设置三角形阻流件的通道内流体流动特性研究

对常物性流体在通道内的周期性充分发展层流流动特性进行二维数值计算分析,所研究的通道是由两平行平板和交错布置于两平行平板上的多个三角形阻流件构成。给出了不同阻流件高度、顶角和间距以及不同Re 数下的流函数图和阻力特性曲线。     

Marrying personality and job resources and their effect on engagement via critical psychological states

This study examined the process by which individuals become engaged with their jobs by integrating seminal engagement theory. More specifically, we suggest that an individual factor (i.e. autotelic personality) and two contextual factors (i.e. feedback environment, job autonomy) interact to predict work engagement through three critical psychological states – namely availability, meaningfulness, and safety. This moderated mediation framework was tested using a cross section of the US population (n = 284); data were collected at two points in time with 3 months in between. Availability and meaningfulness mediated the relationship between autotelic personality and work engagement. Autotelic personality’s indirect effect on work engagement through meaningfulness and safety was conditional such that the nature of feedback environment’s effect depended on job autonomy level. Theory and practice implications are discussed.     

矿井通风三维可视化系统及优化

系统建立了三维仿真框架,建立了三维空间属性模型和非空间属性模型,分别对空间数据和非空间数据进行储存和管理。并建立了Hardy-Cross迭代模型和离散反馈型神经网络模型优化通风网络模型。并以C#语言来实现系统的功能。     

Revisiting the risk-return relation in the Chinese stock market: Decomposition of risk premium and volatility feedback effect

The empirical results of the risk-return relationship are mixed for both mature and merging markets. In this paper, we develop a new volatility model to revisit the risk-return relation of the aggregate stock market index by extending the Realized GARCH model of Hansen et al. (2012) with the Wang and Yang (2013) framework, in which the overall risk-return relation is decomposed into a risk premium and a volatility feedback effect. An empirical analysis of three major Chinese stock indices reveals positive risk premium and negative volatility feedback effect, and those findings are stable across different markets and sub-samples. However, their relative magnitudes differ between markets and varies through time.     

Separate when equal? Racial inequality and residential segregation

This paper sets out a new mechanism involving the emergence of middle-class black neighborhoods that can lead segregation in American cities to increase as racial inequality narrows. The formation of such neighborhoods requires a critical mass of highly educated blacks in the population, and leads to an increase in segregation when those communities are attractive for blacks who would otherwise reside in middle-class white neighborhoods. To assess the empirical importance of this “neighborhood formation” mechanism, we propose a two-part research design. First, inequality and segregation should be negatively related in cross section for older blacks if our mechanism operates strongly, as we find using both the 1990 and 2000 Censuses. Second, a negative relationship should also be apparent over time, particularly for older blacks. Here, we show that increased educational attainment of blacks relative to whites in a city between 1990 and 2000 leads to a significant rise in segregation, especially for older blacks, and to a marked increase in the number of middle-class black communities. These findings draw attention to a negative feedback loop between racial inequality and segregation that has implications for the dynamics of both phenomena.     

The Road to Sustainability: Exploring the Process of Corporate Environmental Strategy Over Time

We explore corporate environmental strategy over time, investigating the patterns of evolving environmental investment decisions. Longitudinal case studies provide evidence that environmental strategy evolves through a feedback process, wherein outcomes of earlier decisions have an impact on subsequent decisions. Specifically, positive feedback from outcomes like innovation triggers higher goals, enhancing the undertaking of advanced investments, whereas negative feedback from outcomes, such as increased costs, decelerates the adoption of further investments. The study points to an emergent view of environmental strategy, where capabilities that are gradually developed in concomitance with environmental outcomes lead to an upgrading of environmental goals, thus triggering the feedback process. The process eventually culminates in higher levels of environmental conduct, being more and more integrated with business strategy and competitive advantage. Managers' values and environmental attitudes influence environmental decisions and actions, affecting the acceleration of the feedback process and the magnitude of responses. Managerial implications are discussed. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment     

Monetary policy rules with PID control features: evidence from the UK,USA and EU

ABSTRACT

This paper considers the extent to which the monetary policy operations of three major central banks can be regarded as an application of Proportional-Integral-Derivative (PID) control rules. The paper outlines the general PID framework and estimates a series of dynamic models to identify how interest rate policy adjustments are affected by the rate of inflation and the level of macroeconomic activity. The paper examines data for the UK, the USA and the Eurozone. The results suggest that the PID rules can provide a useful theoretical and empirical framework for estimating central bank responses to the inflation and macroeconomic activity variables by improving the explanatory power of the Taylor rule model and determining the effect of the parameters.     

一种多功能液压试验台控制系统设计

本文介绍了一种多功能液压试验台控制系统设计,液压控制模块的设计采用了模块化设计方式,可以缩短产品设计开发周期减少开发成本。液压系统采用LUDV负载反馈控制技术能实现对不同负载压力的多个执行元件同时系统流量自动按比例分配。     

Resilience of sustainability‐oriented and financially‐driven organizations

To answer key questions concerning how negative and positive financial performance gaps motivate organizations to build more resilient systems, we develop a conceptual process model to reveal the process by which financially and sustainability‐driven organizations can translate these negative and positive financial performance gaps into organizational resilience. We specify the different modes of search behaviors that these organizations pursue when encountering negative and positive financial performance gaps. We then expand on group engagement model to theorize that vicarious search is likely to encourage limiting behaviors, whereas internal search is likely to foster promotion behaviors. Finally, we explain how both promoting and limiting behaviors can be helpful in improving organizational resilience. In this way, we hope to advance research that connects and integrates relatively disparate realms and, more specifically, to contribute to the sustainability, resilience, and performance feedback literatures.