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In this paper, we propose an efficient saliency map generation method, called Group score-weighted Class Activation Mapping (Group-CAM), which adopts the "split-transform-merge" strategy to generate saliency maps. Specifically, for an input image, the class activations are firstly split into groups. In each group, the sub-activations are summed and de-noised as an initial mask. After that, the initial masks are transformed with meaningful perturbations and then applied to preserve sub-pixels of the input (i.e., masked inputs), which are then fed into the network to calculate the confidence scores. Finally, the initial masks are weighted summed to form the final saliency map, where the weights are confidence scores produced by the masked inputs. Group-CAM is efficient yet effective, which only requires dozens of queries to the network while producing target-related saliency maps. As a result, Group-CAM can be served as an effective data augment trick for fine-tuning the networks. We comprehensively evaluate the performance of Group-CAM on common-used benchmarks, including deletion and insertion tests on ImageNet-1k, and pointing game tests on COCO2017. Extensive experimental results demonstrate that Group-CAM achieves better visual performance than the current state-of-the-art explanation approaches. The code is available at https://github.com/wofmanaf/Group-CAM., Comment: Group-CAM is an efficient region-based saliency method, which can be used as an effective data augmentation trick

In this paper, we propose a direct Eulerian generalized Riemann problem (GRP) scheme for a blood flow model in arteries. It is an extension of the Eulerian GRP scheme, which is developed by Ben-Artzi, et. al. in J. Comput. Phys., 218(2006). By using the Riemann invariants, we diagonalize the blood flow system into a weakly coupled system, which is used to resolve rarefaction wave. We also use Rankine-Hugoniot condition to resolve the local GRP formulation. We pay special attention to the acoustic case as well as the sonic case. The extension to the two dimensional case is carefully obtained by using the dimensional splitting technique. We test that the derived GRP scheme is second order accuracy.

This paper presents an efficient multi-scale vision Transformer, called ResT, that capably served as a general-purpose backbone for image recognition. Unlike existing Transformer methods, which employ standard Transformer blocks to tackle raw images with a fixed resolution, our ResT have several advantages: (1) A memory-efficient multi-head self-attention is built, which compresses the memory by a simple depth-wise convolution, and projects the interaction across the attention-heads dimension while keeping the diversity ability of multi-heads; (2) Position encoding is constructed as spatial attention, which is more flexible and can tackle with input images of arbitrary size without interpolation or fine-tune; (3) Instead of the straightforward tokenization at the beginning of each stage, we design the patch embedding as a stack of overlapping convolution operation with stride on the 2D-reshaped token map. We comprehensively validate ResT on image classification and downstream tasks. Experimental results show that the proposed ResT can outperform the recently state-of-the-art backbones by a large margin, demonstrating the potential of ResT as strong backbones. The code and models will be made publicly available at https://github.com/wofmanaf/ResT., Comment: ResT is an efficient multi-scale vision Transformer that can tackle input images with arbitrary size. arXiv admin note: text overlap with arXiv:2103.14030 by other authors

Ultrasonic shot peening(USP) is an advanced surface treatment technology for obtaining excellent surface properties or manufacturing a three-dimensional curved surface of the metal sheets. The impact of the medium driven by ultrasonic vibration is significant to parameter optimization and excellent performance of the USP technology. However, the impact characteristics of the medium lack careful study, which is a complex dynamic analysis involving many factors, such as collision, plastic deformation, air pressure, etc. In this paper, a detection system is successfully developed to investigate the needle impact force and frequency against the material surface, consisting of a piezoelectric load sensor, oscilloscope, and a single needle USP device. Moreover, the FE model of the needle impact is developed simultaneously to study the characteristics of residual stress implantation induced by needle impact. Based on the experiment and FE simulation results, it is discovered that the impacts with high speed primarily determine the thickness of the modified layer implanted with residual stress during multiple impacts at different rates. According to residual stress implantation characteristics, the low-speed impact whose speed does not reach 50% of the maximum impact speed was defined as the ineffective impact. Besides, increasing the amplitude of ultrasonic vibration results in a significant increase in the maximum impact force and the effective impact frequency. The travel distance of needle impact has a considerable effect on the effective impact frequency, but it has little effect on the maximum impact force. Finally, it was concluded that the low air pressure plays a positive role in the needle impact. Furthermore, excessive air pressure hinders the needle impact and results in a decline in the effective impact frequency and the maximum impact force.

With the gradual improvement of the Beidou system, the Beidou navigation receiver begins to be widely used, but due to the low power of navigation signal, the navigation receiver is easily disturbed and cannot work normally. This paper take Beidou navigation receiver as experiment object, and study the sensitive voltage and effect under the condition of ESD, The experiment shows that the positioning function of the receiver is not affected by ESD, but the data output serial port is susceptible to interference, so that the upper computer cannot obtain the effective information of navigation and positioning in time. The conclusion provides a basis for the electromagnetic protection of the navigation receiver.

Ultrasonic vibratory stress relief (UVSR) is a novel method for residual stress relieving of metal parts. In this paper, the UVSR method was applied to treat a random-sized plate, which is not designed to match with the resonant frequency of the ultrasonic transducer. The UVSR system includes an ultrasonic generator, a 20 kHz ultrasonic transducer and specially designed fixtures to exert ultrasonic vibration to the treated parts. Based on the experimental results, the average stress relief ratio reached 53% and the final residual stress distribution interval was reduced by 57. The vibratory stress introduced by the ultrasonic vibration was obtained accurately by matching the FE model with the measured vibration amplitude distribution. It is found that local yield stress, instead of macroscopic yield stress, should be used as the threshold of residual stress relieving. Moreover, if the local yield stress of a material is constant, the local yield stress of 6082 aluminum alloy is reduced by at least 27% during the UVSR. Finally, it is found that the residual stress relief rate in one direction is proportional to the vibratory stress introduced in that direction.

Microstrip filter plays an important role in harmonic suppression of vector network analyzer source. Based on microstrip theory, microstrip filter can be designed with professional EDA simulation software. This article describes the design of a 16–20GHz band-pass filter. It is applied in the stimulate source of vector network analyzer after verified on PCB. Ultimately second harmonic suppression reached −72 dBc, improving harmonic suppression by 44dB.

To solve the gradually serious electromagnetic pollution problem, more and more electromagnetic shielding alloys are designed because of its higher conductivities and better workability. However, the increasing incident electromagnetic frequency with the more powerful energy enhance the electromagnetic wave penetrates ability and relatively weakens the alloys' shielding properties. Some researches indicate that the shielding material with laminated structure exhibit better shielding property at higher incident electromagnetic frequency. Accordingly, a novel duplex Mg-9Li alloy with laminated structure of 24-1 interfaces of strips for electromagnetic shielding was designed and fabricated by accumulative roll bonding (ARB) up to 4 cycles at ambient temperature. With the analysis of microstructure evolution and bonding mechanism, the relative conductivity and the density of the alloy are decreased from 15.38% to 12.03% and from 100% to 94%, respectively. Such changes are attributed to insulted oxide or contaminant during roll bonding. The shielding effectiveness (SE) of the sheets are increased from 56 dB to 73 dB at 1350 MHz with the increasing of phase interlayers interface through ARB process which can be ascribed to the laminated structure of Mg-Li alloy processed by ARB shielding properties according to shielding mechanism.

The Nadanhada terrane, a Jurassic disrupted terrane in Heilongjiang Province of China, is principally composed of Permo- Carboniferous limestone and greenstone, Triassic bedded chert and middle Jurassic siliceous shale, all enclosed within younger (presumably Late Jurassic- Early Cretaceous) clastics. Palaeontological and lithological characteristics and structural features of these formations are entirely identical to those of the Mino terrane of the Japanese Islands. Prior to opening of the Sea of Japan, these terranes formed a single superterrane together with the Western Sikhote-Alin terrane. Tectono-stratigraphic terranes very similar to the Nadanhada and Mino terranes are also found in the Ryukyu are, the Philippines and probably in Borneo. All these terranes constituted a belt of accretionary complexes during Late Jurassic and / or Early Cretaceous time along the eastern continental margin of Asia after completion of the Triassic collage of the Chinese continent.

From Donghai County of Jiangsu Province to Rongcheng County of Shandong Province on the southern border of the Sulu orogen, there exposes an ultramafic belt, accompanied with an ultrahigh-pressure metamorphic zone. It can be further divided into the Xugou belt (the northern belt), and the Maobei-Gangshang belt (the southern belt). One grain of diamond has been discovered from the Zhimafang pyrope peridotite in the southern belt using the heavy mineral method. The diamond grain is 2.13 mm × 1.42 mm × 0.83 mm in size and weighs 9.4 mg. The occurrence of the diamond suggests that the Zhimafang pyrope peridotite xenolith is derived from the lithospheric upper mantle. The tectonic emplacement mechanism of the pyrope peridotite xenoliths in granite-gneisses is obviously different from those in kimberlite. The Sulu orogen was located on the active continental margin of the Sino-Korean craton in the Neoproterozoic. The relatively cold and water-bearing oceanic crustal tholeiite slab subducted beneath the lithospheric mantle of the Sino-Korean craton, and partly melted to produce granitic magma and water-bearing fluids. The magma and fluids pierced through and fractured the overlying lithospheric mantle, and ascended to the crustal level together with the ultramafic mantle fragments as xenoliths.

In Elliptic Curve Cryptography(ECC), due to the characteristic of high efficiency, the modular multiplication operation in type II optimal normal basis(II-ONB) over binary field has become a key research trend. Based on B. Sunar’s basis conversion theory, in this paper, an improved II-ONB modular multiplication algorithm has been proposed and an efficient reconfigurable modular multiplier, which can support different lengths has been implemented. This work has been simulated using ModelSim and synthesized under 0.18μm CMOS technology. Then, complexity comparison has also been accomplished. The results prove that our proposed reconfigurable II-ONB modular multiplier can not only guarantee high flexibility for arbitrary modular multiplication, but also have area advantage in resource-constrained ECC applications.

This paper describes work performed to determine some of the properties of the electroless Ni-W-P amorphous deposits. Phosphorus contents were varied up to 32 at.%, and the amorphous structure was found to be present at phosphorus contents above 5 at.%. Irrespective of P content, all the deposits exhibited excellent adhesion to metallic substrates. The addition of even small amounts of W provided greatly increased hardness compared with the plain Ni-P deposits. The wettability properties of the Ni-W-P deposits were found to be comparable to those of Ni-P and N-B-P deposits but inferior to those of Ni-B deposits. (C) Elsevier Science Inc., 1996

This paper summarizes the latest advances in research on the terrane tectonics of China. The terranes of China distributed around various plates may be divided into four terrane belts of different ages and sizes, i. e., the East China, Northwest China, Southwest China and Qinling-Dabie terrane belts. Among them, the East China belt may be subdivided into three composite terrane groups; each terrane group is composed of several terranes that were formed roughly at the same time and have distinct geologic histories. The accretion of China’s terranes involves three types: the collision type, the flake-thrusting type, and the docking type. The results of the latest study in the five widening fields and some advances in the methods of research on the terrane tectonics in China are presented in the present paper.

S-parameters have been used in analyzing linear networks for more than half a century. Despite the great success of S-parameters, they are severely limited. In fact in real world, all systems are nonlinear. It's a hard work to characterizing the nonlinear network and thus it becomes a hot issue today. This article introduces two methods of nonlinear modeling, X-parameters and scattering functions. We give a conclusion on the relation of these two methods after comparing their basic concept and extraction systems. At the end of this paper, we present an extraction system which can adopt either X-parameters or Scattering functions for the nonlinear characterizing and modeling.

In this paper it is shown that the meet-inaccessible degrees are dense in R. The construction uses an 0′-priority argument. As a consequence, the meet-inaccessible degrees and the meet-accessible degrees give a partition of R into two sets, either of which is a nontrivial dense subset of R and generates R − {0} under joins (thus an automorphism base of R).

The dissipative structure is an ordered structure. When a system is far from reaching equilibrium in the condition of non-equilibrium and exchanges some energy and material with the surroundings, this structure will be formed and preserved. Starting with the analysis of practical data, we attempt to use this theory to discuss the tectono-geochemical problems of some rock and ore-forming systems in faults.

The preparation, formation and corrosion properties of electroless Ni-W-P amorphous alloys were studied systematically. The effects of the concentration of sodium tungstate and sodium citrate, and pH value on the compositions of deposit and deposition rates were measured. The range of amorphous structure for the deposits was established. It was confirmed that the amorphous deposits with higher phosphorus content showed better corrosion resistance than those with lower phosphorus content in acid or alkaline solutions; also an amorphous deposit showed better corrosion resistance in alkaline solutions than in acid solutions. Compared with the corrosion resistance of electroless amorphous Ni-P deposits, the addition of W into M-P deposits did not usually improve the corrosion resistance.