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

Thermoforming of planar polymer optical waveguides for integrated optics in smart packaging materials

The innovations in smart packaging will open up a wide range of opportunities in the future. This work describes the processing of additive manufactured and planar integrated polymer optical waveguides for use in smart packaging products. The previously published combination of flexographic and Aerosol Jet printing is complemented by thermoforming and thus creates three-dimensional integrated multimode waveguides with optical attenuation of 1.9 dB/cm ± 0.1 dB/cm @ 638 nm. These properties will be the basis to develop smart applications in packaging materials

Parallel processing area extraction and data transfer number reduction for automatic GPU offloading of IoT applications

For Open IoT, we have proposed Tacit Computing technology to discover the devices that have data users need on demand and use them dynamically and an automatic GPU offloading technology as an elementary technology of Tacit Computing. However, it can improve limited applications because it only optimizes parallelizable loop statements extraction. Thus, in this paper, to improve performances of more applications automatically, we propose an improved method with reduction of data transfer between CPU and GPU. We evaluate our proposed offloading method by applying it to Darknet and find that it can process it 3 times as quickly as only using CPU.Comment: 6 pages, 4 figures, in Japanese, IEICE Technical Report, SC2018-3

Optimistic Parallelism on GPUs

Abstract. We present speculative parallelization techniques that can exploit parallelism in loops even in the presence of dynamic irregulari-ties that may give rise to cross-iteration dependences. The execution of a speculatively parallelized loop consists of five phases: scheduling, com-putation, misspeculation check, result committing, and misspeculation recovery. While the first two phases enable exploitation of data paral-lelism, the latter three phases represent overhead costs of using specu-lation. We perform misspeculation check on the GPU to minimize its cost. We perform result committing and misspeculation recovery on the CPU to reduce the result copying and recovery overhead. The scheduling policies are designed to reduce the misspeculation rate. Our program-ming model provides API for programmers to give hints about potential misspeculations to reduce their detection cost. Our experiments yielded speedups of 3.62x-13.76x on an nVidia Tesla C1060 hosted in an Intel(R) Xeon(R) E5540 machine.

Prospectus, April 30, 1980

STUDENT GOV\u27T ELECTIONS TODAY, TOMORROW; Week in Review: World, Nation; Skyrocket interest rates force insurance borrowing; PC student heads to DC; Parkland Teacher Aide Program hosts Recognition Banquet Wed.; Illinois future can be as bright as ever; Arbor Day celebrated last Friday; Dental students to be capped; Males can survive; Women\u27s Program offers workshops; Community colleges can contribute; Open house of woods; Westerners celebrate different May Day; StuGo sponsors spring activities featuring balloons, kites, jazz; Letters to the Editor: Philemon lauded, Faculty thieves; One parent families are discussed; Cheap trick...; and Ted Nugent rock Assembly Hall; Classifieds; Dates to live by; Sports in Review: Baseball, Basketball, Hockey; Garden workshop concludes; Journ instructor gets textbook published; Forum presented Wed.; Track ready for state; Umpires clinic scheduled; Lucy coin sends Cobras to state; Cobras rounding out for sectional; New track gets workout; Parkland Baseball Statisticshttps://spark.parkland.edu/prospectus_1980/1028/thumbnail.jp

Multistable perception elicits compensatory alpha activity in older adults

Multistable stimuli lead to the perception of two or more alternative perceptual experiences that spontaneously reverse from one to the other. This property allows researchers to study perceptual processes that endogenously generate and integrate perceptual information. These endogenous processes appear to be slowed down around the age of 55 where participants report significantly lower perceptual reversals. This study aimed to identify neural correlates of this aging effect during multistable perception utilizing a multistable version of the stroboscopic alternative motion paradigm (SAM: endogenous task) and a control condition (exogenous task). Specifically, age-related differences in perceptual destabilization and maintenance processes were examined through alpha responses. Electroencephalography (EEG) of 12 older and 12 young adults were recorded during SAM and control tasks. Alpha band activity (8–14 Hz) was obtained by wavelet-transformation of the EEG signal and analyzed for each experimental condition. Endogenous reversals induced gradual decrease in posterior alpha activity in young adults which is a replication of previous studies’ findings. Alpha desynchronization was shifted to anterior areas and prevalent across the cortex except the occipital area for older adults. Alpha responses did not differ between the groups in the control condition. These findings point to recruitment of compensatory alpha networks for maintenance of endogenously generated percepts. Increased number of networks responsible for maintenance might have extended the neural satiation duration and led to decreased reversal rates in older adults