Generation of Langmuir circulations by surface waves ---- a feedback mechanism

Surface gravity waves propagating obliquely through a surface current pattern (U(y), V(y)) representative of Langmuir circulations exert a force on the water which tends to produce surface convergences at maxima of U(y). Moreover, the waves achieve their largest amplitude at maxima of U(y) and so are most likely to dissipate there and give up their momentum to the mean flow. A feedback mechanism thus exists..

Three Key Principles for Improving Discussion-Based Learning in College Classrooms

Discussion-Based Learning (DBL) can be an effective pedagogical tool for student engagement and developing higher-order thinking skills. However, DBL can be a challenging endeavor for college teachers for various reasons. The purposes of this article are to identify those challenges, present three key principles, and share several practical ideas that will help improve discussions in college classrooms

Fast high dimensional approximation via random embeddings

In the big data era, dimension reduction techniques have been a key tool in making high dimensional geometric problems tractable. This thesis focuses on two such problems - hashing and parameter estimation. We study locality sensitive hashing(LSH), which is a framework for randomized hashing that efficiently solves an approximate version of nearest neighbor search. We propose an efficient and provably optimal hash function for LSH that builds on a simple existing hash function called cross-polytope LSH. In the context of parameter estimation, we focus on regression, for which the well-known LASSO requires precise knowledge of the unknown noise variance. We provide an estimator for this noise variance when the signal is sparse that is consistent and faster than a single iteration of LASSO. Finally, we discuss notions of distance between probability distributions for the purposes of quantization and propose a distance metric called the Rényi divergence, that achieves both large and small scale bounds.Mathematic

The Law on Police Use of Force in the United States

Recent events in the United States have highlighted the fact that American police resort to force, including deadly force, much more often than in many other Western countries. This Article describes how the current regulatory regime may ignore or even facilitate these aggressive police actions. The law governing police use of force in the United States derives in large part from the Fourth Amendment to the United States Constitution, which prohibits unreasonable searches and seizures. As construed by the United States Supreme Court, the Fourth Amendment provides police wide leeway in using deadly force, making custodial arrests, and stopping and frisking individuals. While state and local police departments can develop more restrictive rules, they often do not. Additionally, the remedies for violations of these rules are weak. The predominant remedy is exclusion of evidence, the impact of which falls primarily on the prosecutor and in any event only has a deterrent effect when evidence is sought. Civil and criminal sanctions have been significantly limited by the Supreme Court, particularly through the doctrine of qualified immunity (applied to individual officers) and the policy or custom defense (applied to municipalities). This minimal regulatory regime is one reason police-citizen encounters in the United States so often result in death or serious bodily harm to citizens, in particular those who are Black. The Article ends with a number of reform proposals

Variability of the flow through the Strait of Belle Isle

For periods between about two days and one month the surface flow through the Strait of Belle Isle, represented by the sea level difference across it, is highly coherent with the large scale atmospheric pressure gradient normal to the strait. This suggests that the flow is driven by a sea level difference between opposite ends of the strait induced by large scale winds...

Gendered Imprisonment in Japan: An Examination of Imprisonment for Stimulant Drug Offenses

Japan is well known as a society that has not only low crime rates but also for using incarceration sparingly, sending few convicted offenders to prison. Yet, certain crimes, such as drug offenses, receive little leniency in the Japanese criminal justice system. Johnson (1996b) found empirical support for both a chivalry and evil woman effect in the system’s treatment of female drug offenders. This paper reexamines and extends the core issues in Johnson’s (1996b) exploration of women’s imprisonment in Japan. It traces the patterns in female incarceration where data is available from the post-war period until 2004. It specifically examines the incidences of incarceration of women for stimulus drug offenses and identifies key correlates on the macro-level associated with changes in imprisonment practices

On the turbulent co-spectrum of two scalars and its effect on acoustic scattering from oceanic turbulence

Author Posting. © Cambridge University Press, 2004. This article is posted here by permission of Cambridge University Press for personal use, not for redistribution. The definitive version was published in Journal of Fluid Mechanics 514 (2004): 107-119, doi:10.1017/S0022112004000126.While acoustic scatter from oceanic turbulence is sensitive to temperature–salinity covariations, there are unfortunately no published measurements of the turbulent temperature–salinity co-spectrum. Several models have been proposed for the form of the co-spectrum of two scalars in turbulence, but they all produce unsatisfactory results when applied to the turbulent scattering equations (either predicting negative scattering cross-sections in some regimes or predicting implausible levels of correlation between temperature and salinity at some scales). A new model is proposed and shown to give physically plausible scattering predictions in all density regimes. High-frequency acoustic data illustrate the importance of the co-spectrum for acoustic scattering, but were collected in a density regime where there is little difference between the co-spectrum models.This work was supported by NSERC and by ONR under grant #N00014-93-1-0362

Proceedings of the Desert Fishes Council Special Publication 2021

Integrative Biolog