Radiative cooling systems(RCSs)possess the distinctive capability to dissipate heat energy via solar and thermal radiation,making them suitable for thermal regulation and energy conservation applications,essential for...Radiative cooling systems(RCSs)possess the distinctive capability to dissipate heat energy via solar and thermal radiation,making them suitable for thermal regulation and energy conservation applications,essential for mitigating the energy crisis.A comprehensive review connecting the advancements in engineered radiative cooling systems(ERCSs),encompassing material and structural design as well as thermal and energy-related applications,is currently absent.Herein,this review begins with a concise summary of the essential concepts of ERCSs,followed by an introduction to engineered materials and structures,containing nature-inspired designs,chromatic materials,meta-structural configurations,and multilayered constructions.It subsequently encapsulates the primary applications,including thermal-regulating textiles and energy-saving devices.Next,it highlights the challenges of ERCSs,including maximized thermoregulatory effects,environmental adaptability,scalability and sustainability,and interdisciplinary integration.It seeks to offer direction for forthcoming fundamental research and industrial advancement of radiative cooling systems in real-world applications.展开更多
Piezoelectric materials are capable of actuation and sensing and have been used in a wide variety of smart devices and structures.Active fiber composite and macro fiber composite are newly developed types of piezoelec...Piezoelectric materials are capable of actuation and sensing and have been used in a wide variety of smart devices and structures.Active fiber composite and macro fiber composite are newly developed types of piezoelectric composites,and show superior properties to monolithic piezoelectric wafer due to their distinctive structures.Numerous work has focused on the performance prediction of the composites by evaluation of structural parameters and properties of the constituent materials with analytical and numerical methods.Various applications have been explored for the piezoelectric fiber composites,including vibration and noise control,health monitoring,morphing of structures and energy harvesting,in which the composites play key role and demonstrate the necessity for further development.展开更多
The unmanned aerial vehicle(UAV)-assisted mobile edge computing(MEC)has been deemed a promising solution for energy-constrained devices to run smart applications with computationintensive and latency-sensitive require...The unmanned aerial vehicle(UAV)-assisted mobile edge computing(MEC)has been deemed a promising solution for energy-constrained devices to run smart applications with computationintensive and latency-sensitive requirements,especially in some infrastructure-limited areas or some emergency scenarios.However,the multi-UAVassisted MEC network remains largely unexplored.In this paper,the dynamic trajectory optimization and computation offloading are studied in a multi-UAVassisted MEC system where multiple UAVs fly over a target area with different trajectories to serve ground users.By considering the dynamic channel condition and random task arrival and jointly optimizing UAVs'trajectories,user association,and subchannel assignment,the average long-term sum of the user energy consumption minimization problem is formulated.To address the problem involving both discrete and continuous variables,a hybrid decision deep reinforcement learning(DRL)-based intelligent energyefficient resource allocation and trajectory optimization algorithm is proposed,named HDRT algorithm,where deep Q network(DQN)and deep deterministic policy gradient(DDPG)are invoked to process discrete and continuous variables,respectively.Simulation results show that the proposed HDRT algorithm converges fast and outperforms other benchmarks in the aspect of user energy consumption and latency.展开更多
The year of 2013 is considered the first year of smart city in China. With the development of informationization and urbanization in China, city diseases(traffic jam, medical problem and unbalanced education) are more...The year of 2013 is considered the first year of smart city in China. With the development of informationization and urbanization in China, city diseases(traffic jam, medical problem and unbalanced education) are more and more apparent. Smart city is the key to solving these diseases. This paper presents the overall smart city development in China in term of market scale and development stages, the technology standards, and industry layout. The paper claims that the issues and challenges facing smart city development in China and proposes to make polices to support smart city development.展开更多
Computing students face the problem with time and quality of the work while managing their graduation/senior projects.Rapid Application Development(RAD)model is based on continual user involvement for the process of r...Computing students face the problem with time and quality of the work while managing their graduation/senior projects.Rapid Application Development(RAD)model is based on continual user involvement for the process of requirement gathering via prototyping.After each iteration,the developers can validate the requirements that are completed in the iteration.Managing a project with RAD is easier but not flexible.On the other hand,Agile project management techniques focus on flexibility,agility,teamwork and quality based on user stories.Continual user involvement is avoided,which requires extensive maintenance time for fixing iteration and release of the story points.This also makes it necessary to provide onsite training to the users of the application.This research provides the pros and cons of RAD and Agile project management techniques,to help students in deciding the best approach for managing their graduation projects.For the evaluation of these techniques,similar case studies were given to the senior project students(having similar CGPAs)for building similar functionality-based applications.The two projects“Life Organizer”developed and managed using RAD and“Smart Patient Assistant(SPA)”developed and managed through Agile methodology were evaluated against the quality assurance criteria for senior projects.The study found that the project developed with RAD methodology performed 13.33%better in providing extensive and elaborated documentation than the students following the Agile technique.On the other hand,SPA-Agile based project,due to teamwork had 2.5%better implementation than Life Organizer-RAD based project.展开更多
In the past decade,several efforts around the world were started with the goal of introducing "smart metering" capabilities into the power grid.These efforts have spurred renewed interest in the design of ne...In the past decade,several efforts around the world were started with the goal of introducing "smart metering" capabilities into the power grid.These efforts have spurred renewed interest in the design of next generation Narrowband Power Line Communications(NB-PLC) transceivers.In the past few years,ITU-T and IEEE have standardized a family of next generation OFDM-based NB-PLC transceivers some of which are today being considered for massive deployments in Europe and Asia.This paper addresses the important role that PLC has not only for smart metering but also for many other Smart Grid applications,and also gives an overview of the main differences between these next generation NB-PLC standards.展开更多
With the continuous advancement and exploration of science and technology,the future trend of energy technology will be the deep integration of digitization,networking,intelligence with energy applications.The increas...With the continuous advancement and exploration of science and technology,the future trend of energy technology will be the deep integration of digitization,networking,intelligence with energy applications.The increasing maturity of digital technologies,such as the Internet of Things,big data,and cloud computing,has given rise to the creation and use of a potential technology–Digital Twin.Currently,research on Digital Twin has produced many concepts and outcomes that have been applied in many fields.In the energy sector,while some relevant ideas and case studies of Digital Twin have been generated,there are still many gaps to be explored.As a potential technology with advantages in many aspects,Digital Twin is bound to generate more promotion and applications in the energy fields.This paper systematically reviews the existing Digital Twin approaches and their possible applications in the energy fields.In addition,this paper attempts to analyze Digital Twin from different perspectives,such as definitions,classifications,main features,case studies and key technologies.Finally,the directions and challenges of possible future applications of Digital Twin in the energy fields have been presented.展开更多
Smart mobile applications are software applications that are designed to run on smart phones, tablets, and other mobile electronic devices. In this era of rapid technological advances, these applications have become o...Smart mobile applications are software applications that are designed to run on smart phones, tablets, and other mobile electronic devices. In this era of rapid technological advances, these applications have become one of the primary tools we use daily both in our personal and professional lives. The applications play key roles in facilitating many applications that are pivotal in our today＇s society including communication, education, business, entertainment, medical, finance, travel, utilities, social, and transportation. This paper reviewed the opportunities and challenges of the applications related to transportation. The opportunities revealed include route planning, ridesharing/carpooling, traffic safety, parking information, transportation data collection, fuel emissions and consumption, and travel information. The potential users of these applications in the field of transportation include （I） transportation agencies for travel data collection, travel information, ridesharing/carpooling, and traffic safety, （2） engineering students for field data collection such as travel speed, travel time, and vehicle count, and （3） general traveling public for route planning, ridesharing/carpooling, parking, traffic safety, and travel information. Significant usage of smart mobile applications can be potentially very beneficial, particularly in automobile travel mode to reduce travel time, cost, and vehicle emissions. In the end this would make travel safer and living environments greener and healthier. However, road users＇ interactions with these applications could manually, visually, and cognitively divert their attention from the primary task of driving or walking. Distracted road users expose themselves and others to unsafe behavior than undistracted. Road safety education and awareness programs are vital to discourage the use of applications that stimulate unsafe driving/walking behaviors. Educating the traveling public about the dangers of unsafe driving/walking behavior could have significant safety benefits to all road users. Future research needs to compare accuracies of the applications and provide guidelines for selecting them for certain transportation related applications.展开更多
To fully leverage‘‘smart”transportation infrastructure data-stream investments,the creation of applications that provide real-time meaningful and actionable corridorperformance metrics is needed.However,the presenc...To fully leverage‘‘smart”transportation infrastructure data-stream investments,the creation of applications that provide real-time meaningful and actionable corridorperformance metrics is needed.However,the presence of gaps in data streams can lead to significant application implementation challenges.To demonstrate and help address these challenges,a digital twin smart-corridor application case study is presented with two primary research objectives:(1)explore the characteristics of volume data gaps on the case study corridor,and(2)investigate the feasibility of prioritizing data streams for data imputation to drive the real-time application.For the first objective,a K-means clustering analysis is used to identify similarities and differences among data gap patterns.The clustering analysis successfully identifies eight different data loss patterns.Patterns vary in both continuity and density of data gap occurrences,as well as time-dependent losses in several clusters.For the second objective,a temporal-neighboring interpolation approach for volume data imputation is explored.When investigating the use of temporalneighboring interpolation imputations on the digital twin application,performance is,in part,dependent on the combination of intersection approaches experiencing data loss,demand relative to capacity at individual locations,and the location of the loss along the corridor.The results indicate that these insights could be used to prioritize intersection approaches suitable for data imputation and to identify locations that require a more sensitive imputation methodology or improved maintenance and monitoring.展开更多
基金support from the Contract Research(“Development of Breathable Fabrics with Nano-Electrospun Membrane”,CityU ref.:9231419“Research and application of antibacterial and healing-promoting smart nanofiber dressing for children’s burn wounds”,CityU ref:PJ9240111)+1 种基金the National Natural Science Foundation of China(“Study of Multi-Responsive Shape Memory Polyurethane Nanocomposites Inspired by Natural Fibers”,Grant No.51673162)Startup Grant of CityU(“Laboratory of Wearable Materials for Healthcare”,Grant No.9380116).
文摘Radiative cooling systems(RCSs)possess the distinctive capability to dissipate heat energy via solar and thermal radiation,making them suitable for thermal regulation and energy conservation applications,essential for mitigating the energy crisis.A comprehensive review connecting the advancements in engineered radiative cooling systems(ERCSs),encompassing material and structural design as well as thermal and energy-related applications,is currently absent.Herein,this review begins with a concise summary of the essential concepts of ERCSs,followed by an introduction to engineered materials and structures,containing nature-inspired designs,chromatic materials,meta-structural configurations,and multilayered constructions.It subsequently encapsulates the primary applications,including thermal-regulating textiles and energy-saving devices.Next,it highlights the challenges of ERCSs,including maximized thermoregulatory effects,environmental adaptability,scalability and sustainability,and interdisciplinary integration.It seeks to offer direction for forthcoming fundamental research and industrial advancement of radiative cooling systems in real-world applications.
基金Project(51072235) supported by the National Natural Science Foundation of ChinaProject(11JJ1008) supported by the Natural Science Foundation of Hunan Province,China+2 种基金Project(20110162110044) supported by the PhD Program Foundation of Ministry of Education of ChinaProject(7433001207) supported by Hunan Provincial Innovation Foundation for Postgraduate,ChinaProject(2001JF3215) supported by Hunan Provincial Science and Technology Plan,China
文摘Piezoelectric materials are capable of actuation and sensing and have been used in a wide variety of smart devices and structures.Active fiber composite and macro fiber composite are newly developed types of piezoelectric composites,and show superior properties to monolithic piezoelectric wafer due to their distinctive structures.Numerous work has focused on the performance prediction of the composites by evaluation of structural parameters and properties of the constituent materials with analytical and numerical methods.Various applications have been explored for the piezoelectric fiber composites,including vibration and noise control,health monitoring,morphing of structures and energy harvesting,in which the composites play key role and demonstrate the necessity for further development.
基金supported by National Natural Science Foundation of China(No.62471254)National Natural Science Foundation of China(No.92367302)。
文摘The unmanned aerial vehicle(UAV)-assisted mobile edge computing(MEC)has been deemed a promising solution for energy-constrained devices to run smart applications with computationintensive and latency-sensitive requirements,especially in some infrastructure-limited areas or some emergency scenarios.However,the multi-UAVassisted MEC network remains largely unexplored.In this paper,the dynamic trajectory optimization and computation offloading are studied in a multi-UAVassisted MEC system where multiple UAVs fly over a target area with different trajectories to serve ground users.By considering the dynamic channel condition and random task arrival and jointly optimizing UAVs'trajectories,user association,and subchannel assignment,the average long-term sum of the user energy consumption minimization problem is formulated.To address the problem involving both discrete and continuous variables,a hybrid decision deep reinforcement learning(DRL)-based intelligent energyefficient resource allocation and trajectory optimization algorithm is proposed,named HDRT algorithm,where deep Q network(DQN)and deep deterministic policy gradient(DDPG)are invoked to process discrete and continuous variables,respectively.Simulation results show that the proposed HDRT algorithm converges fast and outperforms other benchmarks in the aspect of user energy consumption and latency.
文摘The year of 2013 is considered the first year of smart city in China. With the development of informationization and urbanization in China, city diseases(traffic jam, medical problem and unbalanced education) are more and more apparent. Smart city is the key to solving these diseases. This paper presents the overall smart city development in China in term of market scale and development stages, the technology standards, and industry layout. The paper claims that the issues and challenges facing smart city development in China and proposes to make polices to support smart city development.
文摘Computing students face the problem with time and quality of the work while managing their graduation/senior projects.Rapid Application Development(RAD)model is based on continual user involvement for the process of requirement gathering via prototyping.After each iteration,the developers can validate the requirements that are completed in the iteration.Managing a project with RAD is easier but not flexible.On the other hand,Agile project management techniques focus on flexibility,agility,teamwork and quality based on user stories.Continual user involvement is avoided,which requires extensive maintenance time for fixing iteration and release of the story points.This also makes it necessary to provide onsite training to the users of the application.This research provides the pros and cons of RAD and Agile project management techniques,to help students in deciding the best approach for managing their graduation projects.For the evaluation of these techniques,similar case studies were given to the senior project students(having similar CGPAs)for building similar functionality-based applications.The two projects“Life Organizer”developed and managed using RAD and“Smart Patient Assistant(SPA)”developed and managed through Agile methodology were evaluated against the quality assurance criteria for senior projects.The study found that the project developed with RAD methodology performed 13.33%better in providing extensive and elaborated documentation than the students following the Agile technique.On the other hand,SPA-Agile based project,due to teamwork had 2.5%better implementation than Life Organizer-RAD based project.
文摘In the past decade,several efforts around the world were started with the goal of introducing "smart metering" capabilities into the power grid.These efforts have spurred renewed interest in the design of next generation Narrowband Power Line Communications(NB-PLC) transceivers.In the past few years,ITU-T and IEEE have standardized a family of next generation OFDM-based NB-PLC transceivers some of which are today being considered for massive deployments in Europe and Asia.This paper addresses the important role that PLC has not only for smart metering but also for many other Smart Grid applications,and also gives an overview of the main differences between these next generation NB-PLC standards.
基金National Key Research and Development Program of China(Grant No.2020YFB1712400).
文摘With the continuous advancement and exploration of science and technology,the future trend of energy technology will be the deep integration of digitization,networking,intelligence with energy applications.The increasing maturity of digital technologies,such as the Internet of Things,big data,and cloud computing,has given rise to the creation and use of a potential technology–Digital Twin.Currently,research on Digital Twin has produced many concepts and outcomes that have been applied in many fields.In the energy sector,while some relevant ideas and case studies of Digital Twin have been generated,there are still many gaps to be explored.As a potential technology with advantages in many aspects,Digital Twin is bound to generate more promotion and applications in the energy fields.This paper systematically reviews the existing Digital Twin approaches and their possible applications in the energy fields.In addition,this paper attempts to analyze Digital Twin from different perspectives,such as definitions,classifications,main features,case studies and key technologies.Finally,the directions and challenges of possible future applications of Digital Twin in the energy fields have been presented.
文摘Smart mobile applications are software applications that are designed to run on smart phones, tablets, and other mobile electronic devices. In this era of rapid technological advances, these applications have become one of the primary tools we use daily both in our personal and professional lives. The applications play key roles in facilitating many applications that are pivotal in our today＇s society including communication, education, business, entertainment, medical, finance, travel, utilities, social, and transportation. This paper reviewed the opportunities and challenges of the applications related to transportation. The opportunities revealed include route planning, ridesharing/carpooling, traffic safety, parking information, transportation data collection, fuel emissions and consumption, and travel information. The potential users of these applications in the field of transportation include （I） transportation agencies for travel data collection, travel information, ridesharing/carpooling, and traffic safety, （2） engineering students for field data collection such as travel speed, travel time, and vehicle count, and （3） general traveling public for route planning, ridesharing/carpooling, parking, traffic safety, and travel information. Significant usage of smart mobile applications can be potentially very beneficial, particularly in automobile travel mode to reduce travel time, cost, and vehicle emissions. In the end this would make travel safer and living environments greener and healthier. However, road users＇ interactions with these applications could manually, visually, and cognitively divert their attention from the primary task of driving or walking. Distracted road users expose themselves and others to unsafe behavior than undistracted. Road safety education and awareness programs are vital to discourage the use of applications that stimulate unsafe driving/walking behaviors. Educating the traveling public about the dangers of unsafe driving/walking behavior could have significant safety benefits to all road users. Future research needs to compare accuracies of the applications and provide guidelines for selecting them for certain transportation related applications.
基金supported in part by the City of Atlanta(CoA)under Research Project FC-9930-Smart Cities Traffic Congestion Mitigation Program and in part by the National Center of Sustainable Transportation(NCST)under NCST Dissertation Fund.
文摘To fully leverage‘‘smart”transportation infrastructure data-stream investments,the creation of applications that provide real-time meaningful and actionable corridorperformance metrics is needed.However,the presence of gaps in data streams can lead to significant application implementation challenges.To demonstrate and help address these challenges,a digital twin smart-corridor application case study is presented with two primary research objectives:(1)explore the characteristics of volume data gaps on the case study corridor,and(2)investigate the feasibility of prioritizing data streams for data imputation to drive the real-time application.For the first objective,a K-means clustering analysis is used to identify similarities and differences among data gap patterns.The clustering analysis successfully identifies eight different data loss patterns.Patterns vary in both continuity and density of data gap occurrences,as well as time-dependent losses in several clusters.For the second objective,a temporal-neighboring interpolation approach for volume data imputation is explored.When investigating the use of temporalneighboring interpolation imputations on the digital twin application,performance is,in part,dependent on the combination of intersection approaches experiencing data loss,demand relative to capacity at individual locations,and the location of the loss along the corridor.The results indicate that these insights could be used to prioritize intersection approaches suitable for data imputation and to identify locations that require a more sensitive imputation methodology or improved maintenance and monitoring.
