The city of Addis Ababa,the capital of Ethiopia is experiencing tremendous changes,spatial as well as social and economic.The urban transformation of the city has shifted towards fragmented urban fabrics which fall sh...The city of Addis Ababa,the capital of Ethiopia is experiencing tremendous changes,spatial as well as social and economic.The urban transformation of the city has shifted towards fragmented urban fabrics which fall short of coherent integration and enclosure of urban spaces for social interaction.This research evaluates recent commercial corridors of the city with regard to currently employed design regulations and guidelines.The paper reports findings of a site investigation,describes the emerging urban characteristics of Addis Ababa and the factors leading up to such urban form.The paper emphasizes on the importance of employing architectural limits on local design standards as they offer potential to achieve a coherent urban"whole".展开更多
Optical coherence is a fundamental property of light,playing a key role in understanding interference,propagation,and light-matter interactions for both classical and quantum light.Measuring the coherence properties o...Optical coherence is a fundamental property of light,playing a key role in understanding interference,propagation,and light-matter interactions for both classical and quantum light.Measuring the coherence properties of an optical field is crucial for a wide range of applications.However,despite many proposed measurement schemes,significant challenges still remain.In this work,we present a protocol to measure the full-dimensional coherence properties of a partially coherent beam.The method is based on tomographing the complex coherent modes of the partially coherent field within its coherence time.Once the complex coherent modes are reconstructed,all coherence properties including field correlation and its higher-order correlations(e.g.,intensity correlation)can be recovered for beams that are either spatially uniformly or non-uniformly correlated.We perform a proof-of-principle experiment to measure the complex field correlation and intensity correlation of a structured partially coherent beam synthesized by random modes.Additionally,we discuss the application of full-dimensional complex coherence function tomography in coherence-based multi-cipher information security.The robustness of our system in complex environments is also evaluated.展开更多
AIM:To assess the ganglion cell complex(GCC)thickness in diabetic eyes without retinopathy. METHODS:Two groups included 45 diabetic eyes without retinopathy and 21 non diabetic eyes. All subjects underwent full me...AIM:To assess the ganglion cell complex(GCC)thickness in diabetic eyes without retinopathy. METHODS:Two groups included 45 diabetic eyes without retinopathy and 21 non diabetic eyes. All subjects underwent full medical and ophthalmological history,full ophthalmological examination,measuring GCC thickness and central foveal thickness(CFT)using the RTVue~? spectral domainoptical coherence tomography(SD-OCT),and HbA1C level.RESULTS:GCC focal loss volume(FLV%)was significantly more in diabetic eyes(22.2% below normal)than normal eyes(P=0.024). No statistically significant difference was found between the diabetic group and the control group regarding GCC global loss volume(GLV%)(P=0.160). CFT was positively correlated to the average,superior and inferior GCC(P=0.001,0.000 and 0.001 respectively)and negatively correlated to GLV% and FLV%(P=0.002 and0.031 respectively)in diabetic eyes. C/D ratio in diabetic eyes was negatively correlated to average,superior and inferior GCC(P=0.015,0.007 and 0.017 respectively). The FLV% was negatively correlated to the refraction and level of Hb A1c(P=0.019 and 0.013 respectively)and positively correlated to the best corrected visual acuity(BCVA)in log MAR in diabetic group(P=0.004).CONCLUSION:Significant GCC thinning in diabetes predates retinal vasculopathy,which is mainly focal rather than diffuse. It has no preference to either the superior or inferior halves of the macula. Increase of myopic error is significantly accompanied with increased focal GCC loss. GCC loss is accompanied with increased C/D ratio in diabetic eyes.展开更多
Hanbury-Brown and Twiss(HBT)effect is the foundation for stellar intensity interferometry.However,it is a phase insensitive two-photon interference effect.Here we extend the HBT interferometer by mixing intensity-matc...Hanbury-Brown and Twiss(HBT)effect is the foundation for stellar intensity interferometry.However,it is a phase insensitive two-photon interference effect.Here we extend the HBT interferometer by mixing intensity-matched reference fields with the input fields before intensity correlation measurement.With the freely available coherent state serving as the reference field,we experimentally demonstrate the phase sensitive two-photon interference effect when the input fields are thermal fields in either continuous wave or non-stationary pulsed wave and measure the complete complex second-order coherence function of the input fields without bringing them together from separate locations.Moreover,we discuss how to improve the signal level by using the more realistic continuous wave broadband anti-bunched light fields as the reference field.Our investigations pave the way for developing new technology of remote sensing and interferometric imaging with applications in long baseline high-resolution astronomy.展开更多
文摘The city of Addis Ababa,the capital of Ethiopia is experiencing tremendous changes,spatial as well as social and economic.The urban transformation of the city has shifted towards fragmented urban fabrics which fall short of coherent integration and enclosure of urban spaces for social interaction.This research evaluates recent commercial corridors of the city with regard to currently employed design regulations and guidelines.The paper reports findings of a site investigation,describes the emerging urban characteristics of Addis Ababa and the factors leading up to such urban form.The paper emphasizes on the importance of employing architectural limits on local design standards as they offer potential to achieve a coherent urban"whole".
基金supports from the National Key Research and Development Project of China(2022YFA1404800)the National Natural Science Foundation of China(NSFC)(12404348,12347114,12274311,12274310,12192254,92250304,W2441005)+1 种基金the China Postdoctoral Science Foundation(2024M752311)the Jiangsu Funding Program for Excellent Postdoctoral Talent(2023ZB185).
文摘Optical coherence is a fundamental property of light,playing a key role in understanding interference,propagation,and light-matter interactions for both classical and quantum light.Measuring the coherence properties of an optical field is crucial for a wide range of applications.However,despite many proposed measurement schemes,significant challenges still remain.In this work,we present a protocol to measure the full-dimensional coherence properties of a partially coherent beam.The method is based on tomographing the complex coherent modes of the partially coherent field within its coherence time.Once the complex coherent modes are reconstructed,all coherence properties including field correlation and its higher-order correlations(e.g.,intensity correlation)can be recovered for beams that are either spatially uniformly or non-uniformly correlated.We perform a proof-of-principle experiment to measure the complex field correlation and intensity correlation of a structured partially coherent beam synthesized by random modes.Additionally,we discuss the application of full-dimensional complex coherence function tomography in coherence-based multi-cipher information security.The robustness of our system in complex environments is also evaluated.
文摘AIM:To assess the ganglion cell complex(GCC)thickness in diabetic eyes without retinopathy. METHODS:Two groups included 45 diabetic eyes without retinopathy and 21 non diabetic eyes. All subjects underwent full medical and ophthalmological history,full ophthalmological examination,measuring GCC thickness and central foveal thickness(CFT)using the RTVue~? spectral domainoptical coherence tomography(SD-OCT),and HbA1C level.RESULTS:GCC focal loss volume(FLV%)was significantly more in diabetic eyes(22.2% below normal)than normal eyes(P=0.024). No statistically significant difference was found between the diabetic group and the control group regarding GCC global loss volume(GLV%)(P=0.160). CFT was positively correlated to the average,superior and inferior GCC(P=0.001,0.000 and 0.001 respectively)and negatively correlated to GLV% and FLV%(P=0.002 and0.031 respectively)in diabetic eyes. C/D ratio in diabetic eyes was negatively correlated to average,superior and inferior GCC(P=0.015,0.007 and 0.017 respectively). The FLV% was negatively correlated to the refraction and level of Hb A1c(P=0.019 and 0.013 respectively)and positively correlated to the best corrected visual acuity(BCVA)in log MAR in diabetic group(P=0.004).CONCLUSION:Significant GCC thinning in diabetes predates retinal vasculopathy,which is mainly focal rather than diffuse. It has no preference to either the superior or inferior halves of the macula. Increase of myopic error is significantly accompanied with increased focal GCC loss. GCC loss is accompanied with increased C/D ratio in diabetic eyes.
基金supported in part by the National Natural Science Foundation of China(Grant Nos.12004279,92476113 and 12074283)by City University of Hong Kong(Project No.9610522)+1 种基金the General Research Fund from Hong Kong Research Grants Council(Nos.11315822,11301624)Joint NSFC/RGC Collaborative Research Scheme(No.CRS_CityU103/24).
文摘Hanbury-Brown and Twiss(HBT)effect is the foundation for stellar intensity interferometry.However,it is a phase insensitive two-photon interference effect.Here we extend the HBT interferometer by mixing intensity-matched reference fields with the input fields before intensity correlation measurement.With the freely available coherent state serving as the reference field,we experimentally demonstrate the phase sensitive two-photon interference effect when the input fields are thermal fields in either continuous wave or non-stationary pulsed wave and measure the complete complex second-order coherence function of the input fields without bringing them together from separate locations.Moreover,we discuss how to improve the signal level by using the more realistic continuous wave broadband anti-bunched light fields as the reference field.Our investigations pave the way for developing new technology of remote sensing and interferometric imaging with applications in long baseline high-resolution astronomy.