期刊文献+
共找到15篇文章
< 1 >
每页显示 20 50 100
基于签名与数据流模式挖掘的Android恶意软件检测系统 被引量:11
1
作者 宁卓 邵达成 +1 位作者 陈勇 孙知信 《计算机科学》 CSCD 北大核心 2017年第B11期317-321,共5页
随着Android软件开发和维护的不断增多,以及恶意软件的抗检测能力逐渐增强,主流的静态检测方法开始面临一些问题:签名检测虽然检测速度快,但是对代码混淆、重打包类的恶意软件的检测能力不强;基于数据流的检测方法虽然精度高,但检测效... 随着Android软件开发和维护的不断增多,以及恶意软件的抗检测能力逐渐增强,主流的静态检测方法开始面临一些问题:签名检测虽然检测速度快,但是对代码混淆、重打包类的恶意软件的检测能力不强;基于数据流的检测方法虽然精度高,但检测效率低。针对上述技术存在的缺点,提出了一种混合型静态检测系统。该系统改进了多级签名检测方法,通过对method与class签名进行多级匹配,提高了对代码混淆类恶意软件的检测能力。系统还改进了传统数据流分析技术,通过数据流模式挖掘,找出恶意软件频繁使用的数据流模式,省去了人工确认环节,提高了数据流分析的自动化程度与效率。两种技术的结合使得系统在检测精度与效率两方面达到一个合理的折中点。实验结果表明,该系统对于代码混淆和重打包的恶意软件具有较好的检测能力,对主流恶意软件的检测精确度达到88%。 展开更多
关键词 静态分析 Android恶意软件 签名检测 数据流模式挖掘
下载PDF
一种基于双模式虚拟机的多态Shellcode检测方法 被引量:1
2
作者 罗杨 夏春和 +2 位作者 李亚卓 魏昭 梁晓艳 《计算机研究与发展》 EI CSCD 北大核心 2014年第8期1704-1714,共11页
近年来,Shellcode攻击通常利用多态技术进行自我加密来绕过网络层设备的检测,而现有检测方法无法区分多态Shellcode与加壳保护代码.提出了一种基于双模式虚拟机的多态Shellcode检测方法,该方法改进了现有的GetPC定位机制,实现了Shellcod... 近年来,Shellcode攻击通常利用多态技术进行自我加密来绕过网络层设备的检测,而现有检测方法无法区分多态Shellcode与加壳保护代码.提出了一种基于双模式虚拟机的多态Shellcode检测方法,该方法改进了现有的GetPC定位机制,实现了Shellcode的初步定位,通过IA-32指令识别对网络流量的进行进一步过滤,利用有限自动机及其判别条件实现虚拟机控制流模式和数据流模式之间的切换,并通过结合现有的特征匹配技术实现对多层加密的多态Shellcode的检测.实验结果表明,针对大量真实的网络数据,该方法在保证高检测召回率的同时,能够实现对多态Shellcode与加壳保护软件的有效区分,避免了对正常流量的误报行为,并且时间开销介于静态分析与动态模拟之间,为网络层检测多态Shellcode提供了一种有效方法. 展开更多
关键词 多态Shellcode GetPC定位 指令识别 虚拟机 控制流模式 数据流模式 Define-Use链
下载PDF
云计算环境中的数据安全评估技术量化研究 被引量:8
3
作者 周紫熙 叶建伟 《智能计算机与应用》 2012年第4期40-43,共4页
分析了现有云计算系统中机密性的几种保护机制,并提出了一种基于数据流分析的机密性风险评估模型。通过LKM部署的监控器截获系统调用获得系统的数据流,交由评估器与服务提供的数据流模式集进行比较分析,来对服务机密性进行综合评估。实... 分析了现有云计算系统中机密性的几种保护机制,并提出了一种基于数据流分析的机密性风险评估模型。通过LKM部署的监控器截获系统调用获得系统的数据流,交由评估器与服务提供的数据流模式集进行比较分析,来对服务机密性进行综合评估。实验表明该方法能够有效识别云计算环境中破坏服务和数据机密性的行为。 展开更多
关键词 机密性 系统调用截获 数据流模式 量化评估
下载PDF
合并院校图书馆书目数据调整方式探讨 被引量:1
4
作者 喻名芝 《上海高校图书情报学刊》 2001年第2期45-46,共2页
高校合并时图书馆面临的最大困难是什么?是数以百万计的书,是这些颁发中不同的自动化系统,运用不同的加工方法编制的书目数据的整合《矛盾论》中指出,任何过程如果有多种矛盾存在的话,其中必定有一种是主要的、起决定作用的矛盾,... 高校合并时图书馆面临的最大困难是什么?是数以百万计的书,是这些颁发中不同的自动化系统,运用不同的加工方法编制的书目数据的整合《矛盾论》中指出,任何过程如果有多种矛盾存在的话,其中必定有一种是主要的、起决定作用的矛盾,因此就要用全力找出主要矛盾,抓住了这个主要矛盾,一切总是就迎刃而解了,只有解决书目数据的整合,图书馆才能在高校合并后以崭新面貌展现在高速信息网上。 展开更多
关键词 高校图书馆 合并院校图书馆 书目数据整合 图书馆自动化系统 书目数据流模式
下载PDF
基于NiosⅡ的图像采集和显示的实现 被引量:7
5
作者 罗钧 吴克松 廖红华 《电子技术应用》 北大核心 2007年第2期24-27,共4页
采用OV2610的CMOS图像传感器和26K色的TFT液晶屏,在SOPC上集成了OV2610、TFT液晶控制器和DMA控制器,实现了图像数据流的采集和显示。
关键词 DMA Avalon数据流模式 SDRAM
下载PDF
基于多核处理器的弹载嵌入式系统设计研究 被引量:5
6
作者 齐恩勇 《电子设计工程》 2013年第6期105-107,共3页
基于实现目标探测识别以及高精度目标信息测量等复杂处理算法的目的,采用单片多核DSP TMS320C6678构成弹载高速多任务实时嵌入式处理平台,通过数据流处理模式的并行软件设计方法,将系统处理任务均衡分配到各处理器内核,以实现实时并行处... 基于实现目标探测识别以及高精度目标信息测量等复杂处理算法的目的,采用单片多核DSP TMS320C6678构成弹载高速多任务实时嵌入式处理平台,通过数据流处理模式的并行软件设计方法,将系统处理任务均衡分配到各处理器内核,以实现实时并行处理,提升弹载信息处理系统的功能和性能。开展基于多核处理器的并行软件研制、充分发挥多核处理能力将成为弹载嵌入式系统软件设计的新课题。 展开更多
关键词 多核处理器 并行处理 弹载嵌入式系统 数据流模式 并行软件设计
下载PDF
应用定制可重构流水线多功能寄存器文件设计
7
作者 杜孔飞 王观武 李思昆 《信息工程期刊(中英文版)》 2015年第4期119-125,共7页
可重构流水线具有数据通路和运算部件功能可重构、灵活性高、重构开销小、支持多种数据流计算模式的特点,可显著提高数据密集型计算的效率.为了支持可重构流水线高效数据访问,设计了一种用于高速缓存的多功能寄存器文件MFRF.MFRF 采用... 可重构流水线具有数据通路和运算部件功能可重构、灵活性高、重构开销小、支持多种数据流计算模式的特点,可显著提高数据密集型计算的效率.为了支持可重构流水线高效数据访问,设计了一种用于高速缓存的多功能寄存器文件MFRF.MFRF 采用一套寄存器组设计实现了多端口寄存器文件、堆、栈等多种功能,在没有显著增加面积开销的情况下,既具有普通寄存器文件的特点又具有堆和栈的功能.实验结果表明,该多功能寄存器文件可以有效满足可重构流水线的多种数据流计算模式的需求,运行矩阵乘和FFT 算法等典型算法性能良好. 展开更多
关键词 多功能寄存器文件 可重构流水线 数据流计算模式
下载PDF
Data Flow&Transaction Mode Classification and An Explorative Estimation on Data Storage&Transaction Volume 被引量:3
8
作者 Cai Yuezhou Liu Yuexin 《China Economist》 2022年第6期78-112,共35页
The public has shown great interest in the data factor and data transactions,but the current attention is overly focused on personal behavioral data and transactions happening at Data Exchanges.To deliver a complete p... The public has shown great interest in the data factor and data transactions,but the current attention is overly focused on personal behavioral data and transactions happening at Data Exchanges.To deliver a complete picture of data flaw and transaction,this paper presents a systematic overview of the flow and transaction of personal,corporate and public data on the basis of data factor classification from various perspectives.By utilizing various sources of information,this paper estimates the volume of data generation&storage and the volume&trend of data market transactions for major economies in the world with the following findings:(i)Data classification is diverse due to a broad variety of applying scenarios,and data transaction and profit distribution are complex due to heterogenous entities,ownerships,information density and other attributes of different data types.(ii)Global data transaction has presented with the characteristics of productization,servitization and platform-based mode.(iii)For major economies,there is a commonly observed disequilibrium between data generation scale and storage scale,which is particularly striking for China.(i^v)The global data market is in a nascent stage of rapid development with a transaction volume of about 100 billion US dollars,and China s data market is even more underdeveloped and only accounts for some 10%of the world total.All sectors of the society should be flly aware of the diversity and complexity of data factor classification and data transactions,as well as the arduous and long-term nature of developing and improving relevant institutional systems.Adapting to such features,efforts should be made to improve data classification,enhance computing infrastructure development,foster professional data transaction and development institutions,and perfect the data governance system. 展开更多
关键词 Data factor data classification data transaction mode data generation&storage volume data transaction volume
下载PDF
基于混沌序列的网络异常行为检测系统设计 被引量:1
9
作者 陈锋 王斌 《微型电脑应用》 2022年第8期187-190,共4页
当前常采用大数据技术对网络中的异常行为进行检测,系统运算量较高,对设备性能占用较大,实用性较低,为此提出基于混动序列的网络异常行为检测系统设计。文章构建了网络异常行为检测系统硬件部分,包括数据采集、处理、存储分析计算及数... 当前常采用大数据技术对网络中的异常行为进行检测,系统运算量较高,对设备性能占用较大,实用性较低,为此提出基于混动序列的网络异常行为检测系统设计。文章构建了网络异常行为检测系统硬件部分,包括数据采集、处理、存储分析计算及数据可视化层,利用对网络的数据流频率模式检测分析异常行为存在的可能性。在出现疑似异常行为的情况下,使用网络突变模型计算网络的势函数突变,采用混沌序列算法对相空间网络进行分析运算,确定网络异常行为,实现网络异常行为检测。为了验证系统的有效性,开展了系统测试实验,实验结果显示,设计系统工作时对设备性能占用率较小,同时具有较高的检测准确率,因此所设计的系统存在可行性。 展开更多
关键词 网络异常行为 混沌序列 突变模型 相空间网络 数据流频率模式
下载PDF
Study on Modeling for a New FCC Technique——MIP Riser Reactor
10
作者 Duan Liangwei Zhang Lin +1 位作者 Sun Peng Weng Huixin 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第1期50-55,共6页
This research work developed a model for the MIP riser reactor using the data collected from an industrial MIP unit.Based on analysis of flow patterns in the reactor,three models were established and a comparison was ... This research work developed a model for the MIP riser reactor using the data collected from an industrial MIP unit.Based on analysis of flow patterns in the reactor,three models were established and a comparison was made on each other.The results indicated that Model Ⅲ,which was assumed a plug flow in the first reaction zone and a gas plug flow and a continuously stirred catalyst flow in the second reaction zone,was the best.The results of this research could offer an information and guidance for optimization and development of MIP unit. 展开更多
关键词 MIP reactor model lump kinetic model OLEFINS
下载PDF
Research on Architecture of Campus Mobile Library System based on Cloud Computing
11
作者 Yingpei Wang 《International Journal of Technology Management》 2013年第1期109-111,共3页
Through analysis of cloud computing and characteristics, the paper described cloud computing infrastructure architecture. Mainly discusses cloud computing advantages in the use of the library and the use should pay at... Through analysis of cloud computing and characteristics, the paper described cloud computing infrastructure architecture. Mainly discusses cloud computing advantages in the use of the library and the use should pay attention to the problem, on this basis, we propose a cloud- based library information platform construction model to analyze the basic architecture of cloud computing, cloud-depth study calculated at the library information platform and database access patterns operating mode, and cloud computing future development and application prospects. 展开更多
关键词 cloud computing mobile library information platform
下载PDF
Effects of Atomic Mixing in Inertial Confinement Fusion by Multifluid Interpenetration Mix Model
12
作者 GU Jian-Fa YE Wen-Hua 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第12期1102-1106,共5页
The effects of atomic-level rnixing are systemically investigated in a multifluid interpenetration mix model ,and results are compared with the single-fluid model's simulations and experimental data. It is shown that... The effects of atomic-level rnixing are systemically investigated in a multifluid interpenetration mix model ,and results are compared with the single-fluid model's simulations and experimental data. It is shown that increasing the model free parameter α, shock Mach number, and the initial density discontinuity makes the mix length and fraction of mixing particle increase, resulting in the lower shock temperatures compared with the results of single-fluid model without mixing. Recent high-compressibility direct-drive spherical implosions on OMEGA are simulated by the interpenetration mix modal. The calculations with atomic mixing between fuel and shell match quite well with the observations. Without considering any mixing, the calculated neutron yields and ion temperatures are overpredicted; while inclusion of the interpenetration mix model with the adjustable parameter α could fit the simulated neutron yields and ion temperatures well with experimental data. 展开更多
关键词 multifluid interpenetration mix model atomic mixing inertial confinement fusion
下载PDF
Full-Annulus Simulation of the Surge Inception in a Transonic Centrifugal Compressor 被引量:2
13
作者 I.Trébinjac E.Benichou N.Buffaz 《Journal of Thermal Science》 SCIE EI CAS CSCD 2015年第5期442-451,共10页
Full annulus simulations of the flow which develops in a transonic centrifugal compressor are performed at two stable operating points (peak efficiency and near surge) and during the path to surge. At stable conditi... Full annulus simulations of the flow which develops in a transonic centrifugal compressor are performed at two stable operating points (peak efficiency and near surge) and during the path to surge. At stable conditions, the flow field properties are analyzed by comparisons with experimental data and numerical simulations using a phase lagged approach previously carried out. Regarding the stage overall performance, an excellent agreement is obtained between the numerical results (both with time lagged approach and full-annulus calculation) and the ex- periments. From the full-annnlus simulations, the change in flow pattern from peak efficiency to surge is found to be perfectly similar to that obtained from the simulations using the time lagged approach. In particular, pro- vided that the operating point is stable, the flow proves to be chorochronic. The full-annulus simulations were continued after a unique small change in the throttle law applied at the exit of the numerical domain. The mass flow, pressure ratio and efficiency then significantly drop all the more the time progresses. The simulation becomes unstable and the surge inception well underway. The path to surge is found to be due to the enlargement of the boundary layer separation on the suction side of the diffuser vanes in accordance with the conclusions drawn from the chorochronic simulations and experiments. But as the time progresses, the flow loses its chorochronic character. Stall cells rotating at around 7% of the rotor speed develop and lead to surge in around 5 revolutions. 展开更多
关键词 centrifugal compressor SURGE transonic rotating stall full-annulus simulation URANS
原文传递
Monitoring correlative financial data streams by local pattern similarity
14
作者 Tao JIANG Yu-cai FENG +3 位作者 Bin ZHANG Zhong-sheng CAO Ge FU Jie SHI 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第7期937-951,共15页
Developing tools for monitoring the correlations among thousands of financial data streams in an online fashion can be interesting and useful work. We aimed to find highly correlative financial data streams in local p... Developing tools for monitoring the correlations among thousands of financial data streams in an online fashion can be interesting and useful work. We aimed to find highly correlative financial data streams in local patterns. A novel distance metric function slope duration distance (SDD) is proposed, which is compatible with the characteristics of actual financial data streams. Moreover, a model monitoring correlations among local patterns (MCALP) is presented, which dramatically decreases the computational cost using an algorithm quickly online segmenting and pruning (QONSP) with O(1) time cost at each time tick t, and our proposed new grid structure. Experimental results showed that MCALP provides an improvement of several orders of magnitude in performance relative to traditional naive linear scan techniques and maintains high precision. Furthermore, the model is incremental, parallelizable, and has a quick response time. 展开更多
关键词 Data mining Model Data streams Correlation Local pattern Pattern similarity
原文传递
Summer circulation structure and formation mechanism in the Beibu Gulf 被引量:6
15
作者 GAO JingSong CHEN Bo SHI MaoChong 《Science China Earth Sciences》 SCIE EI CAS CSCD 2015年第2期286-299,共14页
Due to limited in situ data and diagnostic numerical models, the summer circulation structure and formation mechanism in the Beibu Gulf have always been in controversy in the past 50 years. Therefore, a new three-dime... Due to limited in situ data and diagnostic numerical models, the summer circulation structure and formation mechanism in the Beibu Gulf have always been in controversy in the past 50 years. Therefore, a new three-dimensional hindcast model was built within the northwestern South China Sea(SCS), forced with the daily averaged wind, heat flux, lateral flux, as well as tidal harmonic and eight major rivers discharges. And the east boundary was set up far away off the Qiongzhou Strait(QS). Lastly, the model results were consistent with not only the synchronous observation data from the project 908 but also the historical observed data. As a result, the summer circulation structure was revealed that the southern Gulf was occupied by an anticyclonic eddy whereas the northern Gulf was dominated by a cyclonic gyre. Although the circulation major structure was stable, its area and strength had yearly and monthly oscillation. The other three sensitive experiments indicated that the circulations in the southern and northern Gulf were driven by the SCS circulation and monsoon wind, respectively. After the theoretical analysis of the potential vorticity budget, it was further revealed the circulation in the northern Gulf was driven by the positive wind stress curl in summer. Besides, the river discharge was also significant as the vertical circulation had two layer structures outside the mouth of the Red River. Generally, this work calls for the further research on other subjects, such as ocean biogeochemical or marine fisheries. 展开更多
关键词 vorticity yearly monsoon budget tidal northwestern historical averaged ocean dominated
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部