4,459 research outputs found
Reconfiguration based built-in self-test for analogue front-end circuits
Previous work has shown that it is feasible to implement a fully digital test evaluation function to realise partial self-test on an automatic gain control circuit (AGC). This paper extends the technique to INL, DNL, offset & gain error testing of analogue to digital converters (ADC's). It also shows how the same function can be used to test an AGC / ADC pair. An extension to full self-test is also proposed by the on-chip generation of input stimuli through reconfiguration of existing functions
Driven to Despair: Confronting Racial Inequity in North Carolina\u27s License Suspension Practices
Hundreds of thousands of North Carolina drivers have a suspended license for unpaid traffic court fines and fees. The practice of suspending drivers’ licenses for unpaid fines and fees is inequitable and counterproductive. This practice disenfranchises rural drivers and those facing poverty and creates a significant obstacle to employment. Furthermore, African-American drivers are four times as likely as non-Hispanic, white drivers to have a suspended license for unpaid fines and fees. Drawing upon lessons learned from the Driver’s License Restoration Project, the Authors conclude that legislative action is needed to remedy this inequitable and inefficient system of collecting state revenue. North Carolina should cease the practice of suspending licenses for unpaid fines and fees, pursue a decrease in criminal court fees and fines overall, and implement a sliding scale structure for fees and fines that makes a fact-specific determination about an individual’s real wages and ability to pay. This recommendation would lead to greater racial and economic equity, strengthen the North Carolina economy, and increase the aggregate amount of fees and fines collected by the state. This Article is a continuation of a prior published work, The Poverty Penalty: Driver’s License Restoration In North Carolina
Deformations of Fermionic Quantum Field Theories and Integrable Models
Considering the model of a scalar massive Fermion, it is shown that by means
of deformation techniques it is possible to obtain all integrable quantum field
theoretic models on two-dimensional Minkowski space which have factorizing
S-matrices corresponding to two-particle scattering functions S_2 satisfying
S_2(0) = -1. Among these models there is for example the Sinh-Gordon model. Our
analysis provides a complement to recent developments regarding deformations of
quantum field theories. The deformed model is investigated also in higher
dimensions. In particular, locality and covariance properties are analyzed.Comment: 20 page
Ultraviolet singularities in classical brane theory
We construct for the first time an energy-momentum tensor for the
electromagnetic field of a p-brane in arbitrary dimensions, entailing finite
energy-momentum integrals. The construction relies on distribution theory and
is based on a Lorentz-invariant regularization, followed by the subtraction of
divergent and finite counterterms supported on the brane. The resulting
energy-momentum tensor turns out to be uniquely determined. We perform the
construction explicitly for a generic flat brane. For a brane in arbitrary
motion our approach provides a new paradigm for the derivation of the,
otherwise divergent, self-force of the brane. The so derived self-force is
automatically finite and guarantees, by construction, energy-momentum
conservation.Comment: 41 pages, no figures, minor change
Warped Convolutions, Rieffel Deformations and the Construction of Quantum Field Theories
Warped convolutions of operators were recently introduced in the algebraic
framework of quantum physics as a new constructive tool. It is shown here that
these convolutions provide isometric representations of Rieffel's strict
deformations of C*-dynamical systems with automorphic actions of R^n, whenever
the latter are presented in a covariant representation. Moreover, the device
can be used for the deformation of relativistic quantum field theories by
adjusting the convolutions to the geometry of Minkowski space. The resulting
deformed theories still comply with pertinent physical principles and their
Tomita-Takesaki modular data coincide with those of the undeformed theory; but
they are in general inequivalent to the undeformed theory and exhibit different
physical interpretations.Comment: 34 page
Equilibrium free energies from fast-switching trajectories with large time steps
Jarzynski's identity for the free energy difference between two equilibrium
states can be viewed as a special case of a more general procedure based on
phase space mappings. Solving a system's equation of motion by approximate
means generates a mapping that is perfectly valid for this purpose, regardless
of how closely the solution mimics true time evolution. We exploit this fact,
using crudely dynamical trajectories to compute free energy differences that
are in principle exact. Numerical simulations show that Newton's equation can
be discretized to low order over very large time steps (limited only by the
computer's ability to represent resulting values of dynamical variables)
without sacrificing thermodynamic accuracy. For computing the reversible work
required to move a particle through a dense liquid, these calculations are more
efficient than conventional fast switching simulations by more than an order of
magnitude. We also explore consequences of the phase space mapping perspective
for systems at equilibrium, deriving an exact expression for the statistics of
energy fluctuations in simulated conservative systems
Negotiating the Maze: Case based, Collaborative Distance Learning in Dentistry
The module was developed as an elective to give motivated senior dental students an opportunity to expand their horizons in planning oral rehabilitation. It comprised one tutor and 12 students, from five universities world-wide, communicating on the World Wide Web (WWW), to develop oral rehabilitation plans for simulated patients. Trigger material came from one of two Case Profiles and consisted of diagnostic casts and details of the clinical and radiographic examination in WWW/CD-ROM form. No background material was supplied as to the "patient's" age, sex, history or main concern(s). Students worked in groups of three, each student from a different location. Individual students were given a role within the group: "Patient", who developed a "personal background" belonging to the trigger examination material, "Academic" who identified state-of-the-art treatment options available for the dental treatment needs identified by the group and "General Practitioner" who tailored these options to the "patient's" needs and wants. Student feedback focused on their perception of their experience with the program in response to a questionnaire comprising 11 structured and four "open" questions. All students felt that the program increased their confidence in planning oral rehabilitation. Ten students felt that the "best thing about the program" was the interaction with students from other universities and the exposure to different philosophies from the different schools. Eight students mentioned their increased awareness of the importance of patient input into holistic planning. Under the heading "What was the worst thing", students cited some technical hitches and the snowball effect of two sluggish students who were not identified early enough and thus impacted negatively on the working of their groups. Student feedback showed that the module succeeded in its aims but needed modification to improve the logistics of working with an extended campu
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