645 research outputs found
High resolution millimeter wave imaging for self-driving cars
No full textRecent years have witnessed much interest in expanding the use of networking signals beyond communication to sensing, localization, robotics, and autonomous systems. This thesis explores how we can leverage recent advances in 5G millimeter wave (mmWave) technology for imaging in self-driving cars. Specifically, the use of mmWave in 5G has led to the creation of compact phased arrays with hundreds of antenna elements that can be electronically steered. Such phased arrays can expand the use of mmWave beyond vehicular communications and simple ranging sensors to a full-fledged imaging system that enables self-driving cars to see through fog, smog, snow, etc.
Unfortunately, using mmWave signals for imaging in self-driving cars is challenging due to the very low resolution, the presence of fake artifacts resulting from multipath reflections and the absence of portions of the car due to specularity. This thesis presents HawkEye, a system that can enable high resolution mmWave imaging in self-driving cars. HawkEye addresses the above challenges by leveraging recent advances in deep learning known as Generative Adversarial Networks (GANs). HawkEye introduces a GAN architecture that is customized to mmWave imaging and builds a system that can significantly enhance the quality of mmWave images for self-driving cars.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2021-12-01The student, Junfeng Guan, accepted the attached license on 2019-12-09 at 12:07.The student, Junfeng Guan, submitted this Thesis for approval on 2019-12-09 at 12:16.This Thesis was approved for publication on 2019-12-09 at 15:49.DSpace SAF Submission Ingestion Package generated from Vireo submission #14758 on 2020-02-28 at 17:23:56Made available in DSpace on 2020-03-02T22:15:15Z (GMT). No. of bitstreams: 2
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Previous issue date: 2019-12-09Embargo set by: Seth Robbins for item 113927
Lift date: 2022-03-02T22:15:21Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 113927
Lift date: 2022-03-02T22:18:25Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Only Restriction Lifted for Item 113927 on 2022-03-03T10:15:19Z
Single-chain nanoparticle based catalysts
No full textEnzymes achieve their excellent catalytic properties by surrounding the catalytic sites with a polypeptide scaffold. The three-dimensional structure of the peptide chains creates a local environment that supramolecularly binds substrates to facilitate the catalysis. In this dissertation, synthetic polymers are used to serve a similar role, binding substrates and creating an optimal environment for performing efficient catalysis. Several single-chain nanoparticle (SCNP) catalysts have been developed to perform copper(I)-mediated alkyne–azide cycloaddition (CuAAC), “click” reactions, or the photoreduction of azido groups to amines. The nanoparticles are shown to have significantly higher activity when compared to analogous small molecule catalysts. Structure-activity relationships and reaction mechanisms are studied with SCNPs of different structures. The polymeric scaffolds are found to bind substrates in an enzyme-like manner. The catalysts operate in two modes: an “uptake mode” where small molecule substrates bind inside the polymer pockets and an “attach mode” that involves surface binding of protein substrates. The versatility and high efficiency of the nanoparticles lead to applications in protein and cell surface modification. In addition, another SCNP was shown to co-deliver an exogenous enzyme inside cells. The enzyme and SCNP reside and stay active in the endosomes, in essence engineering the endosome into an artificial organelle. The SCNP-enzyme complex can perform both concurrent and tandem reactions performing organic synthesis intracellularly. The combination of SCNP and enzymatic catalysts provides a versatile tool for intracellular organic synthesis with applications in chemical biology.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2022-05-01The student, Junfeng Chen, accepted the attached license on 2020-04-21 at 15:27.The student, Junfeng Chen, submitted this Dissertation for approval on 2020-04-21 at 15:53.This Dissertation was approved for publication on 2020-04-23 at 10:51.DSpace SAF Submission Ingestion Package generated from Vireo submission #15024 on 2020-08-25 at 17:27:49Made available in DSpace on 2020-08-26T23:54:35Z (GMT). No. of bitstreams: 2
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Previous issue date: 2020-04-23Embargo set by: Seth Robbins for item 115727
Lift date: 2022-08-26T23:54:40Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 115727
Lift date: 2022-08-26T23:55:59Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 115727
Lift date: 2022-08-26T23:57:28Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 115727
Lift date: 2022-08-26T23:58:55Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Onl
Solar sail formation flying for deep-space remote sensing
No full textIn this paper we consider how 'near' term solar sails can be used in formation above the ecliptic plane to provide platforms for accurate and continuous remote sensing of the polar regions of the Earth. The dynamics of the solar sail elliptical restricted three-body problem (ERTBP) are exploited for formation flying by identifying a family of periodic orbits above the ecliptic plane. Moreover, we find a family of 1 year periodic orbits where each orbit corresponds to a unique solar sail orientation using a numerical continuation method. It is found through a number of example numerical simulations that this family of orbits can be used for solar sail formation flying. Furthermore, it is illustrated numerically that Solar Sails can provide stable formation keeping platforms that are robust to injection errors. In addition practical trajectories that pass close to the Earth and wind onto these periodic orbits above the ecliptic are identified
Synthesis and anti-glioblastoma effects of artemisinin-isothiocyanate derivatives
No full textA series of novel artemisinin (ART) derivatives containing an isothiocyanate (ITC) group were synthesized. All the compounds showed more potent anti-tumor effects than those of parent dihydroartemisinin (DHA) towards glioblastoma multiforme U87 in vitro. Among them, 5b had the strongest cytotoxic activity which exerted its effects in a concentration-dependent but not time-dependent manner (IC50 7.41 mM for 24 h, 7.35 mM for 72 h). Pyknosis was observed in 5b-treated U87 cells. Multiple intrinsic apoptotic pathways were induced by 5b including the upregulation of caspase 9, the release of cytochrome c, an increase of the proapoptotic protein Bax, a decrease of the anti-apoptotic protein Bcl 2, and the activation of execution pathways by the upregulation of caspase 3. In addition to apoptosis, an autophagic mechanism was also involved in 5b-induced cytotoxicity to human GBM U87 cells by upregulating the expression of LC3-II and downregulating p62. Furthermore, 5b also significantly attenuated the migration of U87 cells. Therefore, our results suggest that 5b may be a promising molecule for the further development of a novel drug for the treatment of glioblastoma
Parametric Study on the Influence of Warping Deformation upon Natural Frequencies of Die Springs
No full textThe free vibrational characteristics of die springs are examined by Riccati transfer matrix method in this study. The warping deformation of spring’s cross section, as a new design factor, is incorporated into the differential equation of motion. Numerical simulations show that the warping deformation is a significant role of the behavior of natural frequencies of die springs and should be considered carefully. Approximately 40% of the errors may occur if warping is neglected. The change laws of warping effect with the parameter variations of springs are also explored, including the height-to-width ratio of the cross section, the cylinder diameter, the helix pitch angle, and the number of coils. The warping effect exhibits the most remarkable changes with the variation in the height-to-width ratio of the cross section. However, this effect is not fairly sensitive to the changes in other parameters, and it is particularly significant when the cross section is relatively narrow regardless of the changes in other parameters. This study evidently answers the key scientific question: “under what working condition should the warping effect be considered or ignored?” The analysis results can be used to guide spring designers in engineering
CMOS Wide-Bandwidth Magnetic Sensors for Contactless Current Measurements
No full textThis Ph.D. dissertation describes the theory and realization of wide-bandwidth magnetic sensors for current measurements which breach the conventional offset and noise constraints in CMOS processes. These are achieved by several circuit-level and system-level innovations, including the use of three orthogonal ripple reduction loops (RRLs) in spinning-current Hall sensors, a multipatharchitecture with double Hall sensors, and a hybrid magnetic sensor system combining Hall sensors and pick-up coils. The prototypes with these techniques have advanced the bandwidth of state-of-the-art CMOS magnetic sensors by more than two orders of magnitude.Junfeng Jiang was born in 1986 in Dalian, China. He received his B.Sc. degree in electrical engineering from Dalian University of Technology, Dalian, China, in 2009, and his M.Sc. degree in microelectronics from Delft University of Technology, Delft, the Netherlands in 2011. He expects to receive his Ph.D. degree from the same university in 2019, for his work on CMOS wide-bandwidth magnetic sensors for contactless current measurements. From 2010 to 2016, he was a visiting scholar at Texas Instruments (Formerly National Semiconductor Corporation), Delft, where he worked on CMOS wide-bandwidth magnetic sensors. From 2016 to 2017, he was with Texas Instruments Deutschland GmbH, Freising, Germany. Since November 2017, he has been with the sensing group of Texas Instruments, Dallas, USA. His interests include the design of precision analog systems, magnetic sensors and mixed-signal integrated circuits. Junfeng Jiang received the A-SSCC 2015 Travel Grant, SSCS Predoctoral Achievement Award 2016-2017 and ESSCIRC 2016 Best Paper Award.Electronic Instrumentatio
Identifying transit deserts in major Texas cities where the supplies missed the demands
No full textCoined by the author, the concept “transit desert” is developed from the now common concept of a “food desert,” which is an area where there is limited or no access to fresh food (Clark et al. 2002; Jiao et al. 2012; Whelan et al. 2002; Wrigley 1993; Wrigley et al. 2002). The food desert concept has received a lot of attention and influenced planning policies and practices. By applying the same idea to transit systems within urban areas, geographic areas can be identified where there is a lack of transit service. This involves identifying the transit dependent populations as a measure of transit demand, calculating the transit supply, and then subtracting the supply from the demand to measure the gap (Jiao & Dillivan 2013). In detail, transit dependent populations are those who might require transit service to get around more than other people. The transit supply is measured by aggregating a number of criteria that contribute to better transit access and measured within a designated geographic area. Transit deserts are defined as areas where the transit demand is significantly greater than the supply
The purification of nitrogen by the micro-aeration enhanced ecological floating bed in sewage
No full textHigh-voltage cable insulation online monitoring in coal mine based on pattern recognition
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