From the perspective of the development of world-class universities,internationalization is an essential strategic choice and external feature,and also an inevitable choice to improve the discourse power and competiti...From the perspective of the development of world-class universities,internationalization is an essential strategic choice and external feature,and also an inevitable choice to improve the discourse power and competitiveness of international higher education.In line with the national“double first-class”international development strategy of higher education,based on the cultivation of students’overall quality,the improvement of teachers’professional ability,and the development of school’s improvement of quality and efficiency,we School of Software,Northwestern Polytechnical University,explore new ideas and new measures for the cultivation of international software engineering talents,build a set of international teaching resources construction system,to form a reference standard and scheme for the cultivation of international software engineering talents.At present,we have achieved excellent results.展开更多
The vibratory roller is a piece of vital construction machinery in the field of road construction.The unmanned vibratory roller efficiently utilizes the automated driving technology in the vehicle engineering field,wh...The vibratory roller is a piece of vital construction machinery in the field of road construction.The unmanned vibratory roller efficiently utilizes the automated driving technology in the vehicle engineering field,which is innovative for the unmanned road construction.This paper develops and implements the autonomous construction system for the unmanned vibratory roller.Not only does the roller have the function of remote-controlled driving,but it also has the capability of autonomous road construction.The overall system design uses the Programmable Logic Controller(PLC)as the kernel controller.It establishes the communication network through multiple Input/Output(I/O)modules,Recommended Standard 232(RS232)serial port,Controller Area Network(CAN)bus,and wireless networks to control the roller vehicle completely.The locating information is obtained through the Global Navigation Satellite System(GNSS)satellite navigation equipment group to support the process of autonomous construction.According to the experimental results,the autonomous construction system can finally enable the roller to perform driving operations and construction independently,which was a significant step forward in engineering application.展开更多
Based on the field survey of dwellings in Tieqiong Village of Waerma Town in Aba County, northwest Tibetan area of Sichuan Province, this paper firstly introduced main characteristics of the construction system in the...Based on the field survey of dwellings in Tieqiong Village of Waerma Town in Aba County, northwest Tibetan area of Sichuan Province, this paper firstly introduced main characteristics of the construction system in the structure, materials and structural system, and analyzed changes in construction practices of various dwellings from traditional to modern time. Finally, it summarized characteristics of spontaneous evolution and research value of the construction system of dwellings in the northwest Tibetan area of Sichuan Province, with rammed earth wooden dwellings in upper and middle Aba areas as representatives.展开更多
Analyze the moral hazard issues in the construction agency system,and enumerate the performance of moral hazard.Deeply analyze the causes,start with strengthening supervision and perfecting incentive measures,eliminat...Analyze the moral hazard issues in the construction agency system,and enumerate the performance of moral hazard.Deeply analyze the causes,start with strengthening supervision and perfecting incentive measures,eliminate the impact of moral hazard,and give play to the advantages of agent construction.展开更多
Characterized by high consumption of natural resources and great generation of environmental impacts,civil construction becomes an important ally to the development of strategies for a more sustainable built environme...Characterized by high consumption of natural resources and great generation of environmental impacts,civil construction becomes an important ally to the development of strategies for a more sustainable built environment.In this context,this article aims to evaluate construction systems of social interest housing and point out their participation in relation to total impacts,in addition to indicating the environmental impacts embedded in the construction materials present in these systems.To this end,a case study was selected to apply Life Cycle Assessment(LCA)methodology and assess impacts of the building materials used in a house of a social housing complex.LCA was applied to masonry,roof,coatings and floor systems.The scope adopted assesses impacts incorporated in construction materials,analyzing the stages of raw material extraction,materials production,transport to construction site,maintenance and materials replacement.Concerning life cycle inventory,Ecoinvent 3.6 database was used and environmental impacts were calculated using CML method with the aid of OpenLCA 1.9 software.In general,results showed that the maintenance phase has the greatest environmental impact participation related to analyzed systems.Furthermore,it was possible to conclude that coatings and masonry systems were the ones that most added to total environmental impacts.展开更多
[Objectives]To explore the evolution of the legal system of farmland protection and explore the rules and characteristics of policy development based on the theory and logic of institutional change since China's r...[Objectives]To explore the evolution of the legal system of farmland protection and explore the rules and characteristics of policy development based on the theory and logic of institutional change since China's reform and opening up,reveal the problems and deep-seated reasons of its legislation,clarify the direction of farmland protection in the new period,and solve the"non-agricultural""non-grain"and ecological problems of farmland.[Methods]Literature analysis and inductive deduction methods were used.[Results]The evolution of the farmland protection legal system has gone through the process of"national consciousness-policy guidelines-institutional system",the change from"single subject to multiple subjects";change from the use of"one-way administrative means to coordinated use of administrative,economic and technical means".The practical problems of the farmland protection legal system are mainly due to the insufficient systematization of the farmland protection legal system itself,the generalization of quantity protection,the transformation of quality protection,and the absence of ecological protection.[Conclusions]It is recommended to improve the existing farmland protection legal system from the establishment of the Farmland Protection Law,the improvement of the farmland protection public participation mechanism and supervision mechanism,the establishment of the farmland quality construction and improvement system,the differentiated farmland occupation and supplementation balance system,and the ecological restoration system.展开更多
As a basic industry in Tibet Autonomous Region,the development of agriculture and animal husbandry circular economy is of great practical significance,which is actively reflected in national high-quality development a...As a basic industry in Tibet Autonomous Region,the development of agriculture and animal husbandry circular economy is of great practical significance,which is actively reflected in national high-quality development and new agriculture and animal husbandry circular model.The development direction and future trend directly determine the promotion and enhancement of regional agriculture and animal husbandry economy,which is highly valued and welcomed by academic circles.This paper mainly expounds the development connotation of agriculture and animal husbandry circular economy system from the perspective of Tibet's agriculture and animal husbandry economic development.It focuses on sorting out the construction and future direction of circular economy development system,effectively puts forward ideas and comprehensive understanding of the circular economy development system of agriculture and animal husbandry in Tibet,effectively promotes the promotion and basic change of circular economy of agriculture and animal husbandry,and effectively changes the traditional development model and new innovation model of agriculture and animal husbandry.展开更多
Whilst industrial robots have been widely used in many industrial sectors, they are predominantly used in a structured factory environment. In recent years, off-site robotics have been investigated extensively and the...Whilst industrial robots have been widely used in many industrial sectors, they are predominantly used in a structured factory environment. In recent years, off-site robotics have been investigated extensively and there are some promising candidates emerging. One such category of robots is exoskeleton robots and this paper provides an in-depth assessment of their suitability in assisting human operators in undertaking manual operations typically found in the construction industry. This work aims to objectively assess the advantages and disadvantages of these two suits and provide recommendations for further improvements of similar system designs. The paper focuses on the passive exoskeleton robotic suits which are commercially available. Three types of activities are designed and a mechatronic methodology has been designed and implemented to capture visual data in order to assess these systems in comparison with normal human operations. The study suggests that these passive suits do reduce the effort required by human operators to undertake the same construction tasks as evidenced by the results from one focused study, though a number of improvements could be made to improve their performance for wider adoption.展开更多
Identifying workers’construction activities or behaviors can enable managers to better monitor labor efficiency and construction progress.However,current activity analysis methods for construction workers rely solely...Identifying workers’construction activities or behaviors can enable managers to better monitor labor efficiency and construction progress.However,current activity analysis methods for construction workers rely solely on manual observations and recordings,which consumes considerable time and has high labor costs.Researchers have focused on monitoring on-site construction activities of workers.However,when multiple workers are working together,current research cannot accu rately and automatically identify the construction activity.This research proposes a deep learning framework for the automated analysis of the construction activities of multiple workers.In this framework,multiple deep neural network models are designed and used to complete worker key point extraction,worker tracking,and worker construction activity analysis.The designed framework was tested at an actual construction site,and activity recognition for multiple workers was performed,indicating the feasibility of the framework for the automated monitoring of work efficiency.展开更多
Extreme rainfall significantly threatens the safety of the landfill cover system,especially under humid climates.This study aims to provide design recommendations for a sustainable landfill cover system consisting of ...Extreme rainfall significantly threatens the safety of the landfill cover system,especially under humid climates.This study aims to provide design recommendations for a sustainable landfill cover system consisting of a low-permeability soil layer underlying a two-layer capillary barrier for humid climates.First,the numerical back-analysis was conducted for verification against a series of flume model tests.Then,a parametric study was performed to investigate the effects of inclination angle,particle size and layer thickness on the lateral diversion length(DL)of the three-layer cover system under the 100-year return period rainfall of humid climates.The results show that the water lateral DL of the cover system can be greatly enhanced by increasing the inclination angle from 3to 18.Moreover,the bottom layer of the cover system with a coarser d10 was more susceptible to the impact of the heavy rainfall,while this can be alleviated by increasing the thickness of the bottom layer.A dimensionless number,defined as the ratio of thickness and d10 of the bottom layer,is proposed for designing lateral diversion of the three-layer cover system under humid climates.To preserve the maximum DL,it is suggested that the proposed dimensionless number should be larger than 95 and 110 for the design of rainfall events with 50-year and 100-year return periods for humid climates,respectively.展开更多
Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capa...Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capacity.Based on panel data from 31 sample provinces,autonomous regions,and municipalities in China from 2005–2017,this study explored the impact of HSFC on grain yield using the difference-in-differences(DID)method.The results showed that HSFC significantly increased total grain production,which is robust to various checks.HSFC increased grain yield through three potential mechanisms.First,it could increase the grain replanting index.Second,it could effectively reduce yield loss due to droughts and floods.Last,HSFC could strengthen the cultivated land by renovating the low-and medium-yielding fields.Heterogeneity analysis found that the HSFC farmland showed a significant increase in grain yield only in the main grain-producing areas and balanced areas.In addition,HSFC significantly increased the yields of rice,wheat,and maize while leading to a reduction in soybean yields.The findings suggest the government should continue to promote HSFC,improve construction standards,and strictly control the“non-agriculturalization”and“non-coordination”of farmland to increase grain production further.At the same time,market mechanisms should be used to incentivize soybean farming,improve returns and stabilize soybean yields.展开更多
Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore structures.The interface friction behavior between mar...Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore structures.The interface friction behavior between marine clay and structural materials with different roughness was studied in this paper by using 3D optical scanning tests,a modified direct shear device and numerical simulation.Relationships between the surface roughness of structures,water content and interface friction angle were presented by model tests.The increase of water contents decreased the interface friction angles.For interfaces with different roughness,the interface friction angles will be smaller than that of the soil when the water content exceeds a certain value.The roughness of the interface and the water content of the soil are mutually coupled to influence the coefficient of friction(COF).This paper proposed a Finite Element Method(FEM)to simulate the interface direct shear tests of structures with different roughness.The surface models with different roughness are established based on the structure data obtained by 3D scanning.The Coupled Eulerian-Lagrangian(CEL)approach was employed to analyse soils sheared by irregular surfaces.The interface behavior for interfaces with different roughness under cyclic shear stresses was analyzed by FEM.展开更多
This research is concentrated on the longitudinal vibration of a tapered pipe pile considering the vertical support of the surrounding soil and construction disturbance.First,the pile-soil system is partitioned into f...This research is concentrated on the longitudinal vibration of a tapered pipe pile considering the vertical support of the surrounding soil and construction disturbance.First,the pile-soil system is partitioned into finite segments in the vertical direction and the Voigt model is applied to simulate the vertical support of the surrounding soil acting on the pile segment.The surrounding soil is divided into finite ring-shaped zones in the radial direction to consider the construction disturbance.Then,the shear complex stiffness at the pile-soil interface is derived by solving the dynamic equilibrium equation for the soil from the outermost to innermost zone.The displacement impedance at the top of an arbitrary pile segment is obtained by solving the dynamic equilibrium equation for the pile and is combined with the vertical support of the surrounding soil to derive the displacement impedance at the bottom of the upper adjacent segment.Further,the displacement impedance at the pile head is obtained based on the impedance function transfer technique.Finally,the reliability of the proposed solution is verified,followed by a sensitivity analysis concerning the coupling effect of the pile parameters,construction disturbance and the vertical support of the surrounding soil on the displacement impedance of the pile.展开更多
With the rapid development of electric power systems,load estimation plays an important role in system operation and planning.Usually,load estimation techniques contain traditional,time series,regression analysis-base...With the rapid development of electric power systems,load estimation plays an important role in system operation and planning.Usually,load estimation techniques contain traditional,time series,regression analysis-based,and machine learning-based estimation.Since the machine learning-based method can lead to better performance,in this paper,a deep learning-based load estimation algorithm using image fingerprint and attention mechanism is proposed.First,an image fingerprint construction is proposed for training data.After the data preprocessing,the training data matrix is constructed by the cyclic shift and cubic spline interpolation.Then,the linear mapping and the gray-color transformation method are proposed to form the color image fingerprint.Second,a convolutional neural network(CNN)combined with an attentionmechanism is proposed for training performance improvement.At last,an experiment is carried out to evaluate the estimation performance.Compared with the support vector machine method,CNN method and long short-term memory method,the proposed algorithm has the best load estimation performance.展开更多
Constructed wetlands(CwW)are well known nature-based systems for water treatment.This study evaluated the efficiency and effectiveness of seven domestic wastewater treatment systems based on horizontal flow CWs in Jar...Constructed wetlands(CwW)are well known nature-based systems for water treatment.This study evaluated the efficiency and effectiveness of seven domestic wastewater treatment systems based on horizontal flow CWs in Jarabacoa,the Dominican Republic.The results showed that the CWs were efficient in reducing the degree of contamination of wastewater to levels below the Dominican wastewater discharge standards for parameters such as the 5-day biochemical oxygen demand(BOD5)and chemical oxygen demand,but not for the removal of phosphorus and fecal coliforms.In addition,a horizontal flow subsurface wetland in the peri-urban area El Dorado was evaluated in terms of the performance of wastewater treatment in tropical climatic conditions.The concentrations of heavy metals,such as zinc,copper,chromium,and iron,were found to decrease in the effluent of the wetland,and the concentrations for nickel and manganese tended to increase.The levels of heavy metals in the effluent were lower than the limit values of the Dominican wastewater discharge standards.The construction cost of these facilities was around 200 USD per population equivalent,similar to the cost in other countries in the same region.This study suggested some solutions to the improved performance of CWs:selection of a microbial flora that guarantees the reduction of nitrates and nitrites to molecular nitrogen,use of endemic plants that bioaccumulate heavy metals,combination of constructed wetlands with filtration on activated carbon,and inclusion of water purification processes that allow to evaluate the reuse of treated water.展开更多
This paper constructs a multiple collaborative service model of industrial competition intelligence with the main purpose of promoting the development of regional industries. The multiple service subjects include ente...This paper constructs a multiple collaborative service model of industrial competition intelligence with the main purpose of promoting the development of regional industries. The multiple service subjects include enterprises, governments, colleges and universities, scientific research institutes, industry associations and for-profit institutions. This article starts from the overall development of regional industrial economy, weighs the mutual relationship between the elements of the service model, and promotes multiple service subjects such as enterprises, governments, universities, research institutes, industry associations, and profit-making organizations to realize the collaborative service of resource intelligence, demand intelligence and data intelligence provides linkage intelligence service for the development and innovation of regional industries. This service model can improve the efficiency of industrial competitive intelligence services and the overall competitiveness of regional industries.展开更多
Automatic control technology is the basis of road robot improvement,according to the characteristics of construction equipment and functions,the research will be input type perception from positioning acquisition,real...Automatic control technology is the basis of road robot improvement,according to the characteristics of construction equipment and functions,the research will be input type perception from positioning acquisition,real-world monitoring,the process will use RTK-GNSS positional perception technology,by projecting the left side of the earth from Gauss-Krueger projection method,and then carry out the Cartesian conversion based on the characteristics of drawing;steering control system is the core of the electric drive unmanned module,on the basis of the analysis of the composition of the steering system of unmanned engineering vehicles,the steering system key components such as direction,torque sensor,drive motor and other models are established,the joint simulation model of unmanned engineering vehicles is established,the steering controller is designed using the PID method,the simulation results show that the control method can meet the construction path demand for automatic steering.The path planning will first formulate the construction area with preset values and realize the steering angle correction during driving by PID algorithm,and never realize the construction-based path planning,and the results show that the method can control the straight path within the error of 10 cm and the curve error within 20 cm.With the collaboration of various modules,the automatic construction simulation results of this robot show that the design path and control method is effective.展开更多
According to constitutional jurisprudence in China,Article 51 of the Constitution is an unenumerated restrictive clause.Such theoretical construction fails to justify the differentiated restrictions established in the...According to constitutional jurisprudence in China,Article 51 of the Constitution is an unenumerated restrictive clause.Such theoretical construction fails to justify the differentiated restrictions established in the Constitution and makes it difficult to explain the constitutional status of human dignity. Article 51 implies the possibility of other theoretical constructions. It is not an unenumerated restriction clause but an unenumerated rights clause. It aims to provide guarantees for general freedom of action not enumerated in the Constitution rather than restricting fundamental rights. The actual benefit of this kind of theoretical construction lies in that it can establish the basis of the constitutional text for general freedom of action and promote the people’s correct understanding of the model of restriction on fundamental rights established by the Constitution of PRC.展开更多
The high-quality development of the construction industry fundamentally stems from the significant improvement of total factor productivity.Therefore,it is of crucial significance for promoting the development of the ...The high-quality development of the construction industry fundamentally stems from the significant improvement of total factor productivity.Therefore,it is of crucial significance for promoting the development of the construction industry to a higher level by scientifically and accurately measuring the total factor productivity of the construction industry and deeply analyzing the influencing factors behind it.Based on a comprehensive consideration of research methods and influencing factors,this paper systematically reviews the existing relevant literature on total factor productivity in the construction industry,aiming to reveal the current research development trend in this field and point out potential problems.This effort aims to provide a solid theoretical foundation and valuable reference for further in-depth research,and jointly promote the continuous progress and development of total factor productivity research in the construction industry.展开更多
The continuous progress of urbanization has driven the continuous development and innovation of landscape planning and design.Focused on the important design method of modern construction art,this study analyzed its c...The continuous progress of urbanization has driven the continuous development and innovation of landscape planning and design.Focused on the important design method of modern construction art,this study analyzed its concepts and characteristics,and made deep exploration to its application in landscape planning and design.The results indicated that modern construction art had a significant impact on landscape spatial planning and layout,spatial design forms,and spatial ornaments.The use of modern construction art concepts could make landscape design more scientific,artistic,and humane,creating higher quality leisure and entertainment venues for audiences.展开更多
文摘From the perspective of the development of world-class universities,internationalization is an essential strategic choice and external feature,and also an inevitable choice to improve the discourse power and competitiveness of international higher education.In line with the national“double first-class”international development strategy of higher education,based on the cultivation of students’overall quality,the improvement of teachers’professional ability,and the development of school’s improvement of quality and efficiency,we School of Software,Northwestern Polytechnical University,explore new ideas and new measures for the cultivation of international software engineering talents,build a set of international teaching resources construction system,to form a reference standard and scheme for the cultivation of international software engineering talents.At present,we have achieved excellent results.
基金This work was supported by the Natural Science Foundation of Jiangsu Province(BK20170681,BK20180701)the National Natural Science Foundation of China(51675281).
文摘The vibratory roller is a piece of vital construction machinery in the field of road construction.The unmanned vibratory roller efficiently utilizes the automated driving technology in the vehicle engineering field,which is innovative for the unmanned road construction.This paper develops and implements the autonomous construction system for the unmanned vibratory roller.Not only does the roller have the function of remote-controlled driving,but it also has the capability of autonomous road construction.The overall system design uses the Programmable Logic Controller(PLC)as the kernel controller.It establishes the communication network through multiple Input/Output(I/O)modules,Recommended Standard 232(RS232)serial port,Controller Area Network(CAN)bus,and wireless networks to control the roller vehicle completely.The locating information is obtained through the Global Navigation Satellite System(GNSS)satellite navigation equipment group to support the process of autonomous construction.According to the experimental results,the autonomous construction system can finally enable the roller to perform driving operations and construction independently,which was a significant step forward in engineering application.
基金Supported by the Open Research Subject of Research Base of Local Culture Protection and Development Research Center(15DFWH016)Research Base of Sichuan Rural Development Research Center(CR1512)Research Base of Sichuan Province Multi-cultural Research Center(DYWH1507)
文摘Based on the field survey of dwellings in Tieqiong Village of Waerma Town in Aba County, northwest Tibetan area of Sichuan Province, this paper firstly introduced main characteristics of the construction system in the structure, materials and structural system, and analyzed changes in construction practices of various dwellings from traditional to modern time. Finally, it summarized characteristics of spontaneous evolution and research value of the construction system of dwellings in the northwest Tibetan area of Sichuan Province, with rammed earth wooden dwellings in upper and middle Aba areas as representatives.
文摘Analyze the moral hazard issues in the construction agency system,and enumerate the performance of moral hazard.Deeply analyze the causes,start with strengthening supervision and perfecting incentive measures,eliminate the impact of moral hazard,and give play to the advantages of agent construction.
文摘Characterized by high consumption of natural resources and great generation of environmental impacts,civil construction becomes an important ally to the development of strategies for a more sustainable built environment.In this context,this article aims to evaluate construction systems of social interest housing and point out their participation in relation to total impacts,in addition to indicating the environmental impacts embedded in the construction materials present in these systems.To this end,a case study was selected to apply Life Cycle Assessment(LCA)methodology and assess impacts of the building materials used in a house of a social housing complex.LCA was applied to masonry,roof,coatings and floor systems.The scope adopted assesses impacts incorporated in construction materials,analyzing the stages of raw material extraction,materials production,transport to construction site,maintenance and materials replacement.Concerning life cycle inventory,Ecoinvent 3.6 database was used and environmental impacts were calculated using CML method with the aid of OpenLCA 1.9 software.In general,results showed that the maintenance phase has the greatest environmental impact participation related to analyzed systems.Furthermore,it was possible to conclude that coatings and masonry systems were the ones that most added to total environmental impacts.
基金Supported by National Natural Science Foundation of China(41771565).
文摘[Objectives]To explore the evolution of the legal system of farmland protection and explore the rules and characteristics of policy development based on the theory and logic of institutional change since China's reform and opening up,reveal the problems and deep-seated reasons of its legislation,clarify the direction of farmland protection in the new period,and solve the"non-agricultural""non-grain"and ecological problems of farmland.[Methods]Literature analysis and inductive deduction methods were used.[Results]The evolution of the farmland protection legal system has gone through the process of"national consciousness-policy guidelines-institutional system",the change from"single subject to multiple subjects";change from the use of"one-way administrative means to coordinated use of administrative,economic and technical means".The practical problems of the farmland protection legal system are mainly due to the insufficient systematization of the farmland protection legal system itself,the generalization of quantity protection,the transformation of quality protection,and the absence of ecological protection.[Conclusions]It is recommended to improve the existing farmland protection legal system from the establishment of the Farmland Protection Law,the improvement of the farmland protection public participation mechanism and supervision mechanism,the establishment of the farmland quality construction and improvement system,the differentiated farmland occupation and supplementation balance system,and the ecological restoration system.
基金Supported by Open Fund Project of Key Laboratory for the Development and Utilization of Rural Renewable Energy of Ministry of Agriculture and Rural Areas(2017015).
文摘As a basic industry in Tibet Autonomous Region,the development of agriculture and animal husbandry circular economy is of great practical significance,which is actively reflected in national high-quality development and new agriculture and animal husbandry circular model.The development direction and future trend directly determine the promotion and enhancement of regional agriculture and animal husbandry economy,which is highly valued and welcomed by academic circles.This paper mainly expounds the development connotation of agriculture and animal husbandry circular economy system from the perspective of Tibet's agriculture and animal husbandry economic development.It focuses on sorting out the construction and future direction of circular economy development system,effectively puts forward ideas and comprehensive understanding of the circular economy development system of agriculture and animal husbandry in Tibet,effectively promotes the promotion and basic change of circular economy of agriculture and animal husbandry,and effectively changes the traditional development model and new innovation model of agriculture and animal husbandry.
文摘Whilst industrial robots have been widely used in many industrial sectors, they are predominantly used in a structured factory environment. In recent years, off-site robotics have been investigated extensively and there are some promising candidates emerging. One such category of robots is exoskeleton robots and this paper provides an in-depth assessment of their suitability in assisting human operators in undertaking manual operations typically found in the construction industry. This work aims to objectively assess the advantages and disadvantages of these two suits and provide recommendations for further improvements of similar system designs. The paper focuses on the passive exoskeleton robotic suits which are commercially available. Three types of activities are designed and a mechatronic methodology has been designed and implemented to capture visual data in order to assess these systems in comparison with normal human operations. The study suggests that these passive suits do reduce the effort required by human operators to undertake the same construction tasks as evidenced by the results from one focused study, though a number of improvements could be made to improve their performance for wider adoption.
基金supported by the National Natural Science Foundation of China(52130801,U20A20312,52178271,and 52077213)the National Key Research and Development Program of China(2021YFF0500903)。
文摘Identifying workers’construction activities or behaviors can enable managers to better monitor labor efficiency and construction progress.However,current activity analysis methods for construction workers rely solely on manual observations and recordings,which consumes considerable time and has high labor costs.Researchers have focused on monitoring on-site construction activities of workers.However,when multiple workers are working together,current research cannot accu rately and automatically identify the construction activity.This research proposes a deep learning framework for the automated analysis of the construction activities of multiple workers.In this framework,multiple deep neural network models are designed and used to complete worker key point extraction,worker tracking,and worker construction activity analysis.The designed framework was tested at an actual construction site,and activity recognition for multiple workers was performed,indicating the feasibility of the framework for the automated monitoring of work efficiency.
基金the financial sponsorship from the National Natural Science Foundation of China(Grant No.U20A20320)the area of excellence project(Grant No.AoE/E-603/18)provided by the Research Grants Council of HKSAR and Shenzhen Science and Technology Program(Grant No.KCXFZ20211020163816023).
文摘Extreme rainfall significantly threatens the safety of the landfill cover system,especially under humid climates.This study aims to provide design recommendations for a sustainable landfill cover system consisting of a low-permeability soil layer underlying a two-layer capillary barrier for humid climates.First,the numerical back-analysis was conducted for verification against a series of flume model tests.Then,a parametric study was performed to investigate the effects of inclination angle,particle size and layer thickness on the lateral diversion length(DL)of the three-layer cover system under the 100-year return period rainfall of humid climates.The results show that the water lateral DL of the cover system can be greatly enhanced by increasing the inclination angle from 3to 18.Moreover,the bottom layer of the cover system with a coarser d10 was more susceptible to the impact of the heavy rainfall,while this can be alleviated by increasing the thickness of the bottom layer.A dimensionless number,defined as the ratio of thickness and d10 of the bottom layer,is proposed for designing lateral diversion of the three-layer cover system under humid climates.To preserve the maximum DL,it is suggested that the proposed dimensionless number should be larger than 95 and 110 for the design of rainfall events with 50-year and 100-year return periods for humid climates,respectively.
基金supported by the National Natural Science Foundation of China(41871184)the National Social Science Fund of China(21ZDA056)the Scientific and Technological Innovation Project of the Chinese Academy of Agricultural Sciences(10-IAED-ZT-01-2023and 10-IAED-RC-07-2023)。
文摘Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capacity.Based on panel data from 31 sample provinces,autonomous regions,and municipalities in China from 2005–2017,this study explored the impact of HSFC on grain yield using the difference-in-differences(DID)method.The results showed that HSFC significantly increased total grain production,which is robust to various checks.HSFC increased grain yield through three potential mechanisms.First,it could increase the grain replanting index.Second,it could effectively reduce yield loss due to droughts and floods.Last,HSFC could strengthen the cultivated land by renovating the low-and medium-yielding fields.Heterogeneity analysis found that the HSFC farmland showed a significant increase in grain yield only in the main grain-producing areas and balanced areas.In addition,HSFC significantly increased the yields of rice,wheat,and maize while leading to a reduction in soybean yields.The findings suggest the government should continue to promote HSFC,improve construction standards,and strictly control the“non-agriculturalization”and“non-coordination”of farmland to increase grain production further.At the same time,market mechanisms should be used to incentivize soybean farming,improve returns and stabilize soybean yields.
基金supported by a grant from the National Natural Science Foundations of China(No.52171282)supported by Taishan Scholars Program of Shandong Province,China(No.tsqn202306098)the Shandong Provincial Key Research and Development Plan,China(No.2021ZLGX04).
文摘Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore structures.The interface friction behavior between marine clay and structural materials with different roughness was studied in this paper by using 3D optical scanning tests,a modified direct shear device and numerical simulation.Relationships between the surface roughness of structures,water content and interface friction angle were presented by model tests.The increase of water contents decreased the interface friction angles.For interfaces with different roughness,the interface friction angles will be smaller than that of the soil when the water content exceeds a certain value.The roughness of the interface and the water content of the soil are mutually coupled to influence the coefficient of friction(COF).This paper proposed a Finite Element Method(FEM)to simulate the interface direct shear tests of structures with different roughness.The surface models with different roughness are established based on the structure data obtained by 3D scanning.The Coupled Eulerian-Lagrangian(CEL)approach was employed to analyse soils sheared by irregular surfaces.The interface behavior for interfaces with different roughness under cyclic shear stresses was analyzed by FEM.
基金National Natural Science Foundation of China under Grand No.51808190the Central Government Guides Local Science and Technology Development Fund Projects under Grand No.XZ202301YD0019C+2 种基金the Foundation of Key Laboratory of Soft Soils and Geoenvironmental Engineering(Zhejiang University)Ministry of Education under Grand No.2022P04the Central University Basic Research Fund of China under Grand No.B220202017。
文摘This research is concentrated on the longitudinal vibration of a tapered pipe pile considering the vertical support of the surrounding soil and construction disturbance.First,the pile-soil system is partitioned into finite segments in the vertical direction and the Voigt model is applied to simulate the vertical support of the surrounding soil acting on the pile segment.The surrounding soil is divided into finite ring-shaped zones in the radial direction to consider the construction disturbance.Then,the shear complex stiffness at the pile-soil interface is derived by solving the dynamic equilibrium equation for the soil from the outermost to innermost zone.The displacement impedance at the top of an arbitrary pile segment is obtained by solving the dynamic equilibrium equation for the pile and is combined with the vertical support of the surrounding soil to derive the displacement impedance at the bottom of the upper adjacent segment.Further,the displacement impedance at the pile head is obtained based on the impedance function transfer technique.Finally,the reliability of the proposed solution is verified,followed by a sensitivity analysis concerning the coupling effect of the pile parameters,construction disturbance and the vertical support of the surrounding soil on the displacement impedance of the pile.
文摘With the rapid development of electric power systems,load estimation plays an important role in system operation and planning.Usually,load estimation techniques contain traditional,time series,regression analysis-based,and machine learning-based estimation.Since the machine learning-based method can lead to better performance,in this paper,a deep learning-based load estimation algorithm using image fingerprint and attention mechanism is proposed.First,an image fingerprint construction is proposed for training data.After the data preprocessing,the training data matrix is constructed by the cyclic shift and cubic spline interpolation.Then,the linear mapping and the gray-color transformation method are proposed to form the color image fingerprint.Second,a convolutional neural network(CNN)combined with an attentionmechanism is proposed for training performance improvement.At last,an experiment is carried out to evaluate the estimation performance.Compared with the support vector machine method,CNN method and long short-term memory method,the proposed algorithm has the best load estimation performance.
基金support of the Yaque del Norte Water Fund(FAYN),INTEC(Grant No.CBA-330810-2020-P-1)Fondo Dominicano de Ciencia y Tecnologia(FONDOCYT)(Grant No.2022-2B2-161)。
文摘Constructed wetlands(CwW)are well known nature-based systems for water treatment.This study evaluated the efficiency and effectiveness of seven domestic wastewater treatment systems based on horizontal flow CWs in Jarabacoa,the Dominican Republic.The results showed that the CWs were efficient in reducing the degree of contamination of wastewater to levels below the Dominican wastewater discharge standards for parameters such as the 5-day biochemical oxygen demand(BOD5)and chemical oxygen demand,but not for the removal of phosphorus and fecal coliforms.In addition,a horizontal flow subsurface wetland in the peri-urban area El Dorado was evaluated in terms of the performance of wastewater treatment in tropical climatic conditions.The concentrations of heavy metals,such as zinc,copper,chromium,and iron,were found to decrease in the effluent of the wetland,and the concentrations for nickel and manganese tended to increase.The levels of heavy metals in the effluent were lower than the limit values of the Dominican wastewater discharge standards.The construction cost of these facilities was around 200 USD per population equivalent,similar to the cost in other countries in the same region.This study suggested some solutions to the improved performance of CWs:selection of a microbial flora that guarantees the reduction of nitrates and nitrites to molecular nitrogen,use of endemic plants that bioaccumulate heavy metals,combination of constructed wetlands with filtration on activated carbon,and inclusion of water purification processes that allow to evaluate the reuse of treated water.
文摘This paper constructs a multiple collaborative service model of industrial competition intelligence with the main purpose of promoting the development of regional industries. The multiple service subjects include enterprises, governments, colleges and universities, scientific research institutes, industry associations and for-profit institutions. This article starts from the overall development of regional industrial economy, weighs the mutual relationship between the elements of the service model, and promotes multiple service subjects such as enterprises, governments, universities, research institutes, industry associations, and profit-making organizations to realize the collaborative service of resource intelligence, demand intelligence and data intelligence provides linkage intelligence service for the development and innovation of regional industries. This service model can improve the efficiency of industrial competitive intelligence services and the overall competitiveness of regional industries.
文摘Automatic control technology is the basis of road robot improvement,according to the characteristics of construction equipment and functions,the research will be input type perception from positioning acquisition,real-world monitoring,the process will use RTK-GNSS positional perception technology,by projecting the left side of the earth from Gauss-Krueger projection method,and then carry out the Cartesian conversion based on the characteristics of drawing;steering control system is the core of the electric drive unmanned module,on the basis of the analysis of the composition of the steering system of unmanned engineering vehicles,the steering system key components such as direction,torque sensor,drive motor and other models are established,the joint simulation model of unmanned engineering vehicles is established,the steering controller is designed using the PID method,the simulation results show that the control method can meet the construction path demand for automatic steering.The path planning will first formulate the construction area with preset values and realize the steering angle correction during driving by PID algorithm,and never realize the construction-based path planning,and the results show that the method can control the straight path within the error of 10 cm and the curve error within 20 cm.With the collaboration of various modules,the automatic construction simulation results of this robot show that the design path and control method is effective.
基金a phased achievement of Constitutional Interpretation in Line with Law and Its Practical Research,a General Project of Humanities and Social Sciences Research of the Ministry of Education for 2019 (Approval No. 19YJA820008)。
文摘According to constitutional jurisprudence in China,Article 51 of the Constitution is an unenumerated restrictive clause.Such theoretical construction fails to justify the differentiated restrictions established in the Constitution and makes it difficult to explain the constitutional status of human dignity. Article 51 implies the possibility of other theoretical constructions. It is not an unenumerated restriction clause but an unenumerated rights clause. It aims to provide guarantees for general freedom of action not enumerated in the Constitution rather than restricting fundamental rights. The actual benefit of this kind of theoretical construction lies in that it can establish the basis of the constitutional text for general freedom of action and promote the people’s correct understanding of the model of restriction on fundamental rights established by the Constitution of PRC.
基金Supported by School-level Natural Science Project of Jiangxi University of Technology(232ZRYB02).
文摘The high-quality development of the construction industry fundamentally stems from the significant improvement of total factor productivity.Therefore,it is of crucial significance for promoting the development of the construction industry to a higher level by scientifically and accurately measuring the total factor productivity of the construction industry and deeply analyzing the influencing factors behind it.Based on a comprehensive consideration of research methods and influencing factors,this paper systematically reviews the existing relevant literature on total factor productivity in the construction industry,aiming to reveal the current research development trend in this field and point out potential problems.This effort aims to provide a solid theoretical foundation and valuable reference for further in-depth research,and jointly promote the continuous progress and development of total factor productivity research in the construction industry.
基金Sponsored by Germplasm Collection and Conservation Project for the Forest and Grass Germplasm Resources in Anhui Province in 2024(hxkt2024111)Science and Technology Plan Project of Huangshan(2022KN-02)+1 种基金Humanities and Social Sciences Research Project of Anhui Higher Education Institutions(SKHS2019B07)Key School-level Project of Huangshan University(2022xkjzd004).
文摘The continuous progress of urbanization has driven the continuous development and innovation of landscape planning and design.Focused on the important design method of modern construction art,this study analyzed its concepts and characteristics,and made deep exploration to its application in landscape planning and design.The results indicated that modern construction art had a significant impact on landscape spatial planning and layout,spatial design forms,and spatial ornaments.The use of modern construction art concepts could make landscape design more scientific,artistic,and humane,creating higher quality leisure and entertainment venues for audiences.