1,912 research outputs found

    LADEE Satellite Modeling and Simulation Development

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    As human activity on and around the Moon increases, so does the likelihood that our actions will have an impact on its atmosphere. The Lunar Atmosphere and Dust Environment Explorer (LADEE), a NASA satellite scheduled to launch in 2013, will orbit the Moon collecting composition, density, and time variability data to characterize the current state of the lunar atmosphere. LADEE will also test the concept of the "Modular Common Bus" spacecraft architecture, an effort to reduce both development time and cost by designing reusable, modular components for use in multiple missions with similar requirements. An important aspect of this design strategy is to both simulate the spacecraft and develop the flight code in Simulink, a block diagram-style programming language that allows easy algorithm visualization and performance testing. Before flight code can be tested, however, a realistic simulation of the satellite and its dynamics must be generated and validated. This includes all of the satellite control system components such as actuators used for force and torque generation and sensors used for inertial orientation reference. My primary responsibilities have included designing, integrating, and testing models for the LADEE thrusters, reaction wheels, star trackers, and rate gyroscopes

    Exploring Cognitive States: Methods for Detecting Physiological Temporal Fingerprints

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    Cognitive state detection and its relationship to observable physiologically telemetry has been utilized for many human-machine and human-cybernetic applications. This paper aims at understanding and addressing if there are unique psychophysiological patterns over time, a physiological temporal fingerprint, that is associated with specific cognitive states. This preliminary work involves commercial airline pilots completing experimental benchmark task inductions of three cognitive states: 1) Channelized Attention (CA); 2) High Workload (HW); and 3) Low Workload (LW). We approach this objective by modeling these "fingerprints" through the use of Hidden Markov Models and Entropy analysis to evaluate if the transitions over time are complex or rhythmic/predictable by nature. Our results indicate that cognitive states do have unique complexity of physiological sequences that are statistically different from other cognitive states. More specifically, CA has a significantly higher temporal psychophysiological complexity than HW and LW in EEG and ECG telemetry signals. With regards to respiration telemetry, CA has a lower temporal psychophysiological complexity than HW and LW. Through our preliminary work, addressing this unique underpinning can inform whether these underlying dynamics can be utilized to understand how humans transition between cognitive states and for improved detection of cognitive states

    Net Farm Income Impacts of Alternative Risk Management Bills

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    The impacts of the bills are measured against the FAPRI January 1999 baseline which may be found at http://hdl.handle.net/10355/3318At the request of Senator Richard Lugar, Chairman of the Committee on Agriculture, Nutrition and Forestry, FAPRI has analyzed impacts of two alternative risk management proposals. The first proposal is the Farmers' Risk Management Act of 1999, sponsored by Senator Lugar (IN) and co-sponsored by Senators McConnell (KY), Fitzgerald (IL), and Helms (NC). The second proposal is the Risk Management for the 21st Century Act, put forth by Senator Roberts (KS) and co-sponsored by Senator Kerrey (NE) and others

    Analysis of Risk Management Proposals

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    An earlier analysis which concentrated on the aggregate net farm income and government outlay impacts may be found at http://hdl.handle.net/10355/3318At the request of several members of the Committee on Agriculture, Nutrition, and Forestry of the Senate, FAPRI has continued to analyze the impacts of two alternative risk management proposals. The proposals are the Farmers' Risk Management Act of 1999 (S. 1666) and the Risk Management for the 21st Century Act (S. 1580)

    THE RELIABILITY OF THE 12-ITEM GRIT SCALE AMONG CROSSFIT PARTICIPANTS

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    Crossfit participation has experienced exponential growth. Like other sports, it may be that successful participation in Crossfit would rely upon a construct known as grit. Grit is considered to be a combination of perseverance of effort (PE) and consistency of interest (CI) and has been assessed in other populations with the 12-point Grit Scale. The ability to reliably assess grit among Crossfit participants may allow participants and coaches to monitor the constructs of PE and CI in order to further develop Crossfit participation skills. Hence, the purpose of this study was to examine the reliability of the 12-point Grit Scale among adult Crossfit participants. The 12-point Grit Scale was electronically administered twice to 25 adult Crossfit participants (female:11, male:14) separated by at least two weeks. The results of the two administrations of the 12-point Grit Scale were then compared with a battery of statistical analyses in order to assess the reliability of the 12-point Grit Scale. The test-retest 12-point Grit Scale scores were: 49.8±5.3 and 50.2±5.4. The reliability statistics along with 90% confidence limits were as follows: interclass reliability coefficient was r=0.87 (UL:0.94, LL:0.73), intraclass reliability coefficient was ICC=0.91 (UL:0.96, LL:0.83), Standard Error of Measurement (SEm)=1.6 (UL:2.2, LL:1.3), ∆Means 12-point Grit Scores= -0.3±2.3 (UL:0.6, LL:-1.2), and typical error CV% =3.4 (UL:4.8, LL:2.7). The Bland-Altman plot suggested agreement between the two administrations of the 12-point Grit Scale with no evidence of heteroscedasticity. The results of the 12-point Grit Scale and subscales ranged from moderately-high to excellent reliability among adult Crossfit participants.  Article visualizations

    Cardiovascular and Psychophysical Response to Repetitive Lifting Tasks in Women

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    BACKGROUND: Understanding the cardiovascular and psychophysical demands of repetitive lifting tasks is important in job design strategies. This study determined the cardiovascular (oxygen consumption (VO) and heart rate (HR) and psychophysical response to repetitive lifting tasks in women. METHODS: Ten female (age 27 ± 5 yrs) participants transferred 11.4, 15.9, and 20.5 kg weights back and forth from a rung 40.6 cm high to a rung 156.2 cm high. Rungs were 195.6 cm apart horizontally. Three, 10 minute bouts (1 = 11.4 kg; 2 = 15.9 kg; 3 = 20.5 kg) were performed at 6 lifts per minute. Cardiovascular and psychophysical (rating of perceived exertion, RPE) parameters were monitored throughout the bouts. VOmax and HRmax were determined via a maximal treadmill test. RESULTS: VO, HR, and RPE were significantly different between each work bout (p \u3c 0.01), with each outcome variable increasing as load increased. VOmax and HRmax equaled 46.5 ± 7.5 mL·kg·min and 191 ± 11 bpm, respectively. Work at 11.4 kg was performed at 38% VOmax and 63% HRmax; at 15.9 kg at 41% VOmax and 72% HRmax; and at 20.5 kg at 49% VOmax and 81% HRmax. RPE at 11.4, 15.9, and 20.5 kgs were: 8.4 ± 1.6, 11.4 ± 1.9, and 15.0 ± 2.2. CONCLUSION: During these repetitive lifting tasks, metabolic cost and perceived exertion increased with weight lifted; average work intensity ranged from 63 to 81% of HRmax and 38 to 49% of VOmax. Results have important implications in relation to job pacing and design, and worksite health promotion strategies aimed at reducing work place injury

    Counseling Children and Adolescents: A Call to Action

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    The ACA 2014 Code of Ethics clearly states the mandate for counselor competence in C.2.a. It is noted that “Counselor practice only within the boundaries of their competence, based on their education, training, supervised experience, state and national credentials, and appropriate professional experience” (p. 8). Given the importance of competencies, ethical standards, and the emphasis on best practice, the paucity of these factors in regard to training and supervision for counselors working with child and adolescent populations is concerning. This article offers a conceptualization of the culture of childhood leading to the need for cultural competency. It outlines information specific to counselors working with a child and adolescent population and is a call to action for the field of counseling

    Comparison of Forward and Reverse Wingate Anaerobic Tests: A Brief Technical Note

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    BACKGROUND: The Wingate anaerobic test (WAT) is traditionally performed in the forward pedaling direction on a cycle ergometer. However, reverse (backward) pedaling during a WAT test may be a novel way to convey meaningful information related to performance and rehabilitation. This study compared peak power measurements between 30-second forward pedaling WAT (FWAT) with a 30-second reverse pedaling WAT (RWAT). METHODS: 10 male and 10 female participants (age 27.6 ± 7.31 yrs, mass 74.9 ± 21.3 kg and height 172.6 ± 10.9 cm) volunteered to participate. Participants performed one FWAT and one RWAT at 7.5% of body mass on a specially modified Monark cycle ergometer. Tests were separated 2 days of rest. Peak power output (PPO), mean power output (MPO), relative PPO (RPPO), relative MPO (RMPO), fatigue index (%FI), and rating of perceived exertion (RPE) were measured. RESULTS: The FWAT power measurements were all significantly greater (p \u3c 0.05) than RWAT power measurements except MPO (p \u3e 0.05); and that RPE was significantly greater (p \u3c 0.05) in FWAT than RWAT. Specifically, FWAT vs. RWAT (M ± SD) are as follows: PPO watts (w) = 731.7 ± 237.1 vs. 529.6 ± 192.2; RPPO w/kg = 10.2 ± 2.3 vs. 7.2 ± 1.6; MPO w = 510.2 ± 162.1 vs. 415.1 ± 146.2; RMPO w/kg = 7.3 ± 1.5 vs. 5.8 ± 1.3; %FI = 49.2 ± 8.7 vs. 37.4 ± 13.7; and RPE = 19.4 ± 1.1 vs. 15.8 ± 1.5. Gender did not impact the relative differences in these relationships. CONCLUSION: Practitioners and clinicians may use this information to begin to understand the power and perceived exertion relationships of forward versus reverse pedaling during a WAT; exercise prescription for rehabilitation and performance may benefit
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