scholarly journals Multiplexing: A

2021 ◽  
pp. 39-58
Author(s):  
Jean Walrand
Keyword(s):  
High Speed ◽  
Probabilistic Models ◽  
Markov Chain Model ◽  
Radio Channel ◽  
Random Variables ◽  
Mean Value ◽  
Chain Model ◽  
Network Provisioning ◽  
Desktop Computers ◽  
Multiple Access Protocol

AbstractThis chapter explores the fluctuations of random variables away from their mean value. You flip a fair coin 100 times. How likely is it that you get 60 heads? Conversely, if you get 60 heads, how likely is it that the coin is fair? Such questions are fundamental in extracting information from data.In Sect. 3.1, we start by exploring the rate available to a user when a random number of them share a link, as illustrated in Sect. 3.1. Such calculations are central to network provisioning. The main analytical tool is the Central Limit Theorem explained in Sect. 3.2 where Gaussian random variables are also introduced and confidence intervals are defined. To share a common link, devices may be attached to a switch. For instance, the desktop computers in a building are typically connected to a switch that then sends the data to a common high-speed link. We explore the delays that packets face through the buffer of a switch in Sect. 3.3. The analysis uses a Markov chain model of the buffer. To share a wireless radio channel, devices use a multiple access protocol that regulates the transmissions. We study such schemes in Sect. 3.4. We use probabilistic models of the protocols.

scholarly journals Train Performance Analysis Using Heterogeneous Statistical Models

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1115
Author(s):  
Jianfeng Wang ◽  
Jun Yu
Keyword(s):  
Statistical Models ◽  
High Speed ◽  
Cox Model ◽  
Markov Chain Model ◽  
Chain Model ◽  
Time Varying ◽  
Weather Variables ◽  
Winter Climate ◽  
Stratified Cox Model ◽  
Snow Precipitation

This study investigated the effect of a harsh winter climate on the performance of high-speed passenger trains in northern Sweden. Novel approaches based on heterogeneous statistical models were introduced to analyse the train performance to take time-varying risks of train delays into consideration. Specifically, the stratified Cox model and heterogeneous Markov chain model were used to model primary delays and arrival delays, respectively. Our results showed that weather variables including temperature, humidity, snow depth, and ice/snow precipitation have a significant impact on train performance.

scholarly journals A combinatorial and probabilistic study of initial and end heights of descents in samples of geometrically distributed random variables and in permutations

2007 ◽  
Vol Vol. 9 no. 1 (Analysis of Algorithms) ◽  
Author(s):  
Guy Louchard ◽  
Helmut Prodinger
Keyword(s):  
Geometric Distribution ◽  
Analysis Of Algorithms ◽  
Markov Chain Model ◽  
Random Variables ◽  
Discrete Distributions ◽  
Chain Model ◽  
Initial Height ◽  
Probabilistic Study ◽  
International Audience ◽  
Expected Values

Analysis of Algorithms International audience In words, generated by independent geometrically distributed random variables, we study the lth descent, which is, roughly speaking, the lth occurrence of a neighbouring pair ab with a>b. The value a is called the initial height, and b the end height. We study these two random variables (and some similar ones) by combinatorial and probabilistic tools. We find in all instances a generating function Ψ(v,u), where the coefficient of vjui refers to the jth descent (ascent), and i to the initial (end) height. From this, various conclusions can be drawn, in particular expected values. In the probabilistic part, a Markov chain model is used, which allows to get explicit expressions for the heights of the second descent. In principle, one could go further, but the complexity of the results forbids it. This is extended to permutations of a large number of elements. Methods from q-analysis are used to simplify the expressions. This is the reason that we confine ourselves to the geometric distribution only. For general discrete distributions, no such tools are available.

scholarly journals Analysis of Nonstationary Characteristics for High-Speed Railway Scenarios

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Tao Zhou ◽  
Cheng Tao ◽  
Kai Liu
Keyword(s):  
Communication Systems ◽  
High Speed ◽  
Markov Chain Model ◽  
Measurement Data ◽  
Channel Modeling ◽  
Death Process ◽  
Chain Model ◽  
Channel Measurements ◽  
High Speed Railway

This paper presents the analysis of nonstationary characteristics for high-speed railway (HSR) scenarios, according to passive long-term evolution- (LTE-) based channel measurements. The measurement data collected in three typical scenarios, rural, station, and suburban, are processed to obtain the channel impulse responses (CIRs). Based on the CIRs, the nonstationarity of the HSR channel is studied focusing on the stationarity interval, and a four-state Markov chain model is generated to describe the birth-death process of multipath components. The presented results will be useful in dynamic channel modeling for future HSR mobile communication systems.

INNOVATIVE METHOD OF SATELLITE COMMUNICATION

2019 ◽  
Author(s):  
Teodor Narytnik ◽  
Vladimir Saiko
Keyword(s):  
Communication Systems ◽  
High Speed ◽  
Satellite Communication ◽  
Radio Channel ◽  
Satellite Communications ◽  
Service Area ◽  
Satellite Systems ◽  
Orbit Satellite ◽  
Geometric Size ◽  
Distributed Satellite

The technical aspects of the main promising projects in the segments of medium and low-orbit satellite communication systems are considered, as well as the project of the domestic low-orbit information and telecommunications system using the terahertz range, which is based on the use of satellite platforms of the micro- and nanosatellite class and the distribution of functional blocks of complex satellite payloads more high-end on multiple functionally related satellites. The proposed system of low-orbit satellite communications represents the groupings of low-orbit spacecraft (LEO-system) with the architecture of a "distributed satellite", which include the groupings of the root (leading) satellites and satellite repeaters (slaves). Root satellites are interconnected in a ring network by high-speed links between the satellites. The geometric size of the “distributed satellite” is the area around the root satellite with a radius of about 1 km. The combination of beams, which are formed by the repeater satellites, make up the service area of the LEO system. The requirements for the integrated service area of the LEO system (geographical service area) determine the requirements for the number of distributed satellites in the system as a whole. In the proposed system to reduce mutual interference between the grouping of the root (leading) satellites and repeater satellites (slaves) and, accordingly, minimizing distortions of the information signal when implementing inter-satellite communication, this line (radio channel) was created in an unlicensed frequency (e.g., in the terahertz 140 GHz) range. In addition, it additionally allows you to minimize the size of the antennas of such a broadband channel and simplify the operation of these satellite systems.

An Efficient Markov Chain Model for the Simulation of Heterogeneous Soil Structure

2004 ◽  
Vol 68 (2) ◽  
pp. 346 ◽  
Author(s):  
Keijan Wu ◽  
Naoise Nunan ◽  
John W. Crawford ◽  
Iain M. Young ◽  
Karl Ritz
Keyword(s):  
Markov Chain ◽  
Soil Structure ◽  
Markov Chain Model ◽  
Chain Model ◽  
Heterogeneous Soil

Data Mining Technique Applied To DNA Sequencing

2015 ◽  
Vol 2 (7) ◽  
pp. 18
Author(s):  
R. Jamuna
Keyword(s):  
Data Mining ◽  
Dna Methylation ◽  
Markov Chain ◽  
Human Genome ◽  
Transition Probabilities ◽  
Markov Chain Model ◽  
Effective Means ◽  
Cpg Islands ◽  
Chain Model ◽  
The Given

CpG islands (CGIs) play a vital role in genome analysis as genomic markers.  Identification of the CpG pair has contributed not only to the prediction of promoters but also to the understanding of the epigenetic causes of cancer. In the human genome [1] wherever the dinucleotides CG occurs the C nucleotide (cytosine) undergoes chemical modifications. There is a relatively high probability of this modification that mutates C into a T. For biologically important reasons the mutation modification process is suppressed in short stretches of the genome, such as ‘start’ regions. In these regions [2] predominant CpG dinucleotides are found than elsewhere. Such regions are called CpG islands. DNA methylation is an effective means by which gene expression is silenced. In normal cells, DNA methylation functions to prevent the expression of imprinted and inactive X chromosome genes. In cancerous cells, DNA methylation inactivates tumor-suppressor genes, as well as DNA repair genes, can disrupt cell-cycle regulation. The most current methods for identifying CGIs suffered from various limitations and involved a lot of human interventions. This paper gives an easy searching technique with data mining of Markov Chain in genes. Markov chain model has been applied to study the probability of occurrence of C-G pair in the given   gene sequence. Maximum Likelihood estimators for the transition probabilities for each model and analgously for the  model has been developed and log odds ratio that is calculated estimates the presence or absence of CpG is lands in the given gene which brings in many  facts for the cancer detection in human genome.

scholarly journals Performance Analysis of Synchronous Multi-Radio Multi-Link MAC Protocols in IEEE 802.11be Extremely High Throughput WLANs

2020 ◽  
Vol 11 (1) ◽  
pp. 317
Author(s):  
Taewon Song ◽  
Taeyoon Kim
Keyword(s):  
Ieee 802.11 ◽  
Markov Chain Model ◽  
Careful Consideration ◽  
Mac Protocols ◽  
Media Access Control ◽  
Chain Model ◽  
Distributed Coordination ◽  
Media Access ◽  
Medium Access ◽  
Coordination Function

The representative media access control (MAC) mechanism of IEEE 802.11 is a distributed coordination function (DCF), which operates based on carrier-sense multiple access with collision avoidance (CSMA/CA) with binary exponential backoff. The next amendment of IEEE 802.11 being developed for future Wi-Fi by the task group-be is called IEEE 802.11be, where the multi-link operation is mainly discussed when it comes to MAC layer operation. The multi-link operation discussed in IEEE 802.11be allows multi-link devices to establish multiple links and operate them simultaneously. Since the medium access on a link may affect the other links, and the conventional MAC mechanism has just taken account of a single link, the DCF should be used after careful consideration for multi-link operation. In this paper, we summarize the DCFs being reviewed to support the multi-radio multi-link operation in IEEE 802.11be and analyze their performance using the Markov chain model. Throughout the extensive performance evaluation, we summarize each MAC protocol’s pros and cons and discuss essential findings of the candidate MAC protocols.

Evaluating basketball player’s rotation line-ups performance via statistical markov chain modelling

2021 ◽  
pp. 174795412110090
Author(s):  
Pavlos Kolias ◽  
Nikolaos Stavropoulos ◽  
Alexandra Papadopoulou ◽  
Theodoros Kostakidis
Keyword(s):  
Markov Chain ◽  
Markov Chain Model ◽  
Specific Rotation ◽  
Multiple Regression Model ◽  
Chain Model ◽  
Know How ◽  
Basketball Game ◽  
Long Run ◽  
Rotation Line ◽  
Rating Category

Coaches in basketball often need to know how specific rotation line-ups perform in either offense or defense and choose the most efficient formation, according to their specific needs. In this research, a sample of 1131 ball possession phases of Greek Basket League was utilized, in order to estimate the offensive and defensive performance of each formation. Offensive and defensive ratings for each formation were calculated as a function of points scored or received, respectively, over possessions, where possessions were estimated using a multiple regression model. Furthermore, a Markov chain model was implemented to estimate the probabilities of the associated formation’s performance in the long run. The model could allow us to distinguish between overperforming and underperforming formations and revealed the probabilities over the evolution of the game, for each formation to be in a specific rating category. The results indicated that the most dominant formation, in terms of offense, is Point Guard-Point Guard-Small Forward-Power Forward-Center, while defensively schema Point Guard-Shooting Guard-Small Forward-Center-Center had the highest rating. Such results provide information, which could operate as a supplementary tool for the coach’s decisions, related to which rotation line-up patterns are mostly suitable during a basketball game.

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