Landscape designs for modern urban open spaces are studied on the basis of traditional aesthetics, while aesthetic basis and development orientation can be provided for such designs through studies on traditional aest...Landscape designs for modern urban open spaces are studied on the basis of traditional aesthetics, while aesthetic basis and development orientation can be provided for such designs through studies on traditional aesthetics. It is hoped that landscape designs from aesthetic perspective can correct people’s aesthetic attitudes towards the city, transform their habitual aesthetic modes, so as to cultivate new aesthetic tastes.展开更多
Fast growth of mobile internet and internet-of-things has propelled the concept formation and research on 5G wireless communications systems which are to be standardized around 2020(IMT-2020).There will be diverse app...Fast growth of mobile internet and internet-of-things has propelled the concept formation and research on 5G wireless communications systems which are to be standardized around 2020(IMT-2020).There will be diverse application scenarios expected for 5G networks.Hence,key performance indicators(KPIs) of 5G systems would be very diverse,not just the peak data rate and average/edge spectral efficiency requirements as in previous generations.For each typical scenario,multiple technologies may be used independently or jointly to improve the transmission efficiency,to lower the cost,and to increase the number of connections,etc.Key enabling technologies are discussed which include massive MIMO,ultradense deployment specific techniques,nonorthogonal transmission,high frequency communications,etc.展开更多
Air traffic controllers face challenging initiatives due to uncertainty in air traffic.One way to support their initiatives is to identify similar operation scenes.Based on the operation characteristics of typical bus...Air traffic controllers face challenging initiatives due to uncertainty in air traffic.One way to support their initiatives is to identify similar operation scenes.Based on the operation characteristics of typical busy area control airspace,an complexity measurement indicator system is established.We find that operation in area sector is characterized by aggregation and continuity,and that dimensionality and information redundancy reduction are feasible for dynamic operation data base on principle components.Using principle components,discrete features and time series features are constructed.Based on Gaussian kernel function,Euclidean distance and dynamic time warping(DTW)are used to measure the similarity of the features.Then the matrices of similarity are input in Spectral Clustering.The clustering results show that similar scenes of trend are not ideal and similar scenes of modes are good base on the indicator system.Finally,actual vertical operation decisions for area sector and results of identification are compared,which are visualized by metric multidimensional scaling(MDS)plots.We find that identification results can well reflect the operation at peak hours,but controllers make different decisions under the similar conditions before dawn.The compliance rate of busy operation mode and division decisions at peak hours is 96.7%.The results also show subjectivity of actual operation and objectivity of identification.In most scenes,we observe that similar air traffic activities provide regularity for initiatives,validating the potential of this approach for initiatives and other artificial intelligence support.展开更多
Based on the analysis of the impact of Doppler shift to the railway dedicated mobile communication quality under the condition of high-speed mobility,this paper presents a Doppler shift measurement approach based on t...Based on the analysis of the impact of Doppler shift to the railway dedicated mobile communication quality under the condition of high-speed mobility,this paper presents a Doppler shift measurement approach based on the phase estimation of frequency correction channel(FCCH) which correctly reflects the time-varying characteristic of the channel with a testing system developed.The Doppler shift data under the high-speed condition is collected,processed,analyzed,and compared with the simulation results.The scientific laws of the Doppler shift distribution of radio channel under high-speed condition are obtained.These data and analysis are essential for the establishment of high-speed railway Doppler power spectrum model and the development of the key technology of antiDoppler shift.展开更多
Hidden terminal problem in spectrum sensing is one of the most challenging problems in cognitive radio network(CRN).To tackle this problem,we propose a novel Cooperative Interference Game scheme in this paper.The sche...Hidden terminal problem in spectrum sensing is one of the most challenging problems in cognitive radio network(CRN).To tackle this problem,we propose a novel Cooperative Interference Game scheme in this paper.The scheme adopted full duplex(FD)mode to sense over multiple sub-bands in an iterative manner without extra sensing devices.The implementation algorithm of the proposed scheme is consisted of three modules:the formulation of the maximum transmit power limitation of second user(SU);the self-interference cancellation coefficient;and the optimal location of SU for an optimized low collision probability.Monte Carlo simulation proved that compared with cooperative spectrum sensing,the proposed scheme significantly improves the performance of spectrum detection and mitigates hidden terminal problem to a large extent with less energy consumption.展开更多
The sparse nature of location finding in the spatial domain makes it possible to exploit the Compressive Sensing (CS) theory for wireless location.CS-based location algorithm can largely reduce the number of online me...The sparse nature of location finding in the spatial domain makes it possible to exploit the Compressive Sensing (CS) theory for wireless location.CS-based location algorithm can largely reduce the number of online measurements while achieving a high level of localization accuracy,which makes the CS-based solution very attractive for indoor positioning.However,CS theory offers exact deterministic recovery of the sparse or compressible signals under two basic restriction conditions of sparsity and incoherence.In order to achieve a good recovery performance of sparse signals,CS-based solution needs to construct an efficient CS model.The model must satisfy the practical application requirements as well as following theoretical restrictions.In this paper,we propose two novel CS-based location solutions based on two different points of view:the CS-based algorithm with raising-dimension pre-processing and the CS-based algorithm with Minor Component Analysis (MCA).Analytical studies and simulations indicate that the proposed novel schemes achieve much higher localization accuracy.展开更多
There are deep-rooted traditions of researches on the youth problems in Russia, By their trends and purposes they partly concur with the traditions of the humanities in Europe and America. In Russia in different times...There are deep-rooted traditions of researches on the youth problems in Russia, By their trends and purposes they partly concur with the traditions of the humanities in Europe and America. In Russia in different timesmit was the same way in the West-diverse youth concepts had been conveying and continue to express the society＇s expectations for new generations. This is in a sense a theoretical mirror of the natural process of generation change. Under modern conditions these concepts can be reduced to three directions： youth-＂no man＇s land＂, youth-social danger, youth-hope of society. At the same time youth theories have the mark of the socio-cultural contexts and contexts of the development of the humanities in Russia. In this article these similarities and distinctions will be examined.展开更多
With Perelman＇s Neo Rhetoric the ＂Rhetorical Empire＂ is built and with the contribution of Koorebyter＇s group this empire gets to its limits by including Opinion also in Natural Sciences. Concomitantly, within com...With Perelman＇s Neo Rhetoric the ＂Rhetorical Empire＂ is built and with the contribution of Koorebyter＇s group this empire gets to its limits by including Opinion also in Natural Sciences. Concomitantly, within communication, the number and variety of opinions tend toward infinity. In this cultural context, a Deontology of Opinion is both possible and necessary. The first part establishes the theoretical frame of the issue on four axes： （1） the historical fate of Opinion; （2） the fundamental and specific Functors; （3） the relation between Certitude, Conviction, and Credence; （4） correctness, the second part presents 10 Deontological Rules of Opinion （out of the 18 possible）; and （5） it is a Code based on 10 Rules thus, a Decalogue. The Code presents each Rule, both in its positive （must） and negative （~must） form. Rules are first enunciated and then explained and illustrated. Being also a theory of Opinion, the paper can be considered a Meta-opinion. It can have four finalities： （1） one, purely theoretical, to be included among similar papers in the field; （2） a methodological one as it offers reference points for the elaboration of particular Deontological Codes; （3） a scientific one offering the background for sociologic researches of Opinion; and （4） an educational one aiming at forming correct （optimum） Opinions in various fields.展开更多
The construction of a barrier-free environment is an important measure that guarantees the safety,right-of-way,and interests of the disabled,the elderly,and other mobility disadvantaged groups.It is also an indispensa...The construction of a barrier-free environment is an important measure that guarantees the safety,right-of-way,and interests of the disabled,the elderly,and other mobility disadvantaged groups.It is also an indispensable part of the low-carbon urban transportation and a necessary way to protect the rights of mobility disadvantaged groups in green travel.In this paper,the researchers conducted life log surveys on the travels of 10 wheelchair users residing in Beijing with IoT Inspector,a self-developed,wheelchairmountable intelligent sensing device.Wheelchair users’travel preferences and reasons were then analyzed using the image and textual data from the surveys.Combined with a mapping workshop,a comparative analysis was performed on the bumpiness of sidewalk paving materials.The study found that wheelchair travelers’preferred non-motor lanes over sidewalks;substandard curb ramps,unleveled tree pools,limited access widths,and bumpy pavement were the main problems faced by wheelchair users in sidewalk accessibility.In addition,the study explores the inclusive needs and challenges of non-motorized right-of-way for new transportation means at urban planning and traffic management levels.Based on multi-sourced data,this paper discusses the possibility of assessing urban barrier-free environment and representing a narrative of the needs of mobility disadvantaged groups,so as to provide practical experience and technical support to the improvement strategies of adaptive roads.展开更多
Knowledge of haze particles in background areas of North China is limited, although they have been studied well in urban settings. Atmospheric aerosol particles were collected at a background site in the North China P...Knowledge of haze particles in background areas of North China is limited, although they have been studied well in urban settings. Atmospheric aerosol particles were collected at a background site in the North China Plain during 16–31 January, 2011. Water soluble inorganic ions of PM2.5 and physicochemical characteristics of individual particles on hazy and clean days were measured by Ion Chromatography(IC) and Transmission Electron Microscopy(TEM), respectively. Average PM2.5 mass concentration was 50.4±29.9 μg m?3 with 62.5±26.8 μg m?3 on hazy days and 19.9±11.5 μg m?3 on clean days. SO42?, NO3?, and NH4+ with a combined mass concentration of 19.0±11.5 μg m?3 accounted for 69.8%–89.4% of the total water soluble inorganic ions. Size distributions of SO42? and NH4+ showed one unimodal peak at 0.56–1.8 μm on hazy days, whereas NO3? appeared as bimodal peaks at 0.56–1.8 and 5.6–10 μm, respectively. Individual particle analyses showed that the dominant aerosols were a mixture of sulfate, nitrate, and carbonaceous species, which together determine their mixing states. 48-h air mass back trajectories on hazy days suggested that air masses crossed the polluted continental areas(such as Jing-jin-ji region and Shandong province) and entrained ground air pollutants 11–19 hours before reaching the background area. During long-range transport particles undergo ageing and tend to be internally mixed mainly due to condensation in the background atmosphere. Our results suggest that hygroscopic and optical properties of these aerosol particles in the background area differ substantially from those in urban areas.展开更多
文摘Landscape designs for modern urban open spaces are studied on the basis of traditional aesthetics, while aesthetic basis and development orientation can be provided for such designs through studies on traditional aesthetics. It is hoped that landscape designs from aesthetic perspective can correct people’s aesthetic attitudes towards the city, transform their habitual aesthetic modes, so as to cultivate new aesthetic tastes.
文摘Fast growth of mobile internet and internet-of-things has propelled the concept formation and research on 5G wireless communications systems which are to be standardized around 2020(IMT-2020).There will be diverse application scenarios expected for 5G networks.Hence,key performance indicators(KPIs) of 5G systems would be very diverse,not just the peak data rate and average/edge spectral efficiency requirements as in previous generations.For each typical scenario,multiple technologies may be used independently or jointly to improve the transmission efficiency,to lower the cost,and to increase the number of connections,etc.Key enabling technologies are discussed which include massive MIMO,ultradense deployment specific techniques,nonorthogonal transmission,high frequency communications,etc.
基金the National Natural Science Foundation of China(Nos.71731001,61573181,71971114)the Fundamental Research Funds for the Central Universities(No.NS2020045)。
文摘Air traffic controllers face challenging initiatives due to uncertainty in air traffic.One way to support their initiatives is to identify similar operation scenes.Based on the operation characteristics of typical busy area control airspace,an complexity measurement indicator system is established.We find that operation in area sector is characterized by aggregation and continuity,and that dimensionality and information redundancy reduction are feasible for dynamic operation data base on principle components.Using principle components,discrete features and time series features are constructed.Based on Gaussian kernel function,Euclidean distance and dynamic time warping(DTW)are used to measure the similarity of the features.Then the matrices of similarity are input in Spectral Clustering.The clustering results show that similar scenes of trend are not ideal and similar scenes of modes are good base on the indicator system.Finally,actual vertical operation decisions for area sector and results of identification are compared,which are visualized by metric multidimensional scaling(MDS)plots.We find that identification results can well reflect the operation at peak hours,but controllers make different decisions under the similar conditions before dawn.The compliance rate of busy operation mode and division decisions at peak hours is 96.7%.The results also show subjectivity of actual operation and objectivity of identification.In most scenes,we observe that similar air traffic activities provide regularity for initiatives,validating the potential of this approach for initiatives and other artificial intelligence support.
基金Supported by the National Natural Science Foundation of China(No.U133420261222105)+1 种基金the Key Grant Project of Chinese Ministry of Education(No.313006)the Project of State Key Lab of Rail Traffic Control and Safety(No.RCS 2014ZT11)
文摘Based on the analysis of the impact of Doppler shift to the railway dedicated mobile communication quality under the condition of high-speed mobility,this paper presents a Doppler shift measurement approach based on the phase estimation of frequency correction channel(FCCH) which correctly reflects the time-varying characteristic of the channel with a testing system developed.The Doppler shift data under the high-speed condition is collected,processed,analyzed,and compared with the simulation results.The scientific laws of the Doppler shift distribution of radio channel under high-speed condition are obtained.These data and analysis are essential for the establishment of high-speed railway Doppler power spectrum model and the development of the key technology of antiDoppler shift.
基金supported by National High-Tech R&D Program(863 Program 2014AA01A707, 2015AA01A705 )
文摘Hidden terminal problem in spectrum sensing is one of the most challenging problems in cognitive radio network(CRN).To tackle this problem,we propose a novel Cooperative Interference Game scheme in this paper.The scheme adopted full duplex(FD)mode to sense over multiple sub-bands in an iterative manner without extra sensing devices.The implementation algorithm of the proposed scheme is consisted of three modules:the formulation of the maximum transmit power limitation of second user(SU);the self-interference cancellation coefficient;and the optimal location of SU for an optimized low collision probability.Monte Carlo simulation proved that compared with cooperative spectrum sensing,the proposed scheme significantly improves the performance of spectrum detection and mitigates hidden terminal problem to a large extent with less energy consumption.
基金supported by the National Natural Science Foundation of China under Grant No.61001119the Fund for Creative Research Groups of China under Grant No.61121001
文摘The sparse nature of location finding in the spatial domain makes it possible to exploit the Compressive Sensing (CS) theory for wireless location.CS-based location algorithm can largely reduce the number of online measurements while achieving a high level of localization accuracy,which makes the CS-based solution very attractive for indoor positioning.However,CS theory offers exact deterministic recovery of the sparse or compressible signals under two basic restriction conditions of sparsity and incoherence.In order to achieve a good recovery performance of sparse signals,CS-based solution needs to construct an efficient CS model.The model must satisfy the practical application requirements as well as following theoretical restrictions.In this paper,we propose two novel CS-based location solutions based on two different points of view:the CS-based algorithm with raising-dimension pre-processing and the CS-based algorithm with Minor Component Analysis (MCA).Analytical studies and simulations indicate that the proposed novel schemes achieve much higher localization accuracy.
文摘There are deep-rooted traditions of researches on the youth problems in Russia, By their trends and purposes they partly concur with the traditions of the humanities in Europe and America. In Russia in different timesmit was the same way in the West-diverse youth concepts had been conveying and continue to express the society＇s expectations for new generations. This is in a sense a theoretical mirror of the natural process of generation change. Under modern conditions these concepts can be reduced to three directions： youth-＂no man＇s land＂, youth-social danger, youth-hope of society. At the same time youth theories have the mark of the socio-cultural contexts and contexts of the development of the humanities in Russia. In this article these similarities and distinctions will be examined.
文摘With Perelman＇s Neo Rhetoric the ＂Rhetorical Empire＂ is built and with the contribution of Koorebyter＇s group this empire gets to its limits by including Opinion also in Natural Sciences. Concomitantly, within communication, the number and variety of opinions tend toward infinity. In this cultural context, a Deontology of Opinion is both possible and necessary. The first part establishes the theoretical frame of the issue on four axes： （1） the historical fate of Opinion; （2） the fundamental and specific Functors; （3） the relation between Certitude, Conviction, and Credence; （4） correctness, the second part presents 10 Deontological Rules of Opinion （out of the 18 possible）; and （5） it is a Code based on 10 Rules thus, a Decalogue. The Code presents each Rule, both in its positive （must） and negative （~must） form. Rules are first enunciated and then explained and illustrated. Being also a theory of Opinion, the paper can be considered a Meta-opinion. It can have four finalities： （1） one, purely theoretical, to be included among similar papers in the field; （2） a methodological one as it offers reference points for the elaboration of particular Deontological Codes; （3） a scientific one offering the background for sociologic researches of Opinion; and （4） an educational one aiming at forming correct （optimum） Opinions in various fields.
文摘The construction of a barrier-free environment is an important measure that guarantees the safety,right-of-way,and interests of the disabled,the elderly,and other mobility disadvantaged groups.It is also an indispensable part of the low-carbon urban transportation and a necessary way to protect the rights of mobility disadvantaged groups in green travel.In this paper,the researchers conducted life log surveys on the travels of 10 wheelchair users residing in Beijing with IoT Inspector,a self-developed,wheelchairmountable intelligent sensing device.Wheelchair users’travel preferences and reasons were then analyzed using the image and textual data from the surveys.Combined with a mapping workshop,a comparative analysis was performed on the bumpiness of sidewalk paving materials.The study found that wheelchair travelers’preferred non-motor lanes over sidewalks;substandard curb ramps,unleveled tree pools,limited access widths,and bumpy pavement were the main problems faced by wheelchair users in sidewalk accessibility.In addition,the study explores the inclusive needs and challenges of non-motorized right-of-way for new transportation means at urban planning and traffic management levels.Based on multi-sourced data,this paper discusses the possibility of assessing urban barrier-free environment and representing a narrative of the needs of mobility disadvantaged groups,so as to provide practical experience and technical support to the improvement strategies of adaptive roads.
基金supported by Distinguished Youth Foundation of Shandong Provin c e(Grant No.JQ20 1413)the Scientific Research Staring Foundation for the Institute of Arid Meteorology,China Meteorology Administration(Grant No.KYS2014SSKY05)+2 种基金the National Basic Research Program of China(Grant No.2011CB403401)Fundamental Research Funds of Shandong University(Grant No.2014QY001)State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry(Grant No.LAPC-KF-2014-03)
文摘Knowledge of haze particles in background areas of North China is limited, although they have been studied well in urban settings. Atmospheric aerosol particles were collected at a background site in the North China Plain during 16–31 January, 2011. Water soluble inorganic ions of PM2.5 and physicochemical characteristics of individual particles on hazy and clean days were measured by Ion Chromatography(IC) and Transmission Electron Microscopy(TEM), respectively. Average PM2.5 mass concentration was 50.4±29.9 μg m?3 with 62.5±26.8 μg m?3 on hazy days and 19.9±11.5 μg m?3 on clean days. SO42?, NO3?, and NH4+ with a combined mass concentration of 19.0±11.5 μg m?3 accounted for 69.8%–89.4% of the total water soluble inorganic ions. Size distributions of SO42? and NH4+ showed one unimodal peak at 0.56–1.8 μm on hazy days, whereas NO3? appeared as bimodal peaks at 0.56–1.8 and 5.6–10 μm, respectively. Individual particle analyses showed that the dominant aerosols were a mixture of sulfate, nitrate, and carbonaceous species, which together determine their mixing states. 48-h air mass back trajectories on hazy days suggested that air masses crossed the polluted continental areas(such as Jing-jin-ji region and Shandong province) and entrained ground air pollutants 11–19 hours before reaching the background area. During long-range transport particles undergo ageing and tend to be internally mixed mainly due to condensation in the background atmosphere. Our results suggest that hygroscopic and optical properties of these aerosol particles in the background area differ substantially from those in urban areas.
