某型导弹技术准备过程具有涉及操作人员多,人员间以及人与设备之间交互多的特点,系统级的安全性分析结果表明,人为致因因素是导致安全问题的重要因素。因此,文章研究了一种基于行为模型的人因安全性分析方法(Extended STPA with Behavio...某型导弹技术准备过程具有涉及操作人员多,人员间以及人与设备之间交互多的特点,系统级的安全性分析结果表明,人为致因因素是导致安全问题的重要因素。因此,文章研究了一种基于行为模型的人因安全性分析方法(Extended STPA with Behaviour Model,BME-STPA)。BME-STPA方法基于行为模型思想,对STPA控制器模型进行扩展,使其更加适用于人为致因因素分析,解决了STPA方法对人因安全性分析针对性不强的问题,具有较强的可操作性。以导弹加注过程中溢出灌增压作为BME-STPA的应用案例,证明了该方法的实用性和有效性。展开更多
Presents a series of new concepts and design ideas about the fuze safety system, establishing thereby a proposed theory and relevant mathematical descriptions. The basic the- ory indicates that any fuze safety system ...Presents a series of new concepts and design ideas about the fuze safety system, establishing thereby a proposed theory and relevant mathematical descriptions. The basic the- ory indicates that any fuze safety system is a physical system comprising finite safety ele- ments each of which can independently affect the system's states, and the arming process is a dynamic one in which the extent of safety of the system changes only gradually. The theory and method can be used to analyse the arming process and to guide the development of fuze safety systems.展开更多
With the rapid development of location-aware devices such as smart phones,Location-Based Services(LBSs) are becoming increasingly popular. Users can enjoy convenience by sending queries to LBS servers and obtaining se...With the rapid development of location-aware devices such as smart phones,Location-Based Services(LBSs) are becoming increasingly popular. Users can enjoy convenience by sending queries to LBS servers and obtaining service information that is nearby.However, these queries may leak the users' locations and interests to the un-trusted LBS servers, leading to serious privacy concerns. In this paper, we propose a Privacy-Preserving Pseudo-Location Updating System(3PLUS) to achieve k-anonymity for mobile users using LBSs. In 3PLUS, without relying on a third party, each user keeps pseudo-locations obtained from both the history locations and the encountered users, and randomly exchanges one of them with others when encounters occur. As a result, each user's buffer is disordered. A user can obtain any k locations from the buffer to achieve k-anonymity locally. The security analysis shows the security properties and our evaluation results indicate that the user's privacy is significantly improved.展开更多
Dependability analysis is an important step in designing and analyzing safety computer systems and protection systems.Introducing multi-processor and virtual machine increases the system faults' complexity,diversi...Dependability analysis is an important step in designing and analyzing safety computer systems and protection systems.Introducing multi-processor and virtual machine increases the system faults' complexity,diversity and dynamic,in particular for software-induced failures,with an impact on the overall dependability.Moreover,it is very different for safety system to operate successfully at any active phase,since there is a huge difference in failure rate between hardware-induced and softwareinduced failures.To handle these difficulties and achieve accurate dependability evaluation,consistently reflecting the construct it measures,a new formalism derived from dynamic fault graphs(DFG) is developed in this paper.DFG exploits the concept of system event as fault state sequences to represent dynamic behaviors,which allows us to execute probabilistic measures at each timestamp when change occurs.The approach automatically combines the reliability analysis with the system dynamics.In this paper,we describe how to use the proposed methodology drives to the overall system dependability analysis through the phases of modeling,structural discovery and probability analysis,which is also discussed using an example of a virtual computing system.展开更多
文摘某型导弹技术准备过程具有涉及操作人员多,人员间以及人与设备之间交互多的特点,系统级的安全性分析结果表明,人为致因因素是导致安全问题的重要因素。因此,文章研究了一种基于行为模型的人因安全性分析方法(Extended STPA with Behaviour Model,BME-STPA)。BME-STPA方法基于行为模型思想,对STPA控制器模型进行扩展,使其更加适用于人为致因因素分析,解决了STPA方法对人因安全性分析针对性不强的问题,具有较强的可操作性。以导弹加注过程中溢出灌增压作为BME-STPA的应用案例,证明了该方法的实用性和有效性。
文摘Presents a series of new concepts and design ideas about the fuze safety system, establishing thereby a proposed theory and relevant mathematical descriptions. The basic the- ory indicates that any fuze safety system is a physical system comprising finite safety ele- ments each of which can independently affect the system's states, and the arming process is a dynamic one in which the extent of safety of the system changes only gradually. The theory and method can be used to analyse the arming process and to guide the development of fuze safety systems.
基金supported by the National Natural Science Foundation of China under Grants No.61003300,No.61272457the Fundamental Research Funds for the Central Universities under Grant No.K5051201041the China 111 Project under Grant No.B08038
文摘With the rapid development of location-aware devices such as smart phones,Location-Based Services(LBSs) are becoming increasingly popular. Users can enjoy convenience by sending queries to LBS servers and obtaining service information that is nearby.However, these queries may leak the users' locations and interests to the un-trusted LBS servers, leading to serious privacy concerns. In this paper, we propose a Privacy-Preserving Pseudo-Location Updating System(3PLUS) to achieve k-anonymity for mobile users using LBSs. In 3PLUS, without relying on a third party, each user keeps pseudo-locations obtained from both the history locations and the encountered users, and randomly exchanges one of them with others when encounters occur. As a result, each user's buffer is disordered. A user can obtain any k locations from the buffer to achieve k-anonymity locally. The security analysis shows the security properties and our evaluation results indicate that the user's privacy is significantly improved.
基金This work was supported in part by National Natural Science Foundation of China under grant No.61272411 and National 973 Basic Research Program of China under grant No.2014CB340600
文摘Dependability analysis is an important step in designing and analyzing safety computer systems and protection systems.Introducing multi-processor and virtual machine increases the system faults' complexity,diversity and dynamic,in particular for software-induced failures,with an impact on the overall dependability.Moreover,it is very different for safety system to operate successfully at any active phase,since there is a huge difference in failure rate between hardware-induced and softwareinduced failures.To handle these difficulties and achieve accurate dependability evaluation,consistently reflecting the construct it measures,a new formalism derived from dynamic fault graphs(DFG) is developed in this paper.DFG exploits the concept of system event as fault state sequences to represent dynamic behaviors,which allows us to execute probabilistic measures at each timestamp when change occurs.The approach automatically combines the reliability analysis with the system dynamics.In this paper,we describe how to use the proposed methodology drives to the overall system dependability analysis through the phases of modeling,structural discovery and probability analysis,which is also discussed using an example of a virtual computing system.
