bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydration Heat Analysis and Temperature Control on Steel Shell Concrete Immersed Tube during Precasting
Authors: Sun Wenhuo , Liu Meimei , Ji Ting
Published: June 2021

In order to support the high-precision and high-quality prefabrication of steel shell concrete immersed tube for Shenzhen-Zhongshan Bridge, this paper analyzes the influence of temperature field produced by concrete hydration heat on the deformation and local stress of steel shell concrete immersed tube considering the influence of strength time-varying, autogenous shrinkage and creep of concrete and casting technology. Then, this paper puts forward the temperature control index of concrete molding based on the control requirements deformation and local stress of immersed tube. The results show that: the hydration heat of concrete is beneficial to the deformation control of steel shell concrete immersed tube, and it has little influence on the final deformation, the molding temperature of concrete should be controlled below 3°C of the ambient temperature to prevent the cracking of steel concrete interface of immersed tube. The research results of this paper have been applied to the control of concrete casting process of steel shell concrete immersed tube for Shenzhen-Zhongshan Bridge, which can make up for the domestic research blank and provide technical reference for similar projects.
Simulation And Prediction Of the Safety Risk Of Tower Crane For Super High-rise Buildings Through Back Propagation Neural Network
Authors: Lin Nan
Published: June 2021

High-rise buildings especially super high-rise buildings are booming with the rapid urbanization because the urban population increases dramatically. For the sustainable development of super high-rise buildings, construction safety is an important issue. Since tower cranes are widely applied on the construction of super high-rise buildings as the lifting and transportation equipment, their safety is closely related to the safety of construction sites. In this study, a reasonable safety evaluation system with clear input and output indicators was first established. Then, the input index was quantified, and their weights were determined according to their importance which were ranked based on the fourth-class division method of safety grade. Subsequently, the neural network model was developed. 90 tower crane accidents were evaluated quantitatively which provided the data to train and verify the model. The results show that prediction of neural network model is reliable. The trained neural network model is capable to predict the tower crane risks of high-rise buildings, which can be helpful to the construction safety management.
Effect of MnO2 and Li2CO3 on Compressive Strength and Thermal Conductivity of Aerated Concrete
Authors: Wei Pengfei , Yin Guansheng , Shi Minghui , Zhang Jintao , Yang Zhaotong , Feng Junjie
Published: June 2021

This study aims to evaluate the effects of catalyst (MnO2) and coagulant (Li2CO3) on the properties of aerated concrete consist of Portland cement, aluminate cement, and grade I fly ash by the chemical foaming method. In this experimental investigation, the compressive strength and thermal conductivity of aerated concrete were tested by more than 70 aerated concrete specimens with catalyst ranging from 0 to 2.0% and coagulant ranging from 0 to 4.0%. The results indicated that catalyst had a positive effect on the foaming efficiency when the foaming agent percentage is 4%. The positive impact reaches the peak when the catalyst percentage on 0.4%. Outcomes show that the compressive strength of aerated concrete decreases slowly with the increase of coagulant content. Still, the thermal conductivity decreases significantly due to the pore size of the foam increases. The study also reveals that the coagulant effect on ordinary Portland cement concrete setting is not apparent.
Seismic performance analysis of new frame columns in a story-adding frame structure
Authors: Shao Zhuhai , Xu Xinsheng , Wang Ning
Published: June 2021

With the rapid development of urbanization in China, the old urban buildings in many cities are facing the problem of weakening function. There are broad prospects for floor-adding renovation and expansion of in-service houses. In this paper, based on the background of the actual project, the direct floor-adding scheme is adopted to design the existing buildings after the reliability evaluation. The key point of the floor-adding reconstruction and expansion is whether the new part can be reliably connected with the old structure. In view of this weak link, this paper makes a further study on the seismic performance of new frame column members with different anchorage depth, which provides a certain guiding significance for the design and construction of story-adding reconstruction and expansion.
Experimental Study on Quasi-Static Energy Absorption Characteristics of Foam Concrete with Different Design Density by Hydroxypropyl Methyl Cellulose
Authors: Shi Minghui , Yin Guansheng , Wei Pengfei , Zhang Jintao , Yang Zhaotong
Published: June 2021

The foam concrete test blocks with different design densities were prepared. Different dosages of hydroxypropyl methylcellulose on the quasi-static energy absorption characteristics of foam concrete were studied through comparative experiments. The results show that the foam nominal load-displacement curve can be divided into three stages: elastic compression stage, plateau stage, and a densification stage. The higher the density of the foam concrete, the higher the initial peak load, the more outstanding the load fluctuation, and the worse the protective performance. The smaller the density, the longer the compression platform stage. 0.06% of HPMC improves the energy absorption characteristics of foam concrete with different densities the most, and the smaller the density, the greater the improvement ratio.
Design and Application of Mechanized Construction Equipment in Shallow Excavation Precast Utility Tunnel
Authors: Qian Kong , Rui Yang
Published: June 2021

Traditional open-cut method for utility tunnel has many disadvantages such as long-term occupation and large area of land, great disturbance to urban traffic and environment, high labour intensity of workers and so on. In order to overcome the disadvantages above, a machine for prefabricated utility tunnel construction was designed which drawing on the working principle of shield machine and pipe jacking machine. The above-machine is applied in shulong road utility tunnel of Chengdu. The applicable results show that: (1) The above-machine achieve movable streamlined synchronous construction of earth excavation, components assembling and earth backfill. It improve the shortcoming of traditional open cut method and cancel the majority of foundation pit bracing structure. (2) The above-machine can make mechanized and assemblage construction of shallow excavation precast utility tunnel come true. It effectively control construction quality and reduce difficulty of construction management.
Research on Construction Method of Self-Compacting Concrete with Machine-Made Sand
Authors: Zhang Yankun , Qian Dongya , He Shiqin , Zhang Zhuoran , Cai Guangzhi
Published: June 2021

Machine-made sand self-compacting concrete is a kind of self compacting concrete with machine-made sand as fine aggregate, which could fill formwork only by its own gravity, without concrete vibration. It is different from ordinary concrete in many aspects, such as fluidity, workability, and configuration method[1]. As a new type of concrete material, machine-made sand self-compacting concrete mix ratio has been studied in depth by many scholars. However, there are relatively few researches on the practical application of machine-made sand self-compacting concrete, especially on construction methods. This paper discusses the characteristics and construction differences between machine-made sand self-compacting concrete and ordinary concrete, and proposes a special construction method for machine-made sand self-compacting concrete.
Research on Geotechnical Investigation and Construction Technology of Construction Engineering
Authors: Yang Lipeng
Published: June 2021

This article mainly analyzes the technical practice of construction engineering geotechnical survey and construction treatment. This project describes the practical significance of geotechnical engineering survey for construction engineering. It analyzes the surveying techniques commonly used in current geotechnical surveys, such as geological surveys, surveying and mapping, and prospecting. Take a construction project as an example to illustrate the application of engineering geotechnical survey and processing technology. This study can provide reference and reference for construction engineering geotechnical survey work.
Analysis of seismic performance of assembled steel structure staggered truss system
Authors: Liu Qin , Liao Tingzhou , Peng Xi , Xu Shuang
Published: June 2021

In order to adapt to the application and development of large-span steel structure, this paper takes a 19-story assembled hybrid staggered truss structure office building as the background. SAP2000 finite element analysis software is used to establish two different forms of assembled steel structure staggered truss system, namely the hybrid staggered truss structure and the vierendeel staggered truss structure. The seismic performance of the structure was analyzed by modal analysis and dynamic elastic-plastic time-history analysis. The main conclusions are as follows: According to the modal analysis of the structure, the directions of the first three modes of the hybrid staggered truss structure are different from those of the vierendeel staggered truss structure. However, the natural vibration period of the two structures gradually decreases with the increase of the vibration mode. The natural vibration period of the vierendeel staggered truss structure is obviously larger than that of the hybrid staggered truss structure, which indicates that the stiffness and quality of the hybrid staggered truss structure are both larger than that of the vierendeel staggered truss structure. Through the dynamic elastic-plastic time-history analysis of the structure, the seismic performance of the two staggered truss structures in the X direction is basically the same. The difference is mainly reflected in the seismic performance in the Y direction. The seismic performance of the hybrid staggered truss structure is obviously better than that of the vierendeel staggered truss structure.
Research on Mechanical Properties of Typical Bracket Set in Traditional Timber Buildings of Song and Yuan Dynasties in Jiangnan Region
Authors: Xiaohu Jia , Qing Chun
Published: June 2021

The bracket set of traditional Chinese timber buildings in Jiangnan region plays a structural and decorative role. The research of it is of great significance for cognitive the characteristics of local traditional timber buildings. In order to further understanding the mechanical properties of typical bracket set in traditional timber buildings of Song and Yuan dynasties in Jiangnan region, the methods of field investigation and numerical simulation were used. The typical bracket set of traditional timber buildings of Song and Yuan dynasties were extracted. The construction practices, mechanical properties and importance of components were studied. The results provide a basis for conservation of bracket set effectively and scientifically.
The effect of the force between rings of large-diameter shield tunnels on the segmental cracking in weak stratum
Authors: Han Xiaoming , He Chuangbo , Xu Chao , Zhong Han , Zhang Feilei
Published: June 2021

Large-diameter shield tunneling in weak strata has the risks of segment floating, segment cracking and seepage, affecting the durability of the tunnel structure. In this paper, the statistical analysis of the cracks of a large-diameter shield tunnel segment was carried out, and the thickness of the force transmission liner was studied. The experiment showed that the average number of cracks per ring was the smallest when using a 3mm liner. Based on the structural characteristics of the segment, four types of stresses, namely simple support of segment boss, double-sided cantilever, single-point cantilever and two-point cantilever, and it is verified through on-site statistics, which has certain guiding significance for crack prevention.
Development of an automatic measurement device for double laser shield tail gap based on image recognition technology
Authors: He Chuangbo , Xu Chao , Xiong Dongdong
Published: June 2021

Shield tail clearance is an important basis for the selection of segment assembly and shield attitude control. It is the most direct factor affecting shield tail brush wear. Poor shield tail clearance is prone to segment damage and shield tail seal failure. Using manual measurement of the shield tail gap, the measurement data has a certain hysteresis, and can not directly reflect the changing trend of the shield tail gap. Based on image recognition technology, a dual laser shield tail gap measurement device was developed to measure the changes in the shield tail gap during shield tunneling. The field test shows that: 1 The measurement device can monitor the shield tail gap in real time, and can simulate the ellipticity of the shield tail, monitor the deformation of the shield tail and the space state of the shield tail and the tube. 2 The acquisition device adopts a dual laser transmitter, meanwhile, the attitude of the shield machine cannot be controlled in real time, Can accurately establish the geometric relationship between the actual distance and the pixel distance, improve the test accuracy of the measuring device, and control the monitoring accuracy at 3.8 mm.
UAV image crop classification based on deep learning with spatial and spectral features
Authors: Fan Chong , Lu Ru
Published: June 2021

Unmanned Aerial Vehicle image analysis technology has become an effective means to classify crops. However, the UAV image classification mostly adopts shallow learning algorithm, with few computing units. These methods have low recognition accuracy and poor generalization ability. Deep learning has powerful function expression and excellent feature learning abilities. The learned features have more essential character for data and have achieved remarkable results in image classification. Therefore, the study proposes a crop classification method based on Unmanned Aerial Vehicle image with deep learning and spatial and spectral feature fusion. The method uses deep convolutional neural network to classify Unmanned Aerial Vehicle images. Simplified AlexNet network structure, which reduces the number of network layers, was used to accelerate the convergence speed of the model while ensuring the accuracy of crop classification in practical applications. Then, the vegetation index and height features of the Unmanned Aerial Vehicle image were extracted. Feature combination and comparative analyses were carried out to find the most effective feature combination and improve the accuracy of crop classification through spatial and spectral feature fusion. In addition, a Sample Expansion Strategy was used to optimize the classification model and further improve the classification result to achieve a perfect performance in the crop classification of drone images. The experimental results showed that the deep learning method can effectively identify crop types in Unmanned Aerial Vehicle images, and the overall classification accuracy is raised from 86.07% to 92.76% when combining spatial and spectral feature fusion with Sample Expansion Strategy.
The Application of Machine Learning in Determining Earthquake Magnitude as an Early Warning
Authors: Sheng Xinxu , Li shanyou , Lu Jianqi
Published: June 2021

Since ancient times, earthquake disasters have always been one of the most harmful natural disasters, and it is necessary to reduce the damage caused by earthquakes effectively. The earthquake early warning is a new technology that has been gradually mature in recent years and can effectively reduce earthquake disasters. The ability to accurately and quickly predict the earthquake magnitude has become an important but difficult part of the earthquake early warning technology. Currently, many countries in the world have been engaged in the projects of establishing and improving the system of earthquake early warning, and completed two methods to predict the earthquake magnitude as a kind of earthquake early warning, namely, the method of characteristic frequency and the method of characteristic amplitude. In recent years, with the constant improvement of deep learning, the application of machine learning in determining the earthquake magnitude as an early warning has been showing great development prospects and application possibility.
An Adaptive Aeromagnetic Compensation Method Based on Local Linear Regression
Authors: Dou Zhenjia , Liu Caihong , Wang Jingran , Han Qi
Published: June 2021

Aeromagnetic compensation plays an important role in airborne magnetic survey to eliminate the magnetic interference from the aircraft. However, the aeromagnetic compensation methods at present still cannot suppress the interference to the extremely low noise level of a high-sensitivity scalar magnetometer due to the common assumption about the time-invariation and the linearity of the Tolles-Lawson model depicting the aircraft magnetic interference. In this paper, an adaptive method based on local linear regression is proposed to improve the precision of aeromagnetic compensation. Instead of only using the whole historical calibration data all at once to estimate the model coefficients in advance as the traditional approach does, the proposed method calculates the coefficients in real-time by local linear regression during an aeromagnetic survey, using not only the historical calibration data but also the online measuring data, and both of them are required to be similar in a limited time window. The measured data were used to test the proposed method and the experimental results demonstrated its efficiency.
Research on Retrieving Landsat8 Sea Surface Temperature Based on Neutral Regression Equations
Authors: Huang Lu , Zhang Caiyun , Li Yan , Shao Hao , Zhang Qi , Yin Xifan
Published: June 2021

To verify the feasibility of applying Neutral Regression Equations to retrieve Landsat8 sea surface temperature (SST), and compares the retrieval accuracy and difference of the two thermal infrared bands, this paper establishes Neutral Regression Equations based on 32 MODIS SST training points, and uses buoy SST and MODIS SST to validate and compare the retrieval results. The results show that the Landsat8 SST retrieved by these Equations has high accuracy and good consistency with MODIS SST. Buoy SST verification shows that the root mean square error (rmse) of the two bands is less than 0.5°C, and the deviations range is less than 1°C; MODIS SST verification shows that the mean deviation(bias) of the 10th and 11th bands are -0.16°C and -0.22°C, respectively, and their deviations range is basically within ± 1°C; the retrieval accuracy of the 10th band is higher than that of the 11th band. Using Neutral Regression Equations to monitor the thermal discharge from Houshi Power Plant has achieved a wonderful effect, the temperature rise plume is jet-like, and affects a large range with a total area of 1.88km2 and a maximum thermal pollution distance of 2.5km.
Orientation of Small UAV Images with Constraint
Authors: Liu Xingxing , Zhou Guoqing , Yuan Man
Published: June 2021

Unmanned aerial vehicle (UAV) platform, especially in image acquisition, has the advantages of low cost and convenience compared with other sensors platform. Due to the limitation of platform load and cost, small UAV integrated positioning and orientation system (POS) has low accuracy, which makes it difficult to accurately reconstruct the geometric position and attitude of the sensor at the imaging time. For this reason, this paper proposes an angle consistent constraint algorithm to improve the accuracy of exterior orientation parameters. In this paper, the small UAV images measured in the field are used for experiments, and the results show that the constraint algorithm can achieve high accuracy when the number of control points is small and the accuracy of initial values is low, which greatly expands the application space of images.
Research on the Application of BIM Technology in the Cost Management of Construction Projects
Authors: Liao Liping
Published: June 2021

Under the premise of ensuring safety, quality compliance, reasonable schedule, and lowest cost are the fundamental goals of construction project management. The realization of this goal, in the final analysis, will fall on the key point of cost management. With the advent of the “Internet + ” era, the construction industry has developed rapidly, especially the application and promotion of BIM technology, which has gradually changed the traditional cost control mode. Based on BIM technology, taking construction project cost management as the research object, introducing the management method based on “BIM + earned value method”, analyzing the application of BIM technology in construction project cost management, constructing a cost management practice model, proposing specific countermeasures, and guiding the project practice.
Hydraulic lifting technology of steel grid roof of a hangar
Authors: Deng Deyuan , Li Zixuan , Zhang Weixiong , Mo Tianfang , Chen Zhou , Chen Zepeng
Published: June 2021

The grid structure is more and more widely used in the civil engineering industry, but due to the large number of rods and complex installation, it is extremely difficult to construct at high altitude. In order to overcome this problem, engineers proposed a hydraulic jacking method. The mechanical properties of steel structures are more complicated, especially in the construction process, the force situation and the design load is quite different. In order to explore the reliability of the hydraulic lifting process of the steel grid, this article takes the hydraulic lifting technology of the steel grid roof of a hangar as the engineering background. This project uses Sap2000 finite element analysis software to model, simulate the construction process of the jacking grid, analyze the mechanical characteristics and stability of the grid during the jacking process, and use it to guide the construction. The results show that: for large grid structures constructed at high altitudes and hydraulic jacking technology can effectively improve the construction efficiency and safety.
A review of domestic residential area suitable aging landscape design research from 2010 to 2020—Visual analysis based on VOSviewer software
Authors: Yao Kang-Kang , Zhang Hua , Zhang Ni-Yan
Published: June 2021

Population aging is a global problem in the 21st century, especially in China, where the elderly population is huge and has become a severe social reality. Therefore, how to make the elderly enjoy their old age and spend their old age happily in the community environment is a problem facing the current society. In this paper, CNKI is taken as the literature source, and relevant keywords such as community aging landscape and elderly community landscape from 2010 to 2020 are searched. The related research hotspots in recent ten years are analyzed by VOSviewer data visualization software, and the current research status is briefly described. It can be seen from the analysis that the research methods are gradually scientific and systematic, and the research hotspots are gradually changing from the formal landscape of the elderly community to more practical and targeted target landscapes such as health care and healing, microclimate and gardening therapy, and the trend of cross-disciplinary research is gradually obvious. On this basis, this paper attempts to analyze the future development trend of the aging community landscape by domestic scholars, with a view to providing help for further research.
Research on Intelligent Construction Intensive Management Based on Building Information Modeling Technology
Authors: Dong Shuzhao , Wang Lin , Huang Wenjuan
Published: June 2021

In the process of construction industry development, due to the slow development of information technology, low level of fine management, various working modes and other problems, it is difficult to form a benign closed loop among construction participants in the planning and decision-making stage, design stage, construction stage, production stage, operation and maintenance stage of the project. This paper proposes the concept of intensive management of intelligent construction based on BIM technology to realize the integrated development of the whole life cycle of buildings. Through studying the connotation, development status, research significance and function of intensive management of intelligent construction, the paper constructs an intensive management system of intelligent construction based on BIM technology, which realizes the independence and interoperability of each stage of the project, thus promoting the industrial upgrading and technology application of the construction industry and realizing sustainable development.
Research status and prospect of seismic transverse beam fall prevention measures for small and medium span beam bridges
Authors: Li Guo , Yan Lei , Wang Xin Yong , An Kang , Xiao Heng , Cheng Long Fei , Guo Yuan Chen , Liu Fang Ping
Published: June 2021

The current research status of seismic lateral bearings and blocks of small and medium span beam bridges are briefly reviewed. The current research status of the block and bearing is analyzed and discussed, and the future research trend is discussed. The research results show that the research on the bearing is focused on the discussion of the mechanism and influence of the friction coefficient, friction force and slip performance of the plate rubber bearing; in terms of the stop, various new stop structure forms emerge in an endless stream; with the in-depth research of the two, Researchers began to pay attention to the mutual interaction of the support and the block when the actual earthquake occurred, and began to test the conceptual design, but how to fully consider the overall seismic performance of the bridge under the interaction of the two in the small and medium-span girder bridge The impact of this requires more in-depth research.
Research on the Utilization Mode of Underground Space in the Protection of Shanghai’s Industrial Architecture Heritage
Authors: Hong Xiaochun , Ji Xiang
Published: June 2021

With the arrival of the era of stock optimization, urban existing industrial areas and industrial buildings through renovation and upgrading to improve the building performance and expand the building function, more and more become an important content of urban renewal. With rich industrial building heritages in Shanghai as an example, the study was based on the ground of the industrial heritage protection status and function of underground space utilization, exploring the development and utilization of underground space to realize city both with industrial zone industrial building heritages protection development, expansion of land space and function optimization, summarized based on the industrial building heritages protection of underground space utilization patterns and their characteristics. It can provide a reference for the existing urban environmental stock renewal and expansion.
Activation of Traditional Villages in Dapeng New District, Shenzhen, China—A Case Study on Wangmu walled-village
Authors: Deng Wenzheng , Luo Wei
Published: June 2021

In this paper, a case study is conducted of Wangmu walled-village, a traditional village in Dapeng New District, Shenzhen, China. It introduces the historical evolution, location overview and current situation of typical traditional Hakka’s walled-village in the eastern part of Shenzhen. With Wangmu walled-village as an example, the settlement space and architectural value of existing walled-village are analyzed. Further, based on a value judgment, the feasibility of activation and application of Wangmu walled-village in the future is explored. An activation scheme is drawn up based on the current situation of the walled-village. Those will provide ideas and suggestions for the activation and promotion of similar traditional villages.
The protection process and measures of Macau’s heritage buildings
Authors: Zheng Liang , Chen Yile
Published: June 2021

In 2005, Macau was merged into the World Cultural Heritage List with the Historic District of Macau. In addition to strengthening the protection and revitalization of the 22 buildings and 8 square fronts in the area, the Macau government has also unearthed a number of historical and cultural heritages. Historical buildings of cultural significance, such as General Ye Ting’s Former Residence, Former Chong Sai Pharmacy, and the Patane Night Watch House. The long historical memory of Macau and even the Lingnan region. This article sorts out the protection process and common measures of Macau’s heritage buildings. Through the study of Macau’s heritage buildings, it discusses specific measures for the protection and activation of heritage buildings, which has a reference for the sustainable development of heritage buildings.
Indoor Intelligent Decoration System based on BIM + VR Technology
Authors: Han Fengyi , Liu Yaping
Published: June 2021

In the interior decoration industry, disputes between design and actual effects, waste of materials, and poor construction quality often occur. In order to improve customer satisfaction, reduce waste of construction resources, and realize smart decoration in the interior decoration industry, BIM + VR technology has begun to take the stage. BIM + VR interior decoration technology is the use of BIM technology to build a three-dimensional model to realize the three-dimensional visual display of the decoration design plan. Users can really feel the effect of interior decoration through VR technology, and modify the unsatisfactory parts of the design before construction, which can more accurately meet the needs of users. And finally achieve the smart decoration function.
Research on evaluation of mining area ecological security based on GF-1 satellite imagery—taking Fushun West open-pit mine for example
Authors: Qi Yu-Na , Liao Shun-Bao , Wang Qiu-Ling
Published: June 2021

Carrying out the evaluation of the ecological environment of the mining area is the basis for the protection and prevention of the environment of the mining area. This paper takes Fushun West Open-pit Mine as the research area, uses the remote sensing image data of Gaofen-1 (GF-1) satellite, and uses remote sensing and GIS technology, firstly obtains high-resolution multi-spectral remote sensing images, and then extracts environmental information of the mining area from the images, such as vegetation coverage, water bodies, soil index, and then normalizes the ecological impact factors, and at last uses the comprehensive index method to construct a comprehensive evaluation model of the mining area’s ecological environment to analyze and evaluate the mining area’s ecological environment. The mining area ecological environment assessment method based on the Gaofen-1 satellite data is simple and easy to implement, and the evaluation results can provide a reference for understanding the mining area’s ecological environment and make reasonable protection measures.
Analysis of Land Use Change in Nanjing Based on Landsat Remote Sensing Images
Authors: Shen Qiwei , Zhang Ao , Zhang Haotian
Published: June 2021

Purpose: Using Landsat OLI remote sensing images in the two phases of 2015 and 2020. Taking Nanjing as the research area. Based on RS and GIS technology, adopting maximum likelihood method for supervised classification, extracting and producing a land use classification map for the two phases of Nanjing from 2015 to 2020. And further, using the land use change transfer matrix to analyze and summarize the characteristics and laws of the dynamic changes of land use in Nanjing. Result: From 2015 to 2020 in Nanjing, the overall land use change showed “two reductions and four increases”. The area of arable land and bare land decreased by 729.46 km2, 332.31 km2; the area of u rban construction land, woodland, grassland, and water area increased by 448.39 km2, 231.67 km2, 216.87 km2 and 164.84 km2. And each land use type has a different amount of area conversion. Conclusion: The analysis of land use change based on Landsat remote sensing image research area can effectively predict the change trend of regional land use. It can provide a basis for the research on the driving forces of land use change in the region, and it can also provide decision-making support for the formulation of land-related policies in the region.
Research on accuracy of field patrol data based on GIS
Authors: Zhu Qifeng , Shi Dong
Published: June 2021

Field patrol is the main method of wildlife protection, which plays a very important role in the protection and management of natural resources and biodiversity in nature reserves. However, it is difficult to completely evaluate the patrol accuracy, because it is impossible to preset the animal site in advance. Based on patrol data collected from the First Ecological Guard Competition, the accuracy of patrol route, animal site and geographical factor of animal site and GIS method are evaluated and analyzed. The results show that: (1) the patrol route has the highest accuracy, and the average accuracy is 87.91%, which indicates that ranger could basically patrol according to the preset patrol route; (2) the accuracy of animal site is not as good as that of patrol route, and the average accuracy is 51.10%, mainly because recorded animals are not right, standardized and complete; (3) the altitude accuracy is high, the slope accuracy is very low. It is recommended that slope data would no longer be recorded in the future and be directly obtained by GIS method. The results are helpful to improve the patrol accuracy evaluation system.
Research on Baiyangdian Lake Water Body Changes and Water Quality Parameters Inversion Based on Landsat Dense Time Series Data
Authors: Cheng Minghua , Jiang Miao , Huang Zhaoqiang , Lei Hua , Yan Dongchuan , Zhu Fuxiao
Published: June 2021

Baiyangdian Lake is the largest wetland ecosystem in North China, which has a special strategic position, so it is of great significance to study its temporal and spatial changes. Based on the 112 Landsat satellite remote sensing data from 1984 to 2020, this paper extracted the thematic information of Baiyangdian Lake open water body, carried out the study on the temporal and spatial evolution of the Baiyangdian Wetland ecosystem, and analyzed its area change trend as “increase-decrease-increase-decrease again-increase again ”. Among them, the Landsat7 ETM SLC-off satellite digital product with band noise during 2003-2012 was repaired, so that it can better reflect the mutation characteristics and overall laws of Baiyangdian Lake water body in the past 30 years. On this basis, the Baiyangdian Lake water quality parameters were inverted, and the conclusions drawn have certain reference significance for maintaining the ecological environment of Baiyangdian Lake.
Ribbon Road Surface Filtering in Vehicle-Borne Laser Scanning Point Cloud Data
Authors: Chen Min , Liu Rufei , Ding Shaopeng
Published: June 2021

Terrain data of road is the most commonly used basic data by the traffic department. The high-precision three-dimensional road data can restore the terrain features under the real scene, which has a wider application range. In order to obtain high-precision three-dimensional point cloud road data, taking the vehicle-borne laser scanning data as the research object, a method of ground filtering for ribbon road is proposed. First, the driving trajectory information of the road data collected by the vehicle is read. Then, according to the road characteristics, characteristics of the vehicle driving trajectory is used to control processing direction, and a grid index of the point cloud data is created. Second, feature descriptors based on the spatial distribution characteristics of road point cloud data are established, and rough road point cloud data is obtained. Finally, the profile data of the vehicle-borne laser point cloud in the vertical trajectory driving direction is extracted, and the accurate ribbon road and the micro-terrain data on both sides are obtained by the horizontal constraint line detection algorithm. The experiment and analysis are carried out by using two different ribbon road data. Experimental results show that the method can be applied to different road scenes.
The research on continuous carrier phase time transfer method based on parameter transfer
Authors: Wang Jiang-Ting , Xu Jing-Xuan , Wang Xiang-Lei
Published: June 2021

The method of continuous GNSS carrier phase time transfer is studied in detail, and the cause of jump in carrier phase time transfer results is analyzed. The relationship between multi-day data jump and daily jump is deduced in theory, and the correctness of the deduced result is verified by the calculation result of actual measured data. Solution is given to daily jump in carrier phase time transfer. Since the time transfer reference signal is a continuously running high-precision atomic clock signal, a continuous PPP time transfer method based on clock difference parameter transfer is proposed. The method proposed in this paper is validated and analyzed with the actual measured data, and compared with the traditional GNSS carrier phase time transfer solution. The results show that the method given in this paper can solve the problem of daily jump jump to a certain extent, effectively improve the continuity, availability and reliability of time transfer results, and also improve the frequency stability of time transfer results.
Analysis of Image Registration Algorithm RANSAC and Its Improved Algorithm
Authors: Pan Zhongtai , Wen Zhenwei
Published: June 2021

The RANSAC (random sampling consensus) algorithm is an estimation method that can obtain the optimal model in samples containing a lot of abnormal data. This algorithm uses a small number of points in the data to estimate the model, and then uses the remaining points to check the model. It is now widely used in computer vision image stitching. This algorithm has disadvantages such as slow operation speed and poor sample adaptability. In order to improve the efficiency of image registration, many researchers have made improvements on the basis of the RANSAC principle. This article introduces the principles and shortcomings of RANSAC, and introduces four ways to improve it in view of its shortcomings. The advantages and problems of the improved algorithm are analyzed to provide a basis for the field of image registration.
Remote Sensing Monitoring of Vegetation Coverage of Hunshandake Sand Based on HJ-1A
Authors: Feng Tianshi , Wang Zhiguo , Pang Zhiguo , Jiang Wei , Li Hao
Published: June 2021

Hunshandake Sand has sparse vegetation and serious desertification, which is one of the main reasons for the dust weather in the Beijing-Tianjin-Hebei region. Dynamic monitoring of vegetation coverage in this area is of great significance for predicting sand and dust weather in the Beijing-Tianjin-Hebei region. Remote sensing technology has the advantages of large area, multiple time phases, and high accuracy. This study is based on the CCD data of the HJ-1A, using NDVI parameters as the main input parameters, and using an improved pixel binary model to invert the vegetation coverage of the study area. On this basis, the land use type data is used to extract another vegetation coverage of the study area during the period. The vegetation coverage in different periods of the study area is calculated by band to achieve the purpose of dynamic monitoring. The results show that desertification is common in the northwest of the study area, and the vegetation coverage is becoming lower and lower, while the vegetation coverage in the northeast and south is increasing, and the overall vegetation coverage in the study area is increasing. The experimental results are more consistent with the actual situation, which confirms that the improved pixel binary model has higher accuracy and a certain degree of universality, and the overall desertification control effect of the Hunshandake Sand is better.
Light deflection Phenomenon Simulation and Calibration of the Earth-Observation Satellite
Authors: Yu Jing , Liang Deyin , Gao Hongtao , Yu Longjiang , Huang Yufei
Published: June 2021

The advance of the resolution of optical observation satellite requires more accurate image acquisition location and geometrical model, therefore, light deflection effect must be taken into account in the geometrical model. The deflection of light is a phenomenon of a deviation between the apparent position and the true position of the observed object, due to the relative velocity of the observer (the remote sensing satellite). This article firstly models the light deflection effect of the earth-observation process of satellite, using this model, the deviation of the “apparent” location and the “real” location of the ground target is calculated. Then the influence of the satellite observation pointing angle to light deflection effect is analyzed. In the end, the correction method of the light deflection effect is advised, and through emulation, we can see that the image acquisition location error can be greatly improved after the correction.
The technology of effective reservoir prediction in fault development zone
Authors: Jiang Zhenhai
Published: June 2021

Reservoir prediction in the middle and late stages of development is not only to predict the sandstone, but also to define the specific location of Petroleum-bearing sandstone. The post-stack seismic data is superimposed on a multi-channel seismic data level, although the signal-to-noise ratio is improved to a certain extent, the average amplitude value is obtained in the superposition process, so that only the effective prediction of the sand body can be realized. However, the pre-stack seismic data can obtain the information of shear wave by the longitudinal wave. The characteristics of the shear wave that cannot propagate in the fluid can effectively predict the reservoir and fluid distribution. In order to further quantify the remaining oil potential in fault area, prestack seismic inversion technology and petrophysical analysis are used to determine the favorable oil-bearing area. On this basis, prestack geostatistical inversion is completed to further clarify sand body with high oil saturation. Combined with numerical simulation, it effectively predicts the residual oil distribution at the edge of fault and the precision of the remaining oil quantitative characterization results is high. The recognition rate of thick layer saturation is more than 90%, and the recognition rate of thin interlayer saturation is more than 70%, which can meet the demand of fine reservoir prediction.
Spatiotemporal Variations of Aksai Chin Lake and its influencing factors during 1972-2018
Authors: Yan Wei , Jiang Ziyun , Zhou Feng , Ning Jia , Hou Shuangshuang , Wang Jian , Han Rumeng , Liu Minghua
Published: June 2021

In the context of increasing lake expansion on the Tibetan Plateau, which is sensitive to climate change, it is of great significance to strengthen the research on the characteristics of lake change and its response to climate change. This paper was designed to investigate the spatiotemporal variations of Aksai Chin Lake (ACL), a typical large lake on the Tibetan Plateau, by using Landsat MSS/TM/ETM+/OLI images during 1972-2018, and to quantitatively discuss the effects of climate on lake changes based on meteorological data from Shiquanhe station. During 1961-2018, annual mean air temperature and precipitation in this region increased at rates of 0.44 °C/decade and 1.35 mm/decade, respectively, with a mutation point of 1999 for temperature, while evaporation decreased at the rate of -54.3 mm/decade, with two mutation points in 1972 and 2014, respectively. The area of ACL had increased at an average rate of 2.51 km2 per year, with a fluctuation of “slight expansion – shrinkage – rapid expansion – slight expansion – rapid expansion” during 1972-2018. Controlled by the topography, the ACL expanded to the southeast by 3851.6 m in total. In terms of the lake area response to climate change, air temperature and evaporation were the main factors affecting ACL area directly, while precipitation mainly regulated ACL by the indirect effect through air temperature and evaporation. Generally, rising air temperature, increasing precipitation and decreasing evaporation all contribute to promote the expansion of ACL.
Collection Method of Arbitrary Laser Echo Based on STM32
Authors: Li Weihao , Zhou Guoqing , Zhou Xiang , Tan Yizhi , Lin Gangchao , Li Xianxing , Deng Ronghua
Published: June 2021

When LIDAR measures the water depth, in most cases the echo signal is more complex, with more backscattering, and it is difficult to observe different parts of the waveform separately, especially the underwater echo signal. Therefore, this paper uses an STM32 controller to design a signal generator to send out pulse signals, which act on the detection device PMT in the LIDAR detection system to control the start and stop of the PMT receiving channel. By adjusting the frequency, duty cycle, and other parameters of this signal generator, the arbitrary part of the waveform can be collected, and the waveform is not disturbed. Using the STM32 instead of a traditional signal generator can reduce system power consumption and load capacity.
Application of 3D Laser Scanning Technology in Monitoring Deformation of Port Trail
Authors: Dang Xiaobin
Published: June 2021

Qinhuangdao Port, as the main hub port for coal transportation from north to south, has become an important coal, oil and other energy export port in China. The port facilities are in continuous operation all the year round, especially in the peak period of coal transportation in the south. The maintenance and monitoring of the equipment are faced with such problems as heavy work tasks, poor working environment, many construction disturbances, and the influence of monitoring on port production. This paper mainly introduces the application of ground 3D laser scanner in building deformation measurement based on the deformation measurement project of positioning car cable track in the unloading department of coal terminal of Qinhuangdao Port. Through actual results illustrate using the ground three-dimensional laser scanner for high-risk, complex structure deformation monitoring operation is of field operation is simple, short construction period, small impact on the continuity of production equipment, complete data and reliable advantages of accuracy, which is the ground three-dimensional laser scanner in Qinhuangdao port for the first time application, for the future of 3 d laser scanning technology in the port risk measuring project and digital 3 d modeling and so on has certain reference value.