Analyzing the Probabilistic Spread of a Virus on Various Networks

In this project we model the spread of a virus on networks as a probabilistic process. We assume the virus breaks out at one vertex on a network and then spreads to neighboring vertices in each time step with a certain probability. Our objective is to find probability distributions that describe the uncertain number of infected vertices at a given time step. The networks we consider are paths, cycles, star graphs, complete graphs, and broom graphs. Through the use of Markov chains and Jordan Normal Form we analyze the probability distribution of these graphs, characterizing the transition matrix for each graph as well as the Jordan Form matrices

Calling Tunes: A Piece in Three Movements for Violin, Clarinet, Violoncello, and Piano

Calling Tunes is a seventeen-minute piece in three movements for violin, clarinet, violoncello, and piano. The title refers to the common jam-session activity of "calling tunes", which represents an expression of common knowledge between musicians within an unrehearsed, improvisation-based ensemble. Each individual in the group shares a common repertory that is used as a backdrop to music-making -- a collection of not only melodies and chords, but a world of performance practices, music theory, and cultural memory that is drawn upon to create music without the need of prior rehearsal or planning. Calling Tunes strives to capture this unrehearsed, impromptu quality as if the piece had been created by an informal gathering of musicians extemporizing on some kind of shared musical language. Each movement focuses on a single originating motive that is developed and transformed throughout like an improviser embellishing a familiar tune. The first movement, Montunos, is based on the piano vamp of Afro-Cuban salsa music, which is often characterized by off-the-beat syncopation and harmonization in thirds. The montuno that opens this movement combines these traditional qualities with metric irregularity and an ambiguous harmony that produces an otherworldly, out-of-tune quality. The second movement, Canzone, acts as an introspective, lyrical interlude within the piece that begins as a chord progression without a melody. The long lines in each instrument combine to form three- and four-note chords that imply fleeting diatonic collections that slowly bleed into each other at a glacial pace. The real canzone is saved until the end where the cello channels the previous glimpses of tonality into a final coda-like cantabile statement. The third movement, Variations on a Riff, takes the simple idea of a G major triad (first presented in the clarinet in mm. 34¬-44) and bends it through multiple permutations and harmonic contexts. This movement is framed by two fast sections in a galloping compound meter whose volatile, slightly unfinished texture sums up the attitude of the entire piece -- a composed musical narrative that seems to have been created in the moment out a subconscious musical language

Apollo Lightcraft Project

The ultimate goal for this NASA/USRA-sponsored Apollo Lightcraft Project is to develop a revolutionary manned launch vehicle technology which can potentially reduce payload transport costs by a factor of 1000 below the Space Shuttle Orbiter. The Rensselaer design team proposes to utilize advanced, highly energetic, beamed-energy sources (laser, microwave) and innovative combined-cycle (airbreathing/rocket) engines to accomplish this goal. The research effort focuses on the concept of a 100 MW-class, laser-boosted Lightcraft Technology Demonstrator (LTD) drone. The preliminary conceptual design of this 1.4 meter diameter microspacecraft involved an analytical performance analysis of the transatmospheric engine in its two modes of operation (including an assessment of propellant and tankage requirements), and a detailed design of internal structure and external aeroshell configuration. The central theme of this advanced propulsion research was to pick a known excellent working fluid (i.e., air or LN sub 2), and then to design a combined-cycle engine concept around it. Also, a structural vibration analysis was performed on the annular shroud pulsejet engine. Finally, the sensor satellite mission was examined to identify the requisite subsystem hardware: e.g., electrical power supply, optics and sensors, communications and attitude control systems

Apollo Lightcraft Project

This second year of the NASA/USRA-sponsored Advanced Aeronautical Design effort focused on systems integration and analysis of the Apollo Lightcraft. This beam-powered, single-stage-to-orbit vehicle is envisioned as the shuttlecraft of the 21st century. The five person vehicle was inspired largely by the Apollo Command Module, then reconfigured to include a new front seat with dual cockpit controls for the pilot and co-pilot, while still retaining the 3-abreast crew accommodations in the rear seat. The gross liftoff mass is 5550 kg, of which 500 kg is the payload and 300 kg is the LH2 propellant. The round trip cost to orbit is projected to be three orders of magnitude lower than the current space shuttle orbiter. The advanced laser-driven 5-speed combined-cycle engine has shiftpoints at Mach 1, 5, 11 and 25+. The Apollo Lightcraft can climb into low Earth orbit in three minutes, or fly to any spot on the globe in less than 45 minutes. Detailed investigations of the Apollo Lightcraft Project this second year further evolved the propulsion system design, while focusing on the following areas: (1) man/machine interface; (2) flight control systems; (3) power beaming system architecture; (4) re-entry aerodynamics; (5) shroud structural dynamics; and (6) optimal trajectory analysis. The principal new findings are documented. Advanced design efforts for the next academic year (1988/1989) will center on a one meter+ diameter spacecraft: the Lightcraft Technology Demonstrator (LTD). Detailed engineering design and analyses, as well as critical proof-of-concept experiments, will be carried out on this small, near-term machine. As presently conceived, the LTD could be constructed using state of the art components derived from existing liquid chemical rocket engine technology, advanced composite materials, and high power laser optics

Updating the NCTUns-6.0 tool to simulate parallel optical burst switching of all-optical ultra-dense WDM systems

Optical burst switching (OBS) is proposed as suitable switching architectures for directly transporting traffic over a bufferless wavelength division multiplexing (WDM) networks. Parallel optical burst switching (POBS) is a variant of the OBS model that takes this concept further by transmitting data bursts wavelength and time dimensions. However, there is a lack of simulator that simulates POBS networks. This paper presents an update to the conventional OBS model in the NCTUns-6.0 simulator (NCTUns-POBS). The NCTUns-POBS tool is capable of simulating POBS networks for ultra-denseWDM. It analyzes the features of POBS networks, enables to adjust the parameters of POBS networks and enhances their switching technology. To test and validate the performance of the tool, the proposed random wavelength assignment technique (RWAT) is compared with the existing sequential wavelength assignment technique (SWAT) of the POBS model and the conventional OBS model. The results of the simulation show that, the NCTUns-POBS successfully simulates the POBS networks in which the proposed RWAT enables the POBS to yield higher throughput compared to the existing SWAT and the OBS conventional techniqu

Carbon nanotubes and graphene oxide applications in optochemical sensors

Simple and sensitive ethanol sensors based on uncladded plastic optical fiber (UCPOF) and tapered silica fiber coated with carbon nanotubes (CNT) and graphene oxide (GO) thin films have been developed for detecting different ethanol concentrations at room temperature. Simple and low-cost techniques were used for the fabrication of the proposed optical fiber sensors. The developed probes were coated with CNT and GO using drop-casting and dip-coating techniques. Experiments demonstrated that the CNT-based UCPOF and GO-based tapered fiber tip sensors show significant sensitivity to aqueous ethanol with superior selectivity to ethanol among different organic compounds. CNT-based UCPOF sensor shows better sensing performance compared with the GO-based tapered fiber because of the absorbance sensing mechanism. The excellent sensing performance of the developed modified optical fiber sensors toward ethanol indicates their high efficiency to be used in practical applications for ensuring safety necessities in the industrial fields