An End-to-End Network for Co-Saliency Detection in One Single Image

As a common visual problem, co-saliency detection within a single image does not attract enough attention and yet has not been well addressed. Existing methods often follow a bottom-up strategy to infer co-saliency in an image, where salient regions are firstly detected using visual primitives such as color and shape, and then grouped and merged into a co-saliency map. However, co-saliency is intrinsically perceived in a complex manner with bottom-up and top-down strategies combined in human vision. To deal with this problem, a novel end-to-end trainable network is proposed in this paper, which includes a backbone net and two branch nets. The backbone net uses ground-truth masks as top-down guidance for saliency prediction, while the two branch nets construct triplet proposals for feature organization and clustering, which drives the network to be sensitive to co-salient regions in a bottom-up way. To evaluate the proposed method, we construct a new dataset of 2,019 nature images with co-saliency in each image. Experimental results show that the proposed method achieves a state-of-the-art accuracy with a running speed of 28fps

Rapid Synthesis of Dittmarite by Microwave-Assisted Hydrothermal Method

Dittmarite was obtained using MgO and (NH4)2HPO4 as raw materials via microwave-assisted hydrothermal method for 3 min at 120°C. The resulting samples were investigated by X-ray powder diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetry-differential thermal analysis. The results indicate that dittmarite can be rapidly synthesized by microwave-assisted hydrothermal method. With higher temperature and longer reaction time, highly crystallized dittmarite can be obtained. Pure dittmarite can be synthesized for 3 min at 120°C, which is faster than with the use of any other reported methods

The Precambrian Khondalite Belt in the Daqingshan area, North China Craton: evidence for multiple metamorphic events in the Palaeoproterozoic era

High-grade pelitic metasedimentary rocks (khondalites) are widely distributed in the northwestern part of the North China Craton and were named the ‘Khondalite Belt’. Prior to the application of zircon geochronology, a stratigraphic division of the supracrustal rocks into several groups was established using interpretative field geology. We report here SHRIMP U–Pb zircon ages and Hf-isotope data on metamorphosed sedimentary and magmatic rocks at Daqingshan, a typical area of the Khondalite Belt. The main conclusions are as follows: (1) The early Precambrian supracrustal rocks belong to three sequences: a 2.56–2.51 Ga supracrustal unit (the previous Sanggan ‘group’), a 2.51–2.45 Ga supracrustal unit (a portion of the previous upper Wulashan ‘group’) and a 2.0–1.95 Ga supracrustal unit (including the previous lower Wulashan ‘group’, a portion of original upper Wulashan ‘group’ and the original Meidaizhao ‘group’) the units thus do not represent a true stratigraphy; (2) Strong tectono-thermal events occurred during the late Neoarchaean to late Palaeoproterozoic, with four episodes recognized: 2.6–2.5, 2.45–2.37, 2.3–2.0 and 1.95–1.85 Ga, with the latest event being consistent with the assembly of the Palaeoproterozoic supercontinent Columbia; (3) During the late Neoarchaean to late Palaeoproterozoic (2.55–2.5, 2.37 and 2.06 Ga) juvenile, mantle-derived material was added to the crust

The Residual Stress Relaxation Behavior of Weldments During Cyclic Loading

Accurate measurement of residual stress is necessary to obtain reliable predictions of fatigue lifetime and enable estimation of time-to-facture for any given stress level. In this article, relaxation of welding residual stresses as a function of cyclic loading was documented on three common steels: AISI 1008, ASTM A572, and AISI 4142. Welded specimens were subjected to cyclic bending (R = 0.1) at different applied stresses, and the residual stress relaxation existing near the welds was measured as a function of cycles. The steels exhibited very different stress relaxation behaviors during cyclic loadings, which can be related to the differences in the microstructures of the specimens. A phenomenological model, which treats dislocation motion during cyclic loading as being analogous to creep of dislocations, is proposed for estimation of the residual stress relaxation

The Effect of Specimen Dimension on Residual Stress Relaxation of the Weldments

The purpose of this study is to evaluate the residual stress relaxation behavior in weldments. The stress relaxation is studied while successively reducing the size of weld specimens. Finite-element modeling was used to simulate the stress relaxation, and then an empirical model was derived based on the experimental and modeling results. The results of this study shall encourage industry users to utilize more plentiful conventional X-ray diffractometers for residual stress measurement of large weld components.This article is published as Qian, Zhongyuan, L. Scott Chumbley, and Eric Johnson. "The Effect of Specimen Dimension on Residual Stress Relaxation of the Weldments." Advanced Materials Research, 996 (2014): 820-826. DOI: 10.4028/www.scientific.net/AMR.996.820. Posted with permission.</p

The Residual Stress Relaxation Behavior of Weldments During Cyclic Loading

Accurate measurement of residual stress is necessary to obtain reliable predictions of fatigue lifetime and enable estimation of time-to-facture for any given stress level. In this article, relaxation of welding residual stresses as a function of cyclic loading was documented on three common steels: AISI 1008, ASTM A572, and AISI 4142. Welded specimens were subjected to cyclic bending (R = 0.1) at different applied stresses, and the residual stress relaxation existing near the welds was measured as a function of cycles. The steels exhibited very different stress relaxation behaviors during cyclic loadings, which can be related to the differences in the microstructures of the specimens. A phenomenological model, which treats dislocation motion during cyclic loading as being analogous to creep of dislocations, is proposed for estimation of the residual stress relaxation.This article is from Metallurgical and Materials Transactions A 44 (2013): 3147-3156, doi: 10.1007/s11661-013-1688-9. Posted with permission.</p

Multi-Scale Vehicle Detection for Foreground-Background Class Imbalance with Improved YOLOv2

Vehicle detection is a challenging task in computer vision. In recent years, numerous vehicle detection methods have been proposed. Since the vehicles may have varying sizes in a scene, while the vehicles and the background in a scene may be with imbalanced sizes, the performance of vehicle detection is influenced. To obtain better performance on vehicle detection, a multi-scale vehicle detection method was proposed in this paper by improving YOLOv2. The main contributions of this paper include: (1) a new anchor box generation method Rk-means++ was proposed to enhance the adaptation of varying sizes of vehicles and achieve multi-scale detection; (2) Focal Loss was introduced into YOLOv2 for vehicle detection to reduce the negative influence on training resulting from imbalance between vehicles and background. The experimental results upon the Beijing Institute of Technology (BIT)-Vehicle public dataset demonstrated that the proposed method can obtain better performance on vehicle localization and recognition than that of other existing methods

Enhanced Effective Detection of Buried Radioactive Waste -10177

ABSTRACT In our previous paper, we presented a matched filtering (MF)-based approach to detect buried radioactive waste using its gamma-ray spectrum. This approach does not require background information and its performance is robust under very low-count conditions. In this paper, we improve this approach when background information is available. The spectral comparison ratio (SCR) method is adopted to normalize the background contribution in energy spectra, and the MF operator is applied on the SCR-transformed data. The resulting SCR MF approach can improve the performance of MF. It can also outperform other widely used techniques, such as energy window and gross count