Direct formulation to Cholesky decomposition of a general nonsingular correlation matrix

We present two novel, explicit representations of Cholesky factor of a nonsingular correlation matrix. The first representation uses semi-partial correlation coefficients as its entries. The second, uses an equivalent form of the square roots of the differences between two ratios of successive determinants. Each of the two new forms enjoys parsimony of notations and offers a simpler alternative to both spherical factorization and the multiplicative partial correlation Cholesky matrix (Cooke et al 2011). Two relevant applications are offered for each form: a simple $t$-test for assessing the independence of a single variable in a multivariate normal structure, and a straightforward algorithm for generating random positive-definite correlation matrix. The second representation is also extended to any nonsingular hermitian matrix.Comment: Accepted to Statistics and Probability Letters, March 201

Identification of tau leptons at the DZero experiment

The article describes the identification of hadronically decaying tau leptons in ppbar collisions at 1.96 TeV collected by the DZero detector at the Fermilab Tevatron. After a brief description of the motivations and the challenges of considering tau leptons in high energy hadronic collisions, details of the tau reconstruction and identification will be discussed. The challenges associated for tau energy measurements in an hadronic environment will be presented including approaches to deal with such measurements

The era of the ‘booty’ and the ‘burqa’

by Dr Poonam Madar, University of Surrey What’s “hot right now” – not to confuse it with Rita Ora’s track – is the ‘hype’ around ‘A Big Booty’, and this concept seems to be endlessly trending on social media. Perhaps we have Vogue to ‘thank’ (or ‘blame’?) for making that initial booty call (no pun intended)

Assessing the student: the PechaKucha approach

With creativity and innovation as dominant buzzwords in higher education, employing PechaKucha to assess students is worth exploring

“Being black”: what is it cool for?

Dr Poonam Madar lectures in Sociology and Criminology, based in London. Her research interests include race, gender, and popular culture. She blogs at: www.poonammadar.blogspot.com and she tweets as @PoonamMadar To find out more, visit Poonam’s Facebook page at: www.facebook.com/PoonamMadar Not so long ago I began temping in an office in Central London. In the first few days, one staff member (a black man) welcomed me and we exchanged ‘hellos’. But when I asked his name, his eyes signalled to the further part of the room where the senior managers were sitting and he laughingly, but sarcastically replied, ‘They call me equal opportunities.’ Before I could react or even have the chance to catch his ‘real’ name he was already out the door

Managing irrigation jointly with farmers: history, present status and future: review of participatory irrigation management in Sri Lanka

Agriculture development has been the main strategy for the socioeconomic development in the country since time immemorial, even though its contribution to GDP has been declining recently. Successive governments of Sri Lanka since independence have invested heavily in the irrigated agriculture sector to address the food security concerns of the country. The continuous investment in irrigation was required to address problems such as spatial and temporal variations in monsoonal rainfall in the country, which has a serious negative impact on food production and livelihoods of people. The need for pursuing irrigation development and management has become more important in the country in the face of rapid population growth and increasing food prices in the world market. In this context, managing irrigation schemes for productivity increase is becoming increasingly important and different irrigation management models have also emerged through attempts made in this direction by countries including Sri Lanka, where irrigation plays a leading role in food production and nation development. Farmers’ active involvement in irrigation management, especially operation and maintenance (O&M) and decision-making as well, has been identified as a key requirement to attain productivity goals and the sustainability of irrigation systems. This paper aims at reviewing participatory irrigation management approaches adopted in medium and major irrigation systems in Sri Lanka with a view to identifying their past and present trends and future directions. The review will contribute to an improved understanding by policymakers, managers of irrigation schemes and farmers of the role of participatory irrigation management, its past and present including institutional structures, responsibilities and performance and the directions it should take to meet future challenges as a dynamic institutional mechanism. As all the medium and major irrigation schemes in the country are jointly managed by farmers and government agencies, the inferences drawn from the review would be important for the agencies and farmers alike to introduce necessary changes in their programs to address future needs and requirements.Length: pp.35-63Participatory managementIrrigation managementFarmers organizationsIndicatorsHistoryIrrigation schemes

Wastewater treatment and reuse: an institutional analysis for Hyderabad, India

River basinsWater pollutionSewageEffluentsPollution controlLegislationWaste managementWater qualityGuidelinesWastewater irrigationHealth hazardsRiceGrassesInstitutional reformCase studies