scholarly journals Recovery Routing Based on Q-Learning for Satellite Network Faults

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Rentao Gu ◽  
Jiawen Qin ◽  
Tao Dong ◽  
Jie Yin ◽  
Zhihui Liu
Keyword(s):  
Fault Detection ◽  
A Priori ◽  
Network Routing ◽  
Simulation Software ◽  
Utilization Rate ◽  
Satellite Network ◽  
Bayesian Decision ◽  
Terrestrial Network ◽  
Main Component ◽  
Two Stages

With the fierce research on the space and terrestrial network, the satellite network as the main component has received increasing attention. Due to its special operating environment, there are temporary link failures caused by interference and permanent port failures caused by equipment problems. In this paper, we propose a new satellite network routing technology for fault recovery based on fault detection. Based on Bayesian decision, this technology judges the probability of each fault by a priori probability of the two faults to achieve the purpose of effectively distinguishing between two types of faults and locate faulty links and node ports. Then, corresponding to the previous two stages of the fault detection, different stages and different methods are updated for different types of fault. We also combine satellite network data from satellite simulation software to validate our study. The results show that the recovery strategy has good performance, and the effective resource utilization rate is improved significantly.

scholarly journals Implementation of the modeling and simulation software of search and rescue system based Korea navigation satellite system

2019 ◽  
Vol 94 ◽  
pp. 01025
Author(s):  
Incheol Jeong ◽  
Sanguk Lee ◽  
Woo-Geun Ahn
Keyword(s):  
Modeling And Simulation ◽  
Satellite System ◽  
Simulation Software ◽  
Search And Rescue ◽  
Satellite Network ◽  
The World ◽  
Rescue System ◽  
Terrestrial Network ◽  
Rf Signal ◽  
Reliability And Availability

This paper describes the development of M&S (Modeling and Simulation) system based COSPAS-SARSAT SAR (Search and Rescue) system. SAR system transmits a distress signal to the terminal and transmits it to the satellite network or the terrestrial network. It recognized distress incident from anywhere in the world. The M&S system is designed to analyze the accuracy, reliability, and availability of the SAR (Search and Rescue) system. It is also designed to simulate the actual distress beacons of a distress situation. It was developed to enable performance analysis. We will verify the validity of the implemented results, applying the RF signal processing based on KNSS.

scholarly journals TTEthernet Transmission in Software-Defined Distributed Robot Intelligent Control System

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Caibing Liu ◽  
Fang Li ◽  
Guohao Chen ◽  
Xin Huang
Keyword(s):  
Internet Of Things ◽  
Real Time ◽  
Performance Test ◽  
New Technologies ◽  
Simulation Software ◽  
Utilization Rate ◽  
Intelligent Control System ◽  
Time Performance ◽  
Industrial Iot ◽  
Smart Technologies

With the integration of new technologies such as smart technologies and cloud computing in the industrial Internet of Things, the complexity of industrial IoT applications is increasing. Real-time performance and determinism are becoming serious challenges for system implementation in these Internet of Things systems, especially in critical security areas. This paper provides a framework for a software-defined bus-based intelligent robot system and designs scheduling algorithms to make TTEthernet play the role of scheduling in the framework. Through the framework, the non-real-time and uncertainties problem of distributed robotic systems can be solved. Moreover, a fragment strategy was proposed to solve the problem of large delay caused by Rate-Constrained traffic. Experimental results indicate that the improved scheme based on fragmentation strategy proposed in this paper can improve the real-time performance of RC traffic to a certain extent. Besides, this paper made a performance test and comparison experiments of the improved scheme in the simulation software to verify the feasibility of the improved scheme. The result showed that the delay of Rate-Constrained traffic was reduced and the utilization rate of network was improved.

PRACTICAL PRODUCTION LAYOUT DESIGN FOR MULTI-PRODUCT AND SMALL-LOT-SIZE PRODUCTION: A CASE STUDY

2016 ◽  
Vol 78 (7) ◽  
Author(s):  
Cheng Ying, Nyeoh ◽  
Hasnida Ab-Samat ◽  
Shahrul Kamaruddin
Keyword(s):  
Manufacturing Systems ◽  
Production Efficiency ◽  
Job Shop ◽  
Flow Line ◽  
Facility Layout ◽  
Layout Design ◽  
Simulation Software ◽  
Utilization Rate ◽  
Lot Size ◽  
Related Data

Facility layout design has an important function in manufacturing systems because it affects manufacturing costs, work in progress, lead times, and production output. This study presents facility layout designs for multi-product and small-lot-sized production lines. This research focuses on the development and analysis of layout alternatives on the basis of performance measures and aims to improve production efficiency. Thus, the tools and techniques available for the layout designed were investigated. Related data were collected, and alternative layouts were developed using the WITNESS simulation software. Finally, the alternative layouts were ana1yzed and evaluated using the analytic hierarchy process to identify the best possible layout. Two important parameters observed in the alternative layouts: the ability to produce a desired output and the flexibility of each layout coherent with the fluctuation of product demands in the industry. Results from analysis shows that suggested Model 3 with the combination of flow line and job shop configurations is the most suitable layout. This model has the highest machine utilization rate and the highest labour utilization rate yet requires only 21 operators, the lowest number of workers. For future work, this type of layout should be tested with different variation in lot sizes.

scholarly journals Application of tomographic inversion in studying airglow in the mesopause region

1998 ◽  
Vol 16 (10) ◽  
pp. 1180-1189 ◽  
Author(s):  
T. Nygrén ◽  
M. J. Taylor ◽  
M. S. Lehtinen ◽  
M. Markkanen
Keyword(s):  
Gravity Waves ◽  
Random Noise ◽  
A Priori ◽  
Lower Thermosphere ◽  
Vertical Plane ◽  
Simulated Data ◽  
Altitude Range ◽  
Priori Information ◽  
Two Stages ◽  
Atmospheric Gravity

Abstract. It is pointed out that observations of periodic nightglow structures give excellent information on atmospheric gravity waves in the mesosphere and lower thermosphere. The periods, the horizontal wavelengths and the phase speeds of the waves can be determined from airglow images and, using several cameras, the approximate altitude of the luminous layer can also be determined by triangulation. In this paper the possibility of applying tomographic methods for reconstructing the airglow structures is investigated using numerical simulations. A ground-based chain of cameras is assumed, two-dimensional airglow models in the vertical plane above the chain are constructed, and simulated data are calculated by integrating the models along a great number of rays with different elevation angles for each camera. After addition of random noise, these data are then inverted to obtain reconstructions of the models. A tomographic analysis package originally designed for satellite radiotomography is used in the inversion. The package is based on a formulation of stochastic inversion which allows the input of a priori information to the solver in terms of regularization variances. The reconstruction is carried out in two stages. In the first inversion, constant regularization variances are used within a wide altitude range. The results are used in determining the approximate altitude range of the airglow structures. Then, in the second inversion, constant non-zero regularization variances are used inside this region and zero variances outside it. With this method reliable reconstructions of the models are obtained. The number of cameras as well as their separations are varied in order to find out the limitations of the method.Key words. Tomography · Airglow · Mesopause · Gravity waves

Communication Constellation Design Trimmed by Network Routing

2012 ◽  
Vol 433-440 ◽  
pp. 4977-4982
Author(s):  
Xiao Yan Chen ◽  
Chao Han
Keyword(s):  
Time Delays ◽  
Design Method ◽  
Network Routing ◽  
Satellite Network ◽  
Communication Service ◽  
Routing Optimization ◽  
Constellation Design ◽  
Routing Performance ◽  
Simulation Scenario ◽  
Independent Design

Communication constellation design and satellite network routing are conventionally treated as two independent design processes; however, the routing results can actually give opinions to the constellation structure on its communication service quality. Based on this consideration, a new communication constellation design method is proposed in this paper which allows the constellation design to be trimmed by the routing in the way of introducing the routing result as a feedback, aiming to achieve a better constellation structure for the routing. The design method rationale is explained and a simulation scenario is given. With a basic Celestri configuration and opening the inclination to several options, the minimum link handovers and time delays offered by routing optimization on each configuration structure are compared. The simulation results show that by altering the Celestri inclination with a small amount, the constellation can achieve better routing performance, which validates the new design method.

An Improved Decision Strategy of Network Routing Based on Ant Colony Algorithm

2014 ◽  
Vol 599-601 ◽  
pp. 1378-1382
Author(s):  
Yu Bo Jia ◽  
Qian Qian Ding ◽  
Dan Li Liu ◽  
Yun Long Zhang ◽  
Jian Feng Zhang
Keyword(s):  
Convergence Rate ◽  
Ant Colony Algorithm ◽  
Memory Device ◽  
Network Routing ◽  
Ant Colony ◽  
Utilization Rate ◽  
Decision Strategy ◽  
Slow Convergence ◽  
Network Utilization ◽  
High Efficient

-Aiming at getting a high efficient network routing decision strategy, to settle problems of slow convergence speed and easily to fall into local optimal, this paper proposes a new decision strategy based on ant colony algorithm. Memory device to record each time pheromone value and pheromone differences value of the adjacent times to decide follow the former route or find a new one are the focus of this paper. The new decision technology accelerates the convergence rate, improves network utilization rate and accuracy of network routing.

scholarly journals Ecumenical issues in Józef Herbut’s philosophy of religion

2020 ◽  
Vol 20 ◽  
Author(s):  
Kazimierz Wolsza
Keyword(s):  
Foreign Language ◽  
Philosophy Of Religion ◽  
A Priori ◽  
Religious Language ◽  
Analytical Philosophy ◽  
Catholic Theology ◽  
Ecumenical Dialogue ◽  
Second Stage ◽  
Two Stages ◽  
Evangelical Theology

The philosophy of religion constituted one of the main fields of research by Prof. Józef Herbut. He created an original version of the analytical philosophy of religion. With the use of logical means, he analysed various dimensions of religion, primarily religious language. During the last period of his work, Herbut included ecumenical issues in his philosophical research. His research on these issues consisted of two stages. During the first stage, Herbut tried to create a specific logic of ecumenism. He hypothesised that the reason for the crisis of ecumenical dialogue consists in the lack of a clearly defined goal. Using the logical set theory, Herbut constructed possible models of doctrinal unity of different denominations. These models were constructed a priori, without reference to actual dialogues. During the second stage of his project, Herbut focused on the content of Catholic and Evangelical doctrines presented in catechisms. Here, he also put forward a research hypothesis that the languages of Catholic and Evangelical theology are different because they include different philosophical assumptions. These assumptions reach back to the medieval problem of universals. The language of Catholic theology is heavily influenced by moderate realism, and the language of Evangelical theology is influenced by moderate nominalism (these are two of the four standpoints in the problem of universals). Herbut's research project is original and innovative in terms of Polish philosophical and theological literature. However, in foreign language literature it is possible to find ones analogous to Herbut's project (József Fuisz, Charles Morerod).

Vehicular Ad-Hoc Network and Routing Design

2014 ◽  
Vol 641-642 ◽  
pp. 829-832 ◽  
Author(s):  
Ning Zhao ◽  
Xue Li ◽  
Mei Yang ◽  
Xin Ting Huang
Keyword(s):  
Routing Protocol ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Network Routing ◽  
Simulation Software ◽  
Vehicular Ad Hoc Network ◽  
Packet Delivery ◽  
Routing Design ◽  
Routing Performance ◽  
Simulation Parameters

To analyze vehicular Ad-Hoc network routing performance, the GPSR routing performance is studied using network simulation software NS2 compared with traffic simulation software VanetMobiSim. 100 nodes communicated with each other was stimulated by adding routing protocol into NS2, building the environment of simulation, setting simulation parameters and writing TCL script. The data packet delivery path was examined by trace files and GPSR routing performance was concluded through Gawk. The average end-to-end transmission delay trends to increase and the average delivery rate trends to drop when the average speed of vehicle nodes increase.

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