Design of invisibility cloaks with an open tunnel

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Symmetry effects on spin switching of adatoms

Highly symmetric magnetic environments have been suggested to stabilize the magnetic information stored in magnetic adatoms on a surface. Utilized as memory devices such systems are subjected to electron tunneling and external magnetic fields. We analyze theoretically how such perturbations affect the switching probability of a single quantum spin for two characteristic symmetries encountered in recent experiments and suggest a third one that exhibits robust protection against surface induced spin flips. Further we illuminate how the switching of an adatom spin exhibits characteristic behavior with respect to low energy excitations from which the symmetry of the system can be inferred

Real-time fundamental frequency estimation by least-square fitting

For real-time applications, a fundamental frequency estimation algorithm must be able to obtain accurate estimates from short signal segments. Characterization of the error function of fitting a sinusoid to the signal segment allows its spectrum to be deduced and the algorithm to be implemented efficiently. Musical signals are discussed in particular.published_or_final_versio

Proportional-integral-plus control applications of state-dependent parameter models

This paper considers proportional-integral-plus (PIP) control of non-linear systems defined by state-dependent parameter models, with particular emphasis on three practical demonstrators: a microclimate test chamber, a 1/5th-scale laboratory representation of an intelligent excavator, and a full-scale (commercial) vibrolance system used for ground improvement on a construction site. In each case, the system is represented using a quasi-linear state-dependent parameter (SDP) model structure, in which the parameters are functionally dependent on other variables in the system. The approach yields novel SDP-PIP control algorithms with improved performance and robustness in comparison with conventional linear PIP control. In particular, the new approach better handles the large disturbances and other non-linearities typical in the application areas considered

Scrambling out of a control clause in Japanese: An argument against the Movement Theory of Control

In this paper, I provide a set of data which is problematic for the movement theory of control (MTC) where claims that the distribution of Obligatory Control (OC) PROs is assimilated to that of NP-traces (cf., e.g., Hornstein 1999, 2001, 2003, Boeckx and Hornstein 2003, 2004, 2006). We observe Takano (2009) and Fujii (2006) which are captured under the MTC. Then I will show the problematic data for Takano (2009), and hence I propose that the MTC is problematic in Japanese. Instead, I propose an alternative analysis of control, an Equi NP Deletion analysis (cf., e.g., Rosenbaum 1967). This analysis can capture the problematic data for the MTC. Therefore, the Equi analysis is superior to the MTC empirically

Periodically Collapsing Bubbles in the Asian Emerging Stock Markets

This paper investigates empirically the existence of periodically collapsing bubbles in the Asian emerging stock markets using the Enders-Siklos (2001) momentum threshold autoregressive model. As explained in Bohl (2003), this non-linear time series technique can be used to analyze bubble driven run-ups in stock prices followed by a crash in a non- cointegration framework with asymmetric adjustment. This technique offers a more potent insight in the stock prices behavior than can possibly be obtained using conventional non-cointegration tests. The empirical findings for ten Asian emerging stock markets from 1993 to 2005 refute the bubble hypothesis