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121.
ISSUES IN SPATIAL DATA ANALYSIS 总被引:2,自引:0,他引:2
Daniel P. McMillen 《Journal of regional science》2010,50(1):119-141
ABSTRACT. Misspecified functional forms tend to produce biased estimates and spatially correlated errors. Imposing less structure than standard spatial lag models while being more amenable to large datasets, nonparametric and semiparametric methods offer significant advantages for spatial modeling. Fixed effect estimators have significant advantages when spatial effects are constant within well-defined zones, but their flexibility can produce variable, inefficient estimates while failing to account adequately for smooth spatial trends. Though estimators that are designed to measure treatment effects can potentially control for unobserved variables while eliminating the need to specify a functional form, they may be biased if the variables are not constant within discrete zones. 相似文献
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Daniel J. Graham Patricia S. Melo Piyapong Jiwattanakulpaisarn Robert B. Noland 《Journal of regional science》2010,50(5):935-951
ABSTRACT The productivity effects of agglomeration economies are often treated as endogenous in empirical work due to the potential for reverse causality. The extent to which these relationships are actually simultaneously determined, however, remains largely unobserved. This paper estimates panel data vector autoregressions for different sectors of the economy to test for bidirectional causality between productivity and both localization and urbanization economies. The aim is to address some key questions that will help to identify the extent of the endogeneity problem. Can we actually observe bidirectionality in the data? Does it feature more for some industries than for others? Is it more prevalent for localization or urbanization economies? The results show that agglomeration economies are not strictly unidirectional and that higher levels of productivity can induce growth in the scale of local urban and industrial environments. The paper discusses the difficulties that these issues pose for the estimation of agglomeration economies. 相似文献
124.
Although sickle blades gloss is known to form during the harvest, which is a dynamic process and although it is known to be a type of wear which is the outcome of the repetitive encounters between the sickle blades working edges and plant stems; there is no common way to quantify its intensity. Since there is no consensus over a specific scale that will enable the estimation of the amount of wear, based on the quantification of gloss brightness intensity. In this paper we propose a new measurement system which is based on the projection of laser (He–Ne) beam on glossed sickle blades and an analysis of the reflected images. The results form a relative scale from which it is possible to infer on the sickle blades level of wear, and to create discard models. 相似文献
125.
Grey DJ 《20 century British history》2010,21(4):441-463
This article examines the reason for the passage of the 1922 Infanticide Act, arguing that it owes much to the influence and work of women's policy networks. Historians have disagreed as to why the Act was passed with relative suddenness in the early 1920s, at a time when infanticide was generally considered a much less pressing social issue than it had been in Victorian England. Moreover, several Bills brought between 1908 and 1913 proposing that the law on this subject be amended so that women who killed their newborns no longer faced the death penalty had all failed. Importantly, the roles of juror and lay magistrate had become open to women in 1920, following the passage of the Sex Disqualification (Removal) Act 1919. The public interest generated by a case of newborn murder tried at the Leicester Assizes in 1921 (particularly amongst women's organizations, including the suffragette group the Women's Freedom League) led several leading women with political connections to push for a change in the law. Without the pressure these women could bring to bear on civil servants and politicians, attempts to bring in new legislation on infanticide would have been postponed well into the twentieth century. 相似文献
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Daniel J. Wescott Kelly Brinsko Marina Faerman Stephanie D. Golda Jeff Nichols Mark Spigelman Bob Stewart Margaret Streeter Robert H. Tykot Ljuba Zamstein 《Archaeological and Anthropological Sciences》2010,2(4):283-305
In 2006 a cast-iron coffin was discovered in an unmarked burial plot in Lexington, Missouri. A multifaceted investigation
was conducted to provide historical documentation and possible identification of the individual. The coffin is an early Fisk
Patent Metallic Burial Case. Osteological analyses indicate that the skeletal remains belong to a 20 to 30 year old white
female who consistently ate an omnivorous diet with significant amounts of C4 plants or seafood. Rib morphology and her burial
garments suggest she frequently wore restrictive clothing. No gross skeletal pathological lesions or trauma were observed
except for a patch of reactive bone and an atypical pattern of bone remodeling on the visceral surface of the sixth rib. Subsequent
bacterial DNA analysis of the ribs and sternum indicate the presence of tuberculosis infection. Although not conclusive, multiple
lines of evidence are consistent with the skeletal remains representing Elizabeth (Triplett) Stewart who died in 1854 of pulmonary
tuberculosis. This multidisciplinary research significantly contributes to the local history of Lexington, Missouri and provides
a likely identification of the deceased individual for the Stewart Family. 相似文献
128.
深圳富士康工人的生活方式,某个程度是一种"疏离都市状态",社会互动机会匮乏。本文从人文地理学角度,探索怎样的结构过程,让深圳富士康工人产生了社会疏离?强调疏离都市状态与劳动过程及其地理空间性有深层关系,多重尺度形构的打工体制,对农民工社会网络发展产生压抑,减少阶层流动机会,加上在企业尺度上的劳动控制因素之交互作用,产生高流动率的工作转换,加剧工人在异地的疏离状态。面对持续的打工城市化现象,我们主张必须朝民工市民化、雇佣关系正规化的方向,推进户籍制度、劳动政策和都市政策三个面向的改革议程。 相似文献
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The landscape around the prehistoric Peruvian ceremonial center of Chavín de Huántar has undergone extensive geomorphic and anthropogenic change since the beginning of monumental construction at the site in approximately 1200 BCE. Archaeological and geomorphic stratigraphy from the site and its near periphery provide the data necessary to characterize these changes in detail. This paper reports on the use of GIS-based interpolation tools to approximate a complex prehistoric land surface using unevenly scattered point data. Such an interpolated surface serves as the basis for the reconstruction of the pre-Chavín landscape and assessment of landscape change contemporary with the site. 相似文献