In conformity with the principle of Design for Manufacture,feature-based design strate- (?)es have been developed.As the“feature”is relevant to the“macro process plan”and“macro NC programs”,obviously,“feature”...In conformity with the principle of Design for Manufacture,feature-based design strate- (?)es have been developed.As the“feature”is relevant to the“macro process plan”and“macro NC programs”,obviously,“feature”is beyond the power of conventional solid modellers.Neverthe- less,substantial breakthrough has not been made in the solid modeling field,except“feature at- taching”or“feature recognizing”methods have been taken on.In this paper,the theory, concepts,system architecture,and algorithm principles of solid modeling tool system have been represented.The practice of Feature Solid Modeling Tool System (FSMTS) developed at Huazhong University has proved that the tool may be a new foundation of Feature-Based Design.展开更多
To mill fine and well-defined micro-dimpled structures,a machining manner of spiral trajectory tool reciprocating motion,where the tool repeats the process of‘feed milling–retract–cutting feed–feed milling again’...To mill fine and well-defined micro-dimpled structures,a machining manner of spiral trajectory tool reciprocating motion,where the tool repeats the process of‘feed milling–retract–cutting feed–feed milling again’along the spiral trajectory,was proposed.From the kinematics analysis,it is found that the machining quality of micro-dimpled structures is highly dependent on the machining trajectory using spiral trajectory tool reciprocating motion.To reveal this causation,simulation modelling and experimental studies were carried out.A simulation model was developed to quantitatively and qualitatively investigate the influence of the trajectory discretization strategies(constant-angle and constant-arc length)and parameters(discrete angle,discrete arc length,and pitch)on surface texture and residual height of micro-dimpled structures.Subsequently,micro-dimpled structures were milled under different trajectory discretization strategies and parameters with spiral trajectory tool reciprocating motion.A comprehensive comparison between the milled results and simulation analysis was made based on geometry accuracy,surface morphology and surface roughness of milled dimples.Meanwhile,the errors and factors affecting the above three aspects were analyzed.The results demonstrate both the feasibility of the established simulation model and the machining capability of this machining way in milling high-quality micro-dimpled structures.Spiral trajectory tool reciprocating motion provides a new machining way for milling micro-dimpled structures and micro-dimpled functional surfaces.And an appropriate machining trajectory can be generated based on the optimized trajectory parameters,thus contributing to the improvement of machining quality and efficiency.展开更多
Efforts are underway to rehabilitate the irrigation districts,such as in the Rio Grande Basin in Texas.Water distribution network models are needed to help prioritize and analyze various rehabilitation options,as well...Efforts are underway to rehabilitate the irrigation districts,such as in the Rio Grande Basin in Texas.Water distribution network models are needed to help prioritize and analyze various rehabilitation options,as well as to scientifically quantify irrigation water demands,usages,and losses,and to help manage gate automation.However,commercially available software packages were limited in applications due to their high cost and operational difficulty.This study aims to develop a modeling tool for modeling the water flow profile in irrigation distribution networks.The goal of developing the modeling tool was to make the modeling process simple,fast,reliable and accurate.On the basis of methodological study,the modeling tool has been developed for branching canal networks with the assumption of steady gradually varied flow.The flow profile calculation of the tool was verified from a single channel with 1%root mean squared error compared to the benchmark calculation and a branching network with 5%to 12%relative errors compared to check point measurement along the network.The developed modeling tool will be able to play an important role in water quantification for planning,analysis and development for modernization of irrigation systems.展开更多
Global forest cover is undergoing significant transformations due to anthropogenic activities and natural disturbances,profoundly impacting hydrological processes.However,the inherent spatial heterogeneity within wate...Global forest cover is undergoing significant transformations due to anthropogenic activities and natural disturbances,profoundly impacting hydrological processes.However,the inherent spatial heterogeneity within watersheds leads to varied hydrological responses across spatiotemporal scales,challenging comprehensive assessment of logging impacts at the watershed scale.Here,we developed multiple forest logging scenarios using the soil and water assessment tool(SWAT)model for the Le'an River watershed,a 5,837 km2 subtropical watershed in China,to quantify the hydrological effects of forest logging across different spatiotemporal scales.Our results demonstrate that increasing forest logging ratios from 1.54% to 9.25% consistently enhanced ecohydrological sensitivity.However,sensitivity varied across spatiotemporal scales,with the rainy season(15.30%-15.81%)showing higher sensitivity than annual(11.56%-12.07%)and dry season(3.38%-5.57%)periods.Additionally,the ecohydrological sensitivity of logging varied significantly across the watershed,with midstream areas exhibiting the highest sensitivity(13.13%-13.25%),followed by downstream(11.87%-11.98%)and upstream regions(9.96%-10.05%).Furthermore,the whole watershed exhibited greater hydrological resilience to logging compared to upstream areas,with attenuated runoff changes due to scale effects.Scale effects were more pronounced during dry seasons((-8.13 to -42.13)×10^(4) m^(3)·month^(-1))than in the rainy season((-11.11 to -26.65)×10^(4) m^(3)·month^(-1)).These findings advance understanding of logging impacts on hydrology across different spatiotemporal scales in subtropical regions,providing valuable insights for forest management under increasing anthropogenic activities and climate change.展开更多
The influence of an acoustic logging tool on borehole guided wave propagation should be considered in the processing and inversion of the guided waves for formation acoustic property estimation. This study introduces ...The influence of an acoustic logging tool on borehole guided wave propagation should be considered in the processing and inversion of the guided waves for formation acoustic property estimation. This study introduces an equivalent-tool theory that models the tool response using an elastic rod with an effective modulus and applies the theory to multipole acoustic logging for both wireline and logging while drilling （LWD） conditions. The theory can be derived by matching the tool’s acoustic impedance/conductance to that of the multipole acoustic wavefield around the tool, assuming that tool radius is small compared to wavelength. We have validated the effectiveness and accuracy of the theory using numerical modeling and its practicality using field data. In field data applications, one can calibrate the tool parameters by fitting the theoretical dispersion curve to field data without having to consider the actual tool’s structure and composition. We use a dispersion correction example to demonstrate an application of the simple theory to field data processing and the validity of the processing result.展开更多
Model parameters estimation is a pivotal issue for runoff modeling in ungauged catchments.The nonlinear relationship between model parameters and catchment descriptors is a major obstacle for parameter regionalization...Model parameters estimation is a pivotal issue for runoff modeling in ungauged catchments.The nonlinear relationship between model parameters and catchment descriptors is a major obstacle for parameter regionalization,which is the most widely used approach.Runoff modeling was studied in 38 catchments located in the Yellow–Huai–Hai River Basin(YHHRB).The values of the Nash–Sutcliffe efficiency coefficient(NSE),coefficient of determination(R2),and percent bias(PBIAS)indicated the acceptable performance of the soil and water assessment tool(SWAT)model in the YHHRB.Nine descriptors belonging to the categories of climate,soil,vegetation,and topography were used to express the catchment characteristics related to the hydrological processes.The quantitative relationships between the parameters of the SWAT model and the catchment descriptors were analyzed by six regression-based models,including linear regression(LR)equations,support vector regression(SVR),random forest(RF),k-nearest neighbor(kNN),decision tree(DT),and radial basis function(RBF).Each of the 38 catchments was assumed to be an ungauged catchment in turn.Then,the parameters in each target catchment were estimated by the constructed regression models based on the remaining 37 donor catchments.Furthermore,the similaritybased regionalization scheme was used for comparison with the regression-based approach.The results indicated that the runoff with the highest accuracy was modeled by the SVR-based scheme in ungauged catchments.Compared with the traditional LR-based approach,the accuracy of the runoff modeling in ungauged catchments was improved by the machine learning algorithms because of the outstanding capability to deal with nonlinear relationships.The performances of different approaches were similar in humid regions,while the advantages of the machine learning techniques were more evident in arid regions.When the study area contained nested catchments,the best result was calculated with the similarity-based parameter regionalization scheme because of the high catchment density and short spatial distance.The new findings could improve flood forecasting and water resources planning in regions that lack observed data.展开更多
In this paper, the authors present the development of a data modelling tool that visualizes the transformation process of an ＂Entity-Relationship＂ Diagram （ERD） into a relational database schema. The authors＇ foc...In this paper, the authors present the development of a data modelling tool that visualizes the transformation process of an ＂Entity-Relationship＂ Diagram （ERD） into a relational database schema. The authors＇ focus is the design of a tool for educational purposes and its implementation on e-learning database course. The tool presents two stages of database design. The first stage is to draw ERD graphically and validate it. The drawing is done by a learner. Then at second stage, the system enables automatically transformation of ERD to relational database schema by using common rules. Thus, the learner could understand more easily how to apply the theoretical material. A detailed description of system functionalities and algorithm for the conversion are proposed. Finally, a user interface and usage aspects are exposed.展开更多
A CNC simulation system based on intemet for operation training of manufacturing facility and manufacturing process simulation is proposed. Firstly, the system framework and a rapid modeling method of CNC machine tool...A CNC simulation system based on intemet for operation training of manufacturing facility and manufacturing process simulation is proposed. Firstly, the system framework and a rapid modeling method of CNC machine tool are studied under the virtual environment based on PolyTrans and CAD software. Then, a new method is proposed to enhance and expand the interactive ability of virtual reality modeling language（VRML） by attaining communication among VRML, JavaApplet, JavaScript and Html so as to realize the virtual operation for CNC machine tool. Moreover, the algorithm of material removed simulation based on VRML Z-map is presented. The advantages of this algorithm include less memory requirement and much higher computation. Lastly, the CNC milling machine is taken as an illustrative example for the prototype development in order to validate the feasibility of the proposed approach.展开更多
The key techniques of modular design of heavy duty NC mathine tools are described. Amodule definition modelfor modular design and manufacturing of heavy duty NC machine tools isbulit and the essential composition of t...The key techniques of modular design of heavy duty NC mathine tools are described. Amodule definition modelfor modular design and manufacturing of heavy duty NC machine tools isbulit and the essential composition of the module definition model (MDM) is discussed in detail. Itis composed of two models: the part definition model (PDM) and the module assembly model(MAM). The PDM and MAM are built and their structures are given. Using object-oriented know-ledge representation and based on these models, an intelligent support system of modular design forheavy duty NC machine tools is developed and implemented This system has been applied to thepractical use of Wuhan Heavy Duty Machine Tool Works展开更多
Changes in natural geographic features and landscape patterns directly influence the hydrology and non-point source pollution processes in the watershed;however,to slow down non-point source pollution,it is necessary ...Changes in natural geographic features and landscape patterns directly influence the hydrology and non-point source pollution processes in the watershed;however,to slow down non-point source pollution,it is necessary to distinguish their effects.But the non-point source pollution process is interactional as a result of multiple factors,and the collinearity between multiple independent variables limits our ability of reason diagnosis.Thus,taking the Burhatong River Basin,Northeast China as an example,the methods of hydrological simulation,geographic detectors,and redundancy analysis have been combined to determine the impact of natural geographic features and landscape patterns on non-point source pollution in the watershed.The Soil&Water Assessment Tool(SWAT)has been adopted to simulate the spatial and temporal distribution characteristics of total nitrogen and total phosphorus in the watershed.The results show that the proportions of agricultural land and forest area and the location-weighted landscape contrast index(LWLI)are the main indicators influencing the rivers total nitrogen and total phosphorus.The interaction of these indicators with natural geographic features and landscape configuration indicators also significantly influences the changes in total nitrogen(TN)and total phosphorus(TP).Natural geographical features and landscape patterns have different comprehensive effects on non-point source pollution in the dry and wet seasons.TN and TP loads are affected mainly by the change in landscape pattern,especially in the wet season.Although the ecological restoration program has improved forest coverage,the purification effect of increased forest coverage on the water quality in the watershed may be offset by the negative impact of increased forest fragmentation.The high concentration and complexity of farmland patches increase the risk of non-point source pollution spread to a certain extent.展开更多
The air quality directive （2008/50/EC （of the European Parliament and of the Council of 21 May 2008）） requires European Member States to design appropriate AQPs （air quality plans） for zones and agglomerations w...The air quality directive （2008/50/EC （of the European Parliament and of the Council of 21 May 2008）） requires European Member States to design appropriate AQPs （air quality plans） for zones and agglomerations where the air quality does not comply with the limit values and to assess possible emission reduction measures to decrease concentration levels. The Portuguese agglomeration of Porto Litoral is one of the several European Union urban areas that had to develop and implement AQPs to reduce particulate matter （PM10）. The AQPs were initially designed based on a scenario approach and using an air quality model, which was applied over the study region for the reference situation with the current PM10 emissions, and for a reduction scenario with PM10 emissions re-estimated considering the implementation of abatement measures. Aiming to cost-efficiently optimize Porto Litoral PM10 abatement measures, the assessment procedure was repeated using an optimization approach based on the RIAT ＋ （regional integrated assessment tool ＋）. Porto Litoral urban area＇s technical and non-technical measures were characterized （including associated costs） and, through the application of the air quality model to 20 emissions abatement scenarios, S-R （source-receptor） relationships were created. This paper comparatively describes the air quality plans designed to improve PM10 levels in the Porto Litoral agglomeration based on both the scenario analysis and the optimization approach.展开更多
Landuse is one of the most influential factors of non-point source pollution. Based on the three-year landuse data( 2000,2005 and 2008),Arc GIS and Fragstat were used to analyze the landuse type and the change of land...Landuse is one of the most influential factors of non-point source pollution. Based on the three-year landuse data( 2000,2005 and 2008),Arc GIS and Fragstat were used to analyze the landuse type and the change of landscape pattern. The relationships between landuse and non-point source-total nitrogen( NPS-TN) and nonpoint source-total phosphorus( NPS-TP) were discussed with the methods of spatially statistical analysis,landscape pattern analysis and principal component analysis. The study results conveyed that agricultural land and forestland,which accounted for over 92% of the study area,were the major landuse type of Ashi River Basin.Meanwhile,the NPS pollution had close connections with landuse type and landscape pattern. When it comes to landuse type,the export risks of NPS-TN and NPS-TP were agricultural land > urban land > grassland > forestland. As for landscape pattern,NPS-TN and NPS-TP were positively related to SHDI and SHEI, while negatively connected with LPI,AI and COHESION. Therefore,the study could reach the conclusion that the more fragmented and complicated the landscape patterns were,the more serious the NPS pollution was.展开更多
Virtual manufacturing is fast becoming an affordable technology with wide-ranging applications in modern manufacturing. Its advantages over existing technology are primarily that users can visualize, feel involvement ...Virtual manufacturing is fast becoming an affordable technology with wide-ranging applications in modern manufacturing. Its advantages over existing technology are primarily that users can visualize, feel involvement and interact with virtual representations of real world activities in real time. In this paper, a virtual cutting system is built which can simulate turning process, estimate tool wear and cutting force using artificial neural network etc. Using the simulated machining environment in virtual reality (VR), the user can practise and preview the operations for possible problems that might occur during implementation. This approach enables designers to evaluate and design feasible machining processes in a consistent manner as early as possible during the development process.展开更多
Abstract： Excess of organic matter and nutrients in water promotes eutrophication process observed in the Ardila River. It was classified as much polluted being critical for Alqueva-Pedrogāo System. The aim of this ...Abstract： Excess of organic matter and nutrients in water promotes eutrophication process observed in the Ardila River. It was classified as much polluted being critical for Alqueva-Pedrogāo System. The aim of this study was to estimate the transported nutrients loads in a transboundary watershed using the SWAT （soil and water assessment tool） model and to determine the contribution of nutrients load in the entire watershed. Ardila watershed is about 3,711 km^2 extended from Spain （78%） to the eastern part of Portugal （22%）. It was discretized into 32 sub-basins using automated delineation routine, and 174 hydrologic response units. Monthly average meteorological data （from 1947 to 1998） were used to generate daily values through the weather generator Model incorporated in SWAT. Real daily precipitation （from 1931 to 2003） was introduced. The model was calibrated and verified for flow （from 1950 to 2000） and nutrients （from 1981 to 1999）. Model performance was evaluated using statistical parameters, such as NSE （Nash-Sutcliffe efficiency） and root mean square error （R2）. Calibration and verification flow results showed a satisfactory agreement between simulated and measured monthly date from 1962 to 1972 （NSE = 0.8; R^2 = 0.9）. The results showed that the most important diffuse pollution comes from the two the main tributary （Spain）. The estimated nitrogen and phosphorous loads contribution per year was respectively 72% and 59% in Spain and 28% and 41% in Portugal. The SWAT model was revealed to be a useful tool for an integrated water management approach that might be improved taking into count the WFD （water framework directive）.展开更多
Aims and Scope.Building Simulation publishes original,high quality,peer-reviewed research papers and review articles dealing with modeling and simulation of buildings including their systems.The goal is to promote the...Aims and Scope.Building Simulation publishes original,high quality,peer-reviewed research papers and review articles dealing with modeling and simulation of buildings including their systems.The goal is to promote the field of building science and technology to such a level that modeling will eventually be used in every aspect of building construction as a routine instead of an exception.Of particular interest are papers that reflect recent developments and applications of modeling tools and their impact on advances of building science and technology.展开更多
It is hard to model a complex system by simply combining its partial characteristics.This paper presents a multi-view collaborative modeling method for complex system.Multi users,multi subjects,multi granularities and...It is hard to model a complex system by simply combining its partial characteristics.This paper presents a multi-view collaborative modeling method for complex system.Multi users,multi subjects,multi granularities and multi models in complex system modeling are unified to multi views.The principles and schemes for the decomposition of complex systems are introduced.According to the principle of separation of concerns,a complex system can be decomposed to a variety of model views.Collaborative modeling means that the views can be associated and integrated to form complete system model through their semantic.According to the form of representation,the models are generalizes to three kinds,i.e.,view models,semantic models and storage models,which provides a unified framework for conversion and mapping between the models.Under the guidance of the method,a tool for the modeling of warship C2 system is developed.Applications show that the tool can support collaborative modeling and design for C2 system outstandingly.展开更多
The extreme rainfall forecast performances of both of ECMWF-IFS and ECMWF-EPS with MET version 5.1 were examined in landing Typhoon Soudelor(1513) with 60 h lead times. In this study the programs for converting ECMWF&...The extreme rainfall forecast performances of both of ECMWF-IFS and ECMWF-EPS with MET version 5.1 were examined in landing Typhoon Soudelor(1513) with 60 h lead times. In this study the programs for converting ECMWF's forecast data(both of ECMWF-IFS and ECMWF-EPS) format into that needed by MET were developed. Also, during landfall, the observed maximum 6-hour accumulated rainfall was investigated, and then the verification of extreme rainfall in Soudelor was carried out. Results showed that while traditional verification gives relatively low scores, by the method for object-based diagnostic evaluation(MODE) the significant rainy areas were well predicted in this case study.展开更多
Various process-based models are extensively being used to analyze and forecast catchment hydrology and water quality. However, it is always important to select the appropriate hydrological and water quality modeling ...Various process-based models are extensively being used to analyze and forecast catchment hydrology and water quality. However, it is always important to select the appropriate hydrological and water quality modeling tools to predict and analyze the watershed and also consider their strengths and weaknesses. Different factors such as data availability, hydrological, hydraulic, and water quality processes and their desired level of complexity are crucial for selecting a plausible modeling tool. This review is focused on suitable model selection with a focus on desired hydrological, hydraulic and water quality processes(nitrogen fate and transport in surface, subsurface and groundwater bodies) by keeping in view the typical lowland catchments with intensive agricultural land use,higher groundwater tables, and decreased retention times due to the provision of artificial drainage. In this study, four different physically based, partially and fully distributed integrated water modeling tools, SWAT(soil and water assessment tool), SWIM(soil and water integrated model),HSPF(hydrological simulation program– FORTRAN) and a combination of tools from DHI(MIKE SHE coupled with MIKE 11 and ECO Lab), have been reviewed particularly for the Tollense River catchment located in North-eastern Germany. DHI combined tools and SWAT were more suitable for simulating the desired hydrological processes, but in the case of river hydraulics and water quality, the DHI family of tools has an edge due to their integrated coupling between MIKE SHE, MIKE 11 and ECO Lab. In case of SWAT, it needs to be coupled with another tool to model the hydraulics in the Tollense River as SWAT does not include backwater effects and provision of control structures. However, both SWAT and DHI tools are more data demanding in comparison to SWIM and HSPF. For studying nitrogen fate and transport in unsaturated, saturated, and river zone, HSPF was a better model to simulate the desired nitrogen transformation and transport processes. However, for nitrogen dynamics and transformations in shallow streams, ECO Lab had an edge due its flexibility for inclusion of user-desired water quality parameters and processes. In the case of SWIM, most of the input data and governing equations are similar to SWAT but it does not include water bodies(ponds and lakes), wetlands and drainage systems. In this review, only the processes that were needed to simulate the Tollense River catchment were considered, however the resulted model selection criteria can be generalized to other lowland catchments in Australia, North-western Europe and North America with similar complexity.展开更多
Liquid smoke is a natural product made up of smoke concentrate which is used to impart a smoky flavour without resorting to the traditional smoking technique:it is practical to use,cheap,easy to dose,able to control t...Liquid smoke is a natural product made up of smoke concentrate which is used to impart a smoky flavour without resorting to the traditional smoking technique:it is practical to use,cheap,easy to dose,able to control the presence of undesirable substances and,above all,with reduced environmental impact,unlike traditional smoking systems.On the other hand,it has a low preservation effect.Thus,the objective of this study was to design the production of an innovative fish product using liquid smoke in combination with natural compounds through three subsequent phases:1)economic concept evaluation to assess the acceptability of the proposed product through a qualitative and quantitative investigation;2)optimisation of the process(individuation of smoking liquid composition and process parameters)using modelling predictive tools,i.e.tertiary and secondary models;3)product realization and its evaluation in terms of microbiological profile,chemical-physical param-eters,and consumers’acceptability.Results show that sea bream and sea bass fillets could be sprayed using a solution composed by lemon extract(0.75%),acetic acid(0.5%),NaCl(2%),and liquid smoke(0.002%),packed under vacuum and stored at 4℃ for at least two weeks,during which spoilage bacteria maintained low cell loads.After 14 days,in fact,smoked fillets showed total viable count and psychrotrophs of about 5 log CFU/g,Pseudomonadaceae about 6 log CFU/g,while for Enterobacteriaceae cell loads of 2-3 log CFU/g were recorded.Other microbial groups were absent and pathogens were never detected.In addition,results from the consumer survey highlight that over 60%of the interviewed sample appeared inclined to accept innovation,with 50%of respondents also willing to pay a premium price of 20%,thus sug-gesting that the proposed eco-smoking technique could be adopted and help in ensuring a more sustainable food production.展开更多
Satellite-and reanalysis-based precipitation products are important data source for precipitation, particularly in areas with a sparse gauge network. Here, five open-access precipitation products, including the newly ...Satellite-and reanalysis-based precipitation products are important data source for precipitation, particularly in areas with a sparse gauge network. Here, five open-access precipitation products, including the newly released China Meteorological Assimilation Driving Datasets for the Soil and Water Assessment Tool(SWAT) model(CMADS)reanalysis dataset and four widely used bias-adjusted satellite precipitation products [SPPs;i.e., Tropical Rainfall Measuring Mission(TRMM) Multisatellite Precipitation Analysis 3B42 Version 7(TMPA 3B42V7), Climate Prediction Center(CPC) morphing technique satellite–gauge blended product(CMORPH-BLD), Climate Hazards Group Infrared Precipitation with Station Data(CHIRPS), and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks–Climate Data Record(PERSIANN-CDR)], were assessed. These products were first compared with the gauge observed data collected for the upper Huaihe River basin, and then were used as forcing data for streamflow simulation by the Xin’anjiang(XAJ) hydrological model under two scenarios with different calibration procedures. The performance of CMADS precipitation product for the Chinese mainland was also assessed. The results show that:(1) for the statistical assessment, CMADS and CMORPH-BLD perform the best, followed by TMPA 3B42V7, CHIRPS, and PERSIANN-CDR, among which the correlation coefficient(CC) and rootmean-square error(RMSE) values of CMADS are optimal, although it exhibits certain significant negative relative bias(BIAS;-22.72%);(2) CMORPH-BLD performs the best in capturing and detecting rainfall events, while CMADS tends to underestimate heavy and torrential precipitation;(3) for streamflow simulation, the performance of using CMADS as input is very good, with the highest Nash–Sutcliffe efficiency(NSE) values(0.85 and 0.75 for calibration period and validation period, respectively);and(4) CMADS exhibits high accuracy in eastern China while with significant negative BIAS, and the performance declines from southeast to northwest. The statistical and hydrological evaluations show that CMADS and CMORPH-BLD have high potential for observing precipitation. As high negative BIAS values showed up in CMADS evaluation, further study on the error sources from original data and calibration algorithms is necessary. This study can serve as a reference for selecting precipitation products in datascarce regions with similar climates and topography in the Global Precipitation Measurement(GPM) era.展开更多
文摘In conformity with the principle of Design for Manufacture,feature-based design strate- (?)es have been developed.As the“feature”is relevant to the“macro process plan”and“macro NC programs”,obviously,“feature”is beyond the power of conventional solid modellers.Neverthe- less,substantial breakthrough has not been made in the solid modeling field,except“feature at- taching”or“feature recognizing”methods have been taken on.In this paper,the theory, concepts,system architecture,and algorithm principles of solid modeling tool system have been represented.The practice of Feature Solid Modeling Tool System (FSMTS) developed at Huazhong University has proved that the tool may be a new foundation of Feature-Based Design.
基金co-supported the National Natural Science Foundation of China(No.52235010)the Heilongjiang Postdoctoral Fund(No.LBH-Z22136)the New Era Longjiang Excellent Master and Doctoral Dissertation Fund(No.LJYXL2022-057).
文摘To mill fine and well-defined micro-dimpled structures,a machining manner of spiral trajectory tool reciprocating motion,where the tool repeats the process of‘feed milling–retract–cutting feed–feed milling again’along the spiral trajectory,was proposed.From the kinematics analysis,it is found that the machining quality of micro-dimpled structures is highly dependent on the machining trajectory using spiral trajectory tool reciprocating motion.To reveal this causation,simulation modelling and experimental studies were carried out.A simulation model was developed to quantitatively and qualitatively investigate the influence of the trajectory discretization strategies(constant-angle and constant-arc length)and parameters(discrete angle,discrete arc length,and pitch)on surface texture and residual height of micro-dimpled structures.Subsequently,micro-dimpled structures were milled under different trajectory discretization strategies and parameters with spiral trajectory tool reciprocating motion.A comprehensive comparison between the milled results and simulation analysis was made based on geometry accuracy,surface morphology and surface roughness of milled dimples.Meanwhile,the errors and factors affecting the above three aspects were analyzed.The results demonstrate both the feasibility of the established simulation model and the machining capability of this machining way in milling high-quality micro-dimpled structures.Spiral trajectory tool reciprocating motion provides a new machining way for milling micro-dimpled structures and micro-dimpled functional surfaces.And an appropriate machining trajectory can be generated based on the optimized trajectory parameters,thus contributing to the improvement of machining quality and efficiency.
基金supported by USDA-Cooperative State Research,Education,and Extension Service(project no.2005-45048-03208)administered by the Texas Water Resources Institute.
文摘Efforts are underway to rehabilitate the irrigation districts,such as in the Rio Grande Basin in Texas.Water distribution network models are needed to help prioritize and analyze various rehabilitation options,as well as to scientifically quantify irrigation water demands,usages,and losses,and to help manage gate automation.However,commercially available software packages were limited in applications due to their high cost and operational difficulty.This study aims to develop a modeling tool for modeling the water flow profile in irrigation distribution networks.The goal of developing the modeling tool was to make the modeling process simple,fast,reliable and accurate.On the basis of methodological study,the modeling tool has been developed for branching canal networks with the assumption of steady gradually varied flow.The flow profile calculation of the tool was verified from a single channel with 1%root mean squared error compared to the benchmark calculation and a branching network with 5%to 12%relative errors compared to check point measurement along the network.The developed modeling tool will be able to play an important role in water quantification for planning,analysis and development for modernization of irrigation systems.
基金supported by the National Natural Science Foundation of China(No.31660234).
文摘Global forest cover is undergoing significant transformations due to anthropogenic activities and natural disturbances,profoundly impacting hydrological processes.However,the inherent spatial heterogeneity within watersheds leads to varied hydrological responses across spatiotemporal scales,challenging comprehensive assessment of logging impacts at the watershed scale.Here,we developed multiple forest logging scenarios using the soil and water assessment tool(SWAT)model for the Le'an River watershed,a 5,837 km2 subtropical watershed in China,to quantify the hydrological effects of forest logging across different spatiotemporal scales.Our results demonstrate that increasing forest logging ratios from 1.54% to 9.25% consistently enhanced ecohydrological sensitivity.However,sensitivity varied across spatiotemporal scales,with the rainy season(15.30%-15.81%)showing higher sensitivity than annual(11.56%-12.07%)and dry season(3.38%-5.57%)periods.Additionally,the ecohydrological sensitivity of logging varied significantly across the watershed,with midstream areas exhibiting the highest sensitivity(13.13%-13.25%),followed by downstream(11.87%-11.98%)and upstream regions(9.96%-10.05%).Furthermore,the whole watershed exhibited greater hydrological resilience to logging compared to upstream areas,with attenuated runoff changes due to scale effects.Scale effects were more pronounced during dry seasons((-8.13 to -42.13)×10^(4) m^(3)·month^(-1))than in the rainy season((-11.11 to -26.65)×10^(4) m^(3)·month^(-1)).These findings advance understanding of logging impacts on hydrology across different spatiotemporal scales in subtropical regions,providing valuable insights for forest management under increasing anthropogenic activities and climate change.
基金supported by the Fundamental Research Funds for the Central Universities and the National Hi-tech Research and Development Program of China (863 Program) (Grant No. 2007AA06Z232 )
文摘The influence of an acoustic logging tool on borehole guided wave propagation should be considered in the processing and inversion of the guided waves for formation acoustic property estimation. This study introduces an equivalent-tool theory that models the tool response using an elastic rod with an effective modulus and applies the theory to multipole acoustic logging for both wireline and logging while drilling （LWD） conditions. The theory can be derived by matching the tool’s acoustic impedance/conductance to that of the multipole acoustic wavefield around the tool, assuming that tool radius is small compared to wavelength. We have validated the effectiveness and accuracy of the theory using numerical modeling and its practicality using field data. In field data applications, one can calibrate the tool parameters by fitting the theoretical dispersion curve to field data without having to consider the actual tool’s structure and composition. We use a dispersion correction example to demonstrate an application of the simple theory to field data processing and the validity of the processing result.
基金funded by the National Key Research and Development Program of China(2017YFA0605002,2017YFA0605004,and 2016YFA0601501)the National Natural Science Foundation of China(41961124007,51779145,and 41830863)“Six top talents”in Jiangsu Province(RJFW-031)。
文摘Model parameters estimation is a pivotal issue for runoff modeling in ungauged catchments.The nonlinear relationship between model parameters and catchment descriptors is a major obstacle for parameter regionalization,which is the most widely used approach.Runoff modeling was studied in 38 catchments located in the Yellow–Huai–Hai River Basin(YHHRB).The values of the Nash–Sutcliffe efficiency coefficient(NSE),coefficient of determination(R2),and percent bias(PBIAS)indicated the acceptable performance of the soil and water assessment tool(SWAT)model in the YHHRB.Nine descriptors belonging to the categories of climate,soil,vegetation,and topography were used to express the catchment characteristics related to the hydrological processes.The quantitative relationships between the parameters of the SWAT model and the catchment descriptors were analyzed by six regression-based models,including linear regression(LR)equations,support vector regression(SVR),random forest(RF),k-nearest neighbor(kNN),decision tree(DT),and radial basis function(RBF).Each of the 38 catchments was assumed to be an ungauged catchment in turn.Then,the parameters in each target catchment were estimated by the constructed regression models based on the remaining 37 donor catchments.Furthermore,the similaritybased regionalization scheme was used for comparison with the regression-based approach.The results indicated that the runoff with the highest accuracy was modeled by the SVR-based scheme in ungauged catchments.Compared with the traditional LR-based approach,the accuracy of the runoff modeling in ungauged catchments was improved by the machine learning algorithms because of the outstanding capability to deal with nonlinear relationships.The performances of different approaches were similar in humid regions,while the advantages of the machine learning techniques were more evident in arid regions.When the study area contained nested catchments,the best result was calculated with the similarity-based parameter regionalization scheme because of the high catchment density and short spatial distance.The new findings could improve flood forecasting and water resources planning in regions that lack observed data.
文摘In this paper, the authors present the development of a data modelling tool that visualizes the transformation process of an ＂Entity-Relationship＂ Diagram （ERD） into a relational database schema. The authors＇ focus is the design of a tool for educational purposes and its implementation on e-learning database course. The tool presents two stages of database design. The first stage is to draw ERD graphically and validate it. The drawing is done by a learner. Then at second stage, the system enables automatically transformation of ERD to relational database schema by using common rules. Thus, the learner could understand more easily how to apply the theoretical material. A detailed description of system functionalities and algorithm for the conversion are proposed. Finally, a user interface and usage aspects are exposed.
基金Selected from Proceedings of the 7th International Conference on Frontiers of Design and Manufacturing (ICFDM'2006)This project is supported by National Natural Science Foundation of China (No.50775047)Scientific and Technological Foundation of Guangdong Province,China(No.2004B10201032).
文摘A CNC simulation system based on intemet for operation training of manufacturing facility and manufacturing process simulation is proposed. Firstly, the system framework and a rapid modeling method of CNC machine tool are studied under the virtual environment based on PolyTrans and CAD software. Then, a new method is proposed to enhance and expand the interactive ability of virtual reality modeling language（VRML） by attaining communication among VRML, JavaApplet, JavaScript and Html so as to realize the virtual operation for CNC machine tool. Moreover, the algorithm of material removed simulation based on VRML Z-map is presented. The advantages of this algorithm include less memory requirement and much higher computation. Lastly, the CNC milling machine is taken as an illustrative example for the prototype development in order to validate the feasibility of the proposed approach.
文摘The key techniques of modular design of heavy duty NC mathine tools are described. Amodule definition modelfor modular design and manufacturing of heavy duty NC machine tools isbulit and the essential composition of the module definition model (MDM) is discussed in detail. Itis composed of two models: the part definition model (PDM) and the module assembly model(MAM). The PDM and MAM are built and their structures are given. Using object-oriented know-ledge representation and based on these models, an intelligent support system of modular design forheavy duty NC machine tools is developed and implemented This system has been applied to thepractical use of Wuhan Heavy Duty Machine Tool Works
基金Under the auspices of the National Key R&D Program(No.2019YFC0409104)the National Natural Science Foundation of China(No.41830643)the National Science and Technology Basic Resources Survey Project(No.2019FY101703)。
文摘Changes in natural geographic features and landscape patterns directly influence the hydrology and non-point source pollution processes in the watershed;however,to slow down non-point source pollution,it is necessary to distinguish their effects.But the non-point source pollution process is interactional as a result of multiple factors,and the collinearity between multiple independent variables limits our ability of reason diagnosis.Thus,taking the Burhatong River Basin,Northeast China as an example,the methods of hydrological simulation,geographic detectors,and redundancy analysis have been combined to determine the impact of natural geographic features and landscape patterns on non-point source pollution in the watershed.The Soil&Water Assessment Tool(SWAT)has been adopted to simulate the spatial and temporal distribution characteristics of total nitrogen and total phosphorus in the watershed.The results show that the proportions of agricultural land and forest area and the location-weighted landscape contrast index(LWLI)are the main indicators influencing the rivers total nitrogen and total phosphorus.The interaction of these indicators with natural geographic features and landscape configuration indicators also significantly influences the changes in total nitrogen(TN)and total phosphorus(TP).Natural geographical features and landscape patterns have different comprehensive effects on non-point source pollution in the dry and wet seasons.TN and TP loads are affected mainly by the change in landscape pattern,especially in the wet season.Although the ecological restoration program has improved forest coverage,the purification effect of increased forest coverage on the water quality in the watershed may be offset by the negative impact of increased forest fragmentation.The high concentration and complexity of farmland patches increase the risk of non-point source pollution spread to a certain extent.
文摘The air quality directive （2008/50/EC （of the European Parliament and of the Council of 21 May 2008）） requires European Member States to design appropriate AQPs （air quality plans） for zones and agglomerations where the air quality does not comply with the limit values and to assess possible emission reduction measures to decrease concentration levels. The Portuguese agglomeration of Porto Litoral is one of the several European Union urban areas that had to develop and implement AQPs to reduce particulate matter （PM10）. The AQPs were initially designed based on a scenario approach and using an air quality model, which was applied over the study region for the reference situation with the current PM10 emissions, and for a reduction scenario with PM10 emissions re-estimated considering the implementation of abatement measures. Aiming to cost-efficiently optimize Porto Litoral PM10 abatement measures, the assessment procedure was repeated using an optimization approach based on the RIAT ＋ （regional integrated assessment tool ＋）. Porto Litoral urban area＇s technical and non-technical measures were characterized （including associated costs） and, through the application of the air quality model to 20 emissions abatement scenarios, S-R （source-receptor） relationships were created. This paper comparatively describes the air quality plans designed to improve PM10 levels in the Porto Litoral agglomeration based on both the scenario analysis and the optimization approach.
基金National Natural Science Foundation of China(No.51179041)the Major Science and Technology Program for Water Pollution Control and Treatment,China(No.2013ZX07201007)+2 种基金Natural Science Foundation of Heilongjiang Province,China(No.E201206)Special Fund for Science and Technology Innovation of Harbin,China(No.2012RFLXS026)the State Key Lab of Urban Water Resource and Environment(Harbin Institute of Technology),China(No.2014TS05)
文摘Landuse is one of the most influential factors of non-point source pollution. Based on the three-year landuse data( 2000,2005 and 2008),Arc GIS and Fragstat were used to analyze the landuse type and the change of landscape pattern. The relationships between landuse and non-point source-total nitrogen( NPS-TN) and nonpoint source-total phosphorus( NPS-TP) were discussed with the methods of spatially statistical analysis,landscape pattern analysis and principal component analysis. The study results conveyed that agricultural land and forestland,which accounted for over 92% of the study area,were the major landuse type of Ashi River Basin.Meanwhile,the NPS pollution had close connections with landuse type and landscape pattern. When it comes to landuse type,the export risks of NPS-TN and NPS-TP were agricultural land > urban land > grassland > forestland. As for landscape pattern,NPS-TN and NPS-TP were positively related to SHDI and SHEI, while negatively connected with LPI,AI and COHESION. Therefore,the study could reach the conclusion that the more fragmented and complicated the landscape patterns were,the more serious the NPS pollution was.
文摘Virtual manufacturing is fast becoming an affordable technology with wide-ranging applications in modern manufacturing. Its advantages over existing technology are primarily that users can visualize, feel involvement and interact with virtual representations of real world activities in real time. In this paper, a virtual cutting system is built which can simulate turning process, estimate tool wear and cutting force using artificial neural network etc. Using the simulated machining environment in virtual reality (VR), the user can practise and preview the operations for possible problems that might occur during implementation. This approach enables designers to evaluate and design feasible machining processes in a consistent manner as early as possible during the development process.
文摘Abstract： Excess of organic matter and nutrients in water promotes eutrophication process observed in the Ardila River. It was classified as much polluted being critical for Alqueva-Pedrogāo System. The aim of this study was to estimate the transported nutrients loads in a transboundary watershed using the SWAT （soil and water assessment tool） model and to determine the contribution of nutrients load in the entire watershed. Ardila watershed is about 3,711 km^2 extended from Spain （78%） to the eastern part of Portugal （22%）. It was discretized into 32 sub-basins using automated delineation routine, and 174 hydrologic response units. Monthly average meteorological data （from 1947 to 1998） were used to generate daily values through the weather generator Model incorporated in SWAT. Real daily precipitation （from 1931 to 2003） was introduced. The model was calibrated and verified for flow （from 1950 to 2000） and nutrients （from 1981 to 1999）. Model performance was evaluated using statistical parameters, such as NSE （Nash-Sutcliffe efficiency） and root mean square error （R2）. Calibration and verification flow results showed a satisfactory agreement between simulated and measured monthly date from 1962 to 1972 （NSE = 0.8; R^2 = 0.9）. The results showed that the most important diffuse pollution comes from the two the main tributary （Spain）. The estimated nitrogen and phosphorous loads contribution per year was respectively 72% and 59% in Spain and 28% and 41% in Portugal. The SWAT model was revealed to be a useful tool for an integrated water management approach that might be improved taking into count the WFD （water framework directive）.
文摘Aims and Scope.Building Simulation publishes original,high quality,peer-reviewed research papers and review articles dealing with modeling and simulation of buildings including their systems.The goal is to promote the field of building science and technology to such a level that modeling will eventually be used in every aspect of building construction as a routine instead of an exception.Of particular interest are papers that reflect recent developments and applications of modeling tools and their impact on advances of building science and technology.
文摘It is hard to model a complex system by simply combining its partial characteristics.This paper presents a multi-view collaborative modeling method for complex system.Multi users,multi subjects,multi granularities and multi models in complex system modeling are unified to multi views.The principles and schemes for the decomposition of complex systems are introduced.According to the principle of separation of concerns,a complex system can be decomposed to a variety of model views.Collaborative modeling means that the views can be associated and integrated to form complete system model through their semantic.According to the form of representation,the models are generalizes to three kinds,i.e.,view models,semantic models and storage models,which provides a unified framework for conversion and mapping between the models.Under the guidance of the method,a tool for the modeling of warship C2 system is developed.Applications show that the tool can support collaborative modeling and design for C2 system outstandingly.
基金supported by STI/CMA through the National Basic Research Program of China (2015CB452806)Projects for Public Welfare (Meteorology) of China (GYHY201506007)WMO-TLFDP and UNESCAP/WMO Typhoon Committee Research Fellowship
文摘The extreme rainfall forecast performances of both of ECMWF-IFS and ECMWF-EPS with MET version 5.1 were examined in landing Typhoon Soudelor(1513) with 60 h lead times. In this study the programs for converting ECMWF's forecast data(both of ECMWF-IFS and ECMWF-EPS) format into that needed by MET were developed. Also, during landfall, the observed maximum 6-hour accumulated rainfall was investigated, and then the verification of extreme rainfall in Soudelor was carried out. Results showed that while traditional verification gives relatively low scores, by the method for object-based diagnostic evaluation(MODE) the significant rainy areas were well predicted in this case study.
基金project BOOT-monitoring in the BMBF program ReWaM(FKZ:033W039A-F)
文摘Various process-based models are extensively being used to analyze and forecast catchment hydrology and water quality. However, it is always important to select the appropriate hydrological and water quality modeling tools to predict and analyze the watershed and also consider their strengths and weaknesses. Different factors such as data availability, hydrological, hydraulic, and water quality processes and their desired level of complexity are crucial for selecting a plausible modeling tool. This review is focused on suitable model selection with a focus on desired hydrological, hydraulic and water quality processes(nitrogen fate and transport in surface, subsurface and groundwater bodies) by keeping in view the typical lowland catchments with intensive agricultural land use,higher groundwater tables, and decreased retention times due to the provision of artificial drainage. In this study, four different physically based, partially and fully distributed integrated water modeling tools, SWAT(soil and water assessment tool), SWIM(soil and water integrated model),HSPF(hydrological simulation program– FORTRAN) and a combination of tools from DHI(MIKE SHE coupled with MIKE 11 and ECO Lab), have been reviewed particularly for the Tollense River catchment located in North-eastern Germany. DHI combined tools and SWAT were more suitable for simulating the desired hydrological processes, but in the case of river hydraulics and water quality, the DHI family of tools has an edge due to their integrated coupling between MIKE SHE, MIKE 11 and ECO Lab. In case of SWAT, it needs to be coupled with another tool to model the hydraulics in the Tollense River as SWAT does not include backwater effects and provision of control structures. However, both SWAT and DHI tools are more data demanding in comparison to SWIM and HSPF. For studying nitrogen fate and transport in unsaturated, saturated, and river zone, HSPF was a better model to simulate the desired nitrogen transformation and transport processes. However, for nitrogen dynamics and transformations in shallow streams, ECO Lab had an edge due its flexibility for inclusion of user-desired water quality parameters and processes. In the case of SWIM, most of the input data and governing equations are similar to SWAT but it does not include water bodies(ponds and lakes), wetlands and drainage systems. In this review, only the processes that were needed to simulate the Tollense River catchment were considered, however the resulted model selection criteria can be generalized to other lowland catchments in Australia, North-western Europe and North America with similar complexity.
基金funded by the project PO FEAMP 2014/2020-Measure 1.26“Valorizzazione di specie ittiche affumicate mediante tecniche tradizionali e innovative”,Apulia region.(CUP N.B71B17000990009Project leader:UNCI-Agroalimentare).
文摘Liquid smoke is a natural product made up of smoke concentrate which is used to impart a smoky flavour without resorting to the traditional smoking technique:it is practical to use,cheap,easy to dose,able to control the presence of undesirable substances and,above all,with reduced environmental impact,unlike traditional smoking systems.On the other hand,it has a low preservation effect.Thus,the objective of this study was to design the production of an innovative fish product using liquid smoke in combination with natural compounds through three subsequent phases:1)economic concept evaluation to assess the acceptability of the proposed product through a qualitative and quantitative investigation;2)optimisation of the process(individuation of smoking liquid composition and process parameters)using modelling predictive tools,i.e.tertiary and secondary models;3)product realization and its evaluation in terms of microbiological profile,chemical-physical param-eters,and consumers’acceptability.Results show that sea bream and sea bass fillets could be sprayed using a solution composed by lemon extract(0.75%),acetic acid(0.5%),NaCl(2%),and liquid smoke(0.002%),packed under vacuum and stored at 4℃ for at least two weeks,during which spoilage bacteria maintained low cell loads.After 14 days,in fact,smoked fillets showed total viable count and psychrotrophs of about 5 log CFU/g,Pseudomonadaceae about 6 log CFU/g,while for Enterobacteriaceae cell loads of 2-3 log CFU/g were recorded.Other microbial groups were absent and pathogens were never detected.In addition,results from the consumer survey highlight that over 60%of the interviewed sample appeared inclined to accept innovation,with 50%of respondents also willing to pay a premium price of 20%,thus sug-gesting that the proposed eco-smoking technique could be adopted and help in ensuring a more sustainable food production.
基金Supported by the National Key Research and Development Program of China(2016YFA0601504)National Natural Science Foundation of China(51979069)+1 种基金Fundamental Research Funds for the Central Universities(B200204029)Program of Introducing Talents of Discipline to Universities by the Ministry of Education and State Administration of Foreign Experts Affairs,China(B08048)。
文摘Satellite-and reanalysis-based precipitation products are important data source for precipitation, particularly in areas with a sparse gauge network. Here, five open-access precipitation products, including the newly released China Meteorological Assimilation Driving Datasets for the Soil and Water Assessment Tool(SWAT) model(CMADS)reanalysis dataset and four widely used bias-adjusted satellite precipitation products [SPPs;i.e., Tropical Rainfall Measuring Mission(TRMM) Multisatellite Precipitation Analysis 3B42 Version 7(TMPA 3B42V7), Climate Prediction Center(CPC) morphing technique satellite–gauge blended product(CMORPH-BLD), Climate Hazards Group Infrared Precipitation with Station Data(CHIRPS), and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks–Climate Data Record(PERSIANN-CDR)], were assessed. These products were first compared with the gauge observed data collected for the upper Huaihe River basin, and then were used as forcing data for streamflow simulation by the Xin’anjiang(XAJ) hydrological model under two scenarios with different calibration procedures. The performance of CMADS precipitation product for the Chinese mainland was also assessed. The results show that:(1) for the statistical assessment, CMADS and CMORPH-BLD perform the best, followed by TMPA 3B42V7, CHIRPS, and PERSIANN-CDR, among which the correlation coefficient(CC) and rootmean-square error(RMSE) values of CMADS are optimal, although it exhibits certain significant negative relative bias(BIAS;-22.72%);(2) CMORPH-BLD performs the best in capturing and detecting rainfall events, while CMADS tends to underestimate heavy and torrential precipitation;(3) for streamflow simulation, the performance of using CMADS as input is very good, with the highest Nash–Sutcliffe efficiency(NSE) values(0.85 and 0.75 for calibration period and validation period, respectively);and(4) CMADS exhibits high accuracy in eastern China while with significant negative BIAS, and the performance declines from southeast to northwest. The statistical and hydrological evaluations show that CMADS and CMORPH-BLD have high potential for observing precipitation. As high negative BIAS values showed up in CMADS evaluation, further study on the error sources from original data and calibration algorithms is necessary. This study can serve as a reference for selecting precipitation products in datascarce regions with similar climates and topography in the Global Precipitation Measurement(GPM) era.
