2,622 research outputs found
Reformulating the rj-McMC Algorithm for 3D Inversion of Passive Seismic Data for Near-Surface Characterization
No full textGeophysical subsurface characterization techniques could, due to their non-invasive nature, play a crucial role in the design and subsequent construction of infrastructure in urban & industrial environ- ments. Geo-data specialist company Fugro sees potential in upgrading their current ambient-seismic- noise-tomography workflow, to make use of state-of-the-art inversion schemes with the main goal of increasing the quality and accuracy of the initial-site characterization delivered to clients. In this thesis I explore the feasibility of utilizing the reverse-jump Markov chain Monte Carlo (rj-McMC) algorithm for the inversion of ambient seismic noise for characterization in urban & industrial environments. Specif- ically, testing the potential of scaling down this inversion algorithm to fit in a small scale, near-surface framework. To achieve this, I first carried out analyses to evaluate the appropriate Rayleigh wave frequency range, after which realistic noise hyperparameters, suited for this reduced scale problem, were obtained. Because of the potential exploitation of in-situ borehole measurements, I reformulated the Bayesian prior within the rj-McMC algorithm to implement these constraining shear wave velocity values appropriately. I conducted extensive synthetic experiments to gain insight into the behavior of this adapted algorithm, from which it was concluded that the inherent dynamic discretization partially prevents these constraints from being implemented to their full extent. Nevertheless, promising results lead me to conclude that the use of the rj-McMC algorithm for application in near-surface urban & industrial environments is feasible.Applied Geophysics | IDEA Leagu
Clowns, Fools, and Killers: An Exploration of Horror, Comedy, and Madness Through the Roles of Murderer 2 and Sir Richard Ratcliffe in William Shakespeare\u27s Richard III
No full textThis document is a thesis submitted in partial fulfillment of the Master of Fine Arts degree in Theatre Arts with a Concentration in Musical Theatre. It is a detailed account of author RJ Magee’s artistic and scholarly process in creating the roles of Murderer 2 and Sir Richard Ratcliffe in William Shakespeare’s Richard III. The production was performed as part of Minnesota State University, Mankato’s mainstage season in October of 2022. In five chapters, this thesis chronicles the actor’s process: a preproduction analysis, a historical and critical perspective, a rehearsal and performance journal, a post-production analysis, and a process development analysis. Appendices and works cited are included
THE DISTANCE TO THE HERCULES SUPERCLUSTER .1. BASIC DATA FOR 220 GALAXIES IN CGCG FIELD-108
No full textA STUDY OF THE RINGED GALAXIES NGC-2273, NGC-4826, AND NGC-6217 .1. H-I LINE OBSERVATIONS
No full textThe ringed galaxies NGC2273, 4826, and 6217 were mapped in the 21 cm H I line at Westerbork with a velocity resolution of 40, 20 and 20 km s-1, and a spatial resolution of 23" x 27", 28" x 60" and 13" x 14" (alpha x delta), respectively. Here we use H(o) = 100 km s-1 Mpc-1.NGC 2273 (= Mk 620) is a type (R')SB(rs)ab galaxy with an inner and two outer pseudo-rings, formed by separate sets of spiral arms. The morphology is atypical compared to most outer-ringed galaxies. NGC 2273 is not very gas-rich for its morphological type (M(HI)/L(B) = 0.13 M./L.). We find the H I to be concentrated in the outer rings at a radius of about 10 kpc, with a maximum average H I column density (corrected to face-on) of sigma(HI) approximately 3 M. pc-2. CO(1-0) line observations indicate that NGC 2273 has a massive "star formation efficiency" similar to that of starburst galaxies, i.e. a L(FIR)/M(H2) ratio of 10-25 L./M. From the undisturbed H I velocity field we derive an almost flat rotation curve, implying a total mass M(T) approximately 1.3 10(11) M. and a total mass-to-light ratio M(T)/L(B) approximately 12 M./L. if we assume circular rotation and a simple spherical mass model.NGC 4826 (= M64), type (R)SA(rs)ab, has an optical inner ring and a weak outer ring. The galaxy is quite gas-poor (M(HI)/L(B) = 0.020 M./L.). NGC 4826 has a normal massive star formation efficiency for its morphological type, 6 L./M.. The H I is distributed in an asymmetric disk which extends far beyond the optical de Vaucouleurs' radius R25; the highest column densities occur at R approximately 3 kpc in or just outside the optical outer pseudoring. Another ring-like H I structure is evident around R approximately 9 kpc as well. The average H I column density sigma-HI is smaller than 1 M. pc-2. The H I velocity field looks undisturbed and the derived rotation curve is flat out to R = 10.5 kpc, or 11 optical disk scale lengths, implying the presence of a substantial dark halo. We derive M(T) approximately 0.6 10(11) M. and a total mass-to-light ratio M(T)/L(B) approximately 10 M./L. within R = 10.5 kpc. We resolved the radio continuum source in the centre of the galaxy.NGC 6217, type (R)SB(rs)bc, shows an inner and outer optical pseudoring. The H I mass-to-light ratio, M(HI)/L(B) = 0.41 M./L., is normal for the galaxy's morphological type. Its star formation efficiency, L(FIR)/M(H2) = 8 L./M. is not abnormally high for its morphological type. The H I is concentrated in the inner and outer pseudorings and beyond, and the H I column density reaches a maximum of approximately 6 M. pc-2 near the centre. From the regular H I velocity field we derive a rotation curve which is flat out to R = 15 kpc, or 11 times the (uncertain) optical disk scale-length, implying M(T) approximately 0.6 10(11) M. and a normal total mass-to-light ratio for a spiral, M(T)/L(B) approximately 9 M./L. within R = 15 kpc.Possible resonances associated with the rings of each of these galaxies are discussed. Only NGC 6217 fits easily into recent work on the dynamics of ringed galaxies.</p
Discovery of a second companion of Dwingeloo 1
No full textDeep near-infrared CCD imaging of the field of the recently discovered nearby galaxies Dwingeloo 1 and 2 has revealed a third, previously unknown galaxy which is most likely a second physical companion of Dwingeloo 1. Only 9'.2 to the southwest of Dwingeloo 1 is a diffuse featureless oval with a diameter of 1'.9 in I. Isophotes are oriented nearly east-west and within 30 degrees of the direction of Dwingeloo 1. Neutral hydrogen studies have failed to reveal a source at this position, and no H alpha emission is evident. Thus, the object is probably a dwarf spheroidal companion of Dwingeloo 1, although there is a small possibility that it is a quiescent gas-rich dwarf with a velocity low enough that its signal is confused with emission from the Milky Way. The galaxy is almost certainly a member of the IC 342-Maffei 1 group, thereby placing it 3+/-1 Mpc away. (C) 1997 American Astronomical Society
THE DISTANCE TO THE HERCULES SUPERCLUSTER .2. APPLICATION OF TERTIARY INDICATORS AND AN ESTIMATE OF THE HUBBLE CONSTANT
No full textLIGHT VARIATIONS OF NONRADIAL PULSATORS - THEORY AND APPLICATION TO THE LINE-PROFILE VARIABLE 53-PERSEI
No full textDISCOVERY OF 2 LIKELY DWARF COMPANIONS OF MAFFEI-1
No full textDeep wide-field CCD images have revealed two likely late-type galaxies about 20 arcmin away from Maffei 1. The brighter object may be a spiral, but the fainter is probably a dwarf irregular galaxy. The two objects are probably members of the IC 342-Maffei group of galaxies. © 1995 American Astronomical Society
The IC 342/Maffei Group revealed
No full textDeep wide-field CCD images in the optical and near-infrared have been acquired for 14 of the 16 known or suspected members of the IC 342/Maffei Group of galaxies, one of the closest groups to the Milky Way, and probably the closest group to M31. Because of their low Galactic latitude, all galaxies are heavily extinguished, and myriads of foreground stars are superimposed. A sophisticated algorithm built around DAOPHOT has been developed which successfully removes the foreground stars, making possible comprehensive morphological and photometric studies. The cleaned near-infrared images reveal the true morphology and extent of many of the galaxies for the first time, three of which are among the largest in the northern sky. Besides surface brightness profiles, precise total magnitudes and colors have been measured. Many of the results represent substantial revisions to previous estimates. The data will make possible new determinations of the distances and masses of the galaxies, which are crucial for evaluating the impact the group may have had upon the dynamical evolution of the Local Group
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