Rate Control In Variable Transmission Rate Image Coders

1990 ◽  
Author(s):  
Herbert Holzlwimmer
Keyword(s):  
Rate Control ◽  
Transmission Rate ◽  
Variable Transmission

A Power Optimization Algorithm for Ad Hoc Networks with Variable Rate Control

2013 ◽  
Vol 470 ◽  
pp. 611-616
Author(s):  
Xuan Jie Ning ◽  
Hai Zhao ◽  
Mao Fan Yang ◽  
Dan Wu
Keyword(s):  
Ad Hoc Networks ◽  
Rate Control ◽  
Ad Hoc ◽  
Transmission Rate ◽  
Mac Protocol ◽  
Network Capacity ◽  
Data Rate ◽  
Medium Access ◽  
High Data ◽  
Hoc Networks

This paper is concerned with the capacity of ad hoc networks employing pure ALOHA medium access control (MAC) protocol under the effect of different transmission power levels and variable data rate control. The data rate of a certain link is related to the signal to interference plus noise ratio (SINR), and SINR is, in turn, related to the transmitted power and link distance. The increasing power conducts a high data rate, resulting in the high interference of networks. Consequently, the optimum power that yields maximum network throughput is a tradeoff between transmission rate and network interference. Mathematical model analysis for the ad hoc network capacity are presented in the paper. A revised expression to the approximate calculating of the capture probability in networks is proposed.

scholarly journals COVID-19 clusters in schools: frequency, size, and transmission rates from crowdsourced exposure reports

2021 ◽  
Author(s):  
Paul Tupper ◽  
Shraddha Pai ◽  
Caroline Colijn ◽  
Keyword(s):  
Cluster Size ◽  
Index Case ◽  
Transmission Rate ◽  
Parameter Estimates ◽  
Variable Rate ◽  
Transmission Rates ◽  
The Us ◽  
Variable Transmission ◽  
Index Cases

The role of schools in the spread of the COVID-19 pandemic is controversial, with some claiming they are an important driver of the pandemic and others arguing that transmission in schools is negligible. School cluster reports that have been collected in various jurisdictions are a source of data about transmission in schools. These reports consist of the name of a school, a date, and the number of students known to be infected. We provide a simple model for the frequency and size of clusters in this data, based on random arrivals of index cases at schools who then infect their classmates with a highly variable rate, fitting the overdispersion evident in the data. We fit our model to reports for several jurisdictions in the US and Canada, providing estimates of mean and dispersion for cluster size, whilst factoring in imperfect ascertainment. Our parameter estimates are robust to variations in ascertainment fraction. We use these estimates in three ways: i) to explore how uneven the distribution of cases is among different clusters in different jurisdictions (that is, what fraction of cases are in the 20% largest clusters), ii) to estimate how long it will be until we see a cluster a given size in jurisdiction, and iii) to determine the distribution of instantaneous transmission rate β among different index case. We show how these latter distribution can be used in simulations of school transmission where we explore the effect of different interventions, in the context of highly variable transmission rates.

scholarly journals Cam based Infinitely Variable Transmission Theoretic Modelling

2022 ◽  
Vol 961 (1) ◽  
pp. 012091
Author(s):  
Muhaimen Faleh ◽  
Amjad Al-Hamood ◽  
Mahir H. Majeed
Keyword(s):  
Transmission Rate ◽  
Angular Speed ◽  
Output Shaft ◽  
Current Investigation ◽  
Discrete Variation ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Performance Research ◽  
Grooved Wheel ◽  
Theoretical Results

Abstract Infinitely variable transmission (IVT) is a system which delivers the ratio between two turning elements to a continuous (non-discrete) variation (including zero). This article uses Solidworks software to build and simulate a cam-based IVT system. There are two identical units in the system under examination. Each unit comprises a cam with an oscillating slot connection that swings on a hinge and can be vertically shifted by changing the transmission rate. This modifier can be a power screw or a hydraulic ram. In addition, a grooved wheel and followers or an actuator are included in the system units. The raised wheels swing rotating movement, such that they are coupled by a single-way clutch to the output shaft (ratchet) to move the output shaft one way. During the performance research, cam shapes are considered and examined inside the mechanism. a mixture of the unchanging speed and 1-5 polynomial shapes, used for the current investigation and tailored for The results produced from the simulation generally reveal the theoretical results expected in accordance with the layout of the current IVT system. For all parts in these units, the findings imply a uniform velocity while each unit is powered. In this investigation, nevertheless, the ratchets used cause remarkable fluctuations in the angular speed of the output axis. Further research is therefore urgently needed in the choice and investigation of more efficient ratchets.

scholarly journals Decline in global transmission rates of COVID-19

2020 ◽  
Author(s):  
Ethan Romero-Severson ◽  
Nick Hengartner ◽  
Grant Meadors ◽  
Ruian Ke
Keyword(s):  
Particle Filtering ◽  
Transmission Rate ◽  
Global Scale ◽  
Initial Growth ◽  
Social Distancing ◽  
Transmission Rates ◽  
Case Count ◽  
Slow Decline ◽  
Detection Probabilities ◽  
Variable Transmission

AbstractOur method uses a hybrid deterministic and stochastic formalism that allows for time variable transmission rates and detection probabilities. The model was fit using iterated particle filtering to case count and death count time series from 51 countries. We found evidence for a declining transmission rate in 42 of the 51 examined countries. Of those 42 countries 34 have significant evidence for subcritical transmission rates, although the decline in new cases are relatively slow compared to the initial growth rates. This suggests that global scale social distancing efforts to slow the spread of COVID-19 are effective although they need to be strengthened in many regions and maintained in others to avoid further resurgence of COVID-19. The slow decline also suggests alternative strategies to control the virus are needed before social distancing efforts are partially relaxed.

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