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This article uses a linear regression model to predict Netflix’s stock from 2018 to 2022, and divides the data set into pre- and post-epidemic analysis. The before-and-after analysis aims to explore the impact of COVID-19 on Netflix stock price. By collecting and collating Netflix’s historical stock price data, financial indicators, and other relevant information, a linear regression model was constructed. Through model training and verification, the prediction results of future stock prices are obtained, and a comparative analysis before and after the epidemic is carried out. The research results have important reference value for investors, analysts and decision makers in formulating investment strategies and risk management.

When the process of urban renewal is accelerating, the issue of preservation and utilization of cultural heritage in cities, particularly, the preservation and adaptive reuse of industrial heritage has sparked enthusiastic discussions in academia. Industrial heritage is the physical carrier symbolizing industrial civilization, and its physical presence is often the focus of people’s attention. The underlined historical, scientific, and artistic values, especially the memory and emotional values, namely its intangible value as the place spirit of industrial heritage, are often not given enough attention. However, these values are becoming increasingly important in shaping urban culture. Taking the preservation and adaptive reuse of industrial heritage in Shanghai in recent years as an example, this paper explores taking the intangible memory value of industrial sites as a narrative text to construct a narrative space for interpreting the memory and emotion of urban culture and to inherit industrial culture and place spirit. The adaptive reuse of industrial heritage will perpetuate and create new memory values through space narrative, preserve the city’s historical features, and shape the urban culture.

Contemporary systems are trending toward 3D computer-aided design systems that integrate, network, and exhibit intelligence. The integration of parametric technology with ancient Chinese architecture can enhance the efficiency and quality of managing information on ancient buildings, thereby expanding the application scenarios of ancient architectural information models. By analyzing the construction characteristics of ancient Chinese carpentry work and modular systems, this research outlines the logic and methods for generating Chinese ancient architecture. The program’s parametric technology allows for adjusting variable parameters to produce carpentry work structures of varying scales and forms. Furthermore, this research establishes a library of parametric 3D components for ancient architecture, which can simplify the design process of contemporary antique architecture. Additionally, the parametrization of Chinese ancient architectures can function as an auxiliary tool for maintenance and repair techniques, serving as a storage mechanism for whole-life cycle information. This can enable the digital archiving of component information and model entities in an informative manner for managing existing ancient architectures.

In response to the low quality of practical teaching in engineering majors, particularly in terms of the effectiveness of experimental teaching, lack of innovation, and other issues, this paper summarizes and analyzes the problems that exist in experimental teaching and innovative practices for cultivating applied undergraduate students, based on the requirements for graduate abilities and knowledge from corporate employers, as well as the situation of engineering practical teaching in China. It explores the composition of various elements in the practical teaching system, standardizes and innovates various elements of experimental teaching activities, and cultivates students' innovative thinking and practical abilities through a multilevel disciplinary competition system, thus constructing an innovative practical teaching system for cultivating applied undergraduate students. The practice has proved that students' practical and innovative abilities are significantly enhanced, their innovative abilities are significantly improved, the quality of graduates' employment is improved, and the social feedback is positive. A large number of high-quality applied undergraduate students have been cultivated for local economic construction.

The concept of low-carbon green development has become a global consensus, and the servitization of manufacturing is a feasible path to achieving green development in manufacturing. This paper takes manufacturing enterprises in 27 provinces and cities in China from 2006 to 2019 as samples, and empirically analyzes the effects of manufacturing servitization to promote carbon emission reduction in a low-carbon economy, which shows that: manufacturing servitization can reduce carbon emissions, and informatization, urbanization and energy structure optimization promote carbon emission reduction; in the less developed and backward central and western regions of the economy, manufacturing servitization promotes carbon emission reduction The effect is obvious. In the future, China should give full play to the digital economy's new advantages, optimize the manufacturing industry's energy use structure, and take the lead in promoting the servitization of the manufacturing industry in less economically developed regions.

Deep learning is increasingly used in short-term load forecasting. However, deep learning models are difficult to train, and adjusting training hyper-parameters takes time and effort. Automated machine learning (AutoML) can reduce human participation in machine learning process and improve the efficiency of modelling while ensuring the accuracy of prediction. In this paper, we compare the usage of three AutoML approaches in short-term load forecasting. The experiments on a real-world dataset show that the predictive performance of AutoGluon outperforms that of AutoPytorch and Auto-Keras, according to three performance metrics: MAE, RMSE and MAPE. AutoPytorch and Auto-Keras have similar performance and are not easy to compare.

It is of great significance to carry out environmental impact assessment on the renovated mining area for the assessment of reclamation benefits. The maturing of UAV technology brings new possibilities for environmental assessment. Aiming at the problem of insufficient environmental impact assessment system of mining area renovation project, this paper constructs the environmental impact assessment system of mining area renovation project, and puts forward a set of scheme to carry out the environmental impact assessment of mining area after reclamation based on the data obtained by UAV platform. The research results have certain value for the benefit assessment of comprehensive renovation and ecological reclamation of mining area

The quality of Tungsten Inert Gas welding is dependent on human supervision, which can’t suitable for automation. This study designed a model for assessing the tungsten inert gas welding quality with the potential of application in real-time. The model used the K-Nearest Neighborhood (KNN) algorithm, paired with images in the visible spectrum formed by high dynamic range camera. Firstly, projecting the image of weld defects in the training set into a two-dimensional space using multidimensional scaling (MDS), so similar weld defects was aggregated into blocks and distributed in hash, and among different weld defects has overlap. Secondly, establishing models including the KNN, CNN, SVM, CART and NB classification, to classify and recognize the weld defect images. The results show that the KNN model is the best, which has the recognition accuracy of 98%, and the average time of recognizing a single image of 33ms, and suitable for common hardware devices. It can be applied to the image recognition system of automatic welding robot to improve the intelligent level of welding robot.

In frozen regions, especially metro tunnel portal sections, which are vulnerable to an externally low-temperature atmosphere, would lead to frozen damage affecting traffic safety. To clarify how the air temperature field at tunnel portal sections varies with periodically changing atmospheric temperature, a site test was conducted on Metro Line 1 in Hohhot in the Inner Mongolia Autonomous Region, and the basic heat transfer equation and principle of energy conservation were introduced to establish a basic theoretical model, which was compared with the results from other regions. By comparison with testing results in other regions, the theoretical model was essentially consistent with the variation rules of the tested temperature. Therefore, the research could theoretically direct the heat preservation and freeze prevention of key facilities and equipment in metro tunnel portal sections in frozen regions.

Residents mainly set the temperature at the range of 25°C to 27°C under cooling conditions. However, they may feel uncomfortable after staying a period in a steady-temperature environment. To make themselves more comfortable, residents will change their postures and even regulate the temperature. To analyze the regulation characteristics, this study combined thermal environment testing, questionnaire survey, video collection, and data mining methods to collect the thermal environment and comfort background, posture, and temperature regulation characteristics. The results showed that Mean Thermal Sensation Vote gradually deviated from neutrality and tended to be cooler even though the thermal environment and thermal comfort were both within the acceptable zone. 12 typical posture regulations were captured and divided into 3 categories: head (face) postures, trunk postures, and limb postures. Head (face) postures were the concentrated expression of adaptive postures (80%). Although the total posture frequency remained unchanged, the head (face) postures gradually increased, which reflected the increase in discomfort. The temperature regulations accounted for nearly 25%. Most people (90%) regulated the temperature at 1 °C with the frequencies of once or twice, and they preferred to set the temperature up than down. In the first 3 hours, there would be a regulation peak every 20 or 30 minutes, while the regulation decrease after 3 hours.

Doubly fed induction generator (DFIG) wind power generation system is widely used in wind farm all over the world. Reactive power can be generated both in grid-side converter and generator-side converter of DFIG. In this paper, working principle and control method of DFIG are introduced, and the reactive power limit of DFIG is derived, finally reactive power regulation is simulated in Simulink.

Power System Stabilizer (PSS) is an important measure to increase damping and suppress low frequency oscillations of power system. During PSS test, the time constant of lead-lag compensator need to be configured, considering the inefficiency and optimization problem when configuring parameters empirically, this paper proposes automatic configuration method of PSS parameters based on Matlab, by setting the expected phase value at each frequency and constructing the objective function with the sum of phase differences square, the automatic calculation of PSS parameters under specific phase requirements at each frequency can be realized, the detailed steps of this method are given, and the method is verified during the PSS test of an 300Mw thermal-power generating unit finally.

Due to the rapid economic development in recent years, the original transformers and other power supply equipment is difficult to meet the demand of the rapid growth of electricity consumption. In order to reduce the cost of power supply, adding photovoltaic/wind power/energy storage system is an effective means to meet the demand of users to achieve regional balance without the overall reform of the system. In this paper, with reference to Ganzhou region under different growth rate of electricity a internal power supply area, considering the three-phase imbalance and photovoltaic (pv) power supply under different weather factors efficiency under different conditions, building composed of piconets and time division at micro network life period earnings are applied to solve the highest net present value as the goal on the premise of micro power grid planning for the next step, meet the increasing social demand of power supply area, improve power supply reliability, provide strong theoretical support. Finally, based on the power supply load of a certain region in Ganzhou, the method is calculated and proved to be effective.

Aiming at the treatment of large volume of oil produced wastewater, the combined technology based on constructed wetland was applied for produced water treatment in a costal oil field. During the stable operation period, the treatment system maintained removal efficiency of 50.2% for chemical oxygen demand (COD), 100% for oil and 85.1% for ammonium nitrogen (NH3-N) under the gradient increase of salinity along the process. Meanwhile, this system has a good ability to adapt the influent fluctuation. When the oil in the influent fluctuated greatly between 11 mg/L to 147 mg/L, the effluent water quality remained stable. The treated water met the national discharge standard for water pollutants from the oilfield industry and can be used for the saline alkali beach wetland as supplement water.

The article aims at the relationship between China’s green insurance, social and economic development, and environmental protection. It analyzes China’s green insurance development measures and operating mechanism. According to the China Statistical Yearbook, based on data from 2011-2019, research variables are selected for empirical analysis and qualitative analysis. It is concluded that the green insurance industry is conducive to sustainable and sustainable development, reduces industrial transformation risks, improves environmental protection capabilities, and improves residents’ living standards. China’s experience in developing the green insurance industry provides a useful reference for the sustainable development and development of green finance in developing countries and regions.

The robustness of power grids plays a very important role in reality. The blackout of power system can make a serious damage for the normal running of whole city or whole area and the loss caused by it is inestimable. This paper aims to propose a simulation method to evaluate the robustness of a power grid and some effective strategies to improve the robustness. Complex network keeps the most important characters of a power grid, and makes the simulation process concise. This paper studies how characters influence the robustness and proposes some conclusions and suggestions for enhancing effectively the robustness by changing these characters. In this paper, for the robustness of a network, it can be found that some parameters like tolerance coefficient are more dominant than others. Some parameters interact obviously, like capacity addition ratio and addition station ratio. Improper capacity addition strategy may have a negative effect on the network. And load node with big degree and small flow is likely an excellent choice to be added capacity by distributed photovoltaic power station. The simulation method and improvement strategy can be used in the engineering of power grid and establishment of distributed photovoltaic power system.

Based on the comprehensive analysis of various stress research schemes for steel-concrete composite truss joints, the current research status of steel-concrete composite truss joints and epoxy resin concrete at home and abroad are systematically elaborated. The existing problems in the current composite truss joints are analyzed, and possible solutions are proposed. At present, the research on epoxy resin concrete has been very extensive. Epoxy resin concrete has high strength, good toughness, high impact strength, good chemical corrosion resistance, wear resistance, water resistance, frost resistance, tensile resistance and compressive resistance, which make it widely used in engineering. The problem of using epoxy resin concrete instead of ordinary concrete in steel-concrete composite truss is put forward, analyzed and discussed.

In order to discuss the factors that affect the regulation behavior of railway technical regulations and perfect the regulation mode, a game model with CRG, railway bureau and railway station as the main body of regulation is constructed. The results show that the intensity and cost of rewards and punishments have an impact on the railway technical regulations and supervision system.

As one of the important facilities in mines, the dump has become one of the major hidden dangers of mine safety management due to its large volume and loose structure. In this paper, based on unsaturated seepage theory of soil and practical engineering slope cases, the slope stability calculation model based on Bishop limit equilibrium method is established. This paper analyzes and calculates the evolution law of slope stability under extreme rainfall, obtains the law of slope stability safety coefficient changing with rainfall under unsaturated characteristics, and puts forward the corresponding countermeasures.

Datong Basin is a typical groundwater irrigation area in northern China contaminated by As. In order to reveal the distribution of As and the adsorption behavior of As(V) onto topsoil in the Datong Basin, a total of 40 topsoil core samples were collected from a 2 m core. Samples were used for chemical composition analysis and an isothermal adsorption experiment. Results show that the collected samples are not contaminated. The adsorption capacity (Stot value) of topsoil for As(V) at the study site ranged from 257 to 1027 nmol/g with an average of 505.2 ± 200.2 nmol/g. Vertically, both Stot value and topsoil components exhibit a vertical zoning with a positive correlation between the Stot value and K2O, CaO, MgO, Al2O3, Fe2O3 contents while Na2O and SiO2 are inversely correlated. Fe2O3 content shows a strong positive correlation with As content while Al2O3 does not. Moreover, the correlation between Stot value and Al2O3 is much better than Fe2O3. These results indicate that Fe minerals are the main reservoirs of As in the natural topsoil at the study site. Furthermore, both Fe minerals and clay minerals can adsorb As(V), but clay minerals have a greater storage potential. This result indicate that a combined effect of Fe minerals and clay minerals for As(V) accumulation onto topsoil should be considered during geochemical modeling and further agricultural management.

With the theory of “sustainable development” as the theoretical support, the public space landscape of Guilin City is taken as the research object, and from the perspective of landscape architecture, the public space landscape and the non-sustainability issues are deeply analyzed.Guilin city has been deeply investigated and studied.According to various types of public space landscape, five problems are concluded:landscape space problem, landscape energy consumption problem, landscape greening and planting problem, landscape rainwater resources digestion and utilization problem and landscape pollution reduction and noise reduction problem.The smooth solution of these five problems can promote the improvement of the urban environment and create sustainable urban public space.

According to the current situation of water quality in drainage basin, the key to improve the prediction accuracy is to select the appropriate prediction model of water quality. The time series method excellently reflected the continuity of the future data in the case of emphasizing historical data. What’s more, the time series method has the higher short-term prediction accuracy and simple modeling process. So, the time series method was used to establish the Auto-Regressive and Moving Average (ARMA) model for the time series of the concentration of dissolved oxygen (DO), biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), ammonia nitrogen (NH3-N) and total nitrogen (TN) at the Guidu fu section of Qingyi River from January 2011 to December 2015. Then, the concentrations of the five water quality indicators from January to June 2016 were predicted, which were verified and analyzed with the measured values. The results show that the model has fine fitting effect and higher prediction accuracy, which can accurately reflect the current and future change trends of the water quality.

With the Guangxi Guilin being listed as an innovative demonstration zone for the national sustainable development agenda in 2018, the urban construction processes in Guilin continued to advance. In the construction of city image, garden planning and design has played an important role. Urban landscaping plays an important role in urban development and has a great influence on the image of the city. The selection of urban landscaping trees is mainly based on native plants, which directly determines the ornamental effect of landscaping. This paper aims to study the application of native tree species in Guilin in garden planning.

In this paper, the authors put forward a design of solar power generation system, mainly due to the authors in the daily learning process often need stability of 5 v DC regulated power supply. The system mainly include solar panels, solar charge controller (i.e., can realize the overcharge, discharge, overvoltage, undervoltage control functions), lithium batteries, DC DC booster module and load equipment. The authors determine the hardware circuit selection through reasonable analysis and calculation. Finally, the stability and reliability of the designed micro solar power generation system were verified by experiments, which meet the expected goals and requirements of the authors.

This paper presents a smart monitoring system for risk management in the underground space. This space has a major role in cities, but it suffers from high vulnerability to hazards such as fire, flood and accidents. The paper provides analysis of the vulnerability of the underground space and shows how a smart monitoring system of human presence, indoor conditions, underground space access and equipment performances with advanced data analysis could help in improving the risk management in this space.

This paper proposes a research method for mitigating wind power fluctuations in a hybrid energy storage system considering the confidence level of wind power volatility. First, the typical daily wind power output is subjected to Fourier spectrum analysis to determine the frequency range of wind power output, and combined with low-pass filtering to find the optimal cutoff frequency, for obtaining energy storage reference power; Then determining the optimal energy storage reference power by comparing the energy storage reference powers solved at different confidence levels. Finally, empirical mode decomposition (EMD) is used to decompose the stored energy into a series of intrinsic mode functions(IMFs), demarcation of the energy storage reference power with minimum aliasing in the instantaneous frequency-time curve, the high frequency part is configured by power type energy storage, and the low frequency part is configured by energy type energy storage. The simulation of the wind farms in a certain area of Hunan Province is carried out. The result shows that proper reduction of confidence level can reduce energy storage power and capacity.

This paper proposed an intelligent algorithm, which can build the shortest path of the intersecting circle sequences in the plane. The problem is transformed to a corresponding problem of computing the shortest path of three disjoint circles. And it is also an in-depth study of the traversal problem for the disjoint circle sequences. On the basis of the previous work, the algorithms are developed to construct such shortest path in polynomial time of O(kn) where 1≤k≤n under a given computational threshold. Since the algorithm is fully polynomial time consuming, this work can be conducted in layered manufacturing of rapid prototyping, displacement of wireless sensor networks, or other related computer-aided design and manufacturing applications.

In the view of Chinese traditional twenty-four solar terms, the circulation of various substances in the material flow system of base production and life is systematically analyzed, and on the basis of the existing system problem point, as well as by combining with the concept of the twenty-four solar terms and the system design method, the author reconstructs each subsystem of the base material flow system, moreover, the author eventually connects the subsystems and reconstructs a material flow system conforming to the traditional Chinese solar terms and conforming to the requirements of ecological sustainability.

Recordings of extracellular spikes have been widely used in various fields ranging from basic neuroscientific research to clinical applications. However, in the extracellular recording system, how to accurately detect spikes from the recorded signal in real time is still a major challenging work. Although the existing algorithms for online spike detection have made great progress, there still remains much room for improvement in terms of accuracy. In this paper, we propose a new method for high accuracy and real time spike detection. Concretely, differential operator is firstly employed to accentuate spikes in the signal for its simplicity and strong capacity to detect significant changes. Then, by exploiting the structural features of spikes, the resolution parameter is introduced to improve the performance of differential operator. Finally, a simple and effective measure is utilized to further reduce the influence of background noise, which makes spike detection more accurate. The results of simulated and real data show that the proposed method is able to precisely detect spikes while maintaining low computational complexity.

This paper aims to perform a factor analysis of e-learning service quality for providing valuable references and proposing strategies, which would advance successful e-training operations. This paper delineates services features and overviews current literature on e-education quality assessment. From e-learning attributes and the outlook of SSCE (services science, management, and engineering), the paper designs an indicator structure consisting of 10 criteria. Based on questionnaires, each indicator is given a certain value, and e-views is employed to calculate principal components. The paper finds six factors are crucial to measure of e-learning services quality for representing a 82.5% proportion in the total variance. Top three factors are ease of use, security, and reliability, indicating that network facilities, e-safety protection, and high-levels of instructing and punctual answering learner–raised questions after class, are leading prerequisites of maintaining superior e-educational quality. E-education suppliers should put efforts into these dimensions for providing quality e-training services.

One of the main evaluations in pork carcass is the lean meat ratio. A method based on Fiber optic sensor and NIR (Near Infrared) to acquire the ratio was put forward. This method acquired the reflected light intensity of the meat inside the pork carcass, by using double optical paths to reduce the errors caused by the instability of light. The fiber was lead into a probe which can be stabbed into the pork carcass, and then the reflected light was detected by a circuit named LIA (lock in amplifiers) to recognize the weak reflected light intensity effectively. The results suggested that the reflected light of the fat part of the pork was much higher than that of lean part, and through medium filter, the conditions of fluctuation was improved. The system was proved to be quick and accuracy for the detection of lean meat ration in pork carcass.

The self-consistent scheme (Budiansky, 1965) is one of the analytical methods to predict the effective properties of heterogeneous material. However, it has been noticed that this scheme cannot take the micro-structural information into the estimation. The full scale numerical simulation considering elaborately the micro-morphological characteristics, under certain conditions, needs too much computational resources (memory and time). A numerical version of self-consistent scheme based on finite element analysis is proposed to overcome the above drawbacks by combining the characteristics of numerical simulation and self-consistent scheme. As a demonstration, such scheme is applied to estimate the effective mechanical properties of bi-continuous composite in which all the constituent phases are on the equal status. The prediction is in good agreement with the full scale numerical simulation while the requirement on computational resource is reduced dramatically.

N-type InGaN/GaN multiple-quantum-wells (MQWs) were grown on sapphire substrates by metal organic chemical vapor deposition (MOCVD). The crystal quality and optical properties of samples after rapid thermal annealing (RTA) at different temperatures in a range from 400 to 800°C are investigated by X-ray diffraction (XRD) and photoluminescence (PL) spectrum. The experimental results show that the peaks of InGaN, InN and In can be observed in all samples. And the results are induced by the phase separation and In-clusters. The luminescence peak of the samples annealed showed a red shift. It is caused by strain stress relaxation during the RTA process. Furthermore, some defects can be eliminated and the best annealing temperature is from 500°C to 700°C.

The Test was to examine the adsorption property of Pb(II) irons by Linde type F (K) zeolite. The zeolite was synthesized by fly ash. The adsorbent dosage, pH, reaction temperature and reaction time were investigated. The adsorption isotherm and adsorption kinetics equation were studied. The results showed the adsorbent dosage, pH, reaction temperature and reaction time had significant effects on the adsorption of Pb(II) irons. The removal rate was improved with the increasing of zeolite dosage. The saturated adsorption capacity was decreased gradually. The adsorption of Pb(II) irons tended to saturate when initial pH was 6. With the increasing of temperature, the equilibration time of adsorption was shorter. Langmuir isotherm was more applicable to explain the monolayer adsorption procedure of Pb(II) on Linde type F(K) zeolite. For adsorption kinetics, pseudo-second order model showed better calculation results.

According to the dynamic heterogeneous spatial information plotting data, this paper presented a new integration method about dynamic heterogeneous spatial data, studied the spatial information plotting object and established the semantic ontology database. It declared the mapping rules in ontology, solved the semantic differences of spatial information plotting objects and finished the automatic or semi-automatic integration of plotting content to integrated automatic or semi-automatic of the content for different plotting situations(same name of different place, different name of same place etc) and different plotting data types(text, images, sound, video etc). So it has great significance to enhance the efficiency of the plotting data integration.

At present, China’s economic and social development has entered into a new normal state, the construction of Hainan international tourism island also has entered into the middle and late period. Hainan tourism has made brilliant achievements, but the development contradictions have become increasingly serious. Based on the analysis of the current situation and realistic problems of Hainan tourism, this paper points out five principal problems of Hainan tourism development--industrial status, supply-demand relationship, cultural preservation, subject-object relationship and government-business relationship, and it also proposes strategic suggestions on the great tourism, large interconnection, great culture, big Hainan and big special zone.

At present ship to air missile is the main force of anti-missile. The warhead damage element’ impact and penetration effect are the main factors for damaging supersonic anti-ship missile (SAM). In this paper, the damage mechanism of the anti-ship missile is studied. Dynamic initial velocity of damage elements is modeled and simulated. The four important parts of SAM with typical material are modeled and simulated based on finite element analysis (FEA). It’s useful to the study of the further model of vulnerability analysis of whole anti-ship missiles.

This paper is used to solve the time-consuming problem of training samples in Adaboost algorithm and propose an improved FTAdaboost algorithm based on feature tailoring. In the beginning, this paper is used to make all samples have the same weight, train them once and tailor the features before the first reflection point of the error rate curve which have high error rate and poor classification ability, then reduce the number of samples and save training time. According to the distribution of facial organs, the algorithm determines whether the specified area meets the characteristics of skin-color space, then eliminates the influence of wrong facial images. The experimental results show that the algorithm based on feature tailoring can shorten the training time significantly and the detection with the skin-color space can decrease the error rate to some extent.