Cloud providers and companies running large-scale data centers offer near-line, cold, and archival data storage, which trade access latency and throughput performance for cost. These often require physical rack-scale storage designs, e.g. Facebook/Open Compute Project (OCP) Cold Storage or Pelican, which co-design the hardware, mechanics, power, cooling and software to minimize costs to support...

OBJECTIVES To describe the incidence, type, and severity of injuries related to the use of bicycle-towed trailers for transporting children and to compare them with injuries associated with the use of child seats mounted on adult bicycles. DESIGN A retrospective analysis of data from the National Electronic Injury Surveillance System of the US Consumer Product Safety Commission for 1990 to 19...

INTRODUCTION Cycling is a major activity for adolescents in Canada and potential differences exist in bicycling-related risk and experience of injury by population subgroup. The overall aim of this study was to inform health equity interventions by profiling stratified analytic methods and identifying potential inequities associated with bicycle-related injury and the use of bicycle helmets amo...

We introduce the notion of N-reduced dynamical cocycles and use these objects to define enhancements of the rack counting invariant for classical and virtual knots and links. We provide examples to show that the new invariants are not determined by the rack counting invariant, the Jones polynomial or the generalized Alexander polynomial.

The main result of this paper is a new classification theorem for links (smooth embeddings in codimension 2). The classifying space is the rack space and the classifying bundle is the first James bundle. We investigate the algebraic topology of this classifying space and report on calculations given elsewhere. Apart from defining many new knot and link invariants (including generalised James-Ho...

Datacenters have traditionally been designed and deployed as a collection of server racks, where each rack consists of approximately 42 units of servers connected to one or two edge switches. In this model, computation is generally localized within a single server, and the edge switches provide 10 or 40 Gbps of non-blocking bandwidth between servers in the same rack. Although the traditional mo...

It is well known that skilled bicycle riders can balance and propel themselves forward using motions of the handlebar. We present the complete nonlinear dynamics and control of such a pedal-less bicycle with a rider. Propulsion is achieved not by pedaling but by a cyclic motion of the steering axis of the bicycle. It is shown that this kind of actuation results in net forward motion of the bicy...

BACKGROUND Because of the increased number of bicycle riders and governmental promotions, a recent increase in the construction of bicycle lanes has occurred. We aimed to characterize injuries specific to bicycle lane accidents by comparing them with injuries that occurred on regular roadways. On the basis of our findings, we provide suggestions on proper preventive strategies. METHODS We per...

We propose a method for disambiguating uncertain detections of events by seeking global explanations for activities. Given a noisy visual input, and exploiting our knowledge of the activity and its constraints, one can provide a consistent set of events explaining all the detections. The paper presents a complete framework that starts with a general way to formalise the set of global explanatio...