scholarly journals Probabilistic Path and Data Capacity Based Handover Decision for Hierarchical Macro- and Femtocell Networks

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Jae-Wook Lee ◽  
Sang-Jo Yoo
Keyword(s):  
Low Cost ◽  
Mobile Station ◽  
Data Rate ◽  
Network Coverage ◽  
Improve Performance ◽  
Femtocell Networks ◽  
Handover Decision ◽  
Communication Capacity ◽  
Data Capacity ◽  
Simulation Results

Femtocells are considered a technology to improve performance of a network by increasing network coverage and communication capacity at a relatively low cost. However, if there are a lot of femtocells in a macrocell, the number of handovers greatly increases, and unnecessary handovers can occur from the mobile station temporarily passing through a femtocell. In this paper, we propose a method that probabilistically estimates the path in a femtocell and makes a handover decision based on the available data capacity of a mobile station on the estimated path. Simulation results show that the proposed method effectively reduces the number of unnecessary handovers while improving the data rate and capacity.

Study and design of dual stator permanent magnet machine with spoke-type configurations using phase-group concentrated-coil windings

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1381-1389
Author(s):  
Dezhi Chen ◽  
Chengwu Diao ◽  
Zhiyu Feng ◽  
Shichong Zhang ◽  
Wenliang Zhao
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
Low Cost ◽  
Dynamic Performance ◽  
Torque Ripple ◽  
Permanent Magnet Machine ◽  
Torque Density ◽  
Phase Group ◽  
High Torque ◽  
Simulation Results

In this paper, a novel dual-stator permanent magnet machine (DsPmSynM) with low cost and high torque density is designed. The winding part of the DsPmSynM adopts phase-group concentrated-coil windings, and the permanent magnets are arranged by spoke-type. Firstly, the winding structure reduces the amount of copper at the end of the winding. Secondly, the electromagnetic torque ripple of DsPmSynM is suppressed by reducing the cogging torque. Furthermore, the dynamic performance of DsPmSynM is studied. Finally, the experimental results are compared with the simulation results.

An Analysis on the Forming Load of AA 2024 Aluminium Alloy in Combined and Sequence Operation Process

2006 ◽  
Vol 519-521 ◽  
pp. 949-954 ◽  
Author(s):  
Beong Bok Hwang ◽  
J.H. Shim ◽  
Jung Min Seo ◽  
H.S. Koo ◽  
J.H. Ok ◽  
...  
Keyword(s):  
Finite Element ◽  
Load Capacity ◽  
Low Cost ◽  
Forming Load ◽  
Mechanical Press ◽  
Combined Operation ◽  
Aa 2024 ◽  
Load Characteristics ◽  
Simulation Results ◽  
Selection Of

This paper is concerned with the analysis of the forming load characteristics of a forward-backward can extrusion in both combined and sequence operation. A commercially available finite element program, which is coded in the rigid-plastic finite element method, has been employed to investigate the forming load characteristics. AA 2024 aluminum alloy is selected as a model material. The analysis in the present study is extended to the selection of press frame capacity for producing efficiently final product at low cost. The possible extrusion processes to shape a forward-backward can component with different outer diameters are categorized to estimate quantitatively the force requirement for forming forward-backward can part, forming energy, and maximum pressure exerted on the die-material interfaces, respectively. The categorized processes are composed of combined and/or some basic extrusion processes such as sequence operation. Based on the simulation results about forming load characteristics, the frame capacity of a mechanical press of crank-drive type suitable for a selected process could be determined along with securing the load capacity and with considering productivity. In addition, it is suggested that different load capacities be selected for different dimensions of a part such as wall thickness in forward direction and etc. It is concluded quantitatively from the simulation results that the combined operation is superior to sequence operation in terms of relatively low forming load and thus it leads to low cost for forming equipments. However, it is also known from the simulation results that the precise control of dimensional accuracy is not so easy in combined operation. The results in this paper could be a good reference for analysis of forming process for complex parts and selection of proper frame capacity of a mechanical press to achieve low production cost and thus high productivity.

scholarly journals Silicon Photonic Micro-Transceivers for Beyond 5G Environments

2021 ◽  
Vol 11 (22) ◽  
pp. 10955
Author(s):  
Kazuhiko Kurata ◽  
Luca Giorgi ◽  
Fabio Cavaliere ◽  
Liam O’Faolain ◽  
Sebastian A. Schulz ◽  
...  
Keyword(s):  
Quantum Dot ◽  
High Temperatures ◽  
Low Cost ◽  
Laser System ◽  
Data Rate ◽  
Ambient Temperatures ◽  
Quantum Dot Laser ◽  
Silicon Photonic ◽  
Order Of Magnitude ◽  
And Performance

Here, we report on the design and performance of a silicon photonic micro-transceiver required to operate in 5G and 6G environments at high ambient temperatures above 105 °C. The four-channel “IOCore” micro-transceiver incorporates a 1310 nm quantum dot laser system and operates at a data rate of 25 Gbps and higher. The 5 × 5 mm micro-transceiver chip benefits from a multimode coupling interface for low-cost assembly and robust connectivity at high temperatures as well as an optical redundancy scheme, which increases reliability by over an order of magnitude.

scholarly journals Ultrasound detection using optical interferometry

2021 ◽  
Author(s):  
Nusrat Jahan Surovy
Keyword(s):  
Thin Film ◽  
Ultrasound Imaging ◽  
Detection System ◽  
Incidence Angle ◽  
Low Cost ◽  
3D Ultrasound ◽  
Attractive Alternative ◽  
Simulation Results ◽  
Exerted Pressure ◽  
Piezoelectric Devices

Ultrasound imaging is a widely used noninvasive imaging technique for biomedical and other applications. Piezoelectric devices are commonly used for the generation and detection of ultrasound in these applications. However, implementation of two-dimensional arrays of piezoelectric transducers for 3D ultrasound imaging is complex and expensive. Optical Fabry-Perot interferometry is an attractive alternative to the piezoelectric devices for detection of ultrasound. In this method a thin film etalon is constructed and used. Light reflected from the two surfaces of this thin film produces an intensity which depends on the film thickness. When ultrasound is incident on the film, it changes the thickness of the film and consequently modulates the light intensity on the film. In our work, we made two types of etalon (Finesse 2) for our experiment. We detected lower frequency ultrasound (0.5 MHz or 1 MHz) using the build etalon. We determined a linear relationship between the strength of the optical signals and the exerted pressure on a film by the ultrasound. The dependence of the etalon performance on the light wavelength was demonstrated indirectly by measuring the signal at various light incidence angle. Simulation results are also presented. Lastly, we proposed the optimum design of this detection system based on the simulation results. This method of ultrasound detection can be a potential low-cost approach for 3D ultrasound imaging.

scholarly journals Prefabricated Urban Underground Utility Tunnels: A Case Study on Mechanical Behaviour with Strain Monitoring and Numerical Simulation

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yonggang Xiao ◽  
Jubing Zhang ◽  
Jie Cao ◽  
Changhong Li
Keyword(s):  
Numerical Simulation ◽  
Working Conditions ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Low Cost ◽  
Side Wall ◽  
Operating Conditions ◽  
Land Occupation ◽  
Depth Analysis ◽  
Simulation Results

The prefabricated urban utility tunnels (UUTs) have many advantages such as short construction period, low cost, high quality, and small land occupation. However, there is still a lack of in-depth analysis of the mechanical performance of the prefabricated urban utility tunnel (UUT) structure with bolted connections under different working conditions. In this paper, the force performance of a prefabricated UUT in Tongzhou District, Beijing, was studied under different working conditions using two methods: field monitoring and numerical simulation. The multichannel strain monitor was used for monitoring, and the internal wall concrete and bolt strain change data under the two conditions of installation and backfill were obtained. Combined with the construction process of the UUTs, a three-dimensional numerical model was established by COMSOL, where the build-in bolt assembly was used to simulate the longitudinal connection of the tunnel. The simulation results were compared with the measured data to verify the rationality of the computational model. The simulation results showed that the concrete and bolts on the inner wall of the tunnel work well under the two conditions of installation and backfilling; The deformation of the top plate of the prefabricated tunnel was approximately parabolic, with the largest vertical displacement (0.37 mm) in the middle and the most sensitive to the vertical load in the central part of the roof. The central portion of the side wall had the largest displacement (0.17 mm) in the inner concave. The tensile stress of bolt 3 increased the most (30.75 MPa) but was still much smaller than the yield strength of the bolt. The concrete and bolts of the UUT were found to work well through force analysis under operating conditions. In conclusion, analysis of structural forces and deformation failure modes will help design engineers understand the basic mechanisms and select the appropriate UUT structure.

scholarly journals An Overview of LoRaWAN

2021 ◽  
Vol 19 ◽  
pp. 231-239
Author(s):  
Biswajit Paul
Keyword(s):  
System Architecture ◽  
Communication Protocol ◽  
Data Rate ◽  
Network Coverage ◽  
Enabling Technology ◽  
Long Distance ◽  
Ism Band ◽  
Enabling Technologies ◽  
Distance Communication

LoRa is an IoT enabling technology which is particularly suitable for low data rate applications. The technology can achieve extended network coverage while operating in unlicensed ISM band and falls into the category of Low­Power­Wide­Area­Networks (LPWANs) technologies. Among the non­cellular based LPWAN enabling technologies, LoRa has got remarkable attention due to its fast adoption by industries. LoRa through wireless modulation enables the end­nodes to establish long distance communication while LoRaWAN refers to the communication protocol and system architecture. In this paper, an overview of LoRaWAN is presented.

scholarly journals Enhancement of Bandwidth using Inset-Fed Patch Antenna for High Frequency Applications

2019 ◽  
Vol 9 (1) ◽  
pp. 1528-1531
Keyword(s):  
Patch Antenna ◽  
High Frequency ◽  
Low Cost ◽  
High Frequencies ◽  
Simulation Results ◽  
Ku Band

Today in communication field, many antennas have been evolved for various applications. The most popularly used antennas are micro-strip antennas. These antennas can be easily fabricated at reasonably low cost. Hence, these antennas are gaining lot of importance in recent times. Many techniques have been in use for micro strip antennas to improve the performance of the antenna parameters. The design of these antennas is slowly moving towards high frequencies, where there is lot of advantage with bandwidth. In this paper a normal and E shaped inset micro-strip antenna in Ku-Band is simulated and the results are presented. It is noted that CST-MS 2015 tool has been used to get the simulation results.

scholarly journals Efficiency Evaluation for Femtocell Spectrum Access in LTE-Advanced

2015 ◽  
Vol 1 (1) ◽  
pp. 96-111
Author(s):  
Omar Arafat ◽  
Mark A Gregory
Keyword(s):  
Performance Analysis ◽  
Low Cost ◽  
Limited Area ◽  
Femtocell Networks ◽  
Indoor Coverage ◽  
Lte Advanced ◽  
Femtocell Network ◽  
Increasing Demand ◽  
Resource Allocation Scheme

Femtocells are considered one of the ultimate solutions for the ever increasing demand in LTE-Advance. Recently, wireless industries have resorted to femtocell networks in order to enhance indoor coverage and quality of service since macro-antennas fail to reach these objectives. In enabling indoor home or enterprise users with mobile broadband solutions, role of femtocells are crucially important. While considering low cost solutions for higher coverage and data rate, femtocells apparently have one of the best potentials for indoor users. Due to the dense self-deployment of femtocells in a limited area, serious inter-femtocell interference (IFI) may cause, which consequently results in severe performance degradation. To mitigate the IFI and utilize spectrum resource more efficiently, this paper proposes a cluster based femtocell deployments along with a capacity based cognitive resource allocation scheme .Three different channel configurations in a hybrid access femtocell network are considered for performance analysis. The results of a performance analysis of the cluster based femtocell configurations in a priority based users’ network are presented.

IBCube

2018 ◽  
Vol 15 (1) ◽  
pp. 27-46
Author(s):  
Qiong Hu ◽  
Hanhua Chen ◽  
Hai Jin ◽  
Chen Tian ◽  
Aobing Sun ◽  
...  
Keyword(s):  
Low Cost ◽  
Packet Delay ◽  
Building Blocks ◽  
Network Interface ◽  
Allocation Scheme ◽  
The Past ◽  
Datacenter Networks ◽  
Construction Scheme ◽  
Economical Design ◽  
Simulation Results

Datacenter networks have attracted a lot of research interest in the past few years. BCube is proved to be a promising scheme due to its low cost. By using a recursive construction scheme, BCube can exponentially scale a datacenter. Industry experiences, however, articulate the importance of incremental expansion of datacenter. In this article, the authors show that BCube's expanding scheme suffers low utilization of switch ports. They propose IBCube, a novel economical design for incrementally building datacenter networks. The insight is that: by letting the number of switches in each BCube layer equal the number of the building blocks, the authors can enable the switch ports to be fully utilized to support the total number of network interface cards of the deployed servers in the datacenters. Accordingly, their IBCube designs a novel automatic port allocation scheme. Simulation results show that the IBCube design reduces the budget for the datacenter networks by 94% as well as improves the packet delay and throughput by 10.3% and 11.5%, respectively, compared to the previous partial BCube design.

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