bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving thermal comfort conditions in K-12 educational buildings in hot and humid climate: a case study in Cucuta, Colombia
Authors: Guerrero D , Ge H , Lee B
Published: December 2021

The school buildings in Colombia are built based on geographical locations and regional construction systems. However, external weather conditions and building design can have a significant impact on the thermal comfort of students, which affects the academic performance and productivity. This paper investigates the thermal comfort performance for an educational building in a hot and humid city in Cucuta, Colombia, built under national guidelines. This school is a concrete structure without mechanical cooling. However, field observation discovered that 82% of the time students experienced thermal discomfort. To investigate causes and provide mitigation strategies, a whole building energy simulation is conducted. Design Builder is used to evaluate the indoor thermal conditions compared to outdoor data collected. ASHRAE 55 adaptative model is used for the evaluation. It is found that 79% of the time the thermal conditions are outside the acceptable range during the year. The effect of mitigation measures i.e., occupancy, roof insulation, and natural ventilation rates are investigated through simulations. It is found that occupancy and natural ventilation rate have a significant impact on the indoor temperature and relative humidity, and thus the thermal comfort. Passive design strategies are proposed in optimizing the school building design to meet ASHARE-55 requirements.
Improving the energy efficiency of an office building by applying a thermal comfort model
Authors: Kiki G , André P , Houngan A , Kouchadé C
Published: December 2021

The building represents one of the main actors of global warming of the planet because of the significant amounts of energy consumed. In Benin, 44,38% of electrical energy is consumed by office and service buildings. This is explained by the excessive use of air conditioning systems due to the lack of a thermal comfort index specific to the region. This work therefore focuses on assessing the impact of the choice of a thermal comfort model on the energy efficiency of buildings. For this purpose, an office building was chosen in the south of Benin and comfort surveys were conducted among the occupants. The model selected for this purpose is the adaptive model developed by López-Pérez and al. for air-conditioned buildings in humid tropical regions. Subsequently, a monitoring campaign of meteorological, hygrothermal and energetic data of the building was carried out during six months. The results obtained show that the average temperature of the offices (Tf
≈ 24°C) during the hours of occupancy is relatively lower than the comfort temperature determined with the model (Tc
= 26.2°C). Moreover, the different simulations carried out under TRNSYS by substituting the office temperatures by the comfort temperature show a reduction of about 20% of the building’s energy consumption. This shows the importance of the comfort model of López-Pérez and al. in improving the energy efficiency of the building.
An Event-Triggered Model Predictive Control for Energy Efficiency and Thermal Comfort Optimization in Buildings
Authors: Shiyu Yang , Wanyu Chen , Pun Wan Man
Published: December 2021

Model predictive control (MPC) is a promising optimal control technique for building automation. However, the high computation load to solve the optimization problem of MPC is challenging its implementation for real-time building control. Typical MPC systems employ the time-triggered mechanism (TTM), which conducts the optimization periodically at each control interval regardless of the necessity. This study proposes an event-triggered mechanism (ETM) for MPC, which conducts the optimization only when there is a triggering event that necessitates it. Contrasting to the conventional ETM that bases only on the current information, the proposed ETM bases on the cost function considering the past, current and future information. An event-triggered model predictive control (ETMPC) system is developed using the proposed ETM. In a simulation environment, the ETMPC system is implemented to control an air-conditioning system. The ETMPC is compared to a MPC employing TTM and a conventional thermostat. The ETMPC improved the computation efficiency by 77.6% - 88.2% as compared to the MPC while achieving similar energy performance as the MPC does (both achieved more than 9% energy savings over the thermostat). The ETMPC only degraded the thermal comfort performance slightly as compared to the MPC but is still much better than the thermostat.
Study on a thermophysiological model for health assessment of showering environment in China
Authors: Ying Y , Shi P C , Li Y N , Tan X , Li Y H , Hokoi S
Published: December 2021

In China, the thermal environment of family showers in old communities is quite different from that of other living spaces, especially when the thermal environment changes drastically during showering, which can easily cause health problems. The human thermal physiological model is an effective tool to predict and evaluate the non-uniform and unstable shower thermal environment and human health risks. In this research, the showering experiment was carried out in a typical bathroom in an old community in China, during which environmental parameters such as air temperature, wall temperature and water temperature of the bathroom during the showering were recorded, and physiological parameters such as skin temperature, core temperature and blood pressure during the whole showering process were detected. Based on the multi-node numerical human body model of Stowljik and a cardiovascular control model with human body temperature as the driving force, a temperature-blood pressure coupling prediction model was established. The validity of the proposed model was examined for blood circulation. This predictive model can accurately reflect changes in physiological parameters and is verified as suitable for the health assessment of showering environment in residential buildings.
IEA EBC Annex 68 – Consequences on ventilation and hygrothermal operation of buildings
Authors: Rode C. , Zukowska D. , Kolarik J.
Published: December 2021

The objective of the IEA EBC Annex 68 Project, “Indoor Air Quality Design and Control in Low Energy Residential Buildings”, has been to develop the fundamental basis for optimal design and control strategies for good Indoor Air Quality (IAQ) in highly energy efficient residential buildings. Focus has been on emission of chemical pollutants from building products and use of ventilation to alleviate IAQ effects. The question has been whether new paradigms for demand control should be developed based on knowledge from this project.

The paper gives an overview of the project’s activities with regards to: - Gathering of laboratory and field data on pollution sources in buildings. - Formulation of a so-called “similarity approach” to predict emissions of volatile organic compounds based on knowledge from moisture transfer properties. - Gathering of a set of contemporary models to simulate the combined heat, air, moisture and pollution conditions of buildings and their assemblies. Based on this background, the project has identified and described an extended set of amenable ways to optimize the provision of ventilation and air-conditioning and to assess possibilities to bring this knowledge into practice. The paper gives an overview of the suggested solutions and their conditions.
Optimal density for balancing the thermal conductivity and compressive strength of foamed ceramic
Authors: Lei Yue , Zheng Xing , Dou Mei , Zheng Lihong , Tang Mingfang , Feng Chi
Published: December 2021

Foamed ceramic becomes increasingly popular in building engineering due to its thermal, acoustic and other advantages. However, conflicts often exist between its different properties. In this paper, we seek a balance between the thermal conductivity and the compressive strength of foamed ceramic. Experiments are performed on foamed ceramic with different densities. Nonlinear regression is then adopted to quantify the relationship between the thermal conductivity/compressive strength and the bulk density. The results indicate that both the thermal conductivity and the compressive strength increase with the rising density. Based on the requirements in the Chinese national standard, the optimum density range of foamed ceramic is proposed, satisfying a balance between the thermal and mechanical performance.
In-situ measurements of the U-value of a ventilated wall assembly
Authors: Rahiminejad M , Khovalyg D
Published: December 2021

The walls in a building envelope have the largest contact area with the exterior environment, and, therefore, a considerable portion of the thermal energy can be lost through the walls compared to the other parts of the building envelope. For energy-saving purposes, the thermal transmittance of walls is typically limited by building energy performance standards at the national level. However, the presence of a ventilated air-space behind the external cladding, which has variable hydro-dynamic behavior, can differently affect the total thermal transmittance of the entire structure. This paper aims to provide an experimental analysis of the total U-value of a ventilated wall assembly measured in a building prototype following the average and dynamic methods defined by ISO 9869-1. Differences between the calculated theoretical U-value and the measured U-value are compared. The contribution of the thermal resistance of the ventilated air-space in the total thermal transmittance of the wall assembly is also analyzed. The results show that the air movement and the enthalpy change in the ventilated cavity can affect the thermal performance of the wall structure to a certain extent.
Hygrothermal simulation on effective dehumidification methods in a museum storage room
Authors: Ishikawa K , Iba C , Ogura D , Hokoi S , Yokoyama M
Published: December 2021

The hygrothermal environment must be controlled in facilities like museums and galleries to suitably conserve the stored cultural artifacts. The present study proposes a humidity control technique for a museum storage room in Kyoto, Japan. This method requires limited energy and no large-scale equipment or major building renovation. The relative humidity of the room measured during the preliminary field survey exceeded the range for the conservation of metal artifacts (under 45%RH) throughout the year, and dehumidification was experimentally performed. The possible range of humidity control and the energy are quantitatively evaluated in the present study by simulating varied ways of operating a dehumidifier in combination with the improvement of the room’s property of being airtight. The results of the study indicated that simple building modifications and operational improvements could improve the storage environment. For instance, measures to ameliorate airtightness and sensing control along with the addition of small-scale equipment such as a home-use compressor-type dehumidifier can yield long-term low humidity suitable for the conservation of metal cultural artifacts. Such measures are also considered advantageous in terms of energy and labor consumption.
Experiences using EN 17037 in evaluation of daylighting of dwellings in Slovakia
Authors: Curpek J , Hraska J
Published: December 2021

The daylighting of indoor spaces depends particularly on the urban and architectural parameters of the building environment. The new standard EN 17037, Daylight in Buildings, has brought several changes and uncertainties in design process of daylighting for buildings. The submitted paper is focused on analysis of the philosophy of the new standard criteria in relation to the daylighting of dwellings along with the criteria that have been used in Central European countries for decades. EN 17037 does not distinguish between differences in the functional use of indoor spaces in terms of daylight provision. The new European standard requires at the half of subjectively determined reference plane to achieve the same value of illumination for half of daylight hours per year for any occupied room. The EN standard does not sufficiently respect the specifics of daylighting of dwellings.
Preliminary assessment of the building design of a new test house in Nuuk, Greenland
Authors: Møller E B , Lading T
Published: December 2021

DTU has established a single-family three-level test house in Nuuk, Greenland. The main idea of the house was to have a relatively small heated area but a split building envelope, where a ventilated space behind the rain screen in some areas could be used as a sunroom. This paper describes the process of transforming the architectural ideas to a test building. Main issues have been how to design the rain screen and how to ventilate the space behind the rain screen.
Re-making the energy profile of (Irish) market towns: as if science matters
Authors: Murray Martin A , Colclough Shane
Published: December 2021

Reduction of building-related carbon emissions within Ireland is predicated on the implementation of an EU mandated nZEB energy standard which defaults to ‘cost optimality’ generic solutions such as an A3 rating for new builds, and a B2 rating for renovations. It is estimated that 500,000 existing buildings will need to be refurbished in this way, within 10 years and that 60% of these are urban in nature. Despite such extensive resource use, the nZEB standard is not set to significantly reduce operational energy which will, in conjunction with 950,000 new electric cars being operational by 2030, place a significant burden on our increasingly decarbonised electrical power grid. Such challenges present opportunities. One opportunity is to significantly expand the renewable capacity of the grid and strengthen its European interconnectivity, while another is to remake our rural market towns and villages with energy considerations and fabric at the centre of the process. Doing both offers an optimal solution. We can amplify societal benefits, community empowerment with grid resilience and community ownership of utilities, efficient local use of energy and low carbon transport. It so doing we ensure buildings and power grid, capable of effectively serving our 2050 energy needs.
Difference of cooling use during sleep between elderly and young people
Authors: Umemiya N , Terao K , Chen Y
Published: December 2021

In Japan, nearly 80% of heatstroke occurrences in recent years have involved people older than 65 years old. This study surveyed the actual use of cooling by elderly people at sleep time compared to those found for younger people. Results revealed the followings.

1) Ratios of cooling use at sleep time were 30.8% for elderly people and 57.4% for younger people. The respective ratios of natural ventilation use at sleep time were 39.9% and 32.4%.

2) Average wet bulb globe temperatures (WBGTs) of bed rooms during sleep were 26.9°C for elderly people and 26.4°C for younger people. 3) Elderly people feel warmer than younger people but they feel more thermally comfortable. 4) Sleep scores were 49.7 for elderly people and 48.5 for younger people. No difference was found for the frequency of night waking or the Sleep maintenance score, but the Fatigue recovery score showed the greatest difference between elderly and younger people.
Research on Monitoring Technology of Intelligent Computer Information Security
Authors: Liang Ren , Zhang Bangwen
Published: December 2021

At present, the development of science and technology in our country is very fast and quickly occupied the larger economic market, at the same time, it also draws great attention in the communication industry. With the development of science and technology, computer technology has attracted the attention of the majority of people in the society with the major concern that whether it can truly keep customers’ privacy. Network information security, for national enterprises or the government, is crucial, but it is difficult to use information in the process of absolute confidentiality. Therefore, in today’s network research and development, it is necessary to carry out more rigorous processing of information to ensure that the information is not leaked during the use of the network. In the actual application process, the information should also be privatized. We can apply the computer security monitoring information network technology to protect information security, reduce virus invasion in order to ensure the green and healthy network. This paper mainly studies the security of the network based on the monitoring technology research while application and development prospects of the current situation of computer information security monitoring technology are described, which can be a good reference for the future construction of security information network.
Recognition of Blurring Alphabet Character on Timing Pulley Drawing Based on Halcon Image Processing Technology
Authors: Huang Bin , Liu Jun , Chen Mingbin , Fan Qidong
Published: December 2021

In order to solve the problem of Inefficiency in the use of manual detection of the information on the engineering drawings in synchronous belt manufacturers. This paper present a method of image processing based on HALCON. Firstly, the image will be inputted to the software platform, then the image will be processing by the means of Image enhancement, threshold segmentation and so on. Thus, the information on the engineering drawings can be recognized. This experience shows that blurring alphabet character on the engineering drawings can be recognized quickly and accurately based on Halcon. It can effectively reduce the workload, increasing the productivity.
Research on Performance Speed Regulation System of Direct Conversion AC-DC Power Conversion Device
Authors: Jiang Bin , Cao Yongcheng , Wang Chengquan , Wang Qiang , Wu Qiong
Published: December 2021

With the continuous development of social economy, the application market of electric motors has become more and more broad. Based on the principle of modular design, this paper designs the hardware circuit system of the matrix converter, and completes the parameter calculation of the input LC filter. The modulation algorithm needs to determine the sector and position angle of the input three-phase voltage. The DC speed regulation system powered by the conversion AC-DC power conversion technology is compared with the Buck circuit power supply system. Practice shows that the system has good static and dynamic indicators and load robustness.
Design and Implementation of Automatic Control System for Intelligent Water Dispenser
Authors: Li Bing , Ji Jinghong
Published: December 2021

In this paper, an intelligent water dispenser automatic control system is designed by using a microcontroller as the core. Relevant signals are collected through temperature sensor, liquid level sensor and other sensors, then send them to the microcontroller for processing and control, and use the liquid crystal display for display. Temperature, effluent and liquid level can be controlled according to their own needs, so as to realize the intelligent control of the water dispenser. The intelligent water dispenser automatic control system designed in this paper has low hardware cost and easy operation in the use process.
Reliability and Dynamic Performance Simulation Based on Relay Protection Summary
Authors: Li Fei , Zhuyuan Luochen
Published: December 2021

With the development of science and technology, national security and social life can not be separated from electricity every moment, and the safety of power grid is becoming more and more important. At present, the research on relay protection model in dynamic simulation of power system in China is still in the primary stage. Because the research is not deep enough, the control law of relay protection elements can not be well grasped. The failure can not be handled well. Therefore, in order to ensure the safe operation of the power system, we must first strengthen the grid structure of the power system, improve the elasticity coefficient, distribute the reserve capacity reasonably, strengthen the adjustment ability of the tie line between the major power grids, and improve the stable reserve of the power grid. In order to improve the authenticity and reliability of dynamic simulation, it is necessary to establish a set of relay protection models, which should be consistent with the actual relay protection. In this way, the stability problem in power system can be analyzed accurately to improve the reliability of power system. The relay protection model established in this paper reduces the complexity of modeling and can reflect the dynamic characteristics of power system after interference. It is of great significance to the analysis and research of power system.
Safety Supervision Method of Power Work Site Based on Computer Machine Learning and Image Recognition
Authors: Li Jiaxuan , Liu Yiyang , Wang Hao
Published: December 2021

China’s traditional power system has been unable to meet the needs of society and the development of The Times. Under the background of intelligence, it is necessary to reform the power industry and increase the application of mobile application technology in the power system, so as to realize the precise management of the power system. The application of mobile application technology in the field operation of electric power construction, based on computer machine learning and image recognition, is helpful to realize the sustainable development of electric power enterprises, improve the service level of electric power enterprises and promote the on-site safety supervision.
Research on Discrete Data Analysis of Vehicle Retread Tire Performance Based on Radial Stiffness Method
Authors: Qi Peng , Chu Jiangwei
Published: December 2021

The retreaded tires of transportation vehicles often cause delamination and tearing of the tread and carcass due to the temperature rise of the tires. For the failure analysis and rational use of the retreaded tires, a steady-state thermal analysis model of the retreaded radial tires in the rolling state is established and carried out the temperature measurement test. On this basis, the numerical simulation, simulation calculation and experimental analysis of the thermal-structure coupling field are carried out, which truly reflects the thermal stress status of the retreaded tire.
Research on Intelligent Traffic Model Based on Neural Network Algorithm
Authors: Qin Yi
Published: December 2021

For the national economic construction and social development, intelligent traffic safety design has a very important role. In addition, cars have entered thousands of households in recent years, and the flow of intelligent traffic has increased significantly. The transformation and design of intelligent traffic safety facilities is an important work related to people’s life safety. Building with GIS technology as the core, the computer interlocking simulation system and join the safety of the application of computer technology, network communication technology, the grading management mode, the implementation of traffic safety monitoring and management of the whole process of engineering construction in the true sense realize the standardization and systematization of safety information construction process management, so that they can master the traffic engineering construction all aspects of the data and safety information, guarantee the quality of project construction.
Prototype System for Dynamic Elastic Protection and Monitoring
Authors: Wang Rui , Ma Lei , Chang Yingxian , Liu Xin , Chen Jianfei , Liu Donglan , Zhang Hao , Huang Xiaoli , Yu Hao
Published: December 2021

With the continuous development of science and technology, security becomes an important content, both from the personal safety and information security, the most basic protection and monitoring security system already cannot satisfy people demand for security, protection and monitoring technology is relatively simple, function is not fully diversified, so the protection and improvement of the monitoring system should be constantly, so the application of dynamic elastic protection and monitoring, protective monitor the implementation of the new type will help the large-scale application of the design process and the improvement of the system. Based on the above content, this paper proposes the construction of the prototype system of dynamic elastic protection and monitoring, and deeply analyzes the principle of its construction.
Research on Routing Algorithm of Smart Grid Atmospheric Optical Communication Network in Cloud Computing Environment
Authors: Wang Yijia
Published: December 2021

With regard to improving the transmission rate of the smart grid atmospheric optical communication network and reducing the output error code and reality, a calculation method of the smart grid atmospheric optical communication network routing based on the operation and calculation of hybrid particle swarm optimization is studied. The link structure model of the smart grid atmospheric optical communication network is established, and the network routing nodes are explored to achieve the dynamic neighborhood and node location of the optical communication network routing. Through practice, improving the transmission rate of the optical communication network of the smart electrical network and reducing the network output timeliness and error codes can be solved by the routing calculation method.
The Design and Application of the Airborne Real-time Image Reconnaissance Computer System for Police UAV
Authors: Zhang Zhixue
Published: December 2021

The rapid development of UAV technology has greatly improved the degree of automation and intelligence. Aiming at the current situation and problems of insufficient aerial reconnaissance methods, this paper proposes an optimized scheme for real-time fusion of reconnaissance images and three-dimensional terrain. First, the reconnaissance target area is rendered and modeled, and then the reconnaissance image is mapped to the reconnaissance area for target tracking. Experimental results show that the system is intuitive and can effectively improve the reconnaissance efficiency of UAVs.
Application of 3D Dynamic Image Technology in Industrial Products
Authors: Zhu Changyong , Zheng Xiaodong , Zhou Chao
Published: December 2021

Aiming at the problems of manual testing of industrial products, a measurement method of industrial products based on three-dimensional dynamic imaging technology is proposed. The products on the production line are dynamically photographed from different angles and within a certain period of time by using cameras. Then the obtained Image denoising processing and contour tracking based on chain code table and line segment table to obtain boundary information and regional information of each enclosed area of the image. Experimental tests show that the test accuracy of this method is 100%, which is suitable for real-time detection. Fully automated research on product testing provides the foundation.
An Intelligent Shopping System based on UHF RFID
Authors: Zhang Zhankun , Liu Shenghan , Yuan Xiaomei
Published: December 2021

In the context of COVID-19, in order to solve the problems that customers need to spend more energy to find products in the supermarket, long checkout queue time, and cumbersome product management, optimize the shopping route of customers, accelerate the shopping process, and reduce the risk of infection; providers exceed Supplier’s sales of goods, and then timely and purposeful selection of goods, simplifying the supply chain process between supermarkets and suppliers. This article designs a multi-terminal interactive intelligent shopping system based on UHF RFID to construct The shopping cart terminal, mobile phone APP terminal, data management system terminal, and three-terminal interactive system with RFID technology as the core are developed. The design uses the UHF RFID system to identify the information in the electronic tags of the goods, and through the navigation function, helps customers locate the desired goods, and realizes the functions of identification, information display, navigation and positioning, and settlement.
Research on Optimization of E-commerce Supply Chain Management Process Based on Internet of Things Technology
Authors: Huang Bingkai
Published: December 2021

With the development of information network technology, online shopping has become more and more accepted and chosen by people, the demand for logistics and express delivery industry is also increasing. In today’s e-commerce era, the global logistics industry has a new development trend, called modern logistics. In modern logistics, the requirements for the important link of warehouse logistics and distribution are also increasing. The goal of supply chain management is to achieve maximum operational efficiency while minimizing capital investment, which is of great significance for e-logistics distribution. Based on this, this paper explores the application of Internet of Things technology in the supply chain management of e-logistics.
Application of 3D Modeling Technology in Engineering Graphics
Authors: Zhang Yan , Li Qinghua , He Chunshan , Pan Liai
Published: December 2021

With the development of technology and the progress of the times, the application methods and expression methods (including teaching methods) of engineering drawings have undergone tremendous changes. This article analyzes the reasons that restrict the three-dimensional design method can not completely replace the two-dimensional drawing in the short term, and proposes the teaching reform direction that combines the three-dimensional modeling with the traditional graphics content. It clarifies the role of 3D modeling content in graphics courses at this stage, and explains the specific methods of introducing 3D modeling in different stages of graphics courses and the choice of teaching software.
Innovative Mode of Visual Communication Design Practice Teaching Based on Big Data
Authors: Wang Xiaojun
Published: December 2021

With the advent of the era of big data, big data has affected all walks of life, and to a certain extent some questions have been raised about the logical way of teaching visual communication design courses. Therefore, there are serious problems in the teaching of visual communication design courses. This article introduces some innovations and practices in practical teaching of creative visual communication design courses, and uses these methods to conduct a series of research and discussion on creative visual communication design courses. Universities in our country must reform their teaching and training methods and cultivate talents who can meet the needs of the development society in the era of big data. Especially some undergraduate colleges that have just entered the undergraduate stage should teach in the course of visual communication design innovation. This path has undergone positive changes. In order to cultivate students’ cultural, creative awareness and technology, visual communication design has a close relationship with the development of creative industries. In the education process, the integration of technology and aesthetics should be emphasized. In the era of mobile media, artistic creation results should be combined with H5, video, illustration, and virtual. Due to the comprehensive effect of reality and other factors, talent training not only possesses the cultural heritage, design power and new technology required by the creative industry. Therefore, innovation and practice of education and teaching for this course are imperative. At present, our country is establishing a dynamic scientific visual communication curriculum education and research system focusing on the development of visual communication symbols and language research. Visual communication design refers to the design of using visual symbol language to convey information. In China, the change of modern design concepts is a new vocabulary that has gradually been accepted by people in the past 10 years and has become an important part of the integration of university design education and traditional design fields. The content and direction can include all educational courses with visual information as the main content. The professional direction is gradually recognized and used in domestic design schools. Experimental research results show that in the current era of big data, the innovative trend of practical teaching of visual communication design is inevitable, and there is an urgent need to reform and innovate teaching methods.
RETRACTED: Construction of E-commerce Personalized Information Recommendation System in the Era of Big Data
Authors: Wang Yaosheng
Published: December 2021

With the continuous expansion of the scale of e-commerce, personalized recommendation technology has been widely used. However, the traditional recommendation system has been unable to meet the current needs of data processing, and good big data processing ability has become the basic requirement of the new personalized recommendation system. In addition, traditional recommendation systems are often limited to tangible goods recommendation, and pay less attention to e-commerce logistics service recommendation. In this paper, through the in-depth study of information personalized recommendation service in e-commerce environment, combined with the application background of big data: Taking the user dissimilarity matrix as the recommendation model, we propose IU usercf and UDB slope one recommendation algorithm. The two algorithms based on incremental update recommendation model have good scalability, can effectively deal with big data, and have high prediction accuracy. The proposed algorithm is applied to the actual system, taking e-commerce logistics service as the recommendation object and iu-usercf as the recommendation algorithm, the personalized recommendation system for e-commerce logistics service is constructed. The e-commerce logistics service recommendation system explores the application practice of recommendation algorithm under big data, and enriches the application scenarios of personalized recommendation technology.
Study of a Multi-Fusion Positioning System Based on Beidou Indoor Inertial Navigation
Authors: Wang Peiguang , Ma Sheng , Nie Haitao , Zang Zhibin , Zhao Jianwei , Zhou Hangfan , Wang Cong
Published: December 2021

This article proposes an indoor combined positioning terminal based on Beidou pseudofiles and micro-inertial navigation sensors. Through the built-in Beidou pseudo lite positioning IP soft core, it can receive and analyse Beidou satellite signals. The article creates BDS ground inertial positioning data receiving hardware; performs inertial positioning data primary information identification authentication on the inertial data received by the hardware; performs multi-inertial data fusion estimation calculation on inertial positioning data after authentication, reduces the dimensional error value, and completes the proposed system Design. The program makes full use of the data resources of the existing airborne equipment, does not need to transmit radio signals, and the user capacity is not limited, which is suitable for highly dynamic users. Through simulation and sports car test, it is proved that the scheme is feasible.
Research on 500kV Transformer on-load Tap Changer Fault Treatment and Physical Properties Testing
Authors: Lan Dongliang
Published: December 2021

This article introduces the intermittent increase of acetylene content in the oil during the operation of a 500kV start-up substation of a power generation company. It is preliminarily judged that there is spark discharge in the oil chromatographic analysis and on-site partial discharge test. After returning to the factory for maintenance and internal inspection, it was found that the movable contact and the fixed contact of the selected part of the on-load tap-changer were not connected in place, which caused intermittent spark discharge and continued to increase acetylene. The problem is solved by adjusting the number of turns of the gear when the tap switch is switched forward and backward, and the transformer resumes normal operation.
Research on Full Link Intelligent Control Platform for Substation Maintenance through Edge-Aware
Authors: Zhu Jiayi , Jiang Keruo , Xiao Lifei , Mou Peifu , Geng Lang , Liu Yicheng
Published: December 2021

In view of the imperfect process control, safety control and data control in substation maintenance operation, this paper proposes a full link intelligent control platform for substation maintenance operation based on edge-aware. The platform is composed of on-site edge-aware system and big data decision service system. The on-site edge-aware system uses various intelligent tools to collect data, carries out real-time safety behavior early warning, maintenance quality control and maintenance process supervision through edge computing technology, and uploads the analyzed and processed information to the big data decision service system. The big data decision service system provides support for online decision-making of substation equipment maintenance according to the panoramic multi-source information of the maintenance site provided by the site edge perception system. The full link intelligent control platform for substation maintenance operation has built a control system for real-time control of on-site maintenance operation process, on-site maintenance information and on-site maintenance safety information, which improves the management efficiency of substation maintenance on-site operation and enhances the safety guarantee of maintenance operation.
Used For Space Irradiation Environment Simulation Equipment Property Analysis of Metal Mirror
Authors: Wang Danyi , Jiang Shanping , Zhang Pengsong , Xiang Yanhong , Li Hongsong , Xu Yanlin , Yang Linhua , Du Jiayu
Published: December 2021

With the development of space science and technology, the requirements of spacecraft environment simulation tests are gradually increasing, and radiation environment simulation has also attracted much attention. Based on space radiation environment simulation equipment of vertical metal reflector material in the solar simulator performance analysis, the systematic analysis of the influence factors of metal reflector, aimed at straight metal mirror blank material performance analysis, including the mechanics analysis and optical analysis, the performance to the blank material for testing. The test results show that the aluminum alloy 6061T6 billet used in the metal mirror can meet the requirements of high irradiation vertical solar simulator, and lay a solid foundation for the subsequent solar irradiation simulation, space illumination simulation and spacecraft thermal environment simulation.
Physical Testing and Surface Morphology Studies of Stainless Steel Irradiated with Xe Ions
Authors: Xu Chaoliang , Liu Xiangbing , Li Yuanfei , Jia Wenqing , Qian Wangjie , Quan Qiwei , Yin Jian
Published: December 2021

6 MeV Xe ions were used to irradiate austenitic stainless steel at room temperature. Three displacement damage levels of 2,7 and 15 dpa were selected. Microstructure and surface morphology were characterized by transmission electron microscopy (TEM), positron annihilation lifetime spectroscopy (PLS) and atomic force microscope (AFM). PLS indicated that vacancy defects were introduced by ions irradiation. Vacancy clusters containing Xe will reduce the positron annihilation lifetime. High density of dislocation loops were observed by TEM. The dislocation loops size and density saturates after 7 dpa and the nature of dislocation loops can be deduced by its distribution. A surface step was detected by AFM measurements between irradiated region (uncovered) and unirradiated region (covered with nickel mesh). This indicate that the irradiation swelling phenomenon occur and swelling is closely related to irradiation damage. According to the step height, the volume swelling is about 1.7% and 4.2% after irradiated to 7 and 15 dpa.
The particles concepts and physical detection schemes of dark matter
Authors: Lin Zhongyi , Xiong Ziheng , Yang Bowen
Published: December 2021

It is still unable to determine the categories of particle that composes the dark matter due to the shortage of detection methods. In this paper, we used the methods of separation of variables, analogy, and dimensional analysis to investigate dark matter detection. The three different models, including the WIMP, axions, and MACHOs, are considered first, which described the properties of dark matter as well. Subsequently, the three currents methods of detecting dark matter, and shortage of those methods are discussed. According to the drawbacks, we have related Gravitational Waves and Cosmic Rays to detecting dark matter, which may contribute to the further detection of dark matter. The milestones achieved these years have also been briefly described, followed by some up-gradations of detectors and further research schemes. These new methods proposed in theory will be upgraded and implemented soon. These results shed light for future dark matter detection.
Research on Influencing Factors of Current-carrying Temperature Rise on Connector Terminal of Current Circuit in UHVDC Converter Station
Authors: Liu Peng , Si Jiajun , Zhang Jian , Zhou Lixian , Li Dongqing
Published: December 2021

Relying on the high current temperature rise test, starting from three aspects of different materials, different structural strengths, and different contact conditions, the research on the current-carrying-temperature rise characteristics of the joint terminals of ±800kV UHVDC converter stations under different conditions is carried out. The results show that, for joint terminals of the same structure type and contact area, the difference in resistivity of joint terminals of different materials has a significant impact on the temperature rise level. When the material is the same, the temperature rise level can be reduced to a certain extent after the silver (tin) layer is added to the contact surface of the terminal. When the contact resistance of the joint terminal and the current density are the same, after increasing the contact area, the temperature rise and decrease level of the aluminum alloy plate lap type joint terminal is significantly better than other types of joint terminals. The contact resistance and temperature rise of the joint terminal decrease with the increase of the bolt tightening torque, and become stable when it reaches more than 80%. When the bolt tightening torque reaches more than 90%, the surface finish of the contact surface has no obvious effect on the contact resistance of the joint terminal. By controlling the material properties, structural strength, contact conditions, significantly reduces the temperature rise of the level of the joint terminal, effectively ensuring the safety ±800kV UHVDC converter station stable operation.
Arrangement Method of Vibration Dampers Considering Frequency Response Physical Characteristics and Stiffness of Conductor
Authors: Weng Yongchun , Zhang Zhao , Li Xiaolai , Yang Shiqiang , Liu Shengchun , Wu Yuxin
Published: December 2021

In order to study the calculation method of installation distance of vibration dampers with higher precision, so as to maximize its anti-vibration performance on the conductor. The arrangement method of dampers based on the frequency response characteristics of conductors is proposed, the dynamic model of conductor considering stiffness is established. The model is solved by finite difference method, the natural frequency and vibration mode of conductor in case of Aeolian vibration are obtained, and the wavelength of conductor vibration is obtained according to its mode, so as to calculate the installation distance of vibration dampers. The calculation results of the new method are compared with those of the traditional method, which proves the advantage of the new method in calculation accuracy. The new method has a good effect on improving the calculation accuracy of the installation distance of the vibration dampers on the conductors, which is greatly influenced by its stiffness. At the same time, the frequency response of the conductor should be considered as much as possible in the calculation of the installation distance of the damper.
UAV Path Planning of Combining Ant Colony and Beetle Antennae Algorithm Using Intelligent Wireless Communication
Authors: Xu Le , Zhao Wenlong
Published: December 2021

In order to settle the problem of UAV path planning under mountain, an algorithm which based on the combination of ant colony algorithm and beetle antennae algorithm is proposed. Three dimensional environment model is established and objective function is constructed. It used ant colony algorithm to initialize the search path and the particle coordinates of all the next steps are updated by the beetle antennae algorithm. The improved algorithm adopted a new step update rule to speed up the convergence of the algorithm and used third-order B-spline interpolation method to smooth the path. Simulation results show that improved fusion algorithm has faster convergence speed and high stability by comparing with other algorithms under the same conditions, which verifies its effectiveness.
The Model of Multi Limits of the Quantity of Electrons in Central Coulomb force Field
Authors: Tan Chengzhuo
Published: December 2021

Based on the theory of periodic bifurcation of iterative equation, a conjectural model of periodic bifurcation of number of electrons in a central Coulomb force field is proposed. After that with the help of the methods Zeng’s The Course of Quantum Mechanics and Wu’s Methods of Mathematical Physics, [1], [2] the wave function of the electrons under the approximate state is solved in the central Coulomb force field. By using the method of separating variables for solving partial differential equations and some transformation and construction techniques, the strict mathematical solution of the Schrödinger equation for the electron in the field of central Coulomb force is obtained, and the iterative formula of the level of electron number is given theoretically. And using MATLAB, the multi-limit model of electron number is simulated under different initial value problems, to explore the change of the limit with the initial value and the factors affecting the limit number to a certain extent. Some potential research value of this model is also proposed.
Characteristics of Cantilever Retaining Wall Composed of Upper Wall and Lower Wall by Physical Testing
Authors: Zhang Yaming , Chen Dongsheng , Liu Jinlong , Zhu Lei
Published: December 2021

Based on the finite element method, the earth pressure and deformation of the cantilever retaining wall composed of upper wall and lower wall are compared and analyzed. The results show that the maximum lateral displacement of the fill occurs near the top of the upper wall, the lower wall has the tendency of overturning to the free surface, while the upper wall has a certain deviation from the free surface. The vertical earth pressure acting on the heel plate of the upper wall and the lower wall presents non-linear characteristics. When the cantilever retaining wall composed of upper wall and lower wall is unstable, there are two slip surfaces in the filling. The first slip surface runs through the filling based on the heel plate root of the lower wall, and the second slip surface runs through the upper filling based on the heel plate root of the upper wall.