MultiNet: Multi-Modal Multi-Task Learning for Autonomous Driving

Autonomous driving requires operation in different behavioral modes ranging from lane following and intersection crossing to turning and stopping. However, most existing deep learning approaches to autonomous driving do not consider the behavioral mode in the training strategy. This paper describes a technique for learning multiple distinct behavioral modes in a single deep neural network through the use of multi-modal multi-task learning. We study the effectiveness of this approach, denoted MultiNet, using self-driving model cars for driving in unstructured environments such as sidewalks and unpaved roads. Using labeled data from over one hundred hours of driving our fleet of 1/10th scale model cars, we trained different neural networks to predict the steering angle and driving speed of the vehicle in different behavioral modes. We show that in each case, MultiNet networks outperform networks trained on individual modes while using a fraction of the total number of parameters.Comment: Published in IEEE WACV 201

Persistence analysis of velocity and temperature fluctuations in convective surface layer turbulence

Persistence is defined as the probability that the local value of a fluctuating field remains at a particular state for a certain amount of time, before being switched to another state. The concept of persistence has been found to have many diverse practical applications, ranging from non-equilibrium statistical mechanics to financial dynamics to distribution of time scales in turbulent flows and many more. In this study, we carry out a detailed analysis of the statistical characteristics of the persistence probability density functions (PDFs) of velocity and temperature fluctuations in the surface layer of a convective boundary layer, using a field-experimental dataset. Our results demonstrate that for the time scales smaller than the integral scales, the persistence PDFs of turbulent velocity and temperature fluctuations display a clear power-law behaviour, associated with self-similar eddy cascading mechanism. Moreover, we also show that the effects of non-Gaussian temperature fluctuations act only at those scales which are larger than the integral scales, where the persistence PDFs deviate from the power-law and drop exponentially. Furthermore, the mean time scales of the negative temperature fluctuation events persisting longer than the integral scales are found to be approximately equal to twice the integral scale in highly convective conditions. However, with stability this mean time scale gradually decreases to almost being equal to the integral scale in the near neutral conditions. Contrarily, for the long positive temperature fluctuation events, the mean time scales remain roughly equal to the integral scales, irrespective of stability

An International Standard : ISO Quality

An International Standard – ISO 9000 quality management system as applicable to service centre is discusse

Boitawl: Soil, Lost and Left

Boitawl ( Boi - lack, devoid of, Tawl - bottom/ ground/ foundation), the word in one of the Bengali dialects refers to one without a ground beneath her feet. The thesis, a hybrid collection of prose and verse including narratives and graphic vignettes, flash, fabulist and short stories, prose poems and free verse imagines the inside worlds of such un-settled existences. In the process, the pieces connect migration, memory, childhood and lost towns with fractured humans caught in between - to reveal what lies under pillars of desires, the shapes of unsaid longings and recurrent images in their dreams

Teachers’ use of reform-oriented mathematics textbooks: A multiple-case study of Delhi government primary school teachers

India in the last two decades has introduced several policy reforms to improve primary school mathematics teaching and learning, especially to make it more accessible for children. One such policy, National Curriculum Framework – 2005, outlines the need for making mathematics relevant to all children and connecting school mathematics to students’ lives. Based on these reforms, the National Council of Educational Research and Training (NCERT) developed new primary school mathematics textbooks. These books are a radical departure from traditional mathematics textbooks, as they explicitly restructure its form, pedagogy and mathematical content. The crucial enabling link in actualising transformational ideals in textbooks are, the teachers. Yet, both in India and globally, very little is understood on how teachers use textbooks in their teaching. To fill this gap, my study explores how teachers view and use textbooks in a reform context. The study adopts a participatory view of the relationship between the textbook and the teacher; which is both influenced by the textbook’s features as well teachers’ thinking. The study explores the cases of ten primary school teachers in Grades 4 and 5, in four government schools of Delhi. Data were collected from classroom observations, semi- structured teacher interviews, and textbooks. Thematic analysis was used to analyse the textbooks, classroom observations as well as interviews. The textbook analysis reveals that several pedagogical changes are introduced within the textbook. The reformed textbook challenges the authority relations between school mathematics and the learner. Additionally, social justice messaging is implicitly embedded within the textbook. Teachers in turn make textbook related choices at two levels: first, at the level of task selection; second at an interpretive level. Challenging the predominant understanding of textbooks-centric teaching, my findings show that teachers use a range of strategies to engage with the textbook. These include following the textbook as a script, customising it to fit their own notions of mathematics teaching and institutional realities, as well as avoidance of the textbooks and the subject all together. There are two important implications of the study. First, in relation to producing reform oriented textbooks, the thesis argues for a simultaneous focus on teachers must be maintained, so that textbooks become educative materials for professional development. Second, the study also highlights the significance of institutional and cultural opportunities and barriers in enabling teachers’ productive interpretations of textbooks

Exploring modes of engagement within reform-oriented primary mathematics textbooks in India

In India, a curriculum reform inspired by critical perspectives has sought to transform primary mathematics teaching and learning. It is aimed at strengthening socio-cultural-political connections between school mathematics and students’ life experiences, thereby challenging traditional textbook culture. At the same time, this initiative has retained the textbook as a vehicle of reform while seeking to subvert many of its established conventions. Guided by Remillard’s idea of modes of engagement, this paper analyses the innovative Math-Magic textbooks associated with the Indian National Curriculum Framework. It investigates how these textbooks represent and communicate the framework ideas, focusing on key curricular elements and on the teacher as reader. Analysing the ‘voice’ and ‘structure’ of the textbooks as well as the ‘contexts’ used, it is revealed that they use a radically unique voice to introduce school mathematics while also attempting to use authentic and socially relevant contexts within their tasks. However, they have limited structural support to communicate these ideas clearly to the teacher-reader. The paper has implications for studying reformed textbooks in primary school mathematics in the Global South, where they remain the main teaching resource for teachers. Further, by focusing on ‘context’, the notion of modes of engagement within textbooks is extended through socio-cultural perspectives

Impact of the Primary Science Capital Teaching Approach

Developing a justice-oriented science teaching approach for primary schools

Level-crossings reveal organized coherent structures in a turbulent time series

In turbulent flows, energy production is associated with highly organized structures, known as coherent structures. Since these structures are three-dimensional, their detection remains challenging in the most common situation, when single-point temporal measurements are considered. While previous research on coherent structure detection from time series employs a thresholding approach, the thresholds are ad-hoc and vary significantly from one study to another. To eliminate this subjective bias, we introduce the level-crossing method and show how specific features of a turbulent time series associated with coherent structures can be objectively identified, without assigning a prior any arbitrary threshold. By using two wall-bounded turbulence time series datasets, we successfully extract through level-crossing analysis the impacts of coherent structures on turbulent dynamics, and therefore, open an alternative avenue in experimental turbulence research. By utilizing this framework further we identify a new metric, characterized by a statistical asymmetry between peaks and troughs of a turbulent signal, to quantify inner-outer interaction in wall turbulence. Moreover, a connection is established between extreme value statistics and level-crossing analysis, thereby allowing additional possibilities to study extreme events in other dynamical systems.Comment: This manuscript has 9 figures and 3 supplementary figure