浅析大学英语教学中的跨文化交际

大学英语教学不仅要传授学生基本的语言知识,而且要注重培养学生英语的综合应用能力,提高学生综合文化素养和跨文化交际的能力。     

Romer revisited: long-term changes in the cyclical sensitivity of unemployment

In this paper we employ microeconomic evidence on the unemployment experiences of American males to evaluate the sensitivity of unemployment to business cycle fluctuations in the late nineteenth century as compared to the mid-twentieth century. Our results indicate a substantial decline in the value of the Okun coefficient (from −0.65 to −0.32) between the 1890s and the 1960s. These findings challenge Christina Romer’s interpretation that the measured decline in cyclical volatility of unemployment over the twentieth century was created by improvements in the statistical record. Rather, it was changes in the underlying dynamics of the labor market over the cycle, most notably the transition to procyclical productivity patterns and the shift from an added to a discouraged worker effect among secondary workers, which may be summarized as the development of modern labor market behavior, that account for the declining cyclical sensitivity of employment and the drop in the cyclical volatility of unemployment over the century.

Addressing unobserved endogeneity bias in accounting studies: control and sensitivity methods by variable type

Together with their associated statistical routines, this paper describes the control and sensitivity methods that can be employed by accounting researchers to address the important issue of unobserved (omitted) variable bias in regression and matching models according to the types of variables employed. As with other social science disciplines, an important and pervasive issue in observational (non-experimental) accounting research is omitted variable bias (endogeneity). Causal inferences for endogenous explanatory variables are biased. This occurs in regression models where an unobserved (confounding) variable is correlated with both the dependent (outcome) variable in a regression model and the causal explanatory (often a selection) variable of interest. The Heckman treatment effect model has been widely employed to control for hidden bias for continuous outcomes and endogenous binary selection variables. However, in accounting studies, limited (categorical) dependent variables are a common feature and endogenous explanatory variables may be other than binary in nature. The purpose of this paper is to provide an overview of contemporary control methods, together with the statistical routines to implement them, which extend the Heckman approach to binary, multinomial, ordinal, count and percentile outcomes and to where endogenous variables take various forms. These contemporary methods aim to improve causal estimates by controlling for hidden bias, though at the price of increased complexity. A simpler approach is to conduct sensitivity analysis. This paper also presents a synopsis of a number of sensitivity techniques and their associated statistical routines which accounting researchers can employ routinely to appraise the vulnerability of causal effects to potential (simulated) unobserved bias when estimated with conventional regression and propensity score matching estimators.     

募集资金投向变更信息披露的市场敏感性实证研究

本文以上市公司募集资金投向变更信息披露的市场敏感性作为研究对象,通过理论和实证分析来研究募集资金投向变更的相关问题。对影响我国上市公司募集资金投向变更的因素和募集资金投向变更这一消息对于市场敏感性进行了回归分析。分析发现上市公司是否为首次变更募集资金投向和是否存在关联交易与变更前后的累积超常收益率存在着显著的负相关,而公司的净资产收益率与变更前后的累积超常收益率存在着显著的正相关。接着使用Logit回归模型验证了上述结论。最后,本文根据上文中募集资金投向变更信息披露的敏感性反应的相关因素,提出了一系列建议。     

冗余资源对环保投资的影响——基于高水敏感性行业A股上市公司的实证研究

高水敏感性行业不仅导致水污染严重,而且对水资源的依赖超过其他行业。以2015—2020年高水敏感性行业的A股上市公司为样本,实证分析冗余资源与环保投资的内在关系,结果表明:冗余资源与企业环保投资之间存在显著的倒“U”型关系,适度冗余资源提升企业环保投资水平,过多冗余资源则降低企业环保投资水平。此外,管理层过度自信会弱化冗余资源与企业环保投资之间的倒“U”型关系。     

中俄天然气管线的光纤预警系统数据处理方法

光纤管道安全光纤预警系统是基于瑞利相干分布式光纤振动传感系统(DVS),以与管道同沟敷设的通信光缆作为传感器,全天候实时监测管道周围土壤震动,可以实时监测土壤的振动数据,一旦发生危害管道安全的破坏事件,系统能第一时间感知.在中俄天然气管道东线,系统长期运行在低温环境下,灵敏度降低,亟须新的数据处理方法提高系统灵敏度.以信噪比作为灵敏度衡量标准,分析当前普遍使用的差分算法的优势和劣势.建立数学模型,得到差分算法提高信号信噪比的条件.通过MATLAB仿真,得到信号频率分布范围与最佳差分方式对应表格.提出一种新的灵敏度提升算法流程,对不同频率分布的信号均起到最佳的灵敏度提升效果,克服了原差分方式的劣势.现场试验表明,采用新算法后信噪比有明显提高.     

Do Improvements in the Information Environment Enhance Insiders’ Ability to Learn from Outsiders?

We examine whether and how an exogenous shock to the information environment changes insiders’ ability to learn from outsiders. We document three main findings. First, we find an increase in investment‐to‐price sensitivity following the adoption of International Financial Reporting Standards (IFRS). Second, we show that the relation between the market reaction to M&A deal announcements and the likelihood of deal completion becomes stronger after IFRS adoption. Third, we find significant improvements in post‐acquisition operating and stock return performance post‐IFRS adoption. These results are more pronounced for firms that experienced significant increases in foreign institutional ownership around IFRS adoption, especially when these foreign investors are from countries that matter for the firm’s growth opportunities. Taken together, our findings suggest that insiders’ ability to learn from outsiders improves post‐IFRS, and this improved ability to learn from outsiders leads to real economic gains.     

A Dynamic Model of the Firm: Structural Explanations of Key Empirical Findings

We derive a dynamic model of the firm in the spirit of the trade‐off theory of capital structure that explains firm behavior in terms of firm characteristics. We show our model is consistent with many important findings about the cross‐section of firms, including the negative relations between profitability and leverage, and between dividends and investment‐cash flow sensitivities. The model also explains the existence of zero‐debt firms and their observed characteristics. These results have been used to challenge the trade‐off theory and the assumption of perfect capital markets. We revisit these critiques and provide structural explanations for the regularities we replicate.     

二次雷达数字时间灵敏度控制处理的实现

如何有效剔除二次雷达系统中存在的干扰目标,提升设备的处理能力和效率,一直是系统最关注的方向之一。区别于传统信道接收机灵敏度简单调节的方法,提出了一种基于可编程门阵列（FPGA）实时计算目标应答信号强度的方法,通过设置有效应答信号范围,在应答脉冲处理阶段剔除时间灵敏度控制（STC）门限外由多径及异步等引起的干扰脉冲,减少了后期处理的信息数据,提升了系统效率和系统的多目标处理能力。通过外场实验验证,该方法能有效减少二次雷达系统内70%的虚警目标。     

辽宁省生态功能区划研究

生态功能区划是根据区域生态系统类型、生态系统受胁迫过程与效应、生态环境敏感性、生态服务功能重要性等特征的空间分异性而进行的地理空间分区,为产业布局、生态环境保护与建设规划提供科学依据。该文在对区域生态环境特征分析的基础上,依据建立的生态功能区划原则、方法和指标体系,以辽宁省生态系统为对象,在生态系统受胁迫过程与效应、生态环境敏感性和生态系统服务功能等指标的基础上,形成了辽宁省生态功能的区划方案,将辽宁省分为3个生态区、14个生态亚区、30个生态功能区。