基于模糊控制的三相异步电动机的软起动系统

本系统主要通过对模糊控制器的设计 ,将异步电动机的起动电流既限制在了一定的范围内 ,又可得到较大的起动力矩。由于又采用了参数自调整作为辅助控制 ,不但改善了起动时的动态性能 ,而且改善了稳定运行时的静态性能     

Total Factor Productivity Growth in U.S. Commercial Banking for 1935–1991: A Latent Variable Approach Using the Kalman Filter

This paper studies total factor productivity (TFP) in U.S. commercial banking for 1935–1991. TFP can contain a procyclical bias when some input factors are not freely variable, causing their shadow and market prices to differ. We correct this bias in TFP by decomposing it into its latent stochastic trend and cyclical components by employing the Kalman filter. Using the FDIC's annual aggregate data on U.S. insured commercial banks, we report that the stochastic trend has been positive during 1935–1991, with an average annual growth rate of 2.27%, and that it exhibits a decaying time path. We attribute the positive TFP growth to technical change.     

The Impact of Multinational Presence on Domestic Investment: Firm‐Level Evidence from South Korea

In order to analyze the effects of foreign multinationals' presence on domestic firms' investment, we use a detailed firm level data set from South Korea for the 2006–2014 period. We combine it with the input‐output tables provided by the Bank of Korea to construct industry level measures of multinational presence in sectors that are horizontally and vertically linked, and estimate dynamic investment equations that are augmented with these foreign presence measures. We find a positive and significant effect of foreign presence in both horizontally and vertically linked industries on domestic firm's investment rate, with larger effects arising from multinational presence in the supplying sectors. Quantitatively, a 2 percentage point increase in the presence of multinational suppliers increases the domestic firm's investment rate by 3.24 percentage points. We also find that this effect is larger for small and medium firms, private firms, nonexporters, firms that are not part of a chaebol, and for firms in external finance dependent industries. A similar 2 percentage point increase in the foreign presence in downstream sectors increases the investment rate of domestic suppliers by 0.55 percentage points. This effect is larger if the domestic firm is part of a chaebol, or is in a less external finance dependent industry. Investment increase by 0.53 percentage points following a 2 percentage point increase in horizontal linkages.     

Extending the Resource‐Based Approach to Livelihoods: An Urban Application to Turkish Gecekondu Households

This article critically examines the existing conceptualizations of and explanations for the socioeconomic behaviour of poor households in order to lay the foundations of a new model designed to extend the existing resource‐based approach to livelihoods. The proposed model groups ‘household responses to poverty’ into four key types: income generation, income allocation, consumption and investment. In explaining household responses and their poverty outcomes, it focuses on the role of different resources beyond income (e.g. social capital), along with the wider structural forces and household characteristics that influence the availability and benefit delivery capacity of these resources. The new model is shown to provide a theoretically more sophisticated framework with greater explanatory power and empirical applicability.     

Performance of investment strategies in the absence of correct beliefs

We study an evolutionary market model with long-lived assets. We show that in the absence of correct beliefs, the strategy which is “closer” to the Kelly rule cannot be driven out of the market. This means that this strategy will either dominate or at least survive. Our techniques are borrowed from the theory of random dynamical systems.     

Transformational Leadership and Organizational Innovation: The Roles of Internal and External Support for Innovation*

Leadership has been suggested to be an important factor affecting innovation. A number of studies have shown that transformational leadership positively influences organizational innovation. However, there is a lack of studies examining the contextual conditions under which this effect occurs or is augmented. Therefore, this study aimed to investigate the impact of transformational leadership on organizational innovation and to determine whether internal and external support for innovation as contextual conditions influence this effect. Organizational innovation was conceptualized as the tendency of the organization to develop new or improved products or services and its success in bringing those products or services to the market. Transformational leadership was hypothesized to have a positive influence on organizational innovation. Furthermore, this effect was proposed to be moderated by internal support for innovation, which refers to an innovation supporting climate and adequate resources allocated to innovation. Support received from external organizations for the purposes of knowledge and resource acquisition was also proposed to moderate the relationship between transformational leadership and organizational innovation. To test these hypotheses, data were collected from 163 research and development (R&D) employees and managers of 43 micro‐ and small‐sized Turkish entrepreneurial software development companies. Two separate questionnaires were used to collect the data. Employees' questionnaires included measures of transformational leadership and internal support for innovation, whereas managers' questionnaires included questions about product innovations of their companies and the degree of support they received from external institutions. Organizational innovation was measured with a market‐oriented criterion developed specifically for developing countries and newly developing industries. Hierarchical regression analysis was used to test the hypothesized effects. The results of the analysis provided support for the positive influence of transformational leadership on organizational innovation. This finding is significant because this positive effect was identified in micro‐ and small‐sized companies, whereas previous research focused mainly on large companies. In addition, external support for innovation was found to significantly moderate this effect. Specifically, the relationship between transformational leadership and organizational innovation was stronger when external support was at high levels than when there was no external support. This study is the first to investigate and empirically show the importance of this contextual condition for organizational innovation. The moderating effect of internal support for innovation, however, was not significant. This study shows that transformational leadership is an important determinant of organizational innovation and encourages managers to engage in transformational leadership behaviors to promote organizational innovation. In line with this, transformational leadership, which is heavily suggested to be a subject of management training and development in developed countries, should also be incorporated into such programs in developing countries. Moreover, this study highlights the importance of external support in the organizational innovation process. The results suggest that technical and financial support received from outside the organization can be a more important contextual influence in boosting up innovation than an innovation‐supporting internal climate. Therefore, managers, particularly of micro‐ and small‐sized companies, should play external roles such as boundary spanning and should build relationships with external institutions that provide technical and financial support. The findings of this study are especially important for managers of companies that plan to or currently operate in countries with developing economies.     

Linking of Manufacturing Strategy,Market Requirements and Manufacturing Attributes In Technology Choice: An Expert System Approach

This paper suggests a framework for acquisition of new manufacturing technology that links the manufacturing strategy, market requirements and manufacturing attributes using an expert system approach. This paper takes a closer took at traditional notion of manufacturing-marketing coordination and attempts to find its links with manufacturing capabilities provided by recent evolving new manufacturing technology. For this purpose we deal with different steps involved in the strategic evaluation process beginning with the choice of a suitable competitive strategy by a firm. Then the chosen competitive strategy is linked with the market requirements, system attributes and appropriate manufacturing technology choices. The proposed model is integrated by an expert system approach that includes strategic factors of both a tangible and an intangible nature and is implemented by using the VP-Expert shell.