Spartan Daily, November 24, 1986

Volume 87, Issue 60https://scholarworks.sjsu.edu/spartandaily/7517/thumbnail.jp

Variational Downscaling, Fusion and Assimilation of Hydrometeorological States via Regularized Estimation

Improved estimation of hydrometeorological states from down-sampled observations and background model forecasts in a noisy environment, has been a subject of growing research in the past decades. Here, we introduce a unified framework that ties together the problems of downscaling, data fusion and data assimilation as ill-posed inverse problems. This framework seeks solutions beyond the classic least squares estimation paradigms by imposing proper regularization, which are constraints consistent with the degree of smoothness and probabilistic structure of the underlying state. We review relevant regularization methods in derivative space and extend classic formulations of the aforementioned problems with particular emphasis on hydrologic and atmospheric applications. Informed by the statistical characteristics of the state variable of interest, the central results of the paper suggest that proper regularization can lead to a more accurate and stable recovery of the true state and hence more skillful forecasts. In particular, using the Tikhonov and Huber regularization in the derivative space, the promise of the proposed framework is demonstrated in static downscaling and fusion of synthetic multi-sensor precipitation data, while a data assimilation numerical experiment is presented using the heat equation in a variational setting

Ordering policies in an environment of stochastic yields and substitutable demands

Includes bibliographical references.Partially supported by the Leaders for Manufacturing Program.Gabriel R. Bitran, Sriram Dasu

Incidence of bruising and dark firm dry beef in cattle carcasses in a commercial abattoir in Zimbabwe: an animal welfare concern

A reseach paper on the beef industry in Zimbabwe.The incidence of carcass bruising and occurrence of dark, firm, dry (DFD) beef in slaughter cattle were investigated from a survey of 9585 cattle delivered to a commercial abattoir. The objectives of the study were to evaluate the extent of occurrence of carcass bruising and DFD in slaughter cattle as these have a major impact on economic returns to the beef producer. In addition, these data can be used as indicators of either good or poor welfare of the animals prior to slaughter. In this study, the overall incidence of bruising was 29.6 percent while that of DFD was 27.4 percent. There were differences between the incidences of both bruising and DFD (p<0.001) in carcasses from bulls, steers and cows. Overall, bulls had the greatest carcass damage and steers the lowest. In addition, bruising increased (r = 0.97; p<0.05) and the incidence of DFD also increased (r = 0.94; p<0.05) with increasing transit distance. Linear regression analysis showed that a sixty kilometer increase in transit distance resulted in a seven percent increment in bruising (equation: y = 6.9 + 7.1 x; R2 = 0.96; p = 0.0047). However, there was no association between bruising and DFD. Among different carcass weights, there was considerable variation in frequency of occurrence of DFD (p<0.001), with the proportion of carcasses showing DFD decreasing as carcass weight increased. The results indicate substantial compromised animal welfare and major economic loss to the entire livestock industry. Further, the results suggest that transit distance appears to contribute substantially to causes of bruising and DFD in slaughter cattle in Zimbabwe

Preliminary study on the potential cost at slaughter of OJD vaccination site lesions to the Australian sheep industry.

This report presents the results of a pilot project to predict the risk of discounts being applied in Australia due to OJD vaccination site lesions as vaccine use expands. This includes a review of discounting in New Zealand as well as a preliminary survey of the prevalence of lesions and actual discounts applied to slaughtered vaccinates in Australia. Information from New Zealand suggests that the greatest discounts are applied to trimmed high value lamb carcases that are destined for export in whole carcase form as a result of downgrading to a lower quality grade. In Australia the greatest risk of discounting is likely to be in purebred merino lambs sold into the prime lamb market, but the low proportion exported as carcases would limit the discount applied. The prevalence of lesions observed was 18% for mutton and 65% for lamb carcases. The value of the trim removed was insignificant, the labour cost of its removal was nil and no carcase was downgraded to a lower value grade. However this study was conducted at a time of low sheep supply in carcases vaccinated at the recommended site and caution should be exercised in extrapolating these results to oversupplied market situations or in sheep vaccinated at alternate sites

Immigrant Economic Assimilation: Evidence from UK Longitudinal Data between 1978 and 2006

We exploit a large and long longitudinal dataset to estimate the immigrant-native earnings gap at entry and over time for the UK between 1978 and 2006. That is, we attempt to separately estimate cohort and assimilation effects. We also estimate the associated immigrant earnings growth rate and immigrant-native earnings convergence rate. Our estimates suggest that immigrants from more recent cohorts fare better than earlier ones at entry. Furthermore, the earnings of immigrants from more recent cohorts catch up faster with natives' earnings. While the convergence took over 30 years for those entering in the post-war, it only took half as long for those entering in the early 2000s. This earnings growth is fastest in the first 10 years, and it considerably slows down after 30 years.Immigration; assimilation; wages; earnings; earnings-gap; UK.