Estimating motion, size and material properties of moving non-line-of-sight objects in cluttered environments

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 111-117).The thesis presents a framework for Non-Line-of-Sight Computer Vision techniques using wave fronts. Using short-pulse illumination and a high speed time-of-flight camera, we propose algorithms that use multi path light transport analysis to explore the environments beyond line of sight. What is moving around the corner interests everyone including a driver taking a turn, a surgeon performing laparoscopy and a soldier entering enemy base. State of the art techniques that do range imaging are limited by (i) inability to handle multiple diffused bounces [LIDAR] (ii) Wavelength dependent resolution limits [RADAR] and (iii) inability to map real life objects [Diffused Optical Tomography]. This work presents a framework for (a) Imaging the changing Space-time-impulse-responses of moving objects to pulsed illumination (b) Tracking motion along with absolute positions of these hidden objects and (c) recognizing their default properties like material and size and reflectance. We capture gated space-time impulse responses of the scene and their time differentials allow us to gauge absolute positions of moving objects with knowledge of only relative times of arrival (as absolute times are hard to synchronize at femto second intervals). Since we record responses at very short time intervals we collect multiple readings from different points of illumination and thus capturing multi-perspective responses allowing us to estimate reflectance properties. Using this, we categorize and give parametric models of the materials around corner. We hope this work inspires further exploration of NLOS computer vision techniques.by Rohit Pandharkar.S.M

Agriculture, nutrition and gender in India

The South Asian region has one of the highest rates of child and maternal undernutrition in the world. Undernutrition is widespread and persistent even in India despite its relatively strong economic performance and is particularly high in rural areas and among those in agriculture based livelihoods. Though agriculture has the enormous potential to contribute to improvements in undernutrition, the evidence so far in the Indian context demonstrates weak linkages between agriculture and nutrition . This research brief summarises the key findings from the different studies focusing on women’s agency and nutrition undertaken by LANSA in India.Department for International Development (DFID)UKAI

Agriculture-nutrition linkages and child undernutrition in India

The South Asian region and in particular India, has one of the highest rates of child undernutrition in the world, and is home to around 40 per cent of the global total of children who are stunted. Child stunting has been shown to have severe lifelong economic, health, and cognitive disadvantages and costs. Despite improvements in some states in recent years, the levels continue to be high. Understanding the reasons for the high prevalence of child undernutrition in India in the face of the relatively strong economic performance has emerged as an important research topic and is an area of focus of LANSA’s research in the region. Under the research theme, ‘How enabling is the wider context in linking agriculture and food systems to other determinants of nutritional status?’, LANSA research in India focuses on understanding the barriers and facilitators to nutrition-sensitive agricultural development in the country. The analyses and empirical work on the available large secondary datasets from India are expected to elaborate on the pathways that connect agriculture and nutrition and the type and degree of interaction with other non-food drivers. This research brief summarises the key findings from some of the studies undertaken by LANSA partners, on agriculture-nutrition linkages and child undernutrition in India.Department for International Development (DFID)UKAI

Knowledge, attitude and practice of preventing spread of COVID-19 amongst orthopaedic surgeons and residents in a tertiary care hospital in Navi-Mumbai

Background: With on-going coronavirus pandemic, there is high incidence of COVID-19 occupational risk exposure among health care professionals. The aim of this study was to assess the knowledge, attitude and practice (KAP) amongst orthopaedic surgeons and residents regarding prevention of spread of COVID-19 at a tertiary care hospital.Methods: A cross-sectional, observational, web-based questionnaire study was conducted at orthopaedic department of a tertiary care hospital in Navi Mumbai. The study included orthopaedic surgeons and residents of either sex. A predesigned KAP questionnaire was used to assess the knowledge, attitude and practice regarding prevention of spread of COVID-19. The web-based questionnaire was circulated to eligible participants and the responses obtained were analysed.Results: Overall, the knowledge regarding hand hygiene, mask etiquette and COVID-19 diagnoses was high. Majority participants knew the proper technique of personal protective equipment (PPE), but few 25% and 35% lacked correct technique for donning and doffing of PPE respectively. Majority participants knew the indications and pre/post-operative protocols for orthopaedic surgeries in COVID-19. Around 40% only knew the type of pressure system used in the COVID-19 operation theatre (OT). Majority felt that mask, hand hygiene and PPE were essential kit for prevention. In practice, majority participants were taking drug prophylaxis and were adequately practicing mask/hand hygiene.Conclusions: Overall, KAP regarding prevention of spread of COVID-19 among orthopaedicians were adequate. Further formal preventive education on COVID-19 and structured hands-on experience workshops are necessary to advance the proper techniques of PPE handling

Hierarchical inverse reinforcement learning from motion capture data

A human motion generally consists of multiple low-level tasks which are performed in a defined order or in parallel to achieve a high level task. For example, making pizza dough consists of several low-level tasks such as measuring water, adding yeast, measuring flour, etc. And these activities must be performed in a definite order to make the dough. For a system to imitate these sequence of activities of a long horizon task with one global reward function is a lot of work. This process can be made easier if there is hierarchical state representation of the task and learning of local rewards for the hierarchies. In this thesis, we have learned to imitate a general day to day human activity of ’setting table for one person’. This work adopts a framework called Hierarchical Inverse Reinforcement Learning (HIRL), which is a model to learn sub-task structure from demonstrations. With this framework, the activity is decomposed into multiple lower level tasks which are performed in a sequence using learned policies. In this work, Maximum Entropy Inverse Reinforcement Learning (MaxEnt-IRL) is used to learn local rewards for the sub-tasks. Together with hierarchical state space representation and local reward functions, the model encodes the high level task objective based on human demonstrations of full body motion performing the high level task. The model achieves a success rate of 84% on average for middle levels and 83% for the top level in the cross validation tests. For visualization, the model is simulated in a 2D representation that takes current environment state as input and runs till the completion of the task

Does strengths of a positive direct antiglobulin test predicts the need for phototherapy and duration of phototherapy? – a single center, retrospective study

BackgroundUse of Direct Antiglobulin test (DAT) in management of neonatal hyperbilirubinemia is conflicting.Objectivewhether strength of positive DAT predicts the need for phototherapy, duration of phototherapy and need for major interventions.MethodsWe retrospectively collected data on all DAT positive neonates with birth gestational age ≥32 weeks over six years (2014–2019). Data regarding blood group, DAT and clinical details were obtained from a hospital database. We also collected data on serial hemoglobin and other relevant laboratory parameters. We also collected data on infants receiving major interventions such as exchange transfusion, in-utero transfusion, immunoglobulins, and postnatal transfusion for the duration of the study period. All of these infants were electronically followed up for a period of 6 weeks. This study was approved by institutional audit authority. All the statistics were performed using SPSS software.ResultsOut of 1285 DAT tests performed, only 91 infants were positive (7%), and 78 DAT positive infants were available for analysis. There were 54 infants with DAT (1+), 15 infants with DAT (2+), 7 infants with DAT (3+) and 2 infants with DAT (4+). There was no significant statistical difference in terms of need for phototherapy, duration of phototherapy, need for major interventions and hemoglobin levels at different time points between the groups (DAT 1+ Vs DAT ≥2+; DAT ≤2+ Vs DAT >2). A Total of 10 infants received major intervention, with one infant receiving all three interventions (DAT 3+ with significant maternal antibodies), 2 additional infants (both DAT1+) received exchange transfusion, 6 additional infants received immunoglobulin (2 infants: DAT 2+; 4 infants: DAT 1+) and one additional infant (DAT 1+) with significant maternal antibodies received a postnatal transfusion.ConclusionStrength of a DAT did not predict the need for phototherapy, duration of phototherapy, and the need for major hemolysis related intervention in the first 6 weeks of life

Women in Agriculture and Nutrition in India

Policy debates around agriculture and nutrition and the crucial role of women needs to be informed by evidence that research programmes like LANSA generate. The available evidence recommends the recognition of women’s roles in agriculture and nutrition. This Policy Brief looks at the following focus polices and programmes: Draft National Policy for Women 2016; National Policy for Empowerment of Women 2001; Supplementary Nutrition Programme under ICDS; National Nutrition Policy 1993; National Food Security Act 2013; National Policy for Farmers 2007.Department for International Development (DFID)UKAI

Importance of WASH and Healthcare for enabling Agriculture-Nutrition linkages in India

State and district level studies linking child undernutrition to agricultural prosperity and provisioning of public services highlight the importance of public health provisioning such as sanitation, vaccination and healthcare facilities in rural areas, public provisioning for maternal health and women’s education as well as social provisioning of food. This policy brief discusses the following focus polices and programmes: National Health Mission; Swachh Bharat Abhiyan 2014; Draft National Policy for Women 2016; Draft National Plan of Action for Children 2016; National Food Security Act 2013; National Policy for Empowerment of Women 2001.Department for International Development (DFID)UKAI