Optimal integral force feedback and structured PI tracking control : application for objective lens positioner

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Changing Channels of Technology: Disaster and (Im)mortality in Don DeLillo’s White Noise, Cosmopolis and Zero K

This article examines the changing representation of technology in three of DeLillo’s novels, White Noise, Cosmopolis and Zero K, and traces the conceptual and philosophical developments in his writing concerning the two key themes of disaster and mortality. Disasters witnessed through technological means consistently distance the ‘real’ from the event in earlier work such as White Noise, whereas in Cosmopolis, Eric Packer, the central character, yearns for disasters to happen to himself. DeLillo’s latest novel Zero K represents a clear sense of ending and longing for disaster. Secondly, technology changes from promoting a fear of death in earlier works, to a fear of life in Zero K, highlighting the bleakness of life in a world ruled\ud by technology. This article will discuss these two progressions in detail across the three novels, followed by a conclusion of the comparisons titled ‘Changing Channels’ for each theme, producing an original perspective of the diachronic changes through DeLillo’s work

Casimir effect of electromagnetic field in Randall-Sundrum spacetime

We study the finite temperature Casimir effect on a pair of parallel perfectly conducting plates in Randall-Sundrum model without using scalar field analogy. Two different ways of interpreting perfectly conducting conditions are discussed. The conventional way that uses perfectly conducting condition induced from 5D leads to three discrete mode corrections. This is very different from the result obtained from imposing 4D perfectly conducting conditions on the 4D massless and massive vector fields obtained by decomposing the 5D electromagnetic field. The latter only contains two discrete mode corrections, but it has a continuum mode correction that depends on the thicknesses of the plates. It is shown that under both boundary conditions, the corrections to the Casimir force make the Casimir force more attractive. The correction under 4D perfectly conducting condition is always smaller than the correction under the 5D induced perfectly conducting condition. These statements are true at any temperature.Comment: 20 pages, 4 figure

U.S. politicians adhere to balanced budget rules because they fear the bond markets, not judicial intervention

In the wake of the European financial crisis, European Union (EU) leaders have reformed Eurozone governance to empower national and EU courts to enforce deficit and debt limits. In designing these reforms, policymakers drew lessons on balanced budget rules in U.S. states. But is the threat of court enforcement actually effective in ensuring balanced budgets in the states? In new research, R. Daniel Kelemen and Terence Teo find that despite their 170-year history, these judicial mechanisms are almost never enforced in court, and that they do not act as a deterrent to breaking budget rules for state officials. They argue instead, that clear balanced budget rules can act as a ‘red line’ for investors and bond markets, which, if broken, will act as a signal for them to punish sovereigns

Magnetic superlens-enhanced inductive coupling for wireless power transfer

We investigate numerically the use of a negative-permeability "perfect lens" for enhancing wireless power transfer between two current carrying coils. The negative permeability slab serves to focus the flux generated in the source coil to the receiver coil, thereby increasing the mutual inductive coupling between the coils. The numerical model is compared with an analytical theory that treats the coils as point dipoles separated by an infinite planar layer of magnetic material [Urzhumov et al., Phys. Rev. B, 19, 8312 (2011)]. In the limit of vanishingly small radius of the coils, and large width of the metamaterial slab, the numerical simulations are in excellent agreement with the analytical model. Both the idealized analytical and realistic numerical models predict similar trends with respect to metamaterial loss and anisotropy. Applying the numerical models, we further analyze the impact of finite coil size and finite width of the slab. We find that, even for these less idealized geometries, the presence of the magnetic slab greatly enhances the coupling between the two coils, including cases where significant loss is present in the slab. We therefore conclude that the integration of a metamaterial slab into a wireless power transfer system holds promise for increasing the overall system performance

An Efficient Computational Approach to a Class of Minmax Optimal Control Problems with Applications

In this paper, an efficient computation method is developed for solving a general class of minmax optimal control problems, where the minimum deviation from the violation of the continuous state inequality constraints is maximized. The constraint transcription method is used to construct a smooth approximate function for each of the continuous state inequality constraints. We then obtain an approximate optimal control problem with the integral of the summation of these smooth approximate functions as its cost function. A necessary condition and a sufficient condition are derived showing the relationship between the original problem and the smooth approximate problem. We then construct a violation function from the solution of the smooth approximate optimal control problem and the original continuous state inequality constraints in such a way that the optimal control of the minmax problem is equivalent to the largest root of the violation function, and hence can be solved by the bisection search method. The control parametrization and a time scaling transform are applied to these optimal control problems. We then consider two practical problems: the obstacle avoidance optimal control problem and the abort landing of an aircraft in a windshear downburst

Focal points and fiscal discipline. ACES Cases No. 2013.2

Many studies suggest that balanced budget rules can restrain sovereign debt and lower sovereign borrowing costs, even if those rules are never enforced in court. Typically, this is explained as a result of a legal deterrence logic, in which the threat of judicial enforcement deters sovereigns from violating the rules. By contrast, we argue that balanced budget rules work by coordinating decentralized punishment of sovereigns by bond markets, rather than by posing a credible threat of judicial enforcement. Therefore, the clarity of the focal point provided by the rule, rather than the strength of its judicial enforcement mechanisms, determines its effectiveness. We develop a formal model that captures the logic of our argument, and we assess this model using data on US states. We then consider implications of our argument for the impact of the balanced budget rules recently imposed on eurozone states in the Fiscal Compact Treaty

Joint measurement of complementary observables in moment tomography

Wigner and Husimi quasi-distributions, owing to their functional regularity, give the two archetypal and equivalent representations of all observable-parameters in continuous-variable quantum information. Balanced homodyning and heterodyning that correspond to their associated sampling procedures, on the other hand, fare very differently concerning their state or parameter reconstruction accuracies. We present a general theory of a now-known fact that heterodyning can be tomographically more powerful than balanced homodyning to many interesting classes of single-mode quantum states, and discuss the treatment for two-mode sources.Comment: 15 pages, 4 figures, conference proceedings for Quantum 2017 in Torin