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22.
Richard L. Francis Timothy J. Lowe Gerard Rushton M. Brenda Rayco 《Geographical analysis》1999,31(1):67-87
When solving a location problem using aggregated units to represent demand, it is well known that the process of aggregation introduces error. Research has focussed on individual components of error, with little work on identifying and controlling total error. We provide a focussed review of some of this literature and suggest a strategy for controlling total error. Consideration of alternative criteria for evaluating aggregation schemes shows that the method selected should be compatible with the objectives of the analyses in which it is used. Experiments are described that show that two different measures of error are related in a nonlinear way to the number of aggregate demand points (q), for any value of the number of facilities (p). We focus on the parameter q/p and show that it is critical for determining the expected severity of the error. Many practical implementations of location algorithms operate within the range of q/p where the rate of change of error with respect to q/p is highest. 相似文献
23.
Francis Ivanhoe Philip W Chu James A Bennyhoff 《International Journal of Osteoarchaeology》1998,8(3):135-179
A quantitative bioenvironmental study of cranioskeletal size has been made of a latitude-ordered sequence of 14 series of adult skeleton sets (N=305): the archaeological remains of aboriginal maritime peoples inhabiting the west coast of North America between southern California and the Arctic. Of eight osteometric parameters of cranioskeletal size developed, the most important are partial skeleton volume (PSK) and cranial capacity (CC); and the principal bone-affecting environmental factors are the northerly climate (CLIM2c), the reconstructed diet deficient in calcium and overabundant in animal foods and vitamin D (DIET3c), and demographic stress (DSg). Prior research has demonstrated that cranioskeletal size increases with geographical latitude and decreases under dietary calcioprivation and unphysiologically high birth rates. Upon linear multifactorial statistical analysis our main finding, limited to the Amerindian subsequence (n=11 series) from the Santa Barbara Channel, the San Francisco Bay Region and the Northwest Coast, is that PSK and CC vary in direct proportion to CLIM2c, and inversely with DIET3c and DSg. Controlling for the latter two osteoantitrophic factors, coastal Amerindian female PSK rises by 9% between 34 and 54°N latitude, CC by 5%; and the male incremental rates are somewhat higher, 13 and 10%, respectively. This newly discovered climate-dependent race cline, an example of Bergmann's Rule, is interpreted as factual evidence of a mid-Wisconsin or earlier arrival date for the first Palaeoindians. Cranioskeletal size of the very small (n=3 series) Western Eskimo subsequence approximates the northernmost values of the coastal Amerindian distribution. © 1998 John Wiley & Sons, Ltd. 相似文献
24.
Despite uniform geochemistry 40Ar/39Ar ages of 0.6, 1.25, and 1.3 Ma on obsidians from a source flow (Worja) and from archeological artifacts at the sites of Kulkuletti (near Gademotta, Ethiopia) have been interpreted to suggest that they derive from different source flows of different ages. A further suggestion is that the magmatic source of the obsidian flows was chemically homogeneous between 1.3 Ma and 0.6 Ma. Chemical analysis of these obsidians indeed suggests that they derive from a single flow. Reexamination of the argon isotopic data reveals that argon isotopes may have been fractionated within the flow, so that the assumption of an atmospheric 40Ar/36Ar ratio of 295.5 is inappropriate to use for computing ages. Three groups of data are apparent, and internally all yield ages near 1.3 Ma if the intercept value for 40Ar/36Ar from an isotope correlation plot is used for computation instead of using the atmospheric ratio. The Soret thermal diffusion effect provides a possible mechanism of fractionation of argon within the obsidian flow that is of approximately the right magnitude to explain the observations by in-diffusion of already fractionated atmospheric argon. 相似文献
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Alan A. Baumeister Jennifer L. Francis 《Journal of the history of the neurosciences》2013,22(3):265-277
This review examines the history of discoveries that contributed to development of the dopamine hypothesis of schizophrenia. The origin of the hypothesis is traced to the recognition that neuroleptic drugs interfere with brain dopamine function. This insight was derived from two distinct lines of research. The first line originated from the discovery in 1956 that reserpine depletes brain serotonin. This finding resulted in a sequence of studies that led to the discovery that brain dopamine is involved in neuroleptic-induced extrapyramidal motor disturbances. The second line of research was aimed at determining the mechanism of action of psychomotor stimulants. This research produced evidence that stimulants directly or indirectly activate brain dopamine receptors. Because nonreserpine neuroleptics such as chlorpromazine block stimulant-induced movement, these findings suggested that neuroleptics were dopamine antagonists. Most previous accounts of the development of the dopamine hypothesis of schizophrenia emphasize the first line of research and ignore the second. 相似文献
28.
AbstractUntil 1965 Holy Trinity parish church, Much Wenlock (Shropshire), was believed to be wholly Norman and later. In that year it was proposed that the south chancel chapel and south nave aisle were Anglo-Saxon. Two vertical strips of squared stones, built into the upper part (a later heightening) of the aisle's south wall, were interpreted as Anglo-Saxon pilaster strips of the type later classified by Dr H. M. Taylor as ‘long-and-short’. If the upper part of that wall was Anglo-Saxon, the lower part must have been earlier Anglo-Saxon, and so must the chapel south wall, which is integral with the lower part of the aisle wall. The Norman nave and chancel must have been added to an-existing Anglo-Saxon structure.We believe, however, that the aisle and chapel must have been added to an existing Norman structure, for the Norman nave had originally a south-east external clasping buttress. Structural and documentary evidence shows that the strips are probably of the later thirteenth or earlier fourteenth century. Moreover similar strips occur in another part of the church that is probably of that date or later. ‘Pilaster strips’ of ‘long-and-short’ appearance may evidently be looked for elsewhere in twelfth-century or later contexts, especially in the heightened parts of unsupported rubble walls. 相似文献
29.
G. P. B. Naish G. De G. Sieveking L. R. Muirhead k. Kidson Martin Robertson Francis H. W. Sheppard 《英国考古学会志》2013,166(1):125-129
AbstractIn the Lady chapel at the east end of the north aisle of the church at Pucklechurch (Gloucestershire) are two effigial monuments, which have received little scholarly attention. The monuments are attributed to William de Cheltenham (d. between 1371 and 1374) and his wife Eleanor, and were set up in his lifetime within the chantry chapel dedicated to St Mary which William received licence to establish at Pucklechurch in 1337. Little remains of the chapel except an exquisite altar frontal. During the 19th century the two effigies were transposed. Various aspects of the conception and design of the Pucklechurch monuments reflect developments in monumental sculpture in Herefordshire. 相似文献
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