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Considering Pigeons for Carrying Delay Tolerant Networking Based Internet Traffic in Developing Countries

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THE ELECTRONIC JOURNAL OF INFORMATION systems IN DEVELOPING COUNTRIES 2017年第1期54卷

作者： Jeremiah Scholl Anders Lindgren Health Informatics Centre Karolinska Institutet Sweden Communication Networks and Systems Lab Swedish Institute of Computer Science Sweden

There are many regions in the developing world that suffer from poor infrastructure and lack of connection to the Internet and Public Switched Telephone networks (PSTN). Delay Tolerant Networking (DTN) is a technology that has been advocated for providing store-and-forward network connectivity in these regions over the past few years. DTN often relies on human mobility in one form or another to support transportation of DTN data. This presents a socio-technical problem related to organizing how the data should be transported. In some situations the demand for DTN traffic can exceed that which is possible to support with human mobility, so alternative mechanisms are needed. In this paper we propose using live carrier pigeons (columba livia) to transport DTN data. Carrier pigeons have been used for transporting packets of information for a long time, but have not yet been seriously considered for transporting DTN traffic. We provide arguements that this mode of DTN data transport provides promise, and should receive attention from research and development projects. We provide an overview of pigeon characteristics to analyze the feasibility of using them for data transport, and present simulations of a DTN network that utilizes pigeon transport in order to provide an initial investigation into expected performance characteristics.

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Marrying safety with privacy: A holistic solution for location privacy in VANETs

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Marrying safety with privacy: A holistic solution for locati...

IEEE Vehicular Networking Conference (VNC)

作者： David Eckhoff Christoph Sommer Computing and Information Systems Department The University of Melbourne Australia Computer Networks and Communication Systems University of Erlangen Germany Dept. of Computer Science Paderborn University Germany

ISBN: (纸本)9781509051984

Existing privacy measures often conflict with the requirements of future vehicular networks. First and foremost, in attempting to achieve local privacy, they interfere with the primary purpose of vehicular networks: to improve road safety. Other solutions undermine accountability or introduce too high overhead to be of practical use. For this reason, proper privacy protection is disregarded in many field experiments, proposals, and standardization documents. In this paper, we take a structured approach to deriving a holistic solution for location privacy protection in Vehicular Ad-Hoc networks (VANETs): Under reasonable assumptions about an adversary's capability, local privacy is neither required nor can it be achieved without compromising traffic safety. Our approach is therefore based on synchronized time-slotted pseudonym pools and the local announcing of pseudonym changes. By this, we overcome the privacy-safety problem while at the same time increasing privacy for all users. Our system is fully compatible with the requirements of vehicular networks and current standardization efforts.

关键词： Privacy Vehicles Safety Proposals Standards Ad hoc networks

Atomic clock performance beyond the geodetic limit

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arXiv 2018年

作者： McGrew, W.F. Zhang, X. Fasano, R.J. Schaffer, S.A. Beloy, K. Nicolodi, D. Brown, R.C. Hinkley, N. Milani, G. Schioppo, M. Yoon, T.H. Ludlow, A.D. National Institute of Standards and Technology 325 Broadway BoulderCO80305 United States Department of Physics University of Colorado BoulderCO80309 United States State Key Laboratory of Advanced Optical Communication Systems and Networks Institute of Quantum Electronics School of Electronics Engineering and Computer Science Peking University Beijing100871 China Niels Bohr Institute University of Copenhagen Blegdamsvej 17 Copenhagen2100 Denmark Georgia Tech Research Institute AtlantaGA30332 United States Stable Laser Systems BoulderCO80301 United States Istituto Nazionale di Ricerca Metrologica Strada delle Cacce 91 Torino10135 Italy Politecnico di Torino Corso duca degli Abruzzi 24 Torino10125 Italy TeddingtonTW110LW United Kingdom Department of Physics Korea University 145 Anam-ro Seongbuk-gu Seoul02841 Korea Republic of

The passage of time is tracked by counting oscillations of a frequency reference, such as Earth's revolutions or swings of a pendulum. By referencing atomic transitions, frequency (and thus time) can be measured more precisely than any other physical quantity, with the current generation of optical atomic clocks reporting fractional performance below the 10-17level1-5. However, the theory of relativity prescribes that the passage of time is not absolute, but impacted by an observer's reference frame. Consequently, clock measurements exhibit sensitivity to relative velocity, acceleration and gravity potential. Here we demonstrate optical clock measurements surpassing the present-day ability to account for the gravitational distortion of space-time across the surface of Earth. In two independent ytterbium optical lattice clocks, we demonstrate unprecedented levels in three fundamental benchmarks of clock performance. In units of the clock frequency, we report systematic uncertainty of 1.4 × 10-18, measurement instability of 3.2 × 10-19and reproducibility characterised by ten blinded frequency comparisons, yielding a frequency difference of [-7±(5)stat±(8)sys] × 10-19. While differential sensitivity to gravity could degrade the performance of these optical clocks as terrestrial standards of time, this same sensitivity can be used as an exquisite probe of geopotential5-9. Near the surface of Earth, clock comparisons at the 1 × 10-18 level provide 1 cm resolution along gravity, outperforming state-of-the-art geodetic techniques. These optical clocks can further be used to explore geophysical phenomena10, detect gravitational waves11, test general relativity12 and search for dark matter. Copyright © 2018, The Authors. All rights reserved.

关键词： Earth (planet)

Negative exponential behavior of image mutual information for pseudo-thermal light ghost imaging: Observation, modeling, and verification

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arXiv 2017年

作者： Li, Junhui Luo, Bin Yang, Dongyue Yin, Longfei Wu, Guohua Guo, Hong State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Center for Quantum Information Technology Peking University Beijing100871 China State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing100876 China School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing100876 China

When use the image mutual information to assess the quality of reconstructed image in pseudo-thermal light ghost imaging, a negative exponential behavior with respect to the measurement number is observed. Based on information theory and a few simple and verifiable assumptions, semi-quantitative model of image mutual information under varying measurement numbers is established. It is the Gaussian characteristics of the bucket detector output probability distribution that leads to this negative exponential behavior. Designed experiments verify the model. Copyright © 2017, The Authors. All rights reserved.

关键词： Probability distributions

Sidebands suppression of 852 nm Cesium Faraday anomalous dispersion optical filter by argon gas

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arXiv 2017年

作者： Xiong, Junyu Yin, Longfei Luo, Bin Chen, Jingbiao Guo, Hong State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Center for Quantum Information Technology Peking University Beijing100871 China State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing100876 China School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing100876 China

In this work, sidebands suppression induced by the buffer gas argon (Ar) in 852 nm cesium Faraday anomalous dispersion optical filter (FADOF) is investigated. FADOF performances at different Ar pressures (0 torr, 1 torr, 5 torr and 10 torr) are compared, and a single-peak transmittance spectrum with peak transmittance up to 80% is achieved when the pressure of Ar reaches 5 torr. A detailed analysis shows that, this sidebands suppression comes from the depopulation enhancement by the buffer gas. This result can be generalized to other FADOFs with similar level structures such as the D2 lines of other alkali metal atoms. Copyright © 2017, The Authors. All rights reserved.

关键词： Cesium

Binary sampling ghost imaging: Add random noise to fight quantization caused image quality decline

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arXiv 2017年

作者： Li, Junhui Yang, Dongyue Luo, Bin Wu, Guohua Yin, Longfei Guo, Hong State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Center for Quantum Information Technology Peking University Beijing100871 China School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing100876 China State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing100876 China

When the sampling data of ghost imaging is recorded with less bits, i.e., experiencing quantization, decline of image quality is observed. The less bits used, the worse image one gets. Dithering, which adds suitable random noise to the raw data before quantization, is proved to be capable of compensating image quality decline effectively, even for the extreme binary sampling case. A brief explanation and parameter optimization of dithering are given. Copyright © 2017, The Authors. All rights reserved.

关键词： Image enhancement

Performance Analysis of Coherent and Noncoherent Modulation under I/Q Imbalance

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arXiv 2017年

作者： Selim, Bassant Muhaidat, Sami Sofotasios, Paschalis C. Sharif, Bayan S. Stouraitis, Thanos Karagiannidis, George K. Al-Dhahir, Naofal Department of Electrical and Computer Engineering Khalifa University of Science and Technology Abu DhabiPO Box 127788 United Arab Emirates Department of Electrical and Computer Engineering Uae and with Institute for Communication Systems Khalifa University of Science and Technology PO Box 127788 Abu Dhabi GuildfordGU2 7XH United Kingdom Department of Electrical and Computer Engineering Khalifa University of Science and Technology PO Box 127788 Abu Dhabi United Arab Emirates Department of Electronics and Communications Engineering Tampere University of Technology Tampere33101 Finland Department of Electrical and Computer Engineering Aristotle University of Thessaloniki Thessaloniki54124 Greece Department of Electrical Engineering University of Texas at Dallas DallasTX75080 United States

In-phase/quadrature-phase Imbalance (IQI) is considered a major performance-limiting impairment in direct-conversion transceivers. Its effects become even more pronounced at higher carrier frequencies such as the millimeter-wave frequency bands being considered for 5G systems. In this paper, we quantify the effects of IQI on the performance of different modulation schemes under multipath fading channels. This is realized by developing a general framework for the symbol error rate (SER) analysis of coherent phase shift keying, noncoherent differential phase shift keying and noncoherent frequency shift keying under IQI effects. In this context, the moment generating function of the signal-to-interference-plusnoise-ratio is first derived for both single-carrier and multi-carrier systems suffering from transmitter (TX) IQI only, receiver (RX) IQI only and joint TX/RX IQI. Capitalizing on this, we derive analytic expressions for the SER of the different modulation schemes. These expressions are corroborated by comparisons with corresponding results from computer simulations and they provide insights into the dependence of IQI on the system parameters. We demonstrate that the effects of IQI differ considerably depending on the considered system as some cases of single-carrier transmission appear robust to IQI, whereas multi-carrier systems experiencing IQI at the RX require compensation in order to achieve a reliable communication link. Copyright © 2017, The Authors. All rights reserved.

关键词： Phase shift keying

SMoNt: An ontology for crime solving through social media

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International Journal of Metadata, Semantics and Ontologies 2017年第2-3期12卷 71-81页

作者： Kalemi, Edlira Yildirim-Yayilgan, Sule Domnori, Elton Elezaj, Ogerta Process and Information Systems Engineering Research Centre University of Surrey Guildford SurreyGU2 7XH United Kingdom Department of Information Security and Communication Technology Norwegian University of Science and Technology Gjøvik2815 Norway Department of Computer Engineering Epoka University Tirana1039 Albania Department of Mathematics Statistics and Applied Informatics University of Tirana Tirana1000 Albania

There are numerous social networks such as Facebook, LinkedIn, Google Plus and Twitter whose data sources are becoming larger every day holding an abundance of valuable information. Among these data, digital crime evidence can be collected from online social networks (OSNs) for crime detection and further analysis. This paper describes the SMONT ontology which has been developed to give support to the process of crime investigation and prevention. The SMONT ontology covers specific data about the crime, digital evidence obtained from OSNs, information archived from police entities, and also details related to people or events which may bring the authorities closer to crime case solving. It is possible to benefit from the ontology in different ways like: intelligence gathering;reasoning over the data;smarter searches and comparisons;open data publication purposes;and for the overall management of the crime solving and prevention process. Copyright © 2017 Inderscience Enterprises Ltd.

关键词： Ontology

Flexible Energy Management Protocol for Cooperative EV-to-EV Charging

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Flexible Energy Management Protocol for Cooperative EV-to-EV...

IEEE Global communications Conference

作者： Rongqing Zhang Xiang Cheng Liuqing Yang State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Peking University Department of Electrical & Computer Engineering Colorado State University

ISBN: (纸本)9781509013296

In this paper, we investigate the flexible power transfer among electric vehicles (EVs) from a cooperation perspective in an energy Internet based EV system. First, we introduce the concept of cooperative EV-to-EV (V2V) charging, which enables active cooperation via charging/discharging operations between EVs as energy consumers and EVs as energy providers. Then, based on the cooperative V2V charging concept, we propose a flexible energy management protocol, which can help the EVs achieve more flexible and smarter charging/discharging behaviors. In the proposed energy management protocol, we define the utilities of the EVs based on the cost and profit through cooperative V2V charging and employ the bipartite graph to model the charging/discharging cooperation between EVs as energy consumers and EVs as energy providers. Based on the constructed bipartite graph, we propose a max-weight V2V matching algorithm, which can lead to an optimized V2V matching in terms of the network social welfare. Simulation results verify the efficiency of our proposed cooperative V2V charging based energy management protocol in improving the EV utilities and the network social welfare as well as reducing the energy consumption of the EVs.

关键词： Protocols Energy management Charging stations Internet Real-time systems Power grids Mobile communication