Commercial air transport hazard warning and avoidance system. Volume 1 - Summary Final report

Operational requirements for commercial air transport hazard warning and avoidance syste

The effect of feedback and information on children's pedometer step counts at school

This study examined whether feedback or feedback plus physical activity information could increase the number of pedometer steps taken during 1 school week. One hundred seventy-seven students (mean age 9.124 ± 1.11 years) in three elementary schools participated. Schools were randomly assigned to control (CON), feedback (FB), or feedback plus information (FB+I) groups. Children wore pedometers during school time for 5 consecutive weekdays. The total steps of the groups were recorded at the end of each school day, with students in the FB and FB+I groups free to view their step counts. In addition, the FB+I group received information and ideas about how they could increase their daily steps. The CON group received no step-count feedback or information. Students in the FB+I group achieved significantly more steps per minute (17.17 ± 4.87) than those in the FB (13.77 ± 4.06, p = 0.003) and CON (12.41 ± 3.12, p = 0.0001) groups. Information, as well as step-count feedback, increased elementary students’ school-based physical activity (number of steps) in the short term. A longer intervention period is necessary to assess the sustained impact of this type of approach

Interplanetary Trajectory Optimization with Powerlimited Propulsion Systems

A trajectory-optimization process is described in which the optimum thrust equations are derived using the calculus of variations. The magnitude of the thrust is constrained within an upper and a lower bound, but the thrust direction is arbitrary. This formulation allows both the constant-thrust program and the variable-thrust program to be considered. For the constant-thrust program, certain propulsion-system parameters are optimized for maximum final vehicle mass. This theory has been used to study interplanetary missions to Venus and Mars using a power-limited propulsion system. Both one-way and round trip rendezvous trajectories are considered. The analysis employs a two-body inverse-square force-field model of three dimensions. An iterative routine used to solve the two-point boundary-value problem is described in the Appendix

Propagation of the 2012 March Coronal Mass Ejections from the Sun to Heliopause

In 2012 March the Sun exhibited extraordinary activities. In particular, the active region NOAA AR 11429 emitted a series of large coronal mass ejections (CMEs) which were imaged by STEREO as it rotated with the Sun from the east to west. These sustained eruptions are expected to generate a global shell of disturbed material sweeping through the heliosphere. A cluster of shocks and interplanetary CMEs (ICMEs) were observed near the Earth, and are propagated outward from 1 AU using an MHD model. The transient streams interact with each other, which erases memory of the source and results in a large merged interaction region (MIR) with a preceding shock. The MHD model predicts that the shock and MIR would reach 120 AU around 2013 April 22, which agrees well with the period of radio emissions and the time of a transient disturbance in galactic cosmic rays detected by Voyager 1. These results are important for understanding the "fate" of CMEs in the outer heliosphere and provide confidence that the heliopause is located around 120 AU from the Sun.Comment: 13 pages, 5 figures, accepted for publication in ApJ Letter

Phase noise characterization of injection locked semiconductor lasers to a 250 MHz optical frequency comb

Two lasers are simultaneously injection locked to the same comb mode and the injection locking quality is assessed in terms of phase noise and phase variance (1 kHz-10 MHz) for various injected powers

Parameter estimates for fractional autoregressive spatial processes

A binomial-type operator on a stationary Gaussian process is introduced in order to model long memory in the spatial context. Consistent estimators of model parameters are demonstrated. In particular, it is shown that $\hat{d}_N-d=O_P(\frac{(\operatorname {Log}N)^3}{N})$, where $d=(d_1,d_2)$ denotes the long memory parameter.Comment: Published at http://dx.doi.org/10.1214/009053605000000589 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

An Analysis of Whole Farm Revenue Safety Net Options in Agriculture

Despite many years of experience, the federal government continues to seek a farm program that holds the potential for providing a politically acceptable safety net for farmers. This study demonstrates that, with the 2002 Farm Bill, AMTA, and marketing loan provisions continuing, a whole farm revenue safety net has the potential for simplifying existing farm programs, while enhancing the financial position of US farmers. There remains the need for further analysis of the impacts of the options analyzed on supply response by farmers.Agricultural and Food Policy,

American Agriculture: What We Can Expect - National Symposium on the Future of American Agriculture, University of Georgia: August 1999

The Agricultural and Food Policy Center (AFPC) of the Texas A&M University System is pleased to be invited to address this symposium addressing the future of U.S. agriculture. As a participant in the FAPRI consortium, AFPC monitors the economic conditions of U.S. agriculture at the farm and ranch level. To accomplish this, AFPC maintains approximately 80 crop, dairy, beef and pork representative farms throughout the nation. In the interest of time, this paper will focus only on the economic condition of the 41 feed grain/oilseeds, wheat, cotton and rice farms through the year 2002. Anyone interested in the livestock operations, or more detail on the crop farms, are directed to the AFPC web site at http://afpc1.tamu.edu. The publications included at this site provide greater detail about the process AFPC employs to develop the representative farms, their structure and their financial characteristics.Agribusiness, Agricultural and Food Policy,

Advanced turbocharger design study program

The advanced Turbocharger Design Study consisted of: (1) the evaluation of three advanced engine designs to determine their turbocharging requirements, and of technologies applicable to advanced turbocharger designs; (2) trade-off studies to define a turbocharger conceptual design and select the engine with the most representative requirements for turbocharging; (3) the preparation of a turbocharger conceptual design for the Curtiss Wright RC2-32 engine selected in the trade-off studies; and (4) the assessment of market impact and the preparation of a technology demonstration plan for the advanced turbocharger

SOIL CONSERVATION OR COMMODITY PROGRAMS: TRADE OFFS DURING THE TRANSITION TO DRYLAND CROP PRODUCTION

Predicted crop yields and wind erosion rates from a multi-year/multi-crop growth simulation model provided input into a multi-period recursive QP model to evaluate erosion implications during the transition to dryland crop production on the Texas Southern High Plains. Three farm-program participation options were considered in this study. Participation in an extension of the current farm program resulted in an increase in net returns and wind erosion rates above nonparticipation. Imposition of a soil loss limit without consideration of a flexible base option can significantly reduce discounted present values. Increasing risk aversion across producers affects crop mix selection which can result in lower per acre wind erosion rates for this particular region.Crop Production/Industries,