500 research outputs found
Linear Quadratic Mean Field Game with Control Input Constraint
International audienceIn this paper, we study a class of linear-quadratic (LQ) mean-field games in which the individual control process is constrained in a closed convex subset Γ of full space R m. The decentralized strategies and consistency condition are represented by a class of mean-field forward-backward stochastic differential equation (MF-FBSDE) with projection operators on Γ. The wellposedness of consistency condition system is obtained using the monotonicity condition method. The related ǫ-Nash equilibrium property is also verified
Backward Stackelberg Differential Game with Constraints: a Mixed Terminal-Perturbation and Linear-Quadratic Approach
We discuss an open-loop backward Stackelberg differential game involving
single leader and single follower. Unlike most Stackelberg game literature, the
state to be controlled is characterized by a backward stochastic differential
equation (BSDE) for which the terminal- instead initial-condition is specified
as a priori; the decisions of leader consist of a static terminal-perturbation
and a dynamic linear-quadratic control. In addition, the terminal control is
subject to (convex-closed) pointwise and (affine) expectation constraints. Both
constraints are arising from real applications such as mathematical finance.
For information pattern: the leader announces both terminal and open-loop
dynamic decisions at the initial time while takes account the best response of
follower. Then, two interrelated optimization problems are sequentially solved
by the follower (a backward linear-quadratic (BLQ) problem) and the leader (a
mixed terminal-perturbation and backward-forward LQ (BFLQ) problem). Our
open-loop Stackelberg equilibrium is represented by some coupled
backward-forward stochastic differential equations (BFSDEs) with mixed
initial-terminal conditions. Our BFSDEs also involve nonlinear projection
operator (due to pointwise constraint) combining with a Karush-Kuhn-Tucker
(KKT) system (due to expectation constraint) via Lagrange multiplier. The
global solvability of such BFSDEs is also discussed in some nontrivial cases.
Our results are applied to one financial example.Comment: 38 page
The role of crosslinking density in surface stress and surface energy of soft solids
Surface stress and surface energy are two fundamental parameters that
determine the surface properties of any materials. While it is commonly
believed that the surface stress and surface energy of liquids are identical,
the relationship between the two parameters in soft polymeric gels remains
debatable. In this work, we measured the surface stress and surface energy of
soft silicone gels with varying weight ratios of crosslinkers in soft wetting
experiments. Above a critical density, , the surface stress was found to
increase significantly with crosslinking density while the surface energy
remained unchanged. In this regime, we can estimate a non-zero surface elastic
modulus that also increases with the ratio of crosslinkers. By comparing the
surface mechanics of the soft gels with their bulk rheology, the surface
properties near the critical density were found to be closely related to
the underlying percolation transition of the polymer networks.Comment: 9 pages, 7 figure
A Personalized Rolling Optimal Charging Schedule for Plug-In Hybrid Electric Vehicle Based on Statistical Energy Demand Analysis and Heuristic Algorithm
To alleviate the emission of greenhouse gas and the dependence on fossil fuel, Plug-in Hybrid Electrical Vehicles (PHEVs) have gained an increasing popularity in current decades. Due to the fluctuating electricity prices in the power market, a charging schedule is very influential to driving cost. Although the next-day electricity prices can be obtained in a day-ahead power market, a driving plan is not easily made in advance. Although PHEV owners can input a next-day plan into a charging system, e.g., aggregators, day-ahead, it is a very trivial task to do everyday. Moreover, the driving plan may not be very accurate. To address this problem, in this paper, we analyze energy demands according to a PHEV owner’s historical driving records and build a personalized statistic driving model. Based on the model and the electricity spot prices, a rolling optimization strategy is proposed to help make a charging decision in the current time slot. On one hand, by employing a heuristic algorithm, the schedule is made according to the situations in the following time slots. On the other hand, however, after the current time slot, the schedule will be remade according to the next tens of time slots. Hence, the schedule is made by a dynamic rolling optimization, but it only decides the charging decision in the current time slot. In this way, the fluctuation of electricity prices and driving routine are both involved in the scheduling. Moreover, it is not necessary for PHEV owners to input a day-ahead driving plan. By the optimization simulation, the results demonstrate that the proposed method is feasible to help owners save charging costs and also meet requirements for driving
MiR-155 protects against sepsis-induced cardiomyocyte apoptosis via activation of NO/cGMP signaling pathway by eNOS
Purpose: To examine the impact of miR-155 on sepsis-induced myocardial apoptosis and heart failure, and to explore its molecular mechanism.
Methods: Mice were divided into four groups and septic myocardial dysfunction was induced by intraperitoneal injection of lipopolysaccharide (LPS, 5 mg/kg). The LPS stimulation expression of miR-155 levels was determined by real time-polymerase chain reaction (RT-PCR). In vivo, echocardiography and TUNEL staining were used to investigate the effects of miR-155 in inhibiting cardiac function and myocardial apoptosis. Changes in the expression of eNOS when miR-155 was overexpressed or inhibited were determined by RT-PCR, while double luciferase gene assay assessed the relationship between eNOS and miR-155, eNOS, expression of iNOS, SGC alpha 1, and PKG protein.
Results: MiR-155 was significantly increased after LPS stimulation (p < 0.01). In vitro, the inhibition of miR-155 by antagomiR significantly down-regulated the apoptosis of cardiomyocytes (p < 0.05), while overexpression of miR-155 by agomiR significantly up-regulated the apoptosis of cardiomyocytes (p < 0.05). In vivo, ejection fraction, fractional shortening and heart weight were significantly increased (p < 0.05), while apoptosis was significantly decreased (p < 0.05). MiR-155 negatively regulated the expression of eNOS (p < 0.01), and targeted the expression of eNOS mRNA (p < 0.001). In addition, the expression of eNOS, sGCα1 and PKA were significantly up-regulated (p < 0.05), while the expression of iNOS was significantly down-regulated (p < 0.05) after the inhibition of miR-155 in LPS mouse model.
Conclusion: MiR-155 regulates sepsis-induced cardiomyocyte apoptosis and heart failure through eNOS /NO/cGMP signaling pathway. Thus, these findings can potentially facilitate the development of an effective strategy for management of heart failure
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