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31.
朱长青 《价值工程》2014,(3):258-259
首先阐述了将数学建模思想融入高等数学教学内容中的意义,接着从高等数学中的基本概念和基本定理出发,通过具体案例说明如何将数学建模案例融入在高等数学教学中。最后给出了根据高等数学内容选编的典型建模案例。  相似文献   
32.
2013年我国人均GDP达到6900美元,标志着我国已居于“上中等收入”国家行列,正面临“中等收入陷阱”的威胁。本文基于日本、韩国、巴西和阿根廷的发展历程,考察了“中等收入陷阱”区间下消费率的变化轨迹,认为成功跨越“中等收入陷阱”的消费率特征是:消费率走势呈U型特征,由波动性变化演变为平稳性运行,并大致在人均GDP4000美元形成“消费率拐点”。其中,收入因素对“消费率拐点”的培育与形成具有较大的制约作用。同时文章对比分析了低中等收入阶段我国消费率变化轨迹,认为我国在人均GDP4283美元水平下形成“消费率拐点”,但当前消费需求的充分释放仍面临较强的挑战,迫切需要相应的政策措施来强化“消费率拐点”的形成。  相似文献   
33.
This paper studies the price‐setting problem of market makers under risk neutrality and perfect competition in continuous time. The classic approach of Glosten–Milgrom is followed. Bid and ask prices are defined as conditional expectations of a true value of the asset given the market makers' partial information that includes the customers' trading decisions. The true value is modeled as a Markov process that can be observed by the customers with some noise at Poisson times. A mathematically rigorous analysis of the price‐setting problem is carried out, solving a filtering problem with endogenous filtration that depends on the bid and ask price processes quoted by the market maker. The existence and uniqueness of the bid and ask price processes is shown under some conditions.  相似文献   
34.
针对某老式卫星返回时雷达跟踪数据曾发生的测量异常及质量较差等情况,为解决此类数据在返回弹道及落点计算中出现的实际困难以及给出应对措施,基于工程实际情况给出了三种不同建模类型下的弹道计算方法——当前统计解耦扩展卡尔曼滤波(EKF)、动力学建模无迹卡尔曼滤波(UKF)、多项式滑窗最小二乘估计算法,并应用该次质量较差的实际观测数据进行了算法应用效果分析与落点计算情况对比,对计算中的经验及教训进行了总结。研究结果表明,所给出的三种算法在面对较差质量数据时性能差异较大,在工程实际应用中可考虑将多种算法互为参考。研究结果及其经验教训对卫星返回弹道及落点的实时估计的工程实施有一定的参考价值。  相似文献   
35.
The organic food category, while still small in terms of world food production, has continued to grow in many markets in the developed world. This article focuses on understanding the barriers and facilitators to purchasing organic food at the final hurdle: the point of purchase (POP). A qualitative study has identified seven factors that influence buyer behavior at the POP, and these are consumer intention to purchase organic food when entering the retail outlet; habit; availability; false assumptions; visibility and access of organic food; visual and olfactory cues; and price. These can often be the final hurdle to consumers choosing (or not) organic food at the POP.  相似文献   
36.
In Europe alone, marketers invest several hundred million of Euros in marketing activities at the point of sale every year. A prominent role is assigned to display promotions. However, despite their large practical importance, surprisingly, there is no measure to pre-evaluate different displays and their design facets so that the display which reached the best pre-evaluation results may be identified and, if poor rated facets were found, those may be altered before production and rollout of the display in question. Therefore, this paper develops and validates a scale to measure the shopper's attitude toward a point of sale display reflecting all relevant facets of a display from the shopper's point of view. Examination of the scale led to satisfactory results in terms of reliability, validity, and its predictive power for purchase intention. Summarizing, the scale can help to improve display designs prior to rollout, thus, enhancing the efficiency of display promotions.  相似文献   
37.
We develop an algorithm that forecasts cascading events, by employing a Green’s function scheme on the basis of the self-exciting point process model. This method is applied to open data of 10 types of crimes happened in Chicago. It shows a good prediction accuracy superior to or comparable to the standard methods which are the expectation–maximization method and prospective hotspot maps method. We find a cascade influence of the crimes that has a long-time, logarithmic tail; this result is consistent with an earlier study on burglaries. This long-tail feature cannot be reproduced by the other standard methods. In addition, a merit of the Green’s function method is the low computational cost in the case of high density of events and/or large amount of the training data.  相似文献   
38.
We review a rich class of point process models, Cox point processes, and illustrate the necessity of more than one observation (point patterns) in performing parameter estimation. Furthermore, we introduce a new Cox point process model by treating the intensity function of the underlying Poisson point process as a random mixture of normal components. The behaviour and performance of the new model are compared with those of popular Cox point process models. The new model is exemplified with an application that involves a single point pattern corresponding to earthquake events in California, USA.  相似文献   
39.
塔脚板是铁塔的关键部位,某些荷载大的塔脚板采用加劲板四周围焊成一圈,以目前的放样软件还不能解决该加劲板的放样,只能采用三维绘图解决,不能实现柔性设计,效率低。针对此问题,本文通过点坐标法推导出计算公式,节省放样时间,缩短加工周期。  相似文献   
40.
杜春生 《价值工程》2015,34(9):180-181
地表管井动态降水在沈阳地铁东~滂区间盾构井的应用,降水井的间距、井深、泵型、下泵深度、水泵开启时间控制,通过动态调整以上参数完成盾构井基坑开挖施工。  相似文献   
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