Dating the Trollesgave site and the Bromme culture – chronological fix-points for the Lateglacial settlement of Southern Scandinavia

The Bromme culture belongs to the Lateglacial, the period when people settled in the recently deglaciated Southern Scandinavia. Until now there have been only a few imprecise fix-points relating to the chronological position of this archaeological culture. This situation can now be improved with the aid of research results from a Bromme culture settlement at Trollesgave in SE Denmark. Using pollen and plant macrofossil data, Lateglacial lacustrine deposits containing waste material from the settlement can be assigned to the end of the climatically mild Allerød period. A series of ¹⁴C dates establishes the age of the settlement as c. 10 826 ± 49 ¹⁴C years BP (12 871–12 590 cal yr BP). By correlation with climate data from the Greenland ice cores, the occupation can be assigned to the early part of the cold climatic zone GS-1, thus demonstrating that the global ice-core climate zones are not absolutely synchronous with the regional division into biozones.     

Toward Self-Sufficiency: Evaluating a Transitional Housing Program for Homeless Families

Homeless families face the economic and personal challenges of sparse employment opportunities and child care and nutrition needs, compounded by the loss of adequate housing. The Family Development Center (FDC) is a transitional housing program in Atlanta, Georgia, designed to provide young homeless mothers an opportunity to emerge from what may well be desperate circumstances and begin the journey to economic self-sufficiency. This paper describes the research on programs for homeless families and presents the results of a comprehensive look at the operation and effectiveness of the FDC program during its first 5 years of existence. The work shows that while many families were able to effect notable positive changes in their lives during and after taking part in the housing program, for some the recovery from homelessness was extremely difficult. For even the most successful formerly homeless families—those that secured employment, housing, and other social supports—the escape from welfare dependence and poverty proved very difficult. The paper concludes with a discussion of the implications for relevant public policy.     

Theory of Comparative Advantage: Do Transportation Costs Matter?

In this paper we present a formal analysis that incorporates returns to transportation into a Ricardian framework to predict trade patterns. The important point gained from this analysis is that increasing returns to transportation, coupled with appropriate distances between trading partners, can be shown to reverse Ricardian predictions even when there are no international differences in tastes, technology, or factor endowments. Additional gains from trade may emerge from reductions in aggregate delivery costs owing to scale economies.     

Der quantitative Beitrag der nach 1933 emigrierten Naturwissenschaftler zur deutschsprachigen physikalischen Forschung

By scientiometrically analyzing the physics-literature produced between 1925 and 1933 it is shown that the purely quantitative contribution of physicists subsequently emigrating from Germany to the literature produced by the physics community in this country was much lower than hitherto estimated. The actual figure is not in the range of 30%, as is generally assumed, but much nearer to 11%. Control analysis of three leading German physics journals and of memberships in the Deutsche Physikalische Gesellschaft confirms this result. Further investigation of university calendars shows that transferring these results to purely academic physics would amount to committing a “universalistic fallacy”. In academic physics emigré-physicists held a total of 15,5% of all teaching postitions. Differentiating the physics literature into various specialties allows further insights into the cognitive and social structure of the German physics community before 1933. Works of emigré-physicists are not randomly distributed over specialities; instead, the distribution reveals a nearly perfect correlation with what could be called “the specialty's paradigmatic age”. The spectrum begins with quantum theory, where future emigrants produced more than 25% of the literature, and fades away with acoustics, where their contribution amounts to less than 4%. The commonly accepted explanation of this phenomenon, which is based on the assumption that time of institutionalization of a specialty, “prestige” of that specialty, and entrance barriers for Jewish scientists are correlated, is falsified by two cases of non- or zero-correlation: by the very old specialties and by the technical disciplines. A new explanans is proposed which is based on the hypothesis of cognitive and social marginality being correlated and on a certain amount of cognitive marginality enhancing the disposition to innovative behavior and creativity.     

ARTIFICIAL NEURAL NETWORKS: A NEW APPROACH TO MODELING INTERREGIONAL TELECOMMUNICATION FLOWS*

ABSTRACT. During the last thirty years there has been much research effort in regional science devoted to modeling interactions over geographic space. Theoretical approaches for studying these phenomena have been modified considerably. This paper suggests a new modeling approach, based upon a general nested sigmoid neural network model. Its feasibility is illustrated in the context of modeling interregional telecommunication traffic in Austria, and its performance is evaluated in comparison with the classical regression approach of the gravity type. The application of this neural network approach may be viewed as a three-stage process. The first stage refers to the identification of an appropriate network from the family of two-layered feedforward networks with 3 input nodes, one layer of (sigmoidal) intermediate nodes and one (sigmoidal) output node (logistic activation function). There is no general procedure to address this problem. We solved this issue experimentally. The input-output dimensions have been chosen in order to make the comparison with the gravity model as close as possible. The second stage involves the estimation of the network parameters of the selected neural network model. This is performed via the adaptive setting of the network parameters (training, estimation) by means of the application of a least mean squared error goal and the error back propagating technique, a recursive learning procedure using a gradient search to minimize the error goal. Particular emphasis is laid on the sensitivity of the network performance to the choice of the initial network parameters, as well as on the problem of overfitting. The final stage of applying the neural network approach refers to the testing of the interregional teletraffic flows predicted. Prediction quality is analyzed by means of two performance measures, average relative variance and the coefficient of determination, as well as by the use of residual analysis. The analysis shows that the neural network model approach outperforms the classical regression approach to modeling telecommunication traffic in Austria.     

The Geography of Knowledge Spillovers Between High-Technology Firms in Europe: Evidence from a Spatial Interaction Modeling Perspective

The focus in this article is on knowledge spillovers between high-technology firms in Europe, as captured by patent citations. The European coverage is given by patent applications at the European Patent Office that are assigned to high-technology firms located in the EU-25 member states (except Cyprus and Malta), the two accession countries Bulgaria and Romania, and Norway and Switzerland. By following the paper trail left by citations between these high-technology patents we adopt a Poisson spatial interaction modeling perspective to identify and measure spatial separation effects to interregional knowledge spillovers. In doing so we control for technological proximity between the regions, as geographical distance could be just proxying for technological proximity. The study produces prima facie evidence that geography matters. First, geographical distance has a significant impact on knowledge spillovers, and this effect is substantial. Second, national border effects are important and dominate geographical distance effects. Knowledge flows within European countries more easily than across. Not only geography, but also technological proximity matters. Interregional knowledge flows are industry specific and occur most often between regions located close to each other in technological space.     

Überlieferungs- und Verständnisprobleme im medizinischen Latein des frühen Mittelalters

In most instances, knowledge is passed on through the medium of language. The author tries to demonstrate to what extent the Latin present in early medieval Latin medical treatises failed to fulfill its role as an efficient medium of communication, which factors may account for this failure and how scholars in the middle ages strove to restore sense in texts in various stages of corruption, an attempt that was bound to be unsuccessful in many cases owing to a lack of reliable dictionaries.