Considerations in the Selection of Inflow States with Finite-State Dynamic Inflow

AIAA Journal ◽  
2021 ◽  
pp. 1-6
Author(s):  
Jimmy C. Ho ◽  
Hyeonsoo Yeo
Keyword(s):  
State Dynamic ◽  
Finite State ◽  
Selection Of

A QUEUE WITH POSITIVE AND NEGATIVE ARRIVALS GOVERNED BY A MARKOV CHAIN

2003 ◽  
Vol 17 (4) ◽  
pp. 487-501 ◽  
Author(s):  
Yang Woo Shin ◽  
Bong Dae Choi
Keyword(s):  
Markov Chain ◽  
Transient State ◽  
Single Server ◽  
Negative Customers ◽  
Service Distribution ◽  
Finite State ◽  
Sojourn Time Distribution ◽  
Absorbing States ◽  
Negative Arrivals ◽  
Selection Of

We consider a single-server queue with exponential service time and two types of arrivals: positive and negative. Positive customers are regular ones who form a queue and a negative arrival has the effect of removing a positive customer in the system. In many applications, it might be more appropriate to assume the dependence between positive arrival and negative arrival. In order to reflect the dependence, we assume that the positive arrivals and negative arrivals are governed by a finite-state Markov chain with two absorbing states, say 0 and 0′. The epoch of absorption to the states 0 and 0′ corresponds to an arrival of positive and negative customers, respectively. The Markov chain is then instantly restarted in a transient state, where the selection of the new state is allowed to depend on the state from which absorption occurred.The Laplace–Stieltjes transforms (LSTs) of the sojourn time distribution of a customer, jointly with the probability that the customer completes his service without being removed, are derived under the combinations of service disciplines FCFS and LCFS and the removal strategies RCE and RCH. The service distribution of phase type is also considered.

Modal analysis of finite-state dynamic inflow for rotary wing systems

2016 ◽  
Vol 23 (7) ◽  
pp. 1086-1094 ◽  
Author(s):  
Zhongyang Fei ◽  
David A Peters
Keyword(s):  
Modal Analysis ◽  
Axial Flow ◽  
Helicopter Rotor ◽  
Mode Shapes ◽  
Harmonic Numbers ◽  
State Dynamic ◽  
Finite State ◽  
Skew Angles ◽  
Rotary Wing ◽  
Velocity Mode

In this paper, the finite-state helicopter rotor inflow modes have been studied based on eigenanalysis. The inflow velocity mode shapes with node lines have been displayed with various skew angles. The eigenvalues are highly coupled especially for higher skew angles, and the mode shapes change significantly for different angles. The changing of eigenvalues with different harmonic numbers is also exhibited in the tables for axial flow of both the Peters–He and Morillo dynamic inflow models. An easy way to estimate the eigenvalues of the Peters–He inflow model is also established.

Evaluation of Finite-State Dynamic Inflow for Rotors

2021 ◽  
pp. 1-15
Author(s):  
Jimmy C. Ho ◽  
Hyeonsoo Yeo
Keyword(s):  
State Dynamic ◽  
Finite State

An Approximate Finite State Dynamic Wake Model for Predictions of Inflow below the Rotor

2021 ◽  
Author(s):  
Feyyaz Guner ◽  
J. V. R. Prasad ◽  
David A. Peters
Keyword(s):  
Velocity Potential ◽  
Dynamic Pressure ◽  
Frequency Control ◽  
Flight Simulation ◽  
Low Frequencies ◽  
Simulation Fidelity ◽  
State Dynamic ◽  
Finite State ◽  
Time Marching ◽  
Wake Model

The velocity potential based finite state dynamic inflow model can predict inflow anywhere in the flow field once velocity potential states and costates are known. However, solution to costate equations requires backward time marching, making it incompatible for integration into real-time flight simulation. This paper explores two types of quasi-steady approximations to the costate equations, both of which eliminate the need for backward time marching. The fidelities of the resulting inflow models are assessed through comparisons of off-disk inflow predictions for an isolated rotor. Further, the implication of the inflow model approximations on the flight simulation fidelity is assessed using the coupled body/rotor/inflow dynamics model of a generic helicopter model. It is shown that, in both cases, the quasi-steady approximations to the inflow model retain simulation model fidelity at low frequencies, a typical frequency range of pilot control inputs. Notable fidelity loss is seen at high-frequency control inputs, specifically for cases where horizontal tail is operating at a higher dynamic pressure within the rotor wake.

scholarly journals Iterative minimization of partial finite state machines

2013 ◽  
Vol 3 (2) ◽  
Author(s):  
Alex Alberto ◽  
Adenilso Simao
Keyword(s):  
Language Processing ◽  
System Modeling ◽  
Finite State Machines ◽  
State Machines ◽  
Iterative Minimization ◽  
Finite State ◽  
Feasible Solutions ◽  
Redundant States ◽  
Selection Of

AbstractFinite state machines have been used in many contexts, e.g., test generation, system modeling, language processing. In these applications, the size of the machine has a great impact on the complexity and quality of the results. Thus, it is desirable to obtain a machine without redundant states, i.e., to minimize the machine. However, the minimization of partially specified finite state machines is a known NP-complete problem, and many heuristics to obtain feasible solutions have been proposed. In this paper, we propose an approach to minimize partial finite state machines based on the selection of compatible states using maximum cliques on the distinction graph. We experimented with our method comparing it with previous methods and the data suggest that our approach is more efficient, generating good results in less time.

Space-time accurate finite-state dynamic inflow modeling for aeromechanics of rotorcraft

2019 ◽  
Vol 95 ◽  
pp. 105454 ◽  
Author(s):  
Felice Cardito ◽  
Riccardo Gori ◽  
Jacopo Serafini ◽  
Giovanni Bernardini ◽  
Massimo Gennaretti
Keyword(s):  
Space Time ◽  
State Dynamic ◽  
Finite State
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