In this paper, we propose an analytical and methodological comparison between two of the most known distance-based methods in the evaluation of the geographic concentration of economic activity. These two methods are Ripley’s K function, a cumulative function popularised by Marcon and Puech (2003) that counts the average number of neighbours of each point within a circle of a given radius, and ...

K e y w o r d s : Kalman Filter; Principal Component Analysis; Stellar Spectral Data; RBF Neural Networks. 1 I n t r o d u c t i o n Current and future large astronomical surveys will yield multiparameter databases on millions or even billions of objects. The scientific exploitation of these will require powerful, robust, and automated classification tools tailored to the specific survey. Partl...

When tracking with multi-sensor systems, the set of sensors used may be asynchronous and there may be communications delays between sensor platforms and the fusion center. Despite these conditions, it is desirable that each sensor maintains an accurate track. It has been recognized for some time that the use of a multiple model filter is superior to the use of a single model filter for tracking...

This paper describes the design of a tightly coupled GPS/INS integration system based on nonlinear Kalman filtering methods. The traditional methods include linearization of the system around a nominal trajectory, and the extended Kalman filtering (EKF) method which linearizes the system around the previous estimate, or the predication, whichever is available. The recently proposed sigma-point ...

Tracking algorithms for the GPS C/A code with an interference rejection capability based on state estimation technique are considered. A swept tone jamming signal is modeled as an autoregressive (AR) process and estimated jointly with the timing delay. A novel Mean-Value Theorem Particle Filter (MVT-PF) is applied to address the highly nonlinear measurement model and its performance is compared...

Voltage-gated K+ channels exhibit a slow inactivation process, which becomes an important influence on the rate of action potential repolarization during prolonged or repetitive depolarization. During slow inactivation, the outer mouth of the permeation pathway undergoes a conformational change. We report here that during the slow inactivation process, the channel progresses through at least th...

Potassium channels selectively conduct K(+) ions across cell membranes and have key roles in cell excitability. Their opening and closing can be spontaneous or controlled by membrane voltage or ligand binding. We used Ba(2+) as a probe to determine the location of the ligand-sensitive gate in an inwardly rectifying K(+) channel (Kir6.2). To a K(+) channel, Ba(2+) and K(+) are of similar sizes, ...

A two-stage state and parameter estimation algorithm for linear systems has been developed. Stage 1 uses a stochastic approximation method for state estimation, while stage 2 considers parameter estimation through a linear Kalman filter. These two stages are conpled in a bootstrap manner. The algorithm is computationally much simpler than the usual extended Kalman filter. A fourth-order numeric...

Surface-enhanced IR absorption spectroscopy (SEIRAS) is a powerful tool for studying the structure of molecules adsorbed on an electrode surface (ATR-SEIRA). Coupled with an electrochemical system, structural changes induced by changes in the electric field can be detected. All the membrane proteins are subjected to the effect of membrane electric field, but conformational changes at different ...

hotolithography and the semiconductor industry are facing a critical juncture. The 32 nm node (at which production photolithographic technology is able to pattern some specific chip features at 32 nm) is only a few years away, and next-generation methods for patterning the even-smaller, sub-30-nanometer-scale dimensions on silicon wafers at the node beyond that are unproved. Scientists at IBM’s...