A two-stage stochastic program for scheduling and allocating cross-trained workers

A two-stage stochastic program is developed for scheduling and allocating cross-trained workers in a multi-department service environment with random demands. The first stage corresponds to scheduling days-off over a time horizon such as a week or month. The second stage is the recourse action that deals with allocating available workers at the beginning of a day to accommodate realized demands. After the general two-stage model is formulated, a special case is introduced for computational testing. The testing helps quantify the value of cross-training as a function of problem characteristics. Results show that cross-training can be more valuable than perfect information, especially when demand uncertainty is high

Information Leakage and Informed Trading Around Unscheduled Earnings Annoucnements

While there has been much judicial discussion regarding the competency of Australia’s continuous disclosure regime with reference to contemporaneous international standards, there has to date been limited empirical analysis of the Australian system’s effectiveness in preventing selective disclosure and information leakage. This paper presents an empirical study of information content and trading behaviour around unscheduled earnings announcements – comprising of profit upgrades, profit warnings and neutral trading statements – made by ASX-listed companies during 2004. The contention is that informed trading impacts on the stock returns and trading volumes of listed entities, and hence abnormal returns or trading volumes observed prior to an announcement provide evidence of information leakage. The paper models a range of factors that potentially influence firm disclosure practices and contribute to the level information asymmetry in the market during the pre-announcement period. Previous research has investigated the influence of firm size and information content in contributing to information leakage. This study further considers the variables of firm growth, capital structure and industry group.INFORMATION LEAKAGE, UNSCHEDULED ANNOUNCEMENTS, DOWNGRADES

CCL19-sorted mature dendritic cells have enhanced lymph node migratory capacity and function

No abstract available

Duncan and the cholera test: public health in mid-nineteenth century Liverpool

Local studies have much to contribute to the study of the history of public health reform in nineteenth-century Britain. They may help elucidate the shifting margins between competition and complementarity in the efforts of local and national government. They can offer a corrective to hasty generalization from narrow, usually London-based, sources. They throw light upon the implementation of legislation and upon the local negotiation of the ideas and strategies of medical and political elites. It is equally important, however, that local studies remain aware of the national context of the issues being examined. Otherwise, the specific significance of the local study will be lost

Duncan and the cholera test: public health in mid-nineteenth century Liverpool

Local studies have much to contribute to the study of the history of public health reform in nineteenth-century Britain. They may help elucidate the shifting margins between competition and complementarity in the efforts of local and national government. They can offer a corrective to hasty generalization from narrow, usually London-based, sources. They throw light upon the implementation of legislation and upon the local negotiation of the ideas and strategies of medical and political elites. It is equally important, however, that local studies remain aware of the national context of the issues being examined. Otherwise, the specific significance of the local study will be lost

A Case Study of Pratt and Whitney Aircraft\u27s Commercial Spares Planning

This case study, which can be used as a teaching case, deals with jet engine spare parts planning at Pratt and Whitney Aircraft Company, a division of United Technologies Corporation. The case includes background on the company\u27s history and an overview of their jet engine manufacturing operations. The primary focus of the case is on the application and evaluation offorecasting models for demand planning within an ERF system environment. An Excel-based decision support system (DSS), which is available from the authors upon request, enables the evaluation of alternative time series forecasting models for a variety of jet engine spare parts. The DSS workbook replicates the many features and options available in SAP\u27s forecasting system, which has been purchased by Pratt and Whitney

Boron nitride nanotubes : pronounced resistance to oxidation

Boron nitride (BN) nanotubes have the same nanostructure as carbon nanotubes but are found to exhibit significant resistance to oxidation at high temperatures. Our systematic study has revealed that BN nanotubes are stable at 700 &deg;C in air and that some thin nanotubes (diameter less than 20 nm) with perfect multiwalled cylindrical structure can survive up to 900 &deg;C. Thermogravimetric analysis reveals an onset temperature for oxidation of BN nanotubes of 800 &deg;C compared with only 400 &deg;C for carbon nanotubes under the same conditions. This more pronounced resistance of BN nanotubes to oxidation is inherited from the hexagonal BN and also depends on the nanocrystalline structure. This high level of resistance to oxidation allows promising BN nanotube applications athigh temperatures<br /

Systematic literature review of hand gestures used in human computer interaction interfaces

Gestures, widely accepted as a humans' natural mode of interaction with their surroundings, have been considered for use in human-computer based interfaces since the early 1980s. They have been explored and implemented, with a range of success and maturity levels, in a variety of fields, facilitated by a multitude of technologies. Underpinning gesture theory however focuses on gestures performed simultaneously with speech, and majority of gesture based interfaces are supported by other modes of interaction. This article reports the results of a systematic review undertaken to identify characteristics of touchless/in-air hand gestures used in interaction interfaces. 148 articles were reviewed reporting on gesture-based interaction interfaces, identified through searching engineering and science databases (Engineering Village, Pro Quest, Science Direct, Scopus and Web of Science). The goal of the review was to map the field of gesture-based interfaces, investigate the patterns in gesture use, and identify common combinations of gestures for different combinations of applications and technologies. From the review, the community seems disparate with little evidence of building upon prior work and a fundamental framework of gesture-based interaction is not evident. However, the findings can help inform future developments and provide valuable information about the benefits and drawbacks of different approaches. It was further found that the nature and appropriateness of gestures used was not a primary factor in gesture elicitation when designing gesture based systems, and that ease of technology implementation often took precedence

History of the software industry: the challenge

Martin Campbell-Kelly opened a new field in the history of computing in his groundbreaking From airline reservation to Sonic the Hedgehog; a history of the software industry. The book is discussed by Adrienne van den Bogaard and Frank Veraart and by Gerard Alberts, followed by a reply by the author. Van den Bogaard and Veraart join great appreciation for the three-sector division Campbell-Kelly developed to describe the history of the software industry, to a slight criticism of his ad hoc-argumentation in explaining why in each sector some enterprises survive and others do not. Lacking, in their view, is a discussion of the dynamics of software itself in the context of emerging practices and businesses. Alberts overcomes his prima facie unease with th