Knowledge modeling for software design

This paper develops a modeling framework for systems engineering that encompasses systems modeling, task modeling, and knowledge modeling, and allows knowledge engineering and software engineering to be seen as part of a unified developmental process. This framework is used to evaluate what novel contributions the 'knowledge engineering' paradigm has made and how these impact software engineering

The effects of the geosynchronous energetic particle radiation environment on spacecraft charging phenomena

The energetic electron environment at the geosynchronous orbit is responsible for a variety of adverse charging effects on spacecraft components. The most serious of these is the degradation and failure of a complementary-metal-oxide-semiconductor (CMOS) electronic components as a result of internal charge-buildup induced by the energetic electrons. Efforts to accurately determine the expected lifetime of these components in this orbit are hampered by the lack of detailed knowledge of the electron spectrum and intensity, particularly of the more penetrating energies greater than 1.5 MeV. This problem is illustrated through the calculation of the dose received by a CMOS device from the energetic electrons and associated bremsstrahlung as a function of aluminum shielding thickness using the NASA AE-6 and the Aerospace measured electron environments. Two computational codes which were found to be in good agreement were used to perform the calculations. For a given shielding thickness the dose received with the two radiation environments differ by as much as a factor of seven with a corresponding variation in lifetime of the CMOS

New England Cod Collapse and the Climate.

To improve fishery management, there is an increasing need to understand the long-term consequences of natural and anthropogenic climate variability for ecological systems. New England's iconic cod populations have been in decline for several decades and have recently reached unprecedented lows. We find that 17% of the overall decline in Gulf of Maine cod biomass since 1980 can be attributed to positive phases of the North Atlantic Oscillation (NAO). This is a consequence of three results: i) a 1-unit increase in the NAO winter index is associated with a 17% decrease in the spring biomass of age-1 cod the following year; ii) this NAO-driven decrease persists as the affected cohort matures; iii) fishing practices appear to exacerbate NAO's direct biological effect such that, since 1913, a 1-unit increase in the NAO index lowers subsequent cod catch for up to 19 years. The Georges Bank cod stock displays similar patterns. Because we statistically detect a delay between the NAO and subsequent declines in adult biomass, our findings imply that observed current NAO conditions can be used in stock forecasts, providing lead time for adaptive policy. More broadly, our approach can inform forecasting efforts for other fish populations strongly affected by natural and anthropogenic climatic variation

Letter, 1937-03-20, Lloyd Gaines to George L. Gaines; Financial account of money Lloyd owes George for helping with education expenses.

No envelope. 2 page note on 3x6 paper, black ink. Addressed from 1017 1/2 East Catherine, Ann Arbor, Michigan, March 20, 1937. Financial account of money Lloyd owes George for helping with education expenses

Letter, 1936-01-08, Lloyd Gaines to George L. Gaines; Account of money owed brother.

No envelope and frayed; paper is yellowing. Addressed from 3932 W. Belle Place, St. Louis, Missouri, January 18, 1936. Account of money owed brother

Letter, 1935-02-13,Lloyd Gaines to George L. Gaines; Discusses Lloyd\u27s financial situation and need for money for school at Lincoln University.

No envelope. 1 page note on 3x6 index card, blue ink. Misc. notes on back of card. Addressed from Lincoln University, Feb. 13th, 1935. Discusses Lloyd\u27s financial situation and need for money for school at Lincoln University

Letter, 1936-10-27, Lloyd Gaines to George L. Gaines; Letter discusses financial needs.

No envelope. 4 page letter on monogrammed stationery. Addressed from 1017 1/2 E. Catherine, Ann Arbor, Michigan, Oct. 27th, 1936. Letter discusses financial needs

Letter, 1937-06-14,Lloyd Gaines to George L. Gaines; Discusses work prospects after master\u27s degree is achieved.

Envelope: Postmarked June 14, 1937, BUFF an CHI W.D. R.P.O.Special Delivery. 1 cancelled 10 cent stamp and 3 cent stamp. Return address: LL Gaines, 1017 1/2 E. Catherine, Ann Arbor, Mich. Addressed to: Mr. Geo D. Gaines, 3932 W. Belle Place, St. Louis, Missouri. Letter, 3 page letter with accompanying newspaper article. Discusses work prospects after master\u27s degree is achieved

Letter, 1933-12-15, George L. Gaines to Lloyd Gaines; Discusses family life and health.

No envelope. Addressed from 3632 W. Belle Pl., St. Louis, 9110, Dec. 15, 1933. 2 page letter on American Royal De luxe Burlington Flyer stationery. Discusses family life and health