Background:Plant nitrogen use efciency(NUE)is an important ecological indicator that refects the capacity of a plant to transform nitrogen into production,which is essential for further elucidating plant growth and te...Background:Plant nitrogen use efciency(NUE)is an important ecological indicator that refects the capacity of a plant to transform nitrogen into production,which is essential for further elucidating plant growth and terrestrial ecosystem productivity.Although there are a growing number of studies that address NUE changes at local scales,the variations of NUE over large spatial scales remain unclear.In this study,we analyzed the geographic patterns of NUE and explored its phylogenic and environmental drivers across 1452 species at 1102 sites in China.Results:NUE tended to decrease with latitude(r=−0.56),whereas it increased with longitude(r=0.54),and varied widely in diferent ecosystems and plant life forms.Furthermore,NUE was negatively correlated with plant foliar phosphorus concentration(r=−0.53),soil pH(r=−0.10),soil total phosphorus(r=−0.13)and available phosphorus(r=−0.05),but positively with the mean annual temperature(r=0.32),annual precipitation(r=0.27),and aridity index(r=0.26).NUE was signifcantly altered with phylogeny and evolved toward a lower value(r=−0.28),which may have been due to increasing nitrogen deposition and fxation in biogeochemical evolution.Overall,the combination of foliar phosphorus concentration,phylogeny,climate,and soil properties accounted for 52.7%of the total variations of NUE.In particular,foliar phosphorus concentration was the most important factor,whereas plant evolutionary history was second in contributing to NUE variations.Conclusions:Our study emphasizes the pivotal role of plant stoichiometry and phylogeny in nitrogen cycling and suggests incorporating them into earth system models to better understanding plant growth and nitrogen cycling in the context of environmental changes.展开更多
Glucose oxidase(GOD)has many practical applications,but its poor thermostability limits its broader use.In this research,three primary mutants of wild-type GOD were designed using rational mutagenesis,and the GODm mut...Glucose oxidase(GOD)has many practical applications,but its poor thermostability limits its broader use.In this research,three primary mutants of wild-type GOD were designed using rational mutagenesis,and the GODm mutant was constructed by combinatorial design.The expression,purifcation,and enzymatic properties of the mutants were studied.The specifc enzyme activity of GODm was 2.10-fold higher than that of wild type,and the(k_(cat)/K_(m))value was increased by 1.45-fold.After treatment at 55℃for 3 h,GODm retained 37.5%of its enzymatic activity,and the half-life(t_(1/2))of GODm at 55℃and 65℃was 2.28-fold and 3.36-fold higher than that of wild type,respectively.By analyzing the three-dimensional structure of wild type and the GODm mutant,it was found that T30V formed a new hydrogen bond with FAD and strengthened the hydrophobic interaction,D315K optimized the surface electrostatic interaction,and A162T improved the efciency of the electron pathway.Thus,a novel mutant with improved thermostability and catalytic efciency was obtained in this research.展开更多
The Internet of Things(IoT)is gaining attention because of its broad applicability,especially by integrating smart devices for massive communication during sensing tasks.IoT-assisted Wireless Sensor Networks(WSN)are s...The Internet of Things(IoT)is gaining attention because of its broad applicability,especially by integrating smart devices for massive communication during sensing tasks.IoT-assisted Wireless Sensor Networks(WSN)are suitable for various applications like industrial monitoring,agriculture,and transportation.In this regard,routing is challenging to nd an efcient path using smart devices for transmitting the packets towards big data repositories while ensuring efcient energy utilization.This paper presents the Robust Cluster Based Routing Protocol(RCBRP)to identify the routing paths where less energy is consumed to enhances the network lifespan.The scheme is presented in six phases to explore ow and communication.We propose the two algorithms:(i)energy-efcient clustering and routing algorithm and (ii)distance and energy consumption calculation algorithm.The scheme consumes less energy and balances the load by clustering the smart devices.Our work is validated through extensive simulation using Matlab.Results elucidate the dominance of the proposed scheme is compared to counterparts in terms of energy consumption,the number of packets received at BS and the number of active and dead nodes.In the future,we shall consider edge computing to analyze the performance of robust clustering.展开更多
This article proposes two new Ranked Set Sampling(RSS)designs for estimating the population parameters:Simple Z Ranked Set Sampling(SZRSS)and Generalized Z Ranked Set Sampling(GZRSS).These designs provide unbiased est...This article proposes two new Ranked Set Sampling(RSS)designs for estimating the population parameters:Simple Z Ranked Set Sampling(SZRSS)and Generalized Z Ranked Set Sampling(GZRSS).These designs provide unbiased estimators for the mean of symmetric distributions.It is shown that for non-uniform symmetric distributions,the estimators of the mean under the suggested designs are more efcient than those obtained by RSS,Simple Random Sampling(SRS),extreme RSS and truncation based RSS designs.Also,the proposed RSS schemes outperform other RSS schemes and provide more efcient estimates than their competitors under imperfect rankings.The suggested mean estimators under perfect and imperfect rankings are more efcient than the linear regression estimator under SRS.Our proposed RSS designs are also extended to cover the estimation of the population median.Real data is used to examine wthe usefulness and efciency of our estimators.展开更多
In the financial sector,alternatives to traditional datasets,such as financial statements and Securities and Exchange Commission filings,can provide additional ways to describe the running status of businesses.Nontrad...In the financial sector,alternatives to traditional datasets,such as financial statements and Securities and Exchange Commission filings,can provide additional ways to describe the running status of businesses.Nontraditional data sources include individual behaviors,business processes,and various sensors.In recent years,alternative data have been leveraged by businesses and investors to adjust credit scores,mitigate financial fraud,and optimize investment portfolios because they can be used to conduct more in-depth,comprehensive,and timely evaluations of enterprises.Adopting alternative data in developing models for finance and business scenarios has become increasingly popular in academia.In this article,we first identify the advantages of alternative data compared with traditional data,such as having multiple sources,heterogeneity,flexibility,objectivity,and constant evolution.We then provide an overall investigation of emerging studies to outline the various types,emerging applications,and effects of alternative data in finance and business by reviewing over 100 papers published from 2015 to 2023.The investigation is implemented according to application scenarios,including business return prediction,business risk management,credit evaluation,investment risk prediction,and stock prediction.We discuss the roles of alternative data from the perspective of finance theory to argue that alternative data have the potential to serve as a bridge toward achieving high efficiency in financial markets.The challenges and future trends of alternative data in finance and business are also discussed.展开更多
Connected vehicles enabled by communication technologies have the potential to improve trafc mobility and enhance roadway safety such that trafc information can be shared among vehicles and infrastructure.Fruitful spe...Connected vehicles enabled by communication technologies have the potential to improve trafc mobility and enhance roadway safety such that trafc information can be shared among vehicles and infrastructure.Fruitful speed advisory strategies have been proposed to smooth connected vehicle trajectories for better system performance with the help of diferent carfollowing models.Yet,there has been no such comparison about the impacts of various car-following models on the advisory strategies.Further,most of the existing studies consider a deterministic vehicle arriving pattern.The resulting model is easy to approach yet not realistic in representing realistic trafc patterns.This study proposes an Individual Variable Speed Limit(IVSL)trajectory planning problem at a signalized intersection and investigates the impacts of three popular car-following models on the IVSL.Both deterministic and stochastic IVSL models are formulated,and their performance is tested with numerical experiments.The results show that,compared to the benchmark(i.e.,without speed control),the proposed IVSL strategy with a deterministic arriving pattern achieves signifcant improvements in both mobility and fuel efciency across diferent trafc levels with all three car-following models.The improvement of the IVSL with the Gipps’model is the most remarkable.When the vehicle arriving patterns are stochastic,the IVSL improves travel time,fuel consumption,and system cost by 8.95%,19.11%,and 11.37%,respectively,compared to the benchmark without speed control.展开更多
Cognitive radio,which is capable of enabling dynamic spectrum access,is a promising technology in future wireless communication.The feasibility of cognitive radio network greatly depends on the energy efciency and rel...Cognitive radio,which is capable of enabling dynamic spectrum access,is a promising technology in future wireless communication.The feasibility of cognitive radio network greatly depends on the energy efciency and reliability of spectrum sensing technology.In this paper,spectrum sensing in cognitive ad-hoc network(CAN)with wide-band dynamic spectrum is considered.A cognitive cluster head(CCH)is set and responsible for dividing the wide-band spectrum into multiple sub-channels;it can either sense sub-channels in a centralized manner,or make use of sensing modules to sense sub-channels in a distributed manner.Then cognitive users(CUs)can get sensing results and access to the available sub-channel.We take the cost of control message into consideration and formulate the energy consumption of CAN in terms of sub-channel sampling rate and whole-band sensing time.We define energy efciency intuitively and solve the energy efciency optimization problem with sensing reliability constraints by constructing a parametric problem and obtain the optimal sampling rate and the wholeband sensing time.Power dissipation model of a practical A/D convertor(ADC)is introduced,and numerical results are given to show the energy efciency performance of two diferent sensing manners.展开更多
With the advent in services such as telemedicine and telesurgery,provision of continuous quality monitoring for these services has become a challenge for the network operators.Quality standards for provision of such s...With the advent in services such as telemedicine and telesurgery,provision of continuous quality monitoring for these services has become a challenge for the network operators.Quality standards for provision of such services are application specic as medical imagery is quite different than general purpose images and videos.This paper presents a novel full reference objective video quality metric that focuses on estimating the quality of wireless capsule endoscopy(WCE)videos containing bleeding regions.Bleeding regions in gastrointestinal tract have been focused in this research,as bleeding is one of the major reasons behind several diseases within the tract.The method jointly estimates the diagnostic as well as perceptual quality of WCE videos,and accurately predicts the quality,which is in high correlation with the subjective differential mean opinion scores(DMOS).The proposed combines motion quality estimates,bleeding regions’quality estimates based on support vector machine(SVM)and perceptual quality estimates using the pristine and impaired WCE videos.Our method Quality Index for Bleeding Regions in Capsule Endoscopy(QI-BRiCE)videos is one of its kind and the results show high correlation in terms of Pearson’s linear correlation coefcient(PLCC)and Spearman’s rank order correlation coefcient(SROCC).An F-test is also provided in the results section to prove the statistical signicance of our proposed method.展开更多
Dike-break floods,characterized by high flood peaks,large volumes,and sudden onsets,seriously threaten the flood control and safety of river basins.In addres sing the computationally intensive and time-consuming probl...Dike-break floods,characterized by high flood peaks,large volumes,and sudden onsets,seriously threaten the flood control and safety of river basins.In addres sing the computationally intensive and time-consuming problem of numerical modeling of large-scale outburst floods,this study proposed a novel hybrid alternative modeling approach.The proposed methodology integrates a low-fidelity(LF)hydrodynamic model with a sparse Gaussian processes(SGP)model,incorporates rotated empirical orthogonal functions(REOF)to address high-dimensional data challenges,streamlines the model structure,and enhances computational efficiency.The SGP model uses training data from the high-fidelity(HF)model to rectify LF model results,enhancing computational efficiency while ensuring precise reproduction of HF model results.Validation in the Yongding River floodplain demonstrates that the hybrid model significantly improves flood extent and depth predictions compared to the LF model,with substantially lower computational costs than the HF model.The results indicate that the REOF-SGP model achieved probability of detection(POD)values higher than 0.8 and rate of false alarm(RFA)values lower than 0.2within the 120-hour simulation period.The prediction error for inundation depth in the floodplain generally fell within the range of(-0.1 m,0.1 m).The computational efficiency was 11 times higher than that of the HF hydrodynamic model.This method enhances large-scale flood inundation calculation efficiency while ensuring refined simulation of dynamic flood area changes,aiding rapid prediction of nonlinear flood evolution and water depth distribution.展开更多
Background:Changes in foliar nitrogen(N)and phosphorus(P)stoichiometry play important roles in predicting the efects of global change on ecosystem structure and function.However,there is substantial debate on the efec...Background:Changes in foliar nitrogen(N)and phosphorus(P)stoichiometry play important roles in predicting the efects of global change on ecosystem structure and function.However,there is substantial debate on the efects of P addition on foliar N and P stoichiometry,particularly under diferent levels of N addition.Thus,we conducted a global meta-analysis to investigate how N addition alters the efects of P addition on foliar N and P stoichiometry across different rates and durations of P addition and plant growth types based on more than 1150 observations.Results:We found that P addition without N addition increased foliar N concentrations,whereas P addition with N addition had no efect.The positive efects of P addition on foliar P concentrations were greater without N addition than with N addition.Additionally,the efects of P addition on foliar N,P and N:P ratios varied with the rate and duration of P addition.In particular,short-term or low-dose P addition with and without N addition increased foliar N concentration,and the positive efects of short-term or low-dose P addition on foliar P concentrations were greater without N addition than with N addition.The responses of foliar N and P stoichiometry of evergreen plants to P addition were greater without N addition than with N addition.Moreover,regardless of N addition,soil P availability was more efective than P resorption efciency in predicting the changes in foliar N and P stoichiometry in response to P addition.Conclusions:Our results highlight that increasing N deposition might alter the response of foliar N and P stoichiometry to P addition and demonstrate the important efect of the experimental environment on the results.These results advance our understanding of the response of plant nutrient use efciency to P addition with increasing N deposition.展开更多
Equitable and efficient allocation of emergency resources is critical to ensure the success of relief efforts.The challenge comes largely from two aspects:the resources available for allocation are usually limited in ...Equitable and efficient allocation of emergency resources is critical to ensure the success of relief efforts.The challenge comes largely from two aspects:the resources available for allocation are usually limited in quantity,especially in the early period of emergency response;and a large amount of uncertain information in the relief process affects the decision making of resource allocation.A multiperiod allocation model of emergency resources that takes into account both efficiency and equity based on uncertain disaster information is proposed.Interval number and triangular fuzzy number are introduced to describe the different sources of uncertainty(for example,demand,transportation time,and maximum transport amount),and the loss caused by unmet demand is used to quantify equity.Then,the deterministic transformation method of uncertain parameters is designed and the linear weighted sum method is applied to solve the proposed model.Finally,a computational case based on the 2017 Jiuzhaigou earthquake in Sichuan Province,China was conducted to validate the proposed model.The results show that the proposed model is feasible in the multiperiod allocation of emergency resources among multidisaster sites,and the findings can help emergency managers to allocate emergency resources more scientifically,equitably,and effectively under uncertainty.展开更多
Tin perovskites with exemplary optoelectronic properties ofer potential application in lead-free perovskite solar cells.However,Sn vacancies and undercoordinated Sn ions on the tin perovskite surfaces can create deep-...Tin perovskites with exemplary optoelectronic properties ofer potential application in lead-free perovskite solar cells.However,Sn vacancies and undercoordinated Sn ions on the tin perovskite surfaces can create deep-level traps,leading to nonradiative recombination and absorption of nucleophilic O_(2)molecules,impeding further device efciency and stability.Here,in this study,a new additive of semicarbazide hydrochloride(SEM-HCl)with a N–C=O functional group was introduced into the perovskite precursor to fabricate high-quality flms with a low concentration of deep-level trap densities.This,in turn,serves to prevent undesirable interaction between photogenerated carriers and adsorbed oxygen molecules in the device’s operational environment,ultimately reducing the proliferation of superoxide entities.As the result,the SEM-HCl-derived devices show a peak efciency of 10.9%with improved device stability.These unencapsulated devices maintain almost 100%of their initial efciencies after working for 100 h under continuous AM1.5 illumination conditions.展开更多
A flow gas low-pressure multi-wire proportional chamber（LPMWPC） with an active area of 180 mm× 80 mm has been developed for the flying time test of the recoil nuclei on super heavy nuclear experiments. The LPMW...A flow gas low-pressure multi-wire proportional chamber（LPMWPC） with an active area of 180 mm× 80 mm has been developed for the flying time test of the recoil nuclei on super heavy nuclear experiments. The LPMWPC detector can be operated in single as well as double step operational modes. In the case of double step operational mode with a high gas amplification factor, signals from α-particles reside well above the electronic noise. The gas leakage rate and time resolution obtained from the α239Pu source are shown and discussed at the condition of 3 mbar Isobutane gas. It was shown that the time resolution was better than 2.9 ns at the best work condition, and the detecting efciency was larger than 98% at the low energy α particles. So the LPMWPC is fit to measure the flying time in the super heavy nuclear fragments experiment.展开更多
In recent years,the notion of resilience has been developed and applied in many technical areas,becoming exceptionally pertinent to disaster risk science.During a disaster situation,accurate sensing information is the...In recent years,the notion of resilience has been developed and applied in many technical areas,becoming exceptionally pertinent to disaster risk science.During a disaster situation,accurate sensing information is the key to efficient recovery efforts.In general,resilience aims to minimize the impact of disruptions to systems through the fast recovery of critical functionality,but resilient design may require redundancy and could increase costs.In this article,we describe a method based on binary linear programming for sensor network design balancing efficiency with resilience.The application of the developed framework is demonstrated for the case of interior building surveillance utilizing infrared sensors in both twoand three-dimensional spaces.The method provides optimal sensor placement,taking into account critical functionality and a desired level of resilience and considering sensor type and availability.The problem formulation,resilience requirements,and application of the optimization algorithm are described in detail.Analysis of sensor locations with and without resilience requirements shows that resilient configuration requires redundancy in number of sensors and their intelligent placement.Both tasks are successfully solved by the described method,which can be applied to strengthen the resilience of sensor networks by design.The proposed methodology is suitable for large-scale optimization problems with many sensors and extensive coverage areas.展开更多
基金The National Natural Science Foundation of China(31988102,31625006)the International Collaboration Program of Chinese Academy of Sciences(131A11KYSB20180010).
文摘Background:Plant nitrogen use efciency(NUE)is an important ecological indicator that refects the capacity of a plant to transform nitrogen into production,which is essential for further elucidating plant growth and terrestrial ecosystem productivity.Although there are a growing number of studies that address NUE changes at local scales,the variations of NUE over large spatial scales remain unclear.In this study,we analyzed the geographic patterns of NUE and explored its phylogenic and environmental drivers across 1452 species at 1102 sites in China.Results:NUE tended to decrease with latitude(r=−0.56),whereas it increased with longitude(r=0.54),and varied widely in diferent ecosystems and plant life forms.Furthermore,NUE was negatively correlated with plant foliar phosphorus concentration(r=−0.53),soil pH(r=−0.10),soil total phosphorus(r=−0.13)and available phosphorus(r=−0.05),but positively with the mean annual temperature(r=0.32),annual precipitation(r=0.27),and aridity index(r=0.26).NUE was signifcantly altered with phylogeny and evolved toward a lower value(r=−0.28),which may have been due to increasing nitrogen deposition and fxation in biogeochemical evolution.Overall,the combination of foliar phosphorus concentration,phylogeny,climate,and soil properties accounted for 52.7%of the total variations of NUE.In particular,foliar phosphorus concentration was the most important factor,whereas plant evolutionary history was second in contributing to NUE variations.Conclusions:Our study emphasizes the pivotal role of plant stoichiometry and phylogeny in nitrogen cycling and suggests incorporating them into earth system models to better understanding plant growth and nitrogen cycling in the context of environmental changes.
基金The authors are grateful for the fnancial support from the National First-class Discipline Program of Light Industry Technology and Engineering(Grant No.LITE2018-04)the Topnotch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP),and the National Natural Science Foundation of China(NSFC)(32072162).
文摘Glucose oxidase(GOD)has many practical applications,but its poor thermostability limits its broader use.In this research,three primary mutants of wild-type GOD were designed using rational mutagenesis,and the GODm mutant was constructed by combinatorial design.The expression,purifcation,and enzymatic properties of the mutants were studied.The specifc enzyme activity of GODm was 2.10-fold higher than that of wild type,and the(k_(cat)/K_(m))value was increased by 1.45-fold.After treatment at 55℃for 3 h,GODm retained 37.5%of its enzymatic activity,and the half-life(t_(1/2))of GODm at 55℃and 65℃was 2.28-fold and 3.36-fold higher than that of wild type,respectively.By analyzing the three-dimensional structure of wild type and the GODm mutant,it was found that T30V formed a new hydrogen bond with FAD and strengthened the hydrophobic interaction,D315K optimized the surface electrostatic interaction,and A162T improved the efciency of the electron pathway.Thus,a novel mutant with improved thermostability and catalytic efciency was obtained in this research.
文摘The Internet of Things(IoT)is gaining attention because of its broad applicability,especially by integrating smart devices for massive communication during sensing tasks.IoT-assisted Wireless Sensor Networks(WSN)are suitable for various applications like industrial monitoring,agriculture,and transportation.In this regard,routing is challenging to nd an efcient path using smart devices for transmitting the packets towards big data repositories while ensuring efcient energy utilization.This paper presents the Robust Cluster Based Routing Protocol(RCBRP)to identify the routing paths where less energy is consumed to enhances the network lifespan.The scheme is presented in six phases to explore ow and communication.We propose the two algorithms:(i)energy-efcient clustering and routing algorithm and (ii)distance and energy consumption calculation algorithm.The scheme consumes less energy and balances the load by clustering the smart devices.Our work is validated through extensive simulation using Matlab.Results elucidate the dominance of the proposed scheme is compared to counterparts in terms of energy consumption,the number of packets received at BS and the number of active and dead nodes.In the future,we shall consider edge computing to analyze the performance of robust clustering.
基金The authors extend their appreciation to Deanship of Scientic Research at King Khalid University for funding this work through Research Groups Program under Grant No.R.G.P.2/68/41.I.M.A.and A.I.A.received the grant.
文摘This article proposes two new Ranked Set Sampling(RSS)designs for estimating the population parameters:Simple Z Ranked Set Sampling(SZRSS)and Generalized Z Ranked Set Sampling(GZRSS).These designs provide unbiased estimators for the mean of symmetric distributions.It is shown that for non-uniform symmetric distributions,the estimators of the mean under the suggested designs are more efcient than those obtained by RSS,Simple Random Sampling(SRS),extreme RSS and truncation based RSS designs.Also,the proposed RSS schemes outperform other RSS schemes and provide more efcient estimates than their competitors under imperfect rankings.The suggested mean estimators under perfect and imperfect rankings are more efcient than the linear regression estimator under SRS.Our proposed RSS designs are also extended to cover the estimation of the population median.Real data is used to examine wthe usefulness and efciency of our estimators.
基金sponsored by the National Natural Science Foundation of China(72371032)the National Key Research and Development Program of China(2023YFC3305401).
文摘In the financial sector,alternatives to traditional datasets,such as financial statements and Securities and Exchange Commission filings,can provide additional ways to describe the running status of businesses.Nontraditional data sources include individual behaviors,business processes,and various sensors.In recent years,alternative data have been leveraged by businesses and investors to adjust credit scores,mitigate financial fraud,and optimize investment portfolios because they can be used to conduct more in-depth,comprehensive,and timely evaluations of enterprises.Adopting alternative data in developing models for finance and business scenarios has become increasingly popular in academia.In this article,we first identify the advantages of alternative data compared with traditional data,such as having multiple sources,heterogeneity,flexibility,objectivity,and constant evolution.We then provide an overall investigation of emerging studies to outline the various types,emerging applications,and effects of alternative data in finance and business by reviewing over 100 papers published from 2015 to 2023.The investigation is implemented according to application scenarios,including business return prediction,business risk management,credit evaluation,investment risk prediction,and stock prediction.We discuss the roles of alternative data from the perspective of finance theory to argue that alternative data have the potential to serve as a bridge toward achieving high efficiency in financial markets.The challenges and future trends of alternative data in finance and business are also discussed.
文摘Connected vehicles enabled by communication technologies have the potential to improve trafc mobility and enhance roadway safety such that trafc information can be shared among vehicles and infrastructure.Fruitful speed advisory strategies have been proposed to smooth connected vehicle trajectories for better system performance with the help of diferent carfollowing models.Yet,there has been no such comparison about the impacts of various car-following models on the advisory strategies.Further,most of the existing studies consider a deterministic vehicle arriving pattern.The resulting model is easy to approach yet not realistic in representing realistic trafc patterns.This study proposes an Individual Variable Speed Limit(IVSL)trajectory planning problem at a signalized intersection and investigates the impacts of three popular car-following models on the IVSL.Both deterministic and stochastic IVSL models are formulated,and their performance is tested with numerical experiments.The results show that,compared to the benchmark(i.e.,without speed control),the proposed IVSL strategy with a deterministic arriving pattern achieves signifcant improvements in both mobility and fuel efciency across diferent trafc levels with all three car-following models.The improvement of the IVSL with the Gipps’model is the most remarkable.When the vehicle arriving patterns are stochastic,the IVSL improves travel time,fuel consumption,and system cost by 8.95%,19.11%,and 11.37%,respectively,compared to the benchmark without speed control.
基金the National Natural Science Foundation of China(Nos.61102052 and 60972050)the National Basic Research Program(973)of China(No.2010CB731803)+1 种基金the China Ministry of Education Fok Ying Tung Fund(No.122002)the National Science and Technology Major Project of China(Nos.2010ZX03002-007-01 and 2010ZX03003-001-01)
文摘Cognitive radio,which is capable of enabling dynamic spectrum access,is a promising technology in future wireless communication.The feasibility of cognitive radio network greatly depends on the energy efciency and reliability of spectrum sensing technology.In this paper,spectrum sensing in cognitive ad-hoc network(CAN)with wide-band dynamic spectrum is considered.A cognitive cluster head(CCH)is set and responsible for dividing the wide-band spectrum into multiple sub-channels;it can either sense sub-channels in a centralized manner,or make use of sensing modules to sense sub-channels in a distributed manner.Then cognitive users(CUs)can get sensing results and access to the available sub-channel.We take the cost of control message into consideration and formulate the energy consumption of CAN in terms of sub-channel sampling rate and whole-band sensing time.We define energy efciency intuitively and solve the energy efciency optimization problem with sensing reliability constraints by constructing a parametric problem and obtain the optimal sampling rate and the wholeband sensing time.Power dissipation model of a practical A/D convertor(ADC)is introduced,and numerical results are given to show the energy efciency performance of two diferent sensing manners.
基金supported by Innovate UK,which is a part of UK Research&Innovation,under the Knowledge Transfer Partnership(KTP)program(Project No.11433)supported by the Grand Information Technology Research Center Program through the Institute of Information&Communications Technology and Planning&Evaluation(IITP)funded by the Ministry of Science and ICT(MSIT),Korea(IITP-2020-2020-0-01612)。
文摘With the advent in services such as telemedicine and telesurgery,provision of continuous quality monitoring for these services has become a challenge for the network operators.Quality standards for provision of such services are application specic as medical imagery is quite different than general purpose images and videos.This paper presents a novel full reference objective video quality metric that focuses on estimating the quality of wireless capsule endoscopy(WCE)videos containing bleeding regions.Bleeding regions in gastrointestinal tract have been focused in this research,as bleeding is one of the major reasons behind several diseases within the tract.The method jointly estimates the diagnostic as well as perceptual quality of WCE videos,and accurately predicts the quality,which is in high correlation with the subjective differential mean opinion scores(DMOS).The proposed combines motion quality estimates,bleeding regions’quality estimates based on support vector machine(SVM)and perceptual quality estimates using the pristine and impaired WCE videos.Our method Quality Index for Bleeding Regions in Capsule Endoscopy(QI-BRiCE)videos is one of its kind and the results show high correlation in terms of Pearson’s linear correlation coefcient(PLCC)and Spearman’s rank order correlation coefcient(SROCC).An F-test is also provided in the results section to prove the statistical signicance of our proposed method.
基金supported by the National Key R&D Program of China(Grant No.2023YFC3008502)National Natural Science Foundation of China(Grant No.52309103)+3 种基金Key Science and Technology Project of Ministry of Water Resources of China(Grant No.SKS-2022002)Open Subject Fund of Engineering Research Centre for Embankment Safety and Disaster Prevention and Control of Ministry of Water Resources(Grant No.LSDP202201)Technology Research and Development and Sustainable Development Agenda Innovation Demonstration Zone Special Science and Technology Plan Project of Chengde City(Grant No.202305B009)Tianjin Flood Control and Emergency Command Platform Construction Project。
文摘Dike-break floods,characterized by high flood peaks,large volumes,and sudden onsets,seriously threaten the flood control and safety of river basins.In addres sing the computationally intensive and time-consuming problem of numerical modeling of large-scale outburst floods,this study proposed a novel hybrid alternative modeling approach.The proposed methodology integrates a low-fidelity(LF)hydrodynamic model with a sparse Gaussian processes(SGP)model,incorporates rotated empirical orthogonal functions(REOF)to address high-dimensional data challenges,streamlines the model structure,and enhances computational efficiency.The SGP model uses training data from the high-fidelity(HF)model to rectify LF model results,enhancing computational efficiency while ensuring precise reproduction of HF model results.Validation in the Yongding River floodplain demonstrates that the hybrid model significantly improves flood extent and depth predictions compared to the LF model,with substantially lower computational costs than the HF model.The results indicate that the REOF-SGP model achieved probability of detection(POD)values higher than 0.8 and rate of false alarm(RFA)values lower than 0.2within the 120-hour simulation period.The prediction error for inundation depth in the floodplain generally fell within the range of(-0.1 m,0.1 m).The computational efficiency was 11 times higher than that of the HF hydrodynamic model.This method enhances large-scale flood inundation calculation efficiency while ensuring refined simulation of dynamic flood area changes,aiding rapid prediction of nonlinear flood evolution and water depth distribution.
基金supported by the National Natural Science Foundation of China(Grant Nos.31870602,31901295,and 32071745)the Program of Sichuan Excellent Youth Sci-Tech Foundation(20JCQN0145)+2 种基金the Chinese Postdoctoral Science Foundation(2020M673278)the CAS“Light of West China”Program(Y8C2021)Chengming You also acknowledges the China Scholarship Council for supporting a Ph.D.programme Grant(201806910030)。
文摘Background:Changes in foliar nitrogen(N)and phosphorus(P)stoichiometry play important roles in predicting the efects of global change on ecosystem structure and function.However,there is substantial debate on the efects of P addition on foliar N and P stoichiometry,particularly under diferent levels of N addition.Thus,we conducted a global meta-analysis to investigate how N addition alters the efects of P addition on foliar N and P stoichiometry across different rates and durations of P addition and plant growth types based on more than 1150 observations.Results:We found that P addition without N addition increased foliar N concentrations,whereas P addition with N addition had no efect.The positive efects of P addition on foliar P concentrations were greater without N addition than with N addition.Additionally,the efects of P addition on foliar N,P and N:P ratios varied with the rate and duration of P addition.In particular,short-term or low-dose P addition with and without N addition increased foliar N concentration,and the positive efects of short-term or low-dose P addition on foliar P concentrations were greater without N addition than with N addition.The responses of foliar N and P stoichiometry of evergreen plants to P addition were greater without N addition than with N addition.Moreover,regardless of N addition,soil P availability was more efective than P resorption efciency in predicting the changes in foliar N and P stoichiometry in response to P addition.Conclusions:Our results highlight that increasing N deposition might alter the response of foliar N and P stoichiometry to P addition and demonstrate the important efect of the experimental environment on the results.These results advance our understanding of the response of plant nutrient use efciency to P addition with increasing N deposition.
基金This work was supported by the National Social Science Foundation of China(Grant No.21CGL044).
文摘Equitable and efficient allocation of emergency resources is critical to ensure the success of relief efforts.The challenge comes largely from two aspects:the resources available for allocation are usually limited in quantity,especially in the early period of emergency response;and a large amount of uncertain information in the relief process affects the decision making of resource allocation.A multiperiod allocation model of emergency resources that takes into account both efficiency and equity based on uncertain disaster information is proposed.Interval number and triangular fuzzy number are introduced to describe the different sources of uncertainty(for example,demand,transportation time,and maximum transport amount),and the loss caused by unmet demand is used to quantify equity.Then,the deterministic transformation method of uncertain parameters is designed and the linear weighted sum method is applied to solve the proposed model.Finally,a computational case based on the 2017 Jiuzhaigou earthquake in Sichuan Province,China was conducted to validate the proposed model.The results show that the proposed model is feasible in the multiperiod allocation of emergency resources among multidisaster sites,and the findings can help emergency managers to allocate emergency resources more scientifically,equitably,and effectively under uncertainty.
基金supported in part by the National Natural Science Foundation of China(Grant No.62274094)the Natural Science Foundation of Jiangsu Higher Education Institutions(No.22KJB510011)+2 种基金the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF012)the Key Laboratory of Modern Optical Technologies of Education Ministry of China,Soochow University(No.KJS2260)the Huali Talents Program of Nanjing University of Posts and Telecommunications,and the Jiangsu Provincial Government Scholarship for Overseas Studies.
文摘Tin perovskites with exemplary optoelectronic properties ofer potential application in lead-free perovskite solar cells.However,Sn vacancies and undercoordinated Sn ions on the tin perovskite surfaces can create deep-level traps,leading to nonradiative recombination and absorption of nucleophilic O_(2)molecules,impeding further device efciency and stability.Here,in this study,a new additive of semicarbazide hydrochloride(SEM-HCl)with a N–C=O functional group was introduced into the perovskite precursor to fabricate high-quality flms with a low concentration of deep-level trap densities.This,in turn,serves to prevent undesirable interaction between photogenerated carriers and adsorbed oxygen molecules in the device’s operational environment,ultimately reducing the proliferation of superoxide entities.As the result,the SEM-HCl-derived devices show a peak efciency of 10.9%with improved device stability.These unencapsulated devices maintain almost 100%of their initial efciencies after working for 100 h under continuous AM1.5 illumination conditions.
基金Supported by NNSFG-CAS Joint Fund for Research Based on Large-scale Scientific Facilities(10979064)Major State Basic Research Development Program of China(973 Program)(2010CD834204)National Natural Science Foundation of China(11205221)
文摘A flow gas low-pressure multi-wire proportional chamber（LPMWPC） with an active area of 180 mm× 80 mm has been developed for the flying time test of the recoil nuclei on super heavy nuclear experiments. The LPMWPC detector can be operated in single as well as double step operational modes. In the case of double step operational mode with a high gas amplification factor, signals from α-particles reside well above the electronic noise. The gas leakage rate and time resolution obtained from the α239Pu source are shown and discussed at the condition of 3 mbar Isobutane gas. It was shown that the time resolution was better than 2.9 ns at the best work condition, and the detecting efciency was larger than 98% at the low energy α particles. So the LPMWPC is fit to measure the flying time in the super heavy nuclear fragments experiment.
基金funded by the Integrating Energy and Computing Networks project funded through the USACE Military Programs
文摘In recent years,the notion of resilience has been developed and applied in many technical areas,becoming exceptionally pertinent to disaster risk science.During a disaster situation,accurate sensing information is the key to efficient recovery efforts.In general,resilience aims to minimize the impact of disruptions to systems through the fast recovery of critical functionality,but resilient design may require redundancy and could increase costs.In this article,we describe a method based on binary linear programming for sensor network design balancing efficiency with resilience.The application of the developed framework is demonstrated for the case of interior building surveillance utilizing infrared sensors in both twoand three-dimensional spaces.The method provides optimal sensor placement,taking into account critical functionality and a desired level of resilience and considering sensor type and availability.The problem formulation,resilience requirements,and application of the optimization algorithm are described in detail.Analysis of sensor locations with and without resilience requirements shows that resilient configuration requires redundancy in number of sensors and their intelligent placement.Both tasks are successfully solved by the described method,which can be applied to strengthen the resilience of sensor networks by design.The proposed methodology is suitable for large-scale optimization problems with many sensors and extensive coverage areas.
