Past editions of the American Association of State Highway and Transportation Officials （AASHTO） Guide for Design of Pavement Structures have served well for several decades; nevertheless, many serious limitations e...Past editions of the American Association of State Highway and Transportation Officials （AASHTO） Guide for Design of Pavement Structures have served well for several decades; nevertheless, many serious limitations exist for their continued use as the nation＇s primary pavement design procedures. Researchers are now incorporating the latest advances in pavement design into the new Mechanistic-Empirical Pavement Design Guide （MEPDG）, developed under the National Cooperative Highway Research Program （NCHRP） 1-37A project and adopted and published by AASHTO. The MEPDG procedure offers several dramatic improvements over the current pavement design guide and presents a new paradigm in the way pavement design is performed. However, MEPDG is substantially more complex than the AASHTO Design Guide by considering the input parameters that influence pavement performance, including traffic, climate, pavement structure and material properties, and applying the principles of engineering mechanics to predict critical pavement responses. It requires significantly more input from the designer. Some of the required data are either not tracked previously or are stored in locations not familiar to designers, and many data sets need to be preprocessed for use in the MEPDG. As a result, tremendous research work has been conducted and still more challenges need to be tackled both in federal and state levels for the full implementation of MEPDG. This paper, for the first time, provides a comprehensive bird＇s eye view for the MEPDG procedure, including the evolvement of the design methodology, an overview of the design philosophy and its components, the research conducted during the development, improvement, and implementation phases, and the challenges remained and future developments directions. It is anticipated that the efforts in this paper aid in enhancing the mechanistic-empirical based pavement design for future continuous improvement to keep up with changes in trucking, materials, construction, design concepts, computers, and so on.展开更多
This study explains various modes that can be applied for protected area. It analyses the requirements for good governance of protected area. A study area(Kara Kara National Park) is selected for identifying key chall...This study explains various modes that can be applied for protected area. It analyses the requirements for good governance of protected area. A study area(Kara Kara National Park) is selected for identifying key challenges for implementing good governance of protected area. The challenges of good governance of protected area were investigated in this paper. The last part is based on the results from the third section and explores the strategies for addressing these challenges.展开更多
Traditionally,public goods and services have been provided by the government.In recent decades,however,public-private partnerships(PPP)were created to assist the best use of both public and private sector resources to...Traditionally,public goods and services have been provided by the government.In recent decades,however,public-private partnerships(PPP)were created to assist the best use of both public and private sector resources to enhance and extend public infrastructure assets and services.Throughout history,although governments have adopted such a combination of public and private ventures,the 1990s and early 21st centuries have witnessed a clear trend of governments across the world making significant use of different PPP arrangements.The rapid growth of PPPs has occurred since the 1990s throughout the globe as it was considered the preferred tool for public procurement of infrastructure and services.This paper examines the relevant literature of PPP and attempts to identify the historical development,the major reasons,the main types,forms,benefits of building PPP,as well as challenging issues facing the implementation of PPP in today’s world.展开更多
The FAIR principles articulate the behaviors expected from digital artifacts that are Findable,Accessible,Interoperable and Reusable by machines and by people.Although by now widely accepted,the FAIR Principles by des...The FAIR principles articulate the behaviors expected from digital artifacts that are Findable,Accessible,Interoperable and Reusable by machines and by people.Although by now widely accepted,the FAIR Principles by design do not explicitly consider actual implementation choices enabling FAIR behaviors.As different communities have their own,often well-established implementation preferences and priorities for data reuse,coordinating a broadly accepted,widely used FAIR implementation approach remains a global challenge.In an effort to accelerate broad community convergence on FAIR implementation options,the GO FAIR community has launched the development of the FAIR Convergence Matrix.The Matrix is a platform that compiles for any community of practice,an inventory of their self-declared FAIR implementation choices and challenges.The Convergence Matrix is itself a FAIR resource,openly available,and encourages voluntary participation by any self-identified community of practice(not only the GO FAIR Implementation Networks).Based on patterns of use and reuse of existing resources,the Convergence Matrix supports the transparent derivation of strategies that optimally coordinate convergence on standards and technologies in the emerging Internet of FAIR Data and Services.展开更多
文摘Past editions of the American Association of State Highway and Transportation Officials （AASHTO） Guide for Design of Pavement Structures have served well for several decades; nevertheless, many serious limitations exist for their continued use as the nation＇s primary pavement design procedures. Researchers are now incorporating the latest advances in pavement design into the new Mechanistic-Empirical Pavement Design Guide （MEPDG）, developed under the National Cooperative Highway Research Program （NCHRP） 1-37A project and adopted and published by AASHTO. The MEPDG procedure offers several dramatic improvements over the current pavement design guide and presents a new paradigm in the way pavement design is performed. However, MEPDG is substantially more complex than the AASHTO Design Guide by considering the input parameters that influence pavement performance, including traffic, climate, pavement structure and material properties, and applying the principles of engineering mechanics to predict critical pavement responses. It requires significantly more input from the designer. Some of the required data are either not tracked previously or are stored in locations not familiar to designers, and many data sets need to be preprocessed for use in the MEPDG. As a result, tremendous research work has been conducted and still more challenges need to be tackled both in federal and state levels for the full implementation of MEPDG. This paper, for the first time, provides a comprehensive bird＇s eye view for the MEPDG procedure, including the evolvement of the design methodology, an overview of the design philosophy and its components, the research conducted during the development, improvement, and implementation phases, and the challenges remained and future developments directions. It is anticipated that the efforts in this paper aid in enhancing the mechanistic-empirical based pavement design for future continuous improvement to keep up with changes in trucking, materials, construction, design concepts, computers, and so on.
文摘This study explains various modes that can be applied for protected area. It analyses the requirements for good governance of protected area. A study area(Kara Kara National Park) is selected for identifying key challenges for implementing good governance of protected area. The challenges of good governance of protected area were investigated in this paper. The last part is based on the results from the third section and explores the strategies for addressing these challenges.
文摘Traditionally,public goods and services have been provided by the government.In recent decades,however,public-private partnerships(PPP)were created to assist the best use of both public and private sector resources to enhance and extend public infrastructure assets and services.Throughout history,although governments have adopted such a combination of public and private ventures,the 1990s and early 21st centuries have witnessed a clear trend of governments across the world making significant use of different PPP arrangements.The rapid growth of PPPs has occurred since the 1990s throughout the globe as it was considered the preferred tool for public procurement of infrastructure and services.This paper examines the relevant literature of PPP and attempts to identify the historical development,the major reasons,the main types,forms,benefits of building PPP,as well as challenging issues facing the implementation of PPP in today’s world.
基金FAIRsharing is funded by grants awarded to SAS that include elements of this workspecifically,grants from the UK BBSRC and Research Councils(BB/L024101/1,BB/L005069/1)+1 种基金European Union(H2020-EU.3.1,634107,H2020-EU.1.4.1.3,654241,H2020-EU.1.4.1.1,676559),IMI(116060)and NIH(U54 AI117925,1U24AI117966-01,1OT3OD025459-01,1OT3OD025467-01,1OT3OD025462-01)the new FAIRsharing award from the Wellcome Trust(212930/Z/18/Z),as well as a related award(208381/A/17/Z).
文摘The FAIR principles articulate the behaviors expected from digital artifacts that are Findable,Accessible,Interoperable and Reusable by machines and by people.Although by now widely accepted,the FAIR Principles by design do not explicitly consider actual implementation choices enabling FAIR behaviors.As different communities have their own,often well-established implementation preferences and priorities for data reuse,coordinating a broadly accepted,widely used FAIR implementation approach remains a global challenge.In an effort to accelerate broad community convergence on FAIR implementation options,the GO FAIR community has launched the development of the FAIR Convergence Matrix.The Matrix is a platform that compiles for any community of practice,an inventory of their self-declared FAIR implementation choices and challenges.The Convergence Matrix is itself a FAIR resource,openly available,and encourages voluntary participation by any self-identified community of practice(not only the GO FAIR Implementation Networks).Based on patterns of use and reuse of existing resources,the Convergence Matrix supports the transparent derivation of strategies that optimally coordinate convergence on standards and technologies in the emerging Internet of FAIR Data and Services.
