Temporary staffing services: a data mining perspective

Research on the temporary staffing industry discusses different topics ranging from workplace safety to the internationalization of temporary labor. However, there is a lack of data mining studies concerning this topic. This paper meets this void and uses a financial dataset as input for the estimated models. Bagged decision trees were utilized to cope with the high dimensionality. Two bagged decision trees were estimated: one using the whole dataset and one using the top 12 predictors. Both had the same predictive performance. This means we can highly reduce the computational complexity, without losing accuracy

What is post/colonial literature, and why are they saving such terrible things about it?

Why is it that, in a conspicuously neocolonial global environment, the terrn «postcolonialisrn)) has achieved such widespread acadernic currency? This paper analyzes the current vogue for postcolonial studies in western universities, presenting both a challenge to its commodified intellectual status and a defense of its capacity for cultural critique. «Postcolonialism,» the paper argues, does not imply that the colonial era is over; on the contrary, it confronts the «neocoloniality» of our present times

Low-dimensional hybrid perovskites containing an organic cation with an extended conjugated system : tuning the excitonic absorption features

Low-dimensional hybrid perovskites are receiving increased attention. One of the advantages of the low-dimensional hybrids over their 3D counterparts is their greater structural flexibility towards the incorporation of bigger, more complex, organic cations. In this communication, we introduce a pyrene derivative as an organic cation containing an extended pi-system for use in a variety of low-dimensional hybrids. We show that materials with different excitonic absorption features can be obtained by tuning the iodide/lead ratio in the precursor solutions, using the same pyrene cation. In this way, hybrids with optical characteristics corresponding to 2D, 1D and 0D hybrid perovskites are obtained. The formation and thermal stability of the different hybrids is analysed and compared

Sensitivity of fluvial sediment source apportionment to mixing model assumptions: A Bayesian model comparison

Mixing models have become increasingly common tools for apportioning fluvial sediment load to various sediment sources across catchments using a wide variety of Bayesian and frequentist modeling approaches. In this study, we demonstrate how different model setups can impact upon resulting source apportionment estimates in a Bayesian framework via a one-factor-at-a-time (OFAT) sensitivity analysis. We formulate 13 versions of a mixing model, each with different error assumptions and model structural choices, and apply them to sediment geochemistry data from the River Blackwater, Norfolk, UK, to apportion suspended particulate matter (SPM) contributions from three sources (arable topsoils, road verges, and subsurface material) under base flow conditions between August 2012 and August 2013. Whilst all 13 models estimate subsurface sources to be the largest contributor of SPM (median ∼76%), comparison of apportionment estimates reveal varying degrees of sensitivity to changing priors, inclusion of covariance terms, incorporation of time-variant distributions, and methods of proportion characterization. We also demonstrate differences in apportionment results between a full and an empirical Bayesian setup, and between a Bayesian and a frequentist optimization approach. This OFAT sensitivity analysis reveals that mixing model structural choices and error assumptions can significantly impact upon sediment source apportionment results, with estimated median contributions in this study varying by up to 21% between model versions. Users of mixing models are therefore strongly advised to carefully consider and justify their choice of model structure prior to conducting sediment source apportionment investigations

Book review: Bulgarian Literature as World Literature

Book review:Bulgarian Literature as World Literature, Edited by Mihaela P. Harper and Dimitar Kambourov, New York: Bloomsbury Academic, 2020, iv + 283 pp. ISBN: HB: 978-1-5013-4810-5; ePDF: 978-1-5013-4812-9; eBook: 978-1-5013-4811-2.[Българската литература като световна литература. Под редакцията на Михаела П. Харпър и Димитър Камбуров

High-temporal resolution fluvial sediment source fingerprinting with uncertainty: a Bayesian approach

This contribution addresses two developing areas of sediment fingerprinting research. Specifically, how to improve the temporal resolution of source apportionment estimates whilst minimizing analytical costs and, secondly, how to consistently quantify all perceived uncertainties associated with the sediment mixing model procedure. This first matter is tackled by using direct X-ray fluorescence spectroscopy (XRFS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analyses of suspended particulate matter (SPM) covered filter papers in conjunction with automatic water samplers. This method enables SPM geochemistry to be quickly, accurately, inexpensively and non-destructively monitored at high-temporal resolution throughout the progression of numerous precipitation events. We then employed a Bayesian mixing model procedure to provide full characterization of spatial geochemical variability, instrument precision and residual error to yield a realistic and coherent assessment of the uncertainties associated with source apportionment estimates. Applying these methods to SPM data from the River Wensum catchment, UK, we have been able to apportion, with uncertainty, sediment contributions from eroding arable topsoils, damaged road verges and combined subsurface channel bank and agricultural field drain sources at 60- and 120-minute resolution for the duration of five precipitation events. The results presented here demonstrate how combining Bayesian mixing models with the direct spectroscopic analysis of SPM-covered filter papers can produce high-temporal resolution source apportionment estimates that can assist with the appropriate targeting of sediment pollution mitigation measures at a catchment level

Големи истории, малки литератури и световни автори

In his article "Major Histories, Minor Literatures, and World Authors" Theo D'haen discusses how the idea of world literature has made a remarkable comeback in literary studies. A major feature of this revival has been increased attention from a "world perspective" to literatures until recently little studied beyond disciplinary boundaries, particularly so some "major" literatures such as Chinese, Japanese, Arabic, and various Indian-language literatures. As such, these literatures have come to join what has usually been thought of as "European" world literature. What this move, however to be welcomed in itself, obscures is the even further peripheralization of a number of "smaller" literatures, amongst them many European ones. Thus world literature in its newly emerging guise is merely upping the ante for such minor literatures, or, alternatively, reshaping such literatures in the image and interest of the few "major" literatures which are deemed worthy of inclusion in the "new" world literature.В статията си „Големи истории, малки литератури и световни автори“ Тео Д’хаен разглежда как идеята за световна литература е направила невероятно завръщане в литературните изследвания. Важна характеристика на това нейно възраждане е повишеният интерес от „световна гледна точка“ към литератури, които досега са били сравнително малко изучавани извън дисциплинарните си рамки, особено когато става въпрос за някои „големи“ литератури, сред които са китайската, японската, арабската и различни индоезични литератури. По този начин тези литератури се присъединяват към това, което по принцип се е смятало за „Европейска“ световна литература. Колкото и положителна да е тази стъпка, всъщност тя прикрива все по-задълбочаващото се периферизиране на редица „по-малки“ литератури, между които и много европейски. Следователно световната литература в този си нов образ само вдига летвата за подобни „малки“ литератури или алтернативно ги променя според образа и интереса на няколкото „големи“ литератури, които се считат за достойни да бъдат включени в „новата“ световна литература

An extended Bayesian sediment fingerprinting mixing model for the full Bayes treatment of geochemical uncertainties

Recent advances in sediment fingerprinting research have seen Bayesian mixing models being increasingly employed as an effective method to coherently translate component uncertainties into source apportionment results. Here, we advance earlier work by presenting an extended Bayesian mixing model capable of providing a full Bayes treatment of geochemical uncertainties. The performance of the extended full Bayes model was assessed against the equivalent empirical Bayes model and traditional frequentist optimisation. The performance of models coded in different Bayesian software (‘JAGS’ and ‘Stan’) was also evaluated, alongside an assessment of model sensitivity to reduced source representativeness and non-conservative fingerprint behaviour. Results revealed comparable accuracy and precision for the full and empirical Bayes models across both synthetic and real sediment geochemistry datasets, demonstrating that the empirical treatment of source data here represents a close approximation of the full Bayes treatment. Contrasts in the performance of models coded in JAGS and Stan revealed that the choice of software employed can impact significantly upon source apportionment results. Bayesian models coded in Stan were the least sensitive to both reduced source representativeness and non-conservative fingerprint behaviour, indicating Stan as the preferred software for future Bayesian sediment fingerprinting studies. Whilst the frequentist optimisation generally yielded comparable accuracy to the Bayesian models, uncertainties around apportionment estimates were substantially greater and the frequentist model was less effective at dealing with non-conservative behaviour. Overall, the effective performance of the extended full Bayes mixing model coded in Stan represents a notable advancement in source apportionment modelling relative to previous approaches. Both the mixing model and the software comparisons presented here should provide useful guidelines for future sediment fingerprinting studies