3,067 research outputs found
Elastic-DF: Scaling Performance of DNN Inference in FPGA Clouds through Automatic Partitioning
No full textCustomized compute acceleration in the datacenter is key to the wider roll-out of applications based on deep neural network (DNN) inference. In this article, we investigate how to maximize the performance and scalability of field-programmable gate array (FPGA)-based pipeline dataflow DNN inference accelerators (DFAs) automatically on computing infrastructures consisting of multi-die, network-connected FPGAs. We present Elastic-DF, a novel resource partitioning tool and associated FPGA runtime infrastructure that integrates with the DNN compiler FINN. Elastic-DF allocates FPGA resources to DNN layers and layers to individual FPGA dies to maximize the total performance of the multi-FPGA system. In the resulting Elastic-DF mapping, the accelerator may be instantiated multiple times, and each instance may be segmented across multiple FPGAs transparently, whereby the segments communicate peer-to-peer through 100 Gbps Ethernet FPGA infrastructure, without host involvement. When applied to ResNet-50, Elastic-DF provides a 44% latency decrease on Alveo U280. For MobileNetV1 on Alveo U200 and U280, Elastic-DF enables a 78% throughput increase, eliminating the performance difference between these cards and the larger Alveo U250. Elastic-DF also increases operating frequency in all our experiments, on average by over 20%. Elastic-DF therefore increases performance portability between different sizes of FPGA and increases the critical throughput per cost metric of datacenter inference. Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Computer Engineerin
Differentiable functions with surjective Clarke Jacobians
No full textWe construct, for any n,m ∈ N \{0}, a differentiable locally Lipschitz function f : Rn →Rm which is C1 on the complement of an H1-null set E ⊂ Rn and has the property that the range of its limiting Jacobian on E contains the family of all nonempty compact connected sets of (m×n)-matrices. As a consequence, the Clarke Jacobian Jcf is surjective, that is, its range contains every nonempty compact convex subset of (m×n)-matrices. This reveals a significant difference between differentiable functions and C1-functions, since for a C1-function the Clarke Jacobian is always a singleton. As a by-product, we also obtain examples of C1-smooth functions from Rn to Rm (for any n,m ∈ N\{0}) with surjective derivative, that is, Im(Df) = Rm×n
Hierarchical Population Genetic Structure in a Direct Developing Antarctic Marine Invertebrate
No full textHoffman J, Clarke A, Clark MS, Peck LS. Hierarchical Population Genetic Structure in a Direct Developing Antarctic Marine Invertebrate. PLoS ONE. 2013;8(5): e63954.Understanding the relationship between life-history variation and population structure in marine invertebrates is not straightforward. This is particularly true of polar species due to the difficulty of obtaining samples and a paucity of genomic resources from which to develop nuclear genetic markers. Such knowledge, however, is essential for understanding how different taxa may respond to climate change in the most rapidly warming regions of the planet. We therefore used over two hundred polymorphic Amplified Fragment Length Polymorphisms (AFLPs) to explore population connectivity at three hierachical spatial scales in the direct developing Antarctic topshell Margarella antarctica. To previously published data from five populations spanning a 1500 km transect along the length of the Western Antarctic Peninsula, we added new AFLP data for four populations separated by up to 6 km within Ryder Bay, Adelaide Island. Overall, we found a nonlinear isolation-by-distance pattern, suggestive of weaker population structure within Ryder Bay than is present over larger spatial scales. Nevertheless, significantly positive Fst values were obtained in all but two of ten pairwise population comparisons within the bay following Bonferroni correction for multiple tests. This is in contrast to a previous study of the broadcast spawner Nacella concinna that found no significant genetic differences among several of the same sites. By implication, the topshell's direct-developing lifestyle may constrain its ability to disperse even over relatively small geographic scales
Hydrodynamical turbulence by fractal fourier decimation
No full textWe present a systematic numerical investigation of high-resolution 3D isotropic and homogeneous turbulence resolved on a decimated set of Fourier modes. Fractal decimation acts to decrease the effective dimensionality of the flow by allowing triadic interactions only in a set of Fourier modes N(k) proportional to k^DF for large k. While keeping the symmetries of the original 3D Navier-Stokes equations unchanged, a dramatic change in small-scale statistics is detected at decreasing the fractal dimension DF . Already at fractal dimension DF = 2.8, a global self-similar behaviour is observed in the inertial range of scales, the consequence of such transition are the restoration of the scaling symmetry and vorticity distribution that becomes close to Gaussian. We relate the results to the different roles of local vs non-local interactions in the energy transfer range
'Response by the author, Daniel F. Vukovich.'
No full textResponse by the author (Vukovich) to a review of Illiberal China (my 2019 monograph
DF AND HF LASER SPECTRA
No full textW. B. Roh and K. Narahari Rao, J. Mol. Spectrosc. 49, 317 (1974).""Author Institution: Department of Physics, The Ohio State University; Department of Electrical Engineering, The Ohio State UniversityA pulsed laser was used as a source to study DF and HF infrared laser spectra with a grating spectrometer. The rotational structure observed for the 1-0, 2-1, and 3-2 bands of DF, and the 1-0 and 2-1 bands of HF has been measured by following a procedure similar to that used for the CO laser Molecular constants derived by combining these laser measurements with other available data will be presented
OPTOACOUSTIC MEASUREMENT OF DF LASER ABSORPTION BY METHANE
No full textAuthor Institution:An optoacoustic system has been constructed for measurement of absorption of DF laser radiation. Absorption by methane in Argon and Nitrogen has been measured at 15 DF laser lines in the 3.6 – 4.0 region. Construction and calibration of the spectrophone will be discussed
Distinct migratory and non-migratory ecotypes of an endemic New Zealand eleotrid (Gobiomorphus cotidianus) – implications for incipient speciation in island freshwater fish species
No full textBackground: Many postglacial lakes contain fish species with distinct ecomorphs. Similar evolutionary scenarios might be acting on evolutionarily young fish communities in lakes of remote islands. One process that drives diversification in island freshwater fish species is the colonization of depauperate freshwater environments by diadromous (migratory) taxa, which secondarily lose their migratory behaviour. The loss of migration limits dispersal and gene flow between distant populations, and, therefore, is expected to facilitate local morphological and genetic differentiation. To date, most studies have focused on interspecific relationships among migratory species and their non-migratory sister taxa. We hypothesize that the loss of migration facilitates intraspecific morphological, behavioural, and genetic differentiation between migratory and non-migratory populations of facultatively diadromous taxa, and, hence, incipient speciation of island freshwater fish species.
Results: Microchemical analyses of otolith isotopes (Sr-88, Ba-137 and Ca-43) differentiated migratory and non-migratory stocks of the New Zealand endemic Gobiomorphus cotidianus McDowall (Eleotridae). Samples were taken from two rivers, one lake and two geographically-separated outgroup locations. Meristic analyses of oculoscapular lateral line canals documented a gradual reduction of these structures in the non-migratory populations. Amplified fragment length polymorphism (AFLP) fingerprints revealed considerable genetic isolation between migratory and non-migratory populations. Temporal differences in reproductive timing (migratory = winter spawners, non-migratory = summer spawners; as inferred from gonadosomatic indices) provide a prezygotic reproductive isolation mechanism between the two ecotypes.
Conclusion: This study provides a holistic look at the role of diadromy in incipient speciation of island freshwater fish species. All four analytical approaches (otolith microchemistry, morphology, spawning timing, population genetics) yield congruent results, and provide clear and independent evidence for the existence of distinct migratory and non-migratory ecotypes within a river in a geographically confined range. The morphological changes within the non-migratory populations parallel interspecific patterns observed in all non-migratory New Zealand endemic Gobiomorphus species and other derived gobiid taxa, a pattern suggesting parallel evolution. This study indicates, for the first time, that distinct ecotypes of island freshwater fish species may be formed as a consequence of loss of migration and subsequent diversification. Therefore, if reproductive isolation persists, these processes may provide a mechanism to facilitate speciation
Comparison of system architecture and converter topology for a solar powered electric vehicle charging station
No full textAccepted Author ManuscriptOld - EWI-ESE-DC&S DC systems & StoragePhotovoltaic Materials and Device
Simulation of a surface-transverse wave (STW) biosensor for DF-1 cells
No full textA 250 MHz Surface-Transverse Wave (STW) resonator is employed as a sensor element for the
detection of DF-1 cells. STW belongs to the shear-horizontal acoustic plate modes (SH-APM) waves’
family where it has attracted plenty considerable interest. STWs are horizontally polarized shear waves
which are generated and detected by the interdigital transducers (IDTs) similar to surface-acoustic wave
(SAW) resonators [1]. Detection of chemical and biological agents in aqueous solutions is a difficult
problem, especially when the detection technique has to be sensitive, power-efficient and very handy.
Acoustic plate mode is a mode of vibration where particle motion is parallel to the surface. This makes it
possible to produce a sensitive sensor capable of operating in fluids [2]. This paper presents the biosensor
prototype utilizing STW resonator
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