Double Exponential Instability of Triangular Arbitrage Systems

If financial markets displayed the informational efficiency postulated in the efficient markets hypothesis (EMH), arbitrage operations would be self-extinguishing. The present paper considers arbitrage sequences in foreign exchange (FX) markets, in which trading platforms and information are fragmented. In Kozyakin et al. (2010) and Cross et al. (2012) it was shown that sequences of triangular arbitrage operations in FX markets containing 4 currencies and trader-arbitrageurs tend to display periodicity or grow exponentially rather than being self-extinguishing. This paper extends the analysis to 5 or higher-order currency worlds. The key findings are that in a 5-currency world arbitrage sequences may also follow an exponential law as well as display periodicity, but that in higher-order currency worlds a double exponential law may additionally apply. There is an "inheritance of instability" in the higher-order currency worlds. Profitable arbitrage operations are thus endemic rather that displaying the self-extinguishing properties implied by the EMH.Comment: 22 pages, 22 bibliography references, expanded Introduction and Conclusion, added bibliohraphy reference

Safety hazards associated with the charging of lithium/sulfur dioxide cells

A continuing research program to assess the responses of spirally wound, lithium/sulfur dioxide cells to charging as functions of charging current, temperature, and cell condition prior to charging is described. Partially discharged cells that are charged at currents greater than one ampere explode with the time to explosion inversely proportional to the charging current. Cells charged at currents of less than one ampere may fail in one of several modes. The data allows an empirical prediction of when certain cells will fail given a constant charging current

Chemical analysis of charged Li/SO(sub)2 cells

The initial focus of the program was to confirm that charging can indeed result in explosions and constitute a significant safety problem. Results of this initial effort clearly demonstrated that cells do indeed explode on charge and that charging does indeed constitute a real and severe safety problem. The results of the effort to identify the chemical reactions involved in and responsible for the observed behavior are described

High Rate Discharge Studies of LI/SO2 Batteries

A battery composed of twelve lithium/sulfur dioxide D size cells in series is forced discharged at 21 amperes. This current is established by the proposed use of the battery and represented a discharge condition which might produce venting. Discharge of the battery into voltage reversal results not only in cells venting but also in the violent rupture of at least one cell

Determining the influence and effects of manufacturing variables on sulfur dioxide cells

A survey of the Li/SO2 manufacturing community was conducted to determine where variability exists in processing. The upper and lower limits of these processing variables might, by themselves or by interacting with other variables, influence safety, performance, and reliability. A number of important variables were identified and a comprehensive design experiment is being proposed to make the proper determinations

Furthering alternative cultures of valuation in higher education research

The value of higher education is often implicit or assumed in educational research. The underlying and antecedent premises that shape and influence debates about value remain unchallenged which perpetuates the dominant, but limiting, terms of the debate and fosters reductionism. I proceed on the premise that analyses of value are not self–supporting or self-referential but are embedded within prevailing cultures of valuation. I contend that challenging, and providing alternatives to, dominant narratives of higher education requires an appreciation of those cultures. I therefore highlight some of the existing cultures of valuation and their influence. I then propose Sayer’s concept of lay normativity as a culture of valuation and discuss how it translates into the practices of research into higher education, specifically the practice of analysis. I animate the discussion by detecting the presence of lay normativity in the evaluative space of the capability approach

Let me entertain you: the ambivalent role of university lecturers as educators and performers

In England, higher education is more marketised than ever before as the difference between students and consumers is increasingly blurred, propelled by the rise in tuition fees. With students demanding more for their money, the role of university lecturers continues to change. This study explores the ways in which lecturers re-evaluate and reconstruct their roles and responsibilities in light of heightened student expectations. We draw on 30 in-depth interviews with lecturers from the social sciences, across two post-1992 universities in England, where tuition fees have tripled since 2012. We focus on lecturers’ views and experiences of student expectations, as well as the support available to students as we shift towards a more consumerist approach in higher education. We find examples of tension between academic values and consumeristic student expectations as lecturers discuss their precarious positions as an educator as well as an entertainer. We believe that the expanding role of lecturers merits an urgent review at the institutional and national level, to promote and ensure clarity of the boundaries and expectations of teaching staff

The geographies of access to enterprise finance: the case of the West Midlands, UK

The geographies of access to enterprise finance: the case of the West Midlands, UK, Regional Studies. Whilst there is a long history of credit rationing to small and medium-sized enterprises (SMEs) in the UK, the financial crisis has seen banks retreat further from lending to viable SMEs due to a reassessment of risk and lack of available capital. In so doing, the credit crunch is thought to be creating new geographies of financial exclusion. This paper explores the financial inclusion of enterprise through community development finance institutions (CDFIs) which provide loan finance to firms at the commercial margins in the West Midlands, UK. The paper concludes that CDFIs could partially address the financial exclusion of enterprise as an additional, alternative source of finance to that of mainstream banks

A Classification of Minimal Sets of Torus Homeomorphisms

We provide a classification of minimal sets of homeomorphisms of the two-torus, in terms of the structure of their complement. We show that this structure is exactly one of the following types: (1) a disjoint union of topological disks, or (2) a disjoint union of essential annuli and topological disks, or (3) a disjoint union of one doubly essential component and bounded topological disks. Periodic bounded disks can only occur in type 3. This result provides a framework for more detailed investigations, and additional information on the torus homeomorphism allows to draw further conclusions. In the non-wandering case, the classification can be significantly strengthened and we obtain that a minimal set other than the whole torus is either a periodic orbit, or the orbit of a periodic circloid, or the extension of a Cantor set. Further special cases are given by torus homeomorphisms homotopic to an Anosov, in which types 1 and 2 cannot occur, and the same holds for homeomorphisms homotopic to the identity with a rotation set which has non-empty interior. If a non-wandering torus homeomorphism has a unique and totally irrational rotation vector, then any minimal set other than the whole torus has to be the extension of a Cantor set.Comment: Published in Mathematische Zeitschrift, June 2013, Volume 274, Issue 1-2, pp 405-42

Student budgets and widening participation: Comparative experiences of finance in low and higher income undergraduates at a Northern Red Brick University

Drawing on a thematic analysis of longitudinal qualitative data (ntotal = 118), this article takes a “whole student lifecycle” approach to examine how lower and higher income students at an English northern red brick university variously attempted to manage their individual budgets. It explores how students reconcile their income—in the form of loans, grants, and bursaries—with the cost of living. Four arenas of interest are described: planning, budgeting, and managing “the student loan”; disruptions to financial planning; the role of familial support; and strategies of augmenting the budget. In detailing the micro‐level constraints on the individual budgets of lower and higher income undergraduates, the article highlights the importance of non‐repayable grants and bursaries in helping to sustain meaningful participation in higher tariff, more selective, higher education institutions. It also supports an emerging body of literature that suggests that the continuing amendments to the system of funding higher education in England are unlikely to address inequality of access, participation, and outcome