Strong convergence rates of probabilistic integrators for ordinary differential equations

Probabilistic integration of a continuous dynamical system is a way of systematically introducing discretisation error, at scales no larger than errors introduced by standard numerical discretisation, in order to enable thorough exploration of possible responses of the system to inputs. It is thus a potentially useful approach in a number of applications such as forward uncertainty quantification, inverse problems, and data assimilation. We extend the convergence analysis of probabilistic integrators for deterministic ordinary differential equations, as proposed by Conrad et al. (Stat Comput 27(4):1065–1082, 2017. https://doi.org/10.1007/s11222-016-9671-0), to establish mean-square convergence in the uniform norm on discrete- or continuous-time solutions under relaxed regularity assumptions on the driving vector fields and their induced flows. Specifically, we show that randomised high-order integrators for globally Lipschitz flows and randomised Euler integrators for dissipative vector fields with polynomially bounded local Lipschitz constants all have the same mean-square convergence rate as their deterministic counterparts, provided that the variance of the integration noise is not of higher order than the corresponding deterministic integrator. These and similar results are proven for probabilistic integrators where the random perturbations may be state-dependent, non-Gaussian, or non-centred random variables.

     

国家铁路货物整车运输比价关系探讨

铁路整车货运运价率结构对于货运整体收入及市场竞争力具有重要影响。通过对国家铁路货运总体运营价格水平与整车运价率、整车运价率基价1与基价2之间比价关系的分析发现,整车货运比价关系存在的主要问题体现在运价号设置的结构性、对运输成本的抵补、价率水平的均衡性以及与货物品类的对应关系等方面。因此,提出在"一口价"模式下充分考虑运输市场竞争因素、适当调整各运价号基价1与基价2增幅及比值关系、增设新运价号以及与运价浮动管理相结合充分利用3号运价等调整建议。     

建立专科运营助理制度推动科室精细化运营管理

精细化、科学化管理是现代医院运营管理的方向,通过组建专业的医院运营管理团队,明确专科运营助理岗位的工作内容,分析各科室经营情况,评估各项资源配置,参与科室绩效、流程和项目管理的研究 ,科室医疗服务能力不断增长,成本管控良好。绩效方案优化后员工工作积极性提高,科室流程得到优化,运营效率显著提升。专科运营助理对科室人力、财力、物资、空间与流程等资源的评估,能及时发现运营中存在的问题并予以改善。专科运营助理制度的设立推进了医院管理模式由经验式、粗放式转向科学化、精细化,实现医院的精细化运营管理。     

Making Sense of Organizational Change: Voices of Older Volunteers

The role of voluntary and community sector organizations in the delivery of public services is increasing and these changes bring new responsibilities and benefits to organizations that have the capacity to participate. There are concerns within the sector about the implications for citizenship and participation. The sector is highly dependent on volunteers yet little is known about how organizational change in response to new relationships with the statutory sector impact upon the commitment and well-being of people who volunteer. This paper addresses that gap in knowledge for older volunteers. Drawing upon collaborative research with a voluntary organization in the north of England, the authors explore the meanings and aspirations of volunteering for older people, and explain how and why changes associated with closer engagement with public service delivery and less grant dependency can be disempowering for them.

现代学术视野下的彝族研究

选择现代彝族研究的起点、转型、现代彝族研究与现代学术的渊源关系等问题,在较为广阔的现代学术背景下,透视彝族研究的发展和演变,强调的是尽管人们对这门学术研究的重视程度以及研究水平与其学术价值远不相称,尤其是过去关于彝族研究的历史叙述,在其叙事深处或隐或显地潜藏着某种意识形态结构,一直受宏大学术史叙述背景的影响,但现代彝族研究丰富复杂的学术蕴藏决定了它非同一般的学术价值,这也是我们要对其学术史进行梳理的主要目的和意义.     

Influence of urbanization on the occurrence and activity of aerial insectivorous bats

Activity and species-specific responses of insectivorous bats in different urban-forest conditions provides a general perspective on the adaptability and vulnerability of bat species towards urbanization intensity. Here we evaluated species richness and activity patterns of aerial insectivorous bats across an urbanized landscape in the highlands of Chiapas, in Mexico. Acoustic monitoring of echolocation calls was conducted for 27 nights over a period of four months. Species richness and relative activity of insectivorous bats were estimated in a landscape with different conditions of urbanization intensity: urban areas, non-urban and forest areas. We identified a total of 14 bat species and three phonotypes. Bat species richness and relative activity was similar (X² = 0.568, gl = 2, p > 0.05), but species composition differed among conditions. We observed a significant higher occurrence of Bauerus dubiaquercus, Eptesicus brasiliensis and Myotis californicus in forest sites. Urban sites presented higher occurrence of Molossus rufus and phonotype Molossidae 2, while non-urban sites presented a higher occurrence of Eptesicus furinalis and phonotype Molossidae 2. We were able to identify bat species according to their relative activity in relation todifferent landscape conditions. Species of the Molossidae family presented the highest activity in urban sites, which was positively affected by the number of streetlights, while species of the Vespertilionidae presented the highest activity in forest sites, which was positively related totree density. While urbanization tends to diminish native biodiversity and alter faunal communities, our results show a similar richness and relative activity of aerial insectivorous bats along the urban ecosystem. The effect of urbanization intensity becomes more apparent in species-specific bat activity; the response of species towards particular habitat conditions depends on local habitat quality and characteristics (i.e., presence of streetlights, vegetation cover and tree density).     

听写训练在英语听力教学中的实证研究

加强听写训练是提高学生听力水平、增强听力教学效果的有效手段。通过分析图示、解码与听力理解之间的关系,并根据低年级英语专业学生的特点,提出了在低年级英语专业听力教学中采用自下而上解码信息,加强听力听写训练的教学策略。教学实验证明,在两组受试对象中(均为英语专业一年级学生),接受了听力听写训练的一组对象表现出了良好的听力理解能力。     

木:祭天习俗与民族文化意蕴

语言是文化信息的载体之一,民族语言可以表达某一方面的民族文化。"木"是古老的象形字,研究"木"字包容的古汉民族与古纳西族祭木的文化意蕴,可以从中探寻到汉民族古文化与纳西族古文化的契合点与同质性。这是文化语言学在语言基础上对文化历史作出的重新认识,展示了汉语研究的又一新的前景。     

Foreign Direct Investment in the Caribbean

This article addresses the question of whether the Caribbean is particularly attractive or unattractive to foreign investors, and if it has specific characteristics that attract or deter FDI. An econometric analysis of data from 135 countries for 1980‐2002 shows that the Caribbean does not suffer from low inflows of FDI; on the contrary, Caribbean countries receive more FDI than comparable countries in other regions. This reflects two contradictory effects. On the one hand, FDI inflows may be particularly sensitive to political instability in the region; on the other hand, the absence of regulation appears to have been a particularly beneficial factor in attracting FDI to the Caribbean.