We have developed approximate Riemann solvers for ideal MHD equations based on a relaxation approach in [4], [5]. These lead to entropy consistent solutions with good properties like guaranteed positive density. We de...We have developed approximate Riemann solvers for ideal MHD equations based on a relaxation approach in [4], [5]. These lead to entropy consistent solutions with good properties like guaranteed positive density. We describe the extension to higher order and multiple space dimensions. Finally we show our implementation of all this into the astrophysics code FLASH.展开更多
为准确有效地确定导弹发射阵地选址位置,克服目前阵地选址过程中主观因素较强和难以判断选址方案优劣的弊端,提出基于地理信息系统(geographic information system,GIS)与改进优劣解距离法(technique for order preference by similarit...为准确有效地确定导弹发射阵地选址位置,克服目前阵地选址过程中主观因素较强和难以判断选址方案优劣的弊端,提出基于地理信息系统(geographic information system,GIS)与改进优劣解距离法(technique for order preference by similarity to an ideal solution,TOPSIS)的两阶段阵地选址方法。初选阶段,构建影响发射阵地选址的指标体系,利用改进层次分析法得到各指标综合权重,针对定量指标,采用GIS技术建立多环缓冲区进行空间分析,得到发射阵地选址备选方案;精选阶段,结合备选方案各指标得分,针对定性指标,利用灰色关联改进的TOPSIS进行综合评价,得到导弹发射阵地最优选址方案。实例验证表明:该方法具有较好的可操作性和适用性,主观因素影响较小,能够为导弹发射阵地选址提供决策依据。展开更多
文摘We have developed approximate Riemann solvers for ideal MHD equations based on a relaxation approach in [4], [5]. These lead to entropy consistent solutions with good properties like guaranteed positive density. We describe the extension to higher order and multiple space dimensions. Finally we show our implementation of all this into the astrophysics code FLASH.
文摘为准确有效地确定导弹发射阵地选址位置,克服目前阵地选址过程中主观因素较强和难以判断选址方案优劣的弊端,提出基于地理信息系统(geographic information system,GIS)与改进优劣解距离法(technique for order preference by similarity to an ideal solution,TOPSIS)的两阶段阵地选址方法。初选阶段,构建影响发射阵地选址的指标体系,利用改进层次分析法得到各指标综合权重,针对定量指标,采用GIS技术建立多环缓冲区进行空间分析,得到发射阵地选址备选方案;精选阶段,结合备选方案各指标得分,针对定性指标,利用灰色关联改进的TOPSIS进行综合评价,得到导弹发射阵地最优选址方案。实例验证表明:该方法具有较好的可操作性和适用性,主观因素影响较小,能够为导弹发射阵地选址提供决策依据。