皮带运输机皮带跑偏成因及解决办法

为保障皮带运输机的安全运作,避免跑偏状况出现,本文针对皮带运输机的结构和工作原理进行分析,详细研究了可能引起皮带跑偏的一些原因,并针对原因提出了相应解决办法.     

Is it still economic to build a new coal-fired power plant in the U.S.? A real option analysis

In the U.S., virtually no new coal-fired power plants have been built in recent years. Both industry experts and academics seem to believe that no rational firm will build a new coal-fired plant. Will such a trend continue in the future? To provide insights into this question, we investigate the optimal decision of an electricity company with an irreversible and deferrable opportunity to build either a new coal-fired or natural gas-fired power plant as its new base-load resource. According to our real option analysis, the optimal decision depends on the location. In the case of the eastern U.S., it is optimal to choose a natural gas plant if a firm is given a choice among a new natural gas plant, a new coal plant and deferring the investment. However, contrary to the common sentiment in the industry and academia, building a new coal plant in the western U.S. is still more economical than building a new natural gas plant in the absence of emission pricing. Furthermore, introducing carbon pricing to western U.S. states, as California did, can substantially increase the probability that a firm will optimally choose a natural gas plant over a coal plant.     

股价信息含量与投资-股价敏感性——基于融资融券的准自然实验

本文利用2006-2015年间的数据研究了融资融券对投资-股价敏感性的影响。利用融资融券作为股价信息含量的一个外生冲击变量,本文研究发现,我国A股市场确实存在反馈效应,融资融券政策的实施增强了标的公司投资-股价敏感性,这个结论在采用倾向得分模型(PSM)配对后依然成立,说明融资融券使股价融入了更多有利于管理层投资决策的信息。其次,融资融券对投资-股价敏感性的影响在机构投资者比例高、流动性高、处于新兴行业的这类管理层反馈效应更强的股票组中更显著。参照以往研究考虑了融资约束对反馈效应的调节作用,同样发现融资融券对投资-股价敏感性的影响在国有企业和规模较大的企业组中更显著。最后,融资融券交易规模越大,投资对股价的敏感性越强。     

The effect of immigrants on the extensive and intensive margins of trade

This study examines the impact of immigrants on the extensive and intensive margins of South Korean exports. Since trade data contain excessive zero trade flows, we adopt recently suggested Poisson and Gamma pseudo maximum likelihoods. ???Our finding shows that immigrant stock in South Korea has significant effect on both the extensive and intensive margins of South Korean exports. Immigrants’ network seems to decrease variable as well as fixed costs of trade.     

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.     

Using a mobile application to test the impact of giving feedback onteam-level conflict

The authors explored using a mobile application called DevelapMe for 278 business undergraduates in 54 teams to give real-time peer-based feedback during a 5-week group project. Two online surveys, Time 1 (T1) and Time 2 (T2), were administered. Results included finding three promising, new give-feedback scales: positive rating with comments, negative rating with comments, and negative/neutral rating without comments. Relationship conflict and task conflict were the outcomes. Relationship conflict significantly increased from T1 to T2. Only positive rating with comments had a significant relationship to T2 relational conflict and task conflict. Research exposing students to real-time feedback apps will prepare them for future work in teams.     

The (potential) demise of HRM?

This article seeks to provoke that human resource management (HRM), both as an academic field of study and as a form of professional practice, is at risk of impoverishment. The main reasoning for this is because of ideological individualism and marketisation with an attendant neglect on wider organisational, employee, and societal concerns. Following a review of the context of financialised capitalism, three contemporary developments in HRM are used to illustrate the argument: reward strategies, talent management, and high performance work systems. Implications for the practice of HRM and the way the subject area is taught in mainstream business schools are considered.     

Street-level new public governances in integrated services-as-a-system

The paper explores the emergence of street-level public service integration in eight cities, in five countries using a new framework: services-as-a-system to explore new public governances in health and social care integration. Data is analysed from eight cities in six countries (Australia, Canada, The Netherlands, Spain, UK, and USA) gathered in over 100 semi-structured interviews with key agents. We show that whilst culture and context shape the form and processes of governances there are underlying processual drivers of new public governances, in particular where users are involved in the co-design and co-production of integrated services.     

Audit Firm Attributes and Auditor Litigation Risk

This study examines the association between auditors' litigation risk and audit firm attributes. Using professional liability insurance premiums as a proxy for auditors' litigation risk, we present evidence that the risk is lower in audit firms having: (1) separate non-audit and audit divisions; (2) a higher proportion of partners; and (3) a higher annual growth in number of CPAs employed. Additionally, we find that the risk is higher in audit firms having: (1) operating losses; and (2) high revenue growth. Our results are consistent with the idea that audit firms' financial condition and organizational structure affect their independence/ expertise, and, in turn, their litigation risk. Our results are broadly supportive of the PCAOB's (2015) and US Department of Treasury's (2008) views that investors, audit committees, management, and other regulators could benefit from having access to financial and organizational information about audit firms.