scholarly journals Dynamic Traffic Detection and Modeling for Beidou Satellite Networks

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yanyu Qu ◽  
Fangling Pu ◽  
Jianguo Yin ◽  
Lingzi Liu ◽  
Xin Xu

Beidou navigation system (BDS) has been developed as an integrated system. The third BDS, BSD-3, will be capable of providing not only global positioning and navigation but also data communication. When the volume of data transmitted through BDS-3 continues to increase, BDS-3 will encounter network traffic congestion, unbalanced resource usage, or security attacks as terrestrial networks. The network traffic monitoring is essential for automatic management and safety assurance of BDS-3. A dynamic traffic detection method including traffic prediction by Long Short-Term Memory (LSTM) and a dynamically adjusting polling strategy is proposed to unevenly sample the traffic of each link. A distributed traffic detection architecture is designed for collection of the detected traffic and its related temporal and spatial information with low delay. A time-varying graph (TVG) model is introduced to represent the dynamic topology, the time-varying link, and its traffic. The BDS-3 network is simulated by STK. The WIDE dataset is used to simulate the traffic between the satellite and ground station. Simulation results show that the dynamic traffic detection method can follow the variation of the traffic of each link with uneven sampling. The detected traffic can be transmitted to the ground station in near real time through the distributed traffic detection architecture. The traffic and its related information are stored by using Neo4j in terms of the TVG model. The nodes, edges, and traffic of BDS-3 can be quickly queried through Neo4j. The presented dynamic traffic detection and representation schemes will support BDS-3 to establish automatic management and security system and develop business.

2021 ◽  
Vol 15 (1) ◽  
pp. 38-52
Author(s):  
Folasade Dahunsi ◽  
Oluwasina Aderinwale ◽  
Abayomi Adesida ◽  
Abiola Alayande ◽  
J. Ojo ◽  
...  

Satellite communication is a wireless means of transmission of intelligible signals/information. When properly utilized it will bring about a great and positive development on the economic growth of any nation. The Federal Government of Nigeria made a giant step in the communication sector by launching five satellites into space: NigeriaSat-1, NigComSat- 1, NigeriaSat-2r, NigeriaSat-X and NigComSat-1R. With adequate spatial information, informed decisions can be made by stakeholders and adequate steps taken to ensure the growth of the nation. Demand for training capacity building in space technology is increasing. Unfortunately, space technology is a relatively expensive field with ongoing research for affordable training approaches. This paper presents methods of building capacity by developing Demo Satellites that receive telemetry data with radiofrequency and internet of things communication protocol. Web Dashboard was developed for remote monitoring of ground station and for exploring mobility in data communication, Localization was achieved to also track the Demo Satellites and the ground station in real-time. It is shown that the implementation of a low-cost capacity building programme is not only possible but a goal that should be aimed at. Multiple segments in the design of the schematics produced can be reused. It presents a pioneer satellite constellation prototype that displays the capabilities of a satellite in solving some of the country’s challenges and creating awareness on space research and its trends.


2014 ◽  
Vol 530-531 ◽  
pp. 802-805
Author(s):  
Feng Li ◽  
Hai Ying Wang

This study based on characteristics of network traffic is significant, it can improve network design, improve network performance, is often used in the abnormal traffic detection and so on. In this paper, the significance of abnormal flow monitoring is design based on an analysis of network behavior anomaly traffic monitoring system, the system for use of the network traffic characteristics of network attacks detected has a good prospect.


Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1902
Author(s):  
Martin Oberascher ◽  
Aun Dastgir ◽  
Jiada Li ◽  
Sina Hesarkazzazi ◽  
Mohsen Hajibabaei ◽  
...  

Smart rainwater harvesting (RWH) systems can automatically release stormwater prior to rainfall events to increase detention capacity on a household level. However, impacts and benefits of a widespread implementation of these systems are often unknown. This works aims to investigate the effect of a large-scale implementation of smart RWH systems on urban resilience by hypothetically retrofitting an Alpine municipality with smart rain barrels. Smart RWH systems represent dynamic systems, and therefore, the interaction between the coupled systems RWH units, an urban drainage network (UDN) and digital infrastructure is critical for evaluating resilience against system failures. In particular, digital parameters (e.g., accuracy of weather forecasts, or reliability of data communication) can differ from an ideal performance. Therefore, different digital parameters are varied to determine the range of uncertainties associated with smart RWH systems. As the results demonstrate, smart RWH systems can further increase integrated system resilience but require a coordinated integration into the overall system. Additionally, sufficient consideration of digital uncertainties is of great importance for smart water systems, as uncertainties can reduce/eliminate gained performance improvements. Moreover, a long-term simulation should be applied to investigate resilience with digital applications to reduce dependence on boundary conditions and rainfall patterns.


2009 ◽  
Vol 24 (3) ◽  
pp. 16-25 ◽  
Author(s):  
Martin Rehák ◽  
Michal Pechoucek ◽  
Martin Grill ◽  
Jan Stiborek ◽  
Karel Bartoš ◽  
...  

2006 ◽  
Vol 13C (3) ◽  
pp. 283-294
Author(s):  
Koo-Hong Kang ◽  
Jin-Tae Oh ◽  
Jong-Soo Jang

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Wenmin Li ◽  
Sanqi Sun ◽  
Shuo Zhang ◽  
Hua Zhang ◽  
Yijie Shi

Aim. The purpose of this study is how to better detect attack traffic in imbalance datasets. The deep learning technology has played an important role in detecting malicious network traffic in recent years. However, it suffers serious imbalance distribution of data if the traffic model skews towards the modeling in the benign direction, because only a small portion of traffic is malicious, while most network traffic is benign. That is the reason why the authors wrote this manuscript. Methods. We propose a cost-sensitive approach to improve the HTTP traffic detection performance with imbalanced data and also present a character-level abstract feature extraction approach that can provide features with clear decision boundaries in addition. Finally, we design a spark-based HTTP traffic detection system based on these two approaches. Results. The methods proposed in this paper work well in imbalanced datasets. Compared to other methods, the experiment results indicate that our system has F1-score in a high precision. Conclusion. For imbalanced HTTP traffic detection, we confirmed that the method of feature extraction and the cost function is very effective. In the future, we may focus on how to use the cost function to further improve detection performance.


2021 ◽  
Vol 77 (5) ◽  
pp. 628-644
Author(s):  
Gabrielle Illava ◽  
Richard Jayne ◽  
Aaron D. Finke ◽  
David Closs ◽  
Wenjie Zeng ◽  
...  

Serial synchrotron crystallography (SSX) is enabling the efficient use of small crystals for structure–function studies of biomolecules and for drug discovery. An integrated SSX system has been developed comprising ultralow background-scatter sample holders suitable for room and cryogenic temperature crystallographic data collection, a sample-loading station and a humid `gloveless' glovebox. The sample holders incorporate thin-film supports with a variety of designs optimized for different crystal-loading challenges. These holders facilitate the dispersion of crystals and the removal of excess liquid, can be cooled at extremely high rates, generate little background scatter, allow data collection over >90° of oscillation without obstruction or the risk of generating saturating Bragg peaks, are compatible with existing infrastructure for high-throughput cryocrystallography and are reusable. The sample-loading station allows sample preparation and loading onto the support film, the application of time-varying suction for optimal removal of excess liquid, crystal repositioning and cryoprotection, and the application of sealing films for room-temperature data collection, all in a controlled-humidity environment. The humid glovebox allows microscope observation of the sample-loading station and crystallization trays while maintaining near-saturating humidities that further minimize the risks of sample dehydration and damage, and maximize working times. This integrated system addresses common problems in obtaining properly dispersed, properly hydrated and isomorphous microcrystals for fixed-orientation and oscillation data collection. Its ease of use, flexibility and optimized performance make it attractive not just for SSX but also for single-crystal and few-crystal data collection. Fundamental concepts that are important in achieving desired crystal distributions on a sample holder via time-varying suction-induced liquid flows are also discussed.


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