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Nanoelectrodes allow precise and quantitative measurements of important biological processes at the single living-cell level in real time. Cylindrical nanowire electrodes (NWEs) required for intracellular measurements create a great challenge for achieving excellent electrochemical and mechanical performances. Herein, we present a facile and robust solution to this problem based on a unique SiC-core-shell design to produce cylindrical NWEs with superior mechanical toughness provided by the SiC nano-core and an excellent electrochemical performance provided by the ultrathin carbon shell that can be used as such or platinized. The use of such NWEs for biological applications is illustrated by the first quantitative measurements of ROS/RNS in individual phagolysosomes of living macrophages. As the shell material can be varied to meet any specific detection purpose, this work opens up new opportunities to monitor quantitatively biological functions occurring inside cells and their organelles.

The power consumption of modern high-performance computing HPC systems that are built using power hungry commodity servers is one of the major hurdles for achieving Exascale computation. Several efforts have been made by the HPC community to encourage the use of low-powered system-on-chip SoC embedded processors in large-scale HPC systems. These initiatives have successfully demonstrated the use of ARM SoCs in HPC systems, but there is still a need to analyze the viability of these systems for HPC platforms before a case can be made for Exascale computation. The major shortcomings of current ARM-HPC evaluations include a lack of detailed insights about performance levels on distributed multicore systems and performance levels for benchmarking in large-scale applications running on HPC. In this paper, we present a comprehensive evaluation of results that covers major aspects of server and HPC benchmarking for ARM-based SoCs. For the experiments, we built an unconventional cluster of ARM Cortex-A9s that is referred to as Weiser and ran single-node benchmarks STREAM, Sysbench, and PARSEC and multi-node scientific benchmarks High-performance Linpack HPL, NASA Advanced Supercomputing NAS Parallel Benchmark, and Gadget-2 in order to provide a baseline for performance limitations of the system. Based on the experimental results, we claim that the performance of ARM SoCs depends heavily on the memory bandwidth, network latency, application class, workload type, and support for compiler optimizations. During server-based benchmarking, we observed that when performing memory intensive benchmarks for database transactions, x86 performed 12% better for multithreaded query processing. However, ARM performed four times better for performance to power ratios for a single core and 2.6 times better on four cores. We noticed that emulated double precision floating point in Java resulted in three to four times slower performance as compared with the performance in C for CPU-bound benchmarks. Even though Intel x86 performed slightly better in computation-oriented applications, ARM showed better scalability in I/O bound applications for shared memory benchmarks. We incorporated the support for ARM in the MPJ-Express runtime and performed comparative analysis of two widely used message passing libraries. We obtained similar results for network bandwidth, large-scale application scaling, floating-point performance, and energy-efficiency for clusters in message passing evaluations NBP and Gadget 2 with MPJ-Express and MPICH. Our findings can be used to evaluate the energy efficiency of ARM-based clusters for server workloads and scientific workloads and to provide a guideline for building energy-efficient HPC clusters. Copyright © 2015 John Wiley & Sons, Ltd.

The simulations of the low velocity and dynamic deformation of a multi-layer 1050-H14 Al trapezoidal zig-zag corrugated core sandwich were investigated using the homogenized models (solid models) of a single core layer (without face sheets). In the first part of the study, the LS-DYNA MAT-26 material model parameters of a single core layer were developed through experimental and numerical compression tests on the single core layer. In the second part, the fidelities of the developed numerical models were checked by the split-Hopkinson pressure bar direct impact, low velocity compression and indentation and projectile impact tests. The results indicated that the element size had a significant effect on the initial peak and post-peak stresses of the homogenized models of the direct impact testing of the single-layer corrugated sandwich. This was attributed to the lack of the inertial effects in the homogenized models, which resulted in reduced initial peak stresses as compared with the full model and experiment. However, the homogenized models based on the experimental stress–strain curve of the single core layer predicted the low velocity compression and indentation and projectile impact tests of the multi-layer corrugated sandwich with an acceptable accuracy and reduced the computational time of the models significantly.

Summary To overcome the limitations of the existing brute force cracking method of Wi-Fi Protected Access/Wi-Fi Protected Access II (WPA/WPA2)-pre-shared key (PSK) based on single core CPU or one core of a multi-core CPU, a new distributed multi-core CPU and GPU parallel cracking method (DMCG) was first proposed. Colored Petri nets was used to validate the four-way handshake protocol and proved that DMCG could successfully crack WPA/WPA2-PSK. In DMCG, the PSK list was distributed to each PC reasonably using distributed technology. Multiple computing cores were made up of multi-core CPU and GPU on single PC to crack in parallel. GPU contributed to the cracking speed improvement due to the strong computing power for intensive parallel tasks. Experimental results showed that DMCG improved the cracking speed by two orders of magnitude and would exhibit more notable advantages with high-performance distributed system as the cracking speed improved by three or four orders of magnitude, compared with the computing power of one CPU core. An improved Amdahl's law was first proposed, by which the upper bound of the cracking speedup was analyzed. Aiming to the DMCG expansion of cloud computing based on GPU, a lightweight framework called Dandelion computing model was first proposed. Moreover, the analysis of the influences of the graphics card parameters on the cracking speed was processed, and accordingly, the decision support for choosing graphics card in DMCG based on analytic hierarchy process was provided. Finally, the performance optimization of DMCG was processed. Copyright © 2013 John Wiley & Sons, Ltd.

A new core structure is proposed to improve the saturation property of an inductor made of iron powder core. In the conventional structure made of a single core material, converging flux lines cause local magnetic saturation at the inner side of the corners of the magnetic path. Therefore, the conventional inductor shows worse saturation property than expected from its core material. This degradation mechanism is solved in the proposed core structure through homogenization of the flux distribution at the corners. Experiments are performed to evaluate the flux homogenization and improvement of the saturation property. Results show a homogenized flux distribution in the proposed core structure. Furthermore, the flux level improved by 28% while the inductance decreased by 40% of its initial value. Both these results are consistent with theoretical expectations, except that a larger improvement is found in the experiment compared to the 16% improvement predicted by numerical calculation. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Purpose: Two new codes,PENEASY and PENEASYLINAC, which automate the Monte Carlo simulation of Varian Clinacs of the 600, 1800, 2100, and 2300 series, together with their electron applicators and multileaf collimators, are introduced. The challenging case of a relatively small and far-from-axis field has been studied with these tools. Methods: PENEASY is a modular, general-purpose main program for the PENELOPEMonte Carlo system that includes various source models, tallies and variance-reduction techniques (VRT). The code includes a new geometry model that allows the superposition of voxels and objects limited by quadric surfaces. A variant of the VRT known as particle splitting, called fan splitting, is also introduced. PENEASYLINAC, in turn, automatically generates detailed geometry and configuration files to simulate linacs with PENEASY. These tools are applied to the generation of phase-space files, and of the corresponding absorbed dose distributions in water, for two 6 MV photon beams from a Varian Clinac 2100 C/D: a 40 × 40 cm2 centered field; and a 3 × 5 cm2 field centered at (4.5, −11.5) cm from the beam central axis. This latter configuration implies the largest possible over-traveling values of two of the jaws. Simulation results for the depth dose and lateral profiles at various depths are compared, by using the gamma index, with experimental values obtained with a PTW 31002 ionization chamber. The contribution of several VRTs to the computing speed of the more demanding off-axis case is analyzed. Results: For the 40 × 40 cm2 field, the percentages γ1 and γ1.2 of voxels with gamma indices (using 0.2 cm and 2% criteria) larger than unity and larger than 1.2 are 0.2% and 0%, respectively. For the 3 × 5 cm2 field, γ1 = 0%. These figures indicate an excellent agreement between simulation and experiment. The dose distribution for the off-axis case with voxels of 2.5 × 2.5 × 2.5 mm3 and an average standard statistical uncertainty of 2% (1σ) is computed in 3.1 h on a single core of a 2.8 GHz Intel Core 2 Duo processor. This result is obtained with the optimal combination of the tested VRTs. In particular, fan splitting for the off-axis case accelerates execution by a factor of 240 with respect to standard particle splitting. Conclusions: PENEASY and PENEASYLINAC can simulate the considered Varian Clinacs both in an accurate and efficient manner. Fan splitting is crucial to achieve simulation results for the off-axis field in an affordable amount of CPU time. Work to include Elekta linacs and to develop a graphical interface that will facilitate user input is underway.

Purpose: Collapsed-cone convolution/superposition (CCCS) dose calculation is the workhorse for IMRTdose calculation. The authors present a novel algorithm for computing CCCS dose on the modern graphic processing unit (GPU). Methods: The GPU algorithm includes a novel TERMA calculation that has no write-conflicts and has linear computation complexity. The CCCS algorithm uses either tabulated or exponential cumulative-cumulative kernels (CCKs) as reported in literature. The authors have demonstrated that the use of exponential kernels can reduce the computation complexity by order of a dimension and achieve excellent accuracy. Special attentions are paid to the unique architecture of GPU, especially the memory accessing pattern, which increases performance by more than tenfold. Results: As a result, the tabulated kernel implementation in GPU is two to three times faster than other GPU implementations reported in literature. The implementation of CCCS showed significant speedup on GPU over single core CPU. On tabulated CCK, speedups as high as 70 are observed; on exponential CCK, speedups as high as 90 are observed. Conclusions: Overall, the GPU algorithm using exponential CCK is 1000–3000 times faster over a highly optimized single-threaded CPU implementation using tabulated CCK, while the dose differences are within 0.5% and 0.5 mm. This ultrafast CCCS algorithm will allow many time-sensitive applications to use accurate dose calculation.

The geological structure in the mountainous regions of western China is quite complicated, and the elevation varies violently. At present, the main approach for seismic data imaging is the prestack Kirchhoff time migration, however, violent variation of surface elevation makes the datum plane selection of prestack time migration very difficult. This article proposed a new prestack time migration method through modifying the routine travel time computation, this method can greatly raise the imaging effect in mountainous region with obvious variation of surface elevation. In addition, this paper also introduced application of GPU in prestack time migration, by which the prestack time migration has been optimized and implemented, and the computation efficiency of single NVIDIA Tesla C1060 GPU can be more than 70 times faster than single core CPU with main frequency of 2.5 GHZ when without the I/O problem.

SUMMARYThe paper presents an original analytical procedure giving analytical expressions for the determination of groundfault current distribution for a fault located anywhere along a feeding line consisting of three single-core cables. Thederived analytical expressions are mathematically rigorous and take into account all the relevant factors withoutintroducing some larger approximations or idealizations of the real electrical circuit. Correct estimation of groundfault current distribution is necessary in contemporary power engineering practice due to at least two importantreasons. One of them is the possibility to a correct estimation of dangerous potential differences, touch and stepvoltage,whichmayappearduringagroundfaultatgroundingsystemofthesuppliedstation.Thesecondreasonisthepossibility to choose single-core cablesof the feeding cable lines with a metallic sheathcross-section large enough towithstandthermalstrainscausedbyfaultcurrents.Thefinalresultoftheuseoftheanalyticalexpressionsderivedhereis the possibility to determine safe and cost-effective solutions regarding the grounding systems of the suppliedstations and regarding the cross-sections of the metallic sheaths of single-core cables. The validation of the derivedexpressions is verified by experimental measurements. Copyright # 2007 John Wiley & Sons, Ltd.key words: cable sheath; ground fault current; distribution substation; grounding system; safety conditions

We propose new dual core chromophore materials with blue emission. One of these derivatives, TP-AP-TP, exhibits a high luminance EQE value of 7.51% and twice the lifetime of a commercialized material, MADN. The dual core chromophore materials have narrower PL and EL spectra and better thermal properties than the single core chromophore materials.

Mature, infectious HIV-1 particles contain a characteristic cone-shaped core that encases the viral RNA and replication proteins. The architectures of mature virions and isolated cores were studied using cryo-electron microscopy. The average size ( approximately 145 nm) of the virion was unchanged during maturation. Most virions contained a single core but roughly one-third contained two or more cores. Consideration of the capsid protein concentration during core assembly indicated that core formation in vivo is template-mediated rather than concentration-driven. Although most cores were conical, 7% were tubular. These displayed a stacked-disc arrangement with 7-, 8-, 9- or 10-fold axial symmetry. Layer line filtration of these images showed that the capsid subunit arrangement is consistent with a 9.6 nm hexamer resembling that previously seen in the helical tubes assembled from purified capsid protein. A common reflection (1/3.2 nm) shared between the tubular and conical cores suggested they share a similar organization. The extraordinary flexibility observed in the assembly of the mature core appears to be well suited to accommodating variation and hence there may be no single structure for the infectious virion.

Purpose: It is a known fact that Monte Carlo simulations of radiation transport are computationally intensive and may require long computing times. The authors introduce a new paradigm for the acceleration of Monte Carlo simulations: The use of a graphics processing unit (GPU) as the main computing device instead of a central processing unit (CPU). Methods: A GPU-based Monte Carlo code that simulates photon transport in a voxelized geometry with the accurate physics models fromPENELOPE has been developed using the CUDA™ programming model (NVIDIA Corporation, Santa Clara, CA). Results: An outline of the new code and a sample x-ray imaging simulation with an anthropomorphic phantom are presented. A remarkable 27-fold speed up factor was obtained using a GPU compared to a single core CPU. Conclusions: The reported results show that GPUs are currently a good alternative to CPUs for the simulation of radiation transport. Since the performance of GPUs is currently increasing at a faster pace than that of CPUs, the advantages of GPU-based software are likely to be more pronounced in the future.

A new approach for partitioning test items into dimensionally distinct item clusters is introduced. The core of the approach is a new item-pair conditional-covariancebased proximity measure that can be used with hierarchical cluster analysis. An extensive simulation study designed to test the limits of the approach indicates that when approximate simple structure holds, the procedure can correctly partition the test into dimensionally homogeneous item clusters even for very high correlations between the latent dimensions. In particular, the procedure can correctly classify (on average) over 90% of the items for correlations as high as .9. The cooperative role that the procedure can play when used in conjunction with other dimensionality assessment procedures is discussed. The increasing recognition of the multidimensional nature of educational and psychological measurement instruments has given rise to a concurrent increasing need for more efficient and more effective dimensionality assessment tools. In response to this need, this article deals with the development of a new dimensionality estimation tool based on the use of agglomerative hierarchical cluster analysis (HCA) with new dimensionally sensitive proximity measures. If successful HCA dimensionality methods can be developed such that clusters of items that appear to measure a common dimension can be located, then such methods will not only be useful by themselves, but will also be a valuable aid to existing procedures such as DIMTEST (Nandakumar & Stout, 1993; Stout, 1987), DETECT (Kim, 1994; Zhang & Stout, 1995, 1996), and nonlinear factor analysis. This is because all exploratory or confirmatory dimensionality analyses can benefit from beginning either with a single core set of dimensionally homogeneous items or with multiple sets of such items. The selection of such sets of items has been a very difficult problem in the history of dimensionality analysis, and the present article offers a potentially very effective solution. For example, in using DIMTEST to determine whether a test is unidimensional, the practitioner is required to identify one or more sets of items that are suspected of being dimensionally homogeneous; these are then tested for dimensional distinctiveness from the rest of the test. The clusters

The metallic subscriber line is composed of the cascade connection of cables with different core radius and the openended branch line called bridge-tap. Previously, the line equalizer for such a line has been constructed by combining the f equalizer, which has the equalization function for the single core cable, and the DFE circuit. The DFE circuit has a structure suited to LSI implementation, but has a problem in that a decision error propagates to succeeding bits, since the result of the decision is fed back as the compensation waveform for the intersymbol interference. This paper proposes a line equalizer based on the DFE circuit, which includes the DFE pre-equalizer to stabilize the DFE circuit. The design principle is presented. More precisely, the error propagation in the DFE circuit is analyzed. Combined with the analysis of the subscriber line characteristics, the required characteristics for the DFE equalizer are shown. Then a discussion is made on the number of taps in the DFE circuit, which determines the scale of the DFE circuit. Finally, a design example is presented for 320 kbit/s TCM transmission-line equalizer based on the design method presented. By experiment, the desired characteristics are verified.