Coda file system. [This definition is too vague; it suggests a broad topic but
not an approach to the topic.]
Protecting against temporary link failures in mobile computing: A design for the coda file system.
Engine starting and warm-up behavior.
Effects of fuel enrichment on engine starting and warm-up behavior.
Problem statements often have three elements:
These elements should be brief so that the reader does not get lost.
A recent trend in the design of new aircraft is the addition of winglets, which are small fins attached to the ends of the main wing. After an aircraft has taken off and is cruising, winglets improve its performance by reducing the drag caused by the main wing. However, during the critical stages of aircraft takeoff and landing, the winglets cause two problems. First, they cause vibrations in the main wing, commonly called buffeting. Second, they cause the aircraft to lose some control of yaw, the motion of the nose right and left. In a study funded by NASA [Ref. 2], the main wing of a DC-10 transport aircraft was outfitted with winglets, and it experienced significant buffeting during takeoff and landing.
[approach of the current research]
In our current project, we examine winglet-induced
buffeting in three wing designs. We record buffeting and yaw under experimental wind-tunnel
takeoff and landing conditions for (1) a wing without winglets, (2) another wing with conventional
winglets, and (3) a wing with spheroid winglets. Our objective is to determine the degree to which
differences between load lifts on the wings and their winglets during takeoff and landing are causing
the performance problems we have described.
[purpose and scope of current document]
In this study, we develop theoretical models of
winglet load lifts and compare these to the lifts of wings and winglets actually recorded during testing
--Tan T. Trinh, "Winglets at Takeoffs and Landings"