Browsing by Subject "Delay"

Now showing 1 - 15 of 15

Open Access
Bargaining, reference points, and limited influence
(Birkhauser, 2020-07) Kara, Tarık; Karagözoğlu, Emin; Özcan-Tok, E.
We study the emergence of reference points in a bilateral, infinite horizon, alternating offers bargaining game. Players’ preferences exhibit reference dependence, and their current offers have the potential to influence each other’s future reference points. However, this influence is limited in that it expires in a finite number of periods. We first construct a subgame perfect equilibrium that involves an immediate agreement and study its properties. Later, we also show the existence of an equilibrium where agreement is reached with delay. We show that expiration lengths and initial reference points play a crucial role for the existence of this equilibrium. For instance, we show that equilibrium with a delayed agreement does not exist when the initial reference point is (0, 0). Finally, we provide comparative static analyses on model parameters, compare two variations of our model, and compare our findings with those of the closest paper to ours, Driesen et al. (Math Soc Sci 64:103–118, 2012).
Open Access
A coupled model for healthy and cancerous cells dynamics in Acute Myeloid Leukemia
(IFAC, 2014) Avila, J. L.; Bonnet, C.; Özbay, Hitay; Clairambault, J.; Niculescu, S. I.; Hirsch, P.; Delhommeau, F.
In this paper we propose a coupled model for healthy and cancerous cell dynamics in Acute Myeloid Leukemia. The PDE-based model is transformed to a nonlinear distributed delay system. For an equilibrium point of interest, necessary and sufficient conditions of local asymptotic stability are given. Simulation examples are given to illustrate the results.
Open Access
Distributed output feedback control of decomposable LPV systems with delay and switching topology: application to consensus problem in multi-agent systems
(Taylor & Francis, 2020-01-08) Zakwan, Muhammad; Ahmed, Saeed
This paper presents distributed output feedback control of a class of distributed linear parameter varying systems with switching topology and parameter varying time delay. To formulate the synthesis conditions for the distributed controller in terms of LMIs, the delay dependent bounded-real lemma based on parameter-dependent Lyapunov–Krasovskii functionals is used. The efficacy of the result is illustrated by applying it to two real-world examples pertaining to the consensus problem of multi-agent systems.
Open Access
Distributed output feedback control of decomposable lpv systems with delay: application to multi-agent nonholonomic systems
(IEEE, 2019) Zakwan, Muhammad; Ahmed, Saeed
This paper presents distributed output feedback control of a class of distributed linear parameter varying systems with a parameter-dependent time-varying delay. A delaydependent bounded-real lemma approach, based on parameterdependent Lyapunov-Krasovskii functionals, is used to formulate the synthesis condition in terms of linear matrix inequalities. We demonstrate the efficacy of our result by applying it to formation control of multi-agent nonholonomic mobile robots.
Open Access
Dynamic output feedback stabilization of switched linear systems with delay via a trajectory based approach
(Elsevier, 2018) Ahmed, Saeed; Mazenc, F.; Özbay, Hitay
A new technique is proposed to construct observers and to achieve output feedback stabilization of a class of continuous-time switched linear systems with a time-varying delay in the output. The delay is a piecewise continuous bounded function of time and no constraint is imposed on the delay derivative. For stability analysis, an extension of a recent trajectory based approach is used; this is fundamentally different from classical Lyapunov function based methods. A stability condition is given in terms of the upper bound on the time-varying delay to ensure global uniform exponential stability of the switched feedback system. The main result applies in cases where some of the subsystems of the switched system are not stabilizable and not detectable.
Open Access
Effect of Network Density and Size on the Short-Term Fairness Performance of CSMA Systems
(Springer Open Journal, 2012) Koseoglu, M.; Karasan, E.; Alanyali, M.
As the penetration of wireless networks increase, number of neighboring networks contending for the limited unlicensed spectrum band increases. This interference between neighboring networks leads to large systems of locally interacting networks. We investigate whether the short-term fairness of this system of networks degrades with the system size and density if transmitters employ random spectrum access with carrier sensing (CSMA). Our results suggest that (a) short-term fair capacity, which is the throughput region that can be achieved within the acceptable limits of short-term fairness, reduces as the number of contending neighboring networks, i.e., degree of the conflict graph, increases for random regular conflict graphs where each vertex has the same number of neighbors, (b) short-term fair capacity weakly depends on the network size for a random regular conflict graph but a stronger dependence is observed for a grid deployment. We demonstrate the implications of this study on a city-wide Wi-Fi network deployment scenario by relating the short-term fairness to the density of deployment. We also present related results from the statistical physics literature on long-range correlations in large systems and point out the relation between these results and short-term fairness of CSMA systems.
Open Access
Local pinning of networks of multi-agent systems with transmission and pinning delays
(Institute of Electrical and Electronics Engineers, 2016) Lu, W.; Atay, F. M.
We study the stability of networks of multi-agent systems with local pinning strategies and two types of time delays, namely the transmission delay in the network and the pinning delay of the controllers. Sufficient conditions for stability are derived under specific scenarios by computing or estimating the dominant eigenvalue of the characteristic equation. In addition, controlling the network by pinning a single node is studied. Moreover, perturbation methods are employed to derive conditions in the limit of small and large pinning strengths. Numerical algorithms are proposed to verify stability, and simulation examples are presented to confirm the efficiency of analytic results. ï¿½ 2015 IEEE.
Open Access
A new model of cell dynamics in Acute Myeloid Leukemia involving distributed delays
(2012) Avila, J. L.; Bonnet, C.; Clairambault, J.; Özbay, Hitay; Niculescu, S. I.; Merhi, F.; Tang, R.; Marie, J. P.
In this paper we propose a refined model for the dynamical cell behavior in Acute Myeloid Leukemia (AML) compared to (Özbay et al, 2012) and (Adimy et al, 2008).We separate the cell growth phase into a sequence of several sub-compartments. Then, with the help of the method of characteristics, we show that the overall dynamical system of equations can be reduced to two coupled nonlinear equations with four internal sub-systems involving distributed delays. © 2012 IFAC.
Open Access
A note on efficient signaling of bargaining power
(Springer, 2000) Bac, M.
Strategic delay and restricted offers are two modes of signaling bargaining power in alternating offers bargaining games. This paper shows that when both modes are available, the best signaling strategy of the "strong" type of the informed player consists of a pure strategic delay followed by an offer on the whole pie. There is no signaling motivation for issue-by-issue bargaining when the issues are perfectly substitutable.
Open Access
Observer design and output feedback Stabilization of time varying systems
(2018-07) Ahmed, Saeed
We study observer design and output feedback stabilization of switched and nonlinear time varying systems. To establish the stability of feedback switched systems with delay, we develop a new extension of a recently proposed trajectory based approach which is fundamentally different from classical Lyapunov function based methods. This new extension of trajectory based approach, which is of interest for its own sake, can be applied to a wide range of time varying systems with time varying delays and it tackles the issue of finding appropriate Lyapunov functions to establish stability results. Our stabilization methodology does not require stabilizability and detectability of all of the subsystems of the switched system and we do not impose any constraint on the derivative of the time varying delay. For nonlinear time varying systems, we build a new type of finite-time smooth observer in the case where a state dependent disturbance affects the linear approximation. We combine this finite time observer design and a switched systems approach to develop stabilizing feedbacks for nonlinear time varying systems whose outputs are only available on some finite time intervals. Again, we use an extension of the trajectory based approach to conclude the stability of the closed-loop system. Motivated by the fact that the measured components of the state do not need to be estimated, we also construct reduced order finite time observers for a broad class of nonlinear time varying systems. We show how these reduced order finite time observers can be used to solve dynamic output feedback stabilization problem for multiple input, multiple output nonlinear time varying systems. Finally, we design a finite time observer to estimate the exact state of a continuous-time linear time varying system from sampled output in the presence of a piecewise continuous disturbance.
Open Access
On the existence of Hopf cycles in optimal growth models with time delay
(2008) Yüksel, Mustafa Kerem
In this thesis, we analyzed the existence of cycles `a la Poincar´e-AndronovHopf in optimal growth models with time delay. The analysis builds upon a new method developed, which investigates the number of pure imaginary roots of the characteristic equation. The method was applied to the time-tobuild models of Asea and Zak (1999) and Winkler (2004).
Open Access
Signaling bargaining power: strategic delay versus restricted offers
(Springer, 2000) Bac, M.
I study the first-round separating equilibrium of a buyer-seller bargaining game, extended to allow for asymmetric information, strategically delayed offers and offers restricted to a portion of the good. When bargaining is over a consumption good, in equilibrium the “strong” buyer uses a restricted offer if his optimal consumption path is conservative relative to the “weak” buyer. A pure restricted offer may even be a costless, efficient signal. When the good is durable, a pure strategic delay is involved in signaling a strong bargaining position if the discount factor is high.
Open Access
State feedback stabilization of switched systems with delay: trajectory based approach
(IEEE, 2017) Mazenc, F.; Ahmed, Saeed; Özbay, Hitay
We present a new trajectory based approach for state feedback stabilization of switched linear continuous-time systems with a time-varying input delay. In contrast with finding classical common Lyapunov function or multiple Lyapunov functions for establishing the stability of the closed-loop switched system, the new trajectory based approach relies on verifying certain inequalities along the solution of a supplementary system. This study does not make any assumption regarding the stabilizability of all of the constituent subsystems of the switched system. Moreover, no assumption is needed about the differentiability of the delay and no constraint is imposed on the upper bound of the delay derivative. Finally, an illustrative example is included to illustrate the applicability of our results.
Open Access
A theory of trade concessions
(Elsevier BV, 1997) Bac, M.; Raff, H.
We present a model of tariff disputes and concessions consisting of an infinitely repeated game under bilateral incomplete information. Given potential agreements to be reached through unilateral or reciprocal concessions, we find that an agreement involving reciprocal concessions is reached immediately if the discount factor is large and/or the volume of trade is small. Otherwise prior beliefs about country type matter: when both countries hold pessimistic priors, immediate reciprocal concessions still occur. Very different prior beliefs lead to an immediate unilateral concession of the pessimistic country, whereas optimistic priors coupled with low discount factors may generate delayed agreements. (C) 1997 Elsevier Science B.V.
Open Access
Time-varying fairness concerns, delay, and disagreement in bargaining
(Elsevier, 2018) Karagözoğlu, Emin; Keskin, K.
We study an alternating-offers, bilateral bargaining game where players may derive disutility from accepting shares below what they deem as fair. Moreover, we assume that the values they attach to fairness (i.e., their sensitivity to violations of their fairness judgments) decrease over time, as the deadline approaches. Our results offer a new explanation to delays and disagreements in dynamic negotiations. We show that even mutually compatible fairness judgments do not guarantee an immediate agreement. We partially characterize conditions for delay and disagreement, and study the changes in the length of delay in response to changes in the model parameters.