微纳卫星组网星间链路设计及关键技术分析

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。     

京沪高速铁路生态现代化的思考——基于区域生态系统项目的技术经济评价模型

京沪高速铁路生态系统建设将是中国东部六省市率先实现生态现代化的重大契机,正外部性效应是京沪高速铁路生态系统项目技术经济评价的主要特征,管理部门有必要定量测算其复合生态系统的生态正外部性并使正外部效应内部化.根据京沪高速铁路生态系统的收益应该等于其具有私人品属性的正产品收益和具有正公共品属性的副产品收益之和这一原理,可以设计京沪高速铁路生态系统技术经济评价的三个主要指标,它不仅可以用于其项目评价,而且从理论上为政府最大限度地支持生态系统的发展,提供一个定量测度的工具.     

Knowledge diversity and coordination: The effect of intrafirm inventor task networks on absorption speed

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.     

烤箱风扇转速及发热管功率对烤鸡翅的影响

为探究烤箱风扇转速及发热管功率对烤鸡翅的影响,本文以肉鸡中翅为主要原料,通过改变风扇转速和发热管功率,研究不同组合条件对烤鸡翅表皮强度的影响,最后以感官评价的方式对测试结果进行验证.结果表明,相对于原样机的参数条件,改变为60％初始转速、130％初始发热功率与或130％初始转速、70％初始发热功率条件,均对鸡翅的表皮强...     

Sailing speed optimization for container ships in a liner shipping network

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.     

The Output Effect of a Transition to Price Stability When Velocity Is Time Varying

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.     

Co-creation with clients of hotel services: the moderating role of top management support

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.     

Broadband speed and unemployment rates: Data and measurement issues

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.     

正项级数收敛性的判别法的进一步研究

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。     

“模糊+PI”控制技术在开关磁阻电动机调速系统中的应用

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。