Cryptographic Lightweight Encryption Algorithm with Dimensionality Reduction in Edge Computing

Edge Computing is one of the radically evolving systems through generations as it is able to effectively meet the data saving standards of consumers, providers and the workers. Requisition for Edge Computing based items have been increasing tremendously. Apart from the advantages it holds, there remain lots of objections and restrictions, which hinders it from accomplishing the need of consumers all around the world. Some of the limitations are constraints on computing and hardware, functions and accessibility, remote administration and connectivity. There is also a backlog in security due to its inability to create a trust between devices involved in encryption and decryption. This is because security of data greatly depends upon faster encryption and decryption in order to transfer it. In addition, its devices are considerably exposed to side channel attacks, including Power Analysis attacks that are capable of overturning the process. Constrained space and the ability of it is one of the most challenging tasks. To prevail over from this issue we are proposing a Cryptographic Lightweight Encryption Algorithm with Dimensionality Reduction in Edge Computing. The t-Distributed Stochastic Neighbor Embedding is one of the efficient dimensionality reduction technique that greatly decreases the size of the non-linear data. The three dimensional image data obtained from the system, which are connected with it, are dimensionally reduced, and then lightweight encryption algorithm is employed. Hence, the security backlog can be solved effectively using this method.     

Growth mechanism and gas-sensing characteristics of organic-additive-free zinc oxide of various shapes

Zinc oxide is widely used in gas sensors, solar cells, and photocatalysts because of its wide bandgap and exciton binding energy of 60 meV in various metal oxides. To use ZnO as a gas sensor, it is necessary to synthesize it with surface defects and a large specific surface area. In this study, hydrothermal synthesis without surfactants was employed to obtain organic-additive-free ZnO. For morphology control, we varied the ratio of the hydroxide ion concentration to the zinc ion concentration. To confirm the growth mechanism of ZnO, we performed X-ray diffraction, scanning electron microscopy, and transmission electron microscopy analyses. Raman spectroscopy and photoluminescence measurements were performed to analyze the surface properties. The Brunauer–Emmett–Teller method and probe stations were used to measure the specific surface area and sensitivity of the gas sensor, respectively. The results confirmed that flower-shaped ZnO is the most suitable gas-sensing material.     

Simulation of thermal barrier coating spallation induced by the initiation/growth/coalescence of internal crack and interfacial crack based on a real image model

In the furnace cycle test, the growth of oxide film leads to the propagation and coalescence of multiple cracks near the interface, which should be responsible for the spallation of thermal barrier coatings (TBCs). A TBC model with real interface morphology is created, and the near-interface large pore is retained. The purpose of this work is to clarify the mechanism of TBC spallation caused by successive initiation, propagation, and linkage of cracks near the interface during thermal cycle. The dynamic growth of thermally grown oxide (TGO) is carried out by applying a stress-free strain. The crack nucleation and arbitrary path propagation in YSZ and TGO are simulated by the extended finite element method (XFEM). The debonding along the YSZ/TGO/BC interface is evaluated using a surface-based cohesive behavior. The large-scale pore in YSZ near the interface can initiate a new crack. The ceramic crack can propagate to the YSZ/TGO interface, which will accelerate the interfacial damage and debonding. For the TGO/BC interface, the normal compressive stress and small shear stress at the valley hinder the further crack propagation. The growth of YSZ crack and the formation of through-TGO crack are the main causes of TBC delamination. The accelerated BC oxidation increases the lateral growth strain of TGO, which will promote crack propagation and coalescence. The optimization design proposed in this work can provide another option for developing TBC with high durability.     

基于归一化水体指数及其阈值自适应算法的水体遥感反演效果分析

归一化水体指数（NDWI）是水体遥感反演的一种重要指标，其阈值及修正直接影响反演结果的精度。基于Landsat-8与GF-1光学多光谱影像，使用归一化水体指数法阈值0（TH₀）、最大类间方差法（OTSU）自适应阈值（TH_otsu）与均值漂移聚类算法（Mean-Shift）自适应阈值（TH_MS）分别对典型正常水体、云雾覆盖水体、富营养化水体、高含泥沙水体进行水体遥感提取与效果分析，结果表明：正常水体以TH₀为阈值提取精度最高，THMS提取精度次之，TH_otsu提取精度最差；而云雾覆盖水体、富营养化水体以及含泥沙水体使用THMS提取精度最高，尤其少量云雾覆盖下的水体，TH_MS具有更明显的优势，TH₀提取精度次之，TH_otsu提取精度最差；对于不同的阈值，Land?sat-8比GF-1总体表现出更高的水体提取精度。Mean-Shift算法应用于NDWI阈值修正与水体遥感反演具有快速、水质适应性强、效果稳定的优势，对尤其是复杂条件下的水体信息遥感反演具有较好的提取效果。     

Community involvement critical for revitalization: Grass-roots initiative key to environmental remediation and restoration in the Great River (St. Lawrence River)

This paper describes the creation of an environmentally conscious community group, the Great River Network, and the role that it has played in the remediation and restoration process as part of one of the Great Lakes environmental programs. Community engagement was initiated in the region as part of the Remedial Action Plan for the Area of Concern at Cornwall/Akwesasne/Massena within the Upper St. Lawrence River. The community group formalised as a network representing 50+ organisations in response to perceived inadequacies in the agency of the community to respond to new environmental concerns outside of the scope of the existing programs. As a grass-roots initiative, the Great River Network has successfully completed remediation and restoration actions of significant value to the environment. These include a series of river clean ups (>42 tonnes of garbage removed), fish habitat restoration, and addressing shoreline erosion issues. Success has been achieved through partnering with a range of organisations, including Indigenous, non-profit, governmental, Conservation Authorities, businesses and industry partners. The action-oriented approach showcases how remediation and restoration led by, and embedded in, the community can result in true revitalization. A simplified framework for adaptive management practices for remediation and restoration efforts that lead to revitalization, including knowledge translation, is proposed. This case study highlights the transformational opportunities that remediation and restoration initiatives can bring. In this instance, the process is intensely local and cooperative and lays the foundation for moving towards a collective impact approach for the region.     

Preparation and pore-forming mechanism of MgO–Al2O3–CaO-based porous ceramics using phosphorus tailings

A simple strategy for preparing MgO–Al₂O₃–CaO-based porous ceramics (MACPC) with high strength and ultralow thermal conductivity has been proposed in this work based on the raw material of phosphorus tailings. The effects of phosphorus tailings content, carbon black addition and heat treatment temperature on the properties of MACPC were studied, and their pore-forming mechanism during sintering was revealed. The results showed that the main phase composition of MACPC was magnesia alumina spinel and calcium aluminate after sintering at 1225 °C. Furthermore, the MACPC exhibited excellent comprehensive properties when 60 wt% phosphorus tailings and 40 wt% alumina were added, whose apparent porosity was 62.8%, cold compressive strength was 14.8 MPa, and the thermal conductivity was 0.106 W/(m·K) at 800 °C. The synchronously enhanced strength and thermal insulation properties of MACPC were related to the formation of uniformly distributed micropores (<2 μm) and passages in the matrix, which originated from the decomposition of phosphorus tailings and the burnt out of carbon black during the sintering process. The preparation of MACPC with high temperature resistance and excellent mechanical and thermal insulation properties with the raw material of phosphorus tailings provided an effective method for the high-value utilization of phosphorus tailings.     

Orthorhombic to tetragonal polymorphic transformation of YTa3O9 and its inhibition through the design of high-entropy (Y0.2La0.2Ce0.2Nd0.2Gd0.2)Ta3O9

To explore the mechanism of phase transformation, YTa₃O₉ was prepared by an integrated one-step synthesis and sintering method at 1500 °C using Y₂O₃ and Ta₂O₅ powders as starting materials. High-temperature XRD patterns and Raman spectra showed that a phase transformation from orthorhombic to tetragonal took place in YTa₃O₉ through the bond length and angle changes at 300–400 °C, which caused a thermal conductivity rise. To inhibit the phase transformation, a high-entropy (Y_0.2La_0.2Ce_0.2Nd_0.2Gd_0.2)Ta₃O₉ (HE RETa₃O₉) was designed and synthesized at 1550 °C using the integrated solid-state synthesis and sintering method. In tetragonal structured HE RETa₃O₉, phase transformation was inhibited by the high-entropy effect. Furthermore, HE RETa₃O₉ exhibited low thermal conductivity, and its tendency to increase with temperature was alleviated (1.69 W/m·K, 1073 K). Good phase stability, low thermal conductivity and comparable fracture toughness to YSZ make HE RETa₃O₉ promising as a new thermal barrier coating material.     

Enhanced structural,electromagnetic and absorption features of CoSm ferrite-metamaterial absorbers through synergistic effects

Currently, materials with outstanding absorption abilities, such as thin size, better absorbing power, and light weight are the need of industry to resolve the electromagnetic issues. However, the research on optimizing the composition of the material, microstructure and the structure of the absorber are also the important factors for enhancing the absorption features. A metamaterial microwave absorber (MMA) based on nano ferrites with desirable absorption peaks is proposed and simulated. Sol-gel auto combustion route is used to prepare the nanosized Sm doped Co ferrite with Co_1+xSm_xFe_2-2xO₄ at x = 0.00, 0.03, 0.06, 0.09, respectively. XRD, VSM, FESEM, and VNA were employed to evaluate the structural, magnetic, morphological, and dielectric features. Rietveld refinement of the XRD patterns of samples was evaluated. Refined parameters show the spinel phase's emergence and the Fe₂O₃ phase. Grain size and crystallite size were increased with Sm doping in Co ferrite. Electromagnetic studies depicted that the highest dielectric constant value was found at x = 0.09 and the minimum value at x = 0.03, respectively. Sm doped Co ferrite at x = 0.09 depicted high Q values at higher frequencies. The coercivity values first decreased and then increased. All samples exhibit variations in coercivity and magneto-crystalline anisotropy constant. This variation was attributed to the super-exchange interactions and strong LS coupling of the cations. The multiple absorption peaks are attained for TE-polarization, and the absorptivity is considerably improved for x = 0.09. The proposed absorber simulated from CST depicted the absorption peaks of the S-band and C-band of the microwave regime. The synergistic effects among the metamaterial and ferrite layers may enhance the absorption feature and would be useful for satellite communication applications.     

基于改进相干增强扩散与纹理能量测度和高斯混合模型的导光板表面缺陷检测方法

针对液晶屏(LCD)导光板表面缺陷检测方法存在漏检率和误检率较高,对产品表面复杂渐变的纹理结构适应性差的问题,提出一种基于改进相干增强扩散(ICED)与纹理能量测度和高斯混合模型(TEM-GMM)的LCD导光板表面缺陷检测方法。首先,构建ICED模型,基于结构张量引入平均曲率流扩散(MCF)滤波,使得相干增强扩散(CED)模型对缺陷的细线状纹理有良好的边缘保持效果,并利用相干性得到缺陷纹理增强和背景纹理抑制的滤波后图像;然后,根据Laws纹理能量测度(TEM)提取图像纹理特征,将图像的背景纹理特征作为离线阶段高斯混合模型(GMM)的训练数据,使用期望最大化(EM)算法估计GMM参数;最后,计算待检测图像各像素的后验概率,并将其作为在线检测阶段缺陷像素的判断依据。实验结果表明,该检测方法在导光颗粒随机、规则两种分布的缺陷图像测试数据组上的漏检率和误检率分别为3.27%、4.32%和3.59%、4.87%。所提检测方法适用范围广,可有效检测出LCD导光板表面划痕、异物、脏污和压伤等类型的缺陷。     

Preparation of P(St-NMA) microsphere inks and their application in photonic crystal patterns with brilliant structural colors

Patterned photonic crystals with structural colors on textile substrates have attracted a special attention due to the great advantages in application, which currently become a research hot-spot. This study utilized an ink-jet printing technology to prepare high-quality photonic crystal patterns with structural colors on polyester substrates. The self-assembly temperature of poly(styrene-N-methylol acrylamide) (P(St-NMA)) microspheres set to construct photonic crystals were deeply optimized. Moreover, the structural colors of prepared photonic crystal patterns were characterized and evaluated. When the mass fraction of P(St-NMA) microspheres was 1.0 wt.%, the pH value ranged from 5 to 7, and the surface tension was in the range of 63.79 to 71.20 mN/m, inks could present the best print performance. At 60 °C, prepared P(St-NMA) microsphere inks were good for printing to obtain patterned photonic crystals with regular arrangement and beautiful structural colors. Specifically, photonic crystals with different colors could be constructed by regulating the diameter of microspheres in inks, and prepared structural colors exhibited distinct iridescent phenomenon. The present results could provide a theoretical basis for the industrial realization of patterned photonic crystals by ink-jet printing technology.