1,883 research outputs found
The calculation of efficient high precision orbits by optimum matching of the formulation and numerical integrator
The development of improved computer algorithms is considered for calculating earth satellite orbital trajectories by optimum selection of the analytical method that minimizes the number of perturbative acceleration computations for a given accuracy. A variation of parameter algorithm considering the equation of motion for a satellite proved superior for the geosynchronous orbit
Flight Mechanics/Estimation Theory Symposium
The conference emphasizes orbital position estimation and trajectory calculation methods that consider flight mechanical parameters
Mathematical theory of the Goddard trajectory determination system
Basic mathematical formulations depict coordinate and time systems, perturbation models, orbital estimation techniques, observation models, and numerical integration methods
Goddard trajectory determination subsystem: Mathematical specifications
The mathematical specifications of the Goddard trajectory determination subsystem of the flight dynamics system are presented. These specifications include the mathematical description of the coordinate systems, dynamic and measurement model, numerical integration techniques, and statistical estimation concepts
Optimization of a Fast-Pick Area in a Cosmetics Distribution Center
Fast-pick areas are commonly used in order picking warehouses to improve labor efficiency by concentrating picking activities within a compact area, thus minimizing the distance traveled by the pickers. One problem that must be solved when a fast-pick area is to be implemented is the so-called assignment-allocation problem. This deals with deciding which products should be assigned to the fast-pick area, and how much space should be allocated to these products. This research was motivated by the picking operation of a cosmetics distribution center where several fast-pick areas are in place. A mixed integer linear programming formulation is proposed for solving the variant of the assignment-allocation problem found in this company. Our computational experiments show that the proposed model is efficient for solving small yet realistic instances of the problem
The motion of a satellite of the moon
Analytical solution for motion of lunar orbital satellit
Bifenthrin Baseline Susceptibility and Evaluation of Simulated Aerial Applications in \u3ci\u3eStriacosta albicosta\u3c/i\u3e (Lepidoptera: Noctuidae)
Striacosta albicosta (Smith) is a maize pest that has recently expanded its geographical range into the eastern United States and southeastern Canada. Aerial application of pyrethroids, such as bifenthrin, has been a major practice adopted to manage this pest. Reports of field failure of pyrethroids have increased since 2013. Striacosta albicosta populations were collected in 2016 and 2017 from maize fields in Nebraska, Kansas, and Canada and screened with bifenthrin active ingredient in larval contact dose-response bioassays. Resistance ratios estimated were generally low in 2016 (1.04- to 1.32-fold) with the highest LC50 in North Platte, NE (66.10 ng/cm2) and lowest in Scottsbluff, NE (50.10 ng/cm2). In 2017, O’Neill, NE showed the highest LC50 (100.66 ng/cm2) and Delhi, Canada exhibited the lowest (6.33 ng/cm2), resulting in a resistance ratio variation of 6.02- to 15.90-fold. Implications of bifenthrin resistance levels were further investigated by aerial application simulations. Experiments were conducted with a spray chamber where representative S. albicosta populations were exposed to labeled rates of a commercial bifenthrin formulation. Experiments resulted in 100% mortality for all populations, instars, insecticide rates, and carrier volumes, suggesting that levels of resistance estimated for bifenthrin active ingredient did not seem to impact the efficacy of the correspondent commercial product under controlled conditions. Results obtained from this research indicate that control failures reported in Nebraska could be associated with factors other than insecticide resistance, such as issues with the application technique, environmental conditions during and/or after application, or the insect’s natural behavior. Data generated will assist future S. albicosta resistance management programs
High-Temperature Monitoring of Refractory Wall Recession Using Frequency-modulated Continuous-wave (FM-CW) Radar Techniques
Furnaces are among the most crucial components in the glass and metallurgical industry. Nowadays, furnaces are being operated at higher temperatures and for longer periods of time thus increasing the rate of wear on the furnace refractory lining. Consequently, there is a great need for a nondestructive tool that can accurately measure refractory wall thickness at high temperatures. In this paper the utility of a frequency-modulated continuous-wave (FM-CW) radar is investigated for this purpose
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