45,783 research outputs found
Some aspects of the cenozoic geology of the Moawhango River region, in the Army training area in Waiouru, North Island, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Quaternary Geology at Massey University
Late Tertiary marine strata of the Waiouru Formation were unconformably deposited on a dissected Late Cretaceous peneplain surface of unusually high relief formed on Torlesse Supergroup greywacke at Waiouru. Central North Island, New Zealand. Waiouru is uniquely located on the southern boundary of the Taupo Volcanic Zone and the northern margin of the Wanganui Basin, an infilled Pliocene basin now subject to Plio-Pleistocene uplift. Two transgressive episodes are identified. The first involved submergence of the peneplain in the Neogene, when Kapitean mudstone was deposited. Then a general marine shallowing occurred around the New Zealand landmass which saw uplift of Waiouru towards the end of the Kapitean Stage, followed by a period of sub-aerial erosion. The second transgressive episode was initiated by subsidence of the Wanganui Basin in the Pliocene, which led to onlap of coarse shallow-water sandstones during the Opoitian Stage. Basement subsidence tended to result in vertical rather than horizontal migration of the shoreline. No evidence has been found for previously recognised eustatic sealevel cycles, due possibly to masking by strong tidal conditions throughout the Opoitian sequence; Waiouru being located on the northern edge of the Pliocene Kuripapango Strait. Eventually, shallow seas supported a faunal population sufficient to produce widespread carbonate skeletal fragments that formed extensive shell limestone beds at the top of the Waiouru Formation. Rapid lateral and vertical changes in the facies are interpreted as due to rapidly changing local depositional conditions. These were caused by the submerging basement initially forming a steep coast with at least two offshore islands. Marine infilling occurred within former incised river valleys 3 km wide and over 300 m in depth. Erosion of local greywacke contributed to the Opoitian sedimentation, as did a granitic source, probably in North-west Nelson, with materials transported from this latter source by currents propagating through the Kuripapango Strait. The presence of abundant granite-derived micas in Opoitian strata, yet their absence in the Kapitean strata provide a limiting age for the arrival of micas in Wanganui Basin strata. As the Wanganui Basin depocentre moved southwards, offlap and emergence occurred with Plio-Pleistocene uplift. The paleo-Moawhango River established its course in the newly uplifted strata, forming superimposed gorges where it cut into exposed basement. Except for initially deposited basal strata, dips in the Neogene marine strata are almost all uniformly consistent with the regional dip. Mapping of the shell limestone beds has shown post-Opoitian development of a small scale (<2 km wide) anticline and a minor associated fault. To the south of the study area, the Waipipian age Taihape Mudstone overlies the Waiouru Formation. The contact between the two is interpreted to be the Opoitian-Waipipian boundary and thus the Waiouru Formation was deposited within the Opoitian Stage
Measurement error in long-term retrospective recall surveys of earnings
Several recent studies in labour and population economics use retrospective surveys to substitute for the high cost and limited availability of longitudinal survey data. Although a single interview can obtain a lifetime history, inaccurate long-term recall could make such retrospective surveys a poor substitute for longitudinal surveys, especially if it induces non-classical error that makes conventional statistical corrections less effective. In this paper, we use the unique Panel Study of Income Dynamics Validation Study to assess the accuracy of long-term recall data. We find underreporting of transitory events. This recall error creates a non-classical measurement error problem. A limited cost-benefit analysis is also conducted, showing how savings from using a cheaper retrospective recall survey might be compared with the cost of applying the less accurate recall data to a specific policy objective such as designing transfers to reduce chronic poverty
How reliable are household expenditures as a proxy for permanent income? Implications for the income-nutrition relationship
Measurement error in short-run expenditures from household surveys may attenuate estimated effects of permanent income on economic outcomes. Repeated observations on households during the year are used to calculate reliability ratios and estimate errors in variables regressions of the impact of income on calorie intakes. In contrast to influential studies finding no effect of income, the results suggest significant nutritional responses to income in poor countries
Measurement error and the effect of inequality on experienced versus reported crime
This paper analyzes measurement errors in crime data to see how they impact econometric estimates, particularly of the key relationship between inequality and crime. Criminal victimization surveys of 140,000 respondents in 37 industrial, transition and developing countries are used. Comparing the crimes experienced by these respondents with those reported to the police, non-random and mean-reverting measurement errors are apparent. Some time-varying factors may also affect the propensity of victims to report crimes to the police, undermining the use of country-specific fixed effects as a means of dealing with measurement errors in official crime data. These measurement errors substantially attenuate both cross-sectional and panel estimates of the effect of inequality on crime
Decoding Reed-Muller codes over product sets
We give a polynomial time algorithm to decode multivariate polynomial codes
of degree up to half their minimum distance, when the evaluation points are
an arbitrary product set , for every . Previously known
algorithms can achieve this only if the set has some very special algebraic
structure, or if the degree is significantly smaller than . We also
give a near-linear time randomized algorithm, which is based on tools from
list-decoding, to decode these codes from nearly half their minimum distance,
provided .
Our result gives an -dimensional generalization of the well known decoding
algorithms for Reed-Solomon codes, and can be viewed as giving an algorithmic
version of the Schwartz-Zippel lemma.Comment: 25 pages, 0 figure
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