Hybrid Satellite-Terrestrial Communication Networks for the Maritime Internet of Things: Key Technologies, Opportunities, and Challenges

With the rapid development of marine activities, there has been an increasing number of maritime mobile terminals, as well as a growing demand for high-speed and ultra-reliable maritime communications to keep them connected. Traditionally, the maritime Internet of Things (IoT) is enabled by maritime satellites. However, satellites are seriously restricted by their high latency and relatively low data rate. As an alternative, shore & island-based base stations (BSs) can be built to extend the coverage of terrestrial networks using fourth-generation (4G), fifth-generation (5G), and beyond 5G services. Unmanned aerial vehicles can also be exploited to serve as aerial maritime BSs. Despite of all these approaches, there are still open issues for an efficient maritime communication network (MCN). For example, due to the complicated electromagnetic propagation environment, the limited geometrically available BS sites, and rigorous service demands from mission-critical applications, conventional communication and networking theories and methods should be tailored for maritime scenarios. Towards this end, we provide a survey on the demand for maritime communications, the state-of-the-art MCNs, and key technologies for enhancing transmission efficiency, extending network coverage, and provisioning maritime-specific services. Future challenges in developing an environment-aware, service-driven, and integrated satellite-air-ground MCN to be smart enough to utilize external auxiliary information, e.g., sea state and atmosphere conditions, are also discussed

Doctor of Philosophy

dissertationHybrid nanomaterials composed of synthetic and biological building blocks possess high potential for the design of nanomedicines. We propose a new therapeutic approach that mimics the mechanism of immune effector cells to crosslink surface receptors of target cells and induce apoptosis. The receptor crosslinking is mediated by biorecognition of high-fidelity natural binding motifs (antibody fragments or oligonucleotides) that are grafted to the side chains of synthetic polymers. This approach features the absence of low-molecular-weight cytotoxic compounds. Thus, we name it "drug-free macromolecular therapeutics." This dissertation describes the development and preclinical evaluation of two drug-free macromolecular therapeutic platforms. The designed therapeutics were tested against B-cell malignancies that highly express the surface antigen CD20. In the first design, a multivalent conjugate comprising high-molecular-weight, linear copolymer of N-(2-hydroxypropyl)methacrylamide (HPMA) grafted with multiple Fab' fragments of an anti-CD20 antibody was synthesized. Exposure of human non- Hodgkin lymphoma (NHL) Raji B-cells to the multivalent construct resulted in crosslinking of CD20 receptors and commencement of apoptosis. In the second design, two hybrid conjugates were produced: (1) an anti-CD20 Fab' attached to an oligonucleotide1, and (2) a linear HPMA copolymer grafted with multiple complementary oligonucleotide2. We showed that the two conjugates selfiv assembled via oligonucleotide hybridization at the surface of CD20+ B-cells, which crosslinked CD20 antigens and initiated apoptosis. When tested in a mouse xenograft model, the two conjugates, either administered consecutively or as a premixture, eradicated Raji cells and produced long-term survivors. The consecutive administration approach was chosen for further studies where a two-step pretargeting strategy was employed. We showed that the time lag between administering the two conjugates can be optimized based on pharmacokinetics and biodistribution of the Fab'-oligonucleotide1 conjugate. Using the optimized treatment regimen, the designed nanomedicine achieved superior anti-lymphoma efficacy to rituximab, a clinically used drug for NHL. We also evaluated the nanomedicine in patient mantle cell lymphoma and chronic lymphocytic leukemia cells. The treatment demonstrated potent apoptosis-inducing activity. In summary, we have developed novel nanotherapeutics that may constitute potent treatments for NHL and other B-cell malignancies. The verified concept can be applied to crosslink receptors other than CD20 and potentially treat different diseases

Standard Young Tableaux and Colored Motzkin Paths

In this paper, we propose a notion of colored Motzkin paths and establish a bijection between the $n$-cell standard Young tableaux (SYT) of bounded height and the colored Motzkin paths of length $n$. This result not only gives a lattice path interpretation of the standard Young tableaux but also reveals an unexpected intrinsic relation between the set of SYTs with at most $2d+1$ rows and the set of SYTs with at most 2d rows.Comment: 21 page