Modelling Spreading Process Induced by Agent Mobility in Complex Networks

Most conventional epidemic models assume contact-based contagion process. We depart from this assumption and study epidemic spreading process in networks caused by agents acting as carrier of infection. These agents traverse from origins to destinations following specific paths in a network and in the process, infecting the sites they travel across. We focus our work on the Susceptible-Infected-Removed (SIR) epidemic model and use continuous-time Markov chain analysis to model the impact of such agent mobility induced contagion mechanics by taking into account the state transitions of each node individually, as oppose to most conventional epidemic approaches which usually consider the mean aggregated behavior of all nodes. Our approach makes one mean field approximation to reduce complexity from exponential to polynomial. We study both network-wide properties such as epidemic threshold as well as individual node vulnerability under such agent assisted infection spreading process. Furthermore, we provide a first order approximation on the agents’ vulnerability since infection is bi-directional. We compare our analysis of spreading process induced by agent mobility against contact-based epidemic model via a case study on London Underground network, the second busiest metro system in Europe, with real dataset recording commuters’ activities in the system. We highlight the key differences in the spreading patterns between the contact-based vs. agent assisted spreading models. Specifically, we show that our model predicts greater spreading radius than conventional contact-based model due to agents’ movements. Another interesting finding is that, in contrast to contact-based model where nodes located more centrally in a network are proportionally more prone to infection, our model shows no such strict correlation as in our model, nodes may not be highly susceptible even located at the heart of the network and vice versa

Pedagogical and Performance Aspects of Three American Compositions for Solo Piano: John Corigliano\u27s Fantasia on an Ostinato, Miguel del Aguila\u27s Conga for Piano, and William Bolcom\u27s Nine New Bagatelles

This research document focuses on three American compositions: John Corigliano\u27s Fantasia on an Ostinato, Miguel del Aguila\u27s Conga for Solo Piano, and William Bolcom\u27s Nine New Bagatelles. These three pieces fall into the category of standard contemporary works which require pianists\u27 advanced technique, sound exploration, and imagination. The intention of this research is to provide guidance for pianists and piano instructors who want to learn, perform, or teach any of these contemporary pieces. There are five chapters in this document. Chapter One highlights the existing literature regarding these three pieces. Chapter Two, John Corigliano, has three main sections. Section one includes a biography of John Corigliano. Section two focuses on how Corigliano has used minimalist technique, music quotation, and aleatoric elements in his Fantasia on an Ostinato. Section three highlights the major technical challenges and their possible solutions in the Fantasia on an Ostinato. It includes discussions of Bebung effect, metric modulation, aleatoric elements, hand shifting, and dynamic control. Chapter Three, Miguel del Aguila, also consists of three main sections. A biography of Miguel del Aguila is presented in section one. Section two provides a brief history of Conga as the Cuban drum and also as the Conga dance. Miguel del Aguila\u27s inspiration in writing the Conga Line in Hell is also discussed in section two. Section three focuses on the structural analysis and the performance concerns of this Conga. Clave pattern, distorted rhythms, salsa-like pattern, tango rhythm, glissando, tempo, dynamics, wrist movement, body posture and balance are discussed in section three. Similarly, Chapter Four, William Bolcom, has three main sections. A biography of William Bolcom is presented in section one. Bolcom\u27s significant piano solo works are discussed in section two, together with the placement of his Nine New Bagatelles among his piano solo works. Section three provides brief structural analysis of each bagatelle as well as the performance concerns of tempo, articulation, pedaling, division between hands, trills, dynamics, tone quality, balance of sound, and voicing in the Nine New Bagatelles. The summary is presented in Chapter Five

Identification and characterization of secreted proteins of Theileria lestoquardi schizonts

T. lestoquardi is a tick-borne parasite that infects leukocytes of sheep and goats. It causes the death of millions of sheep and goats every year and continues to spread in the world. The disease is mainly caused by the schizont stage, which induces transformation of the infected cell to a state of uncontrolled proliferation. In response to the proliferation of infected cells, there is evidence that the host deploys its immune system to eliminate the pathogen by cytotoxic T lymphocyte (CTL) responses. The purpose of this study was to identify schizont secreted proteins, which are likely to include molecules targeted by the immune response as well as those associated with the transformation process. An efficient method for the lysis and purification of schizonts from infected cells was established. This involved use of complement treatment to release schizonts from infected cells and an optimal density of Nycoprep gradient medium to separate schizonts from host cell components. An optimised method for metabolic labelling of schizont-infected cells was also established. Putative secreted proteins were detected in metabolically labelled schizont culture supernatants by SDS-PAGE and autoradiographic analysis. Using two-dimensional electrophoresis, mass spectrometry, including MALDI-TOF and Q-TOF, and N-terminal sequencing analysis, three putative secreted proteins of parasite origin were identified, namely Theileria mhsp70, hsp70 and inorganic pyrophosphatase. Seven host-derived proteins were also identified, namely mhsp70, hsp60, mitochondrial ribosomal protein LI2 (MRPL12, TFS4), ATP synthase-5, ATP synthase 6, PDH-Eip and ATP-dependent proteinase SP-22. Further investigation of the relationship of the host-derived proteins with the schizont using dual-labelling and confocal microscopy analysis provided evidence that the hostderived protein, MRPL12, is associated with intracellular schizonts with some colocalising with schizont mitochondria. The analysis also revealed that some host mitochondria are closely associated with the schizonts of T. lestoquardi

Heterogeneous Multi-sensor Fusion with Random Finite Set Multi-object Densities

This paper addresses the density based multi-sensor cooperative fusion using random finite set (RFS) type multi-object densities (MODs). Existing fusion methods use scalar weights to characterize the relative information confidence among the local MODs, and in this way the portion of contribution of each local MOD to the fused global MOD can be tuned via adjusting these weights. Our analysis shows that the fusion mechanism of using a scalar coefficient can be oversimplified for practical scenarios, as the information confidence of an MOD is complex and usually space-varying due to the imperfection of sensor ability and the various impacts from surveillance environment. Consequently, severe fusion performance degradation can be observed when these scalar weights fail to reflect the actual situation. We make two contributions towards addressing this problem. Firstly, we propose a novel heterogeneous fusion method to perform the information averaging among local RFS MODs. By factorizing each local MODs into a number of smaller size sub-MODs, it can transform the original complicated fusion problem into a much easier parallelizable multi-cluster fusion problem. Secondly, as the proposed fusion strategy is a general procedure without any particular model assumptions, we further derive the detailed heterogeneous fusion equations, with centralized network architecture, for both the probability hypothesis density (PHD) filter and the multi-Bernoulli (MB) filter. The Gaussian mixture implementations of the proposed fusion algorithms are also presented. Various numerical experiments are designed to demonstrate the efficacy of the proposed fusion methods

Enhancing multi-source content delivery in content-centric networks with fountain coding

Fountain coding has been considered as especially suitable for lossy environments, such as wireless networks, as it provides redundancy while reducing coordination overheads between sender(s) and receiver(s). As such it presents beneficial properties for multi-source and/or multicast communication. In this paper we investigate enhancing/increasing multi-source content delivery efficiency in the context of Content-Centric Networking (CCN) with the usage of fountain codes. In particular, we examine whether the combination of fountain coding with the in-network caching capabilities of CCN can further improve performance. We also present an enhancement of CCN's Interest forwarding mechanism that aims at minimizing duplicate transmissions that may occur in a multi-source transmission scenario, where all available content providers and caches with matching (cached) content transmit data packets simultaneously. Our simulations indicate that the use of fountain coding in CCN is a valid approach that further increases network performance compared to traditional schemes

Path-Based Epidemic Spreading in Networks

Conventional epidemic models assume omnidirectional contact-based infection. This strongly associates the epidemic spreading process with node degrees. The role of the infection transmission medium is often neglected. In real-world networks, however, the infectious agent as the physical contagion medium usually flows from one node to another via specific directed routes ( path-based infection). Here, we use continuous-time Markov chain analysis to model the influence of the infectious agent and routing paths on the spreading behavior by taking into account the state transitions of each node individually, rather than the mean aggregated behavior of all nodes. By applying a mean field approximation, the analysis complexity of the path-based infection mechanics is reduced from exponential to polynomial. We show that the structure of the topology plays a secondary role in determining the size of the epidemic. Instead, it is the routing algorithm and traffic intensity that determine the survivability and the steady-state of the epidemic. We define an infection characterization matrix that encodes both the routing and the traffic information. Based on this, we derive the critical path-based epidemic threshold below which the epidemic will die off, as well as conditional bounds of this threshold which network operators may use to promote/suppress path-based spreading in their networks. Finally, besides artificially generated random and scale-free graphs, we also use real-world networks and traffic, as case studies, in order to compare the behaviors of contact- and path-based epidemics. Our results further corroborate the recent empirical observations that epidemics in communication networks are highly persistent