和地面网络的路由表规模增加,天、地网络间的互联效率变得非常低。

支持移动网络的身份验证协议研究

为了解决主机在移动过程中发生跨域时,移动网络应用层的安全性,结合移动网络的特点以及存在的安全威胁,对Kerberos域间身份验证协议进行改进,减少客户端参与的协议报文交互次数,使其适合为移动网络的应用服务提供身份验证服务,并采用形式化方法对改进的身份验证协议进行安全性验证。结果表明改进的安全协议能够提供与原有协议相同的安全性。

FMC网络垃圾语音过滤系统的设计与分析

本文分析了下一代融合网络VoIP及语音类即时通信在安全方面的隐患,并针对目前的SPIT(spam over Internet telephony)过滤和防护方案中存在的问题,提出了综合防护的SPIT系统,从3个层面,包括域、服务器及客户端的防护角度介绍了此系统,并对此防护体系实现SPIT过滤的优势进行了全面的分析。

采油厂保密信息管理系统的设计与实现

为了充分利用采油厂的大容量磁盘系统,安全保存本厂员工的重要资料,采用AD技术实现帐户的统一管理.运用多层数据库和组件技术实现信息管理.通过对用户密钥进行MD5加密和文件内容的3重DES加密保障了数据的安全,即使是管理员也无法看到文件的内容.本系统具有安全、方便、快捷的特点,为大中型企业提供了企业级信息服务的解决方案.

基于CMMI的软件测试流程

对CMMI以及与软件测试相关的关键过程域做了分析和介绍,并对传统的软件测试理论模型(X模型,V模型)做了分析和比较, 基于对这两方面理论知识的理解以及项目实践经验中的总结,对基于CMMI的软件测试流程做了探索和研究,旨在提高软件测试的效率和保 证软件开发的质量。

电子邮件安全扩展协议应用分析

电子邮件是黑客发起网络攻击的主要入口,其中身份仿冒是电子邮件欺诈重要手段。基于邮件身份验证机制,构建属性图以测量政府机构电子邮件安全扩展协议全球采用率。从邮件内容仿冒、域仿冒、信头仿冒3个维度研究安全扩展协议部署效果。结果表明,各国政府机构邮件系统中部署SPF协议的约占70%,部署DMARC协议的不足30%,电子邮件身份检测采用率较低。当欺诈邮件进入收件人邮箱后,邮件服务提供商针对仿冒邮件警告机制有待完善。

A Bregman adaptive sparse-spike deconvolution method in the frequency domain

To improve the anti-noise performance of the time-domain Bregman iterative algorithm,an adaptive frequency-domain Bregman sparse-spike deconvolution algorithm is proposed.By solving the Bregman algorithm in the frequency domain,the influence of Gaussian as well as outlier noise on the convergence of the algorithm is effectively avoided.In other words,the proposed algorithm avoids data noise effects by implementing the calculations in the frequency domain.Moreover,the computational efficiency is greatly improved compared with the conventional method.Generalized cross validation is introduced in the solving process to optimize the regularization parameter and thus the algorithm is equipped with strong self-adaptation.Different theoretical models are built and solved using the algorithms in both time and frequency domains.Finally,the proposed and the conventional methods are both used to process actual seismic data.The comparison of the results confirms the superiority of the proposed algorithm due to its noise resistance and self-adaptation capability.

Domain-specific modeling and verification for C4ISR capability requirements

An approach was proposed to specify the C4ISR capability of domain-specific modeling language.To confine the domain modeling within a standard architecture framework,formally a C4ISR capability meta-ontology was defined according to the meta-model of DoD Architecture Framework.The meta-ontology is used for extending UML Profile so that the domain experts can model the C4ISR domains using the C4ISR capability meta-concepts to define a domain-specific modeling language.The domain models can be then checked to guarantee the consistency and completeness through converting the UML models into the Description Logic ontology and making use of inference engine Pellet to verify the ontology.

Development and Validation of National Cotton Cultivar Registration Index Model in Yangtze River Valley

[Objective] Based on the cotton variety high yielding potential, fiber quality traits, disease resistance, and early maturity characters, a cultivar registration index model was developed to simplify the tedious calculation process in national cotton registration procedure, and thus to enhance the practical application of cultivar regis- tration index in cotton breeding ancl cotton recommending. [Method] By means of correlation analysis, partial correlation analysis and path analysis methods, the cor- relation of cotton main properties and their effects on cultivar registration index were explored using the dataset of national cotton regional trials in Yangtze River Valley during 1996-2013. The cultivar registration index model was constructed with step- wise regression statistical technique to ascertain the quantitative relationship of main characters with cultivar registration index, and the regional cotton trial dataset in 2013 was used to validate the model. [Result] Several characters with larger deter- minants to cultivar registration index were screened out,ie. lint yield increase ratio, pro-frost yield ratio, verticillium wilt index, fiber strength, fusarium wilt index and mi- cronaire value. The cultivar registration index model defined the functional relation- ship of cultivar registration index with the selected main characters, among which lint yield increase ratio, fiber strength and micronaire value contributed most to culti- var registration index. The model validation with regional cotton trials in 2013 indi- cated the root mean square error, RMSE was only 2.77, and the variation coeffi- cient was 6.77%, which confirmed the model prediction effect was quite perfect. [Conclusion] The developed cultivar registration index model was reliable enough to simulate the complicated scoring system in cultivar registration procedure, also sim- plified cotton registration process, and enhanced the practicability of the cultivar reg- istration index.

Hydrological Modeling in a Semi-Arid Catchment Using SWAT Model

In the field of the water resources, hydrologic models have been used to assess water quality performance of complex watersheds and river basins. Hydrologic models can provide essential information for making decisions on sustainable management system of water resources within watersheds. The main objective of this study was to validate the performance of the Soil and Water Assessment Tool （SWAT） and the feasibility of using this model as a simulator of runoff at a catchment scale in semi-arid area in Northwestern Tunisia. Calibration and validation of the model output were performed by comparing predicted runoff with corresponding measurements from the Sarrath outlet for the periods 1990-1995 for calibration and 2000-2005 for validation. The time series for the years 1996-1999 showed discrepancies between the measured rainfall and the observed runoff indicating errors due to either the observations or to a dysfunction in the equipments. Sensitivity analysis shows that sensitive parameters for the simulation of discharge include curve number, soil evaporation compensation factor, depth of water in shallow aquifer and slope of subbasin. Statistical comparisons between monthly simulated results and observed data for the calibration period gave a reasonable agreement with a coefficient of determination （R2） greater than 0.75 and Nash-Sutcliffe Coefficient （NSE） equal to 0.72. These values were respectively 0.70 and 0.64 for validation period. Overall, the SWAT model has the capability to predict runoff within a complex semi-arid catchment.

Climate Change Projections for Mediterranean Region with Focus over Alpine Region and Italy

Climate change projections over the Mediterranean region have been elaborated by using the outputs of ten ENSEMBLES regional climate simulations with an horizontal resolution of 25 km under the SRES A1B emission scenario. The analysis concerns some surface atmospheric variables： mean sea level pressure, temperature, precipitation and wind speed. At first, model validations have been performed by comparing model results with E-OBS and ERA-Interim data in reproducing the last decades over some Italian sub-areas and the Alpine region. In spite of the considerable spread in the models＇ performances to represent the reference climate, a multi-model reconstruction has been computed and some seasonal climate change projections have been elaborated. About the mean climate changes, the more significant signals expected by 2050 are a maximum warming （about 2 ~C） and maximum drying （about 20%） in the southern Europe in summer. Moreover, the results indicate an increasing risk for some severe weather conditions： more days of extremely high temperature in summer over the whole area, a greater occurrence of flooding and storms over coasts during spring and autumn seasons and a more serious wet-snow event over Alpine region in winter. No significant signals of wind changes have been detected.

Overheated Investment in Real Estate Inhibits Innovation:Verification and Analysis in China's Case

Whether rapid real estate investment growth inhibits China's innovation is a critical question for China's economic sustainability. Based on China's provincial panel data and using land supply as an instrumental variable for real estate investment growth, we arrived at the following findings after effectively controlling endogenous factors that could lead to estimation errors. First of all, the faster real estate investment grows in a province, the lower the growth rates of innovation and R&D spending and invention patent authorizations will be in the province, an indication that real estate directly inhibits innovation in China. Such inhibition is particularly pronounced in the industrial sectors. Secondly, in the context of rampant real estate investment, the biased loan maturity structure of China's financial system in favor of the real estate industry further inhibits innovation. This paper has verified the existence of the direct effect of real estate investment growth on regional innovation and its indirect effect on regional innovation through the biased long maturity structure of the financial system. The empirical findings of this paper provide practical policy implications for China to strike a balance between real estate development and an innovation-driven development strategy.

一种改进的安全电子交易协议

引言 随着网络的普及,电子商务对金融服务行业将产生巨大的影响.付费系统及其相关金融机构将在电子商务领域扮演极其重要的角色.安全电子交易协议(SET)凭其高安全性成为公开网络上最受欢迎的电子付费协议之一.但为了满足众多安全要求,SET协议中双签名加密机制采用了RSA签名加密算法,这种算法必须与SET交易同时运行,从而使得系统运行的计算和管理开销非常大.为提高SET交易过程的效率,我们提出了基于域验证签名加密算法(DVSS)的简单安全电子交易协议.在具体操作过程中,简单安全电子交易协议比安全电子交易协议花费更少的计算和通讯开销.