scholarly journals A Brief Review of Multipath TCP for Vehicular Networks

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2793
Author(s):  
Luomeng Chao ◽  
Celimuge Wu ◽  
Tsutomu Yoshinaga ◽  
Wugedele Bao ◽  
Yusheng Ji

Multipath TCP (MPTCP) is one of the most important extensions to TCP that enables the use of multiple paths in data transmissions for a TCP connection. In MPTCP, the end hosts transmit data across a number of TCP subflows simultaneously on one connection. MPTCP can sufficiently utilize the bandwidth resources to improve the transmission efficiency while providing TCP fairness to other TCP connections. Meanwhile, it also offers resilience due to multipath data transfers. MPTCP attracts tremendous attention from the academic and industry field due to the explosive data growth in recent times and limited network bandwidth for each single available communication interface. The vehicular Internet-of-Things systems, such as cooperative autonomous driving, require reliable high speed data transmission and robustness. MPTCP could be a promising approach to solve these challenges. In this paper, we first conduct a brief survey of existing MPTCP studies and give a brief overview to multipath routing. Then we discuss the significance technical challenges in applying MPTCP for vehicular networks and point out future research directions.

2020 ◽  
Vol 15 ◽  
Author(s):  
Fei Sun ◽  
Guohe Li ◽  
Qi Zhang ◽  
Meng Liu

: Cr12MoV hardened steel is widely used in the manufacturing of stamping die because of its high strength, high hardness, and good wear resistance. As a kind of mainstream cutting technology, high-speed machining has been applied in the machining of Cr12MoV hardened steel. Based on the review of a large number of literature, the development of high-speed machining of Cr12MoV hardened steel was summarized, including the research status of the saw-tooth chip, cutting force, cutting temperature, tool wear, machined surface quality, and parameters optimization. The problems that exist in the current research were discussed and the directions of future research were pointed out. It can promote the development of high-speed machining of Cr12MoV hardened steel.


Author(s):  
Xiaodong Yu ◽  
Yu Wang ◽  
Junfeng Wang ◽  
Wenkai Zhou ◽  
Hongwei Bi ◽  
...  

Background: Hydrostatic bearings have the advantages of strong bearing capacity, good stability, small friction coefficient and long life. The performance of liquid hydrostatic bearings directly affect the accuracy and efficiency of CNC machining equipment. The performance is conducive to the development of CNC machine tools towards high speed and heavy load, so it is necessary to sort out and summarize the existing research results. Objective: This study summarizes the current development status of hydrostatic bearings and explains the development trend of hydrostatic bearings. Methods: According to the recently published journal articles and patents, the recent experimental research on hydrostatic thrust bearings is summarized. This paper summarizes many factors that affect the performance of hydrostatic bearings, and discusses the causes of various factors on hydrostatic bearings. Finally, future research on hydrostatic bearings is presented. Results: The study discusses experimental methods, simulation processes, and experimental results. Conclusion: This study can produce dynamic and static pressure effects by changing the structure of the oil cavity of the hydrostatic bearing. This effect can make up for the static pressure loss. By improving the theoretical formula and mathematical model and proposing a new simulation method, the accuracy of the hydrostatic bearing simulation is satisfied; the future development trend of the hydrostatic bearing is proposed.


Author(s):  
Jin Xu ◽  
Yuting Zhao

Background: Detuning is the main problem that affects the efficiency and transmission distance of the resonant coupling Wireless Power Transmission (WPT). The distance of load and the offset of the load position could cause serious detuning. Methods: This paper presents an adjustable coil in which inductance can be adjusted. Then a model of WPT was established that could compensate resonant frequency automatically using the adjustable coil. Next, the relationship between the primary resonant frequency and the transmission efficiency is analyzed from the circuit. The analysis proved that the design of the adjustable coil could improve the transmission efficiency of the WPT system. Finally, a prototype of WPT system was built. Results: The experimental results showed that WPT system with adjustable coil can improve the transmission efficiency which proves the theoretical research. At the same time, it has essential reference value for the future research of WPT. Conclusion: In this paper, aiming at the system detuning caused by some other factors, such as the position shift of the load during the wireless power transmission, an adjustable coil is proposed.


VLSI Design ◽  
2007 ◽  
Vol 2007 ◽  
pp. 1-11 ◽  
Author(s):  
Srinivasan Murali ◽  
David Atienza ◽  
Luca Benini ◽  
Giovanni De Micheli

Networks on Chips (NoCs) are required to tackle the increasing delay and poor scalability issues of bus-based communication architectures. Many of today's NoC designs are based on single path routing. By utilizing multiple paths for routing, congestion in the network is reduced significantly, which translates to improved network performance or reduced network bandwidth requirements and power consumption. Multiple paths can also be utilized to achieve spatial redundancy, which helps in achieving tolerance against faults or errors in the NoC. A major problem with multipath routing is that packets can reach the destination in an out-of-order fashion, while many applications require in-order packet delivery. In this work, we present a multipath routing strategy that guarantees in-order packet delivery for NoCs. It is based on the idea of routing packets on partially nonintersecting paths and rebuilding packet order at path reconvergent nodes. We present a design methodology that uses the routing strategy to optimally spread the traffic in the NoC to minimize the network bandwidth needs and power consumption. We also integrate support for tolerance against transient and permanent failures in the NoC links in the methodology by utilizing spatial and temporal redundancy for transporting packets. Our experimental studies show large reduction in network bandwidth requirements (36.86% on average) and power consumption (30.51% on average) compared to single-path systems. The area overhead of the proposed scheme is small (a modest 5% increase in network area). Hence, it is practical to be used in the on-chip domain.


2021 ◽  
Vol 1 (3) ◽  
pp. 657-671
Author(s):  
Claudia Luger-Bazinger ◽  
Cornelia Zankl ◽  
Karin Klieber ◽  
Veronika Hornung-Prähauser ◽  
Karl Rehrl

This study investigates the perceived safety of passengers while being on board of a driverless shuttle without a steward present. The aim of the study is to draw conclusions on factors that influence and contribute to perceived safety of passengers in driverless shuttles. For this, four different test rides were conducted, representing aspects that might challenge passengers’ perceived safety once driverless shuttles become part of public transport: passengers had to ride the shuttle on their own (without a steward present), had to interact with another passenger, and had to react to two different unexpected technical difficulties. Passengers were then asked what had influenced their perceived safety and what would contribute to it. Results show that perceived safety of passengers was high across all different test rides. The most important factors influencing the perceived safety of passengers were the shuttle’s driving style and passengers’ trust in the technology. The driving style was increasingly less important as the passengers gained experience with the driverless shuttle. Readily available contact with someone in a control room would significantly contribute to an increase in perceived safety while riding a driverless shuttle. For researchers, as well as technicians in the field of autonomous driving, our findings could inform the design and set-up of driverless shuttles in order to increase perceived safety; for example, how to signal passengers that there is always the possibility of contact to someone in a control room. Reacting to these concerns and challenges will further help to foster acceptance of AVs in society. Future research should explore our findings in an even more natural setting, e.g., a controlled mixed traffic environment.


Countering a quantum computer in the process of illegal ultra-high-speed decryption of messages is technically feasible. Information owner must oppose the competitor's computer with tasks, the solution of which requires an infinite number of operations during decryption. For example, the dependence of functions on an infinite number of informative features. The owner encrypts by integrating the functions, the recipient decrypts by solving the integral equations. It is not a discrete but an analog approach that prevails here. The basis for the implementation of this approach was created by Polish scientists. Mathematician Stefan Banach (1892-1945), who created modern functional analysis, and Marian Mazur (1909-1983), the author of " The Qualitative Theory of Information". Their theory was created in contrast with the "Quantitative Information Theory". Cryptologists who have devoted their whole lives to improving the "discrete" theory and found themselves close to power (and finance), try not to recall that Claude Shannon in his basic work "Communication Theory of Secrecy Systems" more than once emphasized the discrete focus of his developments anticipating future research on the specific limitations of his work adapted to the communication theory. Forgetting about the unlimited speeds and amounts of memory of quantum computers the orthodox talk about redundancy and further purely technical issues, including administrative leverages for counteracting against opponents. It is impossible to stop the progress of science. Experiments have shown the reality of creating such post-quantum-level cryptographic systems.


Author(s):  
Ivan Mozghovyi ◽  
Anatoliy Sergiyenko ◽  
Roman Yershov

Increasing requirements for data transfer and storage is one of the crucial questions now. There are several ways of high-speed data transmission, but they meet limited requirements applied to their narrowly focused specific target. The data compression approach gives the solution to the problems of high-speed transfer and low-volume data storage. This paper is devoted to the compression of GIF images, using a modified LZW algorithm with a tree-based dictionary. It has led to a decrease in lookup time and an increase in the speed of data compression, and in turn, allows developing the method of constructing a hardware compression accelerator during the future research.


2021 ◽  
Author(s):  
Shiva Raj Pokhrel ◽  
Neeraj Kumar ◽  
Anwar Walid

Connected Autonomous Vehicles (CAVs) are Not-So-Futuristic. CAVs will be highly dynamic by intelligently exploiting multipath communication over several radio technologies, such as high-speed WiFi and 5G and beyond networks. Yet, the likelihood of data communication loss can be very high and/, or packets arrive at the destination not in correct working order due to erratic and mixed time-varying wireless links. Furthermore, the vehicular data traffic is susceptible to loss and delay variation,which recommends the need to investigate new multipath TCP(MPTCP) protocols for ultra-reliable low latency communication(URLLC) over such heterogeneous networks while reassuring CAVs’ needs. We undertake the challenge by jointly considering network coding and balanced linked adaptation for performing coupled congestion control across multiple wireless paths.Consequently, the proposed low delay MPTCP framework for connecting autonomous vehicles is efficient and intelligent by design. We conduct a rigorous convergence analysis of the MPTCP design framework. In summation, we provide a detailed mathematical study and demonstrate that the latency penalty for the URLLC-MPTCP developed over these networks becomes negligible when considering the possible benefits that multiple network convergence could offer. Our extensive emulation results demonstrate all these lucrative features of URLLC-MPTCP.


2021 ◽  
Author(s):  
FARZAN SHENAVARMASOULEH ◽  
Farid Ghareh Mohammadi ◽  
M. Hadi Amini ◽  
Hamid R. Arabnia

<div>A smart city can be seen as a framework, comprised of Information and Communication Technologies (ICT). An intelligent network of connected devices that collect data with their sensors and transmit them using wireless and cloud technologies in order to communicate with other assets in the ecosystem plays a pivotal role in this framework. Maximizing the quality of life of citizens, making better use of available resources, cutting costs, and improving sustainability are the ultimate goals that a smart city is after. Hence, data collected from these connected devices will continuously get thoroughly analyzed to gain better insights into the services that are being offered across the city; with this goal in mind that they can be used to make the whole system more efficient.</div><div>Robots and physical machines are inseparable parts of a smart city. Embodied AI is the field of study that takes a deeper look into these and explores how they can fit into real-world environments. It focuses on learning through interaction with the surrounding environment, as opposed to Internet AI which tries to learn from static datasets. Embodied AI aims to train an agent that can See (Computer Vision), Talk (NLP), Navigate and Interact with its environment (Reinforcement Learning), and Reason (General Intelligence), all at the same time. Autonomous driving cars and personal companions are some of the examples that benefit from Embodied AI nowadays.</div><div>In this paper, we attempt to do a concise review of this field. We will go through its definitions, its characteristics, and its current achievements along with different algorithms, approaches, and solutions that are being used in different components of it (e.g. Vision, NLP, RL). We will then explore all the available simulators and 3D interactable databases that will make the research in this area feasible. Finally, we will address its challenges and identify its potentials for future research.</div>


2019 ◽  
Vol 16 (1) ◽  
pp. 148-160
Author(s):  
Olga Piterina ◽  
Alexander Masharsky

Abstract Research purpose. The high-speed railway (HSR) construction project in the Baltic States is the largest joint infrastructure project since the restoration of independence of Latvia, Lithuania and Estonia. Rail Baltica (RB) is considered as the most energy-efficient project having the lowest environmental impact. However, the issue of energy consumption of the project was not sufficiently addressed either in the investment justification of the RB construction or in the relevant research works regarding the project. The aim of the current research is to determine the indicators of energy consumption and carbon dioxide (CO2) emissions intensity of the Latvian section of RB, since they are the key factors of the quantitative assessment of sustainability. Design/Methodology/Approach. Critical analysis of the academic research works and reports of the official international organizations dedicated to the topic of energy consumption and CO2 emissions of HSR was conducted prior to the calculation of the above-mentioned indicators. The method of calculation based on International Union of Railways (UIC) was used in order to conduct the cluster analysis within the framework of current work. The main points considered are electricity consumption, carbon dioxide emissions, and level of passenger and freight demand. Statistical databases of UIC and International Energy Agency were used. Findings. The calculations carried out by the authors of the given article demonstrate substantial figures of CO2 emissions intensity for Latvian section of the project related to the train load rate and traffic intensity which is evened out only by the CO2 emissions factor in Latvia. Originality/Value/Practical implications. On this basis the authors present the directions for future research required for the development of the effective strategy for the Latvian Republic with the aim of achieving the increase in the RB project’s ecological efficiency.


Sign in / Sign up

Export Citation Format

Share Document