A modelling framework based on functional surface is presented to support conceptual design of mechanical products. The framework organizes product information in an abstract and multilevel manner. It consists of two ...A modelling framework based on functional surface is presented to support conceptual design of mechanical products. The framework organizes product information in an abstract and multilevel manner. It consists of two mapping processes: function decomposition process and form reconstitution process. The steady mapping relationship from function to form (function-functional surface-form) is realized by taking functional surface as the middle layer. It farthest reduces the possibilities of combinatorial explosion that can occur during function decomposition and form reconstitution. Finally, CAD tools are developed and an auto-bender machine is applied to demonstrate the proposed approach展开更多
A systems approach is used to describe the generation and variation of wastewater in an urban area. This is a multivariable system and its combined response at the outlet of this system, which is usually the entrance ...A systems approach is used to describe the generation and variation of wastewater in an urban area. This is a multivariable system and its combined response at the outlet of this system, which is usually the entrance ofa wastewater treatment plant, depends on a number of environmental (precipitation and temperature) as well as social (size of the urban area, population changes, water consumption per capita) variables. There is a large number of available models and tools for describing the urban water system, however, the interactions between the individual components are rarely considered within the same modelling framework. In this paper a parsimonious methodology is proposed in order to understand and estimate the wastewater generation and its characteristics in an urban area using any information provided by the available data. The model incorporates both the flows of stormwater discharge and wastewater production that arrive to the wastewater treatment plant. A state dependent variable is introduced to simulate the consumptive uses in the urban area. Data availability and system's complexity affect the ability to achieve enhanced model performance, however, in the presented case study, preliminary results from the application of the presented model in the Greater Athens Area illustrate the potential of the conceptual modelling approach.展开更多
This study proposes the use of the MERISE conceptual data model to create indicators for monitoring and evaluating the effectiveness of vocational training in the Republic of Congo. The importance of MERISE for struct...This study proposes the use of the MERISE conceptual data model to create indicators for monitoring and evaluating the effectiveness of vocational training in the Republic of Congo. The importance of MERISE for structuring and analyzing data is underlined, as it enables the measurement of the adequacy between training and the needs of the labor market. The innovation of the study lies in the adaptation of the MERISE model to the local context, the development of innovative indicators, and the integration of a participatory approach including all relevant stakeholders. Contextual adaptation and local innovation: The study suggests adapting MERISE to the specific context of the Republic of Congo, considering the local particularities of the labor market. Development of innovative indicators and new measurement tools: It proposes creating indicators to assess skills matching and employer satisfaction, which are crucial for evaluating the effectiveness of vocational training. Participatory approach and inclusion of stakeholders: The study emphasizes actively involving training centers, employers, and recruitment agencies in the evaluation process. This participatory approach ensures that the perspectives of all stakeholders are considered, leading to more relevant and practical outcomes. Using the MERISE model allows for: • Rigorous data structuring, organization, and standardization: Clearly defining entities and relationships facilitates data organization and standardization, crucial for effective data analysis. • Facilitation of monitoring, analysis, and relevant indicators: Developing both quantitative and qualitative indicators helps measure the effectiveness of training in relation to the labor market, allowing for a comprehensive evaluation. • Improved communication and common language: By providing a common language for different stakeholders, MERISE enhances communication and collaboration, ensuring that all parties have a shared understanding. The study’s approach and contribution to existing research lie in: • Structured theoretical and practical framework and holistic approach: The study offers a structured framework for data collection and analysis, covering both quantitative and qualitative aspects, thus providing a comprehensive view of the training system. • Reproducible methodology and international comparison: The proposed methodology can be replicated in other contexts, facilitating international comparison and the adoption of best practices. • Extension of knowledge and new perspective: By integrating a participatory approach and developing indicators adapted to local needs, the study extends existing research and offers new perspectives on vocational training evaluation.展开更多
The Fine Structure Constant (α) is a dimensionless value that guides much of quantum physics but with no scientific insight into why this specific number. The number defines the coupling constant for the strength of ...The Fine Structure Constant (α) is a dimensionless value that guides much of quantum physics but with no scientific insight into why this specific number. The number defines the coupling constant for the strength of the electromagnetic force and is precisely tuned to make our universe functional. This study introduces a novel approach to understanding a conceptual model for how this critical number is part of a larger design rather than a random accident of nature. The Fine Structure Constant (FSC) model employs a Python program to calculate n-dimensional property sets for prime number universes where α equals the whole number values 137 and 139, representing twin prime universes without a fractional constant. Each property is defined by theoretical prime number sets that represent focal points of matter and wave energy in their respective universes. This work aims to determine if these prime number sets can reproduce the observed α value, giving it a definable structure. The result of the FSC model produces a α value equal to 137.036, an almost exact match. Furthermore, the model indicates that other twin prime pairs also have a role in our functional universe, providing a hierarchy for atomic orbital energy levels and alignment with the principal and azimuthal quantum numbers. In addition, it construes stable matter as property sets with the highest ratio of twin prime elements. These results provide a new perspective on a mathematical structure that shapes our universe and, if valid, has the structural complexity to guide future research.展开更多
The problem of shield tunnel uplift is a common issue in tunnel construction.Due to the decrease in shear stiffness at the joints between the rings,uplift is typically observed as bending and dislocation deformation a...The problem of shield tunnel uplift is a common issue in tunnel construction.Due to the decrease in shear stiffness at the joints between the rings,uplift is typically observed as bending and dislocation deformation at these joints.Existing modeling methods typically rely on the Euler-Bernoulli beam theory,only considering the bending effect while disregarding shear deformation.Furthermore,the constraints on the shield tail are often neglected in existing models.In this study,an improved theoretical model of tunnel floating is proposed.The constraint effect of the shield machine shell on the tunnel structure is considered using the structural forms of two finite long beams and one semi-infinite long beam.Furthermore,the Timoshenko beam theory is adopted,providing a more accurate description of tunnel deformation,including both the bending effect and shear deformation,than existing models.Meanwhile,the buoyancy force and stratum resistance are calculated in a nonlinear manner.A reliable method for calculating the shear stiffness correction factor is proposed to better determination of the calculation parameters.The proposed theoretical model is validated through five cases using sitemonitored data.Its applicability and effectiveness are demonstrated.Furthermore,the influences of soil type,buried depth,and buoyancy force on the three key indicators of tunnel floating(i.e.the maximum uplift magnitude,the ring position with the fastest uplift race,and the ring position with the maximum uplift magnitude)are analyzed.The results indicate that the proposed model can provide a better understanding of the floating characteristics of the tunnel structure during construction.展开更多
Spatio-temporal variability and dynamics in Sahelian agro-pastoral zones make each local situation a special case. These specificities must be considered to guide the dissemination of agricultural options with a view ...Spatio-temporal variability and dynamics in Sahelian agro-pastoral zones make each local situation a special case. These specificities must be considered to guide the dissemination of agricultural options with a view to sustainable development. The territorial scale of municipalities is not sufficient for this necessary contextualization;the scale of the “village terroir” seems to be a better option. This is the hypothesis we put forward in the framework of the Global Collaboration for Resilient Food Systems program (CRFS), i.e. local context is spatially defined by village terroir. The study is based on data collected through participatory mapping and surveys in “village terroirs” in three regions of Niger (Maradi, Dosso and Tillabéri). Then the links between farm managers and their cultivated land, as well as the spatio-temporal dynamics of local context are analyzed. This study provides evidence of the existence and functional usefulness of the village terroir for farmers, their land management and their activities. It demonstrates the usefulness of contextualizing agricultural options at this scale. Their analysis elucidates the links between “terroirs village” and the specific functioning of the agrosocio-ecosystems acting on each of them, thus laying the systemic and geographical foundations for a model of the spatio- temporal dynamics of “village terroirs”. This initial work has opened up new perspectives in modeling and sustainable development.展开更多
The Fine Structure Constant (eFSC) Model attempts to give a classical definition to a magical number that underlies much of quantum physics. The Fine Structure Constant (α) value equal to 137.03599206 represents a di...The Fine Structure Constant (eFSC) Model attempts to give a classical definition to a magical number that underlies much of quantum physics. The Fine Structure Constant (α) value equal to 137.03599206 represents a dimensionless constant that characterizes the strength of the electromagnetic (EM) interaction between subatomic charged particles. Python-generated property counts for the twin prime force F{139/137} show that the adjusted ratio gives a value of α = 137.036. This implies a mathematical framework underlying this constant is based on twin prime numbers and set theory. This study attempts to demonstrate a proof of concept that a hierarchy of fractional twin prime (αII) forces replicates the quantum nature of the universe and is aligned with the Standard Model of Particle Physics. An expanded eFSC Model demonstrates that twin prime forces and their property sets are mathematically viable substitutes for nuclear reactions, as demonstrated for the Beta-minus decay of neutrons into protons. Most significantly, the positive and negative prime numbers define these nuclear reactants and products as positive or negatively charged ions. Furthermore, the eFSC Model provides new insights regarding the hierarchy of EM forces underlying the quantum nature of the universe.展开更多
Hydrologic models generally represent the most dominant processes since they are mere simplifications of physical reality and thus are subject to many significant uncertainties. As such, a coupling strategy is propose...Hydrologic models generally represent the most dominant processes since they are mere simplifications of physical reality and thus are subject to many significant uncertainties. As such, a coupling strategy is proposed. To this end, the coupling of the artificial neural network (ANN) with the Xin'anjiang conceptual model with a view to enhance the quality of its flow forecast is presented. The approach uses the latest observations and residuals in runoff/discharge forecasts from the Xin'anjiang model. The two complementary models (Xin'anjiang & ANN) are used in such a way that residuals of the Xin'anjiang model are forecasted by a neural network model so that flow forecasts can be improved as new observations come in. For the complementary neural network, the input data were presented in a patterned format to conform to the calibration regime of the Xin'anjiang conceptual model, using differing variants of the neural network scheme. The results show that there is a substantial improvement in the accuracy of the forecasts when the complementary model was operated on top of the Xin'anjiang conceptual model as compared with the results of the Xin'anjiang model alone.展开更多
The conceptual model is the first time abstraction ceptual model description method based on the UML and the of the real world. The traditional con- text usually has the semantic ambiguity problem. The formal descript...The conceptual model is the first time abstraction ceptual model description method based on the UML and the of the real world. The traditional con- text usually has the semantic ambiguity problem. The formal description method lacks the mechanism of integrity and consistency check. Therefore both of them cannot support the simulation scenario description and the model compos- ability. A simulation conceptual description method based on ontology is put forward. According to the OWL language which was put forward by the W3C organization, a conceptual model description language is established. The OWL language semantic element in the description function in the mili- tary conceptual model is introduced. Then two layers of the military conceptual model framework are built up based on the general ontology and the domain ontology. In the general ontology, the class and property definition are given. While in the domain ontology, they are extended and a relat- ed example is given. The technique advantages of our method include the mechanism of conceptual model consistency and integrity check, the support of composable simulation models, and automatic creation of simulation scenario.展开更多
Urban competitiveness is always the focus of researches on urban economy. The variety of definitions and evaluation systems of urban competitiveness are the results of lack of accurate and comprehensive understanding ...Urban competitiveness is always the focus of researches on urban economy. The variety of definitions and evaluation systems of urban competitiveness are the results of lack of accurate and comprehensive understanding on urban competitiveness. This paper reviews five groups of definitions on urban competitiveness and establishes a conceptual model for urban competitiveness.展开更多
The components of map information are analyzed theoretically in this paper,and the map information includes mainly the spatial information,attributive information and temporal characteristics information.Then the digi...The components of map information are analyzed theoretically in this paper,and the map information includes mainly the spatial information,attributive information and temporal characteristics information.Then the digital map entity is defined according to construction characteristics of the map information.Finally,on the basis of the analyses of the construction characteristics of digital map entity and present conceptual model of digital map database,an abstracted conceptual model of digital map database is presented.And the Normal Form theory of relational database is discussed particularly.展开更多
Reanalysis data from NCEP/NCAR are used to systematically study preceding signals of monthly precipitation anomalies in the early raining season of Guangdong province, from the viewpoints of 500-hPa geopotential heigh...Reanalysis data from NCEP/NCAR are used to systematically study preceding signals of monthly precipitation anomalies in the early raining season of Guangdong province, from the viewpoints of 500-hPa geopotential height field, outgoing longwave radiation (OLR) field, sea surface temperature (SST) and fourteen indexes of general circulation depicting atmosphere activity at high, middle and low latitutes. Being multiple tools of information, a number of conceptual models are formulated that are useful for prediction of the magnitude of monthly precipitation (drought, flood and normal conditionss).展开更多
Aiming at the problem of abstract and polytype information modeling in product conceptual design, a method of conceptual modeling based on logical expression and evolvement is presented. Based on the logic expressions...Aiming at the problem of abstract and polytype information modeling in product conceptual design, a method of conceptual modeling based on logical expression and evolvement is presented. Based on the logic expressions of the product conceptual design information, a fimction/logic/strucmre mapping model is set up. First, the fimction semantics is transformed into logical expressions through fimction/logic mapping. Second, the methods of logical evolvement are utilized to describe the fimction analysis, fimction/strucmre mapping and structure combination. Last, the logical structure scheme is transformed into geometrical sketch through logic/structure mapping. The conceptual design information and modeling process are described uniformly with logical methods in the model, and an effective method for computer aided conceptual design based on the model is implemented.展开更多
The continuous aquifers of the Congolese Cuvette basin constitute the seat of significant water tables reversibly supplying the Congo River basin as well as the water tables they drain. Consisting mainly of sandy-clay...The continuous aquifers of the Congolese Cuvette basin constitute the seat of significant water tables reversibly supplying the Congo River basin as well as the water tables they drain. Consisting mainly of sandy-clayey-sandstone formations, these aquifers contain groundwater which is the main source of drinking water supply for communities in this sector of the departments Cuvette and Cuvette-Ouest. The need for water being more and more acute, these aquifers have been subjected to drilling operations in order to supply drinking water to these populations. The information obtained from these operations is data which made it possible to obtain information relating to the lithology, the hydrogeological parameters of these aquifers and information on the depth and on the lateral variations of the water table. The purpose of this present work is to contribute to the hydrogeological characterization of the aquifer of the Cuvette basin in the departments of Cuvette and Cuvette-Ouest via data from the analysis of the technical sheets of drillings carried out by the ASPERBRAS Company, collected at the Ministry of Major Works and territory planning. This characterization was made using Visual MODFLOW Flex 2015.1 software coupled with Surfer 10 software and Rock Works 17 software. The hydrogeological interpretation of the data shows that this aquifer, whose constitution is essentially made up of sands, clayey sands and clay, is continuous, porous and free. This composition gives the aquifer of Cuvette basin a heterogeneous character. In addition, a piezometric map was produced in order to indicate the direction of the water flows which turned out to be from west to east towards the lowest areas occupied by the valleys of the rivers and rivers. The conceptual model shows that the depth of the aquifer deceases considerably from the Cuvette-Ouest towards the Cuvette.展开更多
Marahoué watershed, located in the Center West of Côte d’Ivoire, has experienced significant population growth in recent decades. And a major economic boom linked to intense agricultural activity and th...Marahoué watershed, located in the Center West of Côte d’Ivoire, has experienced significant population growth in recent decades. And a major economic boom linked to intense agricultural activity and the presence of certain industries. This population growth is also accompanied by seasonal water shortages. Hence it needs to better manage the basin’s groundwater, which is a permanent resource and more resistant than surface water to climatic hazards. The objective of this study is therefore to propose a conceptual model of hydrogeological flow for the sustainable exploitation of groundwater resources in the Marahoué watershed. The establishment of the conceptual model was carried out in two stages. The first step consisted in defining the stratigraphic units. For this purpose, three units have been defined. These are the layer of alterite, the useful fissured horizon and the sound basement. The thickness of the layer of alterite varies from 0 to 80 m with an average of 26 m. As for the useful fissured horizon, its thickness is between 43 and 46.5 with an average of 45 m. In addition, the roof of the basement presents a slightly uneven morphology with a North-West, South-East dip and the altitudes are between 150 and 390 m. The second step corresponds to the phase of determining the hydrodynamic parameters. During this phase, the crack porosity, the transmissivity, the conductivity, the storage coefficient, the hydrological balance and the piezometric map were determined. Indeed, these parameters (the crack porosity, the transmissivity, the conductivity and the storage coefficient) confirm not only the heterogeneity of the medium but that the cracked horizon is sufficiently porous to be assimilated to an equivalent continuous medium during the simulation.展开更多
Firstly,this paper expounds the conceptual connotation of inservice assessment in the new system,then applies modeling and Simulation in the field of in-service assessment,establishes the conceptual model of inservice...Firstly,this paper expounds the conceptual connotation of inservice assessment in the new system,then applies modeling and Simulation in the field of in-service assessment,establishes the conceptual model of inservice assessment and its process,and finally analyzes the application of modeling and simulation in the specific links of in-service assessment.展开更多
How to measure the quality of conceptual models is an important issue in the IS field and related research. This paper conducts a review of research in measuring conceptual model quality and identifies the major theor...How to measure the quality of conceptual models is an important issue in the IS field and related research. This paper conducts a review of research in measuring conceptual model quality and identifies the major theoretical and practical issues that need to be addressed in future studies. We review current classification frameworks for conceptual model quality and practice of measuring conceptual model quality. Based on the review, challenges for studies of measuring the quality of conceptual models are proposed and these challenges are also research points which should be strengthened in future studies.展开更多
Based on the data of sandstorm at 11 stations in Ulanqab City from 1990 to 2021,the spatial and temporal variation characteristics of sand-storm weather were analyzed firstly,and then the conceptual models of cold fro...Based on the data of sandstorm at 11 stations in Ulanqab City from 1990 to 2021,the spatial and temporal variation characteristics of sand-storm weather were analyzed firstly,and then the conceptual models of cold front and Mongolian cyclone sandstorm were obtained by analyzing sandstorm cases.Finally,the forecast points of the two types of sandstorm weather were given to provide some scientific basis and reference for the prediction of local sandstorm weather in the future.展开更多
A solution to compute the optimal path based on a single-line-single-directional(SLSD)road network model is proposed.Unlike the traditional road network model,in the SLSD conceptual model,being single-directional an...A solution to compute the optimal path based on a single-line-single-directional(SLSD)road network model is proposed.Unlike the traditional road network model,in the SLSD conceptual model,being single-directional and single-line style,a road is no longer a linkage of road nodes but abstracted as a network node.Similarly,a road node is abstracted as the linkage of two ordered single-directional roads.This model can describe turn restrictions,circular roads,and other real scenarios usually described using a super-graph.Then a computing framework for optimal path finding(OPF)is presented.It is proved that classical Dijkstra and A algorithms can be directly used for OPF computing of any real-world road networks by transferring a super-graph to an SLSD network.Finally,using Singapore road network data,the proposed conceptual model and its corresponding optimal path finding algorithms are validated using a two-step optimal path finding algorithm with a pre-computing strategy based on the SLSD road network.展开更多
The conventional and intensive observational data of the China Heavy Rain Experiment and Study (CHeRES) are used to specially analyze the heavy rainfall process in the mei-yu front that occurred during 20-21 June 2002...The conventional and intensive observational data of the China Heavy Rain Experiment and Study (CHeRES) are used to specially analyze the heavy rainfall process in the mei-yu front that occurred during 20-21 June 2002, focusing on the meso-β system. A mesoscale convective system (MCS) formed in the warm-moist southwesterly to the south of the shear line over the Dabie Mountains and over the gorge between the Dabie and Jiuhua Mountains. The mei-yu front and shear line provide a favorable synoptic condition for the development of convection. The GPS observation indicates that the precipitable water increased obviously about 2-3 h earlier than the occurrence of rainfall and decreased after that. The abundant moisture transportation by southwesterly wind was favorable to the maintenance of convective instability and the accumulation of convective available potential energy (CAPE). Radar detection reveals that meso-β and -γ systems were very active in the MaCS. Several convection lines developed during the evolution of the MaCS, and these are associated with surface convergence lines. The boundary outflow of the convection line may have triggered another convection line. The convection line moved with the mesoscale surface convergence line, but the convective cells embedded in the convergence line propagated along the line. On the basis of the analyses of the intensive observation data, a multi-scale conceptual model of heavy rainfall in the mei-yu front for this particular case is proposed.展开更多
基金Supported by the National Natural Science Foundation of China (50475129)
文摘A modelling framework based on functional surface is presented to support conceptual design of mechanical products. The framework organizes product information in an abstract and multilevel manner. It consists of two mapping processes: function decomposition process and form reconstitution process. The steady mapping relationship from function to form (function-functional surface-form) is realized by taking functional surface as the middle layer. It farthest reduces the possibilities of combinatorial explosion that can occur during function decomposition and form reconstitution. Finally, CAD tools are developed and an auto-bender machine is applied to demonstrate the proposed approach
文摘A systems approach is used to describe the generation and variation of wastewater in an urban area. This is a multivariable system and its combined response at the outlet of this system, which is usually the entrance ofa wastewater treatment plant, depends on a number of environmental (precipitation and temperature) as well as social (size of the urban area, population changes, water consumption per capita) variables. There is a large number of available models and tools for describing the urban water system, however, the interactions between the individual components are rarely considered within the same modelling framework. In this paper a parsimonious methodology is proposed in order to understand and estimate the wastewater generation and its characteristics in an urban area using any information provided by the available data. The model incorporates both the flows of stormwater discharge and wastewater production that arrive to the wastewater treatment plant. A state dependent variable is introduced to simulate the consumptive uses in the urban area. Data availability and system's complexity affect the ability to achieve enhanced model performance, however, in the presented case study, preliminary results from the application of the presented model in the Greater Athens Area illustrate the potential of the conceptual modelling approach.
文摘This study proposes the use of the MERISE conceptual data model to create indicators for monitoring and evaluating the effectiveness of vocational training in the Republic of Congo. The importance of MERISE for structuring and analyzing data is underlined, as it enables the measurement of the adequacy between training and the needs of the labor market. The innovation of the study lies in the adaptation of the MERISE model to the local context, the development of innovative indicators, and the integration of a participatory approach including all relevant stakeholders. Contextual adaptation and local innovation: The study suggests adapting MERISE to the specific context of the Republic of Congo, considering the local particularities of the labor market. Development of innovative indicators and new measurement tools: It proposes creating indicators to assess skills matching and employer satisfaction, which are crucial for evaluating the effectiveness of vocational training. Participatory approach and inclusion of stakeholders: The study emphasizes actively involving training centers, employers, and recruitment agencies in the evaluation process. This participatory approach ensures that the perspectives of all stakeholders are considered, leading to more relevant and practical outcomes. Using the MERISE model allows for: • Rigorous data structuring, organization, and standardization: Clearly defining entities and relationships facilitates data organization and standardization, crucial for effective data analysis. • Facilitation of monitoring, analysis, and relevant indicators: Developing both quantitative and qualitative indicators helps measure the effectiveness of training in relation to the labor market, allowing for a comprehensive evaluation. • Improved communication and common language: By providing a common language for different stakeholders, MERISE enhances communication and collaboration, ensuring that all parties have a shared understanding. The study’s approach and contribution to existing research lie in: • Structured theoretical and practical framework and holistic approach: The study offers a structured framework for data collection and analysis, covering both quantitative and qualitative aspects, thus providing a comprehensive view of the training system. • Reproducible methodology and international comparison: The proposed methodology can be replicated in other contexts, facilitating international comparison and the adoption of best practices. • Extension of knowledge and new perspective: By integrating a participatory approach and developing indicators adapted to local needs, the study extends existing research and offers new perspectives on vocational training evaluation.
文摘The Fine Structure Constant (α) is a dimensionless value that guides much of quantum physics but with no scientific insight into why this specific number. The number defines the coupling constant for the strength of the electromagnetic force and is precisely tuned to make our universe functional. This study introduces a novel approach to understanding a conceptual model for how this critical number is part of a larger design rather than a random accident of nature. The Fine Structure Constant (FSC) model employs a Python program to calculate n-dimensional property sets for prime number universes where α equals the whole number values 137 and 139, representing twin prime universes without a fractional constant. Each property is defined by theoretical prime number sets that represent focal points of matter and wave energy in their respective universes. This work aims to determine if these prime number sets can reproduce the observed α value, giving it a definable structure. The result of the FSC model produces a α value equal to 137.036, an almost exact match. Furthermore, the model indicates that other twin prime pairs also have a role in our functional universe, providing a hierarchy for atomic orbital energy levels and alignment with the principal and azimuthal quantum numbers. In addition, it construes stable matter as property sets with the highest ratio of twin prime elements. These results provide a new perspective on a mathematical structure that shapes our universe and, if valid, has the structural complexity to guide future research.
基金the National Natural Science Foundation of China (Grant Nos.52379111,51979270 and 52208380).
文摘The problem of shield tunnel uplift is a common issue in tunnel construction.Due to the decrease in shear stiffness at the joints between the rings,uplift is typically observed as bending and dislocation deformation at these joints.Existing modeling methods typically rely on the Euler-Bernoulli beam theory,only considering the bending effect while disregarding shear deformation.Furthermore,the constraints on the shield tail are often neglected in existing models.In this study,an improved theoretical model of tunnel floating is proposed.The constraint effect of the shield machine shell on the tunnel structure is considered using the structural forms of two finite long beams and one semi-infinite long beam.Furthermore,the Timoshenko beam theory is adopted,providing a more accurate description of tunnel deformation,including both the bending effect and shear deformation,than existing models.Meanwhile,the buoyancy force and stratum resistance are calculated in a nonlinear manner.A reliable method for calculating the shear stiffness correction factor is proposed to better determination of the calculation parameters.The proposed theoretical model is validated through five cases using sitemonitored data.Its applicability and effectiveness are demonstrated.Furthermore,the influences of soil type,buried depth,and buoyancy force on the three key indicators of tunnel floating(i.e.the maximum uplift magnitude,the ring position with the fastest uplift race,and the ring position with the maximum uplift magnitude)are analyzed.The results indicate that the proposed model can provide a better understanding of the floating characteristics of the tunnel structure during construction.
文摘Spatio-temporal variability and dynamics in Sahelian agro-pastoral zones make each local situation a special case. These specificities must be considered to guide the dissemination of agricultural options with a view to sustainable development. The territorial scale of municipalities is not sufficient for this necessary contextualization;the scale of the “village terroir” seems to be a better option. This is the hypothesis we put forward in the framework of the Global Collaboration for Resilient Food Systems program (CRFS), i.e. local context is spatially defined by village terroir. The study is based on data collected through participatory mapping and surveys in “village terroirs” in three regions of Niger (Maradi, Dosso and Tillabéri). Then the links between farm managers and their cultivated land, as well as the spatio-temporal dynamics of local context are analyzed. This study provides evidence of the existence and functional usefulness of the village terroir for farmers, their land management and their activities. It demonstrates the usefulness of contextualizing agricultural options at this scale. Their analysis elucidates the links between “terroirs village” and the specific functioning of the agrosocio-ecosystems acting on each of them, thus laying the systemic and geographical foundations for a model of the spatio- temporal dynamics of “village terroirs”. This initial work has opened up new perspectives in modeling and sustainable development.
文摘The Fine Structure Constant (eFSC) Model attempts to give a classical definition to a magical number that underlies much of quantum physics. The Fine Structure Constant (α) value equal to 137.03599206 represents a dimensionless constant that characterizes the strength of the electromagnetic (EM) interaction between subatomic charged particles. Python-generated property counts for the twin prime force F{139/137} show that the adjusted ratio gives a value of α = 137.036. This implies a mathematical framework underlying this constant is based on twin prime numbers and set theory. This study attempts to demonstrate a proof of concept that a hierarchy of fractional twin prime (αII) forces replicates the quantum nature of the universe and is aligned with the Standard Model of Particle Physics. An expanded eFSC Model demonstrates that twin prime forces and their property sets are mathematically viable substitutes for nuclear reactions, as demonstrated for the Beta-minus decay of neutrons into protons. Most significantly, the positive and negative prime numbers define these nuclear reactants and products as positive or negatively charged ions. Furthermore, the eFSC Model provides new insights regarding the hierarchy of EM forces underlying the quantum nature of the universe.
文摘Hydrologic models generally represent the most dominant processes since they are mere simplifications of physical reality and thus are subject to many significant uncertainties. As such, a coupling strategy is proposed. To this end, the coupling of the artificial neural network (ANN) with the Xin'anjiang conceptual model with a view to enhance the quality of its flow forecast is presented. The approach uses the latest observations and residuals in runoff/discharge forecasts from the Xin'anjiang model. The two complementary models (Xin'anjiang & ANN) are used in such a way that residuals of the Xin'anjiang model are forecasted by a neural network model so that flow forecasts can be improved as new observations come in. For the complementary neural network, the input data were presented in a patterned format to conform to the calibration regime of the Xin'anjiang conceptual model, using differing variants of the neural network scheme. The results show that there is a substantial improvement in the accuracy of the forecasts when the complementary model was operated on top of the Xin'anjiang conceptual model as compared with the results of the Xin'anjiang model alone.
文摘The conceptual model is the first time abstraction ceptual model description method based on the UML and the of the real world. The traditional con- text usually has the semantic ambiguity problem. The formal description method lacks the mechanism of integrity and consistency check. Therefore both of them cannot support the simulation scenario description and the model compos- ability. A simulation conceptual description method based on ontology is put forward. According to the OWL language which was put forward by the W3C organization, a conceptual model description language is established. The OWL language semantic element in the description function in the mili- tary conceptual model is introduced. Then two layers of the military conceptual model framework are built up based on the general ontology and the domain ontology. In the general ontology, the class and property definition are given. While in the domain ontology, they are extended and a relat- ed example is given. The technique advantages of our method include the mechanism of conceptual model consistency and integrity check, the support of composable simulation models, and automatic creation of simulation scenario.
文摘Urban competitiveness is always the focus of researches on urban economy. The variety of definitions and evaluation systems of urban competitiveness are the results of lack of accurate and comprehensive understanding on urban competitiveness. This paper reviews five groups of definitions on urban competitiveness and establishes a conceptual model for urban competitiveness.
文摘The components of map information are analyzed theoretically in this paper,and the map information includes mainly the spatial information,attributive information and temporal characteristics information.Then the digital map entity is defined according to construction characteristics of the map information.Finally,on the basis of the analyses of the construction characteristics of digital map entity and present conceptual model of digital map database,an abstracted conceptual model of digital map database is presented.And the Normal Form theory of relational database is discussed particularly.
基金Short-term Climate Prediction Study for Guangdong Province a key project of Guangdong Science and Technology Committee in the national 9th five-year economic development plan Research on Long-term Tendency Prediction System for Floods/Drought and Typh
文摘Reanalysis data from NCEP/NCAR are used to systematically study preceding signals of monthly precipitation anomalies in the early raining season of Guangdong province, from the viewpoints of 500-hPa geopotential height field, outgoing longwave radiation (OLR) field, sea surface temperature (SST) and fourteen indexes of general circulation depicting atmosphere activity at high, middle and low latitutes. Being multiple tools of information, a number of conceptual models are formulated that are useful for prediction of the magnitude of monthly precipitation (drought, flood and normal conditionss).
基金This project is supported by National Natural Science Foundation of China (No. 50405037)Provincial Natural Science Foundation of Zhejiang, China (No. Y105256)Specialized Research Fund for the Doctoral Program of Higher Education, China (No. 20040335060)
文摘Aiming at the problem of abstract and polytype information modeling in product conceptual design, a method of conceptual modeling based on logical expression and evolvement is presented. Based on the logic expressions of the product conceptual design information, a fimction/logic/strucmre mapping model is set up. First, the fimction semantics is transformed into logical expressions through fimction/logic mapping. Second, the methods of logical evolvement are utilized to describe the fimction analysis, fimction/strucmre mapping and structure combination. Last, the logical structure scheme is transformed into geometrical sketch through logic/structure mapping. The conceptual design information and modeling process are described uniformly with logical methods in the model, and an effective method for computer aided conceptual design based on the model is implemented.
文摘The continuous aquifers of the Congolese Cuvette basin constitute the seat of significant water tables reversibly supplying the Congo River basin as well as the water tables they drain. Consisting mainly of sandy-clayey-sandstone formations, these aquifers contain groundwater which is the main source of drinking water supply for communities in this sector of the departments Cuvette and Cuvette-Ouest. The need for water being more and more acute, these aquifers have been subjected to drilling operations in order to supply drinking water to these populations. The information obtained from these operations is data which made it possible to obtain information relating to the lithology, the hydrogeological parameters of these aquifers and information on the depth and on the lateral variations of the water table. The purpose of this present work is to contribute to the hydrogeological characterization of the aquifer of the Cuvette basin in the departments of Cuvette and Cuvette-Ouest via data from the analysis of the technical sheets of drillings carried out by the ASPERBRAS Company, collected at the Ministry of Major Works and territory planning. This characterization was made using Visual MODFLOW Flex 2015.1 software coupled with Surfer 10 software and Rock Works 17 software. The hydrogeological interpretation of the data shows that this aquifer, whose constitution is essentially made up of sands, clayey sands and clay, is continuous, porous and free. This composition gives the aquifer of Cuvette basin a heterogeneous character. In addition, a piezometric map was produced in order to indicate the direction of the water flows which turned out to be from west to east towards the lowest areas occupied by the valleys of the rivers and rivers. The conceptual model shows that the depth of the aquifer deceases considerably from the Cuvette-Ouest towards the Cuvette.
文摘Marahoué watershed, located in the Center West of Côte d’Ivoire, has experienced significant population growth in recent decades. And a major economic boom linked to intense agricultural activity and the presence of certain industries. This population growth is also accompanied by seasonal water shortages. Hence it needs to better manage the basin’s groundwater, which is a permanent resource and more resistant than surface water to climatic hazards. The objective of this study is therefore to propose a conceptual model of hydrogeological flow for the sustainable exploitation of groundwater resources in the Marahoué watershed. The establishment of the conceptual model was carried out in two stages. The first step consisted in defining the stratigraphic units. For this purpose, three units have been defined. These are the layer of alterite, the useful fissured horizon and the sound basement. The thickness of the layer of alterite varies from 0 to 80 m with an average of 26 m. As for the useful fissured horizon, its thickness is between 43 and 46.5 with an average of 45 m. In addition, the roof of the basement presents a slightly uneven morphology with a North-West, South-East dip and the altitudes are between 150 and 390 m. The second step corresponds to the phase of determining the hydrodynamic parameters. During this phase, the crack porosity, the transmissivity, the conductivity, the storage coefficient, the hydrological balance and the piezometric map were determined. Indeed, these parameters (the crack porosity, the transmissivity, the conductivity and the storage coefficient) confirm not only the heterogeneity of the medium but that the cracked horizon is sufficiently porous to be assimilated to an equivalent continuous medium during the simulation.
文摘Firstly,this paper expounds the conceptual connotation of inservice assessment in the new system,then applies modeling and Simulation in the field of in-service assessment,establishes the conceptual model of inservice assessment and its process,and finally analyzes the application of modeling and simulation in the specific links of in-service assessment.
基金supported by the Programs Foundation of Military Theoretical Research under Grant No. 2011C025
文摘How to measure the quality of conceptual models is an important issue in the IS field and related research. This paper conducts a review of research in measuring conceptual model quality and identifies the major theoretical and practical issues that need to be addressed in future studies. We review current classification frameworks for conceptual model quality and practice of measuring conceptual model quality. Based on the review, challenges for studies of measuring the quality of conceptual models are proposed and these challenges are also research points which should be strengthened in future studies.
文摘Based on the data of sandstorm at 11 stations in Ulanqab City from 1990 to 2021,the spatial and temporal variation characteristics of sand-storm weather were analyzed firstly,and then the conceptual models of cold front and Mongolian cyclone sandstorm were obtained by analyzing sandstorm cases.Finally,the forecast points of the two types of sandstorm weather were given to provide some scientific basis and reference for the prediction of local sandstorm weather in the future.
基金The National Key Technology R&D Program of China during the 11th Five Year Plan Period(No.2008BAJ11B01)
文摘A solution to compute the optimal path based on a single-line-single-directional(SLSD)road network model is proposed.Unlike the traditional road network model,in the SLSD conceptual model,being single-directional and single-line style,a road is no longer a linkage of road nodes but abstracted as a network node.Similarly,a road node is abstracted as the linkage of two ordered single-directional roads.This model can describe turn restrictions,circular roads,and other real scenarios usually described using a super-graph.Then a computing framework for optimal path finding(OPF)is presented.It is proved that classical Dijkstra and A algorithms can be directly used for OPF computing of any real-world road networks by transferring a super-graph to an SLSD network.Finally,using Singapore road network data,the proposed conceptual model and its corresponding optimal path finding algorithms are validated using a two-step optimal path finding algorithm with a pre-computing strategy based on the SLSD road network.
基金This project was supported by the National Key Basic Research and Development Project 2004CB418301the National Natural Science Foundation of China under Grant No.40405008.
文摘The conventional and intensive observational data of the China Heavy Rain Experiment and Study (CHeRES) are used to specially analyze the heavy rainfall process in the mei-yu front that occurred during 20-21 June 2002, focusing on the meso-β system. A mesoscale convective system (MCS) formed in the warm-moist southwesterly to the south of the shear line over the Dabie Mountains and over the gorge between the Dabie and Jiuhua Mountains. The mei-yu front and shear line provide a favorable synoptic condition for the development of convection. The GPS observation indicates that the precipitable water increased obviously about 2-3 h earlier than the occurrence of rainfall and decreased after that. The abundant moisture transportation by southwesterly wind was favorable to the maintenance of convective instability and the accumulation of convective available potential energy (CAPE). Radar detection reveals that meso-β and -γ systems were very active in the MaCS. Several convection lines developed during the evolution of the MaCS, and these are associated with surface convergence lines. The boundary outflow of the convection line may have triggered another convection line. The convection line moved with the mesoscale surface convergence line, but the convective cells embedded in the convergence line propagated along the line. On the basis of the analyses of the intensive observation data, a multi-scale conceptual model of heavy rainfall in the mei-yu front for this particular case is proposed.