Showing papers by "Li Liu published in 2009"

An Adaptive and Fast CFAR Algorithm Based on Automatic Censoring for Target Detection in High-Resolution SAR Images

Abstract: An adaptive and fast constant false alarm rate (CFAR) algorithm based on automatic censoring (AC) is proposed for target detection in high-resolution synthetic aperture radar (SAR) images. First, an adaptive global threshold is selected to obtain an index matrix which labels whether each pixel of the image is a potential target pixel or not. Second, by using the index matrix, the clutter environment can be determined adaptively to prescreen the clutter pixels in the sliding window used for detecting. The G 0 distribution, which can model multilook SAR images within an extensive range of degree of homogeneity, is adopted as the statistical model of clutter in this paper. With the introduction of AC, the proposed algorithm gains good CFAR detection performance for homogeneous regions, clutter edge, and multitarget situations. Meanwhile, the corresponding fast algorithm greatly reduces the computational load. Finally, target clustering is implemented to obtain more accurate target regions. According to the theoretical performance analysis and the experiment results of typical real SAR images, the proposed algorithm is shown to be of good performance and strong practicability.

The univariate and bivariate impact of HIV/AIDS on the quality of life: a cross sectional study in the Hubei Province-Central China.

Abstract: This study is aimed to evaluate the quality of life (QOL) for individuals living with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) in Hubei province-central China by using WHOQOL-BREF instrument (Chinese version). One hundred and thirty six respondents (HIV/AIDS individuals) attending out-patient department of Chinese Center for Disease Control and Prevention (Chinese CDC) were administered a structured questionnaire developed by investigators. QOL was evaluated by using WHOQOL-BREF instrument (Chinese version). The results showed that the mean score of overall QOL on a scale of 0-100 was 25.8. The mean scores in 4 domains of QOL on a scale of 0-100 were 82.9 (social domain), 27.5 (psychological domain), 17.7 (physical domain) and 11.65 (environmental domain). The significant difference of QOL was noted in the score of physical domain between asymptomatic (14.6) and early symptomatic individuals (12) (P=0.014), and between patients with early symptoms (12) and those with AIDS (10.43) (P<0.001). QOL in psychological domain was significantly lower in early symptomatic (12.1) (P<0.05) and AIDS patients (12.4) (P<0.006) than in asymptomatic individuals (14.2). The difference in QOL scores in the psychological domain was significant with respect to the income of patients (P<0.048) and educational status (P<0.037). Significantly better QOL scores in the physical domain (P<0.040) and environmental domain (P<0.017) were noted with respect to the occupation of the patients. Patients with family support had better QOL scores in environmental domain. In our research, QOL for HIV/AIDS individuals was associated with education, occupation, income, family support and clinical categories of the patients. It was concluded that WHOQOL-BREF Chinese version was successfully used in the evaluation of QOL of HIV/AIDS individuals in Chinese population and proved to be a reliable and useful tool.

Association between two functional polymorphisms of insulin-like growth factor binding protein 3 and colorectal cancer risk in a Chinese population.

Abstract: Circulating levels of insulin-like growth factor binding protein 3 (IGFBP3) are modulated by functional variants of IGFBP3 and therefore may be associated with higher risk of colorectal cancer development. However, few studies have investigated the role of IGFBP3 polymorphisms in colorectal cancer in Chinese individuals. In this study, two common polymorphisms of IGFBP3 were determined by the Taqman genotyping platform in 202 Chinese colorectal cancer cases diagnosed between 2006 and 2008 and 212 cancer-free population controls. Data showed that the genotype distribution of G2133C (rs2864746), but not A-202C (rs2864744), was significantly different between cancer cases and controls. Unconditional logistic regression analyses revealed that participants carrying the G2133C GC heterozygote or CC homozygote had a significant 1.55-fold increased risk of colorectal cancer development in an allele dose-responsive manner. However, there was no evidence of a dose-effect relationship between number of variants and ...