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71.
The need for experiments to study physical aspects of craft of the past is stated, as well as the necessity for them to have clear aims and to follow the established principles of scientific enquiry. These principles are discussed in this joint paper by ten maritime archaeologists and others, together with methods and some points of management critical to their application in this field.  相似文献   
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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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Abstract. In postcommunist politics many of the ‘new national right’ political formations in Eastern Europe and the former Soviet Union have joined forces with the communist successor parties. Such a combination is, on the surface, a baffling mixture; how is it possible that two fundamentally different ideological approaches (nationalism and internationalist socialism) can coexist and actively cooperate to form such a potent political force? What are the conditions under which such political cooperation emerges? This article attempts to answer the above questions by, first, empirically testing the effects of several factors which might explain postcommunist–nationalist political cooperation. Second, the quantitative analysis is buttressed with a comparison of the Hungarian and Russian cases. The analysis indicates that the most important variable associated with the emergence of postcommunist–nationalist political cooperation is the effect of previous regime type.  相似文献   
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We develop a new conceptual approach to locating inspection stations for hazardous vehicles, prevention, and compare it to the previous, punitive, philosophy of the flow-capturing location model. We implement this preventive protection philosophy with a new mixed integer program that maximizes hazard avoidance by locating a number of inspection stations to detect and remove hazardous vehicles as early in their trips as possible. We test the model's performance and analyze the spatial characteristics of solutions simulating several potential applications. Our computations demonstrate that a relaxed integer-linear program is overly demanding computationally and that a simple greedy heuristic lacks robustness. We suggest further approaches to developing more powerful and efficient solution methods.  相似文献   
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ABSTRACT. This paper uses new estimates of metropolitan factor demand and output supply functions to study how federal, state, and local fiscal policies affect metropolitan economies. We illustrate our work with findings for ten metropolitan areas in five states for changes in state corporate income taxes, local property taxes, the federal corporate income tax, an investment tax credit, interest rates, public capital stocks, output prices, and tax and regulatory policies affecting gross wages. It is clear from these simulations that a policy that is nominally the same everywhere will have repercussions that vary widely across regions and cities.  相似文献   
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This study examined landcover change during 1940–1988 in two contiguous landscapes of approximately 12,400 hectares in central Ohio, USA: an inertial till plain area and a more dynamic moraine area. Agriculture dominated both landscapes throughout, however, the cover of natural vegetation and urban-suburban development increased over time on the moraine while natural vegetation decreased and agriculture increased on the till plain. Markov process models for landcover change were constructed for three 14–17-year time intervals and for the entire forty-eight-year study period. Probabilities of self-replacement for agricultural lands (0.91–0.97) were higher and those for forests (0.54–0.65) lower than those reported for other landscapes. Predictions of landcover percentages for fifty years in the future were made using Markov process models derived from actual cover changes in 1940–1957, 1971–1988, and 1940–1988. All three models produced similar predictions for the inertial till plain area. In contrast, the three models' predictions differed considerably for the moraine area. Only the 1971–1988 transition matrix was sensitive to increases in urbanization and reforestation which began on the moraine in the 1970s. These results indicate that reliance on lengthy study intervals and net rates of change can obscure spatial and temporal patterns of landcover change that are caused by natural and socioeconomic factors operating on shorter time scales.  相似文献   
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ABSTRACT. In this paper a gravity model is formulated to model a hospital patient flow system. Both spatial and nonspatial measures of separation are used to estimate the model. Travel time was found to provide improved fits over linear distance in modeling patient flow behavior. Transformations of travel time (square root and log) were found to improve model performance further. Model diagnostics suggested additional spatial separation measurw, separation measure parameters demonstrated stability over time. The model is used to forecast the effects of health care financing reform and hospital closure on patient flows in an urban hospital market. Universal health coverage was found to dramatically improve access to hospital services for lower income patient populations. Hospitals at risk for closure were forecast to receive increased patient flows. Medical school hospitals are expected to lose patients after implementation of health reform, with important implications for graduate medical education. Hospital closures were shown to have negative effects on access to services in poor neighborhoods, but relatively little effect on access in the system as a whole.  相似文献   
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