关于曲线积分和曲面积分教学中几个难点的突破

加强曲线、曲面积分概念讲解,标准化曲线、曲面积分的计算程序,沟通有关积分之间关系,以消除学生 对斯托克斯等公式的深奥感,有效地突破了曲线、曲面积分教学中的几个难点。     

A two–stage approach to additive time series models

For nonlinear additive time series models, an appealing approach used in the literature to estimate the nonparametric additive components is the projection method. In this paper, it is demonstrated that the projection method might not be efficient in an asymptotic sense. To estimate additive components efficiently, a two–stage approach is proposed together with a local linear fitting and a new bandwidth selector based on the nonparametric version of the Akaike information criterion. It is shown that the two–stage method not only achieves efficiency but also makes bandwidth selection relatively easier. Also, the asymptotic normality of the resulting estimator is established. A small simulation study is carried out to illustrate the proposed methodology and the two–stage approach is applied to a real example from econometrics.     

DEFAULT RISK INSURANCE AND INCOMPLETE MARKETS1

This paper uses the existence of secondary markets for debt instruments with default risk (e.g. corporate bonds) to define default insurance along the lines of financial economics. It examines whether, in the case of several risk-neutral measures, characteristics of default can be uniquely determined by the prices of contracts involving default-prone securities.     

保险业增长预测中数量经济模型的应用研究

科学合理地预测保险业的发展状况，对于明确保险业未来的总体发展目标和战略重点。促进保险业持续健康发展，具有十分重大的意义。本文以内蒙古自治区保险业为例，通过对2006年-2010年内蒙古自治区保费收入的增长预测，提出了综合运用多元线性回归模型和霍尔特指数平滑法进行保险增长预测的预测方法。与传统预测方法相比，它能更好地保证保险增长预测的精确度。     

Asymptotic distributions in random graphs with applications to social networks

Various kinds of subgraph counts have been proposed as important statistics in the social sciences: for instance, in connection with studies of the structural properties of social networks. Since the empirical structure in question often involves an element of randomness, subgraph counts are random variables and, consequently, we need to describe their probabilistic properties. In this paper we give a survey of results dealing with the asymptotic distributions of general subgraph counts for a number of standard graph distributions. Although we do not include proofs for all the results, we illustrate the methodology used through studies of asymptotic behaviour for certain subgraph counts.     

动态死亡率下个人年金的长寿风险分析

传统的精算定价方法假定死亡率是静态的,实际上死亡率是随时间而变动的具有动态不确定性的变量。在动态死亡率的框架下定量分析长寿风险对于个人年金产品定价的影响:引入Wang转换的风险定价方法度量长寿风险的市场价格,并运用模拟分析的方法分析长寿风险对个人年金定价的影响。最后,基于分析结果,就保险公司如何管理这一风险给出建议。     

旅游地投射形象与感知形象对比研究——以秦皇岛滨海长城形象为例

良好的旅游形象可以刺激旅游动机的产生,从而引发相应的旅游决策行为。因此做好旅游目的地旅游形象定位和设计具有重要意义。以秦皇岛为例,基于网络文本数据利用内容分析法分析秦皇岛目的地滨海长城旅游形象。研究发现,官方投射形象与游客感知形象均围绕长城形象构建,但关注核心与构建路径具有差异;官方投射形象所关注的维度依次为人文吸引物、服务与管理、旅游体验、旅游设施、自然吸引物;游客通过感知建构的滨海长城旅游形象的关注维度依次为人文吸引物、旅游体验、自然吸引物、旅游设施、服务与管理。基于此,应将长城与滨海、人文与自然多维融合,立体化塑造滨海长城目的地形象,加强形象宣传力度,提升游客旅游体验感。     

都市更新中“超小区域”重大开发项目的人口影响研究——以闸北苏河湾地区为例

以苏河湾地区为例,重大开发项目建设过程中区域人口与开发节奏、开发力度等具有非常紧密的联系,须根据"大拆大建"过程中拆、建进度与拆、建面积等对人口的影响来估算其对总人口的影响,并依照开发建设进度进行阶段性的处理。结果发现,以往规划中关于苏河湾仅5万人口的设定明显有悖于苏河湾人口的实际情况。苏河湾的案例表明对都市更新背景下大都市"超小区域"重大开发项目的人口影响要建立评估机制与动态监测机制,相关职能部门的公共服务与资源配置也要与阶段性的人口状况相适应。     

基于自适应相关滤波器的人眼定位改进方法

人眼定位是人脸识别、视觉跟踪系统中一个关键步骤。针对传统人眼定位方法定位精度低、误差稳定性差的问题,提出将自适应相关滤波器与灰度积分投影法相结合,在训练和测试阶段做了两点改进。首先对训练得到的自适应相关滤波器,在\[-0.2,-0.1,0,0.1,0.2\]角度范围内旋转得到5个滤波器,选择灰度最大值对应的位置作为初始定位点,然后在该定位点的5×5邻域内,水平和垂直方向分别做灰度积分投影,最后选择积分最小值的位置作为最终的目标定位点。与平均合成精确滤波器、最小输出平方误差和滤波器、自适应合成相关滤波器算法相比,改进算法的定位精度最大提高2.9%,平均绝对误差和标准差均低于原始算法。实验结果表明,提出的改进算法在定位精度和稳定性上均优于以上算法。     

Good global citizen? ASEAN’s image building in the United Nations

ABSTRACT

Based on role theory, the article examines the images that ASEAN member governments project of their organization. It rests on a discourse analysis of 198 speeches in the United Nations General Assembly between 1998 and 2017. Findings suggest that ASEAN does not figure as a top priority for delegates and that an overarching ASEAN role conception is missing. However, their addresses reveal parameters on which a collective role conception can be built. Individual ASEAN countries undertake great efforts to project themselves as ‘good global citizens,’ a role conception that could also be applied to ASEAN.