Atomic Parameters for the 2p53p 2[3/2]2−2p53s 2[3/2]2o2p^53p~^2[3/2]_2 - 2p^53s~^2[3/2]^o_2 Transition of Ne I relevant in nuclear physics

We calculated the magnetic dipole hyperfine interaction constants and the electric field gradients of $2p^53p~^2[3/2]_2$ and $2p^53s~^2[3/2]^o_2$ levels of Ne I by using the multiconfiguration Dirac-Hartree-Fock method. The electronic factors contributing to the isotope shifts were also estimated for the $\lambda = 614.5$ nm transition connecting these two states. Electron correlation and relativistic effects including the Breit interaction were investigated in details. Combining with recent measurements, we extracted the nuclear quadrupole moment values for $^{20}$Ne and $^{23}$Ne with a smaller uncertainty than the current available data. Isotope shifts in the $2p^53p~^2[3/2]_2 - 2p^53s~^2[3/2]^o_2$ transition based on the present calculated field- and mass-shift parameters are in good agreement with the experimental values. However, the field shifts in this transition are two or three orders of magnitude smaller than the mass shifts, making rather difficult to deduce changes in nuclear charge mean square radii. According to our theoretical predictions, we suggest to use instead transitions connecting levels arising from the $2p^53s$ configuration to the ground state, for which the normal mass shift and specific mass shift contributions counteract each other, producing relatively small mass shifts that are only one order of magnitude larger than relatively large field shifts, especially for the $2p^53s~^2[1/2]^o_1 - 2p^6~^1S_0$ transition

SUPPORTING DEVELOPER-ONBOARDING WITH ENHANCED RESOURCE FINDING AND VISUAL EXPLORATION

Understanding the basic structure of a code base and a development team are essential to get new developers up to speed in a software development project. Developers do so through the process of early experimentation with code and the creation of mental models of technical and social structures in a project. However, getting up-to-speed in a new project can be challenging due to difficulties in: finding the right place to begin explorations, expanding the focus to determine relevant resources for tasks, and identifying dependencies across project elements to gain a high-level overview of project structures. In this thesis, I first identified six challenges that developers face during the process of developer onboarding from recent research studies and informal interviews with developers. To address these challenges, I implemented automated tool support with enhanced resource finding and visual exploration. Specifically, I proposed six functional requirements for supporting developers onboarding. I then extended the project tool Tesseract to support these functionalities to help novice developers and relevant resources (files, developers, bugs, etc.) and understand project structures when joining a new project. To understand how the onboarding functionalities work in supporting developers\u27 onboarding process, I conducted a user study with typical onboarding tasks requiring early experimentation and internalizing project structures. The results indicated that enhanced search features, the ability to explore semantic relationships across repositories, and network-centric visualizations of project structures were very effective in supporting onboarding

Time Prognosis of Landslide Based on Unstable Creep

The fundamental characters at each of three stages of creep deformation of rock masses are discussed. A model, a friction element and a dashpot element connected in parallel, suitable for middle and short time prognosis is suggested--landslide happens at accelerated creep stage and its mechanism may be described by progressive deterioration (assuming linear decrease with time) of material parameters which denote the friction and the dashpot of rock masses. The verification for the model is carried out by comparing theoretical results with measured results of three typical landslides