Impact engineering encompasses many events of our lives.Examples include vehicle collisions,catastrophic collapse of infrastructures from explosion,ballistic impact of armour,hitting cricket balls in sports,falling of...Impact engineering encompasses many events of our lives.Examples include vehicle collisions,catastrophic collapse of infrastructures from explosion,ballistic impact of armour,hitting cricket balls in sports,falling off a bicycle.In such an event,an engineer needs to understand and quantify complex issues like identifying the impact loadings,obtaining material properties at high strain rates and evaluating structural responses and consequences.This engineering field receives great interests from industry and the research community.Several monographs have been published over the decades and related journals,such as the International Journal of Impact Engineering and Defence Technology,have been established and disseminate the latest research findings.展开更多
Background: Inadequate antenatal care, both in coverage and standard, has been linked with poor pregnancy outcomes. In a resource poor setting, home delivery is considered very cheap, but the possible outcome of such ...Background: Inadequate antenatal care, both in coverage and standard, has been linked with poor pregnancy outcomes. In a resource poor setting, home delivery is considered very cheap, but the possible outcome of such pregnancies has been a subject of interest. This study evaluated the association of booking status with pregnancy outcomes. Objectives: To examine the factors that influence booking and impact of the booking status on pregnancy outcomes. Methods: This was a hospital-based prospective cohort study of 240 (120 booked and 120 un-booked) pregnant mothers selected through systematic random sampling. The study was carried out at the Department of Obstetrics and Gynaecology, Alex Ekwueme Federal University Teaching Hospital Abakaliki, Nigeria. Chi-square test, t-test and logistic regression were used for analysis. Results: The mean age of the participants was 30.39 ± 5.05 years and 29.05 ± 6.36 years respectively for the booked and unbooked. Marital status (OR = 6.35, 95% CI = 1.24 - 32.59), educational status (OR = 36.40, 95% CI = 5.26-152.83), place of residence (OR = 0.15, 95% CI = 0.06 - 0.41), partner’s support (OR = 0.05, 95% CI = 0.01 - 0.37), family support (OR = 0.03, 95% CI = 0.01 - 0.13), mode of delivery (OR = 0.23, 95% CI = 0.12 - 0.46), APGAR score in first minute (OR = 6.02, 95% CI = 2.45 - 14.83) and NBICU admission (OR = 3.75, 95% CI = 1.67 - 8.43) were associated with booked status. However, being unmarried, nulliparity/grandmultiparity, low level of education, blue colar jobs, low income, rural dwelling and poor partner and poor family support were associated with the unbooked. The booked parturients had a better perinatal outcome compared the unbooked. Conclusion/Recommendation: There was high prevalence of operative deliveries, perinatal morbidity and mortality among the unbooked mothers. Girl child education, employment and poverty alleviation would improve antenatal care utilization.展开更多
The Amazon basin has experienced an extreme drought that started in the austral summer of 2022-23 and extends into 2024. This drought started earlier than other previous droughts. Although some rain fell during the au...The Amazon basin has experienced an extreme drought that started in the austral summer of 2022-23 and extends into 2024. This drought started earlier than other previous droughts. Although some rain fell during the austral summer, totals remained below average. Higher temperatures during austral winter and spring 2023, which affected most of Central South America, then aggravated drought conditions. This coincided with an intense El Niño and abnormally warm tropical North Atlantic Ocean temperatures since mid-2023. Decreased rainfall across the Amazon basin, negative anomalies in evapotranspiration (derived from latent heat) and soil moisture indicators, as well as increased temperatures during the dry-to-wet transition season, September-October-November (SON) 2023, combined to delay the onset of the wet season in the hydrological year 2023-24 by nearly two months and caused it to be uncharacteristically weak. SON 2023 registered a precipitation deficit of the order of 50 to 100 mm/month, and temperatures +3˚C higher than usual in Amazonia, leading to reduced evapotranspiration and soil moisture indicators. These processes, in turn, determined an exceptionally late onset and a lengthening of the dry season, affecting the 2023-2024 hydrological year. These changes were aggravated by a heat wave from June to December 2023. Drought-heat compound events and their consequences are the most critical natural threats to society. River levels reached record lows, or dried up completely, affecting Amazonian ecosystems. Increased risk of wildfires is another concern exacerbated by these conditions.展开更多
Customer churns remains a key focus in this research, using artificial intelligence-based technique of machine learning. Research is based on the feature-based analysis four main features were used that are selected o...Customer churns remains a key focus in this research, using artificial intelligence-based technique of machine learning. Research is based on the feature-based analysis four main features were used that are selected on the basis of our customer churn to deduct the meaning full analysis of the data set. Data-set is taken from the Kaggle that is about the fine food review having more than half a million records in it. This research remains on feature based analysis that is further concluded using confusion matrix. In this research we are using confusion matrix to conclude the customer churn results. Such specific analysis helps e-commerce business for real time growth in their specific products focusing more sales and to analyze which product is getting outage. Moreover, after applying the techniques, Support Vector Machine and K-Nearest Neighbour perform better than the random forest in this particular scenario. Using confusion matrix for obtaining the results three things are obtained that are precision, recall and accuracy. The result explains feature-based analysis on fine food reviews, Amazon at customer churn Support Vector Machine performed better as in overall comparison.展开更多
The process of turning forest area into land is known as deforestation or forest degradation. Reforestation as a fraction of deforestation is extremely low. For improved qualitative and quantitative classification, we...The process of turning forest area into land is known as deforestation or forest degradation. Reforestation as a fraction of deforestation is extremely low. For improved qualitative and quantitative classification, we used Sentinel-1 dataset of State of Para, Brazil to precisely and closely monitor deforestation between June 2019 and June 2023. This research aimed to find out suitable model for classification called Satellite Imaging analysis by Transpose deep neural transformation network (SIT-net) using mathematical model based on Band math approach to classify deforestation applying transpose deep neural network. The main advantage of proposed model is easy to handle SAR images. The study concludes that SAR satellite gives high-resolution images to improve deforestation monitoring and proposed model takes less computational time compared to other techniques.展开更多
Reading is one of the core skills in English learning.It is indispensable for EFL learners to develop good English reading literacy in primary schools.English picture books are consistent with pupils’cognitive and th...Reading is one of the core skills in English learning.It is indispensable for EFL learners to develop good English reading literacy in primary schools.English picture books are consistent with pupils’cognitive and thinking modes,which is valuable to improve their English reading literacy.However,at present,most Chinese pupils have some problems in English reading.The paper aims at analyzing the current problems in Chinese pupils’English reading and digging out the values and strategies of English picture book reading,so as to stimulate their reading interests,cultivate their intercultural awareness,and improve their English reading literacy.展开更多
The paper is based on literature search,introducing and analyzing the book publishing situation of modern Peking University Library from the perspective of the publisher being Peking University Library and its predece...The paper is based on literature search,introducing and analyzing the book publishing situation of modern Peking University Library from the perspective of the publisher being Peking University Library and its predecessor.It is pointed out that the majority of the book printing methods published by the modern Peking University Library are lead printing,and among the types of Chinese library classification,catalogue of library collections is the most common.展开更多
Many modern Chinese libraries have established distribution agencies in other cities to distribute books published or sold on consignment.Huating Bookstore,which was once the Shanghai General Distribution Office of Zh...Many modern Chinese libraries have established distribution agencies in other cities to distribute books published or sold on consignment.Huating Bookstore,which was once the Shanghai General Distribution Office of Zhejiang Library in modern times,is one of them.On the basis of a brief description of modern Zhejiang Library and its book publishing,as well as the overview of Huating Bookstore,the paper introduces and analyzes the ZPL Publishing Book Catalogue sent by Huating Bookstore,and the ZPL publishing and selling consignment books issued by Huating Bookstore.It points out that Huating Bookstore is a bridge between the ZPL located in Hangzhou and various retail ZPL publishing bookstores in Shanghai.Their production and sales relationship is a mutually beneficial one.展开更多
SNAPSHOTS OF NOTABLE BOOKS ON AFRICA.Africa’s Fashion Diaspora By ELIZABETH WAY Yale University Press.The author,Elizabeth Way,associate curator of costume at The Museum at the Fashion Institute of Technology,is the ...SNAPSHOTS OF NOTABLE BOOKS ON AFRICA.Africa’s Fashion Diaspora By ELIZABETH WAY Yale University Press.The author,Elizabeth Way,associate curator of costume at The Museum at the Fashion Institute of Technology,is the curator behind Africa’s Fashion Diaspora(2024).She has also curated several prominent exhibitions.Africa’s Fashion Diaspora is among the first books to delve into the vast influence of the African Diaspora on global fashion.展开更多
Travel in Northern Xizang(Revised Edition of 2024)Author:Ma Lihua.This book is one of the series of books about Ma Lihua's trip to Xizang.It describes the nomadic culture,festivals and daily life of local people,a...Travel in Northern Xizang(Revised Edition of 2024)Author:Ma Lihua.This book is one of the series of books about Ma Lihua's trip to Xizang.It describes the nomadic culture,festivals and daily life of local people,and the vast and magnificent scenery in northern Xizang.Published by China Tibetology Publishing House(ISBN:9787521105094).展开更多
The rapid development and popularization of Internet technology has provided important support for the informatization reform of various industries.University books and materials have the characteristics of large quan...The rapid development and popularization of Internet technology has provided important support for the informatization reform of various industries.University books and materials have the characteristics of large quantities and difficult storage and management.Its digital storage and management platform construction can effectively realize the digital storage and real-time retrieval of books and materials,and help students and teachers to find and use books and materials more quickly.Especially in recent years,with the update of intelligent platforms and other technologies,the resource-sharing platform of university books and materials can realize more convenient book information retrieval without the limitation of time and space.This paper mainly explores the optimization path and platform construction scheme of university libraries and information management under the background of the Internet,hoping to provide some theoretical references for university library managers.展开更多
This article takes the female community platform“Little Red Book”as an example to explore the optimization and innovation of mobile community e-commerce operation mode under Artificial Intelligence(AI)empowerment.Fi...This article takes the female community platform“Little Red Book”as an example to explore the optimization and innovation of mobile community e-commerce operation mode under Artificial Intelligence(AI)empowerment.Firstly,the relevant concepts were defined,and then the unique attributes of mobile community e-commerce were analyzed.As a typical representative of mobile community e-commerce,Little Red Book introduces the background and characteristics of its platform,analyzes its mobile community operation mode,and focuses on exploring how to establish a mobile community e-commerce platform and effective operation mode under the empowerment of AI technology,to provide some reference and inspiration for the development and operation of Little Red Book and other e-commerce platform enterprises.展开更多
This article will firstly discuss the context overview of English teaching and learning in China. Under thiscircumstance, a problematic element will be examined of the New Senior English for China Student’s Book 1 an...This article will firstly discuss the context overview of English teaching and learning in China. Under thiscircumstance, a problematic element will be examined of the New Senior English for China Student’s Book 1 and critical appraisal ofhow this element relates to other elements of curriculum development will be analyzed. The recommended changes and demonstrationmechanisms for evaluating the changes are put forward in the last two parts.展开更多
In this study,we estimated the weekly Gravity Recovery and Climate Experiment(GRACE)spherical harmonic(SH)solutions and regional mascon solutions using GRACE-based Geopotential Difference(GPD)data and investigated the...In this study,we estimated the weekly Gravity Recovery and Climate Experiment(GRACE)spherical harmonic(SH)solutions and regional mascon solutions using GRACE-based Geopotential Difference(GPD)data and investigated their abilities in retrieving terrestrial water storage(TWS)changes over the Amazon River Basin(ARB)from January 2003 to February 2013.The performance of the weekly GPD-SH and GPDmascon solutions was evaluated by comparing them with the weekly GFZ-SH solutions,Global Land Data Assimilation Systems(GLDAS)-NOAH hydrological model outputs,and monthly GFZ-SH,GPD-SH,and CSRmascon solutions in the spatio-temporal and spectral domains.The results demonstrate that the weekly GPD-SH and GPD-mascon present good consistency with the weekly GFZ-SH solutions and GLDAS-NOAH estimates in the spatio-temporal domains,but GPD-mascon presents stronger signal amplitudes and more spatial details.The comparison of the monthly average of weekly estimates and monthly solutions demonstrates that the weekly GPD-mascon and GFZ-SH with DDK1 filtering are close to the monthly CSRmascon and GFZ-SH solutions,respectively.However,the signal amplitudes of TWS changes from GPD-SH and GFZ-SH with 650 km Gaussian filtering are smaller than the monthly solutions,and the corresponding Root Mean Square Errors between the TWS change time series from the monthly average of weekly solutions and monthly estimates are 18.12 mm(GPD-mascon),18.81 mm(GFZ-SH-DDK1),24.93 mm(GPDSH-G650km),and 33.07 mm(GFZ-SH-G650km),respectively.Additionally,the TWS change time series derived from weekly solutions present more high-frequency time-varying information than monthly solutions.Furthermore,the 300 km Gaussian filtering can improve the signal amplitudes of TWS changes from the weekly GPD-SH solutions more than those with 650 km Gaussian filtering,but the corresponding noise level is higher.The weekly GPD-SH and GPD-mascon solutions can extend the application scopes of GRACE and provide good complements to the current GRACE monthly solutions.展开更多
As the demand for used books has grown in recent years,various online/offline market platforms have emerged to support the trade in used books.The price of used books can depend on various factors,such as the state of...As the demand for used books has grown in recent years,various online/offline market platforms have emerged to support the trade in used books.The price of used books can depend on various factors,such as the state of preservation(i.e.,condition),the value of possession,and so on.Therefore,some online platforms provide a reference document to evaluate the condition of used books,but it is still not trivial for individual sellers to determine the price.The lack of a standard quantitative method to assess the condition of the used book would confuse both sellers and consumers,thereby decreasing the user experience of the online secondhand marketplace.Therefore,this paper discusses the automatic examination of the condition of used books based on deep learning approaches.In this work,we present a book damage detection system based on various You Only Look Once(YOLO)object detection models.Using YOLOv5,YOLOR,and YOLOX,we also introduce various training configurations that can be applied to improve performance.Specifically,a combination of different augmentation strategies including flip,rotation,crop,mosaic,and mixup was used for comparison.To train and validate our system,a book damage dataset composed of a total of 620 book images with 3,989 annotations,containing six types of damages(i.e.,Wear,Spot,Notch,Barcode,Tag,and Ripped),collected from the library books is presented.We evaluated each model trained with different configurations to figure out their detection accuracy as well as training efficiency.The experimental results showed that YOLOX trained with its best training configuration yielded the best performance in terms of detection accuracy,by achieving 60.0%(mAP@.5:.95)and 72.9%(mAP@.5)for book damage detection.However,YOLOX performed worst in terms of training efficiency,indicating that there is a trade-off between accuracy and efficiency.Based on the findings from the study,we discuss the feasibility and limitations of our system and future research directions.展开更多
文摘Impact engineering encompasses many events of our lives.Examples include vehicle collisions,catastrophic collapse of infrastructures from explosion,ballistic impact of armour,hitting cricket balls in sports,falling off a bicycle.In such an event,an engineer needs to understand and quantify complex issues like identifying the impact loadings,obtaining material properties at high strain rates and evaluating structural responses and consequences.This engineering field receives great interests from industry and the research community.Several monographs have been published over the decades and related journals,such as the International Journal of Impact Engineering and Defence Technology,have been established and disseminate the latest research findings.
文摘Background: Inadequate antenatal care, both in coverage and standard, has been linked with poor pregnancy outcomes. In a resource poor setting, home delivery is considered very cheap, but the possible outcome of such pregnancies has been a subject of interest. This study evaluated the association of booking status with pregnancy outcomes. Objectives: To examine the factors that influence booking and impact of the booking status on pregnancy outcomes. Methods: This was a hospital-based prospective cohort study of 240 (120 booked and 120 un-booked) pregnant mothers selected through systematic random sampling. The study was carried out at the Department of Obstetrics and Gynaecology, Alex Ekwueme Federal University Teaching Hospital Abakaliki, Nigeria. Chi-square test, t-test and logistic regression were used for analysis. Results: The mean age of the participants was 30.39 ± 5.05 years and 29.05 ± 6.36 years respectively for the booked and unbooked. Marital status (OR = 6.35, 95% CI = 1.24 - 32.59), educational status (OR = 36.40, 95% CI = 5.26-152.83), place of residence (OR = 0.15, 95% CI = 0.06 - 0.41), partner’s support (OR = 0.05, 95% CI = 0.01 - 0.37), family support (OR = 0.03, 95% CI = 0.01 - 0.13), mode of delivery (OR = 0.23, 95% CI = 0.12 - 0.46), APGAR score in first minute (OR = 6.02, 95% CI = 2.45 - 14.83) and NBICU admission (OR = 3.75, 95% CI = 1.67 - 8.43) were associated with booked status. However, being unmarried, nulliparity/grandmultiparity, low level of education, blue colar jobs, low income, rural dwelling and poor partner and poor family support were associated with the unbooked. The booked parturients had a better perinatal outcome compared the unbooked. Conclusion/Recommendation: There was high prevalence of operative deliveries, perinatal morbidity and mortality among the unbooked mothers. Girl child education, employment and poverty alleviation would improve antenatal care utilization.
文摘The Amazon basin has experienced an extreme drought that started in the austral summer of 2022-23 and extends into 2024. This drought started earlier than other previous droughts. Although some rain fell during the austral summer, totals remained below average. Higher temperatures during austral winter and spring 2023, which affected most of Central South America, then aggravated drought conditions. This coincided with an intense El Niño and abnormally warm tropical North Atlantic Ocean temperatures since mid-2023. Decreased rainfall across the Amazon basin, negative anomalies in evapotranspiration (derived from latent heat) and soil moisture indicators, as well as increased temperatures during the dry-to-wet transition season, September-October-November (SON) 2023, combined to delay the onset of the wet season in the hydrological year 2023-24 by nearly two months and caused it to be uncharacteristically weak. SON 2023 registered a precipitation deficit of the order of 50 to 100 mm/month, and temperatures +3˚C higher than usual in Amazonia, leading to reduced evapotranspiration and soil moisture indicators. These processes, in turn, determined an exceptionally late onset and a lengthening of the dry season, affecting the 2023-2024 hydrological year. These changes were aggravated by a heat wave from June to December 2023. Drought-heat compound events and their consequences are the most critical natural threats to society. River levels reached record lows, or dried up completely, affecting Amazonian ecosystems. Increased risk of wildfires is another concern exacerbated by these conditions.
文摘Customer churns remains a key focus in this research, using artificial intelligence-based technique of machine learning. Research is based on the feature-based analysis four main features were used that are selected on the basis of our customer churn to deduct the meaning full analysis of the data set. Data-set is taken from the Kaggle that is about the fine food review having more than half a million records in it. This research remains on feature based analysis that is further concluded using confusion matrix. In this research we are using confusion matrix to conclude the customer churn results. Such specific analysis helps e-commerce business for real time growth in their specific products focusing more sales and to analyze which product is getting outage. Moreover, after applying the techniques, Support Vector Machine and K-Nearest Neighbour perform better than the random forest in this particular scenario. Using confusion matrix for obtaining the results three things are obtained that are precision, recall and accuracy. The result explains feature-based analysis on fine food reviews, Amazon at customer churn Support Vector Machine performed better as in overall comparison.
文摘The process of turning forest area into land is known as deforestation or forest degradation. Reforestation as a fraction of deforestation is extremely low. For improved qualitative and quantitative classification, we used Sentinel-1 dataset of State of Para, Brazil to precisely and closely monitor deforestation between June 2019 and June 2023. This research aimed to find out suitable model for classification called Satellite Imaging analysis by Transpose deep neural transformation network (SIT-net) using mathematical model based on Band math approach to classify deforestation applying transpose deep neural network. The main advantage of proposed model is easy to handle SAR images. The study concludes that SAR satellite gives high-resolution images to improve deforestation monitoring and proposed model takes less computational time compared to other techniques.
基金This paper is one of the results of the research programs the author participated“Research on Primary School English Picture Book Reading Teaching Practice from the Perspective of Subject Core Literacy”(Grant Fund No.2022ZJY1214)the key project of the“14th Five-Year Plan”for Education Science in Guangxi in 2022.
文摘Reading is one of the core skills in English learning.It is indispensable for EFL learners to develop good English reading literacy in primary schools.English picture books are consistent with pupils’cognitive and thinking modes,which is valuable to improve their English reading literacy.However,at present,most Chinese pupils have some problems in English reading.The paper aims at analyzing the current problems in Chinese pupils’English reading and digging out the values and strategies of English picture book reading,so as to stimulate their reading interests,cultivate their intercultural awareness,and improve their English reading literacy.
基金Humanities and Social Sciences Planning Fund Project of the Ministry of Education of P.R.China,titled“Research on the Books Publishing of Modern Chinese Libraries from the Perspective of Generalized Technology”(Project No.19YJA870014).
文摘The paper is based on literature search,introducing and analyzing the book publishing situation of modern Peking University Library from the perspective of the publisher being Peking University Library and its predecessor.It is pointed out that the majority of the book printing methods published by the modern Peking University Library are lead printing,and among the types of Chinese library classification,catalogue of library collections is the most common.
基金the research results of Humanities and Social Science Planning Fund Project of the Ministry of Education of P.R.China,titled“Research on the Books Publishing of Modern Chinese Library from the Perspective of Generalized Technology”(Project number:19YJA870014).
文摘Many modern Chinese libraries have established distribution agencies in other cities to distribute books published or sold on consignment.Huating Bookstore,which was once the Shanghai General Distribution Office of Zhejiang Library in modern times,is one of them.On the basis of a brief description of modern Zhejiang Library and its book publishing,as well as the overview of Huating Bookstore,the paper introduces and analyzes the ZPL Publishing Book Catalogue sent by Huating Bookstore,and the ZPL publishing and selling consignment books issued by Huating Bookstore.It points out that Huating Bookstore is a bridge between the ZPL located in Hangzhou and various retail ZPL publishing bookstores in Shanghai.Their production and sales relationship is a mutually beneficial one.
文摘SNAPSHOTS OF NOTABLE BOOKS ON AFRICA.Africa’s Fashion Diaspora By ELIZABETH WAY Yale University Press.The author,Elizabeth Way,associate curator of costume at The Museum at the Fashion Institute of Technology,is the curator behind Africa’s Fashion Diaspora(2024).She has also curated several prominent exhibitions.Africa’s Fashion Diaspora is among the first books to delve into the vast influence of the African Diaspora on global fashion.
文摘Travel in Northern Xizang(Revised Edition of 2024)Author:Ma Lihua.This book is one of the series of books about Ma Lihua's trip to Xizang.It describes the nomadic culture,festivals and daily life of local people,and the vast and magnificent scenery in northern Xizang.Published by China Tibetology Publishing House(ISBN:9787521105094).
文摘The rapid development and popularization of Internet technology has provided important support for the informatization reform of various industries.University books and materials have the characteristics of large quantities and difficult storage and management.Its digital storage and management platform construction can effectively realize the digital storage and real-time retrieval of books and materials,and help students and teachers to find and use books and materials more quickly.Especially in recent years,with the update of intelligent platforms and other technologies,the resource-sharing platform of university books and materials can realize more convenient book information retrieval without the limitation of time and space.This paper mainly explores the optimization path and platform construction scheme of university libraries and information management under the background of the Internet,hoping to provide some theoretical references for university library managers.
基金Phased Research Key Project of Shanghai China Vocational Education Association“Research on Digital Transformation Path of Vocational Education Driven by AIGC from the Perspective of New Quality Productivity”,Phased Research Project of Shanghai Computer Industry Association“The Reform and Exploration of Cross-border E-commerce Talent Cultivation in Vocational Colleges from the Perspective of Industry Education Integration”(Project No.sctakt202404)。
文摘This article takes the female community platform“Little Red Book”as an example to explore the optimization and innovation of mobile community e-commerce operation mode under Artificial Intelligence(AI)empowerment.Firstly,the relevant concepts were defined,and then the unique attributes of mobile community e-commerce were analyzed.As a typical representative of mobile community e-commerce,Little Red Book introduces the background and characteristics of its platform,analyzes its mobile community operation mode,and focuses on exploring how to establish a mobile community e-commerce platform and effective operation mode under the empowerment of AI technology,to provide some reference and inspiration for the development and operation of Little Red Book and other e-commerce platform enterprises.
文摘This article will firstly discuss the context overview of English teaching and learning in China. Under thiscircumstance, a problematic element will be examined of the New Senior English for China Student’s Book 1 and critical appraisal ofhow this element relates to other elements of curriculum development will be analyzed. The recommended changes and demonstrationmechanisms for evaluating the changes are put forward in the last two parts.
基金funded by the National Natural Science Foundation of China(Nos.41974015,42374002)the Project Supported by the Special Fund of Hubei Luojia Laboratory(No.220100004)。
文摘In this study,we estimated the weekly Gravity Recovery and Climate Experiment(GRACE)spherical harmonic(SH)solutions and regional mascon solutions using GRACE-based Geopotential Difference(GPD)data and investigated their abilities in retrieving terrestrial water storage(TWS)changes over the Amazon River Basin(ARB)from January 2003 to February 2013.The performance of the weekly GPD-SH and GPDmascon solutions was evaluated by comparing them with the weekly GFZ-SH solutions,Global Land Data Assimilation Systems(GLDAS)-NOAH hydrological model outputs,and monthly GFZ-SH,GPD-SH,and CSRmascon solutions in the spatio-temporal and spectral domains.The results demonstrate that the weekly GPD-SH and GPD-mascon present good consistency with the weekly GFZ-SH solutions and GLDAS-NOAH estimates in the spatio-temporal domains,but GPD-mascon presents stronger signal amplitudes and more spatial details.The comparison of the monthly average of weekly estimates and monthly solutions demonstrates that the weekly GPD-mascon and GFZ-SH with DDK1 filtering are close to the monthly CSRmascon and GFZ-SH solutions,respectively.However,the signal amplitudes of TWS changes from GPD-SH and GFZ-SH with 650 km Gaussian filtering are smaller than the monthly solutions,and the corresponding Root Mean Square Errors between the TWS change time series from the monthly average of weekly solutions and monthly estimates are 18.12 mm(GPD-mascon),18.81 mm(GFZ-SH-DDK1),24.93 mm(GPDSH-G650km),and 33.07 mm(GFZ-SH-G650km),respectively.Additionally,the TWS change time series derived from weekly solutions present more high-frequency time-varying information than monthly solutions.Furthermore,the 300 km Gaussian filtering can improve the signal amplitudes of TWS changes from the weekly GPD-SH solutions more than those with 650 km Gaussian filtering,but the corresponding noise level is higher.The weekly GPD-SH and GPD-mascon solutions can extend the application scopes of GRACE and provide good complements to the current GRACE monthly solutions.
文摘As the demand for used books has grown in recent years,various online/offline market platforms have emerged to support the trade in used books.The price of used books can depend on various factors,such as the state of preservation(i.e.,condition),the value of possession,and so on.Therefore,some online platforms provide a reference document to evaluate the condition of used books,but it is still not trivial for individual sellers to determine the price.The lack of a standard quantitative method to assess the condition of the used book would confuse both sellers and consumers,thereby decreasing the user experience of the online secondhand marketplace.Therefore,this paper discusses the automatic examination of the condition of used books based on deep learning approaches.In this work,we present a book damage detection system based on various You Only Look Once(YOLO)object detection models.Using YOLOv5,YOLOR,and YOLOX,we also introduce various training configurations that can be applied to improve performance.Specifically,a combination of different augmentation strategies including flip,rotation,crop,mosaic,and mixup was used for comparison.To train and validate our system,a book damage dataset composed of a total of 620 book images with 3,989 annotations,containing six types of damages(i.e.,Wear,Spot,Notch,Barcode,Tag,and Ripped),collected from the library books is presented.We evaluated each model trained with different configurations to figure out their detection accuracy as well as training efficiency.The experimental results showed that YOLOX trained with its best training configuration yielded the best performance in terms of detection accuracy,by achieving 60.0%(mAP@.5:.95)and 72.9%(mAP@.5)for book damage detection.However,YOLOX performed worst in terms of training efficiency,indicating that there is a trade-off between accuracy and efficiency.Based on the findings from the study,we discuss the feasibility and limitations of our system and future research directions.