Maximum Likelihood Estimation of Latent Affine Processes

This article develops a direct filtration-based maximum likelihood methodology for estimating the parameters and realizations of latent affine processes. The equivalent of Bayes' rule is derived for recursively updating the joint characteristic function of latent variables and the data conditional upon past data. Likelihood functions can consequently be evaluated directly by Fourier inversion. An application to daily stock returns over 1953-96 reveals substantial divergences from EMM-based estimates: in particular, more substantial and time-varying jump risk.

Group actions on labeled graphs and their C*-algebras

We introduce the notion of the action of a group on a labeled graph and the quotient object, also a labeled graph. We define a skew product labeled graph and use it to prove a version of the Gross-Tucker theorem for labeled graphs. We then apply these results to the $C^*$-algebra associated to a labeled graph and provide some applications in nonabelian duality.Comment: 18 pages, updated versio

Weight Control and Wrestling

This brief review article examines some of the beliefs and practices of amateur wrestlers at various levels of competition. Physicians should be aware of the rapid weight loss and weight cycling associated with the sport. These issues may become of increasing concern to pediatricians in the New York Metropolitan area, as programs such as Beat the Streets (http://www.beat-the-streets.org/index.html) increase the popularity of amateur wrestling in the region. Familiarity with the weight management practices of the sport will enable physicians to educate and monitor their patients who participate in wrestling

Questionable Behavior in the Writing Lab

In the setting of a writing center tutoring world where calibrated questioning is typically a core strategy of connecting with, evaluating, and ultimately counseling student writers, my work is an attempt to discover by examination and evaluation the effectiveness of questioning tools and techniques used by writing tutors and teachers. My purpose is to offer potential refinements to common questioning methods so as to help tutors better facilitate student writers in generating their own solutions to writing quandaries, as opposed to being led to preconceived tutor-generated solutions. The content of this paper is based upon my observations of tutoring sessions conducted by experienced tutors in the Utah State University Writing Center and my own experiences as a writing center tutor as informed by the recommended questioning strategies of The New Bedford Guide for Writing Tutors and supplemental readings of educational theorist Paulo Freire, and FBI Chief Negotiator, Christopher Voss. Ultimately this paper concludes that though tutors and teachers often use open ended questions, they use them in sequences of leading questions, the result of which is the transformation of seemingly open-ended questions into highly constrictive questions

The political theology of entropy: A Katechon for the cybernetic age

The digital revolution invites a reconsideration of the very essence of politics. How can we think about decision, control, and will at a time when technologies of automation are transforming every dimension of human life, from military combat to mental attention, from financial systems to the intimate lives of individuals? This article looks back to a moment in the 20th century when the concept of the political as an independent logic was developed, in a time when the boundaries and operations of the classic state were in question. At the same moment, a whole new technological era was opened up with the emergence of intelligent machines and computers in the postwar cybernetic age. Technology, and cybernetics in particular, loomed large in Carl Schmitt’s articulation of the concept of the political, while the problem of radical open decision was at the heart of influential cybernetic approaches to politics. Linking these was the idea of entropic decay. Schmitt’s invocation of the theological concept of the Katechon, who restrains chaos in the time before Christ’s return, in fact exemplifies the new understandings of order in a cybernetic age facing new challenges of technology in a globalized condition