OpenCL Actors - Adding Data Parallelism to Actor-based Programming with CAF

The actor model of computation has been designed for a seamless support of concurrency and distribution. However, it remains unspecific about data parallel program flows, while available processing power of modern many core hardware such as graphics processing units (GPUs) or coprocessors increases the relevance of data parallelism for general-purpose computation. In this work, we introduce OpenCL-enabled actors to the C++ Actor Framework (CAF). This offers a high level interface for accessing any OpenCL device without leaving the actor paradigm. The new type of actor is integrated into the runtime environment of CAF and gives rise to transparent message passing in distributed systems on heterogeneous hardware. Following the actor logic in CAF, OpenCL kernels can be composed while encapsulated in C++ actors, hence operate in a multi-stage fashion on data resident at the GPU. Developers are thus enabled to build complex data parallel programs from primitives without leaving the actor paradigm, nor sacrificing performance. Our evaluations on commodity GPUs, an Nvidia TESLA, and an Intel PHI reveal the expected linear scaling behavior when offloading larger workloads. For sub-second duties, the efficiency of offloading was found to largely differ between devices. Moreover, our findings indicate a negligible overhead over programming with the native OpenCL API.Comment: 28 page

Two-photon interference using background-free quantum frequency conversion of single photons from a semiconductor quantum dot

We show that quantum frequency conversion (QFC) can overcome the spectral distinguishability common to inhomogeneously broadened solid-state quantum emitters. QFC is implemented by combining single photons from an InAs quantum dot (QD) at 980 nm with a 1550 nm pump laser in a periodically-poled lithium niobate (PPLN) waveguide to generate photons at 600 nm with a signal-to-background ratio exceeding 100:1. Photon correlation and two-photon interference measurements confirm that both the single photon character and wavepacket interference of individual QD states are preserved during frequency conversion. Finally, we convert two spectrally separate QD transitions to the same wavelength in a single PPLN waveguide and show that the resulting field exhibits non-classical two-photon interference.Comment: Supercedes arXiv:1205.221

Selected recollections of my relationship with Leo Breiman

During the period 1962--1964, I had a tenure track Assistant Professorship in Mathematics at Cornell University in Ithaca, New York, where I did research in probability theory, especially on linear diffusion processes. Being somewhat lonely there and not liking the cold winter weather, I decided around the beginning of 1964 to try to get a job in the Mathematics Department at UCLA, in the city in which I was born and raised. At that time, Leo Breiman was an Associate Professor in that department. Presumably, he liked my research on linear diffusion processes and other research as well, since the department offered me a tenure track Assistant Professorship, which I happily accepted. During the Summer of 1965, I worked on various projects with Sidney Port, then at RAND Corporation, especially on random walks and related material. I was promoted to Associate Professor, effective in Fall, 1966, presumably thanks in part to Leo. Early in 1966, I~was surprised to be asked by Leo to participate in a department meeting called to discuss the possible hiring of Sidney. The conclusion was that Sidney was hired as Associate Professor in the department, as of Fall, 1966. Leo communicated to me his view that he thought that Sidney and I worked well together, which is why he had urged the department to hire Sidney. Anyhow, Sidney and I had a very fruitful and enjoyable collaboration in probability and, to a much lesser extent, in theoretical statistics, for a number of years thereafter.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS431 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

“Giant Colonic Bezoar”: A Medication Bezoar Due to Psyllium Seed Husks

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74894/1/j.1572-0241.1984.tb05167.x.pd

Actors that Unify Threads and Events

There is an impedance mismatch between message-passing concurrency and virtual machines, such as the JVM. VMs usually map their threads to heavyweight OS processes. Without a lightweight process abstraction, users are often forced to write parts of concurrent applications in an event-driven style which obscures control flow, and increases the burden on the programmer. In this paper we show how thread-based and event-based programming can be unified under a single actor abstraction. Using advanced abstraction mechanisms of the Scala programming language, we implemented our approach on unmodified JVMs. Our programming model integrates well with the threading model of the underlying VM

The SCARE 2020 Guideline: Updating Consensus Surgical CAse REport (SCARE) Guidelines

INTRODUCTION: The SCARE Guidelines were first published in 2016 and were last updated in 2018. They provide a structure for reporting surgical case reports and are used and endorsed by authors, journal editors and reviewers, in order to increase robustness and transparency in reporting surgical cases. They must be kept up to date in order to drive forwards reporting quality. As such, we have updated these guidelines via a DELPHI consensus exercise. METHODS: The updated guidelines were produced via a DELPHI consensus exercise. Members were invited from the previous DELPHI group, as well as editorial board members and peer reviewers of the International Journal of Surgery Case Reports. The expert group completed an online survey to indicate their agreement with proposed changes to the checklist items. RESULTS: A total of 54 surgical experts agreed to participate and 53 (98%) completed the survey. The responses and suggested modifications were incorporated into the new 2020 guideline. There was a high degree of agreement amongst the SCARE Group, with all modified SCARE items receiving over 70% scores 7-9. CONCLUSION: A DELPHI consensus exercise was completed and an updated and improved SCARE Checklist is now presented