Effective information fusion is very important in hybrid source localization. In this paper, the performance analysis of conventional joint direction of arrival(DOA) and time difference of arrival(TDOA) system is deri...Effective information fusion is very important in hybrid source localization. In this paper, the performance analysis of conventional joint direction of arrival(DOA) and time difference of arrival(TDOA) system is derived and it is shown that this hybrid system may inferior to the single system when the ratio of angular measurements error to distance measurements error exceeds a threshold. To avoid this problem, an effective DOA/TDOA adaptive cascaded(DTAC) technique is presented. The rotation feature of UAVs and spatial filtering technique are applied to gain the signal-to-noise ratio(SNR), which leads to more accurate estimation of time delay by using DOAs. Nevertheless, the time delay estimation precision is still limited by the sampling frequency, which is constrained by the finite load of UAV. To break through the limitation, an enhanced self-delay-compensation(SDC) method is proposed, which aims at detecting the overlooked time delay within the sampling interval by adding a tiny time delay. Finally, the position of the source is estimated by the Chan algorithm. Compared to DOA-only algorithm, TDOA-only algorithm and joint DOA/TDOA(JDT) algorithm, the proposed method shows better localization accuracy regardless of different SNRs and sampling frequencies. Numerical simulations are presented to validate the effectiveness and robustness of the proposed algorithm.展开更多
Atmospheric Brown Carbon(BrC)with strong wavelength-dependence light-absorption ability can significantly affect radiative forcing.Highly resolved emission inventories with lower uncertainties are important premise an...Atmospheric Brown Carbon(BrC)with strong wavelength-dependence light-absorption ability can significantly affect radiative forcing.Highly resolved emission inventories with lower uncertainties are important premise and essential in scientifically evaluating impacts of emissions on air quality,human health and climate change.This study developed a bottom-up inventory of primary BrC from combustion sources in China from 1960 to 2016 with a spatial resolution at 0.1°×0.1,based on compiled emission factors and detailed activity data.The primary BrC emission in China was about 593 Gg(500-735 Gg as interquartile range)in 2016,contributing to 7%(5%-8%)of a previously estimated global total BrC emission.Residential fuel combustion was the largest source of primary BrC in China,with the contribution of 67%as the national average but ranging from 25%to 99%among different provincial regions.Signi-ficant spatial disparities were also observed in the relative shares of different fuel types.Coal combustion contribution varied from 8%to 99%across different regions.Heilongjiang and North China Plain had high emissions of primary BrC.Generally,on the national scale,spatial distribution of BrC emission density per area was aligned with the population distribution.Primary BrC emission from combustion sources in China have been declined since a peak of~1300 Gg in 1980,but the temporal trends were distinct in different sectors.The high-resolution inventory developed here enables radiative forcing simulations in future atmospheric models so as to promote better understanding of carbonaceous aerosol impacts in the Earth's climate system and to develop strategies achieving co-benefits of hu-man health protection and climate change.展开更多
Owing to the multipath effect, the source localization in shallow water has been an area of active interest. However, most methods for source localization in shallow water are sensitive to the assumed model of the und...Owing to the multipath effect, the source localization in shallow water has been an area of active interest. However, most methods for source localization in shallow water are sensitive to the assumed model of the underwater environment and have poor robustness against the underwater channel uncertainty, which limit their further application in practical engineering. In this paper, a new method of source localization in shallow water, based on vector optimization concept, is described, which is highly robust against environmental factors affecting the localization, such as the channel depth, the bottom reflection coefficients, and so on. Through constructing the uncertainty set of the source vector errors and extracting the multi-path sound rays from the sea surface and bottom, the proposed method can accurately localize one or more sources in shallow water dominated by multipath propagation. It turns out that the natural formulation of our approach involves minimization of two quadratic functions subject to infinitely many nonconvex quadratic constraints. It shows that this problem （originally intractable） can be reformulated in a convex form as the so-called second-order cone program （SOCP） and solved efficiently by using the well-established interior point method, such as the sottware tool, SeDuMi. Computer simulations show better performance of the proposed method as compared with existing algorithms and establish a theoretical foundation for the practical engineering application.展开更多
The high-resolution shallow seismic technique can be used for more accurately prospecting the position and property of faults and for the preliminary study of fault activity.The author obtains many high quality stack ...The high-resolution shallow seismic technique can be used for more accurately prospecting the position and property of faults and for the preliminary study of fault activity.The author obtains many high quality stack time sections through the prospecting methods of different seismic sources,different group intervals and different observation systems on the Xiadian fault.These sections clearly display the stratum structure and the structure characteristics from several meters to several hundred meters of the Xiadian fault.The resolutions of the different seismic sources,different group intervals and different observing systems are obtained.The prospecting methods and work parameters applicable for goal stratum of different depths and different accuracy requirements are proposed through the analysis of the stack time sections.This lays a good foundation for raising the prospecting resolution of the fault position and the latest active time of the fault.展开更多
Illegal hunting and trafficking of wildlife and their derivatives extort unprecedented population decline of relatively many species pushing them towards extinction.Notwithstanding contemporary counteracting intervent...Illegal hunting and trafficking of wildlife and their derivatives extort unprecedented population decline of relatively many species pushing them towards extinction.Notwithstanding contemporary counteracting interventions at international,regional,national and local levels,wildlife farming is advocated as an alternative approach to minimize pressure on wild populations.For wildlife farming to be an effective conservation tool,the integration of wildlife forensics is inevitable to allow distinction between captive-bred and wild-caught species.To this end,we analyzed methylation rates of skeletal muscle samples(pectoralis major,triceps brachii,gastrocnemius,biceps femoris,and neck muscles)from 60 captive-bred and 30 wild-caught Common Pheasant.A total of 13,507 differentially methylated regions were identified between five wild-caught and five captive-bred individuals through whole-genome methylation sequencing(WGBS).Based on the selected five methylation sites,LOC116231076,LOC116242223,ATAD2B,EGFL6,and HS2ST,quantitative detection technique was developed using methylation-sensitive high-resolution melting curve(MS-HRM)to measure methylation rates.The results showed significant differences in methylation rates at all differential sites between wild-caught and captive-bred individuals(|t|=0.67–33.10,P=0.000–0.042).The discrimination accuracy rate of each locus was highest in the gastrocnemius muscle and lowest in the neck muscle.The discrimination accuracy rate on LOC116231076,LOC116242223,ATAD2B,EGFL6,and HS2ST methylation sites for gastrocnemius muscle was 64.98%,100.00%,68.54%,63.79%,and 63.70%,respectively;and for neck muscle it was 67.42%,68.06%,83.61%,65.04%,and68.85%,respectively.The united discrimination accuracy rate of the five loci were 100.00%for gastrocnemius muscle,99.78%for biceps femoris muscle,97.52%for pectoralis major muscle,93.96%for triceps brachii muscle,and 91.63%for neck muscle,respectively.The panel also revealed excellent repeatability,reproducibility,sensitivity and universality to mammals and avian species.This study establishes an effective,accurate and low-cost identification technology for the identification of wild and farmed Common Pheasant,and also provides a reference for the development of identification methods for other species.展开更多
Background China is progressing towards the goal of schistosomiasis elimination,but there are still some problems,such as difficult management of infection source and snail control.This study aimed to develop deep lea...Background China is progressing towards the goal of schistosomiasis elimination,but there are still some problems,such as difficult management of infection source and snail control.This study aimed to develop deep learning models with high-resolution remote sensing images for recognizing and monitoring livestock bovine,which is an intermediate source of Schistosoma japonicum infection,and to evaluate the effectiveness of the models for real-world application.Methods The dataset of livestock bovine’s spatial distribution was collected from the Chinese National Platform for Common Geospatial Information Services.The high-resolution remote sensing images were further divided into training data,test data,and validation data for model development.Two recognition models based on deep learning methods(ENVINet5 and Mask R-CNN)were developed with reference to the training datasets.The performance of the developed models was evaluated by the performance metrics of precision,recall,and F1-score.Results A total of 50 typical image areas were selected,1125 bovine objectives were labeled by the ENVINet5 model and 1277 bovine objectives were labeled by the Mask R-CNN model.For the ENVINet5 model,a total of 1598 records of bovine distribution were recognized.The model precision and recall were 81.9%and 80.2%,respectively.The F1 score was 0.81.For the Mask R-CNN mode,1679 records of bovine objectives were identified.The model precision and recall were 87.3%and 85.2%,respectively.The F1 score was 0.87.When applying the developed models to real-world schistosomiasis-endemic regions,there were 63 bovine objectives in the original image,53 records were extracted using the ENVINet5 model,and 57 records were extracted using the Mask R-CNN model.The successful recognition ratios were 84.1%and 90.5%for the respectively developed models.Conclusion The ENVINet5 model is very feasible when the bovine distribution is low in structure with few samples.The Mask R-CNN model has a good framework design and runs highly efficiently.The livestock recognition models developed using deep learning methods with high-resolution remote sensing images accurately recognize the spatial distribution of livestock,which could enable precise control of schistosomiasis.展开更多
The construction of major marine infrastructure projects and the exploration and development of deep-sea mineral resources require fine imaging of seabed strata and structures.The highresolution marine seismic explora...The construction of major marine infrastructure projects and the exploration and development of deep-sea mineral resources require fine imaging of seabed strata and structures.The highresolution marine seismic exploration based on a high broadband sparker source is an important approach to reveal seabed stratum and reservoir structure,and identify geohazard.To optimize the performance of sparker seismic source,we investigated the electro-acoustic characteristics of spark discharge under conditions of different charging voltages and electrode numbers.Results show that the sound source level increased with the increase of the charging voltage,whereas the main frequency decreased when the charging voltage increases.In addition,it was found that the charging capacitance had more obvious influence on the main frequency than the sound source level did.Although the load energy decreased with increasing electrode number,the sound source level still increased but the main frequency decreased.Meanwhile,the primary to bubble(P/B)ratio increased with the increase of the electrode number.To gain a deeper insight into the electro-acoustic characteristics,we investigate the relationship between sound source level and power peak,from which a good correlation was observed.A more practical statistical analysis on the rise rate of current was processed,and a perfect logarithmic function was derived.Furthermore,we found that the main frequency was most possibly subjected to the electrical energy,especially the charging energy per electrode.The results indicate that the charging energy per electrode less than 10 J could increase the main frequency to above 300 Hz.At last,the main frequency could be reduced to 20 Hz when the charging energy of a single-electrode discharge was enhanced to over 4 kJ.This study shall be helpful in developing a sparker seismic source and improving the performance for marine engineering exploration and geohazard assessment.展开更多
基金co-supported by China Scholarship Council(201806830081)National science foundation of China(61827801,61371169,61601167,61601504)+3 种基金Jiangsu NSF(BK20161489)the open research fund of State Key Laboratory of Millimeter Waves,Southeast University(No.K201826)the Fundamental Research Funds for the Central Universities(NO.NE2017103and NT2019013)the postgraduate Research and Practice Innovation Program of Jiangsu Province(KYCX18_0293).
文摘Effective information fusion is very important in hybrid source localization. In this paper, the performance analysis of conventional joint direction of arrival(DOA) and time difference of arrival(TDOA) system is derived and it is shown that this hybrid system may inferior to the single system when the ratio of angular measurements error to distance measurements error exceeds a threshold. To avoid this problem, an effective DOA/TDOA adaptive cascaded(DTAC) technique is presented. The rotation feature of UAVs and spatial filtering technique are applied to gain the signal-to-noise ratio(SNR), which leads to more accurate estimation of time delay by using DOAs. Nevertheless, the time delay estimation precision is still limited by the sampling frequency, which is constrained by the finite load of UAV. To break through the limitation, an enhanced self-delay-compensation(SDC) method is proposed, which aims at detecting the overlooked time delay within the sampling interval by adding a tiny time delay. Finally, the position of the source is estimated by the Chan algorithm. Compared to DOA-only algorithm, TDOA-only algorithm and joint DOA/TDOA(JDT) algorithm, the proposed method shows better localization accuracy regardless of different SNRs and sampling frequencies. Numerical simulations are presented to validate the effectiveness and robustness of the proposed algorithm.
基金Under the auspices of National Natural Science Foundation(No.42077328)。
文摘Atmospheric Brown Carbon(BrC)with strong wavelength-dependence light-absorption ability can significantly affect radiative forcing.Highly resolved emission inventories with lower uncertainties are important premise and essential in scientifically evaluating impacts of emissions on air quality,human health and climate change.This study developed a bottom-up inventory of primary BrC from combustion sources in China from 1960 to 2016 with a spatial resolution at 0.1°×0.1,based on compiled emission factors and detailed activity data.The primary BrC emission in China was about 593 Gg(500-735 Gg as interquartile range)in 2016,contributing to 7%(5%-8%)of a previously estimated global total BrC emission.Residential fuel combustion was the largest source of primary BrC in China,with the contribution of 67%as the national average but ranging from 25%to 99%among different provincial regions.Signi-ficant spatial disparities were also observed in the relative shares of different fuel types.Coal combustion contribution varied from 8%to 99%across different regions.Heilongjiang and North China Plain had high emissions of primary BrC.Generally,on the national scale,spatial distribution of BrC emission density per area was aligned with the population distribution.Primary BrC emission from combustion sources in China have been declined since a peak of~1300 Gg in 1980,but the temporal trends were distinct in different sectors.The high-resolution inventory developed here enables radiative forcing simulations in future atmospheric models so as to promote better understanding of carbonaceous aerosol impacts in the Earth's climate system and to develop strategies achieving co-benefits of hu-man health protection and climate change.
基金This Project supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No.20122304120011)the Fundamental Research Funds for the Central Universities of Ministry of Education of China (Grant No.HEUCFR1119)
文摘Owing to the multipath effect, the source localization in shallow water has been an area of active interest. However, most methods for source localization in shallow water are sensitive to the assumed model of the underwater environment and have poor robustness against the underwater channel uncertainty, which limit their further application in practical engineering. In this paper, a new method of source localization in shallow water, based on vector optimization concept, is described, which is highly robust against environmental factors affecting the localization, such as the channel depth, the bottom reflection coefficients, and so on. Through constructing the uncertainty set of the source vector errors and extracting the multi-path sound rays from the sea surface and bottom, the proposed method can accurately localize one or more sources in shallow water dominated by multipath propagation. It turns out that the natural formulation of our approach involves minimization of two quadratic functions subject to infinitely many nonconvex quadratic constraints. It shows that this problem （originally intractable） can be reformulated in a convex form as the so-called second-order cone program （SOCP） and solved efficiently by using the well-established interior point method, such as the sottware tool, SeDuMi. Computer simulations show better performance of the proposed method as compared with existing algorithms and establish a theoretical foundation for the practical engineering application.
基金supported by the project of "Experimental Exploration of Urban Active Faults" of the National Development and Reform Commission of China (20041138)
文摘The high-resolution shallow seismic technique can be used for more accurately prospecting the position and property of faults and for the preliminary study of fault activity.The author obtains many high quality stack time sections through the prospecting methods of different seismic sources,different group intervals and different observation systems on the Xiadian fault.These sections clearly display the stratum structure and the structure characteristics from several meters to several hundred meters of the Xiadian fault.The resolutions of the different seismic sources,different group intervals and different observing systems are obtained.The prospecting methods and work parameters applicable for goal stratum of different depths and different accuracy requirements are proposed through the analysis of the stack time sections.This lays a good foundation for raising the prospecting resolution of the fault position and the latest active time of the fault.
基金supported by the Fundamental Research Funds for the Central Universities(2572020DR10)Project on the Investigation,Supervision and Industry Regulation of Rare and Endangered Species(2024)。
文摘Illegal hunting and trafficking of wildlife and their derivatives extort unprecedented population decline of relatively many species pushing them towards extinction.Notwithstanding contemporary counteracting interventions at international,regional,national and local levels,wildlife farming is advocated as an alternative approach to minimize pressure on wild populations.For wildlife farming to be an effective conservation tool,the integration of wildlife forensics is inevitable to allow distinction between captive-bred and wild-caught species.To this end,we analyzed methylation rates of skeletal muscle samples(pectoralis major,triceps brachii,gastrocnemius,biceps femoris,and neck muscles)from 60 captive-bred and 30 wild-caught Common Pheasant.A total of 13,507 differentially methylated regions were identified between five wild-caught and five captive-bred individuals through whole-genome methylation sequencing(WGBS).Based on the selected five methylation sites,LOC116231076,LOC116242223,ATAD2B,EGFL6,and HS2ST,quantitative detection technique was developed using methylation-sensitive high-resolution melting curve(MS-HRM)to measure methylation rates.The results showed significant differences in methylation rates at all differential sites between wild-caught and captive-bred individuals(|t|=0.67–33.10,P=0.000–0.042).The discrimination accuracy rate of each locus was highest in the gastrocnemius muscle and lowest in the neck muscle.The discrimination accuracy rate on LOC116231076,LOC116242223,ATAD2B,EGFL6,and HS2ST methylation sites for gastrocnemius muscle was 64.98%,100.00%,68.54%,63.79%,and 63.70%,respectively;and for neck muscle it was 67.42%,68.06%,83.61%,65.04%,and68.85%,respectively.The united discrimination accuracy rate of the five loci were 100.00%for gastrocnemius muscle,99.78%for biceps femoris muscle,97.52%for pectoralis major muscle,93.96%for triceps brachii muscle,and 91.63%for neck muscle,respectively.The panel also revealed excellent repeatability,reproducibility,sensitivity and universality to mammals and avian species.This study establishes an effective,accurate and low-cost identification technology for the identification of wild and farmed Common Pheasant,and also provides a reference for the development of identification methods for other species.
基金National Natural Science Foundation of China(No.32161143036,No.82173633,No.81960374)Science and Technology research project of Shanghai Municipal Health Commission(No.20194Y0359)National Key Research and Development Program of China(No.2021YFC2300800,2021YFC2300803)
文摘Background China is progressing towards the goal of schistosomiasis elimination,but there are still some problems,such as difficult management of infection source and snail control.This study aimed to develop deep learning models with high-resolution remote sensing images for recognizing and monitoring livestock bovine,which is an intermediate source of Schistosoma japonicum infection,and to evaluate the effectiveness of the models for real-world application.Methods The dataset of livestock bovine’s spatial distribution was collected from the Chinese National Platform for Common Geospatial Information Services.The high-resolution remote sensing images were further divided into training data,test data,and validation data for model development.Two recognition models based on deep learning methods(ENVINet5 and Mask R-CNN)were developed with reference to the training datasets.The performance of the developed models was evaluated by the performance metrics of precision,recall,and F1-score.Results A total of 50 typical image areas were selected,1125 bovine objectives were labeled by the ENVINet5 model and 1277 bovine objectives were labeled by the Mask R-CNN model.For the ENVINet5 model,a total of 1598 records of bovine distribution were recognized.The model precision and recall were 81.9%and 80.2%,respectively.The F1 score was 0.81.For the Mask R-CNN mode,1679 records of bovine objectives were identified.The model precision and recall were 87.3%and 85.2%,respectively.The F1 score was 0.87.When applying the developed models to real-world schistosomiasis-endemic regions,there were 63 bovine objectives in the original image,53 records were extracted using the ENVINet5 model,and 57 records were extracted using the Mask R-CNN model.The successful recognition ratios were 84.1%and 90.5%for the respectively developed models.Conclusion The ENVINet5 model is very feasible when the bovine distribution is low in structure with few samples.The Mask R-CNN model has a good framework design and runs highly efficiently.The livestock recognition models developed using deep learning methods with high-resolution remote sensing images accurately recognize the spatial distribution of livestock,which could enable precise control of schistosomiasis.
基金Supported by the National Natural Science Foundation of China(No.42276195)the Natural Science Foundation of Zhejiang Province(No.LQ22D060006)the Science Foundation of Zhejiang Sci-Tech University(No.21022092-Y)。
文摘The construction of major marine infrastructure projects and the exploration and development of deep-sea mineral resources require fine imaging of seabed strata and structures.The highresolution marine seismic exploration based on a high broadband sparker source is an important approach to reveal seabed stratum and reservoir structure,and identify geohazard.To optimize the performance of sparker seismic source,we investigated the electro-acoustic characteristics of spark discharge under conditions of different charging voltages and electrode numbers.Results show that the sound source level increased with the increase of the charging voltage,whereas the main frequency decreased when the charging voltage increases.In addition,it was found that the charging capacitance had more obvious influence on the main frequency than the sound source level did.Although the load energy decreased with increasing electrode number,the sound source level still increased but the main frequency decreased.Meanwhile,the primary to bubble(P/B)ratio increased with the increase of the electrode number.To gain a deeper insight into the electro-acoustic characteristics,we investigate the relationship between sound source level and power peak,from which a good correlation was observed.A more practical statistical analysis on the rise rate of current was processed,and a perfect logarithmic function was derived.Furthermore,we found that the main frequency was most possibly subjected to the electrical energy,especially the charging energy per electrode.The results indicate that the charging energy per electrode less than 10 J could increase the main frequency to above 300 Hz.At last,the main frequency could be reduced to 20 Hz when the charging energy of a single-electrode discharge was enhanced to over 4 kJ.This study shall be helpful in developing a sparker seismic source and improving the performance for marine engineering exploration and geohazard assessment.
