检索结果-内蒙古大学图书馆

Compact 517 MHz soliton mode-locked Er-doped fiber ring laser

Photonics Research 2016年第1期4卷 27-29页

作者： Jian Zhang Ziyun Kong Yizhou Liu Aimin Wang Zhigang Zhang State Key Laboratory of Advanced Optical Communication System and Networks School of Electronics Engineering and Computer Science Peking University

We report on a compact passive mode-locked Er:fiber ring laser operated at the fundamental repetition rate of 517 MHz, which we believe is the highest fundamental repetition rate ever reported in a ring cavity fiber *** key technique is the employment of two innovative high-power wavelength domain multiplexer collimators with all gain fiber cavity suited for the high power(up to 2 W) pumping. The laser is featured with a direct chirpfree output pulse, which is 97 fs without extracavity compression at an average output power of 90 mW.

关键词： mode rate Compact 517 MHz soliton mode-locked Er-doped fiber ring laser ring

来源：评论

学校读者我要写书评

暂无评论

Interoperability and security challenges of Industrie 4.0 47

Interoperability and security challenges of Industrie 4.0

引用

47. Jahrestagung der Gesellschaft fur Informatik, Informatik 2017 - 47th Annual Meeting of the German Informatics Society (GI), Informatics 2017

作者： Watson, Venesa Tellabi, Asmaa Sassmannshausen, Jochen Lou, Xinxin University of Siegen Faculty of Science and Engineering Chair for Data Communication Systems Hölderlinstraße 3 Siegen57068 Germany Bielefeld University Department of Computer Networks and Distributed Systems Universitätsstraße 25 Bielefeld33615 Germany

ISBN: (纸本)9783885796695

Industrie 4.0 (I4.0) is the fourth industrial revolution, which will see the digital transformation of manufacturing, through the integration on Industrial Internet of Things (IIoT), Data and Services, and the convergence of Information Technology (IT) and Operational Technology (OT). With any such transformation, there exists challenges that must first be addressed for a successful outcome. For I4.0, these are interoperability and security, which respectively arise from the interconnection of devices from different manufacturers and/or with different communication protocols;and the interconnection of networks with competing critical and non-critical traffic, and the increased access to initially isolated networks. This paper presents an overview of standards, such as IEC 62443, the ISO 27000 series, IEC 62541 Open Connectivity Unified Architecture (OPC UA) and Time Sensitive networks (TSN) (IEEE 1722-2016), which addresses these challenges. © 2017 Gesellschaft fur Informatik (GI). All rights reserved.

关键词： Interoperability

来源：评论

学校读者我要写书评

暂无评论

Towards SDN Based Queuing Delay Estimation

引用

China communications 2016年第3期13卷 27-36页

作者： MA Haiyan YAN Jinyao Panagiotis Georgopoulos Bernhard Plattner Faculty of Science and Technology Communication University of China Computer Engineering and Networks Laboratory Swiss Federal Institute of Technology Zurich (ETH Zurich)

As one of Qo S(Quality of Service) metrics, delay is critical important to delay sensitive applications, such as interactive video, network game and online surgery. In this paper, we exploit SDN(Software Defined Networking) advantages to solve delay Qo S problem. Our work mainly focuses on SDN based queuing delay estimation with real traffic and end-to-end delay control. First, we propose a queuing estimation model and extended it for end-to-end delay of the whole path. It is proved to be feasible and accurate with experimental results in SDN environment. Second, in order to demonstrate the use of our proposed model, we also implement an end-to-end delay control application in SDN. It fulfills specific delay Qo S requirements by dynamically switching flows to a suitable queue based on estimation results and delay requirements.

关键词： autonomic Qo S dynamic model delay performance SDN

来源：评论

学校读者我要写书评

暂无评论

SGsim: Co-simulation framework for ICT-enabled power distribution grids 18th

SGsim: Co-simulation framework for ICT-enabled power distrib...

引用

18th International GI/ITG Conference on Measurement, Modelling and Evaluation of Computing Systems and Dependability and Fault Tolerance, MMB and DFT 2016

作者： Awad, Abdalkarim Bazan, Peter German, Reinhard Computer Networks and Communication Systems Department of Computer Science University of Erlangen Erlangen Germany

ISBN: (纸本)9783319315584

Empowering power grids with ICT is fundamental for the future power grid. Simulation plays an essential role for evaluating emerging smart grid applications. The presented co-simulation framework SGsim is based on two main simulators, OMNeT++ and Open DSS. With newly added components, smart grid applications in the electricity distribution network can now be investigated and evaluated. Conservation Voltage Reduction (CVR) is a mechanism to reduce the power demand which eventually will reduce the energy consumption. In a case study, the co-simulation framework is used to explore the potential energy saving by applying a closed-loop CVR inside a residential power grid. © Springer International Publishing Switzerland 2016.

关键词： Smart power grids

来源：评论

学校读者我要写书评

暂无评论

Label distribution learning forests 17

Label distribution learning forests

引用

Proceedings of the 31st International Conference on Neural Information Processing Systems

作者： Wei Shen Kai Zhao Yilu Guo Alan Yuille Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai Institute for Advanced Communication and Data Science School of Communication and Information Engineering Shanghai University and Department of Computer Science Johns Hopkins University Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai Institute for Advanced Communication and Data Science School of Communication and Information Engineering Shanghai University Department of Computer Science Johns Hopkins University

ISBN: (纸本)9781510860964

Label distribution learning (LDL) is a general learning framework, which assigns to an instance a distribution over a set of labels rather than a single label or multiple labels. Current LDL methods have either restricted assumptions on the expression form of the label distribution or limitations in representation learning, e.g., to learn deep features in an end-to-end manner. This paper presents label distribution learning forests (LDLFs) - a novel label distribution learning algorithm based on differentiable decision trees, which have several advantages: 1) Decision trees have the potential to model any general form of label distributions by a mixture of leaf node predictions. 2) The learning of differentiable decision trees can be combined with representation learning. We define a distribution-based loss function for a forest, enabling all the trees to be learned jointly, and show that an update function for leaf node predictions, which guarantees a strict decrease of the loss function, can be derived by variational bounding. The effectiveness of the proposed LDLFs is verified on several LDL tasks and a computer vision application, showing significant improvements to the state-of-the-art LDL methods.

关键词：

来源：评论

学校读者我要写书评

暂无评论

QoE aware placement of content in edge networks on the example of a photo album cloud service 6

QoE aware placement of content in edge networks on the examp...

引用

6th IEEE International Conference on communications and Electronics, IEEE ICCE 2016

作者： Dinh-Xuan, Lam Seufert, Michael Wamser, Florian Tran-Gia, Phuoc Department of Communication Networks Institute of Computer Science University of Wurzburg Germany

ISBN: (纸本)9781509019311

The paradigm of Software as a Service has gained great achievements in the last decade. By transferring computation and storage to the cloud and migrating services to the edge network, users benefit from using demanding services on lightweight devices. However, the user perceived quality of experience (QoE) for these services is facing the challenges of network impairments and the accessibility of users. Unlike a typical PC-based software, the cloud provides users a location-Aware, flexible placement of resource for a cost effective service. The geographical placement of content is therefore one of the key factors that affects the user's satisfaction. The closer the content to the user geographically is, the faster it will be delivered to the user that will also increase the user perceived QoE. In this work, we estimate more precisely the QoE for photo loading time in a particular usage of a photo album cloud service with regard to the influence of various parameters. Firstly, we validate a TCP throughput model and use it to calculate the photo loading time from a given photo size and network QoS. Thereafter, we formulate a mapping function to calculate the MOS value from a QoE model adding the output of the TCP model. From this mapping function, we can estimate QoE for photo loading time from a given photo size, its placement and network QoS. Our main contribution is to determine the tradeoff between the size of photo and its placement to acquire a high QoE for photo loading time, which is important for the development of a photo album cloud service. © 2016 IEEE.

关键词： Mapping

来源：评论

学校读者我要写书评

暂无评论

Single-RF multi-antenna transmission with peak power constraint

Single-RF multi-antenna transmission with peak power constra...

引用

作者： Zhou, Lin Khan, Fahd Ahmed Ratnarajah, Tharmalingam Papadias, Constantinos B. Institute for Digital Communication School of Engineering University of Edinburgh EdinburghEH8 9YL United Kingdom School of Electrical Engineering and Computer Science National University of Science and Technology Islamabad Pakistan Broadband Wireless and Sensor Networks Research Group Athens Information Technology Athens15125 Greece

—Electronically steerable parasitic array radiator (ESPAR) technology enables the implementation of antenna arrays of a number of elements with a single radio frequency (RF) source. Two approaches to achieve stable transmission using an ESPAR antenna (EA) are to increase the self-resistance of an EA or to transmit signals closely approximating the actual signals that keep the EA stable. Both approaches did not take into account the impact of limited power on an EA transmission, which is a practical constraint on power amplifier design. We propose a new transmission scheme to enable an EA to provide stable multiple antenna functionality taking into account the instantaneous total power requirement. This problem is formulated as a non-convex optimization problem and it is solved analytically by coordinate transformation and geometric analysis. The optimal approximate signals are obtained using root finding and interior-point algorithms. Moreover, it is shown through simulations that our proposed scheme achieves similar symbol error rate performance to that of the standard multiple antenna transmitter with multiple RF chains under power limited single-user and multi-user transmission scenarios. Furthermore, it is shown that increasing the self-resistance of an EA to achieve stability is highly power inefficient. © 2017 IEEE.

关键词： Power amplifiers

来源：评论

学校读者我要写书评

暂无评论

A secure and high-performance multi-controller architecture for software-defined networking

引用

Frontiers of Information Technology & Electronic Engineering 2016年第7期17卷 634-646页

作者： Huan-zhao WANG Peng ZHANG Lei XIONG Xin LIU Cheng-chen HU Department of Computer Science and Technology Xi'an Jiaotong UniversityXi'an 710059China Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory Shijiazhuang 050081China MOE Key Laboratory for Intelligent Networks and Network Security Xi'an Jiaotong UniversityXi'an 710049China

Controllers play a critical role in software-defined networking(SDN).However,existing singlecontroller SDN architectures are vulnerable to single-point failures,where a controller's capacity can be saturated by flooded flow *** addition,due to the complicated interactions between applications and controllers,the flow setup latency is relatively *** address the above security and performance issues of current SDN controllers,we propose distributed rule store(DRS),a new multi-controller architecture for *** DRS,the controller caches the flow rules calculated by applications,and distributes these rules to multiple controller *** controller instance holds only a subset of all rules,and periodically checks the consistency of flow rules with each *** from switches are distributed among multiple controllers,in order to mitigate controller capacity saturation *** the same time,when rules at one controller are maliciously modified,they can be detected and recovered in *** implement DRS based on Floodlight and evaluate it with extensive *** results show that DRS can effectively maintain a consistently distributed rule store,and at the same time can achieve a shorter flow setup time and a higher processing throughput,compared with ONOS and Floodlight.

关键词： Software-defined networking(SDN) Security Multi-controller Distributed rule store

来源：评论

学校读者我要写书评

暂无评论

Increasing secret key capacity of OFDM systems: a geometric program approach

Increasing secret key capacity of OFDM systems: a geometric ...

引用

作者： Cheng, Longwang Li, Wei Zhou, Li Zhu, Chunsheng Wei, Jibo Guo, Yantao School of Electronic Science and Engineering National University of Defense Technology Changsha410073 China Department of Electrical and Computer Engineering The University of British Columbia VancouverBCV6T 1Z1 Canada Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory Shijiazhuang050000 China

Extracting secret keys from the common randomness of wireless channels has attracted prominent attention recently. Orthogonal frequency-division multiplexing (OFDM) systems can provide extra randomness in view of the use of multiple subchannels. So far, the secret key capacity of OFDM systems is still an open issue. In this paper, the secret key capacity of OFDM systems based on the subchannel state information is analyzed, and an expression of the secret key capacity is derived under the assumption that the subchannels are independent. To increase the secret key capacity, a power allocation scheme based on geometric program is proposed. Furthermore, an underlying propagation protocol is designed to realize the power allocation scheme. Performance simulations show that the proposed scheme achieves greater secret key capacity in comparison with equal power allocation scheme, especially at low signal-to-noise ratio region. Besides, the secret key bits mismatch rate during the secret key generation based on the power allocated subchannels is decreased. Copyright © 2016 John Wiley & Sons, Ltd.

关键词： Orthogonal frequency division multiplexing

来源：评论

学校读者我要写书评

暂无评论

Overlapping Coalition Formation Game Based Opportunistic Cooperative Localization Scheme for Wireless networks

Overlapping Coalition Formation Game Based Opportunistic Coo...

引用

作者： Zhang, Rongqing Zhao, Zijun Cheng, Xiang Yang, Liuqing State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Peking University Beijing100080 China Department of Electrical and Computer Engineering Colorado State University Fort CollinsCO80523 United States Research Center for Development Strategy China Electronics Technology Group Corporation Beijing100041 China

Cooperative localization has emerged as a promising technique which can complement or even replace global positioning systems (GPS) in many practical scenarios, such as GPS-denied environments. In this paper, we concentrate on the distributed cooperative localization design. The conventional distributed cooperative localization approaches usually yield high computational complexity and communication overhead, due to the lack of an efficient link selection mechanism. For this purpose, we propose a novel concept named opportunistic cooperative localization, based on which each agent is able to select the most informative links rather than utilize all the possible links in a distributed, self-organized, and self-optimized manner. To achieve effective opportunistic selection, overlapping coalition formation (OCF) game is employed. In addition, we also provide an optimized terminating criterion, based on which the agents will be able to know whether and when they are well localized, and thus can terminate their localization procedure efficiently. Through simulations, we observe that by virtue of the proposed OCF game based opportunistic cooperative localization scheme along with the provided terminating criterion, the limitations of conventional distributed cooperative localization can be alleviated at the cost of negligible performance degradation. © 1972-2012 IEEE.

关键词： Global positioning system

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：