Retrospective Cost Attitude Filtering with Noisy Measurements and Unknown Gyro Bias

Attitude filtering is a critical technology with applications in diverse domains such as aerospace engineering, robotics, computer vision, and augmented reality. Although attitude filtering is a particular case of the state estimation problem, attitude filtering is uniquely challenging due to the special geometric structure of the attitude parameterization. This paper presents a novel data-driven attitude filter, called the retrospective cost attitude filter (RCAF), for the SO(3) attitude representation. Like the multiplicative extended Kalman filter, RCAF uses a multiplicative correction signal, but instead of computing correction gains using Jacobians, RCAF computes the corrective signal using retrospective cost optimization and measured data. The RCAF filter is validated numerically in a scenario with noisy attitude measurements and noisy and biased rate-gyro measurements

Parameterized validation of UML-Like models for reactive embedded systems

Ph.DDOCTOR OF PHILOSOPH

Retrospective-Cost-Based Adaptive Input and State Estimation for the Ionosphere–Thermosphere

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140666/1/1.I010286.pd

Evaluation of the response rate of chemo-radiation and brachytherapy in patients with locally advanced carcinoma cervix in a tertiary care center

Background: Incidence and mortality estimates are used to measure the burden of cancer in a population and survival estimates are ideal for evaluating the outcome of cancer control activities. Survival studies evaluate the quality and quantity of life of a group of patients after diagnosing the disease. The patient survival after the diagnosis of cervical cancer is indirectly influenced by socio-economic factors. The present study was carried out with an aim to evaluate the success rate of chemo-radiation followed by brachytherapy to the patients of locally advanced carcinoma (Ca.) cervix in a tertiary care center.Methods: All cases were staged according to the International Federation of Gynaecologists and Oncologists (FIGO) staging system. To illustrate the observed survival of cancer patients Kaplan-Meier curve was plotted. All the patients, except one, completed chemo-radiation and were retrospectively analyzed for the presence of local residual disease, local recurrence, distant metastases, radiation reactions, disease-free survival, and overall survival.Results: There were 22 patients of Carcinoma cervix reported in the radiation oncology department in the year 2018 and 2019. The overall treatment time ranged from 30 days to 178 days, with a median of 63 days. All the patients had a complete response after the treatment. The median follow-up time for all the patients was 15 months. Three patients had a metastatic recurrence and one patient developed distant metastases as well as local recurrence. Overall survival rate was 100% while the disease-free survival rate was 81.82%.Conclusions: The response to chemo-radiation in the treatment of locally advanced Carcinoma cervix is comparable to historic data and is well tolerated

Flow visualization of pollutant mixing in freshwater body near the density maximum

Mixing in water bodies forms a major part of the environmental hydraulic studies. In the present study, effects of density variations in freshwater manifested in the form of convection currents on the water quality parameters is studied. Convection forms a dominant mixing mechanism for near-stagnant lakes i.e. with high residence times. However, due to tedious computations involved in simulating natural convection, water quality models available commercially or open-source solve vertically hydrostatic equations which fail to capture the circulation currents. A hydrodynamic model is conceptualized for describing the setting up of vertical circulation currents driven by the buoyancy. 2D incompressible Navier-Stokes, plus equations for transport of scalars (heat and concentration) are formulated and solved. Concentration profile of a conservative parameter is simulated to study the anomaly in temperature-density relationship on mixing.Density is assumed to be a function of temperature only (at 0.1Mpa) and various formulations like linear, quadratic and IAWPS(The International Association for the Properties of Water and Steam)are used in the model. The phenomenon is investigated near 4°C i.e. at the anomalous behavior of temperature-density curve. Impact of this anomaly on the hydrodynamics and subsequently on the mixing of water quality parameter is studied and visualized to facilitate interpretation and use. Modeling and simulation results for the hydrodynamics are validated against reported work

Experimental Flight Testing of an Adaptive Autopilot with Parameter Drift Mitigation

This paper modifies an adaptive multicopter autopilot to mitigate instabilities caused by adaptive parameter drift and presents simulation and experimental results to validate the modified autopilot. The modified adaptive controller is obtained by including a static nonlinearity in the adaptive loop, updated by the retrospective cost adaptive control algorithm. It is shown in simulation and physical test experiments that the adaptive autopilot with proposed modifications can continually improve the fixed-gain autopilot as well as prevent the drift of the adaptive parameters, thus improving the robustness of the adaptive autopilot.Comment: 6 pages, 16 figures, submitted to IROS 202

Serum Gamma Glutamyltransferase (GGT) in Coronary Artery Disease: Exploring the Asian Indian Connection

BACKGROUND: There is a need to identify novel markers for CAD, independent of traditional CV risk factors. One of these is gamma-glutamyl transferase (GGT), a marker of increased oxidative stress. Given the high prevalence of CAD in Asian Indians, the link of GGT and CAD in them needs to be studied. AIM: To assess GGT in patients with angiographically documented CAD. METHODS AND RESULTS: Two hundred patients aged 58.1 ± 9.95 years, 73% males, hypertension 56%, diabetes 40% were included. Mean GGT was 63.6 ± 44.33 (10–269 U/L). The levels of GGT progressively increased in those with single/double or triple-vessel CAD (36.5, 61.5, and 87 U/L, respectively, P \u3c 0.001). Using objective criteria of CAD burden (SYNTAX and Gensini scores), we reaffirmed these findings. GGT in patients with SYNTAX tertiles 0–22, 23–32, and ≥ 33 was 33, 62, and 97 U/L, respectively and in Gensini tertiles 0–17.65, 17.66–56.65, ≥56.66 was 32, 52, and 88 U/L, respectively, all P \u3c 0.001. SYNTAX score ≥ 23 was present in only 23% patients in GGT tertile 1 (\u3c41 U/L), whereas60% and 94% in GGT tertiles 2 and 3 had SYNTAX ≥ 23. Significant positive correlation was seen between GGT and SYNTAX (r = 0.634) and Gensini score (r = 0.772). CONCLUSIONS: In this study, GGT had an independent correlation with angiographic severity of CAD and SYNTAX and Gensini scores. Although the existing evidence seems biologically plausible, more studies are needed to explore the potential role of this inexpensive marker for predicting disease burden in patients with CAD

Impacts of household sources on air pollution at village and regional scales in India

Approximately 3 billion people worldwide cook with solid fuels, such as wood, charcoal, and agricultural residues. These fuels, also used for residential heating, are often combusted in inefficient devices, producing carbonaceous emissions. Between 2.6 and 3.8 million premature deaths occur as a result of exposure to fine particulate matter from the resulting household air pollution (Health Effects Institute, 2018a; World Health Organization, 2018). Household air pollution also contributes to ambient air pollution; the magnitude of this contribution is uncertain. Here, we simulate the distribution of the two major health-damaging outdoor air pollutants (PM_(2.5) and O₃) using state-of-the-science emissions databases and atmospheric chemical transport models to estimate the impact of household combustion on ambient air quality in India. The present study focuses on New Delhi and the SOMAARTH Demographic, Development, and Environmental Surveillance Site (DDESS) in the Palwal District of Haryana, located about 80 km south of New Delhi. The DDESS covers an approximate population of 200 000 within 52 villages. The emissions inventory used in the present study was prepared based on a national inventory in India (Sharma et al., 2015, 2016), an updated residential sector inventory prepared at the University of Illinois, updated cookstove emissions factors from Fleming et al. (2018b), and PM_(2.5) speciation from cooking fires from Jayarathne et al. (2018). Simulation of regional air quality was carried out using the US Environmental Protection Agency Community Multiscale Air Quality modeling system (CMAQ) in conjunction with the Weather Research and Forecasting modeling system (WRF) to simulate the meteorological inputs for CMAQ, and the global chemical transport model GEOS-Chem to generate concentrations on the boundary of the computational domain. Comparisons between observed and simulated O₃ and PM_(2.5) levels are carried out to assess overall airborne levels and to estimate the contribution of household cooking emissions. Observed and predicted ozone levels over New Delhi during September 2015, December 2015, and September 2016 routinely exceeded the 8 h Indian standard of 100 µg m⁻³, and, on occasion, exceeded 180 µg m⁻³. PM_(2.5) levels are predicted over the SOMAARTH headquarters (September 2015 and September 2016), Bajada Pahari (a village in the surveillance site; September 2015, December 2015, and September 2016), and New Delhi (September 2015, December 2015, and September 2016). The predicted fractional impact of residential emissions on anthropogenic PM_(2.5) levels varies from about 0.27 in SOMAARTH HQ and Bajada Pahari to about 0.10 in New Delhi. The predicted secondary organic portion of PM_(2.5) produced by household emissions ranges from 16 % to 80 %. Predicted levels of secondary organic PM_(2.5) during the periods studied at the four locations averaged about 30 µg m⁻³, representing approximately 30 % and 20 % of total PM_(2.5) levels in the rural and urban stations, respectively