Purpose: This paper describes the strategies and practices of National Science Library(NSL),Chinese Academy of Sciences(CAS) in promoting open access(OA) and developing OA resources.Design/methodology/approach: Multi-...Purpose: This paper describes the strategies and practices of National Science Library(NSL),Chinese Academy of Sciences(CAS) in promoting open access(OA) and developing OA resources.Design/methodology/approach: Multi-facet frameworks are devised to guide the development of OA strategies and practices. Key OA initiatives are briefly described along the main aspects of the strategies as they contribute to implementation of the OA strategies.Findings: NSL defined its role as the Chief OA Officer for CAS and a key OA promoter for China. Accordingly,NSL has engaged in multiple fronts of promoting OA,including development of OA strategies for CAS,establishment of itself as an OA knowledge &promotion center,development of the CAS IR system,and support for OA publishing by CAS authors.Research limitations: OA is still evolving,so are the strategies and practices as many actions are experimental and explorative in nature. Open books,open data,and open educational resources are yet to be covered. Comparative studies are needed,so is the evidence-based impact analysis.Practical implications: Institutions can adopt,adapt,or compare with examples and lessons learned are described here.Originality/value: The multi-faceted frameworks,working principles,and lessons learned are based on NSL's practices which can be valuable to the overall OA development.展开更多
Metacognitive strategies are regarded as advanced strategies in all the learning strategies.This study focuses on the application of metacognitive strategies in English listening in the web-based self-access learning ...Metacognitive strategies are regarded as advanced strategies in all the learning strategies.This study focuses on the application of metacognitive strategies in English listening in the web-based self-access learning environment(WSLE) and tries to provide some references for those students and teachers in the vocational colleges.展开更多
Dynamic spectrum access(DSA) based on cognitive radios(CR) technique is an effective approach to address the "spectrum scarcity" issue. However, traditional CR-enabled DSA system employs only single DSA stra...Dynamic spectrum access(DSA) based on cognitive radios(CR) technique is an effective approach to address the "spectrum scarcity" issue. However, traditional CR-enabled DSA system employs only single DSA strategy, which might not be suited to the dynamic network environment. In this paper, we propose a multi-strategy DSA(MS-DSA) system, where the primary and the secondary system share spectrum resources with multiple DSA strategies simultaneously. To analyze the performance of the proposed MS-DSA system, we model it as a continuous-time Markov chain(CTMC) and derive the expressions to compute the corresponding performance metrics. Based on this, we define a utility function involving the concerns of effective throughput, interference quantity on primary users, and spectrum leasing cost. Two optimization schemes, named as spectrum allocation and false alarm probability selection, are proposed to maximize the utility function. Finally, numerical simulations are provided to validate our analysis and demonstrate that the performance can be significantly improved caused by virtues of the proposed MS-DSA system.展开更多
Cloud computing.based heterogeneous networks(C.Het Nets) have been considered as promising network architecture of future wireless communication systems. However, its performance is constrained by the capability of fr...Cloud computing.based heterogeneous networks(C.Het Nets) have been considered as promising network architecture of future wireless communication systems. However, its performance is constrained by the capability of fronthaul. To study the performance limit of C.Het Nets, the coverage performance of the open access strategy in C.Het Nets is analyzed in this paper. In particular, the non.ideal condition of fronthaul in C.Het Nets is characterized by establishing a stochastic geometry.based model, and a tight lower bound on coverage probability is derived for downlink transmissions. Based on the derived results, the constraint of the fronthaul is given to ensure that open access strategy can achieve the best coverage performance. Finally, the simulation results are provided to verify the theoretical results and show the impact of fronthaul constrains.展开更多
Cognitive radio is a promising technology that deals with the scarcity of radio spectrum. In this paper, we propose a new multi-channel transmission strategy for dynamic spectrum access in cognitive radio network. Sta...Cognitive radio is a promising technology that deals with the scarcity of radio spectrum. In this paper, we propose a new multi-channel transmission strategy for dynamic spectrum access in cognitive radio network. Starting with the model of spectrum activities, we present the multi-channel transmission strategy which has primary user's protection mechanism to improve the spectrum efficiency and study its performance under perfect and imperfect sensing. Numerical example results reveal that the performance of the proposed strategy has the superiority with respect to capacity performance of cognitive users and the protection of primary users.展开更多
Open access(OA) resources are becoming a main part of scholarly information. The paper summarizes the fast growth of OA journals and OA repositories, the outstanding OA journal impact increase, the rise of mega-OA jou...Open access(OA) resources are becoming a main part of scholarly information. The paper summarizes the fast growth of OA journals and OA repositories, the outstanding OA journal impact increase, the rise of mega-OA journals like PLoS ONE, the overwhelming support of research communities to open access of publicly funded research, and the quick building up of OA support structures. These forces work together to push scholarly communications toward a turning point where OA resources occupy a major and increasing share of scholarly research resources and when management of OA resources becomes a strategic, yet unfamiliar, and potentially disruptive task for research libraries. This paper is composed of two parts. The first part will focus on the development of OA resources, while the second part will analyze the challenges in management of OA resources and develop an OA resource strategy exemplified by some of NSL's initiatives.展开更多
该文运用空间分析工具和地理信息系统(Geographic Information System,GIS),探究了山东大学体育场所的空间分布与可达性情况,以期为山东大学体育设施的规划与建设提供参考和建议。研究结果表明:山东大学体育场所总体数量较少,分布不均衡,呈现...该文运用空间分析工具和地理信息系统(Geographic Information System,GIS),探究了山东大学体育场所的空间分布与可达性情况,以期为山东大学体育设施的规划与建设提供参考和建议。研究结果表明:山东大学体育场所总体数量较少,分布不均衡,呈现出以中心市区为最为集中、周边县区为补充的格局。同时,城市建成区或主城区域的体育场所的空间可达性较好,而城市郊区体育场所的可达性较差。针对以上问题,本研究提出了进一步提升体育设施的服务均等性、优化体育场所类型结构、优化财政分配多渠道集资的优化策略。以翼能为新时期山东大学体育场所的科学布局和合理运用提供参考,也为优化地方体育服务发展水平提供意见和建议。展开更多
As an important marine enterprise, marine scientific research serves to national marine strategy. Since the 21st century, with the development of international geopolitics, South Pacific in becoming an important sea a...As an important marine enterprise, marine scientific research serves to national marine strategy. Since the 21st century, with the development of international geopolitics, South Pacific in becoming an important sea area, so the marine scientific research in this sea area is becoming hot points. At present, extraterritorial nations including Germany, America, China and UK are conducting marine scientific research in this sea area mainly because of its abundant deep-sea resources, the need to protect marine environment and serving for marine strategic access. With deep-sea＇s technology improving continually, deep-sea resources in South Pacific will be explored further, marine scientific research cooperation＇s potential for extraterritorial nations will be great, so more and more nations will involve in conducting marine scientific research in South Pacific. As far as China is concerned, marine scientific research is not only the basis for it to practice marine strategy in South Pacific region, but also the important topic for it to cooperate with extraterritorial nations and pacific islands nations.展开更多
The High Speed Downlink Packet Access(HSDPA)technology is employed for the data service in the Time Division Synchronous Code Division Multiple Access(TD-SCDMA)mobile communication system.Theoretically,the HSDPA peak ...The High Speed Downlink Packet Access(HSDPA)technology is employed for the data service in the Time Division Synchronous Code Division Multiple Access(TD-SCDMA)mobile communication system.Theoretically,the HSDPA peak data throughput per Time Slot(TS)available in the terminals reaches 560kb/s.Since the data service often occurs indoors,flexible TS allocation between uplink and downlink is applied in TD-SCDMA networking.That is,TS1 and TS2 are uplink time slots and TS3,TS4,TS5 and TS6 are downlink time slots in the indoor cell;and symmetry TS allocation is made for the outdoor cell.In the intra-frequency cell network,it can cause intra-frequency interference between cells.So the research on the intra-frequency crossed time slots interference is done and the suggestions on the intra-frequency crossed time slots networking strategy are proposed in this paper.展开更多
With the rapid development of Internet of Things(IoT)service,the provision of network connection is vital for data transmission of widely deployed IoT devices.To provide the global coverage for IoT devices,non-terrest...With the rapid development of Internet of Things(IoT)service,the provision of network connection is vital for data transmission of widely deployed IoT devices.To provide the global coverage for IoT devices,non-terrestrial networks(NTN)has its inherent advantages with the help of satellite communication.In this paper,we propose a Q-learning based intelligent access strategy to make access control for IoT devices in NTN scenario.With satellite assistance,access control is optimized so that IoT devices can get the connection efficiently.IoT devices interact with the environment and learn gradually to find the proper RACH type,preamble and random access(RA)slot for success access.Besides,a novel RACH procedure is also designed with flexible access type selection between 2-step and 4-step RACH.With the corporation between IoT devices and network,access congestion can be avoided.Simulation results validate that the effectiveness of the proposed access strategy in terms of access efficiency,collision rate and access latency.展开更多
文摘Purpose: This paper describes the strategies and practices of National Science Library(NSL),Chinese Academy of Sciences(CAS) in promoting open access(OA) and developing OA resources.Design/methodology/approach: Multi-facet frameworks are devised to guide the development of OA strategies and practices. Key OA initiatives are briefly described along the main aspects of the strategies as they contribute to implementation of the OA strategies.Findings: NSL defined its role as the Chief OA Officer for CAS and a key OA promoter for China. Accordingly,NSL has engaged in multiple fronts of promoting OA,including development of OA strategies for CAS,establishment of itself as an OA knowledge &promotion center,development of the CAS IR system,and support for OA publishing by CAS authors.Research limitations: OA is still evolving,so are the strategies and practices as many actions are experimental and explorative in nature. Open books,open data,and open educational resources are yet to be covered. Comparative studies are needed,so is the evidence-based impact analysis.Practical implications: Institutions can adopt,adapt,or compare with examples and lessons learned are described here.Originality/value: The multi-faceted frameworks,working principles,and lessons learned are based on NSL's practices which can be valuable to the overall OA development.
文摘Metacognitive strategies are regarded as advanced strategies in all the learning strategies.This study focuses on the application of metacognitive strategies in English listening in the web-based self-access learning environment(WSLE) and tries to provide some references for those students and teachers in the vocational colleges.
基金supported in part by the National Natural Sciences Foundation of China (NSFC) under Grant 61525103the National Natural Sciences Foundation of China under Grant 61501140the Shenzhen Fundamental Research Project under Grant JCYJ20150930150304185
文摘Dynamic spectrum access(DSA) based on cognitive radios(CR) technique is an effective approach to address the "spectrum scarcity" issue. However, traditional CR-enabled DSA system employs only single DSA strategy, which might not be suited to the dynamic network environment. In this paper, we propose a multi-strategy DSA(MS-DSA) system, where the primary and the secondary system share spectrum resources with multiple DSA strategies simultaneously. To analyze the performance of the proposed MS-DSA system, we model it as a continuous-time Markov chain(CTMC) and derive the expressions to compute the corresponding performance metrics. Based on this, we define a utility function involving the concerns of effective throughput, interference quantity on primary users, and spectrum leasing cost. Two optimization schemes, named as spectrum allocation and false alarm probability selection, are proposed to maximize the utility function. Finally, numerical simulations are provided to validate our analysis and demonstrate that the performance can be significantly improved caused by virtues of the proposed MS-DSA system.
基金supported in part by the National Natural Science Foundation of China (Grant 61501045)in part by State Major Science and Technology Special Projects (Grant 2016ZX03001017-004)
文摘Cloud computing.based heterogeneous networks(C.Het Nets) have been considered as promising network architecture of future wireless communication systems. However, its performance is constrained by the capability of fronthaul. To study the performance limit of C.Het Nets, the coverage performance of the open access strategy in C.Het Nets is analyzed in this paper. In particular, the non.ideal condition of fronthaul in C.Het Nets is characterized by establishing a stochastic geometry.based model, and a tight lower bound on coverage probability is derived for downlink transmissions. Based on the derived results, the constraint of the fronthaul is given to ensure that open access strategy can achieve the best coverage performance. Finally, the simulation results are provided to verify the theoretical results and show the impact of fronthaul constrains.
基金Supported by National Natural Science Foundation of China (No. 60772062)863 Program (No. 2009AA01Z 241)
文摘Cognitive radio is a promising technology that deals with the scarcity of radio spectrum. In this paper, we propose a new multi-channel transmission strategy for dynamic spectrum access in cognitive radio network. Starting with the model of spectrum activities, we present the multi-channel transmission strategy which has primary user's protection mechanism to improve the spectrum efficiency and study its performance under perfect and imperfect sensing. Numerical example results reveal that the performance of the proposed strategy has the superiority with respect to capacity performance of cognitive users and the protection of primary users.
文摘Open access(OA) resources are becoming a main part of scholarly information. The paper summarizes the fast growth of OA journals and OA repositories, the outstanding OA journal impact increase, the rise of mega-OA journals like PLoS ONE, the overwhelming support of research communities to open access of publicly funded research, and the quick building up of OA support structures. These forces work together to push scholarly communications toward a turning point where OA resources occupy a major and increasing share of scholarly research resources and when management of OA resources becomes a strategic, yet unfamiliar, and potentially disruptive task for research libraries. This paper is composed of two parts. The first part will focus on the development of OA resources, while the second part will analyze the challenges in management of OA resources and develop an OA resource strategy exemplified by some of NSL's initiatives.
文摘该文运用空间分析工具和地理信息系统(Geographic Information System,GIS),探究了山东大学体育场所的空间分布与可达性情况,以期为山东大学体育设施的规划与建设提供参考和建议。研究结果表明:山东大学体育场所总体数量较少,分布不均衡,呈现出以中心市区为最为集中、周边县区为补充的格局。同时,城市建成区或主城区域的体育场所的空间可达性较好,而城市郊区体育场所的可达性较差。针对以上问题,本研究提出了进一步提升体育设施的服务均等性、优化体育场所类型结构、优化财政分配多渠道集资的优化策略。以翼能为新时期山东大学体育场所的科学布局和合理运用提供参考,也为优化地方体育服务发展水平提供意见和建议。
文摘As an important marine enterprise, marine scientific research serves to national marine strategy. Since the 21st century, with the development of international geopolitics, South Pacific in becoming an important sea area, so the marine scientific research in this sea area is becoming hot points. At present, extraterritorial nations including Germany, America, China and UK are conducting marine scientific research in this sea area mainly because of its abundant deep-sea resources, the need to protect marine environment and serving for marine strategic access. With deep-sea＇s technology improving continually, deep-sea resources in South Pacific will be explored further, marine scientific research cooperation＇s potential for extraterritorial nations will be great, so more and more nations will involve in conducting marine scientific research in South Pacific. As far as China is concerned, marine scientific research is not only the basis for it to practice marine strategy in South Pacific region, but also the important topic for it to cooperate with extraterritorial nations and pacific islands nations.
文摘The High Speed Downlink Packet Access(HSDPA)technology is employed for the data service in the Time Division Synchronous Code Division Multiple Access(TD-SCDMA)mobile communication system.Theoretically,the HSDPA peak data throughput per Time Slot(TS)available in the terminals reaches 560kb/s.Since the data service often occurs indoors,flexible TS allocation between uplink and downlink is applied in TD-SCDMA networking.That is,TS1 and TS2 are uplink time slots and TS3,TS4,TS5 and TS6 are downlink time slots in the indoor cell;and symmetry TS allocation is made for the outdoor cell.In the intra-frequency cell network,it can cause intra-frequency interference between cells.So the research on the intra-frequency crossed time slots interference is done and the suggestions on the intra-frequency crossed time slots networking strategy are proposed in this paper.
基金supported by the Mobile Information Networks-National Science and Technology Major Project(No.2025ZD1302500).
文摘With the rapid development of Internet of Things(IoT)service,the provision of network connection is vital for data transmission of widely deployed IoT devices.To provide the global coverage for IoT devices,non-terrestrial networks(NTN)has its inherent advantages with the help of satellite communication.In this paper,we propose a Q-learning based intelligent access strategy to make access control for IoT devices in NTN scenario.With satellite assistance,access control is optimized so that IoT devices can get the connection efficiently.IoT devices interact with the environment and learn gradually to find the proper RACH type,preamble and random access(RA)slot for success access.Besides,a novel RACH procedure is also designed with flexible access type selection between 2-step and 4-step RACH.With the corporation between IoT devices and network,access congestion can be avoided.Simulation results validate that the effectiveness of the proposed access strategy in terms of access efficiency,collision rate and access latency.
