In tomographic statics seismic data processing, it 1s crucial to cletermme an optimum base for a near-surface model. In this paper, we consider near-surface model base determination as a global optimum problem. Given ...In tomographic statics seismic data processing, it 1s crucial to cletermme an optimum base for a near-surface model. In this paper, we consider near-surface model base determination as a global optimum problem. Given information from uphole shooting and the first-arrival times from a surface seismic survey, we present a near-surface velocity model construction method based on a Monte-Carlo sampling scheme using a layered equivalent medium assumption. Compared with traditional least-squares first-arrival tomography, this scheme can delineate a clearer, weathering-layer base, resulting in a better implementation of damming correction. Examples using synthetic and field data are used to demonstrate the effectiveness of the proposed scheme.展开更多
Geometric model construction is the basis of infrared image theory simulation. Taking the construction of the geometric model of one building in Harbin as an example, this paper analyzes the theoretical groundings of ...Geometric model construction is the basis of infrared image theory simulation. Taking the construction of the geometric model of one building in Harbin as an example, this paper analyzes the theoretical groundings of simplification and principles of geometric model construction of buildings. It then discusses some particular treatment methods in calculating the radiation transfer coefficient in geometric model construction using the Monte Carlo Method.展开更多
The acquisition of digital regional-scale information and ecological environmental data has high requirements for structural texture,spatial res-olution,and multiple parameter categories,which is challenging to achiev...The acquisition of digital regional-scale information and ecological environmental data has high requirements for structural texture,spatial res-olution,and multiple parameter categories,which is challenging to achieve using satellite remote sensing.Considering the convenient,facilitative,and flexible characteristics of UAV(unmanned air vehicle)remote sensing tech-nology,this study selects a campus as a typical research area and uses the Pegasus D2000 equipped with a D-MSPC2000 multi-spectral camera and a CAM3000 aerial camera to acquire oblique images and multi-spectral data.Using professional software,including Context Capture,ENVI,and ArcGIS,a 3D(three-dimensional)campus model,a digital orthophoto map,and multi-spectral remote sensing map drawing are realized,and the geometric accuracy of typical feature selection is evaluated.Based on a quantitative remote sensing model,the campus ecological environment assessment is performed from the perspectives of vegetation and water body.The results presented in this study could be of great significance to the scientific management and sustainable development of regional natural resources.展开更多
In order to support enterprise integration, a kind of model construct based enterprise model architecture and its modeling approach are studied in this paper. First, the structural makeup and internal relationships of...In order to support enterprise integration, a kind of model construct based enterprise model architecture and its modeling approach are studied in this paper. First, the structural makeup and internal relationships of enterprise model architecture are discussed. Then, the concept of reusable model construct (MC) which belongs to the control view and can help to derive other views is proposed. The modeling approach based on model construct consists of three steps, reference model architecture synthesis, enterprise model customization, system design and implementation. According to MC based modeling approach a case study with the background of one-kind-product machinery manufacturing enterprises is illustrated. It is shown that proposal model construct based enterprise model architecture and modeling approach are practical and efficient.展开更多
In regard to knowledge economy,the current concept in the model construction of online education,including distance education and online learning,generally refers to a kind of network-based learning behavior,similar t...In regard to knowledge economy,the current concept in the model construction of online education,including distance education and online learning,generally refers to a kind of network-based learning behavior,similar to the concept of online training.Compared with traditional offline education methods,through the application of information technology and internet technology for content dissemination and rapid learning,online education has the characteristics of high efficiency,convenience,low threshold,and rich teaching resources.Online education covers a wide range of people,different forms of learning,and its classification methods are more diverse.Online education services are the fastest growing field of education informatization.At the moment,the most pressing problems include effectively integrating educational resources with internet technology,launching online education services and products that are highly interactive and would encourage personalized learning,increasing user stickiness,as well as avoiding trend-following and conceptualized investment.展开更多
Against the backdrop of continuous social development and growing public health demands,the efficiency and scientific nature of the emergency care system are of paramount importance.This paper focuses on researching t...Against the backdrop of continuous social development and growing public health demands,the efficiency and scientific nature of the emergency care system are of paramount importance.This paper focuses on researching the construction of an emergency care system based on the concept of“linkage”,delving into its theoretical foundations,exploring innovative construction models,and analyzing practical cases.The study indicates that an emergency care system under the“linkage”concept can effectively integrate resources and enhance efficiency,providing new insights for improving the construction of the emergency care system.It aims to promote the development of the emergency care system towards a more scientific,efficient,and collaborative direction.展开更多
Objective:To address the prediction of hemorrhagic transformation(HT)after rt-PA thrombolysis in acute cerebral infarction(ACI)patients,a predictive model integrating data engineering,algorithm optimization,and modula...Objective:To address the prediction of hemorrhagic transformation(HT)after rt-PA thrombolysis in acute cerebral infarction(ACI)patients,a predictive model integrating data engineering,algorithm optimization,and modularity was constructed.This model resolves the technical limitation of traditional clinical statistical models that overemphasize analysis while neglecting deployment readiness,thereby providing a reusable technical solution for the implementation of medical risk prediction systems.Methods:A standardized dataset was built using data from 300 ACI patients who underwent rt-PA thrombolysis.Automated data cleaning,outlier correction,and feature engineering optimization(recursive feature elimination+variance inflation factor test)were applied to select core features.An L2-regularized logistic regression algorithm was employed to construct the prediction model,which was visualized via a nomogram.Multi-dimensional performance validation was conducted through cross-validation and probability calibration techniques.Results:The incidence of HT was20.0%.Multivariate analysis identified NIHSS score(OR=1.626),blood glucose(OR=1.662),platelet count(OR=0.975),age(OR=1.091),and history of diabetes(OR=0.343)as core predictors(P<0.05).Engineering validation demonstrated excellent discrimination(AUC=0.800,95%CI:0.752-0.856).After optimization with Platt scaling,the calibration curve was highly consistent with the actual probability,with a Brier score of0.092.The prediction time per sample was<50 ms,and the convergence efficiency of model training was improved by 30%.Conclusion:This model integrates core technologies including data preprocessing,feature optimization,and algorithm improvement,exhibiting low-latency,high stability,and deployability.It provides a standardized technical framework for transforming medical prediction models from statistical conclusions into engineered products.展开更多
New energy-storage systems play a pivotal role in the development of the new power system for advancing the energy transition in China.In the“14th Five-Year Plan”for the New Energy-Storage Development,it is proposed...New energy-storage systems play a pivotal role in the development of the new power system for advancing the energy transition in China.In the“14th Five-Year Plan”for the New Energy-Storage Development,it is proposed to expand investment and construction models by promoting the deployment of energy-storage facilities through the ways of self-construction,leasing,and purchasing,and to encourage the development of the shared energy-storage.However,the current scarcity in the model of the shared energy-storage invest-ment and construction substantially restricts its development,particularly due to unclear mechanisms for cost and benefit allocation,which also discourages potential investors.To address the issue,this paper proposes investment and construction models for shared energy-storage that aligns with the present stage of energy storage development.In specific,three main models are introduced:(1)Cen-tralized Self-built Shared Energy-Storage model(CSSES),(2)Third-party Investment Shared Energy-Storage model(TISES),and(3)Distributed Self-built Shared Energy Storage(DSSES)model.The cost–benefit analysis is conducted for each model.The results indicate that the CSSES model achieves the highest internal rate of return(11.5%)and the shortest payback period,while the DSSES model per-forms acceptable with an IRR of 9.4%.In contrast,the TISES model shows the lowest IRR(6.7%)and requires higher electricity price for being feasible.Furthermore,the study employs the entropy weight method and the analytic hierarchy process(AHP)for indicator eval-uation,and integrates the technique for order preference by the similarity to an ideal solution(TOPSIS)for scheme optimization.The results show that both the CSSES model and the DSSES model achieve the highest proximity scores.Under environmental regulations,these models demonstrate superior economic benefits by optimizing energy storage utilization,reducing user costs,and enhancing overall profitability.展开更多
The process of understanding natural language can be viewed as the process of model construction. This paper? employing Kripke frame for intuitionistic logic semantics as the implement of model construction for natura...The process of understanding natural language can be viewed as the process of model construction. This paper? employing Kripke frame for intuitionistic logic semantics as the implement of model construction for natural language, introduces a method of incremental model construction.展开更多
This paper introduces the model of China's direct grain subsidy policy, adopts computable general equilibrium (CGE) theory, and advances the scheme of constructing the model of China's direct grain subsidy pol...This paper introduces the model of China's direct grain subsidy policy, adopts computable general equilibrium (CGE) theory, and advances the scheme of constructing the model of China's direct grain subsidy policy. On the basis of some assumptions, such as conforming to the complete competition of market, inexistence of move of capital and labor forces among countries, unchanged exchange rate and incomplete substitution, and the main body of behavior comprising representative households, producers, local government and central government, the model established in this paper includes production module and demand module. Moreover, the model takes into account equilibrium structure, the definition of profiting and macro condition for closure, the related coefficients this CGE model needs include Armingtion substitution elasticity of intermediate composite product, investment composite product and consumption composite product between import and domestic production; substitution elasticity among production factors; conversion elasticity of total sales between domestic absorption and export; elasticity of residents' expenditure; elasticity of price; elasticity of export demand; the relative share of all sectors in capital stock. This paper also points out the advantages and limitations of CGE model in analyzing direct grain subsidy policy.展开更多
This paper starts from the theoretical basis of constructivism and development evaluation study that learns the principles of communication, the use of educational psychology and other disciplines of knowledge. It is ...This paper starts from the theoretical basis of constructivism and development evaluation study that learns the principles of communication, the use of educational psychology and other disciplines of knowledge. It is to build a developmental evaluation and characteristics for the idea to the attention of the relevant confidence to meet and the evaluator＇ s expectations as of the five elements to stimulate learning motivation, build developmental evaluation principles to stimulate learning motivation of process model. Seven strategies are to stimulate and sustain the motivation of college students, while emphasizing mentor in the process of converting role as learner and developmental evaluation. Related strategies are used in the actual teaching of ＂Mechanical Engineering Materials＂ , ＂Graduation Design＂ , ＂Engineer Training＂ course, and it achieved satisfactory teaching effect, playing a role in promoting real learning and comprehensive evaluation of the development of college students.展开更多
With brick-wall solar greenhouses in Changli area as the research object,using temperature dynamic monitoring and statistical methods,the greenhouse structure suitable for promoting early cultivation of local peach tr...With brick-wall solar greenhouses in Changli area as the research object,using temperature dynamic monitoring and statistical methods,the greenhouse structure suitable for promoting early cultivation of local peach trees was selected by studying the temperature data of the solar greenhouses during the winter solstice,and a prediction model for daily average temperature was constructed.The results showed that greenhouse Ⅰ had reasonable structural parameters and good daylight during the day.However,due to the low wall thickness and poor insulation material,the minimum temperature was significantly lower than other greenhouses.The thermal insulation performance of greenhouse Ⅱ and Ⅲ was better than that of greenhouse Ⅰ,but the depth-span ratio and the front roof lighting angle were smaller.During the winter solstice,the average temperature of the three greenhouses was between 10 and 15℃,which was suitable for early cultivation of peach trees.The prediction model of daily average temperature was obtained:Daily average temperature=1.02+0.69×Daily average temperature of the previous day+0.02×Maximum temperature of the previous day-0.01×Minimum temperature of the previous day.To sum up,the structural parameters of brick-wall solar greenhouses suitable for early cultivation of peach trees in Changli area were as follows:span 6.5-8.5 m,depth-span ratio 0.47,front roof lighting angle 30°and wall thickness greater than 55 cm.展开更多
This article analyzes the application strategies of Building Information Modeling(BIM)support technology in a first-class highway reconstruction and expansion project based on its actual situation.According to the bas...This article analyzes the application strategies of Building Information Modeling(BIM)support technology in a first-class highway reconstruction and expansion project based on its actual situation.According to the basic situation of BIM technology and its application goals in this project,it explores application strategies such as BIM model construction,BIM prefabricated structural model deepening and schedule simulation,BIM collision detection,and BIM tunnel pre-construction simulation.Through this analysis,it is hoped to provide a reference for the rational application of BIM support technology and ensure the high-quality and efficient completion of first-class highway reconstruction and expansion projects.展开更多
More space truss construction has been planned to develop and utilize space resources.These trusses are designed in the way of large-scale,complex,modular,and on-orbit assembly.To meet the upcoming challenge of large-...More space truss construction has been planned to develop and utilize space resources.These trusses are designed in the way of large-scale,complex,modular,and on-orbit assembly.To meet the upcoming challenge of large-scale space infrastructure construction,it is necessary to study space truss automation design and robotic construction.This paper proposes an ordinal finite screw adjacency matrix model(OFSAMM),focusing on the relationship between assembly motions,to express and compute a space truss structure.In this model,a space truss is abstracted as a set of ordered assembly motions,each of which is recorded as a finite screw as the basic element of the truss and its assembly.The operation of truss transformation is also derived under this model.Therefore,the truss configuration,the assembly sequence,the truss sub-assembly,the truss components,and the on-orbit assembly task can be expressed and calculated in a unified model,which is calculated and stores the truss topology and assembly with the minimum storage cost.At the end of this paper,we introduce how to synthesize and optimize space truss design through two cases.The study will help to improve design efficiency.Furthermore,it provides a theoretical basis for the automatic construction of space truss structures,especially in the next stage.展开更多
It has been a focus of debate for a large time on construction methods for large-span loess tunnel.Reasonable construction method has much effect on stability of tunnel and construction schedule.Deformation and failur...It has been a focus of debate for a large time on construction methods for large-span loess tunnel.Reasonable construction method has much effect on stability of tunnel and construction schedule.Deformation and failure of surrounding rock are quite complex.Associating with the large-span loess tunnel of Zhengzhou- Xi'an high-speed passenger rail line in China,large scale model test with geometric proportion 1:20 is applied to study on dynamic mechanical behavior of various construction methods.They include full-face excavation with support and no support,and benching method with support.It is found that pre-deformation and stress accumulation take place ahead of working face.The effects of three construction methods are further studied,particularly in terms of tunnel displacement and stress changes.It is revealed that benching method transfers load to an unexcavated area,limits horizontal deformation,reduces stress concentration effectively,lengthens the distance between location of peak for stress concentration and working face,and consequently increases stability.The model test results not only supply theoretical foundation for determination of reasonable construction method,but also can act as reference for similar tunnel and underground engineering construction.展开更多
The method of building 3D model was discussed at first.Aiming at the feature of mine vacant place,a method to build the 3D vacant place model based on multi TIN(triangular irregular network)was put forward,and the dat...The method of building 3D model was discussed at first.Aiming at the feature of mine vacant place,a method to build the 3D vacant place model based on multi TIN(triangular irregular network)was put forward,and the data structure and visualization of vacant place were discussed.Then some crucial technologies of realizing function in 3D-GIS were proposed.In addition,the software about special 3D mapping and assaying was introduced.展开更多
Basic conditions and new countryside construction of Ganlu Town, Zizhong County, Neijiang City were analyzed, SWOT adopted to analyze internal strengths, weaknesses, external opportunities and threats of its new count...Basic conditions and new countryside construction of Ganlu Town, Zizhong County, Neijiang City were analyzed, SWOT adopted to analyze internal strengths, weaknesses, external opportunities and threats of its new countryside construction. On this basis, positive and practical strategies were put forward to promote the new countryside construction in the local area, and provide references for the new countryside construction in other regions.展开更多
Broadband network plays an increasingly important strategic role in the development of new rural economy,society and culture.Based on the analysis of the construction of rural agricultural informatization and existing...Broadband network plays an increasingly important strategic role in the development of new rural economy,society and culture.Based on the analysis of the construction of rural agricultural informatization and existing problems in our country,this paper gives the path selection and measures of " broadband village" combined with regional characteristics to select the construction path of " broadband village",it needs to build the long term mechanism of " broadband village" investment and financing,determine the goal of the regional construction of " broadband village" and focus on promoting the development of rural informatization services.展开更多
Through careful study, it found that the key and difficult points of affecting and restricting Xi＇an to reach the model city construction standards in provincial and national levels were ＂urban air environment quali...Through careful study, it found that the key and difficult points of affecting and restricting Xi＇an to reach the model city construction standards in provincial and national levels were ＂urban air environment quality standards＂ and ＂water qualification rate of urban water environment function area＂. In order to tackle with the weak links, highlight the important points and focus on the difficult points to strengthen scientific and technological innovation, we actively explored new ideas and ways to resolve the dilemma in meeting the two standards of model city construction, and we managed to put forward the countermeasures to resolve the dilemma through innovating system and mechanism. ＂Place master system＂ should be carded out quickly to meet the ＂urban air environment quality standards＂, while ＂river master system＂ should be implemented as soon as possible to reach the ＂water qualification rate of urban water environment function area＂. The aim of this study was to enhance the qualification rates of the indicators for model city construction to make Xi＇an successfully pass the provincial and national assessment of model city construction through dealing with the weak links to accelerate the realization of becoming model environmental protection city.展开更多
基金funded by the National Science VIP specialized project of China(Grant No.2011ZX05025-001-03)by the National Science Foundation of China(Grant No.41274117)
文摘In tomographic statics seismic data processing, it 1s crucial to cletermme an optimum base for a near-surface model. In this paper, we consider near-surface model base determination as a global optimum problem. Given information from uphole shooting and the first-arrival times from a surface seismic survey, we present a near-surface velocity model construction method based on a Monte-Carlo sampling scheme using a layered equivalent medium assumption. Compared with traditional least-squares first-arrival tomography, this scheme can delineate a clearer, weathering-layer base, resulting in a better implementation of damming correction. Examples using synthetic and field data are used to demonstrate the effectiveness of the proposed scheme.
文摘Geometric model construction is the basis of infrared image theory simulation. Taking the construction of the geometric model of one building in Harbin as an example, this paper analyzes the theoretical groundings of simplification and principles of geometric model construction of buildings. It then discusses some particular treatment methods in calculating the radiation transfer coefficient in geometric model construction using the Monte Carlo Method.
基金supported by the National Natural Science Foundation of China (Grant No.42171311)the Open Fund of State Key Laboratory of Remote Sensing Science (Grant No.OFSLRSS202218)+1 种基金the Key Research and Development Program of the Hainan Province,China (Grant No.ZDYF2021SHFZ105)the Training Program of Excellent Master Thesis of Zhejiang Ocean University.
文摘The acquisition of digital regional-scale information and ecological environmental data has high requirements for structural texture,spatial res-olution,and multiple parameter categories,which is challenging to achieve using satellite remote sensing.Considering the convenient,facilitative,and flexible characteristics of UAV(unmanned air vehicle)remote sensing tech-nology,this study selects a campus as a typical research area and uses the Pegasus D2000 equipped with a D-MSPC2000 multi-spectral camera and a CAM3000 aerial camera to acquire oblique images and multi-spectral data.Using professional software,including Context Capture,ENVI,and ArcGIS,a 3D(three-dimensional)campus model,a digital orthophoto map,and multi-spectral remote sensing map drawing are realized,and the geometric accuracy of typical feature selection is evaluated.Based on a quantitative remote sensing model,the campus ecological environment assessment is performed from the perspectives of vegetation and water body.The results presented in this study could be of great significance to the scientific management and sustainable development of regional natural resources.
文摘In order to support enterprise integration, a kind of model construct based enterprise model architecture and its modeling approach are studied in this paper. First, the structural makeup and internal relationships of enterprise model architecture are discussed. Then, the concept of reusable model construct (MC) which belongs to the control view and can help to derive other views is proposed. The modeling approach based on model construct consists of three steps, reference model architecture synthesis, enterprise model customization, system design and implementation. According to MC based modeling approach a case study with the background of one-kind-product machinery manufacturing enterprises is illustrated. It is shown that proposal model construct based enterprise model architecture and modeling approach are practical and efficient.
文摘In regard to knowledge economy,the current concept in the model construction of online education,including distance education and online learning,generally refers to a kind of network-based learning behavior,similar to the concept of online training.Compared with traditional offline education methods,through the application of information technology and internet technology for content dissemination and rapid learning,online education has the characteristics of high efficiency,convenience,low threshold,and rich teaching resources.Online education covers a wide range of people,different forms of learning,and its classification methods are more diverse.Online education services are the fastest growing field of education informatization.At the moment,the most pressing problems include effectively integrating educational resources with internet technology,launching online education services and products that are highly interactive and would encourage personalized learning,increasing user stickiness,as well as avoiding trend-following and conceptualized investment.
文摘Against the backdrop of continuous social development and growing public health demands,the efficiency and scientific nature of the emergency care system are of paramount importance.This paper focuses on researching the construction of an emergency care system based on the concept of“linkage”,delving into its theoretical foundations,exploring innovative construction models,and analyzing practical cases.The study indicates that an emergency care system under the“linkage”concept can effectively integrate resources and enhance efficiency,providing new insights for improving the construction of the emergency care system.It aims to promote the development of the emergency care system towards a more scientific,efficient,and collaborative direction.
文摘Objective:To address the prediction of hemorrhagic transformation(HT)after rt-PA thrombolysis in acute cerebral infarction(ACI)patients,a predictive model integrating data engineering,algorithm optimization,and modularity was constructed.This model resolves the technical limitation of traditional clinical statistical models that overemphasize analysis while neglecting deployment readiness,thereby providing a reusable technical solution for the implementation of medical risk prediction systems.Methods:A standardized dataset was built using data from 300 ACI patients who underwent rt-PA thrombolysis.Automated data cleaning,outlier correction,and feature engineering optimization(recursive feature elimination+variance inflation factor test)were applied to select core features.An L2-regularized logistic regression algorithm was employed to construct the prediction model,which was visualized via a nomogram.Multi-dimensional performance validation was conducted through cross-validation and probability calibration techniques.Results:The incidence of HT was20.0%.Multivariate analysis identified NIHSS score(OR=1.626),blood glucose(OR=1.662),platelet count(OR=0.975),age(OR=1.091),and history of diabetes(OR=0.343)as core predictors(P<0.05).Engineering validation demonstrated excellent discrimination(AUC=0.800,95%CI:0.752-0.856).After optimization with Platt scaling,the calibration curve was highly consistent with the actual probability,with a Brier score of0.092.The prediction time per sample was<50 ms,and the convergence efficiency of model training was improved by 30%.Conclusion:This model integrates core technologies including data preprocessing,feature optimization,and algorithm improvement,exhibiting low-latency,high stability,and deployability.It provides a standardized technical framework for transforming medical prediction models from statistical conclusions into engineered products.
基金supported by the Humanities and Social Sciences of Ministry of Education Planning Fund of China(Grant No.21YJA790009)the National Natural Science Foundation of China(Grant No.72140001).
文摘New energy-storage systems play a pivotal role in the development of the new power system for advancing the energy transition in China.In the“14th Five-Year Plan”for the New Energy-Storage Development,it is proposed to expand investment and construction models by promoting the deployment of energy-storage facilities through the ways of self-construction,leasing,and purchasing,and to encourage the development of the shared energy-storage.However,the current scarcity in the model of the shared energy-storage invest-ment and construction substantially restricts its development,particularly due to unclear mechanisms for cost and benefit allocation,which also discourages potential investors.To address the issue,this paper proposes investment and construction models for shared energy-storage that aligns with the present stage of energy storage development.In specific,three main models are introduced:(1)Cen-tralized Self-built Shared Energy-Storage model(CSSES),(2)Third-party Investment Shared Energy-Storage model(TISES),and(3)Distributed Self-built Shared Energy Storage(DSSES)model.The cost–benefit analysis is conducted for each model.The results indicate that the CSSES model achieves the highest internal rate of return(11.5%)and the shortest payback period,while the DSSES model per-forms acceptable with an IRR of 9.4%.In contrast,the TISES model shows the lowest IRR(6.7%)and requires higher electricity price for being feasible.Furthermore,the study employs the entropy weight method and the analytic hierarchy process(AHP)for indicator eval-uation,and integrates the technique for order preference by the similarity to an ideal solution(TOPSIS)for scheme optimization.The results show that both the CSSES model and the DSSES model achieve the highest proximity scores.Under environmental regulations,these models demonstrate superior economic benefits by optimizing energy storage utilization,reducing user costs,and enhancing overall profitability.
基金This paper was supported by the National Natural Science Foundation of China and the National '863' Hi-Tech Programme of China.
文摘The process of understanding natural language can be viewed as the process of model construction. This paper? employing Kripke frame for intuitionistic logic semantics as the implement of model construction for natural language, introduces a method of incremental model construction.
文摘This paper introduces the model of China's direct grain subsidy policy, adopts computable general equilibrium (CGE) theory, and advances the scheme of constructing the model of China's direct grain subsidy policy. On the basis of some assumptions, such as conforming to the complete competition of market, inexistence of move of capital and labor forces among countries, unchanged exchange rate and incomplete substitution, and the main body of behavior comprising representative households, producers, local government and central government, the model established in this paper includes production module and demand module. Moreover, the model takes into account equilibrium structure, the definition of profiting and macro condition for closure, the related coefficients this CGE model needs include Armingtion substitution elasticity of intermediate composite product, investment composite product and consumption composite product between import and domestic production; substitution elasticity among production factors; conversion elasticity of total sales between domestic absorption and export; elasticity of residents' expenditure; elasticity of price; elasticity of export demand; the relative share of all sectors in capital stock. This paper also points out the advantages and limitations of CGE model in analyzing direct grain subsidy policy.
文摘This paper starts from the theoretical basis of constructivism and development evaluation study that learns the principles of communication, the use of educational psychology and other disciplines of knowledge. It is to build a developmental evaluation and characteristics for the idea to the attention of the relevant confidence to meet and the evaluator＇ s expectations as of the five elements to stimulate learning motivation, build developmental evaluation principles to stimulate learning motivation of process model. Seven strategies are to stimulate and sustain the motivation of college students, while emphasizing mentor in the process of converting role as learner and developmental evaluation. Related strategies are used in the actual teaching of ＂Mechanical Engineering Materials＂ , ＂Graduation Design＂ , ＂Engineer Training＂ course, and it achieved satisfactory teaching effect, playing a role in promoting real learning and comprehensive evaluation of the development of college students.
基金Supported by Modern Agricultural Industry Technology System Innovation Team Construction in Hebei Province(HBCT2023130404).
文摘With brick-wall solar greenhouses in Changli area as the research object,using temperature dynamic monitoring and statistical methods,the greenhouse structure suitable for promoting early cultivation of local peach trees was selected by studying the temperature data of the solar greenhouses during the winter solstice,and a prediction model for daily average temperature was constructed.The results showed that greenhouse Ⅰ had reasonable structural parameters and good daylight during the day.However,due to the low wall thickness and poor insulation material,the minimum temperature was significantly lower than other greenhouses.The thermal insulation performance of greenhouse Ⅱ and Ⅲ was better than that of greenhouse Ⅰ,but the depth-span ratio and the front roof lighting angle were smaller.During the winter solstice,the average temperature of the three greenhouses was between 10 and 15℃,which was suitable for early cultivation of peach trees.The prediction model of daily average temperature was obtained:Daily average temperature=1.02+0.69×Daily average temperature of the previous day+0.02×Maximum temperature of the previous day-0.01×Minimum temperature of the previous day.To sum up,the structural parameters of brick-wall solar greenhouses suitable for early cultivation of peach trees in Changli area were as follows:span 6.5-8.5 m,depth-span ratio 0.47,front roof lighting angle 30°and wall thickness greater than 55 cm.
文摘This article analyzes the application strategies of Building Information Modeling(BIM)support technology in a first-class highway reconstruction and expansion project based on its actual situation.According to the basic situation of BIM technology and its application goals in this project,it explores application strategies such as BIM model construction,BIM prefabricated structural model deepening and schedule simulation,BIM collision detection,and BIM tunnel pre-construction simulation.Through this analysis,it is hoped to provide a reference for the rational application of BIM support technology and ensure the high-quality and efficient completion of first-class highway reconstruction and expansion projects.
基金financial support under the Manned Aerospace Research Project(Grant No.040102)。
文摘More space truss construction has been planned to develop and utilize space resources.These trusses are designed in the way of large-scale,complex,modular,and on-orbit assembly.To meet the upcoming challenge of large-scale space infrastructure construction,it is necessary to study space truss automation design and robotic construction.This paper proposes an ordinal finite screw adjacency matrix model(OFSAMM),focusing on the relationship between assembly motions,to express and compute a space truss structure.In this model,a space truss is abstracted as a set of ordered assembly motions,each of which is recorded as a finite screw as the basic element of the truss and its assembly.The operation of truss transformation is also derived under this model.Therefore,the truss configuration,the assembly sequence,the truss sub-assembly,the truss components,and the on-orbit assembly task can be expressed and calculated in a unified model,which is calculated and stores the truss topology and assembly with the minimum storage cost.At the end of this paper,we introduce how to synthesize and optimize space truss design through two cases.The study will help to improve design efficiency.Furthermore,it provides a theoretical basis for the automatic construction of space truss structures,especially in the next stage.
基金the National Natural Science Foundation of China(Nos. 50978172 and 51078318)the New Century Excellent Talents in University(No. 10-0667)
文摘It has been a focus of debate for a large time on construction methods for large-span loess tunnel.Reasonable construction method has much effect on stability of tunnel and construction schedule.Deformation and failure of surrounding rock are quite complex.Associating with the large-span loess tunnel of Zhengzhou- Xi'an high-speed passenger rail line in China,large scale model test with geometric proportion 1:20 is applied to study on dynamic mechanical behavior of various construction methods.They include full-face excavation with support and no support,and benching method with support.It is found that pre-deformation and stress accumulation take place ahead of working face.The effects of three construction methods are further studied,particularly in terms of tunnel displacement and stress changes.It is revealed that benching method transfers load to an unexcavated area,limits horizontal deformation,reduces stress concentration effectively,lengthens the distance between location of peak for stress concentration and working face,and consequently increases stability.The model test results not only supply theoretical foundation for determination of reasonable construction method,but also can act as reference for similar tunnel and underground engineering construction.
文摘The method of building 3D model was discussed at first.Aiming at the feature of mine vacant place,a method to build the 3D vacant place model based on multi TIN(triangular irregular network)was put forward,and the data structure and visualization of vacant place were discussed.Then some crucial technologies of realizing function in 3D-GIS were proposed.In addition,the software about special 3D mapping and assaying was introduced.
文摘Basic conditions and new countryside construction of Ganlu Town, Zizhong County, Neijiang City were analyzed, SWOT adopted to analyze internal strengths, weaknesses, external opportunities and threats of its new countryside construction. On this basis, positive and practical strategies were put forward to promote the new countryside construction in the local area, and provide references for the new countryside construction in other regions.
基金Supported by Jiangsu Modern Information Services Decision and Consulting Research Base Project(NYJD217010)Philosophy and Social Science Research Project of Jiangsu Universities(2014SJB006)
文摘Broadband network plays an increasingly important strategic role in the development of new rural economy,society and culture.Based on the analysis of the construction of rural agricultural informatization and existing problems in our country,this paper gives the path selection and measures of " broadband village" combined with regional characteristics to select the construction path of " broadband village",it needs to build the long term mechanism of " broadband village" investment and financing,determine the goal of the regional construction of " broadband village" and focus on promoting the development of rural informatization services.
文摘Through careful study, it found that the key and difficult points of affecting and restricting Xi＇an to reach the model city construction standards in provincial and national levels were ＂urban air environment quality standards＂ and ＂water qualification rate of urban water environment function area＂. In order to tackle with the weak links, highlight the important points and focus on the difficult points to strengthen scientific and technological innovation, we actively explored new ideas and ways to resolve the dilemma in meeting the two standards of model city construction, and we managed to put forward the countermeasures to resolve the dilemma through innovating system and mechanism. ＂Place master system＂ should be carded out quickly to meet the ＂urban air environment quality standards＂, while ＂river master system＂ should be implemented as soon as possible to reach the ＂water qualification rate of urban water environment function area＂. The aim of this study was to enhance the qualification rates of the indicators for model city construction to make Xi＇an successfully pass the provincial and national assessment of model city construction through dealing with the weak links to accelerate the realization of becoming model environmental protection city.
