In the lush heart of Uganda’s Busoga sub-region,Isaac Imaka is charting a new course for rural development.After seven years in national media,he left the newsroom and stepped into the soil.The former reporter with t...In the lush heart of Uganda’s Busoga sub-region,Isaac Imaka is charting a new course for rural development.After seven years in national media,he left the newsroom and stepped into the soil.The former reporter with the Daily Monitor was driven by the belief that communities like his in Jinja North deserved more than chronic poverty and hand-to-mouth survival.展开更多
Dear Editor,This letter deals with the stabilization of a resilient model predictive control(MPC)algorithm with a dynamic event-triggered mechanism subject to Denial-of-Service(Do S)attacks.Different from previous wor...Dear Editor,This letter deals with the stabilization of a resilient model predictive control(MPC)algorithm with a dynamic event-triggered mechanism subject to Denial-of-Service(Do S)attacks.Different from previous works,this letter is based on the designed threshold function to dynamically trigger and gives the upper bound conditions for intersampling intervals with attack and attack-free scenarios to converge.展开更多
When a vehicle moves over a flexible pavement structure,it generates loading and unloading cycles that produce recoverable(resilient)and permanent(plastic)deformations in the granular base and subbase layers,which are...When a vehicle moves over a flexible pavement structure,it generates loading and unloading cycles that produce recoverable(resilient)and permanent(plastic)deformations in the granular base and subbase layers,which are made of unbound granular materials(UGMs).The primary parameter used to evaluate the resilient response of UGMs in pavements is the resilient modulus(MR).The MR is widely used in calculating stress-strain states for flexible pavement design and as a control parameter during the construction process.It is also employed to understand the progression of distresses,such as fatigue cracking and rutting.The main objective of this study was to conduct a literature review on the resilient behavior of UGMs.This manuscript presents and describes the MR and the factors that influence it.It also outlines the evolution of the mathematical equations most commonly used to estimate and predict this physical parameter.Conclusions and recommendations for future research are provided at the end of the article.Despite the large amount of research done on the subject,the resilient behavior of UGM has not yet been fully understood.This is since these materials are highly heterogeneous and show nonlinear-anisotropic behavior under different cyclic loading paths and water contents.Likewise,these materials undergo different behaviors depending on their macro and microscopic properties(gradation,density,porosity,texture,mineralogy,particle geometry and orientation,temperature,among others).On the other hand,the main limitation of the mathematical equations is that their parameters are difficult to determine experimentally and are not constants of the material(they are state variables that can change with multiple factors).Additionally,these equations do not consider the boundary conditions to which UGM in pavements are exposed.Moreover,they are obtained from repeated load triaxial(RLT)tests,which cannot simulate the three cyclic stress components(vertical,horizontal,and shear)to which UGMs are subjected in a pavement.In recent years,there has been an increase in studies evaluating the use of recycled aggregates and the effect of temperature(particularly at subzero temperatures),but more research is still needed to reach definitive conclusions.展开更多
The International Textile Manufac-turers Federation(ITMF),has releasedthe results of its Global Textile IndustrySurvey(GTIS)for March 2025.Thissurvey,conducted regularly across allkey regions and segments of the texti...The International Textile Manufac-turers Federation(ITMF),has releasedthe results of its Global Textile IndustrySurvey(GTIS)for March 2025.Thissurvey,conducted regularly across allkey regions and segments of the textilevalue chain,revealed a complex pictureof a deteriorated business situation,cau-tious op timism,regional divergence,andongoing structural challenges.展开更多
As key technologies in 6G,Space-Air-Ground Integrated Networks(SAGIN)promises to provide seamless global coverage through a comprehensive,ubiquitous communication system,while Integrated Sensing and Communications(ISA...As key technologies in 6G,Space-Air-Ground Integrated Networks(SAGIN)promises to provide seamless global coverage through a comprehensive,ubiquitous communication system,while Integrated Sensing and Communications(ISAC)effectively addresses spectrum congestion by sharing spectrum resources and transceivers for simultaneous communication and sensing operations.However,existing ISAC research has primarily focused on terrestrial networks,with limited exploration of its applications in SAGIN environments.This paper proposes a novel SAGIN-ISAC scheme leveraging High-Altitude Platform Stations(HAPS).In this scheme,HAPS serves as a relay node that not only amplifies and forwards communication signals but also receives and processes target echo signals for parameter estimation.The satellite employs Resilient Massive Access(RMA)to provide communication services to different User Terminals(UTs).To address scenarios with an unknown number of targets,we develop a Two-threshold Detection and Parameter Multiple Signal Classification(MUSIC)algorithm(TDPM),which employs dual-threshold correlation detection to determine the number of targets and utilizes the MUSIC algorithm to estimate targets’Angle of Arrival(AoA),range,and relative velocity.Furthermore,we establish a joint optimization framework that considers both communication and sensing performance,optimizing energy efficiency,detection probability,and the Cramér-Rao bound.The power allocation coefficients are derived through Nash equilibrium,while the precoding matrix is optimized using Sequential Convex Approximation(SCA)to address the non-convex nature of the optimization problem.Experimental results demonstrate that our proposed scheme significantly enhances the overall performance of the SAGIN-ISAC system.展开更多
Self-centering systems are increasingly studied after devastating earthquakes in the 2010s that caused irreparable damage to buildings.Currently,there is conflicting evidence as to whether the re-centering(restoring)c...Self-centering systems are increasingly studied after devastating earthquakes in the 2010s that caused irreparable damage to buildings.Currently,there is conflicting evidence as to whether the re-centering(restoring)capabilities are gained at the expense of hysteretic damping,potentially leading to larger peak displacements and damage to non-structural elements.This study examines the earthquake response of self-centering and non-self-centering systems through analyses of 4-storey and 8-storey steel-braced frames.The Resilient Slip Friction Joint(RSFJ)dampers,combined with steel braces in series,represent the self-centering bracing system,whereas the Buckling Restrained Braces(BRBs)represent the non-self-centering bracing system.Results suggest that peak displacements,base shears,and floor accelerations were comparable between the two systems.A possible explanation is that the peak response occurs on the first major excursion;similar peaks result from similar backbone curves in the run-up to the peak.Conversely,the amount of hysteretic damping only begins to affect the post-peak behavior.For instance,the RSFJ system reintroduces seismic energy into the structure post-peak(rather than dissipating it like the BRB).Subsequently,it leads to larger vibration amplitudes about the central position,increasing the risk of secondary peaks.This contrasts with the BRB system,which exhibits smaller vibration amplitudes about an increasingly deformed position due to seismic ratcheting.Unsurprisingly,residual deformations were high for the BRBs(1.7%on average)and negligible for the RSFJ.However,RSFJ produced smaller peak inter-storey drifts between 13%–18%but higher peak accelerations by 4%–5%.The results suggest that multi-storey braced frames could be designed with similar or smaller forces when self-centering systems are used.展开更多
Any single Positioning,Navigation and Timing(PNT)technology has its vulnerability and limits,even the powerful Global Navigation Satellite System(GNSS)is no exception.To provide continuous and reliable PNT information...Any single Positioning,Navigation and Timing(PNT)technology has its vulnerability and limits,even the powerful Global Navigation Satellite System(GNSS)is no exception.To provide continuous and reliable PNT information to users,the theory and technique of comprehensive PNT information system and resilient PNT application system have attracted great attention from Chinese scholars.We try to summarize the progress and development of the synthetic PNT system,including the proposal,the modification and the improvement of the comprehensive PNT,as well as the follow-up resilient PNT.The frame of China’s comprehensive PNT system consisted of comprehensive PNT infrastructure and comprehensive PNT application system is initially described;the achievements on some main PNT technologies are introduced;the conceptual models of resilient PNT are given;besides,existing researches on resilient function models and stochastic models are summarized according to different user scenarios.展开更多
As Africa marks a decade since the adoption of Agenda 2063,its bold and ambitious seven aspirations have positioned the continent as a strong,united,resilient,and influential global player and partner.Reaffirming its ...As Africa marks a decade since the adoption of Agenda 2063,its bold and ambitious seven aspirations have positioned the continent as a strong,united,resilient,and influential global player and partner.Reaffirming its Pan-Africanism and African renaissance plan,aspiration seven of Agenda 2063 underscores the importance of Africa’s unity and solidarity in the face of major challenges emanating from the changing nature of globalisation,climate change,and economic and political environment.展开更多
The application of mass timber elements in different structures has gained publicity over the last few years,pri-marily due to climate change adaptation policies and net zero carbon targets.Timber is a renewable const...The application of mass timber elements in different structures has gained publicity over the last few years,pri-marily due to climate change adaptation policies and net zero carbon targets.Timber is a renewable construction material that can outperform other building materials regarding environmental impact.However,when used in seismically active regions,its application has been limited due to the uncertainties on their seismic behaviour in respect with different design standards and limited ductility in conventional connections.Conventional timber connections typically suffer from stiffness and strength degradation under cyclic loads.Their repairability is also low due to permanent damage in the fasteners and the associated crushing in the wood fibres.The use of friction connections can be an efficient way to mitigate these issues.They offer many advantages as they are economical and yet provide a high level of reliable and continuous energy dissipation.In recent years,a new generation of friction connections has been developed that can provide self-centring behaviour(i.e.,the ability of the structure to return to its original position at the end of an earthquake).However,how these connections perform compared to a mass timber system with conventional timber connections is still unknown.Several studies in the literature have suggested that these connections can enhance the performance of mass timber structures.However,the seismic performance of such systems specifically in terms of base shear,response drifts and response accelerations-has not been thoroughly investigated.This paper examines various design aspects of conventional friction connections and self-centring friction connections,providing insights into their differences concerning key seismic performance indicators.It compares the seismic performance of mass timber buildings equipped with both solutions,highlighting their advantages and limitations and drawing conclusions based on the results.The key findings are that friction connections can provides a superior seismic performance for timber structures.However,that may need to be combined with a parallel system avoid residual displacements.展开更多
Urban food systems need remedies due to the global rise of food insecurity. Aquaponics has emerged as a circular agricultural mode to shape edible cities and features multiple food-water-energy (FWE) nexus. Here we pr...Urban food systems need remedies due to the global rise of food insecurity. Aquaponics has emerged as a circular agricultural mode to shape edible cities and features multiple food-water-energy (FWE) nexus. Here we provide a generalizable methodology and framework to capture the FWE nexus flows of aquaponics systems within city jurisdiction. To test the framework in Beijing, China, we offer an evidence-based tradeoff analysis of urban rooftop aquaponics (RA) and ground aquaponics (GA) from a FWE nexus perspective. The results show that urban aquaponics performs well in terms of water effi-ciency, which saves 42%-44% of water consumption than traditional greenhouses (TG) during the on-farm stage, but generates 2.3-3.0 times higher energy consumption and 1.1-2.1 times more carbon emis-sions. “From farm to table” aquaponics helps decrease 14%-44% of the energy, water, and carbon impacts during the off-farm stage. With diversely optimized strategies for renewable electricity, fish food, infras-tructure materials, and recycling actions, urban aquaponics can hopefully reduce energy consumption and carbon emissions by 80%-85% in the on-farm stage. In addition to greenhouse agriculture, utilizing a total of 155 km2 of RA and GA potential areas could increase urban vegetable self-sufficiency by 15%, and avoid 82% of the energy, water, and carbon footprints during upstream food supply chains beyond cities. Our findings could provide policy insights for urban stakeholders to create edible landscapes by integrating RA and GA, and thus direct resilient and sustainable agricultural transformation.展开更多
The growth and scale of urbanisation in Indonesia poses various challenges,including the availability of affordable housing,which has forced many low-income people to live in informal settlements.Fires account for 15%...The growth and scale of urbanisation in Indonesia poses various challenges,including the availability of affordable housing,which has forced many low-income people to live in informal settlements.Fires account for 15%of all disasters in Indonesia,particularly in densely populated urban areas such as informal settlements.The nature of informal settlements,which lack basic services along with poor living conditions,increases the like-lihood of fire.The topic of informal settlement fires in Indonesia is relatively unresearched,especially studies tailored to waterfront informal settlements typologies which prevents an understanding of fire risk and its impact in the area.This study aims to investigate what aspects influence fire risk in the area and to increase the resilience of informal settlements to fire outbreaks with the intention of improving community resilience.A case study with mixed methods is employed in this study.Our study consists of two phases of data analysis.The first phase consists of spatial analysis,derivation of weight,risk assessment,sensitivity analysis,and identification of policy drivers.Meanwhile,the second phase of our data analysis consists of analysing conditions,challenges,and opportunities,resilient strategies development,and scenario testing.The results of this study revealed that the risk of fire in the area is considered high-to-very high,which is driven primarily by moderate hazard,high vulnerability,and low-to-very low capacity against fire.Primary drivers of fire risk in the area are building materials,electrical connection and equipment,road width,and building density.As a result,this study proposed nine physical and non-physical resilient strategies which has been categorised into three distinct aspects:development planning,development regulations,and risk management and response.Spatial analysis revealed that,if fully implemented and operationalised,these strategies could reclassify 90%of the area to moderate risk.Further research is should examine the causal factors of past fire incidents,the institutional capacity for fire management,and the socioeconomic conditions of the community.展开更多
The increasing frequency and severity of natural disasters,exacerbated by global warming,necessitate novel solutions to strengthen the resilience of Critical Infrastructure Systems(CISs).Recent research reveals the si...The increasing frequency and severity of natural disasters,exacerbated by global warming,necessitate novel solutions to strengthen the resilience of Critical Infrastructure Systems(CISs).Recent research reveals the sig-nificant potential of natural language processing(NLP)to analyze unstructured human language during disasters,thereby facilitating the uncovering of disruptions and providing situational awareness supporting various aspects of resilience regarding CISs.Despite this potential,few studies have systematically mapped the global research on NLP applications with respect to supporting various aspects of resilience of CISs.This paper contributes to the body of knowledge by presenting a review of current knowledge using the scientometric review technique.Using 231 bibliographic records from the Scopus and Web of Science core collections,we identify five key research areas where researchers have used NLP to support the resilience of CISs during natural disasters,including sentiment analysis,crisis informatics,data and knowledge visualization,disaster impacts,and content analysis.Furthermore,we map the utility of NLP in the identified research focus with respect to four aspects of resilience(i.e.,preparedness,absorption,recovery,and adaptability)and present various common techniques used and potential future research directions.This review highlights that NLP has the potential to become a supplementary data source to support the resilience of CISs.The results of this study serve as an introductory-level guide designed to help scholars and practitioners unlock the potential of NLP for strengthening the resilience of CISs against natural disasters.展开更多
Objective:Existing research mainly relies on quantitative indicators.However,the subjectivity of qualitative indicators and the problem of their difficulty in quantification limit the comprehensiveness of evaluation.T...Objective:Existing research mainly relies on quantitative indicators.However,the subjectivity of qualitative indicators and the problem of their difficulty in quantification limit the comprehensiveness of evaluation.Therefore,a resilience supplier evaluation method based on the improved Z-number-ORESTE is proposed.Methods:Through the construction of a multi-tiered evaluation index system incorporating supplier capabilities,resources,strategic aspects,and resilience,Z-numbers are harnessed to signify qualitative indicators.An advanced Z-number distance metric is implemented,meticulously considering the impact exerted by the reliability portion of Z-numbers on information risk.The refined ORESTE ranking algorithm introduces the concepts of strong and weak orderings and capitalizes on the Borda assignment function.This approach facilitates a more precise appraisal of the performance of alternative solutions.By amalgamating the improved Z-number distance measurement approach with the ORESTE ranking methodology for multi-attribute decision-making,it becomes feasible to more efficiently assess the recovery capacities and adaptability of suppliers in the face of unforeseen incidents and risks.Results:Through the analysis of the comprehensive performance of the existing suppliers of a certain electronics enterprise,the results regarding the suppliers’recovery capabilities and adaptability when facing unexpected events and risks are obtained.Eventually,the suppliers that are in line with the long-term development strategy of the enterprise are selected.Conclusion:This evaluation system has verified its feasibility and effectiveness.Moreover,the system is capable of effectively identifying and selecting resilient suppliers,providing more reliable decision-making support for the enterprise’s supply chain management.展开更多
The Congolese population is organised into households, which are thus headed by a chief who ensures the social well-being, development and integration into working life of the individuals in his charge. This study exa...The Congolese population is organised into households, which are thus headed by a chief who ensures the social well-being, development and integration into working life of the individuals in his charge. This study examines the functional principles of new housing design as an instrument for transforming the (current) failing economy into a strong and resilient one. Accordingly, a literature review of the practice of designing and building housing in human settlements in the Congo revealed the state of the art on this subject. An analysis of the existing housing stock from a demographic, social and economic point of view made it possible to identify the most common household sizes and numbers, as well as the lifestyle processes that determine the need for developed space. To this end, the experimental method was used to propose configuration plans for various new types of dwelling. To this end, the study highlighted the link between people’s standard of living and the effectiveness of their involvement in the local economy. To achieve the aims of the National Development Plan (NDP), particular attention must be paid to solving the housing problem. The existing housing stock actively contributes to the problems associated with unemployment and insecurity. Functional principles for the design of new types of housing have been developed. Four model types are proposed in line with the demographic structure of the population, their socio-economic characteristics and their lifestyle.展开更多
Resilient wheels are extensively used in urban rail transit, especially for tramway systems, owing to its advantages in noise reduction. A new type of resilient wheel for a metro is designed, and its characteristics o...Resilient wheels are extensively used in urban rail transit, especially for tramway systems, owing to its advantages in noise reduction. A new type of resilient wheel for a metro is designed, and its characteristics of vibration and sound radiation, including the rolling noise of a resilient single wheel coupled with a track, are studied in this paper. A two-step research is presented. Firstly, laboratory experiments were conducted to obtain the vibration response of the designed resilient wheel under the radial excitation on its tread. Secondly, the rolling noise model of the resilient wheel coupled with a slab track used in a metro line is developed. The wheel model is based on the 3 D finite elementand boundary element methods and verified by using the experimental results obtained from the laboratory. The track vibration model is based on the wavenumber finite element method, and the track sound radiation is calculatedby using an e cient frequency-domain Rayleigh method. The interaction of the resilient wheel and the slab track is analyzed considering the measured wheel/rail roughness of the metro. The contribution of the resilient wheel to the reduction of wheel/rail system noise is analyzed. The results show that the resilient wheel can e ectively reduce the wheel/rail rolling noise by approximately 2 dB(A) to 3 dB(A), mainly because the radiated noise by the rail is reduced. In addition, the elastic modulus of the rubber has an important influence on the noise reduction of resilient wheels.展开更多
Connected automated vehicles(CAVs)serve as a promising enabler for future intelligent transportation systems because of their capabilities in improving traffic efficiency and driving safety,and reducing fuel consumpti...Connected automated vehicles(CAVs)serve as a promising enabler for future intelligent transportation systems because of their capabilities in improving traffic efficiency and driving safety,and reducing fuel consumption and vehicle emissions.A fundamental issue in CAVs is platooning control that empowers a convoy of CAVs to be cooperatively maneuvered with desired longitudinal spacings and identical velocities on roads.This paper addresses the issue of resilient and safe platooning control of CAVs subject to intermittent denial-of-service(DoS)attacks that disrupt vehicle-to-vehicle communications.First,a heterogeneous and uncertain vehicle longitudinal dynamic model is presented to accommodate a variety of uncertainties,including diverse vehicle masses and engine inertial delays,unknown and nonlinear resistance forces,and a dynamic platoon leader.Then,a resilient and safe distributed longitudinal platooning control law is constructed with an aim to preserve simultaneous individual vehicle stability,attack resilience,platoon safety and scalability.Furthermore,a numerically efficient offline design algorithm for determining the desired platoon control law is developed,under which the platoon resilience against DoS attacks can be maximized but the anticipated stability,safety and scalability requirements remain preserved.Finally,extensive numerical experiments are provided to substantiate the efficacy of the proposed platooning method.展开更多
The resilient modulus(MR)of subgrade soils is usually used to characterize the stiffness of subgrade and is a crucial parameter in pavement design.In order to determine the resilient modulus of compacted subgrade soil...The resilient modulus(MR)of subgrade soils is usually used to characterize the stiffness of subgrade and is a crucial parameter in pavement design.In order to determine the resilient modulus of compacted subgrade soils quickly and accurately,an optimized artificial neural network(ANN)approach based on the multi-population genetic algorithm(MPGA)was proposed in this study.The MPGA overcomes the problems of the traditional ANN such as low efficiency,local optimum and over-fitting.The developed optimized ANN method consists of ten input variables,twenty-one hidden neurons,and one output variable.The physical properties(liquid limit,plastic limit,plasticity index,0.075 mm passing percentage,maximum dry density,optimum moisture content),state variables(degree of compaction,moisture content)and stress variables(confining pressure,deviatoric stress)of subgrade soils were selected as input variables.The MR was directly used as the output variable.Then,adopting a large amount of experimental data from existing literature,the developed optimized ANN method was compared with the existing representative estimation methods.The results show that the developed optimized ANN method has the advantages of fast speed,strong generalization ability and good accuracy in MR estimation.展开更多
文摘In the lush heart of Uganda’s Busoga sub-region,Isaac Imaka is charting a new course for rural development.After seven years in national media,he left the newsroom and stepped into the soil.The former reporter with the Daily Monitor was driven by the belief that communities like his in Jinja North deserved more than chronic poverty and hand-to-mouth survival.
文摘Dear Editor,This letter deals with the stabilization of a resilient model predictive control(MPC)algorithm with a dynamic event-triggered mechanism subject to Denial-of-Service(Do S)attacks.Different from previous works,this letter is based on the designed threshold function to dynamically trigger and gives the upper bound conditions for intersampling intervals with attack and attack-free scenarios to converge.
文摘When a vehicle moves over a flexible pavement structure,it generates loading and unloading cycles that produce recoverable(resilient)and permanent(plastic)deformations in the granular base and subbase layers,which are made of unbound granular materials(UGMs).The primary parameter used to evaluate the resilient response of UGMs in pavements is the resilient modulus(MR).The MR is widely used in calculating stress-strain states for flexible pavement design and as a control parameter during the construction process.It is also employed to understand the progression of distresses,such as fatigue cracking and rutting.The main objective of this study was to conduct a literature review on the resilient behavior of UGMs.This manuscript presents and describes the MR and the factors that influence it.It also outlines the evolution of the mathematical equations most commonly used to estimate and predict this physical parameter.Conclusions and recommendations for future research are provided at the end of the article.Despite the large amount of research done on the subject,the resilient behavior of UGM has not yet been fully understood.This is since these materials are highly heterogeneous and show nonlinear-anisotropic behavior under different cyclic loading paths and water contents.Likewise,these materials undergo different behaviors depending on their macro and microscopic properties(gradation,density,porosity,texture,mineralogy,particle geometry and orientation,temperature,among others).On the other hand,the main limitation of the mathematical equations is that their parameters are difficult to determine experimentally and are not constants of the material(they are state variables that can change with multiple factors).Additionally,these equations do not consider the boundary conditions to which UGM in pavements are exposed.Moreover,they are obtained from repeated load triaxial(RLT)tests,which cannot simulate the three cyclic stress components(vertical,horizontal,and shear)to which UGMs are subjected in a pavement.In recent years,there has been an increase in studies evaluating the use of recycled aggregates and the effect of temperature(particularly at subzero temperatures),but more research is still needed to reach definitive conclusions.
文摘The International Textile Manufac-turers Federation(ITMF),has releasedthe results of its Global Textile IndustrySurvey(GTIS)for March 2025.Thissurvey,conducted regularly across allkey regions and segments of the textilevalue chain,revealed a complex pictureof a deteriorated business situation,cau-tious op timism,regional divergence,andongoing structural challenges.
基金supported in part by the Natural Science Foundation of Chongqing under Grant CSTB2023NSCQ-LZX0118in part by the National Natural Science Foundation of China under Grant 62471052in part by the Beijing University of Posts and Telecommunications(BUPT)Excellent Ph.D.Students Foundation under Grant CX2023139.
文摘As key technologies in 6G,Space-Air-Ground Integrated Networks(SAGIN)promises to provide seamless global coverage through a comprehensive,ubiquitous communication system,while Integrated Sensing and Communications(ISAC)effectively addresses spectrum congestion by sharing spectrum resources and transceivers for simultaneous communication and sensing operations.However,existing ISAC research has primarily focused on terrestrial networks,with limited exploration of its applications in SAGIN environments.This paper proposes a novel SAGIN-ISAC scheme leveraging High-Altitude Platform Stations(HAPS).In this scheme,HAPS serves as a relay node that not only amplifies and forwards communication signals but also receives and processes target echo signals for parameter estimation.The satellite employs Resilient Massive Access(RMA)to provide communication services to different User Terminals(UTs).To address scenarios with an unknown number of targets,we develop a Two-threshold Detection and Parameter Multiple Signal Classification(MUSIC)algorithm(TDPM),which employs dual-threshold correlation detection to determine the number of targets and utilizes the MUSIC algorithm to estimate targets’Angle of Arrival(AoA),range,and relative velocity.Furthermore,we establish a joint optimization framework that considers both communication and sensing performance,optimizing energy efficiency,detection probability,and the Cramér-Rao bound.The power allocation coefficients are derived through Nash equilibrium,while the precoding matrix is optimized using Sequential Convex Approximation(SCA)to address the non-convex nature of the optimization problem.Experimental results demonstrate that our proposed scheme significantly enhances the overall performance of the SAGIN-ISAC system.
文摘Self-centering systems are increasingly studied after devastating earthquakes in the 2010s that caused irreparable damage to buildings.Currently,there is conflicting evidence as to whether the re-centering(restoring)capabilities are gained at the expense of hysteretic damping,potentially leading to larger peak displacements and damage to non-structural elements.This study examines the earthquake response of self-centering and non-self-centering systems through analyses of 4-storey and 8-storey steel-braced frames.The Resilient Slip Friction Joint(RSFJ)dampers,combined with steel braces in series,represent the self-centering bracing system,whereas the Buckling Restrained Braces(BRBs)represent the non-self-centering bracing system.Results suggest that peak displacements,base shears,and floor accelerations were comparable between the two systems.A possible explanation is that the peak response occurs on the first major excursion;similar peaks result from similar backbone curves in the run-up to the peak.Conversely,the amount of hysteretic damping only begins to affect the post-peak behavior.For instance,the RSFJ system reintroduces seismic energy into the structure post-peak(rather than dissipating it like the BRB).Subsequently,it leads to larger vibration amplitudes about the central position,increasing the risk of secondary peaks.This contrasts with the BRB system,which exhibits smaller vibration amplitudes about an increasingly deformed position due to seismic ratcheting.Unsurprisingly,residual deformations were high for the BRBs(1.7%on average)and negligible for the RSFJ.However,RSFJ produced smaller peak inter-storey drifts between 13%–18%but higher peak accelerations by 4%–5%.The results suggest that multi-storey braced frames could be designed with similar or smaller forces when self-centering systems are used.
基金Key Program of National Natural Science Foundation of China(No.41931076)Laoshan Laboratory(No.LSKJ202205101)+1 种基金National Key R&D Program of China(No.2020YFB0505800)National Natural Science Foundation of China for Young Scholar(No.41904042)。
文摘Any single Positioning,Navigation and Timing(PNT)technology has its vulnerability and limits,even the powerful Global Navigation Satellite System(GNSS)is no exception.To provide continuous and reliable PNT information to users,the theory and technique of comprehensive PNT information system and resilient PNT application system have attracted great attention from Chinese scholars.We try to summarize the progress and development of the synthetic PNT system,including the proposal,the modification and the improvement of the comprehensive PNT,as well as the follow-up resilient PNT.The frame of China’s comprehensive PNT system consisted of comprehensive PNT infrastructure and comprehensive PNT application system is initially described;the achievements on some main PNT technologies are introduced;the conceptual models of resilient PNT are given;besides,existing researches on resilient function models and stochastic models are summarized according to different user scenarios.
文摘As Africa marks a decade since the adoption of Agenda 2063,its bold and ambitious seven aspirations have positioned the continent as a strong,united,resilient,and influential global player and partner.Reaffirming its Pan-Africanism and African renaissance plan,aspiration seven of Agenda 2063 underscores the importance of Africa’s unity and solidarity in the face of major challenges emanating from the changing nature of globalisation,climate change,and economic and political environment.
文摘The application of mass timber elements in different structures has gained publicity over the last few years,pri-marily due to climate change adaptation policies and net zero carbon targets.Timber is a renewable construction material that can outperform other building materials regarding environmental impact.However,when used in seismically active regions,its application has been limited due to the uncertainties on their seismic behaviour in respect with different design standards and limited ductility in conventional connections.Conventional timber connections typically suffer from stiffness and strength degradation under cyclic loads.Their repairability is also low due to permanent damage in the fasteners and the associated crushing in the wood fibres.The use of friction connections can be an efficient way to mitigate these issues.They offer many advantages as they are economical and yet provide a high level of reliable and continuous energy dissipation.In recent years,a new generation of friction connections has been developed that can provide self-centring behaviour(i.e.,the ability of the structure to return to its original position at the end of an earthquake).However,how these connections perform compared to a mass timber system with conventional timber connections is still unknown.Several studies in the literature have suggested that these connections can enhance the performance of mass timber structures.However,the seismic performance of such systems specifically in terms of base shear,response drifts and response accelerations-has not been thoroughly investigated.This paper examines various design aspects of conventional friction connections and self-centring friction connections,providing insights into their differences concerning key seismic performance indicators.It compares the seismic performance of mass timber buildings equipped with both solutions,highlighting their advantages and limitations and drawing conclusions based on the results.The key findings are that friction connections can provides a superior seismic performance for timber structures.However,that may need to be combined with a parallel system avoid residual displacements.
基金supported by the National Natural Science Foun-dation of China(72174028 and 52225902)the Strategic Research and Consulting Project of Chinese Academy of Engineer-ing(2024-XZ-47).
文摘Urban food systems need remedies due to the global rise of food insecurity. Aquaponics has emerged as a circular agricultural mode to shape edible cities and features multiple food-water-energy (FWE) nexus. Here we provide a generalizable methodology and framework to capture the FWE nexus flows of aquaponics systems within city jurisdiction. To test the framework in Beijing, China, we offer an evidence-based tradeoff analysis of urban rooftop aquaponics (RA) and ground aquaponics (GA) from a FWE nexus perspective. The results show that urban aquaponics performs well in terms of water effi-ciency, which saves 42%-44% of water consumption than traditional greenhouses (TG) during the on-farm stage, but generates 2.3-3.0 times higher energy consumption and 1.1-2.1 times more carbon emis-sions. “From farm to table” aquaponics helps decrease 14%-44% of the energy, water, and carbon impacts during the off-farm stage. With diversely optimized strategies for renewable electricity, fish food, infras-tructure materials, and recycling actions, urban aquaponics can hopefully reduce energy consumption and carbon emissions by 80%-85% in the on-farm stage. In addition to greenhouse agriculture, utilizing a total of 155 km2 of RA and GA potential areas could increase urban vegetable self-sufficiency by 15%, and avoid 82% of the energy, water, and carbon footprints during upstream food supply chains beyond cities. Our findings could provide policy insights for urban stakeholders to create edible landscapes by integrating RA and GA, and thus direct resilient and sustainable agricultural transformation.
文摘The growth and scale of urbanisation in Indonesia poses various challenges,including the availability of affordable housing,which has forced many low-income people to live in informal settlements.Fires account for 15%of all disasters in Indonesia,particularly in densely populated urban areas such as informal settlements.The nature of informal settlements,which lack basic services along with poor living conditions,increases the like-lihood of fire.The topic of informal settlement fires in Indonesia is relatively unresearched,especially studies tailored to waterfront informal settlements typologies which prevents an understanding of fire risk and its impact in the area.This study aims to investigate what aspects influence fire risk in the area and to increase the resilience of informal settlements to fire outbreaks with the intention of improving community resilience.A case study with mixed methods is employed in this study.Our study consists of two phases of data analysis.The first phase consists of spatial analysis,derivation of weight,risk assessment,sensitivity analysis,and identification of policy drivers.Meanwhile,the second phase of our data analysis consists of analysing conditions,challenges,and opportunities,resilient strategies development,and scenario testing.The results of this study revealed that the risk of fire in the area is considered high-to-very high,which is driven primarily by moderate hazard,high vulnerability,and low-to-very low capacity against fire.Primary drivers of fire risk in the area are building materials,electrical connection and equipment,road width,and building density.As a result,this study proposed nine physical and non-physical resilient strategies which has been categorised into three distinct aspects:development planning,development regulations,and risk management and response.Spatial analysis revealed that,if fully implemented and operationalised,these strategies could reclassify 90%of the area to moderate risk.Further research is should examine the causal factors of past fire incidents,the institutional capacity for fire management,and the socioeconomic conditions of the community.
基金financial support from the National Science Foundation(NSF)EPSCoR R.I.I.Track-2 Program,awarded under the NSF grant number 2119691.
文摘The increasing frequency and severity of natural disasters,exacerbated by global warming,necessitate novel solutions to strengthen the resilience of Critical Infrastructure Systems(CISs).Recent research reveals the sig-nificant potential of natural language processing(NLP)to analyze unstructured human language during disasters,thereby facilitating the uncovering of disruptions and providing situational awareness supporting various aspects of resilience regarding CISs.Despite this potential,few studies have systematically mapped the global research on NLP applications with respect to supporting various aspects of resilience of CISs.This paper contributes to the body of knowledge by presenting a review of current knowledge using the scientometric review technique.Using 231 bibliographic records from the Scopus and Web of Science core collections,we identify five key research areas where researchers have used NLP to support the resilience of CISs during natural disasters,including sentiment analysis,crisis informatics,data and knowledge visualization,disaster impacts,and content analysis.Furthermore,we map the utility of NLP in the identified research focus with respect to four aspects of resilience(i.e.,preparedness,absorption,recovery,and adaptability)and present various common techniques used and potential future research directions.This review highlights that NLP has the potential to become a supplementary data source to support the resilience of CISs.The results of this study serve as an introductory-level guide designed to help scholars and practitioners unlock the potential of NLP for strengthening the resilience of CISs against natural disasters.
文摘Objective:Existing research mainly relies on quantitative indicators.However,the subjectivity of qualitative indicators and the problem of their difficulty in quantification limit the comprehensiveness of evaluation.Therefore,a resilience supplier evaluation method based on the improved Z-number-ORESTE is proposed.Methods:Through the construction of a multi-tiered evaluation index system incorporating supplier capabilities,resources,strategic aspects,and resilience,Z-numbers are harnessed to signify qualitative indicators.An advanced Z-number distance metric is implemented,meticulously considering the impact exerted by the reliability portion of Z-numbers on information risk.The refined ORESTE ranking algorithm introduces the concepts of strong and weak orderings and capitalizes on the Borda assignment function.This approach facilitates a more precise appraisal of the performance of alternative solutions.By amalgamating the improved Z-number distance measurement approach with the ORESTE ranking methodology for multi-attribute decision-making,it becomes feasible to more efficiently assess the recovery capacities and adaptability of suppliers in the face of unforeseen incidents and risks.Results:Through the analysis of the comprehensive performance of the existing suppliers of a certain electronics enterprise,the results regarding the suppliers’recovery capabilities and adaptability when facing unexpected events and risks are obtained.Eventually,the suppliers that are in line with the long-term development strategy of the enterprise are selected.Conclusion:This evaluation system has verified its feasibility and effectiveness.Moreover,the system is capable of effectively identifying and selecting resilient suppliers,providing more reliable decision-making support for the enterprise’s supply chain management.
文摘The Congolese population is organised into households, which are thus headed by a chief who ensures the social well-being, development and integration into working life of the individuals in his charge. This study examines the functional principles of new housing design as an instrument for transforming the (current) failing economy into a strong and resilient one. Accordingly, a literature review of the practice of designing and building housing in human settlements in the Congo revealed the state of the art on this subject. An analysis of the existing housing stock from a demographic, social and economic point of view made it possible to identify the most common household sizes and numbers, as well as the lifestyle processes that determine the need for developed space. To this end, the experimental method was used to propose configuration plans for various new types of dwelling. To this end, the study highlighted the link between people’s standard of living and the effectiveness of their involvement in the local economy. To achieve the aims of the National Development Plan (NDP), particular attention must be paid to solving the housing problem. The existing housing stock actively contributes to the problems associated with unemployment and insecurity. Functional principles for the design of new types of housing have been developed. Four model types are proposed in line with the demographic structure of the population, their socio-economic characteristics and their lifestyle.
基金Supported by National Key R&D Program of China(Grant No.2017YFB1201103-08)National Nature Science Foundation of China(Grant No.51605318)
文摘Resilient wheels are extensively used in urban rail transit, especially for tramway systems, owing to its advantages in noise reduction. A new type of resilient wheel for a metro is designed, and its characteristics of vibration and sound radiation, including the rolling noise of a resilient single wheel coupled with a track, are studied in this paper. A two-step research is presented. Firstly, laboratory experiments were conducted to obtain the vibration response of the designed resilient wheel under the radial excitation on its tread. Secondly, the rolling noise model of the resilient wheel coupled with a slab track used in a metro line is developed. The wheel model is based on the 3 D finite elementand boundary element methods and verified by using the experimental results obtained from the laboratory. The track vibration model is based on the wavenumber finite element method, and the track sound radiation is calculatedby using an e cient frequency-domain Rayleigh method. The interaction of the resilient wheel and the slab track is analyzed considering the measured wheel/rail roughness of the metro. The contribution of the resilient wheel to the reduction of wheel/rail system noise is analyzed. The results show that the resilient wheel can e ectively reduce the wheel/rail rolling noise by approximately 2 dB(A) to 3 dB(A), mainly because the radiated noise by the rail is reduced. In addition, the elastic modulus of the rubber has an important influence on the noise reduction of resilient wheels.
基金supported in part by Australian Research Council Discovery Early Career Researcher Award(DE210100273)。
文摘Connected automated vehicles(CAVs)serve as a promising enabler for future intelligent transportation systems because of their capabilities in improving traffic efficiency and driving safety,and reducing fuel consumption and vehicle emissions.A fundamental issue in CAVs is platooning control that empowers a convoy of CAVs to be cooperatively maneuvered with desired longitudinal spacings and identical velocities on roads.This paper addresses the issue of resilient and safe platooning control of CAVs subject to intermittent denial-of-service(DoS)attacks that disrupt vehicle-to-vehicle communications.First,a heterogeneous and uncertain vehicle longitudinal dynamic model is presented to accommodate a variety of uncertainties,including diverse vehicle masses and engine inertial delays,unknown and nonlinear resistance forces,and a dynamic platoon leader.Then,a resilient and safe distributed longitudinal platooning control law is constructed with an aim to preserve simultaneous individual vehicle stability,attack resilience,platoon safety and scalability.Furthermore,a numerically efficient offline design algorithm for determining the desired platoon control law is developed,under which the platoon resilience against DoS attacks can be maximized but the anticipated stability,safety and scalability requirements remain preserved.Finally,extensive numerical experiments are provided to substantiate the efficacy of the proposed platooning method.
基金Project(51878078)supported by the National Natural Science Foundation of ChinaProject(2018-025)supported by the Training Program for High-level Technical Personnel in Transportation Industry,ChinaProject(CTKY-PTRC-2018-003)supported by the Design Theory,Method and Demonstration of Durability Asphalt Pavement Based on Heavy-duty Traffic Conditions in Shanghai Area,China。
文摘The resilient modulus(MR)of subgrade soils is usually used to characterize the stiffness of subgrade and is a crucial parameter in pavement design.In order to determine the resilient modulus of compacted subgrade soils quickly and accurately,an optimized artificial neural network(ANN)approach based on the multi-population genetic algorithm(MPGA)was proposed in this study.The MPGA overcomes the problems of the traditional ANN such as low efficiency,local optimum and over-fitting.The developed optimized ANN method consists of ten input variables,twenty-one hidden neurons,and one output variable.The physical properties(liquid limit,plastic limit,plasticity index,0.075 mm passing percentage,maximum dry density,optimum moisture content),state variables(degree of compaction,moisture content)and stress variables(confining pressure,deviatoric stress)of subgrade soils were selected as input variables.The MR was directly used as the output variable.Then,adopting a large amount of experimental data from existing literature,the developed optimized ANN method was compared with the existing representative estimation methods.The results show that the developed optimized ANN method has the advantages of fast speed,strong generalization ability and good accuracy in MR estimation.
