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In traditional target tracking methods, the angle error and range error are often measured by the empirical value, while observation noise is a constant. In this paper, the angle error and range error are analyzed. They are influenced by the signal-to-noise ratio (SNR). Therefore, a model related to SNR has been established, in which the SNR information is applied for target tracking. Combined with an advanced nonlinear filter method, the extended Kalman filter method based on the SNR model (SNR-EKF) and the unscented Kalman filter method based on the SNR model (SNR-UKF) are proposed. There is little difference between the SNR-EKF and SNR-UKF methods in position precision, but the SNR-EKF method has advantages in computation time and the SNR-UKF method has advantages in velocity precision. Simulation results show that target tracking methods based on the SNR model can greatly improve the tracking performance compared with traditional tracking methods. The target tracking accuracy and convergence speed of the proposed methods have significant improvements. [ABSTRACT FROM AUTHOR]

Background. Incidence rates of breast cancer continue to rise in the People's Republic of China. The purpose of this study was to describe Chinese trends in radical surgical modalities and influential imaging and demographic factors for breast malignancies. Materials and Methods. This study was a hospital-based, multicenter, 10-year (1999-2008), retrospective study. Descriptive statistical tests were used to illustrate information regarding radical surgical trends for the treatment of breast malignancies. Chi-square tests were used to assess effect of demographic factors in addition to imaging and pathological data on the specific surgical method. Results. A total of 4,211 patients were enrolled in the survey. Among them, 3,335 patients with stage 0 to stage III disease undergoing mastectomy or breast-conserving surgery (BCS) were included in the final analysis. The rate of BCS increased from 1.53% in 1999 to 11.88% in 2008. The rate of mastectomy declined over this time period, from 98.47% in 1999 to 88.12% in 2008, with increasing use of diagnostic imaging methods and pathological biopsies. A significantly greater percentage of patients with office work, high education levels, unmarried status, younger age, and early pathological stages preferred BCS compared with mastectomy. Conclusion. Rates of mastectomy in China remain elevated due to diagnosis at higher stages; however, because of increased use of diagnostic imaging, improvement of biopsy methods, and patient education, rates of less invasive lumpectomy are increasing and rates of mastectomy have decreased in China. [ABSTRACT FROM AUTHOR]

Background and Objective. Incidence of and mortality rates for breast cancer continue to rise in the People's Republic of China. The purpose of this study was to analyze differences in characteristics of breast malignancies between China and the U.S. Methods. Data from 384,262 breast cancer patients registered in the U.S. Surveillance, Epidemiology, and End Results (SEER) program from 2000 to 2010 were compared with 4,211 Chinese breast cancer patients registered in a Chinese database from 1999 to 2008. Outcomes included age, race, histology, tumor and node staging, laterality, surgical treatment method, and reconstruction. The Pearson chi-square and Fisher's exact tests were used to compare rates. Results. Infiltrating ductal carcinoma was the most common type of malignancy in the U.S. and China. The mean number of positive lymph nodes was higher in China (2.59 vs. 1.31, p < .001). Stage at diagnosis was higher in China (stage IIA vs. I, p < .001). Mean size of tumor at diagnosis was higher in China (32.63 vs. 21.57 mm). Mean age at diagnosis was lower in China (48.28 vs. 61.29 years, p < .001). Moreover, 2.0% of U.S. women underwent radical mastectomy compared with 12.5% in China, and 0.02% in China underwent reconstructive surgery. Conclusion. Chinese women were diagnosed at younger ages with higher stage and larger tumors and underwent more aggressive surgical treatment. Prospective trials should be conducted to address screening, surgical, and tumor discrepancies between China and the U.S. [ABSTRACT FROM AUTHOR]