Spam - solutions and their problems

We analyze the success of filtering as a solution to the spam problem when used alone or concurrently with sender and/or receiver pricing. We find that filters alone may exacerbate the spam problem if the spammer attempts to evade them by sending multiple variants of the message to each consumer. Sender and receiver prices can effectively reduce or eliminating spam, either on their own or when used together with filtering. Finally, we discuss the impli- cations for social welfare of using the different spam controls.Spam; filtering; email; receiver pricing; sender pricing

Perspectives on Competition Law: Problems and Solutions

This essay suggests that it does not follow that competition between jurisdictions is good merely because competition between economic operators in pursuit of economic goals is a good thing. The result, as the discussion on television indicated, may simply be a jurisdictional mess, as Dr. Markus Wagemann put it. You end up with all sorts of people seeking to pursue their own values: cultural values, regional values, and linguistic values; and the economic operator simply does not know where he or she stands in this jurisdictional competition. This point can perhaps be completed by simply mentioning a remark made to me by Klaus Dieter Ehlermann, the former Director General of Competition and of the legal service of the Commission: ‘It is the lawyers who make the good distinctions; politicians only make the distinctions that are convenient for them.‘ It is important to begin by making sure what we are talking about. My second point arises out of Professor Dr. Friedl Weiss\u27s paper. From the vantage point of a judge, we are increasingly faced, not with a hierarchy of norms, but a competition between norms of apparently equal value. This essay then reflects that this is not the first time we have experienced a world in which there was the fullest competition between lower level jurisdictions. Third, this essay considers the importance of taking state aid into account. This essay concludes that greater jurisdictional autonomy leads to greater barriers to trade

Assessment of atomic data: problems and solutions

For the reliable analysis and modelling of astrophysical, laser-produced and fusion plasmas, atomic data are required for a number of parameters, including energy levels, radiative rates and electron impact excitation rates. Such data are desired for a range of elements (H to W) and their many ions. However, measurements of atomic data, mainly for radiative and excitation rates, are not feasible for many species and therefore calculations are needed. For some ions (such as of C, Fe and Kr) there are a variety of calculations available in the literature, but often they significantly differ from one another. Therefore, there is a great demand from the user community to have data `assessed' for accuracy so that they can be confidently applied to the modelling of plasmas. In this paper we highlight the difficulties in assessing atomic data and offer some solutions for improving the accuracy of calculated results.Comment: 17 pages of Text only with 60 References - to be published in FS&T (2013

Problems and Solutions in Knowledge Transfer

A central feature of innovation systems is that innovation arises from interaction between organizational units. This requires 'cognitive distance' that is sufficiently large to yield novelty of combinations, but not too large for mutual understanding. Two problems and solutions in the transfer of knowledge, especially to small firms, are identified and discussed. There is a problem not only of expressing tacit knowledge, but also of absorbing new knowledge when it needs to replace existing tacit knowledge. Next to issues of learning or competence development there are also issues of governance, in the management of relational risk of dependence and spillover. The analysis yields a number of tasks and functions for regional systems of innovation.knowledge transfer;regional innovation systems;small business;technology policy

Sharing practice, problems and solutions for institutional change

This chapter critiques the roles of different forms of representation of practice as part of an institutional change process. It discusses how these representations can be used both to design and to share learning activities at the various levels of decision-making in a university. We illustrate our arguments with empirical data gathered on change processes associated with an institution-wide change programme: the introduction of a new virtual learning environment (VLE). In particular, we describe a case study of the introduction of the VLE tools in a business course. We focus on two particular forms of representations to describe the essence of the innovation: a pedagogical pattern and a visual learning design. We argue that pedagogical patterns and learning design have emerged as parallel approaches to describing practice in recent years. Despite their very different origins, both provide complementary representations, which emphasize different aspects of the practice being described. We are attempting to combine these approaches. We briefly outline the Open University Learning Design initiative, of which this work is part, and describe its key underpinning philosophies. We believe our approach provides a vehicle for enabling a better articulation of design principles and the discussion of issues concerning the re-use of educational resources and activities