In a global dynamic analysis,the coexisting attractors and their basins are the main tools to understand the system behavior and safety.However,both basins and attractors can be drastically influenced by uncertainties...In a global dynamic analysis,the coexisting attractors and their basins are the main tools to understand the system behavior and safety.However,both basins and attractors can be drastically influenced by uncertainties.The aim of this work is to illustrate a methodology for the global dynamic analysis of nondeterministic dynamical systems with competing attractors.Accordingly,analytical and numerical tools for calculation of nondeterministic global structures,namely attractors and basins,are proposed.First,based on the definition of the Perron-Frobenius,Koopman and Foias linear operators,a global dynamic description through phase-space operators is presented for both deterministic and nondeterministic cases.In this context,the stochastic basins of attraction and attractors’distributions replace the usual basin and attractor concepts.Then,numerical implementation of these concepts is accomplished via an adaptative phase-space discretization strategy based on the classical Ulam method.Sample results of the methodology are presented for a canonical dynamical system.展开更多
The quality of information flow management has a remarkable effect on the entire life cycle of buildings.Manual retrieval of technical specifications and features of building components and their performance assessmen...The quality of information flow management has a remarkable effect on the entire life cycle of buildings.Manual retrieval of technical specifications and features of building components and their performance assessment leads to increased cost and time and efficiency reduction,especially during the facility management(FM)stage.The introduction of building information modeling(BIM)in the construction industry can provide a valuable means of improving the organization and exchange of information.BIM tools integrate multiple levels of information within a single digital model of a building.Nevertheless,the support given by BIM to FM is far from being fully effective.Technicians can benefit from real-time communication with the data repository whenever the need for gathering contextual information and/or updating any data in the digital model arises.The framework proposed in this study aims to develop a system that supports on-site operations.Information requirements have been determined from the analyses of procedures that are usually implemented in the building life cycle.These studies set the standard for the development of a digital model of a building,which will be shared among various actors in charge of FM and accessed via a cloud platform.Moreover,mixed reality is proposed to support specific information that is relevant to geometric features and procedures to be followed by operators.This article presents three use-cases supported by the proposed framework.In addition,this research article describes the first proof of concept regarding real-time support for FM.展开更多
The rheological properties of the bituminous components （bitumen and bituminous mastic） within asphalt mixtures contribute significantly to the major distresses of flexible pavements （i.e. rutting, fatigue and low ...The rheological properties of the bituminous components （bitumen and bituminous mastic） within asphalt mixtures contribute significantly to the major distresses of flexible pavements （i.e. rutting, fatigue and low temperature cracking）. Asphalt mixtures are usually composed of mastic-coated aggregates rather than pure bitumen-coated aggre- gates. The purpose of this study is to investigate the effects of mineral fillers on the theological behaviour of several polymer-modified bitumens （PMBs） through laboratory mixing. A neat bitumen and two types of polymers （elastomeric and plastomeric） were used to produce PMBs, and two fillers with different minerals （limestone and basalt） were selected to obtain mastics. The dynamic shear rheometer （DSR） and bending beam rheometer （BBR） were used to characterize the theological properties of PMBs and mastics. In particular, multiple stress creep recovery （MSCR） tests were performed to evaluate the rutting potential at high temperatures, whereas BBR tests were carried out to investigate the low temperature behaviour of these materials. BBR results for unmodified mastics show that the increase of stiffness is similar regardless of the filler type, whereas results for polymer-modified mastics indicate that the degree of stiffening depends on the combi- nation of filler/polymer types. MSCR results show that adding filler leads to a reduced susceptibility of permanent deformation and an enhanced elastic response, depending on the combination of filler/polymer types. Overall results suggest that a physical-chemical interaction between the filler and bitumen occurs, and that the interaction level is highly dependent on the type of polymer modification.展开更多
The use of alternative renewable sources to totally or partially replace bitumen is one of the most current challenges in the road pavement sector.The growing energy cost and environmental concerns lead to the necessi...The use of alternative renewable sources to totally or partially replace bitumen is one of the most current challenges in the road pavement sector.The growing energy cost and environmental concerns lead to the necessity to find alternative solutions,by supporting at the same time sustainability and circular economy principles.Within this framework,this paper presents the application of a powder lignin,a natural bio-polymer deriving from byproducts of wood pulp and paper industry,to replace part of bitumen.The bituminous blend consisting in 70%of bitumen and 30%of powder lignin(by weight)was made in laboratory through the use of a high shear stirring mixer,and a reference plain bitumen characterized by a similar consistency(i.e.,same penetration grade)was used as comparison.Then,an extensive investigation on chemical and rheological properties of the bio-binder is presented.Fourier transform infrared spectroscopy(FTIR),saturates,aromatics,resins and asphaltenes(SARA),bending beam rheometer(BBR),frequency sweep tests and multiple stress creep recovery tests(MSCR)with a dynamic shear rheometer(DSR)were performed.Moreover,unaged,short-and long-term aging conditions were considered.Results indicated that powder lignin dominates the rheological behavior of the bio-binder and,from chemical analysis,it seems that it partially acts as a filler and partially as a binder.This would result in improved performances at both low and high temperatures,leading to a wider temperature range of performance grade(PG).Moreover,despite a stiffening effect is recognized,lignin also offers an antioxidant potentiality,reducing the aging susceptibility of the investigated bio-binder.展开更多
In the wide context of facility management,several processes,such as operations,maintenance,retrofitting,and renovations,ensure that buildings comply with the principles of efficiency,cost-effectiveness,and indoor com...In the wide context of facility management,several processes,such as operations,maintenance,retrofitting,and renovations,ensure that buildings comply with the principles of efficiency,cost-effectiveness,and indoor comfort.Apart from ordinary operation,facility management is responsible for the renovation of and long-term performance improvement of building facilities.In such a scenario,the cyber–physical system(CPS)paradigm with holonic architecture,which is the focus of this study,can successfully guide the operation management and long-term refurbishment processes of buildings.Analogous to the manufacturing field,the developed CPS maximizes holons’self-configuration and self-organization and overall throughput effectiveness metrics to detect the best corrective actions toward system improvements.Consequently,suggestions and lessons learned from the evaluation of building efficiency are redirected to the building information model.Hence,the digital model acts as a repository of currently available equipment for operations management and the history of diagnoses that support decision-making during the maintenance,retrofitting,and renovation processes.Evidently,the repeated detection of a specific issue,which is unaffected by operations management,should be considered an opportunity to act and enhance the performances of existing building components.Similar to a goods-producing industry,the building management system developed in this study applies the aforementioned methodology to provide services related to indoor comfort and building health.This approach indicates that a method for automatic real-time diagnosis is tested in a case study consisting of a multi-use and large public building.The current paper,which is an extended version of the one presented in the Creative Construction Conference 2018,deepens the decision support tool and the supervision policy.Moreover,the developed system is contextualized by providing an example of use case and highlighting the step forward in the field of smart buildings.展开更多
Pavement skid resistance plays a crucial role in ensuring road safety and avoiding accidents.In the past,the laboratory evaluation of the skid resistance was carried out by studying only the coarse aggregates of the w...Pavement skid resistance plays a crucial role in ensuring road safety and avoiding accidents.In the past,the laboratory evaluation of the skid resistance was carried out by studying only the coarse aggregates of the wearing course.To overcome this drawback,the Wehner-Schulze(WS)machine was developed in Germany in the 1960s.This equipment,composed of a polishing unit and a measuring unit,has great potential in predicting pavement skid resistance and its evolution over time,but is still little known in the pavement community(especially outside Europe).For these reasons,there is a need of a comprehensive review of the existing technical-scientific literature concerning the use of the WS machine.Specifically,this paper focuses on the main factors affecting the skid resistance in WS tests,the correlation of WS data with other laboratory test methods and with field skid resistance/polishing,and the available prediction models that have been validated through WS measurements.The critical analysis of the existing literature highlights that it is possible to correlate WS data with typical skid resistance field measurements as well as WS polishing with traffic polishing,but further efforts are needed in this regard.Future work should focus especially on open-graded mixtures and innovative asphalt mixtures(e.g.,containing recycled materials and additives).From the perspective of pavement management,based on a theoretical background,the WS test results could be used as starting point for simplified prediction models of the in-situ skid resistance.展开更多
The authors use the asymptotic expansion method by P.G.Ciarlet to obtain a Kirchhoff-Love-type plate model for a linear soft ferromagnetic material.They also give a mathematical justification of the obtained model by ...The authors use the asymptotic expansion method by P.G.Ciarlet to obtain a Kirchhoff-Love-type plate model for a linear soft ferromagnetic material.They also give a mathematical justification of the obtained model by means of a strong convergence result.展开更多
基金support of the Brazil-ian research agencies,the National Council for Scientific and Technological Development (CNPq)(Nos. 301355/2018-5 and 200198/2022-0)FAPERJ-CNE (No. E-26/202.711/2018)+1 种基金FAPERJ Nota 10 (No. E-26/200.357/2020)CAPES (Finance code 001 and 88881.310620/2018-01)。
文摘In a global dynamic analysis,the coexisting attractors and their basins are the main tools to understand the system behavior and safety.However,both basins and attractors can be drastically influenced by uncertainties.The aim of this work is to illustrate a methodology for the global dynamic analysis of nondeterministic dynamical systems with competing attractors.Accordingly,analytical and numerical tools for calculation of nondeterministic global structures,namely attractors and basins,are proposed.First,based on the definition of the Perron-Frobenius,Koopman and Foias linear operators,a global dynamic description through phase-space operators is presented for both deterministic and nondeterministic cases.In this context,the stochastic basins of attraction and attractors’distributions replace the usual basin and attractor concepts.Then,numerical implementation of these concepts is accomplished via an adaptative phase-space discretization strategy based on the classical Ulam method.Sample results of the methodology are presented for a canonical dynamical system.
文摘The quality of information flow management has a remarkable effect on the entire life cycle of buildings.Manual retrieval of technical specifications and features of building components and their performance assessment leads to increased cost and time and efficiency reduction,especially during the facility management(FM)stage.The introduction of building information modeling(BIM)in the construction industry can provide a valuable means of improving the organization and exchange of information.BIM tools integrate multiple levels of information within a single digital model of a building.Nevertheless,the support given by BIM to FM is far from being fully effective.Technicians can benefit from real-time communication with the data repository whenever the need for gathering contextual information and/or updating any data in the digital model arises.The framework proposed in this study aims to develop a system that supports on-site operations.Information requirements have been determined from the analyses of procedures that are usually implemented in the building life cycle.These studies set the standard for the development of a digital model of a building,which will be shared among various actors in charge of FM and accessed via a cloud platform.Moreover,mixed reality is proposed to support specific information that is relevant to geometric features and procedures to be followed by operators.This article presents three use-cases supported by the proposed framework.In addition,this research article describes the first proof of concept regarding real-time support for FM.
基金supported by the Ministry of EducationUniversities and Research project"Damage and healing of innovative nano-structured and polymer-modified bituminous materials"(Grant RBFR10JOWO)under the"FIRB-Futuro in Ricerca 2010"funding program
文摘The rheological properties of the bituminous components （bitumen and bituminous mastic） within asphalt mixtures contribute significantly to the major distresses of flexible pavements （i.e. rutting, fatigue and low temperature cracking）. Asphalt mixtures are usually composed of mastic-coated aggregates rather than pure bitumen-coated aggre- gates. The purpose of this study is to investigate the effects of mineral fillers on the theological behaviour of several polymer-modified bitumens （PMBs） through laboratory mixing. A neat bitumen and two types of polymers （elastomeric and plastomeric） were used to produce PMBs, and two fillers with different minerals （limestone and basalt） were selected to obtain mastics. The dynamic shear rheometer （DSR） and bending beam rheometer （BBR） were used to characterize the theological properties of PMBs and mastics. In particular, multiple stress creep recovery （MSCR） tests were performed to evaluate the rutting potential at high temperatures, whereas BBR tests were carried out to investigate the low temperature behaviour of these materials. BBR results for unmodified mastics show that the increase of stiffness is similar regardless of the filler type, whereas results for polymer-modified mastics indicate that the degree of stiffening depends on the combi- nation of filler/polymer types. MSCR results show that adding filler leads to a reduced susceptibility of permanent deformation and an enhanced elastic response, depending on the combination of filler/polymer types. Overall results suggest that a physical-chemical interaction between the filler and bitumen occurs, and that the interaction level is highly dependent on the type of polymer modification.
文摘The use of alternative renewable sources to totally or partially replace bitumen is one of the most current challenges in the road pavement sector.The growing energy cost and environmental concerns lead to the necessity to find alternative solutions,by supporting at the same time sustainability and circular economy principles.Within this framework,this paper presents the application of a powder lignin,a natural bio-polymer deriving from byproducts of wood pulp and paper industry,to replace part of bitumen.The bituminous blend consisting in 70%of bitumen and 30%of powder lignin(by weight)was made in laboratory through the use of a high shear stirring mixer,and a reference plain bitumen characterized by a similar consistency(i.e.,same penetration grade)was used as comparison.Then,an extensive investigation on chemical and rheological properties of the bio-binder is presented.Fourier transform infrared spectroscopy(FTIR),saturates,aromatics,resins and asphaltenes(SARA),bending beam rheometer(BBR),frequency sweep tests and multiple stress creep recovery tests(MSCR)with a dynamic shear rheometer(DSR)were performed.Moreover,unaged,short-and long-term aging conditions were considered.Results indicated that powder lignin dominates the rheological behavior of the bio-binder and,from chemical analysis,it seems that it partially acts as a filler and partially as a binder.This would result in improved performances at both low and high temperatures,leading to a wider temperature range of performance grade(PG).Moreover,despite a stiffening effect is recognized,lignin also offers an antioxidant potentiality,reducing the aging susceptibility of the investigated bio-binder.
文摘In the wide context of facility management,several processes,such as operations,maintenance,retrofitting,and renovations,ensure that buildings comply with the principles of efficiency,cost-effectiveness,and indoor comfort.Apart from ordinary operation,facility management is responsible for the renovation of and long-term performance improvement of building facilities.In such a scenario,the cyber–physical system(CPS)paradigm with holonic architecture,which is the focus of this study,can successfully guide the operation management and long-term refurbishment processes of buildings.Analogous to the manufacturing field,the developed CPS maximizes holons’self-configuration and self-organization and overall throughput effectiveness metrics to detect the best corrective actions toward system improvements.Consequently,suggestions and lessons learned from the evaluation of building efficiency are redirected to the building information model.Hence,the digital model acts as a repository of currently available equipment for operations management and the history of diagnoses that support decision-making during the maintenance,retrofitting,and renovation processes.Evidently,the repeated detection of a specific issue,which is unaffected by operations management,should be considered an opportunity to act and enhance the performances of existing building components.Similar to a goods-producing industry,the building management system developed in this study applies the aforementioned methodology to provide services related to indoor comfort and building health.This approach indicates that a method for automatic real-time diagnosis is tested in a case study consisting of a multi-use and large public building.The current paper,which is an extended version of the one presented in the Creative Construction Conference 2018,deepens the decision support tool and the supervision policy.Moreover,the developed system is contextualized by providing an example of use case and highlighting the step forward in the field of smart buildings.
基金financially supported by the Sustainable Mobility Center (Centro Nazionale per la Mobilita Sostenibile-MOST), Spoke 7 (Connected Networks and Smart Infrastructure), Work Package 4 (Resilience of networks, structural health monitoring and asset management) under the National Recovery and Resilience Plan (Piano Nazionale di Ripresa e Resilienza-PNRR)funded by the European Union-NextGenerationEU
文摘Pavement skid resistance plays a crucial role in ensuring road safety and avoiding accidents.In the past,the laboratory evaluation of the skid resistance was carried out by studying only the coarse aggregates of the wearing course.To overcome this drawback,the Wehner-Schulze(WS)machine was developed in Germany in the 1960s.This equipment,composed of a polishing unit and a measuring unit,has great potential in predicting pavement skid resistance and its evolution over time,but is still little known in the pavement community(especially outside Europe).For these reasons,there is a need of a comprehensive review of the existing technical-scientific literature concerning the use of the WS machine.Specifically,this paper focuses on the main factors affecting the skid resistance in WS tests,the correlation of WS data with other laboratory test methods and with field skid resistance/polishing,and the available prediction models that have been validated through WS measurements.The critical analysis of the existing literature highlights that it is possible to correlate WS data with typical skid resistance field measurements as well as WS polishing with traffic polishing,but further efforts are needed in this regard.Future work should focus especially on open-graded mixtures and innovative asphalt mixtures(e.g.,containing recycled materials and additives).From the perspective of pavement management,based on a theoretical background,the WS test results could be used as starting point for simplified prediction models of the in-situ skid resistance.
文摘The authors use the asymptotic expansion method by P.G.Ciarlet to obtain a Kirchhoff-Love-type plate model for a linear soft ferromagnetic material.They also give a mathematical justification of the obtained model by means of a strong convergence result.
