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基于Dubins路径的A~*算法的多无人机路径规划 被引量:22
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作者 宋雪倩 胡士强 《电光与控制》 北大核心 2018年第11期25-29,共5页
以两架固定翼无人机在同高度、有障碍物环境下的路径规划为应用背景,针对传统基于网格的A*搜索算法没有考虑飞行性能约束的问题,首先利用Dubins曲线找到有效节点,结合A*启发式搜索的思想,分别为每架无人机离线构建由Dubins曲线组成的最... 以两架固定翼无人机在同高度、有障碍物环境下的路径规划为应用背景,针对传统基于网格的A*搜索算法没有考虑飞行性能约束的问题,首先利用Dubins曲线找到有效节点,结合A*启发式搜索的思想,分别为每架无人机离线构建由Dubins曲线组成的最短避障路径;在两机同高度飞行过程中,通过相对运动关系判断是否碰撞,使用"向量共享"解得航向改变量以及在线路径重规划,得到两机的防撞避障路径。仿真表明,与传统A*搜索相比,此算法可更快地得到更短的连续安全路径;通过在线重规划,可以得到两机的防撞避障路径。 展开更多
关键词 UAV 航迹规划 Dubins曲线 A^*搜索 防撞 避障
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Relief Degree of Land Surface and Population Distribution of Mountainous Areas in China 被引量:13
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作者 LIU Ying DENG Wei song xue-qian 《Journal of Mountain Science》 SCIE CSCD 2015年第2期518-532,共15页
Evaluation on the population pressure in the mountainous areas is a necessary condition for the protection and good governance. The evaluation depends on accurate population density assessment. Traditional methods use... Evaluation on the population pressure in the mountainous areas is a necessary condition for the protection and good governance. The evaluation depends on accurate population density assessment. Traditional methods used to calculate population density often adopt the administrative region as a scale for statistical analysis. These methods did not consider the effects of the relief degree of land surface(RDLS) on the population distribution. Therefore they cannot accurately reflect the degree of population aggregation, especially in mountainous areas. To explore this issue further, we took the mountainous areas of China as the research area. China has A total area of 666 km2 can be classified as mountainous area,accounting for 69.4% of the country's total landmass. The data used in this research included the digital elevation model(DEM) of China at a scale of 1:1,000,000, National population density raster data, the DEM and the national population density raster data. First, we determined the relief degree of land surface(RDLS). Next, we conducted a correlation analysis between the population distribution and the RDLS using the Statistical Package for Social Science(SPSS). Based on the correlation analysis results and population distribution, this new method was used to revise the provincial population density of themountainous areas. The revised results were used to determine the population pressure of different mountainous areas. Overall, the following results were obtained:(1) The RDLS was low in most mountainous areas(with a value between 0 and 3.5) and exhibited a spatial pattern that followed the physiognomy of China;(2) The relationship between the RDLS and population density were logarithmic, with an R2 value up to 0.798(p<0.05), and the correlation decreased from east to west;(3) The difference between the revised population density(RPD) and the traditional population density(PD) was larger in the southeastern region of China than in the northwestern region;(4) In addition, compared with traditional results, the revised result indicated that the population pressure was larger. Based on these results, the following conclusions were made:(1) the revised method for estimating population density that incorporates the RDLS is reasonable and practical,(2) the potential population pressure in the southeastern mountainous areas is substantial,(3) the characteristics of the terrain in the high mountainous areas are important for the scattered distribution of the population, and(4) the population distribution of mountainous areas in China should be guided by local conditions, such as social, economic, and topographic conditions. 展开更多
关键词 Land surface Relief degree Population density Population pressure Population distribution MOUNTAIN China
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Spatial Spillover and the Factors Influencing Public Service Supply in Sichuan Province, China 被引量:9
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作者 song xue-qian DENG Wei LIU Ying 《Journal of Mountain Science》 SCIE CSCD 2014年第5期1356-1371,共16页
This article examines the spatial characteristics of public service supply and the factors influencing such supply in cities of Sichuan Province, China using spatial-autocorrelation and spatial econometric models with... This article examines the spatial characteristics of public service supply and the factors influencing such supply in cities of Sichuan Province, China using spatial-autocorrelation and spatial econometric models with statistical data in 2012. The results demonstrate that expenditures on different types of public services present different spatial autocorrelation patterns. Although the spatial differences in basic public service expenditures are relatively small, a clear fan-shaped spillover to the east can be seen in Chengdu City. Chengdu also shows high clustering of advanced public service expenditures, being a typical core-periphery pattern. Post-earthquake reconstruction expenditures are clustered in the "5.12 Wenchuan earthquake" region and spill over toward cities to the east. The efficiency of public services in the mountainous areas in western Sichuan is low and exhibits a pattern of low-low spatial autocorrelation. The efficiency of public service supply is affected by economic, social, political and geographical factors. Based on the results of this analysis, we recommend a supply strategy that incorporates different types of public services and a specialized public service supply strategy for mountainous areas. Overall public service efficiency should be enhanced by focusing on narrowing the gap in farmers' income among regions and accelerating urbanization. Decision-makers should consider moresupportive policies with regard to providing basic public services in mountainous areas to ensure an equalized supply of basic public services. To enhance the efficiency of advanced public service supply, additional growth pole should be encouraged and incentivized; however, investments are required to drive the development of the peripheral regions through regional economic integration. Both software and hardware types of infrastructure are required to supply services efficiently during post-disaster reconstruction. 展开更多
关键词 Public services Spatial Spillover Spatial Econometric Model Relief Degree of Land Surface China
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基于循环神经网络的螺丝锁附状态检测 被引量:1
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作者 宋雪倩 周稻祥 +1 位作者 韩晓红 李心宇 《中北大学学报(自然科学版)》 CAS 2020年第3期226-231,237,共7页
自动锁螺丝机是精密电子产品装配流水线的重要组成部分之一,而螺丝锁附状态的检测对整个流水线和电子产品质量起着举足轻重的作用.传统检测方法通常采用感应器或伸缩弹簧,具有检测类别单一、性能不稳定、实时性差等问题.鉴于此,本文提... 自动锁螺丝机是精密电子产品装配流水线的重要组成部分之一,而螺丝锁附状态的检测对整个流水线和电子产品质量起着举足轻重的作用.传统检测方法通常采用感应器或伸缩弹簧,具有检测类别单一、性能不稳定、实时性差等问题.鉴于此,本文提出一种基于循环神经网络的智能螺丝锁附状态检测方法,该方法以锁附过程产生的角度、扭矩、速度序列数据为研究基础,以循环神经网络为研究手段.研究结果表明本文模型相比传统检测方法,具有检测故障类别更多、检测方式更稳定、检测过程更快等优点.对OK、浮锁、未锁进和锁斜4种状态的检测达到了优良的准确率. 展开更多
关键词 螺丝锁附状态检测 序列数据分类 自动锁螺丝机 循环神经网络
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复合手术治疗硬脊膜外动静脉瘘合并硬脊膜动静脉瘘1例并文献复习
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作者 李欢欢 宋雪倩 +5 位作者 陈迎春 李俊 盛柳青 别毕洲 汪志忠 马廉亭 《中国临床神经外科杂志》 2020年第10期667-669,共3页
目的总结硬脊膜外动静脉瘘(SEDAVF)合并硬脊膜动静脉瘘(SDAVF)的复合手术治疗经验。方法回顾性分析复合手术治疗的1例SEDAVF合并SDAVF的临床资料,并结合文献分析。结果首先经动脉途径进行ONYX胶栓塞,因胶弥散效果不佳,仅封堵供血动脉,... 目的总结硬脊膜外动静脉瘘(SEDAVF)合并硬脊膜动静脉瘘(SDAVF)的复合手术治疗经验。方法回顾性分析复合手术治疗的1例SEDAVF合并SDAVF的临床资料,并结合文献分析。结果首先经动脉途径进行ONYX胶栓塞,因胶弥散效果不佳,仅封堵供血动脉,瘘口及引流静脉仍可显影;然后,开放性手术烧灼硬脊膜外扩张迀曲的静脉丛血管,但未剪开硬脊膜探查,术后7 d因并存SDAVF加重血流动力学改变并引起症状加重,再次行介入栓塞时处理SDAVF。术后6个月随访双下肢肌力恢复至4级,大小便功能正常。结论SEDAVF处理的关键在于闭塞瘘口及近端引流静脉,对于合并的SDAVF,可选择介入治疗。单纯SEDAVF,可选择开放性手术灼闭硬脊膜外扩张迂曲的静脉湖;SEDAVF合并SDAVF,可先行介入栓塞瘘口,解除脊髓静脉高压综合征及硬脊膜外静脉湖压迫症状;如仍末治愈,可行开放手术灼闭硬脊膜外扩张迀曲的静脉湖,解除对脊髓的压迫。 展开更多
关键词 硬脊膜外动静脉瘘 硬脊膜动静脉瘘 复合手术
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德州市2021年医疗专业卫生行政处罚情况分析
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作者 周淑玲 宋学谦 刘晓惠 《中国卫生监督杂志》 2022年第2期190-193,共4页
目的通过对德州市2021年医疗专业卫生行政处罚情况进行统计分析,进一步探索医疗卫生监督工作的新思路,为进一步做好医疗卫生监督工作提出建设性意见。方法收集汇总德州市2021年医疗专业卫生行政处罚案例数据,对行政处罚基本情况、案件... 目的通过对德州市2021年医疗专业卫生行政处罚情况进行统计分析,进一步探索医疗卫生监督工作的新思路,为进一步做好医疗卫生监督工作提出建设性意见。方法收集汇总德州市2021年医疗专业卫生行政处罚案例数据,对行政处罚基本情况、案件来源、地区分布及处罚情况、履行情况、案由及处罚主体分布等方面进行统计分析。结果2021年全市医疗专业行政处罚案件499件,其中罚款225件,罚款金额242.5165万元,没收违法所得26家,没收金额6.5888万元,没收药品器械14家。其中无证行医32件,医疗机构违法执业467件。结论打击非法行医仍是医疗卫生监督工作的重点,除卫生健康行政部门加大依法惩戒力度外,还需要司法部门、公安部门等协同构建联席会议机制,确保形成执法合力,进一步净化医疗服务市场。 展开更多
关键词 医疗卫生监督 行政处罚 分析
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