可信密码模块符合性测试方法研究

提出了一种可信密码模块(TCM)符合性测试的形式化方法,采用基于扩展有限状态机(EFSM)模型与测试向量相结合的方式对TCM的标准进行形式化建模.由于该建模方法结合TCM自身特点给出了命令依赖关系图的获取算法以及EFSM模型与测试向量获取算法,所以能够更好地对标准进行形式化建模,并用于测试用例的产生.通过测试结果分析以及与其他相关工作的对比,表明该方法能够有效地产生测试用例,并提高TCM符合性测试的错误检测率.

可信平台模块的形式化分析和测试

可信平台模块(Trusted Platform Module,TPM)是可信计算平台的核心和基础,可信平台模块的功能测试和验证是保证可信平台模块的实现正确性以及规范一致性的重要手段,但是目前尚不存在一种有效严格的可信平台模块测试和功能验证方法,同时可信计算组织给出的TPM规范是描述性的,不利于产品的开发和测试.文中在分析可信平台模块目前存在的一些问题的基础上,以TPM密码子系统为例给出了该子系统的形式化规格说明,并且基于该规格说明,给出了扩展有限状态机模型,最后,将该有限状态机模型应用于测试用例的自动生成,并通过实验验证了形式化测试的有效性.

可信平台模块分析与测试技术研究

在可信计算平台的体系结构中，可信平台模块的基础性地位决定了其在可信计算平台的研究中居于中心的地位。本文对可信平台模块中可信机制特别是隐私性保护机制进行了详细的分析，并以可信平台模块作为建模的对象，对其进行形式化分析，探讨利用形式化模型生成测试用例，进行符合性测试的技术。本文主要取得了以下几个方面的成果： 1、针对现有的隐私性保护方案即BCC方案在多信任域环境下的不足，提出了一种多信任域内的直接匿名证明方案，该方案为直接匿名证明方案在多信任域的网络环境下的应用奠定了基础。 2、针对BCC方案匿名性机制中“验证着相关的完全或无”匿名性的缺陷，提出了带子群隐私保护的隐私性保护方案，该方案为小群体内应用隐私性保护方案提供了可行的解决方法，增强了现有隐私性保护方案匿名机制的灵活性。 3、提出了一种新的基于双线性映射的直接匿名证明方案，该方案的计算量小，签名长度短，为下一代基于椭圆曲线的可信平台模块提供了可行的隐私性保护方案。 4、针对目前可信平台模块符合性测试缺少自动化测试方案的现实，本文提出了一个新的针对可信平台模块的测试方案，该方案利用EFSM形式化模型生成测试用例，支持覆盖度的分析，可以实现测试的自动化，在符合性测试中可以帮助提高测试的覆盖程度与工作效率。 5、最后，本文首次对可信平台模块的本地化产品可信密码模块进行了系统的分析，指出了其中的AP授权协议的一些缺陷，并给出了改进意见，对可信密码模块和可信平台模块进行了详细的对比和分析，指出可信密码模块存在的不足和优势。 总的说来，本文的研究成果为可信平台模块的推广提供了有力的支撑，并且为我国可信密码模块的发展提供了借鉴。 关键词：可信平台模块、可信计算平台、 符合性测试、直接匿名证明

基于支持向量机的Internet流量分类研究

准确的网络流量分类是众多网络研究工作的基础,也一直是网络测量领域的研究热点.近年来,利用机器学习方法处理流量分类问题成为了该领域一个新兴的研究方向.在目前研究中应用较多的是朴素贝叶斯(nave Bayes,NB)及其改进算法.这些方法具有实现简单、分类高效的特点.但该方法过分依赖于样本空间的分布,具有内在的不稳定性.因此,提出一种基于支持向量机(support vector machine,SVM)的流量分类方法.该方法利用非线性变换和结构风险最小化(structural risk minimization,SRM)原则将流量分类问题转化为二次寻优问题,具有良好的分类准确率和稳定性.在理论分析的基础上,通过在实际网络流集合上与朴素贝叶斯算法的对比实验,可以看出使用支持向量机方法处理流量分类问题,具有以下3个优势:1)网络流属性不必满足条件独立假设,无须进行属性过滤;2)能够在先验知识相对不足的情况下,仍保持较高的分类准确率;3)不依赖于样本空间的分布,具有较好的分类稳定性.

P-选择素CR结构域功能的模拟预测

<正>选择素(selectin)与其配体间相互作用介导的细胞粘附在炎症级联反应、肿瘤转移和淋巴细胞归巢等病理、生理过程中起重要作用。其结构组成从远离细胞表面的N-末端到胞内C-末端,依次为:钙型凝集素功能区(Calcium-type lectin domain,Lec),类上皮生长因子功能区(Epidermal Growth Factor-like module,EGF),具有粘附补体蛋白作用的多个重复序列(Consensus Repeats,CRs),跨膜区(Transmembrane,TM)和胞内区

岷江源头区植被景观与流域土壤侵蚀的动态相关性

作为复杂的生态过程之一，土壤侵蚀常常被空间景观异质性影响。深入地研究土壤侵蚀与植被景观的相关性对以减少水土流失为目的的河流中上游生态恢复工作来说十分重要。本文利用遥感和GIS 技术，对岷江源头区的植被景观和土壤侵蚀动态（1974年～2002 年）进行分析，并从景观生态学的角度，系统地研究了整体植被景观和不同的植被景观类型的景观特征与土壤侵蚀量、侵蚀模数以及土壤侵蚀强度的相关性，得出的结论主要有以下几个方面：1. 从植被景观特征与土壤侵蚀量和土壤侵蚀模数的相关性的角度出发，森林能最大限度地控制土壤侵蚀，草地对土壤侵蚀的控制能力不及森林，而且能在一定程度上增加土壤侵蚀。灌丛与土壤侵蚀量和土壤侵蚀模数的关系则比较复杂，还需要进一步地研究。农用地与森林、灌丛、草地等植被类型不同，它的增加将会明显地增加产沙量。随着各景观类型（灌丛除外）分布的镶嵌性的增强，土壤侵蚀量和侵蚀模数会减少。2. 从植被景观特征与土壤侵蚀强度的相关性的角度出发，在景观水平上，植被景观的景观多样性指数、景观破碎度指数、景观形状指数和景观聚集度指数均与土壤侵蚀强度有明显的相关性。在较轻侵蚀强度的区域中的植被景观具有更丰富的多样性和更低的破碎程度，景观的组分和结构都更加复杂，景观斑块的形状也比较复杂。同时，植被景观的空间异质性也较强。3. 从不同景观类型对土壤侵蚀强度的控制能力大小看：针叶林> 落叶阔叶林>针阔混交林> 灌丛> 草地> 农用地。同时，对于除农用地以外的其他植被景观类型来说，增加其平均斑块面积和形状的复杂性会在一定程度上减少土壤侵蚀强度。而对于农用地来说，斑块形状的简单化以及分布形式的均匀镶嵌化则是减少土壤侵蚀强度的有效手段。 As a complex ecological process, soil erosion is affected by the spatial landscape heterogeneity.The relation between soil erosion and landscape characteristic weights a lot in ecosystemrestoration that aim to control the soil erosion in watershed. By means of RS and GIStechniques, this study analyzed dynamic variations in landscape characteristic and soil erosionin the Minjiang headwater region over a period of 28 years to elucidate the interrelationshipsbetween landscape characteristics and soil erosion. The results are as follows:1. In terms of relation between landscape characteristics and soil erosion module, forest canmitigate the soil erosion much better than grass. The relation between shrub and soil erosionmodule is rather complicated that requests further more study to confirm how those two factorscorrelated with each other. Cultivated land differs from other landscape classes in creatingconditions most favorable for soil erosion. Moreover, the dispersion of all landscape classes,except for shrub, correlates with soil module negatively.II2. In terms of relation between landscape characteristics and soil erosion strength, the diversityindex, fragment index, shape index and contagion index of the vegetation in Minjiangheadwater region at landscape-level correlated with soil erosion clearly. Vegetation landscapein No and Slight erosion region is more diverse, fragmental and constructed in more complexway. The shape of those vegetation patches is also more complicated. The spatial heterogeneityof the vegetation landscape is much more evident than that located in moderate and strong erosion region too.3. At class-level, different landscape classes affected soil erosion strength in different ways.Taking the mitigating effect on erosion strength into consideration, landscape classes can bearranged in this turn: coniferous forest > Deciduous forest > Mixed forest > Shrub > Grassland > Cultivated land. At the same time, for most landscape classes, except for cultivated land,increase the mean patch size and complicate the shape of patch will help to relieve the erosionstrength. However, for cultivated land, simplifying the shape of patch and scattering thepatches have the same effect.

基于电路复用结构的NIM\ECL\TTL电平适配器

In this paper,a multi-functional adapter circuit which can be used to accomplish level adaptation between the NIM,TTL,ECL levels will be described briefly.This circuit is designed based on the multiple-using structure of circuit unit.It is signal-width NIM standard module.The module is used for level adaptation between the different digital signals in the measurement system of nuclear physics experiments.中文文摘：基于单元电路复用结构,设计了NIM、ECL、TTL电平多功能适配器,介绍了电路复用结构和单元电路的设计原理。该插件用于核物理实验测量系统中不同逻辑电平的数字信号的适配与转换。

基于MSP430 单片机和DS18B20 的多分支多通道温度测量系统远程监控软件

This paper present that the system can acquire the remote temperature measurement data of 40 monitoring points,through the RS-232 serial port and the Intranet.System s hardware is consist of TI s MSP430F149 mixed-signal processor and UA7000A network module.Using digital temperature sensor DS18B20,the structure is simple and easy to expand,the sensors directly send out the temperature data.MSP430F149 has the advantage of ultra-low-power and high degree of integration.Using msp430F149,the multi-branch multi-p...中文文摘：文章论述了通过RS-232串口和Intranet网络,来实现对远端的40个温度测量点的监控。系统硬件由TI公司的MSP430F149混合信号处理器和UA7000A网络模块构成。传感器采用数字式温度传感器DS18B20,它将直接得到温度的数字量,结构简单,易于扩展。MSP430F149处理器具有超低功耗和高度集成等优点,利用它构建的多分支多通道温度测量系统功能强大,结构简单,可靠性高,抗干扰能力强。系统客户端软件采用Microsoft Visual C++6.0设计。本监控系统能够很好地完成对4个分支共40个温度测量点的远程实时监控。

Micro Insert: A Prototype Full-Ring PET Device for Improving the Image Resolution of a Small-Animal PET Scanner

A full-ring PET insert device should be able to enhance the image resolution of existing small-animal PET scanners. Methods: The device consists of 18 high-resolution PET detectors in a cylindric enclosure. Each detector contains a cerium-doped lutetium oxyorthosilicate array (12 x 12 crystals, 0.72 x 1.51 x 3.75 mm each) coupled to a position-sensitive photomultiplier tube via an optical fiber bundle made of 8 x 16 square multiclad fibers. Signals from the insert detectors are connected to the scanner through the electronics of the disabled first ring of detectors, which permits coincidence detection between the 2 systems. Energy resolution of a detector was measured using a Ge-68 point source, and a calibrated 68Ge point source stepped across the axial field of view (FOV) provided the sensitivity profile of the system. A Na-22 point source imaged at different offsets from the center characterized the in-plane resolution of the insert system. Imaging was then performed with a Derenzo phantom filled with 19.5 MBq of F-18-fluoride and imaged for 2 h; a 24.3-g mouse injected with 129.5 MBq of F-18-fluoride and imaged in 5 bed positions at 3.5 h after injection; and a 22.8-g mouse injected with 14.3 MBq of F-18-FDG and imaged for 2 h with electrocardiogram gating. Results: The energy resolution of a typical detector module at 511 keV is 19.0% +/- 3.1 %. The peak sensitivity of the system is approximately 2.67%. The image resolution of the system ranges from 1.0- to 1.8-mm full width at half maximum near the center of the FOV, depending on the type of coincidence events used for image reconstruction. Derenzo phantom and mouse bone images showed significant improvement in transaxial image resolution using the insert device. Mouse heart images demonstrated the gated imaging capability of the device. Conclusion: We have built a prototype full-ring insert device for a small-animal PET scanner to provide higher-resolution PET images within a reduced imaging FOV. Development of additional correction techniques are needed to achieve quantitative imaging with such an insert.

Study of the LED based light calibration system for neutron wall detector

The light calibration system is one of the key components of Neutron Wall detector. It is used to calibrate the electronics and to monitor the long-term stability of the detector modules. With the detaile investigations, a calibration system with high-power LED (3W) driven by the fast pulses has been carried out. It is also tested together with the detector module of the Neutron Wall and the result of the preliminary calibration demonstrates that it fulfills the needs. It's a new design proposal to the light calibration system of the fast scintillator detector.

Characteristics of the sampling paddle modules of neutron wall from the cosmic ray test

In the construction of a large area neutron detector (neutron wall) that is used to detect neutrons at GeV energies, the performances of all the sampling paddle modules prepared for the neutron wall are investigated with a specially designed test bench. Tested by cosmic rays, an average intrinsic time resolution of 222.5 ps is achieved at the center of the modules. The light attenuation length and the effective speed of the light in the module are also investigated.

多路信号处理与QDC门信号产生逻辑插件的研制

本论文描述了多路信号处理与QDC（电荷数字转换器）门信号产生逻辑插件的研制过程。该逻辑插件的逻辑电路和模拟电路都经过了精心的设计和调试。核物理研究沿着激发能、核自旋及核同位旋三个自由度深入开展，产生了核物理研究中许多新的前沿领域。随着入射能量的增加，开放的反应道增多，多重探测器投入使用，使核物理实验的数据参数已经从几十路上升到上千路，即需要电子学工作者研制和开发一些高速触发、高密度、高稳定性的电子学硬件系统。本论文描述的多路信号处理与QDC门信号产生逻辑插件，主要用于产生QDC的开门信号。该电路系统早十六路并行、独立的高速放大单元电路、高速比较单元电路、延迟和脉宽成形单元电路、逻辑信号扇出单元电路、触发指示单元电路及多路模拟信号求和单元电路构成。该逻辑插件可接收≥ 20mv的小辐度输入信号而产生32路标准ECL（高电平-0.8V，低电平-1.6V）互补输出逻辑信号。输出ECL逻辑信号用于产生QDC的门控信号。该插件的多路模拟信号求和单元电路对每路输入信号可产生幅度为50mv的输出信号。该输出信号可用于多重符衙事件的鉴别和产生trigger触发信号。总的来说，多路辐度信号处理与QDC门信号产生逻辑插件不仅适用于重离子核物理实验中产生QDC开门信号，也可用于其它核物理实验的多重符合事件的鉴别。该插件的研制成功为多参数获取系统提供了一个良发的前端硬件设备。

Direct characterization of bitter acids in a crude hop extract by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry

The applicability of on-line coupling of reversed-phase high-performance liquid chromatography to atmospheric pressure ionization tandem mass spectrometry for the separation and characterization of hop acids mixture from the crude extract of Humulus lupulus was investigated. The solvent system consisting of acetonitrile-aqueous formic acid was used to give proper separation of the six main hop bitter acids within 30 min. Further structural information about the components was acquired by collision-induced dissociation (CID). On the basis of analyses of the fragmentation patterns of the major alpha- and beta-bitter acids respectively, identification of the minor ones was performed using selected reaction monitoring (SRM) with a group of qualitatively relevant selected precursor-product ion transitions for each bitter acid in a single high performance liquid chromatography (HPLC) run. Using this technique, six minor hop acids, including "adprelupulone" observed for the first time in natural resources, were detected along with the six major acids. This hyphenated techniques provides potency for rapid qualitative determination of analogs and homologs in mixtures. (C) 2004 American Society for Mass Spectrometry.

an integrity assurance mechanism for run-time programs

Chinese Assoc Cryptol Res, State Key Lab Informat Secur, Inst Software, Grad Univ Chinese Acad Sci, Natl Nat Sci Fdn China

Copolymers derived from bismaleimide oligomer with active solvent

An oligomer from 4, 4'-bis(maleimido)diphenyl methane and methylenedianiline were dissolved in active solvent N,N-dimethyl acrylamide in a solid content up to 50-70%; the solution was poured in a sheet-shaped module and irradiated b y Co-60 with the dose from 20 to 350 kGy at room temperature. The polymerized sheet was postcured at 180degreesC to obtain a transparent red-orange sheet with tensile strength above 100 MPa. The glass transition temperature before and after postcuring was around 100degreesC and 150-180degreesC, respectively. Styrene was used along with DMAA to decrease the water absorption for the copolymers.