The uneven distribution of medical resources has led to increasingly frequent patient mobility;however, the interaction between this phenomenon and the healthcare supply-demand relationship remains underexplored. The ...The uneven distribution of medical resources has led to increasingly frequent patient mobility;however, the interaction between this phenomenon and the healthcare supply-demand relationship remains underexplored. The present study constructed the 2023Cross-City Patient Mobility Network in China using one million patient mobility data records obtained from online healthcare platforms. We applied urban network analysis to uncover mobility patterns and used the coupling coordination degree model to assess healthcare supply-demand relationships before and after patient mobility. Explainable machine learning further revealed the impact of supply-demand coupling on patient mobility. The results indicated the following: Patient mobility followed administrative boundaries, although megacities serve areas beyond provincial borders;The scale of healthcare supply and demand displayed a multi-centric spatial pattern with a general decline from east to west, and these characteristics of demand distribution were further solidified by patient mobility;Cities with low supply-demand coupling and undersupply experienced patient outflows, while cities with high coupling and oversupply attracted them. In turn, patient mobility helped balance healthcare supply and demand, optimising the coupling relationship across cities. Thus, this research not only provides a methodological reference for understanding the interaction between patient mobility and healthcare systems but also offers empirical insights for public health policy.展开更多
Cities are the most preferable dwelling places, having with better employment opportunities, educational hubs, medical services, recreational facilities, theme parks, and shopping malls etc. Cities are the driving for...Cities are the most preferable dwelling places, having with better employment opportunities, educational hubs, medical services, recreational facilities, theme parks, and shopping malls etc. Cities are the driving forces for any national economy too. Unfortunately now a days, these cities are producing circa 70% of pollutants, even though they only oeeupy 2% of surface of the Earth. Pub- lic utility services cannot meet the demands of unexpected growth. The filthiness in cities causing decreasing of Quality of Life. In this light our research paper is giving more concentration on necessity of ＂ Smart Cities＂, which are the basis for civic centric services. This article is throwing light on Smart Cities and its important roles. The beauty of this manuscript is scribbling ＂Smart Cities＂ concepts in pictorially. Moreover this explains on ＂Barcelona Smart City＂ using lnternet of Things Technologies. It is a good example in urban paradigm shift. Braeelona is like the heaven on the earth with by providing Quality of Life to all urban citizens. The GOD is Interenet of Things.展开更多
The Internet of Moving Things(IoMT)takes a step further with respect to traditional static IoT deployments.In this line,the integration of new eco-friendly mobility devices such as scooters or bicycles within the Coop...The Internet of Moving Things(IoMT)takes a step further with respect to traditional static IoT deployments.In this line,the integration of new eco-friendly mobility devices such as scooters or bicycles within the Cooperative-Intelligent Transportation Systems(C-ITS)and smart city ecosystems is crucial to provide novel services.To this end,a range of communication technologies is available,such as cellular,vehicular WiFi or Low-Power Wide-Area Network(LPWAN);however,none of them can fully cover energy consumption and Quality of Service(QoS)requirements.Thus,we propose a Decision Support System(DSS),based on supervised Machine Learning(ML)classification,for selecting the most adequate transmission interface to send a certain message in a multi-Radio Access Technology(RAT)set up.Different ML algorithms have been explored taking into account computing and energy constraints of IoMT enddevices and traffic type.Besides,a real implementation of a decision tree-based DSS for micro-controller units is presented and evaluated.The attained results demonstrate the validity of the proposal,saving energy in communication tasks as well as satisfying QoS requirements of certain urgent messages.The footprint of the real implementation on an Arduino Uno is 444 bytes and it can be executed in around 50µs.展开更多
with the rapid development of mobile intemet and Internet of Things applications, the conventional centralized cloud computing is encountering severe challenges, such as high latency, low Spectral Efficiency （SE）, a...with the rapid development of mobile intemet and Internet of Things applications, the conventional centralized cloud computing is encountering severe challenges, such as high latency, low Spectral Efficiency （SE）, and nonadaptive machine type of communication. Motivated to solve these challenges, a new technology is driving a trend that shifts the function of centralized cloud computing to edge devices of networks. Several edge computing technologies originating from different backgrounds to decrease latency, improve SE, and support the massive machine type of communication have been emerging. This paper comprehensively presents a tutorial on three typical edge computing technologies, namely mobile edge computing, cloudlets, and fog computing. In particular, the standardization efforts, principles, architectures, and applications of these three technologies are summarized and compared. From the viewpoint of radio access network, the differences between mobile edge computing and fog computing are highlighted, and the characteristics of fog computing-based radio access network are discussed. Finally, open issues and future research directions are identified as well.展开更多
The advancement of the Internet of Things(IoT)brings new opportunities for collecting real-time data and deploying machine learning models.Nonetheless,an individual IoT device may not have adequate computing resources...The advancement of the Internet of Things(IoT)brings new opportunities for collecting real-time data and deploying machine learning models.Nonetheless,an individual IoT device may not have adequate computing resources to train and deploy an entire learning model.At the same time,transmitting continuous real-time data to a central server with high computing resource incurs enormous communication costs and raises issues in data security and privacy.Federated learning,a distributed machine learning framework,is a promising solution to train machine learning models with resource-limited devices and edge servers.Yet,the majority of existing works assume an impractically synchronous parameter update manner with homogeneous IoT nodes under stable communication connections.In this paper,we develop an asynchronous federated learning scheme to improve training efficiency for heterogeneous IoT devices under unstable communication network.Particularly,we formulate an asynchronous federated learning model and develop a lightweight node selection algorithm to carry out learning tasks effectively.The proposed algorithm iteratively selects heterogeneous IoT nodes to participate in the global learning aggregation while considering their local computing resource and communication condition.Extensive experimental results demonstrate that our proposed asynchronous federated learning scheme outperforms the state-of-the-art schemes in various settings on independent and identically distributed(i.i.d.)and non-i.i.d.data distribution.展开更多
This survey paper provides a general overview on Cloud Computing. The topics that are discussed include characteristics, deployment and service models as well drawbacks. Major aspects of Cloud Computing are explained ...This survey paper provides a general overview on Cloud Computing. The topics that are discussed include characteristics, deployment and service models as well drawbacks. Major aspects of Cloud Computing are explained to give the reader a clearer understanding on the complexity of the platform. Following this, several security issues and countermeasures are also discussed to show the major issues and obstacles that Cloud Computing faces as it is being implemented further. The major part of countermeasures focuses on Intrusion Detection Systems. Moving towards Mobile Cloud Computing and Internet of Things, this survey paper gives a general explanation on the applications and potential that comes with the integration of Cloud Computing with any device that has Internet connectivity as well as the challenges that are before it.展开更多
Home is a place for people to relax and to feel secure.However,there are some external factors,such as temperature and humidity,making living conditions uncomfortable.With the development of Internet of Things(IoT)tec...Home is a place for people to relax and to feel secure.However,there are some external factors,such as temperature and humidity,making living conditions uncomfortable.With the development of Internet of Things(IoT)technology,the research issue of smart home becomes more important.The purpose of this study is to explore the application of IoT technology in indoor air monitoring and control,combined with the analysis of outdoor air quality data.This study develops a prototype system and tests and evaluates the performance of the system through user trial reports.The results show that(1)Air comparison of indoor and outdoor are practical for users,(2)Through the transmission of Bluetooth,restrictions on the practicality should be achieved through the WiFi remote monitoring effect,(3)It can receive multiple sensors at the same time,to achieve multiple indoor space monitoring effects,(4)It can be combined with other home appliances,if the integration of home appliances control will be more practical,(5)The current database is only a record,has not developed other applications,and in the future can develop predictive applications.We hope that through this study,we will provide some suggestions for the application of innovative technology in smart home.展开更多
Puncturing has been recognized as a promising technology to cope with the coexistence problem of enhanced mobile broadband(eMBB) and ultra-reliable low latency communications(URLLC)traffic. However, the steady perform...Puncturing has been recognized as a promising technology to cope with the coexistence problem of enhanced mobile broadband(eMBB) and ultra-reliable low latency communications(URLLC)traffic. However, the steady performance of eMBB traffic while meeting the requirements of URLLC traffic with puncturing is a major challenge in some realistic scenarios. In this paper, we pay attention to the timely and energy-efficient processing for eMBB traffic in the industrial Internet of Things(IIoT), where mobile edge computing(MEC) is employed for data processing. Specifically, the performance of eMBB traffic and URLLC traffic in a MEC-based IIoT system is ensured by setting the threshold of tolerable delay and outage probability, respectively. Furthermore,considering the limited energy supply, an energy minimization problem of eMBB device is formulated under the above constraints, by jointly optimizing the resource blocks(RBs) punctured by URLLC traffic, data offloading and transmit power of eMBB device. With Markov's inequality, the problem is reformulated by transforming the probabilistic outage constraint into a deterministic constraint. Meanwhile, an iterative energy minimization algorithm(IEMA) is proposed.Simulation results demonstrate that our algorithm has a significant reduction in the energy consumption for eMBB device and achieves a better overall effect compared to several benchmarks.展开更多
With the increased emphasis on data security in the Internet of Things(IoT), blockchain has received more and more attention.Due to the computing consuming characteristics of blockchain, mobile edge computing(MEC) is ...With the increased emphasis on data security in the Internet of Things(IoT), blockchain has received more and more attention.Due to the computing consuming characteristics of blockchain, mobile edge computing(MEC) is integrated into IoT.However, how to efficiently use edge computing resources to process the computing tasks of blockchain from IoT devices has not been fully studied.In this paper, the MEC and blockchain-enhanced IoT is considered.The transactions recording the data or other application information are generated by the IoT devices, and they are offloaded to the MEC servers to join the blockchain.The practical Byzantine fault tolerance(PBFT) consensus mechanism is used among all the MEC servers which are also the blockchain nodes, and the latency of the consensus process is modeled with the consideration of characteristics of the wireless network.The joint optimization problem of serving base station(BS) selection and wireless transmission resources allocation is modeled as a Markov decision process(MDP), and the long-term system utility is defined based on task reward, credit value, the latency of infrastructure layer and blockchain layer, and computing cost.A double deep Q learning(DQN) based transactions offloading algorithm(DDQN-TOA) is proposed, and simulation results show the advantages of the proposed algorithm in comparison to other methods.展开更多
In many IIoT architectures,various devices connect to the edge cloud via gateway systems.For data processing,numerous data are delivered to the edge cloud.Delivering data to an appropriate edge cloud is critical to im...In many IIoT architectures,various devices connect to the edge cloud via gateway systems.For data processing,numerous data are delivered to the edge cloud.Delivering data to an appropriate edge cloud is critical to improve IIoT service efficiency.There are two types of costs for this kind of IoT network:a communication cost and a computing cost.For service efficiency,the communication cost of data transmission should be minimized,and the computing cost in the edge cloud should be also minimized.Therefore,in this paper,the communication cost for data transmission is defined as the delay factor,and the computing cost in the edge cloud is defined as the waiting time of the computing intensity.The proposed method selects an edge cloud that minimizes the total cost of the communication and computing costs.That is,a device chooses a routing path to the selected edge cloud based on the costs.The proposed method controls the data flows in a mesh-structured network and appropriately distributes the data processing load.The performance of the proposed method is validated through extensive computer simulation.When the transition probability from good to bad is 0.3 and the transition probability from bad to good is 0.7 in wireless and edge cloud states,the proposed method reduced both the average delay and the service pause counts to about 25%of the existing method.展开更多
A high altitude platform station （HAPS） based communications scenario for providing Intemet access and broadband multimedia services to the passengers on board of a high speed train （traveling up to 300km/h） is pr...A high altitude platform station （HAPS） based communications scenario for providing Intemet access and broadband multimedia services to the passengers on board of a high speed train （traveling up to 300km/h） is proposed. Regarding the addressed scenario, when the propagation link between HAPS and train is blocked by obstacles, a three-dimensional （3-D） geometrical single cylinder spatial-temporal channel model is presented, in which closed form, mathematically tractable space-time correlation functions are obtained. It shows that the correlation functions determined by the 3-D model are of significant difference with those of the conventional 2-D model. Based on the analysis model, the paper derives a realized simulation model using sum-of-sinusoids approach, and applies method of equal areas （MEA） and modified method of equal areas （MMEA） to determine the model parameters. The fitting performance of the simulation model with the analysis one is evaluated by two means-square error （MSE） performance criteria. Finally, numerical simulation results verify the mathematical analysis conclusion, when N ≥21, simulation model has an excellent fitness with the analysis one.展开更多
The present study analyses the differences between the subways systems of two cities, Lisbon (Portugal) and Brasília (Brazil), verifying the extent to which their subway systems are spatially integrated with the ...The present study analyses the differences between the subways systems of two cities, Lisbon (Portugal) and Brasília (Brazil), verifying the extent to which their subway systems are spatially integrated with the respective urban fabric-which would promote a better synchrony in terms of economy and sustainability. For interpreting the data, the methodology and tools of the Theory of the Social Logic of Space were used, by means of axial maps, researching the relationship between the constructed and empty (public spaces) areas of the urban structures. Based on the findings, meaningful differences between the subway systems and the configuration of urban spaces were observed, as a product of specific design matrixes. In Lisbon, the mobility associated to the subway seems to be encouraged by the integration of the system with the potential for movement provided by the urban tissue (making the secondary centralities articulated with the subway stations more dynamic). In Brasilia, however, there are several difficulties for such mobility, due to the predominant role of the empty spaces in the city which weakens the gathering potential of such areas, despite the fact that such articulation with secondary centralities is also present there.展开更多
伴随着“文化转向”与“再物质化”思潮的出现,物质地理学已经成为西方社会文化地理研究中新兴且活跃的研究分支之一,而追踪物质(following the things)是物质地理学中重要的方法论视角,它强调人文地理学所重视的“流动性”,通过追踪特...伴随着“文化转向”与“再物质化”思潮的出现,物质地理学已经成为西方社会文化地理研究中新兴且活跃的研究分支之一,而追踪物质(following the things)是物质地理学中重要的方法论视角,它强调人文地理学所重视的“流动性”,通过追踪特定物质在流动过程中物质性的变化以及能动性,揭示物质流动中的社会关系与文化意义。论文通过梳理和分析西方学界中物质地理学的相关文献,阐述了近年来的研究进展,同时指出现阶段在追踪物质视角下该领域的主要议题为:物质的象征研究、物质与认同研究、生产与消费研究以及权力博弈与协商研究等内容。最后,论文归纳总结了当下物质地理学存在的研究局限与空白,展望了未来中国物质地理学研究可进一步探索的话题与方向,以期打开未来中国与西方国家物质地理学的对话窗口。展开更多
The pre-research on mobility analysis presented a unified-mobility formula and a methodology based on reciprocal screw theory by HUANG, which focused on classical and modem parallel mechanisms. However its range of ap...The pre-research on mobility analysis presented a unified-mobility formula and a methodology based on reciprocal screw theory by HUANG, which focused on classical and modem parallel mechanisms. However its range of application needs to further extend to general multi-loop spatial mechanism. This kind of mechanism is not only more complex in structure but also with strong motion coupling among loops, making the mobility analysis even more complicated, and the relevant research has long been ignored. It is focused on how to apply the new principle for general spatial mechanism to those various multi-loop spatial mechanisms, and some new meaningful knowledge is further found. Several typical examples of the genera/multi-loop spatial mechanisms with motion couple even strong motion couple are considered. These spatial mechanisms include different closing way： over-constraint appearing in rigid closure, in movable closure, and in dynamic closure as well; these examples also include two different new methods to solve this kind of issue： the way to recognize over-constraints by analyzing relative movement between two connected links and by constructing a virtual loop to recognize over-constraints. In addition, over-constraint determination tabulation is brought to analyze the motion couple. The researches above are all based upon the screw theory. All these multi-loop spatial mechanisms with different kinds of structures can completely be solved by following the directions and examples, and the new mobility theory based on the screw theory is also proved to be valid. This study not only enriches and develops the theory and makes the theory more universal, but also has a special meaning for innovation in mechanical engineering.展开更多
Demographic changes in peripheral areas are pressuring the regional public transport systems to adopt innovative strategies.The employment of internet of things(IoT)technologies has proven to be a valid response to mo...Demographic changes in peripheral areas are pressuring the regional public transport systems to adopt innovative strategies.The employment of internet of things(IoT)technologies has proven to be a valid response to mobility challenges in rural areas,and has brought up the concept of"smart land".Framed within the context of the Interreg Central Europe project RUMOBIL,this study tries to shed light on how the deployment of smart mobility solutions within the rural context compare to that within the urban context.Following a literature review,we compared the ease of implementation of different IoT solutions on the urban and the rural contexts,for planners,travellers,and operators,and the relative complexity of common smart mobility issues.In addition,we identified three major challenges for both rural and urban mobility,namely the need for standardized metrics for optimal routes’detection and a dynamic definition of optimal route,as well as the simplification of investments’planning and programming.Both smart cities and smart land can benefit from smart mobility solutions,even if in most cases,each of the two contexts can gain more advantages than the other from the same solution.Even considering the different levels of population scattering,technological infrastructures,social maturity,and economic opportunities,both rural and urban areas offer comparable advantages.For the future of transport,it is up to all policy levels to consider the challenges deriving from expected trends and leverage the untapped potential of IoT technologies to satisfy future travellers’needs and ensure sustainability.展开更多
A comprehensive understanding of city structures and urban dynamics can greatly improve the efficiency and quality of urban planning and management,while the traditional approaches of which,such as manual surveys,usua...A comprehensive understanding of city structures and urban dynamics can greatly improve the efficiency and quality of urban planning and management,while the traditional approaches of which,such as manual surveys,usually incur substantial labor and time.In this paper,we propose a data-driven framework to sense urban structures and dynamics from large-scale vehicle mobility data.First,we divide the city into fine-grained grids,and cluster the grids with similar mobility features into structured urban areas with a proposed distance-constrained clustering algorithm(DCCA).Second,we detect irregular mobility traffic patterns in each area leveraging an ARIMA-based anomaly detection algorithm(ADAM),and correlate them to the urban social and emergency events.Finally,we build a visualization system to demonstrate the urban structures and crowd dynamics.We evaluate our framework using real-world datasets collected from Xiamen city,China,and the results show that the proposed framework can sense urban structures and crowd comprehensively and effectively.展开更多
基金Humanities and Social Sciences Fund of Ministry of Education of China,No.24YJA630097National Natural Science Foundation of China,No.42471304。
文摘The uneven distribution of medical resources has led to increasingly frequent patient mobility;however, the interaction between this phenomenon and the healthcare supply-demand relationship remains underexplored. The present study constructed the 2023Cross-City Patient Mobility Network in China using one million patient mobility data records obtained from online healthcare platforms. We applied urban network analysis to uncover mobility patterns and used the coupling coordination degree model to assess healthcare supply-demand relationships before and after patient mobility. Explainable machine learning further revealed the impact of supply-demand coupling on patient mobility. The results indicated the following: Patient mobility followed administrative boundaries, although megacities serve areas beyond provincial borders;The scale of healthcare supply and demand displayed a multi-centric spatial pattern with a general decline from east to west, and these characteristics of demand distribution were further solidified by patient mobility;Cities with low supply-demand coupling and undersupply experienced patient outflows, while cities with high coupling and oversupply attracted them. In turn, patient mobility helped balance healthcare supply and demand, optimising the coupling relationship across cities. Thus, this research not only provides a methodological reference for understanding the interaction between patient mobility and healthcare systems but also offers empirical insights for public health policy.
基金The financial support is fully funding by Ministry of Human Resource Development(MHRD)
文摘Cities are the most preferable dwelling places, having with better employment opportunities, educational hubs, medical services, recreational facilities, theme parks, and shopping malls etc. Cities are the driving forces for any national economy too. Unfortunately now a days, these cities are producing circa 70% of pollutants, even though they only oeeupy 2% of surface of the Earth. Pub- lic utility services cannot meet the demands of unexpected growth. The filthiness in cities causing decreasing of Quality of Life. In this light our research paper is giving more concentration on necessity of ＂ Smart Cities＂, which are the basis for civic centric services. This article is throwing light on Smart Cities and its important roles. The beauty of this manuscript is scribbling ＂Smart Cities＂ concepts in pictorially. Moreover this explains on ＂Barcelona Smart City＂ using lnternet of Things Technologies. It is a good example in urban paradigm shift. Braeelona is like the heaven on the earth with by providing Quality of Life to all urban citizens. The GOD is Interenet of Things.
基金This work has been supported by the Spanish Ministry of Science,Innovation and Universities,under the Ramon y Cajal Program(ref.RYC-2017-23823)and the projects PERSEIDES(ref.TIN2017-86885-R)and Go2Edge(ref.RED2018-102585-T)the European Commission,under the 5G-MOBIX(Grant No.825496)and IoTCrawler(Grant No.779852)projectsthe Spanish Ministry of Energy,through the project MECANO(ref.PGE-MOVESSING-2019-000104).
文摘The Internet of Moving Things(IoMT)takes a step further with respect to traditional static IoT deployments.In this line,the integration of new eco-friendly mobility devices such as scooters or bicycles within the Cooperative-Intelligent Transportation Systems(C-ITS)and smart city ecosystems is crucial to provide novel services.To this end,a range of communication technologies is available,such as cellular,vehicular WiFi or Low-Power Wide-Area Network(LPWAN);however,none of them can fully cover energy consumption and Quality of Service(QoS)requirements.Thus,we propose a Decision Support System(DSS),based on supervised Machine Learning(ML)classification,for selecting the most adequate transmission interface to send a certain message in a multi-Radio Access Technology(RAT)set up.Different ML algorithms have been explored taking into account computing and energy constraints of IoMT enddevices and traffic type.Besides,a real implementation of a decision tree-based DSS for micro-controller units is presented and evaluated.The attained results demonstrate the validity of the proposal,saving energy in communication tasks as well as satisfying QoS requirements of certain urgent messages.The footprint of the real implementation on an Arduino Uno is 444 bytes and it can be executed in around 50µs.
基金This work was supported in part by the National Natural Science Foundation of China under Grant No. 61361166005, the National High Technology Research and Development Program of China under Grant No. 2014AA01A701, the National Basic Research Program of China （973 Program） under Grant No. 2013CB336600, and the State Major Science and Technology Special Projects （Grant No. 2016ZX03001020-006）.
文摘with the rapid development of mobile intemet and Internet of Things applications, the conventional centralized cloud computing is encountering severe challenges, such as high latency, low Spectral Efficiency （SE）, and nonadaptive machine type of communication. Motivated to solve these challenges, a new technology is driving a trend that shifts the function of centralized cloud computing to edge devices of networks. Several edge computing technologies originating from different backgrounds to decrease latency, improve SE, and support the massive machine type of communication have been emerging. This paper comprehensively presents a tutorial on three typical edge computing technologies, namely mobile edge computing, cloudlets, and fog computing. In particular, the standardization efforts, principles, architectures, and applications of these three technologies are summarized and compared. From the viewpoint of radio access network, the differences between mobile edge computing and fog computing are highlighted, and the characteristics of fog computing-based radio access network are discussed. Finally, open issues and future research directions are identified as well.
文摘The advancement of the Internet of Things(IoT)brings new opportunities for collecting real-time data and deploying machine learning models.Nonetheless,an individual IoT device may not have adequate computing resources to train and deploy an entire learning model.At the same time,transmitting continuous real-time data to a central server with high computing resource incurs enormous communication costs and raises issues in data security and privacy.Federated learning,a distributed machine learning framework,is a promising solution to train machine learning models with resource-limited devices and edge servers.Yet,the majority of existing works assume an impractically synchronous parameter update manner with homogeneous IoT nodes under stable communication connections.In this paper,we develop an asynchronous federated learning scheme to improve training efficiency for heterogeneous IoT devices under unstable communication network.Particularly,we formulate an asynchronous federated learning model and develop a lightweight node selection algorithm to carry out learning tasks effectively.The proposed algorithm iteratively selects heterogeneous IoT nodes to participate in the global learning aggregation while considering their local computing resource and communication condition.Extensive experimental results demonstrate that our proposed asynchronous federated learning scheme outperforms the state-of-the-art schemes in various settings on independent and identically distributed(i.i.d.)and non-i.i.d.data distribution.
文摘This survey paper provides a general overview on Cloud Computing. The topics that are discussed include characteristics, deployment and service models as well drawbacks. Major aspects of Cloud Computing are explained to give the reader a clearer understanding on the complexity of the platform. Following this, several security issues and countermeasures are also discussed to show the major issues and obstacles that Cloud Computing faces as it is being implemented further. The major part of countermeasures focuses on Intrusion Detection Systems. Moving towards Mobile Cloud Computing and Internet of Things, this survey paper gives a general explanation on the applications and potential that comes with the integration of Cloud Computing with any device that has Internet connectivity as well as the challenges that are before it.
文摘Home is a place for people to relax and to feel secure.However,there are some external factors,such as temperature and humidity,making living conditions uncomfortable.With the development of Internet of Things(IoT)technology,the research issue of smart home becomes more important.The purpose of this study is to explore the application of IoT technology in indoor air monitoring and control,combined with the analysis of outdoor air quality data.This study develops a prototype system and tests and evaluates the performance of the system through user trial reports.The results show that(1)Air comparison of indoor and outdoor are practical for users,(2)Through the transmission of Bluetooth,restrictions on the practicality should be achieved through the WiFi remote monitoring effect,(3)It can receive multiple sensors at the same time,to achieve multiple indoor space monitoring effects,(4)It can be combined with other home appliances,if the integration of home appliances control will be more practical,(5)The current database is only a record,has not developed other applications,and in the future can develop predictive applications.We hope that through this study,we will provide some suggestions for the application of innovative technology in smart home.
基金supported by the Natural Science Foundation of China (No.62171051)。
文摘Puncturing has been recognized as a promising technology to cope with the coexistence problem of enhanced mobile broadband(eMBB) and ultra-reliable low latency communications(URLLC)traffic. However, the steady performance of eMBB traffic while meeting the requirements of URLLC traffic with puncturing is a major challenge in some realistic scenarios. In this paper, we pay attention to the timely and energy-efficient processing for eMBB traffic in the industrial Internet of Things(IIoT), where mobile edge computing(MEC) is employed for data processing. Specifically, the performance of eMBB traffic and URLLC traffic in a MEC-based IIoT system is ensured by setting the threshold of tolerable delay and outage probability, respectively. Furthermore,considering the limited energy supply, an energy minimization problem of eMBB device is formulated under the above constraints, by jointly optimizing the resource blocks(RBs) punctured by URLLC traffic, data offloading and transmit power of eMBB device. With Markov's inequality, the problem is reformulated by transforming the probabilistic outage constraint into a deterministic constraint. Meanwhile, an iterative energy minimization algorithm(IEMA) is proposed.Simulation results demonstrate that our algorithm has a significant reduction in the energy consumption for eMBB device and achieves a better overall effect compared to several benchmarks.
基金Supported by the National Key Research and Development Program of China(No.2020YFC1807903)the Natural Science Foundation of Beijing Municipality(No.L192002)。
文摘With the increased emphasis on data security in the Internet of Things(IoT), blockchain has received more and more attention.Due to the computing consuming characteristics of blockchain, mobile edge computing(MEC) is integrated into IoT.However, how to efficiently use edge computing resources to process the computing tasks of blockchain from IoT devices has not been fully studied.In this paper, the MEC and blockchain-enhanced IoT is considered.The transactions recording the data or other application information are generated by the IoT devices, and they are offloaded to the MEC servers to join the blockchain.The practical Byzantine fault tolerance(PBFT) consensus mechanism is used among all the MEC servers which are also the blockchain nodes, and the latency of the consensus process is modeled with the consideration of characteristics of the wireless network.The joint optimization problem of serving base station(BS) selection and wireless transmission resources allocation is modeled as a Markov decision process(MDP), and the long-term system utility is defined based on task reward, credit value, the latency of infrastructure layer and blockchain layer, and computing cost.A double deep Q learning(DQN) based transactions offloading algorithm(DDQN-TOA) is proposed, and simulation results show the advantages of the proposed algorithm in comparison to other methods.
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIT) (No.2021R1C1C1013133)supported by the Institute of Information and Communications Technology Planning and Evaluation (IITP)grant funded by the Korea Government (MSIT) (RS-2022-00167197,Development of Intelligent 5G/6G Infrastructure Technology for The Smart City)supported by the Soonchunhyang University Research Fund.
文摘In many IIoT architectures,various devices connect to the edge cloud via gateway systems.For data processing,numerous data are delivered to the edge cloud.Delivering data to an appropriate edge cloud is critical to improve IIoT service efficiency.There are two types of costs for this kind of IoT network:a communication cost and a computing cost.For service efficiency,the communication cost of data transmission should be minimized,and the computing cost in the edge cloud should be also minimized.Therefore,in this paper,the communication cost for data transmission is defined as the delay factor,and the computing cost in the edge cloud is defined as the waiting time of the computing intensity.The proposed method selects an edge cloud that minimizes the total cost of the communication and computing costs.That is,a device chooses a routing path to the selected edge cloud based on the costs.The proposed method controls the data flows in a mesh-structured network and appropriately distributes the data processing load.The performance of the proposed method is validated through extensive computer simulation.When the transition probability from good to bad is 0.3 and the transition probability from bad to good is 0.7 in wireless and edge cloud states,the proposed method reduced both the average delay and the service pause counts to about 25%of the existing method.
基金Supported by the National Natural Science Foundation of China (No. 60532030).
文摘A high altitude platform station （HAPS） based communications scenario for providing Intemet access and broadband multimedia services to the passengers on board of a high speed train （traveling up to 300km/h） is proposed. Regarding the addressed scenario, when the propagation link between HAPS and train is blocked by obstacles, a three-dimensional （3-D） geometrical single cylinder spatial-temporal channel model is presented, in which closed form, mathematically tractable space-time correlation functions are obtained. It shows that the correlation functions determined by the 3-D model are of significant difference with those of the conventional 2-D model. Based on the analysis model, the paper derives a realized simulation model using sum-of-sinusoids approach, and applies method of equal areas （MEA） and modified method of equal areas （MMEA） to determine the model parameters. The fitting performance of the simulation model with the analysis one is evaluated by two means-square error （MSE） performance criteria. Finally, numerical simulation results verify the mathematical analysis conclusion, when N ≥21, simulation model has an excellent fitness with the analysis one.
基金the financial support during the Doctorate internship carried out at IST-UTL(Lisbon/Portugal).
文摘The present study analyses the differences between the subways systems of two cities, Lisbon (Portugal) and Brasília (Brazil), verifying the extent to which their subway systems are spatially integrated with the respective urban fabric-which would promote a better synchrony in terms of economy and sustainability. For interpreting the data, the methodology and tools of the Theory of the Social Logic of Space were used, by means of axial maps, researching the relationship between the constructed and empty (public spaces) areas of the urban structures. Based on the findings, meaningful differences between the subway systems and the configuration of urban spaces were observed, as a product of specific design matrixes. In Lisbon, the mobility associated to the subway seems to be encouraged by the integration of the system with the potential for movement provided by the urban tissue (making the secondary centralities articulated with the subway stations more dynamic). In Brasilia, however, there are several difficulties for such mobility, due to the predominant role of the empty spaces in the city which weakens the gathering potential of such areas, despite the fact that such articulation with secondary centralities is also present there.
文摘伴随着“文化转向”与“再物质化”思潮的出现,物质地理学已经成为西方社会文化地理研究中新兴且活跃的研究分支之一,而追踪物质(following the things)是物质地理学中重要的方法论视角,它强调人文地理学所重视的“流动性”,通过追踪特定物质在流动过程中物质性的变化以及能动性,揭示物质流动中的社会关系与文化意义。论文通过梳理和分析西方学界中物质地理学的相关文献,阐述了近年来的研究进展,同时指出现阶段在追踪物质视角下该领域的主要议题为:物质的象征研究、物质与认同研究、生产与消费研究以及权力博弈与协商研究等内容。最后,论文归纳总结了当下物质地理学存在的研究局限与空白,展望了未来中国物质地理学研究可进一步探索的话题与方向,以期打开未来中国与西方国家物质地理学的对话窗口。
基金Supported by National Natural Science Foundation of China(Grant No.51005195)Natural Science Research Fund for Youth in Higher Education Institutions of Hebei Province,China(Grant No.QN2014175)
文摘The pre-research on mobility analysis presented a unified-mobility formula and a methodology based on reciprocal screw theory by HUANG, which focused on classical and modem parallel mechanisms. However its range of application needs to further extend to general multi-loop spatial mechanism. This kind of mechanism is not only more complex in structure but also with strong motion coupling among loops, making the mobility analysis even more complicated, and the relevant research has long been ignored. It is focused on how to apply the new principle for general spatial mechanism to those various multi-loop spatial mechanisms, and some new meaningful knowledge is further found. Several typical examples of the genera/multi-loop spatial mechanisms with motion couple even strong motion couple are considered. These spatial mechanisms include different closing way： over-constraint appearing in rigid closure, in movable closure, and in dynamic closure as well; these examples also include two different new methods to solve this kind of issue： the way to recognize over-constraints by analyzing relative movement between two connected links and by constructing a virtual loop to recognize over-constraints. In addition, over-constraint determination tabulation is brought to analyze the motion couple. The researches above are all based upon the screw theory. All these multi-loop spatial mechanisms with different kinds of structures can completely be solved by following the directions and examples, and the new mobility theory based on the screw theory is also proved to be valid. This study not only enriches and develops the theory and makes the theory more universal, but also has a special meaning for innovation in mechanical engineering.
基金Funding for this research was provided by the Interreg Gentral Europe project"RUMOBIL".
文摘Demographic changes in peripheral areas are pressuring the regional public transport systems to adopt innovative strategies.The employment of internet of things(IoT)technologies has proven to be a valid response to mobility challenges in rural areas,and has brought up the concept of"smart land".Framed within the context of the Interreg Central Europe project RUMOBIL,this study tries to shed light on how the deployment of smart mobility solutions within the rural context compare to that within the urban context.Following a literature review,we compared the ease of implementation of different IoT solutions on the urban and the rural contexts,for planners,travellers,and operators,and the relative complexity of common smart mobility issues.In addition,we identified three major challenges for both rural and urban mobility,namely the need for standardized metrics for optimal routes’detection and a dynamic definition of optimal route,as well as the simplification of investments’planning and programming.Both smart cities and smart land can benefit from smart mobility solutions,even if in most cases,each of the two contexts can gain more advantages than the other from the same solution.Even considering the different levels of population scattering,technological infrastructures,social maturity,and economic opportunities,both rural and urban areas offer comparable advantages.For the future of transport,it is up to all policy levels to consider the challenges deriving from expected trends and leverage the untapped potential of IoT technologies to satisfy future travellers’needs and ensure sustainability.
基金We would like to thank the reviewers for their constructive suggestions.This research was supported by the China Fundamental Research Funds for the Central Universities(20720170040)the National Natural Science Foundation of China(Grant No.61802325)Natural Science Foundation of Fujian Province,China(2018J01105).
文摘A comprehensive understanding of city structures and urban dynamics can greatly improve the efficiency and quality of urban planning and management,while the traditional approaches of which,such as manual surveys,usually incur substantial labor and time.In this paper,we propose a data-driven framework to sense urban structures and dynamics from large-scale vehicle mobility data.First,we divide the city into fine-grained grids,and cluster the grids with similar mobility features into structured urban areas with a proposed distance-constrained clustering algorithm(DCCA).Second,we detect irregular mobility traffic patterns in each area leveraging an ARIMA-based anomaly detection algorithm(ADAM),and correlate them to the urban social and emergency events.Finally,we build a visualization system to demonstrate the urban structures and crowd dynamics.We evaluate our framework using real-world datasets collected from Xiamen city,China,and the results show that the proposed framework can sense urban structures and crowd comprehensively and effectively.
