欠驱动漂浮基空间多体系统的递推动力学

针对欠驱动漂浮基空间多体系统,将欠驱动关节分解为主动和被动关节,研究用李群和李代数表示其动力学问题.将牛顿-欧拉反向动力学方法推广到适合于含主被动关节的形式,同时得到了漂浮基空间多体系统的主被动关节递推动力学建模方法.该方法可以用于对链式、树形拓扑结构的空间系统建模,也可用于对采用有限段方法建立的柔性梁式构件的离散模型进行高效率递推计算.结果表明,用李群李代数理论中的方法和符号更有助于形成递推的高效动力学建模,得到的动力学公式简明、清晰.     

A new set of orthogonal functions and its application to the analysis of dynamic systems

The present work proposes a complementary pair of orthogonal triangular function (TF) sets derived from the well-known block pulse function (BPF) set. The operational matrices for integration in TF domain have been computed and their relation with the BPF domain integral operational matrix is shown. It has been established with illustration that the TF domain technique is more accurate than the BPF domain technique as far as integration is concerned, and it provides with a piecewise linear solution.As a further study, the newly proposed sets have been applied to the analysis of dynamic systems to prove the fact that it introduces less mean integral squared error (MISE) than the staircase solution obtained from BPF domain analysis, without any extra computational burden. Finally, a detailed study of the representational error has been made to estimate the upper bound of the MISE for the TF approximation of a function f(t) of Lebesgue measure.     

Temporal modeling of group information foraging: An application to emergency response

This work seeks to uncover and explain the dynamics of information foraging within small groups. The focus of this work is collaborative information foraging within multidisciplinary emergency response teams during the response to a simulated emergency. The study investigates how such groups distribute their effort between the activities of information seeking and handling (i.e., processing) for information that is unique (i.e., initially held by one member) versus common (i.e., initially held by multiple members). Temporal analysis is applied to the data from a laboratory study of three such groups. The results suggest that temporal analysis may be used to model distribution of effort between seeking and handling, but not how this effort is divided between common versus unique information sources. Opportunities for future research along these lines are identified and briefly discussed.     

基于SD中国技术转移系统演化的动态模型研究

技术转移是一个复杂的、非线性的动态系统,现有研究未能将技术转移系统的动态演化纳入到分析框架中。本文借鉴系统动力学方法对中国技术转移系统演化进行动态仿真研究,从纵向视角界定了技术转移系统包括技术研发系统、技术传播系统和技术应用系统及其边界,构建了技术转移系统动力学模型,运用2000年-2009年中国宏观数据,进行仿真实验。实验结果表明,政府的财政科技经费投入强度的增加带来的效果不如企业科技经费投入强度增加带来的效果,且技术传播子系统对于经费投入的敏感度并不高;最后,根据动态仿真实验结果,为促进中国技术转移系统的良性发展提出相应的政策建议。     

Design of observer-based feedback control for time-delay systems with application to automotive powertrain control

A new approach for observer-based feedback control of time-delay systems is developed. Time-delays in systems lead to characteristic equations of infinite dimension, making the systems difficult to control with classical control methods. In this paper, a recently developed approach, based on the Lambert W function, is used to address this difficulty by designing an observer-based state feedback controller via assignment of eigenvalues. The designed observer provides estimation of the state, which converges asymptotically to the actual state, and is then used for state feedback control. The feedback controller and the observer take simple linear forms and, thus, are easy to implement when compared to nonlinear methods. This new approach is applied, for illustration, to the control of a diesel engine to achieve improvement in fuel efficiency and reduction in emissions. The simulation results show excellent closed-loop performance.     

多理论视角下企业云ERP系统转换意愿研究

随着云计算的不断发展,云企业信息系统(EIS)显示出其优势,愈来愈多企业愿意考虑从传统EIS转换到云EIS系统。然而,却很少研究探讨企业在EIS的转换议题,本研究整合信息系统成功模型和技术接受模型,发展一个多理论框架去探索企业向云ERP转换的意愿。我们从企业管理者收集了199份调查问卷,通过结构方程模型验证本研究模型与假设,结果发现有用性和易用性是影响转换意愿重要因素,易用性、信息质量和系统质量则正向影响认知有用性,这些结论,给未来转换意愿研究提供了参考,我们建议云服务供应商应重视系统本身的易用性和有用性,提高系统质量并关注信息质量,以帮助他们提供企业需求的产品,吸引更多企业从传统EIS转换到云EIS。     

Technology and the generation of international knowledge spillovers: An application to Spanish manufacturing firms

In the continuing debate about the positive versus negative effects of inward investments in a host economy, a new perspective has arisen from new firms’ strategy nowadays to internationalise their activity. One aspect is that knowledge that is not completely appropriable by foreign affiliates abroad may spill over into domestic firms. In the absence of conclusive evidence, two questions can be put forward: the first concerns the role played by technology in the generation of those external effects; the second, the micro-assessment of the dynamics of technological spillovers. In this paper, results show that benefits for domestic firms in Spain differ across industries by their technological content. The hypothesis of spillover dynamics is tested and supported by the availability of panel data for manufacturing firms in the 1990s.     

Viable immersion and invariance control for a class of nonlinear systems and its application to aero-engines

This paper presents a novel approach to stabilize a class of nonlinear systems with state constraints. The motivation behind this study is the need to develop a stabilizing state feedback controller that does not require the knowledge of Lyapunov function and can regulate the states to the equilibrium while meeting the constraints. By using an integration of two relatively new tools: immersion and invariance (I&I) theory and viability theory, a sufficient condition for stability and stabilizability of a general nonlinear affine system with state constraints is derived; Then, the related results are exploited to stabilize a class of nonlinear system in feedback form and with state constraints represented by inequalities and the viable I&I stabilizing state feedback controller is obtained constructively. Further, an application to a nonlinear aero-engine model with the temperature constraint is given to illustrate the applicability and the effectiveness of the proposed method. Finally, a comparative simulation is presented, highlighting the advantages of the viable I&I controller.     

信息产业科技创新体系FC M模型动态分析

通过对我国信息产业科技创新体系中各种要素的分析,提出科技创新体系的基本框架。利用层次分析法得出各要素权重,采用模糊认知图分析不同要素间的关系,并通过对各关联因素相互影响的动态过程分析,得出信息产业科技创新的运行机制。这一机制揭示了创新体系中不同阶段各种因素权重的动态变化过程,为科技创新政策的评价提供基础的分析工具。     

胎心监护在临床应用中常见问题分析及处理措施

胎心监护是监测胎儿宫内状况的检查之一,目的在于及时发现胎儿宫内缺氧,已越来越广泛应用于临床。临床应用中,胎监曲线图常常受多种因素的影响,导致假阳性率升高和胎儿宫内窘迫的过度诊断,增加过多的产科干预。文章分析了胎心监护在临床应用中存在的问题,探讨了提高胎心监护曲线准确性的临床技术要领,指出加强临床医师素质和技能培训的重要性,也就仪器的维护和管理提出了建议。     

金融危机企业资产负债表模型对我国的适用性检验-基于动态面板数据模型的分析

摘要：本文根据我国522家制造业上市公司2001-2007年的财务数据,建立动态面板数据模型,分析了Krugman(1999)提出的金融危机企业资产负债表模型对我国的适用性。研究结论认为,在企业存在货币错配的情况下,人民币汇率波动对企业的短期信贷能力有显著的影响,但对长期信贷能力的影响还不明显。而且,这种影响是动态的,人民币汇率波动的滞后1期值比当期值对企业信贷能力的影响更加明显。因而,金融危机企业资产负债表模型对我国具有适用性。       

集群创新网络中结构对自主创新能力的作用机理分析

以系统动力学为基础,基于社会网络分析方法,从创新资源和创新知识二维角度探讨了集群创新网络中结构对自主创新能力的作用机理,构造了RK-MAD模型,并进行了Vensim仿真模拟。研究表明,集群创新网络通过结构的改变影响着集群创新资源利用效果和创新知识传播效应,从而作用于集群自主创新能力;集群自主创新能力也能够改变创新环境使创新主体因适应环境变更行为,从而影响创新网络结构的变化。集群创新网络结构平均最短路径长度与集群自主创新能力负相关,聚集程度与集群自主创新能力正相关,度分布与集群自主创新能力正相关。     

团体动力学理论在高校学生干部培养中的运用

团体动力学理论认为,团体动力取决于团体成员之间相互依存的内在关系,团体气氛、团体目标、团体规范是影响团体效能的动力因素。高校学生干部的培养可以借鉴团体动力学理论进行指导。     

运作优化对企业竞争优势的动力学分析

通过对企业优化前后的状况进行对比分析,研究企业运作优化对其竞争优势的影响,其结果表明:企业的运作是各个结构层次相互促进、相互协调的过程,运作优化从基层开始,由下而上传递至高层。     

A decision-theoretic approach to the evaluation of information retrieval systems

Evaluation research on information retrieval (IR) systems has thus far been narrowly focused and disjointed. This research attempts to narrow the gap by providing a comprehensive and integrated multiple criteria decision-theoretic approach for the evaluation of IR systems. The approach, which is based on the Analytic Hierarchy Process (AHP), is illustrated in the context of a domain-specific IR system. The novelty of this approach lies in the focus on the user aspect and the application of decision-making theories in the IR field.     

企业员工援助计划(EAP)的应用效果及导入

首先介绍了员工援助计划的涵义及内容，然后从提高员工工作生活质量、降低单位管理成本、增加员工投资回报等角度，分析了员工援助计划在西方发达国家的应用效果，最后提出了中国企业导入员工援助计划的思路。     

基于创新力与控制力动态均衡的企业持续成长路径分析

本文提出了一个关于企业持续成长路径的一般性分析框架,认为企业持续成长过程中创新力和控制力的均衡是指两力在适当的对象、适当的时机、适当的方法以及适当的力度四个方面的均衡,企业的持续成长就是创新力和控制力的统一朝着最优均衡状态不断逼近的过程。文章认为企业持续成长的关键在于建立完善的企业创新体系和企业创新推动型控制体系,并实现两者之间的有机融合。     

Building capabilities in natural resource-dependent economies: An innovation systems analysis of the TVET program in Guyana

This paper examines Guyana's technical and vocational education and training (TVET) system in relation to diversifying the country's economy away from natural resource exports. The innovation systems approach is used to examine the effectiveness of TVET as a means of building capabilities in Guyana's key industries, gold and sugar, providing a snapshot of the state of the system in early, 2016. Ten interviewees across several areas of expertise were consulted in Georgetown, Guyana. The analysis of primary and secondary research finds TVET's effectiveness to be limited by a lack of labor market information and funding, energy costs, a “brain drain”, and insufficient information communication technology skills and infrastructure. Recommended remedies include increasing the frequency of labor market surveys, attracting the Guyanese diaspora back to share knowledge, reducing the cost of energy by taking advantage of domestic renewable energy potential, and setting up a Sovereign Wealth Fund.