Comparing Sample-wise Learnability Across Deep Neural Network Models

Estimating the relative importance of each sample in a training set has important practical and theoretical value, such as in importance sampling or curriculum learning. This kind of focus on individual samples invokes the concept of sample-wise learnability: How easy is it to correctly learn each sample (cf. PAC learnability)? In this paper, we approach the sample-wise learnability problem within a deep learning context. We propose a measure of the learnability of a sample with a given deep neural network (DNN) model. The basic idea is to train the given model on the training set, and for each sample, aggregate the hits and misses over the entire training epochs. Our experiments show that the sample-wise learnability measure collected this way is highly linearly correlated across different DNN models (ResNet-20, VGG-16, and MobileNet), suggesting that such a measure can provide deep general insights on the data's properties. We expect our method to help develop better curricula for training, and help us better understand the data itself.Comment: Accepted to AAAI 2019 Student Abstrac

Synchrotron study of the garnet-type oxide Li6CaSm2Ta2O12

Hexalithium calcium disamarium(III) ditantalum(V) dodeca­oxide, Li6CaSm2Ta2O12, crystallizes in a cubic garnet-type structure. In the crystal structure, disordered Li atoms occupy two crystallographic sites. One Li has a tetra­hedral coordination environment in the oxide lattice, whereas the other Li atom occupies a significantly distorted octa­hedral site, with site occupancies for the two Li atoms of 0.26 (7) and 0.44 (2), respectively. Ca and Sm atoms are statistically distributed over the same crystallographic position with a occupancy of 2/3 for Sm and of 1/3 for Ca, and are eightfold coordinated by O atoms. The TaO6 octa­hedron is joined to six others via corner-sharing LiO4 tetra­hedra. One Li and the O atoms lie on general positions, while the other atoms are situated on special positions. The Sm/Ca position has 222, Ta has , and the tetra­hedrally coordinated Li atom has site symmetry

Sonography of Affected and Unaffected Shoulders in Hemiplegic Patients: Analysis of the Relationship Between Sonographic Imaging Data and Clinical Variables

Objective To explore the relationship between a number of clinically relevant variables and sonographic imaging data in respect to the level of impairment experienced in the affected and unaffected shoulders of hemiplegic stroke patients. Method Fifty-one hemiplegic stroke patients (32 males, 19 females; 29 right-sided hemiplegics, 22 left-sided hemiplegics) participated in this study. A musculoskeletal radiologist conducted a sonographic exam on both the affected and unaffected shoulders of all patients and two physicians classified the severity of the injury on a six-point rating scale. Clinical variables including age, sex, duration of injury, spasticity and muscle power of the hemiplegic side, and level of functional activity of the shoulder were assessed. Results The sonographic rating scores of hemiplegic shoulders were positively correlated with age (p<0.01) and negatively correlated with level of muscle spasticity (p<0.05). The sonographic rating scores of unaffected shoulders were positively correlated with duration of injury (p<0.01). Affected shoulders received sonographic rating scores that reflected significantly more impairment than those of unaffected shoulders (p<0.001), and premorbid handedness did not affect the relationship between impairment rating and shoulder injury status. Conclusion Hemiplegic stroke influences not only affected shoulders, but also unaffected sides. Proper management of spasticity, enhancement of motor recovery, and avoidance of unaffected shoulder overuse should be considered to prevent shoulder problems following strokes which result in hemiplegia

The Nerve/Tunnel Index: A New Diagnostic Standard for Carpal Tunnel Syndrome Using Sonography

Objectives—To define the relationship between body indices of healthy adults and cross-sectional areas of the carpal tunnel and median nerve and to obtain the nerve/tunnel index, which represents a new standard for diagnosing carpal tunnel syndrome using sonography. Methods—Body indices (height, weight, and body mass index) were analyzed in 60 healthy adults, and electromyography and sonography were also performed. The crosssectional areas of the proximal and distal median nerve and carpal tunnel were obtained by sonography. The proximal and distal nerve/tunnel indices were obtained by calculating the ratio between the proximal and distal cross-sectional areas of the median nerve to those of the carpal tunnel and multiplying the value by 100. Results—Although the proximal cross-sectional areas of the median nerve and body indices showed statistically significant relationships with weak positive correlations, the proximal and distal areas of the carpal tunnel showed relatively stronger correlations with body indices. Between sexes, there were significant differences in the proximal median nerve cross-sectional area (mean ± SD: male, 10.48 ± 3.21 mm2; female, 8.81 ± 3.21 mm2; P < .05) and proximal carpal tunnel area (male, 182.50 ± 21.15 mm2; female, 151.23 ± 21.14 mm2; P < .05). There was no difference in the proximal nerve/tunnel index (male, 5.80% ± 1.72%; female, 5.91% ± 1.63%). There was a statistically significant difference in the distal carpal tunnel cross-sectional area (male, 138.90 ± 20.95 mm2; female, 121.50 ± 18.99 mm2; P < .05) between sexes, but the distal median area (male, 9.99 ± 3.42 mm2; female, 8.46 ± 1.84 mm2) and distal nerve/tunnel index (male, 7.15% ± 2.00%; female, 7.01% ± 1.38%) showed no significant differences. The proximal index was significantly higher than the distal index (proximal, 5.85% ± 1.66%; distal, 7.08% ± 1.71%). Conclusions—The nerve/tunnel index is unaffected by body indices or sex and thus may be a useful and objective standard for diagnosing carpal tunnel syndrome