Unifying Requirements and Code: an Example

Requirements and code, in conventional software engineering wisdom, belong to entirely different worlds. Is it possible to unify these two worlds? A unified framework could help make software easier to change and reuse. To explore the feasibility of such an approach, the case study reported here takes a classic example from the requirements engineering literature and describes it using a programming language framework to express both domain and machine properties. The paper describes the solution, discusses its benefits and limitations, and assesses its scalability.Comment: 13 pages; 7 figures; to appear in Ershov Informatics Conference, PSI, Kazan, Russia (LNCS), 201

Increased Metabolic Rate in X-linked Hypophosphatemic Mice

Hyp mice are a model for human X-linked hypophosphatemia, the most common form of vitamin D-resistant rickets. It has previously been observed that Hyp mice have a greater food consumption per gram body weight than do normal mice. This led to the search for some alteration in metabolism in Hyp mice. We found that oxygen consumption was significantly higher in Hyp mice than in normal C57BL/6J mice and this was accompanied by an increased percentage of cardiac output being delivered to organs of heat production (liver and skeletal muscle), to the skin, and to bone and a decreased percentage to the gastrointestinal tract of Hyp mice. The increased oxygen consumption in Hyp mice was not associated with increased plasma free T4 levels and was not affected by alterations in plasma phosphate produced by a low phosphate diet. The cause of the increased oxygen consumption is not known, and the role that this change and reported changes in distribution of cardiac output may play in the development of X-linked hypophosphatemia is also unknown. Study of the cardiovascular and thermoregulatory systems in Hyp mice should help increase understanding of the underlying mechanisms of this disease

On the existence of Liapunov functions for the problem of Lurie

Control theory and matrix analysis for existence of Liapunov functions for problem of Luri

A note on contact transformations

Contact transformation

Liapunov functions for the problem of Lurie

Popov criteria for asymptotic stability of Lurie system of differential equations and Liapunov function

Energy functions for Morse Smale system

Construction of energy functions for Morse system of vector fields on manifol

Periodic points of diffeomorphisms

Fixed points of diffeomorphism class of Smale and exponential functio

Normal mode analysis of the IUS/TDRS payload in a payload canister/transporter environment

Special modeling techniques were developed to simulate an accurate mathematical model of the transporter/canister/payload system during ground transport of the Inertial Upper Stage/Tracking and Data Relay Satellite (IUS/TDRS) payload. The three finite element models - the transporter, the canister, and the IUS/TDRS payload - were merged into one model and used along with the NASTRAN normal mode analysis. Deficiencies were found in the NASTRAN program that make a total analysis using modal transient response impractical. It was also discovered that inaccuracies may exist for NASTRAN rigid body modes on large models when Given's method for eigenvalue extraction is employed. The deficiencies as well as recommendations for improving the NASTRAN program are discussed

Data Estimation and Interpretation: An Analysis.

There is an ostensible relationship between whether or not a nation is developed and the interpretation and collection of data in this nation. For instance, if a country is developing, it is difficult to collect figures, though much simpler to interpret them. The opposite is the case in a developed nation: the gathering of data is undemanding, however, the explanation for this data is difficult. Such a relationship has a quite pressing effect on economic performance, and this will be examined using a model assuming Rational Expectations, Adaptive Expectations and certain postulates of Price Theory.Economic Data; Price Theory; Rational Expectations; Adaptive Expectations