Advanced Signal Processing Techniques Applied to Terahertz Inspections on Aerospace Foams

The space shuttle's external fuel tank is thermally insulated by the closed cell foams. However, natural voids composed of air and trapped gas are found as by-products when the foams are cured. Detection of foam voids and foam de-bonding is a formidable task owing to the small index of refraction contrast between foam and air (1.04:1). In the presence of a denser binding matrix agent that bonds two different foam materials, time-differentiation of filtered terahertz signals can be employed to magnify information prior to the main substrate reflections. In the absence of a matrix binder, de-convolution of the filtered time differential terahertz signals is performed to reduce the masking effects of antenna ringing. The goal is simply to increase probability of void detection through image enhancement and to determine the depth of the void

An Evaluation of Early Childhood Education Programs: The Parents’ Perspective of Quality Care

Early childhood education (ECE) programs play a critical role in the social, emotional, and cognitive development of children and help to prepare them for kindergarten. Recognizing the benefits of ECE programs, state and federal governments have made notable efforts to make these programs more accessible. However, with various federal, state, and local governments involved in administering and funding ECE programs, a complex, fragmented, and oftentimes confusing system ensued, making the ECE landscape very difficult for parents to navigate. Parents are often the primary decision-makers when selecting educational programs for their children. Studies often focus on practitioners’ or researchers’ perspectives on quality care rather than parental choice. Through a 3-phase approach, the purpose of this study is to better understand the factors that influence parental decision-making when selecting ECE programs for their 3- and 4-year- old children in a well-populated urban and suburban area of the United States. Data collection included a community scan and mapping of ECE programs in California’s Santa Clara County, an analysis of publically available information of ECE programs, and stakeholder surveys. Findings revealed that there is a disparity in ECE programs in the southern region of the studied area, family/home-based care had the least publically available information, and parents’ cultural background, education level, and household income influences the value they place on family engagement and cultural competency

Threading a path to exascale with chemical scissors and integral compressors in a singular manner

Research presented in this dissertation aims at enabling (correlated) fragmentation methods to explore biochemistry and catalysis effects of macrosystems at high levels of accuracy using exascale computing resources. The target is the second-order MollerPlesset perturbation theory (MP2), and MP2 in the FMO framework (FMO/MP2). First, the 2-electron integral bottleneck is addressed by using the resolution-of-the-identity (RI) approximation to reduce the memory storage and the computational cost of the integral transformation from the atomic orbital (AO) to the molecular orbital (MO) basis. The RI approximation is also combined with the singular value decomposition (SVD) to introduce a flexible compression factor that fully controls the accuracy of the integral compression. The RIMP2 energy and analytic energy gradient are implemented in the GAMESS electronic structure program and are parallelized with an efficient hybrid distributed/shared memory model with the support of the MPI and OpenMP APIs. Both the RI-MP2 energy and gradient are interfaced to the FMO framework for large system calculations

TEACHERS’ PERCEPTIONS ABOUT POWERPOINT USE AS AN ICT TOOL FOR TEACHING VOCABULARY IN VIETNAM

This paper reports a mixed-methods study designed to explore teachers’ perceptions about using PowerPoint (PPT) as an ICT (Information and Communications Technology) tool in vocabulary teaching in Kien Giang province, Vietnam. The data were collected from the questionnaire and interviews. Participants were sixty EFL teachers from five colleges in Kien Giang province. The findings reveal that participating teachers perceived PowerPoint use in vocabulary instruction as a useful instructional tool; however, there was no significant differences in their perceptions. These participants reported obstacles such as time investment, insufficient knowledge in information technology (IT), and lack of IT facilities. Pedagogical implications are made to encourage the potential use of PPT in vocabulary instruction.  Article visualizations