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No full textAbstract American options are different to European style options in that the contract buyer has the right to exercise the option at any time on or before maturity . The freedom to exercise an American option whenever the holder wishes, introduces a boundary problem to solving the Black-Scholes equation popularly used to price the European options. The contract holder will ideally, of course, only exercise the option prior to the expiry date if the present payoff at time t exceeds the discounted expectation of the possible future values of the option from time t to T. So, only if what the holder of the options gets out of exercising early exceeds the market's view of the expected future return in keeping the option alive, early exercise of the options will take place. Otherwise, he or she will continue to hold on to the option. At every time t there will be a region of values of the underlying whereby it is best to exercise the option (Exercise region) and a complimentary region whereby it is best to keep the option (Free region). There will also be a particular value S(t) of the underlying stock which defines the optimal exercise boundary separating the two regions. In this paper, we evaluate the early exercise boundary using an efficient method developed by Ait Sahlia and Lai (1999) in R and provide numerical results and graphs
The Monster Sporadic Group and a Theory Underlying Superstring Models The Monster Sporadic Group and a Theory Underlying Superstring Models
No full textAbstract The pattern of duality symmetries acting on the states of compactified superstring models reinforces an earlier suggestion that the Monster sporadic group is a hidden symmetry for superstring models. This in turn points to a supersymmetric theory of self-dual and anti-self-dual K3 manifolds joined by Dirac strings and evolving in a 13 dimensional spacetime as the fundamental theory. In addition to the usual graviton and dilaton this theory contains matter-like degrees of freedom resembling the massless states of the heterotic string, thus providing a completely geometric interpretation for ordinary matter
Water and the Urban Fabric: a study of towns and waterscapes in the Roman period
No full textSummary This paper highlights the ways in which components of waterscapes -rivers, lakes, pools, wetlands and waterfronts -formed elements of the urban fabric in the Roman period. Urban archaeology has focused mainly on features relating to land whilst nautical archaeology, encouraging studies of rivers, ports and harbours, trade and seafaring, reminds us of the importance of watery contexts. By examining waterscapes in the urban setting we can start to break down some of the traditional dichotomies in archaeology between land and water. Water could form an integral part of the lived environment and acquire cultural meanings that can be studied archaeologically
Early rejection of gangue -How much energy will it cost to save energy?
No full textABSTRACT Comminution accounts for approximately 30 to 40% of the energy consumed on an average mine site (DOE, 2007) and somewhere from 4 to 9% of Australia's total energy consumption These technological advances have the potential to increase the throughput in the comminution circuit, while decreasing the energy consumed per tonne or ounce of metal produced. This paper investigates the energy consumed through sorting, and the optimum position of these technologies in the flow sheet, in terms of energy, cost and risk. The findings form the basis of a methodology that can identify the potential upgrades/changes required to obtain a positive return from these sorting and coarse separation techniques. Reference as: Ballantyne, G.R., Hilden, M., Powell, M.S., 2012. Early rejection of gangueHow much energy will it cost to save energy ?, In Comminution '12, ed. Wills, B. Mineral Engineering, Capetown, South Africa
Case Report Rational Suicide, Euthanasia, and the Very Old: Two Case Reports
No full textSuicide amongst the very old is an important public health issue. Little is known about why older people may express a wish to die or request euthanasia and how such thoughts may intersect with suicide attempts. Palliative care models promote best care as holistic and relieving suffering without hastening death in severely ill patients; but what of those old people who are tired of living and may have chronic symptoms, disability, and reduced quality of life? Two cases of older people who attempted suicide but expressed a preference for euthanasia were it legal are presented in order to illustrate the complexity underlying such requests. The absence of a mood or anxiety disorder underpinning their wishes to die further emphasises the importance of understanding the individual's narrative and the role of a formulation in guiding broad biopsychosocial approaches to management
(E)MIGRATING LEGENDS AND SEA CHANGE
No full textAbstract: In northwestern Europe, the migration of legends has been a growing area of study, exploring their history, development, and geographical/cultural distribution. The past two centuries have been a time of large-scale voluntary or forced migrations that have provided new opportunities for investigating how folklore, including legends, has survived and changed during mass population movements. Cape Breton Island, Nova Scotia, is foremost among the Scottish Gaelic diaspora communities, established in North America during the Highland Clearances, where oral storytelling traditions have been extensively recorded, and provides a unique opportunity for ethnologists to study survival and adaptation of various folklore genres through comparisons with those surviving in the Scottish Highlands from the early 19th century. This article will examine the kinds of legends that have travelled over the Atlantic; how they have adapted; legends that have sprung up in the new environment; and what distinctive new developments have appeared in post-migration tradition. Key words: oral storytelling, migration of legend, legends of Cape Breton Island, Scottish Gaelic diaspora, Highland traditions From the late 18th century, the Highland Clearances resulted in the removal of a large proportion of the Gaelic-speaking population of the Highlands in order to make room for sheep as a means of providing for the needs of a thriving British textile industry. A notable consequence of such economically driven policies was large-scale migration by Gaels to North America and the founding of Highland pioneer settlements. Many such Highland Diaspora communities continued a Gaelic way of life with its oral, musical, linguistic and social culture over some generations and well into the 20th century, and a few have been the subject of directed research by folklorists. Cape Breton Island in the Canadian Maritime province of Nova Scotia is the area where the demotic culture of the Gaels became most firmly established and actively transmitted over nearly two centuries. Annual numbers of Gaels immigrating to Cape Breton during the period of settlement (1800-1850) peaked around 1830. At its height toward the end of the 19th century the Gaelic-speaking population of the island and areas of the nearby mainland has been estimated to have been in excess of 30,000 (Campbell & Ennis 1990: 41), and Gaelic monoglots were known http://haldjas.folklore.ee/folklore/vol37/shaw.pd
Античные мотивы в семейной тематике портретной живописи России второй половины XVIII -начала XIX века
No full textSERVICE CONTROL IN A FINITE BUFFERED QUEUE WITH MULTIPLE SERVICE RATES SERVICE CONTROL IN A FINITE BUFFERED QUEUE WITH MULTIPLE SERVICE RATES
No full textAbstract We consider a finite buffered queue in which the queue length is controlled by dynamically selecting between two possible service rates (low and high). Using the faster service rate requires higher operating costs which may justify using the slower rate from time to time. Moreover, the system incurs holding costs for customers waiting to be processed and setup costs for each service rate change. When both service rates are close to the arrival rate, a heavy traffic (diffusion) approximation is valid for the expected queue length for this system. Furthermore, the approximating dynamic control problem has an explicit solution for a special case of the parameters which leads to an approximate solution for the general case. We present numerical examples that analyze the validity of the heavy traffic approach