2,237 research outputs found
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
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