有効なトルク制御が可能で安全なロボットのための可変トルクリミッタの設計と評価

早大学位記番号:新7966早稲田大

Linear-quadratic stochastic Volterra controls I: Causal feedback strategies

In this paper, we formulate and investigate the notion of causal feedback strategies arising in linear-quadratic control problems for stochastic Volterra integral equations (SVIEs) with singular and non-convolution-type coefficients. We show that there exists a unique solution, which we call the causal feedback solution, to the closed-loop system of a controlled SVIE associated with a causal feedback strategy. Furthermore, introducing two novel equations named a Type-II extended backward stochastic Volterra integral equation and a Lyapunov--Volterra equation, we prove a duality principle and a representation formula for a quadratic functional of controlled SVIEs in the framework of causal feedback strategies.Comment: 29 page

Linear-quadratic stochastic Volterra controls II: Optimal strategies and Riccati--Volterra equations

In this paper, we study linear-quadratic control problems for stochastic Volterra integral equations with singular and non-convolution-type coefficients. The weighting matrices in the cost functional are not assumed to be non-negative definite. From a new viewpoint, we formulate a framework of causal feedback strategies. The existence and the uniqueness of a causal feedback optimal strategy are characterized by means of the corresponding Riccati--Volterra equation.Comment: 35 page

The Implementation of Central Bank Policy in China: The Roles of Commercial Bank Ownership and CEO Faction Membership

We examine the roles of bank ownership and CEO political faction membership in facilitating or hindering the implementation of central bank policy in China. Specifically, we examine the response of China's commercial banks to People's Bank of China (PBC) guidelines intended to decrease mortgage lending and to slow down the rise in residential property prices. We find that both bank ownership and faction membership matter. Central government-owned banks whose CEOs are members of the specialist finance faction within the Chinese Communist Party (CCP) respond most strongly to PBC guidance, whereas provincial or city government-owned banks whose CEOs are members of a generalist faction respond least strongly. The implementation of PBC policy has real effects: in those cities where central government-owned banks with specialist CEOs constitute a larger percentage of total bank branches, house prices grew more slowly, as did the number of residential real estate transactions and the number of new listings. Where in contrast provincial and city government-owned banks with generalist CEOs dominate, the number of transactions grew faster; the rate of house price appreciation and the number of listings were however unaffected. We conclude that China's different levels of government and the CCP's different factions enjoy some discretion in responding to PBC guidance and that they exploit the discretion they are afforded to vary the strength of their response