bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the Electrical Resistivity Characteristics of Statue Remolded Soil
Authors: Qiu Liping , Yang Yaogui , Ma Linyan , Qiao Jiawei
Published: March 2021

In order to study the electrical resistivity characteristics of the statue remodeled soil and make it play a role in the theory and related engineering applications, the electrical resistivity measurement of the statue remodeled soil was carried out using the a two-electrode method.This paper analyzes the law and characteristics between the electrical resistivity of the coarse and fine mud layers of the statue and the water content and dry density, and establishes the empirical model of the electrical resistivity of the coarse and fine mud layers.The measurement indicate that the electrical resistivity of the coarse and fine mud layers of the remodeled soil of the statue shows a power function decrease with the increase of mass water content, and with the increase of dry density.And under the conditions of the same mass water content and dry density, the electrical resistivity of the coarse mud layer is always lower than that of the fine mud layer.Based on the experimental results, the electrical resistivity model of the coarse and fine mud layers of the statue remodeled soil and the relationship model between the electrical resistivity of the earthen plaster of statue and the mass water content are proposed. This will provide reference for the non-destructive testing of the moisture content of the precious cultural relics of the statue and the engineering research and practical engineering application of similar materials such as the reinforced soil slope protection, retaining wall and foundation, etc.
Traditional funeral culture and modern green ecological funeral construction
Authors: He Zhang , Wang Yongkuo , Hu Daoqing , Wang Yingchao
Published: March 2021

Modern green ecological funeral is a sign of the progress of human civilization, the development direction of China’s funeral industry, and the only way of funeral transformation. In China, although the construction of modern green ecological funeral has made some achievements, there are still some problems. We need to strengthen publicity, create strong conditions, further improve the system, and gather the strength of the government, industry and the public to promote the vigorous development of China’s modern green ecological funeral construction.
Research and application of logging technology for annulus fluid production profile in highly deviated wells
Authors: Pan Hongbo
Published: March 2021

In view of the low success rate of logging in annulus fluid production profile in domestic oil fields, the relationship between instrument string and well deviation is carried out Requirements of downhole instruments for annular testing construction in highly deviated wells; The lifting and lowering technology of well entry instruments in highly deviated wells has been systematically studied. After field application, the logging technology has been updated and improved. By using large diameter cable, flexibly connecting and splitting instruments, reducing the outer diameter of instruments, configuring automatic direction finder, enhancing the umbrella collecting strength and other improvements in technology and construction methods, the problem of difficulty in measuring the logging data of liquid production profile in the annulus of highly inclined pumping wells is well solved, and the demand of dynamic monitoring of highly inclined wells in oil fields is met.
Application of the Borehole Shear Test to Loess Slope
Authors: Huang Xiaowei , Yu Yongtang , Zhu Jianmin , Zeng Tao , Zheng Jianguo
Published: March 2021

It is a fundamental and important task to accurately determine the shear strength parameters of soil in the engineering design of slopes. In this study, an in-situ test method called Borehole Shear Test (BST) was applied for the first time to obtain the shear strength parameters of loess slope. Based on the improved Iowa borehole shear instrument, this paper aims at proving the applicability of BST to loess slope, and revealing the testing principles and influencing factors of normal stress and consolidation time to BST. The results show that the normal stress is proportional to displacement, which indicates that the soil is elastic deformations stage. To ensure the reliability of the results, the time for consolidation under the first stage of normal stress should be greater than 10 min while in the subsequent steps, the consolidation time should be no less than 5 min. The shear stress-displacement curves have obvious peak values and exhibit a general strain-softening type. The shear strength parameters determined have good correlation overall and the corresponding correlation coefficient is greater than 0.98. In general, the borehole shear test shows a good performance on the determination of the shear strength parameters of loess, which provides valuable guidance for slope design and future study.
Application of integrated method of HAZOP-AHP and fuzzy comprehensive evaluation in coal mine gas explosion accident
Authors: Li Dan , Cao Qinggui , Wang Junqing , Mi Xin
Published: March 2021

Hazard and Operability analysis (HAZOP), analytic hierarchy process (AHP) and fuzzy comprehensive evaluation methods are all important safety evaluation methods. For HAZOP analysis, the subjectivity is strong, the analysis process is complex, and accurate quantitative analysis cannot be performed. Proposed a safety evaluation method that combines HAZOP, AHP and fuzzy comprehensive evaluation, and integrated the three methods to make the HAZOP analysis method from qualitative analysis to qualitative and quantitative analysis, and improve the accuracy of risk identification. Finally, taking the gas explosion accident as an example, the above method is used to briefly analyze the gas explosion accident to verify the scientificity and feasibility of the method.
New Bionic Tree Water and Soil Protection Device
Authors: Wang Zehao , Zhang Wenbo , Qiu Yukun , Cao Xuewei
Published: March 2021

In view of the existing soil erosion problems in China, a new bionic tree device is designed to solve the shortcomings of the existing tree planting control methods through the research and investigation of soil and water loss control by trees. In a short period of time, it can improve the soil loss and vegetation survival in the area prone to soil erosion by a new treatment method. Compared with the traditional way of afforestation, it has shorter treatment cycle and more convenient treatment method. Combined with natural trees, it can achieve better water and soil protection.
Analysis of stress state of transversely isotropic weak rock stratum
Authors: Zhe Li , Guangze Zhang , Enyu Chen
Published: March 2021

In geotechnical engineering excavation and design, in-situ stress field is a factor that engineers must consider. However, in practical engineering, the testing method of in-situ stress in weak rock stratum is not mature, and how to obtain the distribution of in-situ stress field in weak rock stratum efficiently and accurately has become a research hotspot. According to the in-situ stress test results of known rock strata, based on the principle of deformation coordination of adjacent rock strata, the stress state of rock strata which is difficult to carry out in-situ stress test is deduced. It is considered that considering the transverse isotropy of rock strata will greatly improve the prediction accuracy, which is verified by ABAQUS finite element model. The results show that the transverse isotropic model is far superior to the isotropic model in predicting the distribution of ground stress field in rock strata (shale, slate, etc.) with obvious anisotropy. However, the greater the ratio of elastic modulus between horizontal and vertical direction, the smaller the ratio of elastic modulus between horizontal and vertical direction, and the greater the difference between the predicted and measured rock stress states. The obtained conclusions are applied to the estimation of ground stress of Que Ge Ka fault in Litang Tunnel, sichuan-tibet railway, which provides sufficient theoretical basis for the classification of large deformation in the process of tunnel excavation and design.
Research on the Drop Hammer Impact Test System
Authors: Wang Zhiming , Liu Dongdong , Li Zhongsheng
Published: March 2021

The drop hammer impact test system adopts the multi-purpose and modular design to solve the four problems of the airbag door of automobile test instrument panel: the test conditions are generally inconsistent with the actual conditions; The secondary impact problem exists in the collision test. The experiment does not have the experimental data, cannot provide the technical question for the enterprise; There are some problems in the equipment construction mode, such as universality, repeatability and low utilization rate. The improvement of mechanical structure and control system makes the device simple in structure, powerful in function, able to obtain accurate experimental data, and able to realize the instrument panel airbag door detection of different vehicle models.
Risk Management of Urban Pipe Gallery Based on System Dynamics
Authors: Wang Zihao , Chen Xuedong
Published: March 2021

Under the background of continuous urbanization in China, urban underground comprehensive pipe gallery will become an inevitable trend of urban comprehensive management in the future. After the completion of the management gallery, how to effectively manage the risks in operation and maintenance management has become a topic at this stage. Based on the classic method of AHP combined with DSM method, and through a lot of literature research, to build the relationship between the risk of an integrated pipe rack system, and has carried on the system dynamics simulation using Anylogic software, finally, the simulation results obtained a few of comprehensive pipe gallery has the greatest effect in the overall risk of several risk paths, convenient operational phase in the pipe gallery risk in the future, you can draw on the results of several path for more effective management.
Study on Forming Theory of Inner Strong & Outer Weak Strong Bi-metal Pipe
Authors: Fan Xianyong , Wang Xuesheng , Zhai Shikuan , Chen Qingzhu , Yu Jingjiang
Published: March 2021

As a new type of pipe, bimetallic composite pipe is widely used in various industries in the chemical industry, because its internal and external tubes use different metals, so it can cope with a variety of different working conditions. At present, the application field of composite pipe is mostly inner strong and outer weak strong composite pipe, and this pipe has not been studied accordingly. In this paper, the theory of expansion of inner strong and outer weak strong composite pipe is derived, and a complete set of expansion methods and related parameter calculation formulas are obtained. Abaqus, a finite meta-analysis software, is used to simulate the expansion process and compare it with the theoretical results. The comparative results show that the theoretical formula obtained by derivation has a high degree of credibility, and the results obtained by using this set of theories are close to the results of computer simulation and can be used in industrial production.
Research on False Data Injection Attack in Smart Grid
Authors: Xu Aidong , Zhang Tengyue , Chen Liang , Li Qing , Zhang Yunan , Lin Haojie , Wang Peiyao , Wu Sihui , Zhao Runhui , Jiang Yixin
Published: March 2021

The concealed false data injection (FDI) attack in the smart grid can successfully pass the power system state estimation commonly used in the residual bad data test without being detected by the existing algorithms, resulting in the state estimation error of the control center and disturbing the normal operation of the power system. In this paper, false data injection attack and attack detection are carried out in the actual power edge security protection system, microgrid control system and intelligent energy security protection system. Among them, the false data attack part simulates the attack of the voltage phase angle, and compares it with the ordinary attack method, and demonstrates the success of these attacks in the actual power grid system.
The Application of PAD Teaching Method in Computer Network Course
Authors: Liu Lining , Zhang Yongsheng , Zhang Penglong , Sun Wenqian
Published: March 2021

As a new teaching mode and method, PAD has been developed in recent years. This teaching mode has been applied in the teaching of universities, ordinary primary and secondary schools and vocational colleges. It has achieved good teaching results. In order to improve teaching effect, improve the students’ autonomy and enthusiasm and cultivate the independent innovative talents needed by the society, more and more computer teachers have also begun to apply PAD to the computer classroom. “Computer Network” is a basic and compulsory course for learning computers. “transmission media” in this course is selected as the specific content, and PAD is used for teaching design.
Study on Capacity Improvement of Close Range Dual Runway of Shuangliu Airport under New Wake Classification Standard (RECAT)
Authors: Pan Weijun , Zhang Hengheng , Yin Haoran , Wu Tianyi , Yin Zirui
Published: March 2021

With the increasing number of flights, the gap between the front and rear aircrafts is gradually reduced. The wake separation becomes one of the important factors restricting the reduction of aircraft separation, which results in the runway occupation time can not be further reduced, and the runway capacity is also restricted to a certain extent. In recent years, the wake reclassification (Recat) promoted by FAA has been applied to runway capacity the increase has played a positive role.

In this paper, the capacity of Chengdu Shuangliu International Airport is studied, and the capacity models of approach runway and departure runway are established respectively. According to the relevant characteristics of Chengdu Shuangliu International Airport, the runway capacity model under one landing operation mode is established, and the runway capacity is calculated by using MATLAB software with reference to the new American wake classification standard (Recat). Finally, it is concluded that under the condition of introducing Recat, the capacity of Chengdu Shuangliu International Airport can be increased by 12.3% in theory.
Design and Implementation of a High-precision Campus Intelligent Blackboard Inspection System Based on AI
Authors: Li Nengneng , Xu Xiwei , Wang Rong , Liu Xiaoyang
Published: March 2021

At present, traditional campus smart blackboard detection generally uses manual detection as the main method and equipment detection as the auxiliary method to determine the fault information encountered, and it is still limited to relying on the experience of the campus smart blackboard management and maintenance personnel to judge the fault. Solve the problem. In this paper, aiming at the problems of low efficiency of traditional campus blackboard detection technology, high manual detection cost, and low classroom enthusiasm due to untimely detection, this paper proposes a campus intelligent blackboard monitoring system based on AI technology, and establishes a chain-type intelligent classroom education system. Smart classroom does not affect the development of social education level because of some disadvantages brought about by technological development.
The Design of Smart Car Based on Android Client
Authors: Tang Lili , Huang Wei , Guo Linhai
Published: March 2021

This design is based on the open source Android version 8.0 system to develop the mobile phone platform client, using the eclipse integrated development environment to research and develop Bluetooth control. The remote control of the car is realized by Bluetooth technology, gravity sensor and voice. The design is mainly composed of hardware system and software system. It can realize the car’s forward, backward, rear left turn, rear right turn, front left turn, front right turn and other functions. This design scheme provides a new solution for the design and implementation of wireless remote control vehicle, and also plays a certain reference role for the design of remote control smart home system in the future.
OAS Surface Optimization of Shuangliu Airport based on Collision Probability Calculation
Authors: Lian Jingyu , Chen Pengde , Wang Siyu , Wang Hao
Published: March 2021

Airport clearance safety management is an important part of airport operation indicators. Controlling obstacle height is one of the most important tasks in airport clearance management. The current program design and evaluation in China currently uses the obstacle restriction surface (ILS) and Obstacle Evaluation Surface (OAS). The current program design in our country rarely uses the collision risk mode (CRM), but the obstacles around the airport are gradually increasing. At this stage, the OAS surface is more conservative. A simplified model with a collision probability of approximately 1×10-7 is constructed and compared with the OAS surface to improve it. The results show that the slope of the original OAS surface is larger than that of the simplified model. The improved OAS surface meets the target safety level and solves the problem of being too conservative.
Research on the Spatial Differentiation of Soil Salinization in the north of the Yellow River in Jinan City
Authors: Liu Zhanhong , Dong Fang , Wang Xinyu
Published: March 2021

In this paper, Xiyan Village and Dongyan Village of Jiyang County, Jinan City were taken as the research areas to conduct research and analysis on the spatial distribution law of soil salinity in the spring of 2019. Spatial distribution of soil salt ions in different soil layers were drawn to research spatial distribution characteristics of soil ions. The results show that soil in the research areas was highly mineralized and the negative ions in the chemical components were mainly SO42- and Cl-. In the horizontal direction, the content of Mg2+ and Cl-in all layers all presented the trend of increasing gradually from northwest to southeast. The peak value of ion content occurred in the Midwest.
Research on Estimation of Blood Glucose Based on PPG and Deep Neural Networks
Authors: Deng Hanghang , Zhang Luqiao , Xie Yu , Mo Shasha
Published: March 2021

Diabetes is one of the three major chronic diseases in the world. At present, the number of diabetic patients in the world is increasing year by year, which has become one of the main threats to us. Therefore, it is very important to monitor blood glucose level. Clinically, blood glucose is measured by collecting fingertip blood, but this method has many disadvantages. In this paper, PPG signals are used to estimate BGL using deep neural networks (DNN). Finally, we found that the success rate of our DNN blood glucose estimation model reached 90.25%, and achieved good results. It provides a choice for the commercialization of noninvasive blood glucose detection technology.
Research on the New Development Mode of Metro TOD Based on Tourism Economy——Taking Shijiu Lake Scenic Area in Nanjing as an Example
Authors: Hu Haoxuan , Zhang Yuchen , He Naijun
Published: March 2021

Metro TOD plays an important role in the development of commercial economy and promotes the local industry and economy. Reasonable combination of Metro TOD and tourism economy will help to form a more diversified development model. This paper puts forward a new development mode of Nanjing Shijiu Lake Metro TOD.
Summary of Reliability Analysis Methods of Remote Tower System
Authors: Pan Weijun , Luo Yuming , Han Shuai , Zhong Linfeng
Published: March 2021

The remote tower technology can provide remote control services for small airports in remote areas with low passenger and cargo throughput[2].In the 1990s, European and American countries began the research and development of remote towers. In 2015, Sweden’s Sundsval Airport approved the use of remote tower operations. In 2019, China Xinjiang Airport Group started the remote tower pilot construction. As a new thing, the remote tower system is different from the traditional tower, and its safety and reliability have not been systematically studied in China. This article introduces several methods that can be used to analyze the reliability of the remote tower system in detail. These methods are analyzed and compared. Finally, this article summarizes the methods applicable to the reliability analysis of China’s remote tower system.
Research and Application of Light Combined Composite Material Holding Pole
Authors: Ge Zhaojun , Su Zhaohui , Jia Ning , Zheng Fawei , Zhou Dayan , Liu Qiang
Published: March 2021

Suspension spanning frame is widely used in the construction of newly constructed overhead transmission lines, and plays an important role in protecting the safety of the objects being crossed. The temporary beam of the suspension cable-type span is installed on the transmission tower, and the impact load in the event of an accident will be transmitted to the transmission tower through the temporary beam.Therefore,the installation of temporary beams will have an important impact on the safety of transmission towers. This paper analyzes the typical installation method of the suspension cable spanning frame on the transmission tower, discusses the dynamic simulation method of the suspension cable spanning frame and the transmission tower under the impact of the conductor, selects a 500kV transmission line crossing project to carry out the wire breakage Analysis of the impact of the lower impact load on the transmission tower. The results show that the wrong installation method will have a significant adverse effect on the safety of the transmission tower. Based on the analysis results, suggestions for the installation of temporary beams were proposed, which provided a reference for the suspension construction of the suspension bridge.
Spatial-temporal Variation of Precipitation Concentration Degree and Precipitation Concentration Period in Gansu Province in Recent 50 Years
Authors: Li Qingfeng , Zhao Chuancheng , Yao Shuxia , Wang Shengxia
Published: March 2021

Inhomogeneity is the inherent attribute of precipitation and is usually an important factor affecting the occurrence of hydrological disasters such as floods and debris flows. Based on the monthly precipitation data of 27 national meteorological stations in the past 50 years, the spatial and temporal distribution characteristics of precipitation concentration degree (PCD) and precipitation concentration period (PCP) in Gansu Province were assessed in this study. The results indicated that: (a) the annual precipitation had distinct regional differences (annual average values were between 43.3-605.4 mm) and strong inter-annual fluctuations (coefficient of variation was usually above 0.20, some up to 0.40-0.45); (b) the main range of PCD was from 0.52 to 0.67, with significantly reduced inter-annual fluctuation and a long-term trend of gradual decrease; (c) the spatial-temporal variation of PCP was generally small, mainly concentrated in 192.8°-205.0°(mid-late July), and showed a slightly advanced variation tendency. Under the overall background of warming and wetting, Gansu Province presents evolution characteristics of PCD weakening and PCP advancing, and the formation mechanism and potential effects of this phenomenon require further attention.
Research on Customer Relationship Management in E-commerce Environment
Authors: Guo Feng
Published: March 2021

with the rapid development of e-commerce, many changes have taken place in customer relationship management under the environment of e-commerce. From this point on, this paper analyzes the requirements and characteristics of customer relationship management system in e-commerce environment, and discusses how to effectively integrate customer relationship management system with other information systems to better meet customer needs.
Investigation and Analysis of the Status Quo of Ecological Civilization Education for College Students
Authors: Wang Tingting
Published: March 2021

Objective: Based on theoretical research, this article conducts social surveys, finds problems through surveys, understands the status quo of college students’ ecological civilization education, finds out its existing problems, and conducts in-depth analysis of their causes, in order to enhance college students’ ecological civilization education The effectiveness of this article provides some useful references. Methods: Using questionnaire survey and interview methods, this article randomly selected students from Hunan Biomechanical Vocational and Technical College, Shaoyang College, Hunan Agricultural University, and Central South University on issues related to ecological civilization education. Results: In terms of college students’ awareness of ecological civilization, college students have more than 55% understanding of some common environmental problems, especially the deepest understanding of smog, straw burning, and greenhouse effect; in college students’ awareness of ecological civilization In terms of the situation, 28.33% of the surveyed college students believe that the current environmental situation in our country is very serious, 35.28% of the students think it is fair, and 35% of the students think it is not serious or unclear; what do you think is the relationship between environmental protection and economic development? The survey showed that 18.44% of the students thought it was related, and 33.33% of the students thought that the relationship was not close, and some students who were close thought it was not related or unclear. When asked, “Will you notice the environmental protection signs when you shop?” On the issue, only 5% of the students said they would pay attention, 55% of the students choose not to look at it, and 18.44% of the students are completely unaware of white pollution. The ecological civilization education of college students has achieved certain results, showing a positive development trend, but at the same time, it should be noted that there are still some college students who are indifferent to ecological civilization, and the phenomenon of environmental damage still exists. These are problems that need further solution attention.
Effects of Biochar on the Soil Carbon Cycle in Agroecosystems: An Promising Way to Increase the Carbon Pool in Dryland
Authors: Li Mengying , Xiong Youcai , Cai Liqun
Published: March 2021

Dryland agriculture ecosystems occupy an extremely important position in ensuring global food security. However, they have faced problems of low soil organic matter content and poor long-term soil sustainability. Biochar is regarded as a new means of soil remediation and a pathway of carbon sequestration that has improved the soil structure and function of ecosystems due to its complex physical and chemical properties. Since there are few reviews of biochar’s role in the carbon cycle of agricultural ecosystems, this article examines recent research about its influence on plant carbon assimilation, soil organic carbon mineralization and storage. We highlight the direct or potential effects of biochar on the relationships between plant root architecture and carbon storage, the soil priming effect and soil aggregation, to provide new perspectives on the study of its impacts on the carbon cycle and the implications for carbon management in dryland agriculture ecosystems.
Malicious Domain Name Detection Based on Doc2vec and Hybrid Network
Authors: Ma Donglin , Zhang Shuhuan , Kong Fanqi , Fu Zhaoyang
Published: March 2021

In traditional malicious domain name detection algorithms, machine learning detection methods take a long time to extract features and the extraction methods are more complex; deep learning detection methods are easy to lose the semantic features of the entire domain name, and the detection results of a single neural network for different sample data sets are unstable . In response to the above problems, a malicious domain name detection method based on Doc2vec and hybrid network was proposed, and a new DLR (Doc2vec-LSTM-RNN) detection model was constructed. The word vector is constructed using the Doc2vec algorithm optimized on the basis of the Word2vec algorithm, which retains the semantic information of the domain name as a whole; and mixes the bidirectional LSTM network and the bidirectional RNN network in series to carry out deep-level feature extraction and enhance the robustness of the detection model; finally the Softmax function is used to output the classification result. Experimental data shows that this method has excellent performance in malicious domain name detection. Compared with traditional machine learning and deep learning detection methods, it has higher detection accuracy.
Sketch-based 3D Shape Retrieval Using Similarity Weighting between Multi-View
Authors: Zheng Que , Jiang Junxian
Published: March 2021

3D shape retrieval has always been a hot research topic in the field of computer vision, and the research goal is to perform fast and efficient retrieval to obtain 3D shapes that meet user needs. With the rapid development and popularization of touch screen devices, hand-drawn sketches have undoubtedly become the most convenient and user-friendly input form. However, the huge difference between the 3D shape and the 2D sketch is the main challenge that affects retrieval performance. In this paper, we propose a method of adding a sketch and view feature similarity comparison module during the training process to obtain the scores for the final feature descriptors under the premise of feature extraction of the 3D shape based on multi-view. Specifically, we render the 3D shape into 2D views from multiple different perspectives to represent the shape. Perform feature extraction on two types of inputs through two different networks, and design a similarity weighting module to calculate the scores of each view, so as to obtain the final descriptors. Finally, a final descriptor similarity metric network is trained based on contrastive loss. The experimental results on SHREC’13 dataset demonstrate the superiority and robustness of our method.
High Accuracy Positioning for C-V2X
Authors: Liu Qi , Song Meng , Xv Xingrong , Qiu Jiahui
Published: March 2021

With the rapid development and popularization of 5G and C-V2X, services based on C-V2X are rapidly expanding. Specially, the positioning accuracy is the most basic requirement in V2X service. According to the different requirements for V2X use cases, the positioning accuracies are also different. So the positioning schemes are various according to the positioning requirements. This paper contains a study of requirements, architecture, key technologies and demonstrations in high accuracy positioning for V2X services. Combining the scene analysis and performance requirements, high accuracy positioning, as a key part of the whole C-V2X system, its architecture can be divided into device-centric positioning architecture and network-centric positioning architecture. In addition, we summarize the key technology for high accuracy positioning of vehicles and demonstrate the proposal through testing.
Mobile Edge Computing Based Video Surveillance System Using Special Hardware and Virtualization Technology
Authors: Liu Shaowei , Zhang Tingting , Cui Ningbo , Zhang Hao , Chen Jiayuan
Published: March 2021

As technology evolution, the solution for society security system is a hot research topic. Video surveillance is an important guarantee for society security. To meet various application scenarios, quick end-to-end (E2E) response is the key of video surveillance system. Mobile edge computing (MEC) could reduce E2E delivery delay by processing data nearby the data source. This paper introduces a MEC based solution that uses special hardware, graphics processing units (GPU), to accelerate graphic data processing. Taking the limited resource of edge scenario into consideration, virtualization technology is used to share computing resource on demand. The solution also proposes deployment policy basing on functional component’s requirement. Finally, this paper verifies the solution and puts forward recommendations.
Urban Elderly Community Micro-Renewal Planning and Design -A Case Study of Wuhan Anjing Community
Authors: Liu Fei , Xiong Xinru
Published: March 2021

This paper briefly introduces the general situation of wuhan Anjing community project, and analyzes the existing problems of this elderly community from the perspective of community planning and design on the basis of preliminary investigation. By means of low-impact transformation and micro-governance, this community is designed for transformation from the aspects of road traffic organization, transformation of main entrance and exit gates, micro-renewal of public space, etc. Through functional renewal, the vitality of the old community is explored, the overall environmental quality is improved, and reasonable suggestions are provided for its sustainable development.
Extraction of Urban Green Spaces Based on Gaofen-2 Satellite Imagery
Authors: Khan Babar , Yang Shuwen , Hong Weili , Yan Heng
Published: March 2021

Urban green space (UGS) plays indispensable role to maintain the ecological balance of a city. Remote sensing & GIS techniques can play vital role in the accurate estimation of the UGS. This study attempts at a new method of extracting the UGS from high resolution imagery data of Gaofen-2 satellite. The proposed method combines the strength of different transformation techniques i.e. KT transform, principal component analysis and NDVI in order to accurately map UGS. Different combinations were checked to classify the Gaofen-2 satellite imagery of Lanzhou city. The classified image was assessed for classification accuracy and it was observed that the overall accuracy was 89.78% with the kappa coefficient of 0.8125. It was observed that the proposed method can yield relatively high accuracy compared to the individual transformations such as NDVI thresholding.
Precursory Strong Signal of Abnormal Flood in Xi River and Characteristic Diagnosis of Extreme Value of Flood Water Level
Authors: Peng Duan , Zhang Yu , Xu Chunlin , Zhou Huadi , Liang Qianmin
Published: March 2021

The article uses the signal-to-noise ratio (SNR) method to identify the precursor strong signal of the atmospheric circulation in the early stage of the abnormal flood in the Xi River. And by using the equation derived from the Cross theory, the extreme frequency, duration and interval time of the flood water level of each stage of the Xi River are calculated. This study will help improve the accuracy of mid-and long-term prediction of abnormal floods in the Xi River Basin and provide a basis for government departments to make better water resources planning and flood prevention.
Reaction-limited graphene CVD surpasses silicon production rate
Authors: Chin Hao-Ting , Nguyen Hai-Thai , Chen Szu-Hua , Chen Yi-Fang , Chen Wei-Hung , Chou Zhi-Yang , Chu Yi-Hung , Yen Zhi-Long , Ting Chu-Chi , Hofmann Mario , Hsieh Ya-Ping
Published: March 2021

2D materials are considered enabling constituents in future large-scale electronics, but current production by chemical vapor deposition (CVD) proceeds at significantly lower rates than for traditional semiconductors and limits their usefulness in many envisioned applications. Analysis of previous research indicates that the current 2D materials production-scale is restricted by the low conversion efficiency between precursor and product. We here demonstrate the enhanced efficiency and speed of 2D materials growth by introducing a route to reach the reaction-controlled growth regime. Computational fluid-dynamics highlights the importance of gas-phase kinetics even in LPCVD growth and suggests that reaction-controlled growth can be achieved through optimization of the interaction between precursor and substrate. Applying this new restriction to graphene, growth rates were increased by ∼104 times and graphene synthesis proceeded without limitations from precursor supply even in atomic-scale pores. This advance enabled the synthesis of graphene at areas of several square-meters within 10 min using a research-grade 3″ furnace. The achieved conversion efficiency and production rate surpass existing growth methods by several orders of magnitude and extend 2D materials’ synthesis beyond silicon production capabilities, opening new routes for their application.
Hyperharmonic analysis for the study of high-order information-theoretic signals
Authors: Medina-Mardones Anibal M , Rosas Fernando E , Rodríguez Sebastián E , Cofré Rodrigo
Published: March 2021

Network representations often cannot fully account for the structural richness of complex systems spanning multiple levels of organisation. Recently proposed high-order information-theoretic signals are well-suited to capture synergistic phenomena that transcend pairwise interactions; however, the exponential-growth of their cardinality severely hinders their applicability. In this work, we combine methods from harmonic analysis and combinatorial topology to construct efficient representations of high-order information-theoretic signals. The core of our method is the diagonalisation of a discrete version of the Laplace–de Rham operator, that geometrically encodes structural properties of the system. We capitalise on these ideas by developing a complete workflow for the construction of hyperharmonic representations of high-order signals, which is applicable to a wide range of scenarios.
Gaming the beamlines—employing reinforcement learning to maximize scientific outcomes at large-scale user facilities
Authors: Maffettone Phillip M , Lynch Joshua K , Caswell Thomas A , Cook Clara E , Campbell Stuart I , Olds Daniel
Published: March 2021

Beamline experiments at central facilities are increasingly demanding of remote, high-throughput, and adaptive operation conditions. To accommodate such needs, new approaches must be developed that enable on-the-fly decision making for data intensive challenges. Reinforcement learning (RL) is a domain of AI that holds the potential to enable autonomous operations in a feedback loop between beamline experiments and trained agents. Here, we outline the advanced data acquisition and control software of the Bluesky suite, and demonstrate its functionality with a canonical RL problem: cartpole. We then extend these methods to efficient use of beamline resources by using RL to develop an optimal measurement strategy for samples with different scattering characteristics. The RL agents converge on the empirically optimal policy when under-constrained with time. When resource limited, the agents outperform a naive or sequential measurement strategy, often by a factor of 100%. We interface these methods directly with the data storage and provenance technologies at the National Synchrotron Light Source II, thus demonstrating the potential for RL to increase the scientific output of beamlines, and layout the framework for how to achieve this impact.
Plancherel theory for real spherical spaces: Construction of the Bernstein morphisms
Authors: Delorme Patrick , Knop Friedrich , Krötz Bernhard , Schlichtkrull Henrik
Published: March 2021

This paper lays the foundation for Plancherel theory on real spherical spacesZ=G/HZ=G/H, namely it provides the decomposition ofL2(Z)L^2(Z)into different series of representations via Bernstein morphisms. These series are parametrized by subsets of spherical roots which determine the fine geometry ofZZat infinity. In particular, we obtain a generalization of the Maass-Selberg relations. As a corollary we obtain a partial geometric characterization of the discrete spectrum:L2(Z)disc≠∅L^2(Z)_{\mathrm {disc}}\neq \emptysetifh⊥\mathfrak {h}^\perpcontains elliptic elements in its interior.

In caseZZis a real reductive group or, more generally, a symmetric space our results retrieve the Plancherel formula of Harish-Chandra (for the group) as well as that of Delorme and van den Ban-Schlichtkrull (for symmetric spaces) up to the explicit determination of the discrete series for the inducing datum.
An approximate approach to the structured distance to normality of Toeplitz operators
Authors: Bolourchian Elahe , Ahmadi Kakavandi Bijan
Published: March 2021

A classical theorem from Brown and Halmos asserts that a Toeplitz operator

T
(
f
)

T(f)

is normal if and only if the range of its generator

f
:

T

→

C

f:\mathbb {T}\rightarrow \mathbb {C}

is included in a straight line. In this paper, discretizing

f
(

T

)

f(\mathbb {T})

and using the Principal Component Analysis method to project it onto a ‘best’ line segment in

L
2

L^2

-norm, we propose a numerical method to find the nearest normal Toeplitz operator from

T
(
f
)

T(f)

in the norm
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="StartAbsoluteValue StartAbsoluteValue StartAbsoluteValue upper T left-parenthesis f right-parenthesis EndAbsoluteValue EndAbsoluteValue EndAbsoluteValue colon-equal double-vertical-bar f double-vertical-bar Subscript upper L squared left-parenthesis double-struck upper T right-parenthesis">

|

|

|
T
(
f
)
|

|

|

≔

‖
f

‖

L
2

(

T

)

{\left \vert \kern -0.25ex\left \vert \kern -0.25ex\left \vert T(f)\right \vert \kern -0.25ex\right \vert \kern -0.25ex\right \vert }\coloneq \Vert f \Vert _{L^2(\mathbb {T})}

which is weaker than the operator norm. Besides, we introduce an index for the distance from normality of Toeplitz operators which is invariant under the transformations

f
↦
a
f
+
b

f\mapsto a f+b

for all

a
∈

R

a\in \mathbb {R}

and

b
∈

C

b \in \mathbb {C}

with

a
≠
0

a\neq 0

.
Conservation laws in biology: Two new applications
Authors: Mussel Matan , Slemrod Marshall
Published: March 2021

This paper provides two new applications of conservation laws in biology. The first is the application of the van der Waals fluid formalism for action potentials. The second is the application of the conservation laws of differential geometry (Gauss–Codazzi equations) to produce non-smooth surfaces representing Endoplasmic Reticulum sheets.
American Immigration: A Very Short Introduction
Authors: Gerber David A.
Published: March 2021

American Immigration: A Very Short Introduction traces three massive waves of immigration from the mid-nineteenth century to the present, and analyzes the nature of immigration as a purposeful, structured activity, attitudes supporting or hostile to immigration, policies and laws regulating immigration, and the nature of and prospects for assimilation. There have been some dramatic developments since 2011, including the crisis along the southwestern border and the intense conflict over illegal immigration. The population of the United States has diverse sources: territorial acquisition through conquest and colonialism, the slave trade, and voluntary immigration. Many Americans value the memory of immigrant ancestors, and are sentimentally inclined to immigrant strivings. Alongside this sits the perception that immigration destabilizes social order, cultural coherence, job markets, and political alignments. The nearly 250 years of American nationhood has been characterized by both support for openness to immigration and embrace of a cosmopolitan formulation of American identity and for restrictions and assertions of belief in a core Anglo-American national character.
The contribution of functional traits to the understanding of palaeoenvironmental changes
Authors: Terray Léa , Stoetzel Emmanuelle , Herrel Anthony , Cornette Raphaël
Published: March 2021

Performance traits implicated in feeding interact directly with the environment and are consequently relevant ecological indicators. However, they have rarely been used to better understand palaeoenvironmental variation. Here, we evaluate the usefulness of a performance (i.e. functional) trait, estimated bite force, in reconstructing the palaeoecology of shrews. We investigate the relationships between mandible morphology, bite force estimates and the ecological context. We use geometric morphometrics to quantify mandible shape diversity in shrews of the archaeological site El Harhoura 2 (Rabat, Morocco), dated from the Late Pleistocene to the Holocene. Morphological groups were used instead of taxa as units of diversity. To explore how phenotypic traits are linked to their environment, they were compared with palaeoenvironmental inferences for the El Harhoura 2 site extracted from the literature. Morphological groups acted as phenotypic response units. Estimated bite force was related to palaeoenvironmental variation over the considered period, with a particular sensibility to arid/humid transitions. The complementarity of morphological and performance indicators allowed us to infer functional convergence and divergence among shrews. Our results suggest that functional traits may be relevant indicators of changes in palaeoenvironments. This approach opens up new possibilities to explore the impact of environmental changes on extinct organisms.
Blue Waters, Green Bottoms: Benthic Filamentous Algal Blooms Are an Emerging Threat to Clear Lakes Worldwide
Authors: Vadeboncoeur Yvonne , Moore Marianne V , Stewart Simon D , Chandra Sudeep , Atkins Karen S , Baron Jill S , Bouma-Gregson Keith , Brothers Soren , Francoeur Steven N , Genzoli Laurel , Higgins Scott N , Hilt Sabine , Katona Leon R , Kelly David , Oleksy Isabella A , Ozersky Ted , Power Mary E , Roberts Derek , Smits Adrianne P , Timoshkin Oleg , Tromboni Flavia , Zanden M Jake Vander , Volkova Ekaterina A , Waters Sean , Wood Susanna A , Yamamuro Masumi
Published: March 2021

Nearshore (littoral) habitats of clear lakes with high water quality are increasingly experiencing unexplained proliferations of filamentous algae that grow on submerged surfaces. These filamentous algal blooms (FABs) are sometimes associated with nutrient pollution in groundwater, but complex changes in climate, nutrient transport, lake hydrodynamics, and food web structure may also facilitate this emerging threat to clear lakes. A coordinated effort among members of the public, managers, and scientists is needed to document the occurrence of FABs, to standardize methods for measuring their severity, to adapt existing data collection networks to include nearshore habitats, and to mitigate and reverse this profound structural change in lake ecosystems. Current models of lake eutrophication do not explain this littoral greening. However, a cohesive response to it is essential for protecting some of the world's most valued lakes and the flora, fauna, and ecosystem services they sustain.