Rotation-Invariant Synthetic Discriminant Function Filter for Pattern Recognition

The ring synthetic discriminant function (RSDF) filter for rotation-invariant response is discussed for pattern recognition. This method uses one half of a slice of the Fourier transform of the object to generate the transfer function of the filter. This is accomplished by rotating the one half of a slice in the Fourier domain through 2π rad about the zero-frequency point of the Fourier plane. This filter has the advantage of always matching at least one half of a slice of the Fourier transform of any rotation of the image. An analytical discussion of the filter construction and correlation results are presented along with simulated correlation results for a particular target image. These results and established metrics are used for comparison with benchmark algorithms

SAR Automatic Target Recognition via Non-negative Matrix Approximations

The set of orthogonal eigen-vectors built via principal component analysis (PCA), while very effective for compression, can often lead to loss of crucial discriminative information in signals. In this work, we build a new basis set using synthetic aperture radar (SAR) target images via non-negative matrix approximations (NNMAs). Owing to the underlying physics, we expect a non-negative basis and an accompanying non-negative coefficient set to be a more accurate generative model for SAR profiles than the PCA basis which lacks direct physical interpretation. The NNMA basis vectors while not orthogonal capture discriminative local components of SAR target images. We test the merits of the NNMA basis representation for the problem of automatic target recognition using SAR images with a support vector machine (SVM) classifier. Experiments on the benchmark MSTAR database reveal the merits of basis selection techniques that can model imaging physics more closely and can capture inter-class variability, in addition to identifying a trade-off between classification performance and availability of training

Making Asian learners talk : encouraging willingness to communicate

Developing English for communicative purposes is a key objective of language classes in many parts of the world. As a logical prerequisite to communication practice, learners need to have Willingness to Communicate (WTC) before they will engage in L2 interaction (Macintyre et al., 1998). Teachers can play an important role in helping learners to develop WTC (Dörnyei, 2007), however, since research into this topic is relatively recent, not much is known about how teachers go about this process. For this reason, the present study investigated teachers’ perceptions of their role in fostering WTC through interviews and questionnaires and compared these with observations of their classroom practices. The research was conducted in New Zealand ESOL class that focused predominantly on communicative skills, catering mostly to Asian learners. The results showed that teachers believed they play a key role in helping learners to develop WTC and identified a range of strategies they used in class. Classroom observations confirmed the use of some strategies although no explicit encouragement of language practice outside the classroom was made. This paper identifies some possible reasons for this mismatch and concludes with practical recommendations for ESOL teachers who wish to support learners’ WTC

Gender determines the pattern of correlation between body mass index and major depressive disorder among children and adolescents: Results from iranian children and adolescents' psychiatric disorders study

Background: We aimed to determine the correlation of BMI with depression and to determine the role of gender in this association, in a large study sample. Methods: We used the data of participants in the Iranian Children and Adolescents' Psychiatric Disorders (IRCAP) Study, conducted in 2017. This study was a national community-based, cross-sectional study in which the urban and rural areas of all provinces of Iran were covered. Overall 30,532 children and adolescents, ages 6-18, were randomly selected with the stratified cluster sampling method. Results: Of a total of 30,532 participants, 25,321, whose BMI had been measured and who had been interviewed with Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS), entered the study (12,455 boys and 12,866 girls). We categorized the participants according to the national cutoff points for BMI classification. After controlling for age, father's and mother's job and education, and place of residence, the odds ratio (OR) of depression in underweight, healthy weight, and overweight boys compared with obese boys was 2.19 [95% confidence interval (95% CI): 1.00-4.81], 1.06 (95% CI: 0.73-1.55), and 0.80 (95% CI: 0.49-1.32), respectively. In the girls' subgroup, after controlling for the aforementioned covariates, the OR of depression in healthy weight, overweight, and obese participants compared with underweight subjects was 1.29 (95% CI: 0.52-3.19), 1.54 (95% CI: 0.59-3.98), and 1.79 (95% CI: 0.68-4.69), respectively. Conclusions: Underweight boys were more likely diagnosed with depression than normal weight and overweight boys. While in girls, the probability of depression increased by increased BMI

Gender determines the pattern of correlation between body mass index and major depressive disorder among children and adolescents: Results from iranian children and adolescents' psychiatric disorders study

Background: We aimed to determine the correlation of BMI with depression and to determine the role of gender in this association, in a large study sample. Methods: We used the data of participants in the Iranian Children and Adolescents' Psychiatric Disorders (IRCAP) Study, conducted in 2017. This study was a national community-based, cross-sectional study in which the urban and rural areas of all provinces of Iran were covered. Overall 30,532 children and adolescents, ages 6-18, were randomly selected with the stratified cluster sampling method. Results: Of a total of 30,532 participants, 25,321, whose BMI had been measured and who had been interviewed with Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS), entered the study (12,455 boys and 12,866 girls). We categorized the participants according to the national cutoff points for BMI classification. After controlling for age, father's and mother's job and education, and place of residence, the odds ratio (OR) of depression in underweight, healthy weight, and overweight boys compared with obese boys was 2.19 95% confidence interval (95% CI): 1.00-4.81, 1.06 (95% CI: 0.73-1.55), and 0.80 (95% CI: 0.49-1.32), respectively. In the girls' subgroup, after controlling for the aforementioned covariates, the OR of depression in healthy weight, overweight, and obese participants compared with underweight subjects was 1.29 (95% CI: 0.52-3.19), 1.54 (95% CI: 0.59-3.98), and 1.79 (95% CI: 0.68-4.69), respectively. Conclusions: Underweight boys were more likely diagnosed with depression than normal weight and overweight boys. While in girls, the probability of depression increased by increased BMI