针对低空经济背景下无人机在复杂三维建筑环境中的路径规划需求,提出改进的双向快速搜索树自适应交替双目标偏差搜索(Sampling-Tree Based bidirectional Rapidly-exploring Random Tree,ST-BA-RRT)算法。该算法在采样阶段采用三维环境...针对低空经济背景下无人机在复杂三维建筑环境中的路径规划需求,提出改进的双向快速搜索树自适应交替双目标偏差搜索(Sampling-Tree Based bidirectional Rapidly-exploring Random Tree,ST-BA-RRT)算法。该算法在采样阶段采用三维环境下的椭球采样,并配合双目标偏差策略抑制随机树向障碍区扩展,定向引导其向目标生长;扩展阶段运用自适应交替探索与改进人工势场辅助策略,增强算法环境适应性与局部避障能力。碰撞检测环节通过设计新型代价函数减少障碍物检查频次,优化规划时间;连通性处理利用双向随机采样提升规划效率;最后借助β样条平滑路径。实验结果表明,相较于现有算法,ST-BA-RRT算法生成的路径更短、更平滑,路径规划时间平均减少35%,在路径质量与环境适应性方面优势显著,能够高效生成优化飞行轨迹,满足复杂三维建筑环境下无人机路径规划需求。展开更多
We revisit one of the classical search problems in which a diffusing target encounters a stationary searcher. Under the condition that the searcher’s detection region is much smaller than the search region in which t...We revisit one of the classical search problems in which a diffusing target encounters a stationary searcher. Under the condition that the searcher’s detection region is much smaller than the search region in which the target roams diffusively, we carry out an asymptotic analysis to derive the decay rate of the non-detection probability. We consider two different geometries of the search region: a disk and a square, respectively. We construct a unified asymptotic expression valid for both of these two cases. The unified asymptotic expression shows that the decay rate of the non-detection probability, to the leading order, is proportional to the diffusion constant, is inversely proportional to the search region, and is inversely proportional to the logarithm of the ratio of the search region to the searcher’s detection region. Furthermore, the second term in the unified asymptotic expansion indicates that the decay rate of the non-detection probability for a square region is slightly smaller than that for a disk region of the same area. We also demonstrate that the asymptotic results are in good agreement with numerical solutions.展开更多
Pancreatic adenocarcinoma(PAC) is one of the most deadly malignant neoplasms,and the efficacy of conventional cytotoxic chemotherapy is far from satisfactory. Recent research studies have revealed that immunosuppressi...Pancreatic adenocarcinoma(PAC) is one of the most deadly malignant neoplasms,and the efficacy of conventional cytotoxic chemotherapy is far from satisfactory. Recent research studies have revealed that immunosuppression and inflammation are associated with oncogenesis,as well as tumor development,invasion,and metastasis in PAC. Thus,immunosuppressionrelated signaling,especially that involving immune checkpoint and inflammation,has emerged as novel treatment targets for PAC. However,PAC is an immuneresistant tumor,and it is still unclear whether immune checkpoint or anti-inflammation therapies would be an ideal strategy. In this article,we will review immune checkpoint and inflammation as potential targets,as well as clinical trials and the prospects for immunotherapy in PAC.展开更多
<div style="text-align:justify;"> In recent years, multi-target tracking technology based on Gaussian Mixture- Probability Hypothesis Density (GM-PHD) filtering has become a hot field of information fu...<div style="text-align:justify;"> In recent years, multi-target tracking technology based on Gaussian Mixture- Probability Hypothesis Density (GM-PHD) filtering has become a hot field of information fusion research. This article outlines the generation and development of multi-target tracking methods based on GM-PHD filtering, and the principle and implementation method of GM-PHD filtering are explained, and the application status based on GM-PHD filtering is summarized, and the key issues of the development of GM-PHD filtering technology are analyzed. </div>展开更多
目的评估炎症因子与骨质疏松症(osteoporosis,OP)之间的因果关系。方法从GWAScatalog数据库中获取41个炎症因子和骨密度(bone mineral density,BMD)的GWAS数据,芬兰数据库中获取OP的GWAS数据。采用逆方差加权法(IVW)、MR-Egger回归法(M...目的评估炎症因子与骨质疏松症(osteoporosis,OP)之间的因果关系。方法从GWAScatalog数据库中获取41个炎症因子和骨密度(bone mineral density,BMD)的GWAS数据,芬兰数据库中获取OP的GWAS数据。采用逆方差加权法(IVW)、MR-Egger回归法(MER)、加权中位数法(WME)、简单中位数法和加权中值方法进行两样本孟德尔随机化分析,并以IVW法为主要分析方法。再进行敏感性分析以检验结果的可靠性,留一法评估单核苷酸多态性对结果的影响。最后进行药物预测和分子对接进一步验证炎症因子的药理价值。结果研究表明炎症因子与OP和BMD之间存在因果关系。其中肿瘤坏死因子相关的凋亡诱导配体(TRAIL)和单核细胞趋化蛋白1(MCP-1/MCAF)与OP发生风险呈正相关;肿瘤坏死因子β(TNF-β)与0~15岁人群的BMD呈负相关;白细胞介素7(IL-7)与15~30岁人群的BMD呈负相关;肝细胞生长因子(HGF)与30~45岁人群的BMD呈负相关;巨噬细胞炎性蛋白1α(MIP-1α)和巨噬细胞集落刺激因子(M-CSF)与60岁以上人群的BMD呈负相关;MIP-1α与全年龄段人群的BMD呈负相关。此外,分子对接证明了药物与蛋白质的良好结合,进一步证实了这些靶点的药理价值。结论通过孟德尔随机化方法全面评估了41种炎症因子对OP和BMD的因果效应,表明炎症因子与OP和BMD之间存在因果关联,提示OP患者可以在疾病早期通过干预炎症因子进而干预OP的发生发展过程。展开更多
文摘针对低空经济背景下无人机在复杂三维建筑环境中的路径规划需求,提出改进的双向快速搜索树自适应交替双目标偏差搜索(Sampling-Tree Based bidirectional Rapidly-exploring Random Tree,ST-BA-RRT)算法。该算法在采样阶段采用三维环境下的椭球采样,并配合双目标偏差策略抑制随机树向障碍区扩展,定向引导其向目标生长;扩展阶段运用自适应交替探索与改进人工势场辅助策略,增强算法环境适应性与局部避障能力。碰撞检测环节通过设计新型代价函数减少障碍物检查频次,优化规划时间;连通性处理利用双向随机采样提升规划效率;最后借助β样条平滑路径。实验结果表明,相较于现有算法,ST-BA-RRT算法生成的路径更短、更平滑,路径规划时间平均减少35%,在路径质量与环境适应性方面优势显著,能够高效生成优化飞行轨迹,满足复杂三维建筑环境下无人机路径规划需求。
文摘We revisit one of the classical search problems in which a diffusing target encounters a stationary searcher. Under the condition that the searcher’s detection region is much smaller than the search region in which the target roams diffusively, we carry out an asymptotic analysis to derive the decay rate of the non-detection probability. We consider two different geometries of the search region: a disk and a square, respectively. We construct a unified asymptotic expression valid for both of these two cases. The unified asymptotic expression shows that the decay rate of the non-detection probability, to the leading order, is proportional to the diffusion constant, is inversely proportional to the search region, and is inversely proportional to the logarithm of the ratio of the search region to the searcher’s detection region. Furthermore, the second term in the unified asymptotic expansion indicates that the decay rate of the non-detection probability for a square region is slightly smaller than that for a disk region of the same area. We also demonstrate that the asymptotic results are in good agreement with numerical solutions.
基金Supported by JSPS Grant-in-Aid for Young Scientists(B)No.268605371Astra Zeneca,Eli Lilly and Company,and Bayer AG(to Kondo S)
文摘Pancreatic adenocarcinoma(PAC) is one of the most deadly malignant neoplasms,and the efficacy of conventional cytotoxic chemotherapy is far from satisfactory. Recent research studies have revealed that immunosuppression and inflammation are associated with oncogenesis,as well as tumor development,invasion,and metastasis in PAC. Thus,immunosuppressionrelated signaling,especially that involving immune checkpoint and inflammation,has emerged as novel treatment targets for PAC. However,PAC is an immuneresistant tumor,and it is still unclear whether immune checkpoint or anti-inflammation therapies would be an ideal strategy. In this article,we will review immune checkpoint and inflammation as potential targets,as well as clinical trials and the prospects for immunotherapy in PAC.
文摘<div style="text-align:justify;"> In recent years, multi-target tracking technology based on Gaussian Mixture- Probability Hypothesis Density (GM-PHD) filtering has become a hot field of information fusion research. This article outlines the generation and development of multi-target tracking methods based on GM-PHD filtering, and the principle and implementation method of GM-PHD filtering are explained, and the application status based on GM-PHD filtering is summarized, and the key issues of the development of GM-PHD filtering technology are analyzed. </div>
文摘目的评估炎症因子与骨质疏松症(osteoporosis,OP)之间的因果关系。方法从GWAScatalog数据库中获取41个炎症因子和骨密度(bone mineral density,BMD)的GWAS数据,芬兰数据库中获取OP的GWAS数据。采用逆方差加权法(IVW)、MR-Egger回归法(MER)、加权中位数法(WME)、简单中位数法和加权中值方法进行两样本孟德尔随机化分析,并以IVW法为主要分析方法。再进行敏感性分析以检验结果的可靠性,留一法评估单核苷酸多态性对结果的影响。最后进行药物预测和分子对接进一步验证炎症因子的药理价值。结果研究表明炎症因子与OP和BMD之间存在因果关系。其中肿瘤坏死因子相关的凋亡诱导配体(TRAIL)和单核细胞趋化蛋白1(MCP-1/MCAF)与OP发生风险呈正相关;肿瘤坏死因子β(TNF-β)与0~15岁人群的BMD呈负相关;白细胞介素7(IL-7)与15~30岁人群的BMD呈负相关;肝细胞生长因子(HGF)与30~45岁人群的BMD呈负相关;巨噬细胞炎性蛋白1α(MIP-1α)和巨噬细胞集落刺激因子(M-CSF)与60岁以上人群的BMD呈负相关;MIP-1α与全年龄段人群的BMD呈负相关。此外,分子对接证明了药物与蛋白质的良好结合,进一步证实了这些靶点的药理价值。结论通过孟德尔随机化方法全面评估了41种炎症因子对OP和BMD的因果效应,表明炎症因子与OP和BMD之间存在因果关联,提示OP患者可以在疾病早期通过干预炎症因子进而干预OP的发生发展过程。
