摘要:
Chaos maps and chaotic systems have been proved to be useful and effective for cryptography. In our study, the two-dimensional logistic map with complicated basin structures and attractors are first used for image encryption. The proposed method adopts the classic framework of the permutation-substitution network in cryptography and thus ensures both confusion and diffusion properties for a secure cipher. The proposed method is able to encrypt an intelligible image into a random-like one from the statistical point of view and the human visual system point of view. Extensive simulation results using test images from the USC-SIPI image database demonstrate the effectiveness and robustness of the proposed method. Security analysis results of using both the conventional and the most recent tests show that the encryption quality of the proposed method reaches or excels the current state-of-the-art methods. Similar encryption ideas can be applied to digital data in other formats (e.g., digital audio and video). We also publish the cipher MATLAB open-source-code under the web page https://sites.google.com/site/tuftsyuewu/source-code.
期刊:
Multimedia Tools and Applications,2016年75(23):15601-15617 ISSN:1380-7501
通讯作者:
Zhang, Yudong
作者机构:
[Yang, Gelan] Hunan City Univ, Sch Informat Sci & Engn, Yiyang 413000, Peoples R China.;[Zhang, Yudong; Wang, Shuihua; Ji, Genlin] Nanjing Normal Univ, Sch Comp Sci & Technol, Nanjing 210023, Jiangsu, Peoples R China.;[Zhang, Yudong; Feng, Chunmei; Wang, Qiong; Yang, Jiquan] Jiangsu Key Lab 3D Printing Equipment & Mfg, Nanjing 210042, Jiangsu, Peoples R China.;[Dong, Zhengchao] Columbia Univ, Translat Imaging Div, New York, NY 10032 USA.;[Dong, Zhengchao] Columbia Univ, MRI Unit, New York, NY 10032 USA.
通讯机构:
[Zhang, Yudong] N;[Zhang, Yudong] J;Nanjing Normal Univ, Sch Comp Sci & Technol, Nanjing 210023, Jiangsu, Peoples R China.;Jiangsu Key Lab 3D Printing Equipment & Mfg, Nanjing 210042, Jiangsu, Peoples R China.
摘要:
It is very important to early detect abnormal brains, in order to save social and hospital resources. The wavelet-energy was a successful feature descriptor that achieved excellent performances in various applications; hence, we proposed a novel wavelet-energy based approach for automated classification of MR brain images as normal or abnormal. SVM was used as the classifier, and biogeography-based optimization (BBO) was introduced to optimize the weights of the SVM. The results based on a 5 x 5-fold cross validation showed the performance of the proposed BBO-KSVM was superior to BP-NN, KSVM, and PSO-KSVM in terms of sensitivity and accuracy. The study offered a new means to detect abnormal brains with excellent performance.
关键词:
Mining and manufacturing;Rock weathering;Fertilizer and pesticide use;Principal component analysis;Mixed metal pollution;Surface water pollution
摘要:
This study collected past sampling data on total concentrations of 12 heavy metals (Cd, Pb, Cr, Hg, Zn, Cu, Ni, Al, Fe, Mn, As, and Co) in surface water bodies, i.e., 168 rivers and 71 lakes, from 1972 to 2017. The intent was to investigate the levels and sources of heavy metal pollution across five decades and five continents. Mean heavy metal concentrations in global river and lake water, and the number of heavy metals with concentrations greater than the published threshold limits as per the standards of both the World Health Organization (WHO) and the United States Environmental Protection Agency (USEPA) were generally lower in the 1970s and 1980s than in the 1990s, 2000s, and 2010s. Over time, heavy metal pollution in surface water has changed from single metal pollution to mixed metal pollution. Heavy metal concentrations in water, and the number of heavy metals with concentrations above the threshold limits for both WHO and USEPA standards were lower in the developed countries of Europe and North America, and higher in the developing countries of Africa, Asia, and South America. Over time, the main sources of metal pollution have changed from mining and manufacturing to rock weathering and waste discharge. The main metal sources differed across the five continents, with fertilizer and pesticide use, along with rock weathering, being dominant in Africa. Mining and manufacturing, along with rock weathering, were dominant in Asia and Europe. Mining and manufacturing, along with fertilizer and pesticide use, were dominant sources in North America, while four sources (mining and manufacturing, fertilizer and pesticide use, rock weathering, and waste discharge) were responsible for the majority of heavy metal pollution in the river and lake water bodies of South America. Additionally, implementing rigorous standards on metal emissions and recycling metals from wastewater are effective for controlling heavy metal source pollution. (C) 2020 The Authors. Published by Elsevier B.V.
期刊:
Journal of Mathematical Analysis and Applications,2015年428(1):587-604 ISSN:0022-247X
通讯作者:
Chu, Yu-Ming
作者机构:
[Chu, Yu-Ming; Yang, Zhen-Hang] Hunan City Univ, Sch Math & Computat Sci, Yiyang 413000, Peoples R China.;[Wang, Miao-Kun] Huzhou Univ, Dept Math, Huzhou 813000, Peoples R China.
通讯机构:
[Chu, Yu-Ming] H;Hunan City Univ, Sch Math & Computat Sci, Yiyang 413000, Peoples R China.
关键词:
Quotient of power series;Piecewise monotonicity;Hypergeometric function;Leaden inequality
摘要:
In this paper, we present the necessary and sufficient condition for the monotonicity of the quotient of power series. As applications, some gaps and misquotations in certain published articles are pointed out and corrected, and some known results involving the Landen inequalities for zero-balanced hypergeometric functions are Improved. (C) 2015 Elsevier Inc. All rights reserved.
摘要:
Studies were performed to evaluate influence of biochar addition on physico-chemical process, heavy metals transformation and bacterial community diversity during composting of sediment with agricultural wastes. Simultaneously, the relationships between those parameters including heavy metals and bacterial community compositions were evaluated by redundancy analysis (RDA). The results show that the extraction efficiency of DTPA extractable heavy metals decreased in both piles, and reduced more in pile with biochar addition about 0.1-2.96%. Biochar addition dramatically influenced the bacterial community structure during the composting process. Moreover, the bacterial community composition was significantly correlated with C/N ratio, water soluble carbon (WSC), and organic matter (OM) (P < 0.05) in pile with biochar addition; while significantly correlated with temperature, WSC, and C/N ratio in pile which was free of biochar. This study would provide some valuable information for improving the composting for disposal of river sediment with heavy metals contamination. (C) 2017 Elsevier Ltd. All rights reserved.
摘要:
The aim of this research is reinforcing of concrete with variety of fiber reinforced polymer (FRP) configurations and investigates the load capacity and ductility of these connections using an experimental investigation. Six scaled-down RC exterior joints were tested under moderately monotonic loads. The results show that, the shape of the FRP had a different effect on the joint capacity and the connection ductility coefficient. The greatest effect on increasing the ductility factor was seen in the sample where two reinforcement plates were used on both sides of the beam web (RCS5 sample). For the sample with the presence of FRP plates at the top and bottom of the beam (RCS3 sample), the ductility factor was reduced even the load capacity of this sample increased. Except for the RCS3 sample, the rest of the samples exhibited an increase in the ductility factor due to the FRP reinforcement.
摘要:
Road traffic is an important component of the national economy and social life. Promoting intelligent and Informa ionization construction in the field of road traffic is conducive to the construction of smart cities and the formulation of macro strategies and construction plans for urban traffic development. Aiming at the shortcomings of the current road traffic system, this article, on the basis of combining convolution neural network, situational awareness technology, database and other technologies, takes the road traffic situational awareness system as the research object, and analyzes the information collection, processing, and analysis process of road traffic situational awareness system. Convolutional neural networks (CNN), region-CNN (R-CNN), fast R-CNN, and faster R-CNN are used for vehicle class classification and location identification in road image big data. The deep convolutional neural network model based on road traffic image big data was further established, and the system requirements analysis and system framework design and implementation were carried out. Through the analysis and trial of actual cases, the results show the application effect of the realized road traffic situational awareness system, which provides a scientific reference and basis for the establishment of modern intelligent transportation system.
摘要:
Three-dimensional (3D) BiOBr/BiOI hierarchical microsphere photocatalysts were successfully synthesized via a facile one-pot solvothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), UV–vis diffuse reflectance spectroscopy (UV–vis DRS) and N2 adsorption–desorption isotherms. The photocatalytic activity was evaluated by the photocatalytic degradation of Rhodamine B (RhB) and tetracycline (TC) under visible light irradiation (λ>420 nm). The 50% BiOBr/BiOI composite showed a higher photocatalytic removal efficiency of RhB and TC than 10% and 90% BiOBr/BiOI composites. RhB (C0=15 mg/L) was degraded completely within 40 min and over 83% of TC (C0= 40 mg/L) was degraded within 50 min using a catalyst quantity of 0.4 g/L of 50% BiOBr/BiOI. The enhanced photocatalytic activity of the 50:50 composite was attributed to effective separation of photogenerated carriers and the balance between enhanced visible light absorption and decreased valence band (VB) edge potential.
摘要:
This study aimed at developing a portable multi-channel turbidity system (21 cm in length, 15.5 cm in width and 11.5 cm in depth) by real-time loop-mediated isothermal amplification (LAMP) method for rapid detection of pathogens. The developed system herein includes temperature control unit, photoelectric detection unit, turbidity calibration unit, power management unit, human machine unit, communication unit and ARM-based microcontroller. The coefficient of variation for eight channels is less than 0.25% in noise analysis. Legionella bacteria (LEG) and H7 subtype virus (H7) were successively detected by the designed and developed system within 60 minutes. Moreover, its specificity for LEG is satisfactory and its sensitivity for H7 is 10 copies/mL. Besides, this system for point-of-care diagnosis allows a rapid, small size, low cost, and automatic detection with the characteristics of high-efficiency, excellent stability and high uniformity.
摘要:
We establish two sharp inequalities involving the power mean and generalized elliptic integral of the first kind. As applications, the analogous inequalities concerning the complete p-elliptic integral of the first kind are also derived.
期刊:
Mathematical Inequalities and Applications,2019年22(2):601-617 ISSN:1331-4343
通讯作者:
Chu, Yu-Ming
作者机构:
[Wang, Miao-Kun] Hunan City Univ, Coll Sci, Yiyang 413000, Peoples R China.;[Chu, Yu-Ming] Huzhou Univ, Dept Math, Huzhou 313000, Peoples R China.;[Zhang, Wen] Icahn Sch Med Mt Sinai, Friedman Brain Inst, New York, NY 10029 USA.
摘要:
We establish the monotonicity and convexity properties for several special functions involving the generalized elliptic integrals, and present some new analytic inequalities.