Introduction to Measurement with Theory.

This paper is the introduction to the forthcoming Macroeconomic Dynamics Special Issue on Measurement with Theory. The Guest Editors of the special issue are William A. Barnett, W. Erwin Diewert, Shigeru Iwata, and Arnold Zellner. The authors of this detailed introduction and commentary are William A. Barnett, W. Erwin Diewert, and Arnold Zellner. The included papers are part of a larger initiative to promote measurement with theory in economics.Measurement; index number theory; aggregation theory.

Population Update, Report Number 3

There is more to population study than merely knowing how many people live in a geographical location. Two of the most important other aspects of demography are the age and sex composition of a population. Should planners be thinking about adding space to a grammar school or to a retirement center? By studying age and sex compositions, they will make more accurate decisions. The distribution of a population by age and sex is often shown in a pyramid. The bars in the pyramid (see inside) represent age groups spaced at 5-year intervals. The pyramid is also divided in the middle, with the males at the left and the females at the right. State pyramids for 1960, 1970, and 1975 point up interesting trends. One of the most significant is a lowered birth rate. Thus, the base of the pyramid reflecting the children is shrinking. Statewide services required for the very young may not need expansion. On the other hand, those born around 1960, when the birth rate was higher, are now young adults and form an exaggerated proportion of the state\u27s population. Jobs and higher education are their major concerns. Should we build more colleges and technical schools to accommodate these young people? Look at the age structure at the bottom of the pyramid. In 10 years who is going to fill those schools? Perhaps educators should think in terms of temporary measures to alleviate present difficulties- extension courses, night classes, and the like. Population ratios and indexes like those under the detailed state totals can also be useful. Although pyramids are not portrayed, indexes and ratios as described below are provided for each county

Population Update, Report Number 2

It might be suggested that economics are important in a reverse sort of way. No longer can urban centers offer economic opportunity to potential rural outmigrants, and these people are simply staying at home. Between 1960 and 1970, 53 of South Dakota\u27s 67 counties were losing population. At an extreme, Stanley County dropped 40%; Fall River 30%; and Clark, Harding and Jackson lost nearly one fourth of their inhabitants. In the next 5 years (1970-1975) these same counties had not only stopped losing, but were actually gaining population. While only 14 counties gained population between 1960 and 1970, 38 showed gains between 1970 and 1975. Of the 29 counties still losing population, 19 lost a smaller percentage from 1970 to 1975 than in the decade from 1960 to 1970. Only two counties that gained population between 1960 and 1970 (Yankton and Lawrence) lost population between 1970 and 1975

Introduction to Measurement with Theory

This working paper is the first draft of an overview and commentary on the papers to appear in a Macroeconomic Dynamics Special Issue on Measurement with Theory. The included papers in the special issue are part of a larger initiative to promote "measurement with theory" in economics and planned to appear as special issues of other journals. A later revised draft of this initial commentary is planned to appear as the introduction to the Macroeconomic Dynamics special issue, expected to appear in 2010.Measurement; index number theory; aggregation theory.

Supplementary report on antilock analyses

Generic modulator analysis was performed to quantify the effects of dump and reapply pressure rates on antilock stability and performance. Analysis will include dump and reapply rates, and lumped modulator delay. Based on the results of the generic modulator analysis and earlier toggle optimization analysis (with Mitsubishi modulator), a recommended preliminary antilock design was synthesized and its response and performance simulated. The results of these analyses are documented

Autonomous RPRV Navigation, Guidance and Control

Dryden Flight Research Center has the responsibility for flight testing of advanced remotely piloted research vehicles (RPRV) to explore highly maneuverable aircraft technology, and to test advanced structural concepts, and related aeronautical technologies which can yield important research results with significant cost benefits. The primary purpose is to provide the preliminary design of an upgraded automatic approach and landing control system and flight director display to improve landing performance and reduce pilot workload. A secondary purpose is to determine the feasibility of an onboard autonomous navigation, orbit, and landing capability for safe vehicle recovery in the event of loss of telemetry uplink communication with the vehicles. The current RPRV approach and landing method, the proposed automatic and manual approach and autoland system, and an autonomous navigation, orbit, and landing system concept which is based on existing operational technology are described

40Ar/39Ar ages of lunar impact glasses: Relationships among Ar diffusivity, chemical composition, shape, and size

Lunar impact glasses, which are quenched melts produced during cratering events on the Moon, have the potential to providenot only compositional information about both the local and regional geology of the Moon but also information about the impact flux over time. We present in this paper the results of 73 new 40Ar/39Ar analyses of well-characterized, inclusion-free lunar impact glasses and demonstrate that size, shape, chemical composition, fraction of radiogenic 40Ar retained, and cosmic ray exposure (CRE) ages are important for 40Ar/39Ar investigations of these samples. Specifically, analyses of lunar impact glasses from the Apollo 14, 16, and 17 landing sites indicate that retention of radiogenic 40Ar is a strong function of post-formation thermal history in the lunar regolith, size, and chemical composition. This is because the Ar diffusion coefficient (at a constant temperature) is estimated to decrease by 3–4 orders of magnitude with an increasing fraction of non-bridging oxygens, X(NBO), over the compositional range of most lunar impact glasses with compositions from feldspathic to basaltic. Based on these relationships, lunar impact glasses with compositions and sizes sufficient to have retained 90% of their radiogenic Ar during 750 Ma of cosmic ray exposure at time-integrated temperatures of up to 290 K have been identified and are likely to have yielded reliable 40Ar/39Ar ages of formation. Additionally, 50% of the identified impact glass spheres have formation ages of 6500 Ma, while 75% of the identified lunar impact glass shards and spheres have ages of formation 62000 Ma. Higher thermal stresses in lunar impact glasses quenched from hyperliquidus temperatures are considered the likely cause of poor survival of impact glass spheres, as well as the decreasing frequency of lunar impact glasses in general with increasing age. The observed age-frequency distribution of lunar impact glasses may reflect two processes: (i) diminished preservation due to spontaneous shattering with age; and (ii) preservation of a remnant population of impact glasses from the tail end of the terminal lunar bombardment having 40Ar/39Ar ages up to 3800 Ma. A protocol is described for selecting and analyzing lunar impact glasses

40Ar/39Ar ages of lunar impact glasses: Relationships among Ar diffusivity, chemical composition, shape, and size

Lunar impact glasses, quenched melts produced during cratering events on the Moon, have the potential to provide not only compositional information about both the local and regional geology of the Moon but also information about the impact flux over time. We present in this paper the results of 73 new 40Ar/39Ar analyses of well-characterized, inclusion-free lunar impact glasses and demonstrate that size, shape, chemical composition, fraction of radiogenic 40Ar retained, and cosmic ray exposure (CRE) ages are important for 40Ar/39Ar investigations of these samples. Specifically, analyses of lunar impact glasses from the Apollo 14, 16, and 17 landing sites indicate that retention of radiogenic 40Ar is a strong function of post-formation thermal history in the lunar regolith, size, and chemical composition. Based on the relationships presented in this paper, lunar impact glasses with compositions and sizes sufficient to have retained 90% of their radiogenic Ar during 750 Ma of cosmic ray exposure at time-integrated temperatures of up to 290 K have been identified and are likely to have yielded reliable 40Ar/39Ar ages of formation. Additionally, ~50% of the identified impact glass spheres have formation ages of <500 Ma, while ~75% of the identified lunar impact glass shards and spheres have ages of formation <2000 Ma. The observed age-frequency distribution of lunar impact glasses may reflect two processes: (i) diminished preservation due to spontaneous shattering with age; and (ii) preservation of a remnant population of impact glasses from the tail end of the terminal lunar bombardment having 40Ar/39Ar ages up to 3800 Ma. A protocol is described for selecting and analyzing lunar impact glasses.Comment: Please contact Zellner ([email protected]) for data tables and other supplemental informatio