Photograph used for a story in the Daily Oklahoman newspaper. Caption: "While Debbie White, a Jimmy Carter worker, attempts to rally supporters of the president."

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Those green and white tags beginning to appear on the rear bumpers of cars across the state herald the final phase of Oklahoma five-year tag system."

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Simple blue and white auto tags, top, are giving away to a new green and white five-year-version, bottom which bears an 'Oklahoma is OK' legend and a small state map."

A set of first-order differential state equations is developed from taking finite differences of the partial differential equation that describes groundwater flow during a pump-drawdown test. The number of states in the model is a direct function of the number of discrete spatial segments used in the approximate model. This number of states is studied to determine a reasonably low-order model that preserves the accuracy of resulting simulations when compared with an available analytical solution. The resulting reduced-order model is then used in an extended Kalman filter for combined state and parameter estimation. This report summarizes work done in a recent pilot study to demonstrate the feasibility of these techniques in groundwater research and points the way toward other approaches to this problem area now under study.

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.

Daily newspaper from Stephenville, Texas that includes local, state, and national news along with advertising.

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Gov. George Nigh is greeted with a kiss from Lynn Pounian, Carters's deputy state coordinator."

Photograph used for a newspaper owned by the Oklahoma Publishing Company. Caption: "Stafford, Verna Rae"

Photograph used for a newspaper owned by the Oklahoma Publishing Company. Caption: "Stafford, Verna Rae"

Photograph used for a newspaper owned by the Oklahoma Publishing Company. Caption: "Stafford, Verna Rae"

Photograph used for a story in the Oklahoma Times newspaper. Caption: "Verna Stafford leaves courtroom after receiving two second-degree murder terms Tuesday night."

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Verna Stafford, wife of convicted mass murderer Roger Dale Stafford, was given two concurrent sentences of 10 years to life in prison Tuesday night after pleading guilty to two counts of second-degree murder."

Video footage from the NBC 5/KXAS station in Fort Worth, Texas, to accompany a news story about educating the children of undocumented immigrants in Tyler, Texas. This story was produced for the 6:00 P.M. news broadcast.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

B-roll video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.