74 research outputs found
Power Balance AODV Algorithm of WSN in Agriculture Monitoring
Ā WSN (wireless sensor networks) is a kind of energy-constrained network, which has been widely used in precision agriculture environment monitoring. However, power balance is not taken into account in traditional routing algorithms. In this paper, a novel Power Balance Ad hoc On-Demand Distance Vector (PB-AODV) routing algorithm is proposed on cross-layer design to solve the problem of power balance. The main idea of our proposed algorithm is that, routing path is established by the received signal strength indication (RSSI) value in the route discovery process of PB-AODV. The optimal transmitting power which can be computed by RSSI value, power threshold and nodeās surplus energy is encapsulated into route reply packet (RRP). Thus, the sender node can adaptively adjust its transmission power to save energy with the RRP. Simulation results show that the proposed algorithm is effective for load balancing, and increases the WSNās lifetime about 14.3%
Anatomy of High-Performance GEMM with Online Fault Tolerance on GPUs
General Matrix Multiplication (GEMM) is a crucial algorithm for various
applications such as machine learning and scientific computing, and an
efficient GEMM implementation is essential for the performance of these
systems. While researchers often strive for faster performance by using large
compute platforms, the increased scale of these systems can raise concerns
about hardware and software reliability. In this paper, we present a design for
a high-performance GEMM with algorithm-based fault tolerance for use on GPUs.
We describe fault-tolerant designs for GEMM at the thread, warp, and
threadblock levels, and also provide a baseline GEMM implementation that is
competitive with or faster than the state-of-the-art, proprietary cuBLAS GEMM.
We present a kernel fusion strategy to overlap and mitigate the memory latency
due to fault tolerance with the original GEMM computation. To support a wide
range of input matrix shapes and reduce development costs, we present a
template-based approach for automatic code generation for both fault-tolerant
and non-fault-tolerant GEMM implementations. We evaluate our work on NVIDIA
Tesla T4 and A100 server GPUs. Experimental results demonstrate that our
baseline GEMM presents comparable or superior performance compared to the
closed-source cuBLAS. The fault-tolerant GEMM incurs only a minimal overhead
(8.89\% on average) compared to cuBLAS even with hundreds of errors injected
per minute. For irregularly shaped inputs, the code generator-generated kernels
show remarkable speedups of and
for fault-tolerant and non-fault-tolerant GEMMs, outperforming cuBLAS by up to
.Comment: 11 pages, 2023 International Conference on Supercomputin
Enhanced thermal stability and electrical behavior of Zn-doped Sb2Te films for phase change memory application
Zn-doped SbāTe films are proposed to present the feasibility for phase-change memory application. Zn atoms are found to significantly increase crystallization temperature of Zn x (SbāTe)1āx films and be almost linearly with the wide range of Zn-doping concentration from xā=ā0 to 29.67 at.%. Crystalline resistances are enhanced by Zn-doping, while keeping the large amorphous/crystalline resistance ratio almost constant at ā¼10āµ. Especially, the Zn 26.07 (SbāTe)73.93 and Zn 29.67 (SbāTe)70.33 films exhibit a larger resistance change, faster crystallization speed, and better thermal stability due to the formation of amorphous Zn-Sb and Zn-Te phases as well as uniform distribution of SbāTe crystalline grains
Phase change behaviors of Zn-doped Ge2Sb2Te5 films
This work was financially supported by the Program for
New Century Excellent Talents in University (Grant No.
NCET-10-0976), the International Science & Technology
Cooperation Program of China (Grant No. 2011DFA12040),
the National Program on Key Basic Research Project (973
Program) (Grant No. 2012CB722703), the Natural Science
Foundation of China (Grant Nos. 61008041 and 60978058),
the Natural Science Foundation of Zhejiang Province, China
(Grant No. Y1090996), the Natural Science Foundation of
Ningbo City, China (Grant No. 2011A610092), the Program
for Innovative Research Team of Ningbo city (Grant No.
2009B21007), and sponsored by K. C. Wong Magna Fund in
Ningbo University
Improved phase-change characteristics of Zn-doped amorphous SbāTeā films for high-speed and low-power phase change memory
The superior performance of Zn-doped SbāTeā films might be favorable for the application in phase change memory. It was found that Zn dopants were able to suppress phase separation and form single stable Sb2Te crystal grain, diminish the grain size, and enhance the amorphous thermal stability of SbāTeā film. Especially, Zn 30.19(SbāTeā)69.81 film has higher crystallization temperature (ā¼258āĀ°C), larger crystallization activation energy (ā¼4.15āeV), better data retention (ā¼170.6āĀ°C for 10āyr), wider band gap (ā¼0.73āeV), and higher crystalline resistance. The minimum times for crystallization of Zn 30.19(SbāTeā)69.81 were revealed to be as short as ā¼10āns at a given proper laser power of 70āmW.This work was financially supported by the International
Science & Technology Cooperation Program of China
(Grant No. 2011DFA12040), the National Program on Key
Basic Research Project (973 Program) (Grant No.
2012CB722703), the Natural Science Foundation of China
(Grant Nos. 61008041 and 60978058), the CAS Special
Grant for Postgraduate Research, Innovation and Practice,
the Program for Innovative Research Team of Ningbo city
(Grant No. 2009B21007), and sponsored by K. C. Wong
Magna Fund in Ningbo University
A New Viscoelastic Model for Polycarbonate Compressing Flow
To overcome the weakness of conventional models in describing compressing flow especially in start and end stages the shear rate derivative was added to the right side of PTT constitutive equation. The ability of describing the well-known āshear shinningā and āstretch hardenā phenomena was first illustrated by theoretical analysis. Then the governing equations for compressing flow were established in terms of incompressible and isothermal fluid, and the numerical method was constructed to discretize the equations and get the compressing flow solutions. The experiments with four melt temperatures were conducted and the corresponding simulations were performed. The better agreements with experimental data indicates the modified PPT model is superior to the original PTT model in prediction of compressing flow. In addition, the proposed model is also validated with low and high compressing speed experiments
Novel GeāGaāTeāCsBr Glass System with Ultrahigh Resolvability of Halide
International audienceCO2 molecule, one of the main molecules to create new life, should be probed accurately to detect the existence of life in exoplanets. The primary signature of CO2 molecule is approximately 15 Ī¼m, and traditional S- and Se-based glass fibers are unsuitable. Thus, Te-based glass is the only ideal candidate glass for far-infrared detection. In this study, a new kind of Te-based chalcohalide glass system was discovered with relatively stable and large optical band gap. A traditional melt-quenching method was adopted to prepare a series of (Ge15Ga10Te75)100-x (CsBr)x chalcogenide glass samples. Experiment results indicate that the glass-forming ability and thermal properties of glass samples were improved when CsBr was added in the host of GeāGaāTe glass. GeāGaāTe glass could remarkably dissolve CsBr content as much as 85 at.%, which is the highest halide content in all reports for Te-based chalcohalide glasses. Moreover, ĪT values of these glass samples were all above 100 Ā°C. The glass sample (Ge15Ga10Te75)65 (CsBr)35 with ĪT of 119 Ā°C was the largest, which was 7 Ā°C larger than that of Ge15Ga10Te75 host glass. The infrared transmission spectra of these glasses show that the far-infrared cut-off wavelengths of (Ge15Ga10Te75)100-x (CsBr)x chalcogenide glasses were all beyond 25 Ī¼m. In conclusion, (Ge15Ga10Te75)100-x (CsBr)x chalcogenide glasses are potential materials for far-infrared optical applicatio
Novel NaI improved GeāGaāTe far-infrared chalcogenide glasses
International audienceIn this study, a novel Te-based glass system was investigated. Some properties of GeāGaāTeāNaI chalcogenide glasses such as physical, thermal and optical transmitting were discussed. XRD patterns show this glass system with best amorphous state can dissolve content of NaI as much as 35 at.%. The lowest cut-off wavelength of glass samples is 1645 nm which is the smallest wavelength among the reported Te-based glasses doping with halide. DSC curves indicate that all glass samples have good thermal stabilities (ĪT > 100 Ā°C) and the highest ĪT value corresponding to (Ge15Ga10Te75)85(NaI)15 glass is 120 Ā°C which is 8 Ā°C greater than that of GeāGaāTe host glass. The infrared spectra manifest GeāGaāTeāNaI chalcogenide glass system has a wide infrared transmission window between 1.6 Ī¼m and 20 Ī¼m. Consequently, GeāGaāTeāNaI glasses can be a candidate material for far infrared optic imaging and bio-sensing application
Seleniumādoping induced two antiferromagnetic transitions in thiospinel compounds CuCoāS_(4āx)Se_x (0 ā¤ x ā¤ 0.8)
A series of copper thiospinels compounds, CuCoāS_(4āx)Se_x (x = 0, 0.2, 0.4, 0.6, 0.8), have been successfully synthesized by solid state reaction and their structure and magnetic properties have been studied. The Rietveld refinements of XāRay diffractions indicate that both the lattice constants and the nearest neighbor CuāCu distances increase with increasing selenium doping. A weakly antiferromagnetic transition occurring at about 4 K is observed in CuCoāSā. Two antiferromagnetic transitions at about 3.5 K and 6 K are observed in seleniumādoped samples, which suggest that the exchange couplings associated with CuāS(Se)āCu and CuāSe(S)āCu, respectively, are responsible for the two antiferromagnetic transitions. Detailed analysis of the experimental results further indicate that the nearestāneighbor molecular field coefficient is comparable to the nextāneighbor molecular field coefficient. We propose a reasonable model to explain this phenomenon
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