Heavy Traffic Limit for a Tandem Queue with Identical Service Times

We consider a two-node tandem queueing network in which the upstream queue is M/G/1 and each job reuses its upstream service requirement when moving to the downstream queue. Both servers employ the first-in-first-out policy. We investigate the amount of work in the second queue at certain embedded arrival time points, namely when the upstream queue has just emptied. We focus on the case of infinite-variance service times and obtain a heavy traffic process limit for the embedded Markov chain

THE EFFECTS OF FUTURES TRADING BY LARGE HEDGE FUNDS AND CTAS ON MARKET VOLATILITY

This study uses the newly available data from the CFTC to investigate the market impact of futures trading by large hedge funds and CTAs. Regression results show that there is a positive relationship between the trading volume of large hedge funds and CTAs and market volatility. However, a positive relationship between hedge fund and CTA trading volume and market volatility is consistent with either a private information or noise trader hypothesis. Three additional tests are conducted to distinguish between the private information hypothesis and the noise trader hypothesis. The first test consisted of identifying the noise component exhibited in return variances over different holding periods. The variance ratio tests provide little support for the noise trader hypothesis. The second test examined whether positive feedback trading characterized large hedge fund and CTA trading behavior. These results suggest that trading decisions by large hedge funds and CTAs, although influenced in small part by past price changes, are not driven by past price changes. The third test consists of estimating the profits and losses associated with the open interest positions of large hedge funds and CTAs. This test is based on the argument that speculative trading can only be destabilizing if speculators buy when prices are high and sell when prices are low, which in turn, implies that destabilizing speculators lose money. Across all thirteen markets, the profit for large hedge funds and CTAs is estimated to be just under $400 million. This implies that the trading decisions are likely based on valuable private information. Overall, the evidence presented in this study suggests trading by large hedge funds and CTAs is based on private fundamental information. These findings imply large hedge funds and CTAs benefit market efficiency by bringing valuable, fundamental information to the market through their trading.hedge fund, commodity trading advisor, volatility, market efficiency, futures markets, Marketing,

Biometric surveillance in schools : cause for concern or case for curriculum?

This article critically examines the draft consultation paper issued by the Scottish Government to local authorities on the use of biometric technologies in schools in September 2008 (see http://www.scotland.gov.uk/Publications/2008/09/08135019/0). Coming at a time when a number of schools are considering using biometric systems to register and confirm the identity of pupils in a number of settings (cashless catering systems, automated registration of pupils' arrival in school and school library automation), this guidance is undoubtedly welcome. The present focus seems to be on using fingerprints, but as the guidance acknowledges, the debate in future may encompass iris prints, voice prints and facial recognition systems, which are already in use in non-educational settings. The article notes broader developments in school surveillance in Scotland and in the rest of the UK and argues that serious attention must be given to the educational considerations which arise. Schools must prepare pupils for life in the newly emergent 'surveillance society', not by uncritically habituating them to the surveillance systems installed in their schools, but by critically engaging them in thought about the way surveillance technologies work in the wider world, the various rationales given to them, and the implications - in terms of privacy, safety and inclusion - of being a 'surveilled subject'

Barriers to career advancement for female engineers in Australia’s civil construction industry and recommended solutions

© 2019, © 2019 Engineers Australia. This study explores the challenges that have emerged from the outdated and inflexible workplace culture of the civil construction industry, and how it is affecting female engineers and women in other functional site roles. The study primarily explores issues such as the strong culture of long work hours, the perception of staff who pursue work-life balance, and the perception of part time and flexible working options within the industry. The study was conducted over three phases where members of the industry answered questionnaires on the workplace issues listed above. The first phase aimed to document a female perspective on the construction workplace culture while the second phase focused on the perceptions of the same respondents regarding the industry’s attitude to work-life balance and whether any of the aspects of workplace culture has discouraged them from staying in the industry. The final phase included men and women in management and employer roles to determine their views on part time and flexible working options within the industry. The results of the study are presented and discussed before recommendations are offered for contractor organisations, their employers and staff. The recommendations have been addressed in a way that a gradual culture change can be accepted and acted on throughout the entire workplace

Development of neuroendocrine components of the thyroid axis in the direct-developing frog Eleutherodactylus coqui: formation of the median eminence and onset of pituitary TSH production.

Direct-developing frogs lack, wholly or in part, a wide range of larval features found in metamorphosing species and form adult-specific features precociously, during embryogenesis. Most information on thyroid regulation of direct development relies on hormone manipulations; the ontogeny of many thyroid axis components has not been fully described. This analysis examines differentiation of the median eminence of the hypothalamus and production of thyroid-stimulating hormone (TSH) by the pituitary of the direct-developing frog Eleutherodactylus coqui. The median eminence is established two-thirds of the way through embryogenesis. Cells immunoreactive to human TSHb antibodies are first detected during embryogenesis and quantitative changes in TSHb-IR cells resemble those in metamorphosing amphibians. Formation of the median eminence of the hypothalamus and TSHb production by the pituitary precede or coincide with morphological changes during embryogenesis that occur during metamorphosis in biphasic anurans. Thus, while the onset of neuroendocrine regulation has changed during the evolution of direct development, it is likely that these thyroid axis components still mediate the formation of adult features

Striving for Resilience in Virginia\u27s Transportation Sector

To help address the need for increased resiliency in the Commonwealth’s transportation sector, and in furtherance of the goals set forth in the VDOT [Virginia Department of Transportation] Resilience Plan, this white paper highlights green infrastructure and natural and nature-based features as ways to increase resilience for transportation infrastructure and mitigating impacts from climate change. Additionally, this paper describes potential methods of incorporating resilient best practices with respect to Virginia’s transportation infrastructure and planning decisions. This abstract has been taken from the paper\u27s Section I, Background