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Item Distributed Nonlinear Model Predictive Control for Heterogeneous Vehicle Platoons Under Uncertainty(IEEE Xplore, 2021-09) Shen, Dan; Yin, Jianhua; Du, Xiaoping; Li, Lingxi; Electrical and Computer Engineering, School of Engineering and TechnologyThis paper presents a novel distributed nonlinear model predictive control (DNMPC) for minimizing velocity tracking and spacing errors in heterogeneous vehicle platoon under uncertainty. The vehicle longitudinal dynamics and information flow in the platoon are established and analyzed. The algorithm of DNMPC with robustness and reliability considerations at each vehicle (or node) is developed based on the leading vehicle and reference information from nodes in its neighboring set. Together with the physical constraints on the control input, the nonlinear constraints on vehicle longitudinal dynamics, the terminal constraints on states, and the reliability constraints on both input and output, the objective function is defined to optimize the control accuracy and efficiency by penalizing the tracking errors between the predicted outputs and desirable outputs of the same node and neighboring nodes, respectively. Meanwhile, the robust design optimization model also minimizes the expected quality loss which consists of the mean and standard deviation of node inputs and outputs. The simulation results also demonstrate the accuracy and effectiveness of the proposed approach under two different traffic scenarios.Item A-MnasNet and Image Classification on NXP Bluebox 2.0(ASTES, 2021-01) Shah, Prasham; El-Sharkawy, Mohamed; Electrical and Computer Engineering, School of Engineering and TechnologyComputer Vision is a domain which deals with the challenge of enabling technology with vision capabilities. This goal is accomplished with the use of Convolutional Neural Networks. They are the backbone of implementing vision applications on embedded systems. They are complex but highly efficient in extracting features, thus, enabling embedded systems to perform computer vision applications. After AlexNet won the ImageNet Large Scale Visual Recognition Challenge in 2012, there was a drastic increase in research on Convolutional Neural Networks. The convolutional neural networks were made deeper and wider, in order to make them more efficient. They were able to extract features efficiently, but the computational complexity and the computational cost of those networks also increased. It became very challenging to deploy such networks on embedded hardware. Since embedded systems have limited resources like power, speed and computational capabilities, researchers got more inclined towards the goal of making convolutional neural networks more compact, with efficiency of extracting features similar to that of the novel architectures. This research has a similar goal of proposing a convolutional neural network with enhanced efficiency and further using it for a vision application like Image Classification on NXP Bluebox 2.0, an autonomous driving platform by NXP Semiconductors. This paper gives an insight on the Design Space Exploration technique used to propose A-MnasNet (Augmented MnasNet) architecture, with enhanced capabilities, from MnasNet architecture. Furthermore, it explains the implementation of A-MnasNet on Bluebox 2.0 for Image Classification.Item Technology Systems for Lunar Industrial Development(International Astronautical Congress, 2021-10) Schubert, Peter J.; Electrical and Computer Engineering, School of Engineering and TechnologySelf-sufficiency of lunar operations is essential to establishment of an in-space economy. This work describes a sustainable step-wise pathway to energy, materials, finished goods, and food. The first lunar factory to build solar cells can be delivered from earth and be solar powered, as described in several US patents to the author. An alternative is to create fission fuels from lunar resources for a multi-MW baseload power reactor. Together with wireless power transfer, operations in permanently-shadowed regions can extract icy regolith and thence water, and thus oxygen and hydrogen. This hydrogen can be stored in porous silicon fabricated entirely on the moon. By extracting free iron from the lunar surface, the rails of a circumpolar transport system can be extruded so that a slow-moving train can remain in sunlight to grow food. Electromagnetic catapults using harvested iron as payload canisters can be used to transport solar panels, wires, and other value-added materials from the Moon to various orbits. Combining long-duration hydrogen storage and nuclear fission fuel, plus structural aluminum from an isotope separator, we can build fast ships to reach all portions of the solar system quickly, and with ample protection for human rocketeers. This presentation will integrate prior publications, provide a synopsis of on-going work, and present a framework of a step-by-step advancement towards comprehensive lunar industrial development.Item Performance Estimates for a Fuel-Free Stationary Platform in the Stratosphere(Institute of Electrical and Electronics Engineers, 2022) Schubert, Peter J.; van Wynsberghe, Erinn; Finnell, Abigail J. Kragt; Salgueiro, Cristian; Suri, Ramaa Saket; Electrical and Computer Engineering, School of Engineering and TechnologyHigh-altitude pseudo-satellites (HAPS) may be kept aloft indefinitely with station-keeping provided by plasma air thrusters (PAT) using wireless power transfer (WPT) from a terrestrial phased array antenna (PAA). One example is the patented “Sitallite” superpressure balloon with a rectifying antenna (rectenna) covering its underside, with thrusters around the periphery. Such a stationary platform can provide continuous observation and communications capabilities covering vast areas for a fraction of the cost required for an orbiting satellite. This work builds upon the design and safety study published elsewhere to provide performance estimates for a long-duration, persistent HAPS powered by electronically-steerable microwave beams. Newly-derived efficiency equations are used to provide accurate estimates of free-space WPT transfer efficiency based on the dimensions of the ground-based PAA and the rectenna. Calculations of air drag for a spheroidal bouyant shape are used to derive PAT power requirements, and these, together with power conversion circuitry, are used to size the overall system. Accurate estimates of cost are derived. These performance estimates can be used to help make economic and logistic decisions, as a fuel-free HAPS with PAT and powered by WPT can be lofted in less time, and with lower risk, than an orbital satellite of comparable capabilities.Item Ultra-safe nuclear thermal rockets using lunar-derived fuel(Elsevier, 2021-09-01) Schubert, Peter J.; Marrs, Ian; Daniel, Ebin; Conaway, Adam; Bhaskaran, Amal; Electrical and Computer Engineering, School of Engineering and TechnologyRocket launch failure rate is slightly higher than five percent. Concerned citizens are likely to protest against private-sector launches involving fission reactors. Yet, fission reactors can power long-duration lunar operations for science, observation, and in situ resource utilization. Furthermore, fission reactors are needed for rapid transport around the solar system, especially considering natural radiation doses for crews visiting Mars or an asteroid. A novel approach is to create nuclear fuel on the Moon. In this way, a rocket launched from the earth with no radioactive material can be fueled in outer space, avoiding the risks of spreading uranium across Earth's biosphere. A solution is to harvest fertile thorium on the lunar surface, then transmute it into fissile uranium using the gamma ray fog which pervades the deep sky. It is only at lunar orbit, at the very edge of cislunar space, that the Earth-launched machine becomes a nuclear thermal rocket (NTR). Thorium is not abundant, but can be concentrated by mechanical methods because of its very high specific density relative to the bulk of lunar regolith. Thorium dioxide (ThO2) has an extremely high melting point, such that skull crucible heating can be used to separate it from supernatant magma. When filled into a graphite-lined beryllium container (brought from Earth) and set out on the lunar surface, high-energy gamma rays will liberate neutrons from the Be. After moderation by the graphite, these thermal neutrons are captured by the thorium nucleus, which is transmuted into protactinium (Pa91). This element can be extracted using the THOREX process, and will then decay naturally into U-233 within two or three lunar days. The uranium is oxidized and packed into fuel pellets, ready to be inserted into a non-radioactive machine, which now becomes an NTR. Additionally, hydrogen can be extracted from deposits in permanently-shadowed regions on the Moon, providing reaction mass for the NTR. A novel method of solid-state hydrogen storage, which can be entirely fabricated using in situ resources, can deliver said hydrogen to the fission reactor to provide high and efficient propulsive thrust. These combined operations lead to an ultra-safe (for the Earth) means for private sector, commercial transport and power generation throughout the Solar System. With the hydrogen storage material used as radiation shielding for crewed spacecraft, and greatly-reduced transit times relative to chemical rocketry, this innovative approach could fundamentally transform how humans work, play, and explore in outer space.Item Space Nuclear Power for Terrestrial Utilities(International Astronautical Congress, 2021-10) Schubert, Peter J.; Electrical and Computer Engineering, School of Engineering and TechnologySolar power satellites must be large because sunlight is diffuse. Recent advances in developing fission fuel on the Moon raise the possibility of a nuclear powersat. Modest payloads of uranium oxide, transmuted from lunar thorium, and delivered to GEO are inserted into fission reactors. Eighty such reactors attached to a spacetenna can provide GW-class baseload power to terrestrial utilities. This paper studies the size, logistics, and safety considerations for Space Nuclear Power. A particular technical concern is the thermal management required of a heat engine. The delivery of fuel pins from the Moon is studied, and various transport methods are compared. The transfer of power wirelessly is studied, as it impacts terrestrial communications. Of prime concern to all are the safety considerations, which are partly ameliorated by the use of U-233 as the fissile material. A Risk Analysis is presented, and the highest ranking solutions presented. Life Cycle Analysis considerations demand a practical end-of-life treatment. The design of the nuclear powersat aims to strictly minimize any use as a weapon, with the goal being no greater threat to earth than an inert body of similar mass. Through lunar resource utilization, the time may be advanced when utilities can provide baseload (always on) electric power, which is free of pollution.Item Energy Efficient Multipath Ant Colony Based Routing Algorithm for Mobile Ad hoc Networks(Elsevier, 2021-03) Sharma, Arush; Kim, Dongsoo S.; Electrical and Computer Engineering, School of Engineering and TechnologyThis paper describes the novel wireless routing protocol made for mobile ad hoc networks or wireless sensor networks using the bio-inspired technique. Bio-inspired algorithms include the routing capabilities taken from the social behavior of ant colonies, bird flocking, honey bee dancing, etc and promises to be capable of catering to the challenges posed by wireless sensors. Some of the challenges of wireless sensor networks are limited bandwidth, limited battery life, low memory, etc. An energy-efficient multipath routing algorithm based on the foraging nature of ants is proposed including many meta-heuristic impact factors to provide good robust paths from source to destination to overcome the challenges faced by resource-constrained sensors. Analysis of individual impact factor is represented which justifies their importance in routing performance. The multi-path routing feature is claimed by showing energy analysis as well as statistical analysis in-depth to the readers. The proposed routing algorithm is analyzed by considering various performance metrics such as throughput, delay, packet loss, network lifetime, etc. Finally, the comparison is done against AODV routing protocol by considering performance metrics where the proposed routing algorithm shows a 49% improvement in network lifetime.Item Making the Case for a P2P Personal Health Record(MDPI, 2020-11) Horne, William Connor; Ben Miled, Zina; Electrical and Computer Engineering, School of Engineering and TechnologyImproved health care services can benefit from a more seamless exchange of medical information between patients and health care providers. This exchange is especially important considering the increasing trends in mobility, comorbidity and outbreaks. However, current Electronic Health Records (EHR) tend to be institution-centric, often leaving the medical information of the patient fragmented and more importantly inaccessible to the patient for sharing with other health providers in a timely manner. Nearly a decade ago, several client–server models for personal health records (PHR) were proposed. The aim of these previous PHRs was to address data fragmentation issues. However, these models were not widely adopted by patients. This paper discusses the need for a new PHR model that can enhance the patient experience by making medical services more accessible. The aims of the proposed model are to (1) help patients maintain a complete lifelong health record, (2) facilitate timely communication and data sharing with health care providers from multiple institutions and (3) promote integration with advanced third-party services (e.g., risk prediction for chronic diseases) that require access to the patient’s health data. The proposed model is based on a Peer-to-Peer (P2P) network as opposed to the client–server architecture of the previous PHR models. This architecture consists of a central index server that manages the network and acts as a mediator, a peer client for patients and providers that allows them to manage health records and connect to the network, and a service client that enables third-party providers to offer services to the patients. This distributed architecture is essential since it promotes ownership of the health record by the patient instead of the health care institution. Moreover, it allows the patient to subscribe to an extended range of personalized e-health services.Item SHP2 inhibition reduces leukemogenesis in models of combined genetic and epigenetic mutations(The American Society for Clinical Investigation, 2019-12-02) Pandey, Ruchi; Ramdas, Baskar; Wan, Changlin; Sandusky, George; Mohseni, Morvarid; Zhang, Chi; Kapur, Reuben; Electrical and Computer Engineering, School of Engineering and TechnologyIn patients with acute myeloid leukemia (AML), 10% to 30% with the normal karyotype express mutations in regulators of DNA methylation, such as TET2 or DNMT3A, in conjunction with activating mutation in the receptor tyrosine kinase FLT3. These patients have a poor prognosis because they do not respond well to established therapies. Here, utilizing mouse models of AML that recapitulate cardinal features of the human disease and bear a combination of loss-of-function mutations in either Tet2 or Dnmt3a along with expression of Flt3ITD, we show that inhibition of the protein tyrosine phosphatase SHP2, which is essential for cytokine receptor signaling (including FLT3), by the small molecule allosteric inhibitor SHP099 impairs growth and induces differentiation of leukemic cells without impacting normal hematopoietic cells. We also show that SHP099 normalizes the gene expression program associated with increased cell proliferation and self-renewal in leukemic cells by downregulating the Myc signature. Our results provide a new and more effective target for treating a subset of patients with AML who bear a combination of genetic and epigenetic mutations.Item Development of Surrogate Grass for the Evaluation of Vehicle Road Departure Mitigation Systems(IEEE, 2020-09) Chien, Stanley; Zhou, Jue; Yi, Qiang; Pandey, Seeta Ram; Saha, Abir; Lin, Jun; Chen, Yaobin; Sherony, Rini; Electrical and Computer Engineering, School of Engineering and TechnologyVehicle road departure mitigation system (RDMS), as new active safety technology, has been introduced into the market in recent years. This system can detect roadside objects and road edges to reduce the risk of roadway departure crashes. To evaluate and improve the performance of RDMS, surrogates of roadside objects, which have the same camera, radar, and LiDAR characteristics of the real objects, need to be developed. Grass is the most common road edge in the U.S. as seen from the real road data. This paper describes the development of surrogate grass. The LiDAR (infrared) and radar characteristics of the selected artificial turf (grass) are obtained and compared with those of real grass. In order to make the surrogate grass match the real grass in the view of sensors (LiDAR, radar and camera), a special color coating with high reflectance material is applied to the artificial turf. Both LiDAR and radar measurements confirmed that the surrogate grass closely match the key characteristics of the real grass. Five grass colors and eighteen color patterns were identified based on 1,021 grass road-edge samples from all states of the U.S. 300-meter long surrogate grass was made and successfully used on the test track for the vehicle RDMS evaluation.