Objective To evaluate the utility of virtual reality system in quantitative comparison for cavernous sinus surgical approach. Methods Image data of CT and MRI scan performed in five adult cadaver heads was inputted in...Objective To evaluate the utility of virtual reality system in quantitative comparison for cavernous sinus surgical approach. Methods Image data of CT and MRI scan performed in five adult cadaver heads was inputted into the Destroscope virtual reality system to build 3-D model of cavernous sinus.展开更多
Virtual assembly is a Virtual Reality (VR) based engineering application which allows engineers to evaluate, analyze, and plan the assembly of mechanical systems. To model the virtual assembly process, new methodology...Virtual assembly is a Virtual Reality (VR) based engineering application which allows engineers to evaluate, analyze, and plan the assembly of mechanical systems. To model the virtual assembly process, new methodology must be applied. Based on the idea that the virtual assembly system is an event driven system, the interactive behavior and information model is proposed to describe the dynamic process of virtual assembly. Definition of the object-oriented model of virtual assembly is put forward.展开更多
虚拟电厂(virtual powerplant,VPP)需要在快速变化的运行环境下协同大量分布式能源(distributed energy resources,DERs)满足上级电网的调节需求。当前有关VPP优化运行的研究需在每一个控制时段消耗较多的运算与通讯时间,不易应对快速...虚拟电厂(virtual powerplant,VPP)需要在快速变化的运行环境下协同大量分布式能源(distributed energy resources,DERs)满足上级电网的调节需求。当前有关VPP优化运行的研究需在每一个控制时段消耗较多的运算与通讯时间,不易应对快速变化的运行环境。自趋优(self-approaching optimization,SAO)为VPP运行提供了全新的理念,主张在变化的环境中,以细粒度的时间间隔快速更新DERs,确保VPP不断趋近于最优的运行状态。为实现这一理念,该文提出基于在线分布式优化(online distributed optimization,ODO)的VPPSAO运行方法。首先,建立含非储能型DERs和储能型DERs的VPP运行统一模型;其次,通过模型松弛变换等技术依次解决时间耦合、空间耦合、变量快速更新、激励机制与自主响应等问题,形成基于ODO的自趋算法;进而,定义趋优间隙以量化算法可能产生的最优性损失,并从理论上证明提出的算法具有严格的趋优间隙上确界。以分布式光伏、储能及电动汽车等DERs为例构造测试VPP,与其他不同方法进行算例对比,验证SAO运行方法在约束满足、优化性能、计算效率等方面的优势。展开更多
文摘Objective To evaluate the utility of virtual reality system in quantitative comparison for cavernous sinus surgical approach. Methods Image data of CT and MRI scan performed in five adult cadaver heads was inputted into the Destroscope virtual reality system to build 3-D model of cavernous sinus.
文摘Virtual assembly is a Virtual Reality (VR) based engineering application which allows engineers to evaluate, analyze, and plan the assembly of mechanical systems. To model the virtual assembly process, new methodology must be applied. Based on the idea that the virtual assembly system is an event driven system, the interactive behavior and information model is proposed to describe the dynamic process of virtual assembly. Definition of the object-oriented model of virtual assembly is put forward.