Weighted Measurement Fusion Particle Filter for Nonlinear Systems with Correlated Noises.

The multi-sensor information fusion particle filter (PF) has been put forward for nonlinear systems with correlated noises. The proposed algorithm uses the Taylor series expansion method, which makes the nonlinear measurement functions have a linear relationship by the intermediary function. A weighted measurement fusion PF (WMF-PF) was put forward for systems with correlated noises by applying the full rank decomposition and the weighted least square theory. Compared with the augmented optimal centralized fusion particle filter (CF-PF), it could greatly reduce the amount of calculation. Moreover, it showed asymptotic optimality as the Taylor series expansion increased. The simulation examples illustrate the effectiveness and correctness of the proposed algorithm.

A Weighted Measurement Fusion Particle Filter for Nonlinear Multisensory Systems Based on Gauss-Hermite Approximation.

We addressed the fusion estimation problem for nonlinear multisensory systems. Based on the Gauss-Hermite approximation and weighted least square criterion, an augmented high-dimension measurement from all sensors was compressed into a lower dimension. By combining the low-dimension measurement function with the particle filter (PF), a weighted measurement fusion PF (WMF-PF) is presented. The accuracy of WMF-PF appears good and has a lower computational cost when compared to centralized fusion PF (CF-PF). An example is given to show the effectiveness of the proposed algorithms.

[The three-dimensional nonlinear finite element analysis of force system of the "rocking-chair archwire"].

OBJECTIVE: The purpose of this study was to qualitatively and quantitatively analyze the initial force system of "rocking-chair archwire" on every tooth. METHODS: Three-dimensional finite element model of "rocking-chair archwire" was set up, and nonlinear method was used to analyze the force system. RESULTS: The archwire exerted intruding force, labial force, lingual-root torque and mesial-labial moment on incisors; Extruding force, lingual-root torque and mesial-labial moment were applied on canines and premolars; The archwire also created intruding force, buccal force, buccal-root torque and mesial-labial moment on molars. CONCLUSIONS: "rocking-chair archwire" produced a complicated force system. While intruding incisors, molars and extruding premolars. It has a tendency to induce tooth rotation and tipping.

[The short-term and long-term treatment outcomes in patients with pulmonary tuberculosis positive for drug-resistant and sensitive strains].

OBJECTIVES: To analyze the treatment outcomes in patients with smear positive tuberculosis, and to compare the difference in treatment response among patients infected with drug-sensitive and drug-resistant strains. METHODS: From 1998 to 2000, seven hundred and seventy-seven patients with primary smear-positive tuberculosis, which were from 30 surveillance sites, were followed for two years to monitor their treatment outcomes. RESULTS: At the completion of the 6 months' therapy, the overall rate of treatment failure was 1.8%, 2.6% for the drug-resistant cases and 1.6% for the drug-sensitive cases. Six-month follow-up showed a positive conversion rate of 2.7% in all the cases, 8.5% and 1.2% (P < 0.005) in the drug-resistant and the drug-sensitive cases respectively. One year follow-up showed that the positive conversion rate was 2.6% in all the cases, 6.9% and 1.6% (P < 0.005) in the drug-resistant and the drug-sensitive cases, respectively. Two-year follow-up showed an overall positive conversion rate of 1.3%, 1.0% and 1.3% in the drug-resistant and the drug-sensitive cases, respectively. Of the 152 drug-resistant cases, the rate of treatment failure was 2.6% at the completion of 6 months' therapy, but in cases with MDR-TB the rate was 10.3%. Six-month follow-up showed an overall positive conversion rate of 8.5%, but the rate reached 37.0% in cases with MDR-TB. One-year and two-year follow-up showed that the positive conversion rates were 6.9% and 1.0% respectively in all the drug-resistant cases, but 6.3% and 6.7% respectively in the MDR cases. CONCLUSIONS: Under the guidelines of the National Tuberculosis Program (NTP), the 2H(3)R(3)S(3)Z(3)/4H(3)R(3) regimen for primary smear-positive pulmonary TB was effective. But the cure rate was lower and the positive conversion rate higher in patients with MDR-TB.