Ramsey oscillations typically exhibit an exponential decay envelope due to environmental noise. However,recent experiments have observed nonmonotonic Ramsey fringes characterized by beating patterns, which deviate fro...Ramsey oscillations typically exhibit an exponential decay envelope due to environmental noise. However,recent experiments have observed nonmonotonic Ramsey fringes characterized by beating patterns, which deviate from the standard behavior. These beating patterns have primarily been attributed to charge-noise fluctuations.In this paper, we have experimentally observed Ramsey fringe with beating pattern for transmon qubits, and traced the origin to electric instruments induced flux noise.展开更多
Grating fringe projection 3D measurement techniques are extensively applied in various fields.However,in high dynamic range scenarios with significant surface reflectivity variations,uneven greyscale distribution may ...Grating fringe projection 3D measurement techniques are extensively applied in various fields.However,in high dynamic range scenarios with significant surface reflectivity variations,uneven greyscale distribution may lead to phase errors and poor reconstruction results.To address this problem,an adaptive fringe projection method is introduced.The method involves projecting two sets of dark and light fringes onto the object,enabling the full-field projection intensity map to be generated adaptively based on greyscale analysis.First,dark fringes are projected onto the object to extend exposure time as long as possible without causing overexposure in the image.Subsequently,bright fringes are projected under the same exposure settings to detect overexposed pixels,and the greyscale distribution of these overexposed points from the previous dark fringe projection is analyzed to calculate the corresponding projection intensities.Finally,absolute phase information from orthogonal fringes is used for coordinate matching,enabling the generation of adaptive projection fringe patterns.Experiments on various high dynamic range objects show that compared to conventional fringe projection binocular reconstruction method,the proposed algorithm achieves complete reconstruction of high dynamic range surfaces and shows robust performance against phase calculation errors caused by overexposure and low modulation.展开更多
Recent advancements in artificial intelligence have transformed three-dimensional(3D)optical imaging and metrology,enabling high-resolution and high-precision 3D surface geometry measurements from one single fringe pa...Recent advancements in artificial intelligence have transformed three-dimensional(3D)optical imaging and metrology,enabling high-resolution and high-precision 3D surface geometry measurements from one single fringe pattern projection.However,the imaging speed of conventional fringe projection profilometry(FPP)remains limited by the native sensor refresh rates due to the inherent"one-to-one"synchronization mechanism between pattern projection and image acquisition in standard structured light techniques.Here,we present dual-frequency angular-multiplexed fringe projection profilometry(DFAMFPP),a deep learning-enabled 3D imaging technique that achieves high-speed,high-precision,and large-depth-range absolute 3D surface measurements at speeds 16 times faster than the sensor's native frame rate.By encoding multi-timeframe 3D information into a single multiplexed image using multiple pairs of dual-frequency fringes,high-accuracy absolute phase maps are reconstructed using specially trained two-stage number-theoretical-based deep neural networks.We validate the effectiveness of DFAMFPP through dynamic scene measurements,achieving 10,000 Hz 3D imaging of a running turbofan engine prototype with only a 625 Hz camera.By overcoming the sensor hardware bottleneck,DFAMFPP significantly advances high-speed and ultra-high-speed 3D imaging,opening new avenues for exploring dynamic processes across diverse scientific disciplines.展开更多
1 The Edinburgh Festival Fringe,a three‑week festival of performing arts that takes place in Edinburgh every August,transforms Edinburgh into a dynamic center of creativity and entertainment.This festival draws a wide...1 The Edinburgh Festival Fringe,a three‑week festival of performing arts that takes place in Edinburgh every August,transforms Edinburgh into a dynamic center of creativity and entertainment.This festival draws a wide range of participants,from new artists aiming to make their mark to seasoned performers returning to take in the citys artistic atmosphere.With its open‑access policy,the Fringe truly offers a platform for everyone,providing unique opportunities for artists and audiences to engage in diverse cultural experiences.展开更多
In this work,the incorporation of tantalum(Ta)into p-type metal-oxide(SnO_(x))semiconductor film is investigated to improve the electrical characteristics and suppress the fringe effect of thin film transistors(TFTs)....In this work,the incorporation of tantalum(Ta)into p-type metal-oxide(SnO_(x))semiconductor film is investigated to improve the electrical characteristics and suppress the fringe effect of thin film transistors(TFTs).The Ta-doped SnO_(x)(SnO_(x):Ta)film is deposited by radio-frequency(RF)magnetron sputtering with a Sn:Ta(3 at.%)target and thermally annealed at 270℃ for 30 min.Here,we observe that the SnO_(x):Ta film presents increased crystallinity,reduced defect density(3.25×10^(12)cm^(−2)·eV^(−1)),and widened bandgap(1.98 eV),in comparison with the undoped SnO_(x)film.As a result,the SnO_(x):Ta TFTs exhibit a lower off-state current(Ioff),an improved on/off current ratio(2.17×10^(4)),a remarkably decreased subthreshold swing(SS)by 41%,and enhanced device stability.Additionally,by introducing Ta dopants,the fringe effect as well as the impact of channel width-to-length ratio(W/L)on electrical performances of the p-type oxide TFTs can be effectively suppressed.These results shall contribute to further exploration and development of p-type SnO_(x)TFTs.展开更多
Dual-phase and three-phase grating x-ray interference is a promising new technique for grating-based x-ray differential phase contrast imaging.Dual-phase grating interferometers have been relatively completely studied...Dual-phase and three-phase grating x-ray interference is a promising new technique for grating-based x-ray differential phase contrast imaging.Dual-phase grating interferometers have been relatively completely studied and discussed.In this paper,the corresponding imaging fringe formula of the three-phase grating interferometer is provided.At the same time,the similarities and differences between the three-phase grating interferometer and the dual-phase grating interferometer are investigated and verified,and that the three-phase grating interferometer can produce large-period moiréfringes without using the analyzing grating is demonstrated experimentally.Finally,a simple method of designing three-phase grating and multi-grating imaging systems from geometric optics based on the thin-lens theory of gratings is presented.These theoretical formulas and experimental results provide optimization tools for designing three-phase grating interferometer systems.展开更多
Purpose:The metropolitan cities of Johannesburg,Ekurhuleni and Tshwane play an important role in the economy of the Gauteng province in South Africa.The region constitutes to 22.4 percent of the total population of So...Purpose:The metropolitan cities of Johannesburg,Ekurhuleni and Tshwane play an important role in the economy of the Gauteng province in South Africa.The region constitutes to 22.4 percent of the total population of South Africa and has a strong presence and contributes in areas of manufacturing sector,financial and business services,retail and wholesale trade,etc.The rapid urban population,increase in the informal settlements and socio-economic opportunities has resulted in considerable urban sprawl in and around the urban fringe areas of these metropolitan cities.The urban fringe areas of these metros often come under the influence of rapid urbanization process and pressures.Coupled with the economical and potential land dynamics and lack of priority of spatial development guidelines,these areas attract rapid and haphazard development from communities and developers.Research Design/Methodology:This research is based on a qualitative approach through a comprehensive literature review that included content analysis of key documents on housing sector such as IDPs(Integrated Development Plans),Municipal Annual Reports,Growth Development Strategies,and among other sectoral documents on housing sector.Some of the key priority issues considered in the housing sector included:eradication of housing backlogs,spatial restructuring of housing,provision of choice in terms of location,tenure and housing typology.Findings:The current paper discusses the approaches of metropolitan housing development processes in three metropolitan cities of South Africa from Gauteng region,namely:Johannesburg,Ekurhuleni and Tshwane.The paper discusses the existing housing sectoral scenario along with the fringe areas in three cities with focus on:formal and informal settlements,housing segregation and the backlogs,current institutional arrangements,role of public private participation,and scope for alternate mechanisms.The paper concludes in discussion on sustainable development options for housing development in urban fringe areas.展开更多
Electron density in fusion plasma is usually diagnosed using laser-aided interferometers. The phase difference signal obtained after phase demodulation is wrapped, which is also called a fringe jump. A method has been...Electron density in fusion plasma is usually diagnosed using laser-aided interferometers. The phase difference signal obtained after phase demodulation is wrapped, which is also called a fringe jump. A method has been developed to unwrap the phase difference signal in real time using FPGA, specifically designed to handle fringe jumps in the hydrogen cyanide(HCN) laser interferometer on the EAST superconducting tokamak. This method is designed for a phase demodulator using the fast Fourier transform(FFT) method at the front end. The method is better adapted for hardware implementation compared to complex mathematical analysis algorithms, such as field programmable gate array(FPGA). It has been applied to process the phase measurement results of the HCN laser interferometer on EAST in real time. Electron density results show good confidence in the fringe jump unwrapping method. Further possible application in other laser interferometers, such as the POlarimeter-INTerferometer(POINT)system on EAST tokamak is also discussed.展开更多
Recent studies have underscored the significance of the capillary fringe in hydrological and biochemical processes.Moreover,its role in shallow waters is expected to be considerable.Traditionally,the study of groundwa...Recent studies have underscored the significance of the capillary fringe in hydrological and biochemical processes.Moreover,its role in shallow waters is expected to be considerable.Traditionally,the study of groundwater flow has centered on unsaturated-saturated zones,often overlooking the impact of the capillary fringe.In this study,we introduce a steady-state two-dimensional model that integrates the capillary fringe into a 2-D numerical solution.Our novel approach employs the potential form of the Richards equation,facilitating the determination of boundaries,pressures,and velocities across different ground surface zones.We utilized a two-dimensional Freefem++finite element model to compute the stationary solution.The validation of the model was conducted using experimental data.We employed the OFAT(One_Factor-At-Time)method to identify the most sensitive soil parameters and understand how changes in these parameters may affect the behavior and water dynamics of the capillary fringe.The results emphasize the role of hydraulic conductivity as a key parameter influencing capillary fringe shape and dynamics.Velocity values within the capillary fringe suggest the prevalence of horizontal flow.By variation of the water table level and the incoming flow q0,we have shown the correlation between water table elevation and the upper limit of the capillary fringe.展开更多
Fringe projection profilometry(FPP)has been widely applied to non-contact three-dimensional measurement in industries owing to its high accuracy and speed.The point cloud,which is a measurement result of the FPP syste...Fringe projection profilometry(FPP)has been widely applied to non-contact three-dimensional measurement in industries owing to its high accuracy and speed.The point cloud,which is a measurement result of the FPP system,typically contains a large number of invalid points caused by the background,ambient light,shadows,and object edge regions.Research on noisy point detection and elimination has been conducted over the past two decades.However,existing invalid point removal methods are based on image intensity analysis and are only applicable to simple measurement backgrounds that are purely dark.In this paper,we propose a novel invalid point removal framework that consists of two aspects:(1)A convolutional neural network(CNN)is designed to segment the foreground from the background of different intensity conditions in FPP measurement circumstances to remove background points and the most discrete points in background regions.(2)A two-step method based on the fringe image intensity threshold and a bilateral filter is proposed to eliminate the small number of discrete points remaining after background segmentation caused by shadows and edge areas on objects.Experimental results verify that the proposed framework(1)can remove background points intelligently and accurately in different types of complex circumstances,and(2)performs excellently in discrete point detection from object regions.展开更多
Efficient third-order nonlinearities of the Zinc Oxide and Al-doped Zinc Oxide were studied by Third Harmonic Generation (Third Harmonic Generation) Maker fringes to establish the effect Aluminum of Aluminum doping (A...Efficient third-order nonlinearities of the Zinc Oxide and Al-doped Zinc Oxide were studied by Third Harmonic Generation (Third Harmonic Generation) Maker fringes to establish the effect Aluminum of Aluminum doping (Al-doping) on the cubic nonlinearities. Adding the Al-dopant to the Zinc Oxide crystal structure results in changes that affect the optical and nonlinear characteristics. Presented results indicate that the magnitude of X<sup>(3)</sup> was enhanced at single experimental wavelengths;however, across the broadband experimental spectrum, the effect of Al-doping remained relatively constant. The observed enhancement of third-order nonlinearity was purely from the bound electronic response. The observation is attributed to increased charge carriers and spontaneous polarization in the Zinc Oxide and Al-doped Zinc Oxide crystal structure.展开更多
With Shiling Area of Eastern New District in Chengdu City as a background, concept design scheme was put forward from the perspective of ecological landscape through analyzing present development and ecological landsc...With Shiling Area of Eastern New District in Chengdu City as a background, concept design scheme was put forward from the perspective of ecological landscape through analyzing present development and ecological landscapes of the study area, applying philosophic thinking and Abstract concepts, and also combining with actual conditions of Chengdu, and meanwhile, concepts, orientation and functional structure of the eco-landscape concept planning were proposed. Key points of the planning were elaborated from 4 perspectives of spatial structure, traffic organization, spatial sequence and plant configuration to discuss spatial configuration of ecological landscapes on the fringes of Chengdu City, then further improve functions of ecological landscapes and quality of ecological environment, and put the concept planning into the construction practice of urban fringes.展开更多
On basis of human settlements theory, the research explored status quo of human settlements theory in rural-urban fringe, and analyzed and concluded predicaments confronted by rural-urban fringe, laying foundation for...On basis of human settlements theory, the research explored status quo of human settlements theory in rural-urban fringe, and analyzed and concluded predicaments confronted by rural-urban fringe, laying foundation for human settle- ments theory of rural-urban fringe.展开更多
In response to the strong drive for social and economic development, local governments have implemented urban master plans, providing measures and timeframes to address the continuous demand for land and to alleviate ...In response to the strong drive for social and economic development, local governments have implemented urban master plans, providing measures and timeframes to address the continuous demand for land and to alleviate urban problems. In this paper, a multi-objective model was constructed to discuss the problem, including economic benefits and ecological effectiveness, in terms of land use optimization. A genetic algorithm was then adopted to solve the model, and a performance evaluation and sensitivity analysis were conducted using Pareto optimality. Results showed that a set of tradeoffs could be acquired by the allocation of land use. In addition, the Pareto solutions proved the model to be efficient; for example, a limit of 13,500 ha of urban area conformed to plan recommendations. The reduction in crop land, orchard land, grassland, and unused land provided further efficiencies. These results implied that further potential regional land resources remain and that the urban master plan is able to support sustainable local development in the years to come, as well as verified that it is feasible to use land use allocation multi-objective modeling and genetic algorithms.展开更多
This paper discusses current research and development of fringe projection-based techniques. A system based on Fourier transform profilometry (FTP) is proposed for three-dimensional (3D) shape recovery. The system imp...This paper discusses current research and development of fringe projection-based techniques. A system based on Fourier transform profilometry (FTP) is proposed for three-dimensional (3D) shape recovery. The system improves the method of phase unwrapping to gain accurate 3D shapes of objects. The method uses a region-growing algorithm for the path prediction guided by the quality map to increase the recovering accuracy and provides a fast and simple tool for 3D shape recovery. The shape measurement and data recovery are integrated to offer a new method of 3D modelling. Examples are presented to verify the feasibility of the proposed method.展开更多
The objective of this paper is to analyze land use characteristics of rural settlements in urban fringe so as to provide references for optimizing the regional distribution of rural settlements, consolidating rural se...The objective of this paper is to analyze land use characteristics of rural settlements in urban fringe so as to provide references for optimizing the regional distribution of rural settlements, consolidating rural settlements, and coordinating urban-rural integrated development. The methods of spatial statistical analysis, buffer analysis, Ripley's K function, kernel density analysis based on GIS(Geographic Information System) were used to analyze the characteristics of scale, spatial differentiation and spatial patterns of the rural settlements in Liangjiang New Area in Chongqing Municipality of China. The fractal dimension formula was also developed to reflect fractal feature of the rural settlements. The results show that, the scale of rural settlements in Liangjang New Area takes on distinct characteristics of spatial differentiation along with changes in elevation, gradient, location, geohazards distribution, and the like. The fractal characteristic of rural settlements has obvious regional variations subject to the 6 factors of location in the Liangjiang New Area. Overall, the worse the terrain conditions are, the larger the fractal dimension values become. The better the locationconditions, the larger the fractal dimension values are. The spatial pattern in the township scale presents three kinds of distribution as being aggregated, uniform and random. In contract, the spatial pattern in the plaque scale displays a banding distribution from a general view with several aggregation zones centering on each town center. From the results, we can see that the characteristics of rural settlements in urban fringe are more complicated. For such kind of rural settlements in special regions, in the rural land consolidation more attention should be paid to improve the rural living environments and public services, as well as to promote the harmonious relationship between the urban and rural areas.展开更多
Single-shot high-speed 3D imaging is important for reconstructions of dynamic objects.For fringe projection profilometry(FPP),however,it is still challenging to recover accurate 3D shapes of isolated objects by a sing...Single-shot high-speed 3D imaging is important for reconstructions of dynamic objects.For fringe projection profilometry(FPP),however,it is still challenging to recover accurate 3D shapes of isolated objects by a single fringe image.In this paper,we demonstrate that the deep neural networks can be trained to directly recover the absolute phase from a unique fringe image that involves spatially multiplexed fringe patterns of different frequencies.The extracted phase is free from spectrum-aliasing problem which is hard to avoid for traditional spatial-multiplexing methods.Experiments on both static and dynamic scenes show that the proposed approach is robust to object motion and can obtain high-quality 3D reconstructions of isolated objects within a single fringe image.展开更多
Wave hydrodynamics over fringing reefs is largely controlled by the reef surface roughness and hydrodynamic forcing.It is believed that climate change will result in a net increase in the water depth over the reef fla...Wave hydrodynamics over fringing reefs is largely controlled by the reef surface roughness and hydrodynamic forcing.It is believed that climate change will result in a net increase in the water depth over the reef flat,a degrading of the surface roughness of coral reefs and changes in extreme incident wave heights.For an accurate assessment of how climate change affects the safety of reef-fringed coasts,a numerical study of the impact of climate change on irregular wave run-up over reef-fringed coasts was carried out based on a Boussinesq wave model,FUNWAVE-TVD.Validated with experimental data,the present model shows reasonable prediction of irregular wave evolution and run-up height over fringing reefs.Numerical experiments were then implemented based on the anticipated effects of climate change and carried out to investigate the effects of sea level rise,degrading of the reef surface roughness and increase of extreme incident wave height on the irregular wave run-up height over the backreef beach respectively.Variations of run-up components(i.e.,spectral characteristics of run-up and mean water level)were examined specifically and discussed to better understand the influencing mechanism of each climate change-related effect on the run-up.展开更多
文摘Ramsey oscillations typically exhibit an exponential decay envelope due to environmental noise. However,recent experiments have observed nonmonotonic Ramsey fringes characterized by beating patterns, which deviate from the standard behavior. These beating patterns have primarily been attributed to charge-noise fluctuations.In this paper, we have experimentally observed Ramsey fringe with beating pattern for transmon qubits, and traced the origin to electric instruments induced flux noise.
基金supported by the Science and Technology Program Project of Tianjin(No.24ZXZSSS00300).
文摘Grating fringe projection 3D measurement techniques are extensively applied in various fields.However,in high dynamic range scenarios with significant surface reflectivity variations,uneven greyscale distribution may lead to phase errors and poor reconstruction results.To address this problem,an adaptive fringe projection method is introduced.The method involves projecting two sets of dark and light fringes onto the object,enabling the full-field projection intensity map to be generated adaptively based on greyscale analysis.First,dark fringes are projected onto the object to extend exposure time as long as possible without causing overexposure in the image.Subsequently,bright fringes are projected under the same exposure settings to detect overexposed pixels,and the greyscale distribution of these overexposed points from the previous dark fringe projection is analyzed to calculate the corresponding projection intensities.Finally,absolute phase information from orthogonal fringes is used for coordinate matching,enabling the generation of adaptive projection fringe patterns.Experiments on various high dynamic range objects show that compared to conventional fringe projection binocular reconstruction method,the proposed algorithm achieves complete reconstruction of high dynamic range surfaces and shows robust performance against phase calculation errors caused by overexposure and low modulation.
基金supported by National Key Research and Development Program of China(2022YFB2804603,2022YFB2804605)National Natural Science Foundation of China(U21B2033)+4 种基金Fundamental Research Funds forthe Central Universities(2023102001,2024202002)National Key Laborato-ry of Shock Wave and Detonation Physics(JCKYS2024212111)China Post-doctoral Science Fund(2023T160318)Open Research Fund of JiangsuKey Laboratory of Spectral Imaging&Intelligent Sense(JSGP202105,JSGP202201)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX25_0695,SJCX25_0188)。
文摘Recent advancements in artificial intelligence have transformed three-dimensional(3D)optical imaging and metrology,enabling high-resolution and high-precision 3D surface geometry measurements from one single fringe pattern projection.However,the imaging speed of conventional fringe projection profilometry(FPP)remains limited by the native sensor refresh rates due to the inherent"one-to-one"synchronization mechanism between pattern projection and image acquisition in standard structured light techniques.Here,we present dual-frequency angular-multiplexed fringe projection profilometry(DFAMFPP),a deep learning-enabled 3D imaging technique that achieves high-speed,high-precision,and large-depth-range absolute 3D surface measurements at speeds 16 times faster than the sensor's native frame rate.By encoding multi-timeframe 3D information into a single multiplexed image using multiple pairs of dual-frequency fringes,high-accuracy absolute phase maps are reconstructed using specially trained two-stage number-theoretical-based deep neural networks.We validate the effectiveness of DFAMFPP through dynamic scene measurements,achieving 10,000 Hz 3D imaging of a running turbofan engine prototype with only a 625 Hz camera.By overcoming the sensor hardware bottleneck,DFAMFPP significantly advances high-speed and ultra-high-speed 3D imaging,opening new avenues for exploring dynamic processes across diverse scientific disciplines.
文摘1 The Edinburgh Festival Fringe,a three‑week festival of performing arts that takes place in Edinburgh every August,transforms Edinburgh into a dynamic center of creativity and entertainment.This festival draws a wide range of participants,from new artists aiming to make their mark to seasoned performers returning to take in the citys artistic atmosphere.With its open‑access policy,the Fringe truly offers a platform for everyone,providing unique opportunities for artists and audiences to engage in diverse cultural experiences.
基金supported in part by National Key R&D Program of China(Grant No.2022YFE0141500)National Natural Science Foundation of China(Grant Nos.62004065 and 62274059).
文摘In this work,the incorporation of tantalum(Ta)into p-type metal-oxide(SnO_(x))semiconductor film is investigated to improve the electrical characteristics and suppress the fringe effect of thin film transistors(TFTs).The Ta-doped SnO_(x)(SnO_(x):Ta)film is deposited by radio-frequency(RF)magnetron sputtering with a Sn:Ta(3 at.%)target and thermally annealed at 270℃ for 30 min.Here,we observe that the SnO_(x):Ta film presents increased crystallinity,reduced defect density(3.25×10^(12)cm^(−2)·eV^(−1)),and widened bandgap(1.98 eV),in comparison with the undoped SnO_(x)film.As a result,the SnO_(x):Ta TFTs exhibit a lower off-state current(Ioff),an improved on/off current ratio(2.17×10^(4)),a remarkably decreased subthreshold swing(SS)by 41%,and enhanced device stability.Additionally,by introducing Ta dopants,the fringe effect as well as the impact of channel width-to-length ratio(W/L)on electrical performances of the p-type oxide TFTs can be effectively suppressed.These results shall contribute to further exploration and development of p-type SnO_(x)TFTs.
基金Project supported by LingChuang Research Project of China National Nuclear Corporationthe National Natural Science Foundation of China(Grant No.12027812)。
文摘Dual-phase and three-phase grating x-ray interference is a promising new technique for grating-based x-ray differential phase contrast imaging.Dual-phase grating interferometers have been relatively completely studied and discussed.In this paper,the corresponding imaging fringe formula of the three-phase grating interferometer is provided.At the same time,the similarities and differences between the three-phase grating interferometer and the dual-phase grating interferometer are investigated and verified,and that the three-phase grating interferometer can produce large-period moiréfringes without using the analyzing grating is demonstrated experimentally.Finally,a simple method of designing three-phase grating and multi-grating imaging systems from geometric optics based on the thin-lens theory of gratings is presented.These theoretical formulas and experimental results provide optimization tools for designing three-phase grating interferometer systems.
文摘Purpose:The metropolitan cities of Johannesburg,Ekurhuleni and Tshwane play an important role in the economy of the Gauteng province in South Africa.The region constitutes to 22.4 percent of the total population of South Africa and has a strong presence and contributes in areas of manufacturing sector,financial and business services,retail and wholesale trade,etc.The rapid urban population,increase in the informal settlements and socio-economic opportunities has resulted in considerable urban sprawl in and around the urban fringe areas of these metropolitan cities.The urban fringe areas of these metros often come under the influence of rapid urbanization process and pressures.Coupled with the economical and potential land dynamics and lack of priority of spatial development guidelines,these areas attract rapid and haphazard development from communities and developers.Research Design/Methodology:This research is based on a qualitative approach through a comprehensive literature review that included content analysis of key documents on housing sector such as IDPs(Integrated Development Plans),Municipal Annual Reports,Growth Development Strategies,and among other sectoral documents on housing sector.Some of the key priority issues considered in the housing sector included:eradication of housing backlogs,spatial restructuring of housing,provision of choice in terms of location,tenure and housing typology.Findings:The current paper discusses the approaches of metropolitan housing development processes in three metropolitan cities of South Africa from Gauteng region,namely:Johannesburg,Ekurhuleni and Tshwane.The paper discusses the existing housing sectoral scenario along with the fringe areas in three cities with focus on:formal and informal settlements,housing segregation and the backlogs,current institutional arrangements,role of public private participation,and scope for alternate mechanisms.The paper concludes in discussion on sustainable development options for housing development in urban fringe areas.
基金funded and supported by the Comprehensive Research Facility for Fusion Technology Program of China(No.2018-000052-73-01-001228)the HFIPS Director’s Fund(No.YZJJKX202301)+1 种基金Anhui Provincial Major Science and Technology Project(No.2023z020004)Task JB22001 from the Anhui Provincial Department of Economic and Information Technology。
文摘Electron density in fusion plasma is usually diagnosed using laser-aided interferometers. The phase difference signal obtained after phase demodulation is wrapped, which is also called a fringe jump. A method has been developed to unwrap the phase difference signal in real time using FPGA, specifically designed to handle fringe jumps in the hydrogen cyanide(HCN) laser interferometer on the EAST superconducting tokamak. This method is designed for a phase demodulator using the fast Fourier transform(FFT) method at the front end. The method is better adapted for hardware implementation compared to complex mathematical analysis algorithms, such as field programmable gate array(FPGA). It has been applied to process the phase measurement results of the HCN laser interferometer on EAST in real time. Electron density results show good confidence in the fringe jump unwrapping method. Further possible application in other laser interferometers, such as the POlarimeter-INTerferometer(POINT)system on EAST tokamak is also discussed.
文摘Recent studies have underscored the significance of the capillary fringe in hydrological and biochemical processes.Moreover,its role in shallow waters is expected to be considerable.Traditionally,the study of groundwater flow has centered on unsaturated-saturated zones,often overlooking the impact of the capillary fringe.In this study,we introduce a steady-state two-dimensional model that integrates the capillary fringe into a 2-D numerical solution.Our novel approach employs the potential form of the Richards equation,facilitating the determination of boundaries,pressures,and velocities across different ground surface zones.We utilized a two-dimensional Freefem++finite element model to compute the stationary solution.The validation of the model was conducted using experimental data.We employed the OFAT(One_Factor-At-Time)method to identify the most sensitive soil parameters and understand how changes in these parameters may affect the behavior and water dynamics of the capillary fringe.The results emphasize the role of hydraulic conductivity as a key parameter influencing capillary fringe shape and dynamics.Velocity values within the capillary fringe suggest the prevalence of horizontal flow.By variation of the water table level and the incoming flow q0,we have shown the correlation between water table elevation and the upper limit of the capillary fringe.
基金Supported by National Defense Basic Scientific Research Program of China(Grant No.JCKY2021602B032)。
文摘Fringe projection profilometry(FPP)has been widely applied to non-contact three-dimensional measurement in industries owing to its high accuracy and speed.The point cloud,which is a measurement result of the FPP system,typically contains a large number of invalid points caused by the background,ambient light,shadows,and object edge regions.Research on noisy point detection and elimination has been conducted over the past two decades.However,existing invalid point removal methods are based on image intensity analysis and are only applicable to simple measurement backgrounds that are purely dark.In this paper,we propose a novel invalid point removal framework that consists of two aspects:(1)A convolutional neural network(CNN)is designed to segment the foreground from the background of different intensity conditions in FPP measurement circumstances to remove background points and the most discrete points in background regions.(2)A two-step method based on the fringe image intensity threshold and a bilateral filter is proposed to eliminate the small number of discrete points remaining after background segmentation caused by shadows and edge areas on objects.Experimental results verify that the proposed framework(1)can remove background points intelligently and accurately in different types of complex circumstances,and(2)performs excellently in discrete point detection from object regions.
文摘Efficient third-order nonlinearities of the Zinc Oxide and Al-doped Zinc Oxide were studied by Third Harmonic Generation (Third Harmonic Generation) Maker fringes to establish the effect Aluminum of Aluminum doping (Al-doping) on the cubic nonlinearities. Adding the Al-dopant to the Zinc Oxide crystal structure results in changes that affect the optical and nonlinear characteristics. Presented results indicate that the magnitude of X<sup>(3)</sup> was enhanced at single experimental wavelengths;however, across the broadband experimental spectrum, the effect of Al-doping remained relatively constant. The observed enhancement of third-order nonlinearity was purely from the bound electronic response. The observation is attributed to increased charge carriers and spontaneous polarization in the Zinc Oxide and Al-doped Zinc Oxide crystal structure.
文摘With Shiling Area of Eastern New District in Chengdu City as a background, concept design scheme was put forward from the perspective of ecological landscape through analyzing present development and ecological landscapes of the study area, applying philosophic thinking and Abstract concepts, and also combining with actual conditions of Chengdu, and meanwhile, concepts, orientation and functional structure of the eco-landscape concept planning were proposed. Key points of the planning were elaborated from 4 perspectives of spatial structure, traffic organization, spatial sequence and plant configuration to discuss spatial configuration of ecological landscapes on the fringes of Chengdu City, then further improve functions of ecological landscapes and quality of ecological environment, and put the concept planning into the construction practice of urban fringes.
文摘On basis of human settlements theory, the research explored status quo of human settlements theory in rural-urban fringe, and analyzed and concluded predicaments confronted by rural-urban fringe, laying foundation for human settle- ments theory of rural-urban fringe.
基金National Natural Science Foundation of China,No.41130748 No.41171070+2 种基金 China Postdoctoral Science Foundation,No.200902132 No.20080440511 The Humanities and Social Sciences Project of Ministry of Education,PRC,No.10YJCZH031
文摘In response to the strong drive for social and economic development, local governments have implemented urban master plans, providing measures and timeframes to address the continuous demand for land and to alleviate urban problems. In this paper, a multi-objective model was constructed to discuss the problem, including economic benefits and ecological effectiveness, in terms of land use optimization. A genetic algorithm was then adopted to solve the model, and a performance evaluation and sensitivity analysis were conducted using Pareto optimality. Results showed that a set of tradeoffs could be acquired by the allocation of land use. In addition, the Pareto solutions proved the model to be efficient; for example, a limit of 13,500 ha of urban area conformed to plan recommendations. The reduction in crop land, orchard land, grassland, and unused land provided further efficiencies. These results implied that further potential regional land resources remain and that the urban master plan is able to support sustainable local development in the years to come, as well as verified that it is feasible to use land use allocation multi-objective modeling and genetic algorithms.
基金Project (No. 59965003) supported by the National Natural ScienceFoundation of China
文摘This paper discusses current research and development of fringe projection-based techniques. A system based on Fourier transform profilometry (FTP) is proposed for three-dimensional (3D) shape recovery. The system improves the method of phase unwrapping to gain accurate 3D shapes of objects. The method uses a region-growing algorithm for the path prediction guided by the quality map to increase the recovering accuracy and provides a fast and simple tool for 3D shape recovery. The shape measurement and data recovery are integrated to offer a new method of 3D modelling. Examples are presented to verify the feasibility of the proposed method.
基金partially supported by the special funding of the Ministry of National Land and Resources Public Welfare Industry (2013110604)
文摘The objective of this paper is to analyze land use characteristics of rural settlements in urban fringe so as to provide references for optimizing the regional distribution of rural settlements, consolidating rural settlements, and coordinating urban-rural integrated development. The methods of spatial statistical analysis, buffer analysis, Ripley's K function, kernel density analysis based on GIS(Geographic Information System) were used to analyze the characteristics of scale, spatial differentiation and spatial patterns of the rural settlements in Liangjiang New Area in Chongqing Municipality of China. The fractal dimension formula was also developed to reflect fractal feature of the rural settlements. The results show that, the scale of rural settlements in Liangjang New Area takes on distinct characteristics of spatial differentiation along with changes in elevation, gradient, location, geohazards distribution, and the like. The fractal characteristic of rural settlements has obvious regional variations subject to the 6 factors of location in the Liangjiang New Area. Overall, the worse the terrain conditions are, the larger the fractal dimension values become. The better the locationconditions, the larger the fractal dimension values are. The spatial pattern in the township scale presents three kinds of distribution as being aggregated, uniform and random. In contract, the spatial pattern in the plaque scale displays a banding distribution from a general view with several aggregation zones centering on each town center. From the results, we can see that the characteristics of rural settlements in urban fringe are more complicated. For such kind of rural settlements in special regions, in the rural land consolidation more attention should be paid to improve the rural living environments and public services, as well as to promote the harmonious relationship between the urban and rural areas.
基金This work was supported by National Natural Science Foundation of China(62075096,62005121,U21B2033)Leading Technology of Jiangsu Basic Research Plan(BK20192003)+4 种基金“333 Engineering”Research Project of Jiangsu Province(BRA2016407)Jiangsu Provincial“One belt and one road”innovation cooperation project(BZ2020007)Fundamental Research Funds for the Central Universities(30921011208,30919011222,30920032101)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_0273)Open Research Fund of Jiangsu Key Laboratory of Spectral Imaging&Intelligent Sense(JSGP202105).
文摘Single-shot high-speed 3D imaging is important for reconstructions of dynamic objects.For fringe projection profilometry(FPP),however,it is still challenging to recover accurate 3D shapes of isolated objects by a single fringe image.In this paper,we demonstrate that the deep neural networks can be trained to directly recover the absolute phase from a unique fringe image that involves spatially multiplexed fringe patterns of different frequencies.The extracted phase is free from spectrum-aliasing problem which is hard to avoid for traditional spatial-multiplexing methods.Experiments on both static and dynamic scenes show that the proposed approach is robust to object motion and can obtain high-quality 3D reconstructions of isolated objects within a single fringe image.
基金the National Natural Science Foundation of China(Grant Nos.51679212 and 51809234)the Key Laboratory of Port,Waterway and Sedimentation Engineering,Ministry of Communications,China(Grant No.Yn918002)the Tang Scholar
文摘Wave hydrodynamics over fringing reefs is largely controlled by the reef surface roughness and hydrodynamic forcing.It is believed that climate change will result in a net increase in the water depth over the reef flat,a degrading of the surface roughness of coral reefs and changes in extreme incident wave heights.For an accurate assessment of how climate change affects the safety of reef-fringed coasts,a numerical study of the impact of climate change on irregular wave run-up over reef-fringed coasts was carried out based on a Boussinesq wave model,FUNWAVE-TVD.Validated with experimental data,the present model shows reasonable prediction of irregular wave evolution and run-up height over fringing reefs.Numerical experiments were then implemented based on the anticipated effects of climate change and carried out to investigate the effects of sea level rise,degrading of the reef surface roughness and increase of extreme incident wave height on the irregular wave run-up height over the backreef beach respectively.Variations of run-up components(i.e.,spectral characteristics of run-up and mean water level)were examined specifically and discussed to better understand the influencing mechanism of each climate change-related effect on the run-up.
