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Studying a low-temperature engine with external heat supply

Journal of Physics: Conference Series 2021年第1期1843卷

作者： A D Mekhtiyev V V Yugay A D Alkina Y G Neshina D E Kapanova Department of Electrical Equipment Operation S.Seifullin Kazakh Agrotechnical University Nur-Sultan Kazakhstan Solar Cell Physics Research Laboratory National Research Tomsk Polytechnic University Tomsk Russia Department of The technology of communication systems Karaganda Technical University Karaganda Kazakhstan Department of Information Technology and Security Karaganda Technical University Karaganda Kazakhstan Department of Energy Systems Karaganda Technical University Karaganda Kazakhstan

The article presents some results of studying the most optimal parameters of the displacer and the piston of a low-temperature engine with external heat supply to increase its efficiency when converting low-grade heat. The developed design of the engine does not have a displacer rod, which provides better sealing and reduces mechanical friction losses. Synchronization of the piston and the displacer movement is ensured by the permanent magnets interaction. The analysis of the results of computer simulation of the PV diagram with an increased diameter of the displacer in relation to the piston diameter plays a positive role in increasing the efficiency and power of the engine. Increasing the diameter of the displacer also leads to increasing the area of the PV diagram and its approach to the ideal thermal Stirling cycle. The simulation results show that increasing the diameter of the displacer above 17/1 does not lead to increasing the area of the PV diagram, and with a larger ratio, on the contrary, it reduces the parameters of the engine efficiency. Further increasing the diameter of the displacer is not advisable in terms of technical and economic ratios. The proposed engine with external heat supply is capable of converting heat from geothermal or industrial wastewater, as well as heated water using a solar collector.

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Research of unsupervised entity relation extraction

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Journal of Computers (Taiwan) 2019年第1期30卷 31-41页

作者： Liu, Yun Li, Mingxin Liu, Hui Cheng, Junjun Fu, Yanping Department of Electronic and Information Engineering Key Laboratory of Communication and Information Systems Beijing Municipal Commission of Education Beijing Jiaotong University China China Information Technology Security Evaluation Center Beijing China Key Laboratory of Communication and Information Systems Beijing Municipal Commission of Education Beijing Jiaotong University China

Nowadays, the Internet is growing rapidly and the number of network data is also growing rapidly, which makes it more difficult to get information from the massive network data with traditional methods. Entity relation extraction is an important research direction of natural language processing. It can find and identify the semantic relation of the entity to analyze the abstract textual data. Unstructured network data can also be transformed into structured data by using Entity relation extraction. This paper presents an unsupervised entity relation extraction model, which can overcome the shortcomings of traditional methods, such as needing a lot of man-made work and poor portability. In this model, we create a filter function at first. Then we extract the relational feature words by using context window and parsing. We use affinity propagation clustering algorithm to get the relation of entities, which can obtain better results than k-means clustering algorithm. 2019 © Computer Society of the Republic of China. All Rights Reserved.

关键词： Semantics

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Online observability of boolean control networks

arXiv

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arXiv 2019年

作者： Wu, Guisen Dai, Liyun Liu, Zhiming Chen, Taolue Pang, Jun School of Computer and Information Science Southwest University Chongqing400715 China Department of Computer Science and Information Systems University of London Birkbeck United Kingdom Faculty of Science Technology and Communication Interdisciplinary Centre for Security Reliability and Trust University of Luxembourg

Observabililty is an important topic of Boolean control networks (BCNs). There are four types of observability which are proposed to capture the ability to determine BCNs' initial states by four different algorithms, respectively, and each of them is applied to a kind of applications. In this paper, we study the weakness of the third type of observability for identification problem. It is proposed in Cheng et al. [2011b] that a BCN is identifiable if and only if it satisfies controllability and the third type of observability. But we find that a BCN is identifiable iff it satisfies the controllability and a new type of observability named online observability. Moreover, we then propose decision algorithm for the online observability. Copyright © 2019, The Authors. All rights reserved.

关键词： Controllability

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High Accuracy Synchronization for Distributed Massive MIMO using White Rabbit

High Accuracy Synchronization for Distributed Massive MIMO u...

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IEEE International Symposium on Precision Clock Synchronization for Measurement, Control and communication, ISPCS

作者： Thomas Bigler Albert Treytl David Löschenbrand Thomas Zemen Department for Integrated Sensor Systems Danube University Krems Wr. Neustadt Austria AIT - Austrian Institute of Technology Security & Communication Technologies Vienna Austria

Accurate synchronization is a crucial prerequisite for wireless communication systems and in particular for spatially distributed massive multiple-input multiple-output (MIMO) systems which is also used in the upcoming 5G mobile communication standard. Many applications based on MIMO transmission, such as communication systems or beamforming methods, require synchronization accuracy in the low sub-nanosecond range which surpassed the capabilities of current off-the-shelf system. Furthermore, many of the currently used methods are susceptible to external influences such as temperature or mechanical stress. This paper defines the requirements for such systems and discusses the suitability of some existing synchronization and syn-tonization solutions. The paper further illustrates a measurement setup that allows to evaluate and compare a direct frequency distribution approach over coaxial cables and the White Rabbit timing system using optical fiber. Measurements were conducted under temperature stress to evaluate the performance of the synchronization parameters and their influence on the massive MIMO system. These measurements show that the White Rabbit setup currently meets the requirements for some but not all massive MIMO applications.

关键词： Synchronization Clocks MIMO communication Temperature measurement Radio frequency Coaxial cables Receivers

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An Examination of Pairing Method with Camera and Acceleration Sensor

An Examination of Pairing Method with Camera and Acceleratio...

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International Conference on Mobile Computing and Ubiquitous Networking (ICMU)

作者： Makoto Nagatomo Kentaro Aburada Naonobu Okazaki Mirang Park Security Research Center Kanagawa Institute of Technology Atsugi Japan Department of Computer Science and Systems Engineering University of Miyazaki Miyazaki Japan Department of Information Network and Communication Kanagawa Institute of Technology Atsugi Japan

ISBN: (纸本)9781538667071;9784907626341

Received signal strength (RSS) is used for proximate device authentication in wireless communications, but it changes significantly due to environmental factors. Thus, it is difficult to obtain reliably accurate device authentication with RSS. An alternative is proximity authentication, in which an infrared camera recognizes the movement of a hand-held device. In this method, the camera cannot recognize device inclination, and the user needs to have a special camera. In this paper, we propose a method that performs authentication by pairing a PC having a common camera and a hand-held device having an accelerometer. In this method, the PC recognizes a marker on the display of the device and calculates the similarity between the displacement of the marker and the acceleration of the device. We performed experiments to determine how the similarity changes according to the distance from a device to a camera and whether an eavesdropper outside the camera range can perform pairing. As a result, we found that it is possible to set a threshold for the similarity, but the standard deviation of the similarity was large, making the method unstable.

关键词： Cameras Acceleration Servers Performance evaluation Accelerometers Authentication Wireless communication

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A new QoE fairness index for QoE management

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Quality and User Experience 2018年第1期3卷 1-23页

作者： Hoßfeld, Tobias Skorin-Kapov, Lea Heegaard, Poul E. Varela, Martín Modeling of Adaptive Systems University of Duisburg-Essen Essen Germany Chair of Communication Networks University of Würzburg Würzburg Germany Faculty of Electrical Engineering and Computing University of Zagreb Zagreb Croatia Department of Information Security and Communication Technology NTNU Norwegian University of Science and Technology Trondheim Norway Oulo Finland

The user-centric management of networks and services focuses on the Quality of Experience (QoE) as perceived by the end user. In general, the goal is to maximize (or at least ensure an acceptable) QoE, while ensuring fairness among users, e.g., in terms of resource allocation and scheduling in shared systems. A problem arising in this context is that the notions of fairness commonly applied in the QoS domain do not translate well to the QoE domain. We have recently proposed a QoE fairness index F, which solves these issues. In this paper, we provide a detailed rationale for it, along with a thorough comparison of the proposed index and its properties against the most widely used QoS fairness indices, showing its advantages. We furthermore explore the potential uses of the index, in the context of QoE management and describe future research lines on this topic.

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IAC-17.B4.7.8 :Integrated smallsats and unmanned vehicles for networking in remote locations 68

IAC-17.B4.7.8 :Integrated smallsats and unmanned vehicles fo...

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68th International Astronautical Congress: Unlocking Imagination, Fostering Innovation and Strengthening security, IAC 2017

作者： Birkeland, Roger Palma, David Zolich, Artur Department of Electronic Systems Norwegian University of Science and Technology NTNU Trondheim Norway Department of Information Security and Communication Technology NTNU Norway Department of Engineering Cybernetics NTNU Norway

ISBN: (纸本)9781510855373

The lack of infrastructure in maritime and Arctic regions has a strong impact on many operations, such as the retrieval of scientific data. Nowadays, data logged during these operations must either be collected by manned missions or transmitted over existing satellite links. Unfortunately, both methods face challenges regarding availability, as well as energy and link budget constraints. When considering the throughput of existing satellite links, the effective amount of data that can be transmitted is limited by the links' throughput, periodicity and economic cost. Consequently, it is a common practice to visit research sites in order to manually collect data recorded over extensive time periods, usually spanning from several months to years. However, manual collection of research data, in particular in harsh maritime environments, poses a risk to crews and also incurs significant costs. In order to overcome current communication limitations, the use of small satellites and unmanned vehicles for remote and in-situ sensing has been proposed by several authors. This is motivated by the growing availability of small satellite platforms as well as by the foreseen increase in launch availability, enabling the creation of novel dedicated small satellite missions. Constellations or swarms of small satellites, such as CubeSats, can work together with other unmanned vehicles and play a key role in integrated communication systems. Unmanned vehicles can act as relay nodes or as data mules. The relay node can be used when a vehicle or small satellite is simultaneously in communication-range with research sites and supporting infrastructure, such as other relay nodes. Alternatively, data-mules may also cover regions outside the range of existing infrastructure and reach distant research sites where data is being gathered. In the area of destination, data-mules collect and store data, delivering in when returning to supporting infrastructure. In this paper, we propose an integr

关键词： Data acquisition

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Android malware detection based on static behavior feature analysis

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Journal of Computers (Taiwan) 2018年第6期29卷 243-253页

作者： Chen, Chen Liu, Yun Shen, Bo Cheng, Jun-Jun Department of Electronic and Information Engineering Key Laboratory of Communication and Information Systems Beijing Municipal Commission of Education Beijing Jiaotong University Beijing15120201 China China Information Technology Security Evaluation Center Beijing China

As an open source operating system, Android has groups of users and developers, which result in a great deal of Android application in app markets. But at the same time, app’s benign and malicious behavior cannot be screened, the number of new malware sample for Android platform and infected mobile phone are still soaring, Android malware detection is faced with a tough challenge. Thus this paper proposes an approach that analyze Android malware by extracting app’s static behavior, and information are captured include the use of permission, android’s components and API calls. Then we take the advantage of PCA to extract app’s principle behavior features. Finally, classifiers are trained by Android app dataset to validate the performance. Experiments show that the proposed method is capable of 97.4% true positive rate and 99.8% area under ROC, our lightweight classifiers can detect Android’s unknown malware effectively and accurately. © Computer Society of the Republic of China. All rights reserved.

关键词： Feature extraction

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"I have learned that i must think twice before…". An educational intervention for enhancing students’ privacy awareness in facebook 7th

"I have learned that i must think twice before…". An educat...

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7th International Conference on eDemocracy, e-Democracy 2017

作者： Sideri, Maria Kitsiou, Angeliki Tzortzaki, Eleni Kalloniatis, Christos Gritzalis, Stefanos Privacy Engineering and Social Informatics Laboratory Department of Cultural Technology and Communication University of the Aegean Lesvos81100 Greece Information and Communication Systems Security Laboratory Department of Information and Communications Systems Engineering University of the Aegean Samos83200 Greece

ISBN: (纸本)9783319711164

Social Network Sites have doubtless become part of our lives, facilitating communication and interaction between social actors. Within this frame users disclose personal information for several reasons while at the same time they express privacy concerns. "Privacy Paradox" reveals that despite privacy concerns, users, most of the times, fail to protect their privacy within SNSs, putting thus themselves and other users to risk. In this respect, several researches have shown that users’ privacy awareness increase is of major importance, focusing on the crucial role of education towards this. This research aims to explore the effects of a long-term University-based educational intervention for enhancing students’ digital knowledge and skills in order to protect their privacy in SNSs efficiently. The educational intervention centered on a semester course of a Greek University, provides encouraging findings regarding students’ privacy awareness enhancement. © Springer International Publishing AG 2017.

关键词： Students

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Evolving Bent Quaternary Functions

Evolving Bent Quaternary Functions

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Congress on Evolutionary Computation

作者： Stjepan Picek Karlo Knezevic Luca Mariot Domagoj Jakobovic Alberto Leporati Cyber Security Research Group Delft University of Technology Delft The Netherlands Faculty of Electrical Engineering and Computing University of Zagreb Zagreb Croatia Department of Informatics Systems and Communication Università degli Studi di Milano-Bicocca Milano Italy

Boolean functions have a prominent role in many real-world applications, which makes them a very active research domain. Throughout the years, various heuristic techniques proved to be an attractive choice for the construction of Boolean functions with different properties. One of the most important properties is nonlinearity, and in particular maximally nonlinear Boolean functions are also called bent functions. In this paper, instead of considering Boolean functions, we experiment with quaternary functions. The corresponding problem is much more difficult and presents an interesting benchmark as well as realworld applications. The results we obtain show that evolutionary metaheuristics, especially genetic programming, succeed in finding quaternary functions with the desired properties. The obtained results in the quaternary domain can also be translated into the binary domain, in which case this approach compares favorably with the state-of-the-art in Boolean optimization. Our techniques are able to find quaternary bent functions for up to 8 inputs, which corresponds to obtaining Boolean bent functions of 16 inputs.

关键词： Evolutionary computation

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