Network modelling and evaluation of simple systems

1992 ◽  
pp. 81-100 ◽  
Author(s):  
Roy Billinton ◽  
Ronald N. Allan
Keyword(s):  
Network Modelling ◽  
Simple Systems

Introduction

1978 ◽  
Vol 36 (3) ◽  
pp. 543-544
Author(s):  
W. Bernard
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Nucleic Acid ◽  
Gene Mapping ◽  
Molecular Genetics ◽  
Cell Biology ◽  
Gene Activity ◽  
Close Connection ◽  
Basic Information ◽  
Simple Systems

In comparison to many other fields of ultrastructural research in Cell Biology, the successful exploration of genes and gene activity with the electron microscope in higher organisms is a late conquest. Nucleic acid molecules of Prokaryotes could be successfully visualized already since the early sixties, thanks to the Kleinschmidt spreading technique - and much basic information was obtained concerning the shape, length, molecular weight of viral, mitochondrial and chloroplast nucleic acid. Later, additonal methods revealed denaturation profiles, distinction between single and double strandedness and the use of heteroduplexes-led to gene mapping of relatively simple systems carried out in close connection with other methods of molecular genetics.

Strict Frequency Reuse Algorithm in Downlink 3GPP Random Cellular Networks

2019 ◽  
Vol 9 (3) ◽  
pp. 404-413
Author(s):  
Sinh C. Lam ◽  
Kieu T. Nguyen
Keyword(s):  
Cellular Networks ◽  
Coverage Probability ◽  
Rayleigh Fading ◽  
Analytical Approach ◽  
Frequency Reuse ◽  
Network Modelling ◽  
Cell Edge ◽  
Term Evolution ◽  
Establishment Phase

Background & Objective: In this work, we introduced a mathematical network model which follows on the recommendations of 3GPP to evaluate the downlink Long Term Evolution (LTE) network utilizing Strict Frequency Reuse (FR) scheme. The network modelling bases on the establishment phase and communications of the FR scheme. The user average coverage probability is derived and analysed under Rayleigh fading environment and furthermore the closed-form formulations of the performance are found using Gauss Quadratures. Through the Monte Carlo simulation, it is proved that the proposed analytical approach is more accurate than other approaches in the literature. Conclusion: Furthermore, this paper stated that the overall system can achieve the better performance with a higher number of Cell-Edge Users (CEUs), which contrasts with other works in the literature.

Simple Systems

2017 ◽  
Author(s):  
Jochen Rau
Keyword(s):  
Magnetic Field ◽  
Low Temperatures ◽  
General Framework ◽  
Gibbs State ◽  
Macroscopic System ◽  
Basic Model ◽  
System A ◽  
Paramagnetic Salt ◽  
High And Low Temperatures ◽  
Simple Systems

Even though the general framework of statistical mechanics is ultimately targeted at the description of macroscopic systems, it is illustrative to apply it first to some simple systems: a harmonic oscillator, a rotor, and a spin in a magnetic field. These applications serve to illustrate how a key function associated with the Gibbs state, the so-called partition function, is calculated in practice, how the entropy function is obtained via a Legendre transformation, and how such systems behave in the limits of high and low temperatures. After discussing these simple systems, this chapter considers a first example where multiple constituents are assembled into a macroscopic system: a basic model of a paramagnetic salt. It also investigates the size of energy fluctuations and how—in the case of the paramagnet—these fluctuations scale with the number of constituents.

scholarly journals Role of efficient testing and contact tracing in mitigating the COVID-19 pandemic: a network modelling study

BMJ Open ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. e045886
Author(s):  
Yiying Hu ◽  
Jianying Guo ◽  
Guanqiao Li ◽  
Xi Lu ◽  
Xiang Li ◽  
...  
Keyword(s):  
Real World ◽  
Case Fatality ◽  
Contact Tracing ◽  
Secondary Outcome ◽  
Time Interval ◽  
Fatality Rate ◽  
Real World Data ◽  
Network Modelling ◽  
World Data ◽  
Quantitative Evidence

ObjectivesThis study quantified how the efficiency of testing and contact tracing impacts the spread of COVID-19. The average time interval between infection and quarantine, whether asymptomatic cases are tested or not, and initial delays to beginning a testing and tracing programme were investigated.SettingWe developed a novel individual-level network model, called CoTECT (Testing Efficiency and Contact Tracing model for COVID-19), using key parameters from recent studies to quantify the impacts of testing and tracing efficiency. The model distinguishes infection from confirmation by integrating a ‘T’ compartment, which represents infections confirmed by testing and quarantine. The compartments of presymptomatic (E), asymptomatic (I), symptomatic (Is), and death with (F) or without (f) test confirmation were also included in the model. Three scenarios were evaluated in a closed population of 3000 individuals to mimic community-level dynamics. Real-world data from four Nordic countries were also analysed.Primary and secondary outcome measuresSimulation result: total/peak daily infections and confirmed cases, total deaths (confirmed/unconfirmed by testing), fatalities and the case fatality rate. Real-world analysis: confirmed cases and deaths per million people.Results(1) Shortening the duration between Is and T from 12 to 4 days reduces infections by 85.2% and deaths by 88.8%. (2) Testing and tracing regardless of symptoms reduce infections by 35.7% and deaths by 46.2% compared with testing only symptomatic cases. (3) Reducing the delay to implementing a testing and tracing programme from 50 to 10 days reduces infections by 35.2% and deaths by 44.6%. These results were robust to sensitivity analysis. An analysis of real-world data showed that tests per case early in the pandemic are critical for reducing confirmed cases and the fatality rate.ConclusionsReducing testing delays will help to contain outbreaks. These results provide policymakers with quantitative evidence of efficiency as a critical value in developing testing and contact tracing strategies.

Sign in / Sign up

Export Citation Format

Share Document