In this thesis, we focus on the design of the fault-tolerant routing algorithm for the (n, k)-star graph. We apply the idea of collecting the limited global information used for routing on the n-star graph to the (n, k)-star graph. First, we build the probabilistic safety vector (PSV) with modified cycle patterns. Then, our routing algorithm decides the fault-free routing path with the help of PSV. In order to improve the routing performance with more faulty nodes, we dynamically assign the threshold for our routing algorithm. The performance is judged by the average length of routing paths. Compared with distance first search and safety level, we get the best performance in the simulations.

Fullerene research has advanced to elevated levels in a short period of time due to the unique chemical and physical properties of the caged molecule that have been utilized in numerous applications. Due to the spherical shape of the fullerene molecule which allows for a hollow cavity, encapsulation of atoms or small molecules can occur within the ball structure. This encapsulation creates an endohedral component that is limited from interacting with other molecules which creates potential of control over electronic information of the isolated molecule. Endohedral fullerenes have the potential as serving as the base unit in a quantum computer if control over global alignment is attained. Thus, by using the inherent self-assembling capabilities of some organic materials, ordered endohedral fullerenes can be achieved. This dissertation investigates the ability to use self-assembling strategies to obtain alignment which include ordering within a morphologically controlled copolymer matrix, forming a supramolecular polymer complex with cyclodextrin, and encapsulation within the helical wrap of polymer chains. The ultimate goal is to understand the dynamics that control association and orientation of varying fullerene-based molecules in each strategy in order to maximize control over the final alignment of endohedral elements.

<p>The purpose with this thesis was to study user activities in a business system, MediusFlow. The overall objective was to identify user related problems and to analyse which of the usability data gathering methods to use in the future development process of the company Medius.</p><p>The outcome of this study indicated that a cognitive related user problem was the most important problem to solve. A Star Life Cycle method was preferred. Two low-fidelity prototypes were developed to exemplify an alternative design solution to the identified cognitive user problem. Furthermore, the two best methods to use when gathering user related requirements were heuristic evaluation and expert review.</p><p>In addition a company specific Style Guide was created with generic guidelines as a foundation for development of future applications within Medius.</p>

Zugl.: Hannover, Univ., Diss., 2008

Thesis (D. Min.)--New Orleans Baptist Theological Seminary, 1997. / Includes abstract and vita. Includes bibliographical references (leaves 176-187).

Thesis (M. Arch.)--University of Hong Kong, 2002. / Includes bibliographical references.

The purpose of this study is to examine the bonds that form between people as consumers of popular visual media and to discuss the relationship and impact of the resulting subcultures on the larger culture. Star Wars costumers offer a magnified glance at some of the ways in which people engage with images. As reflections of popular culture, costumers display their textual devotions and opinions; they embody spectatorship by reincarnating their favorite characters and contexts from text-bound sources. Moreover, they embrace modes of visual representation by performing the roles of both image consumer and image producer. I strive to understand the activities shared by audiences after the viewing experience is over; they are highly articulate interpreting media texts in a variety of interesting and unexpected ways. Whether they impart opinions or pursue alternative relationships with some aspect of the text, people do form communities and celebrate their connections to visual texts. As fans, individuals appropriate movie materials to fulfill personal goals and build social connections. While not all-encompassing, these smaller communities say a lot about the social impact of movies---the impact of images on individuals. This thesis combines an ethnographic study of Star Wars costumers within a theoretical framework of cultural studies and performance to investigate the ways in which media images impact individuals. In documenting events from the perspective of the costumer, I seek to understand the costumer as a member of a visual audience, a reflection of popular culture, and a participant in the dominant culture.

The character of the first galaxies at redshifts z [greater-than or equal to] 10 strongly depends on the star formation which takes place during their assembly. Conducting cosmological hydrodynamics simulations, we study how the radiative output and chemical enrichment from the first stars impacts the properties of the first galaxies. We find that the radiative feedback from the first stars suppresses the star formation rate at redshifts z [greater-than or equal to] 15 by a factor of only a few. In turn, this suggests that a large fraction of the first galaxies may form from gas which has already been enriched with the first heavy elements ejected by primordial supernovae. In order to characterize the properties of primordial dwarf galaxies, we carry out radiation hydrodynamics simulations which allow to determine how the luminosities in hydrogen and helium emission lines depend on the initial mass function of the stars in the galaxy. As well, we show that the chemical abundance patterns observed in metal-poor Galactic halo stars contain the signature of the first supernovae, and we use this data to indirectly probe the properties of the first stars. / text

While the process that converts implosion into explosion in core collapse supernovae is poorly understood, their observed asphericity provides new constraints on the physics of these events. Since pulsars are rotating and magnetized neutron stars, there is no doubt that rotation and magnetic fields are inherent to the exploding engine. We have shown that magnetic field amplification is an inevitable by-product of the differential rotation that accompanies core-collapse. We performed 1D core-collapse simulations of rotating iron cores with various rotational profiles and velocities. We found that differential rotation was a generic feature of rotating iron core collapse. As a result, the magnetorotational instability (MRI) generates magnetic fields of order 10¹⁵⁻¹⁷ G in a few tens of milliseconds where the negative shear is the strongest. Although magnetic fields of order 10¹⁵⁻¹⁷ G are very strong, they are not strong enough to modify the equation of state of degenerate electron gas near the proto-neutron star. The corresponding MHD luminosity available is ~10⁵² erg s⁻¹, which can modify the explosion dynamics if the power is sustained for a fraction of a second. When rotational effects are included, we found that there is a critical iron core rotation rate that gives the most rapidly rotating proto-neutron star, faster than which the rotational velocity of the proto-neutron star decreases due to centrifugal support. This non-monotonic behavior of post-collapse core rotation suggests that the progenitor of the most rapidly rotating proto-neutron star is not the most rapidly rotating iron core, but that those iron cores with nearly the critical initial rotation rate may produce the maximum proto-neutron star rotation, the strongest magnetic fields, and the most robust supernova explosions. Even small rotation may induce non-axisymmetric instabilities, which drive magneto-acoustic flux in to the mantle, transporting enegy out of the proto-neutron star to the region near the stalled shock. Further implications for rotation and magnetic fields, pulsars and magnetars, and jet formation mechanisms are discussed. / text

Using various molecular line and continuum emission criteria, we have selected a sample of six isolated, dense concentrations of molecular gas, i.e., “cores”, which are either starless (L694-2, L429, L1517B, and L1689-SMM16) or contain a protostellar Very Low Luminosity Object (VeLLO) and are currently experiencing gravitational collapse (L1014 and L1521F). Studying the molecular emission from dense gas tracers toward this sample of cores will help us gain a more detailed image of the internal physical conditions of dense cores and their evolution. We observed the cores in our sample in NH3 (1,1) and (2,2) emission using the Green Bank Telescope (GBT) and in N2H+ (1−0) emission using the Nobeyama Radio Observatory (NRO). L429 shows the most complicated structure among the cores in our sample. Also, the maxima of molecular line integrated intensities and dust continuum emission toward L429 show a significant offset. The rest of the cores in our sample are roughly round and the morphologies of line integrated intensities follow that of the corresponding continuum emission closely. Cores in our sample have gas kinetic temperatures ∼ 9 − 10 K and therefore show comparable thermal velocity dispersions. L429 and L1517B are, respectively, the most turbulent and most quiescent cores in our sample. Finally, L1521F is the most centrally concentrated core of our sample. L1689-SMM16 is the least previously studied core in our sample and had not yet been probed in molecular emission. Jeans and virial analyses made using updated measurements of core mass and size confirm that L1689-SMM16 is prestellar, i.e., gravitationally bound. It also has accumulated more mass compared to its corresponding Jeans mass in the absence of magnetic fields and therefore is a “super-Jeans” core. The high levels of X(NH3)/X(N2H+) and deuterium fractionation reinforce the idea that the core has not yet formed a protostar. Comparing the physical parameters of the core with those of a Bonnor-Ebert sphere reveals the advanced evolutionary stage of L1689-SMM16 and shows that it might be unstable to collapse. We do not detect any evidence of infall motions toward the core, however. Instead, red asymmetry in the line profiles of HCN (1−0) and HNC (1−0) indicates expansion of the outer layers of the core at a speed of ∼ 0.2 − 0.3 km s−1. For a gravitationally bound core, expansion in the outer layers might indicate that L1689-SMM16 is experiencing oscillations. Radiative transfer modelling of NH3 emission toward L694-2 and L1521F at low and high spatial resolutions show that the less evolved core, L694-2, is best described by relatively constant radial profiles of temperature and fractional NH3 abundance. On the other hand, L1521F, which contains a protostellar VeLLO, is best described by a radial abundance profile that is enhanced toward the core centre and a radial temperature profile that decreases toward the core centre. Comparison of our results with previous studies on L1544, a well-studied starless core, imply that as dense cores evolve and progress toward the moment of collapse, they become more centrally concentrated. As a result, the gas temperatures at their centres decrease, leading to increase in levels of CO depletion factor and increase in NH3 fractional abundance toward the centre. / Graduate