小学数学教学中积极语言使用的探索

积极语言是蕴含正能量的语言,有助于营造和谐师生关系、促进学生积极向上、提高课堂效能.小学数学教学中使用积极语言,策略上需要发掘师生积极因素、把握语言使用时机、因生施策使用语言.提出在教学中评估、优化语言使用、配合使用积极动作、学习汲取他人经验的建议.     

互联网环境下消费信贷行为研究

采用结构方程建模方法,实证分析了感知易用性、感知有用性、感知风险、信用卡效应及使用的态度与互联网环境下消费者使用信用卡支付的意愿之间的作用路径关系,从而建立了互联网环境下消费信贷行为影响因素的概念模型．研究表明,除感知风险与使用的意愿之间存在负相关关系外,其余四个因素与使用的意愿之间均存在正相关关系,其中使用的态度对使用的意愿的影响最大．     

移动互联的金融梦

过去半年当中,在PC上使用软件客户端的用户,下降了7．9％;在PC上使用网页的用户,下降了15．4％。而使用移动APP和使用移动浏览器看网页的用户,在过去8个月当中增长超过了40％。     

考虑使用成本的软件交易方式选择研究

用户使用软件过程中往往需要支付数额不菲的各种成本。永久授权交易方式下,软件使用成本完全由用户负担;软件即服务交易方式下,部分使用成本(如软硬件维护成本)转由软件供应商负担,且供应商借助专业优势通常能压缩其分担的使用成本。对于永久授权和软件即服务两种交易方式,本文分别建立垄断软件供应商的两阶段定价模型,分析用户选择和供应商定价策略,考察软件使用成本、供应商分担部分使用成本及供应商成本压缩在软件交易方式选择中的作用。研究发现,当软件使用成本较高、供应商分担使用成本的比例较大、供应商压缩成本幅度较大时,软件即服务交易方式通常占优;否则,永久授权交易方式通常占优。     

农户家庭天然气接入意愿与持续使用行为——基于陕西案例的UTAUT模型实证分析

在我国广袤的农村,天然气入户是清洁绿色能源革命的重要内容。运用技术接受使用统一模型即UTAUT,以陕西省为案例对象,研究农户家庭对天然气的接入意愿和持续使用行为。结果表明,感知风险、便利条件、绩效预期和社群影响4个方面由强至弱对农村家庭天然气的接入意愿具有正向显著影响。其中,接入意愿正向显著影响持续使用行为,而便利条件不能直接对持续使用行为构成显著影响。年龄、家庭人均年收入分别对绩效预期影响接入意愿具有显著调节作用,人均年收入越高的农户对天然气及其使用预期越高,40～60岁农家主事者对天然气及使用有更高的接入意愿;使用经历对感知风险、社群影响作用于接入意愿具有调节效应。为此,政府部门应强化引导作用,及时出台系统化、完整的一揽子农村天然气推广政策;燃气企业多方组织气源,保障燃气供应,在加强成本核算的同时提供合格的燃气服务和技术支持;农民个人积极增加收入,转变能源消费观念,学习、掌握和安全使用天然气;鼓励有燃气使用经历的农户先行接入使用,辐射带动邻居、亲友接受天然气能源使用。     

CPM网络中机动时间的使用效率及应用

本文研究CPM网络计划中总时差和单时差的使用效率问题及在项目管理中的应用.文章首先探讨了总时差和自由时差的使用对CPM网络中新关键路线形成的影响,得出结论:一般情况下一条路线上各工序分别使用自由时差的方式比某个工序使用总时差的方式具有更高的使用效率.文章随后对这一结论进行了科学性证明,并根据这个结论提出了项目管理中一种运用自由时差节约成本的方法,这种方法能帮助项目管理者提高机动时间使用效率.     

基于序关系法和模糊综合评价法的西安市应急标识有效性评估

为研究西安市应急标识使用效果,运用文献综述法,结合西安市人群聚集场所应急标识实际使用情况,总结出20个影响因素建立西安市应急标识有效性评价指标体系.通过序关系法确定20个影响因素的权重,使用模糊综合评价法综合评价西安市应急标识的使用效果.结果表明:西安市应急标识使用效果较好.从优化标识设计、提高居民应急技能等方面可以提高应急标识有效性.     

基于均衡使用的通用教练机使用计划编排算法

为确保教练机在飞行训练中的均衡使用,构造描述"训练任务"衔接关系的时序网络模型,以此将教练机均衡使用问题转化为时序网络图上寻找教练机执飞"训练任务"的路径计划问题,通过建立满足教练机均衡使用要求的目标函数,为"训练任务"随机赋予教练机编号生成"训练任务"路径计划,进而设计模拟退火算法获取教练机使用计划方案.选取国内某飞行航校"10架教练机、37个训练任务"的训练计划进行分析,结果表明:算法能够提高教练机使用的均衡性;随着训练任务之间衔接松散度的增加,教练机使用计划方案的均衡更好.     

中学生数学教科书使用倾向研究

教科书在课程的学习中发挥着重要作用,将其作为教学资源的研究众多.然而,随着“以学生为中心”的教育理念深入,学生作为课堂的主体,其对教科书的使用也受到广泛关注.本研究通过问卷调查对学生使用教科书的倾向进行定量研究,研究建立了与“使用”一词相关的六种指标(频率、时间、目的、动机、偏好)来体现学生对数学教科书的使用情况.研究结果表明,中学生对教科书的使用主要受教师以及学生自身调节意识的影响.学生使用教科书主要是用于预习,课内学习以及练习,部分学生用于查阅实例以及将其视为参考资料和拓展性习题资料使用,学生倾向于将教科书作为认识概念的字典、解题的模板、备考的指导所使用.     

一道2012年全国联赛试题的源流

原题（2012年全国高中数学联赛第8题）某情报站有A，B，C，D四种互不相同的密码，每周使用其中的一种密码，且每周都是从上周未使用的三种密码中等可能地随机选用一种．设第1周使用A种密码，那么第7周也使用A种密码的概率是——．（用最简分数表示）该问题与以下问题类同：     

A Bayesian approach to the triage problem with imperfect classification

A collection of jobs (or customers, or patients) wait impatiently for service. Each has a random lifetime during which it is available for service. Should this lifetime expire before its service starts then it leaves unserved. Limited resources mean that it is only possible to serve one job at a time. We wish to schedule the jobs for service to maximise the total number served. In support of this objective all jobs are subject to an initial triage, namely an assessment of both their urgency and of their service requirement. This assessment is subject to error. We take a Bayesian approach to the uncertainty generated by error prone triage and discuss the design of heuristic policies for scheduling jobs for service to maximise the Bayes’ return (mean number of jobs served). We identify problem features for which a high price is paid in number of services lost for poor initial triage and for which improvements in initial job assessment yield significant improvements in service outcomes. An analytical upper bound for the cost of imperfect classification is developed for exponentially distributed lifetime cases.     

The least square values and the shapley value for cooperative TU games

The main result proved in this paper is the fact that any Least Square Value is the Shapley value of a game obtained from the given game by rescaling. An Average per capita formula for Least Square Values, similar to the formula for the Shapley value (Dragan (1992)), will lead to this conclusion and allow a parallel computation for these values. The potential for the Least Square Values, a potential basis relative to Least Square Values and an approach similar to the one used for the Shapley value is allowing us to solve the Inverse problem for Least Square Values.     

Optimal Control and Stabilization for Some Fisher-Like Models

This article concerns optimal control and stabilization for some Fisher-like models with control acting in a subdomain ω. We investigate the optimal position of ω for some optimal harvesting problems. First, we refer to a logistic model with diffusion. We remember the necessary optimality conditions, and then obtain an iterative method to improve the position of ω for the optimal harvesting effort (for a simplified model without logistic term). Next, we consider the null stabilization for a controlled Fisher model and obtain a descent method to improve the position of ω in order to get a faster stabilization to zero. Numerical tests illustrating the effect of the last method are given. We also studied the null stabilization for a prey-predator system and have reduced it to the study of the null stabilizability for a related Fisher model.     

Necessary and Sufficient Conditions for Mcshane’s Identity and Variations

Greg McShane introduced a remarkable identity for lengths of simple closed geodesics on the once punctured torus with a complete, finite volume hyperbolic structure. Bowditch later generalized this and gave sufficient conditions for the identity to hold for general type-preserving representations of a free group on two generators Γ to SL(2,C), this was further generalized by the authors to obtain sufficient conditions for a generalized McShane’s identity to hold for arbitrary (not necessarily type-preserving) non-reducible representations in Tan et al. (Submitted). Here we extend the above by giving necessary and sufficient conditions for the generalized McShane identity to hold (Akiyoshi, Miyachi and Sakuma had proved it for type-preserving representations). We also give a version of Bowditch’s variation of McShane’s identity to once-punctured torus bundles, in the case where the monodromy is generated by a reducible element, and provide necessary and sufficient conditions for the variations to hold.     

Pricing strategies for perishable products: the case of Vienna and the hotel reservation system hrs.com

Consider a retailer who sells perishable products for which there is uncertain demand. Yield management with dynamic pricing is a standard practice that firms use for revenue management. For perishable products, recent analysis has focused on the distribution of flight capacity, referred to as ticket sales. Other non- storable, non-transportable, immaterial hospitality products include hotel capacity. The article discusses the extent to which hotel pricing strategies vary within the internet distribution system hrs.com. This study focuses on the distribution of hotel rooms available for booking on the internet for Vienna and gives an outlook to Euroland capitals. The main research interests are the underlying pricing models and the setting of the end price. Data was taken from hrs.com, which is the most important specialist for hotel room internet distribution in Germany according to recent studies by KMPG and others. The results include the identification of different pricing strategy clusters with regard to hotel category and hotel availability over a 22-day period for Vienna and one city from all Euroland countries (the capitals were studied for all cases except for the Netherlands, for which data was collected for Amsterdam). The study took the arrival days Mondays, Tuesdays, Wednesdays and Thursdays into account, and used data for all these days from the 11th of July, 2005, to the 10th of October, 2005, for Vienna, and the first and the last of these dates as a comparison base for the other Euroland cities.     

Half Space and Quarter Space Dirichlet Problems for the Partial Differential Equation

A customary, heuristic, method, by which the Poisson integral formula for the Dirichlet problem, for the half space, for Laplace's equation is obtained, involves Green's function, and Kelvin's method of images. Although this heuristic method leads one to guess the correct result, this Poisson formula still has to be verified directly, independently of the method by which it was arrived at, in order to be absolutely certain that a solution of the Dirichlet problem for the half space, for Laplace's equation, has been actually obtained. A similar heuristic method, as seems to be generally known, could be followed in solving the Dirichlet problem, for the half space, for the equation where is a real constant. However, in Part 1, a different, labor-saving, method is used to study Dirichlet problems for the equation. This method is essentially based on what Hadamard called the method of descent. Indeed, it is shown that he who has solved the half space Dirichlet problem for Laplace's equation has already solved the half space Dirichlet problem for the equation In Part 2, the solution formula for the quarter space Dirichlet problem for Laplace's equation is obtained from the Poisson integral formula for the half space Dirichlet problem for Laplace's equation. A representation theorem for harmonic functions in the quarter space is deduced. The method of descent is used, in Part 3, to obtain the solution formula for the quarter space Dirichlet problem for the equation by means of the solution formula for the quarter space Dirichlet problem for Laplace's equation. So that, indeed, it is also shown that he who has solved the quarter space Dirichlet problem for Laplace's equation has already solved the quarter space Dirichlet problem for the " equation" For the sake of completeness and clarity, and for the convenience of the reader, the appendix, at the end of Part 3, contains a detailed proof that the Poisson integral formula solves the half space Dirichlet problem for Laplace's equation. The Bibliography for Parts 1,2, 3 is to be found at the end of Part 1.     

Modeling stochastic anomalies in an SIS system

We propose a stochastic SIS model to include both a Gaussian and Poissonian perturbation to account for noise and anomalies in the transmission rate. Conditions are given for stability to the disease free equilibrium and for positive Harris recurrence with a unique invariant measure for the endemic.     

Convergence rate analysis of an asynchronous space decomposition method for convex minimization

We analyze the convergence rate of an asynchronous space decomposition method for constrained convex minimization in a reflexive Banach space. This method includes as special cases parallel domain decomposition methods and multigrid methods for solving elliptic partial differential equations. In particular, the method generalizes the additive Schwarz domain decomposition methods to allow for asynchronous updates. It also generalizes the BPX multigrid method to allow for use as solvers instead of as preconditioners, possibly with asynchronous updates, and is applicable to nonlinear problems. Applications to an overlapping domain decomposition for obstacle problems are also studied. The method of this work is also closely related to relaxation methods for nonlinear network flow. Accordingly, we specialize our convergence rate results to the above methods. The asynchronous method is implementable in a multiprocessor system, allowing for communication and computation delays among the processors.

     

The shape of the hazard function for cancer incidence

A population-based cohort consisting of 126,141 men and 122,208 women born between 1874 and 1931 and at risk for breast or colorectal cancer after 1965 was identified by linking the Utah Population Data Base and the Utah Cancer Registry. The hazard function for cancer incidence is estimated from left truncated and right censored data based on the conditional likelihood. Four estimation procedures based on the conditional likelihood are used to estimate the age-specific hazard function from the data; these were the life-table method, a kernel method based on the Nelson Aalen estimator, a spline estimate, and a proportional hazards estimate based on splines with birth year as sole covariate.The results are consistent with an increasing hazard for both breast and colorectal cancer through age 85 or 90. After age 85 or 90, the hazard function for female breast and colorectal cancer may reach a plateua or decrease, although the hazard function for male colorectal cancer appears to continue to rise through age 105. The hazard function for both breast and colorectal cancer appears to be higher for more recent birth cohorts, with a more pronounced birth-cohort effect for breast cancer than for colorectal cancer. The age specific for colorectal cancer appears to be higher for men than for women. The shape of the hazard function for both breast and colorectal cancer appear to be consistent with a two-stage model for spontaneous carcinogenesis in which the initiation rate is constant or increasing. Inheritance of initiated cells appears to play a minor role.