Measuring and attributing greenhouse gas (GHG) emissions remains a challenging problem as the world strives toward meeting emissions reductions targets. As a significant portion of total global emissions, the road transportation sector represents an enormous challenge for estimating and tracking emissions at a global scale. To meet this challenge, we have developed a hybrid approach for estimating road transportation emissions that combines the strengths of machine learning and satellite imagery with localized emissions factors data to create an accurate, globally scalable, and easily configurable GHG monitoring framework.
Responding to infrastructural damage in the aftermath of natural disasters at a national, regional, and local level poses a significant challenge. Damage to road networks, clean water supply, and sanitation infrastructures, as well as social amenities like schools and hospitals, exacerbates the circumstances. As safe water sources are destroyed or mixed with contaminated water during a disaster, the risk of a waterborne disease outbreak is elevated in those disaster-affected locations. A country such as Haiti, where a large quantity of the population is deprived of safe water and basic sanitation facilities, would suffer more in post-disaster scenarios. Early warning of waterborne diseases like cholera would be of great help for humanitarian aid, and the management of disease outbreak perspectives. The challenging task in disease forecasting is to identify the suitable variables that would better predict a potential outbreak. In this study, we developed five (5) models including a machine learning approach, to identify and determine the impact of the environmental and social variables that play a significant role in post-disaster cholera outbreaks. We implemented the model setup with cholera outbreak data in Haiti after the landfall of Hurricane Matthew in October 2016. Our results demonstrate that adding high-resolution data in combination with appropriate social and environmental variables is helpful for better cholera forecasting in a post-disaster scenario. In addition, using a machine learning approach in combination with existing statistical or mechanistic models provides important insights into the selection of variables and identification of cholera risk hotspots, which can address the shortcomings of existing approaches.
Road transportation is one of the largest sectors of greenhouse gas (GHG) emissions affecting climate change. Tackling climate change as a global community will require new capabilities to measure and inventory road transport emissions. However, the large scale and distributed nature of vehicle emissions make this sector especially challenging for existing inventory methods. In this work, we develop machine learning models that use satellite imagery to perform indirect top-down estimation of road transport emissions. Our initial experiments focus on the United States, where a bottom-up inventory was available for training our models. We achieved a mean absolute error (MAE) of 39.5 kg CO$_{2}$ of annual road transport emissions, calculated on a pixel-by-pixel (100 m$^{2}$) basis in Sentinel-2 imagery. We also discuss key model assumptions and challenges that need to be addressed to develop models capable of generalizing to global geography. We believe this work is the first published approach for automated indirect top-down estimation of road transport sector emissions using visual imagery and represents a critical step towards scalable, global, near-real-time road transportation emissions inventories that are measured both independently and objectively.
We describe the recent development of assistive computer vision algorithms for use with the Argus II retinal prosthesis system. While users of the prosthetic system can learn and adapt to the limited stimulation resolution, there exists great potential for computer vision algorithms to augment the experience and significantly increase the utility of the system for the user. To this end, our recent work has focused on helping with two different challenges encountered by the visually impaired: face detection and object recognition. In this paper, we describe algorithm implementations in both of these areas that make use of the retinal prosthesis for visual feedback to the user, and discuss the unique challenges faced in this domain.
This paper describes key aspects of modem hardware designed to operate in free space optical (FSO) links of up to 200 km. The hardware serves as a bridge between 10 gigabit Ethernet client data systems and FSO terminals. The modem hardware alters the client data rate and format for optimal transmission and reception over the FSO link by applying forward error correction (FEC) processing and differential phase shift keying (DPSK) modulation. Optical automatic gain control (OAGC) is also used. The result of these features provide sensitivities approaching -48 dBm with 60 dB of error-free dynamic range while in the presence of turbulent optical conditions to deal with large dynamic range optical power fades.
Reconfigurable computing with Field Programmable Gate Arrays (FPGAs) has demonstrated performance advantages over microprocessor-based systems for many applications. FPGA-based computing systems are well suited to run multiple step algorithms, simulations, and other types of data intensive processing applications. One potential application yet to be fully explored on these architectures is biometrics, or human feature recognition algorithms. The use of reconfigurable computers in facial, iris, and finger/handprint matching situations could dramatically increase the speed, efficiency, and even accuracy of biometric algorithm processing. Our research focuses on the implementation of simultaneous algorithms (to cover multiple situational anomalies) coupled with a decision-making algorithm in the final stage to govern the overall identification matching.