哈尔滨市快递自提点空间布局与影响因素研究

快递自提点作为解决物流"最后一公里"服务瓶颈问题的关键,逐渐成为地理学研究新的关注点.本文基于2020年3月哈尔滨市菜鸟驿站和邮政站点的POI数据,综合运用文本分析、数理统计等方法,分析哈尔滨市快递自提点的空间布局特征和影响因素,研究发现:哈尔滨市快递自提点存在布局不平衡现象已初步显现,市辖区快递自提点布局存在冗余和空间浪费现象,而远郊县快递自提点存在建设较薄弱等问题,并有针对性地提出了哈尔滨市快递网点布局服务体系的优化对策.     

城市综合管沟热力与电力管线同舱敷设可行性研究

综合管沟中热力管线由于温度较高通常独立分舱敷设,以免影响其他管线正常运行,电力线缆对温度较为敏感,高温状态下会加速电缆绝缘层老化增加事故风险.由于场地条件局限或造价成本限制,综合管沟有时采用单舱形式,在这种情况下热力管线产生的热量是否会影响电力线缆的运行和安全性能值得讨论.以某综合管沟项目为例,通过散热量计算管沟温度,分析热力管线对供电电缆的影响,为实际工程设计提供一些参考.     

失败学习对企业绩效的影响机制研究

已有文献认为失败学习对企业绩效具有重要作用，但失败学习通过何种途径促进企业绩效提升的研究并不完善。基于失败学习理论，引入资源拼凑和机会识别作为中介变量，构建失败学习影响企业绩效的多路径模型，探索失败学习对企业绩效的驱动路径及内在机理。实证结果表明：失败学习对企业绩效具有显著积极作用，资源拼凑和机会识别分别在失败学习与企业绩效之间起中介作用，资源拼凑和机会识别在失败学习对企业绩效驱动过程中存在链式中介作用，战略柔性能够强化资源拼凑与企业绩效之间的关系，并正向调节资源拼凑的中介作用。研究结论拓展了失败学习对企业绩效的影响路径，对企业复苏和成长具有重要启示。     

Structural estimation of behavioral heterogeneity

We develop a behavioral asset pricing model in which agents trade in a market with information friction. Profit‐maximizing agents switch between trading strategies in response to dynamic market conditions. Owing to noisy private information about the fundamental value, the agents form different evaluations about heterogeneous strategies. We exploit a thin set—a small sub‐population—to point identify this nonlinear model, and estimate the structural parameters using extended method of moments. Based on the estimated parameters, the model produces return time series that emulate the moments of the real data. These results are robust across different sample periods and estimation methods.     

Stochastic Payments per Claim Incurred

We propose a Bayesian model to quantify the uncertainty associated with the payments per claim incurred (PPCI) algorithm. Based on the PPCI algorithm, two submodels are proposed for the number of reported claims run-off triangle and the PPCI run-off triangle, respectively. The model for the claims amount is then derived from the two submodels under the assumption of independence between the number of incurred claims and the PPCI. The joint likelihood of the number of reported claims and claims amount is derived. The posterior distribution of parameters is estimated via the Hamiltonian Monte Carlo (HMC) sampling approach. The Bayesian estimator, the process variance, the estimation variance, and the predictive distribution of unpaid claims are also studied. The proposed model and the HMC inference engine are applied to to an empirical claims dataset of the WorkSafe Victoria to estimate the unpaid claims of the doctor benefit. The Bayesian modeling procedure is further refined by including a preliminary generalized linear model analysis. The results are compared with those in a PwC report. An alternative model is compared with the proposed model based on various information criteria.     

基于Python平台通过单因子指标法进行地下水质量评价

水质评价关系到水质质量,常见的评价方法有层次分析法、综合评价法等,这些方法评价过程非常复杂,单因子评价方法相比具有操作容易.实际中单因子进行评价时存在概念理解难、计算容易出错等问题.为解决单因子计算问题,本文提出采用Python编程语言进行单因子评价.本文详细分析了Python进行单因子评价流程,从数据采集、数据清洗、数据处理、系统实现进行分析.应用结果表明基于Python编程的单因子评价方法具有评价效率高、准确度高优点.     

内隔墙对小尺寸基坑围护结构变形特性影响研究

深基坑开挖对基坑变形及周围环境的影响一直是工程中关心的问题.而利用好基坑的空间效应则可以控制好变形.本文采用plaxis有限元分析对利用内隔墙产生的二次空间效应来控制基坑变形的影响,分析了内隔墙的刚度、埋入深度和基坑尺寸之间的相互影响.分析结果对城市中心复杂环境下施工过程中对基坑的监测和周围环境保护有较好的指导作用.     

Close relationship with the supervisor may impede employee creativity by suppressing vertical task conflict

Leader‐member exchange as a form of supportive leadership is expected to foster employee creativity. However, empirical evidence suggested this relationship is complex. This study attempts to address this complexity by proposing and testing a curvilinear mechanism, which attenuates the overall positive effect of LMX on creativity by transmitting a curvilinear indirect effect via vertical task conflict. Results drawn from a sample of 276 supervisor–subordinate dyads provided support for the hypothesized curvilinear indirect effect. Specifically, LMX was found to negatively influence employee creativity by suppressing vertical task conflict for subordinates in high‐quality LMX relationships, while the indirect effect was not significant for subordinates in low‐quality LMX relationships.     

企业上市、专利突击与经营绩效——基于创业板上市公司的经验证据

以2009-2018年中国创业板公司为样本,考察公司上市前的专利突击现象,检验专利突击行为对专利质量和经营业绩的影响.研究发现:第一,创业板上市公司IPO前存在明显的专利突击现象,具体表现为专利申请数量在上市前激增,在上市后增长停滞;第二,创业板公司专利突击行为降低了专利质量和上市后的长期经营业绩;第三,相较于发明专利,非发明专利的上市前突击现象更明显;第四,2014年证监会关于创业板上市公司在招股说明书中对专利信息披露的有关规定改变了公司专利申请策略,申请时间前移,上市前已申请但未授权的专利占比降低.最后,企业突击申请专利会使投资者高估公司价值,从而损害投资者利益.研究结论有利于理解我国"专利泡沫"现象的制度诱因,对完善创业板制度和实现注册制转型具有借鉴意义.     

Personal Income Tax Reform in China in 2018 and Its Impact on Income Distribution

In the context of personal income tax (PIT) reform in China in 2018, this paper examines some of the major issues of concern regarding the reform and income distribution. Using the China Personal Income Tax Micro‐simulation model, the paper compares the differences between the 2011 and 2018 PIT systems, and finds that residents relying on different income sources may face a large degree of real tax rate change. Once the tax system is altered to PIT 2018, the coverage of PIT for wage earners will decrease from 46.9 to 23.4 percent, the income redistributive effect will drop from 1.95 to 1.22 percent and the PIT's role in fiscal revenue will also be negatively affected. Nevertheless, if individual income continues to grow, the share of PIT in fiscal revenue is expected to return to the 2018 level in 2022, but its income redistribution function is difficult to recover in the short term. The paper finds that the effect of PIT on income distribution depends on the tax structure. Gradual transition to an “entirely comprehensive” tax system when conditions are appropriate will achieve better income redistribution results at a lower average tax rate.