Feature Learning for Multispectral Satellite Imagery Classification Using Neural Architecture Search

Automated classification of remote sensing data is an integral tool for earth scientists, and deep learning has proven very successful at solving such problems. However, building deep learning models to process the data requires expert knowledge of machine learning. We introduce DELTA, a software toolkit to bridge this technical gap and make deep learning easily accessible to earth scientists. Visual feature engineering is a critical part of the machine learning lifecycle, and hence is a key area that will be automated by DELTA. Hand-engineered features can perform well, but require a cross functional team with expertise in both machine learning and the specific problem domain, which is costly in both researcher time and labor. The problem is more acute with multispectral satellite imagery, which requires considerable computational resources to process. In order to automate the feature learning process, a neural architecture search samples the space of asymmetric and symmetric autoencoders using evolutionary algorithms. Since denoising autoencoders have been shown to perform well for feature learning, the autoencoders are trained on various levels of noise and the features generated by the best performing autoencoders evaluated according to their performance on image classification tasks. The resulting features are demonstrated to be effective for Landsat-8 flood mapping, as well as benchmark datasets CIFAR10 and SVHN

Becoming a teacher: conceptual and practice development in the learning and skills sector

Drawing on a mixed-methods study of in-service learning and skills sector (LSS) trainees, comprising beginning- and end-of-year surveys and six longitudinal case studies together with literature on trainees’ development in the LSS, schools and higher education sectors, conceptual and practice development continua are proposed. Conceptions become more multi-dimensional and increasingly link teaching and learning whilst initial concern with the practicalities of teaching is followed by recognition of learners’ needs. Next, greater emphasis is placed on learner autonomy and catering for individuals’ needs and finally assessment and evaluation is used systematically to shape practice. The continua offer an understanding of the subtleties and complexities of trainee development allowing for different starting and end points and accommodating varied work contexts. I argue that this provides a more adequate basis for the development of initial teacher education (ITE) than the prescriptive approach embedded within recent LSS ITE policy reforms

PRELIMINARY ANALYSIS OF SLEDGE REACTION FORCES DURING CYCLICAL LOADING OF THE TRICEPS SURAE

To date, no methodology exists that can measure Achilles tendon stiffness in a controlled dynamic situation while simultaneously investigating tendon and joint stiffness interactions. Stiffness refers to the ratio between force and elongation, and the aim of this preliminary study was to establish an analysis protocol for sledge reaction forces during cyclical loading of the triceps surae. Results indicated the magnitude of forces was just under 50% of body weight, which was expected. Removal of the first two trials from analysis reduced standard deviation and 95% confidence interval of plantarflexor force, contact time and contact time-flight time ratio, suggesting this protocol is suitable to ensure data gathered is repeatable and consistent. Future work using inverse dynamics and ultrasound shall provide information on Achilles tendon loading and stiffness

Spherical Mechanism Synthesis in Virtual Reality

This paper presents a new approach to using virtual reality (VR) to design spherical mechanisms. VR provides a three dimensional design space where a designer can input design positions using a combination of hand gestures and motions and view the resultant mechanism in stereo using natural head movement to change the viewpoint. Because of the three dimensional nature of the design and verification of spherical mechanisms, VR is examined as a new design interface in this research. In addition to providing a VR environment for design, the research presented in this paper has focused on developing a “design in context” approach to spherical mechanism design. Previous design methods have involved placing coordinate frames along the surface of a constraint sphere. The new “design in context” approach allows a designer to freely place geometric models of movable objects inside an environment consisting of fixed objects. The fixed objects could either act as a base for a mechanism or be potential sources of interference with the motion of the mechanism. This approach allows a designer to perform kinematic synthesis of a mechanism while giving consideration to the interaction of that mechanism with its application environment

DO FLEXIBILITY SCREENING TESTS REFLECT JOINT RANGE OF MOTION DURING DYNAMIC TASKS?

The aim of this study was to investigate if ankle joint range of motion (ROM) during a functional screen test was related to ankle ROM and plantarflexor reactive strength index (RSI) during a dynamic task. The three measures were correlated for the dominant and non-dominant legs to identify what relationship, if any, existed between the three measures. Results showed that there was no relationship between the two measures of ROM, and ROM during the sledge task was positively related to plantarflexor RSI. This is in contrast to other work, possibly due to the isolation of the plantarflexor muscles in the sledge task. Interestingly, between-leg relationships were lower in the dynamic task, suggesting increased variability in the movement strategies used or underlying training differences

PLANTARFLEXOR FORCE PRODUCTION IN ISOMETRIC AND STRETCH-SHORTENING CYCLE TASKS

The ankle joint and its surrounding musculature are vital in sprinting, and recent work has developed a method to isolate the plantarflexor muscle group for analysis of its force-producing capabilities. The aim of this study was to compare values for plantarflexor force obtained using isometric dynamometry and an adapted force sledge in twenty healthy subjects. Results showed low relationships between isometric and dynamic strength measures, probably because the dynamic test utilises a stretch-shortening cycle. No relationship was observed between isometric strength and the sledge foot plate height during the task with a moderate relationship observed between dynamic strength and plate height. This highlights the important role the Achilles tendon plays in dynamic tasks