多任务调度实现四足机器人运动控制

基于μC/OS-Ⅱ实时操作系统的多任务调度原理,对四足机器人规划层的任务进行了划分及详细阐述,并进行了优先级的设计,最终实现了四足机器人的运动控制。     

The impact of a firm's make, pseudo-make, or buy strategy on product performance

The bulk of the product architecture and make-buy choice literature deals with product architecture changes from integral to modular form. This development is often associated with a firm's tendency to change from a make to a buy strategy. However, a few studies investigate the change of product architecture in the reverse direction - from modular to integral form - and the subsequent change in the firm sourcing decision from a buy to a make strategy. These studies hold to the presumption that a firm following a make strategy will outperform firms following a buy strategy in dealing with integral product architectures. Based on the knowledge-based view, we argue for the viability of a sourcing strategy between the pure make and buy strategies - a pseudo-make strategy. We also argue that as product architecture changes from a modular to integral form, firms adopting this pseudo-make strategy are likely to show better product performance than firms following a pure make or buy strategy due to the relative knowledge advantages of the pseudo-make strategy in dealing with the integral product architecture. We examine the impact of the make/pseudo-make/buy strategies on product performance in the U.S. bicycle derailleur and freewheel market from 1980 to 1992 and provide theoretical and managerial implications of our results. Our findings highlight an important distinction between the pseudo-make and make-buy strategies that has not previously been fully appreciated in the extant literature, and as a result increases our understanding of why some firms do not switch strategies from a buy to a make strategy when product architecture changes from modular to integral form as previously expected.     

Lean service operations: Reflections and new directions for capacity expansion in outpatient clinics

This field research in outpatient service operations examines original quantitative data on appointments and analyzes a lean process improvement project that was conducted to increase capacity to admit new patients into a healthcare service operation system. Analysis of 1726 intake appointments for the year preceding and the full year following the lean project showed a 27% increase in service capacity to intake new patients and a 12% reduction in the no-show rate as a result of the transformation of service processes achieved by the lean project. This study's action research methodology leverages the researcher's involvement in redesigning a service system that greatly improved performance and led to reflection on traditional operations management (OM) approaches to appointment scheduling. The study generates insights about effective alignment of resources, develops new strategies for service operations to respond to no-shows, reveals time-related variables that have been overlooked in appointment scheduling research, and challenges traditional OM scheduling performance measures. We provide recommendations for effective and appropriate use of overbooking and identify avenues for future research to continuously improve and increase the capacity of service operations.     

突发事件下应急物资调度评价体系研究

结合突发事件下应急物资调度的现状,提出了影响应急物资调度的4个因素:时间、成本、受灾点的满意度和敏捷性,最后运用层次分析法确定各指标的权重,经计算分析可知应急响应时间是否最短、调度方案是否体现出系统协调性及应急物资调度成本是否最小这3项指标对应急物资调度的影响程度最大。     

MULTIFRACTIONAL STOCHASTIC VOLATILITY MODELS

The aim of this work is to advocate the use of multifractional Brownian motion (mBm) as a relevant model in financial mathematics. mBm is an extension of fractional Brownian motion where the Hurst parameter is allowed to vary in time. This enables the possibility to accommodate for varying local regularity, and to decouple it from long‐range dependence properties. While we believe that mBm is potentially useful in a variety of applications in finance, we focus here on a multifractional stochastic volatility Hull & White model that is an extension of the model studied in Comte and Renault. Using the stochastic calculus with respect to mBm developed in Lebovits and Lévy Véhel, we solve the corresponding stochastic differential equations. Since the solutions are of course not explicit, we take advantage of recently developed numerical techniques, namely functional quantization‐based cubature methods, to get accurate approximations. This allows us to test the behavior of our model (as well as the one in Comte and Renault) with respect to its parameters, and in particular its ability to explain some features of the implied volatility surface. An advantage of our model is that it is able both to fit smiles at different maturities, and to take volatility persistence into account in a more precise way than Comte and Renault.     

A Western Australian Test of Invariant Factorial Structure in the Work Autonomy Scale Between Managerial and Non-Managerial Employee Classifications

ABSTRACT

This paper explores the conceptualisation of work autonomy through an investigation of the factorial structure stability of the Global Work Autonomy Scale at different employee levels. After administering the Global Work Autonomy Scale (Breaugh, 1985) to employees in a public sector organisation, analysis of responses confirmed an a priori three-factor model of work autonomy (method autonomy, scheduling autonomy and criteria autonomy) in a group of non-managerial employees (n = 193). A subsequent multi-sample analysis was conducted to test the invariance of the three-factor model for a group of managerial employees (n = 205). After constraining factor loadings and factor covariances, the hypothesised model continued to provide a reasonable fit to the data, confirming the generalisability of the three-factor model to both employee classifications. The methodological and theoretical implications for research into work autonomy are discussed.     

Scheduling-capable autonomic manager for policy-based IT change management system

Managing large IT environments is expensive and labour intensive. Maintaining and upgrading with minimal disruption and administrative support has always been a challenging task for system administrators. One challenge faced by IT administrators is arriving at schedules for applying one or more change requests to one of the system components. Most of the time, the impact analysis of the proposed changes is done by humans and is often laborious and error-prone. Although this methodology might be suitable to handle changes that are planned way ahead in time, it is completely inappropriate for changes that need to be done sooner. In addition, such manual handling does not scale well with the size of the IT infrastructure. In this article, the focus is on the problem of scheduling change requests in the presence of organisational policies governing the use of its resources. The authors propose two approaches for change management scheduling and present the implementation details of two prototypes that prove the feasibility of the proposed approaches. Their implementation is integrated with an autonomic manager which they had described in their earlier work.     

泊松积分在概率论中的应用

文章介绍了泊松积分在正态分布、二维正态分布、对数正态分布等问题中常见的应用,并给出了具体的例子。     

多元函数积分学考研试题的回顾与展望

对多元函数积分学在历年数学考研中知识点的回顾及统计分析,探究其试题来源,通过对未来试题的预测,提出备考建议。