Evaluating kernels on Xeon Phi to accelerate Gysela application

This work describes the challenges presented by porting parts ofthe Gysela code to the Intel Xeon Phi coprocessor, as well as techniques used for optimization, vectorization and tuning that can be applied to other applications. We evaluate the performance of somegeneric micro-benchmark on Phi versus Intel Sandy Bridge. Several interpolation kernels useful for the Gysela application are analyzed and the performance are shown. Some memory-bound and compute-bound kernels are accelerated by a factor 2 on the Phi device compared to Sandy architecture. Nevertheless, it is hard, if not impossible, to reach a large fraction of the peek performance on the Phi device,especially for real-life applications as Gysela. A collateral benefit of this optimization and tuning work is that the execution time of Gysela (using 4D advections) has decreased on a standard architecture such as Intel Sandy Bridge.Comment: submitted to ESAIM proceedings for CEMRACS 2014 summer school version reviewe

Black soil, green rice

Stephan M. Haefel

Integrated nutrient management and LCC based nitrogen management on soil fertility and yield of rice (Oryza Sativa L.)

The experiment was conducted at lowland series of wet lands, International Rice Research Institute (IRRI) Farm, Los Banos, Laguna, Philippines. The rice variety PSBRc 82 was raised during wet season (June – October), and the experiment was laid out in randomized block design with four replications. There were eleven treatments viz., control, recommended NPK fertilizer, -N, -P, -K, LCC 3, LCC 4, LCC 5, 100% N as fresh rice straw, 50% N through rice straw compost and 50% N as poultry manure and 50% N as combined organic manures (RSC + PM). The P and K were applied to all the treatments except -P and –K treatments, respectively. The fertilizer N @ 90 kg ha-1, P2O5 @ 40 kg ha-1 and K2O @ 60 kg ha-1 were applied in the form of urea, super phosphate and muriate of potash respectively. The application of N at 90 kg level as 50% through RSC + 50% N as PM registered higher available N, P and K contents of soil during different growth stages as compared to the other treatment combinations including recommended NPK fertilizers. The growth and yield attributes were also found to be improved by the above treatment resulting in more grain and straw yield. With regard to N management, LCC 4 and 5 based N applications recorded higher grain yield as a result of higher soil available nutrients during the critical growth stages.Srinivasagam Krishnakumar and Stephan Haefel

Nutrient Management for Higher Productivity of Swarna Sub1 Under Flash Floods Areas

Two field experiments were conducted at Regional Agricultural Research Station, Tarahara, Nepal during 2012 and 2013 to determine the effect of agronomic management on growth and yield of Swarna Sub1 under flash floods. The first experiment was laid out in a split plot design with three replications; and four different nutrient combinations at nursery as main plots and three age groups of rice seedlings as sub plots. The second experiment was laid out in a randomized complete block design and replicated thrice; with three post flood nutrient doses at six and 12 days after de-submergence (dad). The experiments were complete submerged at 10 days after transplanting for 12 days. The survival percentage, at 21 dad, was significantly higher in plots planted with 35 (90.25%) and 40 (91.58%) days-old seedlings compared to 30 days-old seedlings (81.75%). Plots with 35 days-old seedlings produced 5.15 t ha-1 with advantage of 18.83% over 30 days-old seedlings. Plots with 100-50-50 kg N-P2O5-K2O/ha at nursery recorded the highest grain filling of 79.41% and grain yield of 5.068 t/ha with more benefit. Post flood application of 20-20 N-K20kg/ha at 6 dad resulted in higher plant survival and taller plants, leading to significantly higher grain yield of 5.183 t/ha and straw yield of 5.315 t/ha. Hence, 35-40 days old seedlings raised with 100-50-50 kg N-P2O5-K2O /ha in nursery and the additional application of20-20 kg N-K2O /ha at 6 dad improved plant survival and enhanced yield of Swarna Sub1 under flash flood conditions. The practice has prospects of saving crop loss with getting rice yield above national average yield leading to enhanced food security in the flood prone areas of Nepal

A survey: potential impact of genetically modified maize tolerant to drought or resistant to stem borers in Uganda

Maize production in Uganda is constrained by various factors, but especially drought and stem borers contribute to significant yield losses. Genetically modified (GM) maize with increased drought tolerance and/or Bt insect resistance (producing the Bacillus thuringiensis Cry protein) is considered as an option. For an ex ante impact analysis of these technologies, a farmer survey was carried out in nine districts of Uganda, representing the major farming systems. The results showed that farmers did rate stem borer and drought as the main constraints for maize farming. Most farmers indicated a positive attitude towards GM maize, and 86% of all farmers said they would grow GM maize. Farmer estimated yield losses to drought and stem borer damage were on average 54.7% and 23.5%, respectively, if stress occurred. Taking the stress frequency into consideration (67% for both), estimated yield losses were 36.5% and 15.6% for drought and stem borer, respectively. According to the ex-ante partial budget analysis, Bt hybrid maize could be profitable, with an average value/cost ratio of 2.1. Drought tolerant hybrid maize had lower returns and a value/cost ratio of 1.5. Negative returns occurred mainly for farmers with non-stressed grain yields below 2 t·ha−1. The regulatory framework in Uganda needs to be finalized with consideration of strengthening key institutions in the maize sector for sustainable introduction of GM maize.Isaac M. Wamatsembe, Godfrey Asea and Stephan M. Haefel

Retrieval of tropospheric water vapour by using spectra of a 22 GHz radiometer

In this paper, we present an approach to retrieve tropospheric water vapour profiles from pressure broadened emission spectra at 22 GHz, measured by a ground based microwave radiometer installed in the south of Bern at 905 m. <br><br> Classical microwave instruments concentrating on the troposphere observe several channels in the center and the wings of the water vapour line (20–30 Ghz), whereas our retrieval approach uses spectra with a bandwidth of 1 GHz and a high resolution around the center of the 22 GHz water vapour line. <br><br> The retrieval is sensitive up to 7 km with a vertical resolution of 3–5 km. Comparisons with profiles from operational balloon soundings, performed at Payerne, 40 km away from the radiometer location, showed a good agreement up to 7 km with a correlation of above 0.8. The retrievals shows a wet bias of 10–20% compared to the sounding

Meta-models for fatigue damage estimation of offshore wind turbines jacket substructures

One of the main structural components of offshore wind turbines is the substructure which bridges the gap between seabed and tower foot. One possible concept employed in intermediate water depths for turbines with high-rated power is the jacket. This structure is excited by several environmental impacts like wind and wave loads or centrifugal loads from the rotor motion. In order to reach competitive costs of energy, it is crucial to minimize the lifetime capital expenses by means of robust and reliability-based design. However, a simulation-based optimization approach on the full scale model requires high numerical capacity. In this work, the problem of numerically expensive fatigue life evaluation is addressed by the utilization of a meta-model approach. The performance of two meta-models solutions, namely Kriging and Interval Predictor Model, is compared. In particular, the different behavior of the probabilistic confidence intervals of the Kriging regression and the interval bounds of the IPM is discussed. © 2017 The Authors. Published by Elsevier Ltd