聚变堆主机关键系统综合研究设施(Comprehensive Research Facility for Fusion Technology,CRAFT)负离子源中性束注入(Negative Neutral Beam Injection,NNBI)电源首次采用逆变型整流方案,但离子源的时变、非线性及高可控等负荷特征给...聚变堆主机关键系统综合研究设施(Comprehensive Research Facility for Fusion Technology,CRAFT)负离子源中性束注入(Negative Neutral Beam Injection,NNBI)电源首次采用逆变型整流方案,但离子源的时变、非线性及高可控等负荷特征给电源电压和纹波控制带来了挑战。采用傅里叶变换分析逆变型直流高压电源拓扑,针对低频开关信号,提出一种新的逆变型直流高压电源传递函数分析方法以快速建立系统近似模型。通过PWM方式控制逆变器开关管占空比,相控整流控制直流母线电压,实现系统输出电压闭环控制以及提升纹波抑制能力,并设计1200 V/5 A实验测试平台验证控制方法的有效性。展开更多
The North-East Caucasus is a multi-ethnic mountain macroregion with a rich cultural heritage,insufficiently studied in the context of the ecotourism development.To fill this gap and identify promising directions of en...The North-East Caucasus is a multi-ethnic mountain macroregion with a rich cultural heritage,insufficiently studied in the context of the ecotourism development.To fill this gap and identify promising directions of environmentally safe forms of tourism,the author used in-depth review of modern literature to investigate the features of ecological tourism and the problems of preserving ethno-cultural heritage,and used historical and comparative-geographical methods to analyze the development of the tangible and intangible cultural heritage of the indigenous peoples of the North-Eastern Caucasus in different historical periods and to identify the geographical peculiarities of the distribution of historical and cultural monuments(tower buildings),pilgrimage sites and centers of traditional crafts and trades.As part of the planned expeditions,the author personally visited some historical monuments and handicraft centers for a deeper study of ethno-cultural heritage.The cartographic method made it possible to visualize the results.The results of the research show that the ethnocultural heritage of the North-East Caucasus is formed by material(historical and cultural monuments)and immaterial elements of culture(language,customs,traditions,ethnic identification)of those peoples,who live here.The ethnocultural heritage is considered as the most important factor in the development of the tourism industry.It is revealed that this region has a large potential for development in various areas of eco-tourism.The highest concentration of religious buildings focused in mountainous areas.Medieval tower structures were erected in mountainous and high-altitude areas.From ancient times to the present day there have been preserved various types of crafts and trades(pottery,metalworking,burka making,jewelry making,carpet weaving,gold embroidery,wood and stone carving,etc.),which can become objects of ecotourism.The ethnocultural heritage of the North-East Caucasus needs to be preserved and protected.To solve this problem,the author recommends to focus on a balanced combination of traditions and innovations in this industry,also considering the current state and development of the tourism industry in the country and in the world.The research highlights that the development of scientific approaches to plan and manage tourism development can contribute to the preservation of tangible and intangible cultural heritage of indigenous peoples.This is a complex and labour-intensive task,but its solution will have a multiplier effect in the social sphere,in economic development and in environmental security,which is in line with the principles and concept of sustainable development.展开更多
In the design realm of fusion power supplies,structural components play a pivotal role in ensuring the safety of fusion devices.To verify the reliability of the converter structure design at the Comprehensive Research...In the design realm of fusion power supplies,structural components play a pivotal role in ensuring the safety of fusion devices.To verify the reliability of the converter structure design at the Comprehensive Research Facility for Fusion Technology(CRAFT),meticulous analysis of the converter's dynamic impact is carefully performed based on the worst fault current(400k A),firstly.Subsequently,the thermal stress analysis based on the maximum allowable steadystate temperature is finished,and the equivalent thermal stress,thermal deformation,maximum shear stress of a single bridge arm and the whole converter are studied.Furthermore,a simple research method involving the current-sharing characteristics of a bridge arm with multithyristor parallel connection is proposed using a combination of Simplorer with Q3D in ANSYS.The results show that the current-sharing characteristics are excellent.Finally,the structural design has been meticulously tailored to meet the established requirements.展开更多
Activity 1.Think about the following questions and write down your answers before reading the text.1.Do you know any traditional crafts?2.How can young people be encouraged to learn traditional crafts?
This review explores the evolution of the textile handicraft industry in Saudi Arabia, emphasizing its cultural and economic significance. The study highlights the transition from traditional practices to modern innov...This review explores the evolution of the textile handicraft industry in Saudi Arabia, emphasizing its cultural and economic significance. The study highlights the transition from traditional practices to modern innovations and examines the impact of globalization and technological advancements on the industry. Key innovations are discussed, demonstrating their role in enhancing textile production while preserving cultural heritage. Major challenges, such as competition from industrial textiles and the need for sustainable practices, are identified. Opportunities for growth are explored, including leveraging tourism and international markets to promote Saudi handicrafts. The social and cultural impacts of the sector are underscored, particularly in sustaining community traditions and providing economic opportunities for artisans. Strategic recommendations for supporting and advancing the industry are offered, ensuring its continued relevance and sustainability in a rapidly changing global market. This analysis provides a robust framework for understanding the current state and future potential of Saudi Arabia’s textile handicraft industry.展开更多
单脉冲搜索作为脉冲星探测的有力工具,在探测旋转射电暂现源以及快速射电暴中扮演着重要角色。为了从海量的射电巡天数据中快速筛选出最有价值的单脉冲搜索候选体,候选体识别已经从早期启发式阈值判断发展到基于机器学习自动识别。对于F...单脉冲搜索作为脉冲星探测的有力工具,在探测旋转射电暂现源以及快速射电暴中扮演着重要角色。为了从海量的射电巡天数据中快速筛选出最有价值的单脉冲搜索候选体,候选体识别已经从早期启发式阈值判断发展到基于机器学习自动识别。对于FAST观测,研究了基于机器学习的单脉冲搜索候选体识别应用到CRAFTS(the commensal radio astronomy FAST survey)超宽带脉冲星数据的性能表现。在评估过程中,使用单脉冲事件组识别(SPEGID)和单脉冲搜索器(SPS)两类自动识别方法,通过7种不同机器学习分类器对CRAFTS基准数据集产生的单脉冲搜索候选体进行自动识别;作为对比,也使用了启发式阈值判断的方法(RRATtrap和Clusterrank)。结果表明,SPEGID具有最好的性能表现(最高的F1-score值95.1%、次高的召回率95.4%、最低的假阳性率4.7%),SPS具有最快的筛选速度(平均每小时筛选4010个候选体)。通过对比分析结果,探讨了如何基于FAST观测数据开展高效的单脉冲搜索候选体识别。展开更多
Evaluation of calligraphic copy is the core of Chinese calligraphy appreciation and in-heritance.However,previous aesthetic evaluation studies often focussed on photos and paintings,with few attempts on Chinese callig...Evaluation of calligraphic copy is the core of Chinese calligraphy appreciation and in-heritance.However,previous aesthetic evaluation studies often focussed on photos and paintings,with few attempts on Chinese calligraphy.To solve this problem,a Siamese regression aesthetic fusion method is proposed,named SRAFE,for Chinese calligraphy based on the combination of calligraphy aesthetics and deep learning.First,a dataset termed Evaluated Chinese Calligraphy Copies(E3C)is constructed for aesthetic evalu-ation.Second,12 hand‐crafted aesthetic features based on the shape,structure,and stroke of calligraphy are designed.Then,the Siamese regression network(SRN)is designed to extract the deep aesthetic representation of calligraphy.Finally,the SRAFE method is built by fusing the deep aesthetic features with the hand‐crafted aesthetic features.Experimental results show that scores given by SRAFE are similar to the aesthetic evaluation label of E3C,proving the effectiveness of the authors’method.展开更多
For Automatic Optical Inspection (AOI) machines that were introduced to Printed Circuit Board market more than five years ago, illumination technique and light devices are outdated. Images captured by old AO...For Automatic Optical Inspection (AOI) machines that were introduced to Printed Circuit Board market more than five years ago, illumination technique and light devices are outdated. Images captured by old AOI machines are not easy to be recognized by typical optical character recognition (OCR) algorithms, especially for dark silk. How to effectively increase silk recognition accuracy is indispensable for improving overall production efficiency in SMT plant. This paper uses fine tuned Character Region Awareness for Text Detection (CRAFT) method to build model for dark silk recognition. CRAFT model consists of a structure similar to U-net, followed by VGG based convolutional neural network. Continuous two-dimensional Gaussian distribution was used for the annotation of image segmentation. CRAFT model is good at recognizing different types of printed characters with high accuracy and transferability. Results show that with the help of CRAFT model, accuracy for OK board is 95% (error rate is 5%), and accuracy for NG board is 100% (omission rate is 0%).展开更多
基金The study was supported by grant(project no.23-17-00218“Ecological tourism and recreational nature management in the North-East Caucasus”(https://rscf.ru/project/23-17-00218/))from the Russian Science Foundation.
文摘The North-East Caucasus is a multi-ethnic mountain macroregion with a rich cultural heritage,insufficiently studied in the context of the ecotourism development.To fill this gap and identify promising directions of environmentally safe forms of tourism,the author used in-depth review of modern literature to investigate the features of ecological tourism and the problems of preserving ethno-cultural heritage,and used historical and comparative-geographical methods to analyze the development of the tangible and intangible cultural heritage of the indigenous peoples of the North-Eastern Caucasus in different historical periods and to identify the geographical peculiarities of the distribution of historical and cultural monuments(tower buildings),pilgrimage sites and centers of traditional crafts and trades.As part of the planned expeditions,the author personally visited some historical monuments and handicraft centers for a deeper study of ethno-cultural heritage.The cartographic method made it possible to visualize the results.The results of the research show that the ethnocultural heritage of the North-East Caucasus is formed by material(historical and cultural monuments)and immaterial elements of culture(language,customs,traditions,ethnic identification)of those peoples,who live here.The ethnocultural heritage is considered as the most important factor in the development of the tourism industry.It is revealed that this region has a large potential for development in various areas of eco-tourism.The highest concentration of religious buildings focused in mountainous areas.Medieval tower structures were erected in mountainous and high-altitude areas.From ancient times to the present day there have been preserved various types of crafts and trades(pottery,metalworking,burka making,jewelry making,carpet weaving,gold embroidery,wood and stone carving,etc.),which can become objects of ecotourism.The ethnocultural heritage of the North-East Caucasus needs to be preserved and protected.To solve this problem,the author recommends to focus on a balanced combination of traditions and innovations in this industry,also considering the current state and development of the tourism industry in the country and in the world.The research highlights that the development of scientific approaches to plan and manage tourism development can contribute to the preservation of tangible and intangible cultural heritage of indigenous peoples.This is a complex and labour-intensive task,but its solution will have a multiplier effect in the social sphere,in economic development and in environmental security,which is in line with the principles and concept of sustainable development.
基金supported by the Talent Research Fund of Hefei University(No.21-22RC09)National Natural Science Foundation of China(No.U22A20225)。
文摘In the design realm of fusion power supplies,structural components play a pivotal role in ensuring the safety of fusion devices.To verify the reliability of the converter structure design at the Comprehensive Research Facility for Fusion Technology(CRAFT),meticulous analysis of the converter's dynamic impact is carefully performed based on the worst fault current(400k A),firstly.Subsequently,the thermal stress analysis based on the maximum allowable steadystate temperature is finished,and the equivalent thermal stress,thermal deformation,maximum shear stress of a single bridge arm and the whole converter are studied.Furthermore,a simple research method involving the current-sharing characteristics of a bridge arm with multithyristor parallel connection is proposed using a combination of Simplorer with Q3D in ANSYS.The results show that the current-sharing characteristics are excellent.Finally,the structural design has been meticulously tailored to meet the established requirements.
文摘Activity 1.Think about the following questions and write down your answers before reading the text.1.Do you know any traditional crafts?2.How can young people be encouraged to learn traditional crafts?
文摘This review explores the evolution of the textile handicraft industry in Saudi Arabia, emphasizing its cultural and economic significance. The study highlights the transition from traditional practices to modern innovations and examines the impact of globalization and technological advancements on the industry. Key innovations are discussed, demonstrating their role in enhancing textile production while preserving cultural heritage. Major challenges, such as competition from industrial textiles and the need for sustainable practices, are identified. Opportunities for growth are explored, including leveraging tourism and international markets to promote Saudi handicrafts. The social and cultural impacts of the sector are underscored, particularly in sustaining community traditions and providing economic opportunities for artisans. Strategic recommendations for supporting and advancing the industry are offered, ensuring its continued relevance and sustainability in a rapidly changing global market. This analysis provides a robust framework for understanding the current state and future potential of Saudi Arabia’s textile handicraft industry.
文摘单脉冲搜索作为脉冲星探测的有力工具,在探测旋转射电暂现源以及快速射电暴中扮演着重要角色。为了从海量的射电巡天数据中快速筛选出最有价值的单脉冲搜索候选体,候选体识别已经从早期启发式阈值判断发展到基于机器学习自动识别。对于FAST观测,研究了基于机器学习的单脉冲搜索候选体识别应用到CRAFTS(the commensal radio astronomy FAST survey)超宽带脉冲星数据的性能表现。在评估过程中,使用单脉冲事件组识别(SPEGID)和单脉冲搜索器(SPS)两类自动识别方法,通过7种不同机器学习分类器对CRAFTS基准数据集产生的单脉冲搜索候选体进行自动识别;作为对比,也使用了启发式阈值判断的方法(RRATtrap和Clusterrank)。结果表明,SPEGID具有最好的性能表现(最高的F1-score值95.1%、次高的召回率95.4%、最低的假阳性率4.7%),SPS具有最快的筛选速度(平均每小时筛选4010个候选体)。通过对比分析结果,探讨了如何基于FAST观测数据开展高效的单脉冲搜索候选体识别。
文摘Evaluation of calligraphic copy is the core of Chinese calligraphy appreciation and in-heritance.However,previous aesthetic evaluation studies often focussed on photos and paintings,with few attempts on Chinese calligraphy.To solve this problem,a Siamese regression aesthetic fusion method is proposed,named SRAFE,for Chinese calligraphy based on the combination of calligraphy aesthetics and deep learning.First,a dataset termed Evaluated Chinese Calligraphy Copies(E3C)is constructed for aesthetic evalu-ation.Second,12 hand‐crafted aesthetic features based on the shape,structure,and stroke of calligraphy are designed.Then,the Siamese regression network(SRN)is designed to extract the deep aesthetic representation of calligraphy.Finally,the SRAFE method is built by fusing the deep aesthetic features with the hand‐crafted aesthetic features.Experimental results show that scores given by SRAFE are similar to the aesthetic evaluation label of E3C,proving the effectiveness of the authors’method.
文摘For Automatic Optical Inspection (AOI) machines that were introduced to Printed Circuit Board market more than five years ago, illumination technique and light devices are outdated. Images captured by old AOI machines are not easy to be recognized by typical optical character recognition (OCR) algorithms, especially for dark silk. How to effectively increase silk recognition accuracy is indispensable for improving overall production efficiency in SMT plant. This paper uses fine tuned Character Region Awareness for Text Detection (CRAFT) method to build model for dark silk recognition. CRAFT model consists of a structure similar to U-net, followed by VGG based convolutional neural network. Continuous two-dimensional Gaussian distribution was used for the annotation of image segmentation. CRAFT model is good at recognizing different types of printed characters with high accuracy and transferability. Results show that with the help of CRAFT model, accuracy for OK board is 95% (error rate is 5%), and accuracy for NG board is 100% (omission rate is 0%).
