Question

Consider the $H_2 / \mathrm{M} / 1$ queueing system in which the parameters for $\tau$ are $q_1=0.4, \mu_1=0.5 \lambda$, and $\mu_2=3 \lambda$. Show that $E[\tau]=1 / \lambda$ and that the equation $$ 1-\pi_0=A^*\left[\mu \pi_0\right] $$ reduces to the quadratic equation $$ \pi_0^2+(3.5 \rho-1) \pi_0+1.5 \rho(\rho-1)=0 . $$ Show, also, that the unique value of $\pi_0$ such that $0<\pi_0<1$ is given by $$ \pi_0=0.5-1.75 \rho+\sqrt{1.5625 \rho^2-0.25 \rho+0.25} . $$

    Consider the $H_2 / \mathrm{M} / 1$ queueing system in which the parameters for $\tau$ are $q_1=0.4, \mu_1=0.5 \lambda$, and $\mu_2=3 \lambda$. Show that $E[\tau]=1 / \lambda$ and that the equation
$$
1-\pi_0=A^*\left[\mu \pi_0\right]
$$
reduces to the quadratic equation
$$
\pi_0^2+(3.5 \rho-1) \pi_0+1.5 \rho(\rho-1)=0 .
$$
Show, also, that the unique value of $\pi_0$ such that $0<\pi_0<1$ is given by
$$
\pi_0=0.5-1.75 \rho+\sqrt{1.5625 \rho^2-0.25 \rho+0.25} .
$$
Show more…
Probability, Statistics, and Queuing Theory with Computer Science Applications, Second Edition (Computer Science and Scientific Computing)
Probability, Statistics, and Queuing Theory with Computer Science Applications, Second Edition (Computer Science and Scientific Computing)
Arnold O. Allen 2nd Edition
Chapter 5, Problem 63 ↓

Instant Answer

verified

Step 1

4$ and $q_2 = 1 - q_1 = 0.6$, and rates $\mu_1 = 0.5 \lambda$ and $\mu_2 = 3 \lambda$, respectively, the expected value of $\tau$, $E[\tau]$, is calculated as follows: \[ E[\tau] = \frac{1}{\mu_1} q_1 + \frac{1}{\mu_2} q_2 = \frac{1}{0.5 \lambda} \cdot 0.4 +  Show more…

Show all steps

lock
AceChat toggle button
Close icon
Ace pointing down

Please give Ace some feedback

Your feedback will help us improve your experience

Thumb up icon Thumb down icon
Thanks for your feedback!
Profile picture
Consider the $H_2 / \mathrm{M} / 1$ queueing system in which the parameters for $\tau$ are $q_1=0.4, \mu_1=0.5 \lambda$, and $\mu_2=3 \lambda$. Show that $E[\tau]=1 / \lambda$ and that the equation $$ 1-\pi_0=A^*\left[\mu \pi_0\right] $$ reduces to the quadratic equation $$ \pi_0^2+(3.5 \rho-1) \pi_0+1.5 \rho(\rho-1)=0 . $$ Show, also, that the unique value of $\pi_0$ such that $0<\pi_0<1$ is given by $$ \pi_0=0.5-1.75 \rho+\sqrt{1.5625 \rho^2-0.25 \rho+0.25} . $$
Close icon
Play audio
Feedback
Powered by NumerAI
*

Labs

-

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

*

Key Concepts

-
Utilization Factor and Quadratic Equations
The utilization factor (often denoted ?) represents the proportion of time that the server is busy, typically expressed as the ratio of the arrival rate to the service rate in a queueing system. In many steady?state analyses, deriving the expression for ?? leads to algebraic equations—often quadratic—whose admissible roots (lying between 0 and 1) correspond to physically meaningful probabilities. This concept is central to ensuring that all performance measures are consistent with probabilistic constraints.
Laplace Transforms in Queueing Theory
Laplace transforms are a powerful mathematical tool used in queueing theory to convert complicated time-domain functions into a simpler algebraic form in the s-domain. This approach facilitates the analysis of complex probability functions, such as the interarrival time distribution, and is especially useful for establishing relationships between system parameters through equations like A*[???].
Hyperexponential Distribution
A hyperexponential distribution is a probabilistic model representing a mixture of several exponential distributions with different rates and associated weights. It is used to capture high variability in interarrival or service times and its expected value is the weighted sum of the individual means, which in many cases simplifies the analysis of the overall system behavior.
Steady?State Analysis in Queueing Systems
Steady?state analysis involves determining the long-run probabilities that a queueing system is in particular states, such as being empty or having a certain number of customers. The probability ?? that the system is empty is derived from balance equations, ensuring that the inflow and outflow of probability across states are equal. This analysis is crucial for system performance evaluation and for understanding service capacity.

*

Recommended Videos

-
consider-a-queuing-system-modeled-by-dx-dt-max-x-x1-the-model-is-nonlinear-and-the-dynamics-of-the-system-changes-significantly-with-the-queuing-length-see-example-312-investigate-the-situat-58364

Consider a queuing system modeled by dx/dt = λ - μmax(x/(x+1)). The model is nonlinear and the dynamics of the system change significantly with the queuing length; see Example 3.12. Investigate the situation when a PI controller is used for admission control. The arrival intensity λ is then given by λ = kp(r - x) + ki ∫(r(t) - x(t))dt. The controller parameters are determined from the approximate model dx/dt = λ. Find controller parameters that give the closed loop characteristic polynomial s^2 + 2s + 1 for the approximate model. Investigate the behavior of the control strategy for the nonlinear model by simulation for the input r = 5 + 4sin(0.1t). (Åström, and Richard M. Murray. Feedback Systems: An Introduction for Scientists and Engineers. Ex: 2.10)

problem-in-queueing-theory-problem-2-let-be-positive-scalars-satisfying-2-let-w1-be-the-average-time-a-customer-spends-in-an-mm1-queueing-system-with-arrival-rate-and-service-rate-2-in-stead-46676

Problem in Queueing Theory Problem 2. Let λ, μ be positive scalars satisfying λ < 2μ. Let W(1) be the average time a customer spends in an M/M/1 queueing system with arrival rate λ and service rate 2μ in steady-state, and let W(2) be the average time a customer spends in an M/M/2 queueing system with arrival rate λ and service rate μ in steady-state. Compare W(1) and W(2).

Need help? Use Ace
Ace is your personal tutor. It breaks down any question with clear steps so you can learn.
Start Using Ace
Ace is your personal tutor for learning
Step-by-step explanations
Instant summaries
Summarize YouTube videos
Understand textbook images or PDFs
Study tools like quizzes and flashcards
Listen to your notes as a podcast
Continue solving this problem
Create a free account to:
  • View full step-by-step solution
  • Ask follow-up questions with Ace AI
  • Save progress and study later
Continue Free
Numerade

Get step-by-step video solution
from top educators

Continue with Clever
or



By creating an account, you agree to the Terms of Service and Privacy Policy
Already have an account? Log In

A free answer
just for you

Watch the video solution with this free unlock.

Numerade

Log in to watch this video
...and 100,000,000 more!


EMAIL

PASSWORD

OR
Continue with Clever