scholarly journals A Review of Routing Algorithms Based on Multi-Layer Satellite Networks

2021 ◽  
Vol 2136 (1) ◽  
pp. 012040
Author(s):  
Xialu Zhang ◽  
Xiaoxi Hu ◽  
Tianjiao Xie
Keyword(s):  
Single Layer ◽  
Orbital Plane ◽  
Development Trend ◽  
Routing Algorithms ◽  
Satellite Networks ◽  
Spectrum Efficiency ◽  
System Throughput ◽  
General Situation ◽  
Satellite Network ◽  
Advantages And Disadvantages

Abstract Compared with single layer satellite network, satellite distribution of multi-layer satellite networks in the double layer or multilayer orbital plane, combines all the advantages of engaging subjects of the satellite, therefore contains its low vulnerability, good robustness, high stability, high spectrum efficiency and system throughput, channel characteristics such as large capacity, in the satellite network is a very promising direction. Multilayer satellite network also has some inevitable disadvantages, that is, the number of nodes and the number of links is large, so it has the characteristics of frequent changes in network topology, which requires higher routing algorithm. There are many researches on routing algorithms based on multi-layer satellite networks at home and abroad. This paper introduces the general situation of multi-layer satellite network, classifies the existing routing algorithms of multi-layer satellite network according to different standards, analyzes several typical routing algorithms in detail, points out the advantages and disadvantages, and summarizes the future development trend.

Recent Patents on the Angular Contact Ball Bearing of High-Speed Motorized Spindle

2020 ◽  
Vol 13 ◽  
Author(s):  
Yudong Bao ◽  
Linkai Wu ◽  
Yanling Zhao ◽  
Chengyi Pan
Keyword(s):  
High Speed ◽  
Ball Bearing ◽  
Rapid Development ◽  
Ceramic Materials ◽  
Development Trend ◽  
Numerical Control ◽  
Angular Contact Ball Bearing ◽  
Practical Applications ◽  
High Speed Cutting ◽  
Advantages And Disadvantages

Background:: Angular contact ball bearings are the most popular bearing type used in the high speed spindle for machining centers, The performance of the bearing directly affects the machining efficiency of the machine tool, Obtaining a higher value is the direction of its research and development. Objective:: By analyzing the research achievements and patents of electric spindle angular contact bearings, summarizing the development trend provides a reference for the development of electric spindle bearings. Methods:: Through the analysis of the relevant technology of the electric spindle angular contact ball bearing, the advantages and disadvantages of the angular contact ball bearing are introduced, and the research results are combined with the patent analysis. Results:: With the rapid development of high-speed cutting and numerical control technology and the needs of practical applications, the spindle requires higher and higher speeds for bearings. In order to meet the requirements of use, it is necessary to improve the bearing performance by optimizing the structure size and improving the lubrication conditions. Meanwhile, reasonable processing and assembly methods will also have a beneficial effect on bearing performance. Conclusion:: With the continuous deepening of bearing technology research and the use of new structures and ceramic materials has made the bearing's limit speed repeatedly reach new highs. The future development trend of high-speed bearings for electric spindles is environmental protection, intelligence, high speed, high precision and long life.

scholarly journals Graphene-Based Nanosystems: Versatile Nanotools for Theranostics and Bioremediation

2021 ◽  
Author(s):  
Marlene Lúcio ◽  
Eduarda Fernandes ◽  
Hugo Gonçalves ◽  
Sofia Machado ◽  
Andreia C. Gomes ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Quantum Physics ◽  
Single Layer ◽  
The Body ◽  
Diagnostic Tools ◽  
Honeycomb Lattice ◽  
Two Dimensional ◽  
Advantages And Disadvantages ◽  
Broad Variety ◽  
Imaging Strategy

Since its revolutionary discovery in 2004, graphene— a two-dimensional (2D) nanomaterial consisting of single-layer carbon atoms packed in a honeycomb lattice— was thoroughly discussed for a broad variety of applications including quantum physics, nanoelectronics, energy efficiency, and catalysis. Graphene and graphene-based nanomaterials (GBNs) have also captivated the interest of researchers for innovative biomedical applications since the first publication on the use of graphene as a nanocarrier for the delivery of anticancer drugs in 2008. Today, GBNs have evolved into hybrid combinations of graphene and other elements (e.g., drugs or other bioactive compounds, polymers, lipids, and nanoparticles). In the context of developing theranostic (therapeutic + diagnostic) tools, which combine multiple therapies with imaging strategies to track the distribution of therapeutic agents in the body, the multipurpose character of the GBNs hybrid systems has been further explored. Because each therapy and imaging strategy has inherent advantages and disadvantages, a mixture of complementary strategies is interesting as it will result in a synergistic theranostic effect. The flexibility of GBNs cannot be limited to their biomedical applications and, these nanosystems emerge as a viable choice for an indirect effect on health by their future use as environmental cleaners. Indeed, GBNs can be used in bioremediation approaches alone or combined with other techniques such as phytoremediation. In summary, without ignoring the difficulties that GBNs still present before being deemed translatable to clinical and environmental applications, the purpose of this chapter is to provide an overview of the remarkable potential of GBNs on health by presenting examples of their versatility as nanotools for theranostics and bioremediation.

Technology of Grid-Connected Wind Power Generation

2012 ◽  
Vol 542-543 ◽  
pp. 47-51 ◽  
Author(s):  
Jie Li ◽  
Yu Jie Zhang
Keyword(s):  
Power Generation ◽  
Wind Power ◽  
Development Trend ◽  
Wind Power Generation ◽  
Constant Frequency ◽  
Advantages And Disadvantages ◽  
Variable Speed Constant Frequency ◽  
Power Generation System ◽  
Doubly Fed ◽  
Further Development

Based on the synthesis of several common grid-connected methods of wind generator, the paper compares their advantages and disadvantages when these methods are used in theapplication of wind power generation respectively, then predicts their further development trend of wind power grid-connected technologies. Besides, brushless doubly-fed generators are widely applied inVSCF(Variable Speed Constant Frequency) wind power generation system

Structural Comparison and Project Cost Analysis on Two Kinds of Frame Structures

2012 ◽  
Vol 193-194 ◽  
pp. 1197-1200
Author(s):  
Zhong Min Liu ◽  
Xue Hua Liu ◽  
Jing Ji
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structure ◽  
Steel Structure ◽  
Development Trend ◽  
Economic Benefits ◽  
System Structure ◽  
Frame Structure ◽  
Reinforced Concrete Structure ◽  
Project Cost ◽  
Advantages And Disadvantages

This article introduces two kinds of frame structure system structure for steel structure and reinforced concrete structure, analyzes the similarities and differences in the structural properties, structural occupied area, time limit for a project, project cost and comprehensive economic benefits and other aspects. The advantages and disadvantages of them are analyzed, and the engineering cost is compared and analyzed. Results show that the steel structure has more the advantage than reinforced concrete structure, and it is development trend of factories and high-rise building in the future.

scholarly journals A Fast Hybrid Beamforming Scheme for High-Speed Railway Communications

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 998
Author(s):  
Yu Xiao ◽  
Gang Qiu ◽  
Yafeng Wang
Keyword(s):  
High Speed ◽  
Low Complexity ◽  
Spectrum Efficiency ◽  
System Throughput ◽  
Quality Of Services ◽  
Communication Service ◽  
High Speed Railway ◽  
High Speed Trains ◽  
Hybrid Beamforming

With the increasingly demand for reliable mobile communication service in the high-speed railway (HSR) system, the service stability of HSR communication is of great concern in recent research. Focusing on ensuring the quality of services (QoS) and system throughput, massive multi-input multi-output (massive MIMO) and beamforming technologies have been widely applied. In this paper, aiming to minimize the communication outage probability (OP) and not to decrease spectrum efficiency (SE) too much, we propose a fast HBF (F-HBF) scheme for HSR communications. The proposed scheme uses a low-complexity beam-searching algorithm to trace high-speed trains in real time. The simulation results verify that the proposed scheme can significantly reduce OP without too much SE degradation.

Research of Localization Issues in Underwater Sensor Networks

2012 ◽  
Vol 157-158 ◽  
pp. 424-427
Author(s):  
Xian Min Wei
Keyword(s):  
Sensor Networks ◽  
Target Tracking ◽  
Real Time ◽  
Development Trend ◽  
Underwater Sensor Networks ◽  
Localization Problem ◽  
Advantages And Disadvantages ◽  
Localization Algorithms ◽  
Underwater Localization ◽  
The Development Trend

Localization problem has great significance in the applications of underwater sensor networks (UWSN), such as real-time monitoring, target tracking and navigation. This paper analized a series of challenges in underwater localization problem, introduced exsiting localization algorithms and discussed their advantages and disadvantages, and then the development trend of localization problem is discussed. Finally, we give some suggestions in the design of localization algoprithms.

Analysis on De-Icing Methods for 4-Bundle 500kV Transmission Lines

2013 ◽  
Vol 694-697 ◽  
pp. 790-794
Author(s):  
Shun Xin Liu ◽  
You Han Guo
Keyword(s):  
Transmission Line ◽  
South China ◽  
Transmission Lines ◽  
Research Direction ◽  
Development Trend ◽  
Ice Melting ◽  
Power Networks ◽  
Advantages And Disadvantages ◽  
Prevention And Treatment ◽  
The Development Trend

In view of the massive transmission lines suffered disaster of ice coating at the beginning of 2008 in south China. In this paper, several typical schemes for the prevention and treatment of ice coating occurred in power networks home and abroad are analyzed. Common melting ice methods can be divided into three kinds: thermal ice-melting, mechanical de-icing and new de-icing. This paper describes a 500 kV transmission line and analyses each of these measures briefly. At the same time, the advantages and disadvantages of various measures and their applications were summarized. At last, the development trend and the research direction were pointed out．

Research Status and Development Trend of Electromagnetic Defect Detection Logging

2013 ◽  
Vol 325-326 ◽  
pp. 856-860
Author(s):  
Zheng Guo Yan ◽  
Lin Zhao
Keyword(s):  
Defect Detection ◽  
Hot Spot ◽  
Development Trend ◽  
Research Status ◽  
Advantages And Disadvantages ◽  
Detection Technology ◽  
Metal Thickness ◽  
Theory Research ◽  
The Development Trend

Electromagnetic defect detection logging can measure multilayer pipeline and provide the information of casing defect and the remaining metal thickness, is the hot spot of the casing defect detection technology. This paper elaborates the advantages and disadvantages of electromagnetic defect detection logging and the present instrument situation, compares technical indexes of several new electromagnetic casing defect detection instruments, summarizes the latest research status, points out the problems existed in current researches and the development trend combining with the instrument index and theory research.

The Overview of Energy Storage Technology

2014 ◽  
Vol 940 ◽  
pp. 336-338 ◽  
Author(s):  
You Jie Ma ◽  
Hong Kun Lu ◽  
Xue Song Zhou
Keyword(s):  
Energy Storage ◽  
Power System ◽  
Magnetic Energy ◽  
Lithium Ion ◽  
Development Trend ◽  
Super Capacitor ◽  
Advantages And Disadvantages ◽  
Storage Technology ◽  
The Stability ◽  
Battery Technology

Power storage technology serves to cut the peak and fill valley, regulate the power frequency, improve the stability, and raise the utilization coefficient of the grid in the power system. This paper introduces various types of storage technology such as superconducting magnetic energy storage, super capacitor energy storage, sodium sulfur battery, lithium ion, flow battery technology, and discusses their advantages and disadvantages. The development trend and the different applications of storage technology in the power system are also summarized.

A Survey on Detecting Methods for Harmonic of Power System

2012 ◽  
Vol 614-615 ◽  
pp. 907-910
Author(s):  
Xue Song Zhou ◽  
Guang Zhu Chen ◽  
You Jie Ma
Keyword(s):  
Power System ◽  
Reactive Power ◽  
Detection Method ◽  
Response Speed ◽  
Development Trend ◽  
Detection Methods ◽  
Detection Accuracy ◽  
Harmonic Detection ◽  
Advantages And Disadvantages ◽  
Power System Harmonics

This paper describes Detecting Methods for Harmonics of power system has been considered one of the serious harms for power system. The research of harmonics has obtained high attention among people. The researches of harmonics detection have many methods, such as Based on Fryze theory of harmonic power detection, Instantaneous reactive power theory detection method, Fourier Transformation harmonic detection method, wavelet transform detection method, neural networks harmonic detection method etc. Aiming at harmonic detection, the different detection methods of power system harmonics are summarized and compared. This paper reviews the existing harmonic detection methods, and discuss their advantages and disadvantages in terms of detection accuracy and response speed, and finally summarizes the development trend of the harmonic detection method.

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