两两NQD序列下非参数回归函数估计的相合性

在两两NQD序列误差下讨论Priestly,M.B.和Chao,M.T.[1]提出的一类给参数回归函数加权核估计的相合性.     

加权相似系数在公路主枢纽站场布局决策中的应用

针对层次分析法、模糊综合评价法等方法存在较多人为因素的缺陷,提出一种新的决策评价方法,即加权相似系数法。它把层次分析法与聚类分析中相似系数的概念结合起来,克服了主成分分析法、关联分析法等方法的不足,具有科学、简便、实用性强的特点。     

高斯投影在高速公路测量中的实际应用

结合高斯投影在新台高速公路二期工程建设中的运用,解决导线测量及施工放线时高斯投影在高速公路建设中的实际应用,可供同行参考。     

Marcinkiewicz积分交换子的加权Lipschitz估计

讨论了齐性核的Marcinkiewicz积分μπ和某一类加权Lipschitz空间的函数b生成的交换子肛乞的性质,利用sharp极大函数技术,证明Marcinkiewicz积分交换子μπ^b是由L^p（v）到L^q（v^1-q）的连续映照,改进了一些已知结果。     

内河航道船舶尾气快速排放清单研究——以长江江苏段为例

为高效计算和分配内河航道船舶尾气污染排放,支撑船舶排放控制区建设,提出了一种内河航道船舶尾气排放清单快速计算方法。以长江江苏段为例,选取10个控制断面,基于船舶自动识别系统（Automatic Identification System, AIS）和劳氏船级社数据库,采用船舶交通排放估算模型（Ship Traffic Emission Assessment Model, STEAM）,建立10个控制断面的船舶排放清单,在分析各断面污染物空间分布特征的基础上,采用反距离加权插值法（Inverse Distance Weighted, IDW）建立连续排放模型,计算断面间的船舶排放。结果表明：2017年长江江苏段船舶尾气排放SO2, NOx, PM10, PM2.5, CO和挥发性有机物（Volatile Organic Compound, VOC）分别为5.53万t, 19.21万t, 1.25万t, 0.95万t, 0.98万t和0.45万t。与使用全部AIS数据的传统STEAM相比,该方法在保证80%计算精度的基础上,能显著减少计算所需数据量和时间。     

动车组车轮多边形磨耗形成与发展过程仿真研究

针对动车组车轮多边形磨耗愈发严重的问题,基于车辆-轨道耦合动力学模型、轮轨接触模型、Archard磨耗模型和循环迭代模型,建立车轮多边形磨耗长期磨损迭代模型;模拟我国某型高速动车组20阶车轮多边形的发展过程,结果与实际情况吻合,证实模型的准确性.基于长期磨损迭代模型,研究车辆运行速度、轮轨模态振动特性和轨道参数对车轮多...     

任意多边形窗口的有效线裁剪算法

已有的线剪裁算法大都是针对矩形窗口或凸多边形窗口的,对于任意多边形窗口的线剪裁,目前尚无有效的算法,而这样的算法却有更普遍的应用意义.提出了一个多边形裁剪线段的有效算法,该算法运算高效、稳定.     

Entropy weighted average method for the determination of a single representative path flow solution for the static user equilibrium traffic assignment problem

The formulation of the static user equilibrium traffic assignment problem (UETAP) under some simplifying assumptions has a unique solution in terms of link flows but not in terms of path flows. Large variations are possible in the path flows obtained using different UETAP solution algorithms. Many transportation planning and management applications entail the need for path flows. This raises the issue of generating a meaningful path flow solution in practice. Past studies have sought to determine a single path flow solution using the maximum entropy concept. This study proposes an alternate approach to determine a single path flow solution that represents the entropy weighted average of the UETAP path flow solution space. It has the minimum expected Euclidean distance from all other path flow solution vectors of the UETAP. The mathematical model of the proposed entropy weighted average method is derived and its solution stability is proved. The model is easy to interpret and generalizes the proportionality condition of Bar-Gera and Boyce (1999). Results of numerical experiments using networks of different sizes suggest that the path flow solutions for the UETAP using the proposed method are about identical to those obtained using the maximum entropy approach. The entropy weighted average method requires low computational effort and is easier to implement, and can therefore serve as a potential alternative to the maximum entropy approach in practice.     

Identifying Suitable Sites for Macroalgae Cultivation on the Swedish West Coast

Special attention has been paid to sustainable macroalgae cultivation in Europe. The question on where suitable cultivation areas lie, without conflicting with current marine socio-economic activities and respecting the environment, remains a great challenge. Considering 13 criteria critical to seaweed farming such as depth, shipping traffic, and distance to ports, this paper aimed to identify suitable and sustainable offshore areas on the West Coast of Sweden for the cultivation of the Sugar Kelp, Saccharina latissima. An integrated approach with the tools geographic information systems (GIS) and multi-criteria analysis (MCA) was used to aggregate the criteria by means of Boolean and weighted linear combination (WLC) techniques. The Boolean method singled out 544?km² as suitable, whereas the WLC method indicated 475?km² as highly suitable. Both techniques complement each other in finding optimal sites. Furthermore, the integrated models excelled in providing an overview for effective spatial decision-making that fosters sustainable development of macroalgae cultivations within marine and coastal systems.

• Highlights

• To the authors’ knowledge no study on seaweed aquaculture site selection has been conducted using such a range of criteria with the purpose of including sustainability aspects within a comparative GIS-MCDA.

• The large areas identified on the West Coast of Sweden as suitable highlight the potential of this new industry and the complexity of associated marine spatial planning.

• Boolean and weighted linear combination methods were applied and compared, providing valuable insights in the selection of methods for spatial decision-making support. These insights should support a more sustainable development of macroalgae cultivation in the region, as well as a more resilient marine spatial planning process for blue growth strategies.

     

边缘提取在涂胶缺陷检测中的方法研究

船舶发动机盖外板与内板之间常涂覆一层防震密封胶,但具体涂胶形态难以观测,常用机器视觉手段获取产品涂胶图片。针对涂胶区域分割和检测精度低,效率慢的问题,提出一种新的边缘提取算法获取涂胶区域。为了避免传统Canny边缘检测方法易受噪声干扰的缺点,采用具有保边特性的加权最小二乘法滤波器对图像滤波去燥,增加45°和135°两个方向计算图像梯度,利用改进后的Canny算法获取边缘,对获取到的边缘点用区域生长方式将涂胶区域提取出来,最后将提取到的涂胶区域与标准涂胶区域进行配准和减影,得到减影结果即为涂胶缺陷。试验仿真表明：本算法能够很好的提取到胶水区域,并且获取胶水缺陷。