Gravitational Lensing of Epoch-of-reionization Gas

I present a weak lensing sensitivity estimate for upcoming high redshift (epoch of reionization and beyond) 21cm surveys. Instruments such as PAST, LOFAR and SKA should be able to measure the weak lensing power spectrum to precisions far exceeding conceivable optical surveys. Three types of sources are detectable, which include the re-ionization stromgren spheres, large scale structure, and minihalos. Tomography allows the measurement of the time evolution of the dark matter power spectrum. Raw sensitivities allow measurement of many cosmological parameters, including dark energy, neutrino mass and cosmic equations of state, to percent accuracy. It also has the potential for inflationary gravity wave measurements. Ultimate limits may be achievable through radio observations of 10^18 minihalos. Inflationary Hubble parameters H_I down to 10^-9 M_Planck can be detected through this effect. Second order effects may also be observable, allowing tests for backreaction and the quantum mechanical origin of perturbations.Comment: 14 pages, including 2 figures, accepted in New Astronom

Training, Quality Assurance Factors, and Tools Investigation: a Work Report and Suggestions on Software Quality Assurance

Previously, several research tasks have been conducted, some observations were obtained, and several possible suggestions have been contemplated involving software quality assurance engineering at NASA Johnson. These research tasks are briefly described. Also, a brief discussion is given on the role of software quality assurance in software engineering along with some observations and suggestions. A brief discussion on a training program for software quality assurance engineers is provided. A list of assurance factors as well as quality factors are also included. Finally, a process model which can be used for searching and collecting software quality assurance tools is presented

Self-calibration of robot-sensor system

The process of finding the coordinate transformation between a robot and an external sensor system has been addressed. This calibration is equivalent to solving a nonlinear optimization problem for the parameters that characterize the transformation. A two-step procedure is herein proposed for solving the problem. The first step involves finding a nominal solution that is a good approximation of the final solution. A varational problem is then generated to replace the original problem in the next step. With the assumption that the variational parameters are small compared to unity, the problem that can be more readily solved with relatively small computation effort