Travel times have been traditionally estimated from data collected by roadway sensors. Recently, new tech- nologies, such as cell phone tracking, license plate matching, automatic vehicle identifications and video det...Travel times have been traditionally estimated from data collected by roadway sensors. Recently, new tech- nologies, such as cell phone tracking, license plate matching, automatic vehicle identifications and video detection, are employed for this purpose. In this study, the data collected by TRANSMIT readers, Bluetooth sensors, and INRIX are assessed by comparing each to the ＂ground truth＂ travel times collected by probe vehicles carrying GPS-based naviga- tion devices. Travel times of probe vehicles traveling on the study segment of 1-287 in New Jersey were collected in 2009. Statistical measures, such as standard deviation, average absolute speed error, and speed error bias, were used to make an in-depth analysis. The accuracy of each travel time estimation method is analyzed. The data collected by Bluetooth sensors and the TRANSMIT readers seem more consistent with the ground true data, and slightly outperform the data reported by 1NRIX. This study established a procedure for analyzing the accuracy of floating car data （FCD） collected by different technologies.展开更多
Thermal diffusivity is a physical quantity that represents the thermal properties of soil.Amid the climate change known as global warming faced by humanity,Antarctica is one of the regions most affected by such change...Thermal diffusivity is a physical quantity that represents the thermal properties of soil.Amid the climate change known as global warming faced by humanity,Antarctica is one of the regions most affected by such changes.Therefore,in order to counter the effects of climate change,the thermal diffusivity of Antarctic regions is estimated in advance.展开更多
Organic matter is crucial in aerosol-climate interactions,yet the physicochemical properties and origins of organic aerosols remain poorly understood.Here we show the seasonal characteristics of submicron organic aero...Organic matter is crucial in aerosol-climate interactions,yet the physicochemical properties and origins of organic aerosols remain poorly understood.Here we show the seasonal characteristics of submicron organic aerosols in Arctic Svalbard during spring and summer,emphasizing their connection to transport patterns and particle size distribution.Microbial-derived organic matter(MOM)and terrestrial-derived organic matter(TOM)accounted for over 90%of the total organic mass in Arctic aerosols during these seasons,comprising carbohydrate/protein-like and lignin/tannin-like compounds,respectively.In spring,aerosols showed high TOM and low MOM intensities due to biomass-burning influx in the central Arctic.In contrast,summer exhibited elevated MOM intensity,attributed to the shift in predominant atmospheric transport from the central Arctic to the biologically active Greenland Sea.MOM and TOM were associated with Aitken mode particles(<100 nm diameter)and accumulation mode particles(>100 nm diameter),respectively.This association is linked to the molecular size of biomolecules,impacting the number concentrations of corresponding aerosol classes.These findings highlight the importance of considering seasonal atmospheric transport patterns and organic source-dependent particle size distributions in assessing aerosol properties in the changing Arctic.展开更多
The increased prevalence of the Internet of Things(IoT)and the integration of digital technology into our daily lives have given rise to heightened security risks and the need for more robust security measures.In resp...The increased prevalence of the Internet of Things(IoT)and the integration of digital technology into our daily lives have given rise to heightened security risks and the need for more robust security measures.In response to these challenges,physical unclonable functions(PUFs)have emerged as promising solution,offering a highly secure method to generate unpredictable and unique random digital values by leveraging inherent physical characteristics.However,traditional PUFs implementations often require complex hardware and circuitry,which can add to the cost and complexity of the system.We present a novel approach using a random wrinkles PUF(rw-PUF)based on an optically anisotropic,facile,simple,and cost-effective material.These wrinkles contain randomly oriented liquid crystal molecules,resulting in a two-dimensional retardation map corresponding to a complex birefringence pattern.Additionally,our proposed technique allows for customization based on specific requirements using a spatial light modulator,enabling fast fabrication.The random wrinkles PUF has the capability to store multiple data sets within a single PUF without the need for physical alterations.Furthermore,we introduce a concept called‘polyhedron authentication,’which utilizes three-dimensional information storage in a voxelated random wrinkles PUF.This approach demonstrates the feasibility of implementing high-level security technology by leveraging the unique properties of the rw-PUF.展开更多
文摘Travel times have been traditionally estimated from data collected by roadway sensors. Recently, new tech- nologies, such as cell phone tracking, license plate matching, automatic vehicle identifications and video detection, are employed for this purpose. In this study, the data collected by TRANSMIT readers, Bluetooth sensors, and INRIX are assessed by comparing each to the ＂ground truth＂ travel times collected by probe vehicles carrying GPS-based naviga- tion devices. Travel times of probe vehicles traveling on the study segment of 1-287 in New Jersey were collected in 2009. Statistical measures, such as standard deviation, average absolute speed error, and speed error bias, were used to make an in-depth analysis. The accuracy of each travel time estimation method is analyzed. The data collected by Bluetooth sensors and the TRANSMIT readers seem more consistent with the ground true data, and slightly outperform the data reported by 1NRIX. This study established a procedure for analyzing the accuracy of floating car data （FCD） collected by different technologies.
基金financially supported by the Korea Polar Research Institute(KOPRI)Project(PE19200)Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2019R1A6A1A03033167).
文摘Thermal diffusivity is a physical quantity that represents the thermal properties of soil.Amid the climate change known as global warming faced by humanity,Antarctica is one of the regions most affected by such changes.Therefore,in order to counter the effects of climate change,the thermal diffusivity of Antarctic regions is estimated in advance.
基金National Research Foundation(NRF)of Korea NRF-2021M1A5A1065425(KOPRI-PN24011)The FT-ICR MS analysis was supported by the Korea Basic Science Institute under the R&D program(Project No.C330430)supervised by the Ministry of Science and ICT.
文摘Organic matter is crucial in aerosol-climate interactions,yet the physicochemical properties and origins of organic aerosols remain poorly understood.Here we show the seasonal characteristics of submicron organic aerosols in Arctic Svalbard during spring and summer,emphasizing their connection to transport patterns and particle size distribution.Microbial-derived organic matter(MOM)and terrestrial-derived organic matter(TOM)accounted for over 90%of the total organic mass in Arctic aerosols during these seasons,comprising carbohydrate/protein-like and lignin/tannin-like compounds,respectively.In spring,aerosols showed high TOM and low MOM intensities due to biomass-burning influx in the central Arctic.In contrast,summer exhibited elevated MOM intensity,attributed to the shift in predominant atmospheric transport from the central Arctic to the biologically active Greenland Sea.MOM and TOM were associated with Aitken mode particles(<100 nm diameter)and accumulation mode particles(>100 nm diameter),respectively.This association is linked to the molecular size of biomolecules,impacting the number concentrations of corresponding aerosol classes.These findings highlight the importance of considering seasonal atmospheric transport patterns and organic source-dependent particle size distributions in assessing aerosol properties in the changing Arctic.
基金This work was supported by National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2021R1A4A1032762)This work partially supported Culture,Sports and Tourism R&D Program through the Korea Creative Content Agency grant funded by the Ministry of Culture,Sports and Tourism in 2023(Project Name:Development of copyright protection service for content distributed in smart glasses,Project Number:RS-2023-00217481,Contribution Rate:10%).
文摘The increased prevalence of the Internet of Things(IoT)and the integration of digital technology into our daily lives have given rise to heightened security risks and the need for more robust security measures.In response to these challenges,physical unclonable functions(PUFs)have emerged as promising solution,offering a highly secure method to generate unpredictable and unique random digital values by leveraging inherent physical characteristics.However,traditional PUFs implementations often require complex hardware and circuitry,which can add to the cost and complexity of the system.We present a novel approach using a random wrinkles PUF(rw-PUF)based on an optically anisotropic,facile,simple,and cost-effective material.These wrinkles contain randomly oriented liquid crystal molecules,resulting in a two-dimensional retardation map corresponding to a complex birefringence pattern.Additionally,our proposed technique allows for customization based on specific requirements using a spatial light modulator,enabling fast fabrication.The random wrinkles PUF has the capability to store multiple data sets within a single PUF without the need for physical alterations.Furthermore,we introduce a concept called‘polyhedron authentication,’which utilizes three-dimensional information storage in a voxelated random wrinkles PUF.This approach demonstrates the feasibility of implementing high-level security technology by leveraging the unique properties of the rw-PUF.
