bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Non-structural Big Data Analysis Algorithm of Communication Network Based on Feature Fusion
Authors: Meng Xin
Published: August 2021

Nowadays, Along with the fast development of information technology, the scale of data is increasing in an exponential way, and the worth of big data has been paid increasingly interested. At present, there are two key problems in the category of big data: how to delegate big data as a integrate model and what efficiently reduce dimensions of big data. Although the processing technology of various mold of data has been studied, the efficiency of parallel query has not been optimized deeply. Especially, it is more difficult to analyze the information of online users with widely dispersed information. A communication network non-structural big data analysis algorithm based on semantic relevance feature fusion is proposed, which reconstructs the high-dimensional phase space of the distributed information flow of cloud storage big data, extracts the semantic relevance dimension feature quantity of big data from the reconstructed phase space, and conducts adaptive learning training with the extracted feature quantity as the test set. Knowable from the simulation experiment that the algorithm effectively reduces the generation of redundant messages and improves the network running environment.
Application of BERT+Attention Model in Emotion Recognition of Metizens during Epidemic Period
Authors: Wang Xuyang , Tong Yixuan
Published: August 2021

In 2020, SARS-CoV-2 will affect the hearts of people all over the country, and Weibo will become the representative of people expressing their feelings on the Internet. Traditional emotion dictionary and machine learning methods have poor text emotion recognition effect, while BERT pre-training model is based on bidirectional Transformer model, which can better obtain the emotion expressed by the text and effectively improve the accuracy of the model. On the basis of improving BERT pre-training model, attention mechanism is introduced, and the key features are weighted to make emotion classification more accurate. According to the analysis of emotions expressed by netizens on Weibo during the epidemic, compared with textCNN model, BILSTM model and BILSTM+Attention model, the accuracy rate has increased by 6.25%, 4.69% and 2.67% respectively. The overall performance of this model is the best, and it can effectively recognize text emotion.
Evolutionary modeling algorithm of ordinary differential equations based on genetic modeling
Authors: Chen Zhiqin
Published: August 2021

Differential equations are often used to describe complex systems and nonlinear systems related to time, but it is difficult to establish an ideal model for such systems based on some observed data. Especially when dealing with unknown chaotic system data, it is blind and difficult to combine existing nonlinear analysis results with relevant experience. In this paper, through the study of genetic modeling, the optimization process of model parameters using GA is embedded in the optimization process of model structure using GP, and the local search process of neighborhood solution generated by GP-based standard mutation operator is carried out for some individuals in each evolution generation, and the evolution modeling algorithm of ordinary differential equations is designed and implemented, and an application example is given.
Coarse-to-Fine Siamese Network for Tooth Object Tracking
Authors: Wang Xiaofeng , Ao Houjun , Shen Hongbin , Cai Hongbin , Lu Guanghui
Published: August 2021

At present, object tracking algorithms based on deep learning have been widely used in the computer vision industry and has great application value. In this paper, we track the tooth, which has the problem of poor texture and high similarity, with the object tracking algorithm. In general, previously existing single object tracking algorithms are derived from the siamese network architecture. These algorithms have the problem of losing a tracked object with poor textures and high similarities. In order to address the issue of object loss, we put forward a novel coarse-to-fine siamese network (CFSN) for tooth object tracking. The coarse detection network is based on the features extracted by the Feature Pyramid Networks (FPN) and the Region Proposal Network (RPN). The fine detection network has a similar structure to the coarse detection network, and the main purpose is to fine-tune the results of the previous stage. Based on the coarse-to-fine network, a framework of multi-task is proposed, that is, the mask prediction branch is added to the fine detection network, which lead to significant improvements in tracking efficiency. Through the comprehensive experimental evaluation of the tooth dataset, we find that the CFSN model is more effective in tracking tooth objects than the existing methods.
Design and Implementation of Virtual Host Based on Machine Learning Algorithm
Authors: Ji Xuan
Published: August 2021

The research of face modeling and animation technology has a history of 30 years. With the development of virtual reality, video entertainment, videophone, human-computer interaction and other applications, this research field has attracted more and more attention. Based on machine learning algorithm, this paper studies the personalized 3D face modeling and real-time rendering of virtual hosts. The research lines of this paper are the establishment of neutral face model data structure, face feature extraction, improvement of personalized face model matching and real-time rendering in scene roaming. A realistic 3D facial lip animation system based on MPEG-4 standard and driven by voice files is designed and implemented. The system is easy to operate, versatile and efficient, and meets the needs of real-time voice-driven lip animation.
English Teaching Ability Evaluation Based on Fuzzy K-means Clustering Algorithm
Authors: Li Yan
Published: August 2021

With the continuous progress of my country’s social economy and the continuous improvement of people’s material living standards, people’s demand for teaching standards is increasing. In recent years, many higher vocational colleges in our country have hired many foreign teachers when opening English classes. Higher vocational colleges are different from traditional schools. They pay particular attention to cultivating students’ skills. Using foreign teachers in English classrooms can enable students to understand English knowledge and improve their later use ability. However, in English classroom teaching, too many foreign teachers have brought a lot of problems to the teaching ability evaluation system of English foreign teachers and caused difficulties to the teaching management of higher vocational colleges. Based on the fuzzy K-means clustering algorithm, this paper has launched a series of research and discussion on the evaluation of English teaching ability. In the context of the modern big data era, in order to improve the teaching ability of English teachers, improve the quality of college teachers, and provide students with better teaching services, teachers can start with the main factors that influence and influence the improvement of college English teaching ability. In this paper, by designing a college English teaching ability evaluation system, based on the establishment of the constraint parameter index analysis model, the ability evaluation of the big data information model is carried out, and the ability constraint function information is extracted. A combination of K-means clustering algorithms, clustering and integrating proficiency index parameters, completing the preparation of an educational resource allocation plan, and achieving scientific evaluation of the English language ability. The experimental results show that the use of the K-means fuzzy clustering algorithm to evaluate the English language proficiency has an excellent information fusion analysis capability. This improves the accuracy of educational ability evaluation and the efficiency of educational resources.
Research on Detection and Tracking Technology of Moving Objects in Sports Video Based on Data Mining
Authors: Fang Wu
Published: August 2021

The uniqueness of sports video brings a great challenge to target detection and tracking technology. The tracking of moving objects in sports videos is characterized by complexity, which is manifested in complex scenes, complex moving directions and so on. In the process of tracking moving objects, there will be various disturbances, which will affect the tracking accuracy. To improve the tracking accuracy, it is necessary to choose the appropriate target detection and tracking algorithm. In order to improve the tracking accuracy of moving targets, an intelligent tracking method of moving targets in sports video based on data mining technology is proposed, and the improved background update difference method is used to detect moving targets. This method can track the moving target in sports video accurately and quickly, and the real-time performance of moving target tracking is better than other tracking methods.
Research on Application Technology of Computer Communication and Network Development Based on Data Mining Technology
Authors: Fu Ning , Zhang Dongxia
Published: August 2021

With the development of computer technology and internet communication, every country in the world began to implement information management, and applied technical means to upgrade the development scale of social industry, so as to promote the development of national economy in an all-round way. Computers break the limitation of people’s spatial communication, can give full play to the role of network resource sharing, and contribute to the high-speed processing of information. Scientific and rational application of computers can quickly transmit data, which plays an important role in promoting China’s economic development. With the advent of the Internet era, the rapid development of information technology has provided convenience for people’s lives and greatly improved their comprehensive national strength. With the development of digital science, computers and networks are widely used. The development of computer communication and network has been widely used in various fields. From the perspective of technology research and development, this paper explores and analyzes the application and function coordination of computer and network based on data mining technology.
Research on Load Balancing of Cloud Storage Server Based on Fully Connected Group
Authors: Chen Xiaodan , Pang Shuanglong , Wang Haiyan , Zeng Desheng
Published: August 2021

The scheduling problem of online cloud storage traffic is a hot topic in current network research. Aiming at the scheduling problem of file upload requests in online cloud storage systems, the existing schemes rarely meet the requirement of providing users with different bandwidth guarantees. One of the purposes of using multiple volume servers is to let multiple volume servers share the system load evenly and avoid the system performance bottleneck. Once the load is aggregated and one of the multiple volume servers is overloaded, the volume server will become the system bottleneck again, which will greatly affect the overall performance of the system. On the basis of analyzing the existing scheduling algorithms of server clusters, this paper proposes a dormant scheduling algorithm of fully connected groups, which can automatically equip servers with I D, redirect tasks according to the actual processing capacity, and ensure load balance by unlimited increase. The experimental results show that the load balancing strategy among multi-volume servers ensures the overall reading and writing performance of the system, and effectively improves the I/O throughput and I/O times per second.
Information Automatic Sharing Model Based on Big Data Mining Algorithm
Authors: Xiaqiu Long
Published: August 2021

The advent of the era of big data has promoted the transformation of traditional financial management models, and the automated sharing of public financial information has gradually appeared in the public’s field of vision. Gradually recognized by business managers, there has been an upsurge in the application of public financial information automated sharing models. Especially it has been widely used in large enterprises and multinational enterprises, and it has also attracted the attention of many large enterprises. With the continuous maturity of big data technology, financial information has shown diversified characteristics, and more accurate financial analysis capabilities are required. The management of enterprises has gradually realized that applying big data mining algorithms to the automated sharing of public financial information should be possible. Bring new progress to sharing centers and enterprises. Slowly, with the continuous development of technology, more and more senior corporate managers realize the importance of automated sharing of public financial information and the practicality of big data mining algorithms. Research shows that this article mainly uses the literature research method to study the origin, definition and implementation process of the public financial information automation sharing model by domestic and foreign scholars, and proposes the process modules that need to be improved and optimized under the big data environment. Studies have proved that the company’s products have gradually gained advantages after 2015, reflecting that the company’s profitability is gradually recovering, and the utility of the automatic sharing model of public financial information based on big data mining algorithms has begun to gradually come into play. At the same time, the main business income and net profit respectively showed a downward trend in 2015, and showed a steady increase after 2009. In 2008, the company’s public financial information automatic sharing model based on big data mining algorithms incurred relatively large costs in the early stage, which also had a greater impact on the company’s related profit indicators.
Information System Construction and Prediction Model of Leaving Using Big Data Mining and Random Forest
Authors: Zhao Qiaoyue
Published: August 2021

University talents play an important role in building the core competitiveness of universities and play a decisive role in improving the quality of university education. With the opening up and progress of society, the flow of talents in colleges and universities has become more and more frequent. Therefore, more and more attention has been paid to the analysis of factors affecting the turnover of outstanding college teachers. This paper establishes a random forest model to find out the key factors affecting the turnover of outstanding teachers in colleges and universities, and integrates these variables into an index to help colleges and universities understand which outstanding teachers need to be focused and predict the outstanding teachers on the job, and judge the probability of their departure., Which can formulate effective talent retention measures for the university managers. The experimental results verify that the work itself, work pressure and welfare remuneration are the most important factors affecting the turnover tendency of college teachers, followed by leadership management and development prospects. Relatively speaking, the impact of interpersonal relationships is the least. The evaluation model of university teachers’ turnover intention based on the random forest model proposed in this paper can be further applied to the study of teacher turnover intention.
Information System Establishment and Prediction Analysis for SVM Model of RBF Kernel Function
Authors: Wu Siyun
Published: August 2021

The effective prediction of Shanghai Composite Index can provide much useful information for relative organizations to analyze the changes of stock market and then make right decision. Therefore, the prediction of the Shanghai Composite Index is meaningful. In this study, supported vector machine (SVM) algorithm is employed to construct the prediction model, and MSE R2 are used for error test. The result shows SVM model has high accuracy, which indicates the prediction model established in this study is reliable.
Research and application of privacy protection technology based on big data environment
Authors: Ding Zhiping
Published: August 2021

With the development of the Internet of Things, the popularization of the mobile Internet, and the rapid promotion of social networks, the growth of data has entered a big explosion, and the development of information technology has caused a torrent of big data. The continuous development of technology brings people convenience, speed and comfort, but also hides hidden worries. Combined with differential privacy and clustering, a clustering-based differential privacy universal dataset release method for mixed datasets is proposed: using k-prototype clustering algorithm to group records in the hybrid dataset to reduce differential privacy Query sensitivity and the amount of noise to be added to improve data utility while providing data privacy protection; perform attribute difference calculations for numerical attributes and categorical attributes combined with weights, and measure their information loss separately. Finally, Experimental results show that this algorithm can improve the usability of data publishing.
Research on the Method of Landscape Creation Based on Virtual Reality
Authors: Ren Wang
Published: August 2021

The landscape creation process based on the concept of virtual reality, the landscape creation as a dynamic process, from subjective and objective two aspects discusses the evolution history of landscape creation, system creation process model. Based on the concept of process method, this paper summarizes and puts forward the concept and form, rules and operation, output and result oriented process method and related technology import mode. The overall analysis of the whole process of the innovative landscape creation has formed a comprehensive, innovative, holistic and process of the system creation method, to provide overall guidance for the further research of landscape space and form creation method. This paper discusses and analyses the application of VR technology from the aspects of landscape creation and landscape expression. On the one hand, the application of virtual reality technology in landscape creation can promote the diversification of design thinking and creation process, stimulate the multi direction thinking, further emancipate the creative thinking and improve the design quality. On the other hand, the virtual reality technology has created a more powerful expressive force with its vividness, interactivity, authenticity and accuracy, and expanded the content and meaning of the architectural expression. In addition, the author also discusses the landscape design and the essence of landscape in the virtual reality era.
Research on Energy Saving Distribution in Cloud Computing Environment
Authors: Zheng Bigeng
Published: August 2021

With the huge increase of cloud infrastructure and the continuous expansion of cloud computing scale, the consumption promotion role of IT resources has been increasing, which has greatly hindered the development of IT industry. Energy consumption has become an important factor restricting the development of cloud computing. How to reduce energy consumption and improve the efficiency of energy utilization in cloud computing has become a new problem. At present, most of the cloud computing task scheduling algorithms are also carried out in job scheduling, which does not consider the allocation and energy consumption of resources. Therefore, the rational allocation of resources is an effective way to improve the efficiency of energy utilization and energy utilization. In this paper, the concept of resource waiting and resource consumption is proposed. It is considered that resource allocation is an effective way to improve the efficiency of platform software. In this paper, the resource space time energy consumption of intelligent energy is defined. The optimal ratio of known energy consumption to 0 and the resource needed for resource tasks and tasks is called map / task allocation and resource allocation. In this paper, the best resources than W test and wait for the relationship between the specific energy and resource; then, to verify that the map / mountain ice task division rationality by experiment; then the experimental data to verify the R2 algorithm can reduce the energy consumption of resources, improve the utilization rate of node resources, optimizing the energy efficiency of Map/Reduce task. The proposed resource ratio model and resource W method can be applied to existing map reduction system, which is of theoretical significance and practical value for improving and optimizing energy efficiency in cloud computing models.
Personalized adaptive online learning analysis model based on feature extraction and its implementation
Authors: Lihua Bi
Published: August 2021

Modern people pay more and more attention to individualized learning. The traditional teaching method is to explain all the learning contents in a unified way. The setting of teaching contents and courseware are relatively fixed, which can not provide individualized choices for different learners. The core of the adaptive learning system based on feature extraction studied in this paper is that the system recommends personalized learning content for learners according to the learner model. To establish and personalize the self-adaptive learning engine mechanism, a personalized self-adaptive learning content presentation based on clustering is proposed. This study can analyze the data of students’ learning behavior and knowledge mastery, recommend reasonable learning path and learning resources with appropriate difficulty, give timely and accurate feedback to students’ learning effect, provide personalized service intervention, and promote teaching and learning.
Design and Research of Digital Painting Online Learning and Communication System Based on Visual Semantics
Authors: Niu Zhuke
Published: August 2021

This paper mainly describes the design and implementation of digital painting online learning and communication system. Based on the research results of publishing and matching mechanism of visual services and the needs of service resource management, this paper designs a publishing and matching model of visual services, and implements a prototype system by using technology, which enables users to conveniently publish, query, manage and share visual service resources, and the prototype system has good scalability and is easy to upgrade. And the overall operation flow of the system and the data flow diagram of the three user function modules, i.e. administrator, teacher and student, are designed in detail. Finally, each information data table of the background database of the digital digital painting online learning and communication system is designed.
Blockchain periodic storage space recovery method based on blockchain consensus algorithm
Authors: Cao Hongping
Published: August 2021

Decentralized encryption digital cash has been proved to be a successful application mode, and the users of the application can also be the maintainers of this application. To solve the problem of fast growth of blockchain data on Ethereum platform, this paper proposes a method to recycle the periodic storage space of blockchain deployed on blockchain based on blockchain consensus algorithm. On the principle of decentralization, the problem of mutual trust between nodes is solved. And that stability value of the update storage node is recorded, and the high-stability node is selecte to store the newly generated data copy, so that the stability of data storage is improved. Finally, some bytecode fragments are replaced by a suitable algorithm. Tests show that the massive small file system supporting file deletion has no obvious decline in file reading and writing performance compared with the original one, and the storage space of smart contracts can be saved by nearly 46%.
Research on an Adaptive Heterogeneous Database Middleware and Visualization Technology
Authors: Zhou Bin , Yang Mingling
Published: August 2021

In order to improve the efficiency of MIS development based on heterogeneous data sources, an adaptive heterogeneous database middleware and key visualization technology are proposed to realize the automatic creation of data access layers through visualization operations on the basis of heterogeneous databases. This research focused on the general access mode of various data sources in middleware, the interface of data and operation mapping between entity classes and object-oriented virtual heterogeneous databases, the associated interface technology between associated entity classes and corresponding data tables, the interface technology of cross-table and cross-database operation, the algorithm model for optimizing data access, the visualized operation interface, with the purpose is to provide a universal, powerful and easy-to-use middleware for the development of WEB-based MIS software. It will enable program developers to complete the development of data access layers (library building, entity class creation, data access operation method establishment, etc.) through simple visualized operations, and generate program code for the data access layer, which will greatly reduce the development workload and time of the MIS software in this procedure and improve the efficiency of software development.
Framework design of sports image analysis system based on three-dimensional image technology
Authors: Chen Xianming
Published: August 2021

Sports image analysis system based on computer vision image processing technology is a hot project in urgent need of society at present. Due to various objective and subjective factors, the application environment of intelligent module in sports image analysis system is limited, and there is still a certain gap from the social requirements. In this paper, the hardware selection of the system is focused on the applicability and cost. Based on the idea of the inherent hardware of the organizers of the grass-roots sports meeting, the system combining camera, video capture card and PC is selected, which has a high ratio of information to price. A fuzzy enhancement system of 3D digital image based on data mining is designed. Analyze the motion information in video stream to a certain extent, extract the physical characteristics and behavioral characteristics of moving objects, and use the fusion of the two to complete the dynamic target analysis in video surveillance images. The sports image analysis system based on 3D image technology designed in this paper has good universality and good application and popularization value.
Simulation study of turbulent mixing characteristics of tight lattice with triangular arrangement under blockage condition
Authors: Li Yunxiang , Luo Dongmei , Yang Xinyu , Zhang Chuyun
Published: August 2021

The study of turbulent mixing in the gaps of fluid sub-channels in the tight lattice under blockage conditions is of great significance to the prediction of the thermal-hydraulic behavior of fuel assemblies under accident conditions. The CFD method was used to simulate the fluid flow phenomenon in the blockage condition in the tight lattice, and the velocity field and the turbulent mixing coefficient distribution in the section and downstream of the blockage under different blockage conditions were further compared and analyzed. The analysis results show that the blockage mainly affects the flow field of the sub-channel where it is located and the adjacent sub-channels. The turbulent mixing coefficient in these channels will increase significantly; when the sub-channel blockage rate is small, the turbulent mixing coefficient downstream of the blockage will be reduced; the short length will make the flow field near the top of blockage segment more complicated. The obtained changes of transverse and axial turbulent mixing coefficients under different blockage conditions can provide a reference for the parameter setting of the sub-channel analysis program.
Introduction on Research and Application of Exothermic Welding Technology
Authors: Fan Pingcheng , Liu Xiao , Sun Zengwei , Gong Weiwei
Published: August 2021

With the development of society, the welding process presents the trend of diversification, high efficiency and specialization. A variety of advanced modern welding processes begin to replace the traditional welding technology. Exothermic welding is one of them, which is widely used in all kinds of engineering construction due to a lot of advantages. However, exothermic welding also has its own shortcomings, this paper mainly expounded the main shortcomings of exothermic welding, and put forward some improvement methods. Aiming to deepen the understanding of exothermic welding and make better use of this modern welding process.
Analysis on the lubrication performance of spiral-grooved journal bearing using CFD technique
Authors: Chen Yu , Wu Kai , Zhong Taisheng , Wang Yu
Published: August 2021

As the main element, the lubrication characteristics of spiral-grooved journal bearing would decide the stability of mechanical systems. And, a effectivee model will represent the hydrodynamic characteristics of spiral-grooved journal bearing effectively. Based on the CFD technique, this work presents the simulation methodology for analyze the effects of spiral-grooved parameters on the lubrication performance of journal bearing. Compared with the published data, the proposed method is demonstrated effectiveness. Moreover, the influences of eccentricity ratio, groove number, spiral angle, groove width and groove depth are discussed by the orthogonal design method, which provide a reference for the optimized design of spiral-grooved journal bearing.
An improved splashing model for supercooled large droplets based on minimum mass loss ratio
Authors: Ma Honglin , Li Weibin , Wang Yuejun , Zhao Fan , Wang Yingyu
Published: August 2021

Supercooled large droplets widely exist in clouds, which have poor aerodynamic follow-up and strong dynamic characteristics, making the relevant experiments and numerical simulation more difficult. Splash is the main influencing factor of droplet collection efficiency, and it is easier to be recorded and quantified. In the LEWICE model, little or no splash happened around stagnation point. Focus on this problem, an improved large droplet splashing model is proposed based on the idea of minimum mass loss ratio. In the numerical simulation part, the advantages and disadvantages of the proposed model are analyzed by comparing with several classical splashing models and experimental data. Based on the experimental data of airfoil MS317, the validity of the model is verified. Moreover, airfoil NACA23012 and ARJ cruise configuration are chosen to obtain the droplet collection efficiency, which shows the feasibility of the proposed model.
Research Situation of Welding Performance for P92 Heat Resistant Steel
Authors: Zhang Zhihao , Han Kuo , Zhao Xiaochun , Gao Yunpeng
Published: August 2021

In this paper, the welding performance of P92 ferritic heat resistant steel in recent years was introduced. P92 steel was a ferritic/martensitic steel, which had been brought to commercial maturity during the last decade due to its excellent high temperature performances. However, the welding related problems of P92 steel was gradually exposed with the wide application, causing a serious impact on the production and operation of boiler unit. Therefore, Strengthening research and development of suitable welding process and post weld heat treatment process that can lead P92 heat-resistant steel to being better serve in the power industry for our country will be the focus of metal workers in the next step.
Analysis on Two-phase Heat Transfer Characteristics in Horizontal Mini-tubes
Authors: An Tong , Zhang Beichen , Wang Yuan , Pan Yulong , Chen Haishan
Published: August 2021

The two-phase heat transfer characteristics of degassed water flow boiling in horizontal mini-tubes are experimentally investigated in this paper. The inner diameters (di) of the tubes are 1.2mm, 1.6mm, and 2.0mm. Experiments are conducted with heat fluxes between 1.5kW/m2 and 155.75kW/m2 at mass fluxes of 21.19, 42.39, and 84.77kg/(m2s). The boiling curves of the three tubes are obtained. Incipient hysteresis is observed only in the tube with di = 1.2mm. Two-phase dominant heat transfer mechanisms are analyzed in the tubes with di = 1.2mm and di = 2.0mm based on the curves of local heat transfer coefficient versus vapor quality and the visualization results. The trend of peak value of the local heat transfer coefficient versus heat flux at different mass fluxes in the tube with di = 1.2mm is discussed in accordance with the thickness variation of the liquid film in annular flow.
Design and analysis of a Ventral Diverterless Supersonic Inlet
Authors: Ge Changjie , Shang Yinhui , Xiao Lianghua
Published: August 2021

The diverterless supersonic inlet (DSI) has the advantages of good stealth performance and light structure weight. In this paper, the Bump surface is designed based on the flow field obtained by Taylor-Maccoll equation solving the supersonic conical flow, and a ventral diverterless supersonic inlet is given by the method. Numerical simulation is used to study the mechanism of the Bump surface for diverting the boundary layer. Results indicates: (1) the lateral pressure gradient created by the shock wave at the leading edge of the Bump surface is the main reason of pushing the boundary layer away; (2) the total pressure loss due to the shock wave will be small for better combination of the Bump surface and the lip; (3) it is necessary to design the duct of the DSI inlet with refinement to achieve low distortion.
Simulation on the Influence of Type-S Current-limiting Railing on the Passenger Flow at the Entrance
Authors: Zhang Bosi
Published: August 2021

The type-S current-limiting railing is usually set in front of the entrance of stations to relief the backlog of passengers and the congestion at the entrance. The influences of type-S current-limiting railing on the passenger flow at entrance were investigated through numerical simulation. Results showed that the type-S current-limiting railing increased the walking distance of passengers to the entrance. Therefore, it resulted in the decrease of the passenger flow rate and pedestrian density in front of the entrance, as well as the increase of the interval time between passengers went through the entrance. The passenger flow rate at the entrance increased with the total number of passengers. When the number of passengers that queueing up at the entrance was large, the congestion would be formed even the type-S current-limiting railing was set, while the passengers inside the railings were well-organized under the effects of current-limiting railing. The influence of railing number on the passenger flow rate at entrance was not significant, while the pedestrian density in the railings decreased with the railing number. When the railing width was large, the pedestrians might walk abreast and speed up to surpass the passengers ahead of them in the railings. The passenger flow rate at the entrance increased linearly, and the interval time between passengers decreased linearly with the railing width. Therefore, limiting the railing width could decrease the passenger flow rate at the entrance and relief the operation pressure of stations.
Hurricane Ball Movement Analysis
Authors: Long Ruilin
Published: August 2021

The problem addressed in this paper originates from IYPT 2019 Question 6: By starting with hand rotation and using a tube to blow up towards it, two steel balls connected together can be rotated at a very high frequency and explain to explore this phenomenon. It is found in the pre-experiment that even without the use of the tube blowing, the two-steel-ball system can maintain a fairly long rotation, the kinetic energy decreases slowly, which leads to the steel ball system and the table between the pure roll without friction. The equation of motion of the steel ball system is then derived from the pure roll condition analytically, and the equation illustrates that the angle 9 of buckling of the steel ball system is related to the angular velocity of rotation co and the radius of the ball r. The experimental results are verified with good agreement with the expected results.
Research on Orbit Optimization of Manned Spacecraft Based on Dynamics
Authors: Gong Yanxiang , Wu Xiaomei
Published: August 2021

Based on the dynamics angle, the paper finds a suitable launch window based on the pork-chop diagram, and then uses the conic splicing method to carry out the preliminary design of the orbit. The two-body model is used to design the orbit at each stage, and finally under the precise mechanical model, using differential correction method, accurate track design based on B plane parameters.
Analysis of stress relaxation of paper tube
Authors: Long Ruilin
Published: August 2021

Roll a long paper strip into a tight tube and put it vertically on a table. Why does it often unwind in jerks? What determines the period of the jerks? In the following work, we explain the fact of why the paper tubes unwind in jerks by researching mechanical structure of paper tube theoretically and analyze the data of experiments. Finding that the basic cause of paper tube motion in jerks is stress relaxation. Successfully prove our theory by our experiments. Then we investigate the influence of several physical quantities on period of jerks, such as humidity, friction factor of paper layers. All of these factors determine the period of jerks.
Study on frequency domain response characteristics of straight pipe conveying fluid
Authors: Long Jun , Wu Ji , Wang Zixin
Published: August 2021

In this paper, a transfer matrix method (TMM) for solving the frequency domain response of the straight pipe conveying fluid is established based on 14-equation model by Laplace transformation. The reliability of the method is verified by the frequency domain response results of fluid velocity and structural axial stress in the pipe under free boundary conditions. Then, based on the transfer matrix method, the influence of boundary conditions and fluid density on the frequency domain response characteristics of pipeline vibration is analyzed. The numerical results show that the boundary conditions have a significant effect on the amplitude of the vibration response of the pipeline, but the amplitude changes little under the fixed and simply supported boundary conditions. The vibration frequency is inversely proportional to the density, while the axial vibration response amplitude increases with the increase of fluid density, and the change of density has little effect on the transverse vibration response.
An Improved Hybrid Cartesian/Immersed Boundary Method for Flow Simulation with Moving Boundaries
Authors: Su Guanting , Zheng Mengzong , Li Qiushi
Published: August 2021

To simulate flow problems with moving fluid-solid interfaces, a boundary treatment technique based on a hybrid Cartesian/immersed boundary method is presented. In the vicinity of the immersed boundary, a forcing term is added into the governing flow equations to modify the discretization scheme for the viscous term during its spatial discretization. Addition of such a term enforces desired boundary condition on the immersed boundary. A one-dimensional linear interpolation scheme is used to obtained required information for the modified discretization scheme when dealing with a moving boundary. The present method is essentially second-order accurate and can obtain results that are in good agreement with benchmark references when simulating the flow induced by the in-line oscillation of a circular cylinder.
Balance between poverty alleviation and air pollutant reduction in China
Authors: Li Ruoqi , Shan Yuli , Bi Jun , Liu Miaomiao , Ma Zongwei , Wang Jinnan , Hubacek Klaus
Published: August 2021

Key targets of the sustainable development goals might be in contradiction to each other. For example, poverty alleviation may exacerbate air pollution by increasing production and associated emissions. This paper investigates the potential impacts of achieving different poverty eradication goals on typical air pollutants in China by capturing household consumption patterns for different income groups and locations, and linking it to China’s multi-regional input-output table and various scenarios. We find that ending extreme poverty, i.e. lifting people above the poverty line of USD 1.90 a day in 2011 purchasing power parity (PPP), increases China’s household emissions by only less than 0.6%. The contribution increases to 2.4%–4.4% when adopting the USD 3.20 PPP poverty line for lower-middle-income countries. Technical improvements in economic sectors can easily offset poverty-alleviation-induced emissions in both scenarios. Nevertheless, when moving all impoverished residents below the USD 5.50 PPP poverty line for upper-middle-income countries, household emissions in China would increase significantly by 18.5%–22.3%. Counteracting these additional emissions would require national emission intensity in production to decrease by 23.7% for SO2, 13.6% for NO
x
, 82.1% for PM2.5, and 58.0% for PM10. Required synergies between poverty alleviation and emission reduction call for changes in household lifestyles and production.
Temporal scaling of long-term co-occurring agricultural contaminants and the implications for conservation planning
Authors: Liang Xiuyu , Schilling Keith E , Jones Christopher S , Zhang You-Kuan
Published: August 2021

Stemming the export of agricultural contaminants such as nitrogen, phosphorus, sediment, and bacteria in rivers is needed to improve water quality in agricultural regions. However, patterns and trends of these co-occurring agricultural contaminants are relatively unexplored owing to the lack of long-term and high-frequency data sets needed to capture their fluctuations over different time scales. Using a dataset measured at the Raccoon River in west-central Iowa for more than 17 years, spectral analyses were used to characterize the variability and temporal scaling of co-occurring nutrients, sediment, and bacteria in long-term monitoring data in a water-supply river draining a highly agricultural watershed. Results showed that scaling exponents of pollutant concentrations gradually increased from bacteria (0.27) to sediment (0.64), chloride (1.02), orthophosphate (0.75), and nitrate (1.73). The smaller scaling exponents of bacteria and sediment indicate transport primarily by surface water runoff whereas the larger exponents of nutrients indicate transport by groundwater and subsurface tile drainage. Nitrate export exhibits a chemostatic behavior whereas the other constituents deviate from the chemostatic behavior, indicating that the agricultural watershed has a large reservoir of nitrogen relative to the other pollutants. The results are seen to provide guidance for implementation of conservation practices in agricultural watersheds by helping watershed managers more correctly match the appropriate practice to the dominant hydrologic transport pathway.
Distinct East Asian precipitation variability and predictability in coupled and uncoupled El Niño events
Authors: Liu Yunyun , Wu Renguang , Ding Yihui
Published: August 2021

Previous studies have shown different impacts of eastern (EP) and central (CP) Pacific El Niños on the East Asian precipitation. This study reveals distinct precipitation anomalies over East Asia in coupled and uncoupled El Niños. The uncoupled warm events in 1979, 2004, 2014, 2018, and 2019, which occurred in the autumn–winter transition, represent an unusual form of El Niño diversity. The sea surface temperature anomalies (SSTA) in the western North Pacific (WNP) appear to be an important factor leading to the different distribution of precipitation anomalies over East Asia and the WNP. In coupled El Niños, anomalous lower-level anticyclone over the WNP is a result of combined effects of warm SSTAs in the equatorial CP and EP and cold SSTAs in the WNP. The cold SSTAs are attributed to surface heat flux anomalies that in turn are associated with convection and wind anomalies. The lack of cold SSTAs in the WNP in the uncoupled El Niños leads to a weaker anomalous anticyclone with a northwestward location. The different features of an anomalous anticyclone over the WNP induce discrepancy in the distribution of precipitation anomalies and the associated predictability over East Asia between coupled and uncoupled El Niños. The prediction skill tends to be lower for the uncoupled El Niño events than the coupled ones, which further indicates the necessity to distinguish uncoupled from coupled warm events.
Changes in the implementation of concrete in situ work method to a precast method
Authors: Birowo JB Wowok , Suangga Made , Harimawan
Published: August 2021

Sulfur Jetty Development Project and TUKS Oil and Gas Dredging Project The Balikpapan RDMP RU V Project is located in Balikpapan City, East Kalimantan. In this project there are 2 (two) main work scopes, namely sulfur jetty work and dredging work. Like other projects, an engineering review of the design drawings, work volumes, work methods, and work schedules is also carried out. The purpose of this engineering review is to evaluate whether the change in the method of implementation of concrete works in Situ to Precast can maximize the work in accordance with the concepts of quality, time and cost. For this reason the submission of the amendment to PERTAMINAwas accompanied by several technical reasons that affected the work. For the method change, a number of processes were carried out such as the submission of design changes, changes in work methods, the process of calculating the structure and several other matters related to the quality of the structure due to changes in the method of implementation. From the results of the calculation of the structure has adjusted to the needs in accordance with the initial plan, by changing the installation method but still maintaining the strength of the structure in accordance with the initial plan. With this Precast method, the construction process is relatively safer and measurable in terms of cost and time.
Numerical modelling and cost-duration analysis of roof structure design changes
Authors: Kristianto L , Rarasati A D , Sjah J
Published: August 2021

Determining building design and type of material is very important before initiating a construction project because structural design changes can impact the project’s cost and duration. This study will discuss the impacts of such changes in building design, both on structure and on cost and duration. It will focus on a case study of a showroom office building that intends to change the design of its roof from concrete to steel frames. The research will be carried out using the Finite Element Method numerical modeling, as well as cost and duration analysis. The use of steel frame may shorten the construction duration while the use of concrete roof may lower the cost.
Pipeline installation using horizontal directional drilling method (HDD)
Authors: Arumsari Putri , Tanuwijaya Elisa
Published: August 2021

Pipelines crossing rivers, highways, and railways require special consideration that includes details in both design planning and the field installation. One of the methods used for pipelines crossing is the horizontal directional drilling method (HDD). Risks are associated with the HDD installation such as the failure of the pilot boring and reaming, the ground collapsing, and the failure of the pullback process. Construction method based on these risks will be analysed in this paper. Based on the construction method proposed, the quantity of materials, heavy equipment, and workers, and the cost and time are analysed.