9 research outputs found
Comparative study of vacuum-assisted closure therapy versus vacuum-assisted closure therapy supplemented with vitamin C in compound wound healing
Background: It is imperative for early and precise management of the compound wound for preventing further complication and delaying definitive management. As we all know superiority of vacuum assisted closure (VAC) therapy in wound management over any other method, but adding vitamin C has been shown to accelerate wound healing, reducing hospital stay, and cost of management and prevention of delaying definitive management of wound due to some conspicuous property of vitamin C that serve as superior adjuvant in wound healing.
Methods: A case series of 40 patients who have been inflicted with compound wounds with most following road traffic accidents. We then categorised patients and tried to observe any difference in rate of satisfactorily healing of wound with 20 patients put on VAC therapy alone and other 20 patients put on VAC therapy supplemented with vit C.
Results: Patients who were undergoing VAC dressing and supplemented with vitamin C, not only portrayed a better result of wound healing but also reduced the amount of vacuum dressing sittings.
Conclusions: It was observed that, in general, patients who were undergoing VAC dressing and supplemented with vitamin C, not only portrayed a better result of wound healing but also reduced amount of vacuum dressing sittings, improved rate of granulation tissue, reduced hospital stay, early definitive fixation of associated fracture and skin grafting and showed superior outcomes in terms of better tissue recovery
Maximizing Seaweed Growth on Autonomous Farms: A Dynamic Programming Approach for Underactuated Systems Navigating on Uncertain Ocean Currents
Seaweed biomass offers significant potential for climate mitigation, but
large-scale, autonomous open-ocean farms are required to fully exploit it. Such
farms typically have low propulsion and are heavily influenced by ocean
currents. We want to design a controller that maximizes seaweed growth over
months by taking advantage of the non-linear time-varying ocean currents for
reaching high-growth regions. The complex dynamics and underactuation make this
challenging even when the currents are known. This is even harder when only
short-term imperfect forecasts with increasing uncertainty are available. We
propose a dynamic programming-based method to efficiently solve for the optimal
growth value function when true currents are known. We additionally present
three extensions when as in reality only forecasts are known: (1) our methods
resulting value function can be used as feedback policy to obtain the
growth-optimal control for all states and times, allowing closed-loop control
equivalent to re-planning at every time step hence mitigating forecast errors,
(2) a feedback policy for long-term optimal growth beyond forecast horizons
using seasonal average current data as terminal reward, and (3) a discounted
finite-time Dynamic Programming (DP) formulation to account for increasing
ocean current estimate uncertainty. We evaluate our approach through 30-day
simulations of floating seaweed farms in realistic Pacific Ocean current
scenarios. Our method demonstrates an achievement of 95.8% of the best possible
growth using only 5-day forecasts. This confirms the feasibility of using
low-power propulsion and optimal control for enhanced seaweed growth on
floating farms under real-world conditions.Comment: 8 pages, submitted to 2023 IEEE 62th Annual Conference on Decision
and Control (CDC) Matthias Killer and Marius Wiggert contributed equally to
this wor
Energy-time optimal path planning in strong dynamic flows
Thesis: S.M., Massachusetts Institute of Technology, Center for Computational Science & Engineering, February, 2021Cataloged from the official PDF version of thesis.Includes bibliographical references (pages 55-61).We develop an exact partial differential equation-based methodology that predicts time-energy optimal paths for autonomous vehicles navigating in dynamic environments. The differential equations solve the multi-objective optimization problem of navigating a vehicle autonomously in a dynamic flow field to any destination with the goal of minimizing travel time and energy use. Based on Hamilton-Jacobi theory for reachability and the level set method, the methodology computes the exact Pareto optimal solutions to the multi-objective path planning problem, numerically solving the equations governing time-energy reachability fronts and optimal paths. Our approach is applicable to path planning in various scenarios, however we primarily present examples of navigating in dynamic marine environments. First, we validate the methodology through a benchmark case of crossing a steady front (a highway flow) for which we compare our results to semi-analytical optimal path solutions. We then consider more complex unsteady environments and solve for time-energy optimal missions in a quasi-geostrophic double-gyre ocean flow field.by Manan Doshi.S.M.S.M. Massachusetts Institute of Technology, Center for Computational Science & Engineerin
Over-the-Air Design of GAN Training for mmWave MIMO Channel Estimation
Future wireless systems are trending towards higher carrier frequencies that
offer larger communication bandwidth but necessitate the use of large antenna
arrays. Existing signal processing techniques for channel estimation do not
scale well to this "high-dimensional" regime in terms of performance and pilot
overhead. Meanwhile, training deep learning based approaches for channel
estimation requires large labeled datasets mapping pilot measurements to clean
channel realizations, which can only be generated offline using simulated
channels. In this paper, we develop a novel unsupervised over-the-air (OTA)
algorithm that utilizes noisy received pilot measurements to train a deep
generative model to output beamspace MIMO channel realizations. Our approach
leverages Generative Adversarial Networks (GAN), while using a conditional
input to distinguish between Line-of-Sight (LOS) and Non-Line-of-Sight (NLOS)
channel realizations. We also present a federated implementation of the OTA
algorithm that distributes the GAN training over multiple users and greatly
reduces the user side computation. We then formulate channel estimation from a
limited number of pilot measurements as an inverse problem and reconstruct the
channel by optimizing the input vector of the trained generative model. Our
proposed approach significantly outperforms Orthogonal Matching Pursuit on both
LOS and NLOS channel models, and EM-GM-AMP -- an Approximate Message Passing
algorithm -- on LOS channel models, while achieving comparable performance on
NLOS channel models in terms of the normalized channel reconstruction error.
More importantly, our proposed framework has the potential to be trained online
using real noisy pilot measurements, is not restricted to a specific channel
model and can even be utilized for a federated OTA design of a dataset
generator from noisy data.Comment: 34 pages, 12 figures, 5 tables. Under review for publication in IEEE
Journal of Sel. Areas in Information Theor