Using Local Information to Improve Short-Run Corn Price Forecasts

Author(s):  
Xiaojie Xu

AbstractWe examine the short-run forecasting problem in a data set of daily prices from 134 corn buying locations from seven states – Iowa, Illinois, Indiana, Ohio, Minnesota, Nebraska, and Kansas. We ask the question: is there useful forecasting information in the cash bids from nearby markets? We use several criteria, including a Granger causality criterion, to specify forecast models that rely on the recent history of a market, the recent histories of nearby markets, and the recent histories of futures prices. For about 65% of the markets studied, the model consisting of futures prices, a market’s own history, and the history of nearby markets forecasts better than a model only incorporating futures prices and the market’s own history. That is, nearby markets have predictive content. But the magnitude varies with the forecast horizon. For short-run forecasts, the forecast accuracy improvement from including nearby markets is modest. As the forecast horizon increases, however, including nearby prices tends to significantly improve forecasts. We also examine the role played by physical market density in determining the value of incorporating nearby prices into a forecast model.

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2737
Author(s):  
Ehsan Mostaghimzadeh ◽  
Seyed Mohammad Ashrafi ◽  
Arash Adib ◽  
Zong Woo Geem

Today, variable flow pattern, which uses static rule curves, is considered one of the challenges of reservoir operation. One way to overcome this problem is to develop forecast-based rule curves. However, managers must have an estimate of the influence of forecast accuracy on operation performance due to the intrinsic limitations of forecast models. This study attempts to develop a forecast model and investigate the effects of the corresponding accuracy on the operation performance of two conventional rule curves. To develop a forecast model, two methods according to autocorrelation and wrapper-based feature selection models are introduced to deal with the wavelet components of inflow. Finally, the operation performances of two polynomial and hedging rule curves are investigated using forecasted and actual inflows. The results of applying the model to the Dez reservoir in Iran visualized that a 4% improvement in the correlation coefficient of the coupled forecast model could reduce the relative deficit of the polynomial rule curve by 8.1%. Moreover, with 2% and 10% improvement in the Willmott and Nash—Sutcliffe indices, the same 8.1% reduction in the relative deficit can be expected. Similar results are observed for hedging rules where increasing forecast accuracy decreased the relative deficit by 15.5%. In general, it was concluded that hedging rule curves are more sensitive to forecast accuracy than polynomial rule curves are.


2021 ◽  
Vol 10 (02) ◽  
pp. 170-186
Author(s):  
Normadiah Mahiddin ◽  
Zulaiha Ali Othman ◽  
Nur Arzuar Abdul Rahim

Diabetes is one of the growing chronic diseases. Proper treatment is needed to produce its effects. Past studies have proposed an Interrelated Decision-making Model (IDM) as an intelligent decision support system (IDSS) solution for healthcare. This model can provide accurate results in determining the treatment of a particular patient. Therefore, the purpose of this study is to develop a diabetic IDM to see the increased decision-making accuracy with the IDM concept. The IDM concept allows the amount of data to increase with the addition of data records at the same level of care, and the addition of data records and attributes from the previous or subsequent levels of care. The more data or information, the more accurate a decision can be made. Data were developed to make diagnostic predictions for each stage of care in the development of type 2 diabetes. The development of data for each stage of care was confirmed by specialists. However, the experiments were performed using simulation data for two stages of care only. Four data sets of different sizes were provided to view changes in forecast accuracy. Each data set contained 2 data sets of primary care level and secondary care level with 4 times the change of the number of attributes from 25 to 58 and the number of records from 300 to 11,000. Data were developed to predict the level of diabetes confirmed by specialist doctors. The experimental results showed that on average, the J48 algorithm showed the best model (99%) followed by Logistics (98%), RandomTree (95%), NaiveBayes Updateable (93%), BayesNet (84%) and AdaBoostM1 (67%). Ratio analysis also showed that the accuracy of the forecast model has increased up to 49%. The MAPKB model for the care of diabetes is designed with data change criteria dynamically and is able to develop the latest dynamic prediction models effectively.v


2020 ◽  
Vol 21 (2) ◽  
pp. 143-148
Author(s):  
Michael W. Overton

AbstractBovine respiratory disease (BRD) is a frequent disease concern in dairy cattle and is most commonly diagnosed in young dairy heifers. The impact of BRD is highly variable, depending on the accuracy and completeness of detection, effectiveness of treatment, and on-farm culling practices. Consequences include decreased rate of weight gain, a higher culling risk either as heifers or as cows, delayed age at first service, delayed age at first calving, and in some cases, lower future milk production. In this data set of 104,100 dairy replacement heifers from across the USA, 36.6% had one or more cases diagnosed within the first 120 days of age with the highest risk of new cases occurring prior to weaning. Comparison of the raising cost for heifers with BRD and those without a recorded history of BRD resulted in an estimated cost per incident case occurring in the first 120 days of age of $252 or $282, depending upon whether anticipated future milk production differences were considered or not. Current market conditions contributed to a cost estimate that is significantly higher than previously published estimates, driven in part by the losses associated with selective culling of a subset of heifers that experienced BRD.


Author(s):  
Charles D. Phillips ◽  
Kathleen M. Spry

RÉSUMÉTrès peu de recherches ont été effectuées sur les pensionnaires des maisons de soins ayant manifestés des troubles mentaux chroniques sans démence avant leur entrée en institution. Les données du Minimum Data Set for Nursing Home Resident Assessment and Care Screening (MDS) de 1993 ont été utilisées pouranalyser les différences dans les caractéristiques et les soins se rapportant à ce type de pensionnaires par rapport aux autres pensionnaires. Cette enquête portait sur 70 000 pensionnaires du Kansas, du Maine, du Mississippi et du Dakota du Sud. Les caractéristiques des pensionnaires qui éprouvaient ce type de troubles mentaux chroniques étaient plus fréquemment les suivantes: sexe masculin, 65 ans et plus, bénéficiaires de Medicaid, moins médicalement inaptes et niveau plus élevé de problèmes de comportements. Ces pensionnaires reçoivent aussi davantage de médicaments psychotropes et suivant une thérapie, la prévalence de la thérapie étant cependant moins éleveé. Les informations recueillies pourraient laisser croire que les soins accordés à ces pensionnaires ne sont pas des plus appropriés.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Fan Li ◽  
Yunyun Lv ◽  
Zhengyong Wen ◽  
Chao Bian ◽  
Xinhui Zhang ◽  
...  

Abstract Background Although almost all extant spider species live in terrestrial environments, a few species live fully submerged in freshwater or seawater. The intertidal spiders (genus Desis) built silk nests within coral crevices can survive submerged in high tides. The diving bell spider, Argyroneta aquatica, resides in a similar dynamic environment but exclusively in freshwater. Given the pivotal role played by mitochondria in supplying most energy for physiological activity via oxidative phosphorylation and the environment, herein we sequenced the complete mitogenome of Desis jiaxiangi to investigate the adaptive evolution of the aquatic spider mitogenomes and the evolution of spiders. Results We assembled a complete mitogenome of the intertidal spider Desis jiaxiangi and performed comparative mitochondrial analyses of data set comprising of Desis jiaxiangi and other 45 previously published spider mitogenome sequences, including that of Argyroneta aquatica. We found a unique transposition of trnL2 and trnN genes in Desis jiaxiangi. Our robust phylogenetic topology clearly deciphered the evolutionary relationships between Desis jiaxiangi and Argyroneta aquatica as well as other spiders. We dated the divergence of Desis jiaxiangi and Argyroneta aquatica to the late Cretaceous at ~ 98 Ma. Our selection analyses detected a positive selection signal in the nd4 gene of the aquatic branch comprising both Desis jiaxiangi and Argyroneta aquatica. Surprisingly, Pirata subpiraticus, Hypochilus thorelli, and Argyroneta aquatica each had a higher Ka/Ks value in the 13 PCGs dataset among 46 taxa with complete mitogenomes, and these three species also showed positive selection signal in the nd6 gene. Conclusions Our finding of the unique transposition of trnL2 and trnN genes indicates that these genes may have experienced rearrangements in the history of intertidal spider evolution. The positive selection signals in the nd4 and nd6 genes might enable a better understanding of the spider metabolic adaptations in relation to different environments. Our construction of a novel mitogenome for the intertidal spider thus sheds light on the evolutionary history of spiders and their mitogenomes.


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Kanon Kumar Sen ◽  
◽  
Md. Thasinul Abedin ◽  
Ratan Ghosh ◽  
◽  
...  

We look for the integration of Bangladesh Stock Market with international gold and oil price using most recent monthly data set from January 2003 to December 2020 (2003m1-2020m12). We employ the bounds-testing approach to cointegration between stock market index (DSEX) and international gold and oil price and eventually find an integration and dynamic significant impact of international gold and oil price on DSEX in the long and short-run. We discuss the important policy implications of the dynamic impact of international gold and oil price on stock market index.


Author(s):  
Sara Fuentes-Soriano ◽  
Elizabeth A. Kellogg

Physarieae is a small tribe of herbaceous annual and woody perennial mustards that are mostly endemic to North America, with its members including a large amount of variation in floral, fruit, and chromosomal variation. Building on a previous study of Physarieae based on morphology and ndhF plastid DNA, we reconstructed the evolutionary history of the tribe using new sequence data from two nuclear markers, and compared the new topologies against previously published cpDNA-based phylogenetic hypotheses. The novel analyses included ca. 420 new sequences of ITS and LUMINIDEPENDENS (LD) markers for 39 and 47 species, respectively, with sampling accounting for all seven genera of Physarieae, including nomenclatural type species, and 11 outgroup taxa. Maximum parsimony, maximum likelihood, and Bayesian analyses showed that these additional markers were largely consistent with the previous ndhF data that supported the monophyly of Physarieae and resolved two major clades within the tribe, i.e., DDNLS (Dithyrea, Dimorphocarpa, Nerisyrenia, Lyrocarpa, and Synthlipsis)and PP (Paysonia and Physaria). New analyses also increased internal resolution for some closely related species and lineages within both clades. The monophyly of Dithyrea and the sister relationship of Paysonia to Physaria was consistent in all trees, with the sister relationship of Nerisyrenia to Lyrocarpa supported by ndhF and ITS, and the positions of Dimorphocarpa and Synthlipsis shifted within the DDNLS Clade depending on the employed data set. Finally, using the strong, new phylogenetic framework of combined cpDNA + nDNA data, we discussed standing hypotheses of trichome evolution in the tribe suggested by ndhF.


2021 ◽  
pp. emermed-2020-210412
Author(s):  
Richard Hotham ◽  
Colin O'Keeffe ◽  
Tony Stone ◽  
Suzanne M Mason ◽  
Christopher Burton

BackgroundEDs globally are under increasing pressure through rising demand. Frequent attenders are known to have complex health needs and use a disproportionate amount of resources. We hypothesised that heterogeneity of patients’ reason for attendance would be associated with multimorbidity and increasing age, and predict future attendance.MethodWe analysed an anonymised dataset of all ED visits over the course of 2014 in Yorkshire, UK. We identified 15 986 patients who had five or more ED encounters at any ED in the calendar year. Presenting complaint was categorised into one of 14 categories based on the Emergency Care Data Set (ECDS). We calculated measures of heterogeneity (count of ECDs categories and entropy of categories) and examined their relationship to total number of ED visits and to patient characteristics. We examined the predictive value of these and other features on future attendance.ResultsMost frequent attenders had more than one presenting complaint type. Heterogeneity increased with number of attendances, but heterogeneity adjusted for number of attendances did not vary substantially with age or sex. Heterogeneity was associated with the presence of one or more contacts for a mental health problem. For a given number of attendances, prior mental health contact but not heterogeneity was associated with further attendance.ConclusionsHeterogeneity of presenting complaint can be quantified and analysed for ED use: it is increased where there is a history of mental disorder but not with age. This suggests it reflects more than the number of medical conditions.


2018 ◽  
Vol 46 (1) ◽  
pp. 3-24 ◽  
Author(s):  
Ori Swed ◽  
Jae Kwon ◽  
Bryan Feldscher ◽  
Thomas Crosbie

From an obscure sector synonymous with mercenaryism, the private military and security industry has grown to become a significant complementing instrument in military operations. This rise has brought with it a considerable attention. Researchers have examined the role of private military and security companies in international relations as well as the history of these companies, and, above all, the legal implications of their use in the place of military organizations. As research progresses, a significant gap has become clear. Only a handful of studies have addressed the complex of issues associated with contractors’ demographics and lived experience. This article sheds some light over this lacuna, examining contractors’ demographics using descriptive statistics from an original data set of American and British contractors who died in Iraq between the years 2003 and 2016. The article augments our understanding of an important population of post-Fordist-contracted workforce, those peripheral workers supplementing military activity in high-risk occupations with uncertain long-term outcomes.


2021 ◽  
pp. 285-304
Author(s):  
Ivana Křížková ◽  
Meng Le Zhang ◽  
Dan Olner ◽  
Gwilym Pryce

AbstractInthischapter, we highlight the importance of social frontiers—sharp spatial divisions in the residential make-up of adjacent communities—as a potentially important form of segregation. The handful of studies estimating the impacts of social frontiers have been based in the USA and the UK, both of which are free-market democracies with a long history of immigration, ethnic mix and segregation. There are currently no studies of social frontiers in former socialist countries, for example, or in countries where immigration and ethnic mix are only a recent phenomenon or non-existent. This chapter aims to address this research gap by estimating the impacts of social frontiers on crime rates in a post-socialistcountry, Czechia. We demonstrate how a Bayesianspatial conditional autoregressive estimation can be used to detect social frontiers in this setting, and we use a fixed effect quasi-Poisson model to investigate the impact on crime. Our results suggest that in new immigration destinations, social frontiers may not be associated with higher rates of crime, at least in the short run. Moreover, our use of cultural distance measures helps to promote a more nuanced approach to studying the impact of segregation and highlights the role of cultural diversity in understanding the link between immigrant segregation and crime. We reflect on how this approach could contribute to the study of segregation and inequality in the Chinese context.


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