scholarly journals Switchable Transducers in GaN MEMS Resonators: Performance Comparison and Analysis

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 461
Author(s):  
Imtiaz Ahmed ◽  
Dana Weinstein
Keyword(s):  
Ad Hoc ◽  
Building Blocks ◽  
Resonant Mode ◽  
Performance Comparison ◽  
Superior Performance ◽  
Complete Suppression ◽  
Mems Resonators ◽  
Gan Heterostructure ◽  
Fitting In ◽  
Electromechanical Actuation

This work presents a comprehensive comparison of switchable electromechanical transducers in an AlN/GaN heterostructure toward the goal of reconfigurable RF building blocks in next-generation ad hoc radios. The transducers’ inherent switching was achieved by depleting a 2D electron gas (2DEG) channel, allowing an RF signal launched by interdigital transducers (IDTs) to effectively excite the symmetric (So) Lamb mode of vibration in the piezoelectric membrane. Different configurations for applying DC bias to the channel for electromechanical actuation in the piezoelectric are discussed. Complete suppression of the mechanical mode was achieved with the transducers in the OFF state. Equivalent circuit models were developed to extract parameters from measurements by fitting in both ON and OFF states. This is the first time that an extensive comparative study of the performance of different switchable transducers in their ON/OFF state is presented along with frequency scaling of the resonant mode. The switchable transducer with Ohmic IDTs and a Schottky control gate showed superior performance among the designs under consideration.

Performance Comparison of MANET, VANET and FANET

2018 ◽  
Vol 8 (5) ◽  
pp. 132
Author(s):  
Aarti Sahu ◽  
Laxmi Shrivastava
Keyword(s):  
Fuzzy Logic ◽  
Wireless Network ◽  
Packet Loss ◽  
Ad Hoc Network ◽  
Fuzzy Logic Controller ◽  
Ad Hoc ◽  
Mobile Ad Hoc Network ◽  
Performance Comparison ◽  
Fuzzy Rules ◽  
Mobile Ad Hoc

A wireless ad hoc network is a decentralized kind of wireless network. It is a kind of temporary Computer-to-Computer connection. It is a spontaneous network which includes mobile ad-hoc network (MANET), vehicular ad-hoc network (VANET) and Flying ad-hoc network (FANET). Mobile Ad Hoc Network (MANET) is a temporary network that can be dynamically formed to exchange information by wireless nodes or routers which may be mobile. A VANET is a sub form of MANET. It is an technology that uses vehicles as nodes in a network to make a mobile network. FANET is an ad-hoc network of flying nodes. They can fly independently or can be operated distantly. In this research paper Fuzzy based control approaches in wireless network detects & avoids congestion by developing the ad-hoc fuzzy rules as well as membership functions.In this concept, two parameters have been used as: a) Channel load b) The size of queue within intermediate nodes. These parameters constitute the input to Fuzzy logic controller. The output of Fuzzy logic control (sending rate) derives from the conjunction with Fuzzy Rules Base. The parameter used input channel load, queue length which are produce the sending rate output in fuzzy logic. This fuzzy value has been used to compare the MANET, FANET and VANET in terms of the parameters Throughput, packet loss ratio, end to end delay. The simulation results reveal that usage of Qual Net 6.1 simulator has reduced packet-loss in MANET with comparing of VANET and FANET.

Language, procedures, and the non-perceptual origin of natural number concepts

2016 ◽  
Author(s):  
David Barner
Keyword(s):  
General Framework ◽  
Ad Hoc ◽  
Building Blocks ◽  
Number Words ◽  
Linguistic Markers ◽  
Logical Foundations ◽  
Large Numbers ◽  
Perceptual Representations ◽  
Positive Integers ◽  
Perceptual Systems

Perceptual representations – e.g., of objects or approximate magnitudes –are often invoked as building blocks that children combine with linguisticsymbols when they acquire the positive integers. Systems of numericalperception are either assumed to contain the logical foundations ofarithmetic innately, or to supply the basis for their induction. Here Ipropose an alternative to this general framework, and argue that theintegers are not learned from perceptual systems, but instead arise toexplain perception as part of language acquisition. Drawing oncross-linguistic data and developmental data, I show that small numbers(1-4) and large numbers (~5+) arise both historically and in individualchildren via entirely distinct mechanisms, constituting independentlearning problems, neither of which begins with perceptual building blocks.Specifically, I propose that children begin by learning small numbers(i.e., *one, two, three*) using the same logical resources that supportother linguistic markers of number (e.g., singular, plural). Several yearslater, children discover the logic of counting by inferring the logicalrelations between larger number words from their roles in blind countingprocedures, and only incidentally associate number words with perception ofapproximate magnitudes, in an *ad hoc* and highly malleable fashion.Counting provides a form of explanation for perception but is not causallyderived from perceptual systems.

scholarly journals Identifying home locations in human mobility data: an open-source R package for comparison and reproducibility

2021 ◽  
Author(s):  
Qingqing Chen ◽  
Ate Poorthuis
Keyword(s):  
Software Package ◽  
Ad Hoc ◽  
Human Mobility ◽  
Building Blocks ◽  
R Package ◽  
Location Based Services ◽  
R Software ◽  
Mobility Data ◽  
Residential Population ◽  
Research Goal

Identifying meaningful locations, such as home or work, from human mobility data has become an increasingly common prerequisite for geographic research. Although location-based services (LBS) and other mobile technology have rapidly grown in recent years, it can be challenging to infer meaningful places from such data, which - compared to conventional datasets – can be devoid of context. Existing approaches are often developed ad-hoc and can lack transparency and reproducibility. To address this, we introduce an R software package for inferring home locations from LBS data. The package implements pre-existing algorithms and provides building blocks to make writing algorithmic ‘recipes’ more convenient. We evaluate this approach by analyzing a de-identified LBS dataset from Singapore that aims to balance ethics and privacy with the research goal of identifying meaningful locations. We show that ensemble approaches, combining multiple algorithms, can be especially valuable in this regard as the resulting patterns of inferred home locations closely correlate with the distribution of residential population. We hope this package, and others like it, will contribute to an increase in use and sharing of comparable algorithms, research code and data. This will increase transparency and reproducibility in mobility analyses and further the ongoing discourse around ethical big data research.

scholarly journals PERFORMANCE COMPARISON WITH ACCESSIBILITY PREDICTION AND LINK BREAKAGE PREDICTION IN MANETS

2015 ◽  
pp. 48-54
Author(s):  
TEJAL ARVIND SONAWALE ◽  
SHIKHA NEMA
Keyword(s):  
Ad Hoc ◽  
Power Level ◽  
Performance Comparison ◽  
Delivery Ratio ◽  
Route Discovery ◽  
Network Resources ◽  
Average Delay ◽  
Network Bandwidth ◽  
Multiple Routes ◽  
Hoc Networks

Ad Hoc Networks face a lot of problems due to issues like mobility, power level, load of the network, bandwidth constraints, dynamic topology which lead to link breaks, node break down and increase in overhead. As nodes are changing their position consistently, routes are rapidly being disturbed, thereby generating route errors and new route discoveries. The need for mobility awareness is widely proclaimed. In our dissertation we present a scheme AOMDV-APLP that makes AOMDV aware of accessibility of neighbor nodes in the network. Nodes acquire the accessibility information of other nodes through routine routing operations and keep in their routing table. Based on this information route discovery is restricted to only “accessible” and “start” nodes. Further route with the strongest signal strength is selected from multiple routes using Link life value predicted by Link Breakage prediction technique. Simulation result shows that using accessibility and link life knowledge in route discovery process MAC overhead, routing overhead and average delay is reduced 3 times, and improve the Packet delivery ratio to a large extent than standard AOMDV which reflects effective use of network resources.

scholarly journals Performance Comparison of CDR-MAC at Linear and Random Topology for Wireless Ad Hoc Network

2014 ◽  
Vol 91 (14) ◽  
pp. 26-29
Author(s):  
Md. JahangeerAlam ◽  
Asrar Ahmad Ansari ◽  
Khwaja Mohammad Athar ◽  
Zafrul Hasan
Keyword(s):  
Ad Hoc Network ◽  
Ad Hoc ◽  
Performance Comparison ◽  
Wireless Ad Hoc Network ◽  
Random Topology

scholarly journals PI and LQR controllers for Frequency Regulation including Wind Generation

2018 ◽  
Vol 8 (5) ◽  
pp. 3711 ◽  
Author(s):  
Semaria Ruiz ◽  
Julian Patiño ◽  
Jairo Espinosa
Keyword(s):  
Power Systems ◽  
Wind Turbines ◽  
Frequency Control ◽  
Test System ◽  
Performance Comparison ◽  
Load Frequency Control ◽  
Superior Performance ◽  
Frequency Regulation ◽  
Control Effort ◽  
Load Frequency

<pre>The increasing use of renewable technologies such as wind turbines in power systems may require the contribution of these new sources into grid ancillary services, such as Load Frequency Control. Hence, this work dealt with the performance comparison of two traditional control structures, PI and <span>LQR</span>, for secondary regulation of Load Frequency Control with the participation of variable-speed wind turbines. For this purpose, the doubly-fed induction generator wind turbine was modeled with additional control loops for emulation of the inertial response of conventional machines for frequency regulation tasks. Performance of proposed strategies was verified through simulation in a benchmark adapted from the <span>WSCC</span> 3 machines 9-bus test system. Results showed overall superior performance for <span>LQR</span> controller, although requiring more strenuous control effort from conventional units than PI control.</pre>

Sign in / Sign up

Export Citation Format

Share Document