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51.
Discriminant analyses of distances and angles obtained from 25 coins struck by P. Crepusius in 82 BC permitted the correct chronology for five groups of closely-related dies to be obtained by the method of Carter and Frurip. Twenty distances and 15 angles were measured on 10 x projections of the coins which represented five groups of dies separated in time from each other. The use of all or many variables gave poorer results than the use of five to ten variables having a high ‘figure of merit’, defined as the maximum range of mean values for a given variable in the five groups of dies divided by the mean standard deviation of the variable in the five groups. It is recommended that chronologies of ancient coins be determined from Mahalanobis distances by using only variables of relatively high figure of merit.  相似文献   
52.
The conventional model of the relationship between welfare incentives and poverty rates holds that welfare payments produce an income-enhancement effect that removes families from poverty until some threshold. Beyond this point increased payments engender a work-disincentive effect resulting in increased rates of poverty. We challenge the model's assumption that poverty levels are a simple and spatially invariant response to welfare incentives, contending instead that local employment conditions may substantially alter the relation. Our reformulation of the conventional modeling approach is based on the expansion method. Specifically, we extend the model to include the effects of local labor-market conditions on the response of poverty levels to welfare incentives. In contesting the invariance assumption, the expansion method allows us to determine where and in what contexts welfare is “work discouraging.” The empirical analysis, which is undertaken at the county level, indicates that welfare payments vary in their influence on poverty rates across different employment contexts. A national map portraying this parameter instability demonstrates that female-family poverty rates are most responsive to welfare assistance in the rural South and least responsive in the metropolitan Northeast. Finally, we examine two sharply contrasting locales to illustrate how poverty is governed by specific employment and welfare characteristics.  相似文献   
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This paper demonstrates that the morphology of ordinary rural roads tells much about regional development. It uses southern Ontario as a case study, but the principles may be applied widely. It is a plea for recognition of a deep heritage in unspectacular things: ditches, fence-lines, culverts, jogs in the survey, and more. This paper also encourages local and regional planners to conserve signs of change in the roadscape and to celebrate them. Roadside evolution is worth publicizing, and unnecessary destruction of elements that enhance the story must be discouraged.
Cet essai démontre que la morphologie des routes rurales ordinaires en dit beaucoup au sujet du développement regional. On peut employer cet exemple de /'Ontario du sud mais les principes peuvent s'appliquer d'une manière plus large. Dans ce manuscrit on doit reconnaître /'heritage profond des elements communs: des caniveaux, des clotures, des aqueducs, des irrégularity de I'arpentage, etc. Cet essai encourage aussi les planificateurs i conserver ces signes du paysage routier et à les mettre en Évidence. On doit les faire connaître au public, et décourager leur déstruction.  相似文献   
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A trial, monitored release on the Wingecarribee River over 27 days had a peak discharge below the Wingecarribee Dam of 1090 ML/d, which had a flow duration of 0.95 per cent. Morphological impacts on 29 km of channel below the dam included bank erosion, concentrated neck overflow, bed degradation and channel widening at recent cutoffs, sedimentation in weir pools and overbank flow, particularly at discharges greater than 800 ML/d. Prolonged operational releases at bankfull discharge (400–800 ML/d) will have the greatest morphologic impacts and should be avoided. Pulses which dissipate stream power over a broad, well-vegetated floodplain should be incorporated in the operational release policy, provided such pulses are phased to facilitate channel and vegetation recovery.  相似文献   
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The Early Historic Period in the Mun Valley occupies a critical three centuries, from A.D. 500 to A.D. 800, a period often known as that of Zhenla, a name derived from early Chinese accounts. This article first describes early findings of fieldwork designed to illuminate the prehistory of the upper Mun Valley, a period which covers approximately two millennia, with initial settlement now dated between 1500 and 1000 B.C. It then considers the nature of the transition to the complex polities of Zhenla. This involves a combination of archaeological and documentary evidence. Sources for the latter are rare for the Mun Valley, but by broadening the area considered, it is possible to integrate archaeological and historical sources in order to portray the intensifying social changes which characterize the Early Historic Period. It is suggested that most of the Mun Valley was occupied by Khmer speakers during the Iron Age, people responsible for the transition to increasingly centralized polities of the Early Historic Period. In the upper reaches of the Mun catchment, and in the Chi Valley to the north, the late prehistoric inhabitants spoke Mon. They had close affinities with the Dvaravati polities of Central Thailand. If confirmed, this hypothesis would indicate a series of local trends towards increasing social complexity which we can recognize in the early epigraphic record.  相似文献   
59.
Cultural resource management (CRM) work accounts for most of the archaeology conducted in the United States. A diverse and somewhat fragmented field, CRM has nonetheless achieved a degree of institutional and organizational maturity. CRM archaeology has produced important contributions to archaeological methodology and has established and refined knowledge of regional cultural-historical sequences and settlement and subsistence patterns. The current florescence of historical archaeology is attributable to CRM. Yet the maintenance of high quality in CRM is a pervasive and enduring problem. Academic institutions need to reestablish alliances with the CRM community. The future viability of CRM archaeology depends on factors both internal and external to the discipline: regulatory and statutory “reform,” agency funding levels, looting and other destructive forces, and Native American and other public involvement.  相似文献   
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