Current Search:   Scaling Law (x)

View All Items

  • CSV Spreadsheet
(1 - 2 of 2)
STUDY FOR DEVELOPMENT OF A BLAST LAYER FOR THE VIRTUAL RANGE PROJECT
Title
STUDY FOR DEVELOPMENT OF A BLAST LAYER FOR THE VIRTUAL RANGE PROJECT.
Creator
Rosales, Sergio, Sepulveda, Jose, University of Central Florida
Abstract / Description
In this work we develop a Blast-Propellant-Facility integrated analysis study, which evaluates, by using two different approaches, the blast-related impact of an explosive accident of the Space Shuttle during the first ten seconds after launch at Kennedy Space Center. The blast-related risk associated with an explosion at this stage is high because of the quantity of energy involved in both multiple and complex processes. To do this, one of our approaches employed BlastFX®, a software...
Show moreIn this work we develop a Blast-Propellant-Facility integrated analysis study, which evaluates, by using two different approaches, the blast-related impact of an explosive accident of the Space Shuttle during the first ten seconds after launch at Kennedy Space Center. The blast-related risk associated with an explosion at this stage is high because of the quantity of energy involved in both multiple and complex processes. To do this, one of our approaches employed BlastFX®, a software system that facilitates the estimation of the level of damage to people and buildings, starting from an explosive device and rendering results through a complete report that illustrates and facilitates the evaluation of consequences. Our other approaches employed the Hopkinson-Cranz Scaled Law for estimating similar features at a more distant distance and by evaluating bigger amounts of TNT equivalent. Specifically, we considered more than 500 m and 45,400 kg, respectively, which are the range and TNT content limits that our version of BlastFX® can cover. Much research has been done to study the explosion phenomena with respect to both solid and liquid propellants and the laws that underlie the blast waves of an explosion. Therefore our methodology is based on the foundation provided by a large set of literature review and the actual capacities of an application like BlastFX®. By using and integrating the lessons from the literature and the capabilities of the software, we have obtained very useful information for evaluating different scenarios that rely on the assumption, which is largely studied, that the blast waves' behavior is affected by the distance. All of this has been focused on the Space Shuttle system, in which propellant mass represents the source of our analysis and the core of this work. Estimating the risks involved in it and providing results based on different scenarios augments the collective knowledge of risks associated with space exploration.
Show less
Date Issued
2004
Identifier
CFE0000190, ucf:46171
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0000190
A Psychophysical Approach to Standardizing Texture Compression for Virtual Environments
Title
A Psychophysical Approach to Standardizing Texture Compression for Virtual Environments.
Creator
Flynn, Jeremy, Szalma, James, Fidopiastis, Cali, Jentsch, Florian, Shah, Mubarak, University of Central Florida
Abstract / Description
Image compression is a technique to reduce overall data size, but its effects on human perception have not been clearly established. The purpose of this effort was to determine the most effective psychophysical method for subjective image quality assessment, and to apply those findings to an objective algorithm. This algorithm was used to identify the minimum level of texture compression noticeable to the human, in order to determine whether compression-induced texture distortion impacted...
Show moreImage compression is a technique to reduce overall data size, but its effects on human perception have not been clearly established. The purpose of this effort was to determine the most effective psychophysical method for subjective image quality assessment, and to apply those findings to an objective algorithm. This algorithm was used to identify the minimum level of texture compression noticeable to the human, in order to determine whether compression-induced texture distortion impacted game-play outcomes. Four experiments tested several hypotheses. The first hypothesis evaluated which of three magnitude estimation (ME) methods (absolute ME, absolute ME plus, or ME with a standard) for image quality assessment was the most reliable. The just noticeable difference (JND) point for textures compression against the Feature Similarity Index for color was determined The second hypothesis tested whether human participants perceived the same amount of distortion differently when textures were presented in three ways: when textures were displayed as flat images; when textures were wrapped around a model; and when textures were wrapped around models and in a virtual environment. The last set of hypotheses examined whether compression affected both subjective (immersion, technology acceptance, usability) and objective (performance) gameplay outcomes. The results were: the absolute magnitude estimation method was the most reliable; no difference was observed in the JND threshold between flat textures and textures placed on models, but textured embedded within the virtual environment were more noticeable than in the other two presentation formats. There were no differences in subjective gameplay outcomes when textures were compressed to below the JND thresholds; and those who played a game with uncompressed textures performed better on in-game tasks than those with the textures compressed, but only on the first in-game day. Practitioners and researchers can use these findings to guide their approaches to texture compression and experimental design.
Show less
Date Issued
2018
Identifier
CFE0007178, ucf:52250
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0007178