在数学建模中培养学生创新性思维及建议

本文论述了数学建模对培养学生创新能力、提高综合素质的重要作用,指出大学生创新性思维能力的培养是数学建模活动的核心目标,对在数学建模活动中如何培养学生的创新性思维能力作了讨论,并根据学校开设数学建模课程及参加数学建模竞赛活动的现状,就如何提高数学建模成绩提出了一些建议.     

When do B2B brands influence the decision making of organizational buyers? An examination of the relationship between purchase risk and brand sensitivity

The dominant perspective on organizational buying behavior suggests that buyers tend to rely on objective criteria when making product choice decisions and that the potential influence of subjective cues, such as brands, on buyer decision making decreases with increasing risk. An alternative perspective, confirmed in this study by in-depth interviews with various managers, suggests that brands serve as a risk-reduction heuristic, whereby the influence of brands on decision making increases as a function of risk. Building on risk and information processing theories, this research builds on these complementary perspectives to propose that risk and brand sensitivity relate in a U-shaped manner, where brand sensitivity is highest in relatively low- or high-risk situations. The results of scenario- and survey-based field studies—involving 206 and 180 members of buying centers, respectively—suggest that both perspectives have merit and support the proposed nonlinear relationship. Moreover, the findings reveal that the risk-brand sensitivity relationship is moderated by competitive intensity, such that the linear (negative) and quadratic (positive) effects are stronger when competitive intensity is low.     

Accommodating spatial correlation across choice alternatives in discrete choice models: an application to modeling residential location choice behavior

This paper presents a modeling methodology capable of accounting for spatial correlation across choice alternatives in discrete choice modeling applications. Many location choice (e.g., residential location, workplace location, destination location) modeling contexts involve choice sets where alternatives are spatially correlated with one another due to unobserved factors. In the presence of such spatial correlation, traditional discrete choice modeling methods that are often based on the assumption of independence among choice alternatives are not appropriate. In this paper, a Generalized Spatially Correlated Logit (GSCL) model that allows one to represent the degree of spatial correlation as a function of a multi-dimensional vector of attributes characterizing each pair of location choice alternatives is formulated and presented. The formulation of the GSCL model allows one to accommodate alternative correlation mechanisms rather than pre-imposing restrictive correlation assumptions on the location choice alternatives. The model is applied to the analysis of residential location choice behavior using a sample of households drawn from the 2000 San Francisco Bay Area Travel Survey (BATS) data set. Model estimation results obtained from the GSCL are compared against those obtained using the standard multinomial logit (MNL) model and the spatially correlated logit (SCL) model where only correlations across neighboring (or adjacent) alternatives are accommodated. Model findings suggest that there is significant spatial correlation across alternatives that do not share a common boundary, and that the GSCL offers the ability to more accurately capture spatial location choice behavior.     

农民专业合作社自愿供给机制分析

农民专业合作社在产品(和服务)的供给上是具有"自我决策—自我筹资—自我提供"特征的自愿供给。从需求发现、供给决策、服务提供、绩效评价与监督激励、信息反馈等五个密切联系、相互呼应的环节分析农民专业合作社的自愿供给机制,发现因其具有简洁有效的需求发现机制、公开民主的决策机制、公平有效的提供机制、直接有效的绩效评价与监督激励机制、及时有效的信息反馈机制,在及时有效地满足社员的公共需求上具有独特优势,能够更迅捷、准确地了解农民的需求,实现供需均衡。     

农村公共产品多元合作供给效应实证研究

农村公共产品的多元合作供给有利于改善供给绩效。在理论研究的基础上,根据结构方程模型的相关原理构建了农村公共产品多元合作供给与供给绩效关系的假设模型。通过调查问卷的发放、分析和数据处理,获得了农村公共产品多元合作供给与供给绩效关系的相关数据。运用结构方程模型的研究方法,对假设模型进行了检验。结果表明:农村公共产品多元合作供给的各影响因素与供给绩效有显著的正相关关系,农村公共产品的多元合作供给对供给绩效有积极的正向影响作用。     

农户经济视角下的我国农村土地流转影响因素——基于Multiple Choice Model的调查研究

利用农户土地流转问卷调查所得到的微观数据,采用统计分析、Probit multiple choicemodel方法,将农户经济行为中的保障性行为、投资行为、就业行为和产业选择行为引入土地流转的实证研究领域。研究结果显示：目前的土地流转多为暂时性流转,土地流转结构性供需矛盾严重;农户对土地的需求目的更多来自于保障性需要;农户的投资行为、就业行为、社会保障行为对土地流转有着重要影响。     

浅谈培养和提高学生数学建模能力的对策

数学建模是一种数学思想方法,可以帮助学生灵活地综合地应用所学的知识来处理和解决一些现实生活中的问题.文章首先对数学建模的步骤、数学建模能力作了介绍;接着分析学生在数学建模中存在的问题,并针对问题提出培养和提高学生数学建模能力的对策.     

基于SC-FDMA的认知无线电网络的研究

物理层数据传输方案的选择是认知无线电（CR）技术能在实际中广泛应用的重要基础。给出了将SC—FDMA（单载波频分多址）技术应用于CR网络中的传输方案,并与传统的NC—OFDM（非连续的OFDM）技术进行分析比较。仿真结果和相应分析表明：在CR网络中,总体而言SC—FDMA的性能比NC—OFDM更为优良,特别是在严重的频率选择性衰落环境中,或者是当认知用户的可用频谱资源（子载波）比较稀少时,SC—FDMA的性能优势更加明显。因此SC—FDMA是一种很有前景的技术,在不久的将来有希望取代NC—OFDM,成为CR网络的物理层传输方案。     

基于QualNet的战术数据链三维动态仿真

基于QualNet仿真软 件设计并实现了战术数据链在模拟环境下的三维动态仿真。将战术数据链仿真拓展到三维空 间,加入目标的机动性因素,给出了三维仿真的动态模型及其满足的更普遍关系式,具有一 定的参考价值和指导意义。     

基于案例推理的非常规突发事件资源需求预测

近年来非常规突发事件频繁发生,严重危害了人民的生命财产安全,而如何及时预测灾害发生后的资源需求成为一个重要课题。文章提出了一种精确的预测方法,将模糊集理论,神经网络Hebb学习规则和多元线性回归与案例推理法相结合。这种方法很好地解决了非常规突发事件资源需求预测这类信息不完备、不精确问题,能够比较准确的作出资源的需求预测。该模型对灾害资源需求预测具有一定的参考价值。