Скачать книгу - Revision

This comprehensive, revised edition offers how-to information for starting a small business in specialized retailing, from the mom and pop operation to a chain memorabilia store. Highly practical, it incorporates the newest developments within retail sales, including information on the changing economy (such as how e-commerce affects small business owners).

What role can the ordinary citizen perform in news reporting? This question goes to the heart of current debates about citizen journalism, one of the most challenging issues confronting the news media today. In this timely and provocative book, Stuart Allan introduces the key concept of ‘citizen witnessing’ in order to rethink familiar assumptions underlying traditional distinctions between the ‘amateur’ and the ‘professional’ journalist. Particular attention is focused on the spontaneous actions of ordinary people – caught-up in crisis events transpiring around them – who feel compelled to participate in the making of news. In bearing witness to what they see, they engage in unique forms of journalistic activity, generating firsthand reportage – eyewitness accounts, video footage, digital photographs, Tweets, blog posts – frequently making a vital contribution to news coverage. Drawing on a wide range of examples to illustrate his argument, Allan considers citizen witnessing as a public service, showing how it can help to reinvigorate journalism’s responsibilities within democratic cultures. This book is required reading for all students of journalism, digital media and society.

This book has two main purposes. On the one hand, it provides a concise and systematic development of the theory of lower previsions, based on the concept of acceptability, in spirit of the work of Williams and Walley. On the other hand, it also extends this theory to deal with unbounded quantities, which abound in practical applications. Following Williams, we start out with sets of acceptable gambles. From those, we derive rationality criteria–avoiding sure loss and coherence–and inference methods–natural extension–for (unconditional) lower previsions. We then proceed to study various aspects of the resulting theory, including the concept of expectation (linear previsions), limits, vacuous models, classical propositional logic, lower oscillations, and monotone convergence. We discuss n-monotonicity for lower previsions, and relate lower previsions with Choquet integration, belief functions, random sets, possibility measures, various integrals, symmetry, and representation theorems based on the Bishop-De Leeuw theorem. Next, we extend the framework of sets of acceptable gambles to consider also unbounded quantities. As before, we again derive rationality criteria and inference methods for lower previsions, this time also allowing for conditioning. We apply this theory to construct extensions of lower previsions from bounded random quantities to a larger set of random quantities, based on ideas borrowed from the theory of Dunford integration. A first step is to extend a lower prevision to random quantities that are bounded on the complement of a null set (essentially bounded random quantities). This extension is achieved by a natural extension procedure that can be motivated by a rationality axiom stating that adding null random quantities does not affect acceptability. In a further step, we approximate unbounded random quantities by a sequences of bounded ones, and, in essence, we identify those for which the induced lower prevision limit does not depend on the details of the approximation. We call those random quantities 'previsible'. We study previsibility by cut sequences, and arrive at a simple sufficient condition. For the 2-monotone case, we establish a Choquet integral representation for the extension. For the general case, we prove that the extension can always be written as an envelope of Dunford integrals. We end with some examples of the theory.