447 research outputs found

    Adaptive guidance and control for future remote sensing systems

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    A unique approach to onboard processing was developed that is capable of acquiring high quality image data for users in near real time. The approach is divided into two steps: the development of an onboard cloud detection system; and the development of a landmark tracker. The results of these two developments are outlined and the requirements of an operational guidance and control system capable of providing continuous estimation of the sensor boresight position are summarized

    Experimental and simulation study results for video landmark acquisition and tracking technology

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    A synopsis of related Earth observation technology is provided and includes surface-feature tracking, generic feature classification and landmark identification, and navigation by multicolor correlation. With the advent of the Space Shuttle era, the NASA role takes on new significance in that one can now conceive of dedicated Earth resources missions. Space Shuttle also provides a unique test bed for evaluating advanced sensor technology like that described in this report. As a result of this type of rationale, the FILE OSTA-1 Shuttle experiment, which grew out of the Video Landmark Acquisition and Tracking (VILAT) activity, was developed and is described in this report along with the relevant tradeoffs. In addition, a synopsis of FILE computer simulation activity is included. This synopsis relates to future required capabilities such as landmark registration, reacquisition, and tracking

    Evaluation of automated decisionmaking methodologies and development of an integrated robotic system simulation. Volume 2, Part 2: Appendixes B, C, D and E

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    The derivation of the equations is presented, the rate control algorithm described, and simulation methodologies summarized. A set of dynamics equations that can be used recursively to calculate forces and torques acting at the joints of an n link manipulator given the manipulator joint rates are derived. The equations are valid for any n link manipulator system with any kind of joints connected in any sequence. The equations of motion for the class of manipulators consisting of n rigid links interconnected by rotary joints are derived. A technique is outlined for reducing the system of equations to eliminate contraint torques. The linearized dynamics equations for an n link manipulator system are derived. The general n link linearized equations are then applied to a two link configuration. The coordinated rate control algorithm used to compute individual joint rates when given end effector rates is described. A short discussion of simulation methodologies is presented

    Evaluation of automated decisionmaking methodologies and development of an integrated robotic system simulation, volume 2, part 1. Appendix A: Software documentation

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    Documentation of the preliminary software developed as a framework for a generalized integrated robotic system simulation is presented. The program structure is composed of three major functions controlled by a program executive. The three major functions are: system definition, analysis tools, and post processing. The system definition function handles user input of system parameters and definition of the manipulator configuration. The analysis tools function handles the computational requirements of the program. The post processing function allows for more detailed study of the results of analysis tool function executions. Also documented is the manipulator joint model software to be used as the basis of the manipulator simulation which will be part of the analysis tools capability

    Application of advanced technology to space automation

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    Automated operations in space provide the key to optimized mission design and data acquisition at minimum cost for the future. The results of this study strongly accentuate this statement and should provide further incentive for immediate development of specific automtion technology as defined herein. Essential automation technology requirements were identified for future programs. The study was undertaken to address the future role of automation in the space program, the potential benefits to be derived, and the technology efforts that should be directed toward obtaining these benefits

    Study and simulation results for video landmark acquisition and tracking technology (Vilat-2)

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    The results of several investigations and hardware developments which supported new technology for Earth feature recognition and classification are described. Data analysis techniques and procedures were developed for processing the Feature Identification and Location Experiment (FILE) data. This experiment was flown in November 1981, on the second Shuttle flight and a second instrument, designed for aircraft flights, was flown over the United States in 1981. Ground tests were performed to provide the basis for designing a more advanced version (four spectral bands) of the FILE which would be capable of classifying clouds and snow (and possibly ice) as distinct features, in addition to the features classified in the Shuttle experiment (two spectral bands). The Shuttle instrument classifies water, bare land, vegetation, and clouds/snow/ice (grouped)

    Organic photovoltaics: The current challenges

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    Organic photovoltaics are remarkably close to reaching a landmark power conversion efficiency of 20%. Given the current urgent concerns regarding climate change, research into renewable energy solutions is crucially important. In this perspective article, we highlight several key aspects of organic photovoltaics, ranging from fundamental understanding to implementation, that need to be addressed to ensure the success of this promising technology. We cover the intriguing ability of some acceptors to undergo efficient charge photogeneration in the absence of an energetic driving force and the effects of the resulting state hybridization. We explore one of the primary loss mechanisms of organic photovoltaics - non-radiative voltage losses - and the influence of the energy gap law. Triplet states are becoming increasingly relevant owing to their presence in even the most efficient non-fullerene blends, and we assess their role as both a loss mechanism and a potential strategy to enhance efficiency. Finally, two ways in which the implementation of organic photovoltaics can be simplified are addressed. The standard bulk heterojunction architecture could be superseded by either single material photovoltaics or sequentially deposited heterojunctions, and the attributes of both are considered. While several important challenges still lie ahead for organic photovoltaics, their future is, indeed, bright

    Residual Spiritual Shifts Regarding the Homeless Resulting From a College Poverty Immersion Experience

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    We report the results of a qualitative study, having interviewed 20 students who had 1.5 years previously been involved in a collegiate, weekend poverty immersion experience. We coded the transcripts, analyzed the data from a phenomenological framework, provided checks for internal validity, and report the common themes from the participants’ interviews.Three overall results were evident. First, participants reported believing that, generally, the church is ignorant regarding the needs of the poor and impoverished people around them. Second, students generally did not believe that the church was doing enough in order to combat poverty and/or homelessness, mentioning that the church’s outreach ministries are often ineffective. Third, students reported believing that the church is responsible to care for the poor and thus, Christians as a whole should be more involved than they are presently. The study’s results are discussed in the context of social psychology findings, published research literature reading how contemporary Christians generally fare at helping impoverished individuals, and the long term effectiveness of active, experiential learning in higher education

    Evaluating the Concurrent Validity of Three Web-based IQ Tests and the Reynolds Intellectual Assessment Scales (RIAS)

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    In a double-blind study, 60 General Psychology students, selected in low, average, and high ACT ranges, were administered the Reynolds Intellectual Assessment Scales (RIAS). On a separate occasion, the students also completed web-based internet IQ tests from tickle.com, queendom.com, and iqtest.com. MANOVA results showed that ACT level had a significant effect on all four IQ scores combined (Wilk’s Lambda = .451,
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