8,550 research outputs found
External Forces That Impact Profitability in the Insurance Industry
The insurance industry is influenced by many factors that impact profitability. Insurers must do their best to make predictions based on expectations to remain solvent and profitable. Inevitably, they are faced with external factors that are outside of their control. Insurers must be aware of these external forces that may impact profits. External forces impact entire sub-industries of the insurance industry and some companies maintain profitability while others fail. This work intends to take a look at the major external forces that each insurance sub-industry faces and discuss some of the potential solutions that have been developed to minimize the negative impact of these forces, if applicable
Modeling and Control of a Flexible Structure Incorporating Inertial Slip-Stick Actuators
Shape and vibration control of a linear flexible structure by means of a new type of inertial slip-stick actuator are investigated. A nonlinear model representing the interaction between the structure and a six-degree-of-freedom Stewart platform system containing six actuators is derived, and closed-loop stability and performance of the controlled systems are investigated. A linearized model is also derived for design purposes. Quasistatic alignment of a payload attached to the platform is solved simply by using a proportional controller based on a linear kinematic model. The stability of this controller is examined using a dynamic model of the complete system and is validated experimentally by introducing random thermal elongations of several structural members. Vibration control is solved using an Hâ loop-shaping controller and, although its performance is found to be less satisfactory than desired, the nonlinear model gives good predictions of the performance and stability of the closed-loop system
Folding Large Antenna Tape Spring
This paper presents a novel concept for a low-mass, 50-m^2-deployable, P-band dual polarization antenna that can measure terrestrial biomass levels from a spacecraft in a low Earth orbit. A monolithic array of feed and radiating patches is bonded to a transversally curved structure consisting of two Kevlar sheets. The first sheet supports the array and the other sheet supports a ground plane. The two sheets are connected by a compliant Kevlar core that allows the whole structure to be folded elastically and to spring back to its original, undamaged shape. Test pieces have been made to demonstrate both the radio frequency and mechanical aspects of the design, particularly the radio frequency performance before and after folding the structure. It is concluded that the proposed design concept has high potential for large, low-frequency antennas for low-cost missions
Sensorless position control of permanent magnet motors with pulsating current injection and compensation of motor end-effects
End effects in linear tubular motors and compensated position sensorless control based on pulsating voltage injection
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