施工进度管理与控制研究

目前国内一些施工工程因为进度不达标而不得不推迟工期,产生工期延误现象,进而就会造成项目不必要的工期和经济损失.施工工程延期的影响因素复杂,作为建筑工程项目管理三大控制中的一环,进度控制直接对工程造价、建筑经济以及项目社会效益产生影响,文章在对工程项目进度一般理论研究的基础上,分析人为、环境、资源、资金等影响因素,并提出适应性解决方案,为工程项目的进度管理研究提供理论基础.     

水文地质调查在地热资源勘查中的应用

在经济的发展和城市化推进的过程中,不可避免地会对自然环境造成污染与破坏,因此,有必要对污染环境进行勘察与研究,进而解决其中存在的问题,保障人们长远的生存与发展利益.其中,污染环境的地质水文勘察工作,是环境管理与保护工作中的重要环节、关键内容,更是后续工作开展的重要先决条件.本文通过对污染环境地质水文勘察技术的分析与探讨,总结分析出更有利于开展这一工作的方法与策略,提高污染环境地质水文勘察技术的应用水平.     

Improving forecasting performance using covariate-dependent copula models

Copulas provide an attractive approach to the construction of multivariate distributions with flexible marginal distributions and different forms of dependences. Of particular importance in many areas is the possibility of forecasting the tail-dependences explicitly. Most of the available approaches are only able to estimate tail-dependences and correlations via nuisance parameters, and cannot be used for either interpretation or forecasting. We propose a general Bayesian approach for modeling and forecasting tail-dependences and correlations as explicit functions of covariates, with the aim of improving the copula forecasting performance. The proposed covariate-dependent copula model also allows for Bayesian variable selection from among the covariates of the marginal models, as well as the copula density. The copulas that we study include the Joe-Clayton copula, the Clayton copula, the Gumbel copula and the Student’s $t$-copula. Posterior inference is carried out using an efficient MCMC simulation method. Our approach is applied to both simulated data and the S&P 100 and S&P 600 stock indices. The forecasting performance of the proposed approach is compared with those of other modeling strategies based on log predictive scores. A value-at-risk evaluation is also performed for the model comparisons.     

How is Benevolent Leadership Linked to Employee Creativity? The Mediating Role of Leader–Member Exchange and the Moderating Role of Power Distance Orientation

Previous research has shown that virtuous leader behavior in the form of benevolent leadership has considerable impact on employee creativity. However, little is known as to how and under what conditions these constructs are linked. In the current research, we proposed and tested a moderated mediation model positing leader–member exchange (LMX) as a mediator, and employee power-distance orientation as a moderator of this relationship. Two studies were conducted to test our hypothesized model. In Study 1, repeated measured data collected from 284 Chinese employees in an information technology company demonstrated that benevolent leadership had a lagged effect on LMX. In Study 2, analyses of multisource and lagged data from 391 Chinese employees in 42 research and development teams, and their direct supervisors indicated that benevolent leadership was positively related to supervisor-rated employee creativity via LMX. In addition, the relationship between benevolent leadership and LMX was stronger for employees high in power-distance orientation. Theoretical implications of benevolent leadership’s research and practical contributions concerning promoting creativity in organizations where benevolent leaders prevail are also discussed.     

跨越竞争丛林与范式重构：全球治理改革进程中的疫苗产业创新治理

疫苗作为新冠疫情防控的最关键手段之一，已在各国抗疫中发挥积极影响。疫苗研发、生产、注射意愿以及全球分配的公平性与可及性等一系列问题日益受到世界关注。分析全球治理改革中，疫苗作为一种全球公共产品的创新治理问题，讨论疫苗产业发展特征与创新规律演化，剖析西方国家疫苗产业创新治理困境以及“竞争丛林”逻辑，阐释中国行动方案及对全球治理改革的贡献。最终提出疫苗产业创新治理机制对推动全球治理改革的政策含义。     

Board directors with foreign experience and stock price crash risk: Evidence from China

This study examines the impact of board directors with foreign experience (BDFEs) on stock price crash risk. We find that BDFEs help reduce crash risk. This association is robust to a series of robustness checks, including a firm fixed effects model, controlling for possibly omitted variables, and instrumental variable estimations. Moreover, we find that the negative association between BDFEs and crash risk is more pronounced for firms with more agency problems, weaker corporate governance, and less overall transparency. Our findings suggest that the characteristics of board directors matter in determining stock price crash risk.     

基于FDS的体育馆火灾数值模拟分析

对体育馆的防火分区和疏散距离问题进行分析,针对存在的问题提出了相应的消防措施.建立建筑信息模型(BIM)对不同火源位置、火灾热释放速率、自动灭火系统和排烟系统的有效性进行定量分析,设置一系列火灾场景,利用FDS软件对各火灾场景下的烟气蔓延、最小清晰高度处的温度、CO浓度、能见度进行数值模拟,分析消防安全措施的有效性.模拟结果表明,在采取相应的消防措施后,该体育馆在火灾条件下能够满足整体消防安全疏散的要求.     

能效改善与能源节约：助力还是阻力

研究目标：测算中国分行业的能源回弹效应与综合能耗系数。研究方法：通过编制含能源实物流量的价值型能源投入产出可比价序列表，测算出能源回弹效应与综合能耗系数，结合行业综合能耗情况分析了能源回弹效应的行业异质性。研究发现：各行业在能耗方面表现迥异，能源回弹效应也存在典型的行业异质性；中国整体经济能源回弹程度并不高，能效改善可以有效节约能源，但整体经济低能源回弹的表象也掩盖了部分行业能源效率无改善和高能耗行业高能源回弹的事实。研究创新：从系统与结构的视角审视了行业的综合能耗情况，并给出了一种基于能源投入产出表的能源回弹效应计算方法。研究价值：有助于提出整体经济结构优化与节能减排的行业政策。     

非正规就业人员工作自主性与体面劳动感知——情绪耗竭和超时劳动的视角

与正规就业相比较,劳动者选择非正规就业的重要理由是其工作自主性.对于非正规就业人员来说,工作自主性是否能带来体面劳动感知,工作自主性对体面劳动感知影响过程中存在哪些关键变量,学术界尚未有明确的实证结论.基于工作-需求资源模型,本研究利用中国劳动力动态调查数据库对上述猜想进行实证检验,结果发现:工作自主性对体面劳动感知有显著正向作用;工作自主性显著负向影响情绪耗竭;在工作自主性与体面劳动感知之间,情绪耗竭起着部分中介作用;超时劳动负向调节工作自主性与体面劳动感知之间的关系,即超时劳动越严重,工作自主性对体面劳动感知的正向影响越弱;超时劳动在工作自主性和情绪耗竭之间不存在调节作用.通过对正规就业人员与非正规就业人员的对比分析发现,与非正规就业人员相比,正规就业人员工作自主性对情绪耗竭起着显著正向作用,超时劳动正向调节工作自主性与体面劳动感知之间的关系.     

基于经济新常态的长春市水资源开发利用潜力评价

以长春市为研究对象,基于未来经济处于新常态的发展态势,构建包含水资源、社会、经济、生态环境4个子系统的评价指标体系,并确定各指标的评价等级标准;基于模糊数学理论以及层次分析法构建包括目标层、准则层、指标层的3层模糊综合评价模型,以2015年为现状水平年,应用模型对长春市水资源开发利用潜力进行综合评价。结果表明:长春市水资源开发利用程度处于中等偏上水平,各辖区水资源开发利用规模不平衡,可通过产业结构调整提高全市用水效率,为经济持续增长提供保障。