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Scalable single sign-on system 被引量:2
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作者 黄河 单志广 黄冬泉 《Journal of Southeast University(English Edition)》 EI CAS 2007年第3期465-468,共4页
To address the scalability and identity federation problems of the traditional single sign-on system, the proposed scheme divides the security systems into different security domains. Each security domain has its own ... To address the scalability and identity federation problems of the traditional single sign-on system, the proposed scheme divides the security systems into different security domains. Each security domain has its own security servers and service providers, and there are trust relationships between different security domains for identity federation. The security server is responsible for authentication and authorization inside the domain, and offers identity federation capability for different domains. The security assertion markup language (SAML) assertion is used as security token in the system for authentication, authorization, and identity federation. The design of the proposed single sign-on process is based on web service security framework and multiple security domains, and the authorization is always deployed in the local area inside the service provider' s security domain, which enables web service clients, both inside and outside their security domains, to access the services in a simple, scalable, standard and secure way. 展开更多
关键词 security systems ARCHITECTURE web service single sign-on identity federation
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Construction of Land Resource Security System for Core Grain Production Region in Henan Province 被引量:1
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作者 杨建波 卫华鹏 +1 位作者 王莉 邵红旗 《Agricultural Science & Technology》 CAS 2017年第12期2435-2439,共5页
To solve the contradiction between supply and demand of land, the con- struction of land resource security guarantee system is an important part to coordi- nate the economic development and cultivated land protection ... To solve the contradiction between supply and demand of land, the con- struction of land resource security guarantee system is an important part to coordi- nate the economic development and cultivated land protection in the core grain pro- duction region. Based on the deep analysis on the land resources characteristics and problems using the combined method of literature review method with qualita- tive and quantitative analysis, we constructed the land resource security system for different categories according to the land use principles of optimization, intensivism, improvement, and overall planning, and proposed the corresponding supporting mea- sures. The results showed that controlling the new increase, promoting the reclama- tion and improvement of land are the basis for land resource security, clearing the idle, improving the utilization rate of stock are the core of the efficient use of land resources, and establishing a unified urban and rural construction land market is the key to promoting the economical and intensive utilization of land resources, provid- ing scientific basis for the sustainable utilization of land resources in the core grain production regions. 展开更多
关键词 core grain production region Land resources Security system Con-struction
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Security of Application System 被引量:1
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作者 李小平 钟宏 +5 位作者 丁俨 向智 胡海生 吴学林 张琦 朱建学 《Journal of Beijing Institute of Technology》 EI CAS 2002年第2期198-202,共5页
A safe and reliable application system frame based on Internet and Intranet for Stock Supervision and Administration Council of China is built up. An all sided, multi tier and multi technical security method has be... A safe and reliable application system frame based on Internet and Intranet for Stock Supervision and Administration Council of China is built up. An all sided, multi tier and multi technical security method has been adopted, which includes identity recognition, data encryption, digital signature, Domino and WWW servers, access control list, directory service, certificate authorization server, IC card and so on. The recognition system based on CA server is a high efficient, convenient and reliable system. The encryption technology and security method are proved to be reliable. The recognition system is of high security and is worthy of being popularized in some places where some special security requirements need meeting. Multi tier technology can improve the security of database. Double keys method is a useful data encryption method. 展开更多
关键词 INTERNET/INTRANET identity recognition data encryption digital signature security mechanism
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Determination and Analysis of Mitochondrial ND2 Gene Sequence of Anas platyrhynchos 被引量:4
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作者 涂剑锋 司方方 +1 位作者 邢秀梅 杨福合 《Agricultural Science & Technology》 CAS 2009年第3期46-49,共4页
[Objective] The study was to analyze the phylogenesis of Anas platyrhynchos. [Method] Complete sequence of mitochondrial ND2 gene of 4 Anas platyrhynchos was determined by direct DNA sequencing based on PCR products. ... [Objective] The study was to analyze the phylogenesis of Anas platyrhynchos. [Method] Complete sequence of mitochondrial ND2 gene of 4 Anas platyrhynchos was determined by direct DNA sequencing based on PCR products. Combined with ND2 gene sequences of the Anas Linnaeus accessed in GenBank, phylogenetic tree was constructed by Neighbor-joining and maximum parsimony methods. [Result] The ND2 gene sequences of 4 Anas platyrhynchos were identical(1 041 bp in length; the nucleotide contents of A, G, T, and C were 28.91%, 13.35%, 20.75% and 36.98% respectively; A+T content approximated to that of C+G). Sequences of ND2 gene of mallard were same as spotbill duck, and had high homology with others. The phylogenetic trees indicated mallard and spotbilled duck were close in genetic relationship, both shared a haplotype; then Philippine duck, green-winged teal and northern pintail fell into branch ''A". [Conclusion] The domestic duck may be domesticated from mallard and spotbilled duck. 展开更多
关键词 Anas platyrhynchos ND2 gene sequence analysis Phylogenetic tree
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All-Optical Sampling Using Nonlinear Polarization Rotation in a Single Semiconductor Optical Amplifier 被引量:2
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作者 张尚剑 张谦述 +2 位作者 李和平 刘永智 刘永 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第6期1031-1035,共5页
We propose a novel all-optical sampling method using nonlinear polarization rotation in a semiconductor optical amplifier. A rate-equation model capable of describing the all-optical sampling mechanism is presented in... We propose a novel all-optical sampling method using nonlinear polarization rotation in a semiconductor optical amplifier. A rate-equation model capable of describing the all-optical sampling mechanism is presented in this paper. Based on this model, we investigate the optimized operating parameters of the proposed system by simulating the output intensity of the probe light as functions of the input polarization angle, the phase induced by the polarization controller, and the ori- entation of the polarization beam splitter. The simulated results show that we can obtain a good linear slope and a large linear dynamic range,which is suitable for all-optical sampling. The operating power of the pump light can be less than lmW. The presented all-optical sampling method can potentially operate at a sampling rate up to hundreds GS/s and needs low optical power. 展开更多
关键词 optical signal processing all-optical sampling semiconductor optical amplifier nonlinear polarization rotation
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Genetic Analysis of a Biomass Mutant in Oryza sativa 被引量:12
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作者 廖子荣 黄东益 +2 位作者 牛杰 李俏 吴安迪 《Agricultural Science & Technology》 CAS 2008年第2期63-66,共4页
[ Objective ] The study aimed to reveal the genetic model of a biomass mutant in Oryza sativa. [ Method ] In the process of screening and identification of Bar-transgenic rice, a biomass mutant was found in 10 lines o... [ Objective ] The study aimed to reveal the genetic model of a biomass mutant in Oryza sativa. [ Method ] In the process of screening and identification of Bar-transgenic rice, a biomass mutant was found in 10 lines of T1 progenies. The mutant was investigated for genetic analysis and agronomic traits by herbicide spraying and PCR amplification. [ Result] The segregation ratio is consistent with mendelian law(3:1). The mutant assumed not only higher plant height, wider straw and earlier florescence, but also more tillers, bigger spikes and resultantly higher biomass. PCR detections indicated that no co-segregation was observed between mutant traits and target gene(Bar) in the T-DNA inserted, proving that the mutant is not caused by the insertion of T-DNA containing target gene (Bar). [ Conclusion] Our study may avail to understand the cloning of mutant gene and the mechanism of the mutant gene on biomass. 展开更多
关键词 Oryza sativa BIOMASS MUTANT Genetic analysis
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Cloning of the Full-length Gene for Tobacco Ethylene Receptor NTHK2 and Characterization of Its Kinase Domain 被引量:2
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作者 张志刚 巩燕 +4 位作者 何新建 王玉军 孙仲序 张劲松 陈受宜 《Acta Botanica Sinica》 CSCD 2003年第1期68-72,共5页
Previously the partial sequence of an ethylene receptor gene NTHK2 was isolated from tobacco (Nicotiana tabacum L. var. Xanthi) plants and it was wound and drought inducible. In the present study full-length cDNA of N... Previously the partial sequence of an ethylene receptor gene NTHK2 was isolated from tobacco (Nicotiana tabacum L. var. Xanthi) plants and it was wound and drought inducible. In the present study full-length cDNA of NTHK2 was cloned by 5'-RACE method. NTHK2 gene has 3 216 bp, with 509 bp of 5'-non-coding region and 427 lip of 3'-non-coding region, and encodes an ethylene-receptor homolog of 760, amino acids. NTHK2 protein has a putative signal peptide, three transmembrane domains, a histidine kinase domain and a receiver domain. In the putative histidine kinase domain, the histidine at the phosphorylation site was replaced by an asparagine. To study the biochemical property of NTHK2, its kinase domain was expressed as a fusion protein with glutathione S-transferase (GST) using yeast Schizzosaccharomyces pombe as an expression system. In vitro kinase assay showed that NTHK2 kinase domain can autophosphorylate in the presence of Mg2+, indicating that NTHK2 may function as a kinase. Further studies will elucidate the function of NTHK2 in plant. 展开更多
关键词 5 '-RACE NTHK2 kinase activity ethylene-receptor
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Light Simplified Millet Production Technique Adopting Film Mulching and Hole Sowing
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作者 李顺国 刘猛 +6 位作者 宋世佳 程汝宏 赵宇 任晓利 刘斐 南春梅 夏雪岩 《Agricultural Science & Technology》 CAS 2016年第4期887-889,905,共4页
In order to solve the problem that dry-land foxtail millet production completely relies on rainwater with low instable yield and tedious cultivation, Millet Research Institute of Hebei Academy of Agriculture and Fores... In order to solve the problem that dry-land foxtail millet production completely relies on rainwater with low instable yield and tedious cultivation, Millet Research Institute of Hebei Academy of Agriculture and Forestry Sciences integrated a light simplified production technique integrating film mulching, hole sowing and fertilization with mechanized production, forming the light simplified foxtail millet production technique adopting film mulching and hole sowing. This study introduced the light simplified foxtail millet production technique adopting film mulching and hole sowing, including main links such as preparation before sowing, sowing, attached agricultural machines, field management, harvest and residual film recovery. 展开更多
关键词 Foxtail millet Integrated film mulching Hole sowing and fertilization SIMPLIFICATION
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Complete Mitochondrial Genome of the Red Fox (Vuples vuples) and Phylogenetic Analysis with Other Canid Species 被引量:4
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作者 钟华明 张洪海 +2 位作者 沙未来 张承德 陈玉才 《Zoological Research》 CAS CSCD 北大核心 2010年第2期122-130,共9页
The whole mitochondrial genome sequence of red fox (Vuples vuples) was determined. It had a total length of 16 723 bp. As in most mammal mitochondrial genome, it contained 13 protein coding genes, two ribosome RNA g... The whole mitochondrial genome sequence of red fox (Vuples vuples) was determined. It had a total length of 16 723 bp. As in most mammal mitochondrial genome, it contained 13 protein coding genes, two ribosome RNA genes, 22 transfer RNA genes and one control region. The base composition was 31.3% A, 26.1% C, 14.8% G and 27.8% T, respectively. The codon usage of red fox, arctic fox, gray wolf, domestic dog and coyote followed the same pattern except for an unusual ATT start codon, which initiates the NADH dehydrogenase subunit 3 gene in the red fox. A long tandem repeat rich in AC was found between conserved sequence block 1 and 2 in the control region. In order to confirm the phylogenetic relationships of red fox to other canids, phylogenetic trees were reconstructed by neighbor-joining and maximum parsimony methods using 12 concatenated heavy-strand protein-coding genes. The result indicated that arctic fox was the sister group of red fox and they both belong to the red fox-like clade in family Canidae, while gray wolf, domestic dog and coyote belong to wolf-like clade. The result was in accordance with existing phylogenetic results. 展开更多
关键词 Red fox Mitochondrial genome CANIDAE Phylogenetic analysis
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Simulation of a Double-Gate Dynamic Threshold Voltage Fully Depleted Silicon-on-Insulator nMOSFET
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作者 毕津顺 吴峻峰 海潮和 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第1期35-40,共6页
A novel planar DGDT FDSOI nMOSFET is presented, and the operation mechanism is discussed. The device fabrication processes and characteristics are simulated with Tsuprem 4 and Medici. The back-gate n-well is formed by... A novel planar DGDT FDSOI nMOSFET is presented, and the operation mechanism is discussed. The device fabrication processes and characteristics are simulated with Tsuprem 4 and Medici. The back-gate n-well is formed by implantation of phosphorus at a dosage of 3 × 10^13 cm^-2 and an energy of 250keV and connected directly to a front-gate n^+ polysilicon. This method is completely compatible with the conventional bulk silicon process. Simulation results show that a DGDT FDSOI nMOSFET not only retains the advantages of a conventional FDSOI nMOSFET over a partially depleted (PD) SOI nMOSFET--that is the avoidance of anomalous subthreshold slope and kink effects but also shows a better drivability than a conventional FDSOI nMOSFET. 展开更多
关键词 double-gate structure dynamic threshold FDSOI NMOSFET
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Neural Network Ensemble Residual Kriging Application for Spatial Variability of Soil Properties 被引量:37
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作者 SHENZhang-Quan SHIJie-Bin +2 位作者 WANGKe KONGFan-Sheng J.S.BAILEY 《Pedosphere》 SCIE CAS CSCD 2004年第3期289-296,共8页
High quality, agricultural nutrient distribution maps are necessary for precision management, but depend on initial soil sample analyses and interpolation techniques. To examine the methodologies for and explore the c... High quality, agricultural nutrient distribution maps are necessary for precision management, but depend on initial soil sample analyses and interpolation techniques. To examine the methodologies for and explore the capability of interpolating soil properties based on neural network ensemble residual kriging, a silage field at Hayes, Northern Ireland, UK, was selected for this study with all samples being split into independent training and validation data sets. The training data set, comprised of five soil properties: soil pH, soil available P, soil available K, soil available Mg and soil available S,was modeled for spatial variability using 1) neural network ensemble residual kriging, 2) neural network ensemble and 3) kriging with their accuracies being estimated by means of the validation data sets. Ordinary kriging of the residuals provided accurate local estimates, while final estimates were produced as a sum of the artificial neural network (ANN)ensemble estimates and the ordinary kriging estimates of the residuals. Compared to kriging and neural network ensemble,the neural network ensemble residual kriging achieved better or similar accuracy for predicting and estimating contour maps. Thus, the results demonstrated that ANN ensemble residual kriging was an efficient alternative to the conventional geo-statistical models that were usually used for interpolation of a data set in the soil science area. 展开更多
关键词 KRIGING neural networks ensemble RESIDUAL soil properties SPATIALVARIABILITY
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MP-WFRFT and Constellation Scrambling Based Physical Layer Security System 被引量:29
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作者 FANG Xiaojie SHA Xuejun LI Yue 《China Communications》 SCIE CSCD 2016年第2期138-145,共8页
In this paper, a multiple parameters weighted fractional Fourier transform(MPWFRFT) and constellation scrambling(CS) method based physical layer(PHY) security system is proposed. The proposed scheme is executed by two... In this paper, a multiple parameters weighted fractional Fourier transform(MPWFRFT) and constellation scrambling(CS) method based physical layer(PHY) security system is proposed. The proposed scheme is executed by two steps. In the first step, MPWFRFT, implemented as the constellation beguiling(CB) method, is applied to change the signal's identity. In the second step the additional pseudo random phase information, regarded as the encryption key, is attached to the original signal to enhance the security. Typically, the pseudo random phase information can be removed effectively by the legitimate receiver. In contrast to the cryptography based encryption algorithms and the conventional PHY secrecy techniques, the main contribution of the proposed scheme is concentrated on the variation in signal's characteristics. Simulation results show that the proposed scheme can prevent the exchanging signal from eavesdroppers' classifi cation or inception. Moreover, the proposed scheme can guarantee the BER performance at a tolerate increasing in computational complexity for the legitimate receivers. 展开更多
关键词 weighted fractional Fourier transform(WFRFT) physical layer (PHY) security secrecycapacity
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SDSA: A Framework of a Software-Defi ned Security Architecture 被引量:3
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作者 LIU Yanbing LU Xingyu +1 位作者 JIAN Yi XIAO Yunpeng 《China Communications》 SCIE CSCD 2016年第2期178-188,共11页
The fact that the security facilities within a system are closely coupled and the security facilities between systems are unconnected results in an isolated protection structure for systems, and gives rise to a seriou... The fact that the security facilities within a system are closely coupled and the security facilities between systems are unconnected results in an isolated protection structure for systems, and gives rise to a serious challenge to system security integrations and system controls. Also, the need for diversified services and flexible extensions of network security asks for more considerations and contribu?tions from the perspective of software engineering in the process of designing and constructing security systems. Based on the essence of the virtualization technique and the idea of software-defined networks, we in this paper propose a novel software-defi ned security architecture for systems. By abstracting the traditional security facilities and techniques, the proposed security architecture provides a new, simple, effective, and programmable framework in which security operations and security controls can be decoupled, and thereby reduces the software module sizes, decreases the intensity of software deve?lopments, and improves the security extensibility of systems. 展开更多
关键词 information security networksecurity security architecture software-definedsecurity
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Adsorption and desorption on coals for CO_2 sequestration 被引量:3
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作者 WANG Zuo-tang FU Zhen-kun +3 位作者 ZHANG Bang-an WANG Guo-xiong RUDOLPH Victor HUO Li-wen 《Mining Science and Technology》 EI CAS 2009年第1期8-13,共6页
Adsorption and desorption of carbon dioxide, methane and other gases on coals has been investigated experimentally using representative Zhongliangshan coals. Gas adsorption is one of the major concerns for both CO2 se... Adsorption and desorption of carbon dioxide, methane and other gases on coals has been investigated experimentally using representative Zhongliangshan coals. Gas adsorption is one of the major concerns for both CO2 sequestration and methane recovery processes. The experiments were carried out using both single and multi-component mixtures at 25 ℃ and 30 ℃ with the highest pressure of 12 MPa. The coal was under moisture equilibrated conditions. This provides experimental data from which a predictive assessment of CO2 sequestration and/or methane recovery can be conducted. The results show that for pure gasses the CH4 adsorption capacity is higher than the N2 adsorption capacity but lower than the CO2 adsorption capacity. Injection of CO2 or other gases into the coal significantly affects CH4 desorption. This allows the enhancement of CH4 recovery from the coals, thus supplying more clean energy while sequestering significant amounts of CO2 thereby reducing the greenhouse effect from human beings. 展开更多
关键词 MULTI-COMPONENT CO2 sequestration greenhouse gas
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Challenges and Solutions of Information Security Issues in the Age of Big Data 被引量:6
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作者 YANG Mengke ZHOU Xiaoguang +1 位作者 ZENG Jianqiu XU Jianjian 《China Communications》 SCIE CSCD 2016年第3期193-202,共10页
Big data has been taken as a Chinese national strategy in order to satisfy the developments of the social and economic requirements and the development of new information technology. The prosperity of big data brings ... Big data has been taken as a Chinese national strategy in order to satisfy the developments of the social and economic requirements and the development of new information technology. The prosperity of big data brings not only convenience to people's daily life and more opportunities to enterprises, but more challenges with information security as well. This paper has a research on new types and features of information security issues in the age of big data, and puts forward the solutions for the above issues: build up the big data security management platform, set up the establishment of information security system and implement relevant laws and regulations. 展开更多
关键词 information security big data data privacy information technology
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LAPAROSCOPIC SURGERY IN PATIENTS WITH HYPOVOLEMIC SHOCK DUE TO ECTOPIC PREGNANCY 被引量:7
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作者 Zhi-gangLi Jin-huaLeng +3 位作者 Jing-heLang Zhu-fengLiu Da-weiSun ZhuLan 《Chinese Medical Sciences Journal》 CAS CSCD 2005年第1期40-43, ,共4页
Objective To evaluate the feasibility and safety of operative laparoscopy for ectopic pregnancy with hypovolemic shock. Methods Two hundred and fifteen women with ectopic pregnancy underwent operative laparoscopy. The... Objective To evaluate the feasibility and safety of operative laparoscopy for ectopic pregnancy with hypovolemic shock. Methods Two hundred and fifteen women with ectopic pregnancy underwent operative laparoscopy. These patients were divided into two groups. The study group included 21 patients with shock and intraperitoneal hemorrhage more than 1000 mL, and control group included 194 patients, hemodynamically stable, with blood loss less than 1000 mL. Clinical data of perio-perative periods in two groups were retrospectively analyzed. Results All patients were tubal pregnancies. The occurrence rate of tubal rupture was higher in study group than in control group (80.95% vs. 15.98%, P < 0.001). Intraabdominal blood loss was significantly higher in study group than in control group (1900 mL vs. 300 mL, P < 0.001), and autologous blood transfusions were given to 95.24% and 9.3% of patients in study and control group, respectively (P < 0.001). Laparoscopic salpingectomy was performed on 85.7 % and 50.5% of patients in study and control group (P < 0.001). The operative time was somewhat longer in study group than that in control group (60 minutes vs. 45 minutes), but with no significant difference. All patients had no perioperative complications. Conclusion Operative laparoscopy in patients with hopovolemic shock can be safely and effectively performed by experi-enced laparoscopists with the aid of optimal anesthesia, advanced cardiovascular monitoring, and autologous blood transfusion. 展开更多
关键词 laparoscopic surgery ectopic pregnancy hypovolemic shock gynecologic surgical procedures
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Digital Signatures for e-Government - a Long-Term Security Architecture 被引量:1
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作者 Przemyslaw Blaskiewicz Przemyslaw Kubiak Miroslaw Kutylowski 《China Communications》 SCIE CSCD 2010年第6期64-70,共7页
The framework of digital signature based on qualified certificates and X. 509 architecture is known to have many security risks. Moreover, the fraud prevention mechanism is fragile and does not provide strong guarante... The framework of digital signature based on qualified certificates and X. 509 architecture is known to have many security risks. Moreover, the fraud prevention mechanism is fragile and does not provide strong guarantees that can be necessary for flow of legal documents. Mediated signatures have been proposed as a mechanism to effectively disable signature cards. In this paper we propose further mechanisms that can be applied on top of mediated RSA, compatible with the standard format, but providing security guarantees even in the case when RSA becomes broken or the keys are compromised. The solution is immune tokleptographic attacks as only deterministic algorithms are used on user's side. 展开更多
关键词 MRSA PSS padding hash based signatures kleptography deterministic signatures
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Simulation of long-distance pipeline transportation properties of whole-tailings paste with high sliming 被引量:18
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作者 WU Ai-xiang RUAN Zhu-en +4 位作者 WANG Yi-ming YIN Sheng-hua WANG Shao-yong WANG Yong WANG Jian-dong 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第1期141-150,共10页
Based on Bingham rheological model,a three-dimensional numerical simulation model for long-distance pipeline transportation is established by computational fluid dynamics(CFD)to study the pipeline transportationproper... Based on Bingham rheological model,a three-dimensional numerical simulation model for long-distance pipeline transportation is established by computational fluid dynamics(CFD)to study the pipeline transportationproperties of high sliming paste from a copper mine in China.Based on the rheological properties test,the pressure and velocity of pipeline and elbow are simulated by CFD under different mass concentrations and different stowing capacities.The results show that the pipeline resistance of whole-tailings paste with high sliming while without pumping agent is much higher than that with high sliming and pumping agent at the same mass concentration,and the pipeline resistance of whole-tailings paste with high sliming while without pumping agent is much higher than that with low sliming while without pumping agent.It is very important to add pumping agent to whole-tailings paste with high sliming,and the resistance changes with mass concentration and stowing capacity at the same cement-to-sand ratio of1:5and tailings-to-waste ratio of6:1.However,the change is just limited,that is to say,the paste transportation system is of good stability.Furthermore,at the elbow,the maximum pressure and velocity transfer to the outside of the pipe from the inside.However,lubricating layer is formed at the pipe wall because of high content of fine particles in whole-tailings paste,which will protect the elbow from abrasion.CFD provides an intuitive and accurate basis for pipeline transportation study,and would have a wider application space in the study of paste rheological properties and resistance reduction methods. 展开更多
关键词 whole-tailings paste long-distance transportation computational fluid dynamics
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Effects of temperatures and pH values on rheological properties of cemented paste backfill 被引量:9
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作者 ZHANG Qin-li LI Yi-teng +3 位作者 CHEN Qiu-song LIU Yi-kai FENG Yan WANG Dao-lin 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第6期1707-1723,共17页
In this study,different influence mechanisms associated with temperatures and pH values were investigated through cemented paste backfill(CPB)systems.CPB samples were prepared with temperatures ranging from 10 to 50℃... In this study,different influence mechanisms associated with temperatures and pH values were investigated through cemented paste backfill(CPB)systems.CPB samples were prepared with temperatures ranging from 10 to 50℃ in 10℃ increments and pH values of 3,7,and 13.Then,the CPB mixture were subjected to rheological tests,thermogravimetric analysis(TG),derivative thermogravimetry analysis(DTG),Fourier-transform infrared spectroscopy(FT-IR),and scanning electron microscopy(SEM).Results demonstrated that the temperatures had significant effects on the rheological properties of CPB,whereas the effects of pH values were relatively unapparent.Higher temperatures(over 20℃)were prone to bring higher shear stress,yield stress,and apparent viscosity with the same pH value condition.However,an overly high temperature(50℃)cannot raise the apparent viscosity.Non-neutral conditions,for pH values of 3 and 13,could strengthen the shear stress and apparent viscosity at the same temperature.Two different yield stress curves could be discovered by uprising pH values,which also led to apparent viscosity of two various curves under the same temperatures(under 50℃).Microscopically,rheological properties of CPB were affected by temperatures and pH values which enhanced or reduced the cement hydration procedures,rates,products and space structures. 展开更多
关键词 cemented paste backfill(CPB) rheological properties TEMPERATURES pH values cement hydration microscopic analysis
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SGuard:A Lightweight SDN Safe-Guard Architecture for DoS Attacks 被引量:10
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作者 Tao Wang Hongchang Chen 《China Communications》 SCIE CSCD 2017年第6期113-125,共13页
Software Defined Networking(SDN) is a revolutionary networking paradigm towards the future network,experiencing rapid development nowadays.However,its main characteristic,the separation of control plane and data plane... Software Defined Networking(SDN) is a revolutionary networking paradigm towards the future network,experiencing rapid development nowadays.However,its main characteristic,the separation of control plane and data plane,also brings about new security challenges,i.e.,Denial-of-Service(DoS) attacks specific to Open Flow SDN networks to exhaust the control plane bandwidth and overload the buffer memory of Open Flow switch.To mitigate the DoS attacks in the Open Flow networks,we design and implement SGuard,a security application on top of the NOX controller that mainly contains two modules:Access control module and Classification module.We employ novel six-tuple as feature vector to classify traffic flows,meanwhile optimizing classification by feature ranking and selecting algorithms.All the modules will cooperate with each other to complete a series of tasks such as authorization,classification and so on.At the end of this paper,we experimentally use Mininet to evaluate SGuard in a software environment.The results show that SGuard works efficiently and accurately without adding more overhead to the SDN networks. 展开更多
关键词 sguard software defined networking denial-of-service attack security application
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