Demography in a new key

The widespread opinion that demography is lacking in theory is based in part on a particular view of the nature of scientific theory, generally known as logical empiricism [or positivism]. A newer school of philosophy of science, the model-based view, provides a different perspective on demography, one that enhances its status as a scientific discipline. From this perspective, much of formal demography can be seen as a collection of substantive models of population dynamics [how populations and cohorts behave], in short, theoretical knowledge. And many theories in behavioural demography - often discarded as too old or too simplistic - can be seen as perfectly good scientific theory, useful for many purposes, although often in need of more rigorous statement.demographic models, demographic theory, methodology, philosophy of science, population theory, the structure of demographic knowledge

Bounded LTL Model Checking with Stable Models

In this paper bounded model checking of asynchronous concurrent systems is introduced as a promising application area for answer set programming. As the model of asynchronous systems a generalisation of communicating automata, 1-safe Petri nets, are used. It is shown how a 1-safe Petri net and a requirement on the behaviour of the net can be translated into a logic program such that the bounded model checking problem for the net can be solved by computing stable models of the corresponding program. The use of the stable model semantics leads to compact encodings of bounded reachability and deadlock detection tasks as well as the more general problem of bounded model checking of linear temporal logic. Correctness proofs of the devised translations are given, and some experimental results using the translation and the Smodels system are presented.Comment: 32 pages, to appear in Theory and Practice of Logic Programmin

Computer Modelling of Theory: Explanation for the 21st Century

Abstract not availabl

Fertility Decline: Toward a Synthetic Model

Abstract not availabl

Teaching the Fundamentals of Demography: A Models-Based Approach to Family and Fertility

Abstract not availabl

Explaining Human Fertility: One Theory or Many Theories?

Abstract not availabl

Something Ventured: Something Gained: Progress Toward a Unified Theory of Fertility Decline

Abstract not availabl

Error in Demographic and Other Quantitative Data and Analyses

This paper is about errors in statistical data. My remarks are in two parts. The first part deals with the proposition that the statistical data we consume, analyse and produce contain more error from more sources than we sometimes recognise. The second asks: How can we better deal with these errors? The topic of error in statistics can become highly technical, but for the most part this is not a technical presentation. It deals with common sense and experience; much of it is anecdotal

Apparatus for assembling space structure

An apparatus for producing a structure in outer space from rolls of prepunched ribbon or sheet material that are transported from the earth to the apparatus located in outer space is described. The apparatus spins the space structure similar to a spider spinning a web utilizing the prepunched ribbon material. The prepunched ribbon material is fed through the apparatus and is shaped into a predetermined channel-shaped configuration. Trusses are punched out of the ribbon and are bent downwardly and attached to a track which normally is a previously laid sheet of material. The size of the overall space structure may be increased by merely attaching an additional roll of sheet material to the apparatus