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This paper proposes an exact model for the planning and design problem of fog networks. More precisely, a mathematical model is proposed to simultaneously determine the optimal location, the capacity and the number of fog node(s) as well as the interconnection between the installed fog nodes and the cloud. The goal of the model is to minimize the delay in the network and the amount of traffic sent to the cloud data center. To address this multi-objective optimization problem, three optimization techniques are used: the weighted sum, the hierarchical and the trade-off methods. The weighted sum method aggregates all the lone objective functions into a single objective by applying a weighted vector. The hierarchical method takes a sequential approach by tightly constraining the more important objective function. The trade-off method solves a single objective function and translates all other objective functions into constraints. These methods are then compared in terms of average delay, amount of traffic sent to the cloud and amount of CPU time required to find optimal solution(s). Since we are dealing with a multi-objective optimization problem and that multiple optimal solutions can be found, the fuzzy-based mechanism and the hypervolume indicator have been used. Computational results show that as the problem size increases, the delay and the traffic also increase in a linear form; whereas, the solution time increases in non-polynomial time. The weighted sum method was able to achieve the best trade-off results for the delay and the traffic, whereas the hierarchical method was able to return minimum delay but with worse traffic going to the cloud. As the model considers realistic edge device traffic parameters, constraints, and various topology aspects, it can be helpful for the planning and deployment of fog networks and how they operate within a cloud infrastructure.

"A picture is worth a thousand words". Internet plus has brought people into the era of picture reading. Pictures and videos are everywhere. And dynamic video has the characteristics of sound, sound and documentary. It has become a popular media form for the public. Therefore, mobile phone video shooting and production are convenient, and the popularization of video production and dissemination has become inevitable. However, the creation of artistic and innovative video works requires producers to master certain visual thinking methods in addition to film montage theories and techniques. The article briefly outlines the forming process of the concept of visual thinking, and proposes advanced methods of visual thinking: intuitive method, selection method, discovery method, and inquiry method. In the process of video production, some methods of visual thinking are analyzed through a case, such as the visualization of textual information, the figuration of image, the logic of concreteness, and the systematization of logic. We have studied practical visual thinking training methods, from the three stages of video production: script creation, shooting practice, and video packaging

Teacher learning is characterized by informal learning and lifelong learning. Mobile devices and personal space in the information environment provide convenient conditions for the professional development of teachers. China's WeChat uses smart phone terminals as a platform to realize fast and two-way communication of voice, video, pictures, text, location and other information through the network. WeChat friends circle function, users can publish text, pictures and videos at any time, and become a record of life, A handy tool for sharing information with friends. This study uses case study methods, using Python and third-party library jieba, to analyze the text information of a primary school Chinese teacher WeChat friends circle, and assist in interviews and other methods to study the impact of fragmented learning on the professional growth of primary school Chinese teachers. Teachers can consciously improve their moral cultivation, establish a lifelong learning conviction, focus on their own professional development, be good at reflection, and actively carry out teaching reform. This leads to the general conclusion that teachers have a high degree of professional development consciousness and are practitioners of lifelong learning; fragmented and mixed learning is the most important form of learning for teachers; reflection is the best way for teachers to grow; innovative practice To be a smart teacher is the goal of the teacher.

Fluid flow in a rock fracture bounded by two rock surfaces with surface asperities is a complex phenomenon to study. However, precise knowledge of the flow characteristics through a real rock fracture is essential in order to design and estimate the efficiency and production of unconventional oil and gas exploration and geothermal energy extraction projects. The aim of this numerical study, is therefore to incorporate a rock fracture in the modelling platform using a pre-processing procedure and to couple it with the flow parameters. 3-D scanning technology was used to obtain the rock fracture surfaces and to generate the fracture profile in a grid matrix form. In addition, the generated fracture profile was imported in to the COMSOL Multiphysics software package to simulate the flow characteristics of the rock fracture. The COMSOL model was validated using experimental permeability results conducted under triaxial conditions. According to the results, the COMSOL numerical model can simulate the flow characteristics through the rock fracture with more than 90% accuracy compared to the experimental data. The numerical results also reveal that the pressure gradient through a rock fracture is nonlinear and depends on the fracture profile. Furthermore, the nonlinearity of pressure gradient varies on different sections of the fracture, confirming the heterogeneity nature of the fracture. In addition, the results illustrate that the entire fracture width does not contribute to the final flowrate and that it is essential to consider the effective fracture width in flow calculations.

Underground coal mining usually develops vertical stresses and reduces the horizontal stress in front of the coal face, which may trigger the occurrence of coal ruptures and gas outburst hazards. According to the stress change characteristics of the working face using different mining methods, different loading paths (constant confining pressure path and unloading confining pressure path) were selected in this study. Methane permeability tests of coal samples under different loading and unloading paths were conducted. Based on these tests, the effects of the unloading rate on the mechanical behaviour and permeability evolution (including energy evolution and fractal dimension) of the coal was investigated quantitatively. The tests revealed that the higher confining pressure unloading rates yielded a lower compressive strength and ductile strain. The increase in the unloading rate reduced the elastic energy and dissipation energy of the samples. Moreover, the higher unloading rate corresponded to more complex failure structures of coal and a greater fractal dimension, which resulted in greater permeability after the rupture of the coal samples. Furthermore, the higher unloading rates accelerated the rock damage rate and the permeability increase rate, which had a notable effect on the emergence of gas outburst hazards.

In the field of inspection and testing, it is necessary to manually fill a large number of test record forms, and the digital information accounts for a large proportion in the record forms. For the purpose of automatic and accurate recognition of handwritten form data, this paper proposes a handwritten digit recognition method based on Harris corner detection algorithm and convolutional neural network(CNN). The Harris corner detection algorithm is used to identify the positioning marks in the form image, which determine the possible fill-in positions of handwritten digits. Through a 14-layer CNN model, and using the ReLu function as the excitation function, the handwritten digit features of the target area in the image are recognized. The experimental results show that the average recognition accuracy rate of this method on the test set can reach 98.14%. So a technical solution for intelligent recognition of record forms is thus provided.

According to short construction time, great difficulty and deterioration mechanism of cracked highway bridge in splash zone and tide zone, a kind of high performance sulphoaluminate cement (SAC)-based repair concrete was prepared and carried out durability test. Microanalysis such as XRD, SEM show that the hydration products of the SAC-based concrete was homogenous and dense, ettringite of directional crystallization decreased and microstructure of interfacial transition zone improved clearly by using admixture and Compound superplasticizer. Designed reasonable preparation technology and construction method of concrete, and assisted by brushing rusty retardant agent on derusted reinforcement and silicane protective coat on the structure, the repaired and strengthen highway bridge can meet the durability requirements in splash zone and tide zone.

Detailed analyses were undertaken of the natural constituents of red yeast rice, a traditional Chinese medicine and food known for centuries to improve blood circulation. Preparation of red yeast rice following ancient methods by fermenting the fungal strain Monascus purpureus Went on moist and sterile rice indicated the presence of a group of metabolites belonging to the monacolin family of polyketides, together with fatty acids, and trace elements. The presence of these compounds may explain in part the cholesterol-lowering ability associated with this traditional Chinese food.

MPS (Moving Particle Semi-Implicit) is one of Lagrangian particle methods, which has a great advantage in dealing with flow problems with a large deformation of free surface. In this paper, MPS is extended to 3D dam breaking flow problems. The scheme of particle moving is modified, the corrected MPS method (XMPS) can keep particles more orderly, and prevent the penetration of particles each other. Numerical results show that MPS and XMPS have excellent flexibility and reliability in dealing with complicated free surface flows, their numerical simulation can predict the shape and position of free surface very well, even there are turn-up and coalescence of water and impacting on the obstacle. Moreover, the XMPS can give a clearer and smoother shape of free surface and provide more detailed information and features of the complex flows than those obtained by the MPS.