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21.
本文采用电感型接近开关,设计了一种用于检测皮带机带速的保护开关,实现了皮带机的欠速保护,并在日照港裕廊股份有限公司皮带机中成功应用。  相似文献   
22.
徐虎 《经济经纬》2006,2(3):10-12
在如何科学认识经济发展规律,正确把握经济的增长速度方面,我们党有着十分丰富的经验和教训。邓小平在总结这些经验教训的基础上,对我国经济增长速度与社会文明进步、国家稳定发展和深化改革开放、经济快速发展与改善人民生活等许多重大问题,形成了非常深刻与独到的认识。  相似文献   
23.
微纳卫星组网应用可大幅度提高航天装备的能力,较单颗大卫星具有明显的优势。首先,介绍了国内外微纳卫星组网的研究情况,以组网侦察应用为例分析了星间测量与通信链路的技术需求,并进行了系统架构和体制设计;其次,在星座设计基础上开展系统仿真,并提出了一体化设备实现方案;最后,分析了微纳卫星组网系统中几项重要的关键技术及其解决方案,对系统的设计和工程实现具有参考价值。  相似文献   
24.
Research Summary: We combine the absorptive capacity and social network theory approaches to predict how intrafirm “whole” network characteristics affect the firm's speed of absorption of external knowledge to produce inventions. We start from the widely accepted view that distant, externally‐developed knowledge is difficult to absorb into the focal firm's own knowledge production. We suggest that high levels of intrafirm inventor task network diversity and task network density are essential for a diversity of knowledge inputs and coordinated actions regarding knowledge transfer, which in turn, reduces problems related to the absorption of knowledge—especially in the case of knowledge that is distant from the focal firm. The results of an event history study of 113 pharmaceutical firms that engaged in technology in‐licensing from 1986 to 2003 provide general support for our hypotheses. Managerial Summary: Firms keen to keep up with an uncertain and ever‐changing industry environment, can benefit from the speedy introduction of inventions. We examine how firms absorb licensed‐in technologies to nurture the rapid development of own related inventions. We show that a firm's absorption speed depends on the characteristics of the internal collaboration networks among the firm's inventor employees. More specifically, technologically diverse and well‐connected inventor networks improve the firm's ability to absorb external technologies quickly. This applies especially to externally acquired technologies that are unfamiliar to the firm. Depending on the distance of the acquired technology from the focal firm combined with speed‐inducing inventor network characteristics, our estimates suggest that firms can reduce the time needed for absorption by several months.  相似文献   
25.
This paper first calibrates the bunker consumption - sailing speed relation for container ships using historical operating data from a global liner shipping company. It proceeds to investigate the optimal sailing speed of container ships on each leg of each ship route in a liner shipping network while considering transshipment and container routing. This problem is formulated as a mixed-integer nonlinear programming model. In view of the convexity, non-negativity, and univariate properties of the bunker consumption function, an efficient outer-approximation method is proposed to obtain an ε-optimal solution with a predetermined optimality tolerance level ε. The proposed model and algorithm is applied to a real case study for a global liner shipping company.  相似文献   
26.
This paper explores the effect of time‐varying velocity on output responses to policies for reducing/stopping inflation. We study a dynamic general equilibrium model with sticky prices in which we introduce time‐varying velocity. Specifically, we endogenize time‐varying velocity into the model developed by Ireland (1997) for analyzing optimal disinflation. The nonlinear solution method reveals that, depending on velocity, the “disinflationary boom” found by Ball (1994) may disappear even under perfect credibility and that early output losses may be much larger than previously thought. Indeed, we find that a gradual disinflation from a low inflation may even be undesirable.  相似文献   
27.
Hotels can strengthen their competitiveness by expanding their innovation process beyond the boundaries of the firm to exploit the valuable knowledge and skills of their customers. This study examines the effects of new service (NS) co-creation with customers in the hotel industry on NS performance, as well as the moderating role of top management support. The research also explores the main barriers faced by hotels to co-create service innovations. Partial least squares structural equation modelling results indicate that Customer co-creation exerts a direct impact on NS market outcomes and NS development (NSD) speed, which in turn favours NS quality. NS quality translates into better NS customer-related outcomes as well as in improved NS market outcomes. Top management support enhances the effect of Customer co-creation on the NSD speed. The main barrier to NS co-creation in hotels is to find customers interested in devoting time to this activity or with the appropriate knowledge and experience.  相似文献   
28.
We examine the effects of broadband speed on county unemployment rates in the U.S. state of Tennessee. We merge the older National Broadband Map dataset and the newer FCC dataset in lengthening our broadband access data over the period 2011–2015. Extending the dataset improves the precision of the estimates. Our panel regressions control for potential selection bias and reverse causality and show that broadband speed matters: unemployment rates are about 0.26 percentage points lower in counties with high speeds compared to counties with low speeds. Ultra-high speed broadband also appears to reduce unemployment rates; however, we are unable to distinguish between the effects of high and ultra-high speed broadband. We document beneficial effects of the early adoption of high speed broadband on unemployment rates. Better quality broadband appears to have a disproportionately greater effect in rural areas.  相似文献   
29.
骞龙江 《价值工程》2011,30(26):152-153
用初等方法深入研究了正向级数判别法,基于比值判别法和根值判别法判别法思想,研究了更高精度判别法,给出不断提高精度的判别法的构造思想以及一般性定理。  相似文献   
30.
“模糊+PI”控制技术在开关磁阻电动机调速系统中的应用   总被引:2,自引:0,他引:2  
着重研究“模糊 +PI”控制技术在开关磁阻电动机调速系统中的具体应用 ,对解决开关磁阻电动机调速系统的显著非线性问题 ,提高开关磁阻电动机调速系统动态特性做了探讨 ,为开关磁阻调速电动机向更宽、更广的应用领域发展提出了自己的见解 ,以供进一步研究开关磁阻电动机调速系统参考。  相似文献   
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