Eddy current quantitative evaluation of high-speed railway contact wire cracks based on neural network

Purpose–The purpose of this study is to study the quantitative evaluation method of contact wire cracks by analyzing the changing law of eddy current signal characteristics under different cracks of contact wire of high-speed railway so as to provide a new way of thinking and method for the detection of contact wire injuries of high-speed railway.Design/methodology/approach–Based on the principle of eddy current detection and the specification parameters of high-speed railway contact wires in China,a finite element model for eddy current testing of contact wires was established to explore the variation patterns of crack signal characteristics in numerical simulation.A crack detection system based on eddy current detection was built,and eddy current detection voltage data was obtained for cracks of different depths and widths.By analyzing the variation law of eddy current signals,characteristic parameters were obtained and a quantitative evaluation model for crack width and depth was established based on the back propagation(BP)neural network.Findings–Numerical simulation and experimental detection of eddy current signal change rule is basically consistent,based on the law of the selected characteristics of the parameters in the BP neural network crack quantitative evaluation model also has a certain degree of effectiveness and reliability.BP neural network training results show that the classification accuracy for different widths and depths of the classification is 100 and 85.71%,respectively,and can be effectively realized on the high-speed railway contact line cracks of the quantitative evaluation classification.Originality/value–This study establishes a new type of high-speed railway contact wire crack detection and identification method,which provides a new technical means for high-speed railway contact wire injury detection.The study of eddy current characteristic law and quantitative evaluation model for different cracks in contact line has important academic value and practical significance,and it has certain guiding significance for the detection technology of contact line in high-speed railway.

Network Analysis of Research Project Members in Grant-in-Aid for Scientific Research in Japan

The researcher network that appeared in research projects funded by the Japanese government was analyzed. Several static and dynamic network analysis methods were applied to the data for 20 years to explore the fine structure of the researcher’s network for grants. Our analysis shows that the long-term trend of researchers’ group sizes has become smaller, particularly rapidly decreasing in recent years. Some findings on researcher behavior in joining a project have also been reported.

China's landscape in oncology drug research:perspectives from research collaboration networks

Objective： Better understanding of China＇s landscape in oncology drug research is of great significance for discovering anti-cancer drugs in future. This article differs from previous studies by focusing on Chinese oncology drug research communities in co-publication networks at the institutional level. Moreover, this research aims to explore structures and behaviors of relevant research units by thematic community analysis and to address policy recommendations. Methods： This research used social network analysis to define an institutions network and to identify a community network which is characterized by thematic content. Results： A total of 675 sample articles from 2008 through 2012 were retrieved from the Science Citation Index Expanded （SCIE） database of Web of Science, and top institutions and institutional pairs are highlighted for further discussion. Meanwhile, this study revealed that institutions based in the Chinese mainland are located in a relatively central position, Taiwan＇s institutions are closely assembled on the side, and Hong Kong＇s units located in the middle of the Chinese mainland＇s and Taiwan＇s. Spatial division and institutional hierarchy are still critical barriers to research collaboration in the field of anti-cancer drugs in China. In addition, the communities focusing on hot research areas show the higher nodal degree, whereas communities giving more attention to rare research subjects are relatively marginalized to the periphery of network. Conclusions= This paper offers policy recommendations to accelerate cross-regional cooperation, such as through developing information technology and increasing investment. The brokers should focus more on outreach to other institutions. Finally, participation in topics of common interest is conducive to improved efficiency in research and development （R＆D） resource allocation.

THE CHINESE ECOLOGICAL RESEARCH NETWORK

ＴＨＥＣＨＩＮＥＳＥＥＣＯＬＯＧＩＣＡＬＲＥＳＥＡＲＣＨＮＥＴＷＯＲＫＺｈａｏＪｉａｎｐｉｎｇ（赵剑平）（ＢｕｒｅａｕｏｆＲｅｓｏｕｒｃｅｓａｎｄＥｎｖｉｒｏｎｍｅｎｔａｌＳｃｉｅｎｃｅｓ，ｔｈｅＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅ...

Extracting a Heterogeneous Social Network of AcademicResearchers on the Web Based on Information Retrieved from Multiple Sources

The majority of academic researchers present the results of their scientific activity on the Web. This trace can be used to derive useful information of their past, present activity and forecast the future intentions. Hence, social network of academic researchers can be of important value for scientific community. This information can be retrieved from various data source currently available on the Web. From each of them a separate net-work can be built. In this paper we present a method which can be used to combine multiple single-relational networks into a single network which will combine all relations, hence it will be multi-relational.

Chinese Ecosystem Research Network

The article analyzes the development of the Chinese Ecosystem Research Network, and its mission, mandate, and management mechanisms, with examples of research, demonstration and consultation for policy-setting.

EQUATOR Network Library for health research reporting

Introduction EQUATOR Network provides unique access to collated expertise and resources for good reporting of health research, The resources are aimed at researchers （authors of research articles）, journal editors, peer reviewers, and developers of reporting guidelines,

Open Access to Geological Research of China— "Geoscience Periodical Network of China"

"Geoscience Periodical Network of China"is composed of 233 Chinese geological journals,which covers all kinds of geological research fields of China.All papers of this site comprise English abstract,and some papers have figures with English description.Papers present as the PDF format with two types:(1)papers can be downloaded for opening access;and(2)the others

Research Status of Network Attachment Subsystem in NGN

The Network Attachment Subsystem (NASS) is introduced to the Next Generation Network (NGN) architecture to enable services independent from access networks and support nomadism for fixed terminals. The NASS is responsible for managing the users attached to the access network in terms of user authentication, allocation of the IP address, and location management. In NGN R1, Telecommunications and Internet Converged Services and Protocols for Advanced Networking (TISPAN) studied the internal architecture and external interface protocols of NASS and published the relevant technical specifications. In NGN R2, TISPAN focuses on the study of mobility and nomadism as well as the ability to support various access network architectures. There still remain several issues that need further study.

Operation Research Based Techniques in Wireless Sensors Networks

In recent years, we have seen an increasing interest in developing and designing Wireless Sensor Networks (WSNs). WSNs consist of large number of nodes, with wireless communications and computation abilities that can be used in variety of domains. It has been used in areas that have direct contact with monitoring and gathering data, to name few, health monitoring, military surveillance, geological monitoring (Earthquakes, Volcanoes, Tsunami), agriculture control and many more. However, the design and implementation of WSNs face many challenges, due to the power limitation of sensor nodes, deployment and localization, data routing and data aggregation, data security, limited bandwidth, storage capacity and network management. It is known that Operation Research (OR) has been widely used in different areas to solve optimization problems;such as improving network performance and maximizing lifetime of system. In this survey, we present the most recent OR based techniques applied to solve different WSNs problems: the node scheduling problem, energy management problems, nodes allocating issues and other WSNs related complex problems. Different Operational Research techniques are presented and discussed in details here, including graph theory based techniques, linear programing and mixed integer programming related approaches.

Building African Ecosystem Research Network for Sustaining Local Ecosystem Goods and Services

A new form of producing and sharing knowledge has emerged as an international(United States of America,Asia,and Europe) research collaboration,known as the Long-Term Ecological Research(LTER) Network.Although Africa boasts rich biodiversity,including endemic species,it lacks the long-term initiatives to underpin sustainable biodiversity managements.At present,climate change may exacerbate hunger and poverty concerns in addition to resulting in ecosystem degradation,land use change,and other threats in Africa.Therefore,ecosystem monitoring was suggested to understanding the effects of climate change and setting strategies to mitigate these changes.This paper aimed to investigate ecosystem monitoring ground sites and address their coverage gaps in Africa to provide a foundation for optimizing the African Ecosystem Research Network(AERN) ground sites.The geographic coordinates and characteristics of ground sites-based ecosystem monitoring were collected from various networks aligned with the LTER implementation in Africa.Additionally,climatic data and biodiversity distribution maps were retrieved from various sources.These data were used to assess the size of existing ground sites and the gaps in description,ecosystems and biomes.The results reveal that there were 1089 sites established by various networks.Among these sites,30.5%,27.5%,and 28.8% had no information of area,year of establishment,current status,respectively.However,68.0% of them had an area equal to or greater than 1 km2.Sites were created progressively over the course of the years,with 68.9% being created from 2000 to 2005.To date,only 41.5% of the sites were operational.The sites were scattered across Africa,but they were concentrated in Eastern and Southern Africa.The unbalanced distribution pattern of the sites left Central and Northern Africa hardly covered,and many unique ecosystems in Central Africa were not included.To sustain these sites,the AERN should be based on operational sites,seeking secure funding by establishing multiple partnerships.

Open Access to Geological Research of China--"Geoscience Periodical Network of China"

＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/

Research on Traffic Identification Technologies for Peer-to-Peer Networks

The Peer-to-Peer(P2P)network traffic identification technology includes Transport Layer Identification(TLI)and Deep Packet Inspection(DPI)methods.By analyzing packets of the transport layer and the traffic characteristic in the P2P system,TLI can identify whether or not the network data flow belongs to the P2P system.The DPI method adopts protocol analysis technology and reverting technology.It picks up data from the P2P application layer and analyzes the characteristics of the payload to judge if the network traffic belongs to P2P applications.Due to its accuracy,robustness and classifying ability,DPI is the main method used to identify P2P traffic.Adopting the advantages of TLI and DPI,a precise and efficient technology for P2P network traffic identification can be designed.

Research and Design of IPv6 Network Management and Operations Support System

IPv6 is the foundation of the development of Next Generation Internet (NGI). An IPv6 network management and operations support system is necessary for real operable NGI. Presently there are no approved standards yet and relevant equipment interfaces are not perfect. A Network Management System (NMS) at the network layer helps implement the integrated management of a network with equipment from multiple vendors, including the network resources and topology, end-to-end network performance, network failures and customer Service Level Agreement (SLA) management. Though the NMS will finally realize pure IPv6 network management, it must be accommodated to the management of relevant IPv4 equipment. Therefore, modularized and layered structure is adopted for the NMS in order to implement its smooth transition.

有组织教研:人工智能环境下教师研修的有序进化

传统教师教研形式因客观性不强、持续性不够、衔接性不足,与时代所需要的高质量教研相悖,影响了教师的专业发展。基于生态进化理论,建构以人工智能技术为教师提供选题、过程支持、资源制度、工具辅助和协同机制的有组织教研模式,以提升教研与教师的个体适配,形成有组织的多主体行动网络,并在有序原理和整体原理的框架下,建构了智能技术支持的教师有组织教研运行模型。有组织教研的关键问题是教师动态需求的系统捕获、内容进化的智能控制、自适应路径的有效调节、研修空间的适应性调整、语义关联的建立,并形成面对理论与实践冲突、转化机制异化、主体与相关要素不适切等问题的处理机制。要实现人工智能支持的有组织教研,需要按照有组织教研的运行建立设计人工智能元平台,布局大数据采集平台,开发教育人工智能的算力,并在制度和理念的双向演进中通过实践进行优化,实现人工智能下教师研修模式的迭代。

科学数据网络:概念、系统与应用

【应用背景】科学数据具有分散化、差异化、孤岛化等典型特征,构建可打破各种孤岛、有效整合分布式科学数据资源的基础设施具有重要意义。【方法】本文梳理了国内外类网络科学数据平台、技术与系统的进展,阐明了科学数据网络的概念、特征、功能与关键技术,并针对新型科研范式下科学数据的协作利用需求,提出并设计了科学数据协作网络RDCN。【结论】科学数据网络可有效改善科学数据的分散化、差异化、孤岛化问题,RDCN在生物多样性研究、生态系统野外台站观测研究、多信使天文学研究等融合科学协作场景中将发挥重大的作用。

深度学习在多核缓存预取中的应用研究综述

当前人工智能技术应用于系统结构领域的研究前景广阔,特别是将深度学习应用于多核架构的数据预取研究已经成为国内外的研究热点。针对基于深度学习的缓存预取任务进行了研究,形式化地定义了深度学习缓存预取模型。在介绍当前常见的多核缓存架构和预取技术的基础上,全面分析了现有基于深度学习的典型缓存预取器的设计思路。深度学习神经网络在多核缓存预取领域的应用主要采用了深度神经网络、循环神经网络、长短期记忆网络和注意力机制等机器学习方法,综合对比分析现有基于深度学习的数据预取神经网络模型后发现,基于深度学习的多核缓存预取技术在计算成本、模型优化和实用性等方面还存在着局限性,未来在自适应预取模型以及神经网络预取模型的实用性方面还有很大的研究探索空间和发展前景。

基于PMC指数模型的“十四五”基础教育数字化转型政策评价——以江浙沪地区为例

“十四五”是我国推进基础教育数字化转型的关键阶段,区域政策的制订和引领至关重要,因此有必要对其进行科学的评价和全面的审视。江浙沪是基础教育数字化转型的示范地区,相关政策的科学性和有效性值得深入研究。首先,运用社会网络分析和扎根理论研究对全国29份相关政策文件进行文本挖掘,在此基础上构建基于PMC指数模型的评价指标体系。其次,针对江浙沪地区“十四五”期间八份政策样本进行PMC指数计算,并绘制PMC曲面图,得出政策评价结果(1份优秀、6份良好、1份及格)。再次,基于评价数据发现,相关政策在制定过程中目标规划长远、制度保障完善、政策重点分布广泛合理,且地域间各具特色,但在政策时效、课程建设、教育公平等领域还存在一定问题。最后,综合研究结果和实际情况,地方政府应细化政策阶段目标、提升教育公平认同感、加强课程建设和建立跨省沟通机制。