Windows 32/64位代码注入攻击是恶意软件常用的攻击技术,在内存取证领域,现存的代码注入攻击检测技术在验证完整性方面不能处理动态内容,并且在解析内存中数据结构方面无法兼容不同版本的Windows系统。因此提出了通过交叉验证进程堆栈和...Windows 32/64位代码注入攻击是恶意软件常用的攻击技术,在内存取证领域,现存的代码注入攻击检测技术在验证完整性方面不能处理动态内容,并且在解析内存中数据结构方面无法兼容不同版本的Windows系统。因此提出了通过交叉验证进程堆栈和VAD信息定位注入代码方法,将基于遍历栈帧得到的函数返回地址、模块名等信息结合进程VAD结构来检测函数返回地址、匹配文件名以定位注入代码,并且研发了基于Volatility取证框架的Windows代码注入攻击检测插件codefind。测试结果表明,即使在VAD节点被恶意软件修改,方法仍能够有效定位Windows 32/64位注入代码攻击。展开更多
According to the investigations of window opening percentage (WOP) of Shanghai in 2011, the WOP varies significantly from season to season and thus affects the air flow rate of natural ventilation rooms. A three-dimen...According to the investigations of window opening percentage (WOP) of Shanghai in 2011, the WOP varies significantly from season to season and thus affects the air flow rate of natural ventilation rooms. A three-dimensional computional fluid dynamic(CFD) model was applied to simulating the flow fields in a street canyon under different wind speed and WOP. The numerical simulations show that WOP has a significant influence on the static pressure distribution of the downwind building. Therefore, a correction factor k can be used for calculating the flow rate of wind-driven natural ventilation. The results show that k ranges from 0.43 to 0.49 when WOP is 4.44%; when WOP increases to 9.78%, the correction factor k lies in 0.32 and 0.36.展开更多
This paper addresses the open vehicle routing problem with time window(OVRPTW), where each vehicle does not need to return to the depot after completing the delivery task.The optimization objective is to minimize the ...This paper addresses the open vehicle routing problem with time window(OVRPTW), where each vehicle does not need to return to the depot after completing the delivery task.The optimization objective is to minimize the total distance. This problem exists widely in real-life logistics distribution process.We propose a hybrid column generation algorithm(HCGA) for the OVRPTW, embedding both exact algorithm and metaheuristic. In HCGA, a label setting algorithm and an intelligent algorithm are designed to select columns from small and large subproblems, respectively. Moreover, a branch strategy is devised to generate the final feasible solution for the OVRPTW. The computational results show that the proposed algorithm has faster speed and can obtain the approximate optimal solution of the problem with 100 customers in a reasonable time.展开更多
This paper investigated the natural ventilation driven by hot pressure on a typical office building with single window opening.The actual result indicates that the ventilation rate of natural ventilation driven by hot...This paper investigated the natural ventilation driven by hot pressure on a typical office building with single window opening.The actual result indicates that the ventilation rate of natural ventilation driven by hot pressure in the actual single window opening construction is very different from that obtained by the theoretical formula,since the ventilation conditions between actual environment and ventilation driven by hot pressure in the single window opening are different.Therefore,the theoretical formula is amended,and it becomes more consistent with the actual ventilation rate of natural ventilation driven by hot pressure under conditions that the construction is in the form of single window opening.展开更多
基金National Natural Science Foundation of China(No. 51278094)
文摘According to the investigations of window opening percentage (WOP) of Shanghai in 2011, the WOP varies significantly from season to season and thus affects the air flow rate of natural ventilation rooms. A three-dimensional computional fluid dynamic(CFD) model was applied to simulating the flow fields in a street canyon under different wind speed and WOP. The numerical simulations show that WOP has a significant influence on the static pressure distribution of the downwind building. Therefore, a correction factor k can be used for calculating the flow rate of wind-driven natural ventilation. The results show that k ranges from 0.43 to 0.49 when WOP is 4.44%; when WOP increases to 9.78%, the correction factor k lies in 0.32 and 0.36.
基金supported by the National Natural Science Foundation of China (61963022,51665025,61873328)。
文摘This paper addresses the open vehicle routing problem with time window(OVRPTW), where each vehicle does not need to return to the depot after completing the delivery task.The optimization objective is to minimize the total distance. This problem exists widely in real-life logistics distribution process.We propose a hybrid column generation algorithm(HCGA) for the OVRPTW, embedding both exact algorithm and metaheuristic. In HCGA, a label setting algorithm and an intelligent algorithm are designed to select columns from small and large subproblems, respectively. Moreover, a branch strategy is devised to generate the final feasible solution for the OVRPTW. The computational results show that the proposed algorithm has faster speed and can obtain the approximate optimal solution of the problem with 100 customers in a reasonable time.
基金Supported by "Eleventh Five-Year" National Scientific and Technological Support Scheme Funded Projects(2006BAJ02A02,2006BAJ02A05)Ministry of Education,the New Century Talents Scheme Funded Projects(Education and Technology Divi-sion[2007]No.209)National Personnel Merit-Based Projects(Office of Hair People[2007]170)
文摘This paper investigated the natural ventilation driven by hot pressure on a typical office building with single window opening.The actual result indicates that the ventilation rate of natural ventilation driven by hot pressure in the actual single window opening construction is very different from that obtained by the theoretical formula,since the ventilation conditions between actual environment and ventilation driven by hot pressure in the single window opening are different.Therefore,the theoretical formula is amended,and it becomes more consistent with the actual ventilation rate of natural ventilation driven by hot pressure under conditions that the construction is in the form of single window opening.
