Instrumentation 2.0架构:迎接PCI Express和多核的时代

基于Web的应用,包括Google、Wikipedia和YouTub,已经将Web从少数机构为多数消费者提供服务内容的应用模式转变为每个用户定制和定义他/她自己的消费内容的模式.人们把这种新的Web形式称为Web 2.0.     

Adaptive sequential machine learning

Abstract

A framework previously introduced in Wilson et al. (2018 Wilson, C., Veeravalli, V. V., and Nedi?, A. (2018). Adaptive Sequential Stochastic Optimization, IEEE Transactions on Automatic Control 64: 496–509. doi:10.1109/TAC.2018.2816168[Crossref], [Web of Science ®] , [Google Scholar]) for solving a sequence of stochastic optimization problems with bounded changes in the minimizers is extended and applied to machine learning problems such as regression and classification. The stochastic optimization problems arising in these machine learning problems are solved using algorithms such as stochastic gradient descent (SGD). A method based on estimates of the change in the minimizers and properties of the optimization algorithm is introduced for adaptively selecting the number of samples at each time step to ensure that the excess risk—that is, the expected gap between the loss achieved by the approximate minimizer produced by the optimization algorithm and the exact minimizer—does not exceed a target level. A bound is developed to show that the estimate of the change in the minimizers is non trivial provided that the excess risk is small enough. Extensions relevant to the machine learning setting are considered, including a cost-based approach to select the number of samples with a cost budget over a fixed horizon, and an approach to applying cross-validation for model selection. Finally, experiments with synthetic and real data are used to validate the algorithms.     

Triptolide directly inhibits dCTP pyrophosphatase

Triptolide is a potent natural product, with documented antiproliferative, immunosuppressive, anti-inflammatory, antifertility, and antipolycystic kidney disease effects. Despite a wealth of knowledge about the biology of this compound, direct intracellular target proteins have remained elusive. We synthesized a biotinylated photoaffinity derivative of triptolide, and used it to identify dCTP pyrophosphatase 1 (DCTPP1) as a triptolide-interacting protein. Free triptolide interacts directly with recombinant DCTPP1, and inhibits the enzymatic activity of this protein. Triptolide is thus the first dCTP pyrophosphatase inhibitor identified, and DCTPP1 is a biophysically validated target of triptolide.     

Three-Dimensional Electromagnetic and Electrical Simulation of HgCdTe Pixel Arrays

We have investigated the combined electromagnetic and electrical response of HgCdTe-based pixel detector arrays with different geometries. We have computed the propagation of the optical signal in the detector structure by solving Maxwell’s curl equations using a finite-difference time-domain approach. From the field distribution inside the device, we have evaluated the optical carrier generation rate. Using this information in a three-dimensional (3D) numerical model based on a drift–diffusion approach, we have computed the quantum efficiency and photoresponse of a number of pixel geometries. Specifically, we have analyzed the response of both mesa-type and planar detector arrays with and without CdZnTe substrate. Furthermore, the electromagnetic response has also been evaluated for different metal contact dimensions and configurations. It is found that, for mesa-type arrays without the substrate, significant reflection effects take place in the device that lead to resonance peaks in the photoresponse.     

Embedded RF Circuit Diagnostic Technique with Multi-Tone Dither Scheme

This paper provides development of an RF circuit software tool that automatically generates diagnostic programs for device interface boards. The diagnostic tool utilizes novel techniques to differentiate faulty RF circuits embedded in printed circuit boards. We present RF circuit diagnostic techniques using power sensors and multi-tone dither testing, which we integrated into the diagnostic software tool that we developed. The diagnostic tool provides user-transparent pseudocodes with high fault coverage and significantly decreases time to market.     

Driver distraction and driver inattention: definition, relationship and taxonomy

There is accumulating evidence that driver distraction and driver inattention are leading causes of vehicle crashes and incidents. However, as applied psychological constructs, they have been inconsistently defined and the relationship between them remains unclear. In this paper, driver distraction and driver inattention are defined and a taxonomy is presented in which driver distraction is distinguished from other forms of driver inattention. The taxonomy and the definitions provided are intended (a) to provide a common framework for coding different forms of driver inattention as contributing factors in crashes and incidents, so that comparable estimates of their role as contributing factors can be made across different studies, and (b) to make it possible to more accurately interpret and compare, across studies, the research findings for a given form of driver inattention.