Decentralized regulation of dynamic systems

A special class of decentralized control problem is discussed in which the objectives of the control agents are to steer the state of the system to desired levels. Each agent is concerned about certain aspects of the state of the entire system. The state and control equations are given for linear time-invariant systems. Stability and coordination, and the optimization of decentralized control are analyzed, and the information structure design is presented

Effects of thermal conduction in sonoluminescence

We show by numerical hydrodynamic calculations that there are two important effects of thermal conduction in sonoluminescence: (i) the bubble remains close to being isothermal during the expansion phase; and (ii) a cold, dense layer of air is formed at the bubble wall during the contraction phase. These conclusions are not sensitive to the particular equation of state used, although details of the dynamical evolution of the bubble are

Children as Refrigerators: When Would Backward Altruism Appear?

Existing economic theories of the evolution of altruism between kinship members usually emphasize the role that altruism can play in facilitating coordination among kin to achieve an otherwise unachievable efficient (in terms of fitness) equilibrium. In this paper, we explore the background environment against which backward altruism was likely to appear. The instinct of sustaining one’s own life drives one to save for one’s old age. However, since social mechanisms were not sophisticated in a primitive society, the rate of return on savings was not high. As a consequence, the resources that remain for the children might be limited. Suppose a cultural menchanism or a mutation caused an individual to become backward-altruistic. She would then expect her children to adopt the same attitude as herself, and take care of her in her old age. With this expectation in mind, she would avoid inefficient savings voluntarily so that her children could obtain more resources. Thus, backward altruism in our model does not play a role of coordination, but helps parents to avoid inefficient resource disposition. We analyze the possible appearance of backward altruism as the rate of return on savings changes.

Test of the Skyrme Effective Field Theory Using Quenched Lattice QCD

The Skyrme effective field theory is tested by evaluating nucleon ground state matrix elements of the correlation functions for two flavor density operators and two pseudoscalar density operators in the Skyrme model and comparing them with results in quenched lattice QCD. The possiblility of using quenched lattice QCD to study higher-order terms in effective field theory is also discussed.Comment: 20 pages in TeX, 6 figures added using "figures", MIT-CTP-200

A finite difference solution to a mixed boundary value problem for Laplace's equation

Finite difference solution to mixed boundary value problem for Laplace equatio